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排序方式: 共有184条查询结果,搜索用时 31 毫秒
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Vivek Khanna Manish Jain Vishal Singh Jitendra S. Kanshana Prem Prakash Manoj K. Barthwal Puvvada S. R. Murthy Madhu Dikshit 《PloS one》2013,8(10)
Effect of long term cholesterol diet withdrawal on accelerated atherosclerosis in iliac artery of New Zealand White (NZW) rabbits has not been explored so far. Atherosclerosis was thus induced in rabbits by a combination of balloon injury and atherogenic diet (AD) (1% cholesterol and 6% peanut oil) feeding for 8 weeks (baseline) followed by chow diet (CD) feeding for 4, 8, 16, 32, 50 and 64 weeks. The plaque characterization was done using histology, real time RT-PCR and vasoreactivity studies. Significant elevation in plasma lipids with AD feeding was normalized following 16 weeks of CD feeding. However, baseline comparison showed advanced plaque features even after 8 weeks of CD period with significant elevation in intima/media thickness ratio and plaque area later showing reduction at 50 and 64 weeks CD periods. Lesion lipid accumulation and CD68 positivity was maintained till 16 weeks of CD feeding which significantly reduced from 32 to 64 weeks CD periods. Baseline comparison showed significant increase in ground substance, MMP-9 and significant decrease in α-actin and collagen content at 8 weeks CD period indicating features of unstable plaque. These features regressed up to 64 weeks of CD. Partial restoration of functional vasoconstriction and vasorelaxation was seen after 64 weeks of CD feeding. mRNA expression of MCP-1, VCAM-1, collagen type I and III, MMP-9, TIMP-1, IFN-γ, TNF-α, IL-10 and eNOS supported the above findings. The study thus reveals insights into initial plaque instability and subsequent regression on AD withdrawal in this model. These results are suggestive of an appropriate window for drug intervention for plaque stability/regression and restenosis as well as improves understanding of plaque regression phenomenon in this model. 相似文献
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Effect of ovariectomy and estrogen supplementation on brain acetylcholinesterase activity and passive-avoidance learning in rats 总被引:2,自引:0,他引:2
Das A Dikshit M Srivastava SR Srivastava UK Nath C 《Canadian journal of physiology and pharmacology》2002,80(9):907-914
The effect of ovariectomy and estrogen treatment on the brain acetylcholinesterase activity and cognition in rats was investigated in this study. Ovariectomized and nonovariectomized rats were treated subcutaneously with estradiol dipropionate for 8 d. In the single-trial, passive-avoidance test all the groups showed significant learning and retention of memory as evident by the increase in transfer latency time in trial 2 as compared with trial 1. No-transfer response was significantly increased in the estradiol-dipropionate-treated ovariectomized (80%) and nonovariectomized (60%) group as compared with the ovariectomized (30%) group. Specific activity of acetylcholinesterase was assayed spectrophotometrically in salt-soluble and detergent-soluble fractions of various brain areas: frontal cortex, cerebral cortex, striatum, hippocampus and hypothalamus, thalamus, pons, medulla, and cerebellum. The effect of ovariectomy and estradiol dipropionate was varied in both fractions of these brain areas. Estradiol dipropionate treatment could restore the acetylcholinesterase activity to the control level only in the detergent-soluble fraction of hypothalamus and salt-soluble fraction of hypothalamus, thalamus, and medulla in ovariectomized rats. The results indicate that ovariectomy alters acetylcholinesterase activity in the brain areas but not in a uniform manner and affects only qualitative aspects of cognitive function, which could be improved by estrogen supplementation. 相似文献
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Characteristics of glycosylated streptokinase secreted from Pichia pastoris: enhanced resistance of SK to proteolysis by glycosylation 总被引:1,自引:0,他引:1
Degradation of streptokinase (SK) has been frequently observed during large-scale protein production. An enhanced susceptibility
of SK to degradation has been correlated with its existence in a partially unfolded state. The influence of the carbohydrate
moiety on the stability and functional characteristics of SK has been examined by obtaining the glycoform of SK following
its secretion through the methylotrophic yeast Pichia pastoris. Secretion of the protein product was achieved by replacing the native secretion signal codons of SK with those from α-factor
leader peptide and expressing the fusion construct under the control of the methanol-inducible alcohol oxidase (ox) promoter of P. pastoris after its integration into the host chromosome. Western blot and zymographic analysis of proteins secreted from the recombinant
P. pastoris indicated that SK was glycosylated by the host cells, which resulted in the appearance of a SK species migrating slowly,
corresponding to a 55-kDa protein product as compared to the 47-kDa native SK. The glycosylated SK retained a plasminogen
activation capability identical to that of its unglycosylated counterpart. Glycoform SK exhibited an enhanced stability profile
at 25 °C and 37 °C and improved resistance towards protease treatment compared to unglycosylated SK secreted through P. pastoris after tunicamycin treatment or that secreted from the recombinant Escherichia coli. The results presented thus illustrate that N-linked glycosylation of SK results in 30–40% enhancement of the protein stability
and resistance towards degradation but does not interfere with its fibrinolytic function.
