全文获取类型
收费全文 | 17049篇 |
免费 | 1451篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 155篇 |
儿科学 | 619篇 |
妇产科学 | 389篇 |
基础医学 | 2132篇 |
口腔科学 | 376篇 |
临床医学 | 1931篇 |
内科学 | 4120篇 |
皮肤病学 | 261篇 |
神经病学 | 1561篇 |
特种医学 | 539篇 |
外国民族医学 | 8篇 |
外科学 | 2475篇 |
综合类 | 299篇 |
一般理论 | 4篇 |
预防医学 | 1323篇 |
眼科学 | 414篇 |
药学 | 1073篇 |
中国医学 | 5篇 |
肿瘤学 | 874篇 |
出版年
2022年 | 115篇 |
2021年 | 338篇 |
2020年 | 226篇 |
2019年 | 362篇 |
2018年 | 380篇 |
2017年 | 294篇 |
2016年 | 282篇 |
2015年 | 339篇 |
2014年 | 479篇 |
2013年 | 602篇 |
2012年 | 893篇 |
2011年 | 932篇 |
2010年 | 487篇 |
2009年 | 434篇 |
2008年 | 757篇 |
2007年 | 822篇 |
2006年 | 800篇 |
2005年 | 755篇 |
2004年 | 769篇 |
2003年 | 678篇 |
2002年 | 638篇 |
2001年 | 475篇 |
2000年 | 407篇 |
1999年 | 427篇 |
1998年 | 156篇 |
1997年 | 129篇 |
1996年 | 133篇 |
1995年 | 108篇 |
1994年 | 136篇 |
1993年 | 104篇 |
1992年 | 347篇 |
1991年 | 319篇 |
1990年 | 318篇 |
1989年 | 306篇 |
1988年 | 247篇 |
1987年 | 264篇 |
1986年 | 251篇 |
1985年 | 264篇 |
1984年 | 197篇 |
1983年 | 157篇 |
1979年 | 216篇 |
1978年 | 150篇 |
1977年 | 144篇 |
1976年 | 114篇 |
1975年 | 145篇 |
1974年 | 167篇 |
1973年 | 142篇 |
1972年 | 154篇 |
1971年 | 121篇 |
1970年 | 115篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
1.
Sundaram Kavin Piuzzi Nicolas S. Patterson Brendan M. Stearns Kim L. Krebs Viktor E. Mont Michael A. 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2020,30(3):447-453
European Journal of Orthopaedic Surgery & Traumatology - The goals of this study were to compare patient satisfaction and wound-related complications in patients receiving 2-octyl cyanoacrylate... 相似文献
2.
Turnbull Chris D. Stockley James A. Madathil Shyam Huq Syed S. A. Cooper Brendan G. Ali Asad Wharton Simon Stradling John R. Heitmar Rebekka 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2022,260(7):2129-2139
Graefe's Archive for Clinical and Experimental Ophthalmology - Retinal microvascular endothelial dysfunction is thought to be of importance in the development of ocular vascular diseases.... 相似文献
3.
Josh Greenstein Devjani Das Josie Acuna Monica Kapoor Cara Brown Abbas Husain Brendan Lally Barry Hahn 《The American journal of emergency medicine》2019,37(2):313-316
Background
In the emergency department, rib fractures are a common finding in patients who sustain chest trauma. Rib fractures may be a sign of significant, underlying pathology, especially in the elderly patients where rib fractures are associated with significant morbidity and mortality. To date, no studies have evaluated the ability of ultrasound to detect rib fractures using cadaver models and subsequently use this model as a teaching tool.Objectives
The purpose of this study was to determine if it is possible to generate rib fractures on cadaver models which could be accurately identified using ultrasound.Methods
This was a cross-sectional study performed during one session at a cadaver lab. A single hemithorax from four adult cadavers were used as models. Single rib fractures on each of rib five through eight were created. Four subjects, blinded to the normal versus fractured ribs, were asked to identify the presence of a fracture on each rib.Results
A total of 8 of 16 potential ribs had fractured induced by study staff. Mean accuracy was 55% for all subjects. The overall sensitivity and specificity for detecting rib fractures was 50% (CI: 31.89–68.11) and 59.38% (CI: 35.69–73.55) respectively. The overall PPV and NPV was 55.17% and 54.29% respectively.Conclusions
In this pilot study, subjects were not able to detect induced rib fractures using ultrasound on cadaver models. The use of this model as a teaching tool in the detection of rib fractures requires further investigation. 相似文献4.
