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941.
942.
Isolation of a glyphosate-metabolising Pseudomonas: detection,partial purification and localisation of carbon-phosphorus lyase 总被引:1,自引:0,他引:1
A Pseudomonas isolate (GLC11) capable of growth in the presence of up to 125 mM glyphosate [N-phosphonomethyl glycine (PMG)] has been isolated. Unlike the previously isolated Pseudomonas PG2982 and other bacterial strains, isolate GLC11 grows equally well in commercial formulation and analytical grade PMG. Utilisation of PMG as a phosphorus source is repressed by inorganic phosphate (Pi) in both isolates. Enzymatic activity responsible for carbon-phosphorus bond cleavage (C-P lyase) was detected in cell-free extracts of both isolates and was partially purified. Resolution on DE-52 anion exchange chromatography yielded a single peak of C-P lyase activity. The molecular mass of C-P lyase as analysed by gel permeation chromatography is approximately 200 kDa. The enzyme activity was localised in the periplasmic space of bacteria. The specific activity of C-P lyase was different for different phosphonates when used as substrates.
Correspondence to: R. K. Bhatnagar 相似文献
943.
Effect of estrogen deprivation on the reproductive physiology of male and female primates 总被引:12,自引:0,他引:12
Gunapala Shetty H. Krishnamurthy H. N. Krishnamurthy Ajay S. Bhatnagar Raghuveer N. Moudgal 《The Journal of steroid biochemistry and molecular biology》1997,61(3-6):157-166
The availability of CGS 16949A, CGS 20267 and CGP 47645, a series of aromatase inhibitors (AIs) having high specific activity and specificity, made possible this study wherein the need for estrogen (E) for regulating (a) follicular maturation/ovulation, luteal function and pregnancy establishment, and (b) testicular function of the bonnet monkey (Macaca radiata) has been examined. Generally these compounds, used in the range of 500 μg to 2.5 mg/day did not inhibit follicular maturation although they did reduce E levels. Although low doses had no effect on ovulation it appears that relatively high doses of CGS 20267 and CGP 47645 could be inhibiting it. Three oral doses of letrozole (CGS 20267, each dose of 2 mg) during the follicular phase resulted in the formation of multiple follicles in cycling females, and these could be ovulated by exogenous hCG (1000 IU) treatment. Although administration of AI during the early luteal phase had no effect on progesterone (P) production, it prevented pregnancy establishment. Whereas AI administration in the female had no significant effect on luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels (except at high drug dosages), it significantly increased serum testosterone (T) levels in the male. Sustained high levels of T (30–50 ng/ml) could be maintained for 100 days by administering 2.5 mg of CGP 47465 orally once in 5 days. Blockade of E synthesis in the male led to the disruption of testicular germ cell transformation, which in turn resulted in a significant reduction in sperm production. These studies with aromatase inhibitors in the monkey suggest that these compounds have a potential for use as fertility regulating agents in both the male and female primate. 相似文献
944.
Preeti Bhatnagar Abdul Arif Khan Manisha Jain Shuchi Kaushik Sudhir K. Jain 《Indian journal of microbiology》2007,47(3):263-266
Present study was conducted to analyze bacterial contaminants /pathogens in Khoa samples sold in Chambal region of Madhya
Pradesh. Total Fifty samples of Khoa were brought from different localities of Chambal region at random and processed. Bacterial
colony counts were also performed. Staphylococcus species and Streptococcus species were the predominant isolates. The viable counts obtained ranged from 1.3sX104 to 2.1sX106 CFU/g. Contamination of Khoa by pathogenic bacteria could be an important factor of gastrointestinal infections including
food poisoning and food borne illness. Adequate consumer protection can be achieved by measuring the microbiological data
of product. 相似文献
945.
Exposure of adult rats to 0.8 ppm ozone enhanced collagen synthesis in the lungs. Collagen synthesis was studied by estimating hydroxyproline (Hyp) content and by following the activity of prolyl hydroxylase (PH), a crucial enzyme in the pathway of collagen biosynthesis. In the early phases (1–2 day) of ozone-induced injury, PH activity was increased twofold over control values and the amount of collagen synthesized (as estimated by Hyp formation) was double the amount of non-collagenous protein synthesized. This resulted, by the third day, in a significant increase (29%) in total lung collagen. In the later stages of the injury (3–7 day), however, increases in PH activity were more gradual, approaching 2.7 times control levels at the end of the 7-day exposure period. The synthesis of non-collagenous protein during this period increased steadily and by the 7th day the ratio of the amounts of collagen to non-collagenous protein synthesized was comparable to that of controls. When the exposed (0.8 ppm O3/7 days) animals were placed in filtered ambient air, PH activity returned to normal in 13 days whereas Hyp content remained elevated for up to 28 days. These results suggest that environmental ozone exposure could be a contributing factor in pulmonary disorders involving lung collagen synthesis. 相似文献
946.
