全文获取类型
收费全文 | 6779篇 |
免费 | 411篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 141篇 |
妇产科学 | 113篇 |
基础医学 | 888篇 |
口腔科学 | 85篇 |
临床医学 | 928篇 |
内科学 | 1254篇 |
皮肤病学 | 56篇 |
神经病学 | 600篇 |
特种医学 | 308篇 |
外科学 | 755篇 |
综合类 | 42篇 |
一般理论 | 3篇 |
预防医学 | 831篇 |
眼科学 | 97篇 |
药学 | 512篇 |
中国医学 | 64篇 |
肿瘤学 | 490篇 |
出版年
2023年 | 39篇 |
2022年 | 57篇 |
2021年 | 127篇 |
2020年 | 94篇 |
2019年 | 121篇 |
2018年 | 173篇 |
2017年 | 134篇 |
2016年 | 144篇 |
2015年 | 198篇 |
2014年 | 253篇 |
2013年 | 365篇 |
2012年 | 563篇 |
2011年 | 614篇 |
2010年 | 327篇 |
2009年 | 290篇 |
2008年 | 520篇 |
2007年 | 525篇 |
2006年 | 479篇 |
2005年 | 459篇 |
2004年 | 399篇 |
2003年 | 345篇 |
2002年 | 355篇 |
2001年 | 43篇 |
2000年 | 30篇 |
1999年 | 52篇 |
1998年 | 63篇 |
1997年 | 47篇 |
1996年 | 38篇 |
1995年 | 39篇 |
1994年 | 33篇 |
1993年 | 31篇 |
1992年 | 14篇 |
1991年 | 19篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 16篇 |
1986年 | 18篇 |
1985年 | 14篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1979年 | 4篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1970年 | 5篇 |
1967年 | 6篇 |
1966年 | 11篇 |
1933年 | 3篇 |
排序方式: 共有7195条查询结果,搜索用时 15 毫秒
111.
112.
113.
Esther R. C. Janssen Elle E. M. Scheijen Nico L. U. van Meeteren Rob A. de Bie Anton F. Lenssen Paul C. Willems Thomas J. Hoogeboom 《European spine journal》2016,25(5):1533-1541
Purpose
To determine the content of current Dutch expert hospital physiotherapy practice for patients undergoing lumbar spinal fusion (LSF), to gain insight into expert-based clinical practice.Methods
At each hospital where LSF is performed, one expert physiotherapist received an e-mailed questionnaire, about pre- and postoperative physiotherapy and discharge after LSF. The level of uniformity in goals and interventions was graded on a scale from no uniformity (50–60 %) to very strong uniformity (91–100 %).Results
LSF was performed at 34 of the 67 contacted hospitals. From those 34 hospitals, 28 (82 %) expert physiotherapists completed the survey. Twenty-one percent of the respondents saw patients preoperatively, generally to provide information. Stated postoperative goals and administered interventions focused mainly on performing transfers safely and keeping the patient informed. Outcome measures were scarcely used. There was no uniformity regarding advice on the activities of daily living.Conclusion
Dutch perioperative expert physiotherapy for patients undergoing LSF is variable and lacks structural outcome assessment. Studies evaluating the effectiveness of best-practice physiotherapy are warranted.114.
115.
Patil BL Dutt N Briddon RW Bull SE Rothenstein D Borah BK Dasgupta I Stanley J Jeske H 《Virus research》2007,124(1-2):59-67
Cloned DNA-B components, belonging to the bipartite begomoviruses Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV), family Geminiviridae, when co-inoculated along with previously cloned DNA-A components of the respective viruses onto the experimental host Nicotiana benthamiana, generated defective DNAs (def-DNA) ranging in size from 549 to 1555 nucleotides. All the cloned def-DNAs contained the common region (CR) as well as portions of either DNA-A or DNA-B and, in a few cases, both DNA-A and DNA-B, representing recombinant products, the junction points of which correspond to repeats of 2-11 bases found in the parental molecules. The DNA-B-derived def-DNAs were, in some cases, associated with a decrease in levels of DNA-B, with a concomitant change in the symptoms from downward leaf curling in the older leaves to upward leaf-rolling in newly emerging leaves, more typical of monopartite begomoviruses. 相似文献
116.
