全文获取类型
收费全文 | 1480篇 |
免费 | 124篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 26篇 |
妇产科学 | 15篇 |
基础医学 | 156篇 |
口腔科学 | 24篇 |
临床医学 | 142篇 |
内科学 | 295篇 |
皮肤病学 | 10篇 |
神经病学 | 98篇 |
特种医学 | 56篇 |
外科学 | 197篇 |
综合类 | 43篇 |
一般理论 | 6篇 |
预防医学 | 184篇 |
眼科学 | 42篇 |
药学 | 176篇 |
肿瘤学 | 114篇 |
出版年
2022年 | 9篇 |
2021年 | 26篇 |
2020年 | 13篇 |
2019年 | 16篇 |
2018年 | 35篇 |
2017年 | 23篇 |
2016年 | 27篇 |
2015年 | 25篇 |
2014年 | 34篇 |
2013年 | 46篇 |
2012年 | 57篇 |
2011年 | 73篇 |
2010年 | 52篇 |
2009年 | 40篇 |
2008年 | 73篇 |
2007年 | 89篇 |
2006年 | 63篇 |
2005年 | 47篇 |
2004年 | 63篇 |
2003年 | 61篇 |
2002年 | 49篇 |
2001年 | 52篇 |
2000年 | 47篇 |
1999年 | 31篇 |
1998年 | 19篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 21篇 |
1994年 | 9篇 |
1993年 | 11篇 |
1992年 | 40篇 |
1991年 | 31篇 |
1990年 | 23篇 |
1989年 | 18篇 |
1988年 | 29篇 |
1987年 | 29篇 |
1986年 | 23篇 |
1985年 | 23篇 |
1984年 | 25篇 |
1983年 | 21篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 17篇 |
1979年 | 14篇 |
1978年 | 13篇 |
1977年 | 16篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1972年 | 8篇 |
排序方式: 共有1607条查询结果,搜索用时 0 毫秒
991.
992.
993.
Aqeilan RI Trapasso F Hussain S Costinean S Marshall D Pekarsky Y Hagan JP Zanesi N Kaou M Stein GS Lian JB Croce CM 《Proceedings of the National Academy of Sciences of the United States of America》2007,104(10):3949-3954
The WW domain-containing oxidoreductase (WWOX) spans the second most common fragile site of the human genome, FRA16D, located at 16q23, and its expression is altered in several types of human cancer. We have previously shown that restoration of WWOX expression in cancer cells suppresses tumorigenicity. To investigate WWOX tumor suppressor function in vivo, we generated mice carrying a targeted deletion of the Wwox gene and monitored incidence of tumor formation. Osteosarcomas in juvenile Wwox(-/-) and lung papillary carcinoma in adult Wwox(+/-) mice occurred spontaneously. In addition, Wwox(+/-) mice develop significantly more ethyl nitrosourea-induced lung tumors and lymphomas in comparison to wild-type littermate mice. Intriguingly, these tumors still express Wwox protein, suggesting haploinsuffiency of WWOX itself is cancer predisposing. These results indicate that WWOX is a bona fide tumor suppressor. 相似文献
994.
Hagan CC Hoeft F Mackey A Mobbs D Reiss AL 《Journal of the American Academy of Child and Adolescent Psychiatry》2008,47(12):1443-1354
ObjectiveFragile X (FraX) syndrome is caused by mutations of the FraX mental retardation-1 gene—a gene responsible for producing FraX mental retardation protein. The neurocognitive phenotype associated with FraX in female subjects includes increased risk for emotional disorders including social anxiety, depression, and attention deficit. Here, the authors investigated the neurobiological systems underlying emotion attribution in female subjects with FraX syndrome.MethodWhile undergoing functional magnetic resonance imaging, 10 high-functioning female subjects with FraX syndrome and 10 typically developing (TD) female subjects were presented with photographs of happy, sad, and neutral faces and instructed to determine the facial emotion.ResultsNo significant group differences were found for the recognition of happy faces, although the FraX group showed a trend toward a significant difference for the recognition of sad faces and significantly poorer recognition of neutral faces. Controlling for between-group differences in IQ and performance accuracy, the TD group had greater activation than the FraX group in the anterior cingulate cortex (ACC) for neutral faces compared with scrambled faces and the caudate for sad faces compared with scrambled faces (but not for sad faces compared with neutral faces). In the FraX group, FraX mental retardation protein levels positively correlated with activation in the dorsal ACC for neutral, happy, and sad faces when independently compared with scrambled faces. Significantly greater negative correlation between IQ and insula activation for neutral faces relative to scrambled faces was observed in the FraX group compared with the TD group. Significantly greater positive correlation between IQ and ACC activation for neutral faces relative to scrambled faces was observed in the TD group compared with the FraX group.ConclusionsAlthough emotion recognition is generally spared in FraX syndrome, the emotion circuit (i.e., ACC, caudate, insula) that modulates emotional responses to facial stimuli may be disrupted. J. Am. Acad. Child Adolesc. Psychiatry, 2008;47(12):1443-1454. 相似文献
995.
