全文获取类型
收费全文 | 2453篇 |
免费 | 161篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 62篇 |
妇产科学 | 73篇 |
基础医学 | 442篇 |
口腔科学 | 66篇 |
临床医学 | 227篇 |
内科学 | 525篇 |
皮肤病学 | 49篇 |
神经病学 | 155篇 |
特种医学 | 55篇 |
外科学 | 258篇 |
综合类 | 36篇 |
一般理论 | 2篇 |
预防医学 | 204篇 |
眼科学 | 56篇 |
药学 | 194篇 |
中国医学 | 21篇 |
肿瘤学 | 186篇 |
出版年
2024年 | 4篇 |
2023年 | 34篇 |
2022年 | 39篇 |
2021年 | 172篇 |
2020年 | 83篇 |
2019年 | 114篇 |
2018年 | 125篇 |
2017年 | 84篇 |
2016年 | 99篇 |
2015年 | 84篇 |
2014年 | 120篇 |
2013年 | 171篇 |
2012年 | 245篇 |
2011年 | 242篇 |
2010年 | 117篇 |
2009年 | 77篇 |
2008年 | 121篇 |
2007年 | 146篇 |
2006年 | 97篇 |
2005年 | 96篇 |
2004年 | 78篇 |
2003年 | 69篇 |
2002年 | 78篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
1974年 | 2篇 |
1971年 | 3篇 |
排序方式: 共有2620条查询结果,搜索用时 15 毫秒
61.
Richard F. Armenta Alexis M. Roth Karla D. Wagner Steffanie A. Strathdee Stephanie K. Brodine Jazmine Cuevas-Mota Fatima A. Munoz Richard S. Garfein 《Journal of urban health》2015,92(6):1081-1091
Persons who inject drugs (PWID) are at increased risk for blood-borne virus (BBV) infections and overdose resulting from high-risk injecting practices. Studies of prefilled syringe use ([PFSU] using a syringe that already contained drug solution when it was obtained by the user), an injection practice previously described in Eastern Europe, suggest that it increases susceptibility to BBV. However, little is known about this practice in the USA. Data were obtained from an ongoing cohort study of PWID to determine the prevalence and assess correlates of PFSU in San Diego, CA. Baseline interviews assessed socio-demographics and drug use behaviors. Logistic regression was used to identify factors independently associated with ever using a prefilled syringe (yes/no). Participants (n = 574) were predominately males (73.9 %) and white (50.9 %) with a mean age of 43.4 years (range 18–80); 33.3 % reported ever using prefilled syringes, although only 4.9 % reported use in the past 6 months. In multivariable analyses, PFSU was independently associated with ever having a rushed injection due to police presence [adjusted odds ratio (AOR) = 2.51, 95 % CI 1.66, 3.79], ever being in prison (AOR = 1.80, 95 % CI 1.23, 2.63), injecting most often in public versus private places in the past 6 months (AOR = 1.66, 95 % CI 1.11, 2.48), and injecting drugs in Mexico (AOR = 1.70, 95 % CI 1.16, 2.49). Results indicate that a history of PFSU is common and associated with environmental factors that may also increase risk for adverse health outcomes. Studies are needed to better understand PFSU in order to develop interventions to prevent adverse outcomes associated with their use. 相似文献
62.
This paper describes a modified method to prepare monodisperse Fe3O4 magnetic nanoparticles with different shapes (cube, octahedron, and sphere). The shape of the magnetic nanoparticles could be conveniently controlled by changing the types of precursor/capping agent and concentration of capping agent. The prepared samples were characterized using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometry. Cubes and octahedra were formed using ferrous sulfate heptahydrate as an iron source, ethylene glycol as a solvent and potassium hydroxide (KOH) as a capping agent while spheres were formed by using ferric chloride hexahydrate as an iron source, ethylene glycol as a solvent and ammonium acetate as a capping agent. By varying KOH concentration (0.5 M, 1 M, 1.5 M, and 5 M), the shape was transformed from cubes to octahedra because octahedra are developed dominantly at higher concentration of KOH within the reaction mixture. The magnetic studies show superparamagnetic behavior for all samples at room temperature. The Fe3O4 nanoparticles show the magnetic saturation values of 87 emu g−1, 85 emu g−1, and 82 emu g−1 for spheres, cubes, and octahedrons, respectively.This paper describes a modified method to prepare monodisperse Fe3O4 magnetic nanoparticles with different shapes (cube, octahedron, and sphere). 相似文献
63.
Ahmed Kaleem Sohail Esbhani Umer Arif Naseem Zehra Lalani Salima Fatima Syeda Sadia 《International journal of diabetes in developing countries.》2021,41(3):435-440
International Journal of Diabetes in Developing Countries - Metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD) are emerging threats in Pakistan. The prevalence of MetS is... 相似文献
64.
