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   1051篇
  免费   247篇
  国内免费   18篇
儿科学   11篇
妇产科学   7篇
基础医学   21篇
临床医学   45篇
内科学   41篇
皮肤病学   3篇
神经病学   1篇
特种医学   2篇
外科学   563篇
综合类   87篇
预防医学   369篇
眼科学   8篇
药学   146篇
  1篇
中国医学   9篇
肿瘤学   2篇
  2023年   24篇
  2022年   34篇
  2021年   98篇
  2020年   107篇
  2019年   94篇
  2018年   75篇
  2017年   95篇
  2016年   62篇
  2015年   55篇
  2014年   83篇
  2013年   65篇
  2012年   84篇
  2011年   77篇
  2010年   56篇
  2009年   49篇
  2008年   47篇
  2007年   38篇
  2006年   34篇
  2005年   28篇
  2004年   17篇
  2003年   10篇
  2002年   12篇
  2001年   19篇
  2000年   11篇
  1999年   5篇
  1998年   6篇
  1997年   1篇
  1996年   4篇
  1995年   4篇
  1994年   3篇
  1993年   1篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1989年   2篇
  1988年   5篇
  1987年   1篇
  1983年   1篇
排序方式: 共有1316条查询结果,搜索用时 171 毫秒
71.
We undertook this study to assess the rate of poor early graft function (EGF) after laparoscopic live donor nephrectomy (lapNx) and to determine whether poor EGF is associated with diminished long-term graft survival. The study population consisted of 946 consecutive lapNx donors/recipient pairs at our center. Poor EGF was defined as receiving hemodialysis on postoperative day (POD) 1 through POD 7 (delayed graft function [DGF]) or serum creatinine ≥ 3.0 mg/dL at POD 5 without need for hemodialysis (slow graft function [SGF]). The incidence of poor EGF was 16.3% (DGF 5.8%, SGF 10.5%), and it was stable in chronologic tertiles. Poor EGF was independently associated with worse death-censored graft survival (adjusted hazard ratio (HR) 2.15, 95% confidence interval (CI) 1.34–3.47, p = 0.001), worse overall graft survival (HR 1.62, 95% CI 1.10–2.37, p = 0.014), worse acute rejection-free survival (HR 2.75, 95% CI 1.92–3.94, p < 0.001) and worse 1-year renal function (p = 0.002). Even SGF independently predicted worse renal allograft survival (HR 2.54, 95% CI 1.44–4.44, p = 0.001). Risk factors for poor DGF included advanced donor age, high recipient BMI, sirolimus use and prolonged warm ischemia time. In conclusion, poor EGF following lapNx has a deleterious effect on long-term graft function and survival.  相似文献   
72.
73.
Although willingness, attitudes and beliefs surrounding solid‐organ donation have been extensively investigated, much less is known about corneal donation. Despite evidence that a substantial number of families who agree to multiorgan donation also specifically refuse corneal donation, it is unclear why this occurs and what can be done to increase rates of corneal donation. We conducted a survey of 371 Australian adults regarding their views on corneal donation. Although willingness to donate corneas generally reflected a person's willingness to donate all of one's organs, unwillingness to donate corneas appeared to be due to other factors. Specifically, decisions not to donate appear to be driven by a range of concerns surrounding disfigurement. The survey also provides eye banks with reassurance about the acceptability of whole globe procurement, and recognition that research into blindness is a highly valued part of corneal donation. Finally, the survey identifies that many individuals see benefit in having their family engaged in the decision‐making process, suggesting that decisions about donation are more complex than a simple appeal to the autonomy of the deceased.  相似文献   
74.
赵宏峰  王宇  任旋磊  周杰 《实用医学杂志》2011,27(10):1745-1747
目的:探讨在大鼠肝移植供肝切取过程中不同方法对供肝质量的影响。方法:SD大鼠120只,随机分成3组,即标准法组(A组)、快速法组(B组)和改良快速法组(C组),每组各行20对大鼠原位肝移植,观察术中资料和术后3周存活率及冷灌洗后肝脏形态学改变。结果:在供肝切取手术时间上C组明显较A、B两组为短(P<0.05),其术后3周存活率也高于A组(P<0.05)。光镜下C组与A、B两组相比肝窦内未见红细胞。结论:标准法和快速法适合于刚建立大鼠肝移植模型的单位,为提高供肝质量、改善术后存活率应选择改良快速法。  相似文献   
75.
76.
COVID-19 pandemic dramatically impacted transplantation landscape. Scientific societies recommend against the use of donors with active SARS-CoV-2 infection. Italian Transplant Authority recommended to test recipients/donors for SARS-CoV-2-RNA immediately before liver transplant (LT) and, starting from November 2020, grafts from deceased donors with active SARS-CoV-2 infection were allowed to be considered for urgent-need transplant candidates with active/resolved COVID-19. We present the results of the first 10 LTs with active COVID-19 donors within an Italian multicenter series. Only two recipients had a positive molecular test at LT and one of them remained positive up to 21 days post-LT. None of the other eight recipients was found to be SARS-CoV-2 positive during follow-up. IgG against SARS-CoV-2 at LT were positive in 80% (8/10) of recipients, and 71% (5/7) showed neutralizing antibodies, expression of protective immunity related to recent COVID-19. In addition, testing for SARS-CoV-2 RNA on donors’ liver biopsy at transplantation was negative in 100% (9/9), suggesting a very low risk of transmission with LT. Immunosuppression regimen remained unchanged, according to standard protocol. Despite the small number of cases, these data suggest that transplanting livers from donors with active COVID-19 in informed candidates with SARS-CoV-2 immunity, might contribute to safely increase the donor pool.

