全文获取类型
收费全文 | 7077篇 |
免费 | 489篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 81篇 |
儿科学 | 200篇 |
妇产科学 | 258篇 |
基础医学 | 892篇 |
口腔科学 | 112篇 |
临床医学 | 888篇 |
内科学 | 1259篇 |
皮肤病学 | 133篇 |
神经病学 | 581篇 |
特种医学 | 190篇 |
外国民族医学 | 1篇 |
外科学 | 1123篇 |
综合类 | 102篇 |
一般理论 | 3篇 |
预防医学 | 709篇 |
眼科学 | 131篇 |
药学 | 391篇 |
中国医学 | 6篇 |
肿瘤学 | 517篇 |
出版年
2023年 | 60篇 |
2022年 | 93篇 |
2021年 | 191篇 |
2020年 | 126篇 |
2019年 | 193篇 |
2018年 | 214篇 |
2017年 | 136篇 |
2016年 | 172篇 |
2015年 | 160篇 |
2014年 | 263篇 |
2013年 | 339篇 |
2012年 | 490篇 |
2011年 | 478篇 |
2010年 | 261篇 |
2009年 | 227篇 |
2008年 | 389篇 |
2007年 | 366篇 |
2006年 | 356篇 |
2005年 | 343篇 |
2004年 | 284篇 |
2003年 | 286篇 |
2002年 | 290篇 |
2001年 | 129篇 |
2000年 | 145篇 |
1999年 | 114篇 |
1998年 | 51篇 |
1997年 | 40篇 |
1996年 | 29篇 |
1995年 | 47篇 |
1994年 | 25篇 |
1993年 | 31篇 |
1992年 | 82篇 |
1991年 | 87篇 |
1990年 | 77篇 |
1989年 | 83篇 |
1988年 | 70篇 |
1987年 | 79篇 |
1986年 | 72篇 |
1985年 | 70篇 |
1984年 | 52篇 |
1983年 | 68篇 |
1982年 | 43篇 |
1981年 | 41篇 |
1980年 | 37篇 |
1979年 | 52篇 |
1978年 | 30篇 |
1974年 | 41篇 |
1973年 | 25篇 |
1972年 | 32篇 |
1969年 | 27篇 |
排序方式: 共有7577条查询结果,搜索用时 15 毫秒
31.
Summary A strain of avian influenza A virus, originally isolated from an epidemic among turkeys, was adapted to human cells by serial passages. Four passage levels of the virus were compared with respect to their growth potential in human cell monolayers and their plaque morphology in chick embryo fibroblasts and in HeLa cells. The original virus, never passed in human cells before, was already able to replicate in human cells. Serial passages in human epithelial cells increased this ability. Further serial passages in human myeloblasts resulted in the selection of an apparently stable mutant which grew well in human malignant epithelial cells and even better in diploid human fibroblasts. 相似文献
32.
R. Hubert Laeng Heinz A. Gerber Thomas Schaffner Kurt H. Bürki 《Virchows Archiv : an international journal of pathology》1989,415(3):265-273
Summary The present report describes the results of a combined morphological, enzyme- and immunohistochemical analysis of nine cases of malignant non Hodgkin's lymphomas (NHL) clinically presenting as lethal midline granuloma. In a previous report written before antibodies directed against B and T lymphocytes were available, a histiocytic origin of such neoplasms had been suggested. A panel of antibodies reactive with most B cells (L26, MB1, KiB3) and a majority of T cells (MT1, UCHL1) was applied on paraffin sections of formalin fixed tissues as well as antibodies directed against leukocyte common antigen (LCA), myeloid/histiocyte antigen (MAC 387), lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, S-100 protein, prekeratin and immunoglobulin light chains. Enzyme histochemistry included tests for non-specific acid esterase, acid phosphatase, betaglucuronidase and chloroacetate esterase. As a result, five T, two B and two unclassified (malignant histiocytosis probable) NHL were identified, indicating distinct heterogeneity of NHL as causative disorders in lethal midline granuloma. 相似文献
33.
