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981.
《Immunity》2022,55(3):542-556.e5
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982.
目的:体外培养并诱导大鼠骨髓间质干细胞(MSCs)分化为肌样细胞。方法:采用常规技术对SD鼠MSCs进行体外培养传代、鉴定、诱导分化和免疫组化、透射电镜检测分析。结果:流式细胞仪检测, 细胞表达CD29和CD44, 不表达CD11b和CD45;经一定浓度5-氮杂胞苷和两性霉素B诱导分化后细胞desmin和myoglobin染色阳性;电镜观察肌样细胞胞浆靠胞膜缘可见无细胞器的条状肌丝区带。结论:传代贴壁生长的梭形细胞为MSCs。MSCs可能具有表达肌细胞的特异性启动或分化调控基因;5-氮胞苷等化合物可使DNA的胞嘧啶去甲基化, 从而诱导MSCs向肌源性细胞分化。临床有运用MSCs治疗肌萎缩性疾病的前景。  相似文献   
983.
目的 :研究肿瘤抗原多肽致敏的白细胞介素 18(IL 18)基因修饰的树突状细胞体内诱导的抗肿瘤免疫反应。方法 :①以Lewis 3LL肺癌细胞特异性抗原肽mut1冲击致敏IL 18基因修饰的骨髓来源的树突状细胞 (DC IL 18 mut1) ,每次用其 1× 10 5 只皮下免疫小鼠 2次 ,然后测定脾细胞的NK活性及CTL杀伤活性 ;②以DC IL 18 mut1每次 2× 10 5 只皮下免疫 1次 ,然后再以 5× 10 53LL细胞攻击 ,在诱导及效应阶段分别以单抗阻断不同免疫成份 ,观察肿瘤的生长。结果 :以DC IL 18 mut1皮下免疫后可诱导出比DC mut1等免疫组更高水平的 3LL肺癌细胞特异性CTL ,并使NK活性明显增加 ;单抗体内阻断实验提示在DC IL 18 mut1免疫诱导阶段 ,CD4 + T细胞和抗原共刺激分子、IFN γ均起到重要作用 ,而效应阶段CD8+ T、IFN γ、NK起作用 ,而CD4 + T则是非必需的。结论 :DC IL 18 mut1皮下免疫后可诱导高水平的抗肿瘤免疫活性 ,其机理与抗原有效提呈、特异性CTL诱导、NK活性增加以及CD4 + 、CD8+ T、NK细胞、IFN γ参与密切相关。  相似文献   
984.
An increase in bile ductular structures is observed in diverse human liver diseases. These structures harbour the progenitor cell compartment of the liver. Since ATP-binding cassette (ABC) transporters may have a cytoprotective role in liver disease, an immunohistochemical study was performed on human liver specimens from patients with primary biliary cirrhosis (PBC), chronic hepatitis C virus (HCV) infection, submassive cell necrosis, and normal liver. The expression of MDR1, MDR3, BSEP, MRP1, MRP2, and MRP3 was determined using specific antibodies. Dilution series were constructed to determine the critical staining level in order to estimate the factor of up-regulation. In normal liver, hepatocytes showed canalicular staining for MDR3, BSEP, and MRP2. MDR1 stained the canalicular membrane of hepatocytes as well as that of cholangiocytes. MRP3 showed low immunoreactivity of bile duct epithelial cells and centrilobular hepatocytes only. Normal liver showed no immunoreactivity for MRP1. In diseased liver, the expression of MDR3, BSEP, and MRP2 was relatively stable. In PBC, HCV, and submassive necrosis, the expression levels of MDR1, MRP1, and MRP3 were increased. The strongest immunoreactivity was seen after submassive necrosis, where remaining islands of hepatocytes showed strong canalicular staining for MDR1 and MRP3. Regenerating bile ductules at the interface of portal tracts and necrotic areas stained intensely for MDR1, MRP1, and MRP3. In conclusion, MDR1, MRP1, and MRP3 are up-regulated in hepatocytes in severe human liver disease. Strong MDR1, MRP1, and MRP3 reactivity is seen in regenerating human bile ductules.  相似文献   
985.
When human peripheral blood lymphocytes (PBL) are cultured with either concanavalin A (Con A)-treated or control autologous T lymphocytes, the mitogenic responses of the PBL co-cultured with Con A-treated cells are much lower. We have investigated the cell surface receptor changes during culture of T cells with and without mitogen in an attempt to explain this differential regulatory phenomenon. We present data here which show that human T cells cultured in complete medium alone gain helper cells with time. Con A-treated T cells are known to lose helper cells during culture. Erythrocyte rosette-purified T cells were cultured with or without Con A for 84 h and the numbers of cells with receptors for the Fc regions of either IgM (T mu) or IgG (T gamma) were enumerated daily. T mu cells have been associated with helper activity while T gamma cells have predominantly suppressor activity. Treatment with 10 micrograms/ml of Con A decreased T mu by approximately 50%. Untreated cells, however, showed significant increases in T mu (44 +/- 30.5% in twelve individuals). The great variance in T mu increases is due to the fact that individuals having higher initial T mu values showed smaller increases. These changes probably represent the gain or loss of receptors because total cell numbers did not change. There was no significant change in the number of T gamma cells in either control or Con A-treated cultures during the same 84 h period. In co-culture experiments in which the responses of fresh autologous PBL were determined, 60-h control T-cell cultures enhanced the mitogen responses of the fresh cells.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
986.
