全文获取类型
收费全文 | 41521篇 |
免费 | 3073篇 |
国内免费 | 143篇 |
专业分类
耳鼻咽喉 | 402篇 |
儿科学 | 1160篇 |
妇产科学 | 1005篇 |
基础医学 | 6159篇 |
口腔科学 | 526篇 |
临床医学 | 5701篇 |
内科学 | 7952篇 |
皮肤病学 | 784篇 |
神经病学 | 4571篇 |
特种医学 | 1047篇 |
外科学 | 4099篇 |
综合类 | 325篇 |
现状与发展 | 1篇 |
一般理论 | 34篇 |
预防医学 | 4096篇 |
眼科学 | 709篇 |
药学 | 2708篇 |
中国医学 | 44篇 |
肿瘤学 | 3414篇 |
出版年
2024年 | 33篇 |
2023年 | 314篇 |
2022年 | 480篇 |
2021年 | 1032篇 |
2020年 | 690篇 |
2019年 | 1062篇 |
2018年 | 1281篇 |
2017年 | 972篇 |
2016年 | 1074篇 |
2015年 | 1136篇 |
2014年 | 1594篇 |
2013年 | 2073篇 |
2012年 | 3308篇 |
2011年 | 3374篇 |
2010年 | 1866篇 |
2009年 | 1707篇 |
2008年 | 2863篇 |
2007年 | 2983篇 |
2006年 | 2650篇 |
2005年 | 2795篇 |
2004年 | 2549篇 |
2003年 | 2333篇 |
2002年 | 2187篇 |
2001年 | 306篇 |
2000年 | 192篇 |
1999年 | 338篇 |
1998年 | 471篇 |
1997年 | 388篇 |
1996年 | 287篇 |
1995年 | 298篇 |
1994年 | 241篇 |
1993年 | 215篇 |
1992年 | 162篇 |
1991年 | 141篇 |
1990年 | 108篇 |
1989年 | 122篇 |
1988年 | 96篇 |
1987年 | 88篇 |
1986年 | 77篇 |
1985年 | 69篇 |
1984年 | 86篇 |
1983年 | 66篇 |
1982年 | 69篇 |
1981年 | 74篇 |
1980年 | 81篇 |
1979年 | 39篇 |
1978年 | 42篇 |
1977年 | 51篇 |
1976年 | 37篇 |
1974年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The Changing Faces of the Nutcracker Esophagus 总被引:3,自引:0,他引:3
Christine B. Dalton P.A.C. Donald O. Castell M.D. Joel E. Richter M.D. 《The American journal of gastroenterology》1988,83(6):623-628
Although the nutcracker esophagus, characterized by high amplitude peristaltic contractions with mean distal amplitude greater than 180 mm Hg, is the most common esophageal motility disorder associated with noncardiac chest pain, little is known about its natural history. Therefore, we reviewed the manometric tracings of 23 patients with the nutcracker esophagus who had an average of 4.6 studies during a mean period of 32 months. Ten age-matched volunteers with normal baseline manometry who had undergone multiple studies (mean 5.8) over a mean time span of 32 months served as controls. In the 17 nutcracker patients with three or more motility studies, the variability of mean distal amplitudes between studies was 41.9% +/- 4.1 (+/- SE) compared to 27.0% +/- 3.3 for the control subjects (p less than 0.01). Highest distal pressures were noted during the first study in 11 of 17 patients (65%) compared to two of 10 controls (20%). The consistency of the diagnosis of nutcracker esophagus varied considerably: four patients always had high amplitude pressures, three patients only had the nutcracker diagnosis on the initial study, and 10 patients intermittently had pressures in the nutcracker range. Overall, these 17 patients had the diagnosis of the nutcracker esophagus confirmed on only 54% of subsequent studies. Changes in motility patterns were intermittently seen in six of 23 patients: one diffuse spasm and five nonspecific motility disorders. None of the control subjects developed high amplitude contractions or changed their motility pattern on serial testing. The possible pathophysiological implications of the changing faces of the nutcracker esophagus are discussed. 相似文献
92.
93.
