303 research outputs found

    Influence Of A Cobalt-chromium Metal Framework On Surface Roughness And Knoop Hardness Of Visible Light-polymerized Acrylic Resins

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    Although visible light-polymerized acrylic resins have been used in removable partial dentures, it is not clear whether the presence of a metal framework could interfere with their polymerization, by possibly reflecting the light and affecting important properties, such as roughness and hardness, which would consequently increase biofilm accumulation. The aim of this study was to compare the roughness and Knoop hardness of a visible light-polymerized acrylic resin and to compare these values to those of water-bath- and microwave-polymerized resins, in the presence of a metal framework. Thirty-six specimens measuring 30.0 x 4.0 ± 0.5 mm of a microwave- (Onda Cryl), a visible light- (Triad) and a water-bath-polymerized (Clássico) (control) acrylic resins containing a cobalt-chromium metal bar were prepared. After processing, specimens were ground with 360 to 1000-grit abrasive papers in a polishing machine, followed by polishing with cloths and 1-μm diamond particle suspension. Roughness was evaluated using a profilometer (Surfcorder SE 1700) and Knoop hardness (Kg/mm 2) was assayed using a microhardness tester (Shimadzu HMV 2000) at distances of 50, 100, 200, 400 and 800 μm from the metal bar. Roughness and Knoop hardness means were submitted to two-way ANOVA and compared by Tukey and Kruskal Wallis tests at a 5% significance level Statistically significant differences were found (p<0.05) for roughness and Knoop hardness, with light-polymerized resin presenting the highest values (Ra = 0.11 μm and hardness between 20.2 and 21.4 Kg/mm 2). Knoop values at different distances from the metal bar did not differ statistically (p>0.05). Within the limitations of this in vitro study, it was concluded that the presence of metal did not influence roughness and hardness values of any of the tested acrylic resins.143208212Anusavice, K.J., (2003) Philip's Science of Dental Materials. 11 th Ed., p. 96. , 11 St. Louis: Elsevier ScienceBollen, C.M.L., Lambrechts, P., Quirynen, M., Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: A review of the literature (1997) Dent Mater, 13 (4), pp. 258-269Borchers, L., Tavassol, F., Tschernitschek, H., Surface quality achieved by polishing and by varnishing of temporary crown and fixed partial denture resins (1999) J Prosthet Dent, 82 (5), pp. 550-556Braun, K.O., Del Bel Cury, A.A., Cury, J.A., Use of microwave energy for processing acrylic resin near metal (1998) Braz Oral Res, 12 (2), pp. 173-180Curtis, D.A., Eggleston, T.L., Marshall, S.J., Watanabe, L.G., Shear bond strength of visible-light-cured resin relative to heat-cured resin (1989) Dental Mater, 5 (7), pp. 314-318De Clerck, J.P., Microwave polymerization of acrylic resins used in dental prosthesis (1987) J Prosthet Dent, 57 (5), pp. 650-658Khan, Z., Von Fraunhofer, J.A., Razavi, R., The staining characteristics, transverse strength, and microhardness of a visible light-cured denture base material (1987) J Prosthet Dent, 57 (3), pp. 384-386Levin, B., Sanders, J.L., Reitz, P.V., The use of microwave energy for processing acrylic resins (1989) J Prosthet Dent, 61 (3), pp. 381-383Ogle, R.E., Sorensen, S.E., Lewis, E.A., A new visible light-cured resin system applied to removable prosthodontics (1986) J Prosthet Dent, 56 (4), pp. 497-506Quirynen, M., Cml, B., Willems, G., Van Steenberghe, D., Comparison of surface characteristics of six commercially pure titanium abutments (1994) JOMI, 9 (1), pp. 71-76Reitz, P.V., Sanders, J.L., Levin, B., The curing of denture acrylic resins by microwave energy. Physical properties (1985) Quintessence Int, 6 (8), pp. 547-551Rodrigues Garcia, R.C.M., Souza Jr., J.A., Rached, R.N., Del Bel Cury, A.A., Effect of denture cleansers on the surface roughness and hardness of a microwave-cured acrylic resin and dental alloys (2004) J Prosthodont, 13 (3), pp. 1-6Rueggeberg, F.A., Goughman, W.F., Curtis Jr., J.W., Effect of light intensity and exposure duration on cure of resin composite (1994) Oper Dent, 19 (1), pp. 26-32Truong, V.T., Thomasz, F.G., Comparison of denture acrylic resins cured by boiling water and microwave energy (1988) Aust Dent J, 33 (3), pp. 201-204Ulusoy, M., Ulusoy, N., Aydin, A.K., An evaluation of polishing technique on surface roughness of acrylic rsins (1986) J Prosthetic Dent, 56 (1), pp. 107-11

