Fabrication of NiO coated SiO2 and SiO2 coated NiO for the removal of Pb2＋ ions

We have prepared silica,SiO2coated NiO and NiO coated SiO2by sol-gel method.The physicochemical properties of the desired materials were investigated by surface charge properties,scanning electron microscopy（SEM）,energy dispersive X-ray（EDX） spectroscopy,surface area measurements and X-ray diffraction（XRD） analyses.The point of zero charge（PZC） of the solid was determined by the salt addition method.In coated materials,two PZC values were noted representing the surface charge of their counterparts.The SEM image of SiO2coated NiO displays a uniform coating of silica on the surface of NiO whereas in case of NiO coated SiO2,a honeycomb like appearance was observed with highly porous structures.In the diffractograms of NiO,the characteristic peaks were suppressed in NiO coated silica however,no diffraction peak could be seen in SiO2coated NiO.Batch adsorption technique was applied for the removal of Pb2＋ions from aqueous solution.The sorption trend for Pb2＋ions was observed in the order of NiO coated SiO2〉 SiO2coated NiO 〉 NiO 〉 SiO2.This trend confirms that the coated materials have more sorption capacities than their parent counterparts.     

Mathematical analysis on MHD Prandtl‐Eyring nanofluid new mass flux conditions

A speculative investigation has been presented to explore the salient features of magnetohydrodynamic (MHD) Prandtl‐Eyring nanofluid over stretching surface. Effects of Navier slip and convective boundary conditions are included in flow configuration. The effects of higher order chemical reactions along with Nield conditions are assumed in the concentration of nanoparticles. The mathematical modelling of the said flow problem accomplished the nonlinear partial differential equations along with appropriate boundary conditions. The nondimensional form of governing problem is yielded with the aid of similarity variables. The pivotal physical quantities, ie, velocity, temperature, and concentration (in nondimensional form), within boundary layer region are computed with shooting technique. The physical significance of flow controlling parameters on velocity, temperature, and concentration is illustrated through graphs. Additionally, thermophysical aspects of fluid near stretching surface (wall friction factor, wall heat flux, and wall mass flux) are instantiated graphically. A comparison of the current solution with reported data is established to validate the accuracy of adapted procedure. It is observed that the current findings agree with existing data. This led to confidence on adapted numerical procedure.     

Syntheses, Spectral Studies and Bioanalyses of Some Triorganotin(Ⅳ) Complexes of Cephlaxine

Five novel triorganotin(Ⅳ) complexes have been synthesized by refluxing trimethyl, triethyl, tributyl, triphenyl and tribenzyltin chloride with Cephlaxine.These compounds were characterized by spectroscopic (IR,1H, 13C, 119Sn NMR) techniques and elemental analysis.The results obtained through these techniques are in full agreement with the proposed 1:1 stoichiometry.The synthesized compounds were than tested against various microorganisms and fungi.The results of new products obtained showed that the triphenyltin(IV) complex displayed promising activity against all types of bacteria and fungi used while all other compounds showed significant antibacterial and antifungal activity.     

Real-life application of a QCM-based e-nose: quantitative characterization of different plant-degradation processes

Continuous surveillance of composting processes would enable a feedback loop to be obtained for both analysis and process control. For this purpose, we designed e-noses based on a six-electrode quartz-crystal microbalance (QCM) array coated with affinity materials and molecularly imprinted polymers (MIP). They enable quantitative monitoring of volatile organic compounds (VOCs) emitted directly in a compost bin and are highly suitable tools for achieving on-line characterization of the degradation processes occurring. During grass and pine composting (duration 14 days and 40 days, respectively), we observed concentrations of up to 250 ppm of esters, 700 ppm of alcohols, 250 ppm of terpenes, and 90% relative humidity directly on-line with such a system and could validate the data off-line by GC-MS. The sensor also gave direct insight into the differences between the two composting batch types. Besides duration, during grass composting larger amounts of alcohols are emitted whereas relative amount of terpenes is twice as high for pine composting. Detailed correlation of the sensor and the GC-MS data allows approximate estimation of the sensitivity of the sensor materials towards analyte classes such as, e.g., aliphatic alcohols or terpenes. Figure Mass sensitive sensor arrays coated with different molecularly imprinted and affinity materials are a highly suitable tool for quantitatively monitoring solvent patterns during composting procedures on-line in a composter headspace. Dedicated to Professor Udo Brinker on the occasion of his 65th birthday.     

