全文获取类型
收费全文 | 13866篇 |
免费 | 1014篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 523篇 |
妇产科学 | 356篇 |
基础医学 | 1869篇 |
口腔科学 | 174篇 |
临床医学 | 1722篇 |
内科学 | 2483篇 |
皮肤病学 | 271篇 |
神经病学 | 1345篇 |
特种医学 | 297篇 |
外科学 | 1697篇 |
综合类 | 203篇 |
一般理论 | 26篇 |
预防医学 | 1567篇 |
眼科学 | 179篇 |
药学 | 959篇 |
中国医学 | 32篇 |
肿瘤学 | 1123篇 |
出版年
2023年 | 57篇 |
2022年 | 103篇 |
2021年 | 243篇 |
2020年 | 189篇 |
2019年 | 283篇 |
2018年 | 352篇 |
2017年 | 206篇 |
2016年 | 263篇 |
2015年 | 265篇 |
2014年 | 418篇 |
2013年 | 640篇 |
2012年 | 975篇 |
2011年 | 888篇 |
2010年 | 521篇 |
2009年 | 526篇 |
2008年 | 869篇 |
2007年 | 958篇 |
2006年 | 836篇 |
2005年 | 914篇 |
2004年 | 827篇 |
2003年 | 819篇 |
2002年 | 737篇 |
2001年 | 153篇 |
2000年 | 130篇 |
1999年 | 153篇 |
1998年 | 143篇 |
1997年 | 148篇 |
1996年 | 134篇 |
1995年 | 121篇 |
1994年 | 90篇 |
1993年 | 99篇 |
1992年 | 116篇 |
1991年 | 102篇 |
1990年 | 82篇 |
1989年 | 96篇 |
1988年 | 78篇 |
1987年 | 77篇 |
1986年 | 68篇 |
1985年 | 100篇 |
1984年 | 69篇 |
1983年 | 73篇 |
1982年 | 86篇 |
1981年 | 79篇 |
1980年 | 68篇 |
1979年 | 49篇 |
1978年 | 76篇 |
1977年 | 65篇 |
1976年 | 41篇 |
1975年 | 43篇 |
1973年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
J Brent Richards William D Leslie Lawrence Joseph Kerry Siminoski David A Hanley Jonathan D Adachi Jacques P Brown Suzanne Morin Alexandra Papaioannou Robert G Josse Jerilynn C Prior K Shawn Davison Alan Tenenhouse David Goltzman 《Journal of bone and mineral research》2007,22(2):228-234
The impact of clinical risk factor-based absolute risk methods on the prevalence of high risk for osteoporotic fracture is unknown. We applied absolute risk methods to 6646 subjects and found that the prevalence of elderly women deemed to be at high risk increased substantially, whereas the overall prevalence was highly dependent on the threshold used to designate high risk. INTRODUCTION: Many groups have advocated using absolute risk methods that incorporate clinical risk factors to target patients for osteoporosis therapy. We examined how the application of such absolute risk classification systems influences the prevalence of those considered to be at high risk for osteoporotic fracture and compared these systems to one based solely on BMD. MATERIALS AND METHODS: Using 6646 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, randomly selected, population-based cohort, we assessed three different systems for determining prevalence of high risk for osteoporotic fracture: a BMD-based system; a simplified risk factor system incorporating age, sex, BMD, and two clinical risk factors; and a comprehensive system, incorporating age, sex, BMD, and seven clinical risk factors. The 10-year absolute risks of incident fragility fracture were compared across systems using three different high-risk thresholds. RESULTS: The prevalence of a T score < or = -2.5 was 18.8% (95% CI: 17.7-19.9%) in women and 3.9% (95% CI: 3.0-4.7%) in men. Using a 15% 10-year risk of fracture threshold, the prevalence of women at high risk increased to 46.9% (95% CI: 45.4-48.4) and 42.5% (95% CI: 41.1-43.9) when the comprehensive and simplified risk factor classification systems were used, respectively. Using a 25% 10-year absolute risk threshold, the prevalence of high risk was similar to that of the BMD-based system, whereas the 20% threshold gave intermediate rates. All thresholds analyzed resulted in an increased prevalence of older women at high risk for fracture, whereas only the 15% 10-year risk of fracture threshold resulted in an increase in the prevalence of men at high risk. CONCLUSIONS: The application of risk factor-based systems results in an increased prevalence of older women at high risk. The prevalence of individuals at high risk may increase with changes to the methods used to determine those who are eligible for therapy. These data have important implications for the pattern of care and costs of treating osteoporotic fractures. 相似文献
12.
