全文获取类型
收费全文 | 144362篇 |
免费 | 11174篇 |
国内免费 | 3547篇 |
专业分类
耳鼻咽喉 | 1203篇 |
儿科学 | 2878篇 |
妇产科学 | 2044篇 |
基础医学 | 11257篇 |
口腔科学 | 2773篇 |
临床医学 | 17749篇 |
内科学 | 17306篇 |
皮肤病学 | 1281篇 |
神经病学 | 12113篇 |
特种医学 | 3996篇 |
外国民族医学 | 10篇 |
外科学 | 11081篇 |
综合类 | 21359篇 |
现状与发展 | 8篇 |
一般理论 | 1篇 |
预防医学 | 24441篇 |
眼科学 | 1275篇 |
药学 | 16024篇 |
218篇 | |
中国医学 | 6651篇 |
肿瘤学 | 5415篇 |
出版年
2024年 | 591篇 |
2023年 | 2956篇 |
2022年 | 5576篇 |
2021年 | 7137篇 |
2020年 | 6797篇 |
2019年 | 5723篇 |
2018年 | 5469篇 |
2017年 | 4975篇 |
2016年 | 5147篇 |
2015年 | 4968篇 |
2014年 | 10556篇 |
2013年 | 10525篇 |
2012年 | 9180篇 |
2011年 | 9799篇 |
2010年 | 7561篇 |
2009年 | 7309篇 |
2008年 | 7165篇 |
2007年 | 6941篇 |
2006年 | 5798篇 |
2005年 | 4914篇 |
2004年 | 3976篇 |
2003年 | 3384篇 |
2002年 | 2561篇 |
2001年 | 2262篇 |
2000年 | 1864篇 |
1999年 | 1664篇 |
1998年 | 1465篇 |
1997年 | 1380篇 |
1996年 | 1166篇 |
1995年 | 1082篇 |
1994年 | 1026篇 |
1993年 | 861篇 |
1992年 | 816篇 |
1991年 | 758篇 |
1990年 | 615篇 |
1989年 | 537篇 |
1988年 | 526篇 |
1987年 | 484篇 |
1986年 | 443篇 |
1985年 | 588篇 |
1984年 | 501篇 |
1983年 | 308篇 |
1982年 | 328篇 |
1981年 | 302篇 |
1980年 | 283篇 |
1979年 | 172篇 |
1978年 | 173篇 |
1977年 | 145篇 |
1976年 | 105篇 |
1974年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Reiner Mengel Matthias Eigenbrodt Thomas Schünemann Lavin Florès-de-Jacoby 《Journal of clinical periodontology》1996,23(5):437-443
Abstract From August to October 1991, the periodontal status of 1001 Yemenis representing the age groups 12-14, 15-19, 20-24 and 35-44 years was recorded and evaluated with preference to the CPITN, the calculus index and clinical attachment levels. The impact of chewing khat, the leaves of a cultivated, alkaloid shrub, and of using the traditional miswak chewing stick for oral hygiene purposes were investigated. The results show that 6.9% of the juvenile probands (15-19 years) had healthy periodontal tissue (CPITN 0). whereas bleeding on probing and calculus (CPITN 1+2) were registered in 86.2%. In the 35-44 year age group. 1.7% were periodontally healthy, whereas 84.5% displayed plaque retention or shallow pocketing (CPITN 2-3) and 12.5% deep pocketing (CPITN 4). The treatment needs in all age groups are confined primarily to calculus removal and instruction in oral hygiene. The clinical attachment level and the calculus index revealed age-related attachment loss and calculus formation, primarily among male probands. The higher khat consumption among the male population is reflected in its detrimental effect on the periodontal tissue, especially among younger probands. Oral hygiene aids have also an influence on periodontal status, with a toothbrush proving more efficient than the miswak. WHO efforts directed towards prophylactic programs need to be intensified but can be staffed by dental hygienists. 相似文献
62.
