全文获取类型
收费全文 | 132475篇 |
免费 | 7591篇 |
国内免费 | 1239篇 |
专业分类
耳鼻咽喉 | 2078篇 |
儿科学 | 2007篇 |
妇产科学 | 1925篇 |
基础医学 | 21026篇 |
口腔科学 | 3170篇 |
临床医学 | 12323篇 |
内科学 | 23615篇 |
皮肤病学 | 4189篇 |
神经病学 | 10721篇 |
特种医学 | 7540篇 |
外国民族医学 | 3篇 |
外科学 | 17495篇 |
综合类 | 751篇 |
现状与发展 | 3篇 |
一般理论 | 33篇 |
预防医学 | 6954篇 |
眼科学 | 3391篇 |
药学 | 11910篇 |
3篇 | |
中国医学 | 1587篇 |
肿瘤学 | 10581篇 |
出版年
2023年 | 956篇 |
2022年 | 2898篇 |
2021年 | 4617篇 |
2020年 | 2232篇 |
2019年 | 3099篇 |
2018年 | 3884篇 |
2017年 | 3144篇 |
2016年 | 4105篇 |
2015年 | 5705篇 |
2014年 | 6773篇 |
2013年 | 7843篇 |
2012年 | 11746篇 |
2011年 | 11282篇 |
2010年 | 6495篇 |
2009年 | 5552篇 |
2008年 | 7898篇 |
2007年 | 7475篇 |
2006年 | 6730篇 |
2005年 | 6261篇 |
2004年 | 5414篇 |
2003年 | 4684篇 |
2002年 | 4071篇 |
2001年 | 3092篇 |
2000年 | 2836篇 |
1999年 | 2191篇 |
1998年 | 940篇 |
1997年 | 705篇 |
1996年 | 524篇 |
1995年 | 470篇 |
1994年 | 406篇 |
1993年 | 343篇 |
1992年 | 771篇 |
1991年 | 717篇 |
1990年 | 649篇 |
1989年 | 571篇 |
1988年 | 469篇 |
1987年 | 476篇 |
1986年 | 345篇 |
1985年 | 376篇 |
1984年 | 275篇 |
1983年 | 200篇 |
1982年 | 136篇 |
1981年 | 179篇 |
1980年 | 133篇 |
1979年 | 230篇 |
1978年 | 166篇 |
1977年 | 122篇 |
1976年 | 137篇 |
1975年 | 123篇 |
1974年 | 145篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Lee SH Shin MS Park WS Kim SY Dong SM Lee HK Park JY Oh RR Jang JJ Lee JY Yoo NJ 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》1999,107(11):1013-1019
Cross-linking of Fas and Fas ligand (FasL) induces apoptosis in Fas-bearing cells and regulates apoptosis. Fas is widely expressed in normal human tissues, but FasL expression has been considered to be restricted to lymphoid tissues. Recent studies have demonstrated that FasL is also expressed in some nonlymphoid tissues. To screen the in situ expression of FasL in normal human tissues, immunohistochemistry was performed using paraffin-embedded human tissues. FasL immunostaining was easily detected in testis, neurons, trophoblasts, tonsil, lymph node, Paneth cells, hepatocytes, renal tubular epithelium and bronchial epithelium, consistent with previous reports. Surprisingly, FasL was also expressed in many other cell types, including thymic medulla, skeletal muscle, cardiac muscle, pituitary gland, parathyroid gland, prostate glands, oocytes, epithelium of fallopian tube, endometrial glands, and gastric parietal cells. These findings demonstrate that FasL is widely expressed in human tissues and suggest that wide but cell-type specific expression of FasL may not only be implicated in the regulation of immune homeostasis but also in the regulation of cell death and life in many cell types in vivo. 相似文献
993.
Somnay-Wadgaonkar K Nusrat A Kim HS Canchis WP Balk SP Colgan SP Blumberg RS 《International immunology》1999,11(3):383-392
In order to better understand the role of intestinal CD1d, we sought to define the cellular localization and further characterize the biochemical structure of CD1d in human intestinal epithelial cells (IEC). Using a CD1d-specific rabbit anti-gst-CD1d antibody, immunoprecipitation of radiolabeled cell surface proteins detected a previously identified 37 kDa protein as well as a 48-50 kDa protein which were confirmed by Western blotting with a CD1d-specific mAb, D5. Immunoprecipitation of protein lysates with the CD1d-specific mAb, D5 and 51.1.3, and the beta2-microglobulin (beta2m)-specific mAb, BBM.1, followed by N-glycanase digestion and Western blotting with the D5 mAb showed that the 48-50 kDa protein was a beta2m-associated, CD1d glycoprotein. CD1d was immunolocalized to the apical and lateral regions of native small and large intestinal IEC as defined by confocal laser microscopy using the D5 mAb and the rabbit anti-gst-CD1d antibody. In addition, a large apical intracellular pool of CD1d was identified. Identical observations were made with polarized T84 cells. Selective biotin labeling of apical and basolateral cell surfaces followed by immunoprecipitation with the D5 mAb, N-glycanase digestion and avidin blotting confirmed the presence of glycosylated CD1d on both cell surfaces and immunolocalization of the 37 kDa non-glycosylated form of CD1d to the apical cell surface. These studies show that CD1d is located in an ideal position for luminal antigen sampling and presentation to subjacent intraepithelial lymphocytes. 相似文献
994.
