全文获取类型
收费全文 | 5037篇 |
免费 | 524篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 127篇 |
妇产科学 | 94篇 |
基础医学 | 861篇 |
口腔科学 | 155篇 |
临床医学 | 565篇 |
内科学 | 849篇 |
皮肤病学 | 67篇 |
神经病学 | 581篇 |
特种医学 | 182篇 |
外国民族医学 | 1篇 |
外科学 | 806篇 |
综合类 | 40篇 |
一般理论 | 2篇 |
预防医学 | 358篇 |
眼科学 | 100篇 |
药学 | 306篇 |
中国医学 | 5篇 |
肿瘤学 | 329篇 |
出版年
2024年 | 14篇 |
2023年 | 77篇 |
2022年 | 113篇 |
2021年 | 257篇 |
2020年 | 149篇 |
2019年 | 217篇 |
2018年 | 256篇 |
2017年 | 183篇 |
2016年 | 174篇 |
2015年 | 205篇 |
2014年 | 247篇 |
2013年 | 281篇 |
2012年 | 380篇 |
2011年 | 387篇 |
2010年 | 214篇 |
2009年 | 166篇 |
2008年 | 252篇 |
2007年 | 242篇 |
2006年 | 199篇 |
2005年 | 145篇 |
2004年 | 156篇 |
2003年 | 124篇 |
2002年 | 111篇 |
2001年 | 45篇 |
2000年 | 62篇 |
1999年 | 46篇 |
1998年 | 24篇 |
1997年 | 30篇 |
1996年 | 24篇 |
1995年 | 28篇 |
1994年 | 17篇 |
1993年 | 16篇 |
1992年 | 54篇 |
1991年 | 57篇 |
1990年 | 50篇 |
1989年 | 38篇 |
1988年 | 44篇 |
1987年 | 39篇 |
1986年 | 49篇 |
1985年 | 58篇 |
1984年 | 36篇 |
1983年 | 35篇 |
1982年 | 26篇 |
1981年 | 26篇 |
1979年 | 31篇 |
1978年 | 28篇 |
1977年 | 22篇 |
1975年 | 14篇 |
1972年 | 20篇 |
1970年 | 14篇 |
排序方式: 共有5570条查询结果,搜索用时 15 毫秒
81.
Brandon Eilertson Fernanda Maruri Amondrea Blackman Miguel Herrera David C. Samuels Timothy R. Sterling 《Antimicrobial agents and chemotherapy》2014,58(6):3270-3275
Heteroresistance is the coexistence of populations with differing nucleotides at a drug resistance locus within a sample of organisms. Although Sanger sequencing is the gold standard for sequencing, it may be less sensitive than deep sequencing for detecting fluoroquinolone heteroresistance in Mycobacterium tuberculosis. Twenty-seven fluoroquinolone monoresistant and 11 fluoroquinolone-susceptible M. tuberculosis isolates were analyzed by Sanger and Illumina deep sequencing. Individual sequencing reads were analyzed to detect heteroresistance in the gyrA and gyrB genes. Heteroresistance to fluoroquinolones was identified in 10/26 (38%) phenotypically fluoroquinolone-resistant samples and 0/11 (P = 0.02) fluoroquinolone-susceptible controls. One resistant sample was excluded because of contamination with the laboratory strain M. tuberculosis H37Rv. Sanger sequencing revealed resistance-conferring mutations in 15 isolates, while deep sequencing revealed mutations in 20 isolates. Isolates with fluoroquinolone resistance-conferring mutations by Sanger sequencing all had at least those same mutations identified by deep sequencing. By deep sequencing, 10 isolates had a single fixed (defined as >95% frequency) mutation, while 10 were heteroresistant, 5 of which had a single unfixed (defined as <95% frequency) mutation and 5 had multiple unfixed mutations. Illumina deep sequencing identified a higher proportion of fluoroquinolone-resistant M. tuberculosis isolates with heteroresistance than did Sanger sequencing. The heteroresistant isolates frequently demonstrated multiple mutations, but resistant isolates with fixed mutations each had only a single mutation. 相似文献
82.
83.
84.
Brandon Isler Megan Mineau Bronwyn Hunter Sarah Callahan Noah Gelfman Yvita Bustos 《Alcoholism treatment quarterly》2017,35(3):200-212
Approximately 12.5% of children have a parent with a substance use disorder. These children are likely to experience developmental delays, especially if they are placed into foster care. Oxford House recovery homes provide a useful setting that allows children to live with their parents after treatment for substance use. A sample of parents and their children who lived in Oxford Houses were interviewed, using mixed methods, and the outcomes suggest that Oxford Houses may provide a stable and supportive setting for parents and their children. 相似文献
85.
