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991.
Avijit Banerji Pizush Kanti Biswas Debasish Bandyopadhyay Maya Gupta Thierry Prangé Alain Neuman 《Journal of heterocyclic chemistry》2007,44(1):137-143
Investigation of cycloadditions of C‐aryl‐N‐(4‐chlorophenyl)nitrones to N‐cinnamoyl piperidines was carried out. Two diastereoisomeric and one regioisomeric cycloadducts, and in some cases ring‐opened compounds were characterized by spectroscopic and X‐ray data. Molecular modelling was carried out for conformational studies. 相似文献
992.
Ransom C Balan V Biswas G Dale B Crockett E Sticklen M 《Applied biochemistry and biotechnology》2007,137(1-12):207-219
Commercial conversion of lignocellulosic biomass to fermentable sugars requires inexpensive bulk production of biologically active cellulase enzymes, which might be achieved through direct production of these enzymes within the biomass crops. Transgenic corn plants containing the catalytic domain of Acidothermus cellulolyticus E1 endo-1,4-beta glucanase and the bar bialaphos resistance coding sequences were generated after Biolistic (BioRad Hercules, CA) bombardment of immature embryo-derived cells. E1 sequences were regulated under the control of the cauliflower mosaic virus 35S promoter and tobacco mosaic virus translational enhancer, and E1 protein was targeted to the apoplast using the signal peptide of tobacco pathogenesis-related protein to achieve accumulation of this enzyme. The integration, expression, and segregation of E1 and bar transgenes were demonstrated, respectively, through Southern and Western blotting, and progeny analyses. Accumulation of up to 1.13% of transgenic plant total soluble proteins was detected as biologically active E1 by enzymatic activity assay. The corn-produced heterologous E1 could successfully convert ammonia fiber explosion-pretreated corn stover polysaccharides into glucose as a fermentable sugar for ethanol production, confirming that the E1 enzyme is produced in its active form. 相似文献
993.
Lactococcus lactis CM1, an isolate from homemade “Dahi,” a traditional fermented milk from India, used maltose as carbon source to produce a
high level of bacteriocin. The bacterial cell mass and the bacteriocin production correlated with the initial pH of the medium
and were highest when the initial pH was 11.0. The level of bacteriocin reached its peak at the late log phase with concomitant
reduction of culture pH to 4.2, regardless of the initial pH of the medium. A combination of maltose and an initial medium
pH of 11 resulted in the highest bacteriocin production. The antibacterial spectrum of the bacteriocin was closely similar
to that of nisin and it inhibited a number of food spoilage and pathogenic bacteria. Upon sodium dodecyl sulfate polyacrylamide
gel electrophoresis, the compound migrated close to the position of nisin (3.5 kDa). However, it had higher stability than
nisin at a wide range of pH and temperature. PCR amplification using nisin gene-specific primers and sequencing of the amplified
DNA revealed the structural gene for the bacteriocin to be identical to that of nisZ. 相似文献
994.
Let (X,x0) be any one-pointed compact connected Riemann surface of genus g, with g≥3. Fix two mutually coprime integers r>1 and d. Let MX denote the moduli space parametrizing all logarithmic -connections, singular over x0, on vector bundles over X of degree d. We prove that the isomorphism class of the variety MX determines the Riemann surface X uniquely up to an isomorphism, although the biholomorphism class of MX is known to be independent of the complex structure of X. The isomorphism class of the variety MX is independent of the point x0∈X. A similar result is proved for the moduli space parametrizing logarithmic -connections, singular over x0, on vector bundles over X of degree d. The assumption r>1 is necessary for the moduli space of logarithmic -connections to determine the isomorphism class of X uniquely. 相似文献
995.
Roy S Jaiswal S Chatterjee S. Sen A Das S Ghosh S K Raha S Lysan V M Kekelidze G D Myalkovsky V V Biswas S 《Pramana》2021,95(1):1-13
Pramana - This article provides numerical simulations of the time-fractional coupled Korteweg–de Vries and Klein–Gordon equations via the local meshless collocation method (LMCM)... 相似文献
996.
