全文获取类型
收费全文 | 17009篇 |
免费 | 1397篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 673篇 |
妇产科学 | 428篇 |
基础医学 | 2238篇 |
口腔科学 | 350篇 |
临床医学 | 1846篇 |
内科学 | 4138篇 |
皮肤病学 | 296篇 |
神经病学 | 1566篇 |
特种医学 | 518篇 |
外国民族医学 | 8篇 |
外科学 | 2208篇 |
综合类 | 237篇 |
一般理论 | 1篇 |
预防医学 | 1455篇 |
眼科学 | 344篇 |
药学 | 1034篇 |
中国医学 | 12篇 |
肿瘤学 | 1011篇 |
出版年
2022年 | 152篇 |
2021年 | 306篇 |
2020年 | 177篇 |
2019年 | 319篇 |
2018年 | 303篇 |
2017年 | 238篇 |
2016年 | 252篇 |
2015年 | 295篇 |
2014年 | 430篇 |
2013年 | 597篇 |
2012年 | 881篇 |
2011年 | 922篇 |
2010年 | 486篇 |
2009年 | 465篇 |
2008年 | 752篇 |
2007年 | 841篇 |
2006年 | 803篇 |
2005年 | 784篇 |
2004年 | 804篇 |
2003年 | 729篇 |
2002年 | 721篇 |
2001年 | 479篇 |
2000年 | 407篇 |
1999年 | 427篇 |
1998年 | 171篇 |
1997年 | 141篇 |
1996年 | 142篇 |
1995年 | 116篇 |
1994年 | 135篇 |
1993年 | 112篇 |
1992年 | 341篇 |
1991年 | 315篇 |
1990年 | 317篇 |
1989年 | 307篇 |
1988年 | 246篇 |
1987年 | 262篇 |
1986年 | 256篇 |
1985年 | 264篇 |
1984年 | 201篇 |
1983年 | 156篇 |
1979年 | 215篇 |
1978年 | 150篇 |
1977年 | 142篇 |
1976年 | 115篇 |
1975年 | 146篇 |
1974年 | 166篇 |
1973年 | 142篇 |
1972年 | 154篇 |
1971年 | 119篇 |
1970年 | 115篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
1.
2.
3.
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4.
5.
6.
7.
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
8.
Nephronophthisis related to homozygous NPHP1 gene deletion as a cause of chronic renal failure in adults. 总被引:1,自引:0,他引:1
9.
10.
A V Levy E Laska J D Brodie N D Volkow A P Wolf 《Journal of cerebral blood flow and metabolism》1991,11(2):A103-A113
We introduce the concept of the metabolic centroid spectrum as the feature space to characterize the distribution of metabolic activity in three-dimensional brains. The method computes the metabolic centroid of a brain subvolume for each increment of metabolic activity occurring in the whole brain. The result is the metabolic spectral signature, a continuous three-dimensional curve whose shape reflects the distribution of metabolic rates in the brain. The method's sensitivity to metabolic distribution asymmetries is greatly increased over that of the metabolic centroid method, while retaining its advantages; it is almost invariant to head size, head positioning, photon scatter, and the positron emission tomography (PET) camera's full width at half-maximum. It does not require magnetic resonance, computed tomography, or x-ray images. To test the method we analyzed the metabolic PET images of 40 normal subjects and 20 schizophrenics. The results show a unification of several metabolic characteristics of schizophrenic brains, such as laterality, hypofrontality, cortical/subcortical abnormalities, and overall brain hypometabolism, which were identified by different laboratories in separate studies using differing methodologies. Here they are presented by a single automatic objective method. 相似文献