全文获取类型
收费全文 | 141092篇 |
免费 | 14085篇 |
国内免费 | 9245篇 |
专业分类
耳鼻咽喉 | 1094篇 |
儿科学 | 2110篇 |
妇产科学 | 1687篇 |
基础医学 | 13304篇 |
口腔科学 | 2735篇 |
临床医学 | 19498篇 |
内科学 | 17553篇 |
皮肤病学 | 1712篇 |
神经病学 | 5267篇 |
特种医学 | 4905篇 |
外国民族医学 | 44篇 |
外科学 | 11692篇 |
综合类 | 29451篇 |
现状与发展 | 40篇 |
一般理论 | 11篇 |
预防医学 | 13154篇 |
眼科学 | 3887篇 |
药学 | 15954篇 |
234篇 | |
中国医学 | 10803篇 |
肿瘤学 | 9287篇 |
出版年
2024年 | 552篇 |
2023年 | 2145篇 |
2022年 | 5302篇 |
2021年 | 6751篇 |
2020年 | 5551篇 |
2019年 | 4187篇 |
2018年 | 4269篇 |
2017年 | 4698篇 |
2016年 | 4007篇 |
2015年 | 6550篇 |
2014年 | 8040篇 |
2013年 | 8299篇 |
2012年 | 12450篇 |
2011年 | 13149篇 |
2010年 | 10016篇 |
2009年 | 8377篇 |
2008年 | 9254篇 |
2007年 | 8946篇 |
2006年 | 7945篇 |
2005年 | 7059篇 |
2004年 | 4809篇 |
2003年 | 4395篇 |
2002年 | 3667篇 |
2001年 | 2811篇 |
2000年 | 2352篇 |
1999年 | 1806篇 |
1998年 | 1040篇 |
1997年 | 1049篇 |
1996年 | 802篇 |
1995年 | 674篇 |
1994年 | 621篇 |
1993年 | 375篇 |
1992年 | 395篇 |
1991年 | 368篇 |
1990年 | 319篇 |
1989年 | 254篇 |
1988年 | 250篇 |
1987年 | 236篇 |
1986年 | 167篇 |
1985年 | 124篇 |
1984年 | 70篇 |
1983年 | 62篇 |
1982年 | 31篇 |
1981年 | 24篇 |
1980年 | 18篇 |
1979年 | 38篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1974年 | 14篇 |
1973年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
应用小鼠骨髓细胞长周期培养(LTBMC)体系,观察重组人白细胞介素-1α(rhIL-1α)对造血细胞增殖的影响。结果显示,经rhlL-1α作用后,小鼠LTBMC中悬浮细胞数增多,其中粒单系祖细胞(CFU-GM)数量也明显增加,维持时间延长。表明rhIL-1α能促进小鼠造血细胞在体外LTBMC中增殖并分化,而且与剂量有关系。rhIL-1α加入的时间,以骨髓细胞2次接种时同时加入为好,延迟加入则作用减弱。本实验对骨髓干、祖细胞体外扩增和自体骨髓移植等方面的研究有一定意义。 相似文献
172.
用结合^131碘和化疗药物的明胶微球作肝动脉... 总被引:1,自引:0,他引:1
Nine patients with inoperable hepatoma were treated by using hepatic arterial embolization 131I and chemotherapeutic agent gelatin microsphere (131I-CA-GM). The emission CT after operation detected that the microspheres were concentrated on tumor area. The ratio between the radioactivity in tumor and that in liver was 4.1:1. A case died of ictopic embolization; the others survived 3, 4, 5, 19, 24, 7, 8, and 12 months respectively. Three of them were still alive. 131I-CA-GM has triple anticarcinogenic actions, including the arterial occlusion, targeting chemotherapy and internal radiation. The microspheres can selectively accumulate in the tumor artery and can be easily traced by gamma-camera or emission CT. 131I-CA-GM is a hopeful embolic agent for the treatment of liver cancer, but some problems about ectopic arterial embolization should be further studied. 相似文献
173.
Monoclonal antibodies were raised against a specific human sperm protein and designated as the YWK-II mAb. The partial cDNA encoding the protein was isolated from a rat testis lambda gt11 expression library and the amino acid sequence of the protein was deduced. The cytoplasmic-transmembrane domains of the deduced protein had high homology with the A4 amyloid precursor protein of Alzheimer's disease. To evaluate the stage of spermatogenesis when the gene was expressed, single-stranded 35S-labeled RNA probes were prepared from the cDNA. By an in situ hybridization technique the mRNA for the antigen was detected in germ cells at all stages of spermatogenesis. The finding that the gene is expressed in spermatogonia suggests possible involvement in the initiation of germ cell differentiation or in the detachment of spermatogonia from the basement membrane. 相似文献
174.
