全文获取类型
收费全文 | 34879篇 |
免费 | 2715篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 334篇 |
儿科学 | 1043篇 |
妇产科学 | 902篇 |
基础医学 | 5339篇 |
口腔科学 | 472篇 |
临床医学 | 4990篇 |
内科学 | 6165篇 |
皮肤病学 | 700篇 |
神经病学 | 3910篇 |
特种医学 | 806篇 |
外科学 | 3177篇 |
综合类 | 276篇 |
现状与发展 | 1篇 |
一般理论 | 33篇 |
预防医学 | 3725篇 |
眼科学 | 606篇 |
药学 | 2285篇 |
中国医学 | 42篇 |
肿瘤学 | 2883篇 |
出版年
2024年 | 32篇 |
2023年 | 278篇 |
2022年 | 428篇 |
2021年 | 890篇 |
2020年 | 594篇 |
2019年 | 924篇 |
2018年 | 1099篇 |
2017年 | 855篇 |
2016年 | 938篇 |
2015年 | 971篇 |
2014年 | 1373篇 |
2013年 | 1771篇 |
2012年 | 2798篇 |
2011年 | 2882篇 |
2010年 | 1562篇 |
2009年 | 1419篇 |
2008年 | 2426篇 |
2007年 | 2497篇 |
2006年 | 2254篇 |
2005年 | 2350篇 |
2004年 | 2094篇 |
2003年 | 1953篇 |
2002年 | 1833篇 |
2001年 | 243篇 |
2000年 | 137篇 |
1999年 | 288篇 |
1998年 | 391篇 |
1997年 | 321篇 |
1996年 | 236篇 |
1995年 | 238篇 |
1994年 | 191篇 |
1993年 | 178篇 |
1992年 | 119篇 |
1991年 | 107篇 |
1990年 | 88篇 |
1989年 | 96篇 |
1988年 | 78篇 |
1987年 | 67篇 |
1986年 | 59篇 |
1985年 | 50篇 |
1984年 | 71篇 |
1983年 | 52篇 |
1982年 | 59篇 |
1981年 | 66篇 |
1980年 | 66篇 |
1979年 | 31篇 |
1978年 | 30篇 |
1977年 | 37篇 |
1976年 | 29篇 |
1974年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Helmut Seidel Barbara Harazin Kristina Pavlas Christine Sroka Jörg Richter Ralph Blüthner Udo Erdmann Jan Grzesik Barbara Hinz Reinhard Rothe 《International archives of occupational and environmental health》1988,61(1-2):95-106
Summary This study was carried out in order: (1) to examine the effects of isolated and combined prolonged exposures to noise and whole-body vibration on hearing, vision and subjectively experienced strain, and (2) to check the combined effects with repeated exposures. Six male subjects were exposed twice to noise (N) at 92 dBA, whole-body vibration (V) in the Z-axis at 4 Hz and 1.0 ms–2 rms, and noise and vibration (NV) for 90 min with each condition. Temporary threshold shifts of hearing (TTS) and their integrals (ITTS) were measured at 4, 6, 10, and 12 kHz. Visual acuity was examined by means of a very sensitive test. Cross-modality matching (CMM) of the handgrip force was used to judge the subjectively experienced strain. NV induced a clear tendency of higher TTS and ITTS than N, with several significant differences most pronounced at 10 kHz. With repeated exposures, the effect of NV decreased, while the reactions to N and V remained unchanged. The individual reactions to NV differed. The influence of the duration of exposures on vision depended on the condition; N caused time-dependent changes, whereas V did not. CMM-data increased with the duration of the exposure during V and NV. N was generally judged to be more straining than V; NV caused higher strain than V during the first 30 min of exposure only. Correlations between different effects suggest certain links between them. Additionally, less motivation — daily obtained by a questionnaire — often correlated with higher ITTS during N and NV. The results also illustrate the combined effects on the individual susceptibility, repetition of exposure, the kind of response, and, possibly, the actual psychic state.Abbreviations CMM
cross-modality matching
- MVC
maximum voluntary contraction force
- N
exposure condition: noise level 92dBA, no whole-body vibration
- NV
exposure condition: combined exposure to noise with a level of 92 dBA and wholebody vibration with 4 Hz, 1 ms–2 rms
- V
exposure condition: whole-body vibration with 4 Hz, 1 ms–2 rms
- TTS
temporary threshold shift
- ITTS
integral of temporary threshold shift
- WBV
whole-body vibration in the common sense
This work was done in the Temporary International Research Team on Combined Effects of Noise and Vibration of the Council of Mutual Economic Assistance of the Socialist Countries. The authors gratefully acknowledge the help and assistance of L.-M. Brumm, Y. Bening, M. Godau, G. Weber, and R. Vizcaino. 相似文献
82.
