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1.
PAPER CURRENT
Design and synthesis of new series of coumarin-aminopyran derivatives possessing potential anti-depressant-like activity (2014)
Publication Date: 2014-11-22
Description: Publication date: Available online 20 November 2014 Source:Bioorganic & Medicinal Chemistry Letters Author(s): Koneni V. Sashidhara , Ram K. Modukuri , Seema Singh , K. Bhaskara Rao , G. Aruna Teja , Sampa Gupta , Shubha Shukla A new series of coumarin based aminopyran derivatives were designed, synthesized and evaluated for their preclinical antidepressant effect on Swiss albino mice. Among the series, compounds 21, 25, 26, 27, 32 and 33 exhibited significant activity profile in forced swim test (FST). Compound 27 was most efficacious, which at a very low dose of 0.5 mg/kg reduced the time of immobility by 86.5% as compared to the standard drug fluoxetine (FXT) which reduced the immobility time by 69.8% at the dose of 20 mg/kg, i.p. In addition, all active compounds were screened in dose dependent manner (at doses of 0.25, 0.5, 1 mg/kg i.p) in FST and tail suspension test (TST). Interestingly, all active compounds did not exhibit any significant change on locomotor activity of mice as compared to control, indicating that the hybrids did not produce any motor impairment effects. The results indicate that coumarin-aminopyran derivatives may have potential therapeutic value for the management of mental depression. Graphical abstract
Print ISSN: 0960-894X
Electronic ISSN: 1464-3405
Topics: Chemistry and Pharmacology , Medicine
Published by Elsevier
2.
PAPER CURRENT
Bayesian neural networks for detecting epistasis in genetic association studies (2014)
Publication Date: 2014-11-22
Description: Background:Discovering causal genetic variants from large genetic association studies poses many difficult challenges. Assessing which genetic markers are involved in determining trait status is a computationally demanding task, especially in the presence of gene-gene interactions.Results:A non-parametric Bayesian approach in the form of a Bayesian neural network is proposed for use in analyzing genetic association studies. Demonstrations on synthetic and real data reveal they are able to efficiently and accurately determine which variants are involved in determining case-control status. By using graphics processing units (GPUs) the time needed to build these models is decreased by several orders of magnitude. In comparison with commonly used approaches for detecting interactions, Bayesian neural networks perform very well across a broad spectrum of possible genetic relationships.Conclusions:The proposed framework is shown to be a powerful method for detecting causal SNPs while being computationally efficient enough to handle large datasets.
Electronic ISSN: 1471-2105
Topics: Biology , Computer Science
Published by BioMed Central
3.
PAPER CURRENT
A fast algorithm for determining bounds and accurate approximate p -values of the rank product statistic for replicate experiments (2014)
Publication Date: 2014-11-22
Description: Background:The rank product method is a powerful statistical technique for identifying differentially expressed molecules in replicated experiments. A critical issue in molecule selection is accurate calculation of the p-value of the rank product statistic to adequately address multiple testing. Both exact calculation and permutation and gamma approximations have been proposed to determine molecule-level significance. These current approaches have serious drawbacks as they are either computationally burdensome or provide inaccurate estimates in the tail of the p-value distribution.Results:We derive strict lower and upper bounds to the exact p-value along with an accurate approximation that can be used to assess the significance of the rank product statistic in a computationally fast manner. The bounds and the proposed approximation are shown to provide far better accuracy over existing approximate methods in determining tail probabilities, with the slightly conservative upper bound protecting against false positives. We illustrate the proposed method in the context of a recently published analysis on transcriptomic profiling performed in blood.Conclusions:We provide a method to determine upper bounds and accurate approximate p-values of the rank product statistic. The proposed algorithm provides an order of magnitude increase in throughput as compared with current approaches and offers the opportunity to explore new application domains with even larger multiple testing issue. The R code is published in one of the Additional files and is available athttp://www.ru.nl/publish/pages/726696/rankprodbounds.zip.
Electronic ISSN: 1471-2105
Topics: Biology , Computer Science
Published by BioMed Central
4.
PAPER CURRENT
Multilocus microsatellite markers for molecular typing of Candida tropicalis isolates (2014)
Publication Date: 2014-11-22
Description: Background:Candida tropicalis is considered to be the leading pathogen causing nosocomial fungemia and hepatosplenic fungal infections in patients with cancer, particularly those with leukemia. Microsatellite-based typing methods using sets of genetic markers have been developed and reported for population structure analysis of C. albicans, C. glabrata, and C. parapsilosis, but no studies have been published for genetic analysis of C. tropicalis. The objective of this study was to develop new microsatellite loci that have the ability to distinguish among C. tropicalis isolates.Results:DNA sequences containing over 10 bi- or tri-nucleotide repeats were selected from the C. tropicalis genome database. Thirty PCR primers sets specific for the microsatellite loci were designed and tested using eight clinically independent isolates. According to the amplification efficiency, specificity, and observed polymorphisms, eight markers were selected for further population structure analysis and molecular typing. Sixty-five independent C. tropicalis isolates were genotyped using these 8 markers. Based on these analyses, six microsatellite loci were confirmed, although two loci were found to be with unstable flanking areas. The six polymorphic loci displayed 4?22 alleles and 7?27 genotypes. The discriminatory power of the six loci ranged from 0.70 to 0.95. Genotyping results obtained by microsatellite analysis were compared to PCR-fingerprinting and multi-locus sequence typing (MLST). The comparisons showed that microsatellite analysis and MLST had the similar discriminatory power for C. tropicalis, which were more powerful than PCR-fingerprinting.Conclusions:This is the first attempt to develop new microsatellite loci for C. tropicalis. These newly developed markers will be a valuable resource for the differentiation of C. tropicalis isolates. More C. tropicalis isolates will need to be sequenced and analyzed in order to fully show the potential of these newly developed microsatellite markers.
