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1.
A K Ghoshal T H Rushmore P Buc-Calderon M Roberfroid E Farber 《Free radical biology & medicine》1990,8(1):3-7
This study was designed to explore the possible preventive effects of a novel radicophile, N-p-methoxyphenylacetyl-dehydroalanine (AD5) and three other antioxidants, N,N'-diphenyl-p-phenylenediamine (DPPD), butylated hydroxyanisole (BHA) and a water-soluble analogue of vitamin E, trolox C, on the acute effects of the liver of feeding a choline-deficient (CD) diet. It has been suggested that some of the acute effects of a CD diet are related to free radicals, the generation or metabolism of which is disturbed in this acute dietary model. AD5 was found to be very effective in preventing nuclear lipid peroxidation, DNA damage and cell death induced by a CD diet but to have little effect on triglyceride accumulation ("fatty liver"). DPPD, BHA, and trolox C were ineffective. These results add strength to the hypothesis that oxygen free radicals might be an important component in the early events during carcinogenesis induced by feeding a CD diet. 相似文献
2.
Comparative morphology of the stomach of some laboratory mammals 总被引:3,自引:0,他引:3
Histomorphology of the stomach of mouse, rat, hamster, guineapig, gerbil, and rabbit was studied. Although a common structural basis existed in the stomach between these species, the occurrence and distribution of various cells in gastric glands differed considerably between them. In mice, rats, hamsters and gerbils, the lower one-third of the glandular lamina propria was seemingly occupied by a varying proportion of parietal and chief cells. In rabbits, the predominantly occurring chief cells were distributed in the lower three-quarters of the glands intermingling with parietal cells, but in guinea-pigs the chief cells were not discernible. In hamsters, there was, however, a gradual increase of chief cells from the junction between nonglandular-glandular stomach toward the pyloric region. In all these species, parietal cells were the predominant cell type in the upper half to upper one-third of the gastric glands, often extending up to the neck of the glands interspersing between mucus neck cells and occasionally between chief cells. 相似文献
3.
Aditi Banerjee Aloke K. Ghoshal 《International biodeterioration & biodegradation》2011,65(7):1052-1060
Phenol degradation by Bacillus cereus AKG1 MTCC9817 and AKG2 MTCC 9818 was investigated and degradation kinetics are reported for the free and Ca-alginate gel-immobilized systems. The optimal pH for maximum phenol degradation by immobilized AKG1 and AKG2 was found to be 6.7 and 6.9, respectively, while 3% alginate was optimum for both the strains. The degradation of phenol by free as well as immobilized cells was comparable at lower concentrations of phenol (100–1000 mg l−1). However, the degradation efficiency of the immobilized strains was higher than that of the free strains at higher phenol concentrations (1500–2000 mg l−1), indicating the improved tolerance of the immobilized cells toward phenol toxicity. More than 50% of 2000 mg l−1 phenol was degraded by immobilized AKG1 and AKG2 within 26 and 36 days, respectively. Degradation kinetics of phenol by free and immobilized cells are well represented by the Haldane and Yano model. 相似文献
4.
Reversible HuR‐microRNA binding controls extracellular export of miR‐122 and augments stress response 下载免费PDF全文
Kamalika Mukherjee Bartika Ghoshal Souvik Ghosh Yogaditya Chakrabarty Shivaprasad Shwetha Saumitra Das Suvendra N Bhattacharyya 《EMBO reports》2016,17(8):1184-1203
microRNAs (miRNAs), the tiny but stable regulatory RNAs in metazoan cells, can undergo selective turnover in presence of specific internal and external cues to control cellular response against the changing environment. We have observed reduction in cellular miR‐122 content, due to their accelerated extracellular export in human hepatic cells starved for small metabolites including amino acids. In this context, a new role of human ELAV protein HuR has been identified. HuR, a negative regulator of miRNA function, accelerates extracellular vesicle (EV)‐mediated export of miRNAs in human cells. In stressed cells, HuR replaces miRNPs from target messages and is both necessary and sufficient for the extracellular export of corresponding miRNAs. HuR could reversibly bind miRNAs to replace them from Ago2 and subsequently itself gets freed from bound miRNAs upon ubiquitination. The ubiquitinated form of HuR is predominantly associated with multivesicular bodies (MVB) where HuR‐unbound miRNAs also reside. These MVB‐associated pool of miRNAs get exported out via EVs thereby delimiting cellular miR‐122 level during starvation. Therefore, by modulating extracellular export of miR‐122, HuR could control stress response in starved human hepatic cells. 相似文献
5.
