全文获取类型
收费全文 | 789867篇 |
免费 | 44508篇 |
国内免费 | 891篇 |
专业分类
耳鼻咽喉 | 10535篇 |
儿科学 | 26277篇 |
妇产科学 | 22160篇 |
基础医学 | 129318篇 |
口腔科学 | 19181篇 |
临床医学 | 69236篇 |
内科学 | 145376篇 |
皮肤病学 | 17595篇 |
神经病学 | 53341篇 |
特种医学 | 30272篇 |
外国民族医学 | 96篇 |
外科学 | 119700篇 |
综合类 | 14997篇 |
现状与发展 | 3篇 |
一般理论 | 258篇 |
预防医学 | 56364篇 |
眼科学 | 18144篇 |
药学 | 59193篇 |
1篇 | |
中国医学 | 1834篇 |
肿瘤学 | 41385篇 |
出版年
2021年 | 5831篇 |
2018年 | 8824篇 |
2017年 | 6439篇 |
2016年 | 7507篇 |
2015年 | 8416篇 |
2014年 | 11196篇 |
2013年 | 17009篇 |
2012年 | 23519篇 |
2011年 | 25505篇 |
2010年 | 15359篇 |
2009年 | 13785篇 |
2008年 | 23277篇 |
2007年 | 25674篇 |
2006年 | 25135篇 |
2005年 | 24023篇 |
2004年 | 23378篇 |
2003年 | 22364篇 |
2002年 | 21449篇 |
2001年 | 34105篇 |
2000年 | 35009篇 |
1999年 | 29052篇 |
1998年 | 7888篇 |
1997年 | 6885篇 |
1996年 | 6754篇 |
1995年 | 6429篇 |
1992年 | 21780篇 |
1991年 | 23087篇 |
1990年 | 23054篇 |
1989年 | 22599篇 |
1988年 | 20688篇 |
1987年 | 20388篇 |
1986年 | 19062篇 |
1985年 | 18434篇 |
1984年 | 13588篇 |
1983年 | 11613篇 |
1982年 | 6418篇 |
1979年 | 12951篇 |
1978年 | 9273篇 |
1977年 | 7604篇 |
1976年 | 7748篇 |
1975年 | 9145篇 |
1974年 | 10418篇 |
1973年 | 10158篇 |
1972年 | 9395篇 |
1971年 | 8958篇 |
1970年 | 8477篇 |
1969年 | 7797篇 |
1968年 | 7482篇 |
1967年 | 6781篇 |
1966年 | 6052篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Chumakov E. M. Petrova N. N. Limankin O. V. Ashenbrenner Yu. V. 《Neuroscience and behavioral physiology》2022,52(1):45-51
Neuroscience and Behavioral Physiology - Objective. To determine the frequency, structure, and severity of cognitive impairments in patients with bipolar affective disorder (BAD) in remission.... 相似文献
62.
63.
64.
O. Morris M. Fairclough J. Grigg C. Prenant A. McMahon 《Journal of labelled compounds & radiopharmaceuticals》2019,62(1):4-23
Affinity peptide and protein‐ (APP) based radiotracers are an increasingly popular class of radiotracer in positron emission tomography (PET), which was once dominated by the use of small molecule radiotracers. Radiolabelled monoclonal antibodies (mAbs) are important examples of APPs, yet a preference for smaller APPs, which exhibit fast pharmacokinetics and permit rapid PET aided diagnosis, has become apparent. 18F exhibits favourable physical characteristics for APP radiolabelling and has been described as an ideal PET radionuclide. Notwithstanding, 18F radiolabelling of APP is challenging, and this is echoed in the literature where a number of diverse approaches have been adopted. This review seeks to assess and compare the approaches taken to 18F APP radiolabelling with the intention of highlighting trends within this expanding field. Generic themes have emerged in the literature, namely the use of mild radiolabelling conditions, a preference of site‐specific methodologies with an impetus for short, automated procedures which produce high‐yielding [18F]APPs. 相似文献
65.
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66.
67.
Erik de Bakker Mirthe A. M. van der Putten Martijn W. Heymans Sander W. Spiekstra Taco Waaijman Liselotte Butzelaar Vera L. Negenborn Vivian K. Beekman Erman O. Akpinar Thomas Rustemeyer Frank B. Niessen Susan Gibbs 《Experimental dermatology》2021,30(1):169-178
Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R2: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice. 相似文献
68.
69.
70.
Anna Maria Colangelo Giovanni Cirillo Lilia Alberghina Michele Papa Hans V.Westerhoff 《中国神经再生研究》2019,(2)
The recognition that neurogenesis does not stop with adolescence has spun off research towards the reduction of brain disorders by enhancing brain regeneration. Adult neurogenesis is one of the tougher problems of developmental biology as it requires the generation of complex intracellular and pericellular anatomies, amidst the danger of neuroinflammation. We here review how a multitude of regulatory pathways optimized for early neurogenesis has to be revamped into a new choreography of time dependencies. Distinct pathways need to be regulated, ranging from neural growth factor induced differentiation to mitochondrial bioenergetics, reactive oxygen metabolism, and apoptosis. Requiring much Gibbs energy consumption, brain depends on aerobic energy metabolism, hence on mitochondrial activity. Mitochondrial fission and fusion, movement and perhaps even mitoptosis, thereby come into play. All these network processes are interlinked and involve a plethora of molecules. We recommend a deep thinking approach to adult neurobiology. 相似文献