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   579篇
  免费   44篇
耳鼻咽喉   1篇
儿科学   22篇
基础医学   85篇
口腔科学   4篇
临床医学   38篇
内科学   170篇
皮肤病学   4篇
神经病学   74篇
特种医学   45篇
外科学   55篇
综合类   2篇
预防医学   48篇
药学   36篇
肿瘤学   39篇
  2024年   1篇
  2023年   3篇
  2022年   1篇
  2021年   7篇
  2020年   5篇
  2019年   7篇
  2018年   12篇
  2017年   10篇
  2016年   19篇
  2015年   12篇
  2014年   18篇
  2013年   24篇
  2012年   39篇
  2011年   37篇
  2010年   23篇
  2009年   17篇
  2008年   33篇
  2007年   38篇
  2006年   28篇
  2005年   37篇
  2004年   27篇
  2003年   17篇
  2002年   21篇
  2001年   22篇
  2000年   27篇
  1999年   19篇
  1998年   7篇
  1997年   3篇
  1996年   5篇
  1995年   3篇
  1994年   8篇
  1993年   8篇
  1992年   18篇
  1991年   10篇
  1990年   13篇
  1989年   8篇
  1988年   5篇
  1987年   5篇
  1986年   4篇
  1985年   1篇
  1984年   2篇
  1983年   2篇
  1981年   3篇
  1980年   1篇
  1979年   4篇
  1978年   3篇
  1977年   3篇
  1976年   1篇
  1972年   1篇
  1969年   1篇
排序方式: 共有623条查询结果,搜索用时 31 毫秒
31.
32.
In type 2 diabetes mellitus, elevated fasting and postprandial plasma triglycerides, small dense low-density lipoprotein particles, low high-density lipoprotein (HDL) cholesterol levels, and increased action of lipid transfer proteins may enhance peripheral lipid accumulation and increase cardiovascular risk. Despite low HDL cholesterol, plasma’s ability to stimulate cellular cholesterol efflux, reflecting an early step in the reverse cholesterol transport pathway, appears to be maintained, perhaps implicating a compensatory mechanism.  相似文献   
33.
34.
OBJECTIVE: The aim of this study was to develop a radiographic view to detect anteromedial talotibial osteophytes that remain undetected on standard radiographs. DESIGN AND PATIENTS: In 10 cadaver specimens the maximal size was measured of anteromedial tibial osteophytes that remain undetected on a standard lateral radiograph projection, due to the presence of the anteromedial tibial rim. The average projection of the most prominent anterolateral tibial rim over the anteromedial rim was found to be 7.3 mm. A 7 mm barium-clay osteophyte was attached to this anteromedial rim of the distal tibia. Anteromedial osteophytes become most prominent on an oblique view, in which the radiographic beam is tilted into a 45 degrees craniocaudal direction with the leg in 30 degrees external rotation. This oblique view was compared with the findings of arthroscopic surgery in 25 consecutive patients with anterior ankle impingement syndrome. RESULTS: Medially located tibial and talar osteophytes remained undetected on a standard lateral projection and became visible on the oblique anteromedial impingement (AMI) radiograph. Anterolateral tibial and talar osteophytes were well detected on a standard lateral radiograph projection but were invisible on the AMI view. There was a high correlation between the location of the osteophyte and the location of symptoms and the findings at arthroscopy. CONCLUSION: A combination of lateral and oblique radiographs can be used to differentiate between anteromedial and anterolateral bony ankle impingement.  相似文献   
35.
BACKGROUND: Whereas several authors recently reported a positive association between the alpha2-macroglobulin gene (A2M) and late-onset AD (LOAD), others were unable to replicate these findings. Early-onset AD (EOAD) is defined as onset age <65 years. Virtually all patients with LOAD are >65 years of age. OBJECTIVE: To evaluate the role of A2M in AD, the authors conducted a population-based study of EOAD and LOAD as well as a meta-analysis of all studies conducted to date. METHODS: Patients with EOAD (n = 100) were derived from a population-based study in four northern provinces of the Netherlands and the area of metropolitan Rotterdam. Patients with LOAD (n = 344) were drawn from the Rotterdam Study, a population-based prospective study on residents aged 55 years and over of a Rotterdam suburb in the Netherlands. Two polymorphisms were studied, A2M-I/D and A2M-Ile1000Val, in relation to the APOE epsilon4 allele (APOE*4). RESULTS: No genotypic or allelic association was found for either polymorphism in the population-based series of patients with LOAD. In patients with EOAD without APOE*4, a significant increase of carriers of A2M-1000Val was found. The meta-analysis of available published case-control data on these polymorphisms in white and mixed ethnic populations yielded no significant differences between cases and controls. Pooling the Asian studies conducted to date showed a significant decrease in the frequency of A2M-D among patients. CONCLUSIONS: These results suggest that A2M is not genetically associated with LOAD in white patients or mixed populations as found in the United States. In these populations A2M does not have clinical relevance. From a scientific perspective, the findings on EOAD and Asian patients require replication and further research in the A2M region.  相似文献   
36.