Summary The proportions and receptive field properties of X and Y cells in the A and A1 layers of the lateral geniculate nucleus (LGN) were studied in monocularly deprived cats. Contrary to previous reports, we found that there was no change in the relative number of Y cells in the geniculate layers driven by the deprived eye. There was also no marked change in the spatial resolution of X or Y cells driven from the deprived eye as compared to the cells driven from the normally experienced eye. In these same cats, the visual evoked potential from stimulation of the deprived eye with grating patterns was markedly reduced in amplitude. Furthermore, the cell bodies of the cells in the LGN driven by the deprived eye had shrunk. Therefore, these usual consequences of monocular deprivation are not necessarily associated with a loss of geniculate Y cells.  相似文献   
987.
目的研究人血液血管细胞生成素(hemangiopoietin,HAPO)对胎儿骨髓细胞的作用,探讨其生物学特性。方法采用细胞液体培养、半固体培养、MTT方法、免疫荧光标记流式细胞仪测定、免疫组化、显微镜观察照相等方法。结果在液体培养3周的胎儿骨髓单个核细胞中,HAPO组中出现了大量小而圆的早期造血细胞,其中CD34+细胞含量比对照组高20%,对照组CD34+细胞为1.25×105个,而HAPO组CD34+细胞为3.93×106个。取胎儿骨髓悬浮造血细胞进行半固体培养,对照组不能形成CFU-GEMM,而HAPO组形成CFU-GEMM数达到(11.0±2.6)个;HAPO也协同SCF、IL-3、GM-SCF等生长因子促进集落形成,CFU总数是对照组2.6倍,CFU-GEMM数HAPO组是对照组2.1倍。MTT方法发现,HAPO对胎儿骨髓基质细胞也有促增殖作用,HAPO可使基质细胞增长21%;液体培养的胎儿骨髓基质细胞中,有内皮特异性标志的细胞均增高;在甲基纤维素半固体培养中HAPO使胎儿骨髓内皮细胞的集落数增高,并出现条索状排列的集落,有促进血管形成的趋势。进一步证明HAPO可直接促进CD34+KDR+细胞的增殖。结论HAPO对骨髓造血和血管内皮干细胞均有刺激增殖作用。  相似文献   
988.
目的:研究SeO2对急性早幼粒细胞白血病细胞株NB4、红白血病细胞K562、急性粒细胞白血病细胞株HL-60的增生、凋亡、活性氧(ROS)及Ca2+水平等的影响。 方法: 采用不同浓度SeO2(3-30 μmol/L)分别处理3种白血病细胞,用流式细胞术测定细胞凋亡率、细胞中ROS和Ca2+的水平。 结果: 10和30 μmol/L SeO2能抑制3种细胞增生,30 μmol/L SeO2作用48 h能使54.0%的NB4细胞、46.5%的K562细胞和49.6%的HL-60细胞发生凋亡。同时下调细胞内ROS和Ca2+水平。NB4和HL-60细胞中ROS阳性细胞比例随SeO2浓度增加而减少,K562中只有30 μmol/L SeO2才能使ROS出现明显下降。10、30 μmol/L SeO2能使NB4和HL-60细胞内Ca2+水平逐步下降。K562中只有30 μmol/L SeO2才能使细胞内Ca2+水平出现明显下降。 结论: SeO2对3种白血病细胞均有诱导凋亡作用,在凋亡过程中涉及细胞内ROS及Ca2+水平下降。  相似文献   
989.
The activity of the homeobox gene Prox1 is necessary and sufficient for venous blood endothelial cells (BECs) to acquire a lymphatic endothelial cell (LEC) fate. We determined that the differentiated LEC phenotype is a plastic, reprogrammable condition that depends on constant Prox1 activity for its maintenance. We show that conditional down-regulation of Prox1 during embryonic, postnatal, or adult stages is sufficient to reprogram LECs into BECs. Consequently, the identity of the mutant lymphatic vessels is also partially reprogrammed as they acquire some features typical of the blood vasculature. siRNA-mediated down-regulation of Prox1 in LECs in culture demonstrates that reprogramming of LECs into BECs is a Prox1-dependent, cell-autonomous process. We propose that Prox1 acts as a binary switch that suppresses BEC identity and promotes and maintains LEC identity; switching off Prox1 activity is sufficient to initiate a reprogramming cascade leading to the dedifferentiation of LECs into BECs. Therefore, LECs are one of the few differentiated cell types that require constant expression of a certain gene to maintain their phenotypic identity.  相似文献   
990.
热休克蛋白60对小鼠树突状细胞功能影响体外研究   总被引:1,自引:0,他引:1  
目的:探讨动脉粥样硬化中重要炎性物质——热休克蛋白60(HSP60)体外对小鼠树突状细胞(mDC)功能影响.方法:小鼠骨髓提取DC,体外培养成熟后与两种浓度mHSP60孵育,动态观察DC突起改变;流式细胞仪检测孵育前后mDC表面标志改变;MLR测定孵育前后mDC刺激功能变化;ELISA法测定MLR上清液中细胞因子浓度.结果:孵育后,mDC突起增加明显;CD11c^+、CD80及CD86表型显著增加;淋巴细胞刺激功能明显增强;分泌细胞因子IL-12、IFN-γ增加(P<0.01)而IL-4增加不明显(P>0.05),IFN-γ/IL-4比值升高.结论:mHSP60体外可以促进mDC功能,作用呈剂量依赖性.  相似文献   
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