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   790篇
  免费   39篇
  国内免费   5篇
耳鼻咽喉   3篇
儿科学   46篇
妇产科学   11篇
基础医学   94篇
口腔科学   30篇
临床医学   75篇
内科学   118篇
皮肤病学   17篇
神经病学   73篇
特种医学   18篇
外科学   55篇
综合类   9篇
一般理论   1篇
预防医学   101篇
眼科学   6篇
药学   139篇
中国医学   1篇
肿瘤学   37篇
  2022年   17篇
  2021年   21篇
  2020年   9篇
  2019年   16篇
  2018年   25篇
  2017年   14篇
  2016年   22篇
  2015年   13篇
  2014年   28篇
  2013年   31篇
  2012年   50篇
  2011年   53篇
  2010年   38篇
  2009年   28篇
  2008年   50篇
  2007年   42篇
  2006年   38篇
  2005年   42篇
  2004年   45篇
  2003年   30篇
  2002年   36篇
  2001年   14篇
  2000年   14篇
  1999年   12篇
  1998年   5篇
  1997年   3篇
  1995年   4篇
  1994年   3篇
  1993年   4篇
  1992年   8篇
  1991年   4篇
  1990年   4篇
  1989年   10篇
  1988年   6篇
  1987年   4篇
  1986年   6篇
  1985年   6篇
  1983年   5篇
  1982年   4篇
  1981年   6篇
  1980年   3篇
  1979年   11篇
  1978年   6篇
  1977年   5篇
  1976年   6篇
  1975年   4篇
  1974年   3篇
  1972年   3篇
  1970年   3篇
  1967年   3篇
排序方式: 共有834条查询结果,搜索用时 218 毫秒
91.
92.
Background: Hyperglycemia is common in the post-cardiac surgery population and has been associated with increased mortality rates, surgical length of stay, and infection rates. Although hospitalized patients with diabetes are known to have more complications, recent studies in various hospital settings have reported worse outcomes in patients with stress hyperglycemia than in those with diabetes. Aim: The primary objective of this study was to analyze 30- and 90-day mortality rates in post-cardiac surgery patients with stress hyperglycemia and diabetes who were managed to achieve similar moderate blood glucose goals using the University of Michigan Hospital (Ann Arbor, MI) insulin protocol between 2005 and 2008. The secondary outcomes were rates of postoperative complications, including hypoglycemia. Methods: A standardized glucose management program was followed to treat all patients in the cardiac intensive care unit, with a blood glucose goal of 100 to 140 mg/dL. Data from 1973 patients with either diabetes or stress hyperglycemia were analyzed to identify associations between mean postoperative blood glucose levels and mortality, incidence of hypoglycemia, and complication rates. Results: Mortality rates did not differ between patients with diabetes and stress hyperglycemia (3.4 and 2.3%; P = 0.2). Rates of severe hypoglycemia were low (1%) for both groups and were not associated with an increase in mortality (P = 0.95). Other complication rates were similar between patients with diabetes and stress hyperglycemia. Conclusion: Maintaining a blood glucose range between 100 to 140 mg/dL in post-cardiac surgery patients was associated with a low mortality rate, low risk of hypoglycemia, and with complications rates that were similar in patients with diabetes and stress hyperglycemia.  相似文献   
93.
Pain is a leading public health problem in the United States, with an annual economic burden of more than $630 billion, and is one of the most common reasons that individuals seek emergency department (ED) care. There is a paucity of data regarding sex differences in the assessment and treatment of acute and chronic pain conditions in the ED. The Academic Emergency Medicine consensus conference convened in Dallas, Texas, in May 2014 to develop a research agenda to address this issue among others related to sex differences in the ED. Prior to the conference, experts and stakeholders from emergency medicine and the pain research field reviewed the current literature and identified eight candidate priority areas. At the conference, these eight areas were reviewed and all eight were ratified using a nominal group technique to build consensus. These priority areas were: 1) gender differences in the pharmacological and nonpharmacological interventions for pain, including differences in opioid tolerance, side effects, or misuse; 2) gender differences in pain severity perceptions, clinically meaningful differences in acute pain, and pain treatment preferences; 3) gender differences in pain outcomes of ED patients across the life span; 4) gender differences in the relationship between acute pain and acute psychological responses; 5) the influence of physician–patient gender differences and characteristics on the assessment and treatment of pain; 6) gender differences in the influence of acute stress and chronic stress on acute pain responses; 7) gender differences in biological mechanisms and molecular pathways mediating acute pain in ED populations; and 8) gender differences in biological mechanisms and molecular pathways mediating chronic pain development after trauma, stress, or acute illness exposure. These areas represent priority areas for future scientific inquiry, and gaining understanding in these will be essential to improving our understanding of sex and gender differences in the assessment and treatment of pain conditions in emergency care settings.  相似文献   
94.
