全文获取类型
收费全文 | 1220篇 |
免费 | 74篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 69篇 |
妇产科学 | 13篇 |
基础医学 | 142篇 |
口腔科学 | 23篇 |
临床医学 | 153篇 |
内科学 | 226篇 |
皮肤病学 | 7篇 |
神经病学 | 123篇 |
特种医学 | 105篇 |
外科学 | 216篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 80篇 |
眼科学 | 10篇 |
药学 | 43篇 |
中国医学 | 3篇 |
肿瘤学 | 78篇 |
出版年
2021年 | 23篇 |
2020年 | 11篇 |
2019年 | 21篇 |
2018年 | 22篇 |
2017年 | 21篇 |
2016年 | 16篇 |
2015年 | 17篇 |
2014年 | 22篇 |
2013年 | 44篇 |
2012年 | 41篇 |
2011年 | 44篇 |
2010年 | 38篇 |
2009年 | 48篇 |
2008年 | 42篇 |
2007年 | 52篇 |
2006年 | 44篇 |
2005年 | 48篇 |
2004年 | 51篇 |
2003年 | 27篇 |
2002年 | 41篇 |
2001年 | 31篇 |
2000年 | 31篇 |
1999年 | 23篇 |
1998年 | 37篇 |
1997年 | 28篇 |
1996年 | 26篇 |
1995年 | 20篇 |
1994年 | 25篇 |
1993年 | 14篇 |
1992年 | 18篇 |
1991年 | 19篇 |
1990年 | 30篇 |
1989年 | 31篇 |
1988年 | 30篇 |
1987年 | 22篇 |
1986年 | 17篇 |
1985年 | 25篇 |
1984年 | 19篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1978年 | 15篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1973年 | 7篇 |
1971年 | 7篇 |
1969年 | 8篇 |
1968年 | 8篇 |
1967年 | 8篇 |
排序方式: 共有1311条查询结果,搜索用时 0 毫秒
41.
42.
Vandhana Sundaram Sujithra Haridas Meenakshi Dhar CP Harikrishnan 《Indian journal of ophthalmology》2022,70(2):453
Purpose:To compare the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and optic nerve head (ONH) morphological parameters between obstructive sleep apnea (OSA) patients and age-matched controls using spectral domain optical coherence tomography (SD-OCT).Methods:This case control study was conducted in a multi-specialty tertiary care hospital from 2014 to 2016. Patients diagnosed to have OSA by overnight polysomnography were included in the study. Fifty eyes of 25 OSA patients with clinically normal optic disc were compared with 50 eyes of age-matched controls. The study population underwent detailed ophthalmological evaluation including SD-OCT.Results:There was significant thinning of the superior, inferior, and average RNFL in the OSA group when compared to controls. GCL analysis also showed a significant thinning of the six sectors as well as average and minimum ganglion cell layer + inner plexiform layer in OSA patients. The optic nerve head rim area was significantly decreased in OSA patients when compared to controls.Conclusion:OSA patients even with clinically normal optic disc showed significant decrease in the RNFL thickness, GCL thickness, and rim area when compared to age-matched controls. Hence, these patients constitute a high-risk population who need to be regularly screened and followed up for ocular co-morbidities. 相似文献
43.
Amy Hammerich Julie Whitman Paul Mintken Thomas Denninger Venu Akuthota Eric E. Sawyer Melissa Hofmann John D. Childs Joshua Cleland 《Archives of physical medicine and rehabilitation》2019,100(5):797-810
Objective
To examine the effectiveness of epidural steroid injection (ESI) and back education with and without physical therapy (PT) in individuals with lumbar spinal stenosis (LSS).Design
Randomized clinical trial.Setting
Orthopedic spine clinics.Participants
A total of 390 individuals were screened with 60 eligible and randomly selected to receive ESI and education with or without PT (N=54).Interventions
A total of 54 individuals received 1-3 injections and education in a 10-week intervention period, with 31 receiving injections and education only (ESI) and 23 additionally receiving 8-10 sessions of multimodal PT (ESI+PT).Main Outcome Measures
Disability, pain, quality of life, and global rating of change were collected at 10 weeks, 6 months, and 1 year and analyzed using linear mixed model analysis.Results
No significant difference was found between ESI and ESI+PT in the Oswestry Disability Index at any time point, although the sample had significant improvements at 10 weeks (P<.001; 95% confidence interval [CI], ?18.01 to ?5.51) and 1 year (P=.01; 95% CI, ?14.57 to ?2.03) above minimal clinically important difference. Significant differences in the RAND 36-Item Short Form Health Survey 1.0 were found for ESI+PT at 10 weeks with higher emotional role function (P=.03; 95% CI, ?49.05 to ?8.01), emotional well-being (P=.02; 95% CI, ?19.52 to -2.99), and general health perception (P=.05; 95% CI, ?17.20 to ?.78).Conclusions
Epidural steroid injection plus PT was not superior to ESI alone for reducing disability in individuals with LSS. Significant benefit was found for the addition of PT related to quality of life factors of emotional function, emotional well-being, and perception of general health. 相似文献44.
