全文获取类型
收费全文 | 410篇 |
免费 | 2篇 |
专业分类
儿科学 | 32篇 |
妇产科学 | 4篇 |
基础医学 | 22篇 |
口腔科学 | 4篇 |
临床医学 | 19篇 |
内科学 | 152篇 |
皮肤病学 | 4篇 |
神经病学 | 31篇 |
特种医学 | 4篇 |
外科学 | 35篇 |
综合类 | 11篇 |
预防医学 | 74篇 |
眼科学 | 5篇 |
药学 | 5篇 |
中国医学 | 2篇 |
肿瘤学 | 8篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 70篇 |
2018年 | 72篇 |
2017年 | 36篇 |
2016年 | 6篇 |
2014年 | 30篇 |
2013年 | 14篇 |
2012年 | 12篇 |
2011年 | 17篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 11篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 2篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1994年 | 2篇 |
1985年 | 6篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1974年 | 7篇 |
1973年 | 2篇 |
排序方式: 共有412条查询结果,搜索用时 31 毫秒
1.
Visual-evoked potential evidence of chiasmal hypoplasia 总被引:3,自引:0,他引:3
Thompson DA Kriss A Chong K Harris C Russell-Eggitt I Shawkat F Neville BG Aclimandos W Taylor DS 《Ophthalmology》1999,106(12):2354-2361
PURPOSE: To show that chiasmal hypoplasia or aplasia need not be an isolated developmental anomaly and to examine the spectrum of associated clinical findings to explore the possibility that these patients may represent a phenotypic manifestation of a developmental gene anomaly. DESIGN: An observational case series. PARTICIPANTS: Five infants, between several weeks and 7 months of age, in whom the electrophysiologic characteristic of chiasmal hypoplasia had been noted were included. METHODS: Flash electroretinography and flash and pattern visual-evoked potentials (VEPs) were elicited from all patients. Clinical ophthalmologic examinations, including funduscopy, were performed, and all patients had magnetic resonance imaging (MRI) brain scans. MAIN OUTCOME MEASURES: The occipital distribution of monocular VEP response peaks was studied. The symmetry of lateral channel responses was compared for monocular stimulation. RESULTS: All five patients had a crossed asymmetry in the monocular VEP occipital distribution, which is consistent with a paucity of fibers crossing at the chiasm. The MRI findings supported this electrophysiologic observation, illustrating degrees of chiasmal hypoplasia and variable coincidence of other midline abnormalities of the brain. Optic disc appearances varied from normal to hypoplastic and colobomatous. CONCLUSIONS: The ophthalmologic and MRI findings of five patients who showed a crossed asymmetry in monocular flash VEPs are consistent with a paucity of axons crossing at the chiasm. The similarities between achiasmia in humans and mice due to a Pax2 gene anomaly are discussed. 相似文献
2.
农村居民体质指数、腰围与血压变化趋势分析 总被引:1,自引:3,他引:1
目的 研究山东省居民体质指数(BMI)、腰围与血压的关系。方法 采用多阶段随机抽样的方法抽取样本,对确定的调查人群进行问卷调查,测量身高、体重、腰围、臀围和血压,并计算出体质指数和腰臀比。用描述性流行病学方法进行分析。结果 当体质指数(kg/m2)在18.5~23.9,24~27.9,≥28时,血压均值分别是123.5/76.1,128.8/80.0,134.5/85.6mmHg,高血压的患病率分别是15.65%,26.38%和43.78%。当体质指数≥24和/或腰围≥85cm(女性≥80cm),血压增长的速度明显加快,高血压的患病率也明显上升。结论 血压均值和高血压的患病率随着体质指数和腰围的增加而上升.二者是高血压的主要危险因素。 相似文献
3.
Until recently, cardiorespiratory fitness (CRF) has been overlooked as a potential modifier of the inverse association between obesity and mortality (the so-called obesity paradox), observed in patients with known or suspected cardiovascular (CV) disease. Evidence from five observational cohort studies of 30,104 patients (87% male) with CV disease indicates that CRF significantly alters the obesity paradox. There is general agreement across studies that the obesity paradox persists among patients with low CRF, regardless of whether adiposity is assessed by body mass index, waist circumference, or percentage body fat. However, among patients with high CRF, risk of all-cause mortality is lowest for the overweight category in some, but not all, studies, suggesting that higher levels of fitness may modify the relationship between body fatness and survival in patients manifesting an obesity paradox. Further study is needed to better characterize the joint contribution of CRF and obesity on mortality in diverse populations. 相似文献
4.
5.
6.
B. Kowall N. Lehmann A.A. Mahabadi S. Moebus R. Erbel K.H. Jöckel A. Stang 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(3):228-235
Background and aims
There is controversy on the potentially benign nature of metabolically healthy obesity (MHO), i.e., obese persons with few or no metabolic abnormalities. So far, associations between MHO and coronary artery calcification (CAC), a measure of subclinical atherosclerosis, have mainly been studied cross-sectionally in Asian populations. We assessed cross-sectional and longitudinal MHO CAC associations in a Caucasian population.Methods and results
In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. For cross-sectional and longitudinal analyses, we included 1585 participants free of coronary heart disease at baseline, with CAC measurements at baseline and at follow-up, and with either normal weight (BMI 18.5–24.9 kg/m2) or obesity (BMI ≥30.0 kg/m2) at baseline. We used four definitions of MHO. In our main analysis, we defined obese persons as metabolically healthy if they met ≤1 of the NCEP ATP III criteria for the definition of the metabolic syndrome – waist circumference was not taken into account because of collinearity with BMI.Persons with MHO had a higher prevalence of CAC than metabolically healthy normal weight (MHNW) persons (prevalence ratio = 1.59 (95% confidence interval 1.38–1.84) for the main analysis). Persons with MHO had slightly larger odds of CAC progression than persons with MHNW (odds ratios ranged from 1.17 (0.69–1.99) to 1.48 (1.02–2.13) depending on MHO definition and statistical approach).Conclusion
Our analyses on MHO CAC associations add to the evidence that MHO is not a purely benign health condition. 相似文献7.
