Volume 9, Issue 3

Biopolymers have received a lot of interest recently, and academic and industrial research on biopolymers has been refocused. These biopolymers comprise naturally occurring substances as well as artificial substances created from naturally occurring monomers. Plastics have the potential to be replaced by biopolymers because they are hazardous to the environment and rely on nonrenewable resources like petroleum for production. Due to the overwhelming interest in biopolymers, characterization tools and processes have emerged as crucial components in biopolymer research to examine and enhance the characteristics and functionality of materials based on biopolymers. When evaluating the performance of these bio-nanocomposites, using the right tools for characterization is crucial. This review concentrated on high-level analytical methods for characterizing biopolymers, biopolymer-based composites, and their derivatives structurally, physically, and chemically. The most common analytical instrument methods based on microscopy (Optical, laser scanning confocal, scanning tunneling, scanning probe, differential dynamic, scanning, and transmission electron) and spectroscopy (Fourier transform infrared, X-ray diffraction, and Raman). The use of these tools for characterization in current research studies is also highlighted in order to demonstrate how the biopolymer under study might be used in various applications.

In the last few years, there are rising numbers for environmental waste due to factors such as plastic based food packaging that really need to get enough attention in order to prevent the issue from becoming worse and bringing disaster to society. Thus, the uses of plastic composite materials need to be reduced and need to be replaced with materials that are natural and have low degradation to preserve nature. Based on the statistics for the global, the production of plastic has been roughly calculated for passing 400 million metric tons every year and has a high probability of approaching the value of 500 million metric tons at the year of 2025 and this issue needs to be counteracted as soon as possible. Due to that, the increasing number for recent development of natural biopolymer, as an example starch, has been investigated as the substitution for the non-biodegradable biopolymer. Besides, among all biodegradable polymers, starch has been considered as promising substitution polymer due to its renewability, easy availability, and biodegradability. Apart from that, by the reinforcement from the nanocellulose, starch fiber has an increasing in terms of mechanical, barrier and thermal properties. In this review paper, we will be discussing the up-to-date development of nanocellulose fiber reinforced starch biopolymer composites throughout this century.

The thermoplastic-based starch has been increasingly demanding in recent years due to its high potential to substitute conventional plastic usage. Sago has been recognized as one of the sources of starch with a large abundance. This chapter mainly emphasized the modification of sago starch using different additives for biodegradable plastic. The other starch modifications are also discussed, including the effect of epoxidized waste cooking oil (EWCO) addition as a plasticizer, lime juice’s citric acid as a crosslinker on the physical and chemical characteristics of the modified starch composites. The results mainly showed the advantages of reinforcing sago starch with plasticizers, nanoparticles, nanocellulose, fibers, and cross-linking agents, such as increasing the mechanical strength, higher thermal stability, and higher biodegradability. Therefore, the thermoplastic films from sago starch provide a promising potential to be further developed for practical applications.

The concerning issue regarding petrochemical plastic wastes had prompted scientists and researchers to develop biodegradable plastic in effort to tackle environmental pollution. Alternative bioresources such as poly (lactic acid), sugar palm starch and nanocellulose fibre were utilized in producing cheap, biodegradable and sustainable plastic with satisfactory mechanical properties for food packaging application. In this study, sugar palm crystalline nanocellulose (SPCNC) was priorly dispersed in thermoplastic sugar palm starch (TPS) before melt blended with poly (lactic acid) (PLA) and later compress moulded into a sheet form. Initial biodegradation test of PLA100 and all PLA/TPS blends bionanocomposite samples indicated that PLA60TPS40 has the least variation in weight loss due to the good miscibility between TPS and PLA promoting the reinforcement of SPCNC. Greater weight losses in seawater (17.54%), river water (18.97%) and sewer water (22.27%) result in greater mechanical degradation as observed at the reduction of tensile strength from 12.11 MPa to 2.72 MPa in seawater, 1.48 MPa in river water and 0.40 MPa in sewer water. Similarly, higher weight losses in seawater (22.16%), river water (21.6%) and sewer water (23.09%) correlated with the reduction of flexural strength from 18.37 MPa to 3.5 MPa in seawater, 3.83 MPa in river water and 3.6 MPa in sewer water. The scanning electron microscope (SEM) images of tensile fracture morphology demonstrated clear porous structure due to the removal of starch particles by microbial activity. The homogenous structure of PLA60TPS40 had a steady and consistent degradation, which wholly diminished the interfacial adhesion that led to mechanical properties losses. The mechanical strength reduction clarified that the biodegradation rate within the media used might be able to resolve the excessive non-biodegradable plastic waste in open waters.

