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81.
82.
Rudy W; Guckel B; Siebels M; Lindauer M; Meuer SC; Moebius U 《International immunology》1997,9(6):853-860
Introduction of co-stimulatory molecules like CD80 and CD86 represents a
means to augment the immunogenicity of tumor cells and to induce immune
responses directed at tumor antigens. Here we compared CD80- and
CD86-transfected human melanoma cells to induce primary immune responses by
their capacity to promote proliferation of human allogeneic resting T
lymphocytes. CD80- and CD86-transfected SkMel63 melanoma cells induced T
cell activation to a comparable degree, which was found to be independent
of the cell surface density of these co- stimulatory molecules.
Co-expression of CD80 and CD86 did not result in a synergistic increase in
T cell proliferation. Both CD80 and CD86 transfectants induced the
proliferation of isolated CD4+ or CD8+ T cells. Exogenous IL-2, IL-4 and
tumor necrosis factor-alpha respectively enhanced primary T cell
proliferation independent of CD80 or CD86 expression. Interestingly,
differential activities of CD80 and CD86 were observed following
stimulation of resting T cells in the presence of IL-12. Whereas IL-12
increased T cell proliferation in the presence of CD86-transfected melanoma
cells, it exhibited an inhibitory function in the presence of
CD80-expressing SkMel63 cells. Experimental evidence indicates that this
inhibitory effect was mediated by IFN- gamma since (I) IFN-gamma secretion
of stimulated T cells was augmented by IL-12, (II) exogenous IFN-gamma also
inhibited T cell proliferation induced by CD80- but not CD86-transfected
SkMel63 cells and (III) the inhibitory effect of IL-12 was blocked by an
anti-IFN-gamma mAb.
相似文献
83.
84.
Background
A retrospective assessment of contrast enhanced computed tomography (CECT) scan findings in histopathologically proven cases of carcinoma of the gallbladder (GB) was performed to review its role in diagnosis, staging and assessment of surgical resectability.Methods
All the patients had been subjected to a standardised abdominal helical computed tomography scan. Orally administered iodinated contrast was used for opacification of bowel and dynamic intravenous injection of non-ionic iodinated contrast for studying the lesional enhancement and vascular structures.Results
The presence of focal or diffuse mass lesions in the gallbladder fossa, infiltration of a liver and second part of duodenum were the most reliable diagnostic features in carcinoma gallbladder. Regional spread was better delineated on CT scan as compared with ultrasonography.Conclusion
CT scan is an effective method for evaluating, characterizing and detecting the spread of GB carcinomas.Key Words: Gall Bladder, Carcinoma, Computed Tomography 相似文献85.
86.
Congenital heart lesions involving the right ventricular outflow tract (RVOT) are a common problem in paediatric cardiology. These patients need multiple surgical interventions in the form of valved conduits over a lifetime. Surgical re-valvulation was the standard treatment option until the introduction of percutaneous pulmonary valves over a decade ago. These valves can be used to prolong the lifespan of conduits and reduce the number of re-operations. The Melody® valve (Medtronic, Minneapolis, MN, USA) was introduced as the first dedicated percutaneous pulmonary valve. Percutaneous pulmonary valves can be implanted successfully and have the advantage of short hospitalisations. We describe the first three Melody® valve implantations in Africa. 相似文献
87.
Vikrant SUDAN Anup Kumar TEWARI Harkirat SINGH 《Revista do Instituto de Medicina Tropical de S?o Paulo》2015,57(3):205-209
Context and objective:
The molecular characterization of local isolates of Toxoplasma gondii is considered significant so as to assess the homologous variations between the different loci of various strains of parasites.Design and setting:
The present communication deals with the molecular cloning and sequence analysis of the 1158 bp entire open reading frame (ORF) of surface antigen 3 (SAG3) of two Indian T. gondii isolates (Chennai and Izatnagar) being maintained as cryostock at the IVRI.Method:
The surface antigen 3 (SAG3) of two local Indian isolates were cloned and sequenced before being compared with the available published sequences.Results:
The sequence comparison analysis revealed 99.9% homology with the standard published RH strain sequence of T. gondii. The strains were also compared with other established published sequences and found to be most related to the P-Br strain and CEP strain (both 99.3%), and least with PRU strain (98.4%). However, the two Indian isolates had 100% homology between them.Conclusion:
Finally, it was concluded that the Indian isolates were closer to the RH strain than to the P-Br strain (Brazilian strain), the CEP strain and the PRU strains (USA), with respect to nucleotide homology. The two Indian isolates used in the present study are known to vary between themselves, as far as homologies related to other genes are concerned, but they were found to be 100% homologous as far as SAG3 locus is concerned. This could be attributed to the fact that this SAG3 might be a conserved locus and thereby, further detailed studies are thereby warranted to exploit the use of this particular molecule in diagnostics and immunoprophylactics. The findings are important from the point of view of molecular phylogeny. 相似文献88.
89.
90.
The inhibitory effects of exogenous arachidonic acid on rabbit platelet aggregation and the release reaction 总被引:1,自引:0,他引:1
Cattaneo M; Kinlough-Rathbone RL; Perry DW; Chahil A; Vickers JD; Lam SC; Packham MA; Mustard JF 《Blood》1982,60(5):1179-1187
Although arachidonic acid causes rabbit platelet aggregation and the release of granule contents in suspensions of washed platelets when used in concentrations of approximately 50-300 microM, higher concentrations (500 microM) cause neither aggregation nor release. Suspensions of platelets from rabbits wee exposed to arachidonic acid (250 microM) for 15 min, allowed to recover in the presence of PGE1 for 30 min, washed, and resuspended; in some experiments, the platelets were treated with aspirin before being exposed to arachidonic acid. Aggregation of platelets pretreated with arachidonic acid was inhibited in response to ADP; this effect was greater with the non-aspirin- treated platelets and persisted for at least 4 hr after resuspension. The association of 125I-fibrinogen with the platelets as a result of ADP stimulation was also inhibited. Aggregation and release of granule contents in response to collagen and low concentrations of thrombin was inhibited, but the inhibition could be overcome by higher concentrations. Thrombin induced further release of granule contents from platelets exposed to arachidonic acid without pretreatment with aspirin. Platelets that had been exposed to arachidonic acid, either with or without pretreatment with aspirin, did not aggregate or undergo further release upon stimulation with arachidonic acid after they were washed and resuspended. Inhibition of the lipoxygenase pathway with eicosatetraynoic acid (ETYA) or nordihydroguaiaretic acid (NDGA) did not affect the inhibition caused by arachidonic acid, so it is unlikely that a product of this pathway is responsible for the inhibition. Mixing experiments indicated that the pretreated platelets did not form a thromboxane-A2-like activity, and that they were unresponsive to aggregation and release induced by products formed from arachidonic acid. Experiments with 3H-arachidonic acid showed that after 45 min of incubation with platelets, only 1.1% of the 3H-arachidonic acid remained as free arachidonic acid in the platelets. Although cyclic-AMP was slightly increased 1 min after the addition of arachidonic acid, the cyclic-AMP concentration was the same as that of control platelets after the platelets were washed and resuspended, indicating that increased cyclic-AMP is not likely to be responsible for the persistent inhibitory effect. Thus, the inhibitory effect of pretreatment with arachidonic acid is a general effect on responses to a variety of aggregating agents that act through different mechanisms, and the inhibition is not related to thromboxane-A2 formation. The possibility of membrane perturbation resulting in the unavailability of receptors may explain the persistent inhibitory effect, but the responsible reactions have not been identified. 相似文献