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   5911篇
  免费   396篇
  国内免费   42篇
耳鼻咽喉   95篇
儿科学   172篇
妇产科学   270篇
基础医学   727篇
口腔科学   155篇
临床医学   486篇
内科学   1204篇
皮肤病学   122篇
神经病学   241篇
特种医学   266篇
外国民族医学   7篇
外科学   920篇
综合类   115篇
一般理论   6篇
预防医学   442篇
眼科学   238篇
药学   539篇
中国医学   23篇
肿瘤学   321篇
  2023年   63篇
  2022年   210篇
  2021年   347篇
  2020年   182篇
  2019年   225篇
  2018年   303篇
  2017年   195篇
  2016年   200篇
  2015年   176篇
  2014年   276篇
  2013年   373篇
  2012年   420篇
  2011年   427篇
  2010年   247篇
  2009年   208篇
  2008年   249篇
  2007年   245篇
  2006年   236篇
  2005年   246篇
  2004年   203篇
  2003年   167篇
  2002年   143篇
  2001年   83篇
  2000年   86篇
  1999年   86篇
  1998年   28篇
  1997年   22篇
  1996年   32篇
  1995年   20篇
  1994年   25篇
  1993年   18篇
  1992年   61篇
  1991年   66篇
  1990年   58篇
  1989年   58篇
  1988年   38篇
  1987年   34篇
  1986年   38篇
  1985年   34篇
  1984年   27篇
  1983年   17篇
  1982年   14篇
  1981年   10篇
  1979年   25篇
  1978年   13篇
  1976年   11篇
  1974年   11篇
  1973年   13篇
  1971年   11篇
  1970年   9篇
排序方式: 共有6349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.
4.
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   
5.
Perianal mucinous adenocarcinoma is a rare tumour which may be associated with long‐standing chronic perianal sepsis. Early diagnosis is challenging and is based on a high index of clinical suspicion and specific histological features. Definitive treatment is surgical, in the form of an abdomino‐perineal resection. We hereby describe a case of a perianal mucinous adenocarcinoma arising from long‐standing recurrent perianal fistula and complement this with a brief review of the literature pertaining in particular to the management of this condition.  相似文献   
6.
7.
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   
8.
Conference Reports: This section contains reports on topical conferences. Reports are usually written at the request of the editorial office, but unsolicited contributions are also welcome. Suggestions should be sent to the editorial office of the Macromolecular journals, preferably by E‐mail to macromol@wiley‐vch.de.  相似文献   
9.
Smoking delays the healing process and increases morbidity associated with many common musculoskeletal disorders, including long bone fracture. In the current study, a murine model of tibial fracture healing was used to test the hypothesis that smoking delays chondrogenesis after fracture. Mice were divided into two groups, a nonsmoking control group and a group exposed to cigarette smoke for 1 month prior to surgical tibial fracture. Mice were euthanized at 7, 14, and 28 days after surgery. The outcomes measured were immunohistochemical staining for type II collagen protein expression as a marker of cartilage matrix and proliferating cell nuclear antigen (PCNA) staining to measure proliferation at the site of injury. Toluidine blue staining and histomorphometry were used to quantify areas of cartilaginous and noncartilaginous fracture callus. Radiographs were analyzed for evidence of remodeling after injury. At day 7 after injury, mice exposed to cigarette smoke had a smaller fracture callus with less cartilage matrix compared to controls. Proliferation was present at high levels in both groups at this time point, but proliferating cells had a more immature morphology in the smoking group. At day 14, chondrogenesis was more active in smokers compared to controls, while a higher percentage of bone was present in the control animals. At day 28, X-ray analysis revealed a larger fracture callus remaining in the smoking animals. Together, these findings show that the chondrogenic phase of tibial fracture healing is delayed by smoking. This study represents, to our knowledge, the first analysis of molecular and cellular mechanisms of healing in a smoking mouse fracture model.  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