Metal-organic frameworks (MOFs) are tunable porous network compounds composed of inorganic nodes bound by various organic linkers. Here we report the density functional theory (DFT) study of the MOF novel building blocks made of the Cu 4 clusters protected by four organic ligands having two phenyl rings and terminated either with Cl or Br atom (precursors 1 and 2, respectively). The research was performed both in the gas phase and with the implicit effects of acetonitrile included, with two functionals, B3LYP and PBE, both with and without the second-order dispersion correction. We analyzed the structural features of the precursors 1 and 2, their electronic structures, molecular electrostatic potential (MEP) distribution, and global reactivity parameters (GRPs). Both functionals resulted in the singlets of the precursors 1 and 2 as the most stable species. The precursor structures optimized with the hybrid functional were found to be quite similar for both halogens, both containing somewhat distorted from planarity Cu 4 cluster, with the outer phenyls of the ligands rotated relative to the inner phenyls. With both halogens and both DFT approaches, the frontier molecular orbitals (FMOs) of the precursors 1 and 2 were shown to have quite similar compositions. The change of the substituent from Br to Cl was found to cause slight stabilizations or destabilizations of the HOMOs and LUMOs. The central parts and especially the inner phenyl ring parts of the precursors 1 and 2 were suggested to play a role of nucleophile in various chemical reactions due to the significant accumulation of negative electrostatic potential. Also, weak intermolecular interactions might exist between the ligands of neighboring precursor molecules. Finally, with both substituents the precursors 1 and 2 should be relatively unreactive and demonstrate thermodynamic stability. Further, the precursors 1 and 2 should be quite stable in oxidation reactions and more active in reduction processes. Generally, the substituent nature was shown not to affect significantly the reactivity of the precursors 1 and 2, as well as their other properties.

Starch/nanocellulose nanocomposite is of interest because of its potential applications in the field of biodegradable food packaging and biomedical applications thanks to its safe, biodegradable, fabricated by simple traditional methods, and cheap. The starch reinforced by nanocellulose significantly improved the physicochemical properties, especially the mechanical properties, thermal stability as well as barrier properties, compared to the starch matrix. With outstanding advantages compared to polymer nanocomposites derived from petroleum, the starch/nanocellulose composite is considered a potential agent for biodegradable food packaging and biomedical technology.

Brain response to visual stimulation can be probed quantitatively using functional magnetic resonance spectroscopy (fMRS), which relies on the blood oxygenation level dependent (BOLD) contrast mechanism. BOLD effect in fMRS is associated with changes in the areas, widths, and heights of the MR spectra. This study investigated the effect of spectral averaging scheme (NEX value) on BOLD changes in the spectra. Using a visual stimulus at 8 Hz in single and interleaved stimulation paradigms, the BOLD effects in spectra acquired from the occipital brain region of three healthy volunteers (mean age ± SD = 32.7 ± 3.5 years) were compared for two fMRS data sets acquired with two NEX values (“2” and “8”) available on a 3 T MR scanner. BOLD signal changes were estimated as percentage changes in spectral areas, heights, and widths of six cerebral metabolites and water using the SAGE software package (version 7). There was a general trend of lower BOLD effects with NEX = 8 in both stimulation paradigms. In the single stimulation paradigm, NEX = 8 was associated with significantly lower N-acetyl aspartate (NAA) spectral height ( p  = 0.03), creatine ( p  = 0.04) and choline ( p  = 0.02) spectral widths, and NAA ( p  = 0.03), water ( p  < 0.01), and glutamate ( p  = 0.02) spectral areas. In the interleaved stimulation paradigm, NEX = 8 was associated with significantly lower glutamate spectral height ( p  = 0.02), water ( p  = 0.03), and glutamine ( p  = 0.03) spectral widths, but there was no significant difference in all spectral areas between the two NEX values. Even though the two NEX values offered some differences in observable BOLD effects, their spectral areas were not significantly different in the interleaved visual stimulation experiments.

Phytochemical screening of the three extracts (acetone, ethanol and methanol) from Bersama abyssinica leaves revealed the presence of triterpenes, phenolic compounds and coumarins. The evaluation of the total phenolic content was achieved using the method of Folin–Ciocalteu allowed us to say that the acetone extract has the highest content of 41.73 mg EAG/g EX. Fractionation of this extract led to the isolation of two triterpenoids, namely ursolic acid (compound BE1) and its glucoside (compound BE2). Evaluation of antibacterial activity was carried out on three bacterial strains: Escherichia coli , Staphylococcus aureus and Clostridium perfringens using the method of diffusion in a solid medium. Results indicated that the three strains were sensitive to all extracts. Three strains were sensitive to the BE1 and two strains ( E. coli and S. aureus ) to the BE2. These results may justify the traditional use of parts of B. abyssinica in the treatment of some intestinal diseases.

