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   1922406篇
  免费   135299篇
  国内免费   7025篇
耳鼻咽喉   24470篇
儿科学   62004篇
妇产科学   50936篇
基础医学   272196篇
口腔科学   53136篇
临床医学   172467篇
内科学   382904篇
皮肤病学   44970篇
神经病学   149919篇
特种医学   75859篇
外国民族医学   346篇
外科学   294026篇
综合类   43705篇
现状与发展   4篇
一般理论   555篇
预防医学   149060篇
眼科学   41936篇
药学   138038篇
  34篇
中国医学   4317篇
肿瘤学   103848篇
  2018年   19615篇
  2017年   15418篇
  2016年   18132篇
  2015年   20161篇
  2014年   27918篇
  2013年   42024篇
  2012年   52512篇
  2011年   56019篇
  2010年   34481篇
  2009年   33338篇
  2008年   52334篇
  2007年   55937篇
  2006年   57159篇
  2005年   54720篇
  2004年   52795篇
  2003年   50892篇
  2002年   48722篇
  2001年   93625篇
  2000年   95937篇
  1999年   79833篇
  1998年   22896篇
  1997年   20192篇
  1996年   21180篇
  1995年   21089篇
  1994年   19655篇
  1993年   18292篇
  1992年   65022篇
  1991年   63692篇
  1990年   61569篇
  1989年   59360篇
  1988年   54739篇
  1987年   53609篇
  1986年   50649篇
  1985年   48457篇
  1984年   36515篇
  1983年   30770篇
  1982年   18534篇
  1981年   16656篇
  1980年   15767篇
  1979年   32992篇
  1978年   23714篇
  1977年   20025篇
  1976年   18649篇
  1975年   19812篇
  1974年   23269篇
  1973年   22245篇
  1972年   20676篇
  1971年   19117篇
  1970年   17757篇
  1969年   16543篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A significant number of patients undergoing lumbar spine surgery do not obtain pain relief. Such patients with chronic low back or lower extremity pain may be difficult to treat. A frequent component of therapy is the use of spinal cord stimulation to help control pain. With careful patient selection, many patients can achieve reasonable levels of pain relief. We review recent clinical reports, including prospective and randomized studies, that demonstrate up to three quarters of patients implanted with a spinal cord stimulator for the treatment of failed back surgery syndrome may benefit from its use. This technology must not be indiscriminately applied. Careful patient selection and a period of trial stimulation are vital to the successful use of spinal cord stimulation as treatment for chronic pain.  相似文献   
992.
Paclitaxel is an antineoplastic agent derived from the bark of the Pacific yew tree that has activity against many tumors including breast and ovarian carcinomas. In the past, its extravasation quality has been considered to be a local irritant; however, recent reports suggest that the agent may be a vesicant. A patient experienced a delayed vesicant reaction to a paclitaxel extravasation that resulted in severe necrosis. No acute symptoms were reported at the time of extravasation from the 24-hour peripheral paclitaxel infusion. However, on day 11 the patient complained of severe and progressive pain at the site of extravasation. The site was erythematous and had areas of central necrosis requiring debridement and closure by a plastic surgeon. Because paclitaxel possesses vesicant characteristics, health care professionals should be aware of its potential extravasation hazard. Prolonged peripheral infusions should be avoided or administered with extreme caution.  相似文献   
993.
994.
Eleven children with Pseudomonas aeruginosa infection complicating foot puncture wounds were reviewed. Delay in presentation (mean 2 days) and diagnosis (mean 9 days) due to a paucity of clinical signs of deep infection was characteristic of this condition. Septic arthritis (5 patients) and osteomyelitis (3 patients) were frequent complications. Treatment involved multiple surgical debridements and prolonged intravenous antibiotic therapy. The clinical outcome was good although long-term radiographic changes were common.  相似文献   
995.
996.
997.
The aim of this study was to evaluate if intraoperative vascular ultrasonography is of clinical value in the perioperative management of hepatic transplant patients. Fifteen intraoperative ultrasonographic examinations were performed on 13 patients (five female, eight male) during transplantation. These patients had clinically suspected vascular compromise. Among the 13 patients studied intraoperatively, five were correctly diagnosed as having hemodynamically significant vascular compromise. Of the intraoperative vascular sonographic examinations, the results of 13 were in concordance with the surgical impression as to whether further intervention was necessary or if the procedure could be terminated. Intraoperative sonography demonstrates potential to be of aid to the surgeon in recognition of vascular compromise.  相似文献   
998.
BACKGROUND: The etiology of thrombotic thrombocytopenic purpura (TTP) remains undetermined. TTP has been associated with a number of secondary causes including infections, drugs, menses, pregnancy, autoimmune diseases, and bone marrow transplantation. Regardless of the inciting factors, it is widely accepted that endothelial injury and platelet aggregation are integral components. The morbidity and mortality have been significantly reduced with the use of plasmapheresis. However, refractory forms of TTP remain a clinical management challenge. Refractory TTP has not previously been associated with occult bacterial infection. CASE REPORT: Two patients had classic TTP that was refractory to daily plasma exchange with fresh-frozen plasma. Multiple attempts over a period of months to wean these patients off plasma exchange resulted in exacerbations of disease activity, as indicated by increased schistocytosis, decreased hematocrit, increased serum lactate dehydrogenase, and decreased platelet counts. Both patients were empirically treated for infections during hospitalization, although microbial cultures failed to isolate an organism. Discontinuation of antimicrobial therapy on multiple occasions in one patient was associated with recurrence of disease. In the other patient, dental extraction with drainage of an occult periodontal abscess resulted in sustained remission of disease. CONCLUSION: Occult bacterial infection may play a role in triggering and sustaining TTP that is refractory to conventional treatment. A careful search for such an infection and appropriate antimicrobial therapy should be considered in the management of these patients.  相似文献   
999.
Objectives.To test the safety, efficacy, and toxicity of gene therapy using wild-type p53-expressing adenovirus (Ad-CMV-p53) in a nude mouse model with intraperitoneal (ip) 2774 human ovarian cancer cell line that contains a p53 mutation.Study design.An initial study of adenovirus tolerance was determined in nude mice by a single ip injection of increasing doses of Ad-CMV-p53. Nude mice were implanted with an LD100dose of 1 × 107cells. To study the efficacy and specificity of Ad-CMV-p53 treatment, the mice received treatment with different adenovirus constructs. One group received Ad-CMV-p53 and another group received a control adenovirus construct, Ad-CMV-βgal. To study the treatment response to Ad-CMV-p53, the mice were divided into groups and received various treatment schedules of 1 × 108pfu of Ad-CMV-p53.Results.The mice tolerated Ad-CMV-p53 without adverse effects at doses of 1 × 108pfu. The response to Ad-CMV-p53 showed significant survival duration in each dose regimen, with a survival time greater than that of untreated animals (P= 0.0173). However, no statistically significant survival advantage was observed between Ad-CMV-p53- and Ad-CMV-βgal-treated mice.Conclusions.These studies show that at the adenovirus dose and administration regimen used, there is effective but not specific 2774 tumor growth inhibitionin vivo.Efficient introduction of biologically active genes into tumor cells would greatly facilitate cancer therapy. Thus, although promising, these results caution that much effort will be required to realize the potential for clinical application of adenovirus-based ovarian cancer gene therapy.  相似文献   
1000.
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