The aim of this study was to investigate the results of different treatment strategies for osteochondral defects (OCD) of the talus. Electronic databases from 1966 to July 1998 were systematically screened. Based on our inclusion criteria 32 studies describing the results of treatment strategies for OCD of the talus were included. No randomized clinical trials (RCT's) were identified. Fourteen studies described the results of excision alone, 11 the results of (EC), 14 the results of (ECD), 1 the results of cancellous bone grafting after EC, 1 the results of osteochondral transplantation and 3 the results of fixation. The average success rate of non-operative treatment (NT) was 45%. Comparison of different surgical procedures shows that the average highest success rate was reached by excision, curettage and drilling (ECD) (85%) followed by excision and curettage (EC) (78%) and excision alone (38%). Based on this systematic review we conclude that NT and excision alone are not to be recommended in treating talar OCD. Both EC and ECD have been shown to lead to a high percentage good/excellent results. However, due to great diversity in the articles and variability in treatment results, no definitive conclusions can be drawn. Further prospective randomized controlled trials are required to compare the outcome of these two surgical strategies for OCD of the talus.  相似文献   
37.
With a multistage laboratory protocol immunodeficiencies can be efficiently identified. The article presents a diagnostic protocol that consists of three schemes. Scheme 1 describes the diagnostic protocol for the large group of patients with recurrent pulmonary and ENT-infections, where an antibody deficiency can occasionally be found. Scheme 2 presents the diagnostic protocol for the much smaller group of patients with opportunistic infections, wasting or failure to thrive. Several of these patients suffer from a severe T-lymphocyte disorder. Early diagnosis and treatment is important for the prognosis in these patients. Scheme 3 shows the diagnostic protocol for patients with recurrent infections of surface areas and deeper organs; these patients may suffer from a phagocyte disorder.  相似文献   
38.
BACKGROUND: Peroperative peritoneal trauma activates a cascade of peritoneal defense mechanisms responsible for postoperative adhesion formation. The same cascade seems to play a role in the process of intra-abdominal tumor recurrence. Icodextrin is a glucose polymer solution that is absorbed slowly from the peritoneal cavity, allowing prolonged "hydroflotation" of the viscera, thereby decreasing adhesion formation. This study evaluated the adhesion-preventing properties of icodextrin and its effect on peritoneal metastasis. METHODS: Reproducible rat models of peritoneal trauma were used, allowing semiquantitative scoring of adhesion formation or tumor load. In one experiment, peritoneal trauma was inflicted; one group was treated by peroperative intra-abdominal instillation of 7.5% icodextrin, one by instillation of RPMI (placebo), and one had no instillate (controls). In another experiment involving a different model of peritoneal trauma, the coloncarcinoma cell line CC531 was injected intraperitoneally to induce tumor load, again using these three groups. RESULTS: Treatment of peritoneally traumatized rats with icodextrin caused a 51% reduction in postoperative adhesion formation ( P < .001). However, peroperative intra-abdominal treatment with icodextrin did not affect intraperitoneal tumor cell adhesion and growth of free intra-abdominal tumor cells in rats with this model of severe peritoneal trauma. CONCLUSION: A 7.5% icodextrin solution is effective in reducing postoperative adhesions without promoting tumor recurrence and therefore may prove useful and safe in oncologic surgery.  相似文献   
39.
Adenovirus (HAdV) infections are a frequent cause of morbidity and mortality after allogeneic human stem cell transplantation (HSCT). We report a retrospective single-centre study on 328 consecutive paediatric recipients of an allogeneic HSCT. During the first 6 months after HSCT, HAdV infection occurred in 37 children (cumulative incidence 12%). The highest incidence was found in young children up to 5 years of age, transplanted after 1994, with >2 log T-cell depletion of a graft of another than an HLA-genotypically identical related donor (actuarial frequency at 6 months 84%). Persistence of HAdV and spreading of the virus over multiple sites showed a trend towards the development of HAdV disease or death, but did not reach significance. Recovery of immunity after HSCT, that is, serum concentrations of IgM and peripheral blood counts of T cells and subsets, was delayed in children with an HAdV infection compared with noninfected children. In seven out of seven patients with HAdV DNA in serum and decreasing lymphocyte counts, the infection had a fatal course. Manipulation of cellular immunity either by tapering of immunosuppression, infusion of donor lymphocytes or immunotherapy using HAdV-specific T cells should be considered in graft recipients at risk for a severe HAdV infection.  相似文献   
40.
Arthroscopic treatment of anterior impingement in the ankle   总被引:3,自引:0,他引:3  
We performed a prospective study to assess the long-term outcome of 57 arthroscopic debridement procedures carried out to treat anterior impingement in the ankle. Using preoperative radiographs, we grouped patients according to the extent of their osteoarthritis (OA). The symptoms of those with grade-0 changes could be attributed to anterior soft-tissue impingement alone. Patients with grade-I disease had both anterior soft-tissue and osteophytic impingement, but no narrowing of the joint space. In those with grade-II OA, narrowing of the joint space was accompanied by osteophytic impingement. Radiographs taken before and after operation and at follow-up were compared to assess the recurrence of osteophytes and the progression of narrowing of the joint space. At a mean follow-up of 6.5 years (5 to 8) all patients without OA had excellent or good results. There were excellent or good results in 77% of patients with grade-I OA, despite partial or complete recurrence of osteophytes in two-thirds. In most patients with grade-II OA, narrowing of the joint space had not progressed at follow-up. There was a notable improvement in pain in these patients, 53% of whom had excellent or good results. Although some osteophytes recurred, at long-term follow-up arthroscopic excision of soft-tissue overgrowths and osteophytes proved to be an effective way of treating anterior impingement of the ankle in patients who had no narrowing of the joint space.  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