全文获取类型
收费全文 | 3231926篇 |
免费 | 253781篇 |
国内免费 | 30960篇 |
专业分类
耳鼻咽喉 | 41527篇 |
儿科学 | 99624篇 |
妇产科学 | 83868篇 |
基础医学 | 446322篇 |
口腔科学 | 91299篇 |
临床医学 | 309610篇 |
内科学 | 603124篇 |
皮肤病学 | 67418篇 |
神经病学 | 244979篇 |
特种医学 | 124977篇 |
外国民族医学 | 922篇 |
外科学 | 467285篇 |
综合类 | 138914篇 |
现状与发展 | 92篇 |
一般理论 | 1037篇 |
预防医学 | 246380篇 |
眼科学 | 78301篇 |
药学 | 253400篇 |
440篇 | |
中国医学 | 30530篇 |
肿瘤学 | 186618篇 |
出版年
2021年 | 37951篇 |
2020年 | 26732篇 |
2019年 | 32261篇 |
2018年 | 41819篇 |
2017年 | 34574篇 |
2016年 | 35974篇 |
2015年 | 45638篇 |
2014年 | 61012篇 |
2013年 | 79257篇 |
2012年 | 110616篇 |
2011年 | 118560篇 |
2010年 | 72944篇 |
2009年 | 65924篇 |
2008年 | 103159篇 |
2007年 | 107938篇 |
2006年 | 107887篇 |
2005年 | 103872篇 |
2004年 | 95373篇 |
2003年 | 91194篇 |
2002年 | 86751篇 |
2001年 | 147971篇 |
2000年 | 151809篇 |
1999年 | 128501篇 |
1998年 | 37733篇 |
1997年 | 34005篇 |
1996年 | 32907篇 |
1995年 | 31686篇 |
1994年 | 29185篇 |
1993年 | 26269篇 |
1992年 | 97999篇 |
1991年 | 95037篇 |
1990年 | 91936篇 |
1989年 | 88512篇 |
1988年 | 81407篇 |
1987年 | 79751篇 |
1986年 | 75625篇 |
1985年 | 72393篇 |
1984年 | 53526篇 |
1983年 | 45932篇 |
1982年 | 26434篇 |
1979年 | 49456篇 |
1978年 | 34095篇 |
1977年 | 28978篇 |
1976年 | 27183篇 |
1975年 | 28772篇 |
1974年 | 35102篇 |
1973年 | 33739篇 |
1972年 | 31165篇 |
1971年 | 29234篇 |
1970年 | 27027篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Two-color flow cytometry was carried out to determine the correlation between cell-mediated immunity and the levels of proteinuria in 30 patients with membranous nephropathy. Lymphocyte subpopulations were measured by two-color flow cytometry using various monoclonal antibodies of the Leu series. Clinically, the patients were divided into four stages as follows: 1. untreated nephrotic stage, 2. prednisolone (PSL) treated nephrotic stage, 3. persistent proteinuric stage (incomplete remission, ICR) and 4. complete remission (CR). Two-color flow cytometry showed a significant decrease in Leu 2a+15+ (suppressor T) cells and relative increase in Leu 3a+8+ (suppressor inducer T) cells in the untreated nephrotic stage. The mean Leu 3a+8-/Leu 2a+15+ (helper/suppressor) cell ratio was normalized in the persistent proteinuric stage or complete remission after treatment with PSL. Patients with membranous nephropathy showed a significant elevation of Leu 2a+DR+ cells after treatment with PSL. The abnormalities of suppressor T cells and suppressor inducer T cells in the peripheral blood appear to reflect the levels of proteinuria in patients with membranous nephropathy. It was concluded that PSL might stimulate Leu 2a positive cells and then increase the number of Leu 2a+15+ cells in the peripheral blood of patients with membranous nephropathy. 相似文献
992.
993.
