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   424篇
  免费   23篇
  国内免费   8篇
耳鼻咽喉   21篇
儿科学   20篇
妇产科学   14篇
基础医学   30篇
口腔科学   15篇
临床医学   30篇
内科学   133篇
皮肤病学   2篇
神经病学   27篇
特种医学   16篇
外科学   61篇
综合类   3篇
预防医学   17篇
眼科学   10篇
药学   28篇
肿瘤学   28篇
  2023年   3篇
  2022年   4篇
  2021年   9篇
  2020年   2篇
  2019年   8篇
  2018年   10篇
  2017年   9篇
  2016年   6篇
  2015年   10篇
  2014年   12篇
  2013年   20篇
  2012年   20篇
  2011年   21篇
  2010年   9篇
  2009年   14篇
  2008年   46篇
  2007年   47篇
  2006年   25篇
  2005年   34篇
  2004年   44篇
  2003年   24篇
  2002年   25篇
  2001年   6篇
  2000年   6篇
  1999年   6篇
  1998年   1篇
  1996年   1篇
  1995年   3篇
  1994年   4篇
  1993年   2篇
  1992年   3篇
  1991年   4篇
  1990年   1篇
  1989年   4篇
  1988年   2篇
  1987年   3篇
  1986年   1篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
排序方式: 共有455条查询结果,搜索用时 15 毫秒
1.
2.
3.
Dysphoric Rumination Impairs Concentration on Academic Tasks   总被引:3,自引:0,他引:3  
Three studies investigated the effects of dysphoric rumination on concentration during 3 academic tasks—reading a passage from the GRE (Study 1), watching a videotaped lecture (Study 2), and proofreading written text (Study 3). Before performing these tasks, dysphoric and nondysphoric students were induced either to ruminate about themselves or to distract themselves by focusing on neutral images (all three studies) or by planning an event (Study 1). The results supported our hypothesis that dysphoric rumination, relative to distraction, would impair students' concentration. In all 3 studies, dysphoric ruminators reported difficulty concentrating, as well as interfering thoughts, during the relevant academic tasks. Furthermore, dysphoric ruminators were slower than dysphoric distractors in completing the tasks—specifically, reading the GRE passage (Study 1) and answering lecture comprehension questions (Study 2). In addition, dysphoric participants who ruminated showed impaired reading strategies (Study 1), reduced comprehension of academic material (Study 2), and poor proofreading performance (Study 3). These findings suggest that, in addition to its documented adverse effects on mood, thinking, and problem-solving, self-focused rumination interferes with instrumental behavior. Implications for social relationships and job performance are discussed.  相似文献   
4.
Previous studies have reported an association of the cell surface adhesion molecule CD2 with the T cell receptor and with CD45 on mouse and human T lymphocytes. In this study the association of CD2 with cell surface molecules was investigated using cell surface biotinylation of T lymphocytes, coupled with immunoprecipitation using two CD2-specific monoclonal antibodies (mAb) (RM2–5 and 12–15) and analysis by SDS-PAGE. Although both CD2 mAb immunoprecipitated CD2 from lysates of murine lymphocytes, it was found that mAb 12–15, but not RM2–5, co-precipitated two other molecules of 95 and 180 kDa. Subsequent studies revealed that the 95- and 180-kDa molecules were associated with a subspecies of CD2 (? 5%) on thymocytes, the antigen-specific T cell line D10, and splenic T cells but not B cells. Two lines of evidence were obtained consistent with the 95- and 180-kDa molecules being the β and α chains of LFA-1. Firstly, an analysis of 12–15 mAb immunoprecipitates on 4–12% gels under reducing and nonreducing conditions shows that the 95- and 180-kDa molecules have a molecular weight and migration pattern identical to LFA-1. Secondly, depletion of LFA-1 from lysates with LFA-1 mAb abolished the ability of CD2 mAb 12–15 to co-precipitate the 95- and 180-kDa molecules, thereby identifying these as the β and α chains of mouse LFA-1, respectively. These results provide evidence for the first time for an association of LFA-1 and CD2 on mouse T lymphocytes, and suggest that the association occurs with an immunologically distinct subspecies of CD2 molecules.  相似文献   
5.
6.
