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Polypyrrole (PPy)–molybdenum trioxide (MoO3) is a polymer‐metal oxide composite (99.9% pure) obtained when two are mixed mechanically with different wt% in acetone medium to obtain different PPy–MoO3 composite materials. The thick films of pure PPy and PPy–MoO3 polymer‐metal oxide composite are prepared by screen printing technique. The prepared mixed composite polymer‐metal oxide materials are calcinated at 800°C for 8 h in air. The thick films are investigated for structural, electrical, and morphological properties. The surface morphology of the thick films is studied by scanning electron microscope (SEM) which shows that the films are granular and porous in nature. The gas responses of pure PPy and PPy–MoO3 polymer‐metal oxide composite thick films are studied for different gases such as ammonia gas (NH3) and ethanol gas at room temperature. The pure PPy thick film shows the poor response to ammonia and ethanol gas, while the thick film 40PPy–60MoO3 gave good responses to ethanol gas (50 ppm) at room temperature. The gas selectivity, sensitivity, stability, gas response, and recovery time of the sensor are measured and presented. [ABSTRACT FROM AUTHOR]

Tm3+‐doped La2O3 phosphors with different doping concentration are prepared by co‐precipitation method. The prepared phosphor is characterized by X‐ray powder diffraction (XRD), SEM, Fourier transform infrared (FT‐IR) spectroscopy, and photoluminescence (PL) techniques. The XRD analysis confirms the formation of La2O3. PL measurement shows that the phosphor exhibit characteristic Tm3+ bright blue emission attributed to transition from 1D2 → 3F4 of Tm3+ ions, at 363 nm excitation. The Commission International de I'Eclairage (CIE) chromaticity color coordinates of prepared phosphor is calculated and presented. The excitation peak located at 363 nm matches with the emission wavelength of near UV‐LED chip, this indicates that the prepared phosphor is a promising blue light‐emitting candidate for eco‐friendly solid state lighting (W‐LED) application. [ABSTRACT FROM AUTHOR]

In this study, the structural and magnetic properties of Co0.9Zn0.1Fe2O4 ferrite nanoparticles are prepared by using chemical co‐precipitation method and characterized with X‐ray diffraction (XRD) and vibrating sample magnetometer (VSM). The structural results show that the particles have a formation of single‐phase cubic spinel structure and that the particles have a nano scale, with a clear agglomeration between the particles. The crystallite size of the sample is found 6.21 nm by using Scherer's formula, while the lattice parameters is 8.38 Å. The VSM study shows the saturation magnetization (Ms) 30.18 emu g‐1 and coercivity (Hc) 500 Oe along with hysteresis and to calculate the Ms values the Law of approach to saturation is used. The dried sample of ferrite is characterized with an FTIR‐spectrophotometer in wave number range of 4200–800 cm−1. [ABSTRACT FROM AUTHOR]

The paper describes the study of structural and dielectric properties of PVDF blended with organically modified clay. The PVDF/clay nanocomposites are prepared by simple melt mixing method. The prepared nanocomposites are characterized for structural and dielectric properties. The structural characterization done using X‐ray diffraction and infra‐red spectroscopy techniques indicates the crystallization of ferroelectric β phase in nanocomposites. The dielectric study shows the composition‐dependent significant enhancement in the dielectric permittivity, particularly in the low‐frequency region. The enhancement in the dielectric permittivity is explained on the basis of increase in the conductivity and formation of minicapacitor‐like network in the nanocomposites. The dielectric loss spectra of PVDF shows two relaxations corresponding to the glass transition temperature and crystalline relaxation. In case of PVDF/Clay nanocomposites, the dielectric relaxation corresponding to the crystalline relaxation completely disappears, which is attributed to the dielectric manifestation of ferroelectric β phase in nanocomposites. The observed dielectric permittivity data can be very well fitted using Vo‐Shi model, which takes contribution of interphase to the dielectric permittivity. The enhancement in the dielectric permittivity along with ferroelectric β phase in PVDF/clay nanocomposites brings the potential application in energy storage devices. [ABSTRACT FROM AUTHOR]

Theories based on free-volume concepts have been developed to characterize the self and mutual-diffusion coefficients of low molecular weight penetrants in rubbery and glassy polymer-solvent systems. These theories are applicable over wide ranges of temperature and concentration. The capability of free-volume theory to describe solvent diffusion in glassy polymers is reviewed in this article. Two alternative free-volume based approaches used to evaluate solvent self-diffusion coefficients in glassy polymer-solvent systems are compared in terms of their differences and applicability. The models can correlate/predict temperature and concentration dependencies of the solvent diffusion coefficient. With the appropriate accompanying thermodynamic factors they can be used to model concentration profiles in mutual diffusion processes that are Fickian such as drying of coatings. The free-volume methodology has been found to be consistent with molecular dynamics simulations. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 [ABSTRACT FROM AUTHOR]