用小鼠败血症系统感染模型,以感染小鼠肾匀浆活菌计数为标准,以庆大霉素为对照药,探讨日剂量单次与分两次给药两种方案对新氨基糖苷类抗生素89—07体内抗留作用的影响。结果表明大肠杆菌90-020、绿脓假单胞菌3—374、金葡球菌90—506对抗生素89—07和庆大霉素均敏感(MIC范围0.0625~2mg/L);抗生素89—07和庆大霉素日剂量单次给药组(OD)3株实验菌的肾匀浆活菌计数值由给药前的4.94±0.09、4.60±0.27、4.86±0.101gcfu/ml分别降至1.94±0.19、1.84±0.25、1.88±0.251gcfu/ml(给药后7~8h).日剂量分两次给药组(BID)则分别降至2.95±0.48、2.87±0.37、3.44±0.271gcfu/ml。OD组对3株实验菌的最大杀菌作用Emax分别为3.02、2.97和2.851gcfu/ml,OD给药方案的体内杀菌作用明显优于BID方案。 相似文献
994.
995.
F. M. RAAPHORST R. LANGLOIS VAN DEN BERGH J. L. M. WAAIJER J. M. VOSSEN & M. J. D. VAN TOL 《Scandinavian journal of immunology》1997,46(3):292-297
Fetal B lymphocytes in mice and humans use a limited number of the available VH gene segments. Mouse fetal B cells primarily utilize 3' VH elements, suggesting that the localization of these elements determines their rearrangement frequency. The previously reported non-random usage of human VH genes has been more difficult to explain. In this study the authors analysed the expression of the most proximal 3' human VH element (VH 6) using a monoclonal antibody (JE-6). VH 6 expression was assessed in various B cell differentiation stages from fetal liver, bone marrow and spleen at 12–20 weeks of gestation. The authors demonstrate that the level of VH 6 expression does not exceed a stochastic usage frequency. This suggests that the localization of VH 6 does not significantly promote its expression during human fetal life, and that other factors must affect the usage of VH genes during human fetal development. 相似文献
996.
结肠腺瘤与腺癌p53,c—erbB2蛋白及CEA的表达和意义 总被引:1,自引:0,他引:1
应用免疫组化法检测15例正常结肠粘膜,40例结肠瘤及40例结肠癌组织的p53,c-erbB2和CEA的表达。结果发现:结肠癌患者p53,c-erbB2及CEA的阳性表达率均显著高于腺瘤(P〈0.01)。p53阳性表达在不典型增生腺瘤患者中,重度显著高于轻度病例(P〈0.01);在结肠腺癌患者中低分化显著高于高分化病例(P〈0.05);CEA的新型单克隆抗体col-1对结肠癌的敏感性和特异性均高,阳 相似文献
997.
Spleen sizing by ultrasound in polycythaemia and thrombocythaemia: comparison with SPECT 总被引:3,自引:1,他引:2
M. Messinezy L. M. MacDonald T. O. Nunan N. B. Westwood S. Chinn & T. C. Pearson 《British journal of haematology》1997,98(1):103-107
Detection of non-palpable early splenic enlargement may aid diagnosis of primary polycythaemia (PP) and primary thrombocythaemia (PT). In this study linear spleen sizing by ultrasound has been compared with spleen volume estimation by single photon emission computerized tomography (SPECT) in 26 patients. Spleen length by ultrasound correlated well with SPECT volume estimation.
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP. 相似文献
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP. 相似文献
998.
999.
G. V. Petrova V. A. Adarichev A. A. Krivenko G. S. Dymshits A. L. Markel' G. S. Yakobson 《Bulletin of experimental biology and medicine》1997,124(2):773-775
Sensitivity of normotensive Wistar rats and NISAG rats (with hereditary arterial hypertension) to heat stress is compared
at the organism and cell levels. High temperature sensitivity of NISAG rats correlates with a low content of the main heat
shock protein HSP70. This relationship can serve as a biochemical marker of predisposition to arterial hypertension.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 8, pp. 171–173, August, 1997 相似文献
1000.