过敏性哮喘与骨髓反应   总被引:9,自引:1,他引:9  
过敏性哮喘是以嗜酸细胞在气道浸润为主的慢性炎症 ,激活的嗜酸细胞可分泌多种前炎性蛋白和脂质介质 ,在白三烯 (LTB4 )和血小板激活因子 (PAF)刺激下 ,它还可释放基质蛋白酶、嗜酸细胞阳离子蛋白、嗜酸细胞神经毒素等引起气道上皮破坏、平滑肌痉挛 ,粘液分泌增多[1 ] ,形成慢性气道炎症和气道高反应性 ,介导迟发性哮喘反应 (LAR) [2 ] ;在哮喘患者外周血和气道中嗜酸细胞及其祖细胞明显增多 ,最近发现 ,由于抗原刺激气道后引起炎性介质释放或气道中炎细胞趋化至骨髓 ,引起骨髓中炎细胞的祖细胞 (主要是嗜酸 /嗜碱细胞祖细胞 )扩增…  相似文献   
95.
POEMS (Crow-Fukase) syndrome is a rare plasma cell lymphoproliferative disorder associated with polyneuropathy (P), organomegaly (O), endocrinopathy (E), monoclonal (M) gammopathy and skin (S) abnormalities. The latter are usually not specific and include hyperpigmentation, hypertrichosis, cutaneous angioma and skin-thickening. A 45-year-old Italian woman was admitted to hospital because of muscle weakness, marked fatigue and paresthesia of the upper and lower extremities. Two and a half years earlier, a POEMS syndrome had been diagnosed on the basis of a history of organomegaly and mild lymphadenopathy, IgA-lambda monoclonal gammopathy, hypothyroidism, severe lower and upper limb sensory-motor peripheral neuropathy and a single osteosclerotic lesion in the left humerus. Eight weeks later, she developed skin lesions bioptically shown to be due to calciphylaxis-induced cutaneous vasculitis. To our knowledge, this is the first case of POEMS syndrome with this peculiar type of vasculitis. The absence of predisposing conditions, namely renal failure, hyperparathyroidism or clotting disorders renders the pathogenetic mechanism(s) of this severe type of vasculitis more intriguing.  相似文献   
96.
BACKGROUND: Myocardial contrast echocardiography and dobutamine echocardiographyhave recently emerged as potentially useful clinical tools todetect reversible myocardial dysfunction. However, the relativeaccuracy of these two techniques in predicting regional wallmotion improvement after coronary interventions is still unclear.The aim of the present study was to compare their diagnosticvalue in predicting functional recovery after coronary revascularizationin patients with recent acute myocardial infarction. METHODS AND RESULTS: Twenty-four patients with acute myocardial infarction underwentmyocardial contrast echocardiography and dobutamine echocardiographywithin 2 weeks of hospital admission. Infarct zone contrastscore and wall motion score indexes were derived in each patient.Infarct-related artery revascularization was performed beforehospital discharge in all selected patients. Resting echocardiographywas repeated 3 months after revascularization, and regionalfunction recovery was analysed. The degree of wall motion scoreimprovement at 3-month follow-up and the percentage of positiveresponses to dobutamine echo were greater (P<0·001and P<0·002, respectively) in patients with a higherbaseline contrast score (0·50). Conversely, no significantchanges were observed either during dobutamine echo or afterrevascularization in the group of patients without residualperfusion within the infarct area. Diagnostic agreement betweenboth techniques in predicting reversible dysfunction was high(81% of segments). The sensitivity and negative predictive valuein predicting functional outcome were 100% (95% confidence interval[CI], 87% to 100%) and 100% (95% CI, 93% to 100%) by contrastecho, and 85% (95% CI, 66% to 96%) and 93% (95% CI, 84% to 98%)by dobutamine echo. The specificity and positive predictivevalue were 90% (95% CI, 80% to 96%) and 81% (95% CI, 64% to93%) by contrast echo, and 88% (95% CI, 78% to 95%) and 76%(95% CI, 58% to 90%) by dobutamine echo. The combination ofmyocardial contrast and dobutamine echocardiography positiveresponses improved specificity and positive predictive valuein detecting functional recovery after revascularization to100% (95% CI, 94% to 100%) and 100% (95% CI, 85% to 100%), respectively.However, the sensitivity and negative predictive