Endovascular treatment of cerebral aneuryms is now widely used and has important implications for the neuroanaesthetist. Significant issues include the decision to use general anaesthesia, factors associated with anaesthesia in the interventional radiology suite and treatment of complications. As endovascular treatment is now supported by evidence and established in practice, neuroanaesthetists should be involved in planning these procedures from a process, and individual patient, perspective. 相似文献
13.
14.
Sezen Ozoktay Robert Sarreck Leslie L. Alexander 《Journal of the National Medical Association》1981,73(2):161-163
Primary osteomyelitis of the pubic bone has not been recorded previously. The authors present a case of this unusual entity. 相似文献
15.
Manfred Schmidt Leslie Van Ekeris Barry W. Ache 《The Journal of comparative neurology》1992,318(3):277-290
The organization of sensory afferents in the antennular nerve (AN) of the spiny lobster and the central arborization of the afferents in the lateral and medial antennular neuropils (LAN, MAN) were analyzed by backfilling the AN with biocytin. The MAN receives primarily thick afferents (diameter ≥ 10 μm) with a consistent pattern of arborization from the medial of the three major divisions of the AN. The LAN, in contrast, receives many thin to medium-sized afferents (diameter ≤ 0.3–5 μm), in addition some with diameters ≥ 5 μm, from the lateral and dorsal divisions of the AN. In contrast to the consistent pattern of arborization in the MAN, afferents projecting to the LAN arborize in widely different patterns. Serially arranged, orthogonal side branches that are suggestive of topographical representation of the serially arranged sensilla on the antennule contribute to the stratification of the LAN. Together with existing electrophysiological data, these morphological findings are consistent with the idea that the MAN receives primarily mechanosensory (largely statocyst) input, as previously thought, but that the LAN receives chemosensory as well as mechanosensory input. The chemosensory input to the LAN would represent a novel pathway for processing chemosensory input from the antennule. 相似文献
16.
Hemolytic and sphingomyelinase activities of Clostridium perfringens alpha-toxin are dependent on a domain homologous to that of an enzyme from the human arachidonic acid pathway. 总被引:11,自引:1,他引:10 下载免费PDF全文
The N-terminal domain of Clostridium perfringens alpha-toxin, homologous with the nontoxic phospholipase C of Bacillus cereus, was expressed in Escherichia coli and shown to retain all of the phosphatidylcholine hydrolyzing activity of the alpha-toxin, but not the sphingomyelinase, hemolytic, or lethal activities. The C-terminal domain of alpha-toxin showed sequence and predicted structural homologies with the N-terminal region of arachidonate 5-lipoxygenase, an enzyme from the human arachidonic acid pathway which plays a role in inflammatory and cardiovascular diseases in humans. 相似文献
17.
Abstract A health needs assessment of inner-city, low-income adolescents was conducted by the staff of a nurse-managed, community-oriented primary care clinic. A multiethnic sample of 568 high school students was studied. The findings indicated that the most commonly used source of health care was the family doctor. Barriers to receiving care were fear and costs. Subjects reported insufficient knowledge about many health-related topics, and desired services in the areas of drug and substance use, reproduction and sexuality, family relations, mental health, and dental health. Eighty-four percent of the subjects were interested in using the services of a neighborhood clinic specifically for teens. Survey results were used for decision making, program planning, and implementation of a teen health clinic. 相似文献
18.
19.
20.
We all work in a multigenerational workforce. With extremes in generations, skills are needed to foster understanding among staff. There are many myths and realities about the age-related generations. While there are challenges in working in a multigenerational workforce, the generational differences tend to be exaggerated while the similarities are overlooked. A better understanding of these generations allows us to prevent communication breakdown and to close the communication gaps where they exist, creating a unit of harmony rather that discontent. 相似文献