Increasing use of herbicides has contributed immensely to current soil and water degradation in the tropics. Published works on effects of herbicides on soil organic carbon (SOC) – a major indicator for soil health and macronutrients and their enhancement by biochar are scarce for soils in Africa despite heavy herbicide applications every cropping season. This incubation trial evaluated immediate effects of atrazine application on SOC and selected soil macronutrients. The potential of sawdust (SD) biochar to mitigate associated SOC and macronutrients depletion was also assessed. A total of 950 g soil was placed in each leaching column (20 cm length and 7 cm diameter). The experiment was a factorial combination of four SD biochar types: SD + poultry manure (PM) pyrolyzed at 350 °C, SD-PM at 350 °C, SD + PM at 450 °C and SD-PM at 450 °C applied at two rates of 5 and 10 t/ha equivalent to 2.38 and 4.76 g/950 g soil, respectively. Atrazine alone and absolute control (AC) that received neither biochar nor atrazine were included for comparison. The treatments were replicated thrice in completely randomized design. Appropriate biochar was applied within 5 cm soil depth, moistened to field capacity, and left to equilibrate for 2 weeks. Thereafter, 20 mL atrazine solution was applied at 2.5 kg a.i/ha (achieved through 6.75 g atrazine powder/l of distilled water). Basal NPK 15:15:15 fertilizer mixed with urea at 0.1 and 0.03 g/900 g soil, respectively, was applied to mimic farmers’ practice on atrazine treated fields. Maize seeds were thereafter sown in the treated soils and nurtured for 2 weeks. Data taken on soil pH, SOC, exchangeable bases, available phosphorus, and dry biomass weight (DBW) of maize seedlings at the expiration of the trial were subjected to two-way analysis of variance using Genstat Statistical Package with means separated using LSD at 5% probability level. There were significant reductions in soil pH (5.8%), SOC (31%), and Ex. Ca (27%) in atrazine alone soil compared to AC. Contrarily, similar atrazine treated soil pretreated with SD biochar had increased soil pH, SOC, exchangeable Ca, available P, and DBW by 5.6 (in SD + PM@450 °C), 73.6 (SD-PM@450 °C), 84 (SD + PM@450 °C), 2,338.4 (SD + PM@450 °C), and 154.8% (SD + PM@350 °C), respectively, dominantly at 10 t/ha compared to AC. Sole atrazine treated soil was, however, higher in soil available P (23.8 mg/kg) and TDBW (0.56 g) against 5.42 mg/kg and 0.42 g from AC, respectively. Biochar pH and organic carbon were the most influential biochar properties contributing significantly to SOC sequestration and macronutrient enrichment in the atrazine treated soil. Pretreatment of soils with sawdust biochar prior to atrazine application is, therefore, recommended for mitigating associated organic carbon and macronutrient depletion in the soils for enhanced maize production.

Industrial activities and increased human population have made wastewater streams not entirely amenable to conventional treatment methods. Anaerobic digestion (AD) can treat such wastewaters with the advantage of bioresource recovery. However, the presence of solids and recalcitrant compounds in most wastewater streams may affect the AD process. Thus, combining AD with advanced oxidation processes (AOPs) such as ozonolysis is necessary. Ozonolysis can improve the biodegradability of wastewater substrates or eliminate biorecalcitrant pollutants that escape the AD process. This study combined ozonolysis with AD to treat waste activated sludge (WAS) and distillery wastewater (DWW). When applied as a pre-treatment, ozonolysis caused the rigid cell walls in WAS to rupture and solubilised the extracellular polymeric substances (EPS), leading to increased biodegradability. For the DWW, ozonolysis pre-treatment reduced the biorecalcitrant aromatic compounds to simple aliphatic compounds, thereby increasing biodegradability. In the ensuing anaerobic process, the WAS pre-treatment improved TSS and COD reductions and a 230% increase in cumulative biogas production. For the DWW, the ozonolysis pre-treatment did not significantly impact COD reduction or biogas production; however, ozonolysis as a post-treatment removed the color causing biorecalcitrant melanoidins from the anaerobically digested effluent and solubilised the sludge (TSS) washed out from the AD unit. Therefore, the AD-ozonolysis process configuration depends on the substrate being treated. Ozonolysis is best applied pre-AD for WAS treatment and post-AD for DWW.

The levels of organochlorine and organophosphate pesticide residues in selected cereal crops (beans, cowpea, millet, maize, sorghum, and rice) purchased from major markets in Anambra, south-eastern Nigeria, were assessed and compared with established MRLs. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for extraction and clean-up of pesticide residues. Thereafter detection and quantification were done using GC/MS. The result reveals that the analysed grain samples contained some organochlorine pesticides and organophosphates. The organochlorine was most dominant followed by the organophosphates. Organochlorine pesticide residues varied from 0.048 to 0.298 mg/kg in beans, BDL to 0.398 mg/kg in cowpea, 0.018–0.337 mg/kg in maize, 0.023–0.375 mg/kg in millet, 0.058–0.415 mg/kg in sorghum and 0.045–0.442 mg/kg in rice while organophosphate pesticide residue varied from BDL to 0.315 mg/kg in beans, BDL to 0.113 mg/kg in cowpea, BDL to 0.228 mg/kg in maize, BDL to 0.253 mg/kg in millet, BDL to 0.218 mg/kg in sorghum and BDL to 2.1 35 mg/kg in rice. Highest concentration of endosulphan II (0.442 mg/kg) was detected in rice, followed by aldrin (0.415 mg kg −1 ) in sorghum and endosulphan II (0.40 mg/kg) in sorghum. The pesticide toxicity index (PTI) was above one (1), whereas health index (HI) was less than one (1) and cancer risk were within USEPA reference guideline for crops indicating children will have greater health effect than adults. Hence, strict monitoring and control of pesticide residues in agricultural products is advocated.