Fluid Simulation of Capacitively Coupled HBr/Ar Plasma for Etching Applications

In this work, a fluid model has been applied to study HBr/Ar capacitively coupled plasma discharges that are being used for anisotropic etching process. Based on time average reaction rates, the model identify the most dominant species in HBr/Ar plasma. Our simulation results show that the neutral species like H and Br, which are the key precursors in chemical etching, have bell shape distribution while ions like HBr⁺, Br⁺ and Ar⁺ which plays a dominant role in the physical etching, have double humped distribution and shows peaks near electrodes. The effect of HBr/Ar mixing ratios on densities of dominant species are analyzed. The addition of Ar to HBr plasma decreases H, Br and HBr⁺ densities slightly while increases Br⁺ and Ar⁺ densities. It was found that the dilution of HBr by Ar results in an increase in electron density and electron temperature, which results in more ionization and dissociation. The densities and hence the fluxes of the neutrals and positive ions for etching and subsequently chemical etching versus physical etching in HBr/Ar plasmas discharge can be controlled by tuning Ar concentration in the discharge and the desire etching can be achieved.     

Synthesis,Enzyme Inhibition,and Molecular Docking Studies of Hydrazones from Dichlorophenylacetic Acids

A series of hydrazones 5a–i were synthesized by the condensation of hydrazides derived from dichlorophenylacetic acids with different aromatic aldehydes and ketones. Their structures were confirmed by spectroscopic data and elemental analysis. Hydrazones 5a–i were evaluated for α‐glucosidase and urease inhibition activities. Five compounds exhibited potent α‐glucosidase inhibitory potential with IC₅₀ values 8.5 ± 0.3, 22.2 ± 0.78, 32.9 ± 1.5, 34 ± 2.4, and 170.6 ± 7.5 μM, respectively, which are many times better than that of the standard inhibitor acarbose (IC₅₀ = 840 ± 1.73 μM). Furthermore, molecular docking study was performed to explore the binding mode in the active sites of α‐glucosidase and urease enzymes.     

Reinforcement of hydroxypropylcellulose films by cellulose nanocrystals in the presence of surfactants

Hydroxypropylcellulose (HPC) films were prepared by casting with cellulose nanocrystals in the presence of anionic surfactant sodium dodecylsulphate (SDS) and cationic surfactant hexadecyltrimethyl ammonium bromide (CTAB). The cellulose nanocrystals were isolated from maize straw, a biomass source produced in huge quantities as an agrowaste in Brazil. These bionanocomposite films had good transparency and their surface hydrophilic character was evidenced by static contact angle measurements. Thermogravimetry (TGA) measurement revealed that nanocrystals and surfactants changed the thermal stability of the HPC films. Dynamic mechanical analysis (DMA) showed that the tensile storage and loss moduli of the HPC films increased by increasing the contents of cellulose nanocrystals and surfactants, especially in the case of CTAB. This good reinforcing effect of HPC matrix can be explained as due to electrostatic attractive interactions brought about by the presence of CTAB and the nanocrystals.     

Titanium dioxide-tetra sulphonatophenyl porphyrin nanocomposites for target cellular bio-imaging and treatment of rheumatoid arthritis

Photodynamic therapy (PDT) is one of the latest biomedical technologies used for treatment of various neoplastic and non-neoplastic diseases. However, there still exist some well-known problems regarding its efficacy, e.g. effective concentration of the drug at the desired sites, the irradiation light dosimetry and biocompatibility of the photosensitizer. The introduction of nanotechnology and nanomaterial like biocompatible nano-titania (i.e., nano-TiO₂) may facilitate to solve some of these problems. In this study we have explored the possibility of combining tetra sulphonatophenyl porphyrin (TSPP) with nano-titania (PT) for efficient PDT with least adverse effects. The spectroscopic properties of these nano-composites were characterized by using fluorescence and UV-Vis absorption spectroscopic study. The singlet oxygen quantum yield was determined by using 2,5-diphenyl-3,4-benzofuran (DPBF), while the effect of nano TiO₂ with TSPP on the synovial fibroblast cells from human (HSC) and rat models (RSC) were investigated by confocal laser microscopy and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Our results suggest that nano TiO₂ with TSPP can be readily utilized for effective PDT treatment of Rheumatoid Arthritis (RA).     

