Volume 10, Issue 1

The optimized HCl-catalyzed hydrolysis of alkyl diphenylphosphinates is described. The reaction times and pseudo-first-order rate constants suggested the i Pr > Me > Et ∼ Pr ∼ Bu order of reactivity in respect of the alkyl group of the phosphinates. The MW-assisted p -toluenesulfonic acid (PTSA)-catalyzed variation means a better alternative possibility due to the shorter reaction times, and the alkaline hydrolysis is another option. The transesterification of alkyl diphenylphosphinates took place only in the presence of suitable ionic liquids, such as butyl-methylimidazolium hexafluorophosphorate ([bmim][PF 6 ]) and butyl-methylimidazolium tetrafluoroborate ([bmim][BF 4 ]). The application of ethyl-methylimidazolium hydrosulfate ([emim][HSO 4 ]) and butyl-methylimidazolium chloride ([bmim][Cl]) was not too efficient, as the formation of the ester was accompanied by the fission of the O–C bond resulting in the formation of Ph 2 P(O)OH. This surprising transformation may be utilized in the phosphinate → phosphinic acid conversion.

Generally, adding a certain amount of an additive to pulverized coal can promote its combustion performance. In this paper, the effect of CaO on the combustion characteristics and kinetic behavior of semi-coke was studied by thermogravimetric (TG) analysis. The results show that adding proper amount of CaO can reduce the ignition temperature of semi-coke and increase the combustion rate of semi-coke; with the increase in CaO content, the combustion rate of semi-coke increases first and then decreases, and the results of TG analysis showed that optimal addition amount of CaO is 2 wt%. The apparent activation energy of CaO with different addition amounts of CaO was calculated by Coats–Redfern integration method. The apparent activation energy of semi-coke in the combustion reaction increases first and then decreases with the increase in CaO addition. The apparent activation energies of different samples at different conversion rates were calculated by Flynn–Wall–Ozawa integral method. It was found that the apparent activation energies of semi-coke during combustion reaction decreased with the increase in conversion.

Blue mold caused by Penicillium species is a major fungal disease threatening the viticulture industry in Pakistan, responsible for deteriorating the quality of grapes during handling, transportation, and distribution. Identification-based approaches of Penicillium species provide a better strategy on accurate diagnosis and effective management. In this study, 13 isolates were recovered from symptomatic grape bunches at five main fruit markets of Rawalpindi district, Punjab province. Based on morphological data and multi-loci phylogenetic analysis, the isolates were identified as two distinct species viz . Penicillium expansum (eight isolates) and Penicillium crustosum (five isolates). Meanwhile, the pathogenicity test of Penicillium isolates presented by the inoculation of grape bunches showed various degrees of severity. For improving the fruit quality and eliminating the needs of synthetic fungicides, botanicals such as thyme ( Thymus vulgaris L.), fennel ( Foeniculum vulgare L.), garlic ( Allium sativum L.), ginger ( Zingiber officinale L.), and carum ( Carum capticum L.) essential oils (EOs) at concentrations of 0.6, 0.9, 1.2, and 1.5 mg/mL were evaluated. In vitro studies indicated that thyme EO showed a highly significant reduction of fungal growth. Furthermore, the experiments related to reducing the decay development and average weight loss percentage of grapes revealed similar findings. Based on the results of this study, it is recommended that thyme EO can be used as an eco-friendly botanical fungicide against Penicillium spp. causing blue mold disease.

Waste biomass can be used as a raw material for food packaging. Different concentrations of gelatin (GEL) were introduced into the leftover rice (LR) system to form an interpenetrating polymer network (IPN) for improving the properties of the films. The structure and morphology of films were evaluated by Fourier transform infrared, scanning electron microscopy, and atomic force microscopy, which showed good compatibility between LR and GEL. The moisture content and oil absorption rate of IPN films were down by 105% and 182%, respectively, which showed better water and oil resistance than the LR film. In addition, increasing GEL concentration led to enhancement in the tensile strength of films from 2.42 to 11.40 MPa. The water contact angle value of the IPN films (117.53°) increased by 147% than the LR film (47.56°). The low haze of IPN films was obtained with the increment of the mutual entanglement of LR and GEL. The 30–50% GEL addition improved the water vapor barrier and thermal stability properties of the IPN films. This study highlights that LR as waste biomass can have a practical application in food packaging.

Selenium nanoparticles (SeNPs) are reinforced safe forms of the essential micronutrient selenium (Se) which take a lead in countless biotechnological and biomedical applications. The phycosynthesis of SeNPs was successfully investigated using cell-free extract of the microalgae, Spirulina platensis. The phycosynthesized S. platensis -SeNPs ( Sp SeNPs) were characterized using several characterization techniques such as UV-Visible, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and energy dispersive X-ray. They were effectually achieved using different concentration from sodium selenite (Na 2 SeO 3 ) (1, 5, and 10 mM) to give size means of 12.64, 8.61, and 5.93 nm, respectively, with spherical shapes and highly negative zeta potentialities. The infrared analyses revealed the involvement of many phycochemials in Sp SeNPs production. The antibacterial properties of Sp SeNPs were confirmed, qualitatively and quantitatively, against foodborne microorganisms ( Staphylococcus aureus and Salmonella typhimurium ); the antibacterial activity was correlated and increased with SeNPs’ size diminution. The scanning micrographs of S. typhimurium cells treated with Sp SeNPs indicated the severe action of nanoparticles to destroy bacterial cells in time-dependent manners. The innovative facile phycosynthesis of SeNPs using S. platensis is recommended to generate effectual bioactive agents to control hazardous bacterial species.

Artemisia absinthium L. is a highly medicinal plant with a broad range of biomedical applications. A. absinthium callus cultures were established in response to bio-fabricated single NPs (Ag and Cu) or a combination of both NPs (Ag and Cu) in different ratios (1:2, 2:1, 1:3, and 3:1) along with thidiazuron (TDZ) (4 mg/L) to elicit the biomass accumulation, production of non-enzymatic compounds, antioxidative enzymes, and antioxidant activity. Silver and copper nanoparticles (Ag and Cu NPs) were synthesized using the leaves of Moringa oleifera as reducing and capping agent and further characterized through UV-Visible spectroscopy and SEM. The 30 µg/L suspension of Ag and Cu NPs (1:2, 2:1) and 4 mg/L TDZ showed 100% biomass accumulation as compared to control (86%). TDZ in combination with Ag NPs enhanced biomass in the log phases of growth kinetics. The Cu NPs alone enhanced the superoxide dismutase activity (0.56 nM/min/mg FW) and peroxidase activity (0.31 nM/min/mg FW) in callus cultures. However, the combination of Ag and Cu NPs with TDZ induced significant total phenolic (7.31 µg/g DW) and flavonoid contents (9.27 µg/g DW). Furthermore, the antioxidant activity was highest (86%) in the Ag and Cu NPs (3:1) augmented media. The present study provides the first evidence of bio-fabricated single NPs (Ag and Cu) or a combination of both NPs (Ag and Cu) in different ratios (1:2, 2:1, 1:3, and 3:1) along with TDZ (4 mg/L) on the development of callus culture, production of endogenous enzymes, non-enzymatic components, and further antioxidant activity in callus cultures of A. absinthium .

The extract from Celastrus hindsii ( C. hindsii ), a plant that naturally grows in the forests of several provinces of Vietnam, has been traditionally used as an alternative medicine for the treatment of inflammation because of its anticancer and antitumor properties. This study reported the green synthesis of stable gold nanoparticles (Au-NPs) derived from HAuCl 4 using the extract of C. hindsii as reducing and capping agents. Their particle size could be controlled by adjusting the ratio of the extract to HAuCl 4 solution used (1.25%, 2.5%, 3.75%, 5.0%, and 6.25%). The optimal ratio of the extract was 3.75% (Au-NPs-3.75%). The X-ray powder diffraction analysis demonstrated that the Au-NPs was successfully synthesized. Fourier-transform infrared spectroscopy result indicated the possible presence of phenolic acids and flavonoids (acting as reducing agents and potential natural antioxidants). Transmission electron microscopy images showed that the particle diameter of Au-NPs-3.75% varied between 13 and 53 nm (average: ∼30 nm) in its spherical shape. The biosynthesized Au-NPs-3.75% exhibited dose-dependent cytotoxicity against HeLa cells, and the inhibitory concentration (IC 50 ) was 12.5 µg/mL at 48 h. Therefore, Au-NPs that were synthesized from environmentally friendly method without the presence of potentially toxic chemicals were highly possible in biomedical applications. Graphical abstract Green synthesis of gold nanoparticles from the Celastrus hindsii extract and its application for anticancer activity.

The green biosynthesis of metal nanoparticles of already explored phytomedicines has many advantages such as enhanced biological action, increased bioavailability, etc. In this direction, keeping in view the peculiar medicinal value of Tropaeolum majus L., we synthesized its silver nanoparticles (AgNPs) by adopting eco-friendly and cost-effective protocol by using methanolic and aqueous extract of T. majus . The synthesized AgNPs were characterized by using several techniques including UV spectroscopic analysis, FTIR analysis, and atomic force microscopy. The methanolic/aqueous extracts of T. majus and synthesized AgNPs were assessed for antioxidant potential and antimicrobial effect. The preliminary screening showed that the T. majus extracts have variety of reducing phytochemicals including tannins, terpenoids, flavonoids, and cardiac glycosides. The green synthesis of AgNPs was confirmed by the appearance of sharp peak at 430–450 nm in the UV-Visible spectra. The FTIR spectral analysis of extract and AgNPs exhibited that peaks at 2947.23, 2831.50, 2592.33, 2522.89, and 1,411 cm −1 disappeared in the spectra of FTIR spectra of the AgNPs, indicating carboxyl and hydroxyl groups are mainly accountable for reduction and stabilization of AgNPs. Atomic force microscopic scan of the synthesized AgNPs confirmed its cylindrical shape with size of 25 µm. The extracts and AgNPs were investigated for antioxidant potential by DPPH-free radical essay, which showed that aqueous extract has significant and dose-independent antioxidant activity; however, the synthesized AgNPs showed decline in antioxidant activity. The extracts and synthesized AgNPs were also evaluated for antibacterial activity against Klebsiella pneumonia , Staphylococcus aureus , and Bacillus subtilis. Neither extract nor AgNPs were active against Klebsiella pneumonia. The aqueous and methanolic extract exhibited inhibition against Bacillus subtilis and their synthesized AgNPs were active against Staphylococcus aureus. Our data concluded that the extracts of T. majus have necessary capping and reducing agents which make it capable to develop stable AgNPs. The aqueous extract of T. majus has potential antioxidant effect; however, the AgNPs did not enhance its free radical scavenging effect. The bacterial strains’ susceptibility of the extract and AgNPs was changed from Bacillus subtilis to Staphylococcus aureus , respectively. The biological action of AgNPs is changed in case of antibacterial activity which means that AgNPs might change the specificity of T. majus and likewise other drugs.

Metal-free phthalocyanine (H 2 Pc) has been widely used as photosensitive semiconductors in the organic optoelectronics field because of its unique planar molecular structure and high photocarriers’ generation efficiency. Herein, this paper related to a new facile and efficient one-step method for preparing specific crystal form of H 2 Pc with high crystallinity through ball-milling process, in which α-H 2 Pc can be prepared directly by dry ball-milling, and β-H 2 Pc and X-H 2 Pc can be simply obtained through wet ball-milling in butanone solvent at different temperatures. X-ray diffraction (XRD) was used to characterize the crystal stability of α-H 2 Pc, β-H 2 Pc, and X-H 2 Pc, which revealed that all the three crystalline H 2 Pc prepared had excellent crystal stability under different mechanical conditions. Graphical abstract α-H 2 Pc, β-H 2 Pc, and X-H 2 Pc with excellent crystal stability can be simply prepared by dry/wet ball-milling process.

