全文获取类型
收费全文 | 91023篇 |
免费 | 7374篇 |
国内免费 | 2209篇 |
专业分类
耳鼻咽喉 | 977篇 |
儿科学 | 1975篇 |
妇产科学 | 1255篇 |
基础医学 | 8169篇 |
口腔科学 | 2256篇 |
临床医学 | 10023篇 |
内科学 | 11921篇 |
皮肤病学 | 2393篇 |
神经病学 | 6501篇 |
特种医学 | 2349篇 |
外国民族医学 | 4篇 |
外科学 | 5426篇 |
综合类 | 12381篇 |
现状与发展 | 8篇 |
一般理论 | 2篇 |
预防医学 | 12769篇 |
眼科学 | 1065篇 |
药学 | 10187篇 |
67篇 | |
中国医学 | 6733篇 |
肿瘤学 | 4145篇 |
出版年
2024年 | 200篇 |
2023年 | 1489篇 |
2022年 | 2330篇 |
2021年 | 3463篇 |
2020年 | 3222篇 |
2019年 | 2970篇 |
2018年 | 3005篇 |
2017年 | 3006篇 |
2016年 | 2897篇 |
2015年 | 2829篇 |
2014年 | 6261篇 |
2013年 | 6673篇 |
2012年 | 5797篇 |
2011年 | 6049篇 |
2010年 | 4781篇 |
2009年 | 4404篇 |
2008年 | 4674篇 |
2007年 | 4765篇 |
2006年 | 4077篇 |
2005年 | 3559篇 |
2004年 | 2887篇 |
2003年 | 2659篇 |
2002年 | 2076篇 |
2001年 | 1948篇 |
2000年 | 1606篇 |
1999年 | 1456篇 |
1998年 | 1086篇 |
1997年 | 1134篇 |
1996年 | 939篇 |
1995年 | 958篇 |
1994年 | 845篇 |
1993年 | 669篇 |
1992年 | 710篇 |
1991年 | 640篇 |
1990年 | 535篇 |
1989年 | 521篇 |
1988年 | 498篇 |
1987年 | 438篇 |
1986年 | 352篇 |
1985年 | 373篇 |
1984年 | 305篇 |
1983年 | 234篇 |
1982年 | 252篇 |
1981年 | 204篇 |
1980年 | 185篇 |
1979年 | 132篇 |
1978年 | 112篇 |
1977年 | 95篇 |
1976年 | 73篇 |
1975年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
41.
42.
目的:观察稀土化合物硝酸钇[Y(NO3)3]亚慢性(90 d)暴露对大鼠学习记忆能力的影响,并探究其可能的机制,为全面评估稀土元素钇的健康风险提供科学依据。方法:选用刚离乳(PND21)SD雌性大鼠,根据质量随机分为4组,分别为对照组(ddH2O),Y(NO3)3低剂量组[10 mg/(kg·d)]、中剂量组[40 mg/(kg·d)]和高剂量组[160 mg/(kg·d)],每组15只。连续灌胃受试物90 d后进行旷场实验、高架十字迷宫实验、转棒实验、Morris水迷宫实验。水迷宫检测后,每组取5只雌鼠心脏原位灌注,进行脑组织病理学检查。每组剩余10只雌鼠摘取脑组织,紫外分光光度计检测雌鼠大脑皮质和海马中谷氨酸(Glu)的含量;Western blot检测海马组织中N-甲基-D-天冬氨酸(NMDA)受体蛋白表达情况。结果:与对照组相比,硝酸钇90 d暴露后,转棒实验中160 mg/(kg·d)剂量组大鼠在棒时间、在棒圈数、掉落速度明显升高(P<0.05)。在Morris水迷宫定位航向实验第4天时,40、160 mg/(kg·d)剂量组大鼠逃避潜伏期明显降低(P<0.05);Morris水迷宫空间探索实验中,40 mg/(kg·d)剂量组大鼠穿越平台次数、目标象限游泳时间明显增加(P<0.05);160 mg/(kg·d)剂量组穿越平台次数、进入目标象限次数、目标象限游泳时间明显增加(P<0.05);160 mg/(kg·d)剂量组大鼠东北、东南、西南象限的逃避潜伏期明显低于西北象限的逃避潜伏期(P<0.05)。160 mg/(kg·d)剂量组大鼠海马中Glu含量和NMDA受体NR1含量均明显低于对照组(P<0.05)。40和160 mg/(kg·d)剂量组大鼠海马中NMDA受体NR2A含量明显低于对照组(P<0.05)。结论:硝酸钇亚慢性(90 d)暴露可以引起雌性大鼠空间学习记忆能力增强;硝酸钇可能通过降低海马组织神经元细胞外Glu含量,抑制NMDA受体激活,增强雌性大鼠的空间学习记忆能力。 相似文献
43.
44.
45.
