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   277篇
  免费   10篇
  国内免费   8篇
儿科学   2篇
基础医学   24篇
临床医学   22篇
内科学   140篇
皮肤病学   2篇
神经病学   13篇
特种医学   13篇
外科学   53篇
预防医学   4篇
药学   7篇
肿瘤学   15篇
  2022年   1篇
  2021年   3篇
  2019年   4篇
  2018年   2篇
  2017年   1篇
  2016年   3篇
  2015年   7篇
  2014年   7篇
  2013年   6篇
  2012年   9篇
  2011年   11篇
  2010年   12篇
  2009年   11篇
  2008年   16篇
  2007年   15篇
  2006年   25篇
  2005年   22篇
  2004年   24篇
  2003年   19篇
  2002年   20篇
  2001年   20篇
  2000年   17篇
  1999年   8篇
  1998年   5篇
  1997年   3篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1992年   6篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
排序方式: 共有295条查询结果,搜索用时 31 毫秒
1.
For chronic thromboembolic pulmonary hypertension not amenable to pulmonary endarterectomy, effective medical therapy is desired. In an open-label uncontrolled clinical trial, 104 patients (mean +/- sem age 62 +/- 11 yrs) with inoperable chronic thromboembolic pulmonary hypertension were treated with 50 mg sildenafil t.i.d. At baseline, patients had severe pulmonary hypertension (pulmonary vascular resistance 863 +/- 38 dyn.s.cm(-5)) and a 6-min walking distance of 310 +/- 11 m. Eight patients were in World Health Organization functional class II, 76 in class III and 20 in class IV. After 3 months' treatment, there was significant haemodynamic improvement, with reduction of pulmonary vascular resistance to 759 +/- 62 dyn.s.cm(-5). The 6-min walking distance increased significantly to 361 +/- 15 m after 3 months' treatment, and to 366 +/- 18 m after 12 months' treatment. A subset of 67 patients received a single dose of 50 mg sildenafil during initial right heart catheterisation. The acute haemodynamic effect of this was not predictive of long-term outcome. In this large series of patients with inoperable chronic thromboembolic pulmonary hypertension, open-label treatment with sildenafil led to significant long-term functional improvement. The acute effect of sildenafil may not predict the long-term outcome of therapy.  相似文献   
2.
Adequate flushing for liver donation requires large fluid volumes delivered at a high flow. This can be achieved more effectively with crystalloid solutions than with colloid-based solutions. This study examined the combination of initial histidine-tryptophan-ketoglutarate solution (HTK) graft flush and subsequent storage in University of Wisconsin solution (UW) to that of the single use of each solution. Livers from inbred Wistar rats were procured using aortic perfusion with UW or HTK for initial perfusion and reflushed after 30 minutes using either solution. In a third group, after perfusion with HTK, organs were reflushed with UW. A 60-minute in-vitro recirculating perfusion was performed after 24 hours of cold storage in the subsequent solution, as well as allotransplantation after 18 and 24 hours of cold storage. In extracorporeal perfusion, the HTK flush followed by UW storage was superior compared to the single use of either UW or HTK solution, as measured by portal venous pressure, bile flow, liver enzymes released into the effluent perfusate, glycerol leakage, and histological examinations. These data were consistent with the transplantation study. Histological damage and enzyme release after 5-day survival were lowest in the HTK flush and subsequent UW storage groups following 18 hours of cold storage; likewise, the 5-day survival was superior following 24 hours of cold storage. In conclusion, the combined use of HTK solution for initial graft rinse and subsequent storage in UW solution resulted in a cumulative protection. Choosing low-viscosity HTK solution for the initial organ flush may represent a feasible improvement in liver preservation, which also further reduces the required amount of UW solution.  相似文献   
3.
4.