Christine Liddell Gordon Rae Tom R M Brown David Johnston Vivien Coates John Mallett 《The British journal of general practice》2004,54(506):667-672
BACKGROUND: Providing patients with an audiotape of their medical consultation has been a relatively common practice in oncology clinics for some years. However, broader generalisability of the technique has yet to be examined. AIMS: To investigate the efficacy of providing patients with an audiotape of their consultation in a general practice setting. DESIGN OF STUDY: Randomised controlled trial: 95 experimental participants, 85 controls. SETTING: Routine surgeries run by two general practitioners (GPs) in two different health centres. METHOD: All patients attending GP appointments were eligible for inclusion. Patients were followed up by telephone 7-10 days later. RESULTS: More than half (61%) of the patients who received a tape listened to it. Among listeners, 64% rated the tape useful or very useful; 24% noticed information not heard in the consultation. Half of listeners (46%) said that their understanding of the consultation improved after listening to the tape. Half of the listeners (48%) shared the tape with others, of whom 71% found sharing helpful or very helpful. However, 21% of those who shared the information with others found this unhelpful or very unhelpful, suggesting that patients may need to be briefed on the potential risks of sharing. At follow-up a week later, it emerged that being given a tape had no effect on adherence with GPs' advice, nor on anxiety about conditions. CONCLUSION: Providing patients with an audiotape of their GP consultation was positively rated by many patients. Although there were no detectable clinical effects at follow-up, the technique merits further evaluation in general practice. 相似文献
94.
95.
Thomas F Campbell Christine Dollaghan Janine E Janosky P David Adelson 《J. Speech Lang. Hear. Res.》2007,50(4):1110-1119
PURPOSE: Interpreting the rapidly changing speech skills of young children recovering from neurological injury is difficult because developmental expectations are generally available only at relatively lengthy intervals (e.g., 6 or 12 months). In this research note, the authors describe the process of generating a Percentage of Consonants Correct-Revised (PCC-R; L. D. Shriberg, D. Austin, B. A. Lewis, J. L. McSweeny, & D. L. Wilson, 1997a) performance curve and illustrate some of its applications for assessing change in performance over time. METHOD: The authors compiled mean PCC-R scores from 16 samples of typically developing children (18-172 months) and used curve fitting to test more than 11,000 statistical models of monthly growth in PCC-R. They selected a parsimonious and developmentally plausible model with R(2) = .9839 (p < .0005) and used it to generate the PCC-R, standard deviation, and standard error expected at each monthly age. RESULTS: The PCC-R performance curve distinguished among 65 children (37-57 months of age) diagnosed independently with normal or disordered speech with a high degree of success. More important, the PCC-R performance curve can be used to identify the points at which children (18-172 months) recovering from neurological injury achieve normal-range consonant production. CONCLUSION: The curve-fitting approach holds promise as a means of interpreting temporal variations in speech production at a finer grain than existing normative data currently allow. 相似文献
96.
Psychosocial factors at work and perceived health among agricultural meat industry workers in France
Christine Cohidon Patrick Morisseau Francis Derriennic Marcel Goldberg Ellen Imbernon 《International archives of occupational and environmental health》2009,82(7):807-818
Objective The objective of this study was to describe the perceived health status of the meat industry employees—i.e., working in the
slaughtering, cutting, and boning of large animals and poultry—and its relation to their organisational and psychosocial constraints
at work.
Methods This postal survey included all 3,000 employees of the meat industry (beef, pork and poultry) in four districts in Brittany,
France, whose companies were affiliated with the agricultural branch of the national health insurance fund. The questionnaire
asked for social and demographic data and information describing their job and the organisation of their work. The psychosocial
factors at work were described according to Karasek’s questionnaire (demand, latitude and social support at work). Perceived
health was measured with the Nottingham Health Profile perceived health indicator.
Results This study shows the high prevalence of poor health reported by the workers in this industry. This poor perceived health was
worse in women and increased regularly with age. Among the psychosocial factors studied, high quantitative and qualitative
demand at work, inadequate resources for good work and to a lesser extent, inadequate prospects for promotion appear especially
associated with poor perceived health. Other factors often associated with poor perceived health included young age at the
first job and work hours that disrupt sleep rhythms (especially for women).
Conclusion Our results show that this population of workers is especially vulnerable from the point of view of perceived physical and
psychological health and is exposed to strong physical, organisational and psychosocial constraints at work. They also demonstrate
that poor perceived health is associated with some psychosocial (such as high psychological demand and insufficient resources)
and organisational factors at work. These results, in conjunction with those from other disciplines involved in studying this
industry, may help the companies to develop preventive activities. 相似文献
97.
