Antimicrobial potentiality of Phyllanthus amarus against drug resistant pathogens

The antimicrobial potentiality of the methanolic extract of Phyllanthus amarus (Family: Euphorbiaceae) was studied against some drug resistant pathogenic bacterial strains by disc diffusion and agar dilution method. The extract showed significant concentration-dependent antibacterial activity particularly against gram-negative microbes. The study illustrated the claim of the usefulness of the plant in dysenteric and diarrheal infections and also suggested its use in fever. The antibacterial action was mainly due to the isolated phyllanthin.     

二阶流体通过径向延伸平面时滑移、黏性耗散、焦耳热对MHD流动的影响

研究了二阶导电的非Newton流体,在一个可径向放射状延伸,并伴有部分滑动表面上的流动及其热交换.部分滑移用一个无量纲的滑移因子控制,其取值范围从0(全黏着)到无穷大(全滑移).使用适当的相似变换,把待求的非线性偏微分方程转化为常微分方程.讨论了边界条件的不足,在无需增加任何边界条件下,使用有效的数值格式,求解所得到的微分方程.部分滑移、磁场交互参数以及二阶流体的参数对速度场和温度场的综合分析发现,滑移量的增加,流体的动力边界层和热边界层增厚.因为当滑移量的增加,允许更多的流体通过该平面,表面摩擦因数的数值下降,并在更高的滑移参数下,摩擦因数趋于0,即流体无黏性地通过.还研究了磁场对速度场和温度场的重要影响.     

Experimental Determination of NH3 Solubility in Toluene at Pressures up to 340 kPa at 398 K

Journal of Solution Chemistry - The solubility of ammonia in toluene has been measured at 398 K and at pressures up to 340 kPa using a static, synthetic and isochoric technique....     

A Bioinspired Approach for Shaping Au Nanostructures: The Role of Biomolecule Structures in Shape Evolution

A new approach for shaping Au nanostructures by tuning the molecular structure of biomolecules has been explored. Different molecules, such as catechol, rutin, and quercetin, which have structural similarity to the catechol ring, were used to induce Au nanostructures under similar conditions. The as‐synthesized nanostructures are characterized by using TEM, XPS, XRD, and UV/Vis spectral measurements. The growth mechanism for the formation of these noble metal shapes and the role of the molecular structure of the stabilizing/reducing agent were investigated by using TEM and UV/Vis spectral measurements. The structure and functional groups of the reducing/stabilizing agent play a vital role in the shape evolution of nanostructures. The electrocatalytic activity of different nanostructures in the reduction of oxygen was investigated and was found to be shape‐dependent.     

Quantum chromodynamics phase transition in the early Universe and quark nuggets

A first-order quark hadron phase transition in the early Universe may lead to the formation of quark nuggets. The baryon number distribution of these quark nuggets have been calculated and it has been found that there are sizeable number of quark nuggets in the stable sector. The nuggets can clump and form bigger objects in the mass range of 0.0003M⊙ to 0.12M⊙. It has been discussed that these bigger objects can be possible candidates for cold dark matter.     

Effect of colour singletness of quark-gluon plasma in quark-hadron phase transition

Consequences of the constraint of SU(3) colour singletness of quark-gluon plasma are studied. This restriction increases the free energy barrier for the formation of hadronic bubble in supercooled phase and influences significantly the dynamics of the initial stage of quark-hadron phase transition. It also introduces terms dependent on the volume occupied by the plasma in the energy density and the pressure. These modifactions vanish in the limit of an infinite volume. The last stage of the hadronization of the QGP likely to be formed in relativistic heavy ion collisions is necessarily characterized by a decreasing volume containing the quark matter, and thus these corrections become important. The nucleation of plasma droplets at AGS energies is also seen to be strongly affected by the requirement of colour singletness, and the choice of prefactor. Received: 4 December 1997 / Published online: 15 May 1998     

Development of a honeycomb gas proportional counter array for photon multiplicity measurements in high multiplicity environment

A novel gas-based detector using large arrays of honeycomb cells has been developed and tested for use as a pre-shower photon multiplicity detector (PMD) for STAR and ALICE experiments. The appropriate cell design was arrived at using GARFIELD simulations. Prototype chambers with cell dimensions corresponding to STAR and ALICE were fabricated and tested at CERN PS and SPS. The charged particle detection efficiency and the pre-shower characteristics have been studied using pion and electron beams.     

Synthesis of electron deficient acene derivatives via a bidirectional iterative elongation reaction

Previously, we developed an iterative elongation methodology to synthesize acene esters, nitriles, and imides. The strategy uses the concept of bidirectional synthesis, and we can now make a series of electron deficient anthracene, tetracene, and pentacene derivatives via the bidirectional iterative elongation protocol. Central units, used to initiate the bidirectional elongation, were synthesized by employing a double anionic Fries rearrangement as the key step. The photophysical and electrochemical properties of these novel electron acceptors are investigated and interpreted based on the electron withdrawing power of the substitutions. An excited state charge transfer was proposed for one compound to account for its peculiar fluorescent behavior.     

Development and validation of a liquid chromatography-tandem mass spectrometry method to determine ulifloxacin, the active metabolite of prulifloxacin in rat and rabbit plasma: application to toxicokinetic study

A simple, high‐throughput and specific high‐performance liquid chromatography–tandem mass spectrometry method has been developed and validated according to the FDA guidelines for quantification of ulifloxacin in rat and rabbit plasma. The analyte was separated on a Peerless basic C₁₈ column (33 × 4.6 mm, 3 µm) with an isocratic mobile phase of methanol–water containing formic acid (0.5%, v/v; 9:1, v/v) at a flow rate of 0.5 mL/min. The MS/MS detection was carried out by monitoring the fragmentation of m/z 350.500 → 248.500 for ulifloxacin and m/z 332.400 → 231.400 for ciprofloxacin (internal standard; IS) on a triple quadrupole mass spectrometer. The response to ulifloxacin was linear over the range 0.010–2.500 µg/mL in both plasma. The limit of detection and lower limit of quantification of ulifloxacin were determined in both species to be 0.0025 and 0.010 µg/mL, respectively. The method was successfully applied to quantitatively assess the toxicokinetics of ulifloxacin in rat and rabbit following a single 400 mg/kg (in rat) and 200 mg/kg (in rabbit) oral dose of the prulifloxacin. Copyright © 2010 John Wiley & Sons, Ltd.