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   2313篇
  免费   112篇
  国内免费   14篇
耳鼻咽喉   15篇
儿科学   114篇
妇产科学   44篇
基础医学   352篇
口腔科学   43篇
临床医学   191篇
内科学   409篇
皮肤病学   73篇
神经病学   150篇
特种医学   186篇
外科学   291篇
综合类   21篇
预防医学   231篇
眼科学   43篇
药学   186篇
中国医学   2篇
肿瘤学   88篇
  2021年   45篇
  2020年   22篇
  2019年   33篇
  2018年   39篇
  2017年   27篇
  2016年   27篇
  2015年   36篇
  2014年   60篇
  2013年   56篇
  2012年   95篇
  2011年   108篇
  2010年   74篇
  2009年   58篇
  2008年   80篇
  2007年   70篇
  2006年   77篇
  2005年   83篇
  2004年   74篇
  2003年   73篇
  2002年   79篇
  2001年   66篇
  2000年   50篇
  1999年   44篇
  1998年   53篇
  1997年   62篇
  1996年   56篇
  1995年   51篇
  1994年   25篇
  1993年   32篇
  1992年   35篇
  1991年   39篇
  1990年   32篇
  1989年   40篇
  1988年   50篇
  1987年   42篇
  1986年   48篇
  1985年   34篇
  1984年   21篇
  1983年   23篇
  1981年   25篇
  1979年   29篇
  1978年   24篇
  1977年   19篇
  1975年   26篇
  1973年   20篇
  1971年   22篇
  1970年   22篇
  1969年   23篇
  1968年   21篇
  1967年   24篇
排序方式: 共有2439条查询结果,搜索用时 15 毫秒
1.

Background

Intramedullary nailing is considered a “gold standard” for treatment of tibial shaft fractures. However, some types of fractures are typically considered as “difficult for nailing”. This group includes the periarticular fractures, fractures of both bones at the same level, comminuted and segmental fractures of the tibia. Fixator-assisted nailing (FAN) is an effective method treatment of these types of fractures. The main requirements for the ideal reduction device are an ease of its installation and an ability of multiplanar fracture reduction. Fixator-assisted nailing (FAN) with the use of two perpendicular to each other monolateral tubular frames perfectly meets these requirements. In this study we present this new surgical technique and the analysis of first 30 cases.

Methods

A prospective analysis was conducted for 30 patients with “difficult for nailing” tibial fractures treated with fixator-assisted nailing in our institution between September 1st, 2017, and March 1st, 2018. The duration of surgery and its different stages, the time of fluoroscopy, difficulties encountered during surgery, were analyzed. Clinical and radiological methods were used to evaluated reduction quality.

Results

In all 30 cases the acceptable reduction was achieved. The mean duration of the surgical procedure was 73.7?±?3?min. The mean duration of fluoroscopy 85.9?±?4.8?s. In 7 cases we faced with technical difficulties, which were successfully addressed.

Conclusion

The described technique of FAN is an effective method for the treatment of “difficult for nailing” tibial fractures. Future multi-centered studies with a larger number of patients are needed to validate our results.  相似文献   
2.
To have some insight into the mechanical interplay between the parasternal intercostal and triangularis sterni muscles during breathing, we have examined the isometric contractile properties of these two muscles in the dog. Using piezoelectric crystals, we have also measured the respiratory changes in muscle length in eight spontaneously breathing animals in the supine posture, and we have compared the in situ relaxation length (Lr) of these two muscles to their respective in vitro optimal force-producing length (Lo). The triangularis sterni and parasternal intercostals had similar isometric twitch, force-frequency, and length-tension characteristics. These two muscles, therefore, are intrinsically similar. In supine dogs, however, they operate on quite distinct segments of their length-tension curve. Whereas Lr for the parasternals corresponded to 117% Lo, Lr for the triangularis sterni was only 75% Lo. This suggests that the triangularis sterni in supine dogs operates on a poorly advantageous portion of its length-tension curve. However, shortening of the parasternals during inspiration causes considerable passive distension of the muscle. As a result, the triangularis sterni is much closer to its optimal length when it starts contracting in early expiration.  相似文献   
3.
Zusammenfassung Bericht über ?dintraoperative maschinelle autotransfusion?, kombiniert mit ?pr?operativer plasmapherese?. Mit maschineller autotransfusion kann intraoperativer blutverlust durch rückführung eigener erythrozyten halbiert werden. In kombination mit pr?operativer plasmapherese werden weitere fremdblutkonserven eingespart. übertragung von infektionskrankheiten und erzeugung irregul?rer antikōrper kōnnen verhindert werden. Bei der derzeitigen AIDS-situation wird das infektionsrisiko auf null reduziert.   相似文献   
4.
5.
6.
7.
Detectable TNF levels in sera 33% of patients with sepsis following pancreatitis have been found. No correlation was observed between serum TNF concentration and the severity of illness. However, monocytes and granulocytes of septic patients exerted higher TNF-mediated cytotoxicity than leukocytes of normal blood donors. The in vitro TNF-producing capacity was also higher in the patients in the study group, and it decreased only before fatal outcoming of sepsis. Our results suggest that determination of the TNF-producing capacity of leukocytes might be more informative than measurement of the serum TNF level in the evaluation of the severity or prognosis of sepsis.  相似文献   
8.
9.
The effectiveness, side effects and serum FSH, LH, prolactin, estradiol and progesterone levels were monitored in 79 women taking Anteovin for a total of 506 cycles (mean 6.4 cycles). Anteovin is a biphasic oral contraceptive with 11 tablets containing 0.05 mg levonorgestrel and 0.05 mg ethinyl estradiol, and 10 tablets containing 0.125 mg levonorgestrel and 0.05 mg ethinyl estradiol. There were no pregnancies. 11 women dropped out because of hepatomegaly (1), bleeding disorder (3), gastric pain and nausea (1), breast pain (1), nausea and vomiting (1), and personal reasons (4). 10.3% of those continuing reported minor side effects. Menses occurred every 28 days for 3-5 days, with 2 cases of breakthrough bleeding but no oversuppression. Progesterone ranged from 1.5-2.0 nmol/1, estradiol varied between 68-93 pmol/1, LH stayed constant at 6.3-11 U/1, FSH remained at 5.8-6.8 U-1 without a peak, and prolactin levels were lower than those seen in control cycles. These hormone levels all resemble those observed in anovulatory cycles. This pill is especially suitable for teens and nulliparas.  相似文献   
10.
Capsaicin (50 mg/kg s.c./25 μl) was administered to rats on the 2nd and 5th days after birth. The animals were raised, and from the age of 3 months the properties of the evoked activity were tested in the contralateral barrelfield. This neonatal capsaicin treatment was found to induce profound changes in the responsiveness of the barrel cortex in the adult rats: (1) the receptive field of the neurons in the Cl barrel was expanded; units within a particular barrel were driven by a significantly larger number of vibrissae than in the controls. (2) The rate of discharge evoked by the related vibrissa deflection was enhanced, while (3) the angular sensitivity of the neurons was decreased. (4) The most prominent change in cortical activity was observed by autoradiography: capsaicin-treated rats exhibited an enhanced labelling of different types of neurons throughout the hemisphere (surpassing the cortical representation of stimulated vibrissae). The present observations indicate that neonatal capsaicin affects the functional activity of the rat somatosensory cortex. It is suggested that unmyelinated sensory afferents play a role in the development of the rat somatosensory system.  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