The current study was designed to investigate the potential of Euphorbia wallichii shoot extract for reducting Au 3+ and stabilizing gold nanoparticles. UV-visible spectra of gold nanoparticles showed obvious surface plasmon resonance peak at 548 nm. Microscopy (SEM and TEM) showed spherical dimensions, and the energy dispersive X-ray spectra displayed the strongest optical absorption peak for gold (Au) at 2.1 keV. Dynamic light scattering spectra represent polydispersed mixture with particulate diameter of 2.5–103.2 nm. The IR spectra confirm the potential functional groups of shoot extract responsible for the reduction of Au 3+ to gold nanoparticles which exhibit tremendous antibacterial potential of 76.31%, 68.47%, 79.85%, 48.10%, and 65.53% against Escherichia coli , Staphylococcus aureus , Bacillus pumilus , Pseudomonas aeruginosa , and Klebsiella pneumoniae , respectively. Gold nanoparticles showed markedly elevated fungicidal potency compared to the shoot extract alone against the tested fungal strains. IC 50 for 2,2-diphenyl-1-picrylhydrazyl scavenging was 31.52, 18.29, and 15.32 µg/mL at 30, 60, and 90 min of reaction time, respectively. Both shoot extract and nanoparticles revealed 71% mortality at 100 µg/mL, with LD 90 values of 310.56 µg/mL. Experimental mice acquired dose-dependent analgesia of 54.21%, 82.60%, and 86.53% when treated with gold nanoparticles at 50, 100, and 200 mg/kg bw. Inhibition of gastrointestinal muscular contraction was 21.16%, 30.49%, and 40.19% in mice feed with 50, 100, and 200 mg/kg bw, respectively.

Zinc oxide nanoparticles (ZnO NPs) were synthesized utilizing prepared walnut leaf extract by various amounts of its leaves (5–25 g) via a heater and stirrer adjusted at 60°C and reaction time ranging from 30 to 90 min. Fourier transform infrared spectroscopy and gas chromatography indicated the six main functional groups and 29 bioactive compounds in the provided walnut leaf extract. Antioxidant and antibacterial inhibitory activities of the fabricated ZnO NPs, in powder form, were modeled as a function of two synthesized parameters using response surface methodology, and the fabrication process was optimized. The results indicated that the ZnO NPs synthesized using walnut leaf extract, with 15.51 g of its dried powder and reaction time of 60 min, had maximum antioxidant activity and antibacterial effects against Escherichia coli . X-ray diffraction analysis and scanning electron microscopy image indicated that the synthesized ZnO NPs using optimal processing conditions had crystals in triangular nanoprisms to nearly spherical shape with the particle size ranging from 15 to 40 nm. Finally, prepared biodegradable film composed of thermoplastic starch (5% w/w), polyethylene (93% w/w), and ZnO NPs (2% w/w) indicated high bactericidal inhibitory activity against both Gram-positive ( Staphylococcus aureus ) and Gram-negative ( E. coli ) bacterial strains.

In this study, we prepared Zn-MOFs as an ordinary, low-cost, and efficiency method taking advantage of zinc( ii ) acetate monohydrate and 1,3,5-benzenetricarboxylic acid in microwave-assisted ball milling. The Zn-MOFs were measured via scanning electron microscopy, infrared spectrometry, X-ray diffraction, and thermogravimetry. We explored its use as a photocatalyst for the degradation of tetracycline hydrochloride and Congo red from aqueous solutions. The results demonstrate that the kinetic model was appropriate for the removal of organic pollutants. In general, it is feasible, inexpensive, and effective to use metal organic framework (MOF) to treat waste liquid. Therefore, our findings indicate that Zn-MOFs have broad application vista in wastewater purification. Graphical abstract The Zn-MOFs were prepared as an ordinary, low-cost, and efficiency method taking advantage of zinc( ii ) acetate monohydrate and 1,3,5-benzenetricarboxylic acid in microwave-assisted ball milling. The Zn-MOFs were used as a photocatalyst for the degradation of tetracycline hydrochloride and Congo red from aqueous solutions. The results demonstrate that the kinetic model was appropriate for the removal of organic pollutants. In general, it is feasible, inexpensive, and effective to use metal organic framework (MOF) to treat waste liquid.

The feasibility of industrial waste fly ash as an alternative fluxing agent for silica in carbothermal reduction of medium-low-grade phosphate ore was studied in this paper. With a series of single-factor experiments, the reduction rate of phosphate rock under different reaction temperature, reaction time, particle size, carbon excess coefficient, and silicon–calcium molar ratio was investigated with silica and fly ash as fluxing agents. Higher reduction rates were obtained with fly ash fluxing instead of silica. The optimal conditions were derived as: reaction temperature 1,300°C, reaction time 75 min, particle size 48–75 µm, carbon excess coefficient 1.2, and silicon–calcium molar ratio 1.2. The optimized process condition was verified with other two different phosphate rocks and it was proved universally. The apparent kinetics analyses demonstrated that the activation energy of fly ash fluxing is reduced by 31.57 kJ/mol as compared with that of silica. The mechanism of better fluxing effect by fly ash may be ascribed to the fact that the products formed within fly ash increase the amount of liquid phase in the reaction system and promote reduction reaction. Preliminary feasibility about the recycling of industrial waste fly ash in thermal phosphoric acid industry was elucidated in the paper.

In this study, a new pretreatment for using wet food biomass waste as a high calorific and reactive feedstock for gasification is presented. The method involves the addition of calcium hydroxide, hot water treatment, and dewatering in vegetable oil. Hot water treatment at 230°C reduced the oxygen/carbon atomic ratio of coffee grounds waste to improve the calorific value, but this treatment also formed an inactive cross-linked structure caused by dehydration reactions. By mixing the coffee grounds waste with calcium hydroxide powder before the hot water treatment, cross-linking was suppressed and the gasification rate of the char significantly increased because of the catalytic effect. With or without hot water treatment, the time required to complete gasification for the chars of the grounds mixed with calcium hydroxide was reduced to about one-third of that for the char of the untreated grounds. After heating in vegetable oil at 150°C, moisture was completely removed from the coffee grounds and they became impregnated with a large amount of the oil. As dewatering in oil did not affect the gasification rate of the chars, a combination of these three treatments was found to efficiently convert wet food biomass waste into a gasification feedstock.

Nano-selenium was synthesized using lemon juice as a reducing agent. The experiments showed that pH value affected greatly the shape and the size of the prepared nano-selenium. At pH 9, lemon juice could reduce 50 mmol/L of selenite ions to nano-selenium with particle size between 50 and 90 nm, which was spherical and well dispersed. Lemon juice acted as both a reducing agent and a stabilizer in the synthesis of nano-selenium, in which the chemical interaction between biomolecules and the nano-selenium surface was the basis for the stable existence of nano-selenium. The selenite concentration influenced the formation of nano-selenium, and a low selenite concentration was beneficial to obtain small particles. The achieved nano-selenium exhibited a strong antioxidant activity positively related to concentration. The comparative study showed that the antioxidation of nano-selenium is weaker than that of vitamin C but higher than that of lemon juice. Graphical abstract Green synthesis of nano-selenium from lemon juice, selenium nanoparticles coated with macromolecules, and antioxidant activity.

Thermoanalysis was used in this research to produce a comparative study on the combustion and gasification characteristics of semi-coke prepared under pyrolytic atmospheres rich in CH 4 and H 2 at different proportions. Distinctions of different semi-coke in terms of carbon chemical structure, functional groups, and micropore structure were examined. The results indicated that adding some reducing gases during pyrolysis could inhibit semi-coke reactivity, the inhibitory effect of the composite gas of H 2 and CH 4 was the most observable, and the effect of H 2 was higher than that of CH 4 ; moreover, increasing the proportion of reducing gas increased its inhibitory effect. X-ray diffractometer and Fourier-transform infrared spectrometer results indicated that adding reducing gases in the atmosphere elevated the disordering degree of carbon microcrystalline structures, boosted the removal of hydroxyl- and oxygen-containing functional groups, decreased the unsaturated side chains, and improved condensation degree of macromolecular networks. The nitrogen adsorption experiment revealed that the types of pore structure of semi-coke are mainly micropore and mesopore, and the influence of pyrolytic atmosphere on micropores was not of strong regularity but could inhibit mesopore development. Aromatic lamellar stack height of semi-coke, specific surface area of mesopore, and pore volume had a favorable linear correlation with semi-coke reactivity indexes.

We report herein a simple and efficient one-step synthesis of 8-substituted xanthines and substituted pyrimidopteridine-2,4,6,8-tetraones via reaction of 1,3-dimethyl-5,6-diaminouracil 1 with activated double bond systems 2 assisted by controlled microwave irradiation. The obtained heterocycles are privileged biologically relevant scaffolds. Graphical abstract A green, simple one-pot microwave-assisted synthesis of xanthines and pyrimidopetridines was developed with a high EcoScale and yields.

Subcritical water was used to provide propolis oil in water (O/W) nanoemulsions. To monitor and detect the main bioactive compounds of the prepared propolis extract, gas chromatography demonstrated that there were 47 bioactive materials in the propolis extract, among which pinostrobin chalcone and pinocembrin were the two key components. Effectiveness of two processing parameters such as the amount of saponin (0.5–2.0 g) and propolis extract (0.1–0.6 g), on particle size, polydispersity index (PDI), zeta potential, and antioxidant activity of the provided nanoemulsions, was evaluated. Results demonstrated that more desirable propolis O/W nanoemulsion, with minimum particle size (144.06 nm) and PDI (0.286), and maximum zeta potential (−21.71 mV) and antioxidant activity (90.86%) were made using 0.50 g of saponin and 0.53 g of propolis extract. Further analysis revealed that the prepared nanoemulsion based on optimum processing conditions had spherical shaped propolis nanodroplets in the colloidal solution with turbidity and maximum broad absorption peak of 0.08 a.u. and 292 nm, respectively. The prepared nanoemulsion had high antibacterial activity against both selected bacteria strains namely, Staphylococcus aureus and Escherichia coli.

Heavy alkyl benzene sulfonates are inexpensive surfactants that are extensively used as oil-displacing agents during tertiary oil recovery. Among these, C 16–18 heavy alkyl benzene sulfonates possess an excellent ability to reduce the oil-water interface tension. In this study, hexadecylbenzene sulfonic acid (HBSA) was synthesised in a continuous stirred-tank microreactor using a continuous method with 1,2-dichloroethane (EDC) dilution. Post-sulfonation liquid SO 3 solution was used as a sulfonating agent for hexadecylbenzene (HDB). The effects of reaction conditions, such as the SO 3 :HDB molar ratio, sulfonation temperature and sulfonation agent concentration, on the yield and purity of the product were investigated. Optimisation of the reaction process yielded high-quality HBSA samples with a purity exceeding 99 wt%. The continuous sulfonation process significantly enhanced the production and efficiency in the case of a considerably short residence time (10 s) in the reactor, without the need for aging. The results of this study demonstrate significant potential for application in industrial production.

