全文获取类型
收费全文 | 1056篇 |
免费 | 28篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 17篇 |
妇产科学 | 11篇 |
基础医学 | 62篇 |
口腔科学 | 3篇 |
临床医学 | 354篇 |
内科学 | 56篇 |
皮肤病学 | 2篇 |
神经病学 | 54篇 |
特种医学 | 36篇 |
外科学 | 220篇 |
综合类 | 56篇 |
预防医学 | 71篇 |
眼科学 | 2篇 |
药学 | 25篇 |
1篇 | |
中国医学 | 107篇 |
肿瘤学 | 7篇 |
出版年
2024年 | 1篇 |
2023年 | 18篇 |
2022年 | 21篇 |
2021年 | 41篇 |
2020年 | 34篇 |
2019年 | 39篇 |
2018年 | 54篇 |
2017年 | 29篇 |
2016年 | 25篇 |
2015年 | 25篇 |
2014年 | 91篇 |
2013年 | 85篇 |
2012年 | 46篇 |
2011年 | 91篇 |
2010年 | 55篇 |
2009年 | 46篇 |
2008年 | 69篇 |
2007年 | 49篇 |
2006年 | 43篇 |
2005年 | 44篇 |
2004年 | 23篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 15篇 |
2000年 | 12篇 |
1999年 | 9篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1088条查询结果,搜索用时 31 毫秒
1.
BackgroundLittle is known about the extent of ordering low-value services by.PurposeTo compare the rates of low-value back images ordered by primary care physicians (PCMDs) and primary care nurse practitioners (PCNPs).MethodWe used 2012 and 2013 Medicare Part B claims for all beneficiaries in 18 hospital referral ?regions (HRRs) and a measure of low-value back imaging from Choosing Wisely. Models included random clinician effect and fixed effects for beneficiary age, disability, Elixhauser comorbidities, clinician sex, the emergency department setting, back pain visit volume, organization, and region (HRR).FindingsPCNPs (N = 231) and PCMDs (N = 4,779) order low-value back images at similar rates (NP: all images: 26.5%; MRI/CT: 8.4%; MD: all images: 24.5%; MRI/CT: 7.7%), with no detectable significant difference when controlling for covariates.DiscussionPCNPs and PCMDs order low-value back images at an effectively similar rate. 相似文献
2.
3.
Summary
In the last decades back pain has reached dramatic proportions in industrialized countries. Disorders of the back are nowadays
the leading cause of direct and indirect health care costs. Accurate prevalence estimates are needed to serve as a basis for
health care evaluations. A review of epidemiologic studies in the general population reveals that back pain has reached a
prevalence of 40 % for current pain. 7 to 18 % are “frequently”, “often”, “daily” or “constantly” affected. 75 % of the adult
population suffers from back pain during the last year. 80 to 90 % of the adult population in industrialized countries experience
back pain ever. Gender specific differences are only present in severe, chronic forms which are more often experienced by
women. Back pain has a prevalence maximum at 50 to 64 years. Older persons display lower prevalence estimates. The prevalence
maximum in men is one decade earlier than in women. There are several potential explanations for this prevalence pattern that
are discussed in the article. Back pain can be classified by location, temporal characteristics, pain intensity and pain history.
Currently, for none of these dimensions generally accepted, uniformly employed and validated definitions are available. In
most of the industrialized countries back pain is one of the most expensive symptoms. 75–90 % of the direct and indirect health
care costs were caused by those 5–10 % of patients who are disabled. As predictors of back pain a history of back pain and
job satisfaction play by far a more important role than the extensively studied mechanical factors. For a first episode of
back pain the prognosis is favorable. If the pain persist for more than three months the prognosis is unfavorable. After six
months of absenteeism because of back pain more than half of the afflicted never return to work. Rarely back pain is present
as a single symptom. In more than 80 % back pain is associated with pain in at least one joint. It remains to be studied if
back pain may be viewed as an entity or as part of a more complex pain syndrome.
相似文献
4.
Physical loading and performance as predictors of back pain in healthy adults A 5-year prospective study 总被引:4,自引:0,他引:4
Urho M. Kujala Simo Taimela Tero Viljanen Helena Jutila Jukka T. Vitasalo Tapio Videman Michele C. Battié 《European journal of applied physiology》1996,73(5):452-458
We investigated muscle strength, aerobic power, and occupational and leisure-time physical loading as predictors of back pain in a 5-year follow-up study. A cohort of 456 adults aged 25, 35, 45 and 55 years, free of back pain, participated in measurements of anthropometric characteristics, aerobic power and muscle strength characteristics at baseline. The subjects' levels and types of physical activity and occupational physical loading were also determined. At 5 years after the baseline examinations 356 of these subjects (78.1 %) were reached by mail, and 262 of them (73.6%) properly completed and returned a questionnaire including a detailed back pain history for the 5 years following the baseline measurements. Of this number 56 subjects (21 %) who reported back pain ( > 30 on a scale from 0 to 100) and functional impairment during the 5-year follow-up composed the marked back pain group. Other subjects (n = 71, 27%) noting lesser symptoms were included in the mild back pain group; 135 subjects (52%) reported having had no back pain. The subjects with marked back pain were on average taller than the subjects without back pain, while no such difference was found in body mass. Heavy occupational musculoskeletal loading (P = 0.005) and high general occupational physical demands (P = 0.036) predicted future back pain. Leisuretime physical activity, aerobic power or muscle strength characteristics were not predictive of future back pain. 相似文献
5.
