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   51350篇
  免费   4962篇
  国内免费   2453篇
耳鼻咽喉   104篇
儿科学   3323篇
妇产科学   241篇
基础医学   4197篇
口腔科学   450篇
临床医学   4528篇
内科学   9822篇
皮肤病学   657篇
神经病学   1339篇
特种医学   1241篇
外国民族医学   6篇
外科学   21099篇
综合类   5851篇
现状与发展   14篇
一般理论   2篇
预防医学   850篇
眼科学   1252篇
药学   1590篇
  10篇
中国医学   257篇
肿瘤学   1932篇
  2024年   85篇
  2023年   779篇
  2022年   972篇
  2021年   1733篇
  2020年   1821篇
  2019年   1976篇
  2018年   2042篇
  2017年   1861篇
  2016年   1797篇
  2015年   1730篇
  2014年   2900篇
  2013年   3370篇
  2012年   2445篇
  2011年   3036篇
  2010年   2769篇
  2009年   2854篇
  2008年   2952篇
  2007年   3136篇
  2006年   3164篇
  2005年   2772篇
  2004年   2271篇
  2003年   1907篇
  2002年   1533篇
  2001年   1286篇
  2000年   1091篇
  1999年   836篇
  1998年   770篇
  1997年   672篇
  1996年   621篇
  1995年   523篇
  1994年   583篇
  1993年   319篇
  1992年   436篇
  1991年   309篇
  1990年   198篇
  1989年   199篇
  1988年   206篇
  1987年   133篇
  1986年   110篇
  1985年   130篇
  1984年   92篇
  1983年   47篇
  1982年   62篇
  1981年   56篇
  1980年   39篇
  1979年   34篇
  1978年   30篇
  1977年   24篇
  1976年   16篇
  1972年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
The number of left ventricular assist device (LVAD) implantations is growing as a result of increased waiting periods for cardiac transplantation and the decreased availability of organ donors. Furthermore, the Food and Drug Administration (FDA) has approved permanent LVAD support. After an acute hospitalization, patients with LVADs may need prolonged convalescence in a healthcare facility because they have complex medical needs and are physically disabled. Admission criteria need to be developed as essential patient and nursing competencies need to be defined as a part of a successful LVAD program in an acute rehabilitation center. Acute rehabilitation centers can help patients with LVADs transition to a home setting.  相似文献   
22.
The aim of this prospective randomized study was to determine whether additional doxorubicin chemotherapy improves outcome in patients with hepatocellular carcinoma (HCCA) treated by liver transplantation. Stratification parameters were tumor stage (UICC I-IVa), gender, age 50 years, α-fetoprotein 20 ng/mL, cirrhosis and HbsAg status. For pre-operative chemotherapy doxorubicin (15 mg/m2) was given biweekly, intra-operative chemotherapy was a single dose administered before surgical manipulation. Post-operative chemotherapy from day 10 was as given preoperatively for a total dosage of 300 mg/m2. Outcome parameters were overall survival (OS) and disease-free survival. Of the 75 consecutive patients who received liver transplantation for treatment of HCCA, 62 patients were enrolled. Thirty-four patients were randomized in the chemotherapy group; 28 patients were in the control group and transplanted only. OS rates at 5 years were 38% in the chemotherapy group and 40% in the control group, disease-free survival rates at 5 years 43% and 53%, respectively. Tumor stage and vascular invasion were identified as independent risk factors for recurrence of disease. Doxorubicin chemotherapy did not improve organ survival and disease-free survival in patients undergoing liver transplantation for HCCA.  相似文献   
23.