Gerber PC 《Physician's management》1985,25(1):283-5, 289-91
34.
In the present paper, two experimental models of heart failure, namely hereditary cardiomyopathy in hamsters (BIO 14.6) and cardiac insufficiency due to mild (0.06 microM) isoprenaline overload of rabbit isolated perfused hearts, were compared in terms of resulting alterations at the level of the functionally isolated contractile system of detergent/glycerol treated skinned cardiac fibres. As the main features of Ca activation of tension in these models, the following were found: 1. Within the same species (RB hamsters, BIO 14.6 hamsters or rabbits), the Ca sensitivity, measured as pCa for half maximal Ca activation, was invariably higher in left than in right ventricular skinned fibres. 2. During the development of hereditary cardiomyopathy (BIO 14.6), maximum Ca-activated tension, measured per unit cross-sectional area, was reduced in an age-dependent manner, without any significant reduction in Ca sensitivity. This effect appeared to be more pronounced in left than in right ventricles. 3. In skinned fibres from right or left ventricular papillary muscles from in vitro isoprenaline pretreated rabbit hearts, no significant alteration in the maximum Ca-activated tension (per unit area) was observed in comparison to non-pretreated control hearts, whereas the Ca sensitivity was reduced. Treatment of control or failing heart skinned fibres with cAMP showed no additivity to the Ca desensitization induced by isoprenaline pretreatment. 4. Skinned fibres from isoprenaline pretreated left ventricular rabbit hearts showed a higher susceptibility to the Ca sensitizing effect of APP 201-533 than fibres from unpretreated control hearts. Mild isoprenaline overload and hereditary cardiomyopathy both are forms of heart failure which are presumably not associated with a lack of activator Ca. It is concluded that cardiotonic agents increasing the cardiac myofibrillar sensitivity to Ca ions would be beneficial in both cases, representing a phenomenologically causative treatment in hearts failing due to isoprenaline pretreatment. A main advantage over "classical" cardiotonic agents like cardiac glycosides, beta adrenergic stimulants or phosphodiesterase inhibitors would be the absence of the risk of drug-induced Ca overload. 相似文献
35.
In 60 adult patients undergoing general surgical procedures, the effect of pancuronium or d-tubocurarine "pretreatment" on the injection of a 0.1 mg X kg-1 bolus of atracurium was measured in two separate studies. In study 1, the patients received either 0.5 mg (approximately 0.007 mg X kg-1) or 1.0 mg (approximately 0.015 mg X kg-1) pancuronium, or placebo (saline) three minutes before the injection of atracurium 0.1 mg X kg-1. In study 2, the patients received 0.05 mg X kg-1 or 0.1 mg X kg-1 d-tubocurarine, or a placebo. The degree of neuromuscular blockade was assessed by evoked mechanogram (adductor pollicis muscle) using supramaximal train-of-four stimulation. Patients receiving pancuronium or d-tubocurarine pretreatment (equal to an ED5-ED15 dose) showed significantly greater inhibition of twitch (ED70-ED80) and train-of-four ratio compared with the placebo groups (ED35-ED40). Pretreatment with the larger dose of d-tubocurarine (0.1 mg X kg-1) was associated with significant neuromuscular blockade. It is concluded that pancuronium and d-tubocurarine pretreatments potentiate the clinical action of 0.1 mg X kg-1 atracurium in man by 35-100 per cent. 相似文献
36.
Harris Brett R. Maher Brianna M. Wentworth Leah 《The journal of behavioral health services & research》2022,49(2):252-258
The Journal of Behavioral Health Services & Research - Mental health has long been a challenge on college and university campuses. Though it has historically taken a back seat to physical... 相似文献
37.
