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41.
Comprehensive comparisons of genome organizations for poxviruses of different genera have not previously been reported. Here we have made such a comparison by cross-hybridizing genome fragments from capripoxvirus KS-1 and vaccinia virus WR (VV). This showed that a 100- to 115-kilobase (kb) centrally placed section is essentially colinear in organization in the two viruses and that a small region has translocated between the ends of one or other of the genomes during their divergence. No cross-hybridization could be detected between VV DNA and the respective left- and right-hand terminal 8 and 25 kb of capripoxvirus DNA or between capripoxvirus DNA and the respective left- and right-hand terminal 38 and 35 kb of VV DNA. By using the cross-hybridization data, a 4-kb fragment of KS-1 DNA was identified, which corresponds to the regions of the cowpox virus and VV genomes containing genes for the orthopoxvirus A-type inclusion body protein ("ATI"). The sequence of the KS-1 DNA fragment contains homologs of genes which are on either side of the orthopoxvirus ATI genes but contains no homolog of the ATI gene itself. Overall, these results show that the pattern of genomic conservation and variation between two poxvirus genera reflects the pattern within the orthopoxvirus genus but that, as observed previously, individual genes may not be present in genomic regions which are otherwise conserved in organization.  相似文献   
42.
Liver function and histology, together with the haematological changes, were investigated in 12 patients with Felty''s syndrome. Six of them were anaemic. The red cell mass was either normal or increased, and the anaemia was due to a considerable increase in the plasma volume. Two patients had increased haemolysis associated with red cell sequestration by the enlarged spleens.In eight patients liver function tests were abnormal, while in five the liver histology showed lymphocytic infiltration of the sinusoids and portal tracts together with portal tract fibrosis. One of these was later found to have a macronodular cirrhosis. In another there were apparent nodules without a true cirrhosis, and this appearance was also seen in two other patients with Felty''s syndrome in whom histology was available. An increased blood flow through the spleen was found in the two patients examined.  相似文献   
43.
The inhibition of brain choline kinase by hernicholinium-3   总被引:1,自引:0,他引:1  
Abstract— The calcium-dependent incorporation of choline, ethanolamine and L-serine into the phospholipids of isolated rat brain microsomes has been studied in vitro, and various properties of the incorporation have have been examined. The optimum pH for the incorporation of each base was found to vary inversely with the Ca2- concentration. Conversely, the optimal Ca2 + concentration for the exchange of the bases increased with decreasing pH values. The enzymic system for the incorporation of ethanolamine appeared to be saturated by two substrate concentrations, i.e. 0-2 and 1-7-2-0 mM. At low ethanolamine concentration (0-2 mM] much less incorporation of the base occurred into the alkenylacyl- and alkylacyl-derivatives of ethanolamine phosphoglycerides compared to that into the diacyl species, whereas the difference becomes smaller at a high substrate concentration (1-7 mM). At pH 81 and 2 mM-Ca2+ the apparent Km of ethanolamine at low substrate concentration was 80 × 10-5 M, and this value increased to 16-2 × 10-4.viat 10mM-Ca2+ concentration. At similar pH the Km values for choline and L-serine were 5.88 × 10-4M and 40 × 10-4 M at 2 mM- and 10mM-Ca2 + concentrations, respectively. The properties of the enzyme system show differences for the three substrates when various factors are changed during incubation. These and other results indicate that more than one enzyme is probably involved in the Ca2+-medialed exchange of nitrogenous bases.  相似文献   
44.
The metabolism of [Me-14C]choline in the brain of the rat in vivo   总被引:9,自引:7,他引:2       下载免费PDF全文
[Me-(14)C]Choline was injected intracerebrally into the adult rat, and its uptake into the lipids and their water-soluble precursors in brain was studied. The radioactivity could be detected only in the choline-containing lipids and was confined to the base choline. The results indicated that initial phosphorylation of the free choline followed by the formation of CDP-choline and the subsequent transfer of the phosphorylcholine to a diglyceride is one of the principal routes by which choline lipids in brain are formed. Further evidence for this was obtained in experiments in which either phosphoryl[Me-(14)C]choline or [(32)P]orthophosphate was injected and the radioactivity in the choline-containing water-soluble and lipidbound components studied.  相似文献   
45.
The mechanical properties of certain bone screws have been examined. The torque developed during insertion of 4 mm (5/32″) non-self-tapping and self-tapping screws and their holding power in bone have been measured. Screws should be inserted into tapped holes using a torque limiting device if failures of screws at insertion are to be prevented. The construction of a surgical torque limiting screwdriver is given.  相似文献   
46.
