全文获取类型
收费全文 | 886篇 |
免费 | 65篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 39篇 |
妇产科学 | 10篇 |
基础医学 | 137篇 |
口腔科学 | 24篇 |
临床医学 | 87篇 |
内科学 | 197篇 |
皮肤病学 | 8篇 |
神经病学 | 104篇 |
特种医学 | 60篇 |
外科学 | 84篇 |
综合类 | 21篇 |
预防医学 | 60篇 |
眼科学 | 14篇 |
药学 | 54篇 |
中国医学 | 9篇 |
肿瘤学 | 60篇 |
出版年
2023年 | 11篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 18篇 |
2018年 | 18篇 |
2017年 | 15篇 |
2016年 | 15篇 |
2015年 | 28篇 |
2014年 | 19篇 |
2013年 | 27篇 |
2012年 | 34篇 |
2011年 | 50篇 |
2010年 | 46篇 |
2009年 | 40篇 |
2008年 | 37篇 |
2007年 | 48篇 |
2006年 | 40篇 |
2005年 | 41篇 |
2004年 | 30篇 |
2003年 | 29篇 |
2002年 | 33篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 11篇 |
1998年 | 31篇 |
1997年 | 28篇 |
1996年 | 20篇 |
1995年 | 20篇 |
1994年 | 21篇 |
1993年 | 13篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 7篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1982年 | 14篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1970年 | 5篇 |
1968年 | 5篇 |
排序方式: 共有972条查询结果,搜索用时 31 毫秒
91.
The aims of management in seronegative spondiloarthritides are to control pain and inflammation, maintain optimal mobility of spine and peripheral joints, restoration and preservation of functional ability, prevent contractures and deformities. Non-steroidal anti-inflammatory drugs are the basis of drug treatment. Numerous non-steroidal anti-inflammatory drugs have been shown to reduce pain and inflammation. Apart from non-steroidal anti-inflammatory drugs, in order to control the pain pure analgesics and weak opioids are the most often used drugs. In this paper is discussed use of these drugs in patients with seronegative spondyloarthritides. 相似文献
92.
93.
Simeon Pollack 《International wound journal》2016,13(5):1091-1091
94.
OBJECTIVES: To determine if there is seasonal variation in acute asthmatic visits to accident and emergency (A&E) facilities in Trinidad and to identify the climatic variables associated with such visits. DESIGN AND METHODS: A retrospective census of patients with asthma, defined as those who required emergency bronchodilator nebulization, was taken at two A&E facilities in Trinidad from 1 January 1997 to 31 December 1999. The study included patients aged 64 years and under. Patient demographic data were obtained from the A&E records. Climate variables were taken from the island's sole Meteorological Office. Multiple regression was used to identify climate variables that were independent predictors of A&E asthma visits. RESULTS: There were a total of 45 842 asthma admissions to the two facilities during the study period. Visits exhibited a cyclic pattern over the 3 years that varied according to the island's dry (January-May) and wet (June-December) seasons. There were more visits during the wet season than the dry (40 [SD=2] vs. 32 [SD=2] visits/day; P<0.001). The results of multiple regression indicated that season (P<0.001), barometric pressure (P<0.001), temperature difference (P<0.001), minimum temperature2 (P<0.001) and wind speed2 (P=0.032) were predictors of paediatric visits. Independent predictors of adult visits were season (P<0.001), relative humidity (P<0.001), minimum temperature (P=0.01), temperature difference2 (P<0.001) and minimum temperature2 (P=0.004). Season and climatic variables explained 18% of the variance of the total A&E asthma admissions. CONCLUSION: There is seasonal variation in acute asthma visits to A&E facilities in Trinidad, which remains significant after controlling for climate variables. However, while climate has a role, there are other factors that may also be responsible for increased visits during the wet season. More research is needed to identify these factors. 相似文献
95.
