996 resultados para Load characteristics
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Objective:To analyze the influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students. Method: An analytical cross-sectional and quantitative study, conducted with 151 nursing students in São Paulo between March and April of 2012. A form for socio-demographic characteristics, the Instrument to Evaluate Stress in Nursing Students and the Pittsburgh Sleep Index were applied. Results: High levels of stress was predominant for Time Management (27.8%) and Professional Training (30.5%) and low sleep quality (78.8%). The Professional Communication, Professional Training and Theoretical Activity are positively correlated to sleep quality. Work activity, academic year and time for daily studies contributed to a low quality of sleep. Conclusion: Few stress factors from the academic environment and some socio-demographic characteristics contributed to the reduction of sleep quality in students.
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OBJECTIVES: (1) To evaluate the changes in surface roughness and gloss after simulated toothbrushing of 9 composite materials and 2 ceramic materials in relation to brushing time and load in vitro; (2) to assess the relationship between surface gloss and surface roughness. METHODS: Eight flat specimens of composite materials (microfilled: Adoro, Filtek Supreme, Heliomolar; microhybrid: Four Seasons, Tetric EvoCeram; hybrid: Compoglass F, Targis, Tetric Ceram; macrohybrid: Grandio), two ceramic materials (IPS d.SIGN and IPS Empress polished) were fabricated according to the manufacturer's instructions and optimally polished with up to 4000 grit SiC. The specimens were subjected to a toothbrushing (TB) simulation device (Willytec) with rotating movements, toothpaste slurry and at three different loads (100g/250g/350g). At hourly intervals from 1h to 10h TB, mean surface roughness Ra was measured with an optical sensor and the surface gloss (Gl) with a glossmeter. Statistical analysis was performed for log-transformed Ra data applying two-way ANOVA to evaluate the interaction between load and material and load and brushing time. RESULTS: There was a significant interaction between material and load as well as between load and brushing time (p<0.0001). The microhybrid and hybrid materials demonstrated more surface deterioration with higher loads, whereas with the microfilled resins Heliomolar and Adoro it was vice versa. For ceramic materials, no or little deterioration was observed over time and independent of the load. The ceramic materials and 3 of the composite materials (roughness) showed no further deterioration after 5h of toothbrushing. Mean surface gloss was the parameter which discriminated best between the materials, followed by mean surface roughness Ra. There was a strong correlation between surface gloss and surface roughness for all the materials except the ceramics. The evaluation of the deterioration curves of individual specimens revealed a more or less synchronous course suspecting hinting specific external conditions and not showing the true variability in relation to the tested material. SIGNIFICANCE: The surface roughness and gloss of dental materials changes with brushing time and load and thus results in different material rankings. Apart from Grandio, the hybrid composite resins were more prone to surface changes than microfilled composites. The deterioration potential of a composite material can be quickly assessed by measuring surface gloss. For this purpose, a brushing time of 10h (=72,000 strokes) is needed. In further comparative studies, specimens of different materials should be tested in one series to estimate the true variability.
