Volume 109, Issue 12

To adsorb and separate platinum-group metals efficiently from simulated high-level liquid waste, two adsorbents,  N , N , N ′, N ′-tetra- n -hexyl-3,6-dithiaoctane-1,8-diamide (THDTODA)/SiO 2 -P and (THDTODA + dodecanol)/SiO 2 -P, were prepared by impregnation of THDTODA with or without dodecanol into macroporous silica/styrene–divinylbenzene copolymer composite particles SiO 2 -P. The effect of the addition of dodecanol to THDTODA fixed silica-based adsorbents on the separation of platinum-group metals and other metals was evaluated by batch adsorption and chromatographic separation experiments. THDTODA/SiO 2 -P adsorbed Ru(III) and Rh(III) more than (THDTODA + dodecanol)/SiO 2 -P did in concentrated HNO 3 solution. From the calculated thermodynamic parameters, dodecanol was considered to have little effect on the temperature dependence of the adsorptions of Ru(III), Zr(IV), Mo(VI), and Re(VII) onto the THDTODA adsorbents. Furthermore, in the results of column chromatography experiments, the effects of dodecanol addition on the separation properties were observed for Ru(III), Zr(IV), and Mo(VI), but little effect was observed for Pd(II) and Re(VII).

This work studies the adsorption of zirconium ions by mesoporous titanium dioxide with surface arsenate groups. Experimental maximal adsorption values of zirconium ions were found to be 109.6 mg/g in neutral medium. This process depends on the interaction time, the equilibrium concentration of zirconium ions, and the acidity of the solution. Adsorption kinetics fit well into the kinetic model based on the pseudo-second-order equation ( R 2  = 0.9984). Equilibrium adsorption of zirconium ions is well described by Langmuir’s adsorption theory ( R 2  = 0.9856 and χ 2  = 1.307). Although zirconium ions are less actively adsorbed from a neutral medium than strontium or yttrium ions, in the 2% nitric acid only zirconium is adsorbed out of the mixture of zirconium, strontium, and yttrium. The results obtained by inductively coupled plasma mass spectrometry have shown that the investigated adsorbent selectively adsorbs zirconium ions from their mixture with strontium and yttrium in the range of solution acidity pH = 0–1. The average percentage of maximum extraction of zirconium ions is 94.3 ± 2.4%, and the highest percent of zirconium ions taken up from the mixture with strontium and yttrium is ∼98.4%. Investigated titanium dioxide selectively separate 90 Zr from 90 Sr with the presence of 1000-fold excess of stable 88 Sr in radioactive liquid β − source. This fact is extremely valuable for the age dating of 90 Sr-containing device in nuclear forensics or the determination of 90 Sr in low activity background samples.

Some potential drug active substances with the ability to reduce the effects of radiation on human tissues and cells were investigated. For this purpose, eight different types of sulfamide derivatives were synthesized and nuclear radiation protection parameters were determined. Neutron radiation reduction parameters such as the half-value layer effective removal cross-sections, mean free path, and the number of particles passing through the sample were determined with GEANT4 code. Additionally, the gamma radiation attenuation parameters of the materials examined were determined using Phy-X/PSD software in the energy area of 0.015–15 MeV. These parameters are the half-value layer, mass attenuation coefficient, mean free path, exposure buildup factor and effective atomic number. Neutron radiation absorption experiments were applied using an 241 Am-Be fast neutron source. All results obtained for neutron radiation were compared with paraffin and water. It has been found that the ability of sulfamide derivatives to absorb these radiations is superior to reference materials. To determine whether these derivatives could have adverse effects on human health, their genotoxic potential was determined using the Ames/ Salmonella bacterial reversion test. The results showed that these derivatives can be considered genotoxically safe in tests at concentrations up to 5 mM. Thus, it is suggested that the derivative materials examined in this study can be used as active substances for a drug to be made for protection against both neutron and gamma radiation.

