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991.
Lan S  McLay L  Aronson J  Ly H  Liang Y 《Archives of virology》2008,153(7):1241-1250
A virulent (P18) strain of the Pichinde arenavirus produces a disease in guinea pigs that somewhat mimics human Lassa fever, whereas an avirulent (P2) strain of this virus is attenuated in infected animals. It has been speculated that the composition of viral genomes may confer the degree of virulence in an infected host; the complete sequence of the viral genomes, however, is not known. Here, we provide for the first time genomic sequences of the S and L segments for both the P2 and P18 strains. Sequence comparisons identify three mutations in the GP1 subunit of the viral glycoprotein, one in the nucleoprotein NP, and five in the viral RNA polymerase L protein. These mutations, alone or in combination, may contribute to the acquired virulence of Pichinde virus infection in animals. The three amino acid changes in the variable region of the GP1 glycoprotein subunit may affect viral entry by altering its receptor-binding activity. While NP has previously been shown to modulate host immune responses to viral infection, we found that the R374 K change in this protein does not affect the NP function of suppressing interferon-beta expression. Four out of the five amino acid changes in the L protein occur in a small region of the protein that may contribute to viral virulence by enhancing its function in viral genomic RNA synthesis.  相似文献   
992.
目的探讨在急性冠脉综合征(ACS)中应用他汀类药物对Th1和Th2细胞亚群的影响。方法将56例ACS按照入院前是否应用他汀类药物分为应用他汀组(A组,30例)和未使用他汀组(B组,26例),用流式细胞术检测入院时Th1和Th2细胞比例并进行两组间比较;入院治疗(B组加用他汀)1月后,再次复查和比较Th1和Th2细胞,同时在B组将治疗后和治疗前结果进行自身对比。结果A组在入院时Th1细胞比例较B组低,Th2细胞比例无显著性差异;经加用他汀治疗1月后,两组间Th1和Th2细胞比例均无显著性差异。B组治疗后Th1细胞较治疗前有显著降低。结论在ACS中应用他汀类药物治疗能降低Th1细胞激活程度,改善Th1/Th2细胞比值的不平衡。  相似文献   
993.
Amyloid-β (Aβ) peptides accumulate in the brain and initiate a cascade of pathologic events in Alzheimer's disease. The receptor for advanced glycation end products (RAGE) has been implicated to mediate Aβ-induced perturbations in the neurovascular unit (NVU). We demonstrated that pinocembrin exhibits neuroprotection through inhibition of the Aβ and/or RAGE pathway, but the therapeutic role and mechanism involved are not ascertained. Here, we report that a 3-month treatment with pinocembrin prevents the cognition decline in APP/PS1 transgenic mice without altering Aβ burden and oxidative stress. Instead, pinocembrin is effective in conferring neurovascular protection through maintenance of neuropil ultrastructure, reduction of glial activation and levels of inflammatory mediators, preservation of microvascular function, improving the cholinergic system by conserving the ERK-CREB-BDNF pathway, and modulation of RAGE-mediated transduction. Furthermore, in an in vitro model, pinocembrin provides the NVU protection against fibrillar Aβ1–42, accompanied by regulation of neurovascular RAGE pathways. Our findings indicate that pinocembrin improves cognition, at least in part, attributable to the NVU protection, and highlights pinocembrin as a potential therapeutic strategy for the prevention and/or treatment of Alzheimer's disease.  相似文献   
994.
目的:研究shRAKC1对慢性成瘾小鼠脑组织CREB mRNA、蛋白的表达变化。方法:通过条件性位置偏爱(CPP)实验分析shRAKC1对慢性吗啡成瘾小鼠的作用;通过RT-PCR检测RACK1和CREB的mRNA在成瘾小鼠海马中的表达水平,并采用免疫组化观察RACK1和CREB蛋白的表达情况。结果:慢性成瘾组与生盐水组相比,前者海马区RACK1和CREBmRNA表达升高(p〈0.05),且吗啡诱导的CPP效应增强(p〈0.05),而shRAKC1组与空质粒组相比,前者由吗啡诱导的CPP诱导效应减弱(p〈0.05),同时其海马区RACK1和CREBmRNA表达下降(p〈0.05)。结论:干扰慢性吗啡成瘾小鼠RACK1表达,可以使CREB表达水平下调,并有抑锏吗啡成瘾效应的作用。  相似文献   
995.
The critical role of macrophage migration inhibitory factor (MIF) in mediating inflammatory lung injury in acute respiratory distress syndrome (ARDS) has been raised recently. The present study has identified enhanced MIF protein expression in alveolar capillary endothelium and infiltrating macrophages in lung tissues from ARDS patients. The possibility that MIF up-regulates its synthesis in an autocrine fashion in ARDS was tested using cultured endothelial cells stimulated with MIF and a murine model of lipopolysaccharide (LPS)-induced acute lung injury. MIF induced significant MIF and tumour necrosis factor (TNF)-alpha synthesis in cultured endothelial cells and the effect was blocked by neutralizing anti-MIF antibody. A similar blocking effect was observed when MIF-stimulated endothelial cells were pretreated with neutralizing anti-TNF-alpha antibody or glucocorticoid, supporting the notion that MIF induced TNF-alpha production via an amplifying pro-inflammatory loop. Treatment with anti-MIF or glucocorticoid effectively attenuated pulmonary pathology and the synthesis of MIF or TNF-alpha in mice with LPS-induced acute lung injury. Mildly augmented expression of aquaporin 1 (AQP1) was also detected in alveolar capillary endothelium in ARDS. In vitro studies revealed that both MIF and TNF-alpha induced a small increase of AQP1 synthesis in cultured endothelial cells. These findings suggest that MIF plays a crucial pathological role leading to alveolar inflammation in ARDS. Anti-MIF and early glucocorticoid therapy may represent a novel therapeutic approach for reducing alveolar inflammation in ARDS.  相似文献   
996.
