全文获取类型
收费全文 | 70832篇 |
免费 | 5282篇 |
国内免费 | 476篇 |
专业分类
耳鼻咽喉 | 816篇 |
儿科学 | 1887篇 |
妇产科学 | 1547篇 |
基础医学 | 8940篇 |
口腔科学 | 1247篇 |
临床医学 | 7054篇 |
内科学 | 16046篇 |
皮肤病学 | 1388篇 |
神经病学 | 5591篇 |
特种医学 | 2327篇 |
外国民族医学 | 1篇 |
外科学 | 9843篇 |
综合类 | 1618篇 |
一般理论 | 48篇 |
预防医学 | 4829篇 |
眼科学 | 2325篇 |
药学 | 5276篇 |
1篇 | |
中国医学 | 365篇 |
肿瘤学 | 5441篇 |
出版年
2023年 | 388篇 |
2022年 | 629篇 |
2021年 | 1566篇 |
2020年 | 987篇 |
2019年 | 1381篇 |
2018年 | 1715篇 |
2017年 | 1295篇 |
2016年 | 1449篇 |
2015年 | 1681篇 |
2014年 | 2383篇 |
2013年 | 3135篇 |
2012年 | 4602篇 |
2011年 | 4786篇 |
2010年 | 2710篇 |
2009年 | 2423篇 |
2008年 | 4168篇 |
2007年 | 4476篇 |
2006年 | 4522篇 |
2005年 | 4381篇 |
2004年 | 4102篇 |
2003年 | 3885篇 |
2002年 | 3667篇 |
2001年 | 1382篇 |
2000年 | 1241篇 |
1999年 | 1225篇 |
1998年 | 845篇 |
1997年 | 647篇 |
1996年 | 608篇 |
1995年 | 542篇 |
1994年 | 502篇 |
1993年 | 465篇 |
1992年 | 667篇 |
1991年 | 604篇 |
1990年 | 579篇 |
1989年 | 545篇 |
1988年 | 499篇 |
1987年 | 536篇 |
1986年 | 461篇 |
1985年 | 442篇 |
1984年 | 474篇 |
1983年 | 389篇 |
1982年 | 428篇 |
1981年 | 367篇 |
1980年 | 345篇 |
1979年 | 254篇 |
1978年 | 251篇 |
1977年 | 227篇 |
1976年 | 222篇 |
1975年 | 186篇 |
1974年 | 155篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
51.
52.
53.
Kenneth K. H. Chao BS Eric Cheung BS William B. Armstrong MD Brian J. F. Wong MD 《Otolaryngology--head and neck surgery》2002,126(6):593
Objective: The study goal was to compare the laser spot size created using reflective and refractive micromanipulators with a CO2 laser and to determine the sensitivity of spot size to laser power. Study Design and Setting: A CO2 laser and operating microscope (400-mm focal length) was coupled to either a reflective (Cassegrain-like) or refractive micromanipulator. Laser spot size was determined by measuring the region of ablation created by laser irradiation of wood (dry tongue depressors), exposed photographic film, and agar gel using optical micrometry. Laser power varied from 0.5 to 20 W with pulse durations of 0.1 and 0.5 second. Results: The reflective micromanipulator demonstrated overall smaller spot sizes for a given laser power and lower incremental change in spot size with increasing power. The reflective design demonstrated less sensitivity to increases in laser power. Conclusions: Micromanipulator optical design can result in significant differences in laser spot size. The reflective device used in this study demonstrated less sensitivity to increasing laser power. (Otolaryngol Head Neck Surg 2002;126:593-597.) 相似文献
54.
Reductions in substance use tend to coincide with marriage, as both may occur during emerging adulthood. During the transition to marriage, it is possible that one's spouse may be the influence that causes the reduction in substance use. Data on participants (N = 471 couples) for this report are taken from a longitudinal study of early marriage. The objective of the current analysis is to determine if having a spouse who uses marijuana is associated with a greater likelihood of one's own use. Additionally, we are interested in spousal influence and cessation. The findings support spousal influence. Husbands are more likely to start using marijuana if their wives use marijuana, but the reverse is not true. Husbands also are more likely to stop using if their spouses do not use. During the transition into marriage, the drug use of one spouse does affect the other. However, this influence appears to be unidirectional, with wives influencing their husbands more often. 相似文献
55.