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Exposure to PM10 and PM2.5 (particulate matter with aerodynamic diameter smaller than 10 μm and 2.5 μm, respectively) is associated with a range of adverse health effects, including cancer, pulmonary and cardiovascular diseases. Surface characteristics (chemical reactivity, surface area) are considered of prime importance to understand the mechanisms which lead to harmful effects. A hypothetical mechanism to explain these adverse effects is the ability of components (organics, metal ions) adsorbed on these particles to generate Reactive Oxygen Species (ROS), and thereby to cause oxidative stress in biological systems (Donaldson et al., 2003). ROS can attack almost any cellular structure, like DNA or cellular membrane, leading to the formation of a wide variety of degradation products which can be used as a biomarker of oxidative stress. The aim of the present research project is to test whether there is a correlation between the exposure to Diesel Exhaust Particulate (DEP) and the oxidative stress status. For that purpose, a survey has been conducted in real occupational situations where workers were exposed to DEP (bus depots). Different exposure variables have been considered: - particulate number, size distribution and surface area (SMPS); - particulate mass - PM2.5 and PM4 (gravimetry); - elemental and organic carbon (coulometry); - total adsorbed heavy metals - iron, copper, manganese (atomic adsorption); - surface functional groups present on aerosols (Knudsen flow reactor). (Demirdjian et al., 2005). Several biomarkers of oxidative stress (8-hydroxy-2'-deoxyguanosine and several aldehydes) have been determined either in urine or serum of volunteers. Results obtained during the sampling campaign in several bus depots indicated that the occupational exposure to particulates in these places was rather low (40-50 μg/m3 for PM4). Size distributions indicated that particles are within the nanometric range. Surface characteristics of sampled particles varied strongly, depending on the bus depot. They were usually characterized by high carbonyl and low acidic sites content. Among the different biomarkers which have been analyzed within the framework of this study, mean levels of 8- hydroxy-2'-deoxyguanosine and several aldehydes (hexanal, heptanal, octanal, nonanal) increased during two consecutive days of exposure for non-smokers. In order to bring some insight into the relation between the particulate characteristics and the formation of ROS by-products, biomarkers levels will be discussed in relation with exposure variables.
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Objective To analyze the association between socioeconomic situation, clinical characteristics referred and the family history of cardiovascular disease, with the Self-perceived health of young adults education and their implications for clinical characteristics observed. Method Analytical study conducted with 501 young adults who are students in countryside city in the Brazilian Northeast. We used binary logistic regression. Results The final model explained 83.3% of the self-perceived positive health, confirming the association of Self-perceived health with male, residence in the community, have excellent/very good lifestyle and does not have or do not know that there are cases of stroke in the family. Conclusion Health perception was often optimistic, being important to identify devices to be worked closer to their perception of their actual health condition, increasing the effectiveness of health promotion activities undertaken by professionals.
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OBJECTIVE To assess the association of sociodemographic and self-rated health in the presence of cardiovascular diseases and the association of this perception with the type of disease. METHODS A cross-sectional population survey study carried out with 1,232 individuals aged between 20 and 59 years of both genders living in the metropolitan region of Maringá-PR. Data were analyzed using multiple and simple logistic regression. RESULTS In multivariate analysis, the age range and self-rated health were associated with cardiovascular disease, and in the univariate analysis self-rated regular health was associated with arterial hypertension, while self-rated poor health was associated to heart failure, stroke, and to acute myocardial infarction (heart attack). CONCLUSION The differences in association of self-rated health with these diseases can indicate how individuals with certain characteristics cope with the disease, allowing for more individualized and specific health care.
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OBJECTIVE Investigating the association between quality of life with socio-demographic characteristics and the burden of caregivers for individuals with cerebrovascular accident sequelae. METHOD A descriptive, cross-sectional study with a sample composed of 136 caregivers. For data collection, a semi-structured questionnaire, the Barthel, Burden Interview and Short-Form-36 scales were used. Correlation analysis, t-Student test and F-test were used for the analysis in order to compare averages. RESULTS Significant averages in quality of life were demonstrated in association with female caregivers and those over 60 years in the field 'functional capacity,' and in the domains of 'mental health' and 'vitality' for those with higher income. Regarding burden association, the highlighted areas were 'functional capacity,' 'physical aspects,' 'emotional aspects' and 'pain.' CONCLUSION The creation of public policies and social support to effectively reduce the burden on caregivers is a necessity.
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OBJECTIVEAnalyzing the quality of sleep of hypertensive patients registered in the national registration system and monitoring of hypertensive patients.METHODSA cross-sectional study of quantitative and descriptive analyses with 280 hypertensive patients registered in the National Program of Hypertension and Diabetes of the Federal Government in the months from August to October 2011. Questionnaires were used which allowed for tracking sociodemographic data on hypertension and Pittsburgh Sleep Quality Index (PSQI).RESULTSThe prevalence of poor sleep quality among respondents (156 hypertensive patients) and high rates of using medication for sleeping (106 hypertensive patients) was observed. Other relevant data refers to the quality of sleep among hypertensive patients using sleep medication compared to those who do not use it (p≤0.01).CONCLUSIONIndividuals with high blood pressure have a negative association with sleep quality.
