Ag2O–Al2O3–ZrO2 Trimetallic Nanocatalyst for High Performance Photodegradation of Nicosulfuron Herbicide

Topics in Catalysis - In the present study, Ag2O–Al2O3–ZrO2 based trimetallic oxide nanocatalyst was designed using simple microwave assisted reduction method. It was characterized...     

Chronic Effects of a High Sucrose Diet on Murine Gastrointestinal Nutrient Sensor Gene and Protein Expression Levels and Lipid Metabolism

The gastrointestinal tract (GIT) plays a key role in regulating nutrient metabolism and appetite responses. This study aimed to identify changes in the GIT that are important in the development of diet related obesity and diabetes. GIT samples were obtained from C57BL/6J male mice chronically fed a control diet or a high sucrose diet (HSD) and analysed for changes in gene, protein and metabolite levels. In HSD mice, GIT expression levels of fat oxidation genes were reduced, and increased de novo lipogenesis was evident in ileum. Gene expression levels of the putative sugar sensor, slc5a4a and slc5a4b, and fat sensor, cd36, were downregulated in the small intestines of HSD mice. In HSD mice, there was also evidence of bacterial overgrowth and a lipopolysaccharide activated inflammatory pathway involving inducible nitric oxide synthase (iNOS). In Caco-2 cells, sucrose significantly increased the expression levels of the nos2, iNOS and nitric oxide (NO) gas levels. In conclusion, sucrose fed induced obesity/diabetes is associated with changes in GI macronutrient sensing, appetite regulation and nutrient metabolism and intestinal microflora. These may be important drivers, and thus therapeutic targets, of diet-related metabolic disease.     

Design of band-notched antenna with DG-CEBG

Ultra-wideband (UWB) disc monopole antenna with crescent shaped slot for double band-notched features is presented. Planned antenna discards worldwide interoperability for microwave access (WiMAX) band (3.3–3.6 GHz) and wireless local area network (WLAN) band (5–6 GHz). Defected ground compact electromagnetic band gap (DG-CEBG) designs are used to accomplish band notches in WiMAX and WLAN bands. Defected ground planes are utilised to achieve compactness in electromagnetic band gap (EBG) structures. The proposed WiMAX and WLAN DG-CEBG designs show a compactness of around 46% and 50%, respectively, over mushroom EBG structures. Parametric analyses of DG-CEBG design factors are carried out to control the notched frequencies. Stepwise notch transition from upper to lower frequencies is presented with incremental inductance augmentation. The proposed antenna is made-up on low-cost FR-4 substrate of complete extents as (42 × 50 × 1.6) mm³.Fabricated sample antenna shows excellent consistency in simulated and measured outcomes.     

Investigation of Anti-Cancer Drug Nimustine Interaction with Calf Thymus DNA

Nimustine, a chloroethyl nitrosourea derivative (CENU), is an antineoplastic agent, which is used for the treatment of various types of cancer. The present study focuses on the prediction and investigation of binding properties of nimustine with DNA using molecular modeling and UV–Visible spectroscopic technique. The docking study show that nimustine plausibly binds within the major groove of DNA. Further analysis of docking suggests direct interaction of nimustine with the moieties of heterocyclic nitrogenous bases of DNA. The free binding energy value of the best nimustine-DNA docked conformer is predicted as ?4.31 kcal/mol using docking results.The molecular modeling study also reveals that the interaction between nimustine and DNA is majorly governed by van der Waals forces, hydrogen bonding and hydrophobic interactions, whereas the contribution of electrostatic forces stands negligible. Further, UV–Visible spectra of free calf thymus DNA and its complexes with varying concentration of nimustine indicate the binding constant (K _a ) value as 3.27 × 10³ M^?1, which suggests moderate interaction of nimustine with DNA. The spectroscopic results are further used to calculate the binding free energy of the complex using the relation ΔG = ?RT ln (K _a ). This accounts for a value of ?4.79 kcal/mol. It corroborates well with the docking outcomes. The results of present study may help in designing and synthesis of new chloroethyl nitrosourea derivatives with improved efficacy and specificity for the target molecules.     

Study of Effect of Bended Graphene on Its Magnetoresistance and Spin Filtration

Density functional theory (DFT) is used to investigate the spin-dependent quantum transport through bended graphene. Bending results in reduced bandgap in graphene and affects the spin transport by increasing current in parallel configuration (PC) resulting in an increase in magnetoresistance (MR). In antiparallel configuration (APC), bending limits the spin-down current, which results in higher magnetoresistance at all biases. In bended graphene, the magnetoresistance obtained is higher than the MR obtained in pristine and twisted graphene-based structure. High spin filtration for PC and APC is observed in the case of bended graphene as compared with pristine and twisted graphene. However, pristine graphene gives better spin filtration compared with twisted graphene at low voltages.     

