Physiological effects of different oxygen flow rates and ambient temperatures on pressure-suited subjects performing work at altitude

Physiological effects of oxygen flow rates and ambient temperatures on pressure-suited subjects performing work in altitude chambe

Development of design tools for the evaluation of complex CAD models

The goal of this thesis is to invent means to enable 3D-models, created in SOLIDWORKS CAD-software, to be explored in a low-cost head-mounted display device Oculus Rift. Such a design tool would make possible to study 3D CAD-models in Virtual Reality with a very low cost and share design information for people who are not so familiar with CAD-models. As a result this can lower the product development effort for new products enabling, lower working time and improve both the quality of the final product and customer satisfaction. CAD-models as well as exported graphics format from SOLIDWORKS can’t directly be imported to Oculus Rift device. Therefore transformation pipeline need to be invented between the SOLIDWORKS and Oculus Rift. There are some options for this and their issues are studied in this thesis. As a best option it was found to use a conversion plugin tool to SOLIDWORKS which convert CAD-models to FBX-format. This format can be imported to Unity game engine software which is supported by Oculus Rift device. Graphics file conversion process in known to be imperfect. Therefore conversion of three SOLIDWORKS CAD-models have been analyzed; a Crane, a Pipe system, and a Hydraulic cylinder. This testing gave a good overview of possibilities and limitations of the graphics pipeline. It was found that ordinary CAD-models can be transferred to Oculus Rift without problems. However, there are some special features in CAD models which cause problems for in graphics file conversion

Effect of two corticotomy protocols on periodontal tissue and orthodontic movement

Objective: To compare two corticotomy surgical protocols in rats to verify whether they alter conventional orthodontic movement. Methodology: Sixty Wistar rats were divided into three groups – orthodontic movement (CG), orthodontic movement and corticotomy (G1) and orthodontic movement with corticotomy and decortication (G2) – and euthanized after 7 and 14 days. Tooth movement (mm), bone volume fraction and bone volume ratio to total volume (BV/TV), and bone mineral density (BMD) were evaluated by micro-CT. The total amount of bone was measured in square millimeters and expressed as the percentage of bone area in the histomorphometry. The number of positive TRAP cells and RANK/RANKL/OPG interaction were also investigated. Results: Day 14 showed a statistically significant difference in orthodontic tooth movement in CG compared with G1 (7.52 mm; p=0.009) and G2 (7.36 mm; p=0.016). A micro-CT analysis revealed a difference between CG, G1 and G2 regarding BV/TV, with G1 and G2 presenting a lower BV/TV ratio at 14 days (0.77 and 0.73 respectively); we found no statistically significant differences regarding BMD. There was a difference in the total amount of bone in the CG group between 7 and 14 days. At 14 days, CG presented a significantly higher bone percentage than G1 and G2. Regarding TRAP, G2 had more positive cells at 7 and 14 days compared with CG and G1. Conclusion: Corticotomy accelerates orthodontic movement. Decortication does not improve corticotomy efficiency

Surface properties of composite resins with and without fluorides for bracket bonding / Propriedades de superfície de resinas compostas com e sem fluoretos para colagem de suportes

The aim of this study was to evaluate the surface properties of orthodontic resins with and without fluoride. Forty disks, measuring 2 mm thick by 6 mm in diameter, were made of 4 bracket-bonding composite resins (n=10): Transbond Plus Color Change-3M/Unitek (TPCC); Transbond XT- 3M/Unitek (TXT), Orthocem -FGM (OC); Orthocem UV Trace-FGM (OCUV). The discs were photoactivated for 40 seconds with irradiance of 450 mW/cm2 and manually polished in sequence by silicon carbide sandpapers with 1200 and 2000 grain size and finished with diamond paste and felt disc. The surface microhardness analysis was performed using a Shimadzu Micro Hardness Tester HMV-2,000 (Shimadzu Corporation, Kyoto, Japan) with a load of 50 gF and a 5 second penetration time. Surface roughness readings were taken using a Surf Corder Roughness Meter (SE 1700- Kosaka, Lisboa-Portugal). For data analysis, ANOVA (one-way) was used, followed by Tukey's post-test (?=0.05). The microhardness results showed a difference (p?0.05) in the means of the orthodontic resins between TPCC and TXT with the other groups. After the surface roughness analysis, the averages showed that TPCC resin showed higher roughness compared to OC and OCUV (p?0.05), and there was no statistical difference with TXT. It was concluded that statistically the composite resins with fluoride showed significant difference regarding hardness and roughness