  相似文献   

77.
目的通过集中化筛查模式下的唐氏综合征产前筛查数据分析,了解样本分析前的影响因素,为提高集中筛查模式的筛查质量提供依据。方法对2011年1月~6月参加筛查的宁波市孕妇29 349例,分别将集中或分散二种不同采血方式和不同血清分离方式的血清样本检验结果进行质控分析,并对质控后的1557例数据进行再分析。数据比较采用t检验,P﹤0.05为差异有统计学意义。结果集中采血方式下Freeβ-hCG水平偏高,uE3水平偏低Free(P=0.000);采用分离胶管分离血清法,Freeβ-hCG和uE3水平均偏高(P=0.025,P=0.000)。结论血样本室温下放置过久和分离胶真空采血管分离血浆,会影响产前筛查标志物的检测结果。规范样本采集、贮存、递送流程,使用普通管-离心法分离血清,有利于产前筛查效率的保证。  相似文献   
78.

Background

Endothelial glycocalyx regulates the endothelial function and plays an active role in maintaining vascular homeostasis. During ischema and reperfusion, the glycocalyx is rapidly shed into the blood stream. A Corline heparin conjugate (CHC; Corline systems AB, Uppsala, Sweden) consists of 70 heparin molecules that have the capacity to adhere strongly to biological tissues expressing heparin affinity. We hypothesized that CHC could be used to restore disrupted glycocalyx in vivo in kidneys from brain-dead pigs.

Materials and methods

Brain death was induced in male landrace pigs (n = 6) by inflating a balloon catheter in the epidural space until obtaining negative cerebral perfusion. The recovered kidneys (n = 5 + 5) were perfused by hypothermic machine perfusion using two Lifeport kidney transporters (Organ Recovery Systems, Chicago, IL). CHC (50 mg) (including 25 mg biotinylated CHC) or 50 mg unfractionated heparin (control) was added to the perfusion fluid in the respective machines. In one case, the kidneys were used only for dose escalation of CHC with the same procedure.

Results

CHC was detected by immunofluorescence and confocal microscopy in the inner surface of the vessel walls. The binding of CHC in the kidney was confirmed indirectly by consumption of CHC from the perfusion fluid.

Conclusions

In this first attempt, we show that CHC maybe used to coat the vessel walls of perfused kidneys during hypothermic machine perfusion, an approach that could become useful in restoring endothelial glycocalyx of kidneys recovered from deceased donors to protect vascular endothelium and possibly ameliorate ischemia and reperfusion injuries.  相似文献   
79.
Porcine islet xenotransplantation is a promising alternative to human islet allotransplantation. Porcine pancreas cooling needs to be optimized to reduce the warm ischemia time (WIT) following donation after cardiac death, which is associated with poorer islet isolation outcomes. This study examines the effect of four different cooling Methods on core porcine pancreas temperature (n = 24) and histopathology (n = 16). All Methods involved surface cooling with crushed ice and chilled irrigation. Method A, which is the standard for porcine pancreas procurement, used only surface cooling. Method B involved an intravascular flush with cold solution through the pancreas arterial system. Method C involved an intraductal infusion with cold solution through the major pancreatic duct, and Method D combined all three cooling Methods. Surface cooling alone (Method A) gradually decreased core pancreas temperature to <10 °C after 30 min. Using an intravascular flush (Method B) improved cooling during the entire duration of procurement, but incorporating an intraductal infusion (Method C) rapidly reduced core temperature 15–20 °C within the first 2 min of cooling. Combining all methods (Method D) was the most effective at rapidly reducing temperature and providing sustained cooling throughout the duration of procurement, although the recorded WIT was not different between Methods (P = 0.36). Histological scores were different between the cooling Methods (P = 0.02) and the worst with Method A. There were differences in histological scores between Methods A and C (P = 0.02) and Methods A and D (P = 0.02), but not between Methods C and D (P = 0.95), which may highlight the importance of early cooling using an intraductal infusion. In conclusion, surface cooling alone cannot rapidly cool large (porcine or human) pancreata. Additional cooling with an intravascular flush and intraductal infusion results in improved core porcine pancreas temperature profiles during procurement and histopathology scores. These data may also have implications on human pancreas procurement as use of an intraductal infusion is not common practice.  相似文献   
80.
The consequence of a pancreas injury during the procurement for islet isolation purpose is unknown. The goal of this work was to assess the injuries of the pancreata procured for islet isolation, and to determine their effect on the islet yield. Between January 2007 and October 2013, we prospectively documented every injury of the pancreata processed in our centre for islet isolation. Injuries involving the main duct were classified as major, the others as minor. Donors’ characteristics and islet yields were compared between the groups of injuries. A pancreas injury was identified in 42 of 452 pancreata received for islet isolation (9.3%). In 15 cases, the injury was major (3.3% of all pancreata). Although a minor injury did not affect the islet yield, a major injury was significantly associated with unfavourable outcomes (postpurification mean islet equivalent of 364 ± 181, 405 ± 190 and 230 ± 115 × 103 for absence of injury, minor injury and major injury, respectively). A major injury was significantly more prevalent in lean and short donors. We recommend assessing the quality of the pancreas in the islet isolation centre before starting the isolation procedure. Each centre should determine its own policy based on its financial resources and on the wait list.  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