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   9008篇
  免费   575篇
  国内免费   66篇
耳鼻咽喉   31篇
儿科学   265篇
妇产科学   188篇
基础医学   1338篇
口腔科学   137篇
临床医学   822篇
内科学   2294篇
皮肤病学   173篇
神经病学   980篇
特种医学   204篇
外科学   865篇
综合类   20篇
一般理论   2篇
预防医学   490篇
眼科学   129篇
药学   650篇
中国医学   22篇
肿瘤学   1039篇
  2024年   8篇
  2023年   84篇
  2022年   193篇
  2021年   319篇
  2020年   176篇
  2019年   222篇
  2018年   302篇
  2017年   218篇
  2016年   237篇
  2015年   319篇
  2014年   386篇
  2013年   418篇
  2012年   712篇
  2011年   741篇
  2010年   403篇
  2009年   364篇
  2008年   620篇
  2007年   641篇
  2006年   572篇
  2005年   570篇
  2004年   515篇
  2003年   503篇
  2002年   415篇
  2001年   84篇
  2000年   41篇
  1999年   52篇
  1998年   60篇
  1997年   59篇
  1996年   58篇
  1995年   43篇
  1994年   35篇
  1993年   28篇
  1992年   28篇
  1991年   29篇
  1990年   25篇
  1989年   25篇
  1988年   21篇
  1987年   15篇
  1986年   7篇
  1985年   11篇
  1984年   13篇
  1983年   6篇
  1982年   14篇
  1980年   11篇
  1979年   11篇
  1978年   7篇
  1977年   5篇
  1976年   3篇
  1975年   6篇
  1969年   2篇
排序方式: 共有9649条查询结果,搜索用时 8 毫秒
101.
102.
Metabolic Brain Disease - Aicardi-Goutières Syndrome (AGS) is a monogenic leukodystrophy with pediatric onset, clinically characterized by a variable degree of neurologic impairment. It...  相似文献   
103.
Two nonsense polymorphisms of Z-dependent protease inhibitor (ZPI; Serpina10) have been identified. To assess the risk of venous thromboembolism (VTE) associated with W303x and R67X Serpina10 mutations, we performed a meta-analysis of studies comparing the prevalence of these two mutations in VTE patients and in controls Odds Ratios (ORs) and 95% confidence intervals (CIs) were calculated for each trial and pooled using a random-effects model. Five studies involving 5000 patients were included. R67X and W303X mutations of Serpina10 were not associated with increased VTE risk (OR 1.63; 95% CI 0.84, 3.16 and OR 1.21; 95% CI 0.29, 4.98 respectively).  相似文献   
104.
BACKGROUND: Although risk assessment charts have been proposed to identify patients at high cardiovascular risk, in everyday practice general practitioners (GPs) often use their knowledge of the patients to estimate the risk subjectively. DESIGN: A cross-sectional study aimed to describe how GPs perceive, qualify and grade cardiovascular risk in everyday practice. METHODS: General practitioners had to identify in a random sample of 10% of their contacts the first 20 consecutive patients perceived as being at cardiovascular risk. For each patient essential data were collected on clinical history, physical examination and laboratory tests, for the qualification of risk. At the end of the process GPs subjectively estimated the overall patient's level of risk. General practitioners grading was compared with the risk estimate from a reference chart. RESULTS: Over a mean time of 25 days 3120 patients perceived as being at cardiovascular risk were enrolled. According to the inclusion scheme each GP had contact with more than 200 patients at cardiovascular risk every month. Thirty percent of these patients had atherosclerotic diseases. Up to 72% of patients without any history of atherosclerotic diseases but perceived to be at risk could be classified according to a reference chart as being at moderate to very high risk. Comparing GPs' grading of risk with a chart estimate there was agreement in 42% of the cases. Major determinants of GPs' underestimation of risk were age, sex and smoking habits, while obesity and family history were independently associated with overestimation. CONCLUSIONS: On the basis of their perception GPs properly identify patients at cardiovascular risk in the majority of cases. General practitioners subjective grading of risk level only partially agreed with that given by a chart.  相似文献   
105.