Received: 1 March 1999 / Received last revision: 5 October 1999 / Accepted: 10 October 1999 相似文献
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Barthwal MK Srivastava N Nag D Seth PK Srimal RC Dikshit M 《Redox report : communications in free radical research》2000,5(2-3):75-80
Protective effects of NOS inhibitors and free radical scavengers in cerebral ischemia are well documented. The present study was undertaken to determine the possible effects of NOS inhibition on brain antioxidants. Levels of both enzymatic [glutathione peroxidase (GPx), catalase and superoxide dismutase (SOD)] and non-enzymatic [reduced glutathione (GSH)] antioxidants following nitric oxide synthase (NOS) inhibition by N(G)-nitro-L-arginine methyl ester (L-NAME), D-NAME or 7-nitroindazole (7-NI) have been investigated. NOS activity and antioxidant levels in the rat cerebellum and medulla were estimated 1 h after treatment with L-NAME (10, 30 and 100 mg/kg, i.p.), D-NAME (100 mg/kg, i.p.) or 7-NI (25 mg/kg, i.p.). L-NAME and 7-NI inhibited NOS activity in a dose-dependent manner. D-NAME also exhibited significant NOS inhibition. The activity of SOD and the GSH level remained unaltered following NOS inhibition. However, L-NAME and D-NAME at 100 mg/kg attenuated GPx activity in the cerebellum, though 7-NI had no effect. L-NAME inhibited catalase activity in medulla only at 30 mg/kg, but had no effect in cerebellum. However, 7-NI (25 mg/kg), D-NAME and L-NAME at 100 mg/kg did not affect catalase activity in the rat brain. Thus, NOS inhibition by the three agents did not have major effects on brain antioxidant levels. 相似文献
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Harsh Kumar Dikshit Akanksha Singh Dharmendra Singh Muraleedhar Sidaram Aski Prapti Prakash Neelu Jain Suresh Meena Shiv Kumar Ashutosh Sarker 《PloS one》2015,10(9)
Low productivity of pilosae type lentils grown in South Asia is attributed to narrow genetic base of the released cultivars which results in susceptibility to biotic and abiotic stresses. For enhancement of productivity and production, broadening of genetic base is essentially required. The genetic base of released cultivars can be broadened by using diverse types including bold seeded and early maturing lentils from Mediterranean region and related wild species. Genetic diversity in eighty six accessions of three species of genus Lens was assessed based on twelve genomic and thirty one EST-SSR markers. The evaluated set of genotypes included diverse lentil varieties and advanced breeding lines from Indian programme, two early maturing ICARDA lines and five related wild subspecies/species endemic to the Mediterranean region. Genomic SSRs exhibited higher polymorphism in comparison to EST SSRs. GLLC 598 produced 5 alleles with highest gene diversity value of 0.80. Among the studied subspecies/species 43 SSRs detected maximum number of alleles in L. orientalis. Based on Nei’s genetic distance cultivated lentil L. culinaris subsp. culinaris was found to be close to its wild progenitor L. culinaris subsp. orientalis. The Prichard’s structure of 86 genotypes distinguished different subspecies/species. Higher variability was recorded among individuals within population than among populations. 相似文献
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Decolourization of anaerobically digested and polyaluminium chloride treated distillery spentwash was studied in a fungal
stirred tank aerobic reactor without dilution of wastewater. Aspergillus niger isolate IITB-V8 was used as the fungal inoculum. The main objectives of the study were to optimize the stirrer speed for
achieving maximum decolourization and to determine the kinetic parameters. A mathematical model was developed to describe
the batch culture kinetics. Volumetric oxygen transfer coefficient (k
L
a) was obtained using dynamic method. The maximum specific growth rate and growth yield of fungus were determined using Logistic
equation and using Luedeking–Piret equation. 150 rpm was found to be optimum stirrer speed for overall decolourization of
87%. At the optimum stirrer speed, volumetric oxygen transfer coefficient (k
L
a) was 0.4957 min−1 and the maximum specific growth rate of fungus was 0.224 h−1. The values of yield coefficient (Y
x/s) and maintenance coefficient (m
s) were found to be 0.48 g cells (g substrate)−1 and 0.015 g substrate (g cells)−1 h−1. 相似文献