全文获取类型
收费全文 | 51420篇 |
免费 | 5559篇 |
国内免费 | 103篇 |
专业分类
耳鼻咽喉 | 371篇 |
儿科学 | 1651篇 |
妇产科学 | 1088篇 |
基础医学 | 7066篇 |
口腔科学 | 1345篇 |
临床医学 | 6758篇 |
内科学 | 9882篇 |
皮肤病学 | 803篇 |
神经病学 | 4152篇 |
特种医学 | 1899篇 |
外国民族医学 | 1篇 |
外科学 | 6552篇 |
综合类 | 1238篇 |
一般理论 | 32篇 |
预防医学 | 6073篇 |
眼科学 | 1057篇 |
药学 | 4306篇 |
中国医学 | 90篇 |
肿瘤学 | 2718篇 |
出版年
2021年 | 730篇 |
2020年 | 456篇 |
2019年 | 776篇 |
2018年 | 859篇 |
2017年 | 634篇 |
2016年 | 703篇 |
2015年 | 865篇 |
2014年 | 1139篇 |
2013年 | 1707篇 |
2012年 | 2403篇 |
2011年 | 2500篇 |
2010年 | 1383篇 |
2009年 | 1341篇 |
2008年 | 2335篇 |
2007年 | 2479篇 |
2006年 | 2436篇 |
2005年 | 2356篇 |
2004年 | 2164篇 |
2003年 | 2002篇 |
2002年 | 2010篇 |
2001年 | 1601篇 |
2000年 | 1509篇 |
1999年 | 1520篇 |
1998年 | 666篇 |
1997年 | 518篇 |
1996年 | 516篇 |
1995年 | 518篇 |
1994年 | 470篇 |
1993年 | 506篇 |
1992年 | 1239篇 |
1991年 | 1156篇 |
1990年 | 1093篇 |
1989年 | 1061篇 |
1988年 | 988篇 |
1987年 | 987篇 |
1986年 | 1001篇 |
1985年 | 920篇 |
1984年 | 802篇 |
1983年 | 663篇 |
1982年 | 465篇 |
1981年 | 389篇 |
1980年 | 382篇 |
1979年 | 611篇 |
1978年 | 512篇 |
1977年 | 386篇 |
1976年 | 395篇 |
1974年 | 456篇 |
1973年 | 411篇 |
1972年 | 402篇 |
1969年 | 369篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
ABSTRACT
Introduction
Immune checkpoint inhibitors (ICIs) have proved to be groundbreaking in the field of oncology. However, immune system overactivation from ICIs has introduced a novel medical entity known as immune-related adverse events (irAEs), that can affect any organ or tissue. ICI-induced inflammatory arthritis (ICI-IIA) is the most common musculoskeletal irAE and can lead to significant morbidity and limitation in anti-cancer therapy. 相似文献12.
13.
14.
Fiene Marie Kuijper Uma V. Mahajan Seul Ku Daniel A.N. Barbosa Sheila M. Alessi Sherman C. Stein Kyle M. Kampman Brandon S. Bentzley Casey H. Halpern 《Neuromodulation》2022,25(2):253-262
ObjectivesCocaine is the second most frequently used illicit drug worldwide (after cannabis), and cocaine use disorder (CUD)-related deaths increased globally by 80% from 1990 to 2013. There is yet to be a regulatory-approved treatment. Emerging preclinical evidence indicates that deep brain stimulation (DBS) of the nucleus accumbens may be a therapeutic option. Prior to expanding the costly investigation of DBS for treatment of CUD, it is important to ensure societal cost-effectiveness.AimsWe conducted a threshold and cost-effectiveness analysis to determine the success rate at which DBS would be equivalent to contingency management (CM), recently identified as the most efficacious therapy for treatments of CUDs.Materials and MethodsQuality of life, efficacy, and safety parameters for CM were obtained from previous literature. Costs were calculated from a societal perspective. Our model predicted the utility benefit based on quality-adjusted life-years (QALYs) and incremental-cost-effectiveness ratio resulting from two treatments on a one-, two-, and five-year timeline.ResultsOn a one-year timeline, DBS would need to impart a success rate (ie, cocaine free) of 70% for it to yield the same utility benefit (0.492 QALYs per year) as CM. At no success rate would DBS be more cost-effective (incremental-cost-effectiveness ratio <$50,000) than CM during the first year. Nevertheless, as DBS costs are front loaded, DBS would need to achieve success rates of 74% and 51% for its cost-effectiveness to exceed that of CM over a two- and five-year period, respectively.ConclusionsWe find DBS would not be cost-effective in the short term (one year) but may be cost-effective in longer timelines. Since DBS holds promise to potentially be a cost-effective treatment for CUDs, future randomized controlled trials should be performed to assess its efficacy. 相似文献
15.
16.