Currently, nanotechnology is gaining massive attention compared to conventional methods as the biosynthesis of plant-based nanoparticles is considered safe, effective, and ecofriendly. Therefore, keeping in view the importance of nanotechnology, the present study was designed to synthesize, characterize, and evaluate the biological effectiveness of saffron stigma-based gold nanoparticles (SS-AuNPs) for their in vitro and in vivo biological properties. These gold nanoparticles were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The highest antibacterial effect was observed by the saffron extract against Escherichia coli (22 mm). SS-AuNPs significantly inhibited the activity of enzyme urease (54.98%) and CA-II (64.29%). However, the nonsignificant inhibitory effect was observed in the case of α-chymotrypsin. Maximum analgesic (84.98%) and antiinflammatory (88.98%) effects were observed for SS-AuNPs (10 mg/kg). Similarly, SS-AuNPs demonstrated a significant ( P < 0.01) sedative effect at all tested doses.

The present study was carried out to investigate the beneficial and toxicological effect of plant-based titanium dioxide nanoparticles (TiO 2 NPs) on the morphophysiological attributes of wheat plants under salinity stress. The biogenesis of titanium dioxide nanoparticles was accomplished by using the extract of Buddleja asiatica L. leaves followed by characterization through UV visible spectroscopy, SEM, FTIR, and EDX. NaCl salt was applied in two different concentrations after 21 days of germination followed by foliar applications of various concentrations of TiO 2 NPs (20, 40, 60, 80 mg/L) to salinity-tolerant (Faisalabad-08) and salinity-susceptible (NARC-11) wheat varieties after 10–15 days of application of salt stress. Salinity stress showed remarkable decrease in morphophysiological attributes of selected wheat varieties. Magnificent improvement in plant height, dry and fresh weight of plants, shoot and root length, root and shoot fresh and dry weight, number of leaves per plant, RWC, MSI, chlorophyll a and b, and total chlorophyll contents has been observed when 40 mg/L of TiO 2 NPs was used. However, the plant morphophysiological parameters decreased gradually at higher concentrations (60 and 80 mg/L) in both selected wheat varieties. Therefore, 40 mg/L concentration of TiO 2 NPs was found most preferable to increase the growth agronomic and physiological attributes of selected wheat varieties under salinity.

Although phosphate rock has been considered as a potential new rare earth elements (REEs) resource, the recovery of REEs from phosphate rock is impeded by technical challenges and cost issues. This study investigated the effects of operation conditions on the leaching efficiencies of REEs and phosphorus from Zhijin phosphate ore, a large phosphate deposit in China. The leaching process overtime was also studied by chemical analysis, scanning electron microscope with energy dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD). The results indicated that the REEs from Zhijin phosphate ore were mainly present in fluorapatite and dolomite, and REEs had similar trends of leaching efficiency to those of phosphorus and magnesium. Under the conditions of 25 wt% phosphoric acid concentration in the initial pulp, a weight ratio of liquid to solid of 12 mL/g, a temperature of 60°C, an agitation speed of 220 rpm, and leaching time of 120 min, REEs and phosphorus leaching efficiencies of 97.8% and 99.7% were obtained. Most parts of dissoluble substances were decomposed within 30 min. Chemical analysis, SEM-EDS, and XRD results indicated that leaching efficiencies of minerals in Zhijin phosphate ore increased following the order: quartz, aluminosilicate, pyrite, fluorapatite, dolomite, and calcite.

Bauxite reaction residue (BRR) produced from the poly-aluminum chloride (PAC) coagulant industry is a solid acidic waste that is harmful to environment. A low temperature synthesis route to convert the waste into water glass was reported. Silica dissolution process was systematically studied, including the thermodynamic analysis and the influence of calcium and aluminum on the leaching of amorphous silica. Simulation studies have shown that calcium and aluminum combine with silicon to form hydrated calcium silicate, silica–alumina gel, and zeolite, respectively, thereby hindering the leaching of silica. Maximizing the removal of calcium, aluminum, and chlorine can effectively improve the leaching of silicon in the subsequent process, and corresponding element removal rates are 42.81%, 44.15%, and 96.94%, respectively. The removed material is not randomly discarded and is reused to prepare PAC. The silica extraction rate reached 81.45% under optimal conditions (NaOH; 3 mol L −1 , L S −1 ; 5/1, 75°C, 2 h), and sodium silicate modulus ( n SiO 2 : n Na 2 O) is 1.11. The results indicated that a large amount of silica was existed in amorphous form. Precipitated silica was obtained by acidifying sodium silicate solution at optimal pH 7.0. Moreover, sodium silicate (1.11) further synthesizes sodium silicate (modulus 3.27) by adding precipitated silica at 75°C.

MIL-125(Ti) metal–organic framework-derived nanoporous titanium dioxide–heteropoly acid (PW–TiO 2 ) have been synthesized by a facile hydrothermal approach and subsequent calcination, and the PW–TiO 2 catalysts were investigated using various characterization technologies including FTIR, XRD, SEM, TEM, N 2 -physisorption, and NH 3 -TPD. Further, we investigated the use of PW–TiO 2 composites as heterogeneous acid catalysts for the catalytic esterification of oleic acid. Among all series of catalysts, the calcined PW–TiO 2 at a temperature of 350°C showed excellent activity with a high conversion of 90.5% at 160°C for 4 h. More importantly, the catalyst could be simply separated via centrifugation and reused for six cycles and shows a relatively high conversion of 74.8%.

Chromium( vi ) contaminated sites have been targeted for studying highly chromate-resistant bacteria. From a total of 23 Cr( vi )-resistant bacteria isolated on Luria-Bertani agar medium supplemented with K 2 CrO 4 (1,500 μg/mL), only one strain UT8 ( Staphylococcus simulans ) was able to tolerate high concentration of chromate, i.e., up to 200 mg/mL in agar medium from tannery effluent. In acetate minimal medium (AMM), it showed maximum tolerance of up to 2,500 μg/mL. Cr( vi ) removal potential was 94.6% after 24 h (K 2 CrO 4 1,500 μg/mL). Parametric conditions were optimized in AMM to attain maximum chromate removal. Exopolysaccharides extracted from bacterial cells exposed to chromate exhibited major absorption shifts from 2,500 to 500 cm −1 revealed by Fourier transform infrared spectroscopy. Energy-disperse X-ray spectroscopy further confirmed the adsorption of oxyanions to the bacterial cells. Surface topography of the Cr( vi ) treated cells showed transformation into concave shape by scanning electron microscopy. The presence of resistance genes, i.e., chromate reductase ( chrR ) and class I integrase ( intI1 ), further confirmed tolerance toward chromate. Microarray data analysis of transcriptional gene expression suggested upregulation of cys gene cluster under chromate exposure. Concisely, the present investigations revealed the potential of S. simulans to be an effective candidate for chromate reclamation of wastewater. Graphical abstract Chromate-resistant bacterium UT8 was isolated from tannery effluent. The cultural conditions for strain UT8 were optimized for maximum chromate removal and exopolymer production. SEM-EDS analysis of strain UT8 revealed variations under Cr( vi ) stress related to nonstress. The FTIR analysis of exopolymer under chromate stress indicated vibrational shifts for metal ion chelation.

Phoxim is a significant insecticide, and its current synthesis method has some shortcomings such as the high risk of explosion and the trans structure (main impurity) is hard to control. Our work solved the above disadvantages by introducing macromolecular alcohol (benzyl alcohol, etc.) as the starting material and optimizing the intermediate reaction conditions. Compared with the current synthesis route, the synthetic method has the following advantages: (1) intermediate benzyl nitrite has a high boiling point and strong safety; (2) intermediate α -cyanobenzaldehyde oxime sodium are almost (≥99%) cis structure, and no further refinement was required, which greatly reduced the amount of waste water produced; and (3) The high yield of phoxim was maintained at 72.9%. Graphical abstract A new method to synthesize phoxim.

This study was carried out to analyze the effects of biogenic silver nanoparticles (AgNPs) on physiological, biochemical, and enzymatic attributes of rice plants against Aspergillus flavus . The plant-based AgNPs were synthesized by using the aqueous extract of Moringa oleifera leaves. The characterization of AgNPs was accomplished through UV-visible spectrophotometry, SEM, and energy-dispersive X-ray (EDX) analysis, which confirmed that the nanoparticles are crystalline and are less than 100 nm in size. The exogenous applications of different concentrations of AgNPs (25, 50, 75, and 100 mg/L) on rice plants in field experiments were used to control the proliferation of A. flavus . The effects of biosynthesized AgNPs were evaluated for physiological (relative water content, membrane stability index, and chlorophyll content), nonenzymatic metabolites (total phenolic, total flavonoid, proline, soluble sugar, and protein contents), and enzymatic metabolites (superoxide dismutase, peroxidase, and catalase) in rice plants under biotic stress, and 50 mg/L concentration of AgNPs was found to be effective to elicit biochemical modifications to reduce biotic stress. The 50 mg/L concentration of AgNPs was also effective in controlling the proliferation of fungal pathogen. The applications of AgNPs reduced the biotic stress by decreasing the production level of osmolytes, enzymatic, and nonenzymatic compounds but significantly increased the protein content.

Mixed gel electrolytes were fabricated chemically at a temperature range of 2–5°C using some additives comparing with traditional electrolytes (1.26 g/cm 3 H 2 SO 4 ). The polyacrylamide (PAM) content is kept constant (0.2 wt%), while the propylene glycol (PPG) and nano fumed silica (NFS) contents varied. The material characteristics of samples were assessed by physical appearance observation, electrochemical measurements, and physicochemical methods. The results showed that a hard gel without separation of solutions was found in the case using a PAM/PPG/NFS ternary additive (0.2/0.1/0.6 wt%). The morphological structure (<50 nm) of mixed gel electrolytes was in the range of nanometer. The gas release on the PbSb electrode was strongly inhibited (92.2–93.7% for O 2 and ∼55% for H 2 at the 120th cycle), which will both contributes to reducing the pressure as well as limiting water loss in the sealed lead acid battery, compared with that in the sulfuric acid medium.

The imprinted polymers were prepared to absorb dichlorophen (DCP) by using mesoporous silica with ordered pores and high specific surface area. Both scanning electron microscopy and transmission electron microscopy results suggested that the mesoporous silica nanosphere pores had a periodic distribution. The imprinted layer of polymers was thin and uniform. The adsorption experiments showed that the adsorption of imprinted polymers was obviously improved due to the presence of mesoporous structure. The maximum adsorption capacity of MSNs@MIPs at 318 K was 91.1 mg/g, and the adsorption process rapidly reached the equilibrium within 40 min. The adsorption isotherm was well fitted by the Freundlich isotherm model, indicating that multimolecular layer adsorption mechanism governs the adsorption of DCP by the polymers. The adsorption of MSNs@MIPs complied with pseudo-second-order kinetic model. Both selective and regenerative experiments demonstrated that MSNs@MIPs can be successfully applied for selective adsorption of DCP.

Using synthetic zeolite from fly ash to treat high concentration phosphorus wastewater does not only improve the utilization of fly ash as solid waste but also reduce the environmental pressure caused by eutrophication. A synthetic zeolite was prepared from coal fly ash by one-step hydrothermal synthesis and applied for phosphorus adsorption from industrial wastewater (∼8,000 mg-P/L), and its adsorption characteristics and performance were studied. The results indicated that the product was a well-crystallized Na-P1 zeolite with typical morphology of plate- and rod-shaped crystals. Compared with the original fly ash, the specific surface area and average pore volume of the synthetic zeolite were nine and six times larger than the fly ash, reaching 43.817 m 2 /g and 0.122 cm 3 /g. The results from phosphorus adsorption onto the synthetic zeolite showed that the synthetic zeolite had good phosphorus adsorption properties. The adsorption process highly conformed to the pseudo-second-order kinetic model with the regression coefficient R 2 of 0.998. Phosphorus adsorption on the synthetic zeolite was fitted to the Langmuir monolayer adsorption model, and the regression coefficient R 2 was 0.989. The maximum phosphorus adsorption capacity was 84.4 mg-P/g-zeolite.

