全文获取类型
收费全文 | 17566篇 |
免费 | 1083篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 209篇 |
儿科学 | 359篇 |
妇产科学 | 464篇 |
基础医学 | 2904篇 |
口腔科学 | 428篇 |
临床医学 | 1800篇 |
内科学 | 3196篇 |
皮肤病学 | 342篇 |
神经病学 | 1682篇 |
特种医学 | 877篇 |
外科学 | 2648篇 |
综合类 | 115篇 |
一般理论 | 2篇 |
预防医学 | 937篇 |
眼科学 | 575篇 |
药学 | 1196篇 |
中国医学 | 56篇 |
肿瘤学 | 907篇 |
出版年
2023年 | 69篇 |
2022年 | 119篇 |
2021年 | 279篇 |
2020年 | 155篇 |
2019年 | 294篇 |
2018年 | 337篇 |
2017年 | 285篇 |
2016年 | 344篇 |
2015年 | 363篇 |
2014年 | 499篇 |
2013年 | 723篇 |
2012年 | 986篇 |
2011年 | 981篇 |
2010年 | 664篇 |
2009年 | 624篇 |
2008年 | 972篇 |
2007年 | 1052篇 |
2006年 | 1063篇 |
2005年 | 1078篇 |
2004年 | 882篇 |
2003年 | 874篇 |
2002年 | 854篇 |
2001年 | 175篇 |
2000年 | 135篇 |
1999年 | 181篇 |
1998年 | 190篇 |
1997年 | 150篇 |
1996年 | 143篇 |
1995年 | 146篇 |
1994年 | 117篇 |
1993年 | 118篇 |
1992年 | 91篇 |
1991年 | 79篇 |
1990年 | 72篇 |
1988年 | 68篇 |
1985年 | 67篇 |
1984年 | 83篇 |
1983年 | 63篇 |
1982年 | 90篇 |
1981年 | 80篇 |
1933年 | 97篇 |
1932年 | 93篇 |
1931年 | 81篇 |
1930年 | 83篇 |
1929年 | 76篇 |
1928年 | 78篇 |
1927年 | 69篇 |
1926年 | 80篇 |
1924年 | 77篇 |
1923年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Karl Johnson Katherine W. Saylor Isabella Guynn Karen Hicklin Jonathan S. Berg Kristen Hassmiller Lich 《Genetics in medicine》2022,24(2):262-288
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing. 相似文献
2.
3.
4.
Daniel J. Snyder Thomas R. Kroshus Aakash Keswani Evan B. Garden Karl M. Koenig Kevin J. Bozic David S. Jevsevar Jashvant Poeran Calin S. Moucha 《The Journal of arthroplasty》2019,34(4):613-618
Background
Nursing Home Compare (NHC) ratings, created and maintained by Medicare, are used by both hospitals and consumers to aid in the skilled nursing facility (SNF) selection process. To date, no studies have linked NHC ratings to actual episode-based outcomes. The purpose of this study was to evaluate whether NHC ratings are valid predictors of 90-day complications, readmission, and bundle costs for patients discharged to an SNF after primary total joint arthroplasty (TJA).Methods
All SNF-discharged primary TJA cases in 2017 at a multihospital academic health system were queried. Demographic, psychosocial, and clinical variables were manually extracted from the health record. Medicare NHC ratings were then collected for each SNF. For patients in the Medicare bundle, postacute and total bundle cost was extracted from claims.Results
Four hundred eighty-eight patients were discharged to a total of 105 unique SNFs. In multivariate analysis, overall NHC rating was not predictive of 90-day readmission/major complications, >75th percentile postacute cost, or 90-day bundle cost exceeding the target price. SNF health inspection and quality measure ratings were also not predictive of 90-day readmission/major complications or bundle performance. A higher SNF staffing rating was independently associated with a decreased odds for >75th percentile 90-day postacute spend (odds ratio, 0.58; P = .01) and a 90-day bundle cost exceeding the target price (odds ratio = 0.69; P = .02) but was similarly not predictive of 90-day readmission/complications.Conclusion
Results of our study suggest that Medicare's NHC tool is not a useful predictor of 90-day costs, complications, or readmissions for SNFs within our health system. 相似文献5.
