全文获取类型
收费全文 | 5107篇 |
免费 | 401篇 |
国内免费 | 131篇 |
专业分类
耳鼻咽喉 | 98篇 |
儿科学 | 104篇 |
妇产科学 | 57篇 |
基础医学 | 667篇 |
口腔科学 | 149篇 |
临床医学 | 394篇 |
内科学 | 765篇 |
皮肤病学 | 50篇 |
神经病学 | 672篇 |
特种医学 | 133篇 |
外科学 | 406篇 |
综合类 | 439篇 |
预防医学 | 744篇 |
眼科学 | 87篇 |
药学 | 566篇 |
1篇 | |
中国医学 | 164篇 |
肿瘤学 | 143篇 |
出版年
2024年 | 12篇 |
2023年 | 131篇 |
2022年 | 224篇 |
2021年 | 272篇 |
2020年 | 240篇 |
2019年 | 271篇 |
2018年 | 231篇 |
2017年 | 211篇 |
2016年 | 162篇 |
2015年 | 143篇 |
2014年 | 314篇 |
2013年 | 376篇 |
2012年 | 218篇 |
2011年 | 269篇 |
2010年 | 201篇 |
2009年 | 249篇 |
2008年 | 222篇 |
2007年 | 218篇 |
2006年 | 180篇 |
2005年 | 155篇 |
2004年 | 138篇 |
2003年 | 123篇 |
2002年 | 105篇 |
2001年 | 85篇 |
2000年 | 71篇 |
1999年 | 69篇 |
1998年 | 43篇 |
1997年 | 48篇 |
1996年 | 57篇 |
1995年 | 49篇 |
1994年 | 41篇 |
1993年 | 42篇 |
1992年 | 53篇 |
1991年 | 43篇 |
1990年 | 39篇 |
1989年 | 42篇 |
1988年 | 33篇 |
1987年 | 22篇 |
1986年 | 33篇 |
1985年 | 33篇 |
1984年 | 27篇 |
1983年 | 18篇 |
1982年 | 21篇 |
1981年 | 28篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1974年 | 12篇 |
排序方式: 共有5639条查询结果,搜索用时 31 毫秒
111.
SeungJae Lee Hyunah Kim Byeong Kil Oh HyoIn Choi KiChul Sung Jeonggyu Kang Mi Yeon Lee JongYoung Lee 《Clinical cardiology》2022,45(7):767
BackgroundWe investigated the association between individual components of metabolic syndrome (MetS) and left ventricular (LV) geometric changes, including diastolic dysfunction, in a large cohort of healthy individuals.MethodsOverall, 148 461 adults who underwent echocardiography during a health‐screening program were enrolled. Geographic characteristics on echocardiography and several markers of LV relaxation function were identified according to individual MetS components. Univariate linear regression analysis and a multivariate regression model adjusted for factors known to influence LV relaxation function were conducted.ResultsThe prevalence of LV diastolic dysfunction (LVDD) was higher in the MetS group than in the non‐MetS group (0.56% vs. 0.27%, p < .001). In univariate and multivariate analyses, E/A ratio, e′ velocity, and left atrial volume index were significantly associated with each component of MetS and covariates (all p ≤ .001). In the age‐ and sex‐adjusted model, MetS was significantly associated with LVDD (odds ratio [95% confidence interval], 1.350 [1.103, 1.652]). However, subjects with more MetS components did not have a significantly higher risk of LVDD. As the analysis was stratified by sex, the multivariate regression model showed that MetS was significantly associated with LVDD only in men (1.3 [1.00, 1.68]) with higher risk in more MetS component (p for trend < .001). In particular, triglyceride (TG) and waist circumference (WC) among MetS components were significantly associated with LVDD in men.ConclusionsMetS was associated with the risk of LVDD, especially in men, with a dose‐dependent association between an increasing number of components of MetS and LVDD. TG and WC were independent risk factors for LVDD in men. 相似文献
112.
目的:了解当前我国本科医学院校的布局,并对其区域差异性进行深入分析.方法:对院校数量、院校水平利用频数、构成比进行描述性统计;研究院校地区、省份的分布,对区域GDP总量、区域人口与院校规模做相关性分析;用洛伦兹曲线、基尼系数、泰尔指数深入分析院校分布差异性.结果:我国开设医学类专业的本科院校有420所,且分布不均匀;院... 相似文献
113.