995.
996.
Fifty three bile specimens from 42 patients were reviewed to assess the diagnostic role of the bile cytology and to define more reliable cytologic indicators of malignancy. Forty three bile specimens came from 34 patients with malignant biliary strictures and 10 bile specimens were from eight patients with benign conditions. There were no false positives. The diagnostic specificity of bile cytology was 100% while diagnostic sensitivity was 55.8%. Overall diagnostic accuracy was 64.2%. We identified four key criteria as cytologic indicators of malignancy among 20 variables by using multiple regression analysis: loss of honeycomb arrangement, hyperchromatism, increased N/C ratio, and coarse chromatin. When bile specimens with three or more of these four criteria are thought to represent malignancy, the sensitivity of diagnosis of malignancy was 65.2%, specificity was 90% and diagnostic accuracy was 69.8%. 相似文献
997.
Technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) uptake is known to be increased in breast cancer because of increased blood flow from angiogenesis and heightened metabolism. We performed a 99mTc-MIBI scan in a patient with mammary Paget's disease. The patient had underlying invasive cancer in the same side of the breast. 99mTc-MIBI scan exhibited a scintigraphic image of the uptake from the invasive cancer lesion located deeply in the breast toward the epidermis. 99mTc-MIBI showed an uptake in the deeply located invasive cancer lesion as well as nipple lesion. Especially, the delayed phase of Tc-MIBI scan demonstrated the tumor site more accurately. In conclusion, 99mTc-MIBI scan could be a useful adjunct to clinical decision making in the management of Paget's disease of the breast. 相似文献
998.
Ahn YK Park JC Park WS Kim NH Kim JW Kim SH Cho JH Jeong MH Cho JG Kang JC 《Journal of Korean medical science》1999,14(5):571-574
Epicardial fat may anteriorly produce an echo-free space that can be mistaken for pericardial fluid. We recently experienced a 67-year-old woman with prominent epicardial fat which was presented as an echogenic tumor-like mass. She underwent open pericardiostomy to relieve large amount of pericardial effusion. Operative findings revealed only prominent epicardial fat. Biopsy of the pericardial and fat tissues revealed an inflammation and normal fat cells without any malignant cell infiltration. 相似文献
999.
Kwak JY Beer AE Kim SH Mantouvalos HP 《American journal of reproductive immunology (New York, N.Y. : 1989)》1999,41(1):91-98
PROBLEM: Placental lesions of 71 women with documented recurrent spontaneous abortions of unknown etiology were evaluated using immunohistochemical staining. METHOD OF STUDY: Placental tissue blocks (less than 12 weeks gestation) from prior pregnancy losses were obtained, recut, and analyzed utilizing monoclonal antibody to identify the trophoblast (cytokeratin 8/18) and natural killer (NK) cells (CD57) at the implantation site. The following features were evaluated: trophoblast invasion pattern; syncytium formation; vasculitis and thromboembolism of decidual vessels; decidual inflammation; decidual necrosis; fibrin deposition at the decidual necrosis site; mononuclear-cell infiltration in villi and intervillous space; perivillous fibrin deposition; trophoblast morphology; and quantitation of CD57+ NK cells within the decidual tissue near the implantation site. Controls consisted of 20 healthy women with no history of recurrent pregnancy losses, who had their pregnancies electively terminated. RESULTS: Of the women studied, 29.6% demonstrated elevated CD57+ NK cells at the implantation site (P = 0.030), 54.1% had inadequate cytotrophoblast invasion depth (P = 0.000), 44.1% demonstrated inadequate syncytium formation (P = 0.004), and 33.9% presented thromboembolism in decidual vessels (P = 0.025). CONCLUSION: Some women with recurrent spontaneous abortions demonstrate abnormal placental lesions at the implantation site. Immunopathologic evaluation of the placental implantation site that terminated in a spontaneous abortion may reveal the immunopathogenesis of previous pregnancy losses. 相似文献
1000.