全文获取类型
收费全文 | 2657篇 |
免费 | 159篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 51篇 |
妇产科学 | 48篇 |
基础医学 | 366篇 |
口腔科学 | 122篇 |
临床医学 | 446篇 |
内科学 | 366篇 |
皮肤病学 | 44篇 |
神经病学 | 193篇 |
特种医学 | 59篇 |
外科学 | 301篇 |
综合类 | 40篇 |
一般理论 | 9篇 |
预防医学 | 307篇 |
眼科学 | 45篇 |
药学 | 230篇 |
中国医学 | 6篇 |
肿瘤学 | 173篇 |
出版年
2023年 | 18篇 |
2022年 | 24篇 |
2021年 | 49篇 |
2020年 | 43篇 |
2019年 | 65篇 |
2018年 | 62篇 |
2017年 | 50篇 |
2016年 | 55篇 |
2015年 | 60篇 |
2014年 | 76篇 |
2013年 | 145篇 |
2012年 | 202篇 |
2011年 | 216篇 |
2010年 | 140篇 |
2009年 | 105篇 |
2008年 | 184篇 |
2007年 | 173篇 |
2006年 | 159篇 |
2005年 | 186篇 |
2004年 | 172篇 |
2003年 | 158篇 |
2002年 | 131篇 |
2001年 | 33篇 |
2000年 | 20篇 |
1999年 | 25篇 |
1998年 | 29篇 |
1997年 | 23篇 |
1996年 | 25篇 |
1995年 | 20篇 |
1994年 | 14篇 |
1993年 | 16篇 |
1992年 | 17篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1975年 | 2篇 |
1969年 | 2篇 |
1963年 | 1篇 |
排序方式: 共有2822条查询结果,搜索用时 16 毫秒
91.
Meng LJ Wang P Wolkoff AW Kim RB Tirona RG Hofmann AF Pang KS 《Hepatology (Baltimore, Md.)》2002,35(5):1031-1040
The uptake of the sulfated bile acid sulfolithocholyltaurine (SLCT) was investigated in isolated rat hepatocytes and in HeLa cells transfected with complementary DNAs (cDNAs) of organic anion transporting polypeptides (Oatps) 1 and 2 cloned from rat liver. In hepatocytes, transport of SLCT was greatly reduced by bromosulfophthalein (BSP), estrone sulfate, the precursor bile acids cholyltaurine and lithocholyltaurine, and 4,4'-diisothiocyanostilbene-2-2'-disulfonic acid (DIDS). However, SLCT transport was insensitive to 4-methylumbelliferyl sulfate, harmol sulfate, digoxin, fexofenadine, and lack of sodium ion. Because the estimation of kinetic constants was enhanced with use of inhibitors, BSP (1-50 micromol/L) was added to isolated rat hepatocytes to assess the various transport components for SLCT uptake. The resulting data showed a nonsaturable pathway and at least 2 pathways of different Michaelis-Menten constants (K(m)) (70 and 6 micromol/L) and similar maximum velocities (V(max)) (1.73 and 1.2 nmol/min/mg protein) and inhibition constants of 0.63 and 10.3 micromol/L for BSP. In expression systems, SLCT was taken up by Oatp1 and Oatp2 expressed in HeLa cells with similar K(m) values (12.6 +/- 6.2 and 14.6 +/- 1.9 micromol/L). These K(m) values were comparable to that observed for the high-affinity pathway in rat hepatocytes. In conclusion, the results suggest that transport of SLCT into rat liver is mediated in part by Oatp1 and Oatp2, high-affinity pathways, a lower-affinity pathway of unknown origin, and a nonsaturable pathway that is compatible with a transport system of high K(m) and/or passive diffusion. 相似文献
92.
Sandy R. Shultz Terence J. O’Brien Maria Stefanidou Ruben I. Kuzniecky 《Neurotherapeutics》2014,11(2):347-357
Epilepsy is one of the most common chronic neurological conditions worldwide. Anti-epileptic drugs (AEDs) can suppress seizures, but do not affect the underlying epileptic state, and many epilepsy patients are unable to attain seizure control with AEDs. To cure or prevent epilepsy, disease-modifying interventions that inhibit or reverse the disease process of epileptogenesis must be developed. A major limitation in the development and implementation of such an intervention is the current poor understanding, and the lack of reliable biomarkers, of the epileptogenic process. Neuroimaging represents a non-invasive medical and research tool with the ability to identify early pathophysiological changes involved in epileptogenesis, monitor disease progression, and assess the effectiveness of possible therapies. Here we will provide an overview of studies conducted in animal models and in patients with epilepsy that have utilized various neuroimaging modalities to investigate epileptogenesis. 相似文献
93.