甲型流流感病毒鼠肺适庆型75-39株治疗S37腹水型荷瘤小鼠,存活率达93.3%。体外实验观察流感病毒感染S37肿瘤细胞,到3天时S37细胞经胎盘蓝染色,100%的S37细胞死亡,而对照组肿瘤细胞染色率只有10%左右。 相似文献
175.
人胎儿雪旺氏细胞的体外培养及其纯化研究 总被引:3,自引:1,他引:2
本实验用酶消化法从孕14~19周人胎儿周围神经中分离培养雪旺氏细胞,结合差速贴壁和阿糖胞苷处理进行纯化,根据S-100蛋白免疫细胞化学染色和形态学特征,分析不同时期雪旺氏细胞的纯化程度。实验结果显示:培养4d,倒置相差显微镜下观察,雪旺氏细胞呈典型的双极或三极形,端对端或旋涡状排列,S-100蛋白免疫细胞化学染色呈阳性反应,其比例约占98%;在2~3周内,雪旺氏细胞的纯度维持在85%~90%;培养35d,雪旺氏细胞约占80%;单纯采用阿糖胞苷或差速贴壁处理,培养35d,雪旺氏细胞约占70%;原代培养92d,传代11代细胞生长良好。实验结果表明,多种方法联合使用较单一方法所得的纯度高。本方法快速、简便,能为雪旺氏细胞作为移植材料提供足够的来源。 相似文献
176.
177.
178.
Xuyu Zu Ruilan Yan Sarah Robbins Paulette A Krishack Duan-Fang Liao Deliang Cao 《Toxicological sciences》2007,97(2):562-568
Acrolein is a highly reactive alpha,beta-unsaturated aldehyde produced endogenously during lipid peroxidation and naturally distributed pervasively in living environments, posing serious threats to human health if not properly metabolized. In this study, we report aldose reductase-like-1 (ARL-1) as a novel enzyme that catalyzes the reduction of acrolein and protects cells from their toxicity. Using purified ARL-1 protein, we determined its enzymatic activity in response to acrolein and defined its steady-state kinetics with K(m) and V(max) at 0.110 +/- 0.012 mM and 3122.0 +/- 64.7 nmol/mg protein/min, respectively. By introducing a functional Enhanced Green Fluorescent Protein (EGFP)/ARL-1 fusion protein into 293T cells, we demonstrated that plating efficiency in liquid culture and focus formation in soft agar increased by more than 60% (p < 0.05), compared to the vector control cells. More significantly, at a low dose of 5 microM acrolein, EGFP/ARL-1 expression enhanced both plating efficiency and focus formation by more than threefold, and the foci (in soft agar) of 293T cells expressing EGFP/ARL-1 were significantly larger than those of the vector control cells. At high concentrations of acrolein (25 and 50 microM), EGFP/ARL-1 protein prevented oncotic death of 293T cells induced by acrolein. In summary, our data demonstrated for the first time that the ARL-1 protein protects 293T cells from acrolein toxicity. Due to the high toxicity and wide distribution of acrolein, this finding is important to the understanding of its detoxification mechanisms. 相似文献
179.
180.
原发性胆囊癌CD44v6和bcl-2的表达及其与临床病理的关系 总被引:1,自引:0,他引:1
目的 探讨CD44v6和bcl 2蛋白在原发性胆囊癌组织中的表达及其与癌组织类型、病理分级和转移状况的关系 ,以及CD44v6表达与bcl 2表达的相关性。方法 应用免疫组织化学方法检测 50例原发性胆囊癌、2 0例胆囊腺瘤和 1 0例慢性胆囊炎组织中CD44v6和bcl 2蛋白的表达。结果 胆囊癌组织中CD44v6和bcl 2表达阳性率分别为82 .0 %和 60 .0 % ,均明显高于胆囊腺瘤 (分别为 45 .0 %和 30 .0 % ,P<0 .0 5) ,并随着胆囊癌细胞分化程度的减低、病理分级的增高和转移而明显增高 (P<0 .0 5)。同时 ,CD44v6的表达与bcl 2表达呈正相关 (r =0 .36 ,P<0 .0 5)。结论 CD44v6和bcl 2均是胆囊癌高度恶性和预后不良的重要指标。胆囊癌CD44v6表达与bcl 2蛋白表达可能具有相互协同作用。 相似文献