全文获取类型
收费全文 | 36484篇 |
免费 | 1859篇 |
国内免费 | 249篇 |
专业分类
耳鼻咽喉 | 363篇 |
儿科学 | 966篇 |
妇产科学 | 698篇 |
基础医学 | 4658篇 |
口腔科学 | 1072篇 |
临床医学 | 2872篇 |
内科学 | 9657篇 |
皮肤病学 | 541篇 |
神经病学 | 3366篇 |
特种医学 | 1341篇 |
外科学 | 5709篇 |
综合类 | 129篇 |
一般理论 | 14篇 |
预防医学 | 1823篇 |
眼科学 | 473篇 |
药学 | 2053篇 |
中国医学 | 86篇 |
肿瘤学 | 2771篇 |
出版年
2023年 | 266篇 |
2022年 | 536篇 |
2021年 | 1157篇 |
2020年 | 687篇 |
2019年 | 940篇 |
2018年 | 1236篇 |
2017年 | 829篇 |
2016年 | 959篇 |
2015年 | 1113篇 |
2014年 | 1497篇 |
2013年 | 1838篇 |
2012年 | 2993篇 |
2011年 | 2909篇 |
2010年 | 1743篇 |
2009年 | 1511篇 |
2008年 | 2483篇 |
2007年 | 2449篇 |
2006年 | 2370篇 |
2005年 | 2230篇 |
2004年 | 1977篇 |
2003年 | 1727篇 |
2002年 | 1696篇 |
2001年 | 238篇 |
2000年 | 182篇 |
1999年 | 249篇 |
1998年 | 290篇 |
1997年 | 254篇 |
1996年 | 240篇 |
1995年 | 213篇 |
1994年 | 173篇 |
1993年 | 155篇 |
1992年 | 111篇 |
1991年 | 97篇 |
1990年 | 110篇 |
1989年 | 93篇 |
1988年 | 83篇 |
1987年 | 60篇 |
1986年 | 80篇 |
1985年 | 59篇 |
1984年 | 88篇 |
1983年 | 78篇 |
1982年 | 78篇 |
1981年 | 59篇 |
1980年 | 57篇 |
1979年 | 39篇 |
1978年 | 45篇 |
1977年 | 30篇 |
1976年 | 29篇 |
1975年 | 24篇 |
1973年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 843 毫秒
51.
Catalina Balaguer Alexander Palou Alberto Alonso-Fernández 《Archivos de bronconeumologia》2009,45(9):449-458
Snoring and sleep apnea-hypopnea syndrome (SAHS) are two disorders of considerable relevance due to their high prevalence in the general population and their notable morbidity and mortality, particularly in association with their harmful effects on the cardiovascular system. As well as sex, age, weight, craniofacial malformations, alcohol consumption, and use of hypnotic drugs, it has been suggested that smoking may be a risk factor for developing sleep-disordered breathing. While there is solid evidence for the independent association between snoring and smoking in both children and adults, it is still unclear whether smoking constitutes an independent risk factor for developing SAHS, despite the many studies carried out to assess this link. This is probably because the association, if it exists, is very weak. 相似文献
52.
Luigi Paolo Badano Maria C Albanese Paola De Biaggio Patrizia Rozbowsky Daniela Miani Claudio Fresco Paolo M Fioretti 《Journal of the American Society of Echocardiography》2004,17(3):253-261
Prevalence of isolated left ventricular (LV) diastolic dysfunction has been reported to be as high as one-third of all heart failure (HF) cases, with an increasing prevalence in the elderly population. However, there is a paucity of prospective data about the prevalence and prognosis of isolated LV diastolic dysfunction in an unselected population of patients hospitalized with HF. Therefore, we prospectively evaluated 179 consecutive patients discharged from our hospital with HF to assess the prevalence of systolic versus diastolic LV dysfunction among patients hospitalized with HF and to compare their demographics, clinical features, self-perceived quality of life (QOL), and 6-month readmission rate and mortality. Among them, 133 (59% men, median age 74 years) showed in sinus rhythm and had no significant primary valvular disease. LV diastolic dysfunction was diagnosed on the basis of the European Study Group on Diastolic HF echocardiographic criteria. QOL was assessed at hospital discharge and 6-month follow-up visit using the Minnesota Living with HF questionnaire. Survival of patients with HF was compared with that of age- and sex-matched general population. In all, 29 patients (22%) had isolated LV diastolic dysfunction and 102 (78%) had prevalent LV systolic dysfunction (ie, LV ejection fraction = 45%). There was no difference in age, sex, or New York Heart Association functional class between patients with LV diastolic or systolic dysfunction. QOL scores were similar between the 2 patient groups with HF both at discharge (39.4 and 34) and at 6-month visit (10.4 and 10.4). Both 6-month readmission rate (48% and 48%) and median inhospital length-of-stay during readmissions (10 days and 10 days) were similar between the 2 patient groups with HF. Finally, 6-month survival, adjusted for age and sex, was similar between patients with LV diastolic or systolic dysfunction (hazard ratio 0.68; 95% confidence interval 0.20-2.35). Using standardized echocardiographic criteria, isolated LV diastolic dysfunction among unselected patients hospitalized with HF was less than previously reported. Patients with HF and isolated diastolic dysfunction showed similar clinical symptoms, self-perceived QOL, readmission rate, and 6-month mortality to patients with prevalent LV systolic dysfunction. 相似文献
53.
