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   2668篇
  免费   197篇
  国内免费   7篇
耳鼻咽喉   83篇
儿科学   169篇
妇产科学   91篇
基础医学   247篇
口腔科学   45篇
临床医学   153篇
内科学   504篇
皮肤病学   47篇
神经病学   167篇
特种医学   85篇
外科学   446篇
综合类   68篇
一般理论   1篇
预防医学   97篇
眼科学   156篇
药学   138篇
中国医学   3篇
肿瘤学   372篇
  2023年   19篇
  2022年   31篇
  2021年   67篇
  2020年   40篇
  2019年   66篇
  2018年   88篇
  2017年   66篇
  2016年   81篇
  2015年   66篇
  2014年   130篇
  2013年   103篇
  2012年   179篇
  2011年   198篇
  2010年   105篇
  2009年   83篇
  2008年   137篇
  2007年   139篇
  2006年   131篇
  2005年   105篇
  2004年   79篇
  2003年   95篇
  2002年   113篇
  2001年   60篇
  2000年   73篇
  1999年   70篇
  1998年   24篇
  1997年   19篇
  1996年   22篇
  1995年   15篇
  1992年   34篇
  1991年   44篇
  1990年   35篇
  1989年   28篇
  1988年   19篇
  1987年   22篇
  1985年   20篇
  1984年   12篇
  1983年   17篇
  1981年   11篇
  1979年   12篇
  1977年   16篇
  1976年   18篇
  1975年   12篇
  1973年   13篇
  1972年   16篇
  1971年   12篇
  1970年   11篇
  1969年   11篇
  1968年   15篇
  1967年   12篇
排序方式: 共有2872条查询结果,搜索用时 15 毫秒
1.
Treatment guidelines for management of uncomplicated gonorrhoeae have been recently modified owing to alarming upsurge in azithromycin resistance. This study investigated the prevalence and genetic determinants of gonococcal azithromycin resistance in India. Four (5.7%) of 70 gonococcal isolates were resistant to azithromycin. Of 16 isolates investigated for molecular mechanisms of resistance, 13 (81.3%) and 6 (37.5%) isolates exhibited mutations in coding and promoter regions of mtrR gene, respectively. However, ermA, ermB and ermC genes or mutations in rrl gene were absent in all isolates. Azithromycin resistance is low in India posing no immediate threat to use of dual-therapy for syndromic management.  相似文献   
2.
3.
(18)F-FDG PET has a high accuracy in staging head and neck cancer, but its role in patients with clinically and radiographically negative necks (N0) is less clear. In particular, the value of combined PET/CT has not been determined in this group of patients. METHODS: In a prospective study, 31 patients with oral cancer and no evidence of lymph node metastases by clinical examination or CT/MRI underwent (18)F-FDG PET/CT before elective neck dissection. PET/CT findings were recorded by neck side (left or right) and lymph node level. PET/CT findings were compared with histopathology of dissected nodes, which was the standard of reference. RESULTS: Elective neck dissections (26 unilateral, 5 bilateral; a total of 36 neck sides), involving 142 nodal levels, were performed. Only 13 of 765 dissected lymph nodes harbored metastases. Histopathology revealed nodal metastases in 9 of 36 neck sides and 9 of 142 nodal levels. PET was TP in 6 nodal levels (6 neck sides), false-negative in 3 levels (3 neck sides), true-negative in 127 levels (23 neck sides), and false-positive in 6 levels (4 neck sides). The 3 false-negative findings occurred in metastases smaller than 3 mm or because of inability to distinguish between primary tumor and adjacent metastasis. TP and false-positive nodes exhibited similar standardized uptakes (4.8 +/- 1.1 vs. 4.2 +/- 1.0; P = not significant). Sensitivity and specificity were 67% and 85% on the basis of neck sides and 67% and 95% on the basis of number of nodal levels, respectively. If a decision regarding the need for neck dissection had been based solely on PET/CT, 3 false-negative necks would have been undertreated, and 4 false-positive necks would have been overtreated. CONCLUSION: (18)F-FDG PET/CT can identify lymph node metastases in a segment of patients with oral cancer and N0 neck. A negative test can exclude metastatic deposits with high specificity. Despite reasonably high overall accuracy, however, the clinical application of PET/CT in the N0 neck may be limited by the combination of limited sensitivity for small metastatic deposits and a relatively high number of false-positive findings. The surgical management of the N0 neck should therefore not be based on PET/CT findings alone.  相似文献   
4.
5.
6.
BACKGROUND: The treatment of hepatitis C virus (HCV)-related cirrhosis is difficult due to high frequency of adverse effects. We retrospectively reviewed the case records of patients with HCV cirrhosis to evaluate the efficacy and tolerability of pegylated (peg) interferon and ribavirin treatment in these patients. METHODS: Medical records of 28 patients with HCV-related compensated cirrhosis were reviewed. The treatment protocol was a combination therapy of peg interferon alfa-2b (1 microg/Kg/week) plus oral ribavirin (10-12 mg/Kg/day). Primary endpoint was sustained virological response, with additional endpoints of drug tolerance, clinical or biochemical worsening and death. RESULTS: End-of-treatment virlogic response was seen in 24 of 28 patients (85%) and sustained virologic response in 15 of 28 (53%) patients. Biochemical end-of-treatment response and sustained response were seen in 20 and 16 patients (71% and 57%), respectively. Treatment had to be stopped in 3 patients due to decompensation of liver status in two and drug intolerance in one, while dose modification was required in two patients. CONCLUSIONS: Combination therapy with peg interferon plus ribavirin seems effective in patients with liver cirrhosis. High relapse rate, poor biochemical recovery and possibility of decompensation are issues that need to be kept in mind.  相似文献   
7.
8.
9.
Eight healthy adults and 48 infants 2 and 4 months old were immunized with Haemophilus influenzae type b-Neisseria meningitidis outer membrane protein complex conjugate vaccine (PRP-OMP) to evaluate antibody kinetics in the first days after immunization. Five adults (63%) had some decrease in antibody, although the geometric mean did not decrease significantly. With one exception, the nadir occurred on postimmunization day 3. Seven had an antibody increase by day 7. Of the children, 6 (75%) of 8 and 17 (77%) of 23 had a decrease in antibody in serum obtained on day 2-3 after the first or second dose, respectively, the magnitude of which directly correlated with the preimmunization antibody concentration. However, the geometric mean did not decrease significantly. Within 1 week of immunization, 85% of infants had an increase in antibody, significantly greater after the second dose than after the first. A high concentration of maternally derived antibody before immunization correlated negatively with antibody response. Thus, a transient decrease in antibody occurs in most adults and infants 2-3 days after immunization with PRP-OMP followed by a prompt increase by day 7.  相似文献   
10.
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