全文获取类型
收费全文 | 4036篇 |
免费 | 279篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 67篇 |
妇产科学 | 48篇 |
基础医学 | 498篇 |
口腔科学 | 52篇 |
临床医学 | 477篇 |
内科学 | 867篇 |
皮肤病学 | 30篇 |
神经病学 | 274篇 |
特种医学 | 155篇 |
外科学 | 737篇 |
综合类 | 47篇 |
一般理论 | 3篇 |
预防医学 | 307篇 |
眼科学 | 93篇 |
药学 | 313篇 |
中国医学 | 1篇 |
肿瘤学 | 337篇 |
出版年
2024年 | 4篇 |
2023年 | 49篇 |
2022年 | 62篇 |
2021年 | 170篇 |
2020年 | 64篇 |
2019年 | 141篇 |
2018年 | 155篇 |
2017年 | 104篇 |
2016年 | 105篇 |
2015年 | 120篇 |
2014年 | 203篇 |
2013年 | 229篇 |
2012年 | 359篇 |
2011年 | 380篇 |
2010年 | 222篇 |
2009年 | 157篇 |
2008年 | 263篇 |
2007年 | 284篇 |
2006年 | 237篇 |
2005年 | 241篇 |
2004年 | 209篇 |
2003年 | 207篇 |
2002年 | 181篇 |
2001年 | 25篇 |
2000年 | 20篇 |
1999年 | 15篇 |
1998年 | 29篇 |
1997年 | 18篇 |
1996年 | 12篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有4325条查询结果,搜索用时 203 毫秒
991.
992.
Rizzo JD Brouwers M Hurley P Seidenfeld J Arcasoy MO Spivak JL Bennett CL Bohlius J Evanchuk D Goode MJ Jakubowski AA Regan DH Somerfield MR;American Society of Hematology the American Society of Clinical Oncology Practice Guideline Update Committee 《Blood》2010,116(20):4045-4059
Purpose: To update American Society of Hematology/American Society of Clinical Oncology recommendations for use of erythropoiesis-stimulating agents (ESAs) in patients with cancer. Methods: An Update Committee reviewed data published between January 2007 and January 2010. MEDLINE and the Cochrane Library were searched. Results: The literature search yielded one new individual patient data analysis and four literature-based meta-analyses, two systematic reviews, and 13 publications reporting new results from randomized controlled trials not included in prior or new reviews. Recommendations: For patients undergoing myelosuppressive chemotherapy who have a hemoglobin (Hb) level less than 10 g/dL, the Update Committee recommends that clinicians discuss potential harms (eg, thromboembolism, shorter survival) and benefits (eg, decreased transfusions) of ESAs and compare these with potential harms (eg, serious infections, immune-mediated adverse reactions) and benefits (eg, rapid Hb improvement) of RBC transfusions. Individual preferences for assumed risk should contribute to shared decisions on managing chemotherapy-induced anemia. The Committee cautions against ESA use under other circumstances. If used, ESAs should be administered at the lowest dose possible and should increase Hb to the lowest concentration possible to avoid transfusions. Available evidence does not identify Hb levels ≥ 10 g/dL either as thresholds for initiating treatment or as targets for ESA therapy. Starting doses and dose modifications after response or nonresponse should follow US Food and Drug Administration-approved labeling. ESAs should be discontinued after 6 to 8 weeks in nonresponders. ESAs should be avoided in patients with cancer not receiving concurrent chemotherapy, except for those with lower risk myelodysplastic syndromes. Caution should be exercised when using ESAs with chemotherapeutic agents in diseases associated with increased risk of thromboembolic complications. Table 1 lists detailed recommendations. 相似文献
993.
994.
995.
