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   8730篇
  免费   472篇
  国内免费   9篇
耳鼻咽喉   173篇
儿科学   400篇
妇产科学   219篇
基础医学   958篇
口腔科学   230篇
临床医学   671篇
内科学   2197篇
皮肤病学   270篇
神经病学   581篇
特种医学   279篇
外科学   1487篇
综合类   30篇
一般理论   2篇
预防医学   717篇
眼科学   197篇
药学   394篇
  1篇
中国医学   35篇
肿瘤学   370篇
  2024年   36篇
  2023年   41篇
  2022年   81篇
  2021年   230篇
  2020年   143篇
  2019年   298篇
  2018年   278篇
  2017年   202篇
  2016年   215篇
  2015年   215篇
  2014年   301篇
  2013年   387篇
  2012年   436篇
  2011年   515篇
  2010年   358篇
  2009年   271篇
  2008年   398篇
  2007年   451篇
  2006年   461篇
  2005年   425篇
  2004年   385篇
  2003年   371篇
  2002年   358篇
  2001年   304篇
  2000年   360篇
  1999年   256篇
  1998年   78篇
  1997年   58篇
  1996年   69篇
  1995年   53篇
  1994年   51篇
  1993年   46篇
  1992年   134篇
  1991年   116篇
  1990年   105篇
  1989年   102篇
  1988年   59篇
  1987年   56篇
  1986年   48篇
  1985年   53篇
  1984年   35篇
  1983年   32篇
  1979年   27篇
  1975年   22篇
  1974年   20篇
  1973年   24篇
  1972年   22篇
  1971年   21篇
  1969年   22篇
  1968年   19篇
排序方式: 共有9211条查询结果,搜索用时 0 毫秒
21.
This paper deals with the study of 927 patients of both sexes, with multiprogramable pacemakers implanted during 1987-1988 period, at the "Comandante Manuel Fajardo" Teaching Hospital and the Institute of Cardiology and Cardiovascular Surgery. Complications accounted for 14.9% and the most frequent were, in decreasing order, as follows: sepsis of the pocket (46.7%), hematoma of the pocket, increased threshold and, in a lower percentage, aseptic necrosis (5.7%). Emphasis is made in the role of the nurse in front of a patient with pacemaker and of the different complications presented.  相似文献   
22.
23.
Enterogenic meningitis is an infrequent cause of central nervous system infection. Among these causes the Currarino syndrome may be found presenting sacral agenesis, presacral mass and anorectal stenosis. This syndrome normally causes enterogenic meningitis in the early years of life. The case reported corresponds to a 24-year-old male presenting polymicrobial meningitis with fecal flora germs (anerobic enterococci, Bacteroides fragilis and Escherichia coli). These clinical findings led to radiologic lumbar study with the diagnosis of Currarino syndrome. The existence of neuroenteric fistulas justifies the development of fecal flora meningitis. The nosology of the syndrome as well as the therapeutic strategy are reviewed.  相似文献   
24.
25.
26.
The fragment length polymorphism YNZ22 (D17S5) was analysed for a sample of 207 unrelated individuals living in Madrid (Spanish Caucasians) using PCR-methodology and high resolution separation. Hardy-Weinberg expectations (HWE) were calculated after pooling alleles into four groups. No deviations from HWE were detectable using the conventional 2-test. The power of discrimination was estimated as 0.96 and the mean paternity exclusion chance as 0.7587. A comparison of the allele frequency distribution with those of other Caucasian groups revealed no major differences.  相似文献   
27.
The purpose of these experiments was to study the incidence of stress ulcers in restrained rats and to correlate it with hypothalamic and adrenal cortical and medullary activity, with and without vagotomy. A total of 217 adult rats were used, grouped into 56 sets, and distributed at random in 5 experimental groups. Restraint was followed by a 79% incidence of ulceration in the glandular portion of the gastric mucosa. Vagotomy made these worse (p<0.01). Hypothalamic levels of catecholamines and serotonin showed no significant changes. Urinary measurements revealed decreased excretion of 17-ketosteroids (p<0.001), increased excretion of uropepsinogen (p<0.01), and no significant changes in vanillylmandelic acid among the rats submitted to immobilization. In the adrenal glands of stressed animals, there was a decreased level of catecholamines (p<0.01) and no significant changes in corticosteroid content (17-ketosteroids). These results suggest that hypothalamic stimulation and the participation of the adrenal glands are not essential factors in the pathogenesis of restraint-induced experimental stress ulcer.  相似文献   
28.
Sodium nitroprusside (NPS) is a potent vasodilator which is frequently administered for the control of arterial blood pressure and peripheral resistances. Manual regulation of the dose is difficult and requires a permanent surveillance of patients under treatment. Several attempts have been made to develop an automatized system able to safely control the dose of the drug in clinical practice. However, since now the results have not been completely satisfactory. The aim of our study was to develop of a new automatic-adaptative system able to continuously control the dose of NPS. The system consists of a high precision infusion pump controlled by a microprocessor. Arterial blood pressure is continuously monitorized and according to its values NPS is automatically regulated to maintain blood pressure within a preselected range. A control "fuzzy logic" algorithm was used. We have assessed the efficacy, adaptability, and safeness of the system. The system was tested in 15 mongrel dogs. The protocol was divided into two parts. During the first part a 25% to 30% reduction in blood pressure from baseline values lasting for a period of 4 hours was attempted. The second part was devoted to test the adaptability of the control unit during induced unstable hemodynamic situations. Group I dogs were subjected to volume overload. Group II were treated with noradrenaline to increase blood pressure, and group III underwent a venous bleeding to produce arterial hypotension. Control of arterial blood pressure was achieved after a minimum of 5 min and a maximum of 19 min (mean values = 13.3 min).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
29.
A European approach for resource management and strategic planning has been implemented in the HOSCOM project of AIM by defining information standards needed across countries, as well as a methodology to measure resources and costs at the institutional and interinstitutional level. A Euro Health Data Base (EHDB) has been obtained in order to test data availability and comparability as well as to validate models through macrocomparisons using case-mix (DRG's, refined grouping, disease staging) and microcomparisons based on three diseases (cardiac valve replacement, diabetes mellitus and hip fracture). The EHDB's presently based on 274 164 medical record summaries sampled from 7 countries allowed us to build prototypes (using Clipper, Prolog and SQL) in order to export uniform aggregates in the different countries, with standard software tools for statistical comparisons. It showed the present feasibility of using case-mix based on the European Minimum Basic Data Set (MBDS) and the difficulty of obtaining uniform data on resources and costs other than length of stay across countries. Medical data confidentiality was assured but not yet population-based representativity. Given the present state of the EHDB, problems have been clearly identified in order to be solved by international research and development projects in the near future.  相似文献   
30.
The aim of the present work is to evaluate the usefulness of the Hospital Morbidity Survey for the study of cancer morbidity in Spain. The study covers the period 1977-1987. Age-standardized rates for the following groups have been estimated: "hospital admissions by sex, age and final diagnosis" and "hospital admissions (new cases) by age, sex and final diagnosis". During the period 1983-84 an important increase in the frequency of all malignant tumours has coincided with an equivalent decrease in the non-specified category, leading to the conclusion that an information bias is present. This bias limits the study of temporal series of cancer morbidity in Spain and suggests that a modification of the Spanish Hospital Morbidity Survey is urgently needed.  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