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41.
The interaction of zinc oxide nanoparticles (ZnO NPs) with human haemoglobin (Hb) is studied for the biologically safe application of ZnO NPs in the human body. The Hb corona is formed around the ZnO nanoparticles, directly observed from high‐resolution transmission electron microscopy (HRTEM) images. Hb formed ‘hard corona' on the surface of ZnO NPs from an exponential association mechanism over a very short duration, as well as unfolding of Hb that occurred over a long lifetime. Dynamic light scattering measurements demonstrated that the ZnO NPs were completely covered by Hb with shell thickness of c. 6 nm that formed a ‘hard corona'. Zeta potential measurements represented that the ZnO NPs were fully covered by Hb molecules using an exponential association mechanism. Tryptophans (TRY), as well as heme‐porphyrin moieties of Hb, are the major binding sites for ZnO NPs. The nature of the interaction between ZnO NPs and Hb was analysed from the fluorescence quenching of TRYs. Electrostatic interaction, along with the hydrophobic interaction between ZnO NPs and Hb, is responsible for the conformational change in Hb due to increase in the percentage of β‐sheets together with a decrease in α‐helices. 相似文献
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AbstractAzo dyes are recalcitrant compounds used as a colorant in various industries. The pollution caused by their extensive usage has adversely affected the environment for years. The existing physicochemical methods for dye pollution remediation are rather inefficient and hence there is a dearth of low-cost, potential systems capable of dye degradation. The current research studies the biodegradation potential of immobilized bacterial cells against azo dyes Reactive Orange 16 (RO-16) and Reactive Blue 250 (RB-250). Two indigenous dye degrading bacteria Bacillus sp. VITAKB20 and Lysinibacillus sp. KPB6 was isolated from textile sludge sample. Free cells of Bacillus. sp. VITAKB20 degraded 92.38% of RO-16 and that of Lysinibacillus sp. KPB6 degraded 95.36% of RB-250 within 72?h under static conditions. Upon immobilization with calcium alginate, dye degradation occurred rapidly. Bacillus. sp. VITAKB20 degraded 97.5% of RO-16 and Lysinibacillus sp. KPB6 degraded 98.2% of RB-250 within 48?h under shaking conditions. Further, the nature of dye decolorization was biodegradation as evident by high-performance liquid chromatography (HPLC), and Fourier-transform infrared spectroscopy (FTIR) results. Phytotoxicity and biotoxicity assays revealed that the degraded dye products were less toxic in nature than the pure dyes. Thus, immobilization proved to be a highly likely alternative treatment for dye removal. 相似文献
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Gupta Saurabh Chaubey Kundan Kumar Agarwal Prabhat Kuenstner J. Todd Parashar Deepak Singh Shoor Vir 《Molecular biology reports》2021,48(10):7013-7020
Molecular Biology Reports - A 26-year-old male had a history of frequent bowel movements, mushy stool with mucus and loss of 25 kg body weight in 6 months was diagnosed as a case... 相似文献
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ZnO nanostructures of different morphology (nanorods, nano‐leaf, nanotubes) were favourably grown using a chemical precipitation process. The prepared ZnO nanostructures were characterized systematically using absorption spectroscopy, emission spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared studies. XRD results showed the hexagonal wurtzite phase of the synthesized ZnO nanostructures. Structural properties such as average crystallite size, lattice constants, volume of the unit cell, atomic fraction, and structural bonds were also studied. The optical band gap of the synthesized ZnO nanocrystals varied from 3.52 eV to 3.69 eV with high quantum yield of the blue emission (~420 nm). Urbach energy for ZnO nanocrystals was calculated to be 0.702 eV, 0.901 eV, and 0.993 eV for nanorods, nano‐leaf, and tube like ZnO crystals, respectively. Morphology of the fabricated nanostructures was investigated using SEM. Photocatalytic degradation of rhodamine B (Rh B) in solution under UV irradiation was explored with different ZnO morphology. Photocatalytic experiments showed that ZnO nano‐leaf had a higher degradation rate of photocatalytic activity of photodegrading Rh B compared with the other tube shape and rods shape nanostructures. The Rh B dye degraded considerably by ~79.05%, 74.41%, and 69.8% within 120 min in the presence of the as‐fabricated fern nano‐leaf, nanotubes, and nanorods of the ZnO nanocrystals at room temperature. 相似文献
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Patil Saurabh Gupta Kritika Pandit Ashish Desai Bhushan Gschliesser Siegfried Dandekar Prajakta Jain Ratnesh 《International journal of peptide research and therapeutics》2021,27(4):2831-2844
International Journal of Peptide Research and Therapeutics - The development of peptide-based formulations presents numerous challenges to the formulator due to their complexity, delicate structure... 相似文献
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Papita Das Saha 《Bioremediation Journal》2013,17(1):52-60
ABSTRACT The effluents coming from the dye industries are colored and polluted, and the disposal of these wastes into receiving waters causes damage to the water as well as the environment. The use of rice husk for the removal of dye from wastewater has been explored in a stir tank reactor. The effects of operation variables such as adsorbent dosage, contact time, dye concentration, initial pH, and agitation on the removal of safranin were investigated in a stirred tank reactor. The combined effect of various process parameters on dye removal were analyzed using response surface methodology (RSM), and the modeling of the process parameter had been done using the artificial neural network simulation method. It was observed that response surface methodology can determine the optimization of the process parameters and the model derived from the simulation of the artificial neural network (ANN) (deviation from experimental results was ~0.09%) described the process variable efficiently. It was observed that at the initial solution pH of 6.28 and adsorbent dosage of 15.63 g L?1, dye removal of safranin was 97%. 相似文献
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Jayanta Saha Ruth M. Ruprecht Andre Rosowsky 《Nucleosides, nucleotides & nucleic acids》2013,32(7):1465-1475
Abstract A convenient general method of synthesis of 5′-O-(alkoxycarbonyl)phosphonate esters of 2′,3′-dideoxyribonucleosides is presented, using the 5′-O-(methoxycarbonyl)phosphinyl, 5′-0-(ethoxycarbonyl)phosphinyl, and 5′-O-(cholesterylcarbonyl)phosphinyl derivatives of 3′-azido-3′-deoxythymidine (AZT) and the 5′-0-(ethoxycarbonyl)phosphinyl derivative of 2′,3′-dideoxycytidine (ddC) as examples. Reaction of trimethyl phosphonoformate, methyl phosphonoformate, or dimethyl cholesterylcarbonylphosphonate with phosphorus pentachloride in carbon tetrachloride, followed by direct condensation of the resulting phosphonyl chloride with the nucleoside, gave the fully esterified phosphonoformate derivatives, which on treatment with sodium iodide in tetrahydrofuran underwent selective cleavage of the P-OMe or P-OEt groups, leaving the carboxylate esters intact. The resulting products were converted from sodium salts to ammonium salts by ion-exchange chromatography. 相似文献