value slightlydecreased with the use of both methods (85% [95% CI, 66% to96%)] and (93% [95% CI, 85% to 98%)], respectively. CONCLUSIONS: In patients with recent myocardial infarction, reversible dysfunctionafter coronary revascularization and the response to dobutamineinfusion are strictly dependent on microvascular integrity.However, microvascular perfusion does not always imply functionalrecovery after coronary revascularization. The integration withdob utamine echo results seems particularly helpful to furtherimprove myocardial contrast echo specificity and positive predictivevalues.  相似文献   
97.
98.
99.
Although the development of Attention Deficit Hyperactivity Disorder (ADHD) after traumatic brain injury (TBI) has been described, it is unknown whether children with TBI and ADHD have greater neuropsychological impairments than children with TBI alone. This study examines attention, executive functioning, and memory in children with TBI-only and TBI + ADHD. Caregivers of 82 children with severe TBI completed structured psychiatric interviews at enrollment to diagnose premorbid ADHD and one-year after injury to diagnose post-injury ADHD. Children underwent neuropsychological testing one year after injury. One memory measure significantly differentiated children with TBI-only from children with newly developed ADHD [secondary ADHD (S-ADHD)] and those with premorbid ADHD that persisted after injury [persisting ADHD (P-ADHD)]. Compared with the TBI-only group, children with TBI + ADHD had worse performance on measures of attention, executive functioning, and memory. Results reveal that in children with severe TBI, the behavioral diagnosis of ADHD is associated with more difficulty in attention, executive functioning, and memory. Additionally, results suggest greater deficits in memory skills in the S-ADHD group compared with the P-ADHD group. Although findings provide preliminary support for distinguishing P-ADHD from S-ADHD, further research is needed to investigate neuropsychological differences between these subgroups of children with severe TBI.  相似文献   
100.
BACKGROUND: The HER-2/neu oncogene encodes for a transmembrane glycoprotein with intracellular tyrosine kinase activity. The HER-2/neu receptor belongs to the family of epidermal growth factor receptors that are crucial in the activation of subcellular signal transduction pathways controlling epithelial cell growth and differentiation. Overexpression of HER-2/neu is observed in 20% to 40% of breast cancers and other solid tumors. Although information is limited, one study suggested that 15% of glioblastoma multiforme (GBM) express HER-2/neu by immunohistochemistry (IHC); gene amplification by fluorescence in situ hybridization (FISH) was not investigated. Studies in this area are potentially significant owing to the role of recombinant monoclonal anti-HER-2/neu antibody traztuzumab (Herceptin) in the treatment of tumors. DESIGN: A retrospective clinicopathologic review of 49 patients with GBM with HER-2/neu IHC staining and HER-2/neu gene amplification by FISH was performed. RESULTS: The study included 44 patients (17 women, 27 men; age range 20 to 79 y, mean 57.9 y). Initial surgery involved tumor debulking or subtotal resection in 34 patients. Thirty-six patients received adjuvant radiation therapy and 19 patients received adjuvant chemotherapy. At follow-up (range 1.0 to 49.5 mo, mean 10.5 mo), 40 patients died with tumor and 4 patients were lost to follow-up. All tumors were negative for HER-2/neu protein by IHC and for HER-2/neu gene amplification by FISH. CONCLUSIONS: No GBM demonstrates HER-2/neu protein by IHC or amplification of the HER-2/neu gene by FISH. The HER-2/neu oncogene does not seem to play a role in the pathogenesis of GBM.  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