全文获取类型
收费全文 | 524595篇 |
免费 | 33920篇 |
国内免费 | 21531篇 |
专业分类
耳鼻咽喉 | 5731篇 |
儿科学 | 11337篇 |
妇产科学 | 11429篇 |
基础医学 | 62709篇 |
口腔科学 | 11780篇 |
临床医学 | 59802篇 |
内科学 | 84423篇 |
皮肤病学 | 8099篇 |
神经病学 | 29231篇 |
特种医学 | 22418篇 |
外国民族医学 | 267篇 |
外科学 | 62224篇 |
综合类 | 54033篇 |
现状与发展 | 74篇 |
一般理论 | 37篇 |
预防医学 | 37783篇 |
眼科学 | 13820篇 |
药学 | 48074篇 |
300篇 | |
中国医学 | 18417篇 |
肿瘤学 | 38058篇 |
出版年
2023年 | 4975篇 |
2022年 | 12509篇 |
2021年 | 15989篇 |
2020年 | 12078篇 |
2019年 | 10591篇 |
2018年 | 14670篇 |
2017年 | 13964篇 |
2016年 | 12507篇 |
2015年 | 19389篇 |
2014年 | 22421篇 |
2013年 | 20038篇 |
2012年 | 34349篇 |
2011年 | 31960篇 |
2010年 | 19272篇 |
2009年 | 17522篇 |
2008年 | 19979篇 |
2007年 | 20707篇 |
2006年 | 20703篇 |
2005年 | 28185篇 |
2004年 | 23738篇 |
2003年 | 18597篇 |
2002年 | 12166篇 |
2001年 | 12076篇 |
2000年 | 9607篇 |
1999年 | 13877篇 |
1998年 | 5187篇 |
1997年 | 4848篇 |
1996年 | 4063篇 |
1995年 | 3826篇 |
1994年 | 3267篇 |
1992年 | 9550篇 |
1991年 | 9421篇 |
1990年 | 9238篇 |
1989年 | 8541篇 |
1988年 | 7966篇 |
1987年 | 7528篇 |
1986年 | 7001篇 |
1985年 | 6031篇 |
1984年 | 4097篇 |
1983年 | 3309篇 |
1979年 | 4108篇 |
1978年 | 2519篇 |
1975年 | 2578篇 |
1974年 | 3252篇 |
1973年 | 2854篇 |
1972年 | 2884篇 |
1971年 | 2817篇 |
1970年 | 2620篇 |
1969年 | 2525篇 |
1968年 | 2284篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
Melatonin induces apoptosis of colorectal cancer cells through HDAC4 nuclear import mediated by CaMKII inactivation 下载免费PDF全文
Melatonin induces apoptosis in many different cancer cell lines, including colorectal cancer. However, the precise mechanisms involved remain largely unresolved. In this study, we provide evidence to reveal a new mechanism by which melatonin induces apoptosis of colorectal cancer LoVo cells. Melatonin at pharmacological concentrations significantly suppressed cell proliferation and induced apoptosis in a dose‐dependent manner. The observed apoptosis was accompanied by the melatonin‐induced dephosphorylation and nuclear import of histone deacetylase 4 (HDAC4). Pretreatment with a HDAC4‐specific siRNA effectively attenuated the melatonin‐induced apoptosis, indicating that nuclear localization of HDAC4 is required for melatonin‐induced apoptosis. Moreover, constitutively active Ca2+/calmodulin‐dependent protein kinase II alpha (CaMKIIα) abrogated the melatonin‐induced HDAC4 nuclear import and apoptosis of LoVo cells. Furthermore, melatonin decreased H3 acetylation on bcl‐2 promoter, leading to a reduction of bcl‐2 expression, whereas constitutively active CaMKIIα(T286D) or HDAC4‐specific siRNA abrogated the effect of melatonin. In conclusion, the present study provides evidence that melatonin‐induced apoptosis in colorectal cancer LoVo cells largely depends on the nuclear import of HDAC4 and subsequent H3 deacetylation via the inactivation of CaMKIIα. 相似文献
55.