54.
Francesco Franceschi Rocco Papalia Alberto Di Martino Giacomo Rizzello Robert Allaire Vincenzo Denaro 《Arthroscopy》2007
During revision anterior cruciate ligament (ACL) surgery, femoral interference screws frequently require removal. This may lead to significant tunnel widening and possible graft fixation failure as a result. Solutions include drilling the revision tunnel in a different location, using stacked interference screws, or using bone graft to fill the defect. Autogenous iliac crest graft and allograft are both used, but there are significant comorbidities associated with each. We developed a new technique for harvesting autogenous bone graft that avoids many of the complications associated with other graft sources. By use of the existing surgical incision from the initial harvest of the bone–patellar tendon–bone autograft, bone from the medial tibial metaphyseal safe zone is harvested via an OATS tube harvester (Arthrex, Naples, FL). A bone plug 1 mm larger in size than the femoral defect is harvested and arthroscopically inserted via a press-fit technique. At 3 months after bone grafting, patients undergo revision ACL reconstruction. The proximal tibial metaphysis is a safe bone graft harvest site in revision ACL surgery and offers an effective method for filling large bony defects, allowing anatomic reconstruction of the ACL after bone healing has occurred. Furthermore, it eliminates the problems associated with allograft or use of a remote graft donor site. 相似文献
55.
Cristina Tassorelli Francesca Mancini Laura Balloni Claudio Pacchetti Giorgio Sandrini Giuseppe Nappi Emilia Martignoni 《Movement disorders》2006,21(12):2240-2243
Currently, the best treatment option for idiopathic cervical dystonia (ICD) is injection of botulinum toxin (BTX) into the affected muscles, whereas rehabilitative approaches have given disappointing results. We evaluated whether the association of an ad hoc rehabilitative program may improve the clinical efficacy of BTX treatment in a single-center, cross-over, controlled study. Forty patients with ICD were randomly assigned to two different treatment groups: (1) BTX type A (BTX-A) plus a specific program of physical therapy (BTX-PT) or (2) BTX-A alone (BTX-0). Patients in the BTX-PT group showed a longer duration of the clinical benefit (118.8 vs. 99.1 days) and needed a lower dose of BTX at reinjection (284.5 vs. 325.5 units). In addition, they showed more marked reductions in their disability in activities of daily living (-9.7 vs. -4.85 points) and subjective pain (-13.35 vs. 6.95 points) scores. Association of BTX-A therapy with a specific program of physical therapy may improve ICD treatment outcome. 相似文献
56.
Massimo Bolognesi M.D. Claudio R. Nigg Ph.D. Massimo Massarini M.D. Sonia Lippke Ph.D. 《Annals of behavioral medicine》2006,31(2):179-185
Background: There is an alarming prevalence of obesity and sedentariness in Western countries. An ideal context for health promotion
and preventive medicine seems to be the setting of primary care provided by the general practitioner (GP).Purpose: Therefore, this study evaluated the impact of GPs’brief physical activity counseling for overweight and obese patients.Methods: Individuals recruited during routine physician visits were randomly split into an experimental (n = 48) group that received
the Patient-centered Assessment and Counseling for Exercise (PACE) protocol, and a usual-care control (n = 48) group. Body
mass index (BMI) and abdominal girth were assessed as objective biometrical parameters. Patients in the experimental group
self-reported their readiness for physical activity and self-efficacy.Results: The experimental group had significantly better BMI and abdominal girth compared with the control group after a 5- to 6-month
follow-up. Furthermore, the experimental group progressed in their stage of physical activity readiness and increased their
self-efficacy.Conclusions: The GPs’counseling for physical activity using the PACE protocol influenced mediators and biometrical outcomes in an Italian
primary care context.
An earlier version of this article was presented for the degree thesis in Community Psychology at the Bologna University.
The advisor was Professor Bruna Zani.
We thank the general practitioners who contributed to this project: Marcatelli M., Forgiarini A., Fabbri M., De Astis R.,
Aguzzoni F., Barbarossa L., Montalti M. (Azienda USL-Distretto di Cesena Italy), and we thank Silvano Zanuso (Technogym Research
Center-Gambettola Italy) for his helpful comments. 相似文献
57.