Split liver transplantation (SLT) benefits society by increasing the total number of transplants that can be performed, but it is yet unknown if a decreased post-transplant survival (in comparison to whole liver transplantation) would make participation in SLT less appealing to adult liver transplant candidates. A 20-item questionnaire was administered to 50 adult candidates to assess attitudes toward SLT and organ sharing. The overall attitudes of 60% of participants were classified as utilitarian (maximizing benefit to greatest number of candidates), while 26% were classified as self-preserving (maximizing individual benefit) and 14% were undecided. Ninety percent of participants would be willing to share even if expected survival was less than that of whole liver transplantation, and 69% felt that pediatric candidates should have priority over adult candidates. In conclusion, attitudes toward graft sharing and the possibility of compromised survival benefit are not barriers to SLT for most adult liver transplant candidates.  相似文献   
24.
Laryngeal Transplantation in 2005: A Review   总被引:3,自引:0,他引:3  
There is no good surgical, medical or prosthetic solution to the problems faced by those with a larynx whose function is irreversibly damaged by tumor or trauma. Over the past 10 years, the pace of research designed to establish laryngeal transplantation as a therapeutic option for these persons has increased steadily. The biggest milestone in this field was the world's first true laryngeal transplant performed in Cleveland, Ohio in 1998. The recipient's graft continues to function well, in many respects, even after 7 years. However, it has also highlighted the remaining barriers to full-scale clinical trials. Stimulated by these observations, several groups have accumulated data which point to answers to some of the outstanding questions surrounding functional reinnervation and immunomodulation. This review seeks to outline the progress achieved in this field by 2005 and to point the way forward for laryngeal transplantation research in the 21st century.  相似文献   
25.
The Last 5 Years of Basic Science Investigation in Transplant Immunology   总被引:1,自引:0,他引:1  
Many new insights have been gained over the past 5 years into the mechanisms that regulate immune reactivity to cell and organ transplants. This new knowledge is being applied to the development of innovative experimental strategies that may soon be evaluated in the clinic.  相似文献   
26.
Abstract The outcome of OLT for HBV-related liver disease is dependent on the prevention of allograft re-infection. Over the past decade, major advances have been made in the management of HBV transplant candidates. The advent of long-term hepatitis B immune globulin (HBIG) administration as a prophylaxis against HBV recurrence, and the introduction of new antiviral agents against HBV infection, such as lamivudine (LAM), were a major breakthrough in the management of these patients. Results of OLT for HBV infection are similar to those achieved with other indications. Pre-OLT antiviral treatment such as LAM can suppress HBV replication before OLT and thus decrease the risk of re-infection of the graft. Combination prophylaxis with LAM and HBIG after transplantation highly effectively reduces the rate of HBV re-infection, even in HBV replicative cirrhotic, patients. The optimal HBIG protocol in the LAM era is yet to be defined: dosing of HBIG, routes of administration, and possibility of stopping HBIG. Several antiviral drugs have been developed for the management of HBV infection on the graft, so outcome is currently good.  相似文献   
27.
The significance of anticardiolipin antibodies (ACAs) prior to renal transplantation is unclear. We studied a cohort of 337 patients who underwent renal transplantation from 1996 to 2001. Follow-up continued until allograft loss, patient death or 31 December 2002. The primary outcome was a composite endpoint of death-censored allograft loss or a 25% reduction in estimated glomerular filtration rate (GFR) from 1-month post-transplant. Secondary outcomes were allograft loss, a 25% reduction in GFR, acute rejection and creatinine at 1 year. IgG and IgM ACA titers were positive (> or =15) in 18.1% of recipients. There were no significant differences at baseline between recipients, except coumadin therapy in those with positive ACA titers (20% vs. 7.4%). Post-transplant, there was no increase in the primary outcome in ACA-positive patients, even after adjustment for anticoagulation with coumadin (HR = 1.42 [0.68, 2.96]). There was no difference in secondary outcomes between those with or without positive titers. Two of five patients with very high titers (>50) who were not anticoagulated had early graft loss. A positive ACA titer prior to kidney transplantation was not associated with inferior renal outcomes after transplantation, although more research is required to address the prognostic significance of very high ACA titers.  相似文献   
28.
