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   889篇
  免费   81篇
  国内免费   3篇
耳鼻咽喉   23篇
儿科学   15篇
妇产科学   35篇
基础医学   71篇
口腔科学   34篇
临床医学   120篇
内科学   148篇
皮肤病学   6篇
神经病学   51篇
特种医学   31篇
外科学   165篇
综合类   23篇
一般理论   1篇
预防医学   109篇
眼科学   24篇
药学   84篇
中国医学   2篇
肿瘤学   31篇
  2023年   12篇
  2022年   17篇
  2021年   31篇
  2020年   23篇
  2019年   25篇
  2018年   46篇
  2017年   25篇
  2016年   31篇
  2015年   37篇
  2014年   28篇
  2013年   54篇
  2012年   37篇
  2011年   43篇
  2010年   31篇
  2009年   40篇
  2008年   30篇
  2007年   41篇
  2006年   35篇
  2005年   10篇
  2004年   26篇
  2003年   22篇
  2002年   23篇
  2001年   16篇
  2000年   13篇
  1999年   20篇
  1998年   11篇
  1993年   6篇
  1992年   11篇
  1991年   15篇
  1990年   10篇
  1989年   7篇
  1988年   6篇
  1987年   7篇
  1985年   7篇
  1984年   7篇
  1983年   6篇
  1982年   6篇
  1979年   11篇
  1978年   6篇
  1976年   8篇
  1975年   9篇
  1974年   10篇
  1973年   14篇
  1972年   14篇
  1971年   11篇
  1970年   8篇
  1969年   11篇
  1968年   6篇
  1967年   7篇
  1966年   6篇
排序方式: 共有973条查询结果,搜索用时 8 毫秒
1.
2.
3.
4.
A group of pregnant mothers above 35 years old were collected from the MCH centre in Kafr-El Zayat during a period of 10 months (82). A control group of mothers aged 20-30 years old were also selected during the same period (62). Those with specific diseases from both groups were excluded. During the repeated visits of those mothers to the MCH centre they were subjected to complete history taking, physical examination plus urine analysis & haemoglobin levelling. A special visit was performed by the researcher to the mothers on 7th day after labour to report on the outcome of labour. The present study revealed significant differences between mothers over 35 years and those of 20-30 years in the course of pregnancy, labour and their outcomes where the former group showed greater tendency to be at a higher risk.  相似文献   
5.
? Our previous retrospective audit (Clinical Otolaryngology, December 2004) identified considerable variation in post‐thyroidectomy calcium assessment. This led to a well‐structured protocol. ? The protocol was introduced into two trusts. The results were prospectively collated for 64 thyroid procedures over a period of 6 months. ? All patients that warranted it were tested on day 1, and 71% were tested on day 2 – highlighting a more structured approach, and avoiding unnecessary vene‐ puncture in all thyroid lobectomy patients. ? Such protocols have been proven to be an important tool in the effort to improve the quality and lower the cost of care. ? Resistance to change, established practise and lack of data collection resources prevented this protocol from becoming established in more regional trusts.  相似文献   
6.
7.
There is much controversy in the literature about the effect of blood stasis on the patency rate following microvascular repair. Sixty Sprague Dawley rats underwent transection and repair of their femoral arteries. The rats were divided into three groups, which had their repaired arteries clamped for 1 1/2, 2, and 2 1/2 hours. Patency was evaluated by the "stripping test," and the presence of a "flicker" both immediately and on the second day of the experiment. At the time of evaluation on the second day, all arteries in Group I were patent, in Group II two were thrombosed and in Group III, five out of 20 thrombosed. The only significant statistical difference was found between Groups I and III in both immediate (p less than 0.0025) and second day (p less than 0.05) evaluations. Results indicate that the "safe limit" for blood stasis in a repaired artery of 0.8 mm diameter is 1 1/2 hours.  相似文献   
8.
BACKGROUND: The aim of this study was to assess the use of testicular sperm for ICSI in azoospermic men with hypogonadotrophic hypogonadism unresponsive to gonadotrophin therapy. METHODS: Fifteen patients with hypogonadotrophic hypogonadism who remained azoospermic after hormonal treatment underwent testicular sperm extraction (TESE) and ICSI. These men were recruited from the Egyptian IVF centre over a period of 4 years. All patients were given 75 IU hMG thrice weekly and 5000 IU hCG once or twice weekly for >/=6 months prior to attempting ICSI/TESE. RESULTS: In 11 out of 15 patients (73%), sperm could be retrieved from testicular tissue and were used for ICSI. Two chemical pregnancies resulted but no clinical pregnancies. Nine patients continued gonadotrophin therapy for another 6 months. Sperm appeared in the ejaculate of three of them. The remaining six patients underwent another ICSI cycle, one using cryopreserved sperm and five underwent a second TESE. One chemical pregnancy and three clinical pregnancies were established. One ongoing, one singleton and one twin pregnancies resulted in the delivery of three healthy babies. In total, of 17 ICSI cycles performed using testicular sperm retrieval, the fertilization rate was 41.7% and the cumulative pregnancy rate was 20%. CONCLUSIONS: The use of testicular sperm for ICSI is a treatment option that can be offered to azoospermic males with hypogonadotrophic hypogonadism either not responding or reluctant to continue hormonal treatment. However, prolonged hormonal treatment may improve TESE/ICSI results.  相似文献   
9.
T cell responsiveness to an epitope is affected both by its affinity for the presenting MHC molecule and the affinity of the MHC-peptide complex for TCR. One limitation of cancer immunotherapy is that natural tumor antigens elicit relatively weak T cell responses, in part because high-affinity T cells are rendered tolerant to these antigens. We report here that amino acid substitutions in a natural MHC class I-restricted tumor antigen that increase the stability of the MHC-peptide-TCR complex are significantly more potent as tumor vaccines. The improved immunity results from enhanced in vivo expansion of T cells specific for the natural tumor epitope. These results indicate peptides that stabilize the MHC-peptide-TCR complex may provide superior antitumor immunity through enhanced stimulation of specific T cells.  相似文献   
10.
The "S" Quattro has shown its value in the management of displaced comminuted intra-articular phalangeal fracture dislocations. Since then the system has been used as a dynamic flexible external fixator in the treatment of five maluniting phalangeal fractures, five comminuted condylar and four severe compound fractures. These challenging fractures have been dealt with by easy operations, taking full advantage of the versatility of the "S" Quattro to achieve good results.  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