Distinct properties that nanomaterials possess compared to their bulk counterparts are attributed to their characteristic high surface area to volume ratios, and the prevalence of structure and shape effects at the nanoscale. However, these interesting properties are also accompanied by health hazards that are not seen in bulk materials. In the context of Philippine research and industry, the issue of nanosafety and the creation of nanotechnology guidelines have long been overlooked. This is of particular importance considering that nanotechnology research in the Philippines leans heavily towards medicinal and agricultural applications. In this study, nanomaterial samples from the industry submitted through the Philippine Industrial Technology Development Institute (ITDI) were analyzed using XRD and MTT cytotoxicity assay. XRD results show significant band broadening in the diffraction patterns of halloysite nanoclay, bentonite nanoparticles, silver nanoparticles, and CaCO 3 nanoparticles, indicating that samples were in the nanometer range. The diffraction pattern of TiO 2 , however, did not exhibit band broadening, which may be due to the tendency of TiO 2 nanoparticles to aggregate. Submitted samples were also assessed for their effect on cell viability using MTT cytotoxicity assay. Among these samples, only silver nanoparticles exhibited cytotoxicity to the AA8 cell line.

This study compared two hydrothermally synthesized heterojunctions composites, Bi 24 O 31 Br 10  – carbonaceous (activated carbon from zinc chloride [ACZ], phosphoric acid [ACH], carbonized material [CM]), and Bi 24 O 31 Br 10  – silicates (SBA-15 and MCM-41), with nanosheets structure. The photocatalytic degradation of tetracycline (TC) was used to evaluate the synergistic influence of the catalyst supports for the corresponding heterojunction composites. The X-Ray diffractometry (XRD), Fourier transform infrared spectroscopy and scanning electron microscopy (SEM) confirmed the synthesis of the Bi 24 O 31 Br 10 (BOB) – composites. After 120 min of visible LED light photocatalytic reactions, the degradation trend in removal efficiency of TC was BOB-ACZ > BOB > ACH > BOB-CM > BOB-MCM-41 > BOB-SBA-15 > BOB. The study reveals that Bi 24 O 31 Br 11  – carbonaceous composite exhibits much better degradation efficiency than Bi 24 O 31 Br 11  – silicates. Crucially, the synergistic surface interaction of ACZ with BOB, and the efficient separation of photogenerated charge carriers, from the SEM, XRD analysis, and photocurrent response, confirmed the photocatalytic enhancement of the heterojunction formation of the BOB-ACZ composite. This study further provides convincing insights on the superiority of carbonaceous nanomaterial to silica materials as efficient catalyst support in catalytic applications.

From the leaves of Artocarpus kemando Miq, locally known as pudau plant, a flavonoid has been isolated and identified. The compound was then tested as antibacterial agent against Bacillus subtillis and Escherichia coli . The first step of isolation was extraction by maceration using methanol as solvent, and then followed by fractionation using partition treatment and vacuum liquid chromatography. Finally, the compound was purified using column chromatography method. The purity of the compound was evaluated using thin layer chromatography and melting point measurement, and the compound was subsequently characterized using UV–Vis, IR, and NMR spectroscopy. A total of 66.2 mg of the compound was obtained, in the form of yellow needle crystals with a melting point of 142.8–144 °C, which is a compound of geranylated chalcone, xanthoangelol. Xanthoangelol was the first chalcone compound isolated from  A. kemando . Antibacterial tests were carried out at varied doses of 0.5; 0.4; and 0.3 mg/disk, and revealed that the compound exhibits high inhibitory power against B. subtillis , but has no activity against E. coli . The anticancer activity of xanthoangelol on MCF-7 cells indicated that the compound has an IC 50 value of 7.79 μg/mL, suggesting that the compound possesses an active cytotoxic activity.

Despite being one of the starch producers, barley has yet to be widely studied for thermoplastic starch applications, including nanocellulose thermoplastic composites, due to its uses in the food and beverage industries. However, only 20% of barley is used in the malting industry to produce both alcoholic and non-alcoholic beverages, and 5% is used as an ingredient in a wide variety of foods. As the fourth most important cereal in the world after wheat, corn, and rice, barley can be considered an interesting biomass source to produce biodegradable thermoplastics, stemming from its starch constitution. Therefore, this review attempts to highlight the barley starch properties and its potential utilization for nanocellulose thermoplastic starch composites. Several studies involving barley-based starch in thermoplastic production and nanocellulose reinforcement for properties enhancement are also reviewed, particularly in the attempt to provide various options to reduce and replace the uses of harmful petroleum-based plastic.