Isaac R. Whitman Vratika Agarwal Gregory Nah Jonathan W. Dukes Eric Vittinghoff Thomas A. Dewland Gregory M. Marcus 《Journal of the American College of Cardiology》2017,69(1):13-24
Background
Understanding the relationship between alcohol abuse, a common and theoretically modifiable condition, and the most common cause of death in the world, cardiovascular disease, may inform potential prevention strategies.Objectives
The study sought to investigate the associations among alcohol abuse and atrial fibrillation (AF), myocardial infarction (MI), and congestive heart failure (CHF).Methods
Using the Healthcare Cost and Utilization Project database, we performed a longitudinal analysis of California residents ≥21 years of age who received ambulatory surgery, emergency, or inpatient medical care in California between 2005 and 2009. We determined the risk of an alcohol abuse diagnosis on incident AF, MI, and CHF. Patient characteristics modifying the associations and population-attributable risks were determined.Results
Among 14,727,591 patients, 268,084 (1.8%) had alcohol abuse. After multivariable adjustment, alcohol abuse was associated with an increased risk of incident AF (hazard ratio [HR]: 2.14; 95% confidence interval [CI]: 2.08 to 2.19; p < 0.0001), MI (HR: 1.45; 95% CI: 1.40 to 1.51; p < 0.0001), and CHF (HR: 2.34; 95% CI: 2.29 to 2.39; p < 0.0001). In interaction analyses, individuals without conventional risk factors for cardiovascular disease exhibited a disproportionately enhanced risk of each outcome. The population-attributable risk of alcohol abuse on each outcome was of similar magnitude to other well-recognized modifiable risk factors.Conclusions
Alcohol abuse increased the risk of AF, MI, and CHF to a similar degree as other well-established risk factors. Those without traditional cardiovascular risk factors are disproportionately prone to these cardiac diseases in the setting of alcohol abuse. Thus, efforts to mitigate alcohol abuse might result in meaningful reductions of cardiovascular disease. 相似文献45.
46.
47.
CP Halvorsen SL Bilock C Pilo S-E Sonesson M Norman 《Acta paediatrica (Oslo, Norway : 1992)》2009,98(9):1468-1474
Aim: To perform a 10-year follow up of cardiac structure and function after twin-to-twin transfusion syndrome (TTTS) – a severe foetal circulatory complication associated with myocardial hypertrophy in the recipient twin.
Methods: Cardiac dimensions, systolic and diastolic function as assessed by echocardiography including flow and tissue Doppler velocimetry in 22 healthy survivors of TTTS with a mean age of 9.6 (7.2–11.8) years.
Results: The donor and recipient twin did not show any differences in end-diastolic ventricular size, interventricular septum thickness, diameter of right ventricular outflow tract, cardiac valves, coronary arteries or in systolic blood flow velocities. However, compared with the donors, the recipients had significantly lower E/A ratios because of lower E-waves in both mitral (−0.15 ± 0.10, p < 0.01) and tricuspid (−0.09 ± 0.07, p < 0.01) valves, indicating reduced early diastolic ventricular fillings compared with donors.