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Autism spectrum disorders (ASDs) are a heterogeneous group of disorders with a complex genetic etiology. We used high-resolution whole genome array-based comparative genomic hybridization (array-CGH) to screen 223 ASD patients for gene dose alterations associated with susceptibility for autism. Clinically significant copy number variations (CNVs) were identified in 18 individuals (8%), of which 9 cases (4%) had de novo aberrations. In addition, 20 individuals (9%) were shown to have CNVs of unclear clinical relevance. Among these, 13 cases carried rare but inherited CNVs that may increase the risk for developing ASDs, while parental samples were unavailable in the remaining seven cases. Classification of all patients into different phenotypic and inheritance pattern groups indicated the presence of different CNV patterns in different patient groups. Clinically relevant CNVs were more common in syndromic cases compared to non-syndromic cases. Rare inherited CNVs were present in a higher proportion of ASD cases having first- or second-degree relatives with an ASD-related neuropsychiatric phenotype in comparison with cases without reported heredity (P = 0.0096). We conclude that rare CNVs, encompassing potential candidate regions for ASDs, increase the susceptibility for the development of ASDs and related neuropsychiatric disorders giving us further insight into the complex genetics underlying ASDs.
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Introduction: Because it decreases intubation rate and mortality, NIV has become first-line treatment in case of hypercapnic respiratory failure (HRF). Whether this approach is equally successful for all categories of HRF patients is however debated. We assessed if any clinical characteristics of HRF patients were associated with NIV intensity, success, and outcome, in order to identify prognostic factors. Methods: Retrospective analysis of the clinical database (clinical information system and MDSi) of patients consecutively admitted to our medico-surgical ICU, presenting with HRF (defined as PaCO2 >50 mm Hg), and receiving NIV between January 2009 and December 2010. Demographic data, medical diagnoses (including documented chronic lung disease), reason for ICU hospitalization, recent surgical interventions, SAPS II and McCabe scores were extracted from the database. Total duration of NIV and the need for tracheal intubation during the 5 days following the first hypercapnia documentation, as well as ICU and hospital mortality were recorded. Results are reported as median [IQR]. Comparisons with Chi2 or Kruskal-Wallis tests, p <0.05 (*). Results: 164 patients were included, 45 (27.4%) of whom were intubated after 10 [2-34] hours, after having received 7 [2-19] hours of NIV. NIV successful patients received 15 [5-22] hours of NIV for up to 5 days. Intubation was correlated with increased ICU (20% vs. 3%, p <0.001) and hospital (46.7% vs. 30.2, p >0.05) mortality. Conclusions: A majority of patients requiring NIV for hypercapnic respiratory failure in our ICU have no diagnosed chronic pulmonary disease. These patients tend to have increased ICUand hospital mortality. The majority of patients were non-surgical, a feature correlated with increased hospital mortality. Beside usual predictors of severity such as age and SAPS II, absence of diagnosed chronic pulmonary disease and non-operative state appear to be associated with increased mortality. Further studies should explore whether these patients are indeed more prone to an adverse outcome and which therapeutic strategies might contribute to alter this course.