Joseph F. Levy Rahul Khairnar Alexander V. Louie Timothy N. Showalter C. Daniel Mullins Mark V. Mishra 《Practical radiation oncology》2019,9(2):e172-e179
Purpose
A hydrogel rectal spacer (HRS) is a medical device that is approved by the U.S. Food and Drug Administration to increase the separation between the prostate and rectum. We conducted a cost-effectiveness analysis of HRS use for reduction in radiation therapy (RT) toxicities in patients with prostate cancer (PC) undergoing external beam RT (EBRT).Methods and Materials
A multistate Markov model was constructed from the U.S. payer perspective to examine the cost-effectiveness of HRS in men with localized PC receiving EBRT (EBRT alone vs EBRT + HRS). The subgroups analyzed included site of HRS placement (hospital outpatient, physician office, ambulatory surgery center) and proportion of patients with good baseline erectile function (EF). Data on EF, gastrointestinal and genitourinary toxicities incidence, and potential risks associated with HRS implantation were obtained from a recently published randomized clinical trial. Health utilities and costs were derived from the literature and the 2018 Physician Fee Schedule and were discounted 3% annually. Quality-adjusted life years (QALYs) and costs were modeled for a 5-year period from receipt of RT. Probabilistic sensitivity analysis and value-based threshold analyses were conducted.Results
The per-patient 5-year incremental cost for spacers administered in a hospital outpatient setting was $3578, and the incremental effectiveness was 0.0371 QALYs. The incremental cost-effectiveness ratio was $96,440/QALY for patients with PC undergoing HRS insertion in a hospital and $39,286/QALY for patients undergoing HRS insertion in an ambulatory facility. For men with good baseline EF, the incremental cost-effectiveness ratio was $35,548/QALY and $9627/QALY in hospital outpatient and ambulatory facility settings, respectively.Conclusions
Based on the current Medicare Physician Fee Schedule, HRS is cost-effective at a willingness to pay threshold of $100,000. These results contain substantial uncertainty, suggesting more evidence is needed to refine future decision-making. 相似文献5.
6.
7.
Dane Scantling Robert Kucejko John Williamson Alvaro Galvez Amanda Teichman Ryan Gruner Nicholas Serniak Brendan McCracken 《Injury》2019,50(1):54-60
Background
Most elderly trauma patients suffer blunt head injury and many utilize antithrombotic (AT) medications. The utility of delayed CT-head (D-CTH) in neurologically intact elderly patients using AT who have an intracranial hemorrhage (ICH) on presentation is unknown. We hypothesized that D-CTH would not alter clinical management and aimed to evaluate the role of D-CTH in this population.Methods
A retrospective cohort study was performed. Patients ≥65 years sustaining blunt head injuries from January 2010 to July 2017 were identified using our level 1 trauma center database. AT-patients presenting with ICH who underwent D-CTH were included. Patients with worsened ICH were compared to those with stable to improved ICH on D-CTH. AT-patients were compared to a cohort of non-AT patients. Fisher’s Exact and Mann-Whitney U tests were utilized and a power analysis conducted.Results
137?A?T and 34 non-AT patients were identified. There was no difference in hemorrhage progression or appearance of new ICH. No patient had a change in management from D-CTH in either cohort. AT-patients were slightly older (p?<?0.001), but cohorts were otherwise similar.50 AT-patients with worsened ICH were compared to 87 with stable ICH. There was no difference in cohort demographics. Hemorrhage progression did not vary with type of AT used but did increase if multiple types of synchronous ICH were present (p?<?0.001).Conclusions
Our data supports abstaining from routine D-CTH of elderly ICH patients with an intact neurologic examination who are utilizing aspirin, clopidogrel or warfarin. Conclusions cannot be drawn regarding new oral anticoagulants (NOACs) given low enrollment. Further multicenter study is required to provide adequate power and detect small levels of management change. 相似文献8.
Prevalence of vitamin D depletion among morbidly obese patients seeking gastric bypass surgery 总被引:5,自引:0,他引:5
Arthur M. Carlin M.D. D. Sudhaker Rao MB B.S. F.A.C.P. F.A.C.E. Ali M. Meslemani M.D. Jeffrey A. Genaw M.D. Nayana J. Parikh Shiri Levy M.D. Arti Bhan M.D. Gary B. Talpos M.D. 《Surgery for obesity and related diseases》2006,2(2):696-103
BACKGROUND: Abnormalities in calcium and vitamin D metabolism have been reported after bariatric surgery. The purpose of this study was to evaluate vitamin D nutritional status among morbidly obese patients before gastric bypass surgery. METHODS: We prospectively studied 279 morbidly obese patients seeking gastric bypass surgery for vitamin D nutritional status as assessed by serum 25-hydroxyvitamin D level. In addition, serum samples were analyzed for calcium, alkaline phosphatase (AP), intact parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D. RESULTS: Mean patient age was 43 +/- 9 years; 87% of the study patients were women, and 72% were white. Serum calcium and AP levels were normal in 88% and 89% of the patients, respectively. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level 相似文献
9.
Matthew S Lewis Paul Maruff Brendan S Silbert Lis A Evered David A Scott 《Archives of clinical neuropsychology》2006,21(5):421-427
The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of post-operative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week post-operatively using error and reliability data from a comparable healthy non-surgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within subject standard deviation, expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI. 相似文献
10.