Effective sequestration of Congo red dye with ZnO/cotton stalks biochar nanocomposite: MODELING,reusability and stability

Widespread application of dyes and disposal of their untreated effluents into water bodies adversely affect the ecosystem due to their complex aromatic structures and persistent nature. The present study aims to utilize the cotton stalks biochar (CSB) and its composite with zinc oxide nanoparticles (CSB/ZnONPs) to evaluate for the decontamination their batch scale potential of Congo red dye from wastewater. The characterization of CSB and CSB/ZnONPs was performed with Fourier-transform infra-red (FTIR) spectroscopy, scanning electron microscopy, energy-dispersive X-ray (EDX) and point of zero charge (PZC) to get insight of their potential for the decontamination of CR. The effects of initial CR concentration (25–500 mg/L), dosage of CSB and CSB/ZnONPs (0.5–2 g/L), solution pH (2–10) and contact time (0–180 min) were evaluated on CR removal at temperature (25 ± 1.5 °C). The results disclosed that CSB/ZnONPs showed excellent adsorption potential (556.6 mg/g) in comparison with CSB (250 mg/g) and most of the other adsorbents previously studies in the literature. The equilibrium experimental data were equally explained with Freundlich and Langmuir isotherm models (R² > 0.98) while kinetic data demonstrated the best fit with pseudo second order model. The CSB/ZnONPs composite exhibited excellent reusability (89.65%) after five adsorption/desorption cycles for the sequestration of CR from contaminated systems. The present study demonstrated that metallic nanocomposite of CSB (CSB/ZnONPs) is an excellent candidate for the cost effective and environment friendly decontamination of CR from industrial wastewater and is suggested to be considered for the decontamination of other pollutants from the wastewater.     

Protective Effect of Thymus serrulatus Essential Oil on Cadmium-Induced Nephrotoxicity in Rats,through Suppression of Oxidative Stress and Downregulation of NF-κB,iNOS, and Smad2 mRNA Expression

The purpose of the research was to examine the protective effect of essential oil from Thymus serrulatus Hochst. ex Benth. (TSA oil) against cadmium (Cd)-induced renal toxicity. The experimental protocol was designed using 30 healthy adult Wistar albino rats allocated into five groups containing six animals in each group. Group 1 was treated as normal control and groups 2, 3, 4, and 5 were treated with cadmium chloride (CdCl₂, 3 mg/kg, IP) for 7 days. Group 3 was also treated with silymarin (100 mg/kg, PO) as a standard group, while groups 4 and 5 were administered with TSA oil at doses of 100 and 200 mg/kg PO, respectively. The nephrotoxicity was measured with various parameters such as kidney function markers, oxidative stress markers (glutathione (GSH) and malondialdehyde (MDA)), and messenger ribonucleic acid (mRNA) expression levels of inflammatory factors. The histological studies were also evaluated in the experimental protocol. The CdCl₂-treated groups showed a significant increase in the levels of serum kidney function markers along with MDA levels in kidney homogenate. However, renal GSH level was found to be reduced significantly. It was found that CdCl₂ significantly upregulated the nuclear factor levels of kappaB (NF-κB p65), inducible nitric oxide synthase (iNOS), and small mothers against decapentaplegic (Smad2) as compared to the normal control group. On the other hand, TSA oil significantly improved the increased levels of serum kidney function markers, non-enzymatic antioxidants, and lipid peroxidation. In addition, TSA oil significantly downregulated the increased expression of NF-κB p65, iNOS, and Smad2 in Cd-intoxicated rats. Moreover, the histological changes in the tissue samples of the kidney of Cd-treated groups were significantly ameliorated in the silymarin- and TSA-oil-treated groups. The present study reveals that TSA oil ameliorates Cd-induced renal injury, and it is also proposed that the observed nephroprotective effect could be due to the antioxidant potential of TSA oil and healing due to its anti-inflammatory action.