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   16656篇
  免费   1032篇
  国内免费   686篇
耳鼻咽喉   202篇
儿科学   447篇
妇产科学   112篇
基础医学   982篇
口腔科学   125篇
临床医学   1728篇
内科学   3924篇
皮肤病学   50篇
神经病学   369篇
特种医学   1115篇
外国民族医学   9篇
外科学   2421篇
综合类   2967篇
现状与发展   4篇
预防医学   479篇
眼科学   86篇
药学   1505篇
  5篇
中国医学   949篇
肿瘤学   895篇
  2024年   31篇
  2023年   212篇
  2022年   371篇
  2021年   517篇
  2020年   426篇
  2019年   437篇
  2018年   359篇
  2017年   509篇
  2016年   506篇
  2015年   546篇
  2014年   937篇
  2013年   984篇
  2012年   917篇
  2011年   992篇
  2010年   833篇
  2009年   904篇
  2008年   884篇
  2007年   933篇
  2006年   851篇
  2005年   740篇
  2004年   576篇
  2003年   570篇
  2002年   462篇
  2001年   411篇
  2000年   389篇
  1999年   290篇
  1998年   287篇
  1997年   264篇
  1996年   270篇
  1995年   229篇
  1994年   230篇
  1993年   169篇
  1992年   152篇
  1991年   169篇
  1990年   115篇
  1989年   120篇
  1988年   104篇
  1987年   72篇
  1986年   81篇
  1985年   93篇
  1984年   70篇
  1983年   46篇
  1982年   60篇
  1981年   50篇
  1980年   45篇
  1979年   36篇
  1978年   31篇
  1977年   31篇
  1976年   17篇
  1975年   15篇
排序方式: 共有10000条查询结果,搜索用时 287 毫秒
121.
122.
采用从新生牛肝脏提取的肝细胞再生刺激因子(cHSS)治疗慢性病毒性肝炎82例,总有效率89.0%,与对照组(76.5%)比较有显著性差异(P<0.05)。经治疗后cHSS组病人乏力、纳差、腹胀等症状的改善明显优于对照组,ALT恢复与黄疸消退均较对照组迅速(P<0.01)。治疗过程中未发现任何副作用。提示cHSS对慢性肝炎有较好的疗效,能促进肝功能恢复。  相似文献   
123.
The authors studied 34 patients with juvenile ischemic cerebrovascular disease over a 15-year period. Of the 34 patients, 23 had intracranial occlusions attributed to cerebral thrombosis or embolism and 11 had occlusions resulting from moyamoya disease. Clinicopathological features were evaluated in the 23 cases with ischemic stroke, but not those with moyamoya disease. The cause of the arterial occlusion remained undetermined in 11 patients and was found to be an embolism based on congenital heart disease in 8, on trauma in 3, and on infection in 1. Cerebral angiography was performed in 21 patients. Of these, 17 had stenoses or occlusions corresponding to their symptoms. CT scans were performed in 10 patients; the lesion in question showed no stenosis or occlusion with cerebral angiography. With regard to prognosis, patients with unknown etiology had good outcomes compared with those with congenital heart disease. With respect to acute infantile hemiplegia, 10 patients had convulsive seizures and 4 had a history of an earlier infection. Angiography and CT scans in patients with congenital heart disease demonstrated arterial occlusive sites in the middle cerebral artery region. Three patients had abscesses after their ischemic lesions.  相似文献   
124.
对29例亚急性重症肝炎及13例次淤胆性肝炎肝穿刺标本的光、电镜检查,测算了18例亚急性重症肝炎,9例淤胆性肝炎肝细胞内淤胆的容积百分比、胆汁凝固性坏死的容积百分比与临床资料进行统计学处理,指出这两类肝炎都有肝细胞内淤胆和胆汁凝固性坏死,但淤胆性肝炎肝小叶结构完整,胆汁流出道不破坏,亚急性重症肝炎肝小叶破坏。认为除肝细胞大量坏死外,胆汁流出道破坏是影响预后的另一个重要因素。本文详细描述了胆计凝固性坏死的超微结构改变。  相似文献   
125.
Summary The serum concentrations of 1-acid glycoprotein (AAG), albumin (HSA) and non-esterified fatty acids, and the serum binding of tertatolol were measured in four groups of individuals: healthy control subjects (n=24), and patients with inflammation (n=28), and hepatic (n=20) and renal (n=27) insufficiency.Serum binding of tertatolol was increased in patients with inflammation (94.6%), decreased in patients with hepatic insufficiency (88.8%) and it was unchanged in patients with renal insufficiency (92.8%) as compared to controls (92.7%).Multivariate analysis indicated that the changes were mainly related to concomitant changes in AAG concentration, which could account for 57% of intersubject variability in the bound/free ratio, and to a lesser extent in HSA, which accounted for only 4% of the variability in the binding.The data show that the free fraction of the basic drug tertatolol in serum is affected by pathological conditions that cause changes in AAG concentration.  相似文献   
126.