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To investigate the effect of age and change in body composition on the increase in energy expenditure consecutive to the ingestion of a 75-g glucose load, respiratory exchange measurements were performed on 24 subjects, 12 elderly (mean +/- SEM, 73 +/- 1 yr) and 12 young (25 +/- 1 yr). The body weight was comparable, 62 +/- 2 kg in the elderly group vs 61 +/- 3 in the young, but the body fat content of the elderly group was significantly greater than that of the young (29 +/- 2% vs 19 +/- 2%, p less than 0.001). The elderly group presented a slight glucose intolerance according to the World Health Organization (WHO) criteria, with a 120-min plasma glucose of 149 +/- 9 mg/dl (p less than 0.005 vs young). The postabsorptive resting energy expenditure (REE) was 0.83 +/- 0.03 kcal/min in the elderly group vs 0.98 +/- 0.04 in the young (p less than 0.02); this decrease of 15% was mainly related to the decrease in fat free mass (FFM) in the elderly group, which averaged 14%. The difference was not significant when REE was expressed per kg FFM. The glucose-induced thermogenesis (GIT) expressed as percent of energy content of the load was 6.2 +/- 0.6% in the elderly group and 8.9 +/- 0.9% in the young (p less than 0.05). It is concluded that the glucose-induced thermogenesis is decreased in elderly subjects. However, when expressed per kg FFM, the increment in energy expenditure (EE), in response to the glucose load, is not different in elderly subjects, suggesting that the decrease of thermogenesis may be attributed to the age-related decrease in FFM.
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BACKGROUND: This study evaluates sealing characteristics of two designs of endovascular grafts by angiographic demonstration of exclusion of porcine lumbar arteries. METHODS: 6 endovascular grafts (3 self-expandable with integrated polyurethane wall versus 3 nitinol structures covered with polyester fabric) were implanted in 6 porcine aortae. Perfusion of lumbar arteries was assessed by angiography after implantation and by angiography and dissection at graft explantation after 4 +/- 2 months. Tissue healing was evaluated by light and scanning electron microscopy. RESULTS: Immediate exclusion of the lumbar arteries was achieved in 14/31 vessels (12 by polyurethane grafts and 2 by polyester grafts, p < 0.001). Follow-up angiography and dissection at explantation revealed perfusion of 30/31 lumbar arteries with a collateral network in most cases. Another reason for reperfusion of initially excluded branches was distention of the polyurethane grafts with resulting shortening allowing reperfusion of 8 of the 31 originally covered branches. Histological examination revealed a complete neointimal lining and a tight contact between endovascular grafts and aorta. CONCLUSIONS: The immediate angiographic demonstration of exclusion of lumbar arteries predicts sealing characteristics of endovascular grafts. Later angiographic reappearance is due to development of a collateral network and possible shortening of self-expandable devices.
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This study investigated fatigue-induced changes in spring-mass model characteristics during repeated running sprints. Sixteen active subjects performed 12 × 40 m sprints interspersed with 30 s of passive recovery. Vertical and anterior-posterior ground reaction forces were measured at 5-10 m and 30-35 m and used to determine spring-mass model characteristics. Contact (P < 0.001), flight (P < 0.05) and swing times (P < 0.001) together with braking, push-off and total stride durations (P < 0.001) lengthened across repetitions. Stride frequency (P < 0.001) and push-off forces (P < 0.05) decreased with fatigue, whereas stride length (P = 0.06), braking (P = 0.08) and peak vertical forces (P = 0.17) changes approached significance. Center of mass vertical displacement (P < 0.001) but not leg compression (P > 0.05) increased with time. As a result, vertical stiffness decreased (P < 0.001) from the first to the last repetition, whereas leg stiffness changes across sprint trials were not significant (P > 0.05). Changes in vertical stiffness were correlated (r > 0.7; P < 0.001) with changes in stride frequency. When compared to 5-10 m, most of ground reaction force-related parameters were higher (P < 0.05) at 30-35 m, whereas contact time, stride frequency, vertical and leg stiffness were lower (P < 0.05). Vertical stiffness deteriorates when 40 m run-based sprints are repeated, which alters impact parameters. Maintaining faster stride frequencies through retaining higher vertical stiffness is a prerequisite to improve performance during repeated sprinting.