This study presents a new approach for the recycling of bilayered PET waste in an efficient, continuous process with a depolymerization degree >97%. The complex PET waste was converted by chemolysis into its monomers ethylene glycol (EG) and the corresponding salt of terephthalic acid (TA) in a twin-screw extruder (TSE). Via this method, the starting materials for PET production were recovered, and highly contaminated PET waste and PET composite materials were transformed into valuable starting materials. The PE layer of the composite PET/PE material remained inert under depolymerization conditions and could be separated by filtration. An increase in the rotational speed by 200 rpm in the TSE reduced the residence time, but the degree of depolymerization was not affected in a proportional manner. Thus, the results indicate that a shorter residence time can be compensated with intensified mechanical agitation due to higher rotational speeds to obtain a similar degree of depolymerization. These results support the potential of this recycling concept to substantially contribute to the implementation of a circular PET economy. Graphical abstract

A modified homogeneous precipitation method has been used to synthesize ZnS nanoparticles. Starch and polyvinyl alcohol (PVA) were utilized as capping molecules, and later, the ZnS–PVA-capped nanoparticles were then incorporated with chitosan to form ZnS–chitosan nanocomposites for the removal of Cr( vi ) ion from wastewater. The optical measurements of the synthesized ZnS nanoparticles showed the band gap which was blue-shifted when compared with the bulk ZnS material. The crystalline structures were determined by X-ray diffraction, and the crystalline sizes were estimated from the Scherer formula. XRD spectra confirmed the formation of hexagonal phase for the uncapped ZnS nanoparticles with an average crystalline size of 3.71 nm whereas the starch- and PVA-capped ZnS nanoparticles showed the formation of cubic phase structures with crystalline sizes of 3.26 and 2.88 nm. The TEM image showed spherical particles with regular morphologies and significantly narrow size distributions. The calculated average particle diameters were in good agreement with the estimated XRD result. The removal of Cr( vi ) ion from wastewater was studied through the adsorption process. The effect of pH, dosage, and contact time was investigated. More than 95% of the metal ion recovery was achieved through using ZnS–chitosan nanocomposites. Graphical abstract Preparation of the substituted thiourea ligand, synthesis of ZnS, preparation of polymer nanocomposites, and their application in water treatment.

In recent times, nanoparticles have been the focal point of research in nanoscience due to their wide scope of potential applications in all fields of science. Iron oxide (Fe 3 O 4 ) nanoparticles (NPs) show incredible magnetic saturation, stability, biocompatibility, and intuitive properties on the surface, which makes them ideal for being utilized in several ways. In the present study, Fe 3 O 4 NPs were synthesized by co-precipitation and further coated with silica (SiO 2 ) to avoid aggregation. Synthesized nanoparticles (Fe 3 O 4 @SiO 2 ) were individually functionalized using glycine and malonic acid and characterized by various spectroscopies and microscopies techniques. XRD diffraction analysis showed that the presence of SiO 2 did not alter the diffraction pattern peaks, which represented the existence of Fe 3 O 4 . The presence of Fe 3 O 4 and SiO 2 nanoparticles were further confirmed using EDS. Transmission electron microscope micrographs of the synthesized nanoparticles exhibited spherical shape and confirmed the increase in particle size after coating with SiO 2. Also, the analysis of dynamic light scattering showed that the particle size of Fe 3 O 4 @SiO 2 functionalized with malonic acid (229.433 nm) was greater than those functionalized with glycine (57.2496 nm). However, the surface area was greater in Fe 3 O 4 @SiO 2 -glycine (104.8 m 2 /g) than Fe 3 O 4 @SiO 2 -malonic acid (26.15 m 2 /g). The key findings suggest that the synthesized core-shell Fe 3 O 4 @SiO 2 nanoparticles are a promising candidate for a wide array of applications in the field of medicine and environmental science.

The study assessed the attenuating effect of citrus flavonone, naringenin, and its nanoformulation against cadmium (Cd) toxicity in Nile tilapia ( Oreochromis niloticus ). Nanoparticles of naringenin (NNn) were synthesized; size 165.1 nm (PDI 0.396) in variable shapes; cluster widespread, spherical accumulated, and tubular bacillary. Parallel, mature male Nile tilapia ( n = 120 fish) were used for the exposure study. Group I was negative control. The groups II, III, and IV were exposed to 5 ppm of cadmium chloride monohydrate (CdCl 2 ·H 2 O) for 21 days. Group III was treated with bulk naringenin (BNn) (3 ppm) and group IV was treated with NNn (3 ppm). Group V was exposed only to NNn (3 ppm). Cd-induced oxidative stress was evident from a significant increase in the hepatic malondialdehyde (MDA) levels and modulation of antioxidant enzymes in the liver and kidney. A significant increase in the hepatic metallothionein and HSP70 levels in the gills was observed. Treatment with both BNn and NNn significantly ( p ≤ 0.05) reversed the Cd-induced alterations. However, the protective effect of nano naringenin was more profound on the bioaccumulation of Cd in liver and levels of HSP70 in the gills. These key findings could add to the commercial exploitation of naringenin and its nanosized form as a dietary therapeutic molecule. Graphical abstract Effect of naringenin and its nanoparticles on Cd-induced toxicity in Nile tilapia.

To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO 2 spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO 2 /Ag NPs composites were obtained in situ under UV light irradiating by using mesoporous SiO 2 and Ag NO 3 as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO 2 /Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO 2 /Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureus and Escherichia coli via disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO 2 /CQDs and mesoporous SiO 2 /Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO 2 /Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.

In recent times, research on the synthesis of noble metal nanoparticles (NPs) has developed rapidly and attracted considerable attention. The use of plant extracts is the preferred mode for the biological synthesis of NPs due to the presence of biologically active constituents. Aloe vera is a plant endowed with therapeutic benefits especially in skincare due to its unique curative properties. The present study focused on an environmental friendly and rapid method of phytosynthesis of silver nanoparticles (Ag-NPs) using A. vera gel extract as a reductant. The synthesized Ag-NPs were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier transform infrared (FTIR), and dynamic light scattering (DLS). TEM micrographs showed spherical-shaped synthesized Ag-NPs with a diameter of 50–100 nm. The UV-Vis spectrum displayed a broad absorption peak of surface plasmon resonance (SPR) at 450 nm. The mean size and size distribution of the formed Ag-NPs were investigated using the DLS technique. Antibacterial studies revealed zones of inhibition by Ag-NPs of A. vera (9 and 7 mm) against Pseudomonas aeruginosa and Escherichia coli , respectively. Furthermore, the antifungal activity was screened, based on the diameter of the growth inhibition zone using the synthesized Ag-NPs for different fungal strains. Anticancer activity of the synthesized Ag-NPs against the mouse melanoma F10B16 cell line revealed 100% inhibition with Ag-NPs at a concentration of 100 µg mL −1 . The phytosynthesized Ag-NPs demonstrated a marked antimicrobial activity and also exhibited a potent cytotoxic effect against mouse melanoma F10B16 cells. The key findings of this study indicate that synthesized Ag-NPs exhibit profound therapeutic activity and could be potentially ideal alternatives in medicinal applications.

Silver nanoparticles (AgNPs) are widely used for medical applications particularly as antimicrobial agents against multidrug-resistant microbial strains. Some plants stimulate the reduction of Ag ions to AgNPs. In this study, we prepared AgNPs via the green synthesis approach using fenugreek leaves grown in Saudi Arabia. Furthermore, we characterized these AgNPs and evaluated their antimicrobial activities against pathogenic yeast, bacteria, and fungi. The ultraviolet-visible peak at 380 nm confirmed the biosynthesis of NPs. Transmission electron microscopy analyses revealed particle size in the range of 9–57 nm with a spherical shape. Dynamic light scattering results confirm slight aggregation as the average particle size was shown as 68.71 nm and a polydispersity index of 0.083. The energy-dispersive X-ray spectroscopy results showed an intense peak at 3 keV, indicating the presence of elemental AgNPs. The synthesized AgNPs efficiently inhibit the growth of both Gram-positive and Gram-negative bacteria; however, varying degree of inhibition was shown toward fungi. The potent antimicrobial ability of the synthesized NPs can be attributed to their small size and round shape. Among all test organisms, the growth of Candida albicans and Helminthosporium sativum was remarkably affected by AgNPs treatment.

In order to alter the solubility and bioavailability of various functional lipids and plant essential oils (EOs), it is possible to prepare their oil in water (O/W) nanoemulsions. Thyme O/W nanoemulsions were prepared under subcritical water conditions (at 120°C and pressure of 1.5 atm for 2 h), using Tween 20, Tween 80, saponin, Arabic gum, xanthan gum, and sodium caseinate as emulsifiers. Results indicated that nanoemulsions with minimum mean droplet size of 11.5 and 12.6 nm were produced using Tween 20 and 80, respectively. Moreover, nanoemulsions with minimum polydispersity index (0.139) and maximum mean value of zeta potential (−24.5 mV) were provided utilizing xanthan gum and saponin, respectively. Results also revealed that the prepared nanoemulsions using saponin had maximum antioxidant activity based on percentage of scavenging ability (40.6%) and bactericidal effects against Streptococcus mutans as manifested in the formed clear zone (diameter of 21 mm). Morphological assessment of all the prepared nanoemulsions demonstrated that spherical thyme nanodroplets were formed in the colloidal solutions which revealed that all the prepared nanoemulsions had high thermodynamic stability due to the minimum surface energy level of the formed nanodroplets. This can increase applications of the prepared thyme O/W nanoemulsions in the aqueous food and pharmaceutical formulations.

Fast, simple, and environmentally friendly gold nanoparticles (Au-NPs) capped and stabilized with black cumin ( Bunium persicum ) seed alcohol extract are reported. The aqueous gold ions (Au 3+ ) were treated with B. persicum (BP) seed extract, which resulted in a rapid color change to red, indicating the synthesis of Au-NPs. UV-Vis spectroscopy, FTIR, SEM, energy dispersive X-ray (EDX), and X-ray diffraction (XRD) techniques were used to further characterize the Au-NPs. Its stability was assessed against various pH levels and sodium chloride levels (NaCl), different salts of same concentration as well as at a range of temperature (30–100°C). The UV-Vis spectrum in the Au-NPs produced a 540 nm plasmon surface resonance, and a 25–50 nm range of particulates was shown in the SEM analysis. In addition, the FTIR spectra confirmed the inclusion in the capping and decrease of Au-NPs of amines, amide groups, and alcohols. The EDX analysis confirmed the presence of element Au. Furthermore, Au-NPs were tested for enzyme inhibition and antibacterial and antifungal activities and showed remarkable response. These findings have concluded that BP seed extract is an effective bio-reductant of gold nanoparticle synthesis, which can be further applied in different biomedical and pharmaceutical industries.

