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61.
目的:对比侧柏叶煮散饮片与市售原饮片煎煮质量。方法:应用ITS2序列作为DNA条形码对侧柏叶进行分子鉴定,采用化学指纹图谱表征药材化学组成,评价市售饮片及精准煮散饮片的相似度,测定指标成分槲皮苷的含量,标定指纹图谱共有峰。同时,采用标准汤剂煎煮法,比较市售饮片及精准煮散饮片的煎煮效率,对煮散体系进行综合评价。结果:ITS2序列对侧柏叶药材可实现准确鉴定。与原饮片比较,煮散饮片煎煮效率有所增加,且指纹图谱相似度有所提高,但按标准汤剂煎煮法,煮散饮片出膏率增加20%左右,指标性成分槲皮苷的含量未有显著增长,其余化学成分的煎出率也没有明显变化。结论:精准煮散饮片在一定程度上有利于提高侧柏叶的煎煮效率及药材均一性。 相似文献
62.
高速逆流色谱结合快速生物活性检测方法,特别适合从中药和天然产物中筛选活性成分。结合本课题组的研究和近年研究进展,本文综述了高速逆流色谱在中药和天然产物中快速筛选活性成分的应用进展。 相似文献
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Process apt microbial proteases due to their wide range industrial applications have become the focus of intense scientific research during recent years. Considering the hostile process milieu, the proteases intended for application must be robust enough to withstand the extremes of temperature and pH, and presence of organic solvents and other potential enzyme inhibitors. Current study presents the characterization of a robust protease from a previously isolated bacterium Bacillus subtilis K‐1 (BSK‐1). Purification of BSK‐1 protease (5.21‐fold) was achieved to homogeneity by salt (ammonium sulfate) precipitation, and ion‐exchange (diethyl‐aminoethyl‐sephadex) and size exclusion chromatography (Sephadex G‐100). Molecular weight of BSK‐1 protease was determined by SDS‐PAGE analysis (42 kDa). Though the optimum temperature and pH for BSK‐1 protease activity was 50 °C and 10, respectively, but, the protease exhibited remarkable activity and stability over elevated temperatures (60–80 °C) and a broad pH range (pH 7–11). Protease showed resistance towards several organic solvents/other potential enzyme inhibitors. Drastic activity loss in presence of phenylmethylsulfonyl fluoride indicated that the enzyme is a serine protease. Kinetic parameters (Km and Vmax) for BSK‐1 protease were found to be 0.14 mg ml?1 and 1176 mg min?1, respectively. Putative amino acid sequence of BSK‐1 protease (derived from nucleotide sequence of protease gene) suggested that the enzyme belonged to peptidases S8/S53 super family with multidomain of S8. BSK‐1 protease being stable under harsh conditions may serve a model system for understanding the molecular basis of stability, and may help designing novel proteases that are suitable for industrial applications. 相似文献
68.
Synergistic effect of interleukin‐17 and tumour necrosis factor‐α on inflammatory response in hepatocytes through interleukin‐6‐dependent and independent pathways 下载免费PDF全文
A. Beringer N. Thiam J. Molle B. Bartosch P. Miossec 《Clinical and experimental immunology》2018,193(2):221-233
The proinflammatory cytokines interleukin (IL)‐17 and tumour necrosis factor (TNF)‐α are targets for treatment in many chronic inflammatory diseases. Here, we examined their role in liver inflammatory response compared to that of IL‐6. Human hepatoma cells (HepaRG, Huh7.5 and HepG2 cells) and primary human hepatocytes (PHH) were cultured with IL‐6, IL‐17 and/or TNF‐α. To determine the contribution of the IL‐6 pathway in the IL‐17/TNF‐α‐mediated effect, an anti‐IL‐6 receptor antibody was used. IL‐17 and TNF‐α increased in synergy IL‐6 secretion by HepaRG cells and PHH but not by Huh7.5 and HepG2 cells. This IL‐17/TNF‐α synergistic cooperation enhanced the levels of C‐reactive protein (CRP) and aspartate aminotransferase (ASAT) in HepaRG cell and PHH cultures through the induction of IL‐6. IL‐17/TNF‐α also up‐regulated IL‐8, monocyte chemoattractant protein (MCP)‐1 and chemokine (C‐C motif) ligand 20 (CCL20) chemokines in synergy through an IL‐6‐independent pathway. Interestingly, first exposure to IL‐17, but not to TNF‐α, was crucial for the initiation of the IL‐17/TNF‐α synergistic effect on IL‐6 and IL‐8 production. In HepaRG cells, IL‐17 enhanced IL‐6 mRNA stability resulting in increased IL‐6 protein levels. The IL‐17A/TNF‐α synergistic effect on IL‐6 and IL‐8 induction was mediated through the activation of extracellular signal‐regulated kinase (ERK)‐mitogen‐activated protein kinase, nuclear factor‐κB and/or protein kinase B (Akt)–phosphatidylinositol 3‐kinase signalling pathways. Therefore, the IL‐17/TNF‐α synergistic interaction mediates systemic inflammation and cell damage in hepatocytes mainly through IL‐6 for CRP and ASAT induction. Independently of IL‐6, the IL‐17A/TNF‐α combination may also induce immune cell recruitment by chemokine up‐regulation. IL‐17 and/or TNF‐α neutralization can be a promising therapeutic strategy to control both systemic inflammation and liver cell attraction. 相似文献
69.
Ling Zhou Xuping Niu Jiannan Liang Junqin Li Jiao Li Yueai Cheng Yanfeng Meng Qiang Wang Xiaoli Yang Gang Wang Yu Shi Erle Dang Kaiming Zhang 《Acta histochemica》2018,120(8):734-740
Objective
To directionally-differentiate dermis-derived mesenchymal stem cells (DMSCs) into vascular endothelial cells (VECs) in vitro, providing an experimental basis for studies on the pathogenesis and treatment of vascular diseases.Methods
After separation by adherent culture, VEC line supernatant, vascular endothelial growth factor (VEGF), bone morphogenetic protein-4 and hypoxia were used for the differentiation of VECs from DMSCs. The cell type was authenticated by flow cytometry, matrigel angiogenesis assay in vitro, and immunofluorescent staining during differentiation. The VEGF concentration was investigated by enzyme-linked immunosorbent assay.Results
After 28 days of differentiation, the cell surface marker CD31 was significantly positive (80%–90%) by flow cytometry in the VEC line-conditioned culture, which was significantly higher than in the other groups. Differentiated DMSCs had the ability to ingest Dil-ac-LDL and vascularize in the conditioned culture, but not in the other groups. In the VEC line supernatant, the concentration of VEGF was very low. The VEGF concentration changed along with the differentiation into VECs in the medium of the conditioned culture group.Conclusion
VEC line supernatant can induce the differentiation of DMSCs into VECs, possibly through the pathway except VEGF. 相似文献70.