Evaluation of renal protective effects of the green-tea (EGCG) and red grape resveratrol: role of oxidative stress and inflammatory cytokines

Epigallocatechin-gallate (EGCG) and resveratrol (RSVL) are two of the most promising natural medicines. We verified their capacity to ameliorate cisplatin (CP)-induced disruption of renal glomerular filtration rate (GFR) in rats, and sought the mediatory involvement of lipid peroxidation (malondialdehyde [MDA]-level) and inflammatory cytokine (TNF-α) therein. CP (10 mg kg?1), a single i.p. dose, disrupted GFR (11-fold-rise in proteinuria, 2-5-fold rise in serum creatinine/urea levels) after 7 days, and killed all animals after 10 days. Kidney-homogenates from CP-treated rats displayed higher MDA and TNF-α, but lower reduced-glutathione (GSH) levels. Rats treated with EGCG (50 mg kg?1, but not 25 mg kg?1) had no fatalities and showed significantly-recovered GFR; while their kidney-homogenates had markedly reduced MDA, TNF-α and enhanced GSH levels at 7 days. Conversely, RSVL or quercetin (25, 50 mg kg?1) neither improved GFR nor reduced (MDA)/TNF-α levels after 7 days. Resuming treatment with 50 mg kg?1 for 10 days rescued only 25% of animals (p > 0.05). Correlation studies showed a significant association between creatinine level, and each of MDA (r = 0.91), GSH (r = -0.87), and TNF-α (0.91). The study showed for the first time that EGCG, unlike RSVL, can protect against CP-induced nephrotoxicity. At the molecular level, CP triggers a high level of oxidative stress and systemic inflammation, events that were all abrogated with EGCG; better than RSVL or quercetin.     

The Webster scalar curvature revisited: the case of the three dimensional CR sphere

In this paper we consider the problem of prescribing the Webster scalar curvature on the three CR sphere of ${\mathbb{C}^{2}}$ . We use techniques related to the theory of critical points at infinity, and obtain existence results for curvature satisfying an assumption of Bahri?CCoron type.     

Syntheses of new benzoxazole derivatives

2‐(Arylidene)cyanomethylbenzoxazoles have been prepared in water from benzoxazole‐2‐ylacetonitriles. Using multi‐component reactions, a variety of heterocycles containing benzoxazole and nitrile functionality has been prepared. J. Heterocyclic Chem., (2011).     

Antimicrobial prospect of newly synthesized 1,3-thiazole derivatives

A new series of 1,3-thiazole and benzo[d]thiazole derivatives 10-15 has been developed, characterized, and evaluated for in vitro antimicrobial activity at concentrations of 25-200 μg/mL against Gram+ve organisms such as methicillin-resistant Staphylococcus aureus (MRSA), Gram-ve organisms such as Escherichia coli (E. coli), and the fungal strain Aspergillus niger (A. niger) by the cup plate method. Ofloxacin and ketoconazole (10 μg/mL) were used as reference standards for antibacterial and antifungal activity, respectively. Compounds 11 and 12 showed notable antibacterial and antifungal activities at higher concentrations (125-200 μg/mL), whereas benzo[d]thiazole derivatives 13 and 14 were found to display significant antibacterial or antifungal activity (50-75 μg/mL) against the Gram+ve, Gram-ve bacteria, or fungal cells used in the present study. In addition, a correlation between calculated and determined partition coefficient (log P) was established which allows future development of compounds within this series to be carried out based on calculated log P values. Moreover, compounds 13 and 14 show that the optimum logarithm of partition coefficient (log P) should be around 4.     

Quantitative and sensitive detection of rare mutations using droplet-based microfluidics

