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   136540篇
  免费   8320篇
  国内免费   773篇
耳鼻咽喉   1366篇
儿科学   4324篇
妇产科学   3098篇
基础医学   19648篇
口腔科学   6568篇
临床医学   12071篇
内科学   30081篇
皮肤病学   3355篇
神经病学   12753篇
特种医学   3321篇
外国民族医学   3篇
外科学   13062篇
综合类   839篇
一般理论   55篇
预防医学   14015篇
眼科学   2120篇
药学   9537篇
中国医学   672篇
肿瘤学   8745篇
  2024年   148篇
  2023年   1285篇
  2022年   2849篇
  2021年   4716篇
  2020年   3026篇
  2019年   3977篇
  2018年   4580篇
  2017年   3491篇
  2016年   3912篇
  2015年   4364篇
  2014年   5735篇
  2013年   7355篇
  2012年   11084篇
  2011年   11679篇
  2010年   6322篇
  2009年   5243篇
  2008年   9004篇
  2007年   9007篇
  2006年   8189篇
  2005年   7515篇
  2004年   6730篇
  2003年   6037篇
  2002年   5434篇
  2001年   1258篇
  2000年   1138篇
  1999年   1184篇
  1998年   1027篇
  1997年   792篇
  1996年   702篇
  1995年   588篇
  1994年   554篇
  1993年   453篇
  1992年   568篇
  1991年   449篇
  1990年   461篇
  1989年   438篇
  1988年   418篇
  1987年   321篇
  1986年   339篇
  1985年   277篇
  1984年   264篇
  1983年   234篇
  1982年   214篇
  1981年   170篇
  1980年   173篇
  1979年   184篇
  1978年   168篇
  1977年   131篇
  1974年   133篇
  1973年   121篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence.  相似文献   
22.
23.
24.
25.
26.
27.
28.
29.
Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets.  相似文献   
30.
Family-centered care (FCC) for sick newborns is emerging as a paradigmatic shift in the practice of facility-based newborn care. It seeks to transforming a provider-centered model into a client-centered one and thus build a new therapeutic alliance. FCC is the cornerstone of continuum of care, imparting caregiving competencies to parents/caregivers both within institutions as well as after the discharge. This has potential gains for the newborn, family members, and facility-level staff. The initial model piloted in tertiary-care settings is now undergoing translation at five sites across the country; the outcomes are keenly awaited.  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