6 resultados para curing extent degree

em Universidade Federal do Rio Grande do Norte(UFRN)


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This study evaluated the degree of conversion (DC%) of one experimental and different brands of composite resins light-cured by two light sources (one LED and one argon laser). The percentage of unreacted C = C was determined from the ratio of absorbance intensities of aliphatic C = C (peak at 1637 cm−1) against internal standards before and after curing: aromatic C–C (peak at 1610 cm−1) except for P90, where %C = C bonds was given for C–O–C (883 cm−1) and C–C (1257 cm−1). ANOVA and Tukey’s test revealed no statistically significant difference among Z350 (67.17), Z250 (69.52) and experimental (66.61 ± 2.03) with LED, just among them and Evolu-X (75.51) and P90 (32.05) that showed higher and lower DC%, respectively. For the argon laser, there were no differences among Z250 (70.67), Z350 (69.60), experimental (65.66) and Evolu-X (73, 37), however a significant difference was observed for P90 (36.80), which showed lowest DC%. The light sources showed similar DC%, however the main difference was observed regarding the composite resins. The lowest DC% was observed for the argon laser. P90 showed the lowest DC% for both light-curing sources.

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Objective: The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. Methods: Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm−1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm−1). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey’s test, with a significance level set at 5%. Results: The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001). Conclusions: The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness.

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Hyperhidrosis is an idiopathic condition characterized by excessive sweating. Symptoms generally begin in childhood or early adolescence, and rarely improve with age. The excessive localized sweating generally occurs either spontaneously, or in association with stressful or emotionally charged situations. This prospective study aimed to investigate predictive factors for compensatory hyperhidrosis after thoracoscopic sympathicotomy. From 2000 to 2002, 80 patients (53 female and 27 male) underwent hyperhidrosis surgery. The patients, ranging from 12 to 56 years old, were studied and followed-up for 42.51 ±5.98 months. A satisfaction grading using a visual analogue scale -VAS (0 = not at all satisfied, and 10 = fully satisfied) was used. The surgical procedure was performed bilaterally on the second ganglion (T2) for facial hyperhidrosis, on the third and fourth ganglia (T3 and T4) for axillary hyperhidrosis, and on the third ganglion (T3) for palmar hyperhidrosis. The results showed that, 68 patients (85%) presented with compensatory sweating (CS), which was classified as mild (33.8%), moderate (33.8%) and severe (32.4%). Considering the final surgical results, 70 patients (87.5%) were satisfied with the outcome of the operation, while 10 patients (12.5%) were dissatisfied. Degrees of satisfaction varied according to sex, age, BMI and extent of denervation. Moreover, the compensatory hyperhidrosis was more severe in abdomen and back than in legs. In conclusion, although CS is a frequent adverse effect of sympathicotomy, the degree of patient satisfaction was high. Some factors were related to the occurrence and severity of CS and the most adequate patients to be submitted to this operation are young adult women whose BMI is less than 24.9

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Diabetes Mellitus (DM) and osteoposes are chronic diseases with great socioeconomic consequences, mainly due to the late complications and consequent disabilities. The potential effects of DM on bone metabolism remain a very conroversial issue, and disagreement exists with regard to the clinical implications of diabetic osteopenia and the mechanism of its ocurrence. The issue is further complicated by the contribuicion of the especific factors, such as duration of disease an dthe degree of metabolic control. The objective of this study is to identify the osteopathy in children and adolescents with DM 1 assisted in the hospital of pediatrics, UFRN, through biochemical markers of bone and mineral metabolism and the extent of bone mineral density. The study was composed by 74 diabetics type 1 patients (DM1) of both gender and aged 6 to 20 yars. Normoglicêmic group was composed by 97 healthy subjects of both genders, which showed the same age range of DM1, in addition to same socioeconomic class. These individuals qere students from the networks of public education in the city of Natal-RN, randomly invited to paticipate in our study. Both groups DM1 and NG were divided intofour subgroups, according to the classification of tanner , T1, T2, T3, T4 for achieving a benchmark. Diabetic individuals showed up with a poor glycemic control. the group DN1 T4 showed an incresead value for total protein, albumin, urea and microalbumiuria are predictors of grumelura injury in DM1 patients . The total alkaline phosphatase activitywas kept on high levels for both groups because they are in a stature development age. For osteocalcin there were decreased levels for groups Dm1 T1, T2, and T3 when compared to their NG (s), suggesting that this decrease could be associated with reduction in the number and/or differentiation os osteoblasts thereby contributing to reducing bone formation. There were no changes in the activity of TRAP. The serum concentrations of total and ionized calcium, phosphorus and magnesium were included within the RV. It was observed that the BMD (Z- SCORE ) has always been within the RV for both groups, despite to DM1 T4. Taking all together, our results support the hypothesis that children and adolescents with type 1 DM present the risk in the long run to suffer a reduction in the bone mass, associated to poor glicemic control and disease duration. It could limit the bone growth and increase the probality of development of osteopenia, as well as other complications surch as retinopathy and renal failure