    Spirulina does not decrease muscle damage nor oxdidative stress in cycling athletes with adequate nutritional status

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    The objective of this study was to assess the effect of Spirulina maxima on oxidative stress and muscle damage in cycling athletes subjected to high volume and intensity of training. Eighteen male athletes were randomly divided into an experimental group (n=11) with age 27.8±3.5 and placebo (n=7) with age 34.3±2.3 in a double-blind fashion. They carried out a protocol of Spirulina dietary supplementation (7.5 g/day) of placebo for four weeks and maintained their trainings during this period. A nutritional anamnesis was performed and blood tests were done to determine pre and post levels of creatine kinase (CK), lactic dehydrogenase (LHD), superoxide dismutase (SOD) and malondialdehyde (MDA). The supplemented and placebo groups performed the same volume training, has adequate macronutrients and antioxidant vitamins ingestion before study, as well as initial CK, LDH, SOD and MDA levels. Supplementation did not promote a significant alteration in CK levels on supplemented group (158.4±16.3 for 140.0±16.6 U/l, p>0.05), LDH (420±13.2 for 394.9±27.9 UI/l, p>0.05), MDA (2.8±0.2 for 2.9±0.4 nmol/ml, p>0.05), nor an increase in the SOD (7.3±0.6 for 7.0±0.6 U/mg Hb, p>0.05). We conclude that administration of Spirulina does not interfere in the magnitude of muscle damage nor in antioxidant status of cycling athletes that practice intense training

    Mindful Opportunity to Reflect on Experience: Interdisciplinary Mind–Body Medicine Skills Training for Health-care Professionals

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    Interventions that support employee wellness and resilience hold potential to improve patient care, increase staff engagement, and decrease burnout. This repeat-measures study evaluated whether an abbreviated version of mind–body medicine skills training could decrease stress and improve mindfulness among an interdisciplinary cohort of health-care professionals. The study also assessed whether participants incorporated the mind–body medicine skills into their personal and professional lives. Aggregate results from this unpaired cohort showed decreased stress and increased mindfulness. Postcourse surveys demonstrated increased personal and professional use of mind–body medicine skills. There was high favorability among participants. These preliminary results suggest that a modest investment of time and resources to learn mind–body medicine skills may positively affect employee wellness among health-care professionals. In addition, skills learned could translate into improved patient care and increased staff engagement. Further study with larger cohorts and a paired design is needed

    A versatile capillary gel electrophoresis methodology for in-process and final product characterization of virus-based targets

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    The biopharmaceutical industry is approaching a turning point where new therapeutic modalities such as virus-based biopharmaceuticals are used in several applications such as vaccination, gene therapy and oncolytic therapy. However, the bioprocess of functional viruses still presents challenges, namely due to the availability of suitable analytics for downstream processing monitoring or characterization of the final product. Capillary electrophoresis (CE) is a versatile technique that enables the determination of intact or reduced particle number and the quantification of several product-related impurities, such as host cell DNA and host cell proteins. Although this f platform is commonly used for purity profiling of monoclonal antibodies in the pharmaceutical industry by ultraviolet (UV) detection, it requires a large amount of product, making it not suitable for virus-based pharmaceuticals, where total protein concentration (dose) is relatively low. This work presents a highly sensitive CE methodology for monitoring different bioprocess steps and final product characterization of several viral vectors. A fluorescence labelling procedure using the (3-(2-furoyl) quinoline-2-carboxaldehyde dye was used, enabling the detection of the viral proteins through Sodium dodecyl sulfate-capillary gel electrophoresis (CE-SDS) method coupled to a laser-induced fluorescence (LIF) detector. Please click Download on the upper right corner to see the full abstract