Stefan Pleus Andreas Stuhr Manuela Link Cornelia Haug Guido Freckmann 《Journal of diabetes science and technology》2022,16(3):649
Background:There is an increasing use of continuous glucose monitoring (CGM) by people with diabetes. Measurement performance is often characterized by the mean absolute relative difference (MARD). However, MARD is influenced by a number of factors and little is known about whether MARD is stable throughout the day.Material and Methods:A total of 24 participants with type 1 diabetes were enrolled in the study. The study was performed for seven in-patient days. Participants wore two CGM systems in parallel and performed additional frequent blood glucose (BG) measurements. On two days, glucose excursions were induced.MARD was calculated between pairs of CGM and BG values, with BG values serving as reference values. ARD values calculated from CGM-BG pairs were grouped by hour of the day. Results were analyzed separately for glucose excursion days and for regular days.Results:Total MARDs for the complete study duration were 12.5% ± 3.6% and 13.2% ± 2.4% (n = 24). Throughout the day marked variability of MARD was observed (8.0% ± 1.3%-16.3% ± 2.9% (G5); 9.1% ± 1.4%-16.3% ± 5.3% (FL), up to n = 157 each). Low(est) MARD values were observed before breakfast and dinner, when subjects were in or near a fasting state. Especially after breakfast and lunch, MARD values were higher than average.Conclusions:Analytical performance of the two CGM systems, assessed by MARD, was found to vary markedly throughout the day. Activities of daily life likely triggered these variations. An increasing number of CGM users base therapeutic decisions on CGM values, and they should be aware of these variations of performance throughout the day. 相似文献
114.
目的探讨金属蛋白酶解离素28(ADAM28)反义核酸对人牙囊细胞(HDFC)内ADAM28蛋白表达的影响。方法应用反义核酸技术,设计并合成与ADAM28 mRNA特异序列互补的AS-ODN和正义对照S-ODN转染HDFC后,通过免疫细胞化学、RT-PCR和Western blot检测细胞中ADAM28的表达差异。结果ADAM28 AS-ODN转染HDFC后,在转录、翻译和蛋白水平细胞内ADAM28的表达均明显减弱,统计学分析有显著性差异(P<0.01)。结论ADAM28 AS-ODN可有效封闭HDFC内ADAM28的表达。 相似文献
115.
时间差攻击疗法治疗多重耐药的鲍曼不动杆菌感染的探究 总被引:1,自引:0,他引:1
目的 探索时间差攻击疗法治疗多重耐药的鲍曼不动杆菌感染的治疗方法 .方法 选择多重耐药的鲍曼不动杆菌感染患者67例,随机分为两组.试验组:先予磷霉素4g+5%葡萄糖100ml静脉滴注完毕后60min立即给予头孢哌酮/舒巴坦4 g+0.9%NS 250 ml静脉滴注,每日2次.对照组:予氨苄西林/舒巴坦3g+0.9%NS250ml静脉滴注(每天3次)+环丙沙星0.2 g静脉滴注(每天2次).疗程皆为11d,其余治疗方法 相同.结果 试验组采用的磷霉素+头孢哌酮/舒巴坦的时间差攻击疗法治疗多重耐药的鲍曼不动杆菌感染总有效率优于对照组采用文献推荐的氨苄西林/舒巴坦+环丙沙星治疗的总有效率(x2=9.56,P=0.023).结论 磷霉素+头孢哌酮/舒巴坦的时间差攻击疗法为治疗多重耐药的鲍曼不动杆菌感染的新途径. 相似文献
116.
目的 探索贵州省男性主要少数民族骨量异常的影响因素,为骨量异常的防控提供参考依据。 方法 基于中国多民族队列,采用多阶段分层整群抽样方法调查贵州省苗族、布依族、侗族男性共5 727名。采用随机森林算法、非条件logistic回归和限制性立方样条回归探讨骨量异常的影响因素。结果 骨量异常重要的前5名的因素依次是职业、午睡时长、年龄、BMI、静态行为。布依族(OR=1.223,95%CI:1.065~1.405)、年龄≥50岁(OR=1.254,95%CI:1.038~1.515)、吸烟(OR=1.191,95%CI:1.060~1.338)、有关节炎(OR=1.259,95%CI:1.001~1.583)和有骨折史(OR=1.528,95%CI:1.227~1.902)可能是骨量异常的危险因素。而农林牧渔劳动者(OR=0.787,95%CI:0.626~0.990)、午睡时长≥90分钟(OR=0.725,95%CI:0.612~0.858)、中水平体力活动(OR=0.818,95%CI:0.708~0.946)和高水平体力活动(OR=0.824,95%CI:0.696~0.975)可能是贵州省主要男性少数民族骨量异常的保护因素。BMI与骨量异常的患病关联强度呈非线性关系,业余静态行为时长与骨量异常的患病关联强度呈线性关系。结论 影响贵州省男性主要少数民族骨量异常的因素包括多方面,包括非可控因素和可控因素,建议加强对可控因素的管理以预防骨量异常的发生。 相似文献
117.