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Tuberculosis (TB) is one of the most important health problems being faced worldwide. In Brazil, the responsibility for the actions of to diagnosis and control of this disease was transferred to the municipalities within the Primary Health Care (PHC), aiming at improvement in epidemiological indicators, requiring reorientation of the practice of family health teams and requiring methodologies to analyze the extent to which components of the PHC are being achieved. Thus, this study aims to analyze the performance of primary care services in the city of Natal-RN for the diagnosis and control of TB, from the perspective of health professionals (doctors and nurses). The study is descriptive, cross-sectional and quantitative. Data collection was conducted from March to July 2011 and involved 121 health professionals working in 52 health units (family health unit, basic health unit and mixed units). The instrument is structured based on the Primary Care Assessment Tool (PCAT), validated and adapted to assess attention to TB in Brazil, and includes questions regarding the Structure and Process components of health services. For quantitative analysis, it was constructed indicators, whose response patterns are followed according to the Likert scale between one and five, which meant the degree of preference relation (or agreement) of the claims. Values between 1 and 3 were considered unsatisfactory for the indicator, between 3 and less than 4, regular, and between 4 and 5, satisfactory. With regard to inputs and equipment, the units had satisfactory condition for form (  = 4.26), consultation (  = 4.02) and basic basket (  = 4.24); regular condition to pot (  = 3.56) and unsatisfactory conditions for transportation tickets (  = 1.50) and sputum smear microscopy (  = 2.42) and X-rays (  = 1.07). In relation to actions, there was satisfactory development for those focused on the individual patient. Actions aimed at the collective level, as the search for respiratory symptoms (RS), monitoring of contacts and guidelines for the community ranged from regular to unsatisfactory (  = 3.16 -  = 1.34). With regard to training, 94,2% received training to identify RS. As regards the time for diagnosis, the median time elapsed between the identification of RS and the beginning of treatment it was 22 days. In relation to the difficulties faced by professionals in the diagnosis of TB, 56,2% reported that they are related only to health services, especially for the failure in the rearguard laboratory and in the specialized services reference, the lack of human and material resources and low performing an active search. The professionals perceive the performance of diagnosis and control of TB, permeated with limitations and barriers to organizational and operational character of various sizes, emerging the need for effective coordination of various sectors and key stakeholders of TB care, to adoption of a new intersectoral strategies that aim to increase the responsiveness of the PHC, providing the best performance in service delivery to the user, family and community, and ensuring effective action and resolving the needs of this population group.

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In the world we are constantly performing everyday actions. Two of these actions are frequent and of great importance: classify (sort by classes) and take decision. When we encounter problems with a relatively high degree of complexity, we tend to seek other opinions, usually from people who have some knowledge or even to the extent possible, are experts in the problem domain in question in order to help us in the decision-making process. Both the classification process as the process of decision making, we are guided by consideration of the characteristics involved in the specific problem. The characterization of a set of objects is part of the decision making process in general. In Machine Learning this classification happens through a learning algorithm and the characterization is applied to databases. The classification algorithms can be employed individually or by machine committees. The choice of the best methods to be used in the construction of a committee is a very arduous task. In this work, it will be investigated meta-learning techniques in selecting the best configuration parameters of homogeneous committees for applications in various classification problems. These parameters are: the base classifier, the architecture and the size of this architecture. We investigated nine types of inductors candidates for based classifier, two methods of generation of architecture and nine medium-sized groups for architecture. Dimensionality reduction techniques have been applied to metabases looking for improvement. Five classifiers methods are investigated as meta-learners in the process of choosing the best parameters of a homogeneous committee.