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211.
212.
The present study describes the assimilation of phenanthrene by an aerobic bacterium, Ochrobactrum sp. strain PWTJD, isolated from municipal waste-contaminated soil sample utilizing phenanthrene as a sole source of carbon and energy. The isolate was identified as Ochrobactrum sp. based on the morphological, nutritional and biochemical characteristics as well as 16S rRNA gene sequence analysis. A combination of chromatographic analyses, oxygen uptake assay and enzymatic studies confirmed the degradation of phenanthrene by the strain PWTJD via 2-hydroxy-1-naphthoic acid, salicylic acid and catechol. The strain PWTJD could also utilize 2-hydroxy-1-naphthoic acid and salicylic acid, while the former was metabolized by a ferric-dependent meta-cleavage dioxygenase. In the lower pathway, salicylic acid was metabolized to catechol and was further degraded by catechol 2,3-dioxygenase to 2-hydroxymuconoaldehyde acid, ultimately leading to tricarboxylic acid cycle intermediates. This is the first report of the complete degradation of a polycyclic aromatic hydrocarbon molecule by Gram-negative Ochrobactrum sp. describing the involvement of the meta-cleavage pathway of 2-hydroxy-1-naphthoic acid in phenanthrene assimilation. 相似文献
213.
214.
HO-2 provides endogenous protection against oxidative stress and apoptosis caused by TNF-alpha in cerebral vascular endothelial cells 总被引:4,自引:0,他引:4
Basuroy S Bhattacharya S Tcheranova D Qu Y Regan RF Leffler CW Parfenova H 《American journal of physiology. Cell physiology》2006,291(5):C897-C908
Tumor necrosis factor- (TNF-) causes oxidative stress and apoptosis in a variety of cell types. Heme oxygenase (HO) degrades heme to bilirubin, an antioxidant, and carbon monoxide (CO), a cell cycle modulator, and a vasodilator. Newborn pig cerebral microvascular endothelial cells (CMVEC) highly express constitutive HO-2. We investigated the role of HO-2 in protection against TNF--induced apoptosis in cerebral vascular endothelium. In CMVEC from mice and newborn pigs, 15 ng/ml TNF- alone, or with 10 µg/ml cycloheximide (CHX) caused apoptosis detected by nuclear translocation of p65 NF-B, caspase-3 activation, DNA fragmentation, cell-cell contact destabilization, and cell detachment. TNF- did not induce HO-1 expression in CMVEC. CMVEC from HO-2 knockout mice showed greater sensitivity to apoptosis caused by serum deprivation and TNF- than did wild-type mice. TNF- increased reactive oxygen species generation, including hydrogen peroxide and superoxide radicals, as detected by dihydrorhodamine-123 and dihydroethidium. The TNF- response was inhibited by superoxide dismutase and catalase suggesting apoptosis is oxidative stress related. Inhibition of endogenous HO-2 in newborn pig CMVEC increased oxidative stress and exaggerated apoptosis caused by serum deprivation and TNF-. In HO-1-overexpressing CMVEC (HO-1 selective induction by cobalt portophyrin), TNF- did not cause apoptosis. A CO-releasing compound, CORM-A1, and bilirubin blocked TNF--induced reactive oxygen species accumulation and apoptosis consistent with the antioxidant and antiapoptotic roles of the end products of HO activity. We conclude that HO-2 is critical for protection of cerebrovascular endothelium against apoptotic changes induced by oxidative stress and cytokine-mediated inflammation. carbon monoxide; bilirubin; vascular injury; reactive oxygen species; heme oxygenase; cycloheximide 相似文献
215.
Bhattacharya M Mukhopadhyay C Chakrabarti A 《Journal of biomolecular structure & dynamics》2006,24(3):269-276
The hydrophobic fluorescent probe Prodan binds to the self-associating domain of spectrin with 1:1 stoichiometry. A model of the self-associating domain was generated based on its homology with other domains of spectrin. Prodan was then docked onto the model, and several sites with low interaction energy were identified. To verify whether the binding of Prodan is specific towards the self-associating domain of spectrin, it was docked on to several other domains of spectrin, having a known three-dimensional structure. Analysis of the docking results suggests that the binding of Prodan to the self-associating domain of spectrin will involve hydrophobic and hydrophilic groups of Prodan. The results clearly indicate the preference of Prodan for a particular binding site of the self-associating domain. 相似文献
216.
