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   512篇
  免费   14篇
  国内免费   2篇
耳鼻咽喉   2篇
儿科学   5篇
妇产科学   4篇
基础医学   36篇
口腔科学   7篇
临床医学   54篇
内科学   113篇
皮肤病学   9篇
神经病学   32篇
特种医学   11篇
外科学   181篇
综合类   3篇
预防医学   17篇
眼科学   11篇
药学   17篇
肿瘤学   26篇
  2023年   2篇
  2021年   6篇
  2020年   2篇
  2019年   7篇
  2018年   7篇
  2017年   1篇
  2016年   5篇
  2015年   5篇
  2014年   19篇
  2013年   13篇
  2012年   39篇
  2011年   38篇
  2010年   16篇
  2009年   11篇
  2008年   48篇
  2007年   39篇
  2006年   47篇
  2005年   34篇
  2004年   30篇
  2003年   25篇
  2002年   35篇
  2001年   15篇
  2000年   13篇
  1999年   25篇
  1998年   6篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   3篇
  1990年   7篇
  1989年   2篇
  1987年   2篇
  1986年   3篇
  1984年   1篇
  1983年   1篇
  1979年   1篇
  1978年   1篇
  1974年   2篇
  1972年   3篇
  1971年   1篇
  1969年   1篇
  1968年   2篇
排序方式: 共有528条查询结果,搜索用时 15 毫秒
111.
Vibrio vulnificus is a Gram‐negative marine bacterium that may cause local wound infection, gastroenteritis, or septicaemia. Fatal septicaemia usually presents with fever, shock, and large haemorrhagic bullae on the legs. This report is about a man who had severe V. vulnificus septicaemia but presented with atypical features of leg pain and diffuse purpuric skin lesions. V. vulnificus septicaemia should be suspected if the following are present: septic shock, leg pains associated with diffuse purpuric skin lesions, recent consumption of raw seafood, and a past medical history of liver cirrhosis.  相似文献   
112.
To augment graft cell dose, we evaluated the safety of the combined transplantation of two partially HLA-matched umbilical cord blood (UCB) units. Five patients with transfusion-dependent thalassemia, median age 11.1 years (range 10-13.1), received 2 UCB units after myeloablative conditioning. Cord blood units were a 4/6-HLA-match or better with the recipient, and contained a minimum combined pre-freeze CD34 cell dose of 3.0 x 10(5)/kg. All patients engrafted at a median of 15 days (range 12-19). Four patients with durable trilineage engraftment showed acute grade I-III GVHD; none developed extensive chronic GVHD until the date of last contact. The median times to red blood cell transfusion independence and platelet engraftment were 32 and 49 days after transplant, respectively. With a median follow-up of 18.5 months (range 11-32), four patients transplanted with UCB from two different partially HLA-matched donors were transfusion-independent. Therefore, transfusion of two partially HLA-matched UCB units is safe, and may overcome the cell-dose barrier that limits the use of UCB in long-term recipients of multiple transfusions for thalassemia.  相似文献   
113.
Preprosomatostatin is a gene expressed ubiquitously among vertebrates, and at least two duplications of this gene have occurred during evolution. Somatostatin-28 (S-28) and somatostatin-14 (S-14), C-terminal products of prosomatostatin (ProS), are differentially expressed in mammalian neurons, D cells, and enterocytes. One pathway for the generation of S-14 entails the excision of Arg13-Lys14 in S-28, leading to equivalent amounts of S-28((1-12)). Using an antiserum (F-4), directed to the N-terminal region of S-28 that does not react with S-28((1-12)), we detected a peptide, in addition to S-28 and ProS, that was present in human plasma and in the intestinal tract of rats and monkeys. This F-4 reacting peptide was purified from monkey ileum; and its amino acid sequence, molecular mass, and chromatographic characteristics conformed to those of S-28((1-13)), a peptide not described heretofore. When extracts of the small intestine were measured by RIA, there was a discordance in the ratio of peptides reacting with F-4 and those containing the C terminus of ProS, suggesting sites of synthesis for S-28((1-13)) distinct from those for S-14 and S-28. This was supported by immunocytochemistry, wherein F-4 reactivity was localized in gastrointestinal (GI) endocrine cells and a widespread plexus of neurons within the wall of the distal gut while immunoreactivity to C-terminal domains of S-14 and S-28 in these neurons was absent. Further, F-4 immunoreactivity persisted in similar GI endocrine cells and myenteric neurons in mice with a targeted deletion of the preprosomatostatin gene. We believe that these data suggest a novel peptide produced in the mammalian gut, homologous with the 13 residues of the proximal region of S-28 but not derived from the ProS gene. Pending characterization of the gene from which this peptide is derived, its distribution, and function, we have designated this peptide as thrittene. Its localization in both GI endocrine cells and gut neurons suggests that thrittene may function as both a hormone and neurotransmitter.  相似文献   
114.
The visualization and quantification of intracardiac blood flow have always been a challenging task for the cardiologist. The advent of color Doppler flow imaging substantially enhanced the clinical diagnosis of heart valve disease. Three-dimensional (3-D) color Doppler, a new diagnostic procedure, refines the diagnostic value of color Doppler by providing unique spatial and temporal information about the actual extension, direction, origin, and size of intracardiac flows. Here, we describe the procedure for 3-D color Doppler reconstruction of intracardiac blood flow velocities and reveal the varied findings in different heart pathologies that cause blood flow disturbances. An automated procedure for the segmentation of turbulent and laminar flows, which allows for the measurement of mitral regurgitant jet volumes, is one of the first 3-D quantitative approaches to the clinical assessment of mitral valve regurgitation. The major technical advances of this procedure include the direct use of digital color Doppler velocity data and an automatic voxel count of the turbulent jet flows. Three-dimensional color Doppler not only can disclose the spatial complex geometry of intracardiac blood flow disturbances but also can quantitatively assess the severity of mitral valve regurgitation.  相似文献   
115.
116.
117.

