全文获取类型
收费全文 | 2520761篇 |
免费 | 179593篇 |
国内免费 | 4769篇 |
专业分类
耳鼻咽喉 | 34419篇 |
儿科学 | 82955篇 |
妇产科学 | 69028篇 |
基础医学 | 360189篇 |
口腔科学 | 73907篇 |
临床医学 | 227408篇 |
内科学 | 481017篇 |
皮肤病学 | 58360篇 |
神经病学 | 197904篇 |
特种医学 | 97041篇 |
外国民族医学 | 437篇 |
外科学 | 381335篇 |
综合类 | 54113篇 |
一般理论 | 787篇 |
预防医学 | 183827篇 |
眼科学 | 59622篇 |
药学 | 190785篇 |
13篇 | |
中国医学 | 6105篇 |
肿瘤学 | 145871篇 |
出版年
2019年 | 19891篇 |
2018年 | 29528篇 |
2017年 | 22833篇 |
2016年 | 25505篇 |
2015年 | 28419篇 |
2014年 | 38737篇 |
2013年 | 57501篇 |
2012年 | 79036篇 |
2011年 | 83767篇 |
2010年 | 49399篇 |
2009年 | 45245篇 |
2008年 | 78017篇 |
2007年 | 83121篇 |
2006年 | 83515篇 |
2005年 | 80004篇 |
2004年 | 76782篇 |
2003年 | 73568篇 |
2002年 | 70915篇 |
2001年 | 130263篇 |
2000年 | 133749篇 |
1999年 | 109971篇 |
1998年 | 27868篇 |
1997年 | 24078篇 |
1996年 | 24009篇 |
1995年 | 24181篇 |
1994年 | 22130篇 |
1993年 | 20679篇 |
1992年 | 82361篇 |
1991年 | 79460篇 |
1990年 | 77195篇 |
1989年 | 74134篇 |
1988年 | 67355篇 |
1987年 | 65685篇 |
1986年 | 62003篇 |
1985年 | 58958篇 |
1984年 | 43261篇 |
1983年 | 36785篇 |
1982年 | 20830篇 |
1981年 | 18396篇 |
1979年 | 38404篇 |
1978年 | 26483篇 |
1977年 | 23072篇 |
1976年 | 20923篇 |
1975年 | 22741篇 |
1974年 | 27138篇 |
1973年 | 26108篇 |
1972年 | 24379篇 |
1971年 | 22774篇 |
1970年 | 21068篇 |
1969年 | 19915篇 |
排序方式: 共有10000条查询结果,搜索用时 31 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.
3.
Espersen Caroline Modin Daniel Hoffmann Søren Hagemann Christoffer A. Hagemann Rikke A. Olsen Flemming J. Fritz-Hansen Thomas Platz Elke Møgelvang Rasmus Biering-Sørensen Tor 《The international journal of cardiovascular imaging》2022,38(1):131-140
The International Journal of Cardiovascular Imaging - Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of... 相似文献
4.
Jayaraman Chandrasekaran Embry Kyle R. Mummidisetty Chaithanya K. Moon Yaejin Giffhorn Matt Prokup Sara Lim Bokman Lee Jusuk Lee Younbaek Lee Minhyung Jayaraman Arun 《Journal of neuroengineering and rehabilitation》2022,19(1):1-13
Numerous studies showed that postural balance improves through light touch on a stable surface highlighting the importance of haptic information, seemingly downplaying the mechanical contributions of the support. The present study examined the mechanical effects of canes for assisting balance in healthy individuals challenged by standing on a beam. Sixteen participants supported themselves with two canes, one in each hand, and applied minimal, preferred, or maximum force onto the canes. They positioned the canes in the frontal plane or in a tripod configuration. Statistical analysis used a linear mixed model to evaluate the effects on the center of pressure and the center of mass. The canes significantly reduced the variability of the center of pressure and the center of mass to the same level as when standing on the ground. Increasing the exerted force beyond the preferred level yielded no further benefits, although in the preferred force condition, participants exploited the altered mechanics by resting their arms on the canes. The tripod configuration allowed for larger variability of the center of pressure in the task-irrelevant anterior–posterior dimension. High forces had a destabilizing effect on the canes: the displacement of the hand on the cane handle increased with the force. Given this static instability, these results show that using canes can provide not only mechanical benefits but also challenges. From a control perspective, effort can be reduced by resting the arms on the canes and by channeling noise in the task-irrelevant dimensions. However, larger forces exerted onto the canes can also have destabilizing effects and the instability of the canes needs to be counteracted, possibly by arm and shoulder stiffness. Insights into the variety of mechanical effects is important for the design of canes and the instructions of how to use them. 相似文献
5.
6.
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
7.
8.
Nicla La Verde Agostino Riva Maria Silvia Cona Arianna Gabrieli Monica Cattaneo Cinzia Fasola Giuseppe Lipari Claudia De Stradis Valentina Favorito Benedetta Lombardi Stocchetti Davide Chizzoniti Alice Covizzi Eliana Rulli Francesca Galli Lorenzo Ruggieri Anna Gambaro Sabrina Ferrario Davide Dalu Maciej S. Tarkowski 《International journal of cancer. Journal international du cancer》2023,152(4):661-671
Previous studies on the immunogenicity of SARS-CoV-2 mRNA vaccines showed a reduced seroconversion in cancer patients. The aim of our study is to evaluate the immunogenicity of two doses of mRNA vaccines in solid cancer patients with or without a previous exposure to the virus. This is a single-institution, prospective, nonrandomized study. Patients in active treatment and a control cohort of healthy people received two doses of BNT162b2 (Comirnaty, BioNTech/Pfizer, The United States) or mRNA-1273 (Spikevax, Moderna). Vaccine was administered before starting anticancer therapy or on the first day of the treatment cycle. SARS-CoV-2 antibody levels against S1, RBD (to evaluate vaccine response) and N proteins (to evaluate previous infection) were measured in plasma before the first dose and 30 days after the second one. From January to June 2021, 195 consecutive cancer patients and 20 healthy controls were enrolled. Thirty-one cancer patients had a previous exposure to SARS-CoV-2. Cancer patients previously exposed to the virus had significantly higher median levels of anti-S1 and anti-RBD IgG, compared to healthy controls (P = .0349) and to cancer patients without a previous infection (P < .001). Vaccine type (anti-S1: P < .0001; anti-RBD: P = .0045), comorbidities (anti-S1: P = .0274; anti-RBD: P = .0048) and the use of G-CSF (anti-S1: P = .0151) negatively affected the antibody response. Conversely, previous exposure to SARS-CoV-2 significantly enhanced the response to vaccination (anti-S1: P < .0001; anti-RBD: P = .0026). Vaccine immunogenicity in cancer patients with a previous exposure to SARS-CoV-2 seems comparable to that of healthy subjects. On the other hand, clinical variables of immune frailty negatively affect humoral immune response to vaccination. 相似文献
9.
10.
S. M. White C. L. Shelton A. W. Gelb C. Lawson F. McGain J. Muret J. D. Sherman representing the World Federation of Societies of Anaesthesiologists Global Working Group on Environmental Sustainability in Anaesthesia 《Anaesthesia》2022,77(2):201-212
The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references. 相似文献