马勇  高伟波  朱继红 《中国全科医学》2023,26(17):2120-2124
背景细菌性肝脓肿(PLA)是临床常见的内脏器官感染性疾病,既往PLA发生血小板减少的临床研究较少。目的 分析PLA患者发生血小板减少的流行病学和临床特征,并探讨发生血小板减少的影响因素。方法 纳入北京大学人民医院2011年1月至2020年12月161例因PLA住院的患者为研究对象。收集患者资料,包括年龄、性别、体质指数(BMI)、发病症状(发热、腹痛、恶心、呕吐)、既往病史信息(高血压、糖尿病、冠心病、肝胆疾病、恶性肿瘤);收集患者入院时辅助检查结果,包括白细胞计数、中性粒细胞绝对值、淋巴细胞绝对值(ALC)、单核细胞绝对值、血红蛋白、C反应蛋白(CRP)、降钙素原(PCT)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、总胆红素(TBiL)、尿素氮(BUN)、肌酐(Scr)、白蛋白(ALB)、凝血酶原时间(PT)、活化部分凝血活酶时间、纤维蛋白原、D-二聚体(D-Dimer)、血小板计数(PLT);收集患者肝脓肿影像学检查(腹部CT或超声)结果(是否多个脓肿)、病原学检查结果(血培养、培养出肺炎克雷伯菌比例);收集患者的并发症情况及预后情况。根据外周血PLT是否<1...  相似文献   
127.
针对复兴医院收治的一例伴多种基础疾病的脑脓肿患者进行全方位的护理管理,包括健康宣教、心理疏导、密切病情观察、对症护理管理、强化患者和家属的自我管理以及康复指导等。患者安全出院,对护理工作满意度较高。  相似文献   
128.
To demonstrate ultrastructural events in the early phase of hepatic metastasis of human colon carcinoma, we intrasplenically injected a highly metastasizable, human colon carcinoma cell line LM-H3 (1 x 10(6) cells) into nude mice, and electron microscopically investigated the hepatic metastasis. At 24 h, tumor cells adhered to the endothelial wall of terminal portal venules and periportal sinusoids. At 48-72 h, after extravasation, they deeply invaded the hepatic cell plate and the interstitial tissue of the portal tract, in which they underwent proliferation and made the metastatic foci. Tumor cells were linked with each other or with surrounding hepatocytes by desmosomes. Desmosomes were maintained during the mitosis. When invading tumor cells were exposed to the bile canaliculi, they generated microvilli on the surface. Microvilli were also formed at the luminal surface of intracytoplasmic inclusions. In the interstitial tissue of the portal tract, tumor cells were closely associated with fibroblasts. However, no junctional specializations were seen between them. The present study demonstrated that human colon carcinoma cell line LM-H3 formed desmosomes with hepatocytes soon after invasion of the hepatic cell plate, suggesting the regulatory role of an interaction with hepatocytes in the growth of metastatic foci within the liver parenchyma.  相似文献   
129.
130.
We have previously shown that tumor necrosis factor-α (TNF-α), which is an important angiogenesis-related factor, was over-secreted in male BALB/c mice under social isolation stress as compared with the control, and closely associated with a remarkable elevation of tumor invasion and metastasis of colon 26-L5 carcinoma cells. In the present study, we explored the effect of isolation stress on the angiogenesis caused by colon 26-L5 carcinoma cells in vivo and in vitro. Social isolation lead to the enhancement of tumor growth after intrahepatic implantation with a fragment of colon 26-L5 tumor. Angiogenic response (number of vessels oriented towards tumor mass) and tumor growth (size) were significantly increased in the socially isolated mouse relative to that in the group-housed mice. Furthermore, higher protein level of hepatic TNF-α was found in the stressed mice than that in the control. Expression of mRNA for vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were also elevated in the tumor regions and liver tissues of the stressed mice in comparison with that in group-housed mice. On the other hand, hepatic sinusoidal endothelial (HSE) cells treated with TNF-α exhibited a marked promotion of the migration, invasion, expression of mRNA for matrix metalloproteinase (MMP)-9, and tube-like formation, but no cytotoxicity against the cells in vitro. The above data suggest that the social isolation stress augmented the tumor-induced angiogenesis probably by up-regulating the angiogenesis-related factors, including TNF-α, VEGF and HGF, and consequently mediating the functions of endothelial cells such as migration, invasion, and tube-like formation.  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