Abstract. A prospective randomized study was conducted to evaluate the impact of four different conversion protocols on graft outcome in long-term follow-up. Between January 1986 and May 1987, 128 patients with first cadaveric kidney allografts were randomized at the time of transplantation to four treatment groups of 32 patients each, to be assigned 10 weeks post-transplantation. During the first 10 weeks, all patients received triple therapy with low-dose azathioprine (Aza), cyclosporin (CyA), and methylprednisolone (MP). After 10 weeks, one group continued with triple therapy (group A) while the three other groups received different combinations of two drugs, namely, Aza and CyA (group B), Aza and MP (group C), or CyA and MP (group D). Withdrawal of MP (group B) or especially of CyA (group C) was associated with 4/29 (14%) and 10/28 (36%) acute rejection episodes, respectively, for 60 days after conversion. All rejections were mild and reversible. There were no rejections after Aza withdrawal or in the group that continued on triple therapy during the corresponding time period. The most common reason for dropping out after withdrawal, for those patients who could not continue on the originally randomized medication, was azathioprine intolerance (n= 12). Five patients were switched back to triple therapy after CyA withdrawal due to rejection. Steroid intolerance was rare and CyA in low doses was very well tolerated. At 1 year there were no statistically significant differences in graft survival between groups A, B, C, and D-81 %, 88%, 88%, and 88%, respectively-or in patient survival-88%, 88%, 88%, and 97%, respectively. For those patients continuing with the originally randomized treatment protocol, there were no differences in patient or graft survival either, the means being 91% and 89%, respectively. The most common cause of death after withdrawal was cardiovascular in nature, and there were no more fatal infections under triple drug treatment than with double drug regimens. There were no statistically significant differences in mean serum creatinine values at 1 year. The median serum creatinine values for groups A, B, C, and D were 112, 132, 133, and 133 μmol/l, respectively. At 1 year the mean CyA dose in the groups that continued with CyA was 3. 5–4. 2 mg/kg per day and CyA concentrations were equal.  相似文献   
29.
The pre-operative risk of paediatric liver transplantation candidates (n=41) was assessed in a prospective study by means of clinical symptoms, conventional static and liver blood flow dependent dynamic liver function tests. Nine patients died during the 365-day waiting period. The data were subjected as covariates to a survival analysis in the Cox proportional hazards model. There was a significant relationsship between the results of mono-ethylglycinexylidide (MEGX) formation and ICG test and the 365-day survival rate. In the stepwise analysis, none of the remaining parameters improved the predictive ability when added to the dynamic liver function test results. The assessment of post-transplantation liver function was studied in 27 patients during the first 28 postoperative-day period. In addition, liver function was studied in a cross-sectional study 1–7 years after successful liver transplantation in children with complete or partial rehabilitation. In the early postoperative period severe organ damage was indicated by both static and dynamic liver function tests. In the later course after transplantation no deterioration of liver function measured with MEGX formation was to be observed. These findings demonstrate the usefulness of dynamic liver function tests in the pre- and post-transplant assessment of liver function.  相似文献   
30.
A new technique of choledochoenterostomy was devised to solve some of the problems of enterobiliary anastomosis with a normal calibre. The distal extremity of the common bile duct is completely surrounded by the bowel mucosa to a length of 3 cm after seromyectomy of a bowel wall rectangle of 4 × 1 cm. Experimental studies in rats and dogs demonstrated that this procedure prevents the risks of anastomotic disruption and functions like a mechanical unidirectional valve, which has great efficacy in stopping enterobiliary reflux. Studies in ten patients with obstructive jaundice with an extrahepatic biliary dilation less than 1.2 cm diameter submitted to this procedure Confirmed the experimental results. All patients were asymptomatic, without jaundice and with normalization of the liver enzymes after 2 months. The permeability of the valvular anastomosis studied by cholangiography, the HIDA 99mTc test and manometry was quite similar to other classical biliary-enteric anastomosis. In contrast, anti-reflux efficacy was only demonstrated in patients with a valvular anastomosis.  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