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   55423篇
  免费   5144篇
  国内免费   1399篇
耳鼻咽喉   66篇
儿科学   1958篇
妇产科学   905篇
基础医学   3526篇
口腔科学   836篇
临床医学   6315篇
内科学   19727篇
皮肤病学   194篇
神经病学   1157篇
特种医学   579篇
外科学   2999篇
综合类   9326篇
现状与发展   7篇
一般理论   3篇
预防医学   4502篇
眼科学   1025篇
药学   5728篇
  40篇
中国医学   2704篇
肿瘤学   369篇
  2024年   281篇
  2023年   1225篇
  2022年   2032篇
  2021年   2873篇
  2020年   2521篇
  2019年   2268篇
  2018年   2237篇
  2017年   2176篇
  2016年   2373篇
  2015年   2250篇
  2014年   3794篇
  2013年   4366篇
  2012年   3385篇
  2011年   3544篇
  2010年   2844篇
  2009年   2777篇
  2008年   2594篇
  2007年   2484篇
  2006年   2131篇
  2005年   1914篇
  2004年   1586篇
  2003年   1218篇
  2002年   1037篇
  2001年   983篇
  2000年   787篇
  1999年   648篇
  1998年   572篇
  1997年   508篇
  1996年   443篇
  1995年   397篇
  1994年   376篇
  1993年   370篇
  1992年   328篇
  1991年   281篇
  1990年   254篇
  1989年   248篇
  1988年   242篇
  1987年   183篇
  1986年   168篇
  1985年   179篇
  1984年   190篇
  1983年   75篇
  1982年   158篇
  1981年   103篇
  1980年   126篇
  1979年   68篇
  1978年   62篇
  1977年   49篇
  1976年   39篇
  1970年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
目的 探讨护理干预在2型糖尿病患康复中的作用。方法 对80例2型糖尿病患,随机分成干预组和对照组,干预组实施全程护理干预,对照组实施常规的治疗护理。结果 干预组血糖控制良好,并发症发生率明显降低。结论 护理干预是2型糖尿病康复治疗的有效方法。  相似文献   
22.
目的探讨还原型谷胱甘肽(GSH)在预防糖尿病大鼠勃起功能障碍中的作用。方法通过腹腔注射链脲佐菌素65mg/kg建立糖尿病大鼠模型,然后随机分成DM组和DM+GSH组,DM+GSH组每天肌肉注射GSH200mg/kg。10周后观察大鼠勃起功能,并获取海绵体组织检测其谷胱甘肽、一氧化氮合酶(NOS)与丙二醛(MDA)水平,用TUNEL法检测细胞凋亡。结果成功建立糖尿病大鼠模型。与未注射GSH的DM组相比,DM+GSH组和正常对照组(C组)勃起功能更好,勃起率分别是20%,62.5%和100%。GSH水平DM+GSH组和C组明显比DM组高,其3组含量每克蛋白分别是(75.83±15.62)、(61.47±8.65)和(35.03±12.29)mg(P<0.05);NOS水平在DM+GSH组每毫克蛋白为(133.9±31.9)U,与正常对照组每毫克蛋白为(142.2±31.2)U相当,但较DM组每毫克蛋白为(58.4±18.9)U高(P<0.05);MDA含量在DM组每毫克蛋白为(3.71±0.62)nmol,明显高于正常对照组和DM+GSH组(P<0.05),这两组每毫克蛋白为(2.08±0.34)nmol和(2.44±0.28)nmol;细胞凋亡率在DM组、DM+GSH组和C组的分别是(22.6±3.6)%、(10.8±1.7)%和(7.2±2.1)%(P<0.05)。结论还原型谷胱甘肽对糖尿病大鼠阴茎组织有较好的抗氧化作用,能减少细胞凋亡,对延缓糖尿病性ED的发生有一定的作用。  相似文献   
23.
