全文获取类型
收费全文 | 1603篇 |
免费 | 100篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 35篇 |
妇产科学 | 10篇 |
基础医学 | 143篇 |
口腔科学 | 21篇 |
临床医学 | 217篇 |
内科学 | 627篇 |
皮肤病学 | 4篇 |
神经病学 | 127篇 |
特种医学 | 214篇 |
外科学 | 115篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 77篇 |
眼科学 | 29篇 |
药学 | 41篇 |
中国医学 | 1篇 |
肿瘤学 | 44篇 |
出版年
2023年 | 13篇 |
2021年 | 18篇 |
2020年 | 14篇 |
2019年 | 22篇 |
2018年 | 22篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 27篇 |
2014年 | 26篇 |
2013年 | 41篇 |
2012年 | 59篇 |
2011年 | 43篇 |
2010年 | 48篇 |
2009年 | 42篇 |
2008年 | 47篇 |
2007年 | 86篇 |
2006年 | 62篇 |
2005年 | 46篇 |
2004年 | 40篇 |
2003年 | 35篇 |
2002年 | 35篇 |
2001年 | 31篇 |
2000年 | 25篇 |
1999年 | 30篇 |
1998年 | 40篇 |
1997年 | 41篇 |
1996年 | 39篇 |
1995年 | 33篇 |
1994年 | 50篇 |
1993年 | 25篇 |
1992年 | 20篇 |
1991年 | 31篇 |
1990年 | 29篇 |
1989年 | 61篇 |
1988年 | 71篇 |
1987年 | 68篇 |
1986年 | 49篇 |
1985年 | 48篇 |
1984年 | 46篇 |
1983年 | 38篇 |
1982年 | 26篇 |
1981年 | 18篇 |
1980年 | 20篇 |
1979年 | 17篇 |
1978年 | 17篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1974年 | 15篇 |
1973年 | 15篇 |
1970年 | 13篇 |
排序方式: 共有1745条查询结果,搜索用时 15 毫秒
91.
92.
M K Shear G Ball M Fitzpatrick S Josephson J Klosko A Frances 《The Journal of nervous and mental disease》1991,179(8):468-472
This paper reports results of an open prospective study of 26 patients who met DSM-III criteria for panic disorder or agoraphobia with panic attacks. Cognitive-behavioral treatment alone produced clinically and statistically significant improvement in panic symptoms, including both full-blown and limited symptom episodes. In addition, the treatment produced improvement in associated symptoms of phobic avoidance and generalized anxiety. This work provides further preliminary indication of the usefulness of cognitive-behavioral strategies as an alternative to medication in symptom-oriented treatments. 相似文献
93.
Book reviews in this article: Objective : The purpose of this project was to examine how postural control and balance, which are important to the upkeep of normal physical functioning in the elderly, may be maintained or improved by long‐term water exercise classes. It was hypothesised that hydrotherapy exercise once a week would be shown to positively effect measures of balance, postural control, functional mobility and flexibility in the exercising group when compared to a non‐exercising group. Method : This study comprised two groups. The first group was made up of a convenience sample of 19 subjects all over the age of 70 years, who had been undertaking water exercise sessions run by a Physiotherapist in a heated pool for one hour each week for a minimum of twelve months. The second group was a comparable group consisting of people of the same age, gender, pathology, medication intake and living arrangements who did not undertake any form of exercise above normal activities of daily living. The mean age of the subjects was 80 years and 10 months (SD 6.81 years) and ranged from 70 to 92 years. Measurements included: functional reach tests with the right and left arms, functional step testing using the right and left leg, the timed ‘up and go’ and right and left ankle dorsiflexion range. Results : The water exercise group performed significantly better on all four tests at a significance level of ≥ 0.05. Significant results of correlations with age of all tests except timed ‘up and go’ within the non‐exercising subject group and not the water exercise group highlighted the potential of water exercise to prevent or perhaps reverse the effects of ageing on balance. Conclusions : This data strongly supports the theory that long‐term water exercise classes do positively affect a person's flexibility, mobility and ability to maintain postural control. In turn this is likely to assist their functional status and hence, improve their quality of life. 相似文献
94.
Zimetbaum P Reynolds MR Ho KK Gaziano T McDonald MJ McClennen S Berezin R Josephson ME Cohen DJ 《The American journal of cardiology》2003,92(6):677-681
Health care resource utilization is high for patients presenting with acute atrial fibrillation (AF). The potential for treatment algorithms to safely reduce resource consumption in this setting has not been prospectively evaluated. We designed and implemented a practice guideline for the management of patients presenting to the emergency department (ED) with the primary diagnosis of AF, with emphasis on appropriate cardioversion, use of oral rate-controlling medications, and expedited referral to an outpatient AF clinic. We prospectively collected clinical and resource utilization data on all such patients for 14 months before and after institution of the guideline. Institution of the guideline was associated with a decreased rate of hospital admission (from 74% to 38%), with no differences in ED return visits or hospital readmission within 30 days. No strokes or deaths were observed. This large decrease in resource utilization during the intervention phase of the study translated to an average decrease in 30-day total direct health care costs of approximately $1,400 US dollars per patient. Our clinical and cost outcomes were minimally affected after statistical adjustment for baseline differences between study groups. We conclude that the implementation of our practice guideline was feasible, safe, and effective. Widespread adoption of such practices may have large financial implications for the health care system. 相似文献
95.
