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   199290篇
  免费   11814篇
  国内免费   527篇
耳鼻咽喉   2643篇
儿科学   6214篇
妇产科学   4256篇
基础医学   27044篇
口腔科学   9116篇
临床医学   14755篇
内科学   45161篇
皮肤病学   4928篇
神经病学   16529篇
特种医学   5928篇
外国民族医学   26篇
外科学   25078篇
综合类   1563篇
现状与发展   1篇
一般理论   92篇
预防医学   20528篇
眼科学   3636篇
药学   12284篇
中国医学   832篇
肿瘤学   11017篇
  2023年   1045篇
  2022年   1875篇
  2021年   4479篇
  2020年   2908篇
  2019年   4289篇
  2018年   6011篇
  2017年   4348篇
  2016年   4142篇
  2015年   4826篇
  2014年   6475篇
  2013年   8223篇
  2012年   13009篇
  2011年   13581篇
  2010年   6927篇
  2009年   6071篇
  2008年   10548篇
  2007年   11153篇
  2006年   10304篇
  2005年   10526篇
  2004年   9880篇
  2003年   8987篇
  2002年   6970篇
  2001年   5480篇
  2000年   5528篇
  1999年   4785篇
  1998年   1685篇
  1997年   1384篇
  1996年   1347篇
  1995年   1148篇
  1994年   1128篇
  1993年   1037篇
  1992年   2888篇
  1991年   2753篇
  1990年   2497篇
  1989年   2457篇
  1988年   2216篇
  1987年   2059篇
  1986年   1927篇
  1985年   1821篇
  1984年   1317篇
  1983年   1067篇
  1982年   595篇
  1981年   535篇
  1980年   513篇
  1979年   955篇
  1978年   632篇
  1977年   500篇
  1975年   580篇
  1974年   599篇
  1973年   572篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
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   
6.
7.
8.
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   
9.
10.
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