目的 解析真实世界中乳腺恶性肿瘤患者的人群特征、诊断特征、中西医用药特征,为乳腺癌的临床防治提供参考。方法 采集2002年2月至2015年5月全国60家三级甲等医 院信息系统(Hospital Information System,HIS)中,出院诊断为“乳腺癌”的患者用药信息,采用SAS9.3统计软件,对人口学信息、诊断信息、医嘱用药信息等进行描述性分析。结果 39798例乳腺癌患者,平均年龄(50.93者,平均年龄)岁;多以门诊入院,入院病情以“一般”为主;合并疾病主要为高血压,骨肿瘤,联用西药以抑制肿瘤细胞增殖、治疗并发症、缓解放化疗不良反应为主;中医辨证以痰瘀互结证,气阴两虚证,肝气淤滞证,脾气亏虚证型最为常见,临床清热解毒剂、益气扶正剂,活血化瘀剂应用较多。结论 乳腺癌中西医结合治疗,联用药物广泛,临床治疗基本符合临床指南。 相似文献
46.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2020,30(10):1732-1741
AimsTo explore the association between WWI and the incidence of HTN in the Rural Chinese Cohort Study.Methods and ResultsWe examined data for 10,338 non-hypertensive participants (39.49% men) aged ≥ 18 years from the Rural Chinese Cohort Study who completed a baseline examination during 2007–2008 and follow-up during 2013–2014. WWI was calculated as waist circumference (cm) divided by the square root of weight (kg). Multiple logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the probability of HTN across four WWI categories. Restricted cubic splines analysis was used to model the dose–response association of WWI and HTN. A total of 2078 participants had HTN during a median follow-up of 6 years. After adjusting for potential confounders, as compared with the lowest WWI category (<9.94 cm/√kg), with WWI 9.94 to 10.42, 10.42 to 10.91 and ≥ 10.91 cm/√kg, the ORs (95% CIs) for HTN were 1.12 (0.93–1.35), 1.40 (1.17–1.69) and 1.50 (1.24–1.82), respectively. Results of the sensitivity analyses were robust. The ORs were generally consistent on subgroup analysis by sex, smoking status, systolic blood pressure and diastolic blood pressure. Multiple logistic regression models with restricted cubic splines showed a non-linear positive association between WWI and HTN (Pnonlinearity < 0.001).ConclusionThe highest WWI category was significantly associated with increased risk of HTN. Our findings may facilitate the development and promotion of obesity prevention strategies aimed at reducing the risk of HTN and provide evidence for healthcare policy in rural China. 相似文献
47.
《Journal of Science and Medicine in Sport》2019,22(9):1038-1043
ObjectivesGrowing evidence of the importance of motor competence for developing a healthy lifestyle has been established in the last decade. Nonetheless, no single instrument or observation tool have been able to fully measure this construct, particularly because most were built for the diagnosis of children in risk for motor impairment; are limited to a few years of the developmental span; lack objectivity in the assessment protocols; or do not include the locomotor, stability, and manipulative components. This led to the difficulty of comparing researches, and longitudinally follow children into adulthood. Recently, a novel proposal to assess motor competence was presented - the Motor Competence Assessment (MCA) - and this study aims to present the MCA normative data from 3-to-23 years.Design and methodsTwo thousand and eighty-seven participants (1102 boys) between 3 and 23 years of age were evaluated in the MCA (standing long jump, 10 m shuttle run, throwing velocity, kicking velocity, lateral jumps, shifting platforms). Results for each test were introduced in the LMS Chartmaker 2.3. The best model for test and sex was used, resulting in normative curves and percentile values.ResultsFinal norms showed a good fit to the instrument developmental expectations, allowing to differentiate and classify performances along the age interval.ConclusionsThe MCA age- and sex- normative values allow to assess motor competence from childhood to early adulthood. Future directions will include obtaining a total MCA score and the normative scores for the MCA components (stability, locomotion, object control), and to expand the norms to adulthood and old age. 相似文献
48.
Holly Wagoner 《Teaching and learning in medicine》2019,31(3):270-278
Phenomenon: Academic health centers face significant challenges trying to improve medical education while meeting patient care needs. In response to problems with traditional forms of didactic education, many residency programs have transitioned to Academic Half Day (AHD), a curricular model in which learning is condensed into half-day blocks. In this model, trainees have protected educational time free from clinical responsibilities. However, an understanding of the impact on attending physicians and patient care when residents depart clinical sites for learning activities has not been well described. We sought to explore attending physicians’ perspectives when residents depart clinical sites to attend AHD. Approach: We performed a qualitative study with a grounded theory approach using individual semistructured interviews (December 2016–April 2017) of attending physicians who worked at inpatient and emergency department clinical sites from which residents departed to attend AHD. We used the constant comparative method, generating codes using an iterative approach and continuing sampling until saturation was reached. Major themes were identified and disagreements were resolved by consensus. Findings: Fifteen attending physicians from 6 clinical services were interviewed. Data analysis yielded 5 themes: emotional strain of workload, technology and systems challenges, patient safety and care concerns, disrupted resident learning, and the challenge to optimize resident education. Attending physicians, already working on busy services, felt frustrated and perceived having an increased workload when residents departed for AHD. They were concerned about safely entering orders in the electronic health record, impeded patient workflow, and further disruption of resident schedules already disrupted by duty hour restrictions and continuity clinic. Attending physicians described the importance of experiential learning from caring for patients and from structured didactic learning; however, the optimal balance was uncertain. Insights: We found that attending physicians experienced significant emotional strain, faced technological challenges, and were concerned about impeded workflow and patient safety when residents departed clinical sites for AHD. This is likely to be true whenever residents are pulled out of the clinical setting for any reason. Educators need to partner with hospital administrators to provide appropriate support for attending physicians when residents leave clinical sites, evaluate the effectiveness of different educational models, and determine how structured learning activities fit into the overall curriculum. 相似文献
49.
50.
Is it possible to make a diagnosis of raw,heated, and baked egg allergy in children using cutoffs? A systematic review
下载免费PDF全文
![点击此处可从《Pediatric allergy and immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)