Luminescence properties of near-UV excitable yellow-orange light emitting warm CaSrAl2SiO7:Sm3+ phosphors

Single-phase CaSrAl_2 SiO_7:Sm~(3+) phosphors were synthesized by traditional high temperature solid state reaction method. Formation of samples and phase analysis were confirmed by X-ray diffraction technique. Morphology was done by field emission scanning electron microscopy and elemental compositions were confirmed by energy dispersive X-ray analysis. Present phosphors have tetragonal crystallography with space group P42_1 m. Average crystallite size was calculated by using Scherrer and Williamson-Hall method. Photoluminescence study of CaSrAl_2 SiO_7:Sm~(3+) phosphor was investigated.Under different excitation wavelengths, PL spectra consist of four emission bands at 564, 570, 601 and650 nm. The emission bands located at 564 and 570 nm are associated with the transition ~4 G_(5/2)→~6 H_(5/2)while emission bands at 601 and 650 nm are due to ~4 G_(5/2)→~6 H_(7/2) and ~4 G_(5/2)→~6 H_(9/2),respectively.Intense emission was obtained when phosphor was excited under 404 nm wavelength. Non-radiative energy transfer process involved in concentration quenching, was also discussed. CIE coordinate is found in yellow-orange region, hence CaSrAl_2SiO_7:Sm~(3+) phosphors emit yellow-orange light when efficiently excited by near UV(～400 nm) LED chip. Color purity and CCT of the phosphor were determined; CCT suggests that present phosphor is a good candidate as a warm yellow-orange color emitting phosphor. Effect of different heating rates and different UV exposure time on the TL glow curve of the phosphor was investigated. Activation energies and kinetic parameters for different traps were calculated by using peak shape method. TL emission spectrum was also recorded. Present article explains all the possible mechanisms associated with luminescence process in CaSrAl_2 SiO_7:Sm~(3+) phosphors.     

Vibrational dynamics of poly(L‐glutamine)

In the present paper, we report the Fourier transform infra‐red (FTIR) spectra and an analysis of the normal modes and their dispersion, based on the calculations for an infinite chain and Urey Bradley force field with nonbonded interactions. The results thus obtained agree well with the FTIR spectra. The heat capacity obtained from the dispersion curves via density‐of‐states is in very good agreement with the experimental measurements between 50 and 500 K. We observed that the main contribution to heat capacity comes from the modes involving the coupling of the backbone skeletal and side‐chain motions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Active layer modification of commercial nanofiltration membrane using CuBTC/PVA matrix for improved surface and separation characteristics

The present study proposes a facile route for the modification of commercial nanofiltration (NF) polymeric membrane by embedding metal organic framework (MOF) via dip coating. A mixed membrane matrix comprising of copper benzene-1,3,5-tricarboxylate (CuBTC) and polyvinyl alcohol (PVA) served as the new active layer. The obtained topography, functional group, and surface elemental analysis elucidated the presence of heterogeneous phase and the distribution of the MOF on the membrane. The dip coating well supported the modification through excellent adhesion. The water wettability of the modified membrane displayed a positive correlation with CuBTC loading in the PVA polymer matrix. Permeation and separation characteristics of the resultant membranes were investigated by retaining protein and carbohydrates from synthetic dairy wastewater (SDWW). The permeability rate of modified samples increased to 43% as compared to the commercial NF membrane. A significant improvement in the rejection rate of carbohydrate from 61% to 87% and protein from 88% to 94% was achieved. Membrane Fouling was found to be much lesser for the modified samples. The study highlights the potential of CuBTC as filler material for enhancing the separation characteristic of established NF membrane.     

Visibly Active FeO/ZnO@PANI Magnetic Nano-photocatalyst for the Degradation of 3-Aminophenol

Topics in Catalysis - The water management sector is becoming extremely challenging these days because of poor water quality which is due to the presence of noxious pollutants at an...     

Micellization of Some Bile Salts in Binary Aqueous Solvent Mixtures

The micellization behavior of bile salts—sodium cholate and sodium deoxycholate was studied in aqueous methanol, ethanol and ethylene glycol mixtures (10–20 % v/v) over a temperature range (300–320 K) by surface tension and conductivity methods. Critical micelle concentration, extent of counter ion binding (α), interfacial property (A _min, ζ_max, π-CMC, $ \Updelta G_{\text{ad}}^{ \circ } $ ) and thermodynamic parameters ( $ \Updelta G_{\text{m}}^{ \circ } $ , $ \Updelta H_{\text{m}}^{ \circ } $ , $ \Updelta S_{\text{m}}^{ \circ } $ ) for the micellization process are reported and discussed.