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1.
Optimization of parameters in the batch kinetic studies of glucose isomerisation by arthrobacter sp.
Vital parameters like temperature, pH and agitation are optimized in the kinetic studies of glucose isomerisation carried out in a batch fashion. A 4-litre fermentor with temperature, pH, agitation and other controls is used. It is found that the two parameters — temperature and pH, do not have an interacting effect on each other. A temperature of 60°C, a pH of 8.0 and a speed of 200 rpm are found to be better suited for the production of fructose syrups starting from glucose by arthrobacter sp. An upper limit of 20 minutes on the residence time is suggested for use in the design of flow reactors. 相似文献
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Radiobiology of alpha particles. III. Cell inactivation by alpha-particle traversals of the cell nucleus 总被引:1,自引:0,他引:1
Cell inactivation after exposure to collimated 3.5-MeV alpha particles in three hamster cell lines, V79, CHO-10B, and HS-23, one mouse cell line, C3H 10T1/2, and a human skin fibroblast cell line were studied. Several parameters were investigated for each cell line. Theoretical calculations were performed to find the distribution of energy deposited in the nuclear volume for each cell line. The mean number of alpha-particle traversals required to induce a lethal lesion varied between two for HS-23 cells and six for C3H 10T1/2 cells. The number of traversals per unit area and the total track length of alpha particles that inactivated a cell were found to be nearly constant for the hamster and mouse cell lines. These quantities were found to be lower for the human skin fibroblast cell line. The RBE values for all cell lines were found to be about 3.8 at 10% survival. Thus cell lines that are more sensitive to alpha radiation are also more sensitive to gamma radiation. The average number of alpha-particle traversals producing a single lethal lesion is greater than one. The passages of alpha particles through the cell nucleus that do not kill the cell may lead to carcinogenic effects. 相似文献
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Ravinder Raju Bernard F. Castillo Stewart K. Richardson Meena Thakur Ryan Severins Mitchell Kronenberg Amy R. Howell 《Bioorganic & medicinal chemistry letters》2009,19(15):4122-4125
Four 3″- and 4″-deoxy and -fluorogalactosyl ceramides were synthesized, and their ability to stimulate iNKT cells, based on levels of IL-2 production, was assessed in three NKT cell receptor hybridomas. In two of the hybridomas, 1.2 and 2H4, all of the analogs were immunostimulatory, while in the 1.4 hybridoma only the 4″-fluoro analog led to the production of significant levels of IL-2. 相似文献
5.
Comparison of the Levels of Heat Resistance of Wild-Type, cpe Knockout, and cpe Plasmid-Cured Clostridium perfringens Type A Strains 下载免费PDF全文
An enterotoxin (cpe) plasmid was cured from a Clostridium perfringens non-food-borne gastrointestinal disease (NFBGID) isolate, and the heat resistance levels of wild-type, cpe knockout, and cpe plasmid-cured strains were compared. Our results demonstrated that (i) wild-type cpe has no influence in mediating high-level heat resistance in C. perfringens and (ii) the cpe plasmid does not confer heat sensitivity on NFBGID isolates. 相似文献
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Reactions of Sr(II) and Ba(II) chlorides with 2-hydroxybenzophenone and salicylaldehyde, hydroxyaromatic ketones or β-diketones in 1:1:1 molar ratios have resulted in the formation of mixed ligand complexes of the type [MLL′(H2O)2] (M = Sr(II) or Ba(II); HL = 2-hydroxybenzophenone and HL′ = salicylaldehyde, 2-hydroxyacetophenone, 2-hydroxypropiophenone, pentane-2,4-dione, 1-phenylbutane-1,3-dione or 1,3-diphenylpropane-1,3-dione). These complexes have been characterized by elemental analyses, TLC, IR and 1H NMR spectroscopy. 相似文献
8.
Mamta Sharma Raju Ghosh Suresh Pande 《Archives Of Phytopathology And Plant Protection》2013,46(13-16):797-812
Dry root rot caused by Rhizoctonia bataticola (Macrophomina phaseolina) of chickpea (Cicer arietinum L.) is gaining importance in the changed scenario of climate when growing crop is predisposed to high temperature and moisture stress. Being mainly a soil-inhabiting pathogen, many environmental and soil factors are responsible for the development of disease. No systematic research related to the biology, ecology and epidemiology of dry root rot in chickpea has been conducted so far. Research is needed to improve the identification and characterisation of variability within its epidemiological and pathological niches. Limited literature available on host plant resistance for dry root rot indicated lack of resistant sources for this disease. The present article discusses current status of the disease in the context of climate change and possible management options to alleviate the problem. 相似文献
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In continuation of our work on the conformational analysis of succinic acid (SA) and maleic acid (MA) in different solvents, we present here the experimental dielectric and IR and also the ab initio Hartree–Fock calculations of the two dicarboxylic acids in tetrahydrofuran (THF). The dielectric measurements are carried out at microwave X-band frequency of 9.7 GHz and the calculations are performed at STO-3G and 6-31G(d) basis sets. The dielectric data and the dipole moment determined experimentally are compared with the dipole moment determined from the conformal analysis. It is seen that the dielectric properties of SA/MA in THF are much different from that of SA/MA in 1-4, dioxane (1-4D) that we had reported previously. The IR spectra of SA–THF system is also reported here. The present study indicates the possible formation of nano-clusters of SA/MA in THF due to incomplete solvation by THF. 相似文献
10.
The liver is one of the few organs that possess a high capacity to regenerate after liver failure or liver damage. The parenchymal cells of the liver, hepatocytes, contribute to the majority of the regeneration process. Thus, hepatocyte transplantation presents an alternative method to treating liver damage. However, shortage of hepatocytes and difficulties in maintaining primary hepatocytes still remain key obstacles that researchers must overcome before hepatocyte transplantation can be used in clinical practice. The unique properties of pluripotent stem cells (PSCs) and induced pluripotent stem cells (iPSCs) have provided an alternative approach to generating enough functional hepatocytes for cellular therapy. In this review, we will present a brief overview on the current state of hepatocyte differentiation from PSCs and iPSCs. Studies of liver regenerative processes using different cell sources (adult liver stem cells, hepatoblasts, hepatic progenitor cells, etc.) will be described in detail as well as how this knowledge can be applied towards optimizing culture conditions for the maintenance and differentiation of these cells towards hepatocytes. As the outlook of stem cell-derived therapy begins to look more plausible, researchers will need to address the challenges we must overcome in order to translate stem cell research to clinical applications. 相似文献