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   163987篇
  免费   15767篇
  国内免费   7465篇
耳鼻咽喉   2279篇
儿科学   3737篇
妇产科学   1881篇
基础医学   30054篇
口腔科学   5353篇
临床医学   12618篇
内科学   22061篇
皮肤病学   4427篇
神经病学   9148篇
特种医学   3622篇
外国民族医学   118篇
外科学   14254篇
综合类   25605篇
现状与发展   48篇
预防医学   4327篇
眼科学   3465篇
药学   12653篇
  25篇
中国医学   5016篇
肿瘤学   26528篇
  2024年   131篇
  2023年   2293篇
  2022年   2891篇
  2021年   5608篇
  2020年   5302篇
  2019年   5175篇
  2018年   5356篇
  2017年   5671篇
  2016年   5936篇
  2015年   6757篇
  2014年   9831篇
  2013年   10885篇
  2012年   9424篇
  2011年   10584篇
  2010年   8788篇
  2009年   8421篇
  2008年   8873篇
  2007年   9103篇
  2006年   8258篇
  2005年   7595篇
  2004年   6744篇
  2003年   5839篇
  2002年   4797篇
  2001年   4109篇
  2000年   3385篇
  1999年   2952篇
  1998年   2419篇
  1997年   2363篇
  1996年   2045篇
  1995年   2076篇
  1994年   1837篇
  1993年   1523篇
  1992年   1242篇
  1991年   1169篇
  1990年   901篇
  1989年   845篇
  1988年   788篇
  1987年   632篇
  1986年   587篇
  1985年   779篇
  1984年   702篇
  1983年   485篇
  1982年   510篇
  1981年   403篇
  1980年   345篇
  1979年   256篇
  1978年   179篇
  1977年   140篇
  1976年   107篇
  1975年   42篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Prior studies have conflicting findings regarding the association between gastroesophageal reflux disease (GERD) and esophageal squamous cell carcinoma (ESCC). We examined this relationship in a prospective cohort in a region of high ESCC incidence. Baseline exposure data were collected from 50 045 individuals using in-person interviews at the time of cohort entry. Participants were followed until they developed cancer, died, or were lost to follow up. Participants with GERD symptoms were categorized into any GERD (heartburn or regurgitation), mixed symptoms, or heartburn alone. Multivariable Cox regression was used to assess the relationship between GERD symptom group and histologically confirmed ESCC. The model was adjusted for known risk factors for GERD and ESCC. 49 559 individuals were included in this study, of which 9005 had GERD symptoms. Over 13.0 years of median follow up, 290 individuals were diagnosed with ESCC. We found no association between any GERD and risk of ESCC (aHR 0.90, 95% CI: 0.66-1.24, P = .54). Similar findings were observed for the GERD symptom subtypes. Significant interactions between any GERD and sex (P = .013) as well as tobacco smoking (P = .028) were observed. In post-hoc analyses, GERD was associated with a decreased risk of ESCC in men (aHR 0.51, 95% CI: 0.27-0.98 P = .04) and in smokers (aHR 0.26, 95% CI: 0.08-0.83 P = .02). While there was little evidence for an overall association between GERD symptoms and ESCC risk, significant interactions with sex and smoking were observed. Men and smokers with GERD symptoms had a lower risk of ESCC development.  相似文献   
22.
孔慧  崔彦 《眼科新进展》2022,(9):753-756
视网膜内皮细胞(REC)是参与糖尿病视网膜病变和许多眼部疾病的主要细胞类型之一。视网膜微血管系统有助于血-视网膜屏障的维持,这对正常的视功能至关重要。REC的改变在视网膜疾病的发生发展中起着关键作用。高血糖是糖尿病微血管损伤的重要原因,通过不同的机制导致REC功能障碍,包括向衰老表型改变、迁移和增殖能力增强、炎性凋亡等,最终导致无细胞毛细血管及病理性新生血管形成。本文对糖尿病视网膜病变中REC的功能障碍作一综述。  相似文献   
23.
24.
