全文获取类型
收费全文 | 250397篇 |
免费 | 23079篇 |
国内免费 | 11198篇 |
专业分类
耳鼻咽喉 | 1529篇 |
儿科学 | 6063篇 |
妇产科学 | 3351篇 |
基础医学 | 47495篇 |
口腔科学 | 4856篇 |
临床医学 | 17147篇 |
内科学 | 41986篇 |
皮肤病学 | 4003篇 |
神经病学 | 19543篇 |
特种医学 | 4896篇 |
外国民族医学 | 81篇 |
外科学 | 17128篇 |
综合类 | 35470篇 |
现状与发展 | 51篇 |
一般理论 | 1篇 |
预防医学 | 11935篇 |
眼科学 | 3241篇 |
药学 | 29924篇 |
28篇 | |
中国医学 | 8262篇 |
肿瘤学 | 27684篇 |
出版年
2024年 | 615篇 |
2023年 | 3750篇 |
2022年 | 7719篇 |
2021年 | 9733篇 |
2020年 | 8258篇 |
2019年 | 9184篇 |
2018年 | 8668篇 |
2017年 | 8733篇 |
2016年 | 8821篇 |
2015年 | 10267篇 |
2014年 | 14513篇 |
2013年 | 16855篇 |
2012年 | 14986篇 |
2011年 | 17873篇 |
2010年 | 15097篇 |
2009年 | 14546篇 |
2008年 | 14169篇 |
2007年 | 13230篇 |
2006年 | 12185篇 |
2005年 | 10688篇 |
2004年 | 9450篇 |
2003年 | 8087篇 |
2002年 | 6543篇 |
2001年 | 5703篇 |
2000年 | 4782篇 |
1999年 | 4227篇 |
1998年 | 3639篇 |
1997年 | 3208篇 |
1996年 | 2624篇 |
1995年 | 2223篇 |
1994年 | 1864篇 |
1993年 | 1495篇 |
1992年 | 1219篇 |
1991年 | 1064篇 |
1990年 | 884篇 |
1989年 | 704篇 |
1988年 | 597篇 |
1987年 | 481篇 |
1986年 | 480篇 |
1985年 | 881篇 |
1984年 | 874篇 |
1983年 | 599篇 |
1982年 | 679篇 |
1981年 | 540篇 |
1980年 | 442篇 |
1979年 | 382篇 |
1978年 | 293篇 |
1977年 | 228篇 |
1976年 | 211篇 |
1975年 | 145篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
《Health & place》2022
PurposeAccording to the social determinants of health framework, income inequality is a potential risk factor for adverse mental health. However, few studies have explored the mechanisms suspected to mediate this relationship. The current study addresses this gap through a mediation analysis to determine if social support and community engagement act as mediators linking neighbourhood income inequality to maternal anxiety and depressive symptoms within a cohort of new mothers living in the City of Calgary, Canada.MethodsData collected at three years postpartum from mothers belonging to the All Our Families (AOF) cohort were used in the current study. Maternal data were collected between 2012 and 2015 and linked to neighbourhood socioeconomic data from the 2006 Canadian Census. Income inequality was measured using Gini coefficients derived from 2006 after-tax census data. Generalized structural equation models were used to quantify the associations between income inequality and mental health symptoms, and to assess the potential direct and indirect mediating effects of maternal social support and community engagement.ResultsIncome inequality was not significantly associated with higher depressive symptoms (β = 0.32, 95%CI = −0.067, 0.70), anxiety symptoms (β = 0.11, 95%CI = −0.39, 0.60), or lower social support. Income inequality was not associated with community engagement. For the depression models, higher social support was significantly associated with lower depressive symptoms (β = −0.13, 95%CI = −0.15, −0.097), while community engagement was not significantly associated with depressive symptoms (β = 0.059, 95%CI = −0.15, 0.27). Similarly, for the anxiety models, lower anxiety symptoms were significantly associated with higher levels of social support (β = −0.17, 95%CI = −0.20, −0.13) but not with higher levels of community engagement (β = 0.14, 95%CI = −0.14, 0.41).ConclusionThe current study did not find clear evidence for social support or community engagement mediating the relationship between neighbourhood income inequality and maternal mental health. Future investigations should employ a broader longitudinal approach to capture changes in income inequality, potential mediators, and mental health symptomatology over time. 相似文献
3.
《Cancer cell》2022,40(3):318-334.e9
- Download : Download high-res image (268KB)
- Download : Download full-size image
4.
