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   11327篇
  免费   515篇
  国内免费   7篇
耳鼻咽喉   336篇
儿科学   373篇
妇产科学   467篇
基础医学   909篇
口腔科学   243篇
临床医学   845篇
内科学   2181篇
皮肤病学   368篇
神经病学   780篇
特种医学   615篇
外科学   2817篇
综合类   117篇
一般理论   1篇
预防医学   687篇
眼科学   385篇
药学   274篇
中国医学   3篇
肿瘤学   448篇
  2021年   70篇
  2019年   66篇
  2018年   92篇
  2017年   72篇
  2016年   80篇
  2015年   592篇
  2014年   645篇
  2013年   707篇
  2012年   777篇
  2011年   748篇
  2010年   672篇
  2009年   624篇
  2008年   740篇
  2007年   649篇
  2006年   622篇
  2005年   590篇
  2004年   412篇
  2003年   187篇
  2002年   171篇
  2001年   164篇
  2000年   150篇
  1999年   169篇
  1998年   78篇
  1997年   99篇
  1996年   83篇
  1995年   66篇
  1994年   54篇
  1993年   74篇
  1992年   134篇
  1991年   119篇
  1990年   117篇
  1989年   106篇
  1988年   136篇
  1987年   118篇
  1986年   94篇
  1985年   123篇
  1984年   108篇
  1983年   101篇
  1982年   66篇
  1981年   65篇
  1980年   61篇
  1979年   105篇
  1978年   82篇
  1977年   83篇
  1976年   64篇
  1975年   58篇
  1974年   77篇
  1973年   68篇
  1972年   72篇
  1970年   51篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Zusammenfassung Die Differenzialdiagnose schlafbezogener Atmungsstörungen (SBAS) erfolgt in Anlehnung an die durch die im Jahr 2005 von der American Academy of Sleep Medicine (AASM) neu aufgelegte Internationale Klassifikation von Schlafstörungen (ICSD-2). Die ICSD-2 teilt die derzeit bekannten Schlaf- und Aufwachstörungen in 8 Kategorien ein, die SBAS werden in Kategorie II aufgeführt. Die ICSD-2 ist kompatibel zu den international gebräuchlichen Systemen der Klassifikation von Krankheiten (ICD-9, ICD-10). Grundlage aller differenzialdiagnostischen Erwägungen stellt neben der ausführlichen Anamnese die Polysomnographie dar, ggf. ergänzt durch weiterführende internistische, neurologische, pädiatrische, Hals-Nasen-Ohren-ärztliche, Mund-Kiefer-Gesichts-chirurgische sowie neuropsychologische und neurophysiologische Untersuchungen.  相似文献   
32.
33.
Interstitial cystitis (IC) is a chronic, debilitating inflammatory disease of the urinary bladder, characterized by chronic pelvic pain, urgency/frequency symptoms, and decrease of the functional bladder capacity. Both the etiology and pathogenesis of the condition that predominantly affects women are still not fully understood. Thus, a causal therapeutic approach still does not exist. IC remains a strict diagnosis of exclusion; distinct histopathological findings within the bladder wall are frequently found, although they are not pathognomonic. The diagnostic criteria elaborated by the NIH are helpful in clinical research; their dogmatic utilization will however lead to an underdiagnosis of IC in 60% of the patients. IC-specific symptom questionnaires and validated symptom scales help the physician to assess the therapeutic response during the follow-up of the patients.  相似文献   
34.
Cardiogenic shock remains the major cause of death among patients with acute myocardial infarction. Besides supportive therapy there is clear evidence that revascularization of the infarct related artery should be performed as soon as possible with percutaneous transluminal coronary angioplasty. Placement of coronary stents and administration of platelet glycoprotein IIb/IIIa antagonists may further improve outcome. Intra-aortic balloon pumping should be integral part of this treatment strategy but is unfortunately underused in clinical practice. Routine bypass surgery for cardiogenic shock patients is deferred and restricted to selected patients.  相似文献   
35.
1. Human intestinal epithelial Caco-2 cells have been used to investigate the transepithelial permeation of the cardiac glycoside, digoxin. 2. Transepithelial basal to apical [3H]-digoxin flux exceeds apical to basal flux, a net secretion of [3H]-digoxin being observed. At 200 microM digoxin, net secretory flux (Jnet) was 10.8 +/- 0.6 nmol cm-2 h-1. Maximal secretory flux (Jmax) of vinblastine was 1.3 +/- 0.1 nmol cm-2 h-1. Cellular uptake of digoxin was different across apical and basal cell boundaries. It was greatest across the basal surface at 1 microM, whereas at 200 microM, apical uptake exceeded basal uptake. 3. Net secretion of [3H]-digoxin was subject to inhibition by digitoxin and bufalin but was not inhibited by ouabain, convallatoxin, and strophanthidin (all 100 microM). Inhibition was due to both a decrease in Jb-a and an increase in Ja-b. Uptake of [3H]-digoxin at the apical surface was increased by digitoxin and bufalin. All cardiac glycosides decreased [3H]-digoxin uptake at the basal cell surface (except for 100 microM digitoxin). 4. The competitive P-glycoprotein inhibitors, verapamil (100 microM), nifedipine (50 microM) and vinblastine (50 microM) all abolished net secretion of [3H]-digoxin due to both a decrease in Jb-a and an increase in Ja-b. Cellular accumulation of [3H]-digoxin was also increased across both the apical and basal cell surfaces. I-Chloro-2,4,-dinitrobenzene (10 microM), a substrate for glutathione-S-transferase and subsequent ATP-dependent glutathione-S-conjugate secretion, failed to inhibit net secretion of [3H]-digoxin. The increase in absorptive permeability Pa-b (= Ja-b/Ca) and cellular [3H]-digoxin uptake upon P-glycoprotein inhibition, showed that the intestinal epithelium was rendered effectively impermeable by ATP-dependent extrusion at the apical surface. 5. A model for [3H]-digoxin secretion by the intestinal epithelium is likely to involve both diffusional uptake and Na(+)-K+ pump-mediated endocytosis, followed by active extrusion at the apical membrane.  相似文献   
36.
