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   211260篇
  免费   13528篇
  国内免费   572篇
耳鼻咽喉   2596篇
儿科学   6659篇
妇产科学   4816篇
基础医学   28936篇
口腔科学   8629篇
临床医学   16544篇
内科学   47666篇
皮肤病学   5452篇
神经病学   18088篇
特种医学   6464篇
外国民族医学   26篇
外科学   26265篇
综合类   1698篇
现状与发展   1篇
一般理论   87篇
预防医学   21545篇
眼科学   3841篇
药学   12680篇
中国医学   806篇
肿瘤学   12561篇
  2023年   1196篇
  2022年   2364篇
  2021年   5266篇
  2020年   3406篇
  2019年   4870篇
  2018年   6509篇
  2017年   4813篇
  2016年   4664篇
  2015年   5330篇
  2014年   7208篇
  2013年   9073篇
  2012年   13906篇
  2011年   14439篇
  2010年   7428篇
  2009年   6637篇
  2008年   11120篇
  2007年   11696篇
  2006年   10775篇
  2005年   10971篇
  2004年   10226篇
  2003年   9253篇
  2002年   7176篇
  2001年   5427篇
  2000年   5361篇
  1999年   4830篇
  1998年   1851篇
  1997年   1546篇
  1996年   1495篇
  1995年   1286篇
  1994年   1255篇
  1993年   1131篇
  1992年   2934篇
  1991年   2818篇
  1990年   2563篇
  1989年   2552篇
  1988年   2302篇
  1987年   2125篇
  1986年   2010篇
  1985年   1928篇
  1984年   1406篇
  1983年   1138篇
  1982年   652篇
  1981年   615篇
  1980年   561篇
  1979年   999篇
  1978年   688篇
  1977年   525篇
  1975年   598篇
  1974年   595篇
  1973年   621篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.  相似文献   
3.
4.
5.
6.
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2.  相似文献   
7.
8.
9.
10.
Depigmented lesions may occur as postinflammatory sequelae of subacute cutaneous lupus erythematosus (SCLE), leading to great psychosocial impact. A 53‐year‐old male patient presented with post‐SCLE depigmented facial lesions after five years of disease stability. We proposed surgical treatment with melanocyte‐keratinocyte transplantation procedure (MKTP), and after five months the patient achieved 90% repigmentation, without Koebner phenomenon (KP). In theory, KP is a possible complication of MKTP procedure since the preparation of the receptor area involves the use of dermabrasion. In an attempt to avoid it, we suggest to maintain the treatment of the underlying disease and wait for a minimum period of disease stability before the procedure.  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