Age and Growth of Spotted Snakehead,Channa punctata from the Ganga River

Journal of Ichthyology - The present study was undertaken to estimate age and growth of the spotted snakehead Channa punctata (Bloch, 1793) from the Ganga River, based on 390 fish samples collected...     

Structural basis of ligand recognition by PABC, a highly specific peptide-binding domain found in poly(A)-binding protein and a HECT ubiquitin ligase

The C-terminal domain of poly(A)-binding protein (PABC) is a peptide-binding domain found in poly(A)-binding proteins (PABPs) and a HECT (homologous to E6-AP C-terminus) family E3 ubiquitin ligase. In protein synthesis, the PABC domain of PABP functions to recruit several translation factors possessing the PABP-interacting motif 2 (PAM2) to the mRNA poly(A) tail. We have determined the solution structure of the human PABC domain in complex with two peptides from PABP-interacting protein-1 (Paip1) and Paip2. The structures show a novel mode of peptide recognition, in which the peptide binds as a pair of beta-turns with extensive hydrophobic, electrostatic and aromatic stacking interactions. Mutagenesis of PABC and peptide residues was used to identify key protein-peptide interactions and quantified by isothermal calorimetry, surface plasmon resonance and GST pull-down assays. The results provide insight into the specificity of PABC in mediating PABP-protein interactions.     

"Distant spin trapping": a method for expanding the availability of spin trapping measurements

The technique of spin trapping is used to study a wide range of free radicals in various systems, including those generated in vitro and in vivo. But unfortunately, EPR spectrometers are not always immediately accessible at the site of experimentation, and therefore it is important to find a method that can preserve a radical adduct over longer periods of time. We describe here an alternative method in which the samples can be frozen and transported for EPR measurements at another site. Various spin adducts of DEPMPO were frozen and measured at 0 degrees C at various intervals after freezing to determine their stability in the frozen state. The radical adducts were generated by established methods and stored at two different temperatures; -196 degrees C (liquid nitrogen) and -80 degrees C (dry ice). The experiments were carried out in an aqueous solution with and without a model of reducing environment (2 mM ascorbate). The results indicate that it is feasible to store and transport spin adducts for subsequent analysis. We conclude that this approach, which we term "distant spin trapping", makes it feasible to transport samples to another site for EPR measurements. This should significantly expand the ability to use spin trapping in biology and medicine.     

Towards thermally stable cyclophanediene-dihydropyrene photoswitches

Cyclophanediene dihydropyrenes (CPD-DHP) are photochromic compounds because they change their color by irradiation with lights of different color. Potential use of CPD-DHP photoswitch in memory devices requires a very slow thermal return in the dark in the absence of any side reaction. Herein, thermal return of CPDs to DHPs, and an unwanted sigmatropic shift in DHP is studied through density functional theory calculations at (U)B3LYP/6-31+G(d). The thermal return occurs through symmetry forbidden conrotatory electrocyclic reaction. Dimethyl amino CPD-DHP photoswitch pair has the highest activation barrier for electrocyclization and sigmatropic shifts. The lowest activation barrier for symmetry forbidden electrocyclization is observed for GeBr₃ functionalized CPD. An unprecedented decomposition pathway involving elimination of the internal substituents is predicted for Cl, Br and SMe functionalized DHPs. This study shows great promise in understanding the Woodward Hoffmann forbidden processes and, in reducing the synthetic efforts toward robust photochromes for memory applications.     

Endothelial influences on cerebrovascular tone.

The cerebrovascular endothelium exerts a profound influence on cerebral vessels and cerebral blood flow. This review summarizes current knowledge of various dilator and constrictor mechanisms intrinsic to the cerebrovascular endothelium. The endothelium contributes to the resting tone of cerebral arteries and arterioles by tonically releasing nitric oxide (NO*). Dilations can occur by stimulated release of NO*, endothelium-derived hyperpolarization factor, or prostanoids. During pathological conditions, the dilator influence of the endothelium can turn to that of constriction by a variety of mechanisms, including decreased NO* bioavailability and release of endothelin-1. The endothelium may participate in neurovascular coupling by conducting local dilations to upstream arteries. Further study of the cerebrovascular endothelium is critical for understanding the pathogenesis of a number of pathological conditions, including stroke, traumatic brain injury, and subarachnoid hemorrhage.     

Periodontal Treatment for Preventing Adverse Pregnancy Outcomes: A Meta- and Trial Sequential Analysis

Objectives

Periodontal treatment might reduce adverse pregnancy outcomes. The efficacy of periodontal treatment to prevent preterm birth, low birth weight, and perinatal mortality was evaluated using meta-analysis and trial sequential analysis.

Methods

An existing systematic review was updated and meta-analyses performed. Risk of bias, heterogeneity, and publication bias were evaluated, and meta-regression performed. Subgroup analysis was used to compare different studies with low and high risk of bias and different populations, i.e., risk groups. Trial sequential analysis was used to assess risk of random errors.

