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   1801篇
  免费   122篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   125篇
妇产科学   46篇
基础医学   236篇
口腔科学   48篇
临床医学   219篇
内科学   329篇
皮肤病学   43篇
神经病学   140篇
特种医学   46篇
外国民族医学   1篇
外科学   168篇
综合类   10篇
预防医学   237篇
眼科学   29篇
药学   122篇
中国医学   2篇
肿瘤学   117篇
  2023年   8篇
  2022年   19篇
  2021年   34篇
  2020年   28篇
  2019年   36篇
  2018年   52篇
  2017年   35篇
  2016年   38篇
  2015年   43篇
  2014年   54篇
  2013年   100篇
  2012年   114篇
  2011年   134篇
  2010年   68篇
  2009年   49篇
  2008年   90篇
  2007年   121篇
  2006年   111篇
  2005年   117篇
  2004年   93篇
  2003年   92篇
  2002年   83篇
  2001年   28篇
  2000年   31篇
  1999年   23篇
  1998年   15篇
  1997年   13篇
  1996年   14篇
  1995年   11篇
  1994年   13篇
  1993年   9篇
  1992年   15篇
  1991年   11篇
  1990年   14篇
  1989年   7篇
  1988年   10篇
  1987年   11篇
  1986年   13篇
  1985年   15篇
  1984年   18篇
  1983年   14篇
  1982年   18篇
  1981年   13篇
  1980年   8篇
  1979年   9篇
  1978年   4篇
  1976年   10篇
  1973年   5篇
  1972年   5篇
  1949年   4篇
排序方式: 共有1927条查询结果,搜索用时 15 毫秒
1.
2.
Ocular injuries by vesicatory insects appear exceptional and the authors have not found any reports in the literature. Cantharidine, with toxicity comparable to that of mustard gas, can be present in many species of coleoptera. It results in progressive corneal necrosis ending in ocular perforation in 30 days. The necrotic process persists with long duration because this material is not broken down. It provokes deep ocular injuries (cristalline lens). The inflammatory reaction is severe with acute refractory hypertension. There exists no antidote, only prevention is useful. Emergency penetrating keratoplasty with anterior chamber lavage should help eliminate the toxin. In daily practice, the authors observe similar but less serious injuries; they think that they could be due to dust rich in vesicatory insect debris or their secretions.  相似文献   
3.
Occupational exposure to carcinogenic agents on the decks on six Norwegian crude oil tankers was examined in five harbors. The purpose of the study was to evaluate the need for improving the working environment on deck on these tankers. Technical arrangments and the work itself on the deck were observed during loading or unloading. Occupational monitoring was performed by active sampling of benzene, polyaromatic hydrocarbons, and some aldehydes. The crew answered a questionnaire concerning their work, use of protective equipment, and occurrence of acute symptoms. The levels of air-borne carcinogenic agents were low, probably due to closed loading systems on all tankers. However, the seamen reported discomfort during the work that may be related to other chemical agents in the cargo. The seamen were frequently painting with lead chromate paint without using personal protective equipment. This type of chemical exposure should be evaluated.  相似文献   
4.
Background: Short administration of volatile anesthetics preconditions myocardium and protects the heart against the consequences of subsequent ischemia. Activation of tyrosine kinase is implicated in ischemic preconditioning. The authors investigated whether desflurane-induced preconditioning depends on activation of tyrosine kinase.

Methods: Sixty-four rabbits were instrumented for measurement of left ventricular pressure, cardiac output, and myocardial infarct size (IS). All rabbits were subjected to 30 min of occlusion of a major coronary artery and 2 h of subsequent reperfusion. Rabbits underwent a treatment period consisting of either no intervention for 35 min (control group, n = 12) or 15 min of 1 minimum alveolar concentration desflurane inhalation followed by a 10-min washout period (desflurane group, n = 12). Four additional groups received the tyrosine kinase inhibitor genistein (5 mg/kg) or lavendustin A (1.3 mg/kg) at the beginning of the treatment period with (desflurane-genistein group, n = 11; desflurane-lavendustin A group, n = 12) or without desflurane inhalation (genistein group, n = 9; lavendustin A group, n = 8).