Chidum Ezenwaka Philip Onuoha Dennese Sandy Denise Isreal-Richardson 《International journal of diabetes in developing countries.》2014,34(3):163-168
To assess the views of nurses and dietitians on diabetes self-management education and the preparedness of their work places for implementing diabetes self-care. 1,057 (71 %) of the estimated 1,498 qualified nurses and dietitians employed in the services of the Regional Health Authorities between November 2011 and April 2012 completed the self-administered research questionnaire previously pre-tested on a cohort of student nurses. The questionnaires did not contain any personal identifiers but were serially numbered to avoid receiving duplicate copies from a participant. The questionnaires were distributed to all public hospitals and health centres within the regional health authorities. The head nurse in each facility assisted in the distribution and collection of completed questionnaires from the volunteers. One thousand thirty-two nurses and 25 dietitians participated in the study. While the majorities of the nurses and dietitians agreed that diabetes self-management education will assist to reduce diabetes complications, 68 % and 58 % of them respectively did not think that there was adequate diabetes health education for the patients in their places of work. Furthermore, 73 % of the nurses and dietitians think that the health care system was not prepared for diabetes self-management education given that there were not enough qualified health personnel, educational facilities and economic resources. Although the nurses and dietitians agreed that diabetes self-management education will assist to reduce diabetes complications, inadequate healthcare personnel, economic resources and educational facilities constitute significant barriers. We recommend that governments in the developing countries should invest human and material resources into healthcare education. 相似文献
94.
Lecouvet Frdric E. Pasoglou Vassiliki Van Nieuwenhove Sandy Van Haver Thomas de Broqueville Quentin Denolin Vincent Triqueneaux Perrine Tombal Bertrand Michoux Nicolas 《European radiology》2020,30(6):3083-3093
European Radiology - To compare 3D T1-weighted fast spin echo (FSE) and 3D T1-weighted gradient echo (GE) mDixon as morphologic sequences to complement diffusion-weighted imaging (DWI) for the... 相似文献
95.
96.
97.
Devan Kansagara Anaïs Tuepker Sandy Joos Christina Nicolaidis Eleni Skaperdas David Hickam 《Journal of general internal medicine》2014,29(2):607-613
BACKGROUND
Quality improvement is a central goal of the patient-centered medical home (PCMH) model, and requires the use of relevant performance measures that can effectively guide comprehensive care improvements. Existing literature suggests performance measurement can lead to improvements in care quality, but may also promote practices that are detrimental to patient care. Staff perceptions of performance metric implementation have not been well-researched in medical home settings.OBJECTIVE
To describe primary care staff (clinicians and other staff) experiences with the use of performance metrics during the implementation of the Veterans Health Administration’s (VHA) Patient Aligned Care Team (PACT) model of care.DESIGN
Observational qualitative study; data collection using role-stratified focus groups and semi-structured interviews.PARTICIPANTS
Two hundred and forty-one of 337 (72 %) identified primary care clinic staff in PACT team and clinic administrative/other roles, from 15 VHA clinics in Oregon and Washington.APPROACH
Data coded and analyzed using conventional content analysis techniques.KEY RESULTS
Primary care staff perceived that performance metrics: 1) led to delivery changes that were not always aligned with PACT principles, 2) did not accurately reflect patient-priorities, 3) represented an opportunity cost, 4) were imposed with little communication or transparency, and 5) were not well-adapted to team-based care.CONCLUSIONS
Primary care staff perceived responding to performance metrics as time-consuming and not consistently aligned with PACT principles of care. The gaps between the theory and reality of performance metric implementation highlighted by PACT team members are important to consider as the medical home model is more widely implemented.98.