Pretreatment of aqueous extracts of Zyrulina (Spirulina), Aswagandha (Withania) and Nopane (Boswellia) on colchicine induced chromosome damage showed weakness of clastogenic activity in Swiss albino mice. None of the treatments increased significantly the number of chromosome aberrations. 相似文献
6.
Moche M Shanklin J Ghoshal A Lindqvist Y 《The Journal of biological chemistry》2003,278(27):25072-25080
Delta9 stearoyl-acyl carrier protein (ACP) desaturase is a mu-oxo-bridged di-iron enzyme, which belongs to the structural class I of large helix bundle proteins and that catalyzes the NADPH and O2-dependent formation of a cis-double bond in stearoyl-ACP. The crystal structures of complexes with azide and acetate, respectively, as well as the apoand single-iron forms of Delta9 stearoyl-ACP desaturase from Ricinus communis have been determined. In the azide complex, the ligand forms a mu-1,3-bridge between the two iron ions in the active site, replacing a loosely bound water molecule. The structure of the acetate complex is similar, with acetate bridging the di-iron center in the same orientation with respect to the di-iron center. However, in this complex, the iron ligand Glu196 has changed its coordination mode from bidentate to monodentate, the first crystallographic observation of a carboxylate shift in Delta9 stearoyl-ACP desaturase. The two complexes are proposed to mimic a mu-1,2 peroxo intermediate present during catalytic turnover. There are striking structural similarities between the di-iron center in the Delta9 stearoyl-ACP desaturase-azide complex and in the reduced rubrerythrin-azide complex. This suggests that Delta9 stearoyl-ACP desaturase might catalyze the formation of water from exogenous hydrogen peroxide at a low rate. From the similarity in iron center structure, we propose that the mu-oxo-bridge in oxidized desaturase is bound to the di-iron center as in rubrerythrin and not as reported for the R2 subunit of ribonucleotide reductase and the hydroxylase subunit of methane monooxygenase. The crystal structure of the one-iron depleted desaturase species demonstrates that the affinities for the two iron ions comprising the di-iron center are not equivalent, Fe1 being the higher affinity site and Fe2 being the lower affinity site. 相似文献
7.
Ghoshal D 《Indian journal of experimental biology》2002,40(3):341-344
Angiogenesis and immune suppression are the two important factors responsible for embryo implantation and development of tumor. Therefore, disruption of angiogenesis and upliftment of immune function is essential for control of tumor growth as well as to regulate the activity of post coital contraceptives. BIM is an immunomodulatory cytokine obtained from rodent bone marrow that showed anti-implantation and anti-tumor activities. It also improved T/B cell and monocyte macrophage functions. In this communication the anti-angiogenic property of BIM is demonstrated in pregnant rat model. BIM induced disintegration of uterine myometrium and blood vessels. No implantation was observed compared to control. It is proposed that depending upon the physiological condition of the host BIM could modulate host immune function and exert its anti-angiogenic effect. 相似文献
8.
There is a continuing need for monitoring the health of the environment due to the presence of pollutants. Here, we review the development and attributes of biosensors by which bacteria have been genetically modified to express the luminescence genes, i.e. to glow, in a quantified manner, in response to pollutants. We have concentrated on the detection of organic hydrocarbon pollutants and discussed the molecular mechanisms by which some of these chemicals act as effector molecules on the respective regulatory systems. The future of environmental biosensors is predictably bright. As more knowledge is gathered on the sensing regulatory component, the possibility of developing targeted or pollutant-specific biosensors is promising. Moreover, the repertoire of biosensors for culprit organic pollutants is expected to be enlarged through advances in genomics technology and identification of new sensory or receptor molecules. The need for pollutant detection at concentrations in the parts per trillion range or biosensors configured in a nanoscale is anticipated. 相似文献
9.
10.
The kinetics of microbial degradation of naphthalene from a two-component non-aqueous-phase liquid (NAPL) coated onto uniformly sized nonporous particles were evaluated in a completely mixed batch reactor (CMBR) system and in flow-through column systems to examine the differences in the biodegradation kinetic coefficients, micro(max), the maximum specific growth rate coefficient, and K(s), the half saturation constant in the two systems. The values of these coefficients were estimated by nonlinear least-squares regression of the naphthalene mineralization profiles obtained from both CMBR and column biodegradation experiments. The results show that the range of values for micro(max) and K(s) obtained from column systems are very similar to the range of values obtained from CMBR systems. This suggests that coefficients estimated from CMBR or column systems are equally applicable for modeling studies. The presence of microorganisms and the development of biofilms at the NAPL-water interface reduced the mass transfer rates of naphthalene from the NAPL by 60% in CMBR and by 70% in column systems. If such changes in mass transfer coefficients are not accounted for, significantly erroneous values of biokinetic coefficients may be obtained. 相似文献