Introduction

Liver transplantation is the treatment of choice for end-stage liver disease. However, the shortage of donors is still the major problem in most Asian countries. Using extended donor criteria may maximize the deceased donor pool, but some high-risk donors may show adverse recipient outcomes due to preexisting infection.

Materials and Methods

This study included deceased donor liver transplant patients from June 2002 through June 2007. We retrospectively reviewed the clinical manifestations of donors and recipients. The donors showed no definite infection at the time the organs were matched to the recipients. Routine sputum, urine, blood, and bile cultures were obtained from the donor during the perioperative period. According to the final reports of the cultures, the recipients divided into two groups: donor infection (DI) and no donor infection (NDI).

Results

This study included 59 donor and 72 recipients, including 34 who received a graft from a donor with a positive culture (47.2%) finally, defined as the DI groups, and 38 recipients (52.8%) as the NDI group. Most of them had positive sputum cultures, followed by urine cultures. Staphylococcus aureus was the most common pathogen. Using a stepwise logistical regression model to analyze the significant donor characteristics, donor admission to the intensive care unit (ICU) for 7 days or longer (P ≤ .0001), previous cardiopulmonary cerebral resuscitation (CPCR) (P = .036), and inotropic agents (P = .022) were the only three independent factors to predict donor infection. To compare the outcomes between DI and NDI groups, the days of recipient ICU or hospital admission, the 1-week or 1-month mortality rate, and the overall survival showed no significant difference between both groups. However, the hospital mortality rate was mildly higher in the DI group (P = .050).

Conclusion

Donors with prolonged ICU admissions, rescue by CPCR, and use of inotropic agents carried an high risk of potential infections. Our data did not show a significant increase in adverse outcomes if the recipient received a graft from a potentially infected donor. However, there may be an increased risk of hospital mortality. We should be careful in using these potentially infected donors in selective recipients.  相似文献   
118.
Klappenchirurgie     
Indications for surgery form part of the guidelines for the treatment of valvular heart disease. The goal is to avoid risk associated with surgery as long as possible without reaching the point of irreversible damage to the heart and other organs. Since improvements of surgical techniques have reduced the operative risk these guidelines need revision periodically. Treatment of symptomatic patients is mainly consented. Despite this consensus surgery is denied to a significant number of patients with symptomatic aortic stenosis. Treatment of patients with severe but asymtomatic valvular heart disease is under debate. Excercise testing to detect surgical candidates is recommended but rarely performed. Evidence is evolving that subgroups of patients with asymptomatic aortic stenosis benefit from early surgery, but identification of these patients remains difficult. Advances in surgical reconstruction of leaking mitral or aortic valves have led to recommendations for earlier surgery of mitral insufficiencies; data generation for reconstructive surgery of the aortic valve is underway. Surgical experience with these techniques is of major importance in the process of deciding when to operate.  相似文献   
119.

Objectives

The hypothesis was tested, whether there is a gender-specific association between contractile performance and obesity based on the analysis of isolated human myocardium.

Methods

Right atrial muscle preparations (0.5 x 6 mm) of 77 female and 106 male patients undergoing coronary artery bypass surgery were electrically stimulated at optimal length. Isometric force amplitude (stimulation) and resting force (relaxation) were measured (measurement conditions: 37 °C, Krebs-Henseleit solution, optimal length, supramaximal electrical stimulation). The relationship between body mass index (BMI) and measured parameters was analyzed statistically by using a linear regression model and the student’s T test.

Results

There was a gender-specific decline in isometric force amplitude (mN/mm2) and resting force (mN/mm2) with increasing BMI (p < 0.0001). The effects were more pronounced in women (p < 0.0001).

Conclusions

The data seem to indicate that in isolated human myocardium there is a considerable negative inotropic effect of BMI and this effect is more pronounced in women. Adipose tissue thus may be interpreted as an endocrine organ with the potential to exert important cardio-depressant effects that may contribute to the development of heart failure in overweight patients.  相似文献   
120.
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