Copper biosorption in a column of pretreated Aspergillus niger biomass

In this study, biosorption of Cu(II) was investigated in a column of pretreated Aspergillus niger biomass. The breakthrough was measured as a function of influent flow rate and bed height for a feed solution at 10 mg/l metal ion concentration. Biosorption was evaluated in terms of the equilibrium capacity of the column and the amount of metal loading on the A. niger surface. It has been observed that pretreatment of the biomass enhanced the activity of the surface reactive groups and hence the uptake. The breakthrough data obtained was described by bed depth service time (BDST) and Thomas models. The amount of copper adsorbed per gram of pretreated A. niger was 13.4 ± 0.60 mg/g. The sorbed copper was eluted from the column using 0.1N HCl in five consecutive sorption–desorption cycles. For the same initial metal ion concentration, a packed column reactor shows more uptake of Cu(II) in comparison to a batch reactor.© Elsevie

Noble Metal Nanoparticles: Plant-Mediated Synthesis, Mechanistic Aspects of Synthesis, and Applications

In recent years, the progress of efficient green chemistry approaches for the fabrication of commercially viable noble metallic nanoparticles has become a major focus of researchers. The present review has focused on the various plant-mediated nanoparticle fabrication approaches, with brief discussions on the categories of various plant-mediated synthesis approaches and mechanistic aspects of plant-mediated nanoparticle synthesis. The review also focused on the commercial applications of plant-mediated noble metal nanoparticles. Significant remarks on the limitations of plant-mediated fabrication approaches with prospective future direction are also examined

Biosynthesis of Palladium Nanoparticles Using Delonix regia Leaf Extract and Its Catalytic Activity for Nitro-aromatics Hydrogenation

This work presents the biosynthesis of palladium nanoparticles (Pd-NPs) using Delonix regia (D. regia) leaf extract, and their catalytic activity was evaluated for 2-nitrophenol (2-NP) and 2-nitroaniline (2-NA) hydrogenation reactions. The appearance of a broad continuous absorption spectrum in the visible–ultraviolet region in UV–visible spectra confirmed the synthesis of Pd-NPs. The crystalline structure of Pd-NPs (with size range of 2–4 nm) was confirmed by X-ray diffraction and transmission electron microscopy analysis, respectively. The appearance of an optical absorption peak at 2.80 keV in energy dispersive spectra further confirmed the presence of Pd-NPs. Fourier transform infrared analysis suggested the role of water-soluble polyols present in the D. regia leaf extract in mediating the synthesis of Pd-NPs. Moreover, the catalytic activity of Pd-NPs for hydrogenation reactions was studied by UV–visible spectroscopy. Pd-NPs showed catalytic activity through electron relay effect. The hydrogenation reactions followed pseudo-first-order kinetics with respect to the substrates

Betahistine as an add-on: The magic bullet for postoperative nausea, vomiting and dizziness after middle ear surgery?

Purpose: Patients undergoing middle ear surgery experience variable degrees of postoperative nausea and vomiting (PONV) despite prophylaxis and treatment with ondansetron or other 5HT 3 receptor antagonists. Furthermore vertigo or dizziness are not well controlled perioperatively. Role of betahistine was tested as an add-on to ondansetron in control of PONV and vertigo in middle ear surgery cases. Materials and Methods: We conducted a prospective, randomized, double-blind, placebo controlled study, enrolling one hundred patients undergoing middle ear surgery under local anesthesia into two groups consisting of fifty (n = 50) patients each. Group A patients were given betahistine 16 mg plus ondansetron 8 mg and placebo plus ondansetron 8 mg were given to group B or placebo group, orally 3 hours before starting operation. The incidence of nausea, vomiting, and dizziness was noted during the intraoperative and postoperative 24 hours period. Chi-square test, unpaired ′t′ test, and Fisher′s exact tests were performed for statistical analysis using SPSS version 16 and Open Epi version 2.3.1 softwares. Results: Complete response was obtained in 90% patients in the betahistine group as compared to 66% in the placebo group. Vomiting in the intraoperative and postoperative period was noted in 4% and 8% cases, respectively, in the betahistine group as compared to 18% and 26%, respectively, in the placebo group. Overall, vertigo was 10% versus 32% in betahistine group and placebo group, respectively. Conclusion: Betahistine as an add-on to ondansetron can significantly attenuate PONV and perioperative vertigo, following middle ear surgeries