Ye Ma Lili Huang Lu Zhang Hai Yu Bin Liu 《The American journal of emergency medicine》2018,36(7):1270-1279
Background
Obesity as one of the risk factors for cardiovascular diseases increases mortality in general population. Several clinical studies investigated clinical outcomes in patients with different body mass index (BMI) after cardiac arrest (CA). Controversial data regarding BMI on clinical outcomes in those patients exist in those studies. Therefore, we conducted a meta-analysis to evaluate the effect of BMI on survival condition and neurological prognosis in those patients.Methods
We searched Pubmed, Embase, Ovid/Medline and EBM reviews databases for relational studies investigating the association between BMI and clinical outcomes of patients after CA. Seven studies involving 25,035 patients were included in this meta-analysis. Primary outcome was survival condition and secondary outcome was neurological prognosis. Three comparisons were conducted: underweight (BMI < 18.5) versus normal weight (18.5 ≤ BMI < 25), overweight (25 ≤ BMI < 30) versus normal weight and obese (BMI ≥ 30) versus normal weight.Results
Using normal weight patients as reference, underweight patients had a higher mortality (odds ratio [OR] 1.35; 95% confidence interval [CI] 1.10 to 1.66; P = 0.004; I2 = 17%). Overweight was associated with increased hospital survival (OR 0.80; 95% CI 0.65 to 0.98; P = 0.03; I2 = 62%) and better neurological recovery (OR 0.72; 95% CI 0.61 to 0.85; P < 0.001; I2 = 0%). No significant difference was found in clinical outcomes between obese and normal weight patients.Conclusions
Low BMI was associated with lower survival rate in CA patients. Overweight was associated with a higher survival rate and better neurological recovery. Clinical outcomes did not differ between obese and normal weight patients. Further studies are needed to explore the underlying mechanisms. 相似文献8.
Uninjected postmortem normal lung from 49 children aged 1 hour to 14 years was studied using quantitative morphometric techniques to assess arterial size, number and muscularity, particularly in the respiratory region of lung. Arterial size increased most rapidly during the first 2 months of life, but growth rate remained high during the first 4 years. At all ages, the range of values for the mean external diameter of arteries accompanying peripheral airways was considerable, but marked differences from the normal range were usually associated with a marked difference in stature. Arterial number increased rapidly in the first 2 months, but subsequently arteries multiplied at the same rate as alveoli, and the alveolar:arterial ratio was relatively constant. Mean percentage arterial medial thickness fell quickly during the first 10 days and continued to decrease during the first 3 months of life, after which there was little change. The intra-acinar arteries became more muscular during childhood as they increased in size. Vein muscle wall thickness was low throughout childhood. The normal values given in this paper provide a basis for the evaluation of lung biopsies in childhood. 相似文献
9.
A. Fortin R. Rabasa-Lhoret S. Lemieux M.-E. Labonté V. Gingras 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2018,28(12):1275-1284
Background and aims
The metabolic syndrome (MS) is an emerging complication in patients with type 1 diabetes (T1D), with no preventive or therapeutic treatment reported yet. We wanted to compare the impact of two 6-month nutritional interventions, based on a Mediterranean (MED) or a low-fat diet, on waist circumference, anthropometric and metabolic outcomes in patients with both T1D and the MS.Methods and results
Participants were randomized into 2 intervention groups: 1) MED-diet or 2) low-fat diet. The 6-month study included 9 teaching sessions with a registered dietitian. Anthropometric (primary outcome: waist circumference), metabolic and nutritional assessments were performed at inclusion, 3 and 6-month. We used mixed effects models to assess the effects of both interventions. 28 participants were included (50.9 ± 10.3 years old) with a mean BMI of 30.7 ± 3.3 kg/m2 and a waist circumference of 105.5 ± 8.9 cm at inclusion. A trend towards a greater reduction of dietary fat intakes in the low-fat diet group was observed (P-interaction = 0.09). Waist circumference was reduced at 6-month in both groups (?3.5 cm low-fat; ?1.5 cm MED-diet) with no significant difference between groups (P-interaction = 0.43). Body mass index also significantly decreased in both groups (?0.7 kg/m2 low-fat; ?1.1 kg/m2 MED-diet; P-interaction = 0.56). No significant differences between groups were observed for other metabolic parameters.Conclusions
This study suggests that a 6-month non-restrictive dietary intervention in patients with T1D and MS could contribute to weight management, without significant differences between interventions for anthropometric and metabolic parameters. Further studies should investigate the long-term benefits of these diets.10.
R.Y. Xu Y.Q. Zhou X.M. Zhang Y.P. Wan X. Gao 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2018,28(10):1061-1066