全文获取类型
收费全文 | 35485篇 |
免费 | 2386篇 |
国内免费 | 469篇 |
专业分类
耳鼻咽喉 | 4149篇 |
儿科学 | 464篇 |
妇产科学 | 848篇 |
基础医学 | 2924篇 |
口腔科学 | 2296篇 |
临床医学 | 2444篇 |
内科学 | 2861篇 |
皮肤病学 | 823篇 |
神经病学 | 1306篇 |
特种医学 | 685篇 |
外国民族医学 | 291篇 |
外科学 | 3070篇 |
综合类 | 5418篇 |
现状与发展 | 4篇 |
一般理论 | 2篇 |
预防医学 | 3649篇 |
眼科学 | 484篇 |
药学 | 3140篇 |
10篇 | |
中国医学 | 1896篇 |
肿瘤学 | 1576篇 |
出版年
2024年 | 14篇 |
2023年 | 422篇 |
2022年 | 450篇 |
2021年 | 950篇 |
2020年 | 920篇 |
2019年 | 1022篇 |
2018年 | 1040篇 |
2017年 | 902篇 |
2016年 | 921篇 |
2015年 | 903篇 |
2014年 | 5014篇 |
2013年 | 4375篇 |
2012年 | 2935篇 |
2011年 | 2622篇 |
2010年 | 3911篇 |
2009年 | 3682篇 |
2008年 | 1835篇 |
2007年 | 815篇 |
2006年 | 671篇 |
2005年 | 577篇 |
2004年 | 513篇 |
2003年 | 442篇 |
2002年 | 382篇 |
2001年 | 350篇 |
2000年 | 319篇 |
1999年 | 244篇 |
1998年 | 194篇 |
1997年 | 181篇 |
1996年 | 162篇 |
1995年 | 179篇 |
1994年 | 141篇 |
1993年 | 121篇 |
1992年 | 130篇 |
1991年 | 112篇 |
1990年 | 85篇 |
1989年 | 96篇 |
1988年 | 91篇 |
1987年 | 58篇 |
1986年 | 50篇 |
1985年 | 92篇 |
1984年 | 76篇 |
1983年 | 56篇 |
1982年 | 61篇 |
1981年 | 36篇 |
1980年 | 43篇 |
1979年 | 35篇 |
1978年 | 24篇 |
1977年 | 26篇 |
1976年 | 23篇 |
1975年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
The aim of the present study was to establish survival rates, as well as crestal bone loss (CBL) of narrow diameter implants (NDI), compared to regular diameter implants (RDI). The current review followed the Enhancing the QUAlity and Transparency Of health Research guidelines and Preferred Reporting Items for Systematic Reviews and Meta‐Analyses statement. We searched main databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register) for articles addressing the focused question up to and including May 2018. Meta‐analyses were conducted for CBL and survival rates. Qualitatively, three clinical studies showed comparable CBL and survival rates between NDI and RDI at follow up. Only one study showed increased CBL around NDI compared to RDI. The overall weighted mean difference (WMD) for CBL (WMD = .06, 95% confidence interval [CI] = ‐.38‐.51, P=.76) and risk difference for survival rate (risk difference = .88, 95% CI = .22‐3.50, P=.85) were not significant between the NDI and RDI groups at follow up. NDI and RDI showed comparable CBL and survival rates. However, the findings of the present study should be interpreted with caution due to significant heterogeneity and the low number of included studies. Further randomized, controlled trials should be performed in order to obtain strong conclusions. 相似文献
22.
《Research in social & administrative pharmacy》2022,18(11):3988-3994
BackgroundScarce data exists regarding United States (US) national-level work productivity loss among adults with Multiple Sclerosis (MS).ObjectiveTo address this significant knowledge gap, we examined the national-level productivity loss among adults (18≤ age ≤64 years) with MS compared to propensity score matched non-MS controls.MethodsWe adopted a retrospective, cross-sectional, matched cohort study design with pooled data from alternate years (2005/2007/2009/2011/2013/2015) of the Medical Expenditure Panel Survey (MEPS). We included adults who were employed and alive during the calendar year. Clinical Classification System code of “80” was used to identify individuals with MS. We matched adults with MS to non-MS adults utilizing propensity scores generated based on age, gender, and race/ethnicity using a greedy matching algorithm (8:1-digit matching). Missed workdays measured productivity loss of MEPS respondents. We selected Negative Binomial Regression (NBR) analysis as the count data model for this study. Analyses were conducted using SAS 9.4 and STATA 15.0 and accounted for the complex survey design of MEPS to generate US national-level estimates.ResultsThe final propensity-score matched sample consisted of 104 and 312 (unweighted) adults with and without MS, respectively. US national-level mean [Standard Error (SE)] annual missed workdays among individuals with MS [8.94 (SE:1.59)] was significantly higher (p = 0.001) compared to propensity score matched non-MS controls [3.15 (SE:0.40)]. After adjusting for several factors, NBR showed an approximately two-fold higher rate of missed work days among individuals with MS compared to propensity score matched non-MS controls (Incidence Rate Ratio: 1.98, 95% Confidence Interval: 1.18–3.33). Severity of pain, marital status, region, and hypertension also negatively impacted work productivity in this sample.ConclusionsIndividuals with MS in the US experience significantly higher productivity loss compared to propensity score matched non-MS controls. Interventions (e.g., improved management of MS symptoms) are warranted to reduce productivity loss among individuals with MS. 相似文献
23.
