Chemical speciation of L-glutamine complexes with Co(II), Ni(II) and Cu(II) in cationic micellar medium

The impact of cationic micelles on the protonation equilibria of L-glutamine and chemical speciation of its complexes with Co(II), Ni(II) and Cu(II) have been studied by monitoring hydrogen ion concentration pH metrically at 303 K and at an ionic strength of 0.16 M. The protonation constants and binary stability constants have been calculated with the computer program MINIQUAD75. The best fit chemical models are selected based on standard deviations in the model parameters and residual analysis using crystallographic R-factor and sum of squares of residuals in all mass-balance equations. The trend in the variation of stability constants of the complexes with mole fraction of the surfactant is attributed to the compartmentalization of complexation equilibria. Distribution of species and effect of influential parameters on chemical speciation have also been presented. KEY WORDS: Chemical speciation, complex equilibria, L-glutamine, cationic micelles Bull. Chem. Soc. Ethiop. 2012, 26(3), 383-394.DOI: http://dx.doi.org/10.4314/bcse.v26i3.

Study of gastrointestinal toxicity of selective COX-2 inhibitors in comparison with conventional NSAIDs

Background: Adverse gastrointestinal events are the commonest unwanted effects of the NSAIDs, and are believed to result mainly from the inhibition of gastric COX-1, which is responsible for the synthesis of prostaglandins that normally inhibit acid secretion and protect the mucosa. Previous studies report, that selective COX-2 inhibitors are safer when compared to non-selective cyclooxygenase inhibitors, regarding their adverse effects on gastrointestinal system. But, recent studies reveal, that gastrointestinal safety of these selective COX-2 inhibitors is not much better than that of conventional NSAIDs. In view of the wider usage of selective COX-2 inhibitors, the study has been taken up to report, whether selective COX-2 inhibitors have got any advantages over conventional NSAIDs or not, in regard to their gastrointestinal side effects.Methods: Patients were divided into eight groups, fifteen patients of each. Each group was given one of the NSAIDs from the eight drugs those were selected for the study, for 15 days. In the selected group, along with the symptomatic assessment of gastric toxicity, both pre and post-treatment values of Hb% are estimated, tabulated & subjected to statistical analysis.Results: Both the drugs, diclofenac & meloxicam have shown significant changes in the Hb% values (‘p’ value 0.02 each), whereas selective COX-2 inhibitors like nimesulide & celecoxib were no less in gastric toxicity, in comparison with diclofenac, on symptomatic assessment.Conclusions: In our short-term study, selective COX-2 inhibitors did not show any advantage over non-selective NSAIDs regarding their gastrointestinal toxicity

Umbilical true knot: a case study

Umbilical cord true knot is a rare condition which affects about 1% of all pregnancies. The incidence is not only very low, but it is often undiagnosed antenatally when present despite the availability of prenatal ultrasonography as in this case, where the diagnosis of true knot of umbilical cord was missed even when an ultrasonogram was done 1 week prior to the presentation of patient with decreased fetal movements to opd. Majority of times it does not have any relation with fetal outcome but in certain occasions it is associated with intrauterine fetal demise as in present case presented here. Risk factors include long umbilical cord, polyhydramnios, small fetus, male fetus, etc

SCALABLE FRAMEWORK WITH IDENTICAL MEMORY DIES TO ACHIEVE HIGH-CLOCK FREQUENCY

Our design implements a scalable 3-D-nonuniform memory access (NUMA) architecture according to low latency logarithmic interconnects, which enables stacking of multiple identical memory dies (MDs), supports multiple outstanding transactions, and achieves high clock frequencies because of its highly pipelined nature. We implemented our design with STMicroelectronics CMOS-28-nm low-power technology and acquired time frequency of 500 MHz, as much as eight stacked dies (4 MB) having a memory density loss. Large needed size, and ability to tolerate latency and variations in memory access time make L2 memory a appropriate choice for 3-D integration. Within this paper, we present a synthesizable 3-D-stacking L2 memory IP component, which may be mounted on a cluster-based multicore platform through its network-on-nick interfaces offering high-bandwidth memory access with low average latency. Benchmark simulation results show adding 3-D-NUMA to some multicluster system can result in a typical performance boost of 34%. In addition, experiments and estimations make sure 3-D-NUMA is energy and power efficient, temperature friendly, and it has improvements appropriate for low-cost manufacturing. Finally, improvement is quite possible in 3-D-NUMA in contrast to its 2-D counterparts, while using condition from the art through-plastic-via technologies

Simulation of High Step-Up Resonant Parallel LC Converter for Grid Connected Renewable Energy Sources