The aim of this study is to investigate the effects of internal organ motion on IMRT treatment planning of prostate patients using a spatial dose gradient and probability density function. Spatial dose distributions were generated from a Pinnacle3 planning system using a co-planar, five-field intensity modulated radiation therapy (IMRT) technique. Five plans were created for each patient using equally spaced beams but shifting the angular displacement of the beam by 15 degree increments. Dose profiles taken through the isocentre in anterior-posterior (A-P), right-left (R-L) and superior-inferior (S-I) directions for IMRT plans were analysed by exporting RTOG file data from Pinnacle. The convolution of the 'static' dose distribution D0(x, y, z) and probability density function (PDF), denoted as P(x, y, z), was used to analyse the combined effect of repositioning error and internal organ motion. Organ motion leads to an enlarged beam penumbra. The amount of percentage mean dose deviation (PMDD) depends on the dose gradient and organ motion probability density function. Organ motion dose sensitivity was defined by the rate of change in PMDD with standard deviation of motion PDF and was found to increase with the maximum dose gradient in anterior, posterior, left and right directions. Due to common inferior and superior field borders of the field segments, the sharpest dose gradient will occur in the inferior or both superior and inferior penumbrae. Thus, prostate motion in the S-I direction produces the highest dose difference. The PMDD is within 2.5% when standard deviation is less than 5 mm, but the PMDD is over 2.5% in the inferior direction when standard deviation is higher than 5 mm in the inferior direction. Verification of prostate organ motion in the inferior directions is essential. The margin of the planning target volume (PTV) significantly impacts on the confidence of tumour control probability (TCP) and level of normal tissue complication probability (NTCP). Smaller margins help to reduce the dose to normal tissues, but may compromise the dose coverage of the PTV. Lower rectal NTCP can be achieved by either a smaller margin or a steeper dose gradient between PTV and rectum. With the same DVH control points, the rectum has lower complication in the seven-beam technique used in this study because of the steeper dose gradient between the target volume and rectum. The relationship between dose gradient and rectal complication can be used to evaluate IMRT treatment planning. The dose gradient analysis is a powerful tool to improve IMRT treatment plans and can be used for QA checking of treatment plans for prostate patients. 相似文献
117.
The present study examined theoretical mediators of a parent-based intervention on sunbathing tendencies and sunburn frequencies
based on the work of Turrisi et al. [Turrisi, R., Hillhouse, J., Heavin, S., Robinson, J., Adams, M., & Berry, J. (2004). Journal of Behavioral Medicine, 27, 393–412.]. Three hundred and forty parents in two regions of the United States were educated about the dangers of risky
sun behavior and how to convey information about skin cancer prevention to their children. Attitudes toward sunbathing, health
beliefs, appearance beliefs, and social normative beliefs were examined and found to be significant mediators of program effects
on sunbathing tendencies and sunburn frequencies. The findings are discussed with respect to maximizing the effectiveness
of future skin cancer interventions with children. 相似文献
118.
Kaposi sarcoma Herpes virus (KSHV), also known as human Herpes virus 8 (HHV8), can persist as episome in target cells. The latency-associated nuclear antigen 1 (LANA-1) is a key component of the latency process, and may be a functional equivalent of the EBNA-1 protein of Epstein-Barr virus. EBNA-1 can subdue immune recognition by virtue of a long glycine and alanine-rich repeat, which interferes with the proteasomal degradation of EBNA-1 and in this way averts the presentation of antigenic peptides derived from it. LANA-1 contains a strongly acidic-repeat region of approximately 580 amino acids, which consists almost exclusively of aspartic acid, glutamine, and glutamic acid residues. The LANA-1 repeat is not similar to the EBNA-1 Gly-Ala-rich repeat. We demonstrate that this acidic region could inhibit antigen processing in cis. Upon transfection of expression vectors containing LANA-1-eGFP fusion genes the cells did not present an ovalbumin-derived H2K(b)-restricted CTL epitope inserted at the carboxyl terminus of the GFP reporter. Deletion of the central acidic-repeat region of LANA-1 abolished the capacity of LANA-1 to block antigen presentation. Similar to the EBNA-1-derived Gly-Ala-rich repeat, the LANA-1 repeat does not inhibit presentation in trans: co-transfection of LANA-1 expression vectors does not inhibit presentation of the ova epitope from the GFP(Ova) fusion protein. These data demonstrate for the first time that the acidic-repeat region of LANA-1 could function as an in cis acting inhibitor of antigen presentation. This may contribute to the immune evasion of cells latently infected by KSHV. 相似文献
119.
AbstractThis paper presents findings from a 6-month study of New Psychoactive Substance (NPS) use in Manchester, UK. Drawing on interviews with 53 NPS users and 31 stakeholders, the paper documents a notable shift in the drug using landscape. It highlights how the homeless community – traditionally associated with alcohol dependency and problematic intravenous heroin and/or crack cocaine use – are now switching to smoking synthetic cannabinoid receptor agonists, while men who have sex with men (MSM) and engage in chemsex – who have traditionally been strongly associated with the recreational use of ecstasy and other stimulants – are now developing problematic intravenous drug using habits. The paper goes on to discuss the implications of this shift for existing models of treatment service delivery. In particular, it outlines the necessity for treatment services to develop innovative engagement strategies, alongside clearer referral pathways and improved service integration. 相似文献
120.