A new approach to the automatic extraction of the lumen region and its boundary for gastrointestinal (GI) endoscopic images is presented. First, a quasi region of interest, the darker regions of the image, is segmented using a region splitting scheme termed progressive thresholding. The centre of mass of this segmented region acts as a seed for further processing. Then the lumen region is obtained using a region growing technique called the integrated neighbourhood search (INS). A new quad structure based technique is introduced to enhance the INS speed significantly. A back projection algorithm is suggested to optimise the search for pixels belonging to the lumen region and boundary. A boundary-thinning algorithm is also proposed to remove the redundant pixels from the lumen boundary and to generate a connected single pixel width boundary. The proposed approach does not need a priori knowledge about the image characteristics. The experimental results indicate that the proposed technique enhances the speed of conventional INS by 45.5% to 28.6% based on the lumen size varying from 22,709 pixels to 4947 pixels. The main advantage of the proposed technique is its high-speed response that facilitates real-time analysis of endoscopic images. 相似文献
6.
Merati G Negrini S Sarchi P Mauro F Veicsteinas A 《European journal of applied physiology》2001,85(1-2):41-48
The use of a school backpack is one of the possible causes of back pain in children. Oxygen consumption (
), pulmonary ventilation, and heart rate (f
c) were measured in 35 pre-pubertal subjects [17 girls and 18 boys, mean (SD) age 11.3 (0.6) years]. They took part in a four-step
experiment: (1) standing for 5 min, (2) walking at 3 km·h–1 for 7 min, (3) walking at 3 km·h–1 for 7 min carrying a school backpack weighing 8 kg, and (4) walking at 7 km·h–1 for 5 min with no load. The occurrence of back pain in the last 2–3 years and during the last 15 days was assessed for the
subjects by means of a questionnaire. Mean (SD) standing
was 215 (45) ml.min–1 during walking at 3 km·h–1, 503 (101) ml.min–1 during walking without a load, and increased to 541 (98) ml.min–1 during walking with a load (P<0.01). Carrying a backpack increased f
c only minimally. The energy cost of walking at 3 km.h–1 without the backpack was 10.0 (2.0) ml O2
.m–1, and with the backpack was 10.8 (1.9) ml O2
.m–1 (P<0.01). The net energy cost of locomotion was 0.129 (0.032) ml.kg body mass–1.m–1 for the unloaded condition and slightly lower, at 0.123 (0.025) ml.kg body mass–1.m–1 during loaded walking (P<0.05). Ventilation did not change significantly between unloaded and loaded conditions. When the data were assessed according
to the occurrence of back pain, the f
c/
slope was significantly lower in children without back pain, even though the net energy cost of locomotion was similar. Overall,
these data suggest that the cardiovascular effortrequired for locomotion while carrying a backpack is minimal. However, fatigability
and back pain are more likely to take place in less physical performing subjects. Thus, the occurrence of back pain in schoolchildren
during locomotion while carrying a backpack may improve with an improvement in their level of fitness.
Electronic Publication 相似文献
7.
G. Kristjánsdóttir 《European journal of pediatrics》1996,155(11):984-986
The study considers the prevalence of back pain experienced in a nationwide random sample of 2173 Icelandic school children aged 11–12 and 15–16. The study found a 20.6% prevalence of at least weekly back pain. The prevalence of back pain was significantly more frequent among the older children. No gender or class difference was found in the overall sample. Older children from rural areas have significantly more back pain than those living in the city. The need for a thorough epidemiological investigation of the association of back pain in children is emphasized. 相似文献
8.
目的:评价单一穴位治疗急性腰扭伤的治疗效果.方法:根据统一的诊断标准,在多个临床中心进行随机对照研究.全部病例320例经随机数字表法分为针刺后溪穴观察组和针刺腰痛点对照组.对患者的疼痛程度分别由医师和患者进行评分.结果:治疗2个疗程后,观察组和对照组近期有效率分别为89.4%和82.5%,远期有效率分别为95.6%和93.5%.经Ridit分析,近期疗效差异有统计意义(P<0.05),远期疗效差异无统计意义(P>0.05).结论:针刺单一穴位治疗急性腰扭伤疗效确切,取穴简便,后溪穴疗效好于腰痛点. 相似文献
9.
目的观察浓缩分离的癌性胸腹腔积液蛋白质自体静脉回输的临床疗效.方法采用透析、冷凝、变速离心和抽滤等技术对癌性积液中的蛋白质进行分离提取,将可溶性蛋白稀释在盐水中用于静脉回输.结果该方法提取的蛋白质可浓缩9.78倍,蛋白质浓度可达(262.32±52.36)g/L,其中IL-2、IL-4、IFN 和TNF的浓度(pg/L)分别达到53.34±9.67,47.55±9.25,57.43±15.75和73.50±15.17,提取后浓度明显增加(P<0.05).自体蛋白液回输后无一例发生发热、过敏等副反应,同时水肿也得到一定程度的控制.CD3 、CD8 细胞百分率,总蛋白及IgG浓度均无明显改变(P>0.05),但CD4 细胞百分率和CD4 /CD8 比值明显增加(P<0.05 ).结论通过透析、变速离心及抽滤等技术,可从癌性胸、腹腔积液中浓缩分离出适于静脉输注的蛋白质提取液.自体蛋白质回输以后,水肿得到一定程度的控制,并使CD4 细胞百分率和CD4 /CD8 比值提高. 相似文献
10.
针刺病变部位的腰部夹脊穴,进针深度30 mm,运用平补平泻手法,并配合口服中药桃红四物汤,治疗了162例椎间盘源性腰痛患者.结果显效65例,良好53例,有效37例,无效6例,总有效率96.3%. 相似文献