Catherine Riou Elsa du Bruyn Cari Stek Remy Daroowala Rene T. Goliath Fatima Abrahams Qonita Said-Hartley Brian W. Allwood Nei-Yuan Hsiao Katalin A. Wilkinson Cecilia S. Lindestam Arlehamn Alessandro Sette Sean Wasserman Robert J. Wilkinson 《The Journal of clinical investigation》2021,131(12)
T cells are involved in control of coronavirus disease 2019 (COVID-19), but limited knowledge is available on the relationship between antigen-specific T cell response and disease severity. Here, we used flow cytometry to assess the magnitude, function, and phenotype of SARS coronavirus 2–specific (SARS-CoV-2–specific) CD4+ T cells in 95 hospitalized COVID-19 patients, 38 of them being HIV-1 and/or tuberculosis (TB) coinfected, and 38 non–COVID-19 patients. We showed that SARS-CoV-2–specific CD4+ T cell attributes, rather than magnitude, were associated with disease severity, with severe disease being characterized by poor polyfunctional potential, reduced proliferation capacity, and enhanced HLA-DR expression. Moreover, HIV-1 and TB coinfection skewed the SARS-CoV-2 T cell response. HIV-1–mediated CD4+ T cell depletion associated with suboptimal T cell and humoral immune responses to SARS-CoV-2, and a decrease in the polyfunctional capacity of SARS-CoV-2–specific CD4+ T cells was observed in COVID-19 patients with active TB. Our results also revealed that COVID-19 patients displayed reduced frequency of Mycobacterium tuberculosis–specific CD4+ T cells, with possible implications for TB disease progression. These results corroborate the important role of SARS-CoV-2–specific T cells in COVID-19 pathogenesis and support the concept of altered T cell functions in patients with severe disease. 相似文献
65.
Nosheen Fatima Rana Nicolas Sauvageot Jean-Marie Laplace YinYin Bao Ingolf Nes Alain Rincé Brunella Posteraro Maurizio Sanguinetti Axel Hartke 《Infection and immunity》2013,81(8):2662-2668
Enterococcus faecalis is a highly stress resistant opportunistic pathogen. The intrinsic ruggedness of this bacterium is supposed to be the basis of its capacity to colonize the hostile environments of hospitals and to cause several kinds of infections. We show in this work that general resistance to very different environmental stresses depends on the ability of E. faecalis to maintain redox balance via lactate dehydrogenase (LDH). Furthermore, LDH-deficient mutants are less successful than the wild type at colonizing host organs in a murine model of systemic infection. Taken together, our results, as well as those previously published for Staphylococcus aureus (A. R. Richardson, S. J. Libby, and F. C. Fang, Science 319:1672–1676, 2008), identify LDH as an attractive drug target. These drugs may have additional applications, as in the fight against glycopeptide antibiotic-resistant bacteria and even cancer. 相似文献
66.
Ahmed Aziz Bousfiha Leïla Jeddane Fatima Ailal Waleed Al Herz Mary Ellen Conley Charlotte Cunningham-Rundles Amos Etzioni Alain Fischer Jose Luis Franco Raif S. Geha Lennart Hammarström Shigeaki Nonoyama Hans D. Ochs Chaim M. Roifman Reinhard Seger Mimi L. K. Tang Jennifer M. Puck Helen Chapel Luigi D. Notarangelo Jean-Laurent Casanova 《Journal of clinical immunology》2013,33(6):1078-1087
The number of genetically defined Primary Immunodeficiency Diseases (PID) has increased exponentially, especially in the past decade. The biennial classification published by the IUIS PID expert committee is therefore quickly expanding, providing valuable information regarding the disease-causing genotypes, the immunological anomalies, and the associated clinical features of PIDs. These are grouped in eight, somewhat overlapping, categories of immune dysfunction. However, based on this immunological classification, the diagnosis of a specific PID from the clinician’s observation of an individual clinical and/or immunological phenotype remains difficult, especially for non-PID specialists. The purpose of this work is to suggest a phenotypic classification that forms the basis for diagnostic trees, leading the physician to particular groups of PIDs, starting from clinical features and combining routine immunological investigations along the way. We present 8 colored diagnostic figures that correspond to the 8 PID groups in the IUIS Classification, including all the PIDs cited in the 2011 update of the IUIS classification and most of those reported since. 相似文献
67.
68.
69.
70.
Noor Fatima Majeed Marta Braschi Amirfarzan Christoph Wald Jeremy R Wortman 《The British journal of radiology》2021,94(1123)
Objective:Spectral detector CT (SDCT) has many applications in advanced liver imaging. If appropriately utilized, this technology has the potential to improve image quality, provide new diagnostic information, and allow for decreased radiation dose. The purpose of this review is to familiarize radiologists with the uses of SDCT in liver imaging.Conclusion:SDCT has a variety of post-processing techniques, which can be used in advanced liver imaging and can significantly add value in clinical practice. 相似文献