Nature has evolved highly efficient and complex systems to perform cascade reactions by the elegant combination of desired enzymes, offering a strategy for achieving efficient bioprocess intensification. Chemoenzymatic cascade reactions (CECRs) merge the complementary strengths of chemo-catalysis and bio-catalysis, such as the wide reactivity of chemo-catalysts and the exquisite selective properties of biocatalysts, representing an important step toward emulating nature to construct artificial systems for achieving bioprocess intensification. However, the incompatibilities between the two catalytic disciplines make CECRs highly challenging. In recent years, great advances have been made to develop strategies for constructing CECRs. In this regard, this chapter introduces the general concepts and representative strategies, including temporal compartmentalization, spatial compartmentalization and chemo-bio nanoreactors. Particularly, we focus on what platform methods and technologies can be used, and how to implement these strategies. The future challenges and strategies in this burgeoning research area are also discussed.

This chapter aims to provide the reader with some information about the possibility of starch as a suitable substitute for synthetic polymers in biodegradable food packaging. This is due to the starch has good characteristics which are great biodegradability, low cost and also easy to gain from natural resources. However, some of technical challenges are also introduced before starch-based polymers can be used in more applications. These technical challenges involved preparation methods and incorporation of additives and these are being summarized in this topic. Hence, the enhancement of starch can be done in order to prepare innovative starch-based biodegradable materials.

Potato is a widely available feedstock with biocompatibility and biodegradability properties, making it a strong candidate for producing thermoplastic starch. The application of thermoplastic starch to replace petroleum-based plastic as a sustainable and environmentally friendly approach led to its further improvement through various techniques such as modification and filler reinforcement. Numerous studies have been done addressing the properties enhancement of potato thermoplastic starch through filler reinforcement including nanocellulose. This review focus on the recent and future potential of potato-based starch as one of the feedstocks for producing potato thermoplastic starch composites reinforced with nanocellulose.

Recently, many studies have been carried out on developing green composites that are eco-friendly and more sustainable compared to fuel-derived composites. Thermoplastic starch (TPS) is one of the potential biopolymer materials that can be used as food packaging materials, pharmaceuticals and many other applications. Sago ( Metroxylon sagu ) is unlike other starch-based composite such as cassava and corn, which are highly utilized and popular option sources for variety applications in industries. This renewable starch can be a competitive starch source like other starches if rigorous scientific research study is conducted to explore other findings, which might be important for its production and usage in various industries. Research studies related to sago TPS are still lacked, and it is difficult to compare its performance with TPS made from other starches as its preparation differs based on the starch source. The TPS composite generally exhibits low mechanical strength and poor barrier properties. Reinforcing sago TPS nanocomposites with nanocellulose (NC) is expected to enhance its mechanical and barrier properties. This book chapter covers the overview of characteristics and extraction of sago from its pith as well as its usage to make thermoplastic starch composite. The characteristics of sago TPS nanocomposite reinforced with nanocellulose (NC) is also discussed based on a few research studies due to its published research findings are still limited.

The rising costs of non-renewable plastic and environmental concerns with their industrial usage have encouraged the study and development of renewable products. As an alternative, biological-based materials create a huge opportunity for a healthy and safe environment by replacing non-renewable plastic in a variety of applications. Wheat is one of the world’s most widely cultivated crops. Due to its mechanical and physical properties, wheat starch is vital in the biopolymer industry. Wheat thermoplastic starch exhibits useable properties when plasticizers, elevated temperatures and shear are present. Thus, make it very suitable to be used as packaging material. However, this material suffers from low mechanical properties, which limit its applications. Several studies looked at the feasibility of using plant components which is nanocellulose as a reinforcing agent in wheat starch thermoplastic composites. Overall, the addition of nanocellulose can improve the performance of wheat thermoplastic starch, especially for its mechanical properties. It can potentially be used in several areas of packaging and biomedical. The objective of this review is to discuss several achievements regarding wheat starch/nanocellulose-based composites. Several important aspects of the mechanical performance and the thermal properties of the composites were evaluated. The discussion on wheat starch and nanocellulose was also tackled in this review.

Bimetallic gold (Au) catalysts present an exceptional development trend toward enhancing the catalytic efficiency of the Au based catalysts. The aim of this review is to provide an insight into synergic effect of the bimetallic Au catalysts in enhancing the efficiency of various processes. The review covers some important aspects involving the effect of particle size, composition, metal-support interaction, morphology and the interaction between Au atom and the secondary metal on catalytic properties of the bimetallic Au catalysts. Particularly, the effect of the core–shell and faceted bimetallic Au catalysts morphologies are clearly articulated in the introduction. In the next section, various spectroscopic and microscopic characterization techniques, which often form a basis for the discussion of the synergic effect of the catalysts in enhancing the process efficiency are also discussed. Finally, we provide a summary on the progress made in catalytic exploration of bimetallic Au catalysts focusing in oxidation of hydrocarbons, fuel cell processes, oxidative transformation of the biomass derived products and photocatalysis.