Oral cancer, with an around 50% mortality rate, is one of the most common malignancies world-wide. It is often detected in advanced or terminal stage and has a poor prognosis, although substantial progress in cancer management. Microbiome has become an increasingly recognized factor that may contribute to the cancerous development. Oral microbiological population comprising more than 700 bacterial species, varies since saliva and different habitats of oral cavity. A shift of composition of oral microbiome from usual condition to functional inflammation to pathological state has been discovered amongst patients with premalignant disorders and oral carcinoma, with evidence suggesting the tumor microenvironment (TME) could strongly exacerbate the influence of oral microorganisms. The complex interactions taking place in either cancer formation or progression have been evaluated in several publications, however given their results’ heterogeneity, a review is needed to correctly untangle the potential correlation in this group of pro-carcinogenesis. In this review, we briefly summarize our current knowledge of the role of oral microbiome, focusing on its potential crosstalk with TME in oral squamous cell carcinomas (OSCC) more precisely, and pave the way for manipulating oral microbiome to deal with OSCC in the future.  相似文献   
25.
《Cancer cell》2022,40(11):1392-1406.e7
  1. Download : Download high-res image (241KB)
  2. Download : Download full-size image
  相似文献   
26.
27.
28.
《Diagnostic Histopathology》2022,28(12):522-533
Neoplasms of bone with numerous non-neoplastic osteoclast type giant cells are relatively common and exhibit diverse phenotypes of the neoplastic cells. These tumors have a broad spectrum of biological potential which necessitates accurate recognition and diagnosis. Their clinicopathological features are overlapping, therefore, immunohistochemistry and molecular studies may be required for evaluation. Correlation with imaging studies provides additional information that should be incorporated into the pathological interpretation.  相似文献   
29.
杨旭  朱德兵  王巍炜  唐明伟 《西部医学》2022,34(9):1329-1334+1341
目的 分析术前SCC、CYFRA21-1与肺鳞癌临床病理特征、预后之间的关系。方法 收集2017年3月~2018年4月在云南省肿瘤医院确诊的肺鳞癌患者100例为观察组,确诊为肺良性肿瘤患者90名为肺良性肿瘤组、以及正常人群90名为健康人群组。通过电化学发光法对SCC、CYFRA21-1两种指标进行检测。检测SCC、CYFRA21-1含量,分析在肺鳞癌中表达的临床意义。结果 SCC、CYFRA21-1在肺鳞癌中比在肺良性肿瘤、健康人群中含量要高,差异有统计学意义(P<0.001),并且敏感性均高于其他两组;男性患者的SCC、CYFRA21-1含量高于女性患者,差异具有统计学意义(P<0.05);SCC、CYFRA21-1含量在年龄≥60岁的含量高于<60岁患者,差异无统计学意义(P>0.05);有吸烟史患者的SCC含量高于无吸烟史患者,差异无统计学意义(P>0.05)。CYFRA21-1在吸烟史患者中高表达,差异有统计学意义(P<0.05);SCC、CYFRA21-1在有淋巴结转移、远处转移、肿瘤直径≥5 cm、病理分期为晚期时高表达,差异具有统计学意义(P<0.05);SCC、CYFRA21-1阳性患者OS、PFS比阴性患者短;SCC、CYFRA21-1两者之间呈正相关,相关系数(r)为0.630。结论 SCC、CYFRA21-1在肺鳞癌中表达上调;SCC、CYFRA21-1与性别之间存在某种内在联系;SCC、CYFRA21-1与肺鳞癌的TNM分期呈正相关;SCC、CYFRA21-1阳性患者OS、PFS比阴性患者短;SCC、CYFRA21-1两者之间呈正相关,相关系数(r)为0.630。  相似文献   
30.
The endothelium is a single-layered structure that responds to physical and chemical signals with various factors it synthesizes. In the early days of its discovery, as the inner wall of the vessels, the endothelium was thought to be a simple barrier that lays on the surface. Over time it is discovered that endothelium maintains body homeostasis with the molecules it synthesizes, despite its simple single-layer structure. It has been accepted as an important organ that contributes to the maintenance of vascular tone, cell adhesion, inflammation, vascular permeability and coagulation. Any imbalance in these physiological and pathological events causes endothelial dysfunction. This can cause many diseases such as atherosclerosis, hypertension, diabetes, or it can occur because of these. Endothelial related disorders may also complicate hematopoietic stem cell transplantation (HSCT), which is used to treat various hematologic and neoplastic diseases. These life-threatening complications include graft-versus-host disease, hepatic veno-occlussive disease, transplant-associated thrombotic microangiopathy and diffuse alveolar hemorrhage. They share a similar pathophysiology involving endothelial cells with different clinical presentations. Therefore, current researche on the issue is putting the endothelium under the spotlight for novel markers and treatment options that should be used to monitor or treat at least some of these complications following HSCT.  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