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   2384951篇
  免费   195749篇
  国内免费   4239篇
耳鼻咽喉   34359篇
儿科学   72987篇
妇产科学   63154篇
基础医学   336492篇
口腔科学   67712篇
临床医学   216566篇
内科学   470707篇
皮肤病学   48091篇
神经病学   201721篇
特种医学   96341篇
外国民族医学   890篇
外科学   361817篇
综合类   56340篇
现状与发展   1篇
一般理论   981篇
预防医学   191514篇
眼科学   55593篇
药学   178174篇
  4篇
中国医学   4373篇
肿瘤学   127122篇
  2018年   24364篇
  2016年   20710篇
  2015年   23442篇
  2014年   33776篇
  2013年   51190篇
  2012年   69192篇
  2011年   72761篇
  2010年   42748篇
  2009年   41172篇
  2008年   69274篇
  2007年   73608篇
  2006年   74499篇
  2005年   72492篇
  2004年   69804篇
  2003年   67450篇
  2002年   66677篇
  2001年   112715篇
  2000年   116862篇
  1999年   98555篇
  1998年   27972篇
  1997年   25629篇
  1996年   25547篇
  1995年   24697篇
  1994年   23253篇
  1993年   21633篇
  1992年   79590篇
  1991年   76562篇
  1990年   73769篇
  1989年   70995篇
  1988年   66013篇
  1987年   64957篇
  1986年   61508篇
  1985年   58558篇
  1984年   44344篇
  1983年   37746篇
  1982年   22950篇
  1981年   20399篇
  1980年   19085篇
  1979年   41391篇
  1978年   29078篇
  1977年   24432篇
  1976年   22890篇
  1975年   24055篇
  1974年   29734篇
  1973年   28128篇
  1972年   26317篇
  1971年   24250篇
  1970年   22831篇
  1969年   21154篇
  1968年   19196篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Lesions typical of subacute cutaneous lupus erythematosus developed in an elderly woman after 6 months of PUVA (8-methoxypsoralen and longwave ultraviolet light) therapy for psoriasis. Pancytopenia, antibodies to double-stranded DNA, and hypocomplementemia developed concurrently with the appearance of the cutaneous lesions. With discontinuation of photochemotherapy, the cutaneous lesions disappeared and the pancytopenia improved.  相似文献   
992.
Retrosternal dislocations of the clavicle have been reported previously in adults throughout the orthopedic literature. However, in children few cases have been noted in either the pediatric, emergency, or orthopedic literature. The potential for great vessel injury as well as acute airway compromise makes the retrosternal disruption of the sternoclavicular joint a surgical emergency that must be diagnosed quickly. Diagnosis is enhanced by the cephalic tilt view and by computed tomography (CT scan), as planar x-ray and tomography do not always reveal this potentially life-threatening condition. Surgical consultation must be sought acutely; however, management may need to begin prior to definitive repair. Emergency management begins by suspecting the injury, and with immediate airway and circulatory support for the patient.  相似文献   
993.
994.
995.
Lyme arthritis     
Evanescent arthralgias and myalgias are common early symptoms of Lyme disease. Transient, intermittent episodes of monoarticular, oligoarticular, or sometimes migratory polyarticular arthritis, lasting weeks to months, with disease-free intervals, are frequently observed in untreated patients with erythema chronicum migrans. A minority of patients develop chronic joint involvement, most commonly affecting the knee. Antibiotic therapy given during erythema chronicum migrans is often protective with regard to late joint manifestations. In chronic Lyme arthritis, however, the response to antibiotics is variable.  相似文献   
996.
A patient who had right and left atrial membranes was examined. The diagnosis and the hemodynamic significance of both membranes were detailed by transesophageal echocardiography and were confirmed by magnetic resonance imaging. Transesophageal imaging was found to be superior to routine echocardiography in visualization of these atrial structures.  相似文献   
997.
998.
A variety of nutritional factors influence the bioavailability of calcium and increase a woman's risk of osteoporosis. Eight healthy women completed an 8-week metabolic study designed to investigate the effect of nonalcoholic carbonated beverage consumption on calcium metabolism. Compared with women receiving a control diet, women consuming a diet high in nonalcoholic carbonated beverages demonstrated similar mean serum levels of calcium, ionized calcium, phosphorus, alkaline phosphatase, parathyroid hormone, 1,25-dihydroxyvitamin D3, and osteocalcin. Twenty-four-hour urine volume, creatinine clearance, calcium-creatinine ratio, and phosphorus-creatinine ratio were similar during consumption of the diet high in nonalcoholic carbonated beverages and the control diet. Twenty-four-hour cyclic adenosine monophosphate-creatinine ratio was significantly lower in women consuming the diet high in nonalcoholic carbonated beverage compared with women receiving the control diet (342 +/- 27.4 nmol/mmol vs 409 +/- 22.1 nmol/mmol). Consumption of a diet high in nonalcoholic carbonated beverages on a short-term basis does not appear to affect adversely the serum or urinary markers of calcium metabolism.  相似文献   
999.
There is evidence that leukocyte contaminating red blood cells and platelet concentrates are responsible for refractoriness to platelet transfusions. The efficacy of a cotton-wool filter to remove leukocytes from red blood cells has been documented previously. The present study was designed to evaluate whether the cotton-wool filters can effectively remove leukocytes from platelet concentrates. Sixty pools of random-donor platelets and single-donor plateletpheresis products were filtered through a cotton-wool filter. The efficacy of filtration was determined by measuring the absolute numbers of leukocytes and platelets and subpopulations of mononuclear cells. The average platelet loss was 8% per pool of random platelets and 10% per plateletpheresis product. The average leukocyte removal was 99% from a pool of random platelets and plateletpheresis concentrates collected by CS-3000 and 90% from plateletpheresis concentrates harvested by single-stage COBE/IBM-2997. The filtration removed 100% of granulocytes, 95% of monocytes, 90% of B-lymphocytes, and 85% of T-lymphocytes. We conclude that filtration through a cotton-wool filter is an efficient and cost-effective method for preparation of leukocyte-poor platelets.  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