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   17795篇
  免费   1406篇
  国内免费   506篇
耳鼻咽喉   7篇
儿科学   682篇
妇产科学   568篇
基础医学   1161篇
口腔科学   84篇
临床医学   1714篇
内科学   6857篇
皮肤病学   82篇
神经病学   436篇
特种医学   213篇
外国民族医学   1篇
外科学   626篇
综合类   2697篇
现状与发展   4篇
预防医学   1014篇
眼科学   62篇
药学   2329篇
  7篇
中国医学   919篇
肿瘤学   244篇
  2023年   215篇
  2022年   203篇
  2021年   480篇
  2020年   488篇
  2019年   493篇
  2018年   528篇
  2017年   561篇
  2016年   578篇
  2015年   554篇
  2014年   932篇
  2013年   1483篇
  2012年   996篇
  2011年   1069篇
  2010年   851篇
  2009年   846篇
  2008年   936篇
  2007年   900篇
  2006年   746篇
  2005年   639篇
  2004年   647篇
  2003年   599篇
  2002年   452篇
  2001年   418篇
  2000年   384篇
  1999年   320篇
  1998年   247篇
  1997年   254篇
  1996年   192篇
  1995年   178篇
  1994年   175篇
  1993年   158篇
  1992年   151篇
  1991年   138篇
  1990年   98篇
  1989年   115篇
  1988年   117篇
  1987年   113篇
  1986年   104篇
  1985年   138篇
  1984年   131篇
  1983年   71篇
  1982年   115篇
  1981年   106篇
  1980年   122篇
  1979年   102篇
  1978年   80篇
  1977年   73篇
  1976年   64篇
  1973年   63篇
  1970年   46篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
目的观察iPro2回顾式动态血糖监测优化2型糖尿病预混胰岛素的治疗效果。方法选取40例应用预混胰岛素的患者,随机分为观察组、对照组各20例,对照组在常规SMBG基础上行糖尿病教育,观察组应用美国美敦力公司生产的iPro2回顾式动态血糖监测系统对患者进行个体化糖尿病教育,并观察两组空腹血糖(FBG)、餐后2 h血糖(2 h PG)、糖化血红蛋白(HbA1c)及观察组干预前后平均血糖(MBG)、标准差(SDBG)。结果干预后,两组各指标均明显下降,差异具有统计学意义,P<0.05;与对照组相比,干预后观察组餐后2 h血糖(2 h PG)、MBG、SDBG下降更明显,差异有统计学意义,P<0.05。结论采用iPro2回顾式动态血糖监测指导应用预混胰岛素2型糖尿病患者进行个体化糖尿病教育,优化生活方式,能显著降低患者餐后血糖、平均血糖及血糖波动。  相似文献   
32.
33.
目的:观察镇心省睡益智方水提液及其精油对β淀粉样前体蛋白基因/早老素基因(APP/PS1)双转基因小鼠学习记忆的影响并探讨其可能机制。方法:采用APP/PS1双转基因痴呆小鼠及同月龄相同遗传背景C57BL/6JNju小鼠2种小鼠。C57BL/6JNju小鼠作为正常组,APP/PS1双转基因痴呆小鼠随机分为模型组,镇心省睡益智方精油低、高质量浓度组(12.13,48.50 mg·L~(-1)),镇心省睡益智方水提液组(0.46 g·kg~(-1)),每组12只。每天给药1次,连续给药22 d。给药结束后采用跳台实验、Morris水迷宫实验对小鼠行为学能力进行检测,采用尼氏染色观察海马CA1区神经元变化,采用硫磺素(Th S)染色观察海马DG区老年斑(SP)沉积,采用免疫组化法检测小鼠脑组织中葡萄糖转运蛋白1(GLUT1),胰岛素受体底物-1(IRS-1)的表达,采用酶联免疫吸附测定(ELISA)检测小鼠海马组织中乙酰胆碱(ACH),γ-氨基丁酸(GABA),谷氨酸(GLU)含量的变化。结果:与正常组比较,模型组小鼠跳台实验潜伏期显著缩短,错误次数显著增加(P0.01),Morris水迷宫实验定位航行逃避潜伏期明显延长(P0.05,P0.01),海马CA1区神经元出现缺失,DG区出现明显的老年斑沉积(P0.05),ACH,GLUT1含量均显著下降(P0.01),GABA,GLU水平及IRS-1的表达均显著升高(P0.01);与模型组比较,各给药组均可显著延长小鼠跳台实验潜伏期、减少跳台错误次数(P0.01),明显降低定位航行小鼠逃避潜伏期(P0.05,P0.01),可一定程度保护小鼠海马CA1区神经元,减少DG区老年斑沉积(P0.05,P0.01),明显增加小鼠脑组织中ACH,GLUT1表达(P0.05,P0.01),显著降低GABA,GLU水平及IRS-1的表达(P0.01)。结论:镇心省睡益智方水提液及其精油能够改善APP/PS1小鼠的学习记忆行为,保护神经元,增加脑组织GLUT1的表达,减少脑组织IRS-1的表达,减少老年斑沉积,升高ACH含量,降低GABA,GLU含量,可能是其防治阿尔茨海默症的机制。  相似文献   
34.
35.
36.

