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   1055篇
  免费   72篇
  国内免费   5篇
儿科学   27篇
妇产科学   59篇
基础医学   116篇
口腔科学   4篇
临床医学   52篇
内科学   168篇
皮肤病学   16篇
神经病学   371篇
特种医学   9篇
外科学   107篇
综合类   1篇
预防医学   91篇
眼科学   3篇
药学   45篇
肿瘤学   63篇
  2024年   7篇
  2023年   14篇
  2022年   24篇
  2021年   55篇
  2020年   27篇
  2019年   44篇
  2018年   29篇
  2017年   29篇
  2016年   40篇
  2015年   48篇
  2014年   57篇
  2013年   61篇
  2012年   101篇
  2011年   94篇
  2010年   45篇
  2009年   43篇
  2008年   48篇
  2007年   65篇
  2006年   42篇
  2005年   32篇
  2004年   24篇
  2003年   35篇
  2002年   27篇
  2001年   15篇
  2000年   15篇
  1999年   18篇
  1998年   6篇
  1997年   6篇
  1996年   9篇
  1995年   5篇
  1994年   2篇
  1993年   4篇
  1992年   12篇
  1991年   8篇
  1990年   4篇
  1989年   4篇
  1988年   2篇
  1987年   3篇
  1985年   2篇
  1979年   3篇
  1977年   3篇
  1976年   2篇
  1975年   3篇
  1974年   2篇
  1966年   1篇
  1965年   2篇
  1964年   1篇
  1961年   1篇
  1958年   1篇
  1954年   1篇
排序方式: 共有1132条查询结果,搜索用时 15 毫秒
31.
Although it is assumed that hemodynamic responders to pharmacological therapy after a variceal hemorrhage are adequately protected from rebleeding, there is no evidence that either this response or its protective effect extend beyond the usual 2-year follow-up featured in available studies. We aimed to assess the maintenance of hemodynamic response and its impact on outcomes in a large cohort of hemodynamic responders during a long follow-up. One hundred three patients with cirrhosis admitted with acute variceal bleeding between 2001 and 2010 were prospectively evaluated. The hepatic venous pressure gradient (HVPG) was determined 5 days after the bleeding and repeated 5-7 days after maximal tolerated doses of nadolol and nitrates. Hemodynamic responders (HVPG ≤ 12 mm Hg or ≥ 20% decrease from baseline) were maintained on drugs and followed up with annual HVPG measurements. Forty-eight patients (47%) were hemodynamic responders. The median follow-up was 48 months (range, 2-108 months). Long-term HVPG evaluations could not be performed in eight patients (four deaths, two rebleedings, two follow-ups <1 year). Among the remaining 40 patients, hemodynamic response was maintained in 26 (65%) and lost in 14 (35%). There were no baseline differences between the two subgroups. However, 100% of alcoholic patients who remained abstinent maintained long-term response, compared with 36% of nonabstinent alcoholics and 50% of patients with viral cirrhosis. Patients with loss of hemodynamic response rebled more during follow-up and showed a higher incidence of death or liver transplantation. Conclusions: After variceal bleeding, long-term maintenance of hemodynamic response to drug therapy is mainly restricted to patients with alcoholic cirrhosis who remain abstinent. The loss of this long-term response carries worse clinical outcomes.  相似文献   
32.
Free-living raptors (birds of prey) can act as reservoirs of potentially zoonotic agents, but they also can be affected by microorganisms as target hosts. In this retrospective study, microbiological results (n?=?663) and antibiotic sensitivity profiles (n?=?108) of bacterial isolates were analysed from diseased free-living raptors. Sixty-nine percent of cases (n?=?457) yielded bacteria: 58% were in pure culture and 42% were of different species. Remarkably, samples from necropsies (47%) had higher percentage of pure isolations than those obtained from clinical (31%) samples (P?Escherichia coli was the most common agent (35%), principally recovered from necropsied birds with clinical signs of septicaemia or respiratory disorders. Pseudomonas aeruginosa (7%) was isolated from birds with systemic infection and from oral lesions, especially in nocturnal raptors (P?Staphylococcus spp. (5%), mainly Staphylococcus aureus, was found to be the most prevalent cause of pododermatitis (35%) and Staphylococcus hyicus was isolated from conjunctivitis (18.2%). Interestingly, 8% of samples with lesions compatible with avian tuberculosis were positive to the Mycobacterium avium complex. The most frequent fungi associated with pneumonic lesions and ingluvitis were Aspergillus spp. and Candida spp., respectively. More than 50% of the 108 isolates (34 different bacterial spp.) demonstrated resistance to clindamycin, ampicillin, tetracycline, cefuroxime, enrofloxacin and trimethoprim/sulphamethoxazole. Among the E. coli strains, 71% (27/38) presented a multidrug-resistance pattern to >3 antimicrobials. Detection in wildlife of antimicrobial-resistant pathogens that might be significant at the animal–human–ecosystem interface is of great relevance under the ‘One Health’ approach.  相似文献   
33.
34.
35.
36.
IntroductionPulmonary nocardiosis (PN) is a severe infection with a high morbidity and mortality that mainly affects immunocompromised patients. In recent years, an increase in PN cases has been detected among patients with chronic obstructive pulmonary disease (COPD). The factors that are associated with its presence and determine its prognosis remain unknown.MethodsRetrospective study of COPD patients diagnosed with PN over the period from 1997 to 2009 at the Hospital de la Santa Creu i Sant Pau, in Barcelona (Spain). Demographic, clinical, microbiological and evolution data were evaluated in all cases.ResultsThirty patients were identified with PN and COPD. Mean age (standard deviation) was 76 (7) years and the mean FEV1 was 40 (14)%. Chronic respiratory failure was observed in 56.7% patients and 51.7% had received systemic corticosteroid therapy previous to the PN diagnosis. The most common symptoms were cough and dyspnea (90%). Alveolar infiltrates were observed in 60% of the cases. The most frequently isolated Nocardia species was N. cyriacigeorgica (68%). The one-month mortality rate was 17%, while the one-year mortality rate was 33%. The factors associated with mortality within the first year included previous systemic corticosteroid treatment, less than three months of specific antibiotic therapy and active associated neoplasm.ConclusionsPN affects patients with moderate-severe COPD and has high short- and mid-term mortality rates. Previous corticosteroid treatment, specific antibiotic therapy for less than 3 months and active neoplasia were factors associated with mortality.  相似文献   
37.
38.
Aortoesophageal fistula induced by atherosclerotic thoracic aortic aneurysm is rare, but is usually a fatal disorder, with few survivors reported. We report the case of a 72-year-old man with aortoesophageal fistula successfully treated in a two-stage operation. In the first stage, we performed resection and replacement of the aortic aneurysm with a prosthetic graft in situ, esophagectomy, cervical esophagostomy, and jejunostomy. After the patient recovered well postoperatively, a transmediastinal retrosternal interposition of the stomach was performed, with esophagogastroanastomosis in the cervical area, to re-establish the gastrointestinal tract. We include a discussion of the causes, diagnostic approach, management of the aorta and esophagus, and review of the literature.  相似文献   
39.
40.
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