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   36398篇
  免费   1668篇
  国内免费   172篇
耳鼻咽喉   455篇
儿科学   841篇
妇产科学   446篇
基础医学   4635篇
口腔科学   896篇
临床医学   2425篇
内科学   9430篇
皮肤病学   568篇
神经病学   2585篇
特种医学   1353篇
外科学   6517篇
综合类   148篇
一般理论   3篇
预防医学   1075篇
眼科学   641篇
药学   2616篇
中国医学   120篇
肿瘤学   3484篇
  2023年   156篇
  2021年   469篇
  2020年   292篇
  2019年   411篇
  2018年   534篇
  2017年   478篇
  2016年   529篇
  2015年   528篇
  2014年   746篇
  2013年   996篇
  2012年   1564篇
  2011年   1680篇
  2010年   1007篇
  2009年   913篇
  2008年   1680篇
  2007年   1855篇
  2006年   1825篇
  2005年   1967篇
  2004年   1943篇
  2003年   1918篇
  2002年   1841篇
  2001年   1248篇
  2000年   1329篇
  1999年   1150篇
  1998年   486篇
  1997年   349篇
  1996年   352篇
  1995年   362篇
  1994年   314篇
  1993年   329篇
  1992年   827篇
  1991年   757篇
  1990年   724篇
  1989年   772篇
  1988年   698篇
  1987年   635篇
  1986年   563篇
  1985年   548篇
  1984年   362篇
  1983年   296篇
  1982年   152篇
  1979年   283篇
  1978年   204篇
  1977年   174篇
  1974年   162篇
  1973年   172篇
  1972年   170篇
  1971年   165篇
  1970年   158篇
  1969年   149篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
International Journal of Clinical Oncology - This study aimed to investigate the clinical benefit of dose-dense paclitaxel plus carboplatin (TC) with bevacizumab therapy for advanced ovarian,...  相似文献   
2.
International Journal of Clinical Oncology - The practice of cancer diagnosis disclosure to children has been changed with the times. The regulations of clinical trials in the 2000s might change...  相似文献   
3.
4.
5.
6.
BackgroundAxillary lymph node (LN) dissection after neoadjuvant chemotherapy (NAC) still remains a standard treatment of initially LN-positive primary breast cancer because of the difficulty of assessment of LN status. The aim of this study was to assess the LN status after NAC in initially LN-positive primary breast cancer patients who were assessed as clinically LN-negative after NAC (ycN0) and identify factors associated with loss of LN metastasis.Patients and MethodsThe study cohort comprised 279 patients with cytology-proven LN-positivity before NAC. LN status was assessed by ultrasonography. Regional recurrence-free survival and overall survival according to pathologic LN after NAC (ypN) status were assessed in patients with ycN0.ResultsOf the 279 patients, 179 patients (64.2%) had ycN0. High nuclear grade, estrogen receptor-negative (ER?), and human epidermal growth factor receptor 2-positive (HER2+), were significant predictors of ycN0/ypN0 (P < .001, .007, and .046, respectively). Metastases persisted in 1 or 2 LNs for 5 (20.0%) of 25 patients with ER?/HER2+ and for 4 (21.1%) of 19 patients with ER?/HER2?, and in 3 or more LNs for 0 (0%) of 25 patients with ER?/HER2+ and for 1 (5.3%) of 19 patients with ER?/HER2?. Patients with ER+ tumors had more numerous residual LN metastases than those with ER? tumors (P < .001). Among patients with ycN0, ypN status was not associated with regional recurrence-free survival or overall survival.ConclusionsThree or more residual LN metastases were rare in patients with ER? tumors if assessed as ycN0 by ultrasonography. Prospective studies are needed to confirm the prognostic impact of not performing axillary lymph node dissection in such patients.  相似文献   
7.
8.
1. The non-clinical pharmacokinetic profiles of rovatirelin, a novel thyrotropin-releasing hormone (TRH) analogue, were investigated in vivo and in vitro.

2. Rovatirelin orally administered to rats and dogs was rapidly absorbed and bioavailability was estimated to be 7.3 and 41.3%, respectively. The extent of plasma protein binding of rovatirelin in rats, dogs, and humans was low in all species (~15%). The permeability of rovatirelin from blood to brain (permeability-surface area) ranged from 1.04?±?0.14 to 1.29?±?0.28?μL/min/g in rats, and rovatirelin was stable in rat plasma and brain homogenates.

3. The metabolite pattern was qualitatively similar in vitro and in vivo. In animals, rovatirelin aminopentanoic acid (rovatirelin-acid), rovatirelin aminopentanone (rovatirelin-ketone), rovatirelin pyrrolidine (4S)-hydroxy (rovatirelin-OH), (thiazoylalanyl)methylpyrrolidine (TAMP), 3-(4-thiazoyl)-l-alanine (TA), and unknown metabolites were observed. In human hepatocytes, TAMP was mainly formed and no unique human metabolite was observed.

4. The radioactivity from administered [14C]rovatirelin was predominantly excreted in faeces in rats and dogs, and almost all radioactivity was recovered 168?h after administration. Absorption, brain penetration, and stability of rovatirelin in the brain were greater than for taltirelin.

5. Thus, orally administered rovatirelin is a potentially improved treatment for spinocerebellar degeneration compared with taltirelin.  相似文献   

9.
10.

Introduction

Breast cancer incidence increases from the age of 30 years. As this age range coincides with that in which women usually pursue pregnancy, undergoing medical examinations for conditions such as breast cancer is a concern, especially when pregnancy is uncertain during the first eight weeks. Moreover, in this age range, breast often exhibits a high density, thus compromising diagnosis. For such density, digital breast tomosynthesis (DBT) provides a more accurate diagnosis than 2D mammography given its higher sensitivity and specificity. However, radiation exposure increases during DBT, and it should be determined.

Methods

We determined the entrance surface dose, scattered radiation dose, and average glandular dose (AGD), which can be mutually compared following an international protocol. Using our proposed method, the distribution of scattered radiation can be easily and quickly obtained with a minor load to the equipment. Then, we can determine the indoor scattered radiation and surface dose on patients during DBT.

Results

We obtained a maximum AGD of 2.32 mGy. The scattered radiation was distributed over both sides with maximum of approximately 40 μGy, whereas the maximum dose around the eye was approximately 10 μGy.

Conclusion

By measuring doses using the proposed method, a correct dose information can be provided for patients to mitigate their concerns about radiation exposure. Although the obtained doses were low, their proper management is still required. Overall, the results from this study can help to enhance dose management for patients and safety management regarding indoor radiation.  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