Neal S. Gerstein MD Darren A. Braude MD Orlando Hung MD John C. Sanders MBBS Michael F. Murphy MD 《Journal canadien d'anesthésie》2010,57(6):588-601
Purpose
To provide an evidence-based overview and update on the use of the FastrachTM Intubating Laryngeal Mask Airway® (FT-LMA) when used within operative and non-operative settings.Principal findings
The FT-LMA is available in three sizes to provide ventilation and the ability to pass an endotracheal tube (ETT) into the trachea blindly, semi-blindly, or with indirect visualization for patients over 30 kg. The Chandy maneuver is recommended routinely; the first maneuver optimizes ventilation, and the second maneuver increases success at endotracheal intubation (ETI). The manufacturer’s reinforced tube or a pre-warmed or reversed standard ETT may be utilized. Insertion and ventilation are successful in almost all patients. Blind ETI is highly successful; adjuncts are generally not necessary. The FT-LMA has a proven role in the airway management of anticipated difficult operating room (OR) intubations, unanticipated OR intubations, cervical spine injuries, and limited airway access situations. Literature in the pre-hospital and emergency department settings is limited but favourable. The FT-LMA has compared favourably with fibreoptic intubation, the LMA-Classic?, the laryngeal tube, and the CobraPLA?. Initially, the more expensive LMA CTrach? appeared to be more successful, but overall it is not. The FT-LMA airway seal pressures are excellent; serious complications are uncommon, and the FT-LMA figures prominently in most difficult airway guidelines.Conclusions
The FT-LMA has proven to be a useful difficult airway device both within and outside of the operating room. Effective ventilation is established in nearly all cases, and blind ETI is possible in the vast majority of cases if the optimal techniques described are used. Serious complications are uncommon. 相似文献996.
Darren H. Freed MD PhD Dietrich Henzler MD Chris W. White MD Robert Fowler MD Ryan Zarychanski MD Jamie Hutchison MD Rakesh C. Arora MD PhD Rizwan A. Manji MD PhD Jean-Francois Legare MD Tanya Drews MD Stasa Veroukis MD Murray Kesselman MD Anne-Marie Guerguerian MD Anand Kumar MD 《Journal canadien d'anesthésie》2010,57(3):240-247
Background
From March to July 2009, influenza A (H1N1) 2009 (H1N1-2009) virus emerged as a major cause of respiratory failure that required mechanical ventilation. A small proportion of patients who had this condition developed severe respiratory failure that was unresponsive to conventional therapeutic interventions. In this report, we describe characteristics, treatment, and outcomes of critically ill patients in Canada who had H1N1-2009 infection and were treated with extracorporeal lung support (ECLS).Methods
We report the findings of a case series of six patients supported with ECLS who were included in a cohort study of critically ill patients with confirmed H1N1-2009 infection. The patients were treated in Canadian adult and pediatric intensive care units (ICUs) from April 16, 2009 to August 12, 2009. We describe the nested sample treated with ECLS and compare it with the larger sample.Results
During the study period, 168 patients in Canada were admitted to ICUs for severe respiratory failure due to confirmed H1N1-2009 infection. Due to profound hypoxemia unresponsive to conventional therapeutic interventions, six (3.6%) of these patients were treated with ECLS in four ICUs. Four patients were treated with veno-venous pump-driven extracorporeal membrane oxygenation (vv-ECMO), and two patients were treated with pumpless lung assist (NovaLung iLA). The mean duration of support was 15 days. Four of the six patients survived (66.6%), one of the surviving patients was supported with iLA and the other three surviving patients were supported with ECMO. The two deaths were due to multiorgan failure, which occurred while the patients were on ECLS.Interpretation
Extracorporeal lung support may be an effective treatment for patients who have H1N1-2009 infection and refractory hypoxemia. Survival of these patients treated with ECLS is similar to that reported for patients who have acute respiratory distress syndrome of other etiologies and are treated with ECMO. 相似文献997.
998.
Eugene Y. Kissin Mei Yang Peter V. Balint George A. W. Bruyn Jurgen Craig‐Muller Maria A. D'Agostino Alexander Feoktistov Annamaria Iagnocco Robert W. Ike Ingrid Moller Esperanza Naredo Carlos Pineda Wolfgang A. Schmidt Nanno Swen Darren Tabechian Richard J. Wakefield Gurjit S. Kaeley 《Arthritis care & research》2010,62(2):155-160
Objective
Because musculoskeletal ultrasound (MSUS) is highly user dependent, we aimed to establish whether non‐mentored learning of MSUS is sufficient to achieve the same level of diagnostic accuracy and scanning reliability as has been achieved by rheumatologists recognized as international experts in MSUS.Methods
A group of 8 rheumatologists with more experience in MSUS and 8 rheumatologists with less experience in MSUS participated in an MSUS exercise to assess patients with musculoskeletal abnormalities commonly seen in a rheumatology practice. Patients' established diagnoses were obtained from chart review (gout, osteoarthritis, rotator cuff syndrome, rheumatoid arthritis, and seronegative arthritis). Two examining groups were formed, each composed of 4 less experienced and 4 more experienced examiners. Each group scanned 1 predefined body region (hand, wrist, elbow, shoulder, knee, or ankle) in each of 8 patients, blinded to medical history and physical examination. Structural abnormalities were noted with dichotomous answers, and an open‐ended answer was used for the final diagnosis.Results
Less experienced and more experienced examiners achieved the same diagnostic accuracy (US‐established diagnosis versus chart review diagnosis). The interrater reliability for tissue pathology was slightly higher for more experienced versus less experienced examiners (κ = 0.43 versus κ = 0.34; P = 0.001).Conclusion
Non‐mentored training in MSUS can lead to the achievement of diagnostic accuracy in MSUS comparable to that achieved by highly experienced international experts. Reliability may increase slightly with additional experience. Further study is needed to determine the minimal training requirement to achieve proficiency in MSUS. 相似文献999.