Marie Warrer Petersen Tine Sylvest Meyhoff Marie Helleberg Maj-Brit Nørregaard Kjær Anders Granholm Carl Johan Steensen Hjortsø Thomas Steen Jensen Morten Hylander Møller Peter Buhl Hjortrup Mik Wetterslev Gitte Kingo Vesterlund Lene Russell Vibeke Lind Jørgensen Klaus Tjelle Thomas Benfield Charlotte Suppli Ulrik Anne Sofie Andreasen Thomas Mohr Morten H. Bestle Lone Musaeus Poulsen Mette Friberg Hitz Thomas Hildebrandt Lene Surland Knudsen Anders Møller Christoffer Grant Sølling Anne Craveiro Brøchner Bodil Steen Rasmussen Henrik Nielsen Steffen Christensen Thomas Strøm Maria Cronhjort Rebecka Rubenson Wahlin Stephan Jakob Luca Cioccari Balasubramanian Venkatesh Naomi Hammond Vivekanand Jha Sheila Nainan Myatra Christian Gluud Theis Lange Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375
Introduction
Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.Methods
The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.Discussion
The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.17.
18.
Reem Haj-Ali BDS DDS MS ; Mary Walker DDS PhD ; Karen Williams PhD ; Yong Wang PhD ; Paulette Spencer DDS PhD 《Journal of prosthodontics》2006,15(2):82-88
PURPOSE: The purpose of this study was to compare the dentin/adhesive interfacial characteristics when bonding to noncarious as well as caries-affected dentin. MATERIALS AND METHODS: Seven extracted, unerupted, third molars were sectioned into halves. Artificial caries was created on one-half of each tooth, leaving the other half as a control. Dentin surfaces were treated with UNO adhesive according to the manufacturer's instructions for the wet-bonding technique and under environmental conditions present in the oral cavity. Dentin/adhesive interface sections of each half-tooth were stained with Goldner's trichrome, a classic bone stain, and examined using light microscopy. The width of exposed collagen was measured directly from photomicrographs, and adhesive penetration was analyzed qualitatively. RESULTS: The degree and extent to which the adhesive encapsulated the demineralized dentin matrix were reflected in the color difference in the stained sections with the noncarious dentin sections showing a degree of collagen encapsulation superior to that of the caries-affected dentin sections. The overall mean widths of exposed collagen were significantly (p < or = .05) greater at the caries-affected dentin/adhesive interface, 8.6 (1.7) microm, as compared with those at the noncarious dentin/adhesive interface, 6.0 (1.5) microm. CONCLUSIONS: The morphologic characteristics of the caries-affected dentin/interface suggest an increase in the exposed collagen zone and a decrease in the quality of the adhesive infiltration when compared with noncarious dentin. The evidence suggests that dentin substrate characteristics have a significant effect on the dentin/adhesive interface structure. 相似文献
19.
Sheila A M Rauch Knashawn H Morales Cynthia Zubritsky Kathryn Knott David Oslin 《The American journal of geriatric psychiatry》2006,14(4):316-324
OBJECTIVE: The authors examined 1) rates of trauma and posttraumatic stress (PTS) in older adults in primary care; 2) factors related to more posttraumatic stress symptoms; and 3) the influence of posttraumatic stress and depression on health perceptions and negative health behaviors (i.e., suicidal ideation, smoking, and at-risk drinking). METHODS: As part of participation in a study at the Philadelphia VAMC and the University of Pennsylvania, a random subset (N = 2,718) of older adults (age > or = 65 years) with scheduled primary care visits were screened concerning demographics, the General Health Questionnaire-12, suicidal thoughts, alcohol consumption, cigarette smoking, perceived health status, PTS, and cognitive impairment. RESULTS: The rate of trauma in older adult primary care patients was high in both the VA (37%) and university-based clinics (24%). Many older adults reported interference from at least one of the three posttraumatic stress items assessed (VA, 18%; university-based primary care, 8%). In a model including demographic factors, higher PTS and depression were uniquely related to more negative health perceptions. In a model including demographic factors, both higher PTS and depression were uniquely related to higher likelihood of suicidal ideation. In contrast, PTS no longer contributed to a model of smoking once depression was included. Neither PTS nor depression significantly contributed to a model of at-risk drinking. CONCLUSIONS: Trauma and posttraumatic stress are frequent and significant problems for older adults in primary care. Both posttraumatic stress and depression are related to more negative health perceptions and higher likelihood of suicidal ideation. 相似文献
20.
Caroline A. Harrison BMedSci MRCS ; Martin J. Heaton MD FRCS ; Christopher M. Layton PhD ; Sheila Mac Neil PhD 《Wound repair and regeneration》2006,14(2):203-209
To produce a stable epidermis, keratinocytes need to be firmly attached to the basement membrane. However, following wounding, keratinocytes are required to develop a migratory phenotype in order to reepithelialize the wound. To investigate some of the issues underlying reepithelialization, we have developed a three-dimensional in vitro model of tissue-engineered skin, comprising sterilized human dermis seeded with human keratinocytes and dermal fibroblasts. Using this model, we have shown that the inclusion of fibroblasts within the model increases the stability of keratinocyte attachment. We have also demonstrated that keratinocyte migration occurs most effectively in the absence of a basement membrane and following the inclusion of fibroblasts in the model. In addition, subjecting the keratinocyte layer to mechanical trauma induces a migratory phenotype. We conclude that this three-dimensional in vitro wound model can be used to increase our understanding of the factors that enhance keratinocyte migration and hence wound healing in vivo. 相似文献