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   171442篇
  免费   7593篇
  国内免费   421篇
耳鼻咽喉   2606篇
儿科学   5219篇
妇产科学   3619篇
基础医学   23214篇
口腔科学   6705篇
临床医学   10625篇
内科学   41569篇
皮肤病学   5448篇
神经病学   14003篇
特种医学   4008篇
外国民族医学   2篇
外科学   21271篇
综合类   953篇
一般理论   50篇
预防医学   16267篇
眼科学   4031篇
药学   11812篇
中国医学   901篇
肿瘤学   7153篇
  2023年   1120篇
  2022年   1232篇
  2021年   3984篇
  2020年   2053篇
  2019年   4083篇
  2018年   6597篇
  2017年   3936篇
  2016年   3739篇
  2015年   4098篇
  2014年   4932篇
  2013年   7295篇
  2012年   12322篇
  2011年   13323篇
  2010年   6742篇
  2009年   4852篇
  2008年   10467篇
  2007年   10964篇
  2006年   10089篇
  2005年   9971篇
  2004年   9002篇
  2003年   8342篇
  2002年   7795篇
  2001年   5130篇
  2000年   5965篇
  1999年   4244篇
  1998年   799篇
  1997年   505篇
  1996年   503篇
  1995年   406篇
  1994年   338篇
  1992年   1517篇
  1991年   1288篇
  1990年   1145篇
  1989年   943篇
  1988年   846篇
  1987年   783篇
  1986年   746篇
  1985年   659篇
  1984年   510篇
  1983年   415篇
  1979年   419篇
  1975年   315篇
  1974年   357篇
  1973年   398篇
  1972年   327篇
  1971年   365篇
  1970年   323篇
  1969年   333篇
  1968年   306篇
  1967年   295篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Submitral ventricular aneurysm is a thoroughly studied pathology but is not well known due to its rarity. Clinically, it is manifested by symptoms and signs of heart failure, mitral regurgitation and/or ventricular arrhythmias, and may be associated with thromboembolic phenomena and myocardial ischemia due to compression of the coronary arteries by the aneurysm. A rare complication of this type of aneurysm is rupture into the left atrium. Transthoracic echocardiography plays an important role in the definitive diagnosis of this pathology, although the role of transesophageal echocardiography in the evaluation of these patients is less known. We report a case of a submitral ventricular aneurysm complicated by rupture into the left atrium, which was diagnosed by transesophageal echocardiography.  相似文献   
82.
Three cases with suspected pulmonary artery embolism are presented, in which transesophageal echocardiography showed a mass in the right pulmonary artery consistent with thrombus. The relevant diagnostic contributions of transesophageal echocardiography are discussed.  相似文献   
83.
84.
A 76-year-old woman with an inferior wall myocardial infarction, with right ventricular involvement, developed severe arterial hypoxemia with neurological involvement. Pulmonary edema or embolism and chronic obstructive pulmonary disease were ruled-out, and a right-to-left shunt was demonstrated by contrast echocardiography at the level of the foramen ovale. After inotropic support and oxygen supplementation, the patient recovered, although with significant neurological sequelae. No focal lesions were detected in the central nervous system by computerized tomography. Hypoxemia improved, coinciding with the disappearance of right-to-left shunt by contrast echocardiography.  相似文献   
85.
Captopril is a suitable drug to treat high blood pressure in diabetic patients. This Angiotensin-Converting Enzyme Inhibitor (ACEI) is a vasodilator without tachycardia and saline retention. Furthermore, captopril is one of antihypertensive drugs with less adverse effects. It does not induce metabolic changes, improves glucose tolerance and brake the evolution of renal insufficiency. About 50-60% of patients are under control (DBP < 90 mmHg) with captopril monotherapy. In the present paper, were included 64 women and 16 men with diabetes mellitus and mild-moderate hypertension, I-II phase WHO. The average age (mean +/- S.D.) was 66.6 +/- 9.2 years. All patients were treated with 25 mg/12 h of captopril, for one month. If blood pressure was not under control, captopril treatment enhanced to 50 mg/12 h during second month. After this period of two months, patients under control were got out of this study. 37 patients (46.25%) needed a second drug. In randomized form, 20 patients associated 25 mg HCTZ one time a day (CAP + HCTZ); and 17 patients associated 20 mg/12 h of nifedipine retard (CAP + NIF). The study continued for 4 months more. Both treatments reduced blood pressure in significant form without changes statistical significant in the heart rate, weight, glycemia, cholesterol, triglycerides, c-HDL, uric acid, creatinine, Na+ and K+ blood levels. CAP + HCTZ controlled (DBP < 90 mHg) 85% and CAP + NIF 81.25% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
86.
87.
We studied the hepatic handling of bromosulfophthalein in healthy rabbits with hepatic coccidiosis 28 days after an experimental infection with sporulated oocysts of Eimeria stiedai, an experimental model of liver disease histopathologically resembling primary biliary cirrhosis in man. A pharmacokinetic study of the results was performed following a multicompartmental model with 7 transfer constants to describe the physiological disposition of the dye. The study showed that the plasma disappearance, distribution volume (Vi), hepatic biotransformation and the biliary and urinary elimination of conjugated (BSPc) and unconjugated (BSPu) bromosulfophthalein were markedly altered. Whereas Vi and urinary excretion of the dye were significantly increased, the hepatic clearance, biotransformation and biliary excretion of BSPc and BSPu were drastically reduced in infected rabbits. Satisfactory agreement was obtained between the experimental and estimated data, particularly those relating to biotransformation clearance and biliary and urinary excretion of the dye. These results demonstrate that severe liver disease in rabbits with histopathological liver alterations resembling several hepatic dysfunctions in man markedly reduce hepatic uptake, metabolism and biliary excretion of a xenobiotic such as BSP.  相似文献   
88.
Summary In this study, the largest Nordic study of its kind, investigated psychosexual dysfunction among subjects aged 55–57 years. The cohort included 862 subjects of both sexes and all were interviewed using the Diagnostic Interview Schedule (DIS). Results showed that 122 subjects had a lifetime diagnosis of psychosexual dysfunction. The lifetime prevalence of psychosexual dysfunction was 14.4%; of inhibited sexual desire, 9.8%; of inhibited sexual excitement, 3.5%; of inhibited orgasm, 2.1%; and of functional dyspareunia, 1.3%. Of the subjects with psychosexual dysfunction, 73% were women. The frequency was highest in those who had never married. Separated subjects had rates intermediate between the married and the never-married. The majority (76%) of affected subjects had only one dysfunction. However, 57% of them had received another psychiatric diagnosis at some time. Subjects with psychosexual dysfunction wereless frequently diagnosed as suffering from alcohol abuse and dependence and social phobia than subjects with no psychosexual dysfunction.  相似文献   
89.
Reports of the human teratogenicity of retinoids have raised concern about the potential human teratogenicity of high doses of vitamin A. Nevertheless, there are few human case reports of excess intake of vitamin A during pregnancy and defective outcomes. No epidemiological studies have been carried out on this subject. Here we present the results of an epidemiological study of prenatal exposure to high doses of vitamin A in Spain, using data from the Spanish hospital-based, case-control registry. Although it is difficult to reach conclusions with such a very low exposure level (1.3 per 1,000 livebirths), our results suggest that a teratogenic effect might exist for exposures to high doses of vitamin A (OR = 0.5, p = 0.15 for less than 40,000 FU and OR = 2.7, p = 0.06 for 40,000 1U or more). As we might expect, this effect also seems to be related to the organogenetic status (OR = 5.4, p = 0.1 for 1st –2nd month, OR = 1.8, p = 0.4 for 3rd onwards) at the time of exposure.  相似文献   
90.
The authors give an account of 190 premature infants they treated in 1956-1988, suffering from retinopathy of prematurity--ROP, and for prolonged subsequent periods. As the head of the team followed up all the children, there is an integrated view of the problem. The birth weight of the infants was 640 g--1,900 g. From the total number 76.8% infants had a birth weight of 1,500 g or less, 13.7% had a birthweight of 1,000 g or less. Evidence of the increasing rate is provided by the number of patients treated since birth at the department for premature and pathological infants FNM as well as by the number of children admitted from other departments after development of ROP. In 1956-1970, i. e. in 15 years, the authors looked after 34 patients, in 1971-1988, i. e. in 18 years there were 156 children with ROP. In 1956-70 cases of ROP predominated which developed as a result of absolute or relative hypoxia. They were successfully treated by individually adjusted and carefully controlled oxygen therapy (6.9% blind children). In 1971-1975 the possibility to use this therapy declined briskly because after introduction of modern medical technique the number of findings suggesting a hyperoxic insult increased. At that time the results deteriorated greatly (50% blind children). In 1976-1980 the results were favourably influenced by individual dosage of oxygen therapy in all infants, based on regular monitoring of blood gases (10.5% blind children).(ABSTRACT TRUNCATED AT 250 WORDS)  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