全文获取类型
收费全文 | 1105篇 |
免费 | 121篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 54篇 |
妇产科学 | 10篇 |
基础医学 | 145篇 |
口腔科学 | 7篇 |
临床医学 | 180篇 |
内科学 | 160篇 |
皮肤病学 | 6篇 |
神经病学 | 136篇 |
特种医学 | 36篇 |
外科学 | 73篇 |
综合类 | 94篇 |
预防医学 | 70篇 |
眼科学 | 44篇 |
药学 | 128篇 |
中国医学 | 33篇 |
肿瘤学 | 61篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 16篇 |
2021年 | 23篇 |
2020年 | 23篇 |
2019年 | 53篇 |
2018年 | 46篇 |
2017年 | 45篇 |
2016年 | 36篇 |
2015年 | 63篇 |
2014年 | 90篇 |
2013年 | 108篇 |
2012年 | 64篇 |
2011年 | 78篇 |
2010年 | 61篇 |
2009年 | 66篇 |
2008年 | 62篇 |
2007年 | 67篇 |
2006年 | 47篇 |
2005年 | 46篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 28篇 |
2001年 | 22篇 |
2000年 | 16篇 |
1999年 | 8篇 |
1998年 | 18篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1243条查询结果,搜索用时 437 毫秒
21.
Patient‐ and family‐centred care in the intensive care unit: a challenge in the daily practice of healthcare professionals 下载免费PDF全文
22.
AimsNear-infrared spectroscopy (NIRS) is a non-invasive, easy to apply, optical technology for measuring cerebral blood oxygenation, but there is lack of comprehensive population data to aid interpretation and clinical use. Given the importance of cerebral perfusion in the context of evolving guideline recommendations for more aggressive lowering of blood pressure (BP) in hypertension, even in the oldest old, understanding of normative NIRS values is timely. We estimated normative values of cerebral oxygenation measured by NIRS in a large community-dwelling population sample of adults aged > = 50 years (n = 3110). We hypothesized that measurements would be attenuated by cardiovascular risk factors.MethodsData from Wave 3 of The Irish Longitudinal Study on Ageing (TILDA) was utilized. Frontal lobe cerebral oxygenation was continuously measured via a Portalite, while participants rested in the supine position. Beat-to-beat BP was measured simultaneously. Normative data was modelled using generalized additive models for location, scale, and shape (GAMLSS). Multivariate linear regressions were used to examine associations with cardiovascular risk factors.ResultsAll three measures of NIRS (TSI, O2Hb and HHb) declined with increasing age. O2Hb and HHb were significantly lower in males than females. Increased smoking, excess alcohol intake, a higher waist-hip ratio, diabetes, angina, congestive heart failure, transient ischemic attack and total cardiovascular disease burden were all associated with decreased cerebral oxygenation.ConclusionWe present for the first time, normative resting-state NIRS reference data from a large population, which contributes to clinical interpretation of NIRS and advances the use of NIRS as a standard clinical tool. 相似文献
23.
《Clinical neurophysiology》2021,132(5):1089-1104
ObjectiveDescribe and evaluate the concepts of near fiber electromyography (NFEMG), the features used, including near fiber motor unit potential (NFMUP) duration and dispersion, which relate to motor unit distal axonal branch and muscle fiber conduction time dispersion, and NFMUP segment jitter, a new measure of the temporal variability of neuromuscular junction transmission (NMJ), and axonal branch and muscle fibre conduction for the near fibres (i.e. NF jitter), and the methods for obtaining their values.MethodsTrains of high-pass filtered motor unit potentials (MUPs) (i.e. NFMUP trains) were extracted from needle-detected EMG signals to assess changes in motor unit (MU) morphology and electrophysiology caused by neuromuscular disorders or ageing. Evaluations using simulated needle-detected EMG data were completed and example human data are presented.ResultsNFEMG feature values can be used to detect axonal sprouting, conduction slowing and NMJ transmission delay as well as changes in MU fiber diameter variability, and NF jitter. These changes can be detected prior to alterations of MU size or numbers.ConclusionsThe evaluations clearly demonstrate and the example data support that NFMUP duration and dispersion reflect MU distal axonal branching, conduction slowing and NMJ transmission delay and/or MU fiber diameter variability and that NFMUP jiggle and segment jitter reflect NF jitter.SignificanceNFEMG can detect early changes in MU morphology and/or electrophysiology and has the potential to augment clinical diagnosis and tracking of neuromuscular disorders. 相似文献
24.
25.
26.
27.
28.
29.
Summary Due to a short observation period previous studies may have underestimated prevalence and recurrence risk of IDDM in relatives of IDDM patients. To obtain a more exact life-time risk estimate we identified 310 probands, representative of Danish IDDM patients, characterized by current age more than 50 years, age at onset 40 years or less and diabetes duration of more than 30 years. Family data were obtained from 291 probands. Mean observation times (age) (± SD) for siblings (n = 553) and offspring (n=359) were 59.4 ± 16.1 years and 33.8 ± 8.8 years, respectively. Of the probands 73 (25.1%) had at least one first-degree relative with IDDM. Seventeen percent had at least one affected sibling. An increase from 10.4% to 22.4% of having first-degree relatives with IDDM among probands with age at onset below 20 years was observed during the period from proband at age 21 years up to 1 September 1992. Among affected siblings 48% of the second cases were affected more than 10 years after the first affected sibling. Using the life-table method cumulative recurrence risks from time of birth were calculated for siblings up to age 30 years of 6.4% and up to age 60 years of 9.6%. For offspring the risk up to age 34 years was 6.3%. In addition, we present a life-table method evaluating the cumulative recurrence risk from time of onset in the proband, as this is the most relevant when giving genetic counselling. In conclusion, the long-term risks of IDDM in siblings and offspring are high compared to that shown in previous reports.Abbreviations IDDM
insulin-dependent diabetes mellitus
- SE
standard error 相似文献
30.