Darren R. Hocking Joanne Fielding Louise A. Corben Phillip D. Cremer Lynette Millist Owen B. White Martin B. Delatycki 《Cerebellum (London, England)》2010,9(3):411-418
Friedreich ataxia (FRDA) is the most common genetic cause of ataxia with a prevalence of approximately 1 in 29,000. Ocular
motor abnormalities are common in FRDA and include fixation instability, saccadic dysmetria, and vestibular dysfunction. It
has not yet been determined whether aspects of spatial attention, which are closely coupled to eye movements, are similarly
compromised in FRDA. This study examined attentional engagement and disengagement of eye movements in FRDA using a gap overlap
task. Thirteen individuals with genetically confirmed FRDA and 12 age-matched unaffected controls participated in the experiment.
The gap overlap paradigm was used to examine the effect of early (gap condition), simultaneous (null condition), or late (overlap
condition) removal of a central fixation on saccadic latency to a peripheral target stimulus. Although the FRDA group showed
a larger gap effect (i.e., difference in saccadic latencies between the overlap and gap condition), these participants demonstrated
a greater difference in latencies in the overlap relative to the null condition, suggestive of deficits within the disengagement
process of attentional orienting. We propose a role for the cerebellum in these deficits in the disengagement of spatial attention
based on evidence of cerebellar connectivity with regions involved in exogenous shifts of attention. The significant correlations
between saccadic latency and disease severity as measured by the Friedreich Ataxia Rating Scale further support the proposal
that saccadic latency might be useful as a surrogate marker of disease severity and progression in future clinical trials
in FRDA. 相似文献
1000.
Eugene K. Wai Darren M. Roffey Paul Bishop Brian K. Kwon Simon Dagenais 《The spine journal》2010,10(6):554-566
Background ContextLow back pain (LBP) is a disorder that commonly affects the working population, resulting in disability, health-care utilization, and a heavy socioeconomic burden. Although the etiology of LBP remains uncertain, occupational activities have been implicated. Evaluating these potentially causal relationships requires a methodologically rigorous approach. Occupational repetitive and/or heavy lifting is widely thought to be a risk factor for the development of LBP.PurposeTo conduct a systematic review of the scientific literature to evaluate the causal relationship between occupational lifting and LBP.Study DesignSystematic review of the literature.SampleStudies reporting an association between occupational lifting and LBP.Outcome MeasuresNumerical association between different levels of exposure to occupational lifting and the presence or severity of LBP.MethodsA search was conducted using Medline, EMBASE, CINAHL, Cochrane Library, OSH-ROM, gray literature (eg, reports not published in scientific journals), hand-searching occupational health journals, reference lists of included studies, and content experts. Evaluation of study quality was performed using a modified version of the Newcastle-Ottawa Scale. Levels of evidence were evaluated for specific Bradford-Hill criteria (association, dose-response, temporality, experiment, and biological plausibility).ResultsThis search yielded 2,766 citations, of which 35 studies met eligibility criteria and 9 were considered high methodological quality studies, including four case-controls and five prospective cohorts. Among the high-quality studies, there was conflicting evidence for association with four studies reporting significant associations and five studies reporting nonsignificant results. Two of the three studies that assessed dose-response demonstrated a nonsignificant trend. There were no significant risk estimates that demonstrated temporality. No studies were identified that satisfied the experiment criterion. Subgroup analyses identified certain types of lifting and LBP that had statistically significant results, but there were none that satisfied more than two of the Bradford-Hill criteria.ConclusionsThis review uncovered several high-quality studies examining a relationship between occupational lifting and LBP, but these studies did not consistently support any of the Bradford-Hill criteria for causality. There was moderate evidence of an association for specific types of lifting and LBP. Based on these results, it is unlikely that occupational lifting is independently causative of LBP in the populations of workers studied. Further research in specific subcategories of lifting would further clarify the presence or absence of a causal relationship. 相似文献