This work looked into viability of using fennel-based adsorbents to simultaneously eliminate cadmium, methylene blue, and copper from water solution. Phosphoric acid (H 3 PO 4 ) and calcium hydroxide (Ca(OH) 2 ) solutions were applied to the untreated fennel seeds (PFS) to yield H 3 FS and CaFS, respectively. The presence of –OH, –C–O–C–, and –C=O functional groups on the surface of the adsorbents was confirmed by FTIR results. XRD and UV–Vis results established hydrolysis of cellulose from fennel seeds. According to studies on time and kinetics, the adsorption process was relatively quick in the first 60 min. Furthermore, isotherm models showed that the results fit Langmuir model more closely. This finding indicated that uptake takes place on uniform active sites on adsorbent surfaces. Studies on thermodynamics showed that the adsorption procedure was advantageous and practicable. PFS, H 3 FS, and CaFS had maximum Cu(II) adsorption capacities of 7.208, 5.504, and 5.791 mg/g. It was 2.274, 5.021, and 12.3 mg/g for Cd(II) by PFS, H 3 FS, and CaFS. PFS, H 3 FS, and CaFS could adsorb MB to a maximum of 11.114, 4.071, and 18.468 mg/g. Reusability studies of the adsorbents were also evaluated and the results suggested that the adsorbents can be recycled a number of times.

The work aims to evaluate the effect of temperature and composition on the physical properties of ceramic electrical porcelain insulators, produced from locally sourced materials in Nigeria. The basic raw materials of triaxial porcelain (Kaolin, feldspar, and quartz) were pulverized, milled for 22 h, and sieved using a 200   μm mesh size. The chemical composition and characterization of the raw materials were obtained using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. The mixtures were formulated using sodium silicate as a deflocculant to help produce the ceramic porcelain samples. The green samples were weighed and fired at temperatures of 1200 °C and 1250 °C. The samples were subjected to 1 h of boiling plus 2 h of soaking. The slip casting technique was used in the production of porcelain insulators. The linear shrinkage, water absorbance, apparent porosity, and bulk density were measured and studied as a function of firing temperature. The apparent porosity and water absorption decreased as the firing temperature increased. The bulk density increased gradually from 1200 °C to 1250 °C and the percentage of moisture remained fairly unaffected by the temperature increase. The linear shrinkage was also found to increase as the firing temperature increased. Despite having the same composition, the average physical properties of the locally manufactured insulators revealed that those manufactured at higher temperatures provided a better insulating effect than those manufactured at lower temperatures. In other words, it shows that excellent ceramic porcelain insulators can be manufactured from locally sourced materials using the appropriate composition and firing temperature.

Concentration levels and health risk assessment of residues of organochlorine and organophosphate pesticides in four commonly vegetables (Cucumber, carrot, cabbage, and eggplant) collected from major markets of Port Harcourt city, South-south Nigeria were assessed. The collected samples were analysed using QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction method by gas chromatography coupled with Electron Capture Detector (ECD). Pesticide concentrations were compared with UK/EU maximum residual limits (MRLs). Health risk estimates were analysed using estimated daily intake (EDI), hazard quotient (HQ), and hazard ratio (HR) for children (16.7 kg) and adults (60 kg) weight groups. The results of this study showed that 80% of the vegetable samples contained detectable pesticide residues, of which 70% had residues that exceeded MRLs while 20% had residues below detectable levels. The highest concentrations of HCH residues are present in cabbage with a concentration of 0.25 ± 0.15 mg/kg for α-HCH while the least are present in eggplant with concentration of 0.038 ± 0.025 mg/kg in lindane. Pirimophos-methyl was detected in cucumber at 0.017 mg/kg while parathion and isofenfos was detected only in eggplants at concentration of 0.042 mg/kg and 0.022 mg/kg respectively. Concentrations of parathion, chlorpyrifos, and pirimophos-methyl residues were lower than MRLs in all the detected vegetable samples analysed. Non-carcinogenic health risk estimates for the children consumer groups showed that mevinfos, p, pʹ DDD, aldrin, and heptachlor epoxide detected in eggplant, carrot, and cabbage had HQ > 1. While for adults, only p, pʹ DDD and heptachlor epoxide revealed non-carcinogenic effect in cabbage. Risk was highest for child consumers. However, most of the pesticide residues were less than 1 for the HQs value which is indicative of insignificant health risk. Human risk estimations for the carcinogenic health effect for the studied vegetables showed that lindane and delta HCH could pose carcinogenic health risks to adult, while aldrin, dieldrin, heptachlor, α HCH, β HCH, delta HCH, and heptachlor epoxide could pose carcinogenic health risks to children. The HRI values in some of the detected residues indicate that the cancer benchmark concentrations exceeded the EDI for the respective organochlorine pesticide in the vegetable samples, thus raising serious concerns of possible carcinogenicity. Non carcinogenic and carcinogenic risk assessment of organochlorine pesticide residues in the studied vegetable indicates health threat. Hence, strict monitoring and control of pesticide residues in agricultural products is being suggested, to protect consumers, especially the children who are vulnerable to the adverse effects of pesticides.

