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   4195篇
  免费   323篇
  国内免费   73篇
耳鼻咽喉   45篇
儿科学   168篇
妇产科学   168篇
基础医学   509篇
口腔科学   116篇
临床医学   335篇
内科学   991篇
皮肤病学   68篇
神经病学   154篇
特种医学   283篇
外国民族医学   1篇
外科学   581篇
综合类   170篇
预防医学   327篇
眼科学   179篇
药学   295篇
中国医学   12篇
肿瘤学   189篇
  2023年   34篇
  2022年   71篇
  2021年   167篇
  2020年   79篇
  2019年   97篇
  2018年   122篇
  2017年   124篇
  2016年   116篇
  2015年   104篇
  2014年   201篇
  2013年   232篇
  2012年   216篇
  2011年   243篇
  2010年   184篇
  2009年   179篇
  2008年   171篇
  2007年   208篇
  2006年   162篇
  2005年   158篇
  2004年   132篇
  2003年   107篇
  2002年   90篇
  2001年   91篇
  2000年   80篇
  1999年   68篇
  1998年   96篇
  1997年   79篇
  1996年   80篇
  1995年   65篇
  1994年   62篇
  1993年   56篇
  1992年   64篇
  1991年   55篇
  1990年   63篇
  1989年   70篇
  1988年   52篇
  1987年   42篇
  1986年   52篇
  1985年   47篇
  1984年   33篇
  1983年   26篇
  1982年   21篇
  1981年   13篇
  1980年   13篇
  1979年   24篇
  1978年   17篇
  1977年   11篇
  1976年   22篇
  1975年   11篇
  1973年   11篇
排序方式: 共有4591条查询结果,搜索用时 15 毫秒
1.
Transfusion transmissible infections (TTIs) have been a public health challenge for the accessibility, quality and safety of blood transfusion. The present study aimed to consider the prevalence and the trends of hepatitis B virus (HBV), hepatitis C virus (HCV), Human T-cell leukemia virus type 1 (HTLV-1), human immunodeficiency virus (HIV) and syphilis across the ten years among retrospective blood donors. A retrospective investigation of blood donors’ data covering the period from 22 May 2009 to 22 May 2019 was done. Data was accumulated and analyzed from Blood Transfusion Center records, pertaining to all donors who were screened for various TTIs using respective immunological techniques. Out of the 682,171 screened donors in the 2009–2019 study period, 2470 (0.36 %) were infected with at least one infectious agent. The overall prevalence of HBV, HCV, HTLV-1, HIV and syphilis were 1700 (0.25 %), 184 (0.027 %), 335 (0.05 %), 4 (0.0.05 %) and 247 (0.036 %), respectively. The study showed male dominated donor pool (96.79 %) with higher prevalence (0.34 %) of TTIs compared to female donors (0.02 %) with 3.21 % population. Despite the low prevalence of TTIs in our study, HBV, HCV, syphilis and HIV have remained a big threat to safe blood transfusion in Iran. Strict adherence to selection criteria, algorithm of donor screening, use of highly sensitive and specific methods for detection of TTIs, regular consultation and health education programs, prevention and sanitization strategies to reduce the risk of TTIs are recommended to reduce the risk of TTIs and ensure the safety of blood transfusion for recipient.  相似文献   
2.
3.
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.  相似文献   
4.
Haaga  JR; Beale  SM 《Radiology》1986,161(3):829-830
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).  相似文献   
5.
6.
Antimurine antibody formation following OKT3 therapy   总被引:1,自引:0,他引:1  
OKT3 is an IgG2a murine monoclonal antibody directed against the CD3 antigen receptor of human T lymphocytes. A major concern with OKT3 treatment in solid organ transplant recipients is the development of antimouse antibody, which may preclude retreatment with this agent. We have administered OKT3 on 215 occasions (150 renal, 34 hepatic, 26 cardiac, 5 pancreatic) in 179 patients between April 1982 and December 1988. The mean duration of treatment was 10.5 days (range, 2-22 days). Antimouse antibody data were analyzed on the most recent 133 treatment courses where the antibody status was available pretreatment. Determination of antimouse antibody production was elicited by ELISA technology at days 0, 7, 14, and 28 of OKT3 treatment. Patients were categorized according to the antibody response as follows: (a) absence of antibody; (b) low titer (1:100); or (c) high titer (greater than or equal to 1:1000). Our earlier experience has demonstrated that retreatment with OKT3 is successful in groups a and b. The development of antimurine antibodies was analyzed with regard to the following parameters: (1) The duration of OKT3 treatment; (2) treatment type (prophylactic, primary, or secondary); (3) primary treatment or retreatment; (4) concomitant immunosuppressive regimen (double or triple therapy); (5) dosage of concomitant immunosuppressive drugs; and (6) transplant organ type. The following results were obtained. (1) Duration of treatment had no effect on antibody production (11.0 days in antibody negative and 10.0 days in antibody positive). (2) There was no difference in antibody formation rates for the first treatment of OKT3 when it was used as prophylaxis (26%), primary (19%), or secondary (27%) therapy. (3) Antibody formation rate with first treatment was 29%; with retreatment, patients who were antibody negative following first treatment became positive in 28% of cases, and retreated patients who were low titer positive following first treatment converted to high titer in 57% of cases. (4) Antibody formation was higher in patients receiving double immunosuppressive therapy (36%) than in those receiving triple immunosuppressive therapy (21%) during OKT3 treatment. (5) Concomitant immunosuppression was lower in the antibody-positive group during OKT3 therapy: steroids, 61 mg/day vs. 52 mg/day; azathioprine, 89 mg/day vs. 66 mg/day; CsA, 317 mg/day vs. 186 mg/day. (6) Antibody formation rates were lower in non-renal transplants following first treatment with OKT3 (liver 17%, heart 17%, kidney 28%); this reflects the higher doses of concomitant immunosuppressive therapy used in nonrenal transplants.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
7.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响.  相似文献   
8.
9.
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