全文获取类型
收费全文 | 3837篇 |
免费 | 335篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 132篇 |
妇产科学 | 84篇 |
基础医学 | 458篇 |
口腔科学 | 44篇 |
临床医学 | 537篇 |
内科学 | 578篇 |
皮肤病学 | 47篇 |
神经病学 | 591篇 |
特种医学 | 89篇 |
外科学 | 430篇 |
综合类 | 37篇 |
一般理论 | 11篇 |
预防医学 | 520篇 |
眼科学 | 34篇 |
药学 | 255篇 |
中国医学 | 3篇 |
肿瘤学 | 287篇 |
出版年
2024年 | 12篇 |
2023年 | 43篇 |
2022年 | 73篇 |
2021年 | 177篇 |
2020年 | 116篇 |
2019年 | 151篇 |
2018年 | 175篇 |
2017年 | 144篇 |
2016年 | 115篇 |
2015年 | 133篇 |
2014年 | 150篇 |
2013年 | 253篇 |
2012年 | 287篇 |
2011年 | 311篇 |
2010年 | 180篇 |
2009年 | 144篇 |
2008年 | 222篇 |
2007年 | 284篇 |
2006年 | 233篇 |
2005年 | 213篇 |
2004年 | 190篇 |
2003年 | 157篇 |
2002年 | 147篇 |
2001年 | 24篇 |
2000年 | 23篇 |
1999年 | 29篇 |
1998年 | 29篇 |
1997年 | 21篇 |
1996年 | 18篇 |
1995年 | 17篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 14篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1970年 | 3篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有4180条查询结果,搜索用时 15 毫秒
101.
The purpose of this study was to evaluate the effect of MTAD on the flexural strength and modulus of elasticity of dentin. Dentin bars were randomly assigned to eight groups treated with various concentrations of NaOCl (5.25%, 2.65%, 1.31%, 0.66%), 17% EDTA, MTAD, saline, or according to a clinical protocol with 1.3% NaOCl and then 5 min of MTAD. Specimens were subjected to flexural strength and modulus of elasticity tests. Two-sample t test (alpha = 0.05) showed no statistically significant differences between various groups except for a reduction in flexural strength for the 2-h MTAD group (p = 0.002) and the EDTA group (p = 0.002). A significant reduction of modulus of elasticity for the 2-h MTAD group (p < 0.001), EDTA group (p < 0.001), and 0.6% NaOCl (p < 0.002) also was noted. There was no significant difference in flexural strength and modulus of elasticity between the dentin bars exposed to saline or MTAD when applied according to the clinical protocol (p > 0.05). These results indicate that MTAD can be used as prescribed for clinical use without affecting the physical properties of the dentin. 相似文献
102.
103.
104.
105.
106.
Preterm premature rupture of membranes is the rupture of membranes during pregnancy before 37 weeks' gestation. It occurs in 3 percent of pregnancies and is the cause of approximately one third of preterm deliveries. It can lead to significant perinatal morbidity, including respiratory distress syndrome, neonatal sepsis, umbilical cord prolapse, placental abruption, and fetal death. Appropriate evaluation and management are important for improving neonatal outcomes. Speculum examination to determine cervical dilation is preferred because digital examination is associated with a decreased latent period and with the potential for adverse sequelae. Treatment varies depending on gestational age and includes consideration of delivery when rupture of membranes occurs at or after 34 weeks' gestation. Corticosteroids can reduce many neonatal complications, particularly intraventricular hemorrhage and respiratory distress syndrome, and antibiotics are effective for increasing the latency period. 相似文献
107.
Ladslaus L. Mnyone Matthew J. Kirby Monica W. Mpingwa Dickson W. Lwetoijera Bart G. J. Knols Willem Takken Constantianus J. M. Koenraadt Tanya L. Russell 《Parasitology research》2011,108(2):317-322
Physiological characteristics of insects can influence their susceptibility to fungal infection of which age and nutritional status are among the most important. An understanding of host–pathogen interaction with respect to these physiological characteristics of the host is essential if we are to develop fungal formulations capable of reducing malaria transmission under field conditions. Here, two independent bioassays were conducted to study the effect of age and blood-feeding status on fungal infection and survival of Anopheles gambiae s.s. Giles. Mosquitoes were exposed to 2 × 1010 conidia m−2 of oil-formulated Metarhizium anisopliae ICIPE-30 and of Beauveria bassiana I93-825, respectively, and their survival was monitored daily. Three age groups of mosquitoes were exposed, 2–4, 5–8, and 9–12 days since emergence. Five groups of different feeding status were exposed: non-blood-fed, 3, 12, 36, and 72 h post-blood feeding. Fungal infection reduced the survival of mosquitoes regardless of their age and blood-feeding status. Although older mosquitoes died relatively earlier than younger ones, age did not tend to affect mosquito susceptibility to fungal infection. Non-blood-fed mosquitoes were more susceptible to fungus infection compared to all categories of blood-fed mosquitoes, except for those exposed to B. bassiana 72 h post-blood feeding. In conclusion, formulations of M. anisopliae and B. bassiana can equally affect mosquitoes of different age classes, with them being relatively more susceptible to fungus infection when non-blood-fed. 相似文献
108.
David Ryder Katalin Kraszlan Debbie Lien Elizabeth Allen Tanya Chiplin Suzanne Dick 《Psychiatry, Psychology and Law》2013,20(1):65-75
The Western Australian Court Diversion Service (CDS) is a post‐conviction / pre‐sentence program that aims to divert substance‐using offenders from the prison system and into treatment programs. It has been in operation since 1988, though a formal evaluation has not been conducted. The present study evaluated the outcomes for offenders referred to the program in relation to program completion, sentencing and re‐offending. It utilised a quasi‐experimental within groups design using data from client files from January 1998 to June 1999. Offenders who had higher motivation, attended treatment regularly and had less than 20 prior convictions were more likely to complete the program. A custodial sentence was more likely if the offender was male, had committed a serious offence, had more than 30 prior convictions, had lower motivation and had not completed the CDS program. Predictors of re‐offending included lower motivation and a previous custodial sentence. The offender's level of motivation to change and number of prior convictions were significant predictors of all three outcomes: program completion, sentencing and re‐offending. The findings highlight the importance of considering offender characteristics when assessing eligibility for diversion programs, addressing offender motivation within diversion programs and considering issues of which offenders are most likely to benefit from which programs. 相似文献
109.
Normal aging and executive functions in "old-old" community dwellers: poor performance is not an inevitable outcome 总被引:2,自引:0,他引:2
Piguet O Grayson DA Broe GA Tate RL Bennett HP Lye TC Creasey H Ridley L 《International psychogeriatrics / IPA》2002,14(2):139-159
BACKGROUND: Studies on normal aging and cognitive functioning commonly describe early and more pronounced age-related changes in executive functions (EFs) compared to other cognitive abilities. Two of the three most common neurodegenerative disorders associated with aging (vascular dementia [VaD] and extrapyramidal [EP]-related dementia) show executive dysfunctions in their clinical presentation; and these cognitive deficits are not uncommon in the third one: Alzheimer's disease (AD). METHODS: Nine EF tests (yielding 12 measures) were administered to 123 randomly selected community dwellers, aged 81 years and over, with the view to determine the effect of age on performance. Markers of AD, VaD, and EP-related dementia, as well as sociodemographic and psychological variables, were selected and their contribution to EF performance was investigated. RESULTS: Multiple linear regression analyses revealed the greatest contribution to EF scores from the markers of AD and estimated IQ but not from the markers of VaD and EP-related dementia or from age. CONCLUSIONS: These findings suggest that chronological age acts as a proxy variable mediating the impact of other factors such as subclinical signs of neurodegenerative disorders and that it has little independent contribution to make. They also indicate the importance of cognitive abilities supported by posterior cortical circuits in EF problem resolution. This study demonstrates that cognitive decline is not an ineluctable process that is associated with "normal" aging but rather represents, in many cases, a byproduct of neurodegenerative disorders, albeit themselves highly age-related. 相似文献
110.
Eric A. Storch Monica S. Wu Brent J. Small Erika A. Crawford Adam B. Lewin Betty Horng Tanya K. Murphy 《Comprehensive psychiatry》2014
The current study examined correlates, moderators, and mediators of functional impairment in 98 treatment-seeking adults with obsessive–compulsive disorder (OCD). Participants completed or were administered measures assessing obsessive–compulsive symptom severity, functional impairment, resistance against symptoms, interference due to obsessive–compulsive symptoms, depressive symptoms, insight, and anxiety sensitivity. Results indicated that all factors, except insight into symptoms, were significantly correlated with functional impairment. The relationship between obsessive–compulsive symptom severity and functional impairment was not moderated by patient insight, resistance against obsessive–compulsive symptoms, or anxiety sensitivity. Mediational analyses indicated that obsessive–compulsive symptom severity mediated the relationship between anxiety sensitivity and obsessive–compulsive related impairment. Indeed, anxiety sensitivity may play an important contributory role in exacerbating impairment through increases in obsessive–compulsive symptom severity. Depressive symptoms mediated the relationship between obsessive–compulsive symptom severity and obsessive–compulsive related impairment. Implications for assessment and treatment are discussed. 相似文献