997.
Much is known about specific antibodies and their titers in patients with tuberculosis. However, little is known about the avidity of these antibodies or whether changes in avidity occur during the progression of the disease or during treatment. The aims of this study were to determine the avidity of antibodies to Mycobacterium tuberculosis in patients with pulmonary tuberculosis, to explore the value of avidity determination for the diagnosis of tuberculosis, and to study changes in levels of antibodies and their avidity during treatment. Antibody avidity was measured by an enzyme-linked immunosorbent assay with thiocyanate elution. Avidity indices and serum levels of immunoglobulin G to M. tuberculosis were determined for 22 patients with pulmonary tuberculosis before and during treatment and for 24 patients with other pulmonary diseases. Antibody levels and avidity were both significantly higher in untreated tuberculosis patients than in the controls. Avidity determination had more diagnostic potential than determination of the antibody levels. Tuberculosis patients with a long duration of symptoms had higher antibody avidity than those with a recent onset of symptoms, indicating affinity maturation of specific antibodies during active disease. In the early phase of treatment, a decrease in antibody avidity was observed for 73% of all tuberculosis patients, accompanied by an initial increase in antibody levels in 36% of these patients. These phenomena could be explained by an intense stimulation of the humoral response by antigens released from killed bacteria, reflecting early bactericidal activity of antituberculous drugs leading to the production of low-affinity antibodies against these released antigens.  相似文献   
998.
报道用骨间前血管腕背支骨膜瓣移位修复骨不连、骨坏死的手术方法及疗效。方法:根据应用解剖学研究,设计以骨间前动脉腕背支为蒂的骨膜瓣,顺行移位修复尺、桡骨骨不连,逆行移位修复手舟骨、月骨不连与骨坏死。结果:临床应用19例,随访1年,在术后3~6月均达到骨愈合和骨坏死修复,关节活动功能明显改善。结论:骨间前血管腕背支为蒂的骨膜瓣移位术适合邻近骨不连、骨坏死修复。  相似文献   
999.
目的 :研究郑氏植物蛋白 (Zheng’splant protein ,ZPP)对淋巴细胞的刺激作用及其在乳腺癌早期诊断与治疗中的应用价值。方法 :采用3 H TdR掺入法测定人外周血淋巴细胞(PBL) )的增殖反应。用流式细胞仪测定ZPP对T淋巴细胞CD3+ 、CD4 + 和CD8+ 抗原表达的调节作用。结果 :ZPP对乳腺癌及其前期病变患者PBL有较强的刺激作用 (SI分别为3.0 0± 1.4 5和 2 .5 3± 0 .80 ) ,明显高于对正常对照组和乳管上皮轻度增生患者PBL的刺激指数 (SI分别为 1.0 6± 0 .17和1.18± 0 .19) (P <0 .0 1)。而PHA对各组PBL的增殖反应均有不同程度的刺激作用 ,但各组间无明显差异 (P >0 .0 5 ) .经ZPP刺激后的PBL中CD3+ 、CD4 + 和CD8+ 细胞均发生增殖反应 ,其中CD4 + 和CD8+ 者更为明显。结论 :ZPP可选择性刺激乳腺癌及其前期病变患者的PBL中T细胞发生增殖反应 ,此作用有可能用于乳腺癌的早期诊断与治疗中  相似文献   
1000.
目的 建立检测EBV感染的新方法并观察EBV与鼻咽癌的关系。方法 鼻咽部活检组织和石蜡包埋标本6 6例 ,采用荧光定量聚合酶链反应 (FQ -PCR)和原位杂交 (ISH)两种方法检测EBV ,其检测结果与病理诊断对照。结果 :FQ-PCR检测EBV -DNA阴性 5 2例 ,其中 5 1例为炎性病变 ,另 1例为腺癌 ;EBV -DNA阳性 14例 ,其中 13例为鳞状细胞癌 ,另 1例虽为炎症。但部分上皮细胞呈不典型增生。ISH检测EBV阳性 4 9例 ,其中 4 7例为炎性病变 2例为癌。EBV阳性 17例 ,其中 12例为癌 ,5例为炎性病变。FQ -PCR和ISH检测EBV结果 ,经卡方检测差异无显著性 (P >0 .0 5 )。结论 EBV感染与鼻咽癌有高度相关性。FQ -PCR检测EBV具有方法简单、快速、定量准确等优点。  相似文献   
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