56.
Psoriasis is a chronic inflammatory condition that often requires life-long treatment. Conventional therapies have not fully met the needs of psoriatic patients, because of limited efficacy, adverse effects with cumulative use, and patient inconvenience. In the past decade, biologic immunotherapies have become accepted treatments for psoriasis as a result of perceived efficacy and safety on the part of patients and practitioners. However, most data on these medications come from relatively limited short-term trials. In this review, we will focus on the available long-term data on the efficacy of the biologic agents. We will emphasize the strengths and weakness of the available data of the biologic agents that are Food and Drug Administration (FDA)-approved for the treatment of moderate to severe psoriasis (alefacept, efalizumab, * etanercept, infliximab, and adalimumab), with the inclusion of a newer agent currently under FDA evaluation (ustekinumab). 相似文献
57.
58.
59.
Eric Y. T. Chan Daniel K. Ng Chung-hong Chan Ka-li Kwok Pok-yu Chow Josephine M. Cheung Suk-yu Leung 《Sleep & breathing》2009,13(1):59-63
Background and objective The purpose of this study is to assess whether Chinese children with high apnea–hypopnea index (AHI) are sleepier by a modified Epworth Sleepiness Scale (ESS).
Materials and methods Records were retrospectively reviewed. We included children who were between 3 and 12 years old, admitted for overnight polysomnogram
because of suspected obstructive sleep apnea syndrome (OSAS). A modified ESS was used to assess excessive daytime sleepiness
(EDS) of the children.
Results One hundred ninety-two Chinese children were included. Children with high AHI, defined as AHI > 5.0, were sleepier than children with AHI less than or equal
to 5. After adjustment by age, gender, and obesity, children with high AHI remained significantly sleepier. Modified ESS was
significantly correlated with AHI (rho = 0.124, 95% CI = 0.004–0.281). Modified ESS score of >8 was the best cutoff point
with the sensitivity and specificity of 0.29 and 0.91, respectively. The odds ratio of children with modified ESS > 10 having
high AHI was 4.231 (95%CI = 1.248 to 14.338) and children with modified ESS > 8 had the highest odds ratio, 4.295(95%CI = 1.66
to 11.1), of having high AHI.
Conclusion
Chinese children with high AHI appear to be sleepier than children with low AHI. Children with suspected OSAS and high modified ESS,
i.e., ESS > 8, had significantly higher odds ratio of having high AHI. Increased sleepiness is a specific but not a sensitive
symptom in snoring children with high AHI. Screening for EDS in snoring children may help us identify those with high AHI
and prioritize the management of those children.
All authors worked and the study was carried out in Kwong Wah Hospital in Hong Kong. There was no conflict of interest and
no specific source of funding for the study. 相似文献
60.
Few cases in the history of epidemiology and public health are more famous than John Snow's investigation of a neighborhood cholera outbreak in the St. James, Westminster, area of London in 1854. In this study Snow is assumed to have proven that cholera was water rather than airborne through a methodology that became, and to a great extent remains, central to the science and social science of disease studies. And yet, Snow's work did not satisfy most of his contemporaries who considered his proof of a solely waterborne cholera interesting but unconvincing. Uniquely, this paper asks whether the caution of Snow's contemporaries was reasonable, and secondly, whether Snow might have been more convincing within the science of the day. The answers significantly alter our understanding of this paradigmatic case. It does so in a manner offering insights both into the origins of nineteenth century disease analysis and more generally, the relation of mapping in the investigation of an outbreak of uncertain origin. The result has general relevance—pedagogically and practically—in epidemiology, medical geography, and public health. 相似文献