Leah R. Ketcheson Erin E. Centeio Erin E. Snapp Hayley B. McKown Jeffrey J. Martin 《Disability and health journal》2021,14(1):100952
BackgroundChildren with intellectual and developmental disabilities (IDD) often experience increased barriers to engaging in physical activity (PA) which can stem from lack of gross motor function (GMF) development. Intervening on GMF at an early age can create better opportunities for children with IDD to engage in regular PA. In turn, increased PA can improve health outcomes and increase social skills.ObjectiveThe primary objective of this pilot study was to explore the effectiveness of a community-based GMF-focused PA intervention for improving overall motor skills and PA for children with IDD.MethodsAll study participants (n = 24) engaged in 10 weeks of programming for 1 h each week. A convenience sample was utilized.ResultsResults indicated no statistically significant changes pre to post for motor skill scores. However, a visual analysis of mean changes showed a consistent pattern of increased scores from pre to post on most skills. Additionally, we found that a change in participant locomotor skills significantly predicted change in Moderate to Vigorous Physical Activity (MVPA), F (1,11) = 5.16, Adj R2 = .26, p = .04.ConclusionsThese results suggest individualized attention on GMF may help to increase motor skills for children with IDD. This study adds to the small but growing amount of research examining the efficacy of community based adapted PA interventions. Further, study results should support continued exploration of effective approaches to address the motor delays experienced by children with IDD. 相似文献
38.
Michaela Gaffley Lucas P. Neff Leah M. Sieren Kristen A. Zeller Thomas Pranikoff Tammy Rush John K. Petty 《Journal of pediatric surgery》2021,56(2):297-301
PurposeAbout half of pediatric blunt trauma patients undergo an abdominopelvic computed tomographic (CT) scan, while few of these require intervention for an intraabdominal injury. We evaluated the effectiveness of an evidence-based guideline for blunt abdominal trauma at a Level I pediatric trauma center.MethodsPediatric blunt trauma patients (n = 998) age 0–15 years who presented from the injury scene were evaluated over a 10 year period. After five years, we implemented our guideline in which the decision for CT was standardized based on mental status, abdominal examination, and laboratory results (alanine aminotransferase, aspartate aminotransferase, hemoglobin, urinalysis).ResultsThere were no differences in age, GCS, SIPA or ISS scores between the patients before or after guideline implementation. Nearly half of the patients (48.3%) underwent CT scan before guideline implementation compared to 36.7% after (p < 0.0002). There was no difference in ISS (p = 0.44) between CT scanned patients in either group. No statistical differences were found in rate of intervention (p = 0.20), length of stay (p = 0.65), or readmission rate (0.2%) before versus after guideline implementation. There were no missed injuries.ConclusionImplementation of an evidence-based clinical guideline for pediatric patients with blunt abdominal trauma decreases the rate of CT utilization while accurately identifying significant injuries.Level of evidenceIII. 相似文献
39.
Maggie E. Bosley Michaela W. G. Gaffley Kristen A. Zeller Leah M. Sieren John K. Petty Thomas Pranikoff Lucas P. Neff 《Journal of pediatric surgery》2021,56(4):825-828
The management of choledocholithiasis in children and teenagers is often a two-procedure process with laparoscopic cholecystectomy (LC) and either pre- or post-operative endoscopic retrograde cholangiopancreatography (ERCP). The addition of laparoscopic common bile duct exploration (LCBDE) during LC can provide definitive treatment for choledocholithiasis during a single anesthetic event. In an effort to minimize sedation and radiation exposure from fluoroscopy, we have employed dilating balloons via a transcystic approach to stretch the sphincter of Oddi with subsequent ductal flushing. We describe the technique of balloon sphincteroplasty as a straightforward adjunct within the pediatric surgeon's skill set to manage choledocholithiasis during LC and our clinical experience. 相似文献
40.
Dane Christina Daoud MD Elena M. S. Cartagena MD MSc Katherine J. P. Schwenger RD PhD Nicha Somlaw MD Leah Gramlich MD Scott Whittaker MD David Armstrong MD Brian Jurewitsch PharmD Matreyi Raman MD Donald R. Duerksen MD James D. McHattie MD Johane P. Allard MD 《JPEN. Journal of parenteral and enteral nutrition》2022,46(2):348-356