Bj?rn Stessel Audrey A. Fiddelers Elbert A. Joosten Daisy M.N. Hoofwijk Hans-Fritz Gramke Wolfgang F.F.A. Buhre 《Medicine》2015,94(39)
Traditionally, major complications and unanticipated admission/readmission rates were used to assess outcome after day surgery. However, in view of the relative absence of major complications the quality of recovery (QOR) should be considered one of the principal endpoints after day surgery. In our study, the level of QOR is defined by a combination of the Global Surgical Recovery (GSR) Index and the Quality of Life (QOL).The aim of this study was to analyze prevalence and predictors of QOR after day surgery on the fourth postoperative day.Elective patients scheduled for day surgery from November 2008 to April 2010 were enrolled in a prospective cohort study. Outcome parameters were measured by using questionnaire packages at 2 time points: 1 week preoperatively and 4 days postoperatively. Primary outcome parameter is the QOR and is defined as good if the GSR index >80% as well as the postoperative QOL is unchanged or improved as compared with baseline. QOR is defined as poor if both the GSR index ≤80% and if the postoperative QOL is decreased as compared with baseline. QOR is defined as intermediate in all other cases. Three logistic regression analyses were performed to determine predictors for poor QOR after day surgery.A total of 1118 patients were included. A good QOR was noted in 17.3% of patients, an intermediate QOR in 34.8%, and a poor QOR in 47.8% 4 days after day surgery. The best predictor for poor QOR after day surgery was type of surgery. Other predictors were younger age, work status, and longer duration of surgery. A history of previous surgery, expected pain (by the patient) and high long-term surgical fear were significant predictors of poor QOR in only 1 of 3 prediction models.The QOR at home 4 days after day surgery was poor in the majority of patients and showed a significant procedure-specific variation. Patients at risk for poor QOR can be identified during the preoperative period based on type of surgery, age, work status, and the duration of the surgery. 相似文献
56.
Miguel A. Sanz Pau Montesinos Haesook T. Kim Guillermo J. Ruiz-Argüelles María S. Undurraga María R. Uriarte Lem Martínez Rafael H. Jacomo Homero Gutiérrez-Aguirre Raul A. M. Melo Rosane Bittencourt Ricardo Pasquini Katia Pagnano Evandro M. Fagundes Edo Vellenga Alexandra Holowiecka Ana J. González-Huerta Pascual Fernández Javier De la Serna Salut Brunet Elena De Lisa José González-Campos José M. Ribera Isabel Krsnik Arnold Ganser Nancy Berliner Raul C. Ribeiro Francesco Lo-Coco Bob L?wenberg Eduardo M. Rego 《Annals of hematology》2015,94(8):1347-1356
57.
58.
目的:肌少症对老年肝癌术后恢复及预后的影响。方法:选取2015年1月至2017年12月收治的114例老年肝癌,根据有无合并肌少症,分为肌少症组(n=35)和非肌少症组(n=79)。比较两组患者的术后恢复及生存情况。结果:肌少症组总并发症发生率、住院时间和30 d再入院率均高于对照组,差异均有统计学意义(P<0.05)。肌少症组中位生存时间为25.9个月,1年、2年、3年累积总生存率为74.3%、51.1%、24.5%,而非肌少症组中位生存时间为35.7个月,1年、2年、3年累积总生存率为87.3%、75.6%、49.4%,差异有统计学意义(P=0.004)。单因素分析结果显示,老年肝癌术后预后与Charlson合并症指数(CCI)、肌少症、巴塞罗那分期(BCLC)、甲胎蛋白、肿瘤大小、肿瘤个数、肿瘤分化程度、微血管侵犯(MVI)相关(P<0.05)。Cox多因素分析结果显示,CCI、肌少症、BCLC分期、肿瘤个数、MVI是老年肝癌术后预后的独立危险因素(P<0.05)。结论:肌少症会增加老年肝癌患者术后并发症发生率,延长住院时间,影响术后恢复,同时也会降低总生存率。 相似文献
59.
60.