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   644篇
  免费   33篇
  国内免费   16篇
耳鼻咽喉   2篇
儿科学   33篇
妇产科学   21篇
基础医学   97篇
口腔科学   44篇
临床医学   60篇
内科学   88篇
皮肤病学   25篇
神经病学   32篇
特种医学   82篇
外科学   71篇
综合类   15篇
预防医学   27篇
眼科学   15篇
药学   48篇
中国医学   2篇
肿瘤学   31篇
  2022年   5篇
  2021年   14篇
  2019年   7篇
  2018年   11篇
  2017年   4篇
  2016年   11篇
  2015年   15篇
  2014年   20篇
  2013年   32篇
  2012年   13篇
  2011年   27篇
  2010年   40篇
  2009年   40篇
  2008年   14篇
  2007年   19篇
  2006年   18篇
  2005年   10篇
  2004年   3篇
  2003年   3篇
  2002年   11篇
  2001年   12篇
  2000年   11篇
  1999年   15篇
  1998年   36篇
  1997年   24篇
  1996年   20篇
  1995年   15篇
  1994年   16篇
  1993年   14篇
  1992年   4篇
  1991年   9篇
  1990年   7篇
  1989年   22篇
  1988年   16篇
  1987年   17篇
  1986年   10篇
  1985年   20篇
  1984年   9篇
  1983年   11篇
  1982年   8篇
  1981年   5篇
  1980年   11篇
  1978年   7篇
  1977年   4篇
  1969年   4篇
  1941年   2篇
  1938年   2篇
  1932年   5篇
  1931年   2篇
  1927年   2篇
排序方式: 共有693条查询结果,搜索用时 15 毫秒
1.
Rhabdomyolysis is a syndrome of skeletal muscle injury with release of cellular constituents such as potassium,phosphate,urate and intracellular proteins such as myoglobin into the circulation,which may cause complications including acute kidney injury,electrolyte disturbance and cardiac instability.Abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis.Typically,there is an increase in serum aminotransferases,namely aspartate aminotransferase and alanine aminotransferase.This raises the question of liver injury and often triggers a pathway of investigation which may lead to a liver biopsy.However,muscle can also be a source of the increased aminotransferase activity.This review discusses the dilemma of finding abnormal liver function tests in the setting of muscle injury and the potential implications of such an association.It delves into some of the clinical and experimental evidence for correlating muscle injury to raised aminotransferases,and discusses pathophysiological mechanisms such as oxidative stress which may cause actual liver injury.Serum aminotransferases lack tissue specificity to allow clinicians to distinguish primary liver injury from muscle injury.This review also explores potential approaches to improve the accuracy of our diagnostic tools,so that excessive or unnecessary liver investigations can be avoided.  相似文献   
2.
Kim  SH; Chang  KH; Song  IC; Han  MH; Kim  HC; Kang  HS; Han  MC 《Radiology》1997,204(1):239
  相似文献   
3.
Stroke is a debilitating disease that affects millions each year.While in many cases cerebral ischemic in jury can be limited by effectivw resuscitation or thrombolytic treatment,the injured neurons wither in a process known as delayed neuronal death(DND).Mounting evidence indicates that DND is not simply necrosis played out in slow motion but apoptosis is triggered.Of particular interest are two groups of signal proteins that participate in apoptosis-cyclin dependent kinases(CDKs) and p53-among a myriad of signaling events after an ischemic insult.Recent investigations have shown that CDKs,a family of enzymes initially known for their role in cell cycle regulation,are activated in injured neurons in DND.As for p53,new reports suggest that its up-regulation may represent a failed attempt to rescue in jured neurons,although its up-regulation was previously considered an indication of apoptosis.These observations thus rekindle an old quest to identify new neuroprotective targets to minimize the stroke damage.In this review,the author will examine the evidence that indicates the participation of CDKs and p53 in DND and then introduce pre-clinical data to explore CDK inhibition as a potential neuroprotective target.Finally,using CDK inhibition as an example,this paper will discuss the pertinent criteria for a viable neuroprotective strategy for ischemic in jury.  相似文献   
4.
5.
