全文获取类型
收费全文 | 2918426篇 |
免费 | 200918篇 |
国内免费 | 7861篇 |
专业分类
耳鼻咽喉 | 38897篇 |
儿科学 | 95863篇 |
妇产科学 | 79635篇 |
基础医学 | 421005篇 |
口腔科学 | 78055篇 |
临床医学 | 265918篇 |
内科学 | 571832篇 |
皮肤病学 | 69777篇 |
神经病学 | 234001篇 |
特种医学 | 111831篇 |
外国民族医学 | 774篇 |
外科学 | 435394篇 |
综合类 | 55755篇 |
现状与发展 | 6篇 |
一般理论 | 1043篇 |
预防医学 | 221859篇 |
眼科学 | 64908篇 |
药学 | 213815篇 |
9篇 | |
中国医学 | 5961篇 |
肿瘤学 | 160867篇 |
出版年
2019年 | 22799篇 |
2018年 | 32498篇 |
2017年 | 24906篇 |
2016年 | 28954篇 |
2015年 | 32524篇 |
2014年 | 44538篇 |
2013年 | 66631篇 |
2012年 | 89389篇 |
2011年 | 94993篇 |
2010年 | 57096篇 |
2009年 | 54330篇 |
2008年 | 88464篇 |
2007年 | 94332篇 |
2006年 | 95781篇 |
2005年 | 91597篇 |
2004年 | 88284篇 |
2003年 | 85411篇 |
2002年 | 82393篇 |
2001年 | 139986篇 |
2000年 | 143244篇 |
1999年 | 120586篇 |
1998年 | 34347篇 |
1997年 | 30424篇 |
1996年 | 30702篇 |
1995年 | 29667篇 |
1994年 | 27184篇 |
1993年 | 25589篇 |
1992年 | 93395篇 |
1991年 | 91042篇 |
1990年 | 88387篇 |
1989年 | 85586篇 |
1988年 | 78394篇 |
1987年 | 76855篇 |
1986年 | 71899篇 |
1985年 | 68737篇 |
1984年 | 51033篇 |
1983年 | 43132篇 |
1982年 | 25150篇 |
1981年 | 22523篇 |
1979年 | 45097篇 |
1978年 | 31825篇 |
1977年 | 26802篇 |
1976年 | 25347篇 |
1975年 | 27463篇 |
1974年 | 32080篇 |
1973年 | 30497篇 |
1972年 | 28510篇 |
1971年 | 26582篇 |
1970年 | 24558篇 |
1969年 | 23549篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
82.
Bifid mandibular canal. 总被引:1,自引:0,他引:1
PURPOSE: To determine the incidence and characteristics of bifid mandibular canals. METHODS: A retrospective study was performed using panoramic radiographs of 2012 patients subjected to dental treatment in the Dental Clinic of the Valencia University Dental School (Valencia, Spain) between 1996 and 1999. The goal was to investigate the presence of double mandibular canals. RESULTS: The extraoral panoramic radiographs revealed a total of 7 images suggestive of bifid canals. Mandibular computed tomography revealed the existence of this anatomic variant in 2 of 3 patients. An analysis was performed on the incidence of this type of image in extraoral panoramic radiography, its possible interpretations, and the clinical implications of bifid mandibular canals. CONCLUSIONS: In this study, 0.35% of canals were bifid. All cases were in women. 相似文献
83.
84.
85.
86.
87.
Published data devoted to making and characterization of the properties of polymeric wound dressings with proteolytic action
are reviewed. These data are indicative of individual dependence of the physicochemical properties, activity, and stability
of each particular enzyme on the type of polymer matrix and the method of immobilization. In order to obtain wound dressings,
which are active in physiological medium and retain their activity upon sterilization, it is necessary to optimize the composition
and characteristics of a polymer matrix and the enzyme included into its structure.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 8, pp. 24–28, August, 2006. 相似文献
88.
K P Sylvester S R Desai A U Wells D M Hansell M Awogbade S L Thein A Greenough 《The European respiratory journal》2006,28(4):832-838
The aim of this study was to determine whether patients with sickle cell disease (SCD) in steady state had pulmonary abnormalities seen on high-resolution computed tomography (HRCT) and whether any abnormalities correlated with contemporaneously diagnosed lung function abnormalities. A subsidiary question was whether the results of a noninvasive measure of haemolysis (end-tidal carbon monoxide (ETCO) levels) correlated with pulmonary function abnormalities. Thirty three patients with SCD, median (range) age 36 yrs (17-67 yrs) were examined. The degree of lobar volume loss and ground-glass opacification and prominence of central vessels on HRCT were quantitatively assessed. Pulmonary function was assessed by measurements of lung volumes, spirometry, gas transfer and oxygen saturation. ETCO levels were measured using an end-tidal CO monitor. Forced expiratory volume in one second (FEV1), forced vital capacity and total lung capacity significantly correlated with HRCT findings, particularly lobar volume loss. ETCO levels significantly negatively correlated with FEV1, vital capacity measured using a plethysmograph, specific airway conductance and arterial oxygen saturation measured by pulse oxymetry. In conclusion, the present results suggest that high-resolution computed tomography noninvasive assessment of haemolysis might be useful to identify sickle cell disease patients with respiratory function impairment. 相似文献
89.
F Pitta T Troosters V S Probst M A Spruit M Decramer R Gosselink 《The European respiratory journal》2006,27(5):1040-1055
Accurate assessment of the amount and intensity of physical activity in daily life is considered very important due to the close relationship between physical activity level, health, disability and mortality. For this reason, assessment of physical activity in daily life has gained interest in recent years, especially in sedentary populations, such as patients with chronic obstructive pulmonary disease (COPD). The present article aims to compare and discuss the two kinds of instruments more commonly used to quantify the amount of physical activity performed by COPD patients in daily life: subjective methods (questionnaires, diaries) and motion sensors (electronic or mechanical methods). Their characteristics are summarised and evidence of their validity, reliability and sensitivity is discussed, when available. Subjective methods have practical value mainly in providing the patients' view on their performance in activities of daily living and functional status. However, care must be taken when using subjective methods to accurately quantify the amount of daily physical activity performed. More accurate information is likely to be available with motion sensors rather than questionnaires. The selection of which motion sensor to use for quantification of physical activity in daily life should depend mainly on the purpose of its use. 相似文献
90.
J Müller-Quernheim K I Gaede E Fireman G Zissel 《The European respiratory journal》2006,27(6):1190-1195
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders. 相似文献