    Undamning the Douro river catchment: a stepwise approach for prioritizing dam removal

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    Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime, and degrading the aquatic and riparian habitats. In the present study, which comprised the Douro River basin located in the North of Portugal, the cost-benefit assessment of dams was based upon a balance between the touristic benefits of a dammed Douro, and the ecological benefits of less fragmented Douro sub-catchments. Focused on four sub-catchments (Sabor, Tâmega, Côa and Corgo), a probabilistic stream connectivity model was developed and implemented to recommend priorities for dam removal, where this action could significantly improve the movement of potadromous fish species along the local streams. The proposed model accounts for fish movement across the dam or weir (permeability), which is a novel issue in connectivity models. However, before any final recommendation on the fate of a dam or weir, the connectivity results will be balanced with other important socio-economic interests. While implementing the connectivity model, an inventory of barriers (dams and weirs) was accomplished through an observation of satellite images. Besides identification and location of any obstacles, the inventory comprised the compilation of data on surrounding land use, reservoir water use, characteristics of the riparian gallery, and permeability conditions for fish, among others. All this information was stored in a geospatial dataset that also included geographical information on the sub-catchment drainage network. The linear (drainage network) and point (barriers) source data were processed in a computer program that provided or returned numbers for inter-barrier stream lengths (habitat), and the barrier permeability. These numbers were finally used in the same computer program to calculate a habitat connector index, and a link improvement index, used to prioritize dam removal based upon structural connectivity criteria. The results showed that habitat patch connectivity in the Sabor, Tâmega and Côa sub-catchments is not dramatically affected by the installed obstacles, because most link improvement values were generally low. For the opposite reason, in the Corgo sub-catchment, obstacles may constitute a relatively higher limitation to connectivity, and in this case the removal of eight obstacles could significantly improve this connectivity. Using the probabilistic model of structural connectivity, it was possible to elaborate a preliminary selection of dams/weirs that critically limit stream connectivity, and that will be the focus of field hydraulic characterization to precisely determine fish movement along the associated river stretches. Future work will also include the implementation of a multi-criteria decision support system for dam removal or mitigation of the critical structures, as well to define exclusion areas for additional obstaclesinfo:eu-repo/semantics/publishedVersio

    Dirofilaria immitis parasite infection in cats: first case reported in the Legal Amazon region, Brazil - case report

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    ABSTRACT A case of infection with Dirofilaria immitis in a cat is reported here with clinical signs of apathy, anorexia, dyspnea, polypnea, slight dehydration and pale mucus membranes. The radiographic examination showed cardiomegaly, lobar arteries dilation of the cranial lobes and tortuosity, enlargement of the caudal lobar arteries. In the right lobe of the lung parenchyma, interstitial pulmonary opacification tending to alveolar opacification was seen. The clinical signs, the movements, and the morphology of the microfilariae in the direct examination of fresh blood, peripheral blood smear and Knott’s modified test supported the diagnosis. We alert to the need for clinicians to consider feline heartworm diseases as a differential diagnosis in endemic areas when cats show respiratory signs

    Toxoplasmosis serology: an efficient hemagglutination procedure to detect IgG and IgM antibodies

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    In search of an efficient but simple, low cost procedure for the serodiagnosis of Toxoplasmosis, especially suited for routine laboratories facing technical and budget limitations as in less developed countries, the diagnostic capability of Hematoxo® , an hemagglutination test for toxoplasmosis, was evaluated in relation to a battery of tests including IgG- and IgM-immunofluorescence tests, hemagglutination and an IgM-capture enzymatic assay. Detecting a little as 5 I.U. of IgG antitoxoplasma antibodies, Hematoxo® showed a straight agreement as to reactivity and non-reactivity for the 443 non-reactive and the 387 reactive serum samples, included in this study. In 23 cases presenting a serological pattern of acute toxoplasmosis and showing IgM antibodies, Hematoxo® could detect IgM antibodies in 18, indicated by negativation or a significant decrease in titers as a result of treating samples with 2-mercapto-ethanol. However, a neat increase in sensitivity for IgM specific antibodies could be achieved by previously removing IgG from the sample, as demonstrated in a series of acute toxoplasmosis sera. A simple procedure was developed for this purpose, by reconstituting a lyophilized suspension of Protein A - rich Staphylococcus with the lowest serum dilution to be tested. Of low cost and easy to perform, Hematoxo® affords not only a practical qualitative procedure for screening reactors and non-reactors, as in prenatal services, but also quantitative assays that permit to titrate antibodies as well as to identify IgM antibodies