This article explores the extraction of iodine contents in Ipomoea pes-caprae plants using the modified Mohr’s method applied to a biological extract prepared in an aqueous solution. The plants were collected from three coastal regions of the Arabian Sea at Karachi coast, privileged as iodine resource areas. The size of the stem, leaves, and flowers of collected plants was measured after transportation into the laboratory before preparation of aqueous extract. It was found to be significantly different in size from each other. The electrical conductivity of the biological extract was recorded through a conductometer. For this purpose, the extract of different parts of the I. pes-caprae plants was prepared, followed by heating and filtration, while silver nitrate (AgNO 3 ) was used as a precipitating agent. It was interesting to note that when filtrate was titrated with AgNO 3, the precipitate started to settle down. Results showed the lowest iodine concentration in the flowers of all tested plants, followed by the highest in the leaves. Conductometric precipitation reaction was influential in determining iodine in herbal medicinal plants. It was observed that the size of the plants and collection sites impacted the iodine concentration. It was lowest in I. pes-caprae, collected from sea view Karachi, while highest in plants of Hawksbay. The endpoint of this biochemical reaction was taken when conductivity started rising. The standard curve of KI was prepared to determine the concentration of iodine in plant samples through conductometric titration. Moreover, the presence of Iodine was confirmed through a chemical testing method using HNO 3 , NH 4 OH, and H 2 SO 4 , after a complete precipitation reaction. The iodine quantification was done using a spectrophotometer through hexane solvent after being treated with H 2 SO 4 .

This research is aimed at investigating the anti-colorectal cancer activities of phytochemicals from Mangifera indica (Mango) via the inhibition of thymidylate synthase (TS) and Nuclear Factor kappa B (NF–κB) using computational chemistry tools. Ligands (141 phytochemicals previously isolated from mangoes) and reference drugs (Raltitrexed and Emetine), the drug inhibitors of TS and NF–κB, respectively) were subjected to screening via ADMET profiling, drug-likeness analysis, oral bioavailability, PASS profile, and molecular interactions. Ligands that passed the previously mentioned screening were docked in duplicate against the target receptors (TS and NF–κB) using PyRx software. The mean values were calculated to obtain suitable docking scores. The analysis showed that TS was strongly inhibited by Friedelan-3beta-Ol with its lower binding energy of −9.0 kcal/mol more than Raltitrexed with a binding energy of −8.7 kcal/mol. NF–κB was also inhibited by Friedelan-3beta-Ol and Friedelin with binding energies of −8.0 and −8.1 kcal/mol, respectively, more than Emetine with a binding energy of −6.4 kcal/mol. These two phytochemicals performed much better than the standard drugs, thus selected as the best hits compounds because of their ADMET profile, drug-likeness properties, bioactivity, oral bioavailability, PASS prediction, binding affinities, and their interactions with the amino acids in the active sites of the receptors. Therefore, further studies are necessary for the validation of these claims toward the development of new effective and safer anti-colorectal cancer drugs.

In Cameroon, several species of the genus Acacia are traditionally used for protection in granaries of stored foodstuffs such as cowpeas, maize and millet. The literature review on Acacia hockii made it possible to detect that few studies were carried out on this plant which would traditionally have the properties we seek. The objective of this work is to extract and isolate the active principles and then evaluate the insecticidal and antifungal activities of the extracts and compounds isolated from the fruits of A. hockii . The maceration method was used to obtain hexane, acetone and methanol extracts of A. hockii fruits which were used against adults of Callosobruchus maculatus (Coleoptera: Bruchidae), a pest of cowpea ( Vigna unguiculata ). The most active extract was fractionated by column chromatography and the compounds were elucidated by 1D and 2D NMR spectroscopy. The well-scattering method was used for evaluating the antifungal activity. The results show that all extracts were active against adults of C. maculatus and that the acetone extract was the most active with a 100% mortality rate at the concentration of 0.500 mg/mL and an LD50 of 0.06 g per gram of cowpea. The antifungal activity test of the acetone extract showed sensitivity against all tested strains Fusarium solani, Aspergillus flavus and Penicillium citrinum with MIC of 0.0625; 0.500 mg/mL, respectively. Fractionation of this extract led to the isolation of four compounds, among β -stigmasterol and β -sitosterol, β -stigmasterol-3 β -O-D-glucopyranoside and N-((2 S ,3 S ,4 R ,14 E )-1,3,4-trihydroxyicos-14-en-2-yl)palmitamide, a new sphingolipid with insecticidal and moderate antibacterial activities. A. hockii fruits can be considered a potential source for the production of biopesticides.