A peer-education intervention to reduce injection risk behaviors for HIV and hepatitis C virus infection in young injection drug users 总被引:2,自引:0,他引:2
Garfein RS Golub ET Greenberg AE Hagan H Hanson DL Hudson SM Kapadia F Latka MH Ouellet LJ Purcell DW Strathdee SA Thiede H;DUIT Study Team 《AIDS (London, England)》2007,21(14):1923-1932
OBJECTIVES: To evaluate whether a behavioral intervention, which taught peer education skills, could reduce injection and sexual risk behaviors associated with primary HIV and hepatitis C virus infection (HCV) among young injection drug users (IDU). DESIGN: We conducted a randomized controlled trial involving HIV and HCV antibody-negative IDU, aged 15-30 years, recruited in five United States cities. A six-session, small-group, cognitive behavioral, skills-building intervention in which participants were taught peer education skills (n = 431) was compared with a time-equivalent attention control (n = 423). Baseline visits included interviews for sociodemographic, psychosocial, and behavioral factors during the previous 3 months; HIV and HCV antibody testing; and pre/posttest counselling. Procedures were repeated 3 and 6 months postintervention. RESULTS: The intervention produced a 29% greater decline in overall injection risk 6 months postintervention relative to the control [proportional odds ratio 0.71; 95% confidence limit (CL) 0.52, 0.97], and a 76% decrease compared with baseline. Decreases were also observed for sexual risk behaviors, but they did not differ by trial arm. Overall HCV infection incidence (18.4/100 person-years) did not differ significantly across trial arms (relative risk 1.15; 95% CL 0.72, 1.82). No HIV seroconversions were observed. CONCLUSION: Interventions providing information, enhancing risk-reduction skills, and motivating behavior change through peer education training can reduce injection risk behaviors, although risk elimination might be necessary to prevent HCV transmission. 相似文献
996.
Smyth CM McKiernan SM Hagan R Pilkington R O'Regan M Lawlor E Kelleher D 《European journal of gastroenterology & hepatology》2007,19(6):493-498
BACKGROUND: Hepatitis C virus infection is a major cause of nonA, nonB hepatitis worldwide. A high prevalence of immunological abnormalities has been shown to occur in patients with chronic hepatitis C virus infection. AIM: The aim of this study was to assess the development of sicca syndrome in a cohort of patients infected with a single strain of hepatitis C virus, namely genotype 1b, and correlate this with viral persistence and human leukocyte antigen type of the patients. METHODS: Ninety-five patients infected with the single strain hepatitis C virus were used in this study, 32 of whom were polymerase chain reaction-negative and 63 polymerase chain reaction-positive. Patient details were reviewed for symptoms consistent with sicca syndrome. Human leukocyte antigen class I (A, B and C) and class II (DRB and DQB1) typing was performed on all patients. Auto-antibodies were also measured. RESULTS: DQB1*02 was highly significantly associated with viral persistence (P<0.0001). Nineteen of 21 patients with sicca syndrome were hepatitis C virus-polymerase chain reaction-positive demonstrating a strong association with viral persistence and the development of the syndrome. Human leukocyte antigen DQB1*02 was significantly associated with the development of sicca syndrome, P=0.02. CONCLUSION: The development of autoimmune disease in patients with chronic hepatitis C virus infection depends on the interaction of multiple factors. This study suggests that important factors in this process are viral persistence and human leukocyte antigen type of the patients. 相似文献
997.
998.
Prader-Willi syndrome (PWS) is caused by lack of paternally derived gene expression from the imprinted gene cluster on human chromosome 15q11-q13. PWS is characterized by severe hypotonia, a failure to thrive in infancy and, on emerging from infancy, evidence of learning disabilities and overeating behavior due to an abnormal satiety response and increased motivation by food. We have previously shown that an imprinting center deletion mouse model (PWS-IC) is quicker to acquire a preference for, and consume more of a palatable food. Here we examined how the use of this palatable food as a reinforcer influences learning in PWS-IC mice performing a simple appetitive learning task. On a nonspatial maze-based task, PWS-IC mice acquired criteria much quicker, making fewer errors during initial acquisition and also reversal learning. A manipulation where the reinforcer was devalued impaired wild-type performance but had no effect on PWS-IC mice. This suggests that increased motivation for the reinforcer in PWS-IC mice may underlie their enhanced learning. This supports previous findings in PWS patients and is the first behavioral study of an animal model of PWS in which the motivation of behavior by food rewards has been examined. 相似文献
999.
1000.
June Oliver Candace Coggins Peggy Compton Susan Hagan Deborah Matteliano Marsha Stanton Barbara St. Marie Stephen Strobbe Helen N. Turner 《Pain Management Nursing》2012,13(3):169-183
The American Society for Pain Management Nursing (ASPMN) has updated its position statement on managing pain in patients with substance use disorders. This position statement is endorsed by the International Nurses Society on Addictions (IntNSA) and includes clinical practice recommendations based on current evidence. It is the position of ASPMN and IntNSA that every patient with pain, including those with substance use disorders, has the right to be treated with dignity, respect, and high-quality pain assessment and management. Failure to identify and treat the concurrent conditions of pain and substance use disorders will compromise the ability to treat either condition effectively. Barriers to caring for these patients include stigmatization, misconceptions, and limited access to providers skilled in these two categories of disorders. Topics addressed in this position statement include the scope of substance use and related disorders, conceptual models of addiction, ethical considerations, addiction risk stratification, and clinical recommendations. 相似文献