Herein, we report a simple and ecofriendly synthesis of ZnO nanoparticles (ZnO NPs) employing Digera muricata along with bioassay studies of synthesized NPs. The ZnO NPs obtained were indicated by a colour change from yellow to almost faint yellow giving whitish tinge and supported by the appearance of UV-Vis band at 373 nm and were characterized by using Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray (EDX), and scanning electron microscopy (SEM). The FT-IR spectrum confirmed the presence of biomolecules fabricated on ZnO NPs as indicated by the absorption bands at 1,378 for C–O  cm −1 , and ZnO NPs were also evident from the absorption bands at 440 and 670 cm −1 , the former being the result of symmetric vibration of hexagonal ZnO and the latter belonged to a very weak vibration of ZnO. Its surface morphology was confirmed by SEM, and the zinc and oxygen bonds were confirmed by EDX analysis giving sharp signals for Zn and oxygen with At% of 17.58 and 30.49, respectively. The antimicrobial activity of ZnO nanoparticles was determined by the agar well diffusion method against pathogenic bacterial and fungal strains using imipenem and miconazole as standards. The results reflected that ZnO NPs enhanced the activity of plant extracts against all employed algal ( E. coli , S. faecalis , P. aeruginosa , K. pneumonia , S. aureus , and B. subtilis) and fungal ( T. mentogrophytes , E. floccosum , A. niger , M. canis , and F. culmorum) strains. The antibacterial and antifungal activities of extracts were enhanced by the formation of ZnO NPs. The results indicated that Digera muricata extract contains effective reducing agents for green synthesis of Digera muricata fabricated ZnO NPs, which are more potent antimicrobial than the plant extract and showed almost similar inhibition against lipoxygenase, i.e., the IC 50 value of 83.82 ± 1.15, comparable to the standard.

Low density polyethylene is widely used in agricultural production. It is of low cost and able to significantly improve the quality of fruits. However, its decomposition under natural circumstances needs more than one hundred of years. If not removed in time, it is hazardous to the ecological environment and crops. Up to now, the removal techniques of polyethylene films are polluted, expensive, and difficult to employ. A novel method is proposed for in situ removal of polyethylene by an effective and environmental friendly technique with low cost. The Nb-modified SnO 2 quantum dots are prepared for the efficient photocatalytic degradation of polyethylene under visible light. The green synthesis of the photocatalyst includes the procedures of hydrolysis, oxidation, and hydrothermal treatment in aqueous solution. The Nb-modified SnO 2 has a band gap of 2.95 eV, which enhances its absorption of visible light. A degradation efficiency of 29% is obtained within 6 h under visible irradiation. The hydroxyl radicals ( • OH) are main active species in the degradation process. The prepared Nb-SnO 2 quantum dots demonstrate a promising application in the photocatalytic degradation of polyethylene, contributing a novel strategy for the in situ treatment of agricultural wastes.

Various means have been proposed to solve problems such as high ash content and complex composition in the recycling of nickel-containing residue produced by battery manufacturing enterprises. Microwave roasting pretreatment is proposed to improve the nickel leaching rate from the residue. The effect of different experimental conditions like microwave roasting temperatures, roasting times, and microwave powers on the nickel leaching rate was studied. It was found that the effect of roasting temperature on the nickel leaching rate was more significant than those of roasting time and microwave power. Meanwhile, after microwave roasting pretreatment, the rate of nickel leaching from the residue could be increased by 20.43%, and weight of the material could also be reduced by more than 21%. After microwave roasting at 450°C, there was no significant change in the main phases of the material, but the surface of the particles exhibited an apparent stratified dissociation phenomenon. Response surface methodology (RSM) was used to optimize the parameters of microwave roasting with nickel leaching rate as the response value. The results showed that the nickel leaching rate could reach 93.11% for roasting at the microwave power of 962 W for 6.2 min under the temperature of 452°C.

The green plant-mediated synthesis of silver (GPS-Ag) nanoparticles (NPs) has been increasingly popular due to its eco-friendliness, availability, cost-effectiveness, and the fact that it can be safely handled and possesses a broad variability of metabolites, such as antioxidant and antimicrobial activities. In this current study, the synthesis of AgNPs has been demonstrated using aqueous extracts of fresh leaves of Ficus carica and Salvia rosmarinus (rosemary) that reduced aqueous silver nitrate. This procedure made the synthesis of NPs possible, which was characterized by numerous analytical techniques such as ultraviolet-visible (UV-Vis) spectrophotometry, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, and dynamic light scattering studies. The visual observation indicated that the colour of aqueous silver nitrate turned brownish yellow after treatment with the fresh leaf extracts and was confirmed by UV-Vis spectra. In addition, the TEM analysis showed that the synthesized NPs well dispersed with average sizes less than 22 nm. Furthermore, AgNPs and aqueous leaf extracts of F. carica and rosemary were examined for their antimicrobial activities against different Gram-positive and Gram-negative bacteria strains. The results indicated that the AgNPs, derived from F. carica, have more antibacterial activities than others and inhibited bacterial growth.

The invasion of fish/seafoods by zoonotic pathogens causes health threats to humans. Plant derivatives and phytosynthesized nanometals could promisingly overcome bacterial infections/contaminations. The extract of pomegranate rinds (PRE) was innovatively employed for biosynthesizing selenium nanorods (Se-NRs). These agents were assessed as antibacterial candidates against diverse fish-borne pathogenic species ( Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli , Salmonella typhimurium , and Sphingomonas paucimobilis ). The PRE-synthesized Se-NRs, within 60 min of contact, were negatively charged (‒32 mV) and had mean diameter of 62.31 nm and length range of 443.5–1236.9 nm. The designated infrared spectra for PRE and PRE/Se-NRs composite validated the biosynthesis, bonding, and interactions of the nanocomposite. The antibacterial potentialities of PRE, phytosynthesized Se-NRs, and PRE/Se-NRs composite was confirmed toward the entire challenged pathogens; S. aureus had the highest resistance (with inhibitory concentrations of 72.5, 60.0, and 55.0 mg/L, respectively) and S . paucimobilis was the most sensitive (with inhibitory concentrations of 55.0, 45.0, and 42.5 mg/L, respectively). The ultrastructure of the treated S . paucimobilis with PRE/Se-NRs emphasized the composite potentiality for deforming/distorting cells within 4 h and causing full cells’ destruction and deformation within 8 h of exposure. The PRE-phytosynthesized Se-NRs are advocated as potent antibacterial products against fish-borne pathogens for decontaminating fisheries farms and products.

Modified polyvinylidene fluoride (PVDF) membranes were prepared by the phase inversion method via blending in situ formed nanosilver (Ag) and nanozirconium dioxide (ZrO 2 ). Scanning electron microscopy of the membranes revealed that the surface pore size of the membranes was increased and distributed widely with the addition of modified nanosilver (Ag) and nanozirconium dioxide (ZrO 2 ). The pores of the membrane were reduced due to excessive modification of the material when the content of zirconium dioxide was increased to 0.4%. XRD characterization showed that in situ synthesis of nanosilver (Ag) and nanozirconium dioxide (ZrO 2 ) had been successfully blended in the membranes. The contact angle of the modified membrane ranged from 82.72° to 67.37°, which showed that the hydrophilic properties of the membrane were improved. The pure water flux of the modified membrane increased from 28.43 to 143.2 L/m 2  h, indicating that the hydrophilicity of the modified membrane was enhanced significantly. The flux recovery rate of the modified membrane was obviously increased in the fouling experiment with BSA as the source of organic pollutants. The antimicrobial contamination of the membrane was greatly enhanced with the E. coli microbial contamination experiment.

To research the paracrine role of adipose tissue-derived mesenchymal stem cells (ADMSCs) in promoting angiogenesis under the three-dimensional culture conditions consisting of a functionalized self-assembling peptide nanofiber hydrogel. ADMSCs were isolated, extracted, and then identified. Three kinds of peptides (RADAI-16, RGD, and KLT) were prepared, and a functionalized self-assembling peptide nanofiber hydrogel was produced by mixing RADAI-16, RGD, and KLT in a volume ratio 2:1:1. AFM was used to observe RADAI-16, RGD, KLT, and the functionalized self-assembling peptide nanofiber hydrogel. Then, ADMSCs were cultured under three-dimensional conditions consisting of the peptide nanofiber hydrogel, and AFM was used to observe cell migration. The ADMSCs in the common culture group (37°C, 5% CO 2 cell culture box) and hypoxic culture group (37°C, 10% CO 2 , and 1% O 2 hypoxic culture box) acted as controls. ADMSCs were three-dimensionally cultured in situ for 1 day, and then the concentrations of HGF and VEGF in the supernatant were determined by ELISA. Cells were extracted from the peptide nanofiber hydrogel, and HO-1 expression was detected by western blotting. ADMSCs have high expression levels of CD29, CD90, and CDl05 and low expression levels of CD34 and CD45. In addition, they can differentiate into adipocytes and osteocytes. The diameters of the fibers of RADAI-16, RGD, KLT, and the functionalized self-assembling peptide hydrogel are 17.34 ± 1.82, 15.50 ± 1.41, 13.77 ± 1.18, and 20.26 ± 1.25 nm, respectively. AFM indicated that cells in the functionalized self-assembling peptide nanofiber hydrogel migrated farther than those in RADAI-16. The concentrations of HGF under common, hypoxic, and three-dimensional culture conditions were 47.31 ± 6.75, 247.86 ± 17.59, and 297.25 ± 17.95 pg/mL, respectively, while the concentrations of VEGF were 218.30 ± 3.03, 267.13 ± 4.27, and 289.14 ± 3.11 pg/mL, respectively. Both HGF and VEGF were expressed more in the presence of the functionalized self-assembling peptide nanofiber hydrogel than in its absence ( P < 0.05). Using western blotting, ADMSCs cultured under hypoxic and three-dimensional conditions were found to have high expression levels of HO-1. Culturing ADMSCs under three-dimensional conditions consisting of functionalized self-assembling peptide nanofiber hydrogels can promote their paracrine role in angiogenesis, such as HGF and VEGF, and hypoxia is one of the important elements.

Since the corrosion protection of mild steel samples in corrosive media (1 M of hydrochloric acid [HCl]) was cheap and successful, the ethanol extract of Posidonia oceanica leaves based on polyvinylpyrrolidone ( P. oceanica /PVP) was analyzed using the weight reduction, the open circuit potential, and the potentiodynamic polarization methods. The obtained results explained that the productivity of hindrance increments had the greatest restraint efficiency of ∼81% at 1,000 ppm, as the concentration of the extract increased. Liable for adsorption as a thin layer on the surface of mild steel to protect it, the creation of kaolin-traced phenolic and polysaccharide compounds was confirmed by the Fourier transform infrared spectroscopy analysis. A scanning electron microscope was used to evaluate the inhibitive action of P. oceanica /PVP against steel in corrosive media and the change in surface morphology was considered. It is presumed that the ethanol removed from the Posidonia oceanica leaves can fill in as a compelling consumption inhibitor for gentle steel in HCL solution (1 M).

In this paper, we have presented the method of green synthesis of ZnO and Ag-NPs using the callus extract (CE) of medicinally important Cannabis sativa . The synthesis of nanoparticles (NPs) was confirmed by UV-Vis spectroscopy, while as far as the size and shape of the NPs were concerned, they were validated using the techniques of X-ray diffraction and scanning electron microscopy, respectively. The energy dispersive X-ray analysis graph confirmed the constitution of elements along with the surface chemical state of NPs. Fourier transform-infrared spectroscopy was utilized for the confirmation of biomolecules capping the NPs. In order to test the application of these biosynthesized NPs on biological entities, four bacterial strains, including Bacillus subtilis , Klebsiella pneumonia , Staphylococcus aureus , and Pseudomonas aeruginosa, were used. On the other hand, five fungal strains, namely Mucor , Aspergillus flavus , Aspergillus fumigatus , Aspergillus niger , and Fusarium solani, were utilized for antifungal assay. Cytotoxicity assay was also performed using the HepG2 cell line. The results showed considerable antibacterial and antifungal activities. It also showed better cytotoxicity values as compared to the control.