Dimitrios Z. Politis Stelios M. Potirakis Yiannis F. Contoyiannis Sagardweep Biswas Sudipta Sasmal Masashi Hayakawa 《Entropy (Basel, Switzerland)》2021,23(6)
In this work we present the statistical and criticality analysis of the very low frequency (VLF) sub-ionospheric propagation data recorded by a VLF/LF radio receiver which has recently been established at the University of West Attica in Athens (Greece). We investigate a very recent, strong (M6.9), and shallow earthquake (EQ) that occurred on 30 October 2020, very close to the northern coast of the island of Samos (Greece). We focus on the reception data from two VLF transmitters, located in Turkey and Israel, on the basis that the EQ’s epicenter was located within or very close to the 5th Fresnel zone, respectively, of the corresponding sub-ionospheric propagation path. Firstly, we employed in our study the conventional analyses known as the nighttime fluctuation method (NFM) and the terminator time method (TTM), aiming to reveal any statistical anomalies prior to the EQ’s occurrence. These analyses revealed statistical anomalies in the studied sub-ionospheric propagation paths within ~2 weeks and a few days before the EQ’s occurrence. Secondly, we performed criticality analysis using two well-established complex systems’ time series analysis methods—the natural time (NT) analysis method, and the method of critical fluctuations (MCF). The NT analysis method was applied to the VLF propagation quantities of the NFM, revealing criticality indications over a period of ~2 weeks prior to the Samos EQ, whereas MCF was applied to the raw receiver amplitude data, uncovering the time excerpts of the analyzed time series that present criticality which were closest before the Samos EQ. Interestingly, power-law indications were also found shortly after the EQ’s occurrence. However, it is shown that these do not correspond to criticality related to EQ preparation processes. Finally, it is noted that no other complex space-sourced or geophysical phenomenon that could disturb the lower ionosphere did occur during the studied time period or close after, corroborating the view that our results prior to the Samos EQ are likely related to this mainshock. 相似文献
997.
998.
Anindya Kanti De Subrata Pal G. Thirupathi Richa Khandelwal Anand Biswas Thomas Miebach Steven M. Gasworth 《Plasma Chemistry and Plasma Processing》2014,34(4):997-1018
Expanding thermal plasma (ETP) is a widely used technique for deposition of a thin layer of ceramic materials and metal oxide on a substrate for a wide range of applications including abrasion resistance, UV absorption, as well as conductive and optical coatings. The coating quality is found to be dependent on operating parameters as well as reactor designs. In this article, we have presented a CFD based model of the ETP process to simulate the deposition of silica-like coatings on a polycarbonate substrate. Along with the flow-thermal model of plasma jet expansion process, the study also reports the development of a simplified gas phase and surface reaction model to simulate the coating phenomena. The model has been used further to study the effect of various operating conditions on the coating thickness, viz. reactor pressure, reagent flow rate, distance of the substrate from the arc and substrate alignment. 相似文献
999.
The focus of this work is to obtain detailed information about the physical composition of the individual fuel cell components in order to optimize them and increase cell durability. An approach for the ex‐situ characterization of fuel cell components, such as gas diffusion media or catalyst layers is by using XPS. In this work, we address methodic aspects of depth profiling of direct methanol fuel cell components (microporous layers and catalyst layers) using adhesive tape peel‐off with subsequent XPS analysis. By using this approach, we have successfully demonstrated cross‐over of Ru ions and possibly Pt ions from the anodic catalyst to the cathodic catalyst layer and even to the microporous layer. Moreover, our experimental results allow determining where the dissolved catalyst ions redeposit within the membrane electrode assembly. Finally, our findings suggest that cross‐over of Pt and Ru ions, observed under different operation conditions, are uncoupled. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
1000.
Ambica Kejriwal Achintesh Narayan Biswas Amitava Choudhury Pinaki Bandyopadhyay 《Transition Metal Chemistry》2014,39(8):909-915
The catalytic reactivity of a group of diferric oxo-bridged complexes (1–3) of a tetradentate ligand (bpmen = N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)-1,2-diaminoethane) toward alkane hydroxylation has been evaluated. Among the three complexes, the µ-oxo diiron(III) complex [Fe(bpmen)(µ-O)FeCl3] (1) has been synthesized for the first time. The complex 1 has been characterized by spectroscopic analysis and X-ray crystallography. At room temperature, the µ-oxo diiron(III) complexes 1–3 have been found to be useful catalysts in hydroxylation of alkanes with m-chloroperbenzoic acid as oxidant. [Fe(bpmen)(µ-O)FeCl3] (1) has been found to be the most active catalyst. Moreover, the catalytic ability of the complexes in the oxidation of alcohols to ketones with hydrogen peroxide at room temperature has also been investigated. 相似文献