Evaluation of the wire flexibility used in the Mandibular Advancement Device submitted to thermal cycling / Avaliação da flexibilidade do fio utilizado no Dispositivo de Avanço Mandibular submetido ao ciclagem térmica

Este estudo teve como objetivo avaliar a flexibilidade de fios utilizados na confecção de molar lock do Mandibular Advancement Device (MAD), submetidos à variação de temperatura. Foram utilizados 64 segmentos de fios ortodônticos (n = 8), assim alocados: G1) Dentauro; G2) Leoni; G3) Leoni (Bio Steel); G4) Morelli; G5) Dentaurum + Termociclagem (TC); G6) Leoni + TC; G7) Leoni (Bio Steel) + TC; G8) Morelli + TC. Os segmentos foram analisados pelo método de flexão em três pontos, com auxílio de Máquina Universal de Ensaios. Os grupos submetidos à termociclagem foram submetidos a um total de 2300 ciclos térmicos (5 ° C e 55 ° C) correspondentes a 8 meses. Após esse período, os corpos-de-prova foram novamente imersos em água destilada a 37 ° C e mantidos em estufa por 24 horas. A partir desse processo de termociclagem, as amostras foram submetidas a um ensaio de flexão em três pontos. Os dados foram submetidos à análise de variância (ANOVA-two-way) seguida do teste de Tukey, considerando o nível de significância de 5%. Não houve diferença significativa na flexibilidade entre os grupos com e sem ciclismo, considerando a mesma marca e mesmo ponto (p = 0,05). Sem pedalar, a marca Dentaurum apresentou maior flexão média no ponto de 0,5mm, e Morelli apresentou maior flexão no ponto de 1,0mm (p <0,05). A marca Leoni apresentou valores maiores em 2 e 3 mm, e maiores que a marca Dentaurum no ponto de 2 mm (p <0,05). Para os grupos submetidos à termociclagem, nos pontos de 0,5 mm, não houve diferença estatística entre os grupos, exceto para o grupo Leoni, obtendo maior resistência à flexão em relação ao fio da marca Dentaurum (p <0,05). Em 1, 2 e 3 mm, o fio da marca Leoni apresentou maior flexibilidade em relação ao Dentaurum e Leoni (Bio Steel) e Morelli (p <0,05). A variação da temperatura não influencia nas propriedades de flexibilidade dos fios utilizados na confecção do MAD, porém, existem diferenças entre as diferentes marcas quando avaliadas nas mesmas condições

On the nature of the fourth generation neutrino and its implications

We consider the neutrino sector of a Standard Model with four generations. While the three light neutrinos can obtain their masses from a variety of mechanisms with or without new neutral fermions, fourth-generation neutrinos need at least one new relatively light right-handed neutrino. If lepton number is not conserved this neutrino must have a Majorana mass term whose size depends on the underlying mechanism for lepton number violation. Majorana masses for the fourth generation neutrinos induce relative large two-loop contributions to the light neutrino masses which could be even larger than the cosmological bounds. This sets strong limits on the mass parameters and mixings of the fourth generation neutrinos.Comment: To be published. Few typos corrected, references update

Access to Interdental Brushing in Periodontal Healthy Young Adults: A Cross-Sectional Study

Purpose: Interdental diameter space is largely undefined in adults, which compromises the decision support for daily interdental cleaning during routine practice in individual oral prophylaxis. This study assesses the distribution of diameter access of interdental spaces in an 18- to 25-year-old adult population free of periodontal disease. Methods: In March-April 2015, a cross-sectional study using random sampling was performed at the University Lyon 1, France. The interproximal dental spaces of 99 individuals were examined using a colorimetric calibrated probe associated with the corresponding calibrated interdental brush (IDB). Results: Of the 2,408 out of 2,608 sites, the overall accessibility prevalence of any interdental brushing was 92.3%. In total, 80.6% of the sites required interdental brushes with smaller diameters (0.6–0.7 mm). In anterior sites, the diameter of the interdental brushes used was smaller (55.8% of IDB with 0.6 mm) than the diameter of the interdental brushes used in posterior sites (26.1% of IDB with 0.6 mm) (p < 0.01). The adjusted ORs indicate a significant association with the location of the sites (approximately doubling the risk of bleeding, i.e., OR = 1.9, in posterior sites). Conclusions: Most interdental sites can be cleaned using interdental brushes. Even in healthy people, interdental hygiene requirements are very high. Strengthening the oral hygiene capacity by specifically using interdental brushes can have an effect on the health of the entire population. Screening of the accessibility of the interdental space should be a component of a routine examination for all patients.The study was financially supported by Curaden International AG, Kriens, Switzerlan