96.
W Oh DK Stevenson JE Tyson BH Morris CE Ahlfors G Jesse Bender RJ Wong R Perritt BR Vohr KP Van Meurs HJ Vreman A Das DL Phelps T Michael O’Shea RD Higgins 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(5):673-678
Objectives: To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18–22 months corrected age in extremely low birth weight infants. Method: Total plasma bilirubin and unbound bilirubin were measured in 1101 extremely low birth weight infants at 5 ± 1 days of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18–22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow‐up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors. Results: Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow‐up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow‐up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants. Conclusions: In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma bilirubin and death or adverse neurodevelopmental outcomes at 18–22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants. 相似文献
97.
Jessica Josephson MSc Justine M. Turner MD PhD Catherine J. Field PhD Pamela R. Wizzard BSc Patrick N. Nation DVM PhD Consolato Sergi MD PhD Ronald O. Ball PhD Paul B. Pencharz MD PhD Paul W. Wales MD MSc 《JPEN. Journal of parenteral and enteral nutrition》2015,39(6):677-687
Background: Parenteral nutrition (PN)–associated liver disease (PNALD) remains a significant cause of morbidity and mortality for neonates dependent on PN. Total fat emulsion dose and composition, particularly the large amount of ω‐6 long‐chain polyunsaturated fatty acids in plant oils, have been proposed as risk factors for PNALD. We hypothesized restriction of the dose of emulsion would prevent PNALD, regardless of the composition, but growth could be compromised. Methods: Using a neonatal piglet model, we compared conventional soy oil emulsion (Intralipid), dosed high (SO10, n = 8: 10 g/kg/d) and low (SO5, n = 6: 5 g/kg/d), with fish oil (Omegaven), dosed low (FO5, n = 8: 5 g/kg/d). Piglets were given isonitrogenous PN for 14 days. The normal range for all parameters was determined by measurement in equivalent aged sow‐reared piglets. Results: Bile flow was lower with high‐dose Intralipid, outside the normal range, while higher for the other groups (SO10, 5.4 µg/g; SO5, 8.6 µg/g; FO5, 13.4 µg/g; P = .010; normal range, 6.5–12.2 µg/g). Total body weight was low in all treatment groups (SO10, 4.4 kg; SO5, 4.5 kg; FO5, 5.0 kg; P = .038; normal range, 5.2–7.3 kg). Brain weight was not different between groups (SO10, 40.3 g; SO5, 36.0 g; FO5, 36.6 g; P = .122; normal range, 41.8–51.4 g). Corrected for body weight, brain weight was lowest in the fish oil group (SO10, 9.3 g/kg; SO5, 8.0 g/kg; FO5, 7.3 g/kg; P < .001; normal range, 5.9–9.0 g/kg). Conclusion: Low‐dose fat emulsions reduce the risk of developing PNALD. Further investigation of the risk to brain development in neonates exposed to dose restriction, particularly with fish oil, is required. 相似文献
98.
Thomas Kerr Brandon DL Marshall Cari Miller Kate Shannon Ruth Zhang Julio SG Montaner Evan Wood 《BMC public health》2009,9(1):171-7
Background
Street-involved youth contend with an array of health and social challenges, including elevated rates of blood-borne infections and mortality. In addition, there has been growing concern regarding high-risk drug use among street-involved youth, in particular injection drug use. We undertook this study to examine the prevalence of injection drug use and associated risks among street-involved youth in Vancouver, Canada. 相似文献99.
100.
Brandon DL. Marshall Evan Wood Jean A. Shoveller Jane A. Buxton Julio SG. Montaner Thomas Kerr 《Prevention science》2011,12(2):173-180
The purpose of this study was to determine the incidence and predictors of initiating methamphetamine injection among a cohort
of injection drug users (IDU). We conducted a longitudinal analysis of IDU participating in a prospective study between June
2001 and May 2008 in Vancouver, Canada. IDU who had never reported injecting methamphetamine at the study’s commencement were
eligible. We used Cox proportional hazards models to identify the predictors of initiating methamphetamine injection. The
outcome was time to first report of methamphetamine injection. Time-updated independent variables of interest included sociodemographic
characteristics, drug use patterns, and social, economic and environmental factors. Of 1317 eligible individuals, the median
age was 39.9 and 522 (39.6%) were female. At the study’s conclusion, 200 (15.2%) participants had initiated injecting methamphetamine
(incidence density: 4.3 per 100 person-years). In multivariate analysis, age (adjusted hazard ratio [aHR]: 0.96 per year older,
95%CI: 0.95–0.98), female sex (aHR: 0.58, 95%CI: 0.41–0.82), sexual abuse (aHR: 1.63, 95%CI: 1.18–2.23), using drugs in Vancouver’s
drug scene epicentre (aHR: 2.15 95%CI: 1.49–3.10), homelessness (aHR: 1.43, 95%CI: 1.01–2.04), non-injection crack cocaine
use (aHR: 2.06, 95%CI: 1.36–3.14), and non-injection methamphetamine use (aHR: 3.69, 95%CI: 2.03–6.70) were associated with
initiating methamphetamine injection. We observed a high incidence of methamphetamine initiation, particularly among young
IDU, stimulant users, homeless individuals, and those involved in the city’s open drug scene. These data should be useful
for the development of a broad set of interventions aimed at reducing initiation into methamphetamine injection among IDU. 相似文献