Electronic ISSN: 1471-2180
Topics: Biology
Published by BioMed Central
5.
PAPER CURRENT
China poised to become top science spender (2014)
Publication Date: 2014-11-22
Description: Budgetary pressures on EU, Japan and the US have positioned China to be the highest R&D funder by around 2019, OECD says
Print ISSN: 1473-7604
Electronic ISSN: 1749-5318
Topics: Chemistry and Pharmacology
6.
PAPER CURRENT
Thermal explosion and self-propagating high-temperature synthesis in mechanically activated SiO 2 -Al mixtures (2014)
Publication Date: 2014-11-22
Description: Abstract A thermal explosion and self-propagating high-temperature synthesis in low-calorific SiO2-Al mixtures subjected to preliminary mechanical activation are obtained. Results of x-ray and electron-microscopic investigations of the microstructure and phase composition of activated mixtures and reaction products are reported. It is found that complete reduction of quartz by aluminum occurs only in the thermal explosion mode.
Print ISSN: 0010-5082
Electronic ISSN: 1573-8345
Topics: Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Published by Springer
7.
PAPER CURRENT
Modeling of filtration combustion of gases in a cylindrical porous burner with allowance for radiative heat transfer (2014)
Publication Date: 2014-11-22
Description: Abstract The problem of stabilization of the wave of filtration combustion of a premixed mixture of gases in a porous cylindrical burner is solved numerically. Two formulations of the problem are considered. In the first case, a one-dimensional steady problem of gas combustion in a porous cylindrical burner with allowance for radiative heat transfer inside the porous skeleton and emission of radiation from the burner surface is solved. In the second case, the problem is solved within the framework of the conventional one-dimensional steady diffusion-thermal model of filtration combustion of gases with allowance for radiative heat losses only from the external surface of the burner. The results obtained by two models are compared. It is shown that radiative heat transfer exerts a significant effect on the process of filtration combustion in a porous body, in particular, on the temperature distributions in the gas and the solid, as well as on the radius of stabilization of the combustion front. Heat losses in the form of emission into the ambient medium are found to be caused to a large extent by emission from internal layers of the porous body owing to radiative heat transfer, not only by emission from the external surface of the burner.
Print ISSN: 0010-5082
Electronic ISSN: 1573-8345
Topics: Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Published by Springer
8.
PAPER CURRENT
Miro-hotspot model for the laser initiation of explosive decomposition of energetic materials with melting taken into account (2014)
Publication Date: 2014-11-22
Description: Abstract In this paper, we study a micro-hotspot model for the laser initiation of explosive decomposition taking into account the melting of the matrix of the energetic material and the nanometallic inclusion contained in its volume. The heating features of the nanoparticle in an inert matrix are investigated, and the dependence of the maximum temperature on the surface of the inclusion on its radius is constructed. It is shown that melting leads to a reduction in the maximum heating temperature and a slight change in the radius of the most heated nanoparticle. The dependences of the critical initiation energy density of explosive decomposition of pentaerythritol tetranitrate (PETN) with aluminum nanoparticles on the inclusion radius with and without melting are calculated. With melting taken into account, the model gives higher critical initiation energy density of explosive decomposition. In the case of inclusions of large radius, the formation of the reaction site of explosive decomposition occurs before complete melting of the metal inclusion, which results in solidification of the melt during the induction period.
Print ISSN: 0010-5082
Electronic ISSN: 1573-8345
Topics: Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Published by Springer
9.
PAPER CURRENT
Stability of composite solid propellant ignition by a local source of limited energy capacity (2014)
Publication Date: 2014-11-22
Description: Abstract A numerical simulation of solid-phase ignition of a composite propellant by a single small disk-shaped metal particle heated to a high temperature is performed. In the “heat flux amplitude-ignition delay ” coordinates, an region of stable initiation of combustion of a typical composite solid propellant under local heating by a source of limited energy capacity is selected. The limiting amplitudes of heat fluxes during ignition of the condensed substance under conductive and radiative heating are compared.
Print ISSN: 0010-5082
Electronic ISSN: 1573-8345
Topics: Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Published by Springer
10.
PAPER CURRENT
Effect of barium on the oxidation kinetics of an aluminum-based alloy powder (2014)
Publication Date: 2014-11-22
Description: Abstract The effect of the phase composition of an aluminum-based alloy powder containing 1.3% barium and the products of its interaction with air on the kinetics and mechanism of oxidation was first studied by x-ray diffraction using synchrotron radiation. It is found that the high surface and reactivity of barium lead to the activation of aluminum oxidation due to the heterogeneity of the phase composition of the barrier layer of the reaction products on the particle surface.
Print ISSN: 0010-5082
Electronic ISSN: 1573-8345
Topics: Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Published by Springer