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   4137篇
  免费   289篇
  国内免费   32篇
耳鼻咽喉   41篇
儿科学   125篇
妇产科学   38篇
基础医学   607篇
口腔科学   100篇
临床医学   601篇
内科学   783篇
皮肤病学   77篇
神经病学   260篇
特种医学   405篇
外科学   661篇
综合类   62篇
一般理论   2篇
预防医学   193篇
眼科学   40篇
药学   169篇
  1篇
中国医学   1篇
肿瘤学   292篇
  2022年   29篇
  2021年   61篇
  2020年   49篇
  2019年   63篇
  2018年   74篇
  2017年   45篇
  2016年   77篇
  2015年   93篇
  2014年   104篇
  2013年   148篇
  2012年   173篇
  2011年   129篇
  2010年   142篇
  2009年   137篇
  2008年   179篇
  2007年   191篇
  2006年   164篇
  2005年   164篇
  2004年   139篇
  2003年   135篇
  2002年   107篇
  2001年   107篇
  2000年   111篇
  1999年   133篇
  1998年   125篇
  1997年   119篇
  1996年   99篇
  1995年   83篇
  1994年   68篇
  1993年   61篇
  1992年   50篇
  1991年   76篇
  1990年   57篇
  1989年   91篇
  1988年   90篇
  1987年   65篇
  1986年   55篇
  1985年   49篇
  1984年   35篇
  1983年   35篇
  1982年   29篇
  1981年   29篇
  1980年   25篇
  1979年   35篇
  1978年   49篇
  1977年   28篇
  1976年   27篇
  1975年   27篇
  1973年   31篇
  1972年   30篇
排序方式: 共有4458条查询结果,搜索用时 31 毫秒
21.
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.  相似文献   
22.
Acute respiratory distress syndrome (ARDS) is characterized by perfusion in favor of non-ventilated areas of the lungs as the main cause of intrapulmonary right-to-left shunt and hypoxemia. Therapeutic interventions to selectively influence pulmonary perfusion in ARDS became possible with the introduction of inhaled nitric oxide (iNO), which provided a way not only to reduce pulmonary hypertension, but also to acutely improve ventilation-perfusion mismatch, and thus to treat severe hypoxemia. Clinical studies in ARDS demonstrated that the combination of iNO with other interventions, such as positive end-expiratory pressure (PEEP) and prone positioning, yielded beneficial and additive effects on arterial oxygenation. Although randomized controlled trials of this concept have up to now failed to show an improved outcome, iNO is a valuable option for the treatment of severe refractory hypoxemia in ARDS patients.  相似文献   
23.
The etiology of epidermolysis bullosa acquisita (EBA) is unknown. EBA may be associated with other autoim‐mune systemic diseases; it also has been described in connection with different malignant tumors, showing complete remission after successful treatment of the tumor.In such cases, EBA may be regarded as a paraneo‐plastic dermatosis. We detected a highly differentiated neuroendocrine pancreatic cancer in a 78‐year‐old woman with EBA. Even thought her tumor was completely removed and the patient has been disease‐free for over seven years, a complete regression of her autoimmune bullous dermatosis could not be induced. By using intravenous immunoglobulins in combination with mycophenolate mofetil, further blister formation could be ameliorated.  相似文献   
24.
A lump on the midface of a child can pose as a diagnostic dilemma. There is a wide variety of possible differential diagnoses, ranging from simple benign conditions such as a sebaceous cyst, dermoid cyst, lipoma, neuroma and neurofibroma, to potentially devastating conditions such as odontogenic myxoma.A case of a child in which the formulation of a definite diagnosis was clinically and histologically challenging is presented.  相似文献   
25.
26.
27.
Ambulatory blood pressure monitoring was applied in 27 pediatric patients aged 6.3 – 24.3 (median 15.0) years who had been transplanted 1.5 – 8.4 years previously. Daytime values were compared with the mean of 10 concomitant casual blood pressure recordings. At the time of the study, antihypertensive drugs were given to 17 patients. Inulin clearance ranged from 18 to 116 (median 66) ml/min per 1.73 m2. Ambulatory blood pressure monitoring confirmed hypertension or normotension determined by casual blood pressure measurements in 63% of patients. The physiological nocturnal dip in blood pressure was attenuated or reversed in 8 of 27 patients. It was reduced in all 3 patients with renal artery stenosis of the graft, in 3 of 4 patients with chronic rejection, in the only patient with recurrent focal segmental glomerulosclerosis, and in 1 of 6 patients with past acute rejection. The dipping was not related to inulin clearance. In conclusion, casual blood pressure measurements do not accurately reflect blood pressure in pediatric patients transplanted more than 1.5 years previously. A reduced nocturnal dip in blood pressure may indicate an underlying renovascular or renoparenchymal pathology. Ambulatory blood pressure monitoring should regularly be applied in patients with renal transplants. Received May 23, 1995; received in revised form June 18, 1996; accepted June 20, 1996  相似文献   
28.
29.
30.
Modern stroke care is now comparable to the care for cardiac ischemia. Although there are 100 stroke units in Germany, only a few patients can be treated with all the options available with evidence-based medicine. The stroke network in Essen is based on a concept, which optimizes all elements of stroke care, from the acute onset to rehabilitation. The Essen manual on stroke summarizes all results of the local round table talks. Logistics for acute situations, recommendations for prehospital care, and requirements at admission are explained in detail. With networks for stroke, patient care can be optimized and costs can be saved.  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