Background and aims

Potential associations of vegetarian diet patterns with fasting insulin (FI) and insulin sensitivity remain unclear. We aimed to investigate whether vegetarian diets were associated with FI and insulin sensitivity in a cross-sectional study in Chinese vegetarians and matched omnivores and then to test whether it is independent of body mass index (BMI).

Methods and results

This study included 279 vegetarians (73 vegans, 206 lacto-ovo-vegetarians) and 279 age- and sex-matched omnivores. Fasting blood glucose (FG) and FI concentrations were measured, and β-cell function (HOMA-β) and insulin resistance index (HOMA-IR) were used to evaluate insulin sensitivity. All blood glucose and insulin sensitivity indices were naturally log-transformed, and multiple-linear regression was used to determine the association between vegetarian diet patterns and insulin sensitivity after adjusting for confounders including BMI, visceral fat area, physical activity, sedentary time, income, alcohol consumption, and daily dietary intakes of macronutrients. Compared to omnivores, both vegan diet [β = ?0.25, 95% CI: (?0.38, ?0.14)] and lacto-ovo-vegetarian diet [β = ?0.10, 95% CI: (?0.18, ?0.01)] were negatively associated with HOMA-IR after adjusting for BMI. Vegan diet remained negatively associated with FI [β = ?0.16, 95% CI: (?0.30, ?0.01)] and HOMA-IR [β = ?0.17, 95% CI: (?0.32, ?0.03)] after adjusting for all confounders.

Conclusion

Vegetarian diet, especially vegan diet, is negatively associated with FI and IR, independent of BMI.  相似文献   
37.
The aim of this systematic review and meta‐analysis was to analyze the effects of grape seed extract (GSE) on glycemic control and serum lipoproteins, inflammation and body weight. Two independent authors systematically searched online databases including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science from inception until May 30, 2019. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochrane's Q test and I‐square (I2) statistic. Data were pooled using a random‐effects model and weighted mean difference (WMD) was considered as the overall effect size. Fifty trials were included in this meta‐analysis. Pooling effect sizes from studies demonstrated a significant decrease in fasting plasma glucose (FPG) (WMD): ?2.01; 95% confidence interval (CI): ?3.14, ?0.86), total cholesterol (TC; WMD: ?6.03; 95% CI: ?9.71, ?2.35), low‐density lipoprotein (LDL) cholesterol (WMD: ?4.97; 95% CI: ?8.37, ?1.57), triglycerides (WMD: ?6.55; 95% CI: ?9.28, ?3.83), and C‐reactive protein (CRP) concentrations (WMD: ?0.81; 95% CI: ?1.25, ?0.38) following GSE therapy. Grape seed did not influence HbA1c, HDL cholesterol levels, and anthropometric measurements. This meta‐analysis demonstrated that GSE intake significantly reduced FPG, TC, LDL cholesterol, triglycerides, and CRP levels.  相似文献   
38.
The fat mass and obesity-associated gene (FTO) rs9939609 A-allele is linked to obesity and dyslipidemia, yet the independent influence of this polymorphism on blood lipids remains equivocal. We examined the influence of the FTO rs9939609 polymorphism on fasting and postprandial blood lipids in individuals homozygous for the risk A-allele or T-allele with similar anthropometric and demographic characteristics. 12 AA and 12 TT males consumed a standardized meal after fasting overnight. Blood samples were collected at baseline (−1.5 h), before the meal (0 h), and for five hours postprandially to measure lipid, glucose, and insulin concentrations. Time-averaged total area under the curve (TAUC) values (0–5 h) were calculated and compared between genotypes. Fasting triacylglycerol (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, non-esterified fatty acid (NEFA), glucose, and insulin concentrations were similar between groups (p ≥ 0.293). TAUC for TG was similar in AAs and TTs (95% confidence interval (CI) −0.52 to 0.31 mmol/L/h; p = 0.606). Likewise, TAUC values were similar for NEFA (95% CI −0.04 to 0.03 mmol/L/h; p = 0.734), glucose (95% CI −0.41 to 0.44 mmol/L/h; p = 0.951), and insulin (95% CI −6.87 to 2.83 pmol/L/h; p = 0.395). Blood lipids are not influenced by the FTO rs9939609 polymorphism, suggesting the FTO-dyslipidemia link is mediated by adiposity and weight management is important in preventing FTO-related lipid variations.  相似文献   
39.
40.
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