Luxi Wei Ross Williams Thanasis Loupas Brandon Helfield Peter N. Burns 《Ultrasound in medicine & biology》2021,47(8):2456-2466
Doppler ultrasound has become a standard method used to diagnose and grade vascular diseases and monitor their progression. Conventional focused-beam color Doppler imaging is routinely used in clinical practice, but suffers from inherent trade-offs between spatial, temporal and velocity resolution. Newer, plane-wave Doppler imaging offers rapid simultaneous acquisition of B-mode, color and spectral Doppler information across large fields of view, making it a potentially useful method for quantitative estimation of blood flow velocities in the clinic. However, plane-wave imaging can lead to a substantial error in velocity estimation, which is dependent on the lateral location within the image. This is seen in both clinical and experimental plane-wave systems. In the work described in this article, we quantified this velocity error under different geometric and beamforming conditions using numerical simulation and experimental phantoms. We found that the lateral-dependent velocity errors are caused by asymmetrical geometric spectral broadening, and outline a correction algorithm that can mitigate these errors. 相似文献
86.
Mark L. Kraus MD FASAM J. Harry Isaacson MD FACP Ruth Kahn DNSc Marlon P. Mundt MA MS Linda Baier Manwell BS 《Substance Abuse》2013,34(2):97-104
In June 1998, there were 1.8 million inmates in correctional facilities for adults; 1.2 million in state and federal prisons and 600,000 in municipal/county jails (668 persons per 100,000 U.S. population). Rates of TB, AIDS, mental illness, and substance abuse are 2–13 times higher in persons living in jails and prisons. This study was designed to assess the level of training offered to residents in seven medical specialties in the care of addicted incarcerated persons. The study design involved two stages. The first entailed a mailed survey to 1,831 residency directors in family medicine, internal medicine, osteopathic medicine, pediatrics, obstetrics and gynecology, psychiatry, and emergency medicine. The second stage was a telephone interview, about substance use disorders, of faculty listed by the residency directors as teaching residents. The mailed survey was completed by 1,205 residency directors (66%). The 769 faculty from those identified programs, who participated in the telephone interview, reported that only 14% of their residency programs offered lectures or conferences on the care of incarcerated persons, yet 44% of the programs had residents caring for incarcerated persons with substance abuse problems, in a clinical setting. Only 22% offered clinical experiences for residents in a correctional facility. We recognize that our survey of correctional health and substance abuse training is limited, but as such, a greater number of respondents to our survey do not teach residents addiction medicine topics pertaining to prevention, evaluation, intervention, and management of the addicted criminal offender/patient in a correctional setting or give adequate clinical exposure to this special population. The data suggests a need to develop and implement educational programs on medical care for this high‐risk and expanding population. 相似文献
87.
88.
89.
Joshua M. Klonoski Heather R. Hurtig Brian A. Juber Margaret J. Schuneman Thomas E. Bickett Joshua M. Svendsen Brandon Burum Thomas A. Penfound Grigoriy Sereda James B. Dale Michael S. Chaussee Victor C. Huber 《Vaccine》2014
Influenza virus infections are associated with a significant number of illnesses and deaths on an annual basis. Many of the deaths are due to complications from secondary bacterial invaders, including Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pyogenes. The β-hemolytic bacteria S. pyogenes colonizes both skin and respiratory surfaces, and frequently presents clinically as strep throat or impetigo. However, when these bacteria gain access to normally sterile sites, they can cause deadly diseases including sepsis, necrotizing fasciitis, and pneumonia. We previously developed a model of influenza virus:S. pyogenes super-infection, which we used to demonstrate that vaccination against influenza virus can limit deaths associated with a secondary bacterial infection, but this protection was not complete. In the current study, we evaluated the efficacy of a vaccine that targets the M protein of S. pyogenes to determine whether immunity toward the bacteria alone would allow the host to survive an influenza virus:S. pyogenes super-infection. Our data demonstrate that vaccination against the M protein induces IgG antibodies, in particular those of the IgG1 and IgG2a isotypes, and that these antibodies can interact with macrophages. Ultimately, this vaccine-induced immunity eliminated death within our influenza virus:S. pyogenes super-infection model, despite the fact that all M protein-vaccinated mice showed signs of illness following influenza virus inoculation. These findings identify immunity against bacteria as an important component of protection against influenza virus:bacteria super-infection. 相似文献
90.