The cyclic AMP-phosphodiesterase (EC 3.1.4.17) of buffalo spermatozoa is distributed in the head, mid-piece and tail fractions and has multiple forms, 70% of which is in the bound form. The bound enzyme was not solubilized by Triton X-100, lubrol or hyamine 2389. Kinetic measurements of the soluble enzyme showed two apparent Km values for low and high cAMP concentrations, i.e. 4.5 and 100 micro M with Vmax values of 0.25 and 2.0 nmol cAMP hydrolysed min-1 mg protein-1. The bound enzyme had an apparent Km of 66.6 microM with a Vmax of 0.75 nmol cAMP hydrolysed min-1 mg protein-1. The pH for optimum enzyme activity was 7.5 and Mg2+ was essential for the activity of the soluble and bound enzymes. Methylxanthines, ATP, ADP and ppi inhibited the soluble and bound enzymes, ATP being the most potent inhibitor. 相似文献
947.
Janneth Rodrigues Neema Agrawal Anil Sharma Pawan Malhotra Tridibes Adak Virander S Chauhan Raj K Bhatnagar 《BMC molecular biology》2007,8(1):33
Background
The main vector for transmission of malaria in India is the Anopheles culicifacies mosquito species, a naturally selected subgroup of which is completely refractory (R) to transmission of the malaria parasite, Plasmodium vivax; 相似文献948.
949.
Present study was carried out to understand the possible mechanism of neuroprotective action of the root extract of Withania somnifera Dunal (WS). The study is focused on WS mediated inhibition of nitric oxide production, which is known to mediate neurodegeneration during stress. Adult mice (28 ± 5 g) were exposed to restraint stress for 30 days. Activity of NADPH diaphorase (NADPH-d) and factors (Acetylcholine, serotonin and corticosterone), which regulates NADPH-d activity were studied. Treatment with WS extract for 30 days during stress, significantly reversed the stress induced NADPH-d activation. Observations suggest that inhibition of NADPH-d by WS is not a direct effect of extract on NADPH-d, instead it inhibits via suppressing corticosterone release and activating cholineacetyltransferase, which in turn increase serotonin level in hippocampus to inhibit NADPH-d. Together, the main mechanism underlying the neuroprotective effects of WS can be attributed to its role in the down regulation of nNOS and neurochemical alterations of specific neurotransmitter systems. These observations thus suggest that WS root extract could be developed as a potential preventive or therapeutic drug for stress induced neurological disorders. 相似文献
950.
Vidhi Chaudhary Radha Prasanna Lata Nain S. C. Dubey Vishal Gupta Rajendra Singh Seema Jaggi Ashok Kumar Bhatnagar 《World journal of microbiology & biotechnology》2012,28(12):3301-3310
Biological control of plant pathogens is receiving increasing relevance, as compared to chemical methods, as they are eco-friendly, economical and indirectly improve plant quality and yield attributes. An investigation was undertaken to evaluate the potential of antagonistic cyanobacteria (Anabaena variabilis RPAN59 and A. oscillarioides RPAN69) fortified formulations for suppressing damping off disease in tomato seedlings challenged by the inoculation of a fungal consortium (Pythium debaryanum, Fusarium oxysporum lycopersici, Fusarium moniliforme and Rhizoctonia solani). Treatment with A. variabilis amended formulations recorded significantly higher plant growth parameters, than other treatments, including biological control (Trichoderma formulation) and chemical control (Thiram-Carbendazim). The A. variabilis amended compost-vermiculite and compost formulations exhibited 10?C15?% lower disease severity and 40?C50?% higher values than chemical and biological control treatments in terms of fresh weight and height of the plants. In future, in depth analyses regarding the mechanism involved in biocontrol by cyanobacteria and evaluation of these formulations under field conditions are proposed to be undertaken. 相似文献