目的 探讨西南地区不同性别铁路职业人群高尿酸血症(HUA)患病情况及影响因素。方法 以2020年在中国铁路成都局集团公司联合成都大学附属医院开展的健康列车上体检的23 265名在职职工为研究对象,收集人口学特征和体检指标,采用单因素分析和logistic回归分析,不同性别分层分析。结果 HUA检出率为37.4%,其中男性(39.3%)明显高于女性(13.4%)(P<0.001)。在男性中饮酒、当前吸烟、体质指数(BMI)超标、高甘油三酯(TG)、高低密度脂蛋白胆固醇(LDL-C)、低高密度脂蛋白胆固醇(HDL-C)、慢性肾病(CKD)的检出率分别为71.8%、61.6%、55.6%、46.1%、38.5%、18.5%、2.3%,均高于女性(22.0%、7.3%、29.4%、18.3%、18.6%、5.4%、0.6%,P<0.001)。性别分层logistic回归分析显示:超重/肥胖、高TG、CKD是男性和女性HUA共同的危险因素(OR>1,P<0.05),已婚是共同的保护因素(OR<1,P<0.05)。另外,在男性,行车关键岗位(OR=1.07,95... 相似文献
118.
The current color-difference formulas were developed based on 2D samples and there is no standard guidance for the color-difference evaluation of 3D objects. The aim of this study was to test and optimize the CIELAB and CIEDE2000 color-difference formulas by using 42 pairs of 3D-printed spherical samples in Experiment I and 40 sample pairs in Experiment II. Fifteen human observers with normal color vision were invited to attend the visual experiments under simulated D65 illumination and assess the color differences of the 82 pairs of 3D spherical samples using the gray-scale method. The performances of the CIELAB and CIEDE2000 formulas were quantified by the STRESS index and F-test with respect to the collected visual results and three different optimization methods were performed on the original color-difference formulas by using the data from the 42 sample pairs in Experiment I. It was found that the optimum parametric factors for CIELAB were = 1.4 and = 1.9, whereas for CIEDE2000, = 1.5. The visual data of the 40 sample pairs in Experiment II were used to test the performance of the optimized formulas and the STRESS values obtained for CIELAB/CIEDE2000 were 32.8/32.9 for the original formulas and 25.3/25.4 for the optimized formulas. The F-test results indicated that a significant improvement was achieved using the proposed optimization of the parametric factors applied to both color-difference formulas for 3D-printed spherical samples. 相似文献
119.
Yugui Zhang Jiangtao Niu Shujuan Zhang Xinlei Si Tian-Tian Bian Hongwei Wu Donghui Li Yujing Sun Jing Jia Erdan Xin Xingke Yan Yuefeng Li 《Pharmaceutical biology》2022,60(1):1237
ContextHedysari Radix Praeparata Cum Melle (HRPCM) and Astragali Radix Praeparata Cum Melle (ARPCM) are used interchangeably in clinics to treat spleen-qi deficiency (SQD) symptom mainly including gastrointestinal dysfunction and decreased immunity, which has unknown differences in efficacy.ObjectiveTo investigate the differences between HRPCM and ARPCM on intervening gastrointestinal- and immune-function with SQD syndrome.Materials and methodsAfter the SQD model was established, the Sprague–Dawley (SD) rats were randomly divided into nine groups (n = 10): normal; model; Bu-Zhong-Yi-Qi Pills; 18.9, 12.6 and 6.3 g/kg dose groups of HRPCM and ARPCM. Gastrointestinal function including d-xylose, gastrin, amylase vasoactive intestinal peptide, motilin, pepsin, H+/K+-ATPase, Na+/K+-ATPase, sodium-glucose cotransporter 1 (SGLT1), glucose transporter 2 (GLUT2) and immune function including spleen and thymus index, blood routine, interleukin (IL)-2, IL-6, interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α), immunoglobulin (Ig) M, IgA, IgG and delayed-type hypersensitivity (DTH) were detected. Finally, the efficacy differences were analysed comprehensively by the fuzzy matter-element method.ResultsIn regulating immune, the doses differences in efficacy between HRPCM and ARPCM showed in the high-dose (18.9 g/kg), but there were no differences in the middle- and low- dose (12.6 and 6.3 g/kg); the efficacy differences were primarily reflected in levels of IL-6, IFN-γ, TNF-α and IgM in serum, and the mRNA expression of IL-6 and IFN-γ in the spleen. In regulating gastrointestinal, the efficacy differences were primarily reflected in the levels of D-xylose, MTL, and GAS in serum, and the mRNA and protein expression of SGLT1 and GLUT2 in jejunum and ileum.Discussion and conclusionsHRPCM is more effective than ARPCM on regulating gastrointestinal function and immune function with SQD syndrome. Therefore, we propose that HRPCM should be mainly used to treat SQD syndrome in the future. 相似文献
120.