Fifty couples and their children with Down syndrome (D.S.) were typed for HLA-A and HLA-B antigens and compared to 50 control families and 464 blood donors. The parental origin of the extra chromosome 21 was determined by cytogenetic methods. All individuals were caucasians and there was no history of consanguinity. No excessive HLA sharing was present in D.S. parents. The mothers of D.S. shared no more HLA antigens with their D.S. children than the control mothers with their normal children (14% vs. 18%). Thirteen of the fifty pairs (26%) (parent in whom the nondisjunction occurred and D.S. child) shared three HLA antigens at the A and/or B locus. This was not significantly higher than the proportion in the control group (12/50 or 24%). These data suggest that it is not the sharing of HLA-A and HLA-B antigens between the parents or between the parent who was the origin of the nondisjunction and the D.S. child that is related either to the occurrence of trisomy 21 zygotes or to prenatal survival of affected embryos and fetuses. 相似文献
63.
It has recently been shown that it is possible to discriminate accurately among myoelectric signals underlying different muscle
contraction types, specifically elbow flexion and extension and forearm pronation and supination. It was reported that once
a number of distinctive features had been extracted from the myoelectric signals, a neural network could be trained to distinguish
the contraction types with an impressively high accuracy. In the present paper, we show that a technique known as parallel
cascade identification can be used to construct classifiers that can also accurately, differentiate the contraction types.
The use of parallel cascades has the benefit of dispensing with the need for feature extraction, so that raw myoelectric signal
data can be used directly. In addition, very little data are required to train the parallel cascades to distinguish accurately
novel incoming myoelectric signals. Results of using parallel cascades to distinguish foream pronation, supination, and elbow
flexion are presented. 相似文献
64.
H. J. SPARR C. LEO E. LADNER E. DEUSCH H. BAUMGARTNER 《Acta anaesthesiologica Scandinavica》1997,41(10):1300-1307
Background : The study aimed to assess the relative influence of anaesthesia and muscle relaxation on intubating conditions and the haemodynamic and catecholamine responses to tracheal intubation.
Methods : Sixty ASA 1 or 2 patients were randomly assigned to one of four groups (15 patients each) that differed in the depth of anaesthesia (thiopentone plus fentanyl 2.5 μg kg-1 or thiopentone alone) and the degree of vecuronium–induced neuromuscular block (100% or _>: 65%) at intubation. Muscle relaxation was measured at 0.1 Hz by means of mechanomyography. Heart rate (HR) and mean arterial blood pressure (MAP) were measured before and after induction of anaesthesia, and 1 min and 5 min following intubation, while adrenaline (A) and noradrenaline concentrations (NA) were determined from arterial blood samples.
Results : Intubating conditions were improved primarily by providing complete muscle relaxation at the adductor pollicis muscle (P<0.001) and to a lesser extent by adding fentanyl to thiopentone (P=0.04). The response of HR and MAP to tracheal intubation was attenuated mainly by fentanyl (P<0.001). Complete muscle relaxation further diminished the response of MAP to intubation (P=0.03). Changes in A and NA were dependent on the depth of anaesthesia only (P =>0.01).
Conclusion : The results of the study demonstrate that the sympathoadrenal response to intubation is attenuated by adding fentanyl (2.5 kg-1 ) to an induction regimen with thiopentone, whereas provision of complete muscle relaxation at the adductor pollicis muscle is necessary to attain smooth intubating conditions. 相似文献
Methods : Sixty ASA 1 or 2 patients were randomly assigned to one of four groups (15 patients each) that differed in the depth of anaesthesia (thiopentone plus fentanyl 2.5 μg kg
Results : Intubating conditions were improved primarily by providing complete muscle relaxation at the adductor pollicis muscle (P<0.001) and to a lesser extent by adding fentanyl to thiopentone (P=0.04). The response of HR and MAP to tracheal intubation was attenuated mainly by fentanyl (P<0.001). Complete muscle relaxation further diminished the response of MAP to intubation (P=0.03). Changes in A and NA were dependent on the depth of anaesthesia only (P =>0.01).
