全文获取类型
收费全文 | 5977篇 |
免费 | 400篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 130篇 |
妇产科学 | 100篇 |
基础医学 | 620篇 |
口腔科学 | 205篇 |
临床医学 | 658篇 |
内科学 | 1428篇 |
皮肤病学 | 68篇 |
神经病学 | 527篇 |
特种医学 | 256篇 |
外科学 | 1009篇 |
综合类 | 58篇 |
一般理论 | 1篇 |
预防医学 | 504篇 |
眼科学 | 84篇 |
药学 | 322篇 |
中国医学 | 3篇 |
肿瘤学 | 359篇 |
出版年
2023年 | 44篇 |
2022年 | 58篇 |
2021年 | 185篇 |
2020年 | 85篇 |
2019年 | 145篇 |
2018年 | 208篇 |
2017年 | 113篇 |
2016年 | 112篇 |
2015年 | 155篇 |
2014年 | 177篇 |
2013年 | 274篇 |
2012年 | 379篇 |
2011年 | 417篇 |
2010年 | 205篇 |
2009年 | 166篇 |
2008年 | 295篇 |
2007年 | 271篇 |
2006年 | 270篇 |
2005年 | 247篇 |
2004年 | 244篇 |
2003年 | 171篇 |
2002年 | 183篇 |
2001年 | 123篇 |
2000年 | 124篇 |
1999年 | 103篇 |
1998年 | 37篇 |
1997年 | 35篇 |
1995年 | 31篇 |
1994年 | 34篇 |
1992年 | 74篇 |
1991年 | 91篇 |
1990年 | 87篇 |
1989年 | 80篇 |
1988年 | 90篇 |
1987年 | 73篇 |
1986年 | 70篇 |
1985年 | 67篇 |
1984年 | 59篇 |
1983年 | 35篇 |
1981年 | 35篇 |
1980年 | 37篇 |
1979年 | 57篇 |
1978年 | 48篇 |
1977年 | 45篇 |
1976年 | 39篇 |
1975年 | 35篇 |
1974年 | 48篇 |
1973年 | 43篇 |
1972年 | 40篇 |
1970年 | 35篇 |
排序方式: 共有6384条查询结果,搜索用时 78 毫秒
1.
2.
Ferdynand Hebal Elissa Port Catherine J. Hunter Bryan Malas Jared Green Marleta Reynolds 《Journal of pediatric surgery》2019,54(4):656-662
Background/purpose
Computed tomography (CT) derived Haller Index (HI) remains the standard for quantifying severity in patient with pectus excavatum (PE). Optical scanning described in literature reports optimistic results and new indices that correlate with HI. This study assessed the feasibility of a handheld White Light Scanner (WLS) to obtain 3D measurements and indices of PE deformity.Methods
From April 2015–April 2017, WLS scanning was conducted by orthotists during clinical visits. Included were children with PE up to 18?years. Analysis assessed correlation of a WLS-derived severity index, Hebal-Malas Index (HMI), with physician measured PE Depth (PED), and CT-derived HI.Results
Of 195 participants, 185(94%) patients with PE were scanned and 127(69%) had complete WLS data. For 88 patients undergoing monitoring, HMI correlated with PED (r?=?0.42, p?=?0.004). For 39 patients with pre-operative CT, HMI demonstrated strong correlation with HI (r?=?0.87, p < 0.0001).Conclusions
WLS demonstrated high feasibility of scanning PE. WLS-derived HMI best correlates with HI for patients with severe pectus deformity. Our current data is suggestive that WLS is best applied for severe deformities and yet to be established for milder deformities. Future yearly WLS will provide data on deformity progression and surgical therapy.Level of Evidence
IV.Type of Study
Diagnostic Study. 相似文献3.
Martina A. Steurer Jean Costello Rebecca J. Baer Scott P. Oltman Sky K. Feuer Tania Pacheco-Werner Elizabeth Rogers Marta M. Jankowska Jessica Block Molly McCarthy Matthew S. Pantell Christina Chambers Kelli K. Ryckman Laura L. Jelliffe-Pawlowski 《Paediatric and perinatal epidemiology》2020,34(2):130-138
4.
5.
A K Kant A Schatzkin G Block R G Ziegler M Nestle 《Journal of the American Dietetic Association》1991,91(12):1532-1537
We developed a method for evaluating food group intake patterns using dietary recall data (n = 11,529) from the second National Health and Nutrition Examination Survey. We used this method to examine the relationship of these food group intake patterns to nutrient intake and to selected biochemical indexes of nutritional status. We evaluated each 24-hour dietary intake recall for the presence or omission of five broad food groups--dairy, meat, grain, fruit, and vegetable. The five most prevalent patterns and the proportion of the population reporting them was as follows: all food groups, 33.6%; no fruit, 23.9%; no dairy and fruit, 9.0%; no dairy, 8.0%; and no fruit and vegetable, 5.6%. In the most prevalent pattern, all food groups were consumed; this was the only pattern that provided mean amounts of all of the key vitamins and minerals at levels greater than or equal to the Recommended Dietary Allowances (RDAs). This pattern also was reported by the lowest proportion of individuals consuming less than 100% RDA of the key nutrients. Patterns in which both fruit and vegetables were consumed were associated with highest levels of serum vitamin C. The consistency of these results indicates that screening diets for food group consumption can quickly provide meaningful information about their quality. 相似文献
6.
7.
Cardiac imaging in the evaluation of patients presenting to the emergency department with chest pain
Conclusions Despite the utility and benefits that each imaging modality has to offer, it is easy to see why there is still no perfect
choice for a noninvasive cardiac imaging modality to assist in the management of chest pain patients. All of the current imaging
techniques have their own significant strengths and weaknesses when compared with other modalities. SPECT and echocardiography
are wellestablished technologies that can directly assess the presence of myocardial ischemia and its functional consequence
on RF; newer and more expensive techniques such as MDCT and CMR can directly assess coronary anatomy and have just started
to be evaluated in the acute chest pain setting. There are no studies that directly compare these technologies, and more data
are clearly needed before the question of whether anatomic imaging versus perfusion/function imaging is the better approach
can be answered. Other comparisons such as relative safety, availability, logistics, and cost-effectiveness between the various
technologies are also lacking.
Of all of the imaging modalities discussed, MCE is the only portable technology. The images do not require expensive software
or other technology for offline processing before interpretation, and any trained cardiologist can read the study at the bedside
or, potentially, over the Internet, providing near-instantaneous results in the acute cardiac setting, where time is of the
essence.
MCE is also relatively cheap compared with other technologies, a potential advantage for payors but not necessarily for payees.
How reimbursement rates and fee structures eventually affect clinical practice is also unknown.
Despite these and other questions that need to be answered before any one technique will be used exclusively, the future of
noninvasive cardiac imaging remains an exciting and ever-changing field. The adaptation of any one of these techniques into
its proper role in the ED Journal of Nuclear Cardiology Wyrick and Wei 753 Volume 13, Number 6;749-55 Cardiac imaging in patients
with chest pain will take considerably more time and effort in terms of research, money, and time-tested clinical experience. 相似文献
8.
Pawan Kumar Dhruva Rao Deborah Clements Michael M. Davies Jared Torkington 《Surgical endoscopy》2007,21(6):1036
We present our comments on the above article. 相似文献
9.
10.
A patient with group B streptococcal endocarditis and large vegetations resembling mitral valve myxoma is described. Group B streptococcal endocarditis and the differential diagnosis of vegetations and cardiac tumors are briefly reviewed. 相似文献