全文获取类型
收费全文 | 5374篇 |
免费 | 689篇 |
国内免费 | 178篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 207篇 |
妇产科学 | 55篇 |
基础医学 | 227篇 |
口腔科学 | 108篇 |
临床医学 | 529篇 |
内科学 | 661篇 |
皮肤病学 | 26篇 |
神经病学 | 163篇 |
特种医学 | 92篇 |
外国民族医学 | 4篇 |
外科学 | 382篇 |
综合类 | 796篇 |
一般理论 | 1篇 |
预防医学 | 856篇 |
眼科学 | 92篇 |
药学 | 745篇 |
8篇 | |
中国医学 | 889篇 |
肿瘤学 | 359篇 |
出版年
2024年 | 32篇 |
2023年 | 223篇 |
2022年 | 377篇 |
2021年 | 450篇 |
2020年 | 442篇 |
2019年 | 404篇 |
2018年 | 357篇 |
2017年 | 272篇 |
2016年 | 193篇 |
2015年 | 240篇 |
2014年 | 476篇 |
2013年 | 420篇 |
2012年 | 336篇 |
2011年 | 337篇 |
2010年 | 262篇 |
2009年 | 187篇 |
2008年 | 175篇 |
2007年 | 181篇 |
2006年 | 155篇 |
2005年 | 106篇 |
2004年 | 83篇 |
2003年 | 65篇 |
2002年 | 61篇 |
2001年 | 23篇 |
2000年 | 30篇 |
1999年 | 23篇 |
1998年 | 18篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1985年 | 22篇 |
1984年 | 38篇 |
1983年 | 34篇 |
1982年 | 21篇 |
1981年 | 32篇 |
1980年 | 19篇 |
1979年 | 23篇 |
1978年 | 15篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1975年 | 9篇 |
1974年 | 5篇 |
1973年 | 8篇 |
1972年 | 2篇 |
排序方式: 共有6241条查询结果,搜索用时 15 毫秒
1.
2.
3.
《Vaccine》2022,40(6):904-911
BackgroundGSK initiated a Pregnancy Registry in the United States (US) for the reduced-antigen-content tetanus-diphtheria-acellular pertussis (Tdap; Boostrix, GSK) vaccine with the aim to detect and describe pregnancy outcomes in women vaccinated with Boostrix 28 days before estimated conception or during pregnancy.MethodsVoluntary reports of pregnancy exposure to Boostrix received from spontaneous and post-marketing surveillance sources in the US were assessed. Reports were classified as prospective or retrospective based on the knowledge of pregnancy outcomes at the time of reporting. For completeness, reports of exposure to Boostrix or to the Tdap-inactivated poliovirus vaccine (Boostrix-IPV, GSK) reported to the global safety database from countries outside the US were also evaluated.ResultsFrom May 2005 to August 2019, 1517 (1455 prospective and 62 retrospective) pregnancy reports were received in the Boostrix US Pregnancy Registry. Of the prospective reports, 250 had known outcomes: 244 live infants with no apparent birth defects (BDs), three live infants with BDs, and three spontaneous abortions with no apparent BDs. Of the retrospective reports, 55 had known outcomes: 33 live infants with no apparent BDs, 16 live infants with BDs, one spontaneous abortion with no apparent BDs, four stillbirths with no apparent BDs, and one stillbirth with BDs. Cumulatively, 1321 pregnancy reports (1006 for Boostrix; 315 for Boostrix-IPV) were received from countries outside the US. Of these, 163 prospective reports and 551 retrospective reports had known outcomes. Results were in line with those from the Boostrix US Pregnancy Registry.ConclusionsData currently available from the Boostrix US Pregnancy Registry and from countries outside the US suggested that exposure to Boostrix or Boostrix-IPV during pregnancy does not raise safety concerns related to adverse pregnancy outcomes or BDs. 相似文献
4.
Objective
To empirically assess the effect of adopting Affordable Care Act's Community First Choice (CFC) option on overall state home and community-based services (HCBS) expenditures as well as distribution of HCBS expenditures across different HCBS mechanisms. We also explore the heterogeneous effect of CFC across adopting states.Data Source
We used data from the Medicaid Long Term Services and Support (LTSS) expenditure reports prepared by Truven Analytics and Mathematica for the Centers for Medicare & Medicaid Services from 2008–2018 for all 48 states and the District of Columbia.Study Design
An event-study difference-in-differences model was used to estimate the effect of CFC on HCBS expenditures using Medicaid LTSS expenditure reports from 2008–2018. We also employ the synthetic control method to unmask heterogeneity across CFC adopting states using data from 2008–2018.Data Collection/Extraction Methods
Not applicable.Principal Findings
Overall, CFC was not associated with a change in HCBS expenditures per capita or HCBS expenditures as a proportion of LTSS expenditures. However, there appears to be an increase in HCBS expenditures among states that were institutionally-oriented prior to CFC adoption. Additionally, CFC adoption was associated with an overall decrease in expenditures in alternative HCBS mechanisms (Personal Care Services State Plan Option and 1915(c) waivers), suggesting potential substitution across overlapping programs.Conclusion
Results indicate heterogeneity across states adopting CFC. More institutionally-oriented states appear to use CFC to expand HCBS. In contrast, more HCBS-oriented states appear to employ CFC to strategically restructure their overall portfolio and processes. 相似文献5.