Gil Bellis Marie-Hélène Cazes Alain Parant Maryse Gaimard Cécile Travers Evelyne Le Roux Sophie Ravilly Gilles Rault 《Journal of cystic fibrosis》2007,6(3):179-186
BACKGROUND: In 1992 France set up a national cystic fibrosis observatory (Observatoire national de la mucoviscidose, ONM) to monitor the state of health of patients on an annual basis. Using the ONM data, this study estimates the main indicators for life expectancy and assesses the total number of cystic fibrosis patients. METHODS: The data for the years 1994 to 2003 are divided into 3-year periods. Life tables are drawn up for these periods, from which mean and median lengths of life are determined. Using the most recent life table, the number of births in 2003 and the incidence of the disease, the total population of patients can be estimated, assuming a stationary population. RESULTS: In 2001-2003, life expectancy at birth of patients registered with the ONM was 39.1 years and median length of life was 36.4 years. These results, substantially better than those of 1994-1996, are linked to improved conditions of patient inclusion in the ONM database, to improvements in their healthcare, but also to the limitations of the life tables. Based on the 2003 data, the total theoretical number of patients is 6490, and coverage by the ONM database is thus 63.2%. CONCLUSIONS: These provisional results demonstrate the need to convert the ONM observatory into a registry providing exhaustive coverage of all patients. 相似文献
98.
Christine P Ellis 《American journal of orthodontics and dentofacial orthopedics》2004,126(1):20A-21A; author reply 21A
99.
Lorraine N Clark Eneli Haamer Helen Mejia-Santana Juliette Harris Suzanne Lesage Alexandra Durr Sabine Janin Bs Katja Hedrich Elan D Louis Lucien J Cote Howard Andrews Stanley Fahn Cheryl Waters Blair Ford Steven Frucht William Scott Christine Klein Alexis Brice Hanno Roomere Ruth Ottman Karen Marder 《Movement disorders》2007,22(7):932-937
Parkin mutations account for the majority of familial and sporadic early onset Parkinson's disease (EOPD) cases with a known genetic association. More than 100 mutations have been described in the Parkin gene that includes homozygous, compound heterozygous, and single heterozygous mutations. We have designed a Parkin mutation genotyping array (gene chip) that includes published Parkin sequence variants and allows their simultaneous detection. The chip was validated by screening 85 PD cases and 47 controls previously tested for Parkin mutations. Similar genotyping microarrays have been developed for other genetically heterogeneous diseases including age-related macular degeneration. Here, we show the utility of a genotyping array for Parkinson's disease by analysis of 60 subjects from the Genetic Epidemiology of Parkinson Disease (GEPD) study that includes 15 early-onset PD case probands and 45 relatives. 相似文献
100.
Albertine Dubois Julien Dauguet Anne-Sophie Herard Laurent Besret Edouard Duchesnay Vincent Frouin Philippe Hantraye Gilles Bonvento Thierry Delzescaux 《Journal of cerebral blood flow and metabolism》2007,27(10):1742-1755
Besides the newly developed positron emission tomography scanners (microPET) dedicated to the in vivo functional study of small animals, autoradiography remains the reference technique widely used for functional brain imaging and the gold standard for the validation of in vivo results. The analysis of autoradiographic data is classically achieved in two dimensions (2D) using a section-by-section approach, is often limited to few sections and the delineation of the regions of interest to be analysed is directly performed on autoradiographic sections. In addition, such approach of analysis does not accommodate the possible anatomical shifts linked to dissymmetry associated with the sectioning process. This classic analysis is time-consuming, operator-dependent and can therefore lead to non-objective and non-reproducible results. In this paper, we have developed an automated and generic toolbox for processing of autoradiographic and corresponding histological rat brain sections based on a three-step approach, which involves: (1) an optimized digitization dealing with hundreds of autoradiographic and histological sections; (2) a robust reconstruction of the volumes based on a reliable registration method; and (3) an original 3D-geometry-based approach to analysis of anatomical and functional post-mortem data. The integration of the toolbox under a unified environment (in-house software BrainVISA, http://brainvisa.info) with a graphic interface enabled a robust and operator-independent exploitation of the overall anatomical and functional information. We illustrated the substantial qualitative and quantitative benefits obtained by applying our methodology to an activation study (rats, n=5, under unilateral visual stimulation). 相似文献