Zusammenfassung Mit Hilfe der Daten aus dem Nationalen Gesundheitssurvey wird die Frage diskutiert, inwieweit Angaben zu Krankheiten in einer Befragung zur Abschätzung von Prävalenzen für eine Gesundheitsberichterstattung herangezogen werden können. An dem Beispiel der Selbstangaben zum Herzinfarkt wird die Reliabilität und Plausibilität solcher Daten untersucht. Abschliessend werden diese Zahlen Daten aus anderen Quellen, wie dem Herzinfarkt-Register und Fragebogenerhebungen, gegenübergestellt, um beurteilen zu können, ob die Raten plausibel sind Da jedoch auch die anderen Datenquellen ihre Schwächen und Defizite haben, wird der Nutzen von krankheitsbezogenen Selbsteinschätzungen zum Herzinfarkt insgesamt als positiv bewertet, weil damit auch Beziehungen zu sozialen und verhaltensbezogenen Merkmalen untersucht werden können.
Summary With the data of the German National Health Survey the question is discussed, if self-reports on diseases, gained in a survey, are useful for estimating prevalences within the German population. Self-reports on myocardial infarction serve as an example for examining the reliability and plausibility of such data. The prevalence rate for myocardial infarction in this survey is compared with prevalence rates of other data sources as the MONICA-register and surveys. Because these other data sources have some problems and deficits according to their validity too, the value of self-reports on diseases from the National Health Survey is seen positively for establishing a health reporting system.

Résumé Les données de l'Enquête Nationale de la Santé en RFA sont discutées. La question est de savoir siles données subjectives de l'infarctus du myocarde peuvent être utilisées pour estimer des prévalences dans la population allemande. Dans cette étude les problèmes de compatibilité des données d'un questionnaire sont examinées et comparées avec des études similaires. Carles relevés du registre de l'infarctus du myocarde et d'autres enquêtes ont aussi des problèmes de validité, les données subjectives de l'Enquête Nationale sont jugées positivement pour estimer des prévalences de l'infarctus du myocarde. Avecces données il est posible en outre, d'analyser des prévalences se référant aux indicateurs sociaux et concernant une ligne de conduite pour la santé.
  相似文献   
6.
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.   相似文献   
7.
In a prospective, randomized double-blind study the hemodynamic and respiratory effects of i.v. meptazinol, a new synthetic narcotic agonist-antagonist analgesic given in 2 dosages (2 mg/kg and 4 mg/kg), were compared over 15 min to a control group that received 0.9% saline solution as placebo. In a total of 80 patients scheduled for elective aortocoronary bypass surgery, the study was performed before and during general anesthesia and during extracorporeal circulation (ECC). A dose-dependent increase in mean arterial pressure (MAP) and total systemic resistance (TSR) were the predominant hemodynamic effects of meptazinol before and during anaesthesia (Tables 1 and 2). Within the study period no change in heart rate (HR) or cardiac index (CI) could be observed. Directly measured left ventricular parameters revealed a significant increase in left ventricular pressure (LVEDP, and dp/dtmax (Fig. 1). During ECC meptazinol injection was followed by a dose-dependent increase in perfusion pressure, indicating a direct vasoconstrictive effect; no influence on the capacitance system ("venous pooling") could be observed (Fig. 2). In the spontaneously breathing, premedicated patients (morphine hydrochloride 0.15 mg/kg and flunitrazepam 0.03 mg/kg) paO2 increased and paCO2 decreased, especially after injection of the higher dosage of meptazinol; there was no influence on intrapulmonary right-to-left shunting (Qs/Qt).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
Dimerization of human glycophorin A in erythrocyte membranes is mediated by specific interactions within the helical transmembrane domain of the protein. Rotational resonance NMR provides a unique approach for obtaining high-resolution structural data in membrane systems and has been used to establish intermolecular contacts in the glycophorin A dimer by using hydrophobic peptides that correspond to the transmembrane sequence. Magnetization exchange rates were measured between [13C]methyl labels in the hydrophobic sequence -G79-V80-M81-A82-G83-V84- located in the middle of the transmembrane domain and specific [13C]carbonyl labels along the peptide backbone across the dimer interface. Significant magnetization exchange was observed only between V80 (13CH3) and G79 (13C = O) and between V84 (13CH3) and G83 (13C = O), indicating that these residues are packed in the dimer interface in a "ridges-ingrooves" arrangement.  相似文献   
9.
10.
Two girls (a 5 year old and a 21 month old) experiencing mononucleosis syndrome with coincidental human herpesvirus (HHV)-7 and Epstein-Barr virus (EBV) infections are described. One patient had primary HHV-7 infection and reactivated EBV infection. The other had primary HHV-7 and EBV infections. These cases indicated that HHV-7 is capable of inducing infectious mononucleosis-like illness. Multiple herpesvirus infection in one of the patients also suggests that interaction among herpesviruses can occur in vivo. The consequence of this interaction may have clinical implications.  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