Jorge Polónia Jo?o Maldonado Rui Ramos Susana Bertoquini Mary Duro Cristina Almeida Jo?o Ferreira Loide Barbosa José Alberto Silva Luís Martins 《Revista portuguesa de cardiologia》2006,25(9):801-817
BACKGROUND: Portugal has one of the highest mortality rates from stroke, a high prevalence of hypertension and probably a high salt intake level. AIM: To evaluate Portuguese salt intake levels and their relationship to blood pressure and arterial stiffness in a sample of four different adult populations living in northern Portugal. METHODS: A cross-sectional study evaluating 24-hour urinary excretion of sodium (24 h UNa+), potassium and creatinine, blood pressure (BP), and pulse wave velocity (PWV) as an index of aortic stiffness in adult populations of sustained hypertensives (HT), relatives of patients with previous stroke (Fam), university students (US) and factory workers (FW), in the context of their usual dietary habits. RESULTS: We evaluated a total of 426 subjects, mean age 50 +/- 22 years, 56% female, BMI 27.9+/-5.1, BP 159/92 mmHg, PWV 10.4+/-2.2 m/s, who showed mean 24h UNa+ of 202 +/- 64 mmol/d, corresponding to a daily salt intake of 12.3 g (ranging from 5.2 to 24.8). The four groups were: HT: n = 245, 49 +/- 18 years, 92% of those selected, 69% treated, BP 163/94 mmHg, PWV 11.9 m/s, 24 h UNa+ 212 mmol/d, i.e. 12.4 g/d of salt); Fam: n = 38, 64 +/- 20 years, 57 % of those selected, BP 144/88 mmHg, PWV 10.5 m/s, 24 h UNa+ 194 mmol/d, i.e. 11.1 g/d of salt; US: n = 82, 22 +/- 3 years, 57% of those selected, BP 124/77 mmHg, PWV 8.7 m/s, 24h UNa+ 199 mmol/d, i.e. 11.3 g/d of salt; FW: n = 61, 39 9 years, 47% of those selected, BP 129/79 mmHg, PWV 9.5 m/s, 24 h UNa+ 221 mmol/d, i.e. 12.9 g/d of salt. The ratio of urinary sodium/potassium excretion (1.9 (0.4) was significantly higher in HT than the other three groups. In the 426 subjects, 24h UNa+ correlated significantly (p < 0.01) with systolic BP (r = 0.209) and with PWV (r=0.256) after adjustment for age and BP. Multivariate analysis showed that BP, age and 24h UNa+ correlated independently with PWV taken as a dependent variable. CONCLUSIONS: Four different Portuguese populations showed similarly high mean daily salt intake levels, almost double those recommended by the WHO. Overall, high urinary sodium excretion correlated consistently with high BP levels and appeared to be an independent determining factor of arterial stiffness. These findings suggest that Portugal in general has a high salt intake diet, and urgent measures are required to restrict salt consumption in order to prevent and treat hypertensive disease and to reduce overall cardiovascular risk and events. 相似文献
58.
César Marques Salgado Claudio C Conti Paulo H B Becker 《Applied radiation and isotopes》2006,64(6):700-705
The Monte Carlo method was used to calculate the efficiency, escape and Compton curves of a planar high-purity germanium detector (HPGe) in the 20-150 keV energy. These curves were used for the determination of photons spectra produced by an X-ray machine in order to allow a precise characterization of photon beams applied to medical diagnosis. The detector was modeled with the MCNP5 computer code and validated by comparison with experimental data. The air kerma calculated after the spectra stripping was compared with ionization chamber measurements. 相似文献
59.
M D Kuizon M G Natera S P Alberto L A Perlas J A Desnacido E M Avena R T Tajaon M P Macapinlac 《European journal of clinical nutrition》1992,46(4):257-264
The level of riboflavin intake that will correct riboflavin deficiency in seven non-pregnant and in twelve pregnant Filipino women was determined in order to reassess the adequacy of the current Recommended Dietary Allowance (RDA) for riboflavin in Filipinos. Increasing levels of riboflavin were given to the subjects who were rated as riboflavin-deficient based on an initial erythrocyte glutathione reductase activation coefficient (EGR-AC) of greater than or equal to 1.3 in screening. The minimum riboflavin requirement, defined as the intake of riboflavin required to achieve an EGR-AC of less than 1.3, was estimated from the regression of EGR-AC on riboflavin intake (mg/1000 kcal). The estimates of minimum riboflavin requirement from the non-pregnant women ranged from 0.16 to 0.42 with a mean of 0.35 +/- 0.09 (SD) mg/1000 kcal. For the pregnant subjects, the estimates of minimum riboflavin requirement ranged from 0.36 to 0.81 with a mean of 0.58 +/- 0.18 (SD) mg/1000 kcal. Adding 30% to the mean, to cover the upper limits of 97.5% of the population, the estimated RDA for non-pregnant women is 0.46/1000 kcal. This value is approximately equal to the 1976 Philippine RDA of 0.5 mg riboflavin/1000 kcal. For pregnant women, adding 30% to the mean minimum requirement of 0.58 mg/1000 kcal, the estimated RDA is 0.75 mg/1000 kcal or 1.75 mg/day computed at the energy allowance of 2350 kcal during pregnancy. This value is 25% higher than the current Philippine RDA of 1.4 mg/day for pregnant women.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
60.