首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1038篇
  免费   110篇
耳鼻咽喉   6篇
儿科学   61篇
妇产科学   48篇
基础医学   215篇
口腔科学   24篇
临床医学   114篇
内科学   183篇
皮肤病学   12篇
神经病学   95篇
特种医学   17篇
外科学   102篇
综合类   5篇
预防医学   133篇
眼科学   6篇
药学   90篇
肿瘤学   37篇
  2023年   4篇
  2022年   19篇
  2021年   30篇
  2020年   16篇
  2019年   23篇
  2018年   20篇
  2017年   24篇
  2016年   22篇
  2015年   20篇
  2014年   29篇
  2013年   52篇
  2012年   55篇
  2011年   55篇
  2010年   39篇
  2009年   29篇
  2008年   51篇
  2007年   34篇
  2006年   54篇
  2005年   53篇
  2004年   57篇
  2003年   50篇
  2002年   53篇
  2001年   28篇
  2000年   38篇
  1999年   28篇
  1998年   13篇
  1997年   11篇
  1996年   8篇
  1995年   15篇
  1994年   4篇
  1993年   5篇
  1992年   11篇
  1991年   17篇
  1990年   15篇
  1989年   14篇
  1988年   12篇
  1987年   17篇
  1986年   19篇
  1985年   7篇
  1984年   17篇
  1983年   18篇
  1982年   8篇
  1981年   6篇
  1980年   3篇
  1979年   11篇
  1973年   5篇
  1971年   4篇
  1969年   4篇
  1967年   2篇
  1966年   2篇
排序方式: 共有1148条查询结果,搜索用时 15 毫秒
21.
OBJECTIVE: Based on case-control and prospective studies elevated blood total homocysteine (tHcy) has been suggested to be an independent risk factor for cardiovascular diseases (CVD). The purpose of the study was to explore the joint effect of increased serum tHcy concentration and other risk factors on the risk of CVD mortality in middle-aged men without a history of heart disease or stroke. DESIGN: A prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study. SETTING: Eastern Finland. Subjects. A total of 802 men aged 46-64 years, examined in 1991-93. MAIN OUTCOME MEASURES: CVD mortality event. RESULTS: The mean serum tHcy concentration was 10.8 micromol L(-1) (SD 3.3). During the average follow-up time of 10.8 years 50 men experienced a CVD death. The hazard rate ratio for CVD mortality was 1.80 (95% confidence interval: 1.02-3.19) in men in the highest serum tHcy third versus lower thirds after adjustment for cardiovascular risk factors. Furthermore, elevated serum tHcy concentration appeared to increase the risk of CVD death in men who smoke or who have high circulating concentrations of serum total or LDL cholesterol, apo-B apolipoprotein or plasma fibrinogen. CONCLUSION: We conclude that homocysteine may increase the risk of CVD mortality in middle-aged men from Eastern Finland, and it may especially increase the risk when present with other risk factors for CVD.  相似文献   
22.
High density lipoprotein cholesterol (HDLC) was measured in the population surveys carried out in Finland in 1982 and 1987. The mean (+/- SD) of HDLC for men aged 25-64 years was 1.23 +/- 0.32 mmol/l in 1982 and 1.30 +/- 0.33 mmol/l in 1987, the increase being 5.7%. Respective values in women were 1.46 +/- 0.33 mmol/l and 1.58 +/- 0.35 mmol/l, an increase of 8.2%. The increase was significantly greater in women than in men (P less than 0.001). The prevalence of low HDLC (less than or equal to 0.9 mmol/l) fell from 13.5 to 9.6% in men and from 3.2 to 1.4% in women. Factors associated with low HDLC were the history of ischemic heart disease (IHD), diabetes and hypertension in both sexes and the positive family history of IHD in women. Subjects with low HDLC also had higher body mass index (BMI), waist-hip ratio and serum total cholesterol (TC) concentration than subjects with normal HDLC. Changes in BMI, waist-hip ratio, alcohol intake, leisure time physical activity, prevalence of smoking or in the dietary variables recorded, did not explain the increase in HDLC.  相似文献   
23.
Laminin has been proposed to influence the function of human adrenal cortex. We have studied the distribution of laminin (Ln) chains using immunofluorescence in human fetal and adult adrenal cortex. In the fetal gland Ln alpha2- and alpha5-chains were weakly expressed in the definitive zone, whereas Ln alpha4-, beta1-, and gamma1-chains occurred around vessels. In the adult gland, Ln alpha2-, alpha5-, and gamma1-chains were found in epithelial basement membranes (BM) in all cortical zones, Ln alpha4-chain in vessels, Ln beta1-chain in outer zone, and Ln beta2-chain in the two inner zones of the cortex, respectively. Among the integrins in adult gland, integrin alpha(3)-subunit was confined to basal surfaces of cortical cells, alpha(6) to vessels, alpha(1) to the stroma, and alpha(2) diffusely to epithelial cells. Lutheran glycoprotein and dystroglycan occurred in the fetal gland diffusely in the definitive zone and throughout the epithelium in the adult. The isoform composition of BM of the adult adrenal gland is distinct, with Ln-2 and -10 in BM of the outer zone and Ln-4 and -11 in BM of the two inner zones. The results suggest that integrin alpha(3)beta(1) and Lutheran are candidate receptors for Ln-10 and -11, whereas dystroglycan probably binds Ln-2 and -4.  相似文献   
24.
25.
The effects of acute myocardial infarction on the pharmacokinetics of digoxin were studied. Digoxin, 0.75 mg, was given orally to 12 patients with left-sided cardiac failure due to acute myocardial infarction and to 9 healthy control subjects. Serum concentration of digoxin in the first 4 hours and the area under the serum concentration-time curve in the first 12 hours after administration of the drug were lower in patients with infarction than in control subjects (P less than 0.01). The 24 hour area under the concentration curve, the amount excreted in urine and the renal clearance did not differ between the groups. The 24 hour area under the concentration curve correlated with the predigoxin pulmonary capillary wedge pressure and with heart rate (P less than 0.01). The decrease of renal clearance of digoxin was related to the serum activity of MB isoenzyme of creatine kinase (P less than 0.001). Morphine reduced and delayed the peak serum concentrations of digoxin (P less than 0.001). Thus, the absorption of oral digoxin was slower and the peak concentrations remained lower in patients with acute myocardial infarction than in healthy control subjects. However, the total amount of digoxin absorbed was unchanged.  相似文献   
26.

Background

Self-rated health is an independent predictor of mortality. However, general health checks in populations unselected for disease or risk factors have not been shown to reduce mortality or morbidity.

Aim

To describe new comorbidities and cardiovascular risk factors in apparently healthy people and to relate this to their self-rated health.

Design and setting

A targeted screening programme identified 462 middle-aged people with cardiovascular risk factors without previously diagnosed chronic disease in a Finnish community in 2005–2006.

Method

Home blood pressure monitoring, oral glucose tolerance test, estimated glomerular filtration rate, and ankle brachial index were used to detect previously undiagnosed conditions. The Short-Form Health Survey and Beck’s Depression Inventory were completed by participants before the diagnostic tests were performed.

Results

The prevalence of previously undiagnosed disease was: hypertension 113/462 (24% [95% confidence interval {CI} = 21% to 29%]), diabetes 19/462 (4% [95% CI = 2% to 6%]), renal insufficiency 23/462 (5% [95% CI = 3% to 7%]), and peripheral arterial disease 17/462 (4% [95% CI = 2% to 5%]). Of the 139 participants who regarded their health as ‘fair–poor’, 60 (43%) had a previously undetected condition affecting their vasculature.

Conclusion

Out of the screen-detected apparently healthy cardiovascular risk subjects, one in three had undiagnosed hypertension, diabetes, peripheral arterial disease, or renal insufficiency. Those individuals experiencing ill health tended to be at high risk of cardiovascular problems.  相似文献   
27.
Direct oral anticoagulants provide an alternative to vitamin K antagonists for the anticoagulation therapy in atrial fibrillation (AF). The availability of several treatment options with different attributes makes shared decision‐making appropriate for the choice of anticoagulation therapy. The aim of this study was to understand how physicians choose an oral anticoagulant (OAC) for patients with AF and how physicians view patients’ participation in this decision. Semi‐structured interviews with 17 Finnish physicians (eight general practitioners and nine specialists) working in the public sector were conducted. An interview guide on experience, prescribing and opinions about oral anticoagulants was developed based on previous literature. The data were thematically analysed using deductive and inductive approaches. Based on the interviews, patient's opinion was the most influential factor in decision‐making when there were no clinical factors limiting the choice between OACs. Of patient's preferences, the most important was the attitude towards co‐payments of OACs. Patients’ opinions on monitoring of treatment, dosing and antidote availability were also mentioned by the interviewees. The choice of an OAC in AF was patient‐centred as all interviewees expressed that patient's opinion affects the choice.  相似文献   
28.
White adipose tissue is one of the largest organs of the body. It plays a key role in whole‐body energy status and metabolism; it not only stores excess energy but also secretes various hormones and metabolites to regulate body energy balance. Healthy adipose tissue capable of expanding is needed for metabolic well‐being and to prevent accumulation of triglycerides to other organs. Mitochondria govern several important functions in the adipose tissue. We review the derangements of mitochondrial function in white adipose tissue in the obese state. Downregulation of mitochondrial function or biogenesis in the white adipose tissue is a central driver for obesity‐associated metabolic diseases. Mitochondrial functions compromised in obesity include oxidative functions and renewal and enlargement of the adipose tissue through recruitment and differentiation of adipocyte progenitor cells. These changes adversely affect whole‐body metabolic health. Dysfunction of the white adipose tissue mitochondria in obesity has long‐term consequences for the metabolism of adipose tissue and the whole body. Understanding the pathways behind mitochondrial dysfunction may help reveal targets for pharmacological or nutritional interventions that enhance mitochondrial biogenesis or function in adipose tissue.  相似文献   
29.
Nature offers exciting examples for functional wetting properties based on superhydrophobicity, such as the self-cleaning surfaces on plant leaves and trapped air on immersed insect surfaces allowing underwater breathing. They inspire biomimetic approaches in science and technology. Superhydrophobicity relies on the Cassie wetting state where air is trapped within the surface topography. Pressure can trigger an irreversible transition from the Cassie state to the Wenzel state with no trapped air--this transition is usually detrimental for nonwetting functionality and is to be avoided. Here we present a new type of reversible, localized and instantaneous transition between two Cassie wetting states, enabled by two-level (dual-scale) topography of a superhydrophobic surface, that allows writing, erasing, rewriting and storing of optically displayed information in plastrons related to different length scales.  相似文献   
30.
BackgroundThe most commonly used equation for estimated glomerular filtration rate (eGFR) is nowadays the four-variable Modification of Diet in Renal Disease (MDRD) equation. This formula was derived from patients with non-diabetic chronic kidney disease (CKD) with mean GFR 40 ml/min.MethodsWe compared the MDRD study equation and the recently developed Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation by applying the two formulas in 1747 middle-aged cardiovascular risk persons in primary care.ResultsThe prevalence of renal insufficiency defined as eGFR < 60 ml/min was 6.7% (95% CI 5.6–8.0) according to the MDRD formula, and 3.6% (95% CI 2.8–4.6) according to the CKD-EPI formula. The subjects who were classified as having CKD according to the MDRD equation, but no-CKD according to the CKD-EPI formula, were mostly women (86%) and slightly younger than the subjects having CKD according to both formulas.ConclusionThe characteristics of the subjects commonly treated in primary care resemble more closely the population from which the CKD-EPI than the MDRD study equation was derived from. Thus, we suppose that in general practice, the CKD-EPI equation is more suitable for estimating renal function than the MDRD equation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号