SANMIGUEL CP HAGIIKE M MINTCHEV MP DELA CRUZ R PHILLIPS E CUNNEEN SA CONKLIN JL SOFFER EE 《Neurogastroenterology and motility》2006,18(6):484-485
Background: Electrical stimulation (ES) of the stomach has been shown to modulate LESP. Electrical stimulation, using neural high frequency stimulation (NGES) can induce contractions of the smooth muscle of the gut. The purpose of this study was to determine if electrical stimulation of the LES can affect LESP. Methods: Four female hound dogs, weight: 20–25 kg, underwent an esophagostomy that allowed the introduction of a sleeve manometry catheter into the esophagus. They were also implanted with a pair of electrodes along the longitudinal axis of the LES. After 3 weeks of recovery, they underwent esophageal manometry recording during control and ES, performed randomly on separate days, using 4 different stimulations: 1‐Low frequency: freq: 6 cycles/min, pulse: 350 milisec, amp: 5 mAmp; 2 High‐frequency: freq: 50 Hz, pulse: 1 milisec, amp: 5 mAmp; 3‐ NGES: freq: 50 Hz, pulse:20 milisec, amp:10 volts; 4‐ High‐frequency, circular: freq: 20 Hz, pulse:1 milisec, amp:5 mAmp. All recordings were performed 1 hour after consumption of 3 ounces of canned dog food, to prevent fluctuations in LESP and under mild sedation (acepromazine 0.5 mg kg1). Tests consisted, during ES days, of 3 periods of 20 minutes each: control , stimulation and post stimulation. The effect of NGES was also tested under anesthesia and following administration of L‐NAME 50 mg kg1 IV. and also atropine 0.05 mg kg1 IV. Analysis: area under the curve (AUC) and pressure were compared among the 3 periods. Data shown as mean ± SD, ANOVA and t‐test, p < 0.05. Results: Sustained increase in LESP was observed during low frequency stimulation, 32.1 ± 12.8 vs. 42.4 ± 18.0 vs. 50.1 ± 23.6, control vs. stimulation vs. post stimulation respectively, p = 0.013. AUC also significantly increased during and after stimulation, 39,320.3 ± 15,722 vs. 51,294 ± 21,826 vs. 59,823.6 ± 28,198.4 mmHgxsec, control vs. stimulation vs. post stimulation respectively, p = 0.01. There was no significant change with other types of ES. NGES induced an initial rise in LESP followed within few seconds by relaxation with slow resumption of pressure over a 1 minute period. L‐NAME increased LESP and augmented the initial rise in LESP following NGES but markedly diminished or abolished the relaxation phase. Atropine lowered LESP and abolished the initial rise in LESP induced by NGES. Conclusions: Low frequency ES of the LES increases LESP in conscious dogs. NGES has dual effect on LESP: an initial stimulation, cholinergically mediated, followed by relaxation mediated by nitric oxide. 相似文献
96.
Catalytic properties of cholinesterases: importance of tyrosine 109 in Drosophila protein. 总被引:1,自引:0,他引:1
Tyrosine 109 in the acetylcholinesterase sequence of Drosophila melanogaster corresponds to an aspartate in vertebrate cholinesterases. Mutation of this amino acid to a glycine in the human butyrylcholinesterase gives rise to the 'atypic' phenotype characterized by a reduced activity for charged compounds. We investigated the importance of tyrosine 109 in the Drosophila sequence by in vitro mutagenesis and its expression in the Xenopus oocyte. We show here that tyrosine 109 contributes to the conformation of the active site and the charge of the residue at position 109 is important for catalytic properties. Sensitivity of the enzyme to organophosphorus and carbamate compounds is modified depending on residues present in position 109, therefore this amino acid is a potential site of resistance for insects to insecticides. 相似文献
97.