Cardiac MIBG scintigraphy is a sensitive tool for detecting cardiac sympathetic denervation in Parkinson's disease. 总被引:5,自引:0,他引:5
Frédéric Courbon Christine Brefel-Courbon Claire Thalamas Marie-Jeanne Alibelli Isabelle Berry Jean-Louis Montastruc Olivier Rascol Jean-Michel Senard 《Movement disorders》2003,18(8):890-897
[(123)I]Metaiodobenzylguanidine ([(123)I]MIBG) cardiac scintigraphy could be helpful to differentiate Parkinson's disease (PD) from multiple system atrophy (MSA), demonstrating that, in PD with autonomic failure but not in MSA, there is a myocardial postganglionic sympathetic dysfunction. To investigate whether this method is more sensitive than standard autonomic testing to detect early involvement of sympathetic cardiac efferent, we analyse MIBG myocardial uptake in 8 PD patients with normal autonomic testing (nondysautonomia PD group, NDPD) in comparison with 10 PD patients with abnormal autonomic testing (dysautonomia PD group, DPD) and 10 MSA patients. Global MIBG uptake was assessed using the ratio of [(123)I]MIBG uptake in the heart to the upper mediastinum (H/M) on planar scintigraphic data. Regional MIBG uptake was determined on two single photon emission tomography scans in regions of the left ventricle. The mean H/M ratios were significantly different among the three groups (P < 0.0001). H/M ratios of both NDPD and DPD patients groups (H/M = 1.83 +/- 0.50 and 1.24 +/- 0.40, respectively) were significantly lower than in MSA patients (H/M = 2.52 +/- 0.60). However, in NDPD patients, H/M was significantly higher than in DPD patients. When compared to MSA patients, NDPD patients showed a regional reduction in MIBG uptake in all left ventricle regions markedly in the apex and the inferior wall. Our results suggest that MIBG myocardial scintigraphy (analysis of both H/M ratio and regional MIBG uptake) may be more sensitive than standard autonomic testing for the early detection of silent autonomic dysfunction in PD. 相似文献
83.
84.
85.
86.
Why should depression screening be conducted in chronically ill populations? Depression is a disabling illness and is very common among patients who have chronic illnesses. Despite its high prevalence in this patient population, depression often goes unrecognized. Having a plan for a population-based screening program for depression can not only identify patients who are at risk of depression, but can also help to foster early treatment and enhanced care for these patients. This article provides an overview of commonly-used depression screening tools and presents an example of how this might be carried out in a healthcare organization. 相似文献
87.
Explanations of cancer need to take into account developmental changes in children's cognitive and emotional abilities to understand illness. Children below 5 years of age are usually informed by parents, and older children by medical staff. Information tends to focus on details of treatments and procedures, and less on the seriousness of the disease and length of time involved. There are indications that early and honest information is associated with better behaviour and adjustment in the child, communication within the family and compliance with treatment, although methodological inadequacies in assessment of adjustment and knowledge of cancer limit the ability to generalize these findings. Communication with children should take into account developmental changes in children's ability to understand illness information. Communicators should also provide emotional support to deal with the threatening nature of this information. 相似文献
88.
Lynn Ware M.D. Dr. David Muram M.D. Christine L. Gale M.D. 《Sexuality and disability》1992,10(3):189-192
In some patients with mental retardation, a Q-tip pap smear obtained blindly from the upper vagina may be the only cytologic smear obtainable without subjecting the patient to heavy sedation or to examination under anesthesia. The efficacy of blind Q-tip smears has not been previously determined. Of 31 Q-tip smears obtained from patients with CIN, the Q-tip smear identified the abnormality in 10 (32%) patients. For those patients who will not submit to examination without anesthesia or sedation, routine screening with multiple smears, obtained on an annual basis has the potential to identify many cases of CIN which otherwise would not be identified at all, and in certain patients, this method outweighs the risks of heavy sedation or general anesthesia. Because of the greatly reduced sensitivity of the Q-tip pap, every effort should be made to help the patient and/or her family or guardian to understand the implications and risks of this method. However, if an examination under anesthesia is performed for other indications, a complete gynecologic examination and a direct smear should be obtained at that time. 相似文献
89.
An important methodological issue in depressionanalog research is whether individuals who scoreextremely low on self-report measures like the BeckDepression Inventory (BDI) should be included innondepressed control groups. Joiner, Schmidt, and Metalsky(1994) found that college students with BDI scores of 0or 1 evidenced a fake-good test taking style as measuredby the MMPI validity scales. The present study investigated whether very low BDI scores (BDI= 0 or 1; n = 21) might be associated with an elevatedpositive mood state, extreme optimism, positiveattributional style or social desirability. Resultsindicated that the very low scoring BDI subjects scoredhigher on social desirability than the low scoring group(BDI = 2 9, n = 63). Significant differences on mood,symptom and cognitive measures disappeared when social desirability was entered as a covariate.Findings support Kendall, Hollon, Beck, Hammen, andIngram's (1987) recommendation that subjects who score0 or 1 on the BDI should be excluded from a nondepressed control group. 相似文献
90.
Dianne P. Goeman Robyn E. O'Hehir Christine Jenkins Simon L. Scharf Jo A. Douglass 《The clinical respiratory journal》2007,1(2):99-105
Introduction: Asthma mortality has declined overall because of a range of public health initiatives. In western countries, the majority of asthma deaths now occur in people over the age of 50. The reasons for the poorer response of older age groups to public health asthma initiatives are not known. Objectives: We undertook a study to investigate the disease perspectives of older people with asthma and barriers which may exist and prevent optimal asthma care. Methods: Fifty‐five participants (16 male and 39 female) aged over 50 from an inner city, suburban area and a rural region were recruited. Lung function was measured, and questionnaire data on asthma symptoms, knowledge and control, medication use and respiratory health were collected. Participants were also interviewed in‐depth, and the quantitative and qualitative data were triangulated. Results: Participants with a duration of asthma for >30 years reported significantly fewer symptoms and better quality of life irrespective of asthma severity, indicating less appreciation of symptoms in those with a long asthma duration. Interviews revealed this was related to previous asthma management strategies when treatment options were limited. Participants with a recent diagnosis sought understanding of asthma and the reason for their illness. Initiatives to improve asthma care in older people need to reflect these findings. Conclusions: Self‐management strategies for older people need to be tailored according to the time of disease onset and the duration of disease. Please cite this paper as: Goeman DP, O’Hehir RE, Jenkins C, Scharf SL and Douglass JA. ‘You have to learn to live with it’: a qualitative and quantitative study of older people with asthma. The Clinical Respiratory Journal 2007; 1:99–105. 相似文献