Matthew J. Budoff Sandy Liu David Chow Ferdinand Flores Brian Hsieh Dan Gebow Tony DeFrance Naser Ahmadi 《Atherosclerosis》2014
Background: Previous studies have shown that computed tomography coronary angiography (CTA) in patients with suspected coronary artery disease (CAD) predicts short term adverse events. However, there is no current data on whether identifying atherosclerosis on CTA impacts outcomes. We performed a case–control study to assess whether information from CTA can improve outcomes. Methods: 4244 symptomatic patients (mean age 58 ± 9, 62.5% male) without known CAD who underwent CTA (n = 2538) to rule out CAD were matched to 1706 patients who underwent standard of care in an academic cardiology clinic. Patients were propensity-matched by gender, age, ethnicity, CAD risk factors and follow-up duration. The primary outcome measure was all-cause mortality. Multivariable Cox proportional hazards models incorporated age, gender and traditional risk factors for coronary disease as well as pre-test probability of CAD. Results: There were no significant differences in age, gender, conventional risk factors between groups (p > 0.05). During a mean follow up of 80 ± 11 months, the overall death rate was 6.3% (270 deaths). Death rate was significantly lower in CTA group (n = 106, 4.2%) as compared to the control group (n = 184, 10.8%, p = 0.001). Event free survival was 95.8% and 89.2% in CTA and standard of care groups, respectively. Risk-adjusted hazard ratio of death were 2.5 (95%CI: 1.6–6.7, p = 0.003) in standard of care cohort as compared to CTA group. Multivariate analysis demonstrated that undergoing coronary CTA resulted in a risk reduction of 32%, p = 0·0001. Conclusions: Improved knowledge of atherosclerosis or increased anti-atherosclerotic therapies among those undergoing CTA may have contributed to improved survival. Our results provide evidence of potential benefit from scanning for atherosclerosis with CTA in symptomatic patients. Large randomized trials are warranted. 相似文献
99.
Sandy R. Larson Jessica Chin Xiaotun Zhang Lisha G. Brown Ilsa M. Coleman Bryce Lakely Martin Tenniswood Eva Corey Peter S. Nelson Robert L. Vessella Colm Morrissey 《Clinical & experimental metastasis》2014,31(2):247-256
Approximately 90 % of patients who die of prostate cancer (PCa) have bone metastases, often promoting osteoblastic lesions. We observed that 88 % of castration-resistant PCa (CRPC) bone metastases express prostatic acid phosphatase (PAP), a soluble secreted protein expressed by prostate epithelial cells in predominately osteoblastic (n = 18) or osteolytic (n = 15) lesions. Additionally, conditioned media (CM) of an osteoblastic PCa xenograft LuCaP 23.1 contained significant levels of PAP and promoted mineralization in mouse and human calvaria-derived cells (MC3T3-E1 and HCO). To demonstrate that PAP promotes mineralization, we stimulated MC3T3-E1 cells with PAP and observed increased mineralization, which could be blocked with the specific PAP inhibitor, phosphonic acid. Furthermore, the mineralization promoted by LuCaP 23.1 CM was also blocked by phosphonic acid, suggesting PAP is responsible for the mineralization promoting activity of LuCaP 23.1. In addition, gene expression arrays comparing osteoblastic to osteolytic CRPC (n = 14) identified betacellulin (BTC) as a gene upregulated during the osteoblastic response in osteoblasts during new bone formation. Moreover, BTC levels were increased in bone marrow stromal cells in response to LuCaP 23.1 CM in vitro. Because new bone formation does occur in osteoblastic and can occur in osteolytic CRPC bone metastases, we confirmed by immunohistochemistry (n = 36) that BTC was highly expressed in osteoblasts involved in new bone formation occurring in both osteoblastic and osteolytic sites. These studies suggest a role for PAP in promoting the osteoblastic reaction in CRPC bone metastases and identify BTC as a novel downstream protein expressed in osteoblasts during new bone formation. 相似文献
100.
Bertolotto Michele Campo Irene Sachs Camilla Ciabattoni Riccardo Bucci Stefano Cova Maria Assunta Van Nieuwenhove Sandy 《Abdominal imaging》2020,45(7):1973-1989
Abdominal Radiology - Erectile dysfunction (ED) is defined as the persistent inability to achieve and/or maintain an erection for a satisfactory sexual activity. It is secondary to several organic,... 相似文献