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   4715篇
  免费   385篇
  国内免费   2篇
耳鼻咽喉   33篇
儿科学   88篇
妇产科学   94篇
基础医学   801篇
口腔科学   117篇
临床医学   396篇
内科学   834篇
皮肤病学   68篇
神经病学   893篇
特种医学   135篇
外科学   573篇
综合类   61篇
一般理论   2篇
预防医学   350篇
眼科学   62篇
药学   367篇
中国医学   2篇
肿瘤学   226篇
  2021年   57篇
  2019年   49篇
  2018年   79篇
  2017年   58篇
  2016年   87篇
  2015年   82篇
  2014年   113篇
  2013年   144篇
  2012年   211篇
  2011年   219篇
  2010年   113篇
  2009年   111篇
  2008年   187篇
  2007年   203篇
  2006年   180篇
  2005年   195篇
  2004年   138篇
  2003年   142篇
  2002年   149篇
  2001年   141篇
  2000年   154篇
  1999年   121篇
  1998年   65篇
  1997年   50篇
  1994年   46篇
  1992年   86篇
  1991年   88篇
  1990年   90篇
  1989年   72篇
  1988年   82篇
  1987年   68篇
  1986年   76篇
  1985年   70篇
  1984年   56篇
  1983年   63篇
  1982年   52篇
  1981年   45篇
  1980年   49篇
  1979年   77篇
  1978年   62篇
  1977年   60篇
  1976年   51篇
  1974年   57篇
  1973年   53篇
  1972年   58篇
  1971年   55篇
  1970年   44篇
  1969年   43篇
  1968年   48篇
  1967年   41篇
排序方式: 共有5102条查询结果,搜索用时 15 毫秒
41.
Rats were treated chronically with -methyl-p-tyrosine methyl-ester HCl (-MT) twice daily for 0–14 days. At 1 h after the (last) -MT injection, d-amphetamine sulphate was given and motor activity was measured in an ANIMEX activity meter for 4 h. Amphetamine-induced excitatory and stereotyped behaviour was scored according to a rating scale in a separate experiment. A single dose of -MT markedly reduced the activity response after amphetamine. After 1–3 days of -MT treatment, tolerance to its amphetamine-antagonistic affect started to develop, reaching a maximal degree after 7–14 days. The pattern of the amphetamine response, monophasic in control rats, became biphasic in the -MT tolerant rats with an early (at 0–1 h) and a late (2–4 h) peak of motor activity. The late peak appeared within 3 days, while the early peak appeared after 7 days of -MT treatment. The results on amphetamine-induced excitatory and stereotyped behaviour in essence agreed with the motor-activity data. It is concluded that tolerance to the amphetamine-antagonistic action of -MT is not complete. Its rate of development varies in a complex pattern, indicating the presence of more than one mechanism of tolerance.  相似文献   
42.
Zusammenfassung Das MMPI-Interpretationssystem von Lachar (1974), das gegenüber den bisher verfügbaren Systemen eine Reihe von Vorteilen aufweist, wurde in einer deutschen Version an 1190 stationären psychiatrischen Patienten auf seine Gültigkeit hin untersucht. Von den 153 Texten der Interpretationsbibliothek wurden diejenigen 114 Texte, die voneinander unabhängige Merkmale eines MMPI-Profils interpretieren, bei jedem Vorkommen im Einzelfall von dem behandelnden Psychiater hinsichtlich der interpretativen Treffsicherheit beurteilt. Im Durchschnitt wurden von jeweils 100 Texten 83 als zutreffend bezeichnet. Bei der Analyse der einzelnen Programmteile zeigte sich, daß die Treffsicherheit bei psychopathologisch auffälligen MMPI-Profilen wesentlich höher war als bei Profilen im Normbereich. Die in dieser Untersuchung gefundenen Trefferraten korrelierten hoch mit denen der amerikanischen Originaluntersuchung, was die spezifische und replizierbare Gültigkeit der einzelnen Texte bestätigt. Das vorliegende Interpretationssystem bietet damit auf der Grundlage des MMPI eine Persönlichkeitsbeschreibung, für die in verschiedenen psychiatrischen Einsatzbereichen und verschiedenen Sprachen eine gute interpretative Treffsicherheit im Einzelfall nachgewiesen ist.Eine frühere Fassung dieser Arbeit wurde auf dem 31. Kongreß der Deutschen Gesellschaft für Psychologie in Mannheim vorgetragen. Ich danke Frau Dipl. Psych. Kornelia Zangl und Frau Dr. Pola Engel-Sittenfeld für ihre Hilfe bei der Übersetzung der Interpretationstexte. Langjährige wertvolle Mitarbeit haben Frau Irmtraud Reinhold bei der Testdurchführung, Frau Gabi Kunze bei der Programmierung des Interpretationssystems und bei der Verarbeitung der Daten geleistet  相似文献   
43.