    Impact of a Tutored Theoretical-Practical Training to Develop Undergraduate Students’ Skills for the Detection of Caries Lesions: Study Protocol for a Multicenter Controlled Randomized Study

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    Background: Tutored laboratorial activities could be a manner of improving the competency development of students. However, its impact over conventional theoretical classes has not yet been tested. Additionally, different university contexts could influence this issue and should be explored. Objective: To assess the impact of a tutored theoretical-practical training for teaching undergraduate students to detect caries lesions as compared with theoretical teaching activities. The impact of these teaching/learning activities will be assessed in terms of efficacy, cost/benefit, retention of knowledge/acquired competences, and student acceptability. Methods: Sixteen centers (7 centers from Brazil and 9 centers from other countries throughout the world) are involved in the inclusion of subjects for this protocol. A randomized controlled study with parallel groups will be conducted. One group (control) will be exposed to a 60- to 90-minute conventional theoretical class and the other group (test) will be exposed to the same theoretical class and also a 90-minute laboratory class, including exercises and discussions based on the evaluation of a pool of images and extracted teeth. The mentioned outcomes will be evaluated immediately after the teaching activities and also in medium- and long-term analyses. To compare the long-term outcomes, students who enrolled in the university before the participating students will be interviewed for data collection and these data will be used as a control and compared with the trained group. This stage will be a nonrandomized phase of this study, nested in the main study. Appropriate statistical analysis will be performed according to the aims of this study. Variables related to the centers will also be analyzed and used to model adjustment as possible sources of variability among results. Results: This ongoing study is funded by a Brazilian national funding agency (CNPq- 400736/2014-4). We expect that the tutored theoretical-practical training will improve the undergraduate students’ performance in the detection of caries lesions and subsequent treatment decisions, mainly in terms of long-term retention of knowledge. Our hypothesis is that tutored theoretical-practical training is a more cost-effective option for teaching undergraduate students to detect caries lesions. Conclusions: If our hypothesis is confirmed, the use of laboratory training in conjunction with theoretical classes could be used as an educational strategy in Cariology to improve the development of undergraduate students’ skills in the detection of caries lesions and clinical decision-making

    Trabalho, terra e geração de renda em três décadas de reflorestamentos no alto Jequitinhonha.

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    A partir dos anos 1970, as chapadas do Alto Jequitinhonha, localizadas no nordeste de Minas Gerais, até então áreas de uso comum de agricultores familiares, foram plantadas com eucaliptos. O objetivo deste artigo é comparar os efeitos do reflorestamento sobre a estrutura fundiária, valor da produção agrícola e ocupação rural com os efeitos da produção agrícola familiar sobre essas mesmas variáveis na microrregião homogênea de Capelinha, no Alto Jequitinhonha. Tal microrregião foi escolhida para o estudo por ser a área de maior concentração de eucaliptais da região. Foram utilizados dados secundários dos Censos do IBGE para os anos de 1970, 1980, 1985 e 1996, além de dados secundários de pesquisas realizadas sobre a região em questão, incluindo entrevistas com dirigentes de empresas e lideranças sindicais. O artigo conclui que, em trinta anos, o reflorestamento concentrou terras e criou um número reduzido de empregos; a agricultura familiar, ao contrário, teve suas áreas de terras comprimidas e super-exploradas em decorrência da perda das chapadas, mas continuou sendo a principal responsável pela geração de ocupações e rendas na região
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