Results: Hemodynamic values were similar in all groups during baseline (left ventricular pressure, 87 +/- 14 mmHg [mean +/- SD]; cardiac output, 198 +/- 47 ml/min), during coronary artery occlusion (left ventricular pressure, 78 +/- 12 mmHg; cardiac output, 173 +/- 39 ml/min), and after 2 h of reperfusion (left ventricular pressure, 59 +/- 17; cardiac output, 154 +/- 43 ml/min). IS in the control group was 55 +/- 10% of the area at risk. The tyrosine inhibitors had no effect on IS (genistein group, 56 +/- 13%; lavendustin A group, 49 +/- 13%; each P = 1.0 vs. control group). Desflurane preconditioning reduced IS to 40 +/- 15% (P = 0.04 vs. control group). Tyrosine kinase inhibitor administration had no effect on IS reduction (desflurane-genistein group, 44 +/- 13%; desflurane-lavendustin A group, 44 +/- 16%; each P = 1.0 vs. desflurane group).  相似文献   

5.
The students of Centre des Oeuvres Universitaires de Dakar (COUD) do not seem to participate to the management of their own health status in spite of their financial participation in some services. The aim of this study is to evaluate the students's participation in their own health status. The results obtained from documents and archives, COUD'S responsible and student's opinion have shown a financial participation of 8% from the COUD medical service budget. The students wish to participation actively to the management of the medical service while COUD's responsible have opposite opinion. For an efficiency management of their own health status, students must necessary participate.  相似文献   
6.
7.
We have developed a PCR-based method to detect macrolide resistance and the virulence gene cagA in Helicobacter pylori within 24 h, thereby improving the lengthy process of culture-based approaches. Total DNA was prepared directly from stomach biopsy specimens. The procedure proved to be rapid and reliable and could be utilized for diagnostic purposes.  相似文献   
8.
Staphylococcus aureus isolates (n = 70) from 65 patients (36 canine, 18 equine, 7 bovine, 2 avian, and 2 feline) at seven veterinary teaching hospitals in the United States were studied. The majority of patients (83%) with an S. aureus infection were canine and equine, but this may have reflected a sample bias based on clinic case loads and diagnostic lab submissions at the participating institutions. Fourteen percent of patients with an S. aureus infection were infected with a methicillin-resistant S. aureus (MRSA) isolate. Six of seven institutions had at least one MRSA infection during the study. Pulsed-field gel electrophoresis on 63 of the 70 isolates yielded 58 unique strains of S. aureus. None of the strain types of the MRSA isolates matched each other or the type of any other S. aureus isolate. The proportions of patients infected with an MRSA isolate were not significantly different between institutions or animal species (P > or = 0.222). Methicillin-resistant S. aureus isolates in this study seemed to be community acquired rather than hospital acquired.  相似文献   
9.
A deficiency of all nine complement (C) components in cord sera relative to maternal serum levels was demonstrated. At 4 days of age, C1q (measured immunochemically), C1, C2, C4 and C7 levels were increased markedly to maternal levels. C3 was the only C component which exhibited no significant change between birth and at 4 days of age. A marked deficiency of serum levels of C8 and particularly of C9 was evident at birth.

No haemolytic C was demonstrable in the colostrum from which lipids were previously removed. Functional C3 was measurable by immune adherence with EAC142 intermediate sheep cells. Functional C3PA using cobra venom-induced lysis of unsensitized guinea-pig erythrocytes was also present. Substantial amounts of C3, C4 and C3PA determined immunochemically were found at 24 hr after birth with rapidly decreasing levels at 48 and 72 hr. C1q and C5 were absent. No differences of C components were evident in sera between bottle and breast-fed infants for any of the nine components studied.

  相似文献   
10.
Intelligence testing was completed on 38 newly diagnosed pediatriconcology patients and 29 hemophilia patients between 6 and I7years of age. A low Verbal/high Performance intelligence testpattern was displayed by 39% of the oncology patients as comparedto an expected frequency of 12/14% in the hemophilia controls.Increased amounts of prednisone, vincristine, and number ofdays between diagnosis and intelligence testing correlated withthe Verbal-Performance (V-P) discrepancy scores in the oncologypatients. These findings and previous studies suggest the needfor monitoring the intellectual, emotional, linguistic, andneuropsychological status of pediatric oncology patients beginningat the time of diagnosis.  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