CGH Dahlöf L Falk M Risenfors CP Lewis 《Cephalalgia : an international journal of headache》1998,18(8):546-551
We investigate whether symptoms of pressure, tightness, and/or pain in the chest, neck, and/or throat after administration of the 5HT1B/1D agonist avitriptan were associated with objective impairment of the myocardial function on 12-lead electrocardiogram (ECG), continuous ECG (Holter) monitoring, and echocardiography. Migraine sufferers who in two-thirds of alt attacks treated with sumatriptan had experienced chest/throat/neck symptoms were chosen for study. Baseline measures included vital signs, a 12-lead ECG and an echocardiogram. Patients ( n =51) who had no clinically significant abnormality at baseline received a high dose (150 mg) of avitriptan orally outside of a migraine attack. If pressure, tightness, and/or pain in the chest, neck, and/or throat occurred, an ECG was obtained, and a repeat echocardiogram was done while the symptoms were present in order to monitor for impairment of myocardial function. If symptoms of these types did not occur within 60 min after administration of the study drug, a second echocardiogram was obtained. Forty-five patients (88%) reported at least one adverse event and 23 (45%) experienced pressure, tightness, and/or pain in the chest, neck, and/or throat after administration of avitriptan. No clinically significant myocardial abnormalities were observed in any patient, even in those who had experienced the targeted symptoms. No other serious adverse event occurred. We concluded that the typical 5HT1B/1D agonist-induced chest/throat/neck symptoms are most unlikely to be of cardiovascular origin. 相似文献
98.
Daniel Kotz Geertjan Wesseling Marcus JH Huibers Onno CP van Schayck 《BMC public health》2007,7(1):332
Background
The use of spirometry for early detection of chronic obstructive pulmonary disease (COPD) is still an issue of debate, particularly because of a lack of convincing evidence that spirometry has an added positive effect on smoking cessation. We hypothesise that early detection of COPD and confrontation with spirometry for smoking cessation may be effective when applying an approach we have termed "confrontational counselling"; a patient-centred approach which involves specific communication skills and elements of cognitive therapy. An important aspect is to confront the smoker with his/her airflow limitation during the counselling sessions. The primary objective of this study is to test the efficacy of confrontational counselling in comparison to regular health education and promotion for smoking cessation delivered by specialized respiratory nurses in current smokers with previously undiagnosed mild to moderate airflow limitation. 相似文献99.
100.
女性护理专业学生心理健康相关因素分析 总被引:1,自引:0,他引:1
目的:分析护理专业学生心理健康的影响因素。方法:于2005-12-01/15按整群抽样法抽取西安市高校在读的护理专业学生515名作为被调查对象。症状自评量表总分≥187为高分组,总分≤116为低分组。高分组与低分组配比的条件是均为女性,年龄相差不超过3岁。采用症状自评量表、简易应对方式问卷、自尊量表、护理专业学生相关状况调查表进行问卷调查。对调查变量进行单因素和多因素Logistic回归分析。结果:共发放问卷515份,其中2名学生生病未填写调查表,应答率为99.6%。调查中有效问卷共507份,有效率为98.8%。症状自评量表总分高分组与低分组学生各100名。①护理专业学生心理健康相关个人因素(计量变量)单因素分析结果:高分组积极应对、自尊水平得分明显低于低分组(20.47±5.02,22.15±6.02;25.91±3.60,30.96±3.25),差异有显著性意义(P<0.05,P<0.01)。高分组消极应对得分明显高于低分组(12.57±4.08,8.00±4.12),差异有显著性意义(P<0.01)。②护理专业学生心理健康相关个人因素(二分类变量)单因素分析结果表明,高分组与低分组比较差异有显著性的因素有独生子女、远离家人、孤独、学习压力大、担心拿不到学位、自我实现需要的满足、经常被人误会、受人歧视、失恋、有知心朋友、无处倾诉苦恼、睡眠型态紊乱、近1年来本人健康改变、适应新环境、经常参加体育活动、担心毕业分配、现有最担心的事情。③多因素分析显示,学习压力大(OR=10.017)、近1年来本人健康改变(OR=4.384)为护理专业学生心理健康状况不良的独立危险因素,而自我实现需要的满足(OR=0.037)、高水平自尊(OR=0.357)是保护因素。结论:护理专业学生心理健康状况与教育、成长、社会环境等多方面因素相关,其心理健康干预需考虑学生的个人因素有针对性地进行。 相似文献