Cultural adaptation, content validity and inter-rater reliability of the "STAR Skin Tear Classification System"

AIMS: to perform the cultural adaptation of the STAR Skin Tear Classification System into the Portuguese language and to test the content validity and inter-rater reliability of the adapted version.METHODS: methodological study with a quantitative approach. The cultural adaptation was developed in three phases: translation, evaluation by a committee of judges and back-translation. The instrument was tested regarding content validity and inter-rater reliability.RESULTS: the adapted version obtained a regular level of concordance when it was applied by nurses using photographs of friction injuries. Regarding its application in clinical practice, the adapted version obtained a moderate and statistically significant level of concordance.CONCLUSION: the study tested the content validity and inter-rater reliability of the version adapted into the Portuguese language. Its inclusion in clinical practice will enable the correct identification of this type of injury, as well as the implementation of protocols for the prevention and treatment of friction injuries

Enhancement of the electronic contribution to the low temperature specific heat of Fe/Cr magnetic multilayer

We measured the low temperature specific heat of a sputtered $(Fe_{23\AA}/Cr_{12\AA})_{33}$ magnetic multilayer, as well as separate $1000\AA$ thick Fe and Cr films. Magnetoresistance and magnetization measurements on the multilayer demonstrated antiparallel coupling between the Fe layers. Using microcalorimeters made in our group, we measured the specific heat for $4<T<30 K$ and in magnetic fields up to $8 T$ for the multilayer. The low temperature electronic specific heat coefficient of the multilayer in the temperature range $4<T<14 K$ is $\gamma_{ML}=8.4 mJ/K^{2}g-at$. This is significantly larger than that measured for the Fe or Cr films (5.4 and $3.5 mJ/K^{2}mol$ respectively). No magnetic field dependence of $\gamma_{ML}$ was observed up to $8 T$. These results can be explained by a softening of the phonon modes observed in the same data and the presence of an Fe-Cr alloy phase at the interfaces.Comment: 20 pages, 5 figure

Antimicrobial Photodynamic Therapy for the Treatment of Teeth with Apical Periodontitis: A Histopathological Evaluation

Introduction: This study evaluated the in vivo response of apical and periapical tissues of dogs' teeth with apical periodontitis after one-session endodontic treatment with and without antimicrobial photodynamic therapy (aPDT). Methods: Sixty root canals with experimentally induced apical periodontitis were instrumented and assigned to 4 groups receiving aPDT and root canal filling (RCF) or not: group aPDT+/RCF- (n = 20): aPDT (photosensitizer phenothiazine chloride at 10 mg/mL for 3 minutes and diode laser [2 = 660 nm, 60 mW/cm(2)] for 1 minute) and RCF in the same session; group aPDT+/RCF (n = 10); group aPDT /RCF+ (n = 20), and group aPDT /RCF (n = 10). Teeth were restored, and the animals were killed after 90 days. Sections from the maxillas and mandibles were stained with hematoxylin-eosin and Mallory trichrome and examined under light microscopy. Descriptive (ie, newly formed apical mineralized tissue, periapical inflammatory infiltrate, apical periodontal ligament thickness, and mineralized tissue resorption) and quantitative (ie, periapical lesion size and number of inflammatory cells) microscopic analysis was performed. Quantitative data were analyzed by the Kruskal-Wallis and Dunn tests (alpha =.05). Results: In the aPDT-treated groups, the periapical region was moderately/severely enlarged with no inflammatory cells, moderate neoangiogenesis and fibrogenesis, and the smallest periapical lesions. Conclusions: Although apical closure by mineralized tissue deposition was not achieved, the absence of inflammatory cells, moderate neoangiogenesis, and fibrogenesis in the periapical region in the groups treated with aPDT indicate that this can be a promising adjunct therapy to cleaning and shaping procedures in teeth with apical periodontitis undergoing one-session endodontic treatment. (J Endod 2012;38:360-366