Hemozoin, the detoxification product of hemoglobin heme, piles up as electron-dense material in the food vacuole (FV) of intraerythrocytic malaria parasites (malaria pigment). In infected individuals, pigment is internalized by both circulating and resident phagocytes, thus modulating their functions. Synthetic beta-hematin, prepared in vitro from hematin (ferriprotoporphyrin IX hydroxide) in acidic condition, is spectroscopically identical to hemozoin. In this electron microscopy study, native and synthetic hemozoin also prove to be morphologically indistinguishable (large polygonal crystals with apparent transverse banding) and to undergo the same process when internalized by phagocytes (primarily a direct uptake of crystals, similar to what is described for asbestos fibers). On the contrary,whole parasites appear to follow a classical endocytic pathway. This suggests that there may be differences between the ingestion of free particles and whole parasites in terms of modulation of phagocytes' functions.  相似文献   
106.
Electrochemotherapy (ECT) is a novel treatment for recurrent or in-transit unresectable melanoma metastases based on the administration of anti-neoplastic drugs followed by cancer cell electroporation. Whether ECT can also induce anti-tumour immunity is unclear. We addressed this issue investigating the presence of dendritic cells (DCs) in the inflammatory infiltrate of ECT-treated lesions. Biopsies from melanoma patients (n = 9) were taken before ECT (T0), at d7 and d14 after treatment and studied by immunofluorescence with DCs-related antibodies. Epidermal Langerin+ Langerhans cells (LCs) were the most represented subset before treatment. ECT induced a significant reduction in epidermal LCs number at d7 (p < 0.001), while they were completely replaced at d14. Similarly, the few LCs observed intermingled with metastatic melanoma cells at T0 decreased after treatment (p < 0.001), suggesting an ECT-induced activation of LCs. Consistently, at d1 after ECT (n = 3 patients), LCs were found to express CCR7, which mediates LCs migration to regional lymph nodes, and CD83, the typical DCs maturation marker. In contrast, plasmacytoid DCs (pDCs) were not present at T0, but significantly increased after ECT both in melanoma metastasis (p < 0.001) and perilesionally (p < 0.05). Similarly, CD1c+ dermal DCs (dDCs), observed in low number before ECT, strongly increased at d7 and even more at d14 (p < 0.05 and p < 0.001, respectively). Notably, some dDCs expressed CD83. These data suggest that ECT promotes LCs migration from the tumour to draining lymph nodes and pDCs and dDCs recruitment at the site of the lesion. These findings may help to design new strategies of in situ DCs vaccination in cancer patients.  相似文献   
107.
108.
109.
110.
A 60-year-old male was admitted to our hospital for gastric cancer. Considering his general condition, total gastrectomy and dissection of regional lymph nodes were performed. Macroscopically, a 45 mm × 20 mm × 10 mm-sized, ulcero-infiltrative tumor located in the esophagogastric junction was described. Microscopically, the tumor consisted of a poorly differentiated adenocarcinoma intermingled with dense lymphoid infiltration predominantly composed of T-cell lymphocytes. The tumor cells infiltrated the submucosa, muscularis and subserosal layers of the stomach, respectively the esophageal adventitia. No metastases were noticed in the 58 regional lymph nodes. Based on the histopathological features, the diagnosis was lymphoepithelioma-like carcinoma, pT3N0 stage. In situ hybridization for Epstein–Barr virus showed no nuclear signal in tumor cells. The p53 expression was observed in fewer than 10% of the tumor cells. Real-time PCR analysis showed microsatellite instability without K-ras mutation in codon 12. No recurrences or metastases were reported 6 months after surgical intervention. No adjuvant therapy was performed.  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