120 research outputs found

    stairs and fire

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    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Epithelial Thickness of the Palatal Mucosa: A Histomorphometric Study in Koreans

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    Subepithelial connective tissue grafting (SCTG) is a frequently used method in the field of periodontal plastic surgery. There are relatively few reports defining epithelial thickness criteria for palatal mucosal SCTG. The aim of this study was to histologically measure the epithelial thickness of the palatal mucosa in a sample of Korean patients, with the goal of minimizing epithelium-associated complications after root coverage procedures. A total of 30 Korean patients (12 males and 18 females) were enrolled in this study. To measure epithelial thicknesses, palatal mucosa adjacent to premolars and molars was obtained during procurement of SCTG. The effects of donor site, age and gender on the thickness of the epithelium were assessed and compared by histomorphometric analysis. The mean epithelial thickness of the palatