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   40464篇
  免费   1845篇
  国内免费   177篇
耳鼻咽喉   686篇
儿科学   667篇
妇产科学   733篇
基础医学   5282篇
口腔科学   1220篇
临床医学   2852篇
内科学   9460篇
皮肤病学   545篇
神经病学   3338篇
特种医学   1345篇
外科学   6964篇
综合类   179篇
一般理论   2篇
预防医学   1484篇
眼科学   626篇
药学   3414篇
中国医学   78篇
肿瘤学   3611篇
  2022年   400篇
  2021年   688篇
  2020年   343篇
  2019年   482篇
  2018年   582篇
  2017年   448篇
  2016年   548篇
  2015年   593篇
  2014年   771篇
  2013年   1024篇
  2012年   1650篇
  2011年   1757篇
  2010年   1021篇
  2009年   866篇
  2008年   1694篇
  2007年   1840篇
  2006年   1795篇
  2005年   1760篇
  2004年   1723篇
  2003年   1758篇
  2002年   1708篇
  2001年   1615篇
  2000年   1770篇
  1999年   1494篇
  1998年   474篇
  1997年   383篇
  1996年   356篇
  1995年   297篇
  1994年   278篇
  1993年   247篇
  1992年   1103篇
  1991年   918篇
  1990年   898篇
  1989年   939篇
  1988年   831篇
  1987年   830篇
  1986年   781篇
  1985年   769篇
  1984年   527篇
  1983年   422篇
  1982年   217篇
  1979年   482篇
  1978年   274篇
  1977年   251篇
  1975年   207篇
  1974年   223篇
  1972年   205篇
  1971年   230篇
  1969年   230篇
  1968年   216篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
A 23-year-old male with bronchial asthma developed eosinophilia (eosinophils greater than 2,000/mm3) and was observed at our hospital. After using a prescribed indomethacin suppository for fever at home, he experienced an attack of acute chest pain and severe dyspnea. He suffered cardiac arrest while being transferred to the ward. After resuscitation, he was diagnosed as having acute myocardial infarction on the basis of electrocardiographic and ultrasonic cardiographic findings, and marked elevation of serum concentrations of myocardial enzymes. Thereafter, he often complained of precordial pain and abdominal pain. When he was administered an analgesic in another hospital, he developed severe precordial pain, and marked ST elevation was recorded on the electrocardiogram. Coronary angiography revealed no stenosis nor atherosclerotic changes, suggesting that severe spasm of the coronary arteries and direct myocardial injury by eosinophils were the causes of the myocardial infarction-like symptoms and angina pectoris-like attacks. He was diagnosed as having Churg-Strauss syndrome (allergic granulomatous angiitis) on the basis of the clinical findings; skin biopsy and transbronchial lung biopsy findings were consistent with the diagnosis. Following steroid administration, his angina-like attacks and abdominal pain ceased. This patient developed two episodes of acute cardiovascular symptoms upon administration of antipyretic analgesics. This suggests that in cases of Churg-Strauss syndrome with aspirin-induced asthma, physicians must be aware of the cardiovascular complications, and such drugs should be administered with caution.  相似文献   
72.
Clinical features of 16 patients with mild systemic lupus erythematosus (SLE) were compared with those of 21 control patients with moderate or severe disease. Age at the time of diagnosis of SLE was higher in mild disease group. The incidence of the coexistence of Sj?gren's syndrome (SS) at the time of diagnosis of SLE was higher in patients who later developed mild disease. Anti-Sm antibody and decreased levels of C3, C4, and CH50 occurred less frequently in patients with mild disease. SLE patients with the coexistence of SS at the time of diagnosis of SLE may represent a subset with a benign prognosis.  相似文献   
73.
For the rapid and sensitive detection of p53 gene mutations in esophageal endoscopic biopsy specimens, we combined cell sorting with the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analysis. Mutations in exons 5–8 of the p53 gene were investigated by FCR-SSCF analysis using 103 sorted nuclei obtained from each endoscopic biopsy specimen of 16 patients with esophageal cancer. DNAs extracted from their respective surgical specimens were investigated by a conventional method of PCR-SSCP analysis. Mutations in the biopsy specimens were detected in 6 of the 12 aneuploid tumors but in none of the 4 diploid tumors. After tumor cell enrichment by cell sorting, one mutation in exon 8 became apparent, which could not be detected from the surgical specimen by a conventional method of PCR-SSCP analysis. This method should improve the sensitivity of detecting p53 gene mutations, and provides additional information concerning the DNA ploidy pattern in the tumors.  相似文献   
74.
75.
In our previous study (Nishinaka et al., 1989), a chicken B cell line (HU3R27) deficient in thymidine kinase activity was used as a fusion partner for production of chicken monoclonal antibody. Specific antibody-producing hybridomas were initially obtained, but they soon lost the ability to produce antibody in culture. The present report documents the development of an improved fusion cell line. R27H4, for the production of chicken monoclonal antibody. This cell line was obtained by fusion of HU3R27 cells with spleen cells of immunized chicken. Fusion of R27H4 cells with spleen cells from chicken immunized by keyhole limpet hemocyanin (KLH) resulted in antibody-producing hybridomas. Subcloned hybridomas secreted highly reactive IgG and weakly reactive IgM. Some of the cell lines have been displaying stable antibody secretions for over 6 months.  相似文献   
76.
77.
78.
In order to clarify age-related changes in kidneys, the renal function and histological changes were evaluated in 962 patients with mild mesangial proliferative glomerulonephritis (Mes PGN) whose ages ranged from 7 to 82 years. The glomerular filtration rate (GFR) (Ccr), renal plasma flow (RPF) (CPAH) and PSP excretion rate were significantly lower in nephritic patients than in normal subjects. Age-related decreases of GFR, RPF, PSP excretion rate and maximal urine specific gravity in Fishberg concentration test were found in both groups. Serum levels of creatinine, urea nitrogen and uric acid were significantly higher in nephritic patients than in the normal population. Age-related increases of those parameters were found in both groups. The incidence of sclerotic glomeruli was almost same as that of the normal population estimated by Kaplan et al. The incidence of arterio- and arteriolosclerosis was also higher than that of normal subjects estimated by Bell. Thus, arterio- and arteriolosclerosis seems to be more age-dependent than glomerulosclerosis in patients with mild Mes PGN. In conclusion, renal functions decrease and renal arteriolar lesions increase gradually in proportion to aging. Mes PGN, even mild, can accelerate the physiological age-related decrease of renal function.  相似文献   
79.
Antibacterial effects of combination use of arbekacin (ABK) with cefotiam (CTM) or cefuzonam (CZON) were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and the following results were obtained. 1. Antibacterial effects of combinations of ABK with CTM and with CZON were equally potent against MRSA at clinically expected 1 MIC of ABK in blood. However, at a sub MIC of ABK the different effects were observed between the 2 combinations. The antibacterial effect of the former was strong and that of the latter was a little weak. 2. In either combination the potency of the antibacterial activity was less dependent on the concentration of CTM or CZON, but was strongly dependent on ABK concentrations. These results suggest that antibacterial effects of the combinations were highly dependent on antibacterial potency and concentration of ABK as previously reported for combinations of ABK with other drugs. 3. The combination use of ABK with CTM appears to be useful in cases of infection by MRSA alone while the combination use of ABK with CZON appears to be useful in cases of double infection with MRSA and Gram-negative bacterium.  相似文献   
80.
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