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   41402篇
  免费   2235篇
  国内免费   143篇
耳鼻咽喉   543篇
儿科学   2618篇
妇产科学   728篇
基础医学   4865篇
口腔科学   1155篇
临床医学   3043篇
内科学   7485篇
皮肤病学   1201篇
神经病学   2471篇
特种医学   1221篇
外科学   6331篇
综合类   1316篇
一般理论   21篇
预防医学   2055篇
眼科学   1553篇
药学   4054篇
  1篇
中国医学   353篇
肿瘤学   2766篇
  2023年   338篇
  2022年   978篇
  2021年   1668篇
  2020年   912篇
  2019年   1048篇
  2018年   1458篇
  2017年   1060篇
  2016年   1382篇
  2015年   1402篇
  2014年   2052篇
  2013年   2330篇
  2012年   3246篇
  2011年   3191篇
  2010年   1897篇
  2009年   1500篇
  2008年   2133篇
  2007年   2150篇
  2006年   1967篇
  2005年   1730篇
  2004年   1635篇
  2003年   1385篇
  2002年   1199篇
  2001年   778篇
  2000年   715篇
  1999年   597篇
  1998年   276篇
  1997年   218篇
  1996年   228篇
  1995年   195篇
  1994年   167篇
  1993年   136篇
  1992年   356篇
  1991年   345篇
  1990年   364篇
  1989年   340篇
  1988年   295篇
  1987年   248篇
  1986年   237篇
  1985年   230篇
  1984年   175篇
  1983年   123篇
  1982年   70篇
  1981年   80篇
  1980年   70篇
  1979年   114篇
  1978年   74篇
  1977年   89篇
  1976年   68篇
  1973年   64篇
  1971年   62篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
Autologous bone marrow transplantation.   总被引:1,自引:0,他引:1  
  相似文献   
102.
Complete dislocation of the lens is a rare feature of Marfan's Syndrome. We observed four cases of bilateral complete posterior dislocation of the lens in established cases of Marfan's Syndrome over a one year period. An ophthalmologist may encounter infrequently, unilateral posterior dislocation in one eye and ectopia lentis in the other, but bilateral spontaneous posterior dislocation is rare. All our cases had associated vitreous degeneration with vitreous herniating into the anterior chamber. The pathogenesis of complete posterior dislocation in Marfan's Syndrome is discussed.  相似文献   
103.
A cell line from Wilms' tumour with deletion in short arm of chromosome II   总被引:1,自引:0,他引:1  
A cell line (T3/73) from a Wilms' tumour has been established from a 9 month-old boy with aniridia. The tumour was removed in 1973. On histological examination a diagnosis of Wilms' tumour was made which showed undifferentiated areas, marked tubule formation and abundant striped muscle fibres. The tumour cells, which are fusiform, grew rapidly in culture without the addition of growth factors, and have undergone over 100 passages. Approximately 95% and 5% were positive for desmin and cytokeratin, respectively. The cell doubling time was 28 hr. Cytogenetic studies revealed a karyotype of 46,XY,del(11) (p12::p14). Although the cells stained very intensely with a monoclonal antibody that detects oncogene ras p 21 antigen, Southern blot analysis using c-Ha-ras as a probe failed to reveal an obvious deletion or amplification of either Ha-ras allele.  相似文献   
104.
Eight healthy, young adult males underwent three separate, 10-min 70 degrees head-up tilts (HUT) over a period of nine days, in order to assess the intra- and inter-individual variability of cardiovascular and plasma norepinephrine (NE) responses to the manoeuvre. Cardiovascular parameters and plasma NE were measured in the basal state and at 2-min intervals during the HUT. The results indicate that: (1) the intra-individual variability is a smaller component of the total variability of both cardiovascular and plasma NE responses to HUT; (2) the variability in cardiovascular parameters is smaller than that in plasma NE levels, both basal and in response to postural stress; (3) there does not appear to be any difference in variability when expressed either as the maximal or the mean response to HUT; and (4) there does not appear to be an increase in the variability of the measured parameters over the duration of the HUT.  相似文献   
105.
106.
Recurrence of hepatitis C (HCV) following liver transplantation is common. Herpesvirus reactivation following transplant may have an immunomodulatory effect resulting in increased HCV replication. We studied whether cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) may be associated with HCV recurrence and viral load after transplant. We prospectively followed 66 HCV liver-transplant recipients with serial viral load testing for CMV and HHV-6. Infection and viral load were correlated with the development of biopsy-proven HCV recurrence and HCV viral loads. Histologic recurrence of HCV occurred in 41/66 (62.1%) patients. In the primary analysis, CMV infection and disease, and HHV-6 infection were not associated with HCV recurrence. Peak CMV and HHV-6 viral loads were not significantly different in patients with and without recurrence. No correlation was observed between HCV viral loads at 1 and 3 months post-transplant and peak HHV-6 or CMV viral loads. In a subgroup analysis, HHV-6 infection was associated with the development of more severe recurrence (hepatitis and/or fibrosis score > or = 2) (p = 0.01). Also, fibrosis scores at last follow up were higher in patients with CMV disease (1.67 vs. 0.56; p = 0.016) and in patients with HHV-6 infection (1.18 vs. 0.55; p = 0.031). In conclusion, HHV-6 and CMV infection and viral load were not associated with increased overall rates of HCV recurrence or HCV viral load after liver transplantation but may be associated with more severe forms of recurrence.  相似文献   
107.
A total of 1000 slit-skin smears were taken from multiple sites (both ear lobules, right elbow, dorsal aspect of middle phalanx of the left finger, and dorsum of middle phalanx of the right foot) from 558 leprosy patients. There were 319 sets (1595 smears) from untreated patients and 681 sets (3405 smears) from the treated group. The duration of treatment varied from 6 months (multidrug therapy) to 7 years (dapsone monotherapy). The ear lobules gave significantly higher values for the bacterial index (BI) compared to toes and fingers in the untreated group. The morphological index (MI) was also significantly higher from the ear lobules compared to toes, elbows, and fingers. In five patients from the untreated group, bacilli were found in some other sites when the earlobes did not reveal any. In the treated group, all sites yielded similar BI and MI values, the figures being lowest from elbows and toes but not different statistically. In 20 long-treated patients, bacilli were detected at sites other than the ear lobules. In 28 patients, sites other than the ear lobules gave a higher MI and in 20 patients, solid bacilli were seen at sites other than the ear lobules.  相似文献   
108.
109.
A study of DNA content by flow cytometry revealed a significant difference between rhabdomyosarcomas, which were mainly non-diploid, and other sarcomas of children which were mainly diploid (p = 0.01). There was no association between DNA ploidy and survival or aggressive behaviour of the tumour as indicated for example by advanced clinical stage or unfavourable histology. While DNA ploidy correlated with age, it did not correlate with any other clinical characteristic. The apparent lack of prognostic value of DNA content may have been masked by some high CV values and overridden by the effect of chemotherapy which was the most significant variable in determining a patient's survival (p = 0.00005).  相似文献   
110.
A total of 675 strains of Salmonella bareilly received from different parts of India and France during 1959-92 were phage typed using six bacteriophages. Overall typability achieved was 90.8% with 23 distinct phage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson''s coefficient was applied for diversity index having a value of 0.839. This system was found to be reproducible, stable and epidemiologically useful.  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