This study was performed to validate the previous antimicrobial and cytotoxic data on the influence of ionic liquids as coatings of silver nanoparticles (AgNPs). The antibacterial and cytotoxicity assessments were carried out against different microorganisms and a cancerous cell line. AgNPs with two different ionic-liquid coatings and hydrocarbon chains were synthesized and characterized. We tested the antibacterial activity of these NPs against Salmonella typhi , Bacillus subtilis , Staphylococcus aureus , Escherichia coli , and Candida albicans in planktonic forms and against Enterococcus faecalis and Escherichia coli in biofilm forms. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was employed for toxicity evaluation. The antimicrobial activity of NPs with 12 carbons was significantly higher than those with 18 carbons. Furthermore, NPs with 12 carbons were also effective against bacterial biofilms. All of the NPs tested had good cell viability at different antimicrobial concentrations. The length of the hydrocarbon chain is an essential factor in determining the antimicrobial activity of ionic-liquid-coated AgNPs. The variation in ionic-liquid coatings was not as effective as other influencing factors. Evaluation of AgNPs using other alkyl chain lengths to find the optimal size is recommended.

This work presents results on CO 2 hydrogenation to dimethyl ether (DME) over bifunctional catalysts consisting of In 2 O 3 , supported on natural clay halloysite nanotubes (HNT), and HNT modified with Al-MCM-41 silica arrays. The catalysts were characterized by TEM, STEM, EDX-mapping, NH 3 -TPD, XRD, low-temperature nitrogen adsorption, TPO, and H 2 -TPR techniques. Catalytic properties of In 2 O 3 /HNT and In 2 O 3 /Al-MCM-41/HNT in the CO 2 hydrogenation to DME were investigated in a fixed-bed continuous flow stainless steel reactor at 10–40 atm, in the temperature range of 200–300°C, at GHSV = 12,000 h −1 and molar ratio of H 2 :CO 2 = 3:1. The best catalyst for CO 2 hydrogenation was In 2 O 3 /Al-MCM-41/HNT that provided DME production rate 0.15 g DME ·(g cat ·h) −1 with DME selectivity 53% and at 40 bar, GHSV = 12,000 h −1 , and T = 250°C. It was shown that In 2 O 3 /Al-MCM-41/HNT exhibited stable operation for at least 40 h on stream.

Due to high antimicrobial activity against numerous microorganisms, silver nanoparticles (AgNPs) are being utilized in various areas. Microwave-accelerated AgNPs synthesis using Corylus avellana leaf extract was evaluated. Based on randomly central composite design, 13 mixture solutions containing different amounts of the prepared extract (0.10–0.90 mL) and 1 mM silver nitrate solution (15–25 mL) were prepared and exposed to microwave irradiation for 180 s. Response surface methodology was utilized to evaluate the effects of the two independent variables on particle size and concentration of the synthesized AgNPs, as manifested in the place of broad emission peak ( λ max ) and its absorbance unit, respectively. Fourier transform infrared spectroscopy analysis indicated that the two hydroxyl and carboxylic acid functional groups with reducing activity existed in the prepared extract. Dynamic light scattering and transmission electron microscopy analyses revealed that the formed spherical AgNPs using optimum amounts of C. avellana leaf extract (0.9 mL) and 1 mM silver nitrate solution (25 mL) had minimum particle size (103.5 nm) and polydispersity index (PDI) (0.209), and maximum concentration (140 ppm) and zeta potential (−21.8 mV). Results indicated that the formed AgNPs had high fungicidal effects against the spoiled fungi of Colletotrichum coccodes and Penicillium digitatum .

Generally, several mechanisms influenced the secondary injury chutes following acute spinal cord injury (SCI). Though current SCI therapeutic approaches mostly target single elements in the injury chutes, they have been mostly ineffective in clinical trials. The aim of this study was to design and develop a novel cerium oxide/silk fibroin (CeO 2 /SF) hydrogel material loaded with minocycline (MCN) and transplantation of olfactory ensheathing cells (OEC) for SCI treatment. The prepared CeO 2 /SF hydrogel has an advantageous porous morphological structure and CeO 2 NPs were greatly encapsulated on the surface, which was confirmed by microscopic observations. The results of in vitro analyses established favourable biocompatibility of 94.65% and 89.45%, sustained drug release rate of 89% and 58%, and significant reduction in pro-inflammatory factors for the treatments using cerium oxide loaded silk fibroin (CSF) and CeO 2 NPs, respectively. Meanwhile, the administration of MCN@OEC greatly provides an efficient improvement in BBB score, decreased bladder weight, and histological improvement after SCI when compared to the control. Therefore, the combined MCN and OEC-loaded CSF hydrogel sample could be proved as a low cost, safe, and potential material for the treatment of SCI. Graphical abstract Scheme of the MCN@OEC-loaded CSF hydrogel.

To solve the environmental pollution caused by automobile exhaust in a tunnel, this study has developed a modified nano-TiO 2 based on Fe 3+ and Ce 3+ . The modified nano-TiO 2 is prepared by the sol–gel method, and the modification adopts Fe 3+ single-doping, Ce 3+ sing-doping, and co-doping. The properties were also characterized by X-ray diffraction analysis, UV-vis diffuse reflectance analysis, fluorescence spectroscopy analysis, specific surface area analysis, and paramagnetic resonance popper analysis. The analyses showed that the doping of ions would change the energy band structure of nano-TiO 2 and produce crystal defects, thus improving the photocatalytic activity. Then, a self-fabricated exhaust gas degradation device was used to carry out the exhaust gas degradation experiments. The results showed that the modification improves the catalytic efficiency of nano-TiO 2 , and Fe 3+ , Ce 3+ co-doping > Ce 3+ single-doping > Fe 3+ single-doping > pure TiO 2 . At the dosage of 0.5%, the maximum degradation efficiencies of NO and CO before compensation are 53.85% and 16.39%, respectively, and the maximum degradation rates are 1.04 and 0.93 ppm·min −1 . After compensation, the maximum degradation efficiencies of NO and CO are 20.14% and 6.04%, respectively. The maximum degradation rate is 0.40 and 0.41 ppm·min −1 , respectively.

To improve the biogas potential in anaerobic digestion of cattle manure in cold regions, we investigated, in this study, the potential of the anaerobic digestion of cattle manure through sequencing batch anaerobic digestion experiments at sub-mesophilic temperatures (15°C, 20°C, 25°C, and 37°C) for 50 days. Specifically, the changes in the biogas yield, pH, sCOD concentration, enzyme activity, and microbial community structure were examined. The maximum daily yield of biogas was 19.18 mL·gVS −1 , which was recorded on day 6 at 37°C, and the final biogas accumulation yield at this temperature was 403.64 mL·gTS −1 . The concentration of sCOD gradually increased as enzyme activity increased. The maximum activities of cellulase, hemicellulase, protease, and amylase were recorded in the 37°C experimental group. The decrease in temperature severely limited the activity of different types of enzymes, resulting in a decrease in the activity of microorganisms, which greatly influenced the methanogenic reaction. The dominant bacteria at the phylum level were Bacteroidetes and Proteobacteria , and the dominant methanogen at the genus level was Methanosaeta .

In the present investigation, silver nanoparticles (AgNPs) and silver nanoparticle-based chitosan nanocomposite were synthesized using Cissus arnottiana leaf extract. The biosynthesized nanoparticles and nanocomposites were characterized using SEM, TEM, and AFM to uncover the morphological characteristics such as size and shape. The SEM image depicts the size of the nanocomposite to be 30–40 nm and shape as spherical. The TEM results reveal the shape of the nanocomposite to be spherical and size around 10–60 nm. The XRD results show the crystalline nature of the AgNPs-based chitosan nanocomposite. The SAED analysis pattern seems to be concordant with the XRD results. The AFM image ensured the precise surface morphology of the synthesized silver nanocomposite in the 3-dimensional pattern. The antimicrobial efficacy of the biosynthesized AgNPs, AgNP nanocomposite, and chitosan nanoparticles was tested against oral pathogens. The results revealed a potential antimicrobial effect, which states that it must be converted into nanomedicine to meet future biomedical needs. Graphical abstract Antibacterial potential of silver nanoparticle-based chitosan nanocomposites.

Baeyer–Villiger (BV) oxidation of cyclohexanone to ε -caprolactone was studied by a co-precipitation method using Fe–Sn–O catalysts in an O 2 /benzaldehyde system. The effects of the Fe:Sn ratio, calcination temperature, calcination time, and reaction conditions on the catalytic performance were investigated. The catalysts present the best activity when it is prepared at a Fe:Sn ratio of 1:1, calcination temperature of 850°C, and calcination time of 5 h. Under these conditions, catalysts form a large number of small prisms, which result in a larger specific surface area and enhanced catalytic activity. The optimum reaction conditions for the synthesis of ε -caprolactone in the presence of the Fe–Sn–O catalyst are as follows: catalyst (0.12 g), 1,2-dichloroethane (30 mL), O 2 flow rate of 25 mL min −1 , cyclohexanone to benzophenone of 3:1, reaction temperature of 60°C, and reaction time of 5 h. The conversion of cyclohexanone and the average yield of ε -caprolactone are determined at 98.96% and 83.36%, respectively.

The correlation between catalytic performance and the structure of a carbon-based solid acid (G/F-1/ x ), an amorphous carbon-bearing SO 3 H group, was investigated. Concentrated sulfuric acid was used to carbonize and sulfonate the mixed graphene and fructose powder for the preparation of carbon-based solid acid catalysts with different cross-linked structures. The results showed that the catalyst with a higher fructose loading amount presented higher catalytic performance. The catalytic performance improvement could be attributed to a high density of SO 3 H groups and the fast diffusion of reactants and products enabled by a flexible carbon network. The best furfural yield was obtained up to 69.4% when the weight of graphene and the fructose loading ratio was 1:4. Graphical abstract Poor-cross-linking vs Tight-cross-linking between the carbon sheets.

The structures of lipids are diverse, and thus, lipids show various biological functions. Systematic determination of lipids in organisms has always been a concern. In this paper, a methodology on the matrix-assisted laser desorption ionization mass spectrometry (MALDI MS), with titanium dioxide nanoparticles (TiO 2 NPs) as the matrix, was studied for lipid determination. The results showed that the following conditions were preferable in the determination of small-molecule lipids (such as hypoxanthine, guanosine, uridine, and cytidine), lipid standards (such as GC, GM, TG, phosphatidylethanolamine, phosphatidylcholine, and ceramide), and mixed lipids (extracted from brain homogenate with methanol alone and with the B&D method): TiO 2 NPs as the matrix, absolute ethanol as the solvent, 1 mg of TiO 2 NPs dispersed in 1 mL of absolute ethanol as the matrix solution, NaCl as the ionization reagent, and positive mass spectrometry (MS) as the mode. Modified TiO 2 NP as a new matrix for MALDI MS will be a future research direction; in addition, the characteristics of TiO 2 NPs make it a potential matrix for imaging MS.