Summary The binding of3H-WB 4101, an 1-adrenoceptor antagonist, to membranes of the cerebral cortex, the hypothalamus, and the lower brainstem was examined in adult spontaneously hypertensive (SH) rats and in normotensive Wistar Kyoto (WK) controls. The specific binding of3H-WB 4101 (0.33 nM) was significantly higher in homogenates from the cerebral cortex of SH rats as compared to WK rats. No differences were detected between SH and WK rats in the specific binding of3H-spiroperidol (0.25 nM), a dopamine receptor antagonist, to membranes from the corpus striatum and the limbic forebrain. The locomotor activity was significantly higher in SH rats as compared to WK controls, in all probability due to a lack of habituation to environmental change. It is suggested that the high reactivity of SH rats is related to a dysfunction in the noradrenergic neurons in the central nervous system.  相似文献   
44.
Research in health professions education has been dominated by a research paradigm emphasizing controlled experimentation. Widespread criticism has been voiced by leaders in the research community concerning the adequacy of the paradigm to deal with complex human behavior occurring in complex social environments. This article is concerned with exploring the implications of controlled studies for health professions education and proposing an alternative research strategy.  相似文献   
45.
Does licensure restrict entry fairly, or does it serve as a discriminatory barrier for minorities? The use of the concept of adverse impact, a legally mandated, quantitative tool to assess selection procedures, is a useful mechanism to make such determinations. The results of a study in Michigan of the nursing examination for licensure show how adverse impact may be used. The implications of the outcome of the adverse impact study weigh heavily not only on the nursing examination but also on the use of such tools in other health professions.  相似文献   
46.
47.
Laparoscopic bipolar electrosurgical sterilization has been employed for nearly two decades. This bipolar procedure was intended to reduce the incidence of unintended complications, such as bowel burns. However, compared to the monopolar procedure, it produced a higher failure rate. This study examines the role of the low power-high voltage coagulation waveform on the effectiveness of electrosurgical desiccation on the rat uterine model of the fallopian tube. Desiccations were performed with both Kleppinger and Storz forceps using generator settings from 2 to 6. Desiccations performed to the visual endpoint (blanch, swell, and collapse) required from 23.8 to 30.0 joules, although procedures performed at a generator setting of 2 required long application times, an average 15.4 sec (Storz) and 28.2 (Kleppinger). All bipolar procedures led to a loss of tissue at the desiccation site at 12 weeks postsurgery. Therefore, the electrosurgical coagulation waveform proved to be effective in producing adequate in vivo tissue destruction even at very low generator settings.  相似文献   
48.
In normal muscle, 65-kd heat shock proteins (hsp) were detected on capillary endothelial cells, the mural elements of larger vessels, and some intracellular organelles, probably mitochondria. In the inflammatory myopathies, the 65-kd hsp were detected on inflammatory cells, degenerating and regenerating fibers, and on many but not all nonnecrotic muscle fibers invaded by T cells. The expression of the 65-kd hsp may be an immune-nonspecific response to cellular "stress," but hsp determinants could possibly also serve as autoantigen(s) recognized by autoreactive T cells.  相似文献   
49.
50.
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