全文获取类型
收费全文 | 1155篇 |
免费 | 71篇 |
国内免费 | 106篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 62篇 |
妇产科学 | 25篇 |
基础医学 | 162篇 |
口腔科学 | 76篇 |
临床医学 | 208篇 |
内科学 | 241篇 |
皮肤病学 | 20篇 |
神经病学 | 27篇 |
特种医学 | 81篇 |
外科学 | 157篇 |
综合类 | 40篇 |
预防医学 | 58篇 |
眼科学 | 11篇 |
药学 | 81篇 |
中国医学 | 1篇 |
肿瘤学 | 61篇 |
出版年
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 24篇 |
2014年 | 21篇 |
2013年 | 39篇 |
2012年 | 43篇 |
2011年 | 52篇 |
2010年 | 37篇 |
2009年 | 36篇 |
2008年 | 51篇 |
2007年 | 85篇 |
2006年 | 38篇 |
2005年 | 59篇 |
2004年 | 39篇 |
2003年 | 32篇 |
2002年 | 40篇 |
2001年 | 30篇 |
2000年 | 31篇 |
1999年 | 23篇 |
1998年 | 54篇 |
1997年 | 41篇 |
1996年 | 42篇 |
1995年 | 22篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 35篇 |
1991年 | 14篇 |
1990年 | 27篇 |
1989年 | 30篇 |
1988年 | 22篇 |
1987年 | 31篇 |
1986年 | 29篇 |
1985年 | 22篇 |
1984年 | 10篇 |
1983年 | 13篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1979年 | 7篇 |
1977年 | 12篇 |
1976年 | 16篇 |
1975年 | 9篇 |
1974年 | 7篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1970年 | 8篇 |
1967年 | 6篇 |
排序方式: 共有1332条查询结果,搜索用时 31 毫秒
1.
2.
CM Reid M. Nelson P. Beckinsale P. Ryan LMH Wing LJ Beilin MA Brown GLR Jennings CI Johnston J. Marley JJ McNeil TO Morgan J. Shaw ID Steven MJ West 《Clinical and experimental pharmacology & physiology》1997,24(5):370-373
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial. 相似文献
3.
Analysis is presented of the relationship between decline in ventilatory function and possible symptoms of bronchial hypereactivity. Data comes from three consecutive surveys within a 13-year follow-up study of a population sample of 1747 persons (718 males and 1029 females) who completed spirometric testing and interviews. Chest symptoms recorded in the two initial surveys were used as baselines for the prognostic study on FEV1 change. To evaluate changes in lung function the FEV1 decline index, expressed as percentage of FEV1 loss during the study period, was calculated. Chronic wheezing and asthma-like attacks were very strongly related to FEV1 baseline level. Multiple linear regression analysis for each separate symptom including age and smoking habits as confounders and showed that the FEV1 decline index was higher and more significant when wheezing and asthma-like attacks or chronic cough were present. When the combination of symptoms were introduced into the regression model, the effect of wheezing became insignificant. Only attacks of shortness of breath in both sexes and chronic cough in women were significantly associated with more rapid FEV1 decline. However, the effect of persistent wheezing in men had a rather substantial impact on FEV1 change. Comparing the effect of the number of cigarettes smoked with the effect of symptoms, one can see that FEV1 decline due to attacks of shortness of breath is comparable to that seen with heavy smoking. There was no strong evidence that the symptoms under study precede the more rapid FEV1 decline. 相似文献
4.
5.
6.
Jaros?aw Wysocki 《Skull base》2005,15(2):99-106
One hundred temporal bones obtained from forensic autopsies were dissected to expose injured structures. Longitudinal fractures were present in 82%, transverse fractures in 11%, and mixed fractures in 7% of the cases. Facial canal injuries were present in almost half of the bones with longitudinal fractures (36/82), although cuts of the facial nerve stem were rarely encountered. Damages to the facial canal associated with longitudinal fractures were most frequently seen in the region of the geniculum. However, transverse fractures with facial canal involvement (7/11) most frequently occurred in the labyrinthine portion, causing a complete cut of the facial nerve. Injuries to the jugular bulb were also common (21/100) and associated with all types of temporal bone fractures. Observed damages to the auditory ossicles included disconnection of their joints or fractures of the malleus or stapes. Fractures of the incus were not observed. Injuries to the carotid canal were common (52/100), although an injury to the arterial wall was observed in only one specimen. The frequency and nature of damage in temporal bone fractures strictly reflect the type of fracture, especially in terms of facial nerve disorders: the most serious damage is observed with fractures that involve the otic capsule. 相似文献
7.
BACKGROUND: The recent introduction of urea sensors for dialysis monitoring
has made possible new approaches to urea kinetic modelling. In this study
we show how the equilibrated postdialysis urea concentration (Ceq) and Kt/V
corrected for double-pool urea kinetics (Kt/Vdp) can be accurately
determined using an on-line sensor providing a continuous measure of blood
water urea. A modification of the Smye constant volume double-pool theory
led to the following equations for Ceq and Kt/Vdp [formula: see text] where
Cpre is the blood concentration measured at the start of dialysis, t is the
length of the dialysis session (in min) and S(ex) is the constant slope of
the blood urea logarithm concentration decline following development of the
intercompartmental urea concentration gradient in the first 30-60 min of
dialysis. METHODS: These equations were tested in 11 patients undergoing
165-240 min of paired filtration dialysis with continuous monitoring of
blood urea concentration. Cpre was determined as the plateau concentration
during a preliminary period of 15-20 min of slow isolated ultrafiltration.
S(ex) was accurately determined from linear regression applied to the urea
sensor data from the 80-min point to the end of dialysis. RESULTS: Ceq and
Kt/Vdp determined from the above equations compared closely to values
determined from 25-40 min of urea rebound monitoring with the urea sensor:
10.6 +/- 3.0 versus 10.8 +/- 2.7 mmol/l (mean +/- SD) for Ceq and 1.21 +/-
0.24 versus 1.18 +/- 0.20 for Kt/Vdp, compared to single-pool values of
Kt/V = 1.34 +/- 0.23. CONCLUSION: This technique may be readily programmed
into on-line urea monitors to provide current and extrapolated values of
Ceq and Kt/Vdp from about the first hour of dialysis.
相似文献
8.
9.
10.
Zhao P Qin ZL Ke JS Lu Y Liu M Pan W Zhao LJ Cao J Qi ZT 《第二军医大学学报》2005,26(10):1167-1167
SARS-CoV isa newly identified coronavirus that causes severe acute respiratory syndrome (SARS). Currently, there is no effective method available for prophylaxis and treatment of SARS-CoVinfections. In the present study, the influence of small interfering RNA (siRNA) on SARS-CoV nucleocapsid (N) protein expression was detected in cultured cells and mouse muscles. Four siRNA expression cassettes driven by mouse U6 promoter targeting SARS-CoV N gene were prepared, and their inhibitory effects on expression of N and enhanced green fluorescence protein (EGFP) fusion protein were observed. 相似文献