全文获取类型
收费全文 | 63946篇 |
免费 | 4642篇 |
国内免费 | 211篇 |
专业分类
耳鼻咽喉 | 799篇 |
儿科学 | 1409篇 |
妇产科学 | 843篇 |
基础医学 | 8152篇 |
口腔科学 | 954篇 |
临床医学 | 6815篇 |
内科学 | 13873篇 |
皮肤病学 | 789篇 |
神经病学 | 6402篇 |
特种医学 | 2186篇 |
外国民族医学 | 5篇 |
外科学 | 11475篇 |
综合类 | 625篇 |
一般理论 | 47篇 |
预防医学 | 4370篇 |
眼科学 | 1232篇 |
药学 | 4404篇 |
中国医学 | 71篇 |
肿瘤学 | 4348篇 |
出版年
2024年 | 64篇 |
2023年 | 499篇 |
2022年 | 868篇 |
2021年 | 2006篇 |
2020年 | 1211篇 |
2019年 | 1797篇 |
2018年 | 2187篇 |
2017年 | 1533篇 |
2016年 | 1632篇 |
2015年 | 1875篇 |
2014年 | 2703篇 |
2013年 | 3363篇 |
2012年 | 5252篇 |
2011年 | 5449篇 |
2010年 | 2928篇 |
2009年 | 2690篇 |
2008年 | 4383篇 |
2007年 | 4475篇 |
2006年 | 4262篇 |
2005年 | 4068篇 |
2004年 | 3628篇 |
2003年 | 3462篇 |
2002年 | 3089篇 |
2001年 | 418篇 |
2000年 | 315篇 |
1999年 | 386篇 |
1998年 | 615篇 |
1997年 | 481篇 |
1996年 | 379篇 |
1995年 | 326篇 |
1994年 | 288篇 |
1993年 | 269篇 |
1992年 | 199篇 |
1991年 | 159篇 |
1990年 | 128篇 |
1989年 | 110篇 |
1988年 | 114篇 |
1987年 | 96篇 |
1986年 | 90篇 |
1985年 | 81篇 |
1984年 | 118篇 |
1983年 | 97篇 |
1982年 | 108篇 |
1981年 | 99篇 |
1980年 | 112篇 |
1979年 | 46篇 |
1978年 | 47篇 |
1977年 | 45篇 |
1976年 | 33篇 |
1974年 | 31篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Christopher R. LaFever 《Death Studies》2020,44(12):819-822
32.
33.
34.
A hypothesis for reactivation of pulmonary tuberculosis: How thoracic wall shape affects the epidemiology of tuberculosis
下载免费PDF全文
![点击此处可从《Clinical anatomy (New York, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Aaron R. Casha Liberato Camilleri Alexander Manché Ruben Gatt Daphne Attard Wiktor Wolak Krzysztof Dudek Marilyn Gauci Christopher Giordimaina Joseph N. Grima 《Clinical anatomy (New York, N.Y.)》2015,28(5):614-620
This study was aimed at determining the cause for the high incidence of tuberculosis (TB) reactivation occurring in males with a low body mass index (BMI). Current thinking about pulmonary TB describes infection in the lung apex resulting in cavitation after reactivation. A different hypothesis is put forward for TB infection, suggesting that this occurs in subclinical apical cavities caused by increased pleural stress due to a low BMI body habitus. A finite element analysis (FEA) model of a lung was constructed including indentations for the first rib guided by paramedian sagittal CT reconstructions, and simulations were conducted with varying antero‐posterior (AP) diameters to mimic chests with a different thoracic index (ratio of AP to the transverse chest diameters). A Pubmed search was conducted about gender and thoracic index, and the effects of BMI on TB. FEA modeling revealed a tenfold increase in stress levels at the lung apex in low BMI chests, and a four‐fold increase with a low thoracic index, r2 = 0.9748 P < 0.001. Low thoracic index was related to BMI, P = 0.001. The mean thoracic index was statistically significantly lower in males, P = 0.001, and increased with age in both genders. This article is the first to suggest a possible mechanism linking pulmonary TB reactivation to low BMI due to the flattened thoracic wall shape of young male adults. The low thoracic index in young males may promote TB reactivation due to tissue destruction in the lung apex from high pleural stress levels. Clin. Anat. 28:614–620, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
35.