ObjectiveWe aimed to establish the characteristics of anaphylaxis in childhood.MethodsForty-four patients who had experienced anaphylaxis in a period of 10 years (from 1999 to 2009), were included in the study. Parameters analysed were age, gender, concomitant allergic disease, trigger, setting, clinical symptoms, treatment, prognosis and prophylaxis.ResultsThe total numbers of anaphylaxis cases were 44 in a ten-year period. The ages of patients ranged from 3 to 14 years (11.50 ± 3.87 years) and the majority were male. 33 of the patients (75%) had a concomitant allergic disease. The trigger was determined in 93.2% of the cases, being most frequent: food (27.3%), and SIT (25%), followed by bee sting, medications and others. Respiratory (95.5%), dermatological (90.9%), cardiovascular (20.5%), neuropsychiatric (25%), and gastrointestinal (11.4%) symptoms were seen most frequently. For anaphylaxis triggered by food, the duration of anaphylactic episode was significantly longer (p < 0.05). No biphasic reaction was observed during these attacks. Of our patients, only one developed respiratory failure and cardiac arrest due to SIT, and intensive care support was required.DiscussionAs a trigger for anaphylaxis, the frequency of SIT is so high that it cannot be described by the study group including patients who were followed up in an outpatient allergy clinic.  相似文献   
7.
Summary The authors report four patients with intracranial hydatic cysts. One patient had a pontine lesion which was punctured and aspirated and the cyst wall removed with a satisfactory outcome. The second patient had multiple cysts which was comparable to meningeomatosis. She had a rapidly deteriorating neurologic condition which proved to be fatal in spite of two consecutive surgical interventions. The third patient had nine lesions although only six were evident on the MRI. All of the cysts were removed, while two cysts ruptured. Multiple paracardial cysts of this patient were surgically removed shortly after the craniotomy. The last patient, again with multiple intracranial hydatid cysts had safe, total removal of all cysts. The first postoperative control CT raised the possibility of recurrence since the CT was highly suggestive of a hydatid cyst. However, this was not confirmed in the follow-up CT examination. Problems and the solutions of management are discussed.
Behandlung problematischer intrakranieller Echinococcus-Zysten
Zusammenfassung Die Autoren berichten über vier Fälle mit intrakraniellen Echinococcus-Zysten. Eine Patientin hatte eine Brückenläsion, die durch Punktion und Aspiration des Zysteninhaltes mit Entfernung der Zystenwand behandelt wurde. Die zweite Patientin wies multiple Zysten auf, die mit einer Meningomatose vergleichbar waren. Trotz zweier chirurgischer Interventionen kam es zur raschen neurologischen Verschlechterung mit tödlichem Ausgang. Der dritte Patient hatte neun Herde, von denen sich im Kernspintomogramm nur sechs darstellten. Alle Zysten wurden entfernt. Bei zwei Zysten kam es zur Ruptur. Kurz nach der Kraniotomie wurden bei diesem Patienten multiple parakardiale Zysten chirurgisch entfernt. Bei der vierten Patientin bestanden ebenfalls multiple intrakranielle Echinococcus-Zysten, die alle sicher exstirpiert werden konnten. Beim ersten postoperativen Kontroll-CT bestand aufgrund der zystenähnlichen Strukturen Verdacht auf ein Rezidiv, der sich bei der Wiederholungsuntersuchung jedoch nicht bestätigte. Probleme und therapeutisches Management werden diskutiert.
  相似文献   
8.
9.
Twenty-two patients (19 men) with heart failure (16 ischemic, 6 dilated cardiomyopathy; mean age of 67 +/- 6 years) in New York Heart Association classes I (2 patients), II (18 patients), and III (2 patients) under optimal therapy were strictly monitored after carvedilol supplementation. The Tei index decreased significantly from 0.87 +/- 0.17 to 0.53 +/- 0.29 (p <0.03). Conversely, the ejection fraction and transmitral Doppler flow analysis did not show significant improvement, despite a trend toward the amelioration of the ejection fraction, the E-/A-wave ratio, and atrial contribution. The Tei index could represent an earlier marker to evaluate drug-induced left ventricular function improvement in patients with heart failure and could represent a more sensitive tool to monitor left ventricular function during drug interventions.  相似文献   
10.
Summary Dermabacter species are commonly isolated from the skin and other body sites but rarely show pathogenicity in humans. A case ofDermabacter hominis cerebral abscess is reported which presented as a contrast-enhancing intracranial mass in a renal tranplant patient.  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