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   1287篇
  免费   54篇
  国内免费   9篇
耳鼻咽喉   7篇
儿科学   57篇
妇产科学   10篇
基础医学   153篇
口腔科学   46篇
临床医学   111篇
内科学   273篇
皮肤病学   43篇
神经病学   57篇
特种医学   154篇
外国民族医学   1篇
外科学   198篇
综合类   43篇
预防医学   93篇
眼科学   8篇
药学   62篇
中国医学   1篇
肿瘤学   33篇
  2023年   5篇
  2022年   4篇
  2021年   10篇
  2020年   12篇
  2019年   11篇
  2018年   17篇
  2017年   18篇
  2016年   18篇
  2015年   39篇
  2014年   24篇
  2013年   47篇
  2012年   43篇
  2011年   49篇
  2010年   46篇
  2009年   54篇
  2008年   43篇
  2007年   40篇
  2006年   42篇
  2005年   42篇
  2004年   47篇
  2003年   35篇
  2002年   24篇
  2001年   24篇
  2000年   19篇
  1999年   31篇
  1998年   54篇
  1997年   64篇
  1996年   60篇
  1995年   44篇
  1994年   44篇
  1993年   38篇
  1992年   16篇
  1991年   12篇
  1990年   24篇
  1989年   19篇
  1988年   29篇
  1987年   32篇
  1986年   32篇
  1985年   13篇
  1984年   7篇
  1983年   15篇
  1982年   22篇
  1981年   8篇
  1980年   13篇
  1979年   5篇
  1978年   10篇
  1977年   7篇
  1976年   10篇
  1975年   4篇
  1968年   3篇
排序方式: 共有1350条查询结果,搜索用时 15 毫秒
991.
992.
An inexpensive artifact suppressor/signal inverter has been developed for use with commercially available window discriminators in unit recordings. This device provides a triggered blockade of the signal to prevent erroneous triggering of the window discriminator by the stimulus artifact. The unit is also capable of inverting the signal for easier unit discrimination when the positive component is too close to baseline or there is more than one positive component present.  相似文献   
993.
994.
We report the effects of treatment with plasma-exchange (PE) and intravenous immune globulins (IVIg) in 36 out of 50 patients with Guillain-Barré syndrome (GBS) recruited by an incidence study in the Emilia-Romagna region of Italy. Comparison of the patients treated with PE and IVIg showed no significant differences in terms of effectiveness in improving the clinical course of GBS: at one month, respectively 11.1% and 25% had recovered, and 55.5% and 58.3% had improved by at least one grade. These results are in agreement with those of the Dutch GBS trial. No relapses were observed in either group. Moreover, our results showed no difference in clinical outcome at 1 and 3 months between the patients receiving only one therapy and those receiving two; a second cycle of therapy did not seem to improve the clinical course of the disease significantly. We conclude that PE and IVIg are both safe and effective therapies for GBS.  相似文献   
995.
996.
A nineteen year old white female was referred for an evaluation of severe, rapidly progressive periodontitis. Although the patient was physically healthy and did not demonstrate any remarkable abnormalities in routine laboratory tests or upon physical examination, a detailed immune profile elucidated abnormal findings. Additionally, the patient demonstrated a poor healing response after tooth removal and a continued loss of bone following insertion of dentures.  相似文献   
997.
Ipecac (emetine) is a safe emetic for emergency home use. Its ready availability also provides the potential for child abuse and chronic self-induced emesis. The chronic administration of Ipecac can result in unusual symptom complexes such as chronic diarrhea and vomiting, muscle weakness, colitis, cardiomyopathy, fever, edema, or electrolyte disturbances. We describe patients who were intentionally poisoned and who demonstrated these symptoms. Because of the widespread use of ipecac for therapy in acute accidental poisonings, toxicology laboratories may not look for or report the presence of this drug in their routine screens. This may delay the recognition of chronic ipecac poisoning in patients.  相似文献   
998.
Epipericardial fat pad: CT findings   总被引:1,自引:0,他引:1  
Paling  MR; Williamson  BR 《Radiology》1987,165(2):335-339
Epicardial and mediastinal fat around the apex of the heart may produce the classic appearance of a cardiac fat pad filling in the anterior cardiophrenic angle on a lateral chest radiograph. A review of 50 computed tomographic (CT) scans of the chest that were normal save for possible cardiomegaly, together with chest radiographs obtained within a 14-day interval, revealed a wide variation in the configuration of this fat pad in 16 patients (32%). Depending on geometric circumstances, the fat pad may produce a well-marginated region of increased density, a region of increased density with poor margination, or an area of reduced density lying anterior to the heart. In an additional four patients (8%), however, a simulation of a cardiac fat pad was produced by cardiomegaly alone or by relative levoposition of the heart. In these four patients, the left side of the heart contacted the chest wall on the left over a larger than normal area and thereby excluded lung from the vicinity, simulating the appearance of a fat pad where none existed.  相似文献   
999.
Recommended materials for breath hydrogen collection (plastic syringes with twist lock closure) are only adequate for relatively brief periods because of gradual hydrogen loss and considerable variability between duplicate samples. To document the most favorable storage conditions for breath hydrogen, we compared hydrogen retention in plastic syringes using a conventional twist-in-lock closure versus a simple, inexpensive syringe closure, a Critocap. Hydrogen retention was studied at 25, 5, and -20 degrees C in two different syringe brands over 72 h of storage. An analysis of variance confirms the superiority of Critocaps over twist-in-lock closures (p less than 0.001). Reliability was maximal when samples were placed in environments less than 5 degrees C. When storage time was extended to 7 days, mean hydrogen retention was 86 +/- 6% (means +/- SD).  相似文献   
1000.
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