Christopher J. Destache David J. Guervil Keith S. Kaye 《International journal of antimicrobial agents》2019,53(5):644-649
Background
The clinical experience of ceftaroline fosamil (CPT-F) therapy for Gram-positive infective endocarditis is reported from CAPTURE, a retrospective study conducted in the USA.Methods
Data, including patient demographics, medical history, risk factors, microbiological aetiology and clinical outcomes, were collected by review of patient charts between September 2013 and February 2015.Results
Patients (n=55) with Gram-positive endocarditis were treated with CPT-F. The most common risk factors were intravascular devices (43.6%), diabetes mellitus (40.0%) and injection drug use (38.2%). The most commonly isolated pathogens were meticillin-resistant Staphylococcus aureus (MRSA; 80%), meticillin-susceptible S. aureus (MSSA; 7.3%) and coagulase-negative staphylococci (7.3%). CPT-F was given as first-line therapy in 7.3% of patients and as second-line or later therapy in 92.7% of patients, and as monotherapy in 41.8% of patients and as concurrent therapy in 58.2% of patients. Clinical success was observed in 82.6% (19/23) of patients treated with CPT-F as monotherapy. In patients treated with CPT-F as first-line therapy or second-line or later therapy, 75.0% (3/4) and 70.6% (36/51) achieved success, respectively. Clinical success was observed in 77.3% (34/44) of patients with MRSA and 25% (1/4) of patients with MSSA. Two patients discontinued treatment with CPT-F due to an adverse event.Conclusions
CPT-F treatment was associated with a high rate of clinical success in patients with Gram-positive infective endocarditis, including those with risk factors and infections caused by MRSA. A high rate of clinical success was observed in patients treated with CPT-F used as first- line therapy or second-line or later therapy, or as monotherapy or in combination with other antibiotics. 相似文献36.
Christopher N. Cooley Tyler J. Beranek Matthew A. Warpinski Robert Alexander Amanda O. Esquivel 《The American journal of emergency medicine》2019,37(2):199-203
Introduction
In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.Methods
We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.Results
A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.Conclusion
The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department. 相似文献37.
Amy Y. Zhang Christopher Burant Alex Z. Fu Gerald Strauss Donald R. Bodner Lee Ponsky 《Journal of psychosocial oncology》2020,38(2):210-227
AbstractPurpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.Design: Secondary analysis of data collected from a clinical trial.Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI. 相似文献
38.
39.
40.
Christopher M Jewell Melissa E Hays Yukishige Kondo Nicholas L Abbott David M Lynn 《Journal of controlled release》2006,112(1):129-138
The ability of two redox-active, ferrocene-containing cationic lipids [11-(ferrocenylundecyl)trimethylammonium bromide (FTMA) and bis(11-ferrocenylundecyl)dimethylammonium bromide (BFDMA)] to transfect mammalian cells was investigated. This study sought to determine the range of conditions over which these lipids were capable of transfecting cells and whether the oxidation state of the ferrocenyl groups in these materials could be used to influence the extent of transfection. Experiments conducted in the COS-7 cell line demonstrated that reduced and oxidized FTMA were substantially cytotoxic and did not transfect cells. Subsequent experiments conducted using BFDMA and reporter plasmids encoding enhanced green fluorescent protein (EGFP) and firefly luciferase demonstrated that BFDMA was able to transfect cells. However, the extent of transfection depended significantly upon both the concentration of BFDMA and the oxidation state of the lipid. Quantitative characterization of cytotoxicity and gene expression demonstrated that a window of concentration existed over which reduced BFDMA was non-cytotoxic and yielded high levels of transfection, but over which electrochemically oxidized BFDMA yielded very low (background) levels of transfection. Characterization of lipoplexes using dynamic light scattering demonstrated that reduced and oxidized BFDMA formed small aggregates (ca. 90 to 250nm) at concentrations of lipid ranging from 2 to 10 microM. Taken together, these results demonstrate that the oxidation state of BFDMA, which can be controlled electrochemically, can be used to control the extent of cell transfection. These results could form the basis of transfection procedures that exploit the redox behavior of ferrocene-containing lipids to achieve active spatial and temporal control over transfection using electrochemical methods. 相似文献