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31.
P. Venkatacharyulu K. S. R. Prasad A. Kasturi N. V. L. N. Prasad J. V. Rao 《Crystal Research and Technology》1990,25(4):471-477
Using the coefficient of volume expansion certain thermoacoustic parameters like isobaric (K), isothermal (K″), isochoric (K″) acoustic parameters, free volume (Va/V) and two new dimensionless acoustic parameters A* and B* are estimated in certain alkoxy benzylidene butylanilines, in their isotropic- and mesophases as well as at and in the immediate vicinity of the phase transition temperatures following the method which was suggested by Sharma, for non-mesomorphic systems. 相似文献
32.
The influence of magnesium doping on the properties of tetrakis(thiourea)nickel(II) chloride crystals has been described. The reduction in the intensity observed in powder X-ray diffraction of doped specimen and slight shifts in vibrational frequencies confirm the lattice stress as a result of doping. Surface morphological changes due to doping of the alkaline earth metal are observed by scanning electron microscopy. The incorporation of Mg(II) into the crystal lattice was confirmed by energy dispersive X-ray spectroscopy. Lattice parameters are determined by single crystal XRD analysis. The thermogravimetric and differential thermal analysis studies reveal the purity of the materials and no decomposition is observed up to the melting point. The crystal is further characterized by Kurtz powder technique and dielectric studies. 相似文献
33.
Stability‐indicating HPLC assay for lysine–proline–valine (KPV) in aqueous solutions and skin homogenates 下载免费PDF全文
Kasturi R. Pawar Vanisree Mulabagal Forrest Smith Chandra S. Kolli Vijaya K. Rangari R. Jayachandra Babu 《Biomedical chromatography : BMC》2015,29(5):716-721
A simple, sensitive and stability‐indicating high‐performance liquid chromatographic (HPLC) assay method was developed and validated for a bioactive peptide, lysine–proline–valine (KPV) in aqueous solutions and skin homogenates. Chromatographic separation was achieved on a reversed phase Phenomenex C18 column (4.6 × 250 mm, packed with 5 µm silica particles) with a gradient mobile phase consisting of 0.1% trifluoroacetic acid (TFA) in water (A) and 0.1% TFA in acetonitrile (B). The proposed HPLC method was validated with respect to accuracy, precision, linearity, repeatability, limit of detection (LOD) and limit of quantitation (LOQ). The calibration curve was linear with a correlation coefficient (r) of 0.9999. Relative standard deviation values of accuracy and precision experiments were <2. The LOD and LOQ of KPV were 0.01 and 0.25 µg/mL, respectively. Under stress conditions (acid, alkali and hydrogen peroxide) KPV yielded lys–pro–diketopiperazine as major degradation product, which was identified by flow injection MS analysis. The developed HPLC method was found to be efficient in separating the active peptide from its degradation products generated under various stress conditions. Also, the validated method was able to separate KPV from other peaks arising from endogenous components of the skin homogenate. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
34.
Ulrich Behrens Jürgen Kopf Kasturi Lal William E. Watts 《Journal of organometallic chemistry》1984,276(2):193-198
The structure of tricarbonyl(η-methoxytropylium)chromium tetrafluoroborate has been determined by single-crystal X-ray analysis. The salt crystallises in the triclinic space group P with lattice constants a 740.3(2), b 956.7(3), c 1038.4(2) pm; α 89.10(2), β 73.32(2), γ 74.31(3)°; Z = 2. The final R index for 2914 observed reflections (F ≥ 4σ) is 0.045. The cation contains an approximately planar seven-membered ring symmetrically bonded to a Cr(CO)3 group. The C(1)O(Me) distance (133.8 pm) is intermediate between usual single- and double-bond values. 相似文献
35.
36.
Steven?D?Buckingham Luanda?Pym Andrew?K?Jones Laurence?Brown Mark?SP?Sansom David?B?Sattelle Philip?C?BigginEmail author 《BMC neuroscience》2005,6(1):2
Background
Nicotinic acetylcholine receptors (nAChRs) are pentameric proteins that are important drug targets for a variety of diseases including Alzheimer's, schizophrenia and various forms of epilepsy. One of the most intensively studied nAChR subunits in recent years has been α7. This subunit can form functional homomeric pentamers (α7)5, which can make interpretation of physiological and structural data much simpler. The growing amount of structural, pharmacological and physiological data for these receptors indicates the need for a dedicated and accurate database to provide a means to access this information in a coherent manner. 相似文献37.
L.K. Misra S.R. Kasturi S.K. Kundu Y. Harati C.F. Hazlewood M.G. Luthra W.S. Yamanashi R.P. Munjaal S.R. Amtey 《Magnetic resonance imaging》1982,1(2):75-79
Nuclear magnetic resonance (NMR) techniques were applied to study the muscular dystrophy in chicks. The water proton spin-lattice relaxation times (T1) of fast, slow, and mixed muscles and plasma were measured. The T1 values of dystrophic pectoralis major and posterior latissimus dorsi (PLD) were significantly higher than those of the normal pectoralis and PLD muscles. The present results establish a direct relationship between the differences in T1 values and the severity of muscle degeneration. Consistent with this conclusion, it was also found that the T1 values of muscles unaffected in muscular dystrophy, namely, the gastrocnemius, and anterior latissimus dorsi (ALD), were not different between the normal and dystrophic chicks. Although the affected muscles of dystrophic chicks contained higher percent water and fat than those of normal chicks, the results show that the higher T1 values is dystrophic muscles were not solely due to variations in their water content. The increase in the T1 values is principally a result of altered interaction between cellular water and macromolecules in the diseased muscles. These data also point out the potential use of NMR imaging in evaluating muscle degeneration. 相似文献
38.
39.
CdxZn(1−x)S (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) thin films were deposited by the chemical spray pyrolysis technique using a less used combination of chemicals. Depositions were done at 573 K on cleaned glass substrates. The composition, surface morphology and structural properties of deposited films were studied using EDAX, SEM and X-ray diffraction technique. XRD studies reveal that all the films are crystalline with hexagonal (wurtzite) structure and inclusion of Cd into the structure of ZnS improved the crystallinity of the films. The value of lattice constant ‘a’ and ‘c’ have been observed to vary with composition from 0.382 to 0.415 nm and 0.625 to 0.675 nm, respectively. The band gap of the thin films varied from 3.32 to 2.41 eV as composition varied from x = 0.0–1.0. It was observed that presence of small amount of cadmium results in marked changes in the optical band gap of ZnS. 相似文献
40.
An intramolecular cyclization of 17β‐acetoxy‐3‐methoxy‐9,11‐seco‐1,3,5(10)‐estratriene‐11‐oic acid under different Friedel–Crafts reaction conditions is described. 相似文献