Results

Thirteen randomized clinical trials evaluating 6283 pregnant women were meta-analyzed. Four and nine trials had low and high risk of bias, respectively. Overall, periodontal treatment had no significant effect on preterm birth (odds ratio [95% confidence interval] 0.79 [0.57-1.10]) or low birth weight (0.69 [0.43-1.13]). Trial sequential analysis demonstrated that futility was not reached for any of the outcomes. For populations with moderate occurrence (<20%) of preterm birth or low birth weight, periodontal treatment was not efficacious for any of the outcomes, and trial sequential analyses indicated that further trials might be futile. For populations with high occurrence (≥20%) of preterm birth and low birth weight, periodontal treatment seemed to reduce the risk of preterm birth (0.42 [0.24-0.73]) and low birth weight (0.32 [0.15-0.67]), but trial sequential analyses showed that firm evidence was not reached. Periodontal treatment did not significantly affect perinatal mortality, and firm evidence was not reached. Risk of bias, but not publication bias or patients’ age modified the effect estimates.

Conclusions

Providing periodontal treatment to pregnant women could potentially reduce the risks of perinatal outcomes, especially in mothers with high risks. Conclusive evidence could not be reached due to risks of bias, risks of random errors, and unclear effects of confounding. Further randomized clinical trials are required.     

Optimal and Numerical Solutions for an MHD Micropolar Nanofluid between Rotating Horizontal Parallel Plates

The present analysis deals with flow and heat transfer aspects of a micropolar nanofluid between two horizontal parallel plates in a rotating system. The governing partial differential equations for momentum, energy, micro rotation and nano-particles concentration are presented. Similarity transformations are utilized to convert the system of partial differential equations into system of ordinary differential equations. The reduced equations are solved analytically with the help of optimal homotopy analysis method (OHAM). Analytical solutions for velocity, temperature, micro-rotation and concentration profiles are expressed graphically against various emerging physical parameters. Physical quantities of interest such as skin friction co-efficient, local heat and local mass fluxes are also computed both analytically and numerically through mid-point integration scheme. It is found that both the solutions are in excellent agreement. Local skin friction coefficient is found to be higher for the case of strong concentration i.e. n=0, as compared to the case of weak concentration n=0.50. Influence of strong and weak concentration on Nusselt and Sherwood number appear to be similar in a quantitative sense.     

A role for two‐pore potassium (K2P) channels in endometrial epithelial function

The human endometrial epithelium is pivotal to menstrual cycle progression, implantation and early pregnancy. Endometrial function is directly regulated by local factors that include pH, oxygen tension and ion concentrations to generate an environment conducive to fertilization. A superfamily of potassium channels characterized by two‐pore domains (K2P) and encoded by KCNK genes is implicated in the control of the cell resting membrane potential through the generation of leak currents and modulation by various physicochemical stimuli. The aims of the study were to determine the expression and function of K2P channel subtypes in proliferative and secretory phase endometrium obtained from normo‐ovulatory women and in an endometrial cancer cell line. Using immunochemical methods, real‐time qRT‐PCR proliferation assays and electrophysiology. Our results demonstrate mRNA for several K2P channel subtypes in human endometrium with molecular expression of TREK‐1 shown to be higher in proliferative than secretory phase endometrium (P < 0.001). The K2P channel blockers methanandamide, lidocaine, zinc and curcumin had antiproliferative effects (P < 0.01) in an endometrial epithelial cancer cell line indicating a role for TASK and TREK‐1 channels in proliferation. Tetraethylammonium‐ and 4‐aminopyridine‐insensitive outwards currents were inhibited at all voltages by reducing extracellular pH from 7.4 to 6.6. Higher expression of TREK‐1 expression in proliferative phase endometrium may, in part, underlie linked to increased cell division. The effects of pH and a lack of effect of non‐specific channel blockers of voltage‐gated potassium channels imply a role for K2P channels in the regulation of human endometrial function.     

Mitigation of salinity-induced negative impact on the growth and yield of wheat by plant growth-promoting rhizobacteria in naturally saline conditions

Salinity is one of the major environmental threats for successful crop production, hampering plant growth due to the osmotic effect and nutritional and hormonal imbalances. The application of naturally occurring plant growth-promoting rhizobacteria (PGPR) is an emerging technology aimed at ameliorating the negative impact of salinity. However, the results obtained in the laboratory can sometimes not be reproduced in the field. The aim of the study reported here was to evaluate the effect of PGPR inoculation on seed germination in a saline environment under axenic conditions and on enhancement of the growth and yield of wheat under natural salt-affected field conditions. Wheat seeds were inoculated with pre-isolated strains of Pseudomonas putida, Enterobacter cloacae, Serratia ficaria, and Pseudomonas fluorescens and sown at different salinity levels (1, 2, 3, 6, 9, 12, 15 dS m^-1). Inoculation with these strains was found to enhance the germination percentage, germination rate, and index of wheat seeds up to 43, 51, and 123 %, respectively, over the uninoculated control at the highest salinity level. The potential of these PGPR for improving the growth and yield of wheat was also evaluated at two natural salt-affected sites. Inoculation with PGPR resulted a significant increase in the growth and yield parameters of wheat at both sites. The inoculated plants also improved the nutrient status of the wheat plants. The inoculated plants had low sodium and high nitrogen, phosphorus, and potassium contents. Our results show that such rhizobacterial strains may be used as an effective tool for enhancing plant growth under salinity stress and for maximizing the utilization of salt-affected soils.