Conclusion: At school age, twins surviving TTTS had a cardiac structure and function within normal range. There were no differences in heart structure or systolic ventricular function between twins but, compared with the donor twin, we found a reduced early diastolic function in the recipient. 相似文献
Methods: Cardiac dimensions, systolic and diastolic function as assessed by echocardiography including flow and tissue Doppler velocimetry in 22 healthy survivors of TTTS with a mean age of 9.6 (7.2–11.8) years.
Results: The donor and recipient twin did not show any differences in end-diastolic ventricular size, interventricular septum thickness, diameter of right ventricular outflow tract, cardiac valves, coronary arteries or in systolic blood flow velocities. However, compared with the donors, the recipients had significantly lower E/A ratios because of lower E-waves in both mitral (−0.15 ± 0.10, p < 0.01) and tricuspid (−0.09 ± 0.07, p < 0.01) valves, indicating reduced early diastolic ventricular fillings compared with donors.
Conclusion: At school age, twins surviving TTTS had a cardiac structure and function within normal range. There were no differences in heart structure or systolic ventricular function between twins but, compared with the donor twin, we found a reduced early diastolic function in the recipient. 相似文献
48.
49.
ObjectiveTo investigate the potentials of the root bark of Annona (A.) senegalensis in the control of seizure and related hypnotic and motor incoordination effects in mice using experimental models.MethodsThe methanol extract (ME) of the root bark of A. senegalensis was studied in mice using pentylenetetrazole (PTZ) induced convulsions, phenobarbitone induced sleeping time and motor coordination test on rota-rod performance. Acute toxicity and lethality (LD50) test as well as phytochemical analysis were also carried out.ResultsThe extract (200, 400, 800 mg/kg) exhibited a non-dose dependent significant (P <0.05) delay in the onset of both tonic and clonic phases of seizure induced by PTZ (60 mg/kg, s.c.) as well as offered a 100% protection (200 mg/kg) in mice from PTZ induced seizures. The extract significantly (P <0.05) decreased the latency and increased the duration of phenobarbitone induced sleeping time. At 200 mg/kg, the extract exhibited a significant (P <0.05) motor incoordination. The acute toxicity test revealed an oral LD50 of 1 296 mg/kg, while the phytochemical studies showed the presence of alkaloids, resins, glycosides, carbohydrate, reducing sugar, flavonoids, terpenoids, saponins and tannins.ConclusionThe extract of A. senegalensis possessed anticonvulsant activity with pronounced hypnotic and muscle relaxant effects. 相似文献
50.
Pehlivanov N Sarosiek I Whitman R Olyaee M McCallum R 《Alimentary pharmacology & therapeutics》2002,16(4):743-747
AIM: To investigate the effect of cisapride, a selective 5-hydroxytryptamine-4 receptor agonist, on the frequency of nocturnal transient lower oesophageal sphincter relaxations and oesophageal acid exposure in patients with gastro-oesophageal reflux disease. METHODS: In a double-blind, placebo-controlled study, 10 patients with gastro-oesophageal reflux disease (six male and four female; mean age, 54 +/- 10.4 years) were randomly assigned to 5-day treatments with cisapride, 10 mg q.d.s., or placebo, separated by a 2-day washout period before the treatment crossover. Sleep stages, lower oesophageal sphincter tone and oesophageal pH were monitored overnight at the end of each treatment regimen. Gastric emptying was assessed before treatment. RESULTS: Cisapride decreased the frequency of transient lower oesophageal sphincter relaxations during sleep (1.2 +/- 0.2/h vs. 2.7 +/- 0.5/h with placebo; P=0.004) and oesophageal acid exposure (17.2 +/- 9.9% with placebo vs. 7.2 +/- 4.2% with cisapride; P=0.4). Cisapride increased lower oesophageal sphincter tone from 12.7 +/- 2.8 mmHg with placebo to 16.9 +/- 3.9 mmHg (P=0.03), and decreased heartburn episodes and antacid consumption. All patients had normal gastric retention data over 4 h. CONCLUSIONS: In patients with gastro-oesophageal reflux disease, cisapride significantly decreased the frequency of transient lower oesophageal sphincter relaxations during sleep and increased lower oesophageal sphincter pressure without changing gastric emptying. We hypothesize, therefore, that 5-hydroxytryptamine-4 mechanisms are important in the control of transient lower oesophageal sphincter relaxations in humans. 相似文献