Conclusion : The results of the study demonstrate that the sympathoadrenal response to intubation is attenuated by adding fentanyl (2.5 kg
65.
66.
A postal survey of 100 hospitals throughout the United Kingdom and Ireland was conducted to assess current practice in the pre-operative assessment and use of pulmonary artery catheters in patients undergoing elective abdominal aortic aneurysm repair. Seventy-four completed questionnaires were received. The survey revealed that 53% of respondents hold designated pre-operative assessment clinics, attended by anaesthetists in 54% and cardiologists in 26%. However, only 4% of respondents have a written protocol for stratifying patients and assessing peri-operative risk. By far the commonest investigation of choice for further cardiological assessment is transthoracic echocardiography (67%). Other investigations of choice are multiple update gated acquisition (MUGA) scan (13%), dipyridamole thallium imaging (9%), exercise ECG (6%), stress echocardiography (1%) and stress MUGA (1%). Two units (3%) never undertook further investigation. Pulmonary artery flotation catheters are used as a routine by 9% of respondents, dependent upon left ventricular ejection fraction by 65%, dependent on other factors by 7% and not used at all by 19%. The survey reveals widespread variation in pre-operative assessment of patients undergoing elective repair of abdominal aortic aneurysm. 相似文献
67.
C. M. Morley 《Journal of human nutrition and dietetics》1992,5(6):399-407
The F.I.P. (Financial Information Project) dietetic package allows the collection of basic patient data, which then can be processed to give valuable clinical and management information for use by all dietitians in a dietetic department. The advent of the Korner Reports (DHSS, 1984a) and their implementation highlighted the need to computerize certain aspects of data collection in dietetic departments. Within the West Midlands Regional Health Authority a group of dietitians worked with the Regional Management Services Department to adapt a community nursing system, F.I.P., for use by dietitians. The system was piloted for all paramedical services in 1987 with one health district (North Warwickshire) piloting the dietetic package. It is now used by a range of dietetic and paramedical departments. This paper outlines the system and its uses. 相似文献
68.
Farsin Hamzei Michel Rijntjes Joystone Gbadamosi Kornelius Fuchs Cornelius Weiller Alexander Münchau 《Movement disorders》2003,18(8):959-961
We report on a woman with a an 8-year history of multiple system atrophy with predominance of parkinsonism who developed jaw-locking oromandibular dystonia within hours after insertion of ill-fitting dentures. Dystonia spread rapidly to involve other facial muscles and the larynx causing stridor with respiratory failure necessitating crush intubation. 相似文献
69.
老年2型糖尿病患者胰岛素抵抗相关指标的检测和意义 总被引:1,自引:1,他引:0
目的:探讨老年2型糖尿病胰岛素抵抗(IR)及其相关性,为老年2型糖尿病的合理防治提供临床依据。方法:选择120例老年2型糖尿病患者,按胰岛素敏感指数(HOMA)胰岛素抵抗(HOMA-IR)50百分位点将患者分为两组:胰岛素相对敏感组(HOMA-IR<3.56)和胰岛素相对抵抗组(HOMA-IR≥3.56),比较体重指数(BMI)、腰/臀比(WHR)、血压、血生化学检查等指标。用年龄>40岁,<60岁的2型糖尿病患者做对照组。结果:两组老年患者在年龄、性别、舒张压、空腹血糖、胆固醇、高密度脂蛋白、糖化血红蛋白、HOMA胰岛β细胞功能方面无差异;但BMI、WHR、收缩压、甘油三脂、空腹胰岛素、HOMA-IR差异具有显著性。多线性回归分析后,只有腰/臀比、收缩压、甘油三脂、HOMA-IR存在统计学差异。老年患者与对照组相比,IR发生率明显增加,且两者腰/臀比、收缩压、甘油三脂方面也差异显著。结论:IR与老年2型糖尿病密切相关,是临床防治糖尿病的重要靶点。 相似文献
70.