Calcineurin is an important signalling protein that regulates a number of molecular and cellular processes. Previously, we found that inhibition of calcineurin with cyclosporine reduced renal hypertrophy and blocked glomerular matrix expansion in the diabetic kidney. Isoforms of the catalytic subunit of calcineurin are reported to have tissue specific expression and functions. In particular, the β isoform has been implicated in cardiac and skeletal muscle hypertrophy. Therefore, we examined the role of calcineurin β in diabetic renal hypertrophy and glomerular matrix expansion. Type I diabetes was induced in wild-type and β mice and then renal function, extracellular matrix expansion and hypertrophy were evaluated. The absence of β produced a significant decrease in total calcineurin activity in the inner medulla (IM) and reduced nuclear factor of activated T-cells (NFATc) activity. Loss of β did not alter diabetic renal dysfunction assessed by glomerular filtration rate, urine albumin excretion and blood urea nitrogen. Similarly, matrix expansion in the whole kidney and glomerulus was not different between diabetic wild-type and β mice. In contrast, whole kidney and glomerular hypertrophy were significantly reduced in diabetic β mice. Moreover, β renal fibroblasts demonstrated impaired phosphorylation of Erk1/Erk2, c-Jun N-terminal kinases (JNK) and mammalian target of rapamycin (mTOR) following stimulation with transforming growth factor-β and did not undergo hypertrophy with 48 hrs culture in high glucose. In conclusion, loss of the β isoform of calcineurin is sufficient to reproduce beneficial aspects of cyclosporine on diabetic renal hypertrophy but not matrix expansion. Therefore, while multiple signals appear to regulate matrix, calcineurin β appears to be a central mechanism involved in organ hypertrophy. [ABSTRACT FROM AUTHOR]

A total of 39 microbes were screened for the ability to selectively N-demethylate (3R,5S,E)-7-(4-(4-fluorophenyl)-6-isopropyl-2-(methyl(1-methyl-1H-1,2,4-triazol-5-yl)aminopyrimidin-5-yl)-3,5-dihydroxy-hept-6-enoic acid (I), a potential drug for lowering blood cholesterol levels. Two Streptomyces species were found to carry out the desired N-demethylation. Bioconversion by Streptomyces griseus A.T.C.C. 13273 and product recovery were scaled up to the multi-gram level. [ABSTRACT FROM AUTHOR]

Second-generation paclitaxel analogues that require replacement of the C-4 acetate by other substituents are in development. An enzyme able to specifically remove the C-4 acetate from paclitaxel could simplify preparation of the analogues. Several strains were isolated from soil samples that contain enzyme activities able to 4-deacetylate 10-DAB (10-deacetylbaccatin III). Selection was made using plates containing 10-DAB as the sole carbon source and screening colonies for deacetylation of 10-DAB. Two strains initially isolated were identified as Rhodococcus sp. and deposited with the A.T.C.C. (Manassas, VA, U.S.A.) as strains 202191 and 202192. Whole cells were able to convert 10-DAB into 4,10-DDAB (4-deacetyl-10-deacetylbaccatin III) in 90% yield. The enzyme activity in these strains was not effective with paclitaxel and 10-deacetylpaclitaxel, although 4,10-DDAB was produced from baccatin III. The activity in these strains was associated with an insoluble fraction of cell extracts. Several additional isolates were obtained that were identified as variants of Stenotrophomonas maltophilia, and a soluble C-4 deacetylase was purified approx. 218-fold from one of them. The activity of this enzyme was limited to 10-DAB, and the enzyme was not effective with paclitaxel or baccatin III. [ABSTRACT FROM AUTHOR]

Cell-free extracts derived from yeasts Candida utilis ATCC 26387, Hansenula polymorpha ATCC 26012, Pichia sp. NRRL-Y-11328 Torulopsis sp. strain A1 and Kloeckera sp. strain A2 catalyzed an NAD+-dependent oxidation of secondary alcohols (2-propanol, 2-butanol, 2-pentanol, 2-hexanol) to the corresponding methyl ketones (acetone, 2-butanone, 2-pentanone, 2-hexanone). We have purified a NAD+-specific secondary alcohol dehydrogenase from methanol-grown yeast, Pichia sp. The purified enzyme is homogenous as judged by polyacrylamide gel electrophoresis. The purified enzyme catalyzed the oxidation of secondary alcohols to the corresponding methyl ketones in the presence of NAD+ as an electron acceptor. Primary alcohols were not oxidized by the purified enzyme. The optimum pH for oxidation of secondary alcohols by the purified enzyme is 8.0. The molecular weight of the purified enzyme as determined by gel filtration is 98000 and subunit size as determined by sodium dodecyl sulfate gel electrophoresis is 48000. The activity of the purified secondary alcohol dehydrogenase was inhibited by sulfhydryl inhibitors and metal-binding agents. [ABSTRACT FROM AUTHOR]

Endovascular grafting of abdominal aortic aneurysms provides a good alternative to open surgery, especially in high-risk patients. Endoleaks are a well-recognized complication and are typically diagnosed on CT. We descibe a case in which a patient's endoleak was evaluated by MRI and successfully treated by direct thrombin injection into the site of the leak. [ABSTRACT FROM AUTHOR]

In the title compound, C18H16BrNO4S, the phenyl ring forms a dihedral angle of 83.87 (2)° with the indole ring system. The molecular structure is stabilized by weak intramolecular C—H...O interactions and the crystal packing is stabilized by weak intermolecular C—H...O interactions. [ABSTRACT FROM AUTHOR]

We study two marked point process models based on the Cox process. These models are used to describe the probabilistic structure of the rainfall intensity process. Mathematical formulation of the models is described and some second-moment characteristics of the rainfall depth, and aggregated processes are considered. The derived second-order properties of the accumulated rainfall amounts at different levels ofaggregation are used in order to examine the model fit. A brief dataanalysis is presented. Copyright (c) 1998 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]