Somatic mutations within tumoral DNA can be used as highly specific biomarkers to distinguish cancer cells from their normal counterparts. These DNA biomarkers are potentially useful for the diagnosis, prognosis, treatment and follow-up of patients. In order to have the required sensitivity and specificity to detect rare tumoral DNA in stool, blood, lymph and other patient samples, a simple, sensitive and quantitative procedure to measure the ratio of mutant to wild-type genes is required. However, techniques such as dual probe TaqMan(?) assays and pyrosequencing, while quantitative, cannot detect less than ～1% mutant genes in a background of non-mutated DNA from normal cells. Here we describe a procedure allowing the highly sensitive detection of mutated DNA in a quantitative manner within complex mixtures of DNA. The method is based on using a droplet-based microfluidic system to perform digital PCR in millions of picolitre droplets. Genomic DNA (gDNA) is compartmentalized in droplets at a concentration of less than one genome equivalent per droplet together with two TaqMan(?) probes, one specific for the mutant and the other for the wild-type DNA, which generate green and red fluorescent signals, respectively. After thermocycling, the ratio of mutant to wild-type genes is determined by counting the ratio of green to red droplets. We demonstrate the accurate and sensitive quantification of mutated KRAS oncogene in gDNA. The technique enabled the determination of mutant allelic specific imbalance (MASI) in several cancer cell-lines and the precise quantification of a mutated KRAS gene in the presence of a 200,000-fold excess of unmutated KRAS genes. The sensitivity is only limited by the number of droplets analyzed. Furthermore, by one-to-one fusion of drops containing gDNA with any one of seven different types of droplets, each containing a TaqMan(?) probe specific for a different KRAS mutation, or wild-type KRAS, and an optical code, it was possible to screen the six common mutations in KRAS codon 12 in parallel in a single experiment.     

Helium- and argon-broadening coefficients of phosphine lines in the ν2 and ν4 bands

Pressure broadening of phosphine lines by helium and argon at room temperature has been experimentally investigated by high-resolution diode-laser spectroscopy. The broadening coefficients are measured for 38 transitions of PH₃ in the ^QR branch of the ν₂ band and in the ^PP and ^RP branches of the ν₄ band. The recorded lines with J values ranging from 3 to 14 and K from 0 to 10 are located between 1062 and 1094 cm⁻¹. The retrieval of the collisional widths is carried out by fitting each spectral line with a Voigt profile, a Rautian profile and a speed-dependent Rautian profile. The latter model provides larger broadening coefficients than the Voigt model. They are also calculated on the basis of a semiclassical model involving the atom-atom Lennard-Jones potential. The theoretical results are in reasonable agreement with the experimental data and reproduce the J and K dependencies of the broadenings.     

Spectrum of relaxation times for ising spin clusters in random fields

Summary Exact results on the single-spin-flip Glauber dynamics of six-coupled random field Ising spins with the coordination number of four are presented. Two distributions of random fields (RF), binary (BD) and Gaussian (GD) ones, are investigated. The effects of the static magnetic field are discussed. In the zero-magnetic-field case, the number of diverging relaxation times is equal to the number of energy minima minus one. This rule breaks in the presence of a magnetic field. The longest relaxation times in the absence of the field verify the Arrhenius law with the energy barrier determined by the energy needed to invert the ground-state spin configuration. At low temperature, according to the Arrhenius law, the spectrum of relaxation times shows a two-peaked distribution on a logarithmic scale. In the GD case of RF, the energy barrier distribution is continuous, while it is quasi-discrete in the BD case.     

Numerical simulation for the flow inside V-shapes using grid generation

In this paper, we determined a numerical solution of the Navier-Stokes equations for the flow of incompressible fluid inside the contraction geometry. The governing equations are written in the vorticity-stream function formulations. The numerical solution is based on a technique of automatic numerical generation of a curvilinear coordinate system by transforming the governing equation into the computational plane. The transformed equations are approximated using central differences and solved simultaneously by the alternating direction implicit method and successive over relaxation iteration method.     

Three-dimensional visualization of diffusion flame shapes under acoustic excitation using stereoscopic imaging and reconstruction technique

Stereoscopic imaging and reconstruction technique is introduced to reconstruct the flame structures that are subject to acoustic excitation. The laminar diffusion flame under investigation was created in a cylindrical tube and excited by a loudspeaker. Stereo images were taken at a shutter speed of 1/10000^th second using a ‘stereo camera’ and the depth cue of the flame structures along the camera viewing direction were then computed using machine vision methodology. By visualizing the computed three-dimensional flame models, as well as judging the corresponding attribute such as surface gradient, the understanding of the flame and acoustic wave interaction could be improved.     

Effect of quantum entanglement on Aharonov-Bohm oscillations, spin-polarized transport and current magnification effect

We present a simple model of transmission across a metallic mesoscopic ring. In one of its arm an electron interacts with a single magnetic impurity via an exchange coupling. We show that entanglement between electron and spin impurity states leads to reduction of Aharonov-Bohm oscillations in the transmission coefficient. The spin-conductance is asymmetric in the flux reversal as opposed to the two-probe electrical conductance which is symmetric. In the same model, in contradiction to the naive expectation of a current magnification effect, we observe enhancement as well as suppression of this effect depending on the system parameters. The limitations of this model to the general notion of dephasing or decoherence in quantum systems are pointed out.