全文获取类型
收费全文 | 279795篇 |
免费 | 26765篇 |
国内免费 | 13428篇 |
专业分类
耳鼻咽喉 | 3992篇 |
儿科学 | 4528篇 |
妇产科学 | 6556篇 |
基础医学 | 44061篇 |
口腔科学 | 7555篇 |
临床医学 | 22771篇 |
内科学 | 37454篇 |
皮肤病学 | 5220篇 |
神经病学 | 11863篇 |
特种医学 | 8780篇 |
外国民族医学 | 234篇 |
外科学 | 29040篇 |
综合类 | 46742篇 |
现状与发展 | 67篇 |
一般理论 | 2篇 |
预防医学 | 7877篇 |
眼科学 | 4314篇 |
药学 | 19536篇 |
53篇 | |
中国医学 | 7235篇 |
肿瘤学 | 52108篇 |
出版年
2024年 | 182篇 |
2023年 | 3725篇 |
2022年 | 5431篇 |
2021年 | 9496篇 |
2020年 | 9080篇 |
2019年 | 8496篇 |
2018年 | 8640篇 |
2017年 | 9611篇 |
2016年 | 10543篇 |
2015年 | 11876篇 |
2014年 | 18301篇 |
2013年 | 18557篇 |
2012年 | 16885篇 |
2011年 | 18855篇 |
2010年 | 15445篇 |
2009年 | 14905篇 |
2008年 | 15356篇 |
2007年 | 15853篇 |
2006年 | 14464篇 |
2005年 | 13045篇 |
2004年 | 11088篇 |
2003年 | 9525篇 |
2002年 | 7795篇 |
2001年 | 7058篇 |
2000年 | 5818篇 |
1999年 | 4923篇 |
1998年 | 4032篇 |
1997年 | 3824篇 |
1996年 | 3306篇 |
1995年 | 3329篇 |
1994年 | 2946篇 |
1993年 | 2299篇 |
1992年 | 1912篇 |
1991年 | 1734篇 |
1990年 | 1412篇 |
1989年 | 1288篇 |
1988年 | 1193篇 |
1987年 | 956篇 |
1986年 | 843篇 |
1985年 | 1104篇 |
1984年 | 969篇 |
1983年 | 672篇 |
1982年 | 738篇 |
1981年 | 612篇 |
1980年 | 552篇 |
1979年 | 414篇 |
1978年 | 283篇 |
1977年 | 206篇 |
1976年 | 169篇 |
1975年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Kari Hemminki Kristina Sundquist Jan Sundquist Asta Försti Vaclav Liska Akseli Hemminki Xinjun Li 《International journal of cancer. Journal international du cancer》2023,152(6):1107-1114
Many environmental risk factors for hepatobiliary cancers are known but whether they are associated with specific cancer types is unclear. We present here a novel approach of assessing standardized incidence ratios (SIRs) of previously diagnosed comorbidities for hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cholangiocarcinoma (CCA) and ampullary cancer. The 13 comorbidities included alcohol and nonalcohol related liver disease, chronic obstructive pulmonary disease, gallstone disease, viral and other kinds of hepatitis, infection of bile ducts, hepatic and other autoimmune diseases, obesity and diabetes. Patients were identified from the Swedish Inpatient Register from 1987 to 2018, and their cancers were followed from 1997 onwards. SIRs for HCC were 80 to 100 in men and women diagnosed with hepatitis C virus and they were also >10 in patients diagnosed with hepatitis B virus, other kind of hepatitis, hepatic autoimmune disease and nonalcohol related liver disease. Many of these risks, as well as alcohol related liver disease, were either specific to HCC or were shared with intrahepatic CCA. For GBC, CCA and ampullary cancer infection of bile ducts was the main risk factor. Gallstone disease, nonhepatic autoimmune diseases and diabetes were associated with all hepatobiliary cancers. The limitations of the study include inability to cover some rare risk factors and limited follow-up time. Many of the considered comorbidities are characterized by chronic inflammation and/or overt immune disturbance in autoimmune diseases. The results suggest that local chronic inflammation and a related immune disturbance is the carcinogenic trigger for all these cancers. 相似文献
2.
《Saudi Pharmaceutical Journal》2022,30(6):669-678
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction. 相似文献
3.
4.
5.
6.
