全文获取类型
收费全文 | 7801篇 |
免费 | 863篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 103篇 |
儿科学 | 129篇 |
妇产科学 | 39篇 |
基础医学 | 522篇 |
口腔科学 | 359篇 |
临床医学 | 1170篇 |
内科学 | 2273篇 |
皮肤病学 | 44篇 |
神经病学 | 1034篇 |
特种医学 | 120篇 |
外科学 | 295篇 |
综合类 | 236篇 |
一般理论 | 2篇 |
预防医学 | 1630篇 |
眼科学 | 50篇 |
药学 | 375篇 |
1篇 | |
中国医学 | 22篇 |
肿瘤学 | 297篇 |
出版年
2024年 | 44篇 |
2023年 | 397篇 |
2022年 | 503篇 |
2021年 | 639篇 |
2020年 | 586篇 |
2019年 | 657篇 |
2018年 | 553篇 |
2017年 | 523篇 |
2016年 | 426篇 |
2015年 | 343篇 |
2014年 | 451篇 |
2013年 | 916篇 |
2012年 | 313篇 |
2011年 | 309篇 |
2010年 | 236篇 |
2009年 | 249篇 |
2008年 | 256篇 |
2007年 | 203篇 |
2006年 | 164篇 |
2005年 | 146篇 |
2004年 | 120篇 |
2003年 | 97篇 |
2002年 | 103篇 |
2001年 | 72篇 |
2000年 | 55篇 |
1999年 | 44篇 |
1998年 | 44篇 |
1997年 | 34篇 |
1996年 | 39篇 |
1995年 | 18篇 |
1994年 | 24篇 |
1993年 | 13篇 |
1992年 | 21篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1971年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有8701条查询结果,搜索用时 0 毫秒
1.
2.
Philip A. Rozario Nancy L. Morrow-Howell Enola K. Proctor 《Quality of life research》2006,15(4):755-759
Using the SF-12 to measure physical and mental functioning, the authors examine the intra-individual changes in health-related
quality of life (HRQOL) 6 months post-discharge for depressed older adults. In addition, they examine three sets of predictors
that might influence these changes. The sample of depressed older adults was recruited from an inpatient geropsychiatry unit.
Although their physical and mental health scores on the SF-12 were lower than comparable norms, the sample showed an average
increase in their mental functioning but a decrease in the physical functioning over the 6 months. Negative life-events were
significant predictors of people who reported no change in their mental health functioning and decreases in their physical
health functioning. Interestingly, those who experienced positive life events were more likely to report declines and younger
participants were more likely to report no change in their physical functioning. The findings indicate that the effects of
depression on HRQOL can have enduring effects on a sample of previously hospitalized older adults. The significance of life
event changes might signify the importance of taking into account non-traditional areas of medical interventions. Further,
the findings indicate the usefulness of the SF-12 quantifying HRQOL outcomes. 相似文献
3.
4.
Jessica Swoboda DDS H. Asuman Kiyak MA PhD Rigmor E. Persson DDS MSD G. Rutger Persson DDS PhD David K. Yamaguchi PhD Michael I. MacEntee LDS FRCD© PhD Christopher C.L. Wyatt BSc DMD MSc 《Special care in dentistry》2006,26(4):137-144
There is limited information regarding oral health status and other predictors of oral health‐related quality of life. An association between oral health status and perceived oral health‐related quality of life (OHQOL) might help clinicians motivate patients to prevent oral diseases and improve the outcome of some dental public health programs. This study evaluated the relationship between older persons' OHQOL and their functional dentition, caries, periodontal status, chronic diseases, and some demographic characteristics. A group of 733 low‐income elders (mean age 72.7 ISD=4.71, 55.6% women, 55.1% members of ethnic minority groups in the U.S. and Canada) enrolled in the TEETH clinical trial were interviewed and examined as part of their fifth annual visit for the trial. OHQOL was measured by the Geriatric Oral Health Assessment Index (GOHAI); oral health and occlusal status by clinical exams and the Eichner Index; and demographics via interviews. Elders who completed the four‐year assessment had an average of 21.5 teeth (SD=6.9). with 8.5 occluding pairs (SD=4.6), and 32% with occlusal contacts in all four occluding zones. Stepwise multiple regressions were conducted to predict total GOHAI and its subscores (Physical, Social, and Worry). Functional dentition was a less significant predictor than ethnicity and being foreign‐bom. These variables, together with gender, years since immigrating, number of carious roots, and periodontal status, could predict 32% of the variance in total GOHAI, 24% in Physical, 27% in Social, and 21 % in the Worry subscales. These findings suggest that functional dentition and caries influence older adults' OHQOL, but that ethnicity and immigrant status play a larger role. 相似文献
5.
6.
Marisa Klein-Gitelman 《Clinical and Applied Immunology Reviews》2004,4(5):333-350
Systemic lupus erythematosus (SLE) is the archetypical immunologic disease. Approximately 20% of patients present in the first two decades of life. This article highlights some of the differences between pediatric and adult onset lupus.Children are defined as different from adults on the basis of age. Lupus presents with different gender ratios based on hormonal or pubertal status with more significant skewing toward female patients in the childbearing years. Female patients in the childbearing years appear to have a higher relative risk for mortality. Despite this, children have greater disease severity at onset based on the number of patients who present with significant organ inflammation, the amount of corticosteroids required and the abnormalities in lupus serologies including autoantibodies and low complements. Children present frequently with congenital and acquired complement defects. Children have an increased risk of infections that can be confused with lupus. They have a higher risk of serious pneumococcal infection and may have less protection from vaccinations received at the time of disease onset.The clinical immunology laboratory is critical in the diagnosis and treatment of pediatric SLE. The rapid analysis and transfer of laboratory results can be life saving for the child with suspected new onset lupus. The laboratory is also helpful in determining disease activity through analysis of immunologic trends over time in pediatric lupus patients. This is especially important in the noncompliant adolescent patient who has a correlation between disease activity and lupus serologic tests. Finally, the clinical immunology laboratory is an important tool for better understanding of the immunologic phenomena associated with lupus and of disease pathophysiology. 相似文献
7.
A new decontaminated hassles measure for adults, the Survey of Recent Life Experiences, was developed and validated. An initial pool of 92 items was administered to 100 subjects along with the Perceived Stress Scale. Fifty-one items were selected, based on significant correlations with the latter scale. The alpha reliability of the resultant final form of the Survey of Recent Life Experiences and its correlation with perceived stress were both high. In a separate cross-replication sample of 136 adults, the alpha reliability of the Survey and its correlation against the Perceived Stress Scale remained acceptably high. Moreover, separate-sex analyses supported the reliability and validity of the Survey of Recent Life Experiences across gender. Factor analysis of the Survey yielded six interpretable factors. Intercorrelations among subscales based on these factors were generally modest, suggesting that the scale is relatively free from contamination by psychological distress.The work reported was facilitated by a grant from the Social Sciences and Humanities Research Council of Canada's Small Grant Program, administered by the Office of Research Administration, York University. The authors appreciate the cooperation of staff at the Ontario Science Centre, Toronto, and the assistance of Maria Gurevich in verifying the data. 相似文献
8.
D. Locker 《Community dentistry and oral epidemiology》1997,25(3):199-203
Abstract Although numerous investigators have reported on self-perceived oral health status in adult and older adult populations, few have examined how these perceptions change over time. This paper uses data from a longitudinal oral health survey of community-dwelling Canadians aged 50 years and over to explore this issue. Data were collected at baseline and after 3 years. Change was assessed using a global transition judgement and change scores on four subjective oral health status indicators. These indicators addressed chewing capacity, oral and facial pain symptoms, other oral symptoms, and the psychosocial impact of oral disorders. Overall, 23.0% reported that their oral health had worsened over this period, 66.5% that it had remained the same and 10.5% that it had improved. Change scores on the four indicators showed a similar pattern and were significantly associated with these global judgements. Over the same period, substantial proportions lost one or more teeth, acquired new coronal or root DPS increments or experienced loss of periodontal attachment. An additional 17% complained of dry mouth. However, the only clinical indicator associated with changing perceptions of oral health was tooth loss. Of interest was the fact that rates of tooth loss were equally high among those who reported a worsening of oral health and those who reported an improvement. This suggests that the impact of tooth loss on health status may be positive or negative depending upon the condition of the teeth lost. 相似文献
9.
M. DAHLSTROM M. ESBJ
RNSSON LILJEDAHL J. GIERUP L. KAIJSER E. JANSSON 《Acta physiologica (Oxford, England)》1997,160(1):49-55
A previous study showed that adult female dancers have a high percentage of type I fibres in vastus lateralis. similar to that of endurance-trained female runners ar female cross-country skiers. It is not known if dancers already at an early age are characterized by a high percentage of type I fibres or develop a high percentage of type I fibres as a consequence of dance training. Furthermore. the muscle fibre composition of male dancers has not previously been studied. Therefore the aim of the study was to analyse skeletal muscle fibre characteristics in 10-year-old and 20-year-old dancers of both sexes. Age-matched boys and girls whose physical activity was average for their age groups served as controls. Muscle biopsies for histochemical analysis were obtained from vastus lateralis using the percutaneous needle technique. The major finding of the present study was that the vastus lateralis of young dancers of both sexes had a higher percentage of type I fibres than that of controls. Moreover. the higher type I percentage was seen not only in 20 year aids. but also in 10 year aids. who had begun their dance training at a professional level only a few weeks earlier. No significant difference in this respect was found between female and male dancers. In conclusion. the muscle fibre type composition in young dancers of both sexes differs from that of the average individual of the same age and is characterized by a high percentage of type I fibres. 相似文献
10.
T. Schäfer S. Ruhdorfer† L. Weigl† D. Wessner† J. Heinrich‡ A. Döring‡ H.-E. Wichmann‡§ J. Ring†¶ 《Clinical and experimental allergy》2003,33(10):1360-1367
BACKGROUND: The increase in allergic diseases is still unexplained. It was hypothesized that the intake of unsaturated fatty acids is a contributing cause of this development. We investigated the relationship between serum cholesterol levels, intake of polyunsaturated fatty acids (PUFA) and manifestations of atopy in a population-based setting. METHODS: A nested case-control study was performed within the population of the 3rd MONICA survey in Augsburg (Germany). The serum levels of total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol of 1537 adults (aged 28-78 years, response 61.4%) and the estimated intake of PUFA in a subset of 139 men were compared with the frequency of a doctor's diagnosis of asthma, allergic rhinoconjunctivitis (AR), atopic eczema (AE) and allergic sensitization as measured by skin prick and Radio Allergo Sorbent Test. FINDINGS: In bivariate analyses, we obtained a negative linear association between total and LDL cholesterol levels and the frequency of AR and sensitization, which was no longer significant after adjustment for important confounders. In contrast, positive linear associations were found between HDL cholesterol levels and AR and AE and, furthermore, between the intake of PUFA and allergic sensitization in men (P<0.01). After adjustment, an increasing risk for atopic diseases with increasing levels of HDL cholesterol and an increasing risk for allergic sensitization with increasing intakes of PUFA remained statistically significant. INTERPRETATION: There is indication that HDL cholesterol also plays a role in the complex interaction of fat intake, metabolism and the manifestation of atopy in adults. These findings may contribute to the understanding of time trends and regional differences of allergies. 相似文献