This research investigated the design, chemical modification, characterization and biocidal evaluation of waxes. Tallow (animal fat), bee-wax (insect) and shea butter (plant fat) were first converted to carboxylates by metathesis and later transformed into urea and thiourea complexes. The transformation was monitored using UV–visible, FT-IR and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy. They were also screened for biocidal activities using two white rots ( Pleurotus sajor-cajor and Pleurotus oestratus ), two brown rots ( Sclerotium rolfsii and Rhizotonia solanii ) and a soft rot ( Cheatomium globosum ). The UV–visible absorption peaks shifted to a longer wavelength for the complexes in relation to the carboxylates signifying lower energy and higher activities. Carboxylates showed very sharp peaks around 1700 cm −1 attributable to the carbonyl functional group (C=O) (Scheme 1), the carbonyl (C=O) peaks in the carboxylates were replaced by the appearance of another peaks in the urea and thiourea complexes at around 1600 cm −1 attributable to azomethine (C=N) (Scheme 2 and 3). None of the surface morphologies of the samples (crystalline) is identical. This result further confirmed the formation of the products. The result of fungi assay showed that tallow based carboxylate, urea and thiourea complexes greatly inhibited the growth of all the fungi species used. However, bees wax based carboxylate and its complexes as well as plant-fat based carboxylate and its complexes could not inhibit the growth of Sclerotium rolfsii . For insect and plant-based urea complexes, there were tiny growths (pin head) seen on the plates inoculated with P. sajor-cajor and P. oestratus, respectively. The findings of this work showed that urea and thiourea complexes performed better than carboxylates in fungi inhibition. Tallow-based products (carboxylates, urea and thiourea) showed the greatest anti-fungi properties.

The outbreak of the current pandemic and the evolution of virus resistance against standard drugs led to the emergency of new and potent antiviral agents. Owing to its crucial role in viral replication, the protease enzyme is taken into survey to be a promising target for antiviral drug therapy using computational methods. In order to bring this important class of natural products in the limelight of research for prospective application as chemotherapeutic agents, the anti-SARS-CoV-2 activity of some bioactive molecules obtained from Arbutus serratifolia Salisb which is an Algerian medicinal plant, was investigated using in-silico methods. The molecular docking was performed by AutoDock Vina and UCSF Chimera, as well as ADMET and drug-likeness properties of these molecules were calculated using preADMET web-based application and the Swiss ADME server respectively. The phytochemicals (from Pr(1) to Pr(12)) were tested for their pharmacokinetic properties and docked into the main protease binding site on (PDB ID: 6Y84) in order to find a promising antiviral ligand. All tested molecules induced binding affinities into the binding pocket of (PDB ID: 6Y84) with energy scores ranging from moderate to better (from −6.4 to −8.00 kcal/mol). It is worthy to note that both Pr(2): (1S,5R,6S,8S,9S)-6,8-Dihydroxy-8-methyl-1,5,6,7,8,9-hexahydrocyclopenta [ c ] pyran-1-yl- β - D- glucopyranoside and Pr(7): ((1S,5S,6S,9S)-1-( β-D -Glucopyranosyloxy)-14-oxo-1,5,6,9-tetrahydro- 1H -2,15-dioxacyclopenta [ cd ] inden-8-yl) methyl acetate, were found to be the best inhibitors with binding affinities (−7.7 kcal/mol and −8.0 kcal/mol), respectively, by virtue of the fact that all these tested molecules exhibited good binding affinities compared with those of Ritonavir and Nirmatrelvir (−1.73 and −1.93 kcal/mol), respectively, which are used as standard antiviral drugs to prevent viral growth. The amino acids: His-163; Glu-166; Arg-188; Thr-190 and Gln-192 represent the key residues of the interaction of SARS-CoV-2 main protease with Pr(7). Furthermore, the results of pharmacodynamic and pharmacokinetic investigations revealed that Pr(6), Pr(8) and Pr(9) uphold the drug-likeness criteria and more particularly, these substances can be absorbed by the human intestine. In addition, all these molecules were shown to be neither hepatotoxic nor significantly noxious to human organism. These natural products are therefore promising inhibitor candidates of viral main protease. However, further in-vitro , in-vivo and even clinical assays are required to probe their functional mechanisms and then to assess their antiviral potency against COVID-19.

Nuclear waste water contains many actinides which coordinate with water molecules to form complexes. The hydration of water molecules with varying coordination numbers and modes makes it interesting and intriguing in understanding the extraction process of these radioactive ions. In order to separate these complexes from the nuclear waste water, many organic ligands are being used. However, prior knowledge on the nature of electronic environment of these hydration patterns will help us to understand the extraction mechanism. Therefore, a series of complexes such as [Np(H 2 O) 9 ] 4+ , [Cm(H 2 O) 9 ] 3+ , [Am(H 2 O) 9 ] 3+ , [Pu(H 2 O) 9 ] 4+ , [Pu(H 2 O) 9 ] 3+ , [U(H 2 O) 9 ] 3+ , [NpO 2 (H 2 O) 5 ] + , [UO 2 (H 2 O) 5 ] 2+ and [PuO 2 (H 2 O) 5 ] 2+ have been calculated by means of relativistic DFT. Bond length analysis and energy decomposition analysis are executed with the intention to comprehend the bonding situation of these complexes. To account for the stabilizing interactions amid the radioactive ion and the water molecules, a detailed QTAIM investigation is done. It is seen that the metals having higher oxidation state readily complex with water molecules. Energy decomposition analysis throws light on the significant orbital interactions in the [M(H 2 O) 9 ] n complexes, whereas in the metal oxide complexes significant contribution is resulted from electrostatic interactions. In summary, this investigation brings out the nuances of coordination modes of solvation in nuclear waste water which will help us to explore and design novel extraction techniques in near future.