AIM: To determine the incidence of Type 2 diabetes and to examine the effect of different cut-points for impaired fasting glucose (IFG) on diabetes incidence. METHODS: Population-based longitudinal study (1990-2000) with clinical, anthropometric and biochemical measurements, including an oral glucose tolerance test (OGTT), in 1040 non-diabetic adults aged 40-69 years at baseline. Baseline glucose status was defined as normoglycaemia < 5.6, IFG-lower 5.6-6.0 and IFG-original 6.1-6.9 mmol/l. The all-IFG group included fasting glucose values of 5.6-6.9 mmol/l. RESULTS: The 10-year cumulative incidence of diabetes was 7.3 per 1000 person-years. Diabetes incidence was 2.4 [95% confidence interval (CI) 1.2, 4.8], 6.2 (4.0, 9.8) and 17.5 (12.5, 24.5) per 1000 person-years in those with normoglycaemia, IFG-lower and IFG-original, respectively. Compared with normoglycaemia, the age/sex-adjusted risk [hazard ratio (HR) and 95% CI] for incident diabetes was greatest in the IFG-original category (HR 6.9; 3.1, 15.2) and increased to a lesser degree in the IFG-lower (HR 2.5; 1.1, 5.7) and all-IFG categories (HR 4.1; 1.9, 8.7). When adjusted for confounding factors, the magnitude and direction of associations persisted, with HR 1.9, 4.4 and 2.9, for the categories IFG-lower, IFG-original and all-IFG, respectively. CONCLUSIONS: Diabetes incidence is more strongly related to IFG defined as fasting glucose between 6.1 and 6.9 mmol/l than to the lower category of 5.6-6.0 mmol/l, or entire range of 5.6-6.9 mmol/l. Future studies should examine the association of IFG with cardiovascular outcomes, but for diabetes risk our study supports the use of the IFG cut-point at 6.1 mmol/l.  相似文献   
24.
The Department of Health has funded a national diabetes network to support clinical research. The network will facilitate recruitment into clinical trials and has been widely welcomed by clinicians. However, if the network is to reach its full potential, all those involved will need to advocate a change in attitude towards clinical trials and research, encouraging participation and contribution of data. Clinicians need to be willing to take a proactive view about research studies, and to encourage patients to adopt a positive and altruistic attitude towards trial participation. The future of trials and other important clinical research in the UK may depend on it.  相似文献   
25.
AIMS: To study the time and cost involved in the care of newly registered outpatients with Type 2 diabetes mellitus (DM), compared with patients with hypertension and/or hyperlipidaemia (HTL). METHODS: A total of 313 patients with DM and 58 patients with HTL without diabetes were registered on their first visits to 11 diabetes clinics across Japan. The time and cost involved in their care was recorded over the following 5 months. RESULTS: In the first 3 months, there was an extensive time commitment to both groups. The time spent by physicians was 1.5 times longer for DM than for HTL. The total care time spent by all the care providers for DM was twice that for HTL. The cost of DM care was twice that for HTL, with the cost of medicines excluded. However, half of the cost for DM was for laboratory tests. When these were excluded, and the remaining cost divided by the time spent, the amount for DM was half of that for HTL. Over the 5 months, mean glycated haemoglobin (HbA(1c)) in DM patients improved from 8.0% to 6.5%, and 72% of DM patients achieved the glycaemic target of HbA(1c) < or = 6.5%. CONCLUSIONS: DM care in a diabetes clinic requires a great deal more time and resources than HTL to achieve the best outcome. An educational system for self care, presently lacking in the primary care setting in Japan, would improve glycaemic control for DM patients in the community.  相似文献   
26.
Aims To measure the prevalence of low high‐density lipoprotein (HDL)‐cholesterol (men < 1.03 mmol/l; women < 1.29 mmol/l) in European Type 2 diabetic patients receiving treatment for dyslipidaemia. Methods The pan‐European Survey of HDL‐cholesterol measured lipids and other cardiovascular risk factors in 3866 patients with Type 2 diabetes and 4436 non‐diabetic patients undergoing treatment for dyslipidaemia in 11 European countries. Results Diabetic patients were more likely to be obese or hypertensive than non‐diabetic patients. Most patients received lifestyle interventions (87%) and/or a statin (89%); treatment patterns were similar between groups. Diabetic patients had [means (SD)] lower HDL‐cholesterol [1.22 (0.37) vs. 1.35 mmol/l (0.44) vs. non‐diabetic patients, P < 0.001] and higher triglycerides [2.32 (2.10) vs. 1.85 mmol/l (1.60), P < 0.001]. More diabetic vs. non‐diabetic patients had low HDL‐cholesterol (45% vs. 30%), high triglycerides (≥ 1.7 mmol/l; 57% vs. 42%) or both (32% vs. 19%). HDL‐cholesterol < 0.9 mmol/l was observed in 18% of diabetic and 12% of non‐diabetic subjects. Differences between diabetic and non‐diabetic groups were slightly greater for women. LDL‐ and total cholesterol were lower in the diabetic group [3.02 (1.05) vs. 3.30 mmol/l (1.14) and 5.12 (1.32) vs. 5.38 mmol/l (1.34), respectively, P < 0.001 for each]. Conclusions Low HDL‐cholesterol is common in diabetes: one in two diabetic women has low HDL‐cholesterol and one diabetic man in four has very low HDL‐cholesterol. Management strategies should include correction of low HDL‐cholesterol to optimize cardiovascular risk in diabetes.  相似文献   
27.
