全文获取类型
收费全文 | 2587227篇 |
免费 | 185309篇 |
国内免费 | 7572篇 |
专业分类
耳鼻咽喉 | 34274篇 |
儿科学 | 85199篇 |
妇产科学 | 71568篇 |
基础医学 | 363588篇 |
口腔科学 | 69662篇 |
临床医学 | 234494篇 |
内科学 | 515617篇 |
皮肤病学 | 62451篇 |
神经病学 | 213451篇 |
特种医学 | 99876篇 |
外国民族医学 | 736篇 |
外科学 | 386423篇 |
综合类 | 50400篇 |
现状与发展 | 5篇 |
一般理论 | 968篇 |
预防医学 | 196170篇 |
眼科学 | 56669篇 |
药学 | 187984篇 |
9篇 | |
中国医学 | 5336篇 |
肿瘤学 | 145228篇 |
出版年
2021年 | 19980篇 |
2019年 | 20624篇 |
2018年 | 29293篇 |
2017年 | 22592篇 |
2016年 | 26224篇 |
2015年 | 29500篇 |
2014年 | 40437篇 |
2013年 | 60419篇 |
2012年 | 80217篇 |
2011年 | 84478篇 |
2010年 | 50998篇 |
2009年 | 49140篇 |
2008年 | 79016篇 |
2007年 | 83828篇 |
2006年 | 85559篇 |
2005年 | 81723篇 |
2004年 | 78718篇 |
2003年 | 76036篇 |
2002年 | 73326篇 |
2001年 | 128406篇 |
2000年 | 131330篇 |
1999年 | 110497篇 |
1998年 | 31252篇 |
1997年 | 27919篇 |
1996年 | 28217篇 |
1995年 | 27383篇 |
1994年 | 25067篇 |
1993年 | 23419篇 |
1992年 | 85159篇 |
1991年 | 81563篇 |
1990年 | 78783篇 |
1989年 | 76059篇 |
1988年 | 69468篇 |
1987年 | 67996篇 |
1986年 | 63542篇 |
1985年 | 60510篇 |
1984年 | 44940篇 |
1983年 | 37943篇 |
1982年 | 22456篇 |
1981年 | 19984篇 |
1979年 | 38959篇 |
1978年 | 27439篇 |
1977年 | 23252篇 |
1976年 | 21495篇 |
1975年 | 22813篇 |
1974年 | 26786篇 |
1973年 | 25370篇 |
1972年 | 23749篇 |
1971年 | 21955篇 |
1970年 | 20183篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
S Balzer D T Schneider M B Bernbeck M J?ger O Mils J Schaper R Willers R Krauspe U G?bel R Wessalowski 《International journal of hyperthermia》2006,22(6):451-461
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads. 相似文献
73.
74.
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
75.
76.
77.
78.
79.
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
80.
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