Marine green algae are rich in various bioactive components with known anticancer activity. Some anticancer drugs present in green algae are in clinical trials nowadays. Algae-mediated silver nanoparticles (AgNPs) have been of a great interest in cancer treatment due to their unique physico-chemical properties. In this study, we evaluate the anticancer efficiency of marine alga Chaetomorpha ligustica collected from the Arabian Gulf against colon cancer cell lines HT29 and HCT116. The anticancer potential of biosynthesized AgNPs from C. ligustica extract is also reported. Fourier transform infrared (FTIR) spectroscopy and gas chromatography-mass spectrometry analyses were used to identify the phytoconstituents present in algae extract. The synthesized AgNPs were confirmed via UV-Vis spectroscopy, whereas their morphology and stability were recorded by transmission electron microscopy (TEM), zeta potential, and zetasizer. We recorded absorption peak at 420 nm; TEM images showed an average size of 8.8 nm, whereas zeta potential and zetasizer study showed aggregation of nanoparticles. FTIR spectroscopy peaks of C. ligustica AgNPs were a little different from those of the C. ligustica extract. Both extracts showed cytotoxicity against cancer cell lines in a dose-dependent manner, but nanoparticles were found to be more toxic than algae extract. HT29 was found to be more sensitive than HCT116. For the first time, species of C. ligustica have been used and reported for the synthesis of nanoparticles. C. ligustica and its biogenic nanoparticles need to be scaled up for many biomedical applications especially in cancer research.

During curcumin production in Vietnam, curcumin-removed turmeric oleoresin (CRTO) has been considered as a by-product. It costs to treat the by-product to prevent environmental pollution. In this study, the by-product was utilized as an active ingredient for preparing a botanical fungicide-based nano-emulsion and evaluated for its in vitro and in vivo control efficacy against Colletotrichum gloeosporioides, a causal agent of anthracnose of litchi, in the laboratory as well as a field trial. The nano-emulsion is colloidally stable and uniform with particle sizes of 95–250 nm. CRTO nano-emulsion significantly affected various Colletotrichum species. Notably, this nano-emulsion showed potent inhibition for the mycelial growth of C. gloeosporioides and solidly suppressed the development of anthracnose on litchi fruits. In the in vitro inhibition test, the equivalent half-maximal inhibitory concentration of CRTO in nano-formulation was 0.11 mg·mL −1 , which was 3.0× and 6.1× lower than IC 50 values of CRTO alone (0.33 mg·mL −1 ) and a mixture of curcuminoids (0.48 mg·mL −1 ), respectively. In the field trial, the litchi anthracnose infection was effectively controlled by nano-formulation. These results suggest that CRTO nano-emulsion could be used as an alternative to harmful synthetic fungicides to control anthracnose on litchi fruits.

Fabrication and use of nanoparticles have progressively enlarged within the last decade. Herein the silver nanoparticles (AgNps) were synthesized via the extract from Marsilea quadrifolia ( Mq ) as a decreasing and steadying mediator. The Mq- AgNPs demonstrated superior toxicity on Zika virus vector, Aedes aegypti with the LC 50 value of 10.69 µg·mL −1 . The Mq- AgNPs were established securely to non-target organisms Artemia nauplii and Ceriodaphnia cornuta, and no structural or anatomical alterations confirm its security to the surroundings. The antibacterial activity exposed that Mq- AgNPs showed superior growth inhibition effect against the tested bacteria. Furthermore, the Mq- AgNPs showed strong antioxidant activities when compared to Mq leaf extract. Overall, our results highlight that Mq- AgNPs are hopeful and biodegradable devices against mosquito vectors of therapeutic significance, with moderate toxicity against non-target aquatic animals. Graphical abstract

The present work demonstrated preparation of coal-based electrode materials (CEM)-derived low-rank coal for simultaneous removal of ammonia nitrogen (NH 3 -N) and chemical oxygen demand (COD) from coking wastewater by a three-dimensional electrode system (3DES). The influence of important parameters in 3DES such as processing time, applied voltage, electrode plate spacing, mass of commercially activated carbon (CAC), and initial pH were investigated. Based on the central composite design, the response surface method (RSM) was employed in order to optimize the variable parameters in removal process of pollutants. From the analysis of RSM, the optimum conditions for 3DES were 4.5 h of processing time, 5.5 V of applied voltage, 17 mm electrode plate spacing, 4.5 g CAC, and pH of 3 with higher simultaneous removal rate of COD (74.20%) and NH 3 -N (51.48%). Besides, the content of N element (4.9%) and N containing groups were traced by SEM-EDS and FTIR analysis in order to verify the removal effect. The experiment results showed the capability of CEM for electrode system removal of pollutants from coking wastewater and obtained considerable simultaneous removal rate of NH 3 -N and COD.

In the present study, the synthesis of water-soluble copper-doped CdSe nanoparticles (NPs) via a low cost, facile, and environmentally benign method is reported. Simple reagents such as selenium powder, cadmium chloride, and copper sulphate were used as selenium, cadmium, and copper precursor, respectively, while l -cysteine was used as a capping ligand without the use of an additional stabiliser. The as-synthesised copper-doped CdSe NPs were characterised using ultraviolet (UV-Vis) absorption and photoluminescence (PL) spectroscopy, Fourier-transform infrared spectroscopy, and transmission electron microscopy. By varying the dopant concentration, the temporal evolution of the optical properties and the shape of the nanocrystals were investigated. The observation and the results showed that the colour of the solution changed rapidly from orange to black, and the PL shifted to a longer wavelength at the high dopant concentration. The micrographic images revealed that the as-synthesised materials are small and could be used for bio labelling.

Candida genus includes many hazardous and risky species that can develop resistance toward various antifungal types. Metals nanoparticles (NPs) possess powerful antimicrobial actions, but their potential human toxicity could limit their practices. The algal polysaccharide fucoidan (Fu) was extracted from the macro-brown algae, Cystoseira barbata , analyzed, and used for biosynthesizing nanoparticles of silver (Ag-NPs) and selenium (Se-NPs). The extracted Fu had elevated fucose levels (58.73% of total monosaccharides) and exhibited the main biochemical characteristic of customary Fu. The Fu biosynthesis of Ag-NPs and Se-NPs was achieved via facile direct protocol; Fu-synthesized NPs had 12.86 and 16.18 nm average diameters, respectively. The ultrastructure of Fu-synthesized NPs emphasized well-distributed and spherical particles that were embedded/capped in Fu as combined clusters. The Fu/Ag-NPs and Fu/Se-NPs anticandidal assessments, against Candida albicans , Candida glabrata , and Candida parapsilosis , revealed that both NPs had powerful fungicidal actions against the examined pathogens. The ultrastructure imaging of subjected C. albicans and C. parapsilosis to NPs revealed that Fu/Ag-NPs and Fu/Se-NPs triggered remarkable distortions, pore formation, and destructive lysis in cell surfaces within 10 h of exposure. The innovative usage of C. barbata Fu for Ag-NP and Se-NP synthesis and the application of their composites as powerful anticandidal agents, with minimized human toxicity, are concluded.

Currently, the prime focus in agricultural research is on sustainability and protection of agricultural produce with minimal use of synthetic fungicides. In the present study, silver nanoparticles (AgNPs) were synthesized using fresh leaves of Mentha pulegium (M.p) through a simple, easy, and economical method. The formation of M.p-AgNPs was ascertained with UV-visible spectroscopy that gave a surface plasmon resonance peak at 430 nm. Further, M.p-AgNPs were characterized by energy dispersive X-Ray analysis (EDX), transmission electron microscopy (TEM), dynamic light scattering, and Fourier-transform infrared (FTIR) spectroscopy. The DLS spectrum and TEM microphotographs showed that the M.p-AgNPs were small in size, measuring between 4 and 60 nm. Significant hyphal growth inhibition of some selected fungal phytopathogens was achieved after exposing them to various concentrations of M.p-AgNPs. The M.p-AgNPs (40 µg·mL −1 ) suppressed the fungal mycelial growth of all the test isolates significantly. When compared to the control, Fusarium solani (63% inhibition) and Alternaria alternata (61% inhibition) showed the highest inhibition. Likewise, spore germination was inhibited in a potent manner. Hence, based on the findings of the present study, M.p-AgNPs can be used to create a low cost, nontoxic, eco-friendly fungicide to control the growth and proliferation of some fungal phytopathogens in the agricultural sector.

Herein, we report the supramolecular complexes of cyclohexanocucurbit[6]uril (CyH 6 Q[6]) with Cu(ClO 4 ) 2 , Zn(ClO 4 ) 2 , and Mg(ClO 4 ) 2 in formic acid solution. The crystal structure was determined using single crystal X-ray diffraction. The analysis results showed that CyH 6 Q [6] formed a one-dimensional supramolecular chain with Cu(ClO 4 ) 2 and formed a supramolecular assembly with a mixture ratio of 2:3 with Zn(ClO 4 ) 2 and Mg(ClO 4 ) 2 . In this system, ClO 4 − {\text{ClO}}_{4}^{-} induced CyH 6 Q[6] and metal ions to form supramolecular complexes through ion–dipole interactions. Graphical abstract

l -Cysteine is widely used in food, medicine, and cosmetics. In this study, a recombinant Escherichia coli whole-cell system with tryptophan synthase was used to complete the biological transformation of l -serine to l -cysteine, and bioconversion of l -cysteine was investigated by tryptophan synthase. The biotransformation of l -cysteine was optimized by response surface methodology. The optimal conditions obtained are 0.13 mol·L −1 l -serine, 75 min, 130 W ultrasound operation, where the V max of tryptophan synthase is 25.27 ± 0.16 (mmol·h −1 ·(g-cells) −1 ). The V max of tryptophan synthase for the biosynthesis without ultrasound is 12.91 ± 0.34 (mmol·h −1 ·(g-cells) −1 ). Kinetic analysis of the recombinant Escherichia coli whole-cell system with tryptophan synthase also showed that under the ultrasound treatment, the K m values of l -cysteine biosynthesis increase from 1.342 ± 0.11 mM for the shaking biotransformation to 2.555 ± 0.13 mM for ultrasound operation. The yield of l -cysteine reached 91% after 75 min of treatment after 130 W ultrasound, which is 1.9-fold higher than no ultrasound. Graphical abstract

The resistance of microorganisms towards antibiotics remains a big challenge in medicine. Silver nanoparticles (AgNPs) received attention recently for their characteristic nanosized features and their ability to display antimicrobial activities. This work reports the synthesis of AgNPs using the Citrus sinensis peels extract in their aqueous, mild, and less hazardous conditions. The effect of concentration variation (1%, 2%, and 3%) of the plant extracts on the size and shape of the AgNPs was investigated. The antimicrobial activities were tested against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae . Absorption spectra confirmed the synthesis by the surface Plasmon resonance peaks in the range 400–450 nm for all the AgNPs. FTIR spectra confirmed that Citrus sinensis peels extract acted as both reducing and surface passivating agent for the synthesized AgNPs. TEM revealed spherical AgNPs with average size of 12 nm for 3% concentration as compared to the agglomeration at 1% and 2%. All the AgNPs synthesized using Citrus sinensis peels extracts (1%, 2%, and 3%) exhibited antimicrobial activity against both gram-positive and negative bacteria. These results indicated a simple, fast, and inexpensive synthesis of silver nanoparticles using the Citrus sinensis peels extract that has promising antibacterial activity. Graphical abstract

Hydrogels are promising drug delivery systems attributable to their unique characteristics such as high hydrophilicity, controllability, biocompatibility, and facile production routines. The aim of this research was the preparation of sodium alginate/acrylic acid (AAc) composite hydrogels conjugated to silver nanoparticles to deliver the cephalexin as a model antibiotic compound. The reduction of silver ions into silver nanoparticles as well as the stabilization of created nanoparticles ensued simultaneously with hydrogel backbone formulation during microwave irradiation and monomer cross-linking processes. The impact of AAc and silver ion concentrations and the radiation time of microwave were then investigated on the main characteristics of hydrogels. The results indicated that the hydrogels’ characteristics could be significantly predicted by studying all independent parameters through various second-order polynomial models. The multiple optimization analysis suggested that the prepared hydrogels using 7.8 g AAc and 1.5 g silver nitrate and 1 min microwave radiation could give the best hydrogels with the highest swelling degree, gel fraction, cephalexin absorption, and antibacterial activity. The morphology and either absorption or release kinetics of cephalexin by the optimum prepared hydrogels were also investigated. No significant differences between the experimental and predicted data confirmed the suitability of the suggested models.

