首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   74830篇
  免费   6517篇
  国内免费   3533篇
耳鼻咽喉   661篇
儿科学   1088篇
妇产科学   725篇
基础医学   9103篇
口腔科学   1175篇
临床医学   9096篇
内科学   12250篇
皮肤病学   879篇
神经病学   4884篇
特种医学   3216篇
外国民族医学   19篇
外科学   8572篇
综合类   9089篇
现状与发展   14篇
一般理论   35篇
预防医学   6053篇
眼科学   1785篇
药学   7401篇
  50篇
中国医学   2869篇
肿瘤学   5916篇
  2024年   132篇
  2023年   779篇
  2022年   1565篇
  2021年   3147篇
  2020年   2282篇
  2019年   2195篇
  2018年   2345篇
  2017年   2086篇
  2016年   2246篇
  2015年   3213篇
  2014年   3880篇
  2013年   4082篇
  2012年   6081篇
  2011年   6405篇
  2010年   4360篇
  2009年   3505篇
  2008年   4632篇
  2007年   4752篇
  2006年   4304篇
  2005年   4248篇
  2004年   3447篇
  2003年   3457篇
  2002年   2940篇
  2001年   1453篇
  2000年   1122篇
  1999年   1124篇
  1998年   790篇
  1997年   710篇
  1996年   505篇
  1995年   536篇
  1994年   419篇
  1993年   275篇
  1992年   323篇
  1991年   239篇
  1990年   194篇
  1989年   205篇
  1988年   139篇
  1987年   151篇
  1986年   143篇
  1985年   85篇
  1984年   64篇
  1983年   49篇
  1982年   48篇
  1981年   41篇
  1980年   35篇
  1979年   19篇
  1978年   14篇
  1977年   15篇
  1976年   20篇
  1973年   15篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
61.
目的 研究透明质酸钠玻璃体腔内充填对严重开放性眼球损伤预后的影响。方法 在严重开放性眼球损伤一期手术缝合后玻璃体腔内充填透明质酸钠至眼压Tn。结果 用透明质酸钠在玻璃体腔内充填,眼球萎缩的发生率(6.67%)明显低于用BSS液充填的发生率(70.58%)。结论 透明质酸钠玻璃体腔内充填在严重开放性眼球损伤治疗中的应用对眼球外形维持和视功能恢复有重要作用。  相似文献   
62.
OBJECTIVE: To understand the role of nasal mucous epithelial cells to hypoxia in early stage of nasal polyps(NP) formation. METHODS: Epithelial cells of NP and inferior turbinate (IT) were cultured without serum under normal oxygen and hypoxia, and stimulus of inflammatory cytokines. Erythropoietin (EPO) was regarded as hypoxia mark, and expression of vascular endothelial growth factor(VEGF) mRNA and protein derived from epithelial cells were detected respectively by in situ hybridization and ELISA. RESULTS: 1. Under hypoxia, EPO mRNA was expressed intensely in epithelial cells from NP and IT, and there was no significant difference between both of them. This result suggested that EPO might be regarded as a hypoxic mark. 2. The ability of producing VEGF mRNA increased with cytokines stimulation, especially under hypoxia. Protein level of VEGF from epithelial cells of NP and IT increased with cytokines stimulation, especially in hypoxia and was time-dependent. CONCLUSION: Epithelial cells actively produce vast VEGF under hypoxia. The VEGF induced by hypoxia of the mucosa in middle meatus is of importance in the formation of nasal polyps(NP) in early stage, which may be the major cause of NP formation in middle meatus.  相似文献   
63.
目的 探讨彩超在肾移植术后并发肝脏恶性肿瘤监测中的应用价值。 方法 应用 Acuson12 8XP彩色多普勒超声诊断仪 ,对在我院行异体肾移植手术的终末期尿毒症患者 12 0 0例进行规律随访。 结果 发现 17例恶性肿瘤 ,其中肝癌 7例 ,占 4 1.17%。 5例肿块单发 ,2例多发 ;肿块最大 10 cm× 10 cm,最小 2 .3cm× 2 .1cm。其中 6例手术病理证实 ,1例肝活检证实。 结论 对移植肾术后患者 ,首选彩超随访肝脏变化 ,能早期发现肿瘤 ,为临床选择治疗方案提供时机 ,并提高换肾后发生恶性肿瘤患者的存活率  相似文献   
64.
