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   45219篇
  免费   5112篇
  国内免费   107篇
耳鼻咽喉   323篇
儿科学   1336篇
妇产科学   898篇
基础医学   6234篇
口腔科学   1229篇
临床医学   5708篇
内科学   8947篇
皮肤病学   700篇
神经病学   3635篇
特种医学   1940篇
外国民族医学   1篇
外科学   5964篇
综合类   1168篇
一般理论   26篇
预防医学   5266篇
眼科学   850篇
药学   3792篇
中国医学   78篇
肿瘤学   2343篇
  2021年   583篇
  2020年   356篇
  2019年   642篇
  2018年   734篇
  2017年   521篇
  2016年   596篇
  2015年   706篇
  2014年   944篇
  2013年   1373篇
  2012年   1987篇
  2011年   1995篇
  2010年   1138篇
  2009年   1109篇
  2008年   1905篇
  2007年   2026篇
  2006年   1967篇
  2005年   1884篇
  2004年   1737篇
  2003年   1659篇
  2002年   1618篇
  2001年   1541篇
  2000年   1476篇
  1999年   1470篇
  1998年   621篇
  1997年   488篇
  1996年   500篇
  1995年   500篇
  1994年   437篇
  1993年   486篇
  1992年   1218篇
  1991年   1133篇
  1990年   1086篇
  1989年   1069篇
  1988年   1000篇
  1987年   987篇
  1986年   995篇
  1985年   910篇
  1984年   778篇
  1983年   643篇
  1982年   433篇
  1981年   354篇
  1979年   588篇
  1978年   490篇
  1977年   380篇
  1976年   385篇
  1974年   432篇
  1973年   400篇
  1972年   386篇
  1971年   349篇
  1969年   358篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
We have devised assays to detect both circulating alloantibodies to platelets (indirect assay) and platelet-association IgG and IgM (direct assay) using a flow cytometric technique. A variety of patients with immune thrombocytopenia were studied. Employment of a confocal lens in the flow cytometer increased the discrimination power of the instrument. Patients with autoimmune thrombocytopenia (idiopathic thrombocytic purpura [ITP], systemic lupus erythematosus (SLE), lymphoma, leukemia, and drug-induced thrombocytopenia showed a significant increase in platelet-associated antibody. Circulating antibodies to platelets (alloantibodies) were demonstrated in cases of platelet refractoriness and neonatal isoimmune purpura. Day-today precision of the assays ranged from 3% to 6% (coefficient of variation). No interference was shown in the presence of hemoglobin (5 g/L), triglycerides (10 g/L), or polyclonal and monoclonal immunoglobulinemia (50 g/L: IgG, IgA, IgM). The sensitivity of the direct assay was 500 attograms of IgG or IgM platelet.  相似文献   
82.
Background: Dual therapy with ranitidine bismuth citrate plus clarithromycin twice daily for 14 days is an effective regimen for eradicating Helicobacter pylori infection.
Aim: To determine whether this regimen can be improved by the addition of a second antibiotic, tetracycline hydrochloride, whilst reducing the duration of treatment to 7 days.
Methods: Sixty-one out-patients were enrolled to this open treatment study. All had H. pylori infection, as determined by 13C-urea breath test and, for those undergoing endoscopy, by rapid urease test. Patients were treated with ranitidine bismuth citrate 400 mg, clarithromycin 500 mg and tetracycline hydrochloride 500 mg all twice daily for 7 days. Eradication of H.␣pylori was assessed by two separate 13C-urea breath tests, the first 28–68 days after the completion of treatment, the second 28–162 days later. H. pylori infection was considered cured if both tests were negative.
Results: All 61 patients were included in the intention-to-treat efficacy analysis. Successful eradication of H.␣pylori was achieved in 55/61 patients (90 %; 95% CI: 82–98%). Fifty-nine out of sixty-one patients reported 100% compliance; one patient missed a single dose of medication and the other withdrew at 48 h due to nausea and vomiting. Minor adverse events were reported by 30/61 patients.
Conclusion: One-week triple therapy with ranitidine bismuth citrate, clarithromycin and tetracycline, all twice daily, is a safe and well-tolerated regimen which eradicates H. pylori in 90% of infected patients.  相似文献   
83.
We report a child of 3 years 9 months with the Marshall-Smith syndrome (MSS), characterised by the typical facial features, developmental delay, and advanced bone age. After the diagnosis was made at 5 months of age, careful observation for respiratory complications and failure to thrive was initiated. By 3 1/2 years of age, although our patient had no life threatening respiratory complications, investigation showed significant upper airway obstruction, which has been successfully treated. Aggressive treatment for failure to thrive has also allowed her to maintain a weight on the 50th centile. The purpose of this report is to suggest that early diagnosis and aggressive management may improve the ultimate prognosis with respect to the respiratory and feeding difficulties seen in this rare syndrome.  相似文献   
84.
This report describes a 3-year-old child with a hepatobiliary cystadenoma. Cystadenomas are benign, multilocular, cystic neoplasms that usually occur in middle-aged women. The patients may be asymptomatic, but often there are vague abdominal complaints related to extrinsic compression of the stomach, duodenum, or biliary tree. Recurrence following incomplete excision and the presence of carcinoma within otherwise benign cysts has been documented. Complete resection is the therapy of choice, and thorough histopathologic evaluation is imperative.  相似文献   
85.
Stenting of the carotid artery is usually performed either to prevent an acute neurologic event or to treat episodes of recurrent transient ischemic attacks. Occasionally, it may be performed for other indications. We describe the case of a patient with prior coronary artery bypass grafting using a left internal mammary arterial graft, in addition to left carotid artery to left subclavian artery bypass for symptomatic left subclavian stenosis, who subsequently underwent left common carotid artery stenting to relieve anginal symptoms.  相似文献   
86.
87.
88.
89.
Spinal cord stimulation and the relief of chronic pain.   总被引:1,自引:0,他引:1       下载免费PDF全文
Twenty six patients who had received spinal cord stimulation for chronic pain were evaluated by videotaped structured interviews with staff not directly involved in the patients' care. In addition estimates of pain relief were obtained from clinicians involved in the patients' care and from close relatives and friends. Information about lifestyles and drug usage was also collected and correlated with pain relief. At the time of the interviews half of the patients were receiving 50% or better relief of their pain.  相似文献   
90.
Angiodysplasia of the colon was diagnosed in 31 out of 1,050 patients (3%) presenting with rectal bleeding or anaemia, among 10,000 colonoscoped at St. Mark's Hospital. The lesions were identified in 16 out of 879 (2%) patients with rectal bleeding, in 15 out of 171 (9%) patients with anaemia, and in a further three patients without features of blood loss. The angiodysplasia lesions were predominantly in the right colon (76%) and occurred with a similar frequency (12%) in the transverse and the left colon. Affected patients (59% male and 41% female) were in the older age group (53–89 years; mean age 69.5 years) but only one patient had known aortic valve disease. Angiodysplasia is an important diagnosis to consider in patients presenting with colonic bleeding or anaemia because it can be treated in the majority of cases by endoscopic electrocoagulation. However in our experience it is less common (3%) than previously suggested by other authors (40–67%). Endoscopic over-diagnosis is possible when intramucosal capillaries with no bleeding tendency on local traumatisation or biopsy are included in the diagnosis but these lesions are not true angiodysplasia.  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