Facile way for synthesis silver nanoparticles for obtaining antibacterial textile fabrics.

One pot synthesis of silver nanoparticles (AgNPs) with well-defined size using polyvinyl alcohol (PVA) as stabilizing agent and sodium borohydride (NaBH4) as reducing agent was successfully performed. Preparation of AgNPs was carried out under a variety of conditions including concentrations of AgNPs, PVA and NaBH4. UV-vis spectra and TEM images were employed to characterize AgNPs obtained under the said different conditions. Physical and mechanical properties of cotton/polyester fabric treated with the synthesized silver nanoparticles were measured. SEM and EDX were used to scanning and observe the morphology and elemental change pertaining to fabric surface. Antibacterial activity against E. coli (Gm –ve bacteria) and Staphylococcus aureus (Gm +ve bacteria) were successfully examined against the treated and untreated fabrics.

Densitometric and Spectrometric Determinations of Florfenicol and Buparvaquone.

Three new accurate and sensitive methods were developed for the determination of two veterinary drugs. Florfenicol was analyzed by a stability-indicating TLC/densitometric method in presence of its amine degradation product obtained via acid hydrolysis. It was based on the difference in Rf values of the drug and its degradation product at 254 nm on silica gel 60 GF254 plates using chloroform–methanol (7:3 v/v) as developing solvent (Method A). However, buparvaquone was analyzed through reduction with NaBH4 in methanolto yielda red colored product measured spectrophotometrically at 489 nm (Method B). This reduction product was also measured spectrofluorometrically at 450 nm after excitation at 334 nm (Method C). Good linearity was obtained in the range of 10-100 μg/spot for florfenicol in method A and 10-120 or 0.3-2.4 μg mL-1 for buparvaquone by methods B and C with mean accuracy of 99.94%±0.89, 99.99%±0.99 or 99.66%±1.80, respectively. The densitometric method A proved to be stability-indicating in presence of 10-90% of buparvaquone amine degradation product. The three proposed methods were validated according to ICH guidelines and successfully applied for the assay of the cited drugs in their pharmaceutical formulations.

Detoxification of Glutaraldehyde Treated Porcine Pericardium Using L-arginine & NABH4

BACKGROUND: Calcification is the most frequent cause of clinical failure of bioprosthetic tissues fabricated from GA-fixed porcine valves or bovine pericardium. A multi-factorial approach using different mechanisms was recently developed to reduce the calcification of bioprosthetic tissues. The purpose of the present study was to evaluate the synchronized synergism of using L-arginine and NaBH4, compared with ethanol and L-lysine, in glutaraldehyde treated porcine pericardium from the standpoint of calcification and tissue elasticity. MATERIALS AND METHODS: Porcine pericardium was fixed at 0.625% GA (7 days at room temperature after 2 days at 4degrees C). An interim step of ethanol (80%; 1 day at room temperature) or L-lysine (0.1 M; 2 days at 37degrees C) or L-arginine (0.1 M; 2 days at 37degrees C) was followed by completion of the GA fixation. A final step of NaBH4 (0.1 M; 2 days at room temperature) was followed. Their tensile strength, thickness, and thermal stability were measured. Treated pericardia were implanted subcutaneously into three-week-old Sprague-Dawley rats for 8 weeks. Calcium content was assessed by atomic absorption spectroscopy and histology. RESULTS: L-arginine and NaBH4 pretreatment (1.81+/-0.39 kgf/5 mm p=0.001, 0.30+/-0.08 mm p<0.001) significantly increased tensile strength and thickness compared with the control (0.53+/-0.34 kgf/5 mm, 0.10+/-0.02 mm). In a thermal stability test, L-arginine and NaBH4 pretreatment (84.25+/-1.12degrees C, p=0.023) caused a significant difference from the control (86.25+/-0.00degrees C). L-lysine and NaBH4 pretreatment (183.8+/-42.6 ug/mg, p=0.804), and L-arginine and NaBH4 pretreatment (163.3+/-27.5 ug/mg, p=0.621) did not significantly inhibit calcification compared to the control (175.5+/-45.3 ug/mg), but ethanol and NaBH4 pretreatment did (38.5+/-37.3 ug/mg, p=0.003). CONCLUSION: The combined pretreatment using L-arginine and NaBH4 after GA fixation seemed to increase the tensile strength and thickness of porcine pericardium, fixed with GA. Additionally, it seemed to keep thermal stability. However it could not decrease the calcification of porcine pericardium fixed with GA. NaBH4 pretreatment seemed to decrease the calcification of porcine pericardium fixed with GA, but only with ethanol.

Analysis of Mercury-Rich plants and mine tailings using the Hydride-Generation AAS method

A hydride-generation atomic absorption spectroscopy (AAS) method was developed for the analysis of total Hg in liquid matrices of mercury-rich plants and mine tailings samples. The detection limit for this method was as low as 11.4 ng/mL. The reproducibility of the mercury signals (in terms of relative standard deviation) was 4.6 percent. Accuracy of the method was verified by analyses of deionised water samples spiked with HgCl2 and HgNO3. Recovery values for total mercury ranged from 88.5 to 94.3 percent for both mercury species added. An external certified laboratory validated the analytical method with a maximum discrepancy of 15 percent. Optimal analytical response of the equipment for Hg analysis of plant samples was achieved when the sample volume added to the reaction vessel was 0.25 mL.

Um protocolo para análise do mercúrio (Hg) em amostras líquidas de solo e tecidos vegetais enriquecidos com Hg foi desenvolvido com base na técnica de geração de hidretos. O limite de detecção para este método foi de 11.4 ng/mL. A reproducibilidade do método (calculado com base no desvio padrão relativo) foi de 4.6 por cento. A precisão do método foi verificada pela análise de amostras de água deionizada contendo HgCl2 and HgNO3. Os valores de mercúrio total recuperados variaram de 88.5 a 94.3 por cento para ambas as espécies testadas. O método analítico foi validado por um laboratório externo certificado com discrepância máxima de 15 por cento. O desempenho analítico do equipamento para análise do mercúrio em tecidos vegetais foi considerado ótimo para volumes de amostra de até 0.25 mL.