Effect of Replacement of Wharton Acellular Jelly With FBS on the Expression of Megakaryocyte Linear Markers in Hematopoietic Stem Cells CD34+ 下载免费PDF全文
zahra Jalili Behnam Emamgolizadeh Hossein Abbaszadeh Shahla JaliliMehdi Derakhshani Mehdi YousefiMehdi TalebiKarim Shams Asenjan Ali Akabr Movassaghpour 《Asian Pacific journal of cancer prevention》2022,23(10):3281-3286
Objective: Animal environments for the growth of stem cells cause the transmission of some diseases and immune problems for the recipient. Accordingly, replacing these environments with healthy environments, at least with human resources, is essential. One of the media that can be used as an alternative to animal serums is Wharton acellular jelly (AWJ). Therefore, in this study, we intend to replace FBS with Wharton jelly and investigate its effect on the expression of megakaryocyte-related genes and markers in stem cells. Materials and Methods: In this study, cord blood-derived CD34 positive HSCs were cultured and expanded in the presence of cytokines including SCF, TPO, and FLT3-L. Then, the culture of expanded CD34 positive HSCs was performed in two groups: 1) IMDM culture medium containing 10% FBS and 100 ng / ml thrombopoietin cytokine 2) IMDM culture medium containing 10% AWJ, 100 ng / ml thrombopoietin cytokine. Finally, CD41 expressing cells were analyzed with the flow cytometry method. The genes related to megakaryocyte lineage including FLI1 and GATA2 were also evaluated using the RT-PCR technique. Results: The expression of CD41, a specific marker of megakaryocyte lineage in culture medium containing Wharton acellular jelly was increased compared to the FBS group. Additionally, the expression of GATA2 and FLI1 genes was significantly increased related to the control group. Conclusion: This study provided evidence of differentiation of CD34 positive hematopoietic stem cells from umbilical cord blood to megakaryocytes in a culture medium containing AWJ. 相似文献
7.
8.
《European journal of surgical oncology》2022,48(5):1062-1067
BackgroundSurgical resection is recommended for patients with resectable acinar cell carcinoma (ACC). The aim of this study was to investigate the clinical characteristics and surgical outcomes of resectable ACC in comparison to pancreatic ductal adenocarcinoma (PDAC).MethodA retrospective analysis was performed on all patients who consecutively underwent radical resection with pathologically confirmed ACC and PDAC from December 2011 to December 2018. Clinicopathologic characteristics and follow-up information were analyzed. A 1:3 propensity score matching (PSM) method was used to minimize the bias between ACC and PDAC.ResultsA total of 26 patients with ACC and 1351 with PDAC were included. Compared to PDAC, ACC tended to be larger (4.5 vs. 3.0 cm; p < 0.001) and more frequently located in the pancreatic body/tail (61.5% vs. 36.6%, p = 0.009), with lower total bilirubin levels, lower neutrophil lymphocyte ratio (NLR) levels and lower carbohydrate antigen 19-9 (CA19-9) levels and carcinoembryonic antigen (CEA) levels. There was no difference in postoperative morbidities in patients with ACC and PDAC. The median OS and RFS were longer in ACC when compared to PDAC (OS: 43.5 mo vs. 19.0 mo, p = 0.004; RFS: 24.5 mo vs. 11.6 mo, p = 0.023). After the 1:3 PSM, ACC remained to be a better histological type for OS (p = 0.024), but had comparable RFS with PDAC (p = 0.164).ConclusionPatients with ACC after radical resection had better OS than that with PDAC. However, ACC is also an aggressive tumor with a similar trend of RFS with PDAC after the matching, necessitating the multidisciplinary treatment for resectable ACC disease. 相似文献
9.
10.
Mahmut Gümüş MD Chieh-I Chen MPH Cristina Ivanescu PhD Saadettin Kilickap MD Igor Bondarenko MD Mustafa Özgüroğlu MD Miranda Gogishvili MD Haci M. Turk MD Irfan Cicin MD James Harnett PharmD Vera Mastey MS Ulrike Naumann MS Matthew Reaney MS Gerasimos Konidaris MS Medha Sasane PhD Keri J. S. Brady PhD Siyu Li PhD Giuseppe Gullo MD Petra Rietschel MD Ahmet Sezer MD 《Cancer》2023,129(1):118-129