The aim of this study was to investigate labeling of nimotuzumab (h-R3) with 111 In using p -SCN-Bn-DTPA as bifunctional chelate, evaluate its targeting potential against SK-LU-1, H226, H650, H661, and HCC4006 non-small cell lung carcinoma (NSCLC) cell lines and correlate epidermal growth factor receptor (EGFR) expression level with internalization kinetics, biodistribution and imaging accuracy using Balb/c mice and New Zealand White rabbit (NZWR) animal model. The amount of p -SCN-Bn-DTPA attached to h-R3 was assessed by measuring relative absorbance at 652 nm with ultraviolet (UV) spectrophotometer. High-performance liquid chromatography (HPLC) was used to determine percent radiochemical purity (%RCP) and in vitro stability using excess amount of diethylenetriamine pentaacetate (DTPA). The in vitro stability in rat serum was estimated using iTLC-SG. EGFR expression level in each tumor was assessed by chemiluminescence. In vivo uptake in different organs of Balb/c mice and non-invasive imaging potential using NZWR bearing HCC4006 tumor, was evaluated with gamma camera. UV spectroscopy has confirmed the attachment of five p -SCN-Bn-DTPA (chelate) with one antibody. The HPLC indicated 98.85 ± 0.14% ( n  = 3) %RCP with high yield (>96%), specific activity 3.5 ± 0.0.25 mCi per mg and 94.25 ± 0.34% in vitro stability at 37 °C in mice serum. In excess DTPA no considerable transchelation was experiential from the 111 In labeled p -SCN-Bn-DTPA-h-R3 to the challenger. The EGFR expression in HCC4006 was higher amongst all with band density of 23.53 relative to 1.00 of H226. Initially internalization was lower which went up 1.05 × 10 4 molecules per HCC4006 cell in 48 h. The optimal concentration of h-R3 for maximum uptake was 15 μg per animal. Higher uptake in target organ was observed in animal infected with HCC4006 cells. However, in excess pure h-R3 the uptake was significantly reduced indicating tumor specificity. HCC4006 target site was undistinguishable relative to background activity in the initial phase of imaging due to poor uptake. However, within 60 h the HCC4006 tumor was quite apparent. This experiment suggests that at optimal dosage of 111 In labeled h-R3 can be used for localization and identification of EGFR positive NSCLC using gamma camera.

In the present work, zinc levels were measured in scalp hair and fingernails in order to identify potential risk factors for breast cancer. The samples were collected from 40 Algerian breast cancer female patients and from 20 normal subjects matching the same age range. The concentration of zinc was analyzed using Instrumental neutron activation analysis technique (INAA). In scalp hair samples it was found in the range 119–792 μg/g for the normal subjects and in the range 82–806 μg/g for the patients, with an increase rate of 10.9%. The range of concentration of zinc in fingernails was found between 89 and 247 μg/g for normal subjects and between 75 and 276 μg/g for the patients with an increase rate of 2.5%. The influence of age on zinc concentration was also investigated. The obtained results show some consistency with those obtained by other groups.

Distribution of natural and anthropogenic radionuclides ( 226 Ra, 232 Th, 137 Cs and 40 K) was determined in 32 samples from Ghizer, an Eastern Hindukush district at an altitude of 2286 m in Pakistan using high resolution gamma-ray spectrometry. Mineralogical analysis by X-ray diffractometry identified quartz, calcite, albite and anorthite as major phases whereas actinolite, chlorite serpentine and kaolinite as minor phases. The activity concentrations for 226 Ra, 232 Th, 137 Cs and 40 K varied from 25.2 ± 1.7 to 145.3 ± 10.1 Bq kg −1 , 24.9 ± 1.1 to 197 ± 9 Bq kg −1 , 2.03 ± 0.21 to 16.7 ± 1.1 and 252 ± 6 to 1433 ± 35 Bq kg −1 , respectively. The samples yielded average radium equivalent activity as 178.4 ± 23.3 Bq kg −1 . The majority of the samples revealed external hazard index and representative level index less than one. The average air absorbed dose rate was 91.2 ± 13.6 nGy h −1 corresponding to the annual effective dose rate 111.8 ± 17.4 μSv y −1 . These values were higher than the world averages for air absorbed dose rate and outdoor annual effective dose rate. Principal component analysis was applied to obtain distribution pattern within the samples and among the radionuclides.

In this study, the activity concentration of 226 Ra, 232 Th, 40 K, and 137 Cs in some vegetable and fruit samples frequently consumed in Kastamonu province located in the West Black Sea region of Turkey were determined using a gamma-ray spectrometer. The activity concentrations of 226 Ra, 232 Th and 40 K varied from 0.8 ± 0.1 to 32.8 ± 1.3, 0.7 ± 0.1 to 41.3 ± 21 and 391.8 ± 18.3 to 4679.0 ± 311.4 Bq kg −1 (dw), respectively, in twenty-eight vegetables and 1.3 ± 0.1 to 12.6 ± 0.4, 1.4 ± 0.1 to 15.0 ± 0.5 and 133.0 ± 84 to 777.0 ± 69.4 Bq kg −1 (dw), respectively, in seven fruit samples. The highest activity concentration of 226 Ra and 232 Th was measured in the garlic sample, while the highest activity concentration of 40 K was measured in the spinach sample. Artificial radionuclide 137 Cs was measured only in four vegetable samples; its activity concentration in garlic, eggplant, cucumber and carrot samples was determined as 9.6 ± 0.3, 3.1 ± 0.1, 3.1 ± 0.1 and 2.2 ± 0.1 Bq kg −1 (dw), respectively. The results obtained were compared with the results of similar studies in the literature. Annual effective radiation dose to adults due to the internal irradiation caused by ingestion of the investigated vegetable and fruit samples, and the corresponding excess lifetime cancer risk were estimated as 201 µSv and 8.9 × 10 −5 , respectively. The contribution of 40 K to the total annual effective radiation dose was found as approximately 70%.