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排序方式: 共有368条查询结果,搜索用时 902 毫秒
341.
Khairova RA Malomuzh AI Naumenko NV Urazaev AKh 《Bulletin of experimental biology and medicine》2003,136(2):120-122
Denervation of rat phrenic muscle or block of NO-synthase in vivo increased the cross-section area of muscle fibers and decreased membrane resting potential. Oxotremorine prevented the development of denervation-induced or denervation-like (i.e. induced by NO-synthase blockade) membrane depolarization and increase of the cross-sectional area of muscle fibers. Pirenzepine abolished the effects of oxotremorine. It was concluded that non-quantal acetylcholine can be involved in the regulation of skeletal muscle fiber volume via activation of M1 muscarinic receptors followed by NO synthesis. 相似文献
342.
Bertolino A; Saunders RC; Mattay VS; Bachevalier J; Frank JA; Weinberger DR 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(8):740-748
Focal brain damage occurring early in development can have widespread
repercussions throughout the developing brain. In living adult rhesus
monkeys, we studied the long-term effects of early mesial temporo- limbic
(MTL) lesions on prefrontal cortex (PFC) neurons using proton magnetic
resonance spectroscopic imaging (1H-MRSI), an in vivo neurochemical assay
technique for measuring signals from metabolites such as N-acetyl-aspartate
(NAA, a neuronal marker), choline-containing compounds (CHO) and creatine +
phosphocreatine (CRE). Six monkeys (NL) had undergone surgical ablation of
MTL structures within 3 weeks of birth, six monkeys received the same
lesion at approximately 5 years of age and six monkeys were normal
controls. We found significant bilateral reductions of NAA relative signals
exclusively in the PFC of the NL group in comparison with either of the
other groups. Our results indicate that neonatal MTL damage specifically
affects PFC neurons of adult monkeys as indicated by a reduction of NAA.
The basis of this effect involves developmental processes as implicated by
two arguments: analogous damage during adulthood does not have the same
effect; NAA in the healthy brain increases during development. This finding
may have implications for understanding developmental aspects of
prefrontal- temporolimbic connectivity, and the reduction of NAA levels
observed in prefrontal cortex of patients with schizophrenia.
相似文献
343.
The role of gamma-aminobutyric acid (GABA) in the control of plasma testosterone was studied on male mice of inbred strains (CBA/Lac, A/He and BALB/c) exposed to a sexually receptive female in the same cage but separated by a partition. Within 40 minutes, testosterone levels in plasma increased 1.5-3.5 times depending upon the mouse genotype. This process could be completely blocked if GABA accumulation was induced by pretreatment with the GABA transaminase inhibitor, aminooxyacetic acid (AOAA), or by emotional stress induced by 40 min of restraint. Neither bicuculline-induced blockade of GABA receptors nor a decrease of GABA concentration induced by prior administration of thiosemicarbazide (an inhibitor of glutamate decarboxylase), affected the increase of plasma testosterone that occurred in response to presentation of a receptive female. However, at sexual arousal, the bicuculline blockade of GABA receptors significantly reduced the inhibitory effects of both AOAA administration and emotional stress on plasma testosterone levels. We conclude that the inhibitory effect of emotional stress on female-induced activation of testicular endocrine function is mediated, at least in part, via activation of bicuculline-sensitive receptors. 相似文献
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It has been shown on male mice of A/He strain that the presence of a receptive female placed behind a network partition in a cage with a male mouse caused a sharp rise on the 20-40th min. of the blood level of testosterone resulting from appropriate changes in testicular biosynthetic capacity. This rise of the level of testosterone in the male blood is realized via the transadenohypophyseal route because the antagonist of LH-RH receptor completely blocks this effect. A conclusion has been made that the activating effect of the presence of a receptive female on the blood level of testosterone is realized with the involvement of LH-RH receptors via the transadenohypophyseal route. 相似文献
347.
V S Shchukin E Iu Filin S E Naumenko E V Len'ko E D Bogatina 《Vestnik khirurgii imeni I. I. Grekova》1991,146(1):90-94
Correction of the acquired defect of the mitral valve was performed in 89 patients on the open heart under conditions of nonperfusion hypothermia. Roentgenological assessment of the lung state was used in the postoperative period. Typical morphofunctional alterations were detected after operations under conditions of nonperfusion hypothermia. It was found that the increased volume of +blood transfusions more than 19 ml/kg of the patient's body weight was followed by a reliably increased frequency and degree of ++roentgenological symptoms of injuries of the lungs. 相似文献
348.
Effect of human immunodeficiency virus type-1 envelope glycoprotein gp160 on cytokine production from cord-blood T cells 总被引:2,自引:1,他引:1
We have recently demonstrated that the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp160 enhances the in vitro differentiation of hematopoietic myeloid progenitor cells derived from cord blood by inducing secretion of colony-stimulating factor(s) (CSF) in T cells, presumably through the interaction of gp160 with CD4 molecules. In this study, we investigated the gp 160-induced humoral CSFs in cord blood by enzyme-linked immunosorbent assay (ELISA) and by polymerase chain reaction on reverse-transcribed mRNA (RT-PCR). We demonstrate that gp160 can induce interleukin (IL)-3, IL-6, and granulocyte-macrophage CSF (GM-CSF) protein secretion only in purified cord-blood T cells (CB-T) and not in detectable amounts in whole cord blood cells (WCB); cytokine mRNA induction occurred in purified CB-T and WCB, but was significantly greater in the former. Treatment of gp160 with soluble CD4 (sCD4) abolished the secretion of all three cytokines in CB-T cells, which suggests that interaction of gp160 with CD4 molecules is required for the secretion of these cytokines from CB- T cells. However, in WCB cells, sCD4 treatment of gp160 resulted in inhibition of only IL-3 and GM-CSF mRNA, whereas IL-6 secretion was enhanced. Purified cord-blood monocytes secreted only IL-6 in response to gp160, and the gp160-induced IL-6 secretion by monocytes was also further increased by gp160 + sCD4 complex. Furthermore, monocyte culture supernatants suppressed gp160-induced IL-3 secretion from CB-T cells. These findings indicate that (1) CB-T cells are a potent source of gp160-induced hematopoietic cytokines, and (2) that different mechanisms are involved in the induction of IL-6 by gp160 in the T- and non-T-cell fractions of cord blood. The ability of HIV gp160 to induce hematopoietic CSFs in cord blood may be important in HIV pathogenesis. 相似文献
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