Clinical characteristics of pediatric patients with COVID-19 between Omicron era vs. pre-Omicron era
《Journal of infection and chemotherapy》2022,28(11):1501-1505
IntroductionDetailed data on clinical characteristics in children with the omicron strain of SARS-COV-2 are limited.MethodsWe conducted a retrospective observational study of children with COVID-19 at the National Center for Child Health and Development to evaluate the clinical manifestations during and before the emergence of the omicron variant. Only symptomatic patients without underlying diseases were included. Participants were divided into two temporal groups: the “omicron era” (1/2022–2/2022) and the “pre-omicron era,” where the delta variant predominated (7/2021–11/2021). The patients were subclassified into an older vaccine-eligible group (aged 12–17 years), a younger vaccine-eligible group (aged 5–11 years), and a vaccine-ineligible group (aged 0–4 years).ResultsWe compared 113 patients in the omicron era with 106 in the pre-omicron era. Most patients in both eras had non-severe disease, and no patients required mechanical ventilation or died. Among patients aged 0–4 years, sore throat and hoarseness were more common during the omicron era than the pre-omicron era (11.1% vs. 0.0% and 11.1% vs. 1.5%, respectively). Croup syndrome was diagnosed in all patients with hoarseness. Among patients aged 5–11 years, vomiting was more frequent during the omicron era (47.2%) than during the pre-omicron era (21.7%). Cough and rhinorrhea were less common during the omicron era in patients aged 0–4 and 5–11 years, respectively, than during the pre-omicron era.ConclusionsIn children with COVID-19, clinical manifestations differed between the omicron and pre-omicron eras. In the Omicron era, croup syndrome was more frequent in vaccine-ineligible children. 相似文献
5.
背景 致密性骨炎(OCI)和其他疾病有时难以鉴别,探讨血清骨转换生化标志物可为OCI的鉴别诊断提供依据。 目的 探索女性OCI患者的血清骨转换生化标志物的水平变化及临床意义。 方法 回顾性选取2013年6月至2022年2月在北京积水潭医院门诊及住院诊断为OCI的61例女性患者作为观察组,年龄15~50岁,平均(33.8±6.6)岁,病程2周~15年。选择同期61例女性体检健康者作为对照组,年龄15~48岁,平均(35.6±7.6)岁。比较两组一般临床资料和血清骨转换生化标志物水平,并对血清骨转换生化标志物与病情相关指标进行相关性分析。 结果 观察组血清白蛋白(45.4±2.9)g/L低于对照组(46.5±2.8)g/L(t=2.190,P<0.05)。血清骨转换生化标志物比较结果显示,观察组血清1型胶原羧基末端肽β特殊序列(β-CTX)〔0.28(0.23,0.37)μg/L〕、N-端骨钙素(OC)〔13.1(11.2,16.2)μg/L〕、25-羟维生素D3〔25-(OH)VD3〕〔(14.1±5.1)μg/L〕低于对照组〔0.36(0.29,0.48)μg/L,15.6(13.7,17.3)μg/L,(17.5±6.6)μg/L〕(Z=-2.983、-3.255,t=3.081,P<0.05)。长病程亚组OC水平〔14.6(12.4,18.5)μg/L〕高于短病程亚组〔11.7(10.2,14.0)μg/L〕(Z=-2.407,P<0.05)。多孕亚组β-CTX〔0.25(0.22,0.32)μg/L〕、OC水平〔12.2(10.3,15.0)μg/L〕低于非多孕亚组〔0.33(0.26,0.44)μg/L、13.4(12.0,18.8)μg/L〕(Z=-2.486、-1.897,P<0.05)。相关性分析显示,观察组血清1型前胶原氨基端延长肽(tP1NP)与妊娠次数、生产次数均呈负相关(rs=-0.276、-0.298,P<0.05),OC与体质指数(BMI)、视觉模拟评分法(VAS)评分、妊娠次数均呈负相关(rs=-0.284、-0.374、-0.360,P<0.05),25-(OH)VD3水平与BMI呈正相关(rs=0.275,P<0.05)。 结论 女性OCI患者血清OC、β-CTX水平明显降低,可为鉴别其他疾病提供依据;血清OC水平可以反映OCI患者的严重程度,同时OC水平与患者妊娠次数相关;tP1NP与妊娠次数、生产次数相关。 相似文献
6.
7.
Wuteng Cao Huabin Hu Jiao Li Qianyu Wu Lishuo Shi Biao Li Jie Zhou Xinhua Wang Junhong Chen Chao Wang Huaiming Wang Weihao Deng Yan Huang Yanhong Deng 《International journal of cancer. Journal international du cancer》2023,153(11):1894-1903
Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy. 相似文献
8.
《Cancer cell》2022,40(8):835-849.e8
- Download : Download high-res image (220KB)
- Download : Download full-size image
9.
10.