6.
Andreas Karatsaidis Olav Schreurs Kristen Helgeland Tony Axéll Karl Schenck 《Journal of oral pathology & medicine》2003,32(5):275-281
BACKGROUND: Common clinical forms of oral lichen planus (OLP) and oral lichenoid reactions (OLR) are erythematous (ERY) or reticular (RET). The purpose of this study was to find histopathological changes that differ between these forms. METHODS: Epithelial thickness, epithelial proliferation rate, apoptosis, and HLA-DR expression were compared among 10 reticular and 12 erythematous lesions, and 11 normal oral mucosa samples (NOM). RESULTS: The epithelium in ERY was thinner than in NOM, whereas RET showed values between ERY and NOM. Cell proliferation increased significantly in ERY as compared with RET and NOM, with no difference between RET and NOM. Relative numbers of epithelial cell nuclei displaying visible chromatin condensation were reduced in ERY form. CONCLUSIONS: The markedly increased cell proliferation in ERY supports the notion that this form displays a higher disease activity as compared to RET. It can therefore be important to study each disease form separately. 相似文献
7.
Anne S Hinckers Manfred Laucht Martin H Schmidt Karl F Mann Gunter Schumann Marc A Schuckit Andreas Heinz 《Neuropsychopharmacology》2006,60(3):282-287
BACKGROUND: A low level of response to alcohol has been associated with both the genetic constitution of the regulatory region (SLC6A4) of the human serotonin (5-hydroxytryptamine, 5-HT) transporter (5-HTT) and with future alcohol intake and an increased risk for alcoholism. To date, all studies of relevant polymorphisms have been carried out in populations in the United States. METHODS: Data were extracted from a subset (n = 243) of a cohort of children who have been observed since birth through evaluation of the family history of alcoholism and psychosocial risk influences. At age 16 years, the response to alcohol was assessed with the Self-Rating of the Effects of Alcohol (SRE) questionnaire, and the average amount of alcohol intake per month was assessed during the prior 6 months. Additional variables that were measured included the 5-HTT genotype, externalizing behavior, and sociodemographic variables, such as gender and age. RESULTS: The level of response to alcohol was significantly lower among carriers of two long alleles of the 5-HTT regulatory region compared with carriers of one or two short alleles (Mann-Whitney U = 5225.0, p = .005). In a multiple regression analysis, the level of response to alcohol and externalizing behavior but not psychosocial factors significantly predicted the average amount of alcohol intake per month. CONCLUSIONS: This study demonstrates that, independent of the assessed psychosocial variables, the 5-HTT genotype correlated with the level of response to alcohol and predicted alcohol intake among 16-year-old adolescents. 相似文献
8.
9.
Iver A. Langmoen Tryggve Lundar Ingebjørg Storm-Mathisen Sverre O. Lie Karl H. Hovind 《Child's nervous system》1991,7(1):13-15
We present 36 consecutive patients with intrinsic glioma of the pons. Tumors with exophytic expansion were excluded. There were 16 females and 20 males, ranging in age from 2 to 13 years, median 6 years. The most common presenting symptoms were cranial nerve dysfunction. unsteadiness of gait, and hemiparesis. Computed tomography (CT) showed a hypodense (17/21) or isodense (4/21) expansion of the pons. Five tumors had areas of contrast enhancement. Following information about prognosis and possible types of management, parents decided for or against radiation therapy: twentyfour children underwent irradiation and 12 did not. Median survival among children receiving a full course of irradiation was 280 days, compared to 140 days in an equivalent group of non-irradiated children. Hemiparesis presenting without cranial nerve symptoms and contrast enhancement on CT scan were poor prognostic factors, whereas sex, age, and duration of symptoms at diagnosis were unrelated to prognosis. 相似文献