全文获取类型
收费全文 | 221285篇 |
免费 | 40720篇 |
国内免费 | 9783篇 |
专业分类
耳鼻咽喉 | 3637篇 |
儿科学 | 3772篇 |
妇产科学 | 3244篇 |
基础医学 | 15832篇 |
口腔科学 | 7181篇 |
临床医学 | 40630篇 |
内科学 | 41372篇 |
皮肤病学 | 4523篇 |
神经病学 | 17875篇 |
特种医学 | 8816篇 |
外国民族医学 | 59篇 |
外科学 | 32088篇 |
综合类 | 24647篇 |
现状与发展 | 71篇 |
一般理论 | 7篇 |
预防医学 | 22513篇 |
眼科学 | 5152篇 |
药学 | 14475篇 |
94篇 | |
中国医学 | 7510篇 |
肿瘤学 | 18290篇 |
出版年
2024年 | 1146篇 |
2023年 | 6707篇 |
2022年 | 5436篇 |
2021年 | 8376篇 |
2020年 | 9693篇 |
2019年 | 5690篇 |
2018年 | 10569篇 |
2017年 | 11040篇 |
2016年 | 11466篇 |
2015年 | 13576篇 |
2014年 | 17427篇 |
2013年 | 18934篇 |
2012年 | 14110篇 |
2011年 | 14392篇 |
2010年 | 14488篇 |
2009年 | 15393篇 |
2008年 | 11078篇 |
2007年 | 9728篇 |
2006年 | 10553篇 |
2005年 | 8397篇 |
2004年 | 5971篇 |
2003年 | 5579篇 |
2002年 | 4842篇 |
2001年 | 4869篇 |
2000年 | 3629篇 |
1999年 | 3951篇 |
1998年 | 3409篇 |
1997年 | 3222篇 |
1996年 | 2908篇 |
1995年 | 2515篇 |
1994年 | 1880篇 |
1993年 | 1391篇 |
1992年 | 1389篇 |
1991年 | 1146篇 |
1990年 | 951篇 |
1989年 | 890篇 |
1988年 | 858篇 |
1987年 | 670篇 |
1986年 | 596篇 |
1985年 | 500篇 |
1984年 | 354篇 |
1983年 | 369篇 |
1982年 | 280篇 |
1981年 | 241篇 |
1980年 | 143篇 |
1979年 | 115篇 |
1978年 | 145篇 |
1977年 | 135篇 |
1976年 | 89篇 |
1974年 | 84篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
儿童哮喘的发病率逐年上升.基于卫生假说,抗生素使用可能减少了微生物暴露,从而增加了过敏性疾病发生的风险.近十年来,就早期抗生素暴露与儿童哮喘的关系进行的大量的流行病学调查的结果并不一致.大多数回顾性研究发现正相关联系,但前瞻性研究未发现联系或联系强度较弱.逆向因果和指示混淆可部分解释两者的关系,但也难以否定因果关系的存在. 相似文献
3.
4.
Haya Mohammed BSc MChB M. Yousuf Salmasi MRCS Massimo Caputo PhD Gianni D. Angelini PhD Hunaid A. Vohra PhD 《Journal of cardiac surgery》2020,35(6):1209-1219
Background
Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.Methods
PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.Results
Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.Conclusions
MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.5.
6.
7.
Srdan Verstovsek MD PhD Jean-Jacques Kiladjian MD PhD Alessandro M. Vannucchi MD Ruben A. Mesa MD FACP Peg Squier MD PhD J. E. Hamer-Maansson MSPH Claire Harrison MD 《Cancer》2023,129(11):1681-1690
Background
In a pooled analysis of the phase 3 Controlled Myelofibrosis Study With Oral JAK Inhibitor Treatment I (COMFORT-I) and COMFORT-II clinical trials, adult patients with intermediate-2 or high-risk myelofibrosis who received oral ruxolitinib at randomization or after crossover from placebo or best available therapy (BAT) had improved overall survival (OS).Methods
This post hoc analysis of pooled COMFORT data examined relevant disease outcomes based on the disease duration (≤12 or >12 months from diagnosis) before ruxolitinib initiation.Results
The analysis included 525 patients (ruxolitinib: ≤12 months, n = 84; >12 months, n = 216; placebo/BAT: ≤12 months, n = 66; >12 months, n = 159); the median age was 65.0–70.0 years. Fewer thrombocytopenia and anemia events were observed among patients who initiated ruxolitinib treatment earlier. At Weeks 24 and 48, the spleen volume response (SVR) was higher for patients who initiated ruxolitinib earlier (47.6% vs. 32.9% at Week 24, p = .0610; 44.0% vs. 26.9% at Week 48, p = .0149). In a multivariable analysis of factors associated with spleen volume reduction, a logistic regression model that controlled for confounding factors found that a significantly greater binary reduction was observed among patients with shorter versus longer disease duration (p = .022). At Week 240, OS was significantly improved among patients who initiated ruxolitinib earlier (63% [95% CI, 51%‒73%] vs. 57% [95% CI, 49%‒64%]; hazard ratio, 1.53; 95% CI, 1.01‒2.31; p = .0430). Regardless of disease duration, a longer OS was observed for patients who received ruxolitinib versus those who received placebo/BAT.Conclusions
These findings suggest that earlier ruxolitinib initiation for adult patients with intermediate-2 and high-risk myelofibrosis may improve clinical outcomes, including fewer cytopenia events, durable SVR, and prolonged OS.Plain Language Summary
- Patients with myelofibrosis, a bone marrow cancer, often do not live as long as the general population. These patients may also have an enlarged spleen and difficult symptoms such as fatigue.
- Two large clinical trials showed that patients treated with the drug ruxolitinib lived longer and had improved symptoms compared to those treated with placebo or other standard treatments.
- Here it was examined whether starting treatment with ruxolitinib earlier (i.e., within a year of diagnosis) provided benefits versus delaying treatment.
- Patients who received ruxolitinib within a year of diagnosis lived longer and experienced fewer disease symptoms than those whose treatment was delayed.
8.
Elizabeth A. Mosley PhD MPH Amy J. Schulz PhD MPH MSW Lisa H. Harris MD PhD Barbara A. Anderson PhD 《Women & health》2020,60(7):806-820
ABSTRACT Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood. 相似文献
9.
Tian-Yuan Xiong Fang-Yang Huang Qi Liu Yong Peng Yuan-Ning Xu Jia-Fu Wei 《Annals of medicine》2020,52(7):361-366
Abstract
Background
Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19. 相似文献10.