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BACKGROUND: To test the inflammatory origin of cardiovascular disease, as opposed to its origin in western lifestyle. Population-based assessment of the prevalences of cardiovascular risk factors and cardiovascular disease in an inflammation-prone African population, including electrocardiography and ankle-arm index measurement. Comparison with known prevalences in American and European societies. METHODOLOGY/PRINCIPAL FINDINGS: Traditional population in rural Ghana, characterised by adverse environmental conditions and a high infectious load. Population-based sample of 924 individuals aged 50 years and older. Median values for cardiovascular risk factors, including waist circumference, BMI, blood pressure, and markers of glucose and lipid metabolism and inflammation. Prevalence of myocardial infarction detected by electrocardiography and prevalence of peripheral arterial disease detected by ankle-arm index. When compared to western societies, we found the Ghanaians to have more proinflammatory profiles and less cardiovascular risk factors, including obesity, dysglycaemia, dyslipidaemia, and hypertension. Prevalences of cardiovascular disease were also lower. Definite myocardial infarction was present in 1.2% (95%CI: 0.6 to 2.4%). Peripheral arterial disease was present in 2.8% (95%CI: 1.9 to 4.1%). CONCLUSIONS/SIGNIFICANCE: Taken together, our data indicate that for the pathogenesis of cardiovascular disease inflammatory processes alone do not suffice and additional factors, probably lifestyle-related, are mandatory.
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Clinical experience suggests that longstanding personality characteristics as a person's most distinctive features of all are likely to play a role in how someone with dementia copes with his increasing deficiencies. Personality characteristics may have a pathoplastic effect on both behavioral and psychological symptoms (BPS) or on cognition as well as cognitive decline. Cognitive disorders accompanied by BPS are a tremendous burden for both the patient and their proxies. This review suggests that premorbid personality characteristics are co-determinants of BPS in cognitive disorders, but much effort is needed to clarify whether or not specific premorbid personality traits are associated with specific BPS as no strong links have so far emerged. This review further shows that a growing field of research is interested in the links not only between quite short-lived emotional states and cognitive processes, but also between longstanding personality traits and cognition in both healthy individuals and patients with neurodegenerative disorders. Furthermore, a few studies found that specific premorbid personality traits may be risk factors for neurodegenerative diseases. However, research findings in this area remain scarce despite a huge literature on personality and cognitive disorders in general. An important shortcoming that hampers so far the progress of our understanding in these domains is the confusion in the literature between longstanding premorbid personality traits and transient personality changes observed in neurodegenerative diseases. Few studies have based their assessments on accepted personality theories and carefully investigated premorbid personality traits in patients with cognitive disorders, although assessing personality may be complicated in these patients. Studying the impact of personality characteristics in cognitive disorders is an especially promising field of research in particular when concomitantly using neurobiological approaches, in particular structural brain imaging and genetic studies as suggested by as yet rare studies. Improved understanding of premorbid personality characteristics as determinants of both BPS or cognitive capacities or decline is likely to influence our attitudes towards the treatment of demented patients and ultimately to help in alleviating a patient's and their proxies' burden.
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There is very limited data on isolated systemic relapses of primary central nervous system lymphomas (PCNSL). We retrospectively reviewed the clinical characteristics and outcome of 10 patients with isolated systemic disease among 209 patients with PCNSL mainly treated with methotrexate-based chemotherapy (CT) with or without radiation therapy (RT). Isolated systemic relapse remained rare (4.8%, 10/209 patients). Median time from initial diagnosis to relapse was 33 months (range, 3-94). Sites of relapse were mostly extranodal. Three patients presented with early extra-cerebral (EC) relapse 3, 5 and 8 months from the beginning of initial treatment, respectively, and 7 patients had later relapses (range, 17-94 months). Treatment at relapse included surgery alone, RT alone, CT with or without radiotherapy, or CT with autologous stem cell transplantation (ASCT). Median overall survival (OS) after relapse was 15.5 months (range, 5.8-24.5) compared to 4.6 months (range, 3.6-6.5) for patients with central nervous system (CNS) relapse (p = 0.35). In conclusion, isolated systemic relapses exist but are infrequent. Early EC relapse suggests the presence of systemic disease undetectable by conventional evaluation at initial diagnosis. Patient follow-up must be prolonged because systemic relapse can occur as late as 10 years after initial diagnosis. Whether EC relapses of PCNSL have a better prognosis than CNS relapses needs to be assessed in a larger cohort. Copyright © 2010 John Wiley & Sons, Ltd.