Background: In the early 1980s breast preservation was a rarely applied therapeutic modality in the primary treatment of breast cancer in the Federal Republic of Germany. Reports coming from retrospective studies as well as preliminary results from randomized trials made it desirable to introduce breast preservation in the form of a controlled clinical trial. Study design: In stage pT1 N0 M0 breast cancer, mastectomy as the standard treatment was to be compared with radiotherapy of the remaining breast tissue. The study design originally planned as a randomized trial had to be changed into a prospective observation study due to the low randomization rate. Univariate analysis of prognostic variables was the first step to a valid treatment comparison. Those factors determined as being significant were included together with the treatment effects in a multivariate analysis. A high therapeutic standard was guaranteed by quality control. Results: 1036 out of 1119 recruited patients are evaluable. After a median follow-up of 48 months the following preliminary results can be reported. With the exception of death without recurrence from breast cancer, the 143 events are evenly distributed among the two treatment groups. Locoregional recurrence of the whole patient population was 5%. Out of all prognostic factors examined only tumor size and grading are significant in regard to recurrent disease. Recurrence-free survival decreased in cases with uncertain tumor margins, whereas the width of the margin had no influence on recurrent disease. There was no significant difference in quality of life between the two treatment groups. Conclusions: The four-year results of this study are in accordance with those of other breast preservation trials: There is no significant difference between the two treatment groups in the occurrence of locoregional failure. Incomplete tumorectomy has a negative influence on recurrence. Quality of life seems more dependent on the acceptance of the therapy by the patient than on the therapeutic modality itself. Breast preservation can also be performed appropriately in smaller institutions if the therapeutic standard is guaranteed by quality control.This study was sponsored by the Ministry of Research and Technology (BMFT) of the Federal Republic of Germany.  相似文献   
5.
6.
AIMS: We investigated the value of a novel early biomarker, heart-type fatty acid-binding protein (H-FABP), in risk stratification of patients with acute pulmonary embolism (PE). METHODS AND RESULTS: We prospectively included 107 consecutive patients with confirmed PE. The endpoints were (i) PE-related death or major complications and (ii) overall 30-day mortality. Overall, 29 patients (27%) had abnormal (>6 ng/mL) H-FABP levels at presentation. Of those, 12 (41%) had a complicated course, whereas all patients with normal baseline H-FABP had a favourable 30-day outcome (OR, 71.45; P<0.0001). At multivariable analysis, H-FABP (P<0.0001), but not cardiac troponin T (P=0.13) or N-terminal pro-brain natriuretic peptide (P=0.36), predicted an adverse outcome. Evaluation of a strategy combining biomarker testing with echocardiography revealed that patients with a negative H-FABP test had an excellent prognosis regardless of echocardiographic findings. In contrast, patients with a positive H-FABP test had a complication rate of 23.1% even in the presence of a normal echocardiogram, and this rose to 57.1% if echocardiography also demonstrated right ventricular dysfunction (OR vs. a negative H-FABP test, 5.6 and 81.4, respectively). CONCLUSION: H-FABP is a promising early indicator of right ventricular injury and dysfunction in acute PE. It may help optimize risk stratification algorithms and treatment strategies.  相似文献   
7.
8.
9.

Background  

The diagnosis of myocarditis continues to be a challenging task in clinical practice. The purpose of our study was to investigate cardiovascular magnetic resonance imaging in the diagnostic workup of ambulatory patients with the suspicion of early myocarditis after respiratory or gastrointestinal tract viral infection. The need for accurate diagnosis of early myocarditis arises from the low diagnostic accuracy of routine clinical tests.  相似文献   
10.
The aim of the present study was to improve the viability of marginal livers from non-heart beating donors upon cold preservation using two different techniques for the provision of tissue aerobiosis. Livers from male Wistar rats (250-300 g bw) were harvested after 60 min of cardiac arrest, flushed via the portal vein with 20 mL of heparinized Ringer's solution and 60 mL of histidine-tryptophan-ketoglutarate (HTK) preservation solution. Control livers were then stored submerged in HTK for 24 h at 4 degrees C while other organs were subjected to aerobic conditions by either insufflation of gaseous oxygen via the venous vascular system of the cold stored organ (VSOP) or pulsatile machine perfusion (MP) with oxygenated HTK at 5 mL/min at 4 degrees C. Superoxide dismutase (SOD) (7500 IU) was added to the last 10 mL of HTK in order to prevent adverse effects of high oxygen tensions at hypothermia. Viability of the livers was assessed upon isolated perfusion in vitro with oxygenated Krebs-Henseleit buffer at constant flow. VSOP or MP, both significantly improved vascular conductivity upon reperfusion as evaluated by portal venous pressure, reduced hepatic enzyme release and led to a rise in hepatic bile production upon reperfusion. Induction of apoptosis was also looked for in tissue homogenates by Western analysis for cleavage of poly(ADP-ribose)polymerase (PARP). Expression of cleaved PARP fragment could be found in reperfused control livers but also, though to a lesser extend, after VSOP or MP. In conclusion, provision of oxygen during cold preservation significantly contributes to improve organ viability upon reperfusion and must be regarded as a useful adjunct for marginal or pre-damaged livers. HTK has been shown for the first time to be also suitable for long-term MP preservation of the liver, but, as inferred from these data, simple insufflation of gaseous O2 may be considered a feasible alternative.  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