Summary Preproenkephalin mRNA production by efferent neurons projecting to the gerbil inner ear was assessed using combined in situ hybridization and retrograde labeling with florescent tracers. Virtually all vestibular efferent neurons were positive for preproenkephalin mRNA. Of the cochlear efferents, one-half of the medial olivocochlear neurons were positive for enkephalin. All lateral olivocochlear neurons were negative for enkephalin. The results suggest that there are two, biochemically distinct subpopulations of medial olivocochlear efferents in the gerbil. Offprint requests to: Division of Otolaryngology, ENT, V-112C  相似文献   
37.
Clinical aspects of FK-506 or cyclosporine immunosuppression regimens were evaluated in 48 consecutive pediatric renal transplant recipients. Tapering and discontinuation of prednisone was employed only in children receiving FK-506 who experienced minor or no rejection episodes during the 1st posttransplant month. At 1 year follow-up, 17 of 22 (77%) of all children with functioning allografts were receiving no prednisone (n=13) or a mean dosage of 0.07 mg/kg per day (n=4). During the 1st month, acute cellular rejection was more common in the FK-506 group (0.58 vs. 0.21 rejections per patient,P<0.05) but allograft survival (92%) and renal function at 1 year posttransplant were identical in both groups. Compared with the cyclosporine regimen, FK-506 immunosuppression may be associated with a higher incidence of cytomegalovirus or reversible Epstein-Barr virus-induced lymphoproliferative disease. However, the FK-506 group had less hirsutism and gingival hypertrophy and required fewer antihypertensive medications independent of steroid use. Height standard deviation scores and weight-for-height index improved only in preadolescents receiving FK-506 but no prednisone (P<0.02 andP<0.05, respectively), but did not differ between children on FK-506 plus prednisone and those in the cyclosporine group. We conclude that the major advantages of FK-506 over cyclosporine immunosuppression are a reduced severity of hypertension and an improved cosmetic appearance which may improve long-term medical compliance. When used as monotherapy, FK-506 also shows promise in relieving the growth retardation associated with cyclosporine regimens that include prednisone.  相似文献   
38.
After a fracture of the distal radius, especially with malunion, many patients complain of a decreased range of forearm rotation and pain on the ulnar side of the wrist. The purpose of this article is to describe the therapeutic options available in such cases. Decision making as to whether there is an indication for corrective surgery or not is based on the patient’s symptoms and the clinical findings, whereas the decision as to which surgery to perform must take into account the radiological findings. If possible, reconstruction of the anatomy using a distal radius osteotomy should be carried out.  相似文献   
39.
Zusammenfassung Einleitung: Das Ziel dieser Studie war die Entwicklung eines spezifischen Schweregradklassifizierungssystems für die Beurteilung und Vorhersage von Organfunktionsstörungen und Überleben bei herzchirurgischen Intensivpatienten. Methoden: Hierzu wurden konsekutiv alle erwachsenen Patienten nach einem herzchirurgischen Eingriff unter Einsatz der Herzlungenmaschine über einen Zeitraum von 3 Jahren in die Studie aufgenommen. Im Konstruktionsset erfolgte die Auswahl der Variablen mit Hilfe der Patienten, die mindestens 24 Stunden auf der Intensivstation verbrachten. Die Ergebnisse wurden dann in zwei Validierungssets mit allen Intensivpatienten überprüft. Die Qualität des Scores wurde mit dem Hosmer-Lemeshow-Test (HL) sowie der ROC-Analyse beurteilt, und mit dem APACHE-II- und dem MODS-Score verglichen. Ergebnisse: Insgesamt wurden 3230 Patienten über einen Zeitraum von 3 Jahren auf unserer Intensivstation aufgenommen. Die HL-Werte für den neuen Score waren 5,8 (APACHE-II: 11,3; MODS: 9,7) für das Konstruktionsset, 7,2 (APACHE-II: 8,0; MODS: 4,5) für das Validierungsset I und 5,9 für das Validierungsset II. Die Fläche unter der ROC-Kurve war 0,91 (APACHE-II: 0,86; MODS: 0,84) für den neuen Score im Konstruktionsset, 0,88 (APACHE-II: 0,84; MODS: 0,84) in dem Validierungsset I, und 0,92 in dem Validierungsset II. Schlussfolgerung: Der neue CASUS (Cardiac Surgery Score) zeigt für herzchirurgische Intensivpatienten eine exzellente Kalibrierung und Diskriminierung bezüglich der 30-Tage-Letalität. Die Variablen des CASUS sind einfach, reproduzierbar und werden routinemäßig in herzchirurgischen Intensivstationen erfasst. Der CASUS könnte als Expertensystem für das Diagnostizieren von Organfunktionsstörungen, der Entscheidungsfindung, der Ressourcenauswertung und Vorhersage der Letalität für herzchirurgische Intensivpatienten dienen.  相似文献   
40.
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