Hybrid Mus musculus x Mus caroli embryos were produced by inseminating M. musculus (C57BL/OlaWs) females with M. caroli sperm. Control M. caroli embryos developed more rapidly than did control M. musculus embryos and implanted approximately 1 day earlier. At 1 1/2 days, both the hybrid embryos and those of the maternal species (M. musculus) had cleaved to the 2-cell stage. By 2 1/2 days some of the hybrids were retarded compared to M. musculus, and by 3 1/2 days most were lagging behind. This is consistent with the idea that the rate of development of hybrid embryos declines once it becomes dependent on embryo-coded gene products. We have used this difference in rate of preimplantation development, between hybrid and M. musculus embryos, to try to determine whether the activation of embryonic Gpi-1s genes, that encode glucose phosphate isomerase (GPI-1), is age-related or stage-related. In control M. musculus embryos (both mated and Al groups), the GPI-1AB and GPI-1A allozyme, indicative of paternal gene expression, were detected in 7 of 9 samples of 3 1/2-day compacted morula stage embryos and were seen in all 19 samples of 3 1/2-day blastocysts. In hybrid embryos, these allozymes were detected 1 day later. They were not detected in any 3 1/2-day samples (12 samples of compacted morulae) but were consistently detected at 4 1/2 days (4 samples of blastocysts and 2 samples of uncompacted morulae). Our interpretation of the results is that gene activation in hybrid embryos is stage-specific, rather than age-specific, and probably begins around the 8-cell stage, with detectable levels of enzyme accumulating later. Analysis of GPI-1 electrophoresis indicated that both the paternal (M. caroli) and maternal (M. musculus) Gpi-1s alleles were equally expressed in hybrid embryos and that the paternally derived allele was not activated before the maternally derived allele.  相似文献   
47.
48.
While the effect of TGF-β on malignant B cells in non-Hodgkin lymphoma (NHL) has been previously evaluated, studies to specifically define the role of TGF-β in tumor immunity in B-cell NHL are limited. We found that soluble TGF-β, secreted by both lymphoma cells and intratumoral T cells, is present in the serum of patients with B-cell NHL. Soluble TGF-β promoted regulatory T (Treg) cells by enhancing expression of Foxp3 in CD4+ T cells and suppressed effector helper T (TH) cells by inhibiting expression of IFN-γ and IL-17. Blockade of the IL-2 signaling pathway diminished the effect of soluble TGF-β on T cell differentiation. Furthermore, we found that membrane-bound TGF-β is expressed specifically on the surface of malignant B cells in B-cell NHL. TGF-β was able to bind to the surface of lymphoma B cells through an interaction with heparan sulfate (HS) but not through the TGF-β receptor. We showed that pretreatment of lymphoma B cells with TGF-β significantly inhibits the proliferation and cytokine production of intratumoral T cells. Taken together, these results suggest that tumor-associated soluble and membrane-bound TGF-β are involved in the regulation of intratumoral T cell differentiation and function in B-cell NHL.  相似文献   
49.
The upper temperature tolerances of two South African bivalves, Donax serra Röding and D. sordidus Hanley, and a gastropod, Bullia rhodostoma (Reeve), from sandy beaches in Algoa Bay. were compared by means of median lethal temperatures (LT50) and median burial temperature (BT50) determinations for periods of exposure up to 96 h. Donax serra and D. sordidus adults showed a similar temperature tolerance of 29°C. D. serra juveniles showed a lower tolerance of 27°C. Bullia rhodostoma had a slightly higher thermal tolerance (≈ 31°C) than the bivalves, with small individuals having a greater thermal tolerance than large individuals for the longer exposure periods. These thermal tolerances are discussed in relation to distribution, and compared with those of related species from European waters.  相似文献   
50.
Seasonal changes in the body weight and composition of the bivalve Donax trunculus L. from Azur Plage near Algiers, Algeria, were studied during the period September 1971-June 1974. Percentage dry tissue weight was minimal in October–December and rose to reach a peak in spring or summer, the rise corresponding with rapid maturation of the gonads. Decrease in tissue weight in the autumn also coincided with a rapid decline maturity of the gonads between August and October. Lipid content increased with sexual maturity, while carbohydrate content was greatest in the autumn and declined to a seasonal minimum in April–May. The changes are compared with those for D. trunculus in other Mediterranean populations, and for D. vittatus (da Costa) elsewhere in Europe.  相似文献   
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