The side-chain alkylation of cumene and ethylene over a solid superbase catalyst K/KOH/ γ -Al 2 O 3 is investigated. The effects of the reaction temperature, pressure, and time on the conversion of cumene and selectivity of tert -amylbenzene (TAB) are discussed. The experimental results show that the conversion of cumene to tert -pentylbenzene increases with the increase in reaction temperature and ethylene pressure. The catalytic reaction has certain operational flexibility in terms of the reaction temperature, pressure, and time. In addition, the catalytic reaction can achieve directional conversion. The optimum operating conditions are obtained using a single factor test. The conversion of cumene is 99.8% and the selectivity toward TAB is 97.9% under catalyst concentration of 4 wt%, reaction temperature of 55°C, reaction pressure of 0.45 MPa, and reaction time of 30 min. The deactivation of catalyst is mainly caused by oxygen and water in the raw material.

Requirements for developing new methodologies to biosynthesize nanoparticles are increasing day by day. The typical chemical synthesis of nanoparticles has raised concerns regarding environmental safety and adverse impact on human health. Therefore, there is an urgent need to develop green synthesized nanoparticles that are considered to be safe, ecofriendly, and cost-effective as compared to chemical approaches. Hence, in this study, we synthesized and characterized pomegranate peel extract-based gold nanoparticles (PP-AuNPs) through UV-visible spectroscopy, FT-IR, and AFM microscopy. Furthermore, the biological activities like analgesic, muscle relaxant, and sedative properties of synthesized PP-AuNPs were also determined. The change of color to dark ruby indicates the formation of AuNPs. The surface plasma resonance (SPR) peak in the absorption spectra was shown at 525 nm by using (UV-Vis) spectroscopy. A single distinctive peak implied the shape of nanoparticles to be spherical. AFM images revealed that the biosynthesized nanoparticles were spherical in shape. Furthermore, the images confirm the uniform distribution of PP-AuNPs with particle sizes ranging from 4 to 16 nm. Different classes of phytochemicals were preliminarily identified in extracts. The analgesic effect of extracts (70.04%) and PP-AuNPs (81.98%) demonstrated a significant ( p < 0.001) percent reduction in writhing at a dose of 100 and 15 mg·kg −1 , respectively. A mild muscle relaxant effect was noted against both the tested samples while a significant sedative effect was observed for both samples; however, PP-AuNPs weres more sedative compared to the extract. Pomegranate peel extracts and synthesized PP-AuNPs were found to possess significant analgesic, muscle relaxant, and sedative properties. Graphical abstract

Vinyl acetate, as an essential organic chemical raw material, can be used to produce polyvinyl acetate, polyester vinyl alcohol, and other products. The existing classical vinyl acetate production process has the problems of low product purity and excessive heat load. In this study, in the classical design of the process, acetylene is separated first, and then acetaldehyde is removed with the formation of an azeotrope between ethylene acetate and water. Meanwhile, considering the solubility of acetaldehyde in water and insolubility of vinyl acetate in water, the process was optimized to separate acetic acid after removing acetylene, so as to avoid the azeotrope formation of vinyl acetate and water. The nonrandom two-liquid-Hayden–O’Connell thermodynamic hybrid model was used to simulate the classical process and improved process (IP). Finally, the reflux ratio and theoretical tray number of the main separation equipment of IP were optimized to get the better parameters. The simulated results show that the purity of vinyl acetate increased from 99.1% to 99.8%, the cooling energy consumption was reduced by 16.83%, and the thermal energy consumption was reduced by 6.18%. At the same time, the equipment investment was also decreased.

Nanotechnology has become one of the most important topics since the beginning of the twenty-first century in numerous fields including drug synthesis and delivery, environmental protection, electronics manufacture, and astronomy due to their nanoscale particles and their properties. The traditional semi-quantum dots are replaced by a new category of fluorescent carbon nanomaterials. Carbon dots (CDs) have been explored in the last few years for their simple synthetic accession, good bio-consonance, and several revelation applications. This review explains the fluorescent properties of CDs in brief, giving also a background on CDs discovery, structure, and composition, as well as on nanocomposites, green synthesis, and their applications. Resources conservation can be achieved by using recycled substances for sustainable development which lead to a new technology. Fluorescent CDs synthesized from food wastes like bananas, orange peel waste, sugarcane bagasse, Trapa bispinosa peels, bread, and jaggery have several applications such as sensing, drug delivery, gene transfer, biological imaging, and food safety. In this study, we concentrate on CDs greener methods to prepare effective and biocompatible CDs.

In the present era, due to the increasing incidence of environmental stresses worldwide, the developmental growth and production of agriculture crops may be restrained. Selenium nanoparticles (SeNPs) have precedence over other nanoparticles because of the significant role of selenium in activating the defense system of plants. In addition to beneficial microorganisms, the use of biogenic SeNPs is known as an environmentally friendly and ecologically biocompatible approach to enhance crop production by alleviating biotic and abiotic stresses. This review provides the latest development in the green synthesis of SeNPs by using the results of plant secondary metabolites in the biogenesis of nanoparticles of different shapes and sizes with unique morphologies. Unfortunately, green synthesized SeNPs failed to achieve significant attention in the agriculture sector. However, research studies were performed to explore the application potential of plant-based SeNPs in alleviating drought, salinity, heavy metal, heat stresses, and bacterial and fungal diseases in plants. This review also explains the mechanistic actions that the biogenic SeNPs acquire to alleviate biotic and abiotic stresses in plants. In this review article, the future research that needs to use plant-mediated SeNPs under the conditions of abiotic and biotic stresses are also highlighted.

Organophosphorus pesticides are currently extensively applied on the control of agricultural and forestry pests. The number of poisonings and deaths caused by organophosphorus pesticides are increasing year by year. Because of the complex matrix, numerous interfering substances, and low poison content, pretreatment methods are crucial for the detection and analysis of such cases. As an adsorbent used for pretreatment, magnetic nanoparticles have the advantages of simple preparation, convenient modification, superparamagnetism, and hydrophilicity. Microextraction can be performed with small amount of magnetic nanoparticles in a short time, and the target substances can be separated with an external magnetic field. In this paper, the latest research achievements are reviewed. Based on the introduced characteristics and preparation methods of magnetic nanoparticles, this paper outlines the applications of different functionalized magnetic nanoparticles for the pretreatment of organophosphorus pesticides and predict the potential research prospects.

Hemicellulose is a carbohydrate biopolymer second only to cellulose, which is rich and has a broad application prospect. The limitation of high-value utilization of hemicellulose has been a long-standing challenge due to its complex and diversified structure. The extraction and subsequent modification of hemicellulose from lignocellulosic biomass represent a promising pathway toward this goal. Herein, the extraction processes including physical pretreatment, chemical pretreatment, and combined pretreatment for separating hemicellulose from lignocellulosic biomass were introduced, and the advantages and disadvantages of various extraction procedures were also described. The chemical modification of hemicellulose such as etherification, esterification, grafting, and cross-linking modification was reviewed in detail. The separation and modification of hemicellulose in the future are prospected based on the earlier studies.

The processing of lignocellulosic materials is very limited because of their low solubility in water and some organic solvents. Fifteen ternary deep eutectic solvents (DESs) were prepared and tested as solvents suitable for delignification of unbleached pulp. The selected ternary DESs are composed of quaternary ammonium salts and amino acids as hydrogen-bond acceptors, and organic acids and polyvalent alcohols as hydrogen bond donors, with molar ratios varying for the individual components. The delignification efficiency is significantly influenced by the degree of penetration of the solvent into the pulp fibre structure. Therefore, the density and viscosity analysis of individual solvents was performed. Unbleached beech pulp with initial kappa number 13.9 was treated with the prepared DESs. The kappa number indicates the residual lignin content or the bleachability of pulp. The efficiency of the solvents ranged from 1.4% to 28.1%. The most suitable for the pretreatment of fibres, based on lignin removal efficiency, were found to be three DESs, in the following order: malonic acid/choline chloride/1,3-propanediol (1:1:3) > choline chloride/acetamide/lactic acid (1:2:3) > choline chloride/urea/lactic acid (1:2:3).

The removal of organosulfurs from liquid fuel has become a hot issue due to the serious environmental pollution by sulfur oxide gases. In this study, the removal of thiophene from model oil was carried out using polyethylene glycol (PEG). It was found that deep eutectic solvents formed by PEG as hydrogen bond donor and thiophene as hydrogen bond acceptor could efficiently separate thiophene from model oil. The influencing parameters in this process were discussed, such as extraction time, temperature, mass ratio of PEG to oil, and initial sulfur concentration. The results showed that the single extraction efficiency of PEG-200 and PEG-400 could reach up to 89.0% and 97.1% in optimal conditions, respectively. The extraction efficiency as high as 95.7% and 99.9% could be achieved after three extraction cycles. The kinetic equation of the extractive desulfurization was studied by in situ infrared (IR), and the kinetic constant k 1 of PEG-400 and PEG-200 was compared ( k 1(PEG-400) > k 1(PEG-200) ). The desulfurization mechanism of PEG was studied by IR, 1 H NMR spectra, and density functional theory (DFT). The results showed that the hydrogen bond formed between hydroxyl hydrogen in PEG and sulfur atom in thiophene accounted for the high extraction efficiency.

This article presents the results obtained in the extraction of birch bark with a green solvent. A low transition temperature mixture (LTTM) consisting of choline chloride (ChCl) and lactic acid in a molar ratio of 1:1 was used as the solvent. Extraction was performed at 60°C and 80°C. At both temperatures, the effect of extraction time on the yield of the extracted substances was monitored. The yields reached were compared with those obtained in studies using common solvents such as ethanol, methanol, d -limonene, ethyl acetate, and others. The extract was quantitatively analyzed by HPLC-UV to determine betulin and betulinic acid (0.491–1.788 mg/g dry bark and 0.106–0.316 mg/g dry bark, respectively). Total phenolic content was determined spectrometrically using Folin–Ciocalteu reagent and expressed as Gallic acid equivalents (GAE; 18.6–56.8 mg GAE/g dry bark). This study has shown that extraction with a green solvent composed of ChCl and lactic acid can be an effective method for extracting polyphenolic compounds from birch bark. The process for extracting triterpenes (betulin and betulinic acid) is less suitable compared to conventional methods using the mentioned organic extractants.

Owing to their recyclability, heterogeneous transition metal catalysts represent a means of conserving depletable resources for the synthesis of pharmaceutical, agricultural, and functional chemicals. We recently developed a novel heterogeneous palladium catalyst and demonstrated its synthetic availability for Suzuki–Miyaura cross-coupling. Herein, we report the further application of the present catalyst to cross-coupling reactions in batch and flow, as well as a hydrogenative reduction reaction in flow. We demonstrate the flow synthesis for useful material, a liquid crystal, and a 1 h sequential operation of the coupling reaction and hydrogenation reaction. Graphical abstract

The use of enabling technologies, such as flow reactors, three-dimensional-printed devices, and electrochemistry, in the stereoselective synthesis of enantioenriched compounds is presented, with a special focus on the most significant contributions to the field reported in the last few years.