With the rapid improvement of large-scale renewable energy sources and HVDC grid, it is a capable alternative to connect the renewable energy sources to the HVDC grid with a pure dc system, in which high-power high-voltage step-up dc–dc converters are the key equipment to transmit the electrical energy. This paper presents a High step up LC converter it can achieve high voltage gain using an LC parallel resonant tank.Also provided zero voltage switching (ZVS) technology under switch turn-On condition also at turn-Off conditions at main power switches by rectifying diodes to reduce the conduction losses. The operation principle of the converter and its resonant parameter selection is presented in this paper. The operation principle of the converter has been successfully verified with the help of MATLAB/SIMULINK

Friend Turns Foe: Transformation of Anti-Inflammatory HDL to Proinflammatory HDL during Acute-Phase Response

High-density lipoprotein (HDL) is a major carrier of cholesterol in the blood. Unlike other lipoproteins, physiological functions of HDL influence the cardiovascular system in favorable ways except when HDL is modified pathologically. The cardioprotective mechanism of HDL is mainly based on reverse cholesterol transport, but there has been an emerging interest in the anti-inflammatory and antioxidant roles of HDL. These latter activities of HDL are compromised in many pathological states associated with inflammation. Further, abnormal HDL can become proinflammatory contributing to oxidative damage. In this paper, we discuss the functional heterogeneity of HDL, how alterations in these particles in inflammatory states result in loss of both antioxidant activity and reverse cholesterol transport in relation to atherosclerosis, and the need for assays to predict its functionality

Post traumatic biparietal mirror Extradural haematoma: A case report and review of literature

Bilateral extradural haematomas [EDH] are rare and it is an uncommon consequense of cranio cerebral trauma. The mortality is higher than unilateral extradural haematoma and management of extradural haematomas requires careful planning, judicial surgical exposure and most important is timing of evacuation of extradural haematomas. Emergency evacuation of bilateral extradural haematomas were performed in this case with uneventful postoperative period. The pathophysiology and surgical nuances of this rare entity been discussed

From rods to helices: evidence of a screw-like nematic phase

Evidence of a special chiral nematic phase is provided using numerical simulation and Onsager theory for systems of hard helical particles. This phase appears at the high density end of the nematic phase, when helices are well aligned, and is characterized by the C$_2$ symmetry axes of the helices spiraling around the nematic director with periodicity equal to the particle pitch. This coupling between translational and rotational degrees of freedom allows a more efficient packing and hence an increase of translational entropy. Suitable order parameters and correlation functions are introduced to identify this screw-like phase, whose main features are then studied as a function of radius and pitch of the helical particles. Our study highlights the physical mechanism underlying a similar ordering observed in colloidal helical flagella [E. Barry et al. \textit{Phys. Rev. Lett.} \textbf{96}, 018305 (2006)] and raises the question of whether it could be observed in other helical particle systems, such as DNA, at sufficiently high densities.Comment: List of authors correcte

Genetic structure of Indian populations based on fifteen autosomal microsatellite loci

BACKGROUND: Indian populations endowed with unparalleled genetic complexity have received a great deal of attention from scientists world over. However, the fundamental question over their ancestry, whether they are all genetically similar or do exhibit differences attributable to ethnicity, language, geography or socio-cultural affiliation is still unresolved. In order to decipher their underlying genetic structure, we undertook a study on 3522 individuals belonging to 54 endogamous Indian populations representing all major ethnic, linguistic and geographic groups and assessed the genetic variation using autosomal microsatellite markers. RESULTS: The distribution of the most frequent allele was uniform across populations, revealing an underlying genetic similarity. Patterns of allele distribution suggestive of ethnic or geographic propinquity were discernible only in a few of the populations and was not applicable to the entire dataset while a number of the populations exhibited distinct identities evident from the occurrence of unique alleles in them. Genetic substructuring was detected among populations originating from northeastern and southern India reflective of their migrational histories and genetic isolation respectively. CONCLUSION: Our analyses based on autosomal microsatellite markers detected no evidence of general clustering of population groups based on ethnic, linguistic, geographic or socio-cultural affiliations. The existence of substructuring in populations from northeastern and southern India has notable implications for population genetic studies and forensic databases where broad grouping of populations based on such affiliations are frequently employed

ESTIMATION OF PAROXETINE HYDROCHLORIDE FROM ITS TABLET FORMULATION BY UV SPECTROPHOTOMETRY

A simple, precise and accurate UV Spectrophotometric method was developed for the estimation of Paroxetine hydrochloride. The developed method obeyed Beer-Lambert’s law in the concentration range of 5-30 µg/ml with a correlation coefficient of 0.995. The recovery study was carried out at three different levels and was found to be satisfactory. The percent amount of drug estimated by this method is 100%, found to be in good agreement with label claim of marketed tablet formulation. The validation parameters like linearity, precision, accuracy, robustness and ruggedness were studied and were found to be within limits. The proposed method can be adopted for routine quality control analysis of estimation of Paroxetine hydrochloride in pharmaceutical formulation