65.
66.
67.
抑肽酶预处理防护大鼠肝脏缺血再灌注损伤的实验研究   总被引:5,自引:1,他引:4  
苏东  陶国才  李昆 《重庆医学》2002,31(8):709-710
目的 探讨抑肽酶预处理对肝脏缺血再灌注损伤的防护作用。方法 SD大鼠80只,随机分为抑肽酶预处理和生理盐水预处理两组,观察肝脏缺血再灌注损伤引起及抑肽酶预处理的影响。结果 拟肽酶预处理组大鼠缺血再灌注损伤引起的血清谷丙转氨酶(ALT),谷草转氨酶(AST)活性及肝组织丙二醛(MDA)含量变化均显著低于生理盐水预处理组(P<0.01);肝细胞形态学异常改变也明显较生理盐水预处理组轻。结论 抑肽酶预处理对大鼠肝脏缺血再灌注损伤有明显的防治作用。  相似文献   
68.
AIM: To evaluate the relationship between changes in serum transforming growth factor β1 (TGFβ1) level and curative effect of radiotherapy (RT) in patients with esophageal carcinoma.METHODS: Ninety patients with histologically confirmed esophageal carcinoma were enrolled. Serum samples for TGFβ1 analysis were obtained before and at the end of RT. An enzyme-linked immunosorbent assay was used to measure serum TGFβ1 level. Multivariate analysis was performed to investigate the relationship between disease status and changes in serum TGFβ1 level.RESULTS: Serum TGFβ1 level in patients with esophageal carcinoma before RT was significantly higher than that in healthy controls (P < 0.001). At the end of RT, serum TGFβ1 level was decreased in 67.82% (59/87) of the patients. The overall survival rate at 1,3 and 5 years was 48.28% (42/87), 19.54% (17/87)and 12.64% (11/87), respectively. Main causes of death were local failure and regional lymph node metastasis.In patients whose serum TGFβ1 level decreased after RT,the survival rate at 1, 3 and 5 years was 61.02% (36/59),28.81% (17/59) and 18.64% (11/59), respectively. The survival rate at 1 year was 17.86% (5/28) in patients whose serum TGFβ1 level increased after RT, and all died within 18 mo (P < 0.01).CONCLUSION: Serum TGFβ1 level may be a useful marker for monitoring disease status after RT in patients with esophageal carcinoma.  相似文献   
69.
经颅彩色双功超声是一种新型、无创的超声诊断仪,高空间分辨率显示颅内血管和脑实质的结构,笔者查阅了近年来相关文献,主要综述经颅彩色多普勒血流显像在颅脑血管疾病中的诊断价值,同时讨论二维经颅超声的应用及新的实验性显像技术。  相似文献   
70.
We previously reported that lymphatic mapping using isosulfan blue can be used to identify sentinel nodes (SNs). This study was undertaken to evaluate the feasibility of using the SN technique in treating early gastric cancer and to explore its usefulness for minimal invasive surgery. Twenty-three patients with early gastric cancer who underwent SN biopsy were retrospectively evaluated. Based on SN evaluation, individualized surgery was performed in five patients with T1N0M0 gastric cancer. When pathological examination of frozen sections revealed metastasis in SNs, we performed a standard D2 gastrectomy. Laparoscopic local resection was applied when the SN biopsy was negative. Our results showed that the success rate with SN biopsy in early gastric cancer was 100%, as were the accuracy, sensitivity, and specificity. All five patients with early gastric cancer had SNs negative for metastases both by frozen section and by postoperative pathology. Thus, all these patients underwent laparoscopic local resection without extended lymphadenectomy. We conclude that SN biopsy is a useful tool to individualize the operative procedure, and laparoscopic local resection can be safely performed using SN guidance in selected patients with early gastric cancer.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号