重楼是我国传统的名贵中药,七叶一枝花为历版《中国药典》收载的重楼药材两个基原植物之一,具有清热解毒、消肿止痛、活血化瘀等功效,其主要活性成分为甾体皂苷类物质。由于重楼市场需求量剧增和七叶一枝花成药时间较长,导致大量依靠人工种植。然而,人工种植过程中产地、采收年限和采收月份都会影响七叶一枝花的甾体皂苷含量。本文系统地总结了七叶一枝花中主要活性成分甾体皂苷的种类,以及不同产地、不同生长年限及不同采收月份的七叶一枝花根茎中甾体皂苷含量差异的研究现状,以期为进一步研究七叶一枝花品质差异、野生资源驯化及规范化种植提供参考。 相似文献
6.
《Journal of pediatric surgery》2023,58(9):1613-1617
BackgroundThe goal of this study was to characterize contemporary performance benchmarks and risk factors associated with negative appendectomy (NA) in children with suspected appendicitis.MethodsA multicenter retrospective cohort analysis of children undergoing appendectomy for suspected appendicitis was performed using data from the 2016–2021 NSQIP-Pediatric Appendectomy Targeted Public Use Files. Multivariable regression was used to evaluate the influence of year, age, sex, and WBC count on NA rate, and to generate rate estimates for NA based on different combinations of demographic characteristics and WBC profiles.Results100,322 patients were included from 140 hospitals. The overall NA rate was 2.4%, and rates decreased significantly during the study period (2016: 3.1% vs. 2021: 2.3%, p < 0.001). In adjusted analyses, the highest risk for NA was associated with a normal WBC (<9000/mm3; OR 5.31 [95% CI: 4.87–5.80]), followed by female sex (OR 1.55 [95% CI: 1.42–1.68]) and age <5 years (OR 1.64 [95% CI 1.39, 1.94]). Model-estimated risk for NA varied significantly across demographic and WBC strata, with a 14.4-fold range in rates between subgroups with the lowest and highest predicted risk (males 13–17 years with elevated WBC [1.1%] vs. females 3–4 years with normal WBC [15.8%]).ConclusionsContemporary NA rates have decreased over time, however NA risk remains high in children without a leukocytosis, particularly for girls and children <5 years of age. These data provide contemporary performance benchmarks for NA in children with suspected appendicitis and identify high-risk populations where further efforts to mitigate NA risk should be targeted.Level of EvidenceIII. 相似文献
7.
癫痫是一种常见的神经系统疾病,其反复发作,迁延难愈,对患者的身心造成极大危害。抗癫痫药带来良好的治疗作用的同时也伴发着诸多身心损伤的不良反应。中医药治疗癫痫由来已久,目前除不断丰富传统中医理论治疗癫痫的认知理论外,从分子生物学角度研究中医药治疗癫痫的细胞信号传导机制发展迅速。通过对国内外文献检索发现,癫痫发生与细胞增殖、凋亡、自噬、炎症反应、免疫应答等病理生理过程密切相关;同时中西药的现代医学研究表明,无论是中药单体、单味中药甚至中药复方治疗癫痫的机制的研究均与文中所述信号通路有着直接或间接的关系,其可以通过调控相应信号通路的关键分子表达,达到抑制癫痫发生,控制癫痫发作,保护癫痫脑损伤的作用。该文通过对国内外研究现状进行总结,具体如下:①桔皮素,银杏内酯B等能通过激活磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/Akt)信号通路,抑制凋亡及氧化应激反应。②黄芩苷,蛇床子素等能通过抑制哺乳动物-雷帕霉素靶蛋白(mTOR)信号通路,抑制自噬。③灵芝多糖,黄芪甲苷等能通过抑制丝裂原活化蛋白激酶(MAPK)信号通路,减少细胞凋亡。④红景天苷,白藜芦醇等能通过激活核因子E2相关因子2/抗氧化反应元件/血红素加氧酶1(Nrf2/ARE/HO-1)信号通路,抗氧化应激反应及抑制凋亡。⑤姜黄素,黄芩苷等能通过抑制核转录因子-κB(NF-κB)信号通路,降低炎症反应及减少凋亡。以上总结旨在为中药治疗癫痫的深入研究提供参考依据,也为临床中药治疗癫痫提供新的思路。 相似文献
8.
功能性消化不良(functional dyspepsia, FD)是一种常见的功能性胃肠病(functional gastrointestinal disorder, FGID),属于中医“痞满”“胃脘痛”范畴,多因“气机升降失常”所致。目前,FD发病机制主要涉及脑肠互动异常、胃容受性受损、内脏敏感性增高、胃动力不足、幽门螺杆菌感染、十二指肠异常、心理精神因素等。随着罗马Ⅳ标准的颁布,十二指肠的作用在FD的发病中日益凸显。十二指肠高敏性、十二指肠黏膜屏障受损及十二指肠黏膜低度炎症等在FD病理生理过程中起着非常重要的作用,十二指肠可能是治疗FD的新靶点。本文综述FD发病中十二指肠的作用及中医药研究,为FD的基础研究及临床治疗提供理论依据。 相似文献
9.
10.