24.
25.
《Obesity research & clinical practice》2022,16(6):447-456
It has been widely demonstrated that there are a broad range of individual responses to all weight management regimens, often masked by reports of the mean. Identifying features of responders and non-responders to weight loss regimens enables a more tailored approach to the provision of weight management advice. Low-carbohydrate diets are currently popular, and anecdote suggests that males are more successful at losing weight using this approach. This is feasible given the physiological and socio-psychological differences between the genders. We analysed the extent and variation in weight change for males and females separately through a systematic search for all low-carbohydrate diet trials published since 1985. Very few studies compared weight loss outcomes by gender and, of those that did, most lacked supporting data. The majority of studies reported no gender difference but when a gender difference was found, males were more frequently reported as losing more weight than females on a low-carbohydrate diet. The lack of gender stratification in weight loss trials is concerning, as there are a range of gender-based factors that affect weight loss outcomes. This study highlights the importance of examining weight change for males and females separately, since as failure to do so may mask any potential differences, which, if detected, could assist with better weight loss outcomes. 相似文献
26.
《Obesity research & clinical practice》2022,16(5):400-406
AimThe current pediatric obesity health challenge necessitates a better understanding of the factors affecting weight loss success during interventions. The aim of this observational study was to test the impact of the rate of initial weight loss and body weight variability on weight loss during a 9-month residential, multidisciplinary weight loss program in adolescents with obesity.MethodsThis retrospective study considered a whole sample of 510 adolescents with obesity (12–16 years, 435 girls). Body weight assessment was performed before (T0) and each week during the 9 months of a multidisciplinary weight loss program. Initial weight change (week 4-W4) and overall weight change at week 12 (T1) and the end of the intervention (T2) were considered. Participants were divided into three groups (tertiles), based on their percentage of weight loss between T0 and W4; and weight variability was expressed by the root mean square error (RMSE) around each participant’s regression line at each considered period (W4, T1, T2).ResultsAdolescents with lower initial weight loss at W4 (tertile 3) displayed the lesser weight loss at T1 and T2 compared with adolescents in tertile 1 and 2. The RMSE was positively associated with the percentage of weight loss of the period considered, but when the analyses were adjusted for age and initial body weight, there was no more significant association.ConclusionsThe rate of weight loss during the first few weeks is crucial for weight loss success, and weight variability is positively associated with weight loss in adolescents with obesity. Overall, results show that initial body weight is a determinant characteristic to consider during a lifestyle intervention. Further studies are thus needed to better understand the relationship between body weight change patterns and weight loss during the dynamic state that is adolescence. 相似文献
27.
28.
29.
孟令华 《临床超声医学杂志》2021,23(10)
心脏瓣膜病是较常见的心脏病,随着病情进展可导致心脏血流动力学发生显著变化,血流向量成像技术(VFM)既可用于观察心腔内血流流场的变化,又可用于评估心脏局部和整体功能的改变。本文就VFM技术对于心脏瓣膜疾病的研究进展做一综述。 相似文献
30.
目的探讨以指南为依据的肿瘤放疗患者营养教育咨询方案 在降低质子重离子治疗期间显著体重下降发生率方面的有效性。方法以质子重离子治疗期间的肿瘤放疗患者为研究对象 采用历史对照研究设计 方案实施前以年月至月收治的患者为对照组 方案实施后以年月至月收治的患者为试验组。对照组在方案实施前仍实行原有的常规护理 试验组给予以指南为依据的营养教育咨询方案。结果本研究共纳入例肿瘤患者 其中对照组例 试验组例 两组平均年龄为岁和岁 %和%为头颈部肿瘤患者。放疗期间对照组平均体重下降. kg 平均体重丢失.% 显著体重下降发生率为.% 《肿瘤代谢与营养电子杂志》2021,8(1):54-57
目的探讨以指南为依据的肿瘤放疗患者营养教育咨询方案,在降低质子重离子治疗期间显著体重下降发生率方面
的有效性。方法以质子重离子治疗期间的肿瘤放疗患者为研究对象,采用历史对照研究设计,方案实施前以2016年1月至12月
收治的患者为对照组,方案实施后以2018年1月至8月收治的患者为试验组。对照组在方案实施前仍实行原有的常规护理,试验
组给予以指南为依据的营养教育咨询方案。结果本研究共纳入713例肿瘤患者,其中对照组374例,试验组339例,两组平均年
龄为54岁和53岁,45%和49%为头颈部肿瘤患者。放疗期间对照组平均体重下降0.51 kg,平均体重丢失0.75%,显著体重下降
发生率为11.2%(42例);试验组体重下降0.66 kg,平均体重丢失0.90%,显著体重下降发生率为9.4%(32例)。在控制放疗总剂量、
射线类型、肿瘤部位、同期化疗和性别的混杂因素影响后,试验组显著体重下降的风险下降了34%(OR=0.66,95%CI=0.48~0.91)。
结论以指南为依据的肿瘤放疗患者营养教咨询方案能够帮助改善质子重离子治疗期间的患者营养状态,有效降低显著体重下
降的风险。 相似文献