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   1460篇
  免费   195篇
  国内免费   13篇
耳鼻咽喉   5篇
儿科学   38篇
妇产科学   6篇
基础医学   158篇
口腔科学   45篇
临床医学   219篇
内科学   340篇
皮肤病学   14篇
神经病学   82篇
特种医学   201篇
外科学   93篇
综合类   50篇
预防医学   111篇
眼科学   12篇
药学   117篇
  1篇
肿瘤学   176篇
  2021年   19篇
  2020年   9篇
  2019年   18篇
  2018年   20篇
  2017年   15篇
  2016年   23篇
  2015年   24篇
  2014年   27篇
  2013年   53篇
  2012年   66篇
  2011年   63篇
  2010年   42篇
  2009年   40篇
  2008年   30篇
  2007年   62篇
  2006年   52篇
  2005年   56篇
  2004年   45篇
  2003年   49篇
  2002年   52篇
  2001年   43篇
  2000年   44篇
  1999年   38篇
  1998年   31篇
  1997年   35篇
  1996年   25篇
  1995年   41篇
  1994年   25篇
  1993年   42篇
  1992年   29篇
  1991年   27篇
  1990年   33篇
  1989年   42篇
  1988年   44篇
  1987年   50篇
  1986年   42篇
  1985年   36篇
  1984年   20篇
  1983年   28篇
  1982年   19篇
  1981年   17篇
  1980年   20篇
  1979年   10篇
  1978年   21篇
  1977年   10篇
  1976年   9篇
  1975年   18篇
  1974年   11篇
  1973年   9篇
  1971年   9篇
排序方式: 共有1668条查询结果,搜索用时 62 毫秒
1.
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma.  相似文献   
2.
3.
We conducted a study to evaluate the absorption of endotracheally administered diazepam and the pulmonary pathologic changes induced by its administration. Six cats received diazepam and five cats received saline endotracheally. Serial blood gases and serum diazepam levels were drawn at intervals for 90 minutes after the administration of diazepam. The cats were sacrificed after two days and their lungs were examined by a pathologist. Mean diazepam levels reached a peak two minutes after the administration of diazepam and remained elevated above therapeutic levels for 90 minutes. There was no significant change in pH, PO2, or PCO2 for either group. Histologic examination of the lungs showed a significantly increased incidence of pneumonitis in the diazepam group as compared to the saline group. This study demonstrates that although diazepam is well absorbed when administered endotracheally, it has adverse effects on the lungs that may preclude endotracheal use in the currently available commercial form.  相似文献   
4.
5.
Traditionally, neuropsychological deficits due to Sickle Cell Disease (SCD) have been understudied in adults. We have begun to suspect, however, that symptomatic and asymptomatic Cerebrovascular Events (CVE) may account for an alarming number of deficits in this population. In the current brief review, we critically evaluated the pediatric and adult literatures on the neurocognitive effects of SCD. We highlighted the studies that have been published on this topic and posit that early detection of CVE via neurocognitive testing, neuropsychiatric evaluations, and neuroimaging may significantly reduce adult cognitive and functional morbidities.  相似文献   
6.
7.
Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.  相似文献   
9.
10.
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