The mechanism by which the cytolysin-mediated translocation (CMT) pathway of the Gram-positive pathogen Streptococcus pyogenes injects effector proteins into the cytosol of an infected host cell via the pore-forming protein streptolysin O is unknown. Key questions include whether the pathway can discriminate between different substrates for translocation, and whether the effector protein plays an active or passive role in the translocation process. Here we show that CMT can discriminate between a known effector of the pathway, the S. pyogenes NAD(+) glycohydrolase (SPN), and a second secreted protein, the mitogenic factor (MF), routing the former into the host cell cytosol and the latter into the extracellular milieu. Residues within the amino-terminal 190 residues of SPN were essential for discrimination, as deletions within this domain produced proteins that retained full enzymatic activity, but were completely uncoupled from the translocation pathway. The enzymatic domain itself played a pivotal role in the discrimination as deletions within this domain also produced translocation incompetent proteins and the conversion of MF to a translocation-competent form required fusion with both SPN domains in a contiguous orientation. These data establish that CMT is discriminatory, and that SPN is a multidomain protein that plays an active role in its translocation. 相似文献
217.
Bhattacharya A Ghosal S Bhattacharya SK 《Prostaglandins, leukotrienes, and essential fatty acids》2006,74(2):109-116
The effect of fish oil (FO) derived from Scomberoides commersonianus containing omega-3 polyunsaturated fatty acids was studied on gastric ulcers and as well as on offensive and defensive factors in gastric mucosal damage, following experimental gastric ulceration. FO significantly reduced the severity of ulceration in gastric ulcers induced by aspirin, cold-restraint stress (CRS), alcohol, and pylorus ligation. The results also indicated the potentiality of FO in maintaining the integrity of gastric mucosa by virtue of its effect on both offensive and defensive gastric mucosal factors. It decreased the offensive acid-pepsin secretion and augmented the defensive factors like mucin secretion, cellular mucus and life span of mucosal cells following pylorus ligation. FO significantly increased activity of anti-oxidant enzymes (catalase and glutathione peroxidase) and decreased lipid peroxidation in gastric mucosa of CRS rats. The study indicates the beneficial role of FO in gastric ulceration by inhibition of offensive mucosal factors and oxidative stress, and augmentation of defensive mucosal factors. 相似文献
218.
Diversity of some insect fauna in industrial and non-industrial areas of West Bengal, India 总被引:1,自引:0,他引:1
The present work is designed to study diversity of five insect orders (viz., Hemiptera, Orthoptera, aculeate Hymenoptera,
Lepidoptera and Coleoptera) in the industrial region of Haldia (India) and in non-industrial area of the same district and
to evaluate the impact of industrialization on the biodiversity of those insect orders. The objective also extended to find
out the possibility of existence of bioindicator, if any. Eight study sites were selected from the East part of Midnapur district
covering 40 km aerial distance. Out of eight different study sites, five were distributed in and around Haldia industrial
complex and three in industry-free area. During this study, a total of 120 species under 98 genera in 37 families of insects
were collected. Binary data of 5 orders revealed that the species richness of Hemiptera, Orthoptera and Lepidoptera is higher
in non-industrial zone in comparison to that of industrial zone. Aculeate Hymenoptera shows no particular trend whereas Coleoptera
shows higher species richness in industrial areas. Results of multivariate analyses are compared with the species richness
data for all the eight study sites. It is concluded that even in an apparently homogeneous ecological condition species richness
may drastically change with the influence of industries. Total insect fauna decline by at least 23.33% is noticed in industrial
areas. It is found that some species of lepidopteran, hemipteran and orthopteran insects are susceptible to industrial pollution
and some of the members of these orders may be considered as a bioindicator group. 相似文献
219.
BAL1 and BBAP are regulated by a gamma interferon-responsive bidirectional promoter and are overexpressed in diffuse large B-cell lymphomas with a prominent inflammatory infiltrate 总被引:1,自引:0,他引:1 下载免费PDF全文
Juszczynski P Kutok JL Li C Mitra J Aguiar RC Shipp MA 《Molecular and cellular biology》2006,26(14):5348-5359