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51.
The copper complex of indomethacin (1-(p-chlorobenzoyl)-5-methoxy-2-methyl-indole acetate), a common anti-inflammatory drug, was prepared and characterized. Crystal structure determination revealed the dimeric form of the 1:2 complex, namely Cu2(indomethacin)4 · L2, in the unit cell. Suprisingly, the copper-copper distance (263 pm) was very close to metallic copper (256 pm). The two coordination sites in the copper-copper axis can be readily replaced by superoxide. An intriguing similarity to Cu2(acetate)4 was seen.Due to the lipophilic nature of the indomethacin ligand, this copper complex reacted with superoxide in aprotic solvents. The superoxide dismutating activity was successfully demonstrated in Me2SO/water and acetonitrile/water mixtures using the nitro-blue tetrazolium assay and pulse radiolysis. The second-order rate constant of 6 · 109 M?1 · s?1 in strictly aqueous systems dropped only slightly to 1.1 · 109 M?1 · s?1 when aprotic solvents were used. This is the fastest rate constant ever observed for a copper-dependent dismutation of superoxide. The KO2-induced lipid peroxidation in both erythrocytes and liver microsomes was suppressed by 70% in the presence of 1 · 10?10 mol · ml?1 of Cu2(indomethacin)4. The inhibitory action dropped to 25% when Cu2Zn2superoxide dismutase was employed. The formation of copper · indomethacin in rat serum after administration of indomethacin was shown in vitro and in vivo.  相似文献   
52.
Copper is an essential trace element that is extremely toxic to organisms and organs at high doses. We have investigated the histological and biochemical effects of a toxic dose of copper sulfate on the liver of term Ross broiler chicks. Fertilized eggs were divided into three groups: experimental, injected with 50 mcg/0.1 ml copper sulfate in the air chambers on day 1; sham, injected with 0.1 ml saline; and control, no injection. Term chicks were killed and their livers investigated histologically, with hematoxylin–eosin-stained sections examined under light microscopy, and biochemically, for malondialdehyde and glutathione levels. Histological examinations showed copper-treated samples with granular degeneration and necrosis of hepatocytes and impairment to the cell lining of the remark cords. The samples had a congestive appearance, with blood in the vena centralis and sinusoids, slight connective tissue increase, and lymphocyte infiltration. Control and sham group sections had normal appearances. As oxidative damage parameters, in the copper-treated group, malondialdehyde levels were increased and glutathione levels decreased. In the sham and control groups, there were no significant differences. At this toxic dose, copper sulfate shows oxidative damage according to the histology of term chick liver that are confirmed biochemically by the changes in malondialdehyde and glutathione levels.  相似文献   
53.
The purpose of this review is to provide a global perspective on Oncorhynchus salmonine introductions and put-and-take fisheries based on modern stocking programs, with special emphasis on freshwater ecosystems. We survey the global introductions of nine selected salmonines of the genus Oncorhynchus: golden trout, cutthroat trout, pink salmon, chum salmon, coho salmon, masu/cherry salmon, rainbow trout/steelhead, sockeye salmon/kokanee, and chinook salmon. The information is organized on a geographical basis by continent, and then by species and chronology. Two different objectives and associated definitions of ‘success’ for introductions are distinguished: (a) seed introduction: release of individuals with the purpose of creating a wild-reproducing, self-sustaining population; and (b) put-and-take introduction: release of individuals with the purpose of maintaining some level of wild population abundance, regardless of wild reproduction. We identify four major phenomena regarding global salmonine introductions: (1) general inadequacy of documentation regarding introductions; (2) a fundamental disconnect between management actions and ecological consequences of introductions; (3) the importance of global climate change on success of previous and future introductions; and (4) the significance of aquaculture as a key uncertainty in accidental introductions. We conclude this review with a recognition of the need to terminate ongoing stocking programs for introduced salmonines worldwide.  相似文献   
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One of the major properties of the semi-synthetic minimal cell, as a model for early living cells, is the ability to self-reproduce itself, and the reproduction of the boundary layer or vesicle compartment is part of this process. A minimal bio-molecular mechanism based on the activity of one single enzyme, the FAS-B (Fatty Acid Synthase) Type I enzyme from Brevibacterium ammoniagenes, is encapsulated in 1-palmitoyl-2oleoyl-sn-glycero-3-phosphatidylcholine (POPC) liposomes to control lipid synthesis. Consequently molecules of palmitic acid released from the FAS catalysis, within the internal lumen, move toward the membrane compartment and become incorporated into the phospholipid bilayer. As a result the vesicle membranes change in lipid composition and liposome growth can be monitored. Here we report the first experiments showing vesicles growth by catalysis of one enzyme only that produces cell boundary from within. This is the prototype of the simplest autopoietic minimal cell.  相似文献   
56.

Background  

Identifying essential genes in bacteria supports to identify potential drug targets and an understanding of minimal requirements for a synthetic cell. However, experimentally assaying the essentiality of their coding genes is resource intensive and not feasible for all bacterial organisms, in particular if they are infective.  相似文献   
57.

Background  

Phylogenies capture the evolutionary ancestry linking extant species. Correlations and similarities among a set of species are mediated by and need to be understood in terms of the phylogenic tree. In a similar way it has been argued that biological networks also induce correlations among sets of interacting genes or their protein products.  相似文献   
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59.
Carry-over of deoxynivalenol (DON) into eggs was investigated within the scope of a 16-week experiment with laying hens, in which the birds were fed a maize-based diet containing DON at 11.9 mg/kg dry matter. Eggs were collected during weeks 2, 4, 8, and 16. DON and its metabolite deepoxy-DON were analysed separately in freeze-dried yolk and albumen. Yolk was extracted with water and the extract was purified using an immunoaffinity column (IAC). Albumen was extracted with acetonitrile-water and the extract was pre-cleaned before applying an IAC. All albumen and some yolk samples were incubated with β-glucuronidase prior to extraction. DON and de-epoxy-DON were determined by high performance liquid chromatography (HPLC) with diode array detection (DAD). The detection limits of both toxins were 20 ng/g and 15 ng/g in freezedried yolk and albumen, respectively, corresponding to approximately 10 ng/g and 2 ng/g in fresh samples. The recovery of DON/de-epoxy-DON in spiked samples (50–200 ng/g) was 87/83% (yolk) and 87/77% (albumen) with coefficients of variation of 4–15%. Neither DON nor de-epoxy-DON were detected in any of the samples. In order to achieve lower detection limits, the methods are currently optimized. However, these preliminary results indicate that eggs do not contribute significantly to the dietary DON intake of the consumer. Presented at the 26th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004  相似文献   
60.
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