AIMS: To compare long-term (1 year) efficacy and safety of pioglitazone and gliclazide in patients with Type 2 diabetes. METHODS: This was a double-blind, multicentre, comparative, parallel group trial in 283 patients with Type 2 diabetes, who were randomized to receive 1-year treatment with pioglitazone 30-45 mg/day or gliclazide 80-320 mg/day. Drug dose was titrated on the basis of self-monitored blood glucose (SMBG) measurements and HbA1c values. The 1-year changes in HbA1c, fasting blood glucose (FBG), insulin, HOMA-S (HOmeostatic Model Assessment) and SMBG were compared. In a subgroup of patients (n = 10), systemic glucose production and utilization were determined by a combination of isotopic (deuterated glucose) and clamp techniques. RESULTS: In both groups, there were similar decreases in HbA1c (pioglitazone: -0.79%; gliclazide: -0.79%) and FBG (pioglitazone: -1.0 mmol/l; gliclazide: -0.7 mmol/l), whereas the slope of the reduction of fasting blood glucose was different between groups (P = 0.004). Insulin levels as well as insulin resistance assessed using HOMA-S decreased significantly only after pioglitazone treatment (-11.94 pmol/l and -1.03, respectively, both P = 0.002 vs. baseline). A significantly greater reduction in systemic glucose production was observed in the pioglitazone group (-2.48 micromol/kg/min, P = 0.042) than in the gliclazide group (-1.02 micromol/kg/min). A few, mild adverse events occurred in both groups. CONCLUSIONS: A comparable decrease in HbA1c and FBG was observed with pioglitazone and gliclazide. However, with pioglitazone there was a continuous decrease in FBG over 1 year, whereas gliclazide failed to maintain a similar trend. This favourable effect of pioglitazone was due to its insulin-sensitizing effect and ability to decrease systemic glucose production.  相似文献   
28.
AIMS: To assess the association between abnormal stress myocardial perfusion imaging (MPI) and cardiac events (CE) in asymptomatic patients with diabetes and with > or = 1 additional risk factor. Predictors of abnormal stress MPI were also evaluated. METHODS: Four hundred and forty-seven consecutive patients who underwent stress MPI were prospectively followed for 2.1 [0.5-4.1] years for the subsequent occurrence of hard CE (myocardial infarction and sudden or coronary death) and soft CE (unstable angina and ischaemic heart failure requiring hospitalization). Re-vascularization procedures performed as a result of the screening protocol were not included in the analysis. RESULTS: Follow-up was successful in 419 of 447 patients (94%), of whom 71 had abnormal MPI at baseline. Medical therapy was intensified in all subjects and especially in those with abnormal MPI. Twenty-three patients with abnormal MPI underwent a re-vascularization procedure. CEs occurred in 14 patients, including six of 71 patients (8.5%) with abnormal MPI and eight of 348 patients (2.3%) with normal MPI (P < 0.005). Only two patients developed a hard CE and 12 a soft CE. In multivariate analysis, abnormal MPI was the strongest predictor for CEs [odds ratio (OR) (95% CI) = 5.6 (1.7-18.5)]. Low-density lipoprotein cholesterol > or = 3.35 mmol/l [OR (95% CI) = 7.3; 1.5-34.7] and age > median [OR (95% CI) = 6.0 (1.2-28.6)] were additional independent predictors for CE. The independent predictors for abnormal MPI were male gender, plasma triglycerides > or = 1.70 mmol/l, creatinine clearance < 60 ml/min and HbA1c > 8%, with male gender the strongest [OR (95% CI) = 4.0 (1.8-8.8)]. CONCLUSIONS: Asymptomatic patients with diabetes in this study had a very low hard cardiac event rate over an intermediate period. This could be explained by the effects of intervention or by the low event rate in the background population. Randomized studies of cardiac heart disease screening are required in asymptomatic subjects with diabetes to determine the effectiveness of this intervention.  相似文献   
29.
四氧嘧啶诱发糖尿病大鼠血管紧张素的变化   总被引:1,自引:0,他引:1  
实验观察了四氧嘧啶诱发糖尿病大鼠连续饲养110d后体内肾素一血管紧张素系统的变化。结果表明,血浆和心脏的血管紧张素Ⅱ含量无明显变化,而肾脏的AngⅡ含量却明显低于正常对照组。另外,心脏的心钠素(ANP)含量在糖尿病大鼠与正常对照组之间无差别,血中的糖化血红蛋白含量基本无变化。上述结果表明,糖尿病大鼠早期心脏可能无明显损伤,而肾脏的肾素一血管紧张素系统活性降低。  相似文献   
30.
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