全文获取类型
收费全文 | 4343篇 |
免费 | 230篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 166篇 |
妇产科学 | 42篇 |
基础医学 | 604篇 |
口腔科学 | 232篇 |
临床医学 | 365篇 |
内科学 | 728篇 |
皮肤病学 | 79篇 |
神经病学 | 443篇 |
特种医学 | 179篇 |
外科学 | 614篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 352篇 |
眼科学 | 130篇 |
药学 | 245篇 |
中国医学 | 4篇 |
肿瘤学 | 296篇 |
出版年
2023年 | 37篇 |
2022年 | 58篇 |
2021年 | 105篇 |
2020年 | 78篇 |
2019年 | 95篇 |
2018年 | 111篇 |
2017年 | 62篇 |
2016年 | 127篇 |
2015年 | 113篇 |
2014年 | 146篇 |
2013年 | 220篇 |
2012年 | 293篇 |
2011年 | 276篇 |
2010年 | 168篇 |
2009年 | 150篇 |
2008年 | 310篇 |
2007年 | 290篇 |
2006年 | 313篇 |
2005年 | 262篇 |
2004年 | 234篇 |
2003年 | 240篇 |
2002年 | 225篇 |
2001年 | 53篇 |
2000年 | 42篇 |
1999年 | 48篇 |
1998年 | 62篇 |
1997年 | 37篇 |
1996年 | 35篇 |
1995年 | 33篇 |
1994年 | 35篇 |
1993年 | 39篇 |
1992年 | 28篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 18篇 |
1988年 | 17篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 19篇 |
1978年 | 16篇 |
1977年 | 9篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1972年 | 4篇 |
排序方式: 共有4587条查询结果,搜索用时 0 毫秒
1.
Sylke Andreas Jörg Dirmaier Timo Harfst Stephan Kawski Uwe Koch Holger Schulz 《European psychiatry》2009,24(2):105-111
The aim of this study was to evaluate a case-mix system to classify inpatients with mental disorders in Germany by means of self-report and expert-rated instruments. The use of case-mix systems enhances the transparency of performance and cost structure and can thus improve the quality of mental health care. We analysed a consecutive sample of 1677 inpatients with mental disorders from 11 hospitals using regression tree analysis. The model assigns patients to 17 groups, accounting for 17% of the variance for duration of stay. Patients with eating disorders had a longer duration of stay than patients with anxiety disorder, duration of mental illness of less than 3–5 years, lower levels of interpersonal problems and higher occupational position. The results showed that besides diagnosis, variables such as duration of illness and interpersonal problems are important for classifying inpatients with mental disorders. The results of the study should be critically reviewed regarding the empirical results of other studies and the appropriateness of case group concepts for inpatients with mental disorders. 相似文献
2.
3.
In an era of ongoing improvement in cancer patient survival, available long-term survival figures from cancer registries are often outdated and too pessimistic for two reasons: first, delay in availability of cancer registry data, typically in the order of a few years, and, second, application of cohort-based methods of survival analysis, which provide survival estimates for patients diagnosed many years ago. We developed a model-based period analysis approach aimed to overcome both problems. We provide extensive empirical evaluation of our approach by comparing its performance with that of previously available methods for monitoring of 5- and 10-year relative survival, with the use of data from the nationwide Finnish Cancer Registry of 490,279 patients ages >/=15 years and diagnosed with one of 20 common forms of cancer between 1953 and 1997. We show that, in most cases, the model-based approach predicts 5- and 10-year relative survival expectations of newly diagnosed patients quite closely and much better than any of the previously available methods, including standard period analysis. We conclude that the model-based approach may enable deriving up-to-date cancer survival rates even with the common latency in availability of cancer registry data. 相似文献
4.
Mapping scores onto stages: mini-mental state examination and clinical dementia rating. 总被引:6,自引:0,他引:6
Robert Perneczky Stefan Wagenpfeil Katja Komossa Timo Grimmer Janine Diehl Alexander Kurz 《The American journal of geriatric psychiatry》2006,14(2):139-144
OBJECTIVE: Although the clinical course of Alzheimer disease (AD) is gradual, it is useful for a number of reasons to distinguish between different levels of severity. The Clinical Dementia Rating (CDR) has demonstrated high validity and reliability for this purpose, but it requires a considerable amount of data to be collected both from the patient and from an informant. In the present study, the authors mapped Mini-Mental State Examination (MMSE) scores onto CDR categories to determine how well the MMSE performs as a surrogate of the CDR as a timesaving method of staging dementia. METHOD: Eight hundred sixty-three probands, including 524 patients with probable AD, 92 patients with questionable dementia, and 247 with memory complaints but no objective cognitive impairment, were included. Cutoff scores were identified on one-half of the sample using a receiver operating characteristic analysis. The cutoff values were then applied to the other half of the sample, and the agreement between MMSE score ranges and CDR stages was determined by calculating Cohen's kappa. RESULTS: The MMSE discriminated well between CDR stages 0.5, 1, 2, and 3 but performed poorly in the separation between CDR stages zero and 0.5. The MMSE ranges were 30 for no, 26-29 for questionable, 21-25 for mild, 11-20 for moderate, and 0-10 for severe dementia. Substantial agreement between the two instruments was obtained for the categories mild (kappa=0.62, p<0.001, N=115), moderate (kappa=0.69, p<0.001, N=114), and severe dementia (kappa=0.76, p<0.001, N=39), whereas the agreement was moderate for no (kappa=0.44, p<0.001, N=120) and only fair for questionable dementia (kappa=0.28, p<0.001, N=42). CONCLUSION: The MMSE can be used as a surrogate measure for the CDR for the staging of dementia in AD. 相似文献
5.
E K Koskelo L M Kivisaari U M Saarinen M A Siimes 《Acta paediatrica Scandinavica》1991,80(6-7):682-687
We used ultrasonography to measure muscles in the arms and thighs of 16 children with malignant diseases. Thicknesses of transverse sections of the brachial biceps muscle and the femoral quadriceps muscle were measured by ultrasound at the midpoint of the right arm and thigh. These two measures had a linear correlation (r = 0.76). The ultrasound measurements did not differ from those obtained by the CT scan which was used as a reference standard. The reproducibility of the measurements was good; the coefficient of variation was 2.4% for the midarm muscles and 2.8% for the midthigh muscles. We conclude that the ultrasound method combined with simple anthropometric measurements is helpful in the assessment of nutritional status of children with potential malnutrition. 相似文献
6.
7.
P-fimbriae vaccines 总被引:3,自引:0,他引:3
M. Bernice Kaack Auli Pere Timo K. Korhonen Stefan B. Svenson James A. Roberts 《Pediatric nephrology (Berlin, Germany)》1989,3(4):386-390
To test for cross-protective capacity of two different P-fimbriae vaccines we vaccinated baboons with fimbriae purified from either Escherichia coli strain ER2 or strain JR1. The vaccinated animals showed elevated antibody titers to P-fimbriae from each of the E. coli strains used, suggesting cross-reactivity as was expected from the results of immunoprecipitation of the fimbriae. Enzyme-linked immunosorbent assay inhibition by heterologous P-fimbriae proved this to be true immunologic cross-reactivity. 相似文献
8.
Pekka Jousilahti Veikko Salomaa Katri Hakala Vesa Rasi Elina Vahtera Timo Palosuo 《Annals of allergy, asthma & immunology》2002,89(4):381-385
BACKGROUND: Airway inflammation is a characteristic feature of bronchial asthma. Previous studies have shown an increased local inflammatory activity in the airway mucosa of asthma patients. OBJECTIVES: To analyze the association of asthma with three sensitive markers of systemic inflammation, C-reactive protein, serum amyloid-A (SAA), and plasma fibrinogen. METHODS: A cross-sectional, population-based study including 1,513 Finnish men aged 45 to 74 years, who participated in a chronic disease risk factor survey in 1997. Of the participating men, 97 were classified as asthma patients. The odds ratios of asthma were analyzed by quartile of each inflammation marker. RESULTS: In logistic regression models the age-adjusted odds ratios (second, third, and fourth quartile as compared with the first quartile) of asthma increased gradually with increasing quartile of C-reactive protein (1.28, 1.19, 1.96, P for trend = 0.039), SAA (1.20, 3.00, 3.49, P for trend < 0.001), and fibrinogen (1.22, 1.79, 3.16, P for trend < 0.001). The associations were independent of smoking. Further adjustment for waist-to-hip ratio, a marker of central obesity, and symptoms of chronic bronchitis weakened the observed association, but the increasing trend in the association of SAA and fibrinogen with asthma remained highly significant. CONCLUSIONS: Sensitive markers of systemic inflammation, particularly SAA and fibrinogen, were positively and significantly associated with asthma prevalence. These findings support the hypothesis that not only local, but also systemic, inflammation exist in bronchial asthma. 相似文献
9.
Timo Laatikainen Henri Kurunmäki Aarne Koskimies 《Journal of assisted reproduction and genetics》1988,5(1):14-17
Of 70 cycles stimulated with clomiphene and human menopausal gonadotropin (hMG) for an in vitro fertilization-embryo transfer (IVF-ET) program, a short luteal phase of 11 days or less was found in 18. In this group the mean estradiol and progesterone levels were elevated in the early luteal phase. Despite the elevated initial values, progesterone levels fell rapidly at the mid luteal phase as a sign of premature luteolysis. The mean total amount of gonadotropin administered and the mean number of follicles punctured and of oocytes recovered did not show any significant difference between the groups of normal and short luteal phases. The present findings support the theory that hyperestrogenism in the early luteal phase may initiate the premature luteolysis observed in clomiphene-menopausal gonadotropin-stimulated cycles. 相似文献
10.
Depression-executive dysfunction syndrome in stroke patients. 总被引:6,自引:0,他引:6
Risto Vataja Tarja Pohjasvaara Riitta M?ntyl? Raija Ylikoski Maarit Leskel? Hely Kalska Marja Hietanen Hannu Juhani Aronen Oili Salonen Markku Kaste Antero Lepp?vuori Timo Erkinjuntti 《The American journal of geriatric psychiatry》2005,13(2):99-107
OBJECTIVE: It has been suggested that executive dysfunction could be the core defect in patients with geriatric or vascular depression, and that this depression-dysexecutive syndrome (DES) might be related to frontal-subcortical circuit dysfunction. The authors tested this hypothesis in 158 poststroke patients, of whom 21 had both depression and executive dysfunction. Methods: In this cross-sectional cohort study, a neurological, psychiatric, and neuropsychological examination was carried out 3 months after ischemic stroke, and brain infarcts, white-matter changes, and brain atrophy were recorded by MRI. RESULTS: The 21 patients with DES had significantly more brain infarcts affecting their frontal-subcortical circuit structures than the 137 patients without DES, or the 41 patients with depression but without executive dysfunction. Patients with DES also had more severe depressive symptoms and worse psychosocial functioning, and they coped less well in complex activities of daily living. CONCLUSIONS: DES is a valid concept and may define a subgroup of poststroke patients with frontal-subcortical pathology and with distinct prognosis and treatment options. 相似文献