Molecular tailoring approach for geometry optimization of large molecules: Energy evaluation and parallelization strategies

A linear-scaling scheme for estimating the electronic energy, gradients, and Hessian of a large molecule at ab initio level of theory based on fragment set cardinality is presented. With this proposition, a general, cardinality-guided molecular tailoring approach (CG-MTA) for ab initio geometry optimization of large molecules is implemented. The method employs energy gradients extracted from fragment wave functions, enabling computations otherwise impractical on PC hardware. Further, the method is readily amenable to large scale coarse-grain parallelization with minimal communication among nodes, resulting in a near-linear speedup. CG-MTA is applied for density-functional-theory-based geometry optimization of a variety of molecules including alpha-tocopherol, taxol, gamma-cyclodextrin, and two conformations of polyglycine. In the tests performed, energy and gradient estimates obtained from CG-MTA during optimization runs show an excellent agreement with those obtained from actual computation. Accuracy of the Hessian obtained employing CG-MTA provides good hope for the application of Hessian-based geometry optimization to large molecules.The authors thank C-DAC, UGC (CAS program to the University of Pune) and the Council of Scientific and Industrial Research (CSIR), New Delhi for financial assistance

Preliminary Pharmacological Screening of Ethanolic Extract of Aristoochia indica on Nephrolithiasis Rat

The effect of ethanolic extract of Aristolochia indica was studied on experimentally induced nepharolithatic and urolithuasis in rats. Oxalate urolithiasis was produced by the addition of 0.75% ethylene glycol in the diet for a period for 30 days. Ethylene glycol treatment resulted in a significant increase in the levels of calcium and oxalate. Treatment of ethanolic extract of Aristolochia indica 100mg/kg body weight for 30 days revealed a dose –related effect in the reduction of lithogenic substances, following glycolic acid induced urolithiasis. Simultaneous oral treatment with at a dose of ethanolic extract of Aristolochia indica 100mg/kg for 30 days significantly reversed the ethylene glycol induced nepharolithiasis and urolithiasis. Presumably by preventing the urinary supersaturation of lithogenic substances. Especially of oxalate and calcium. These observation indicate that ethanolic extract of Aristolochia indica can play an important role in the prevention of disorders associated with kidney stone formation

Distortion Analysis of CMOS Based Analog Circuits

The amplifiers are the vital part of the analog circuit designs. The linearity of the CMOS is of most important concern in the design of many analog circuits. There are several aspects regarding nonlinear distortion analysis in analog circuits implemented in CMOS technology. Basically, the investigations visualize the nature of the total harmonic distortion (THD) dependence on the amplitude and frequency of the input signals. In this paper, the basic building blocks of analog integrated circuits such as Common source amplifier with diode connected load and Differential amplifier with current mirror load have been presented for distortion analysis. The MOSFET model used for simulation is BSIM3 SPICE model from 0.13-μm and BSIM4 SPICE model from 22-μm CMOS process technology. HSPICE circuit simulator tool is used for distortion analysis of CMOS circuits. It is evident that the above function gives remarkable insight of the nonlinear behavior of the considered circuits and it is worth considering for further investigations

Exploring the adequacy of informed consent for caesarean section at a tertiary care center

Background: The objective was to study adequacy of valid informed consent in caesarean section and to quantify the proportion of patients who receive a proper informed consent before undergoing caesarean section.Methods: A cross-sectional questionnaire-based study involving 200 registered antenatal women undergoing caesarean section for various reasons both as elective or emergency basis, and data was analyzed.Results: Among the study group, 98.5% patients were informed about the said procedure in their own local language and consent was taken, in 3 (1.5%) patients informed consent was not taken. Detailed procedure was explained to only 29 patients (14.5%) whereas 171 patients (85.5%) had no clue about the detailed nature of the procedure. 193 patients (96.5%) were satisfied with the given informed patients; 7 patients (3.5%) were not satisfied.Conclusions: Women need consistent and adequate information for consent. Sessions should be held regarding the procedure, its risks and benefits; in this way patient will undergo the procedure with proper knowledge, awareness and confidence.

Synthesis and Pharmacological Evaluation of Pyrazoline and Pyrimidine Analogs of Combretastatin-A4 as Anticancer, Anti-inflammatory and Antioxidant Agents

A library of 3,5-diaryl-1-carbothioamide-pyrazoline (5a–j), N1-phenyl sulfonyl pyrazoline (6a–e) and pyrimidine (7a) analogs of combretastatin-A4 were synthesized and evaluated for their in vitro anticancer, anti-inflammatory and antioxidant activity. Results of in vitro assay against human breast cancer cell line (MCF-7) showed several compounds endowed with significant cytotoxicity compared to the adriamycin, a standard anticancer drug. Among the compounds synthesized, 7a was found to possess significant antiproliferative activity (GI50 < 0.1 µM) against the MCF-7 cell line as good as adriamycin (GI50 < 0.1 µM) whereas, compounds 6c, 5j and 5g also displayed good cytotoxicity (GI50 = 25.3–42.6 µM). Besides this, most active compound 7a was also evaluated against human myeloid leukemia cell line K562 and the remarkable result was obtained with GI50 < 0.1 µM, comparable to that of adriamycin (GI50 < 0.1 µM). In addition, all the synthesized compounds were evaluated for their anti-inflammatory and antioxidant activity. The percent inhibition studies revealed that most of the compounds were found to possess substantial anti-inflammatory and antioxidant activities. This work is licensed under a Creative Commons Attribution 4.0 International License

Design, Synthesis, and Spectroscopic Study of 7-Azaindolyl Hydrazones with Anti-Breast Cancer Activity

A series of 7-azaindolyl hydrazones were prepared by reacting of hydrazides of 7-azaindole-3-acetic acids with aromatic aldehydes and N-substituted indolyl-3-carboxyaldehydes. Structure of all the synthesized compounds were satisfactorily correlated by IR, 1H NMR, 13C NMR and mass spectroscopic evidences. The synthesized compounds were evaluated for their possible anticancer potential against MCF-7 induced breast carcinoma. It is worth mentioning that most of the compounds were considerably active against MCF-7 cell line with GI50 values ranging from 22.3–81.0 μM. The hydrazones of N-1-substituted indole-3-carboxyaldehydes 9f, 9g, 9h, 9c, and 9j were active against MCF-7 cell line with GI50 values less than 40 μM (GI50 = 22.3 and 24.9, 29.6, 30.2 and 37.8 μM respectively) with moderate TGI values (TGI = 56.6, 59.5, 65.5, 70.7 and 94.6 μM respectively). The active compounds were also screened against the normal Vero monkey cell line, which showed moderate selectivity against inhibition of cancer cells. This work is licensed under a Creative Commons Attribution 4.0 International License

Productivity and nitrogen use efficiency of rice under conventional and organic nutrition

The current study demonstrates the influence of conventional and organic nutrient management practices on nitrogen use efficiency, growth, yield, and physiological and biochemical parameters in four rice varieties, namely, Jaiva, Ezhome 2, Jyothi and Uma. Growth parameters, grain yield per hill, and physiological and biochemical parameters were higher under conventional management for all rice varieties. Although the nitrogen use efficiency of each variety varied significantly with nutrient management practices, the variation was least in Jaiva (23.8%), which is the organic rice variety released by Kerala Agricultural University. The rice varieties Jaiva and Ezhome 2 showed consistency in the grain weight per panicle under both conventional (Jaiva- 4.57 g, Ezhome 2- 5.86 g) and organic (Jaiva, 4.24 g, Ezhome 2, 4.54 g) management. The soil nitrogen content at the tillering stage (0.66**) showed a significantly higher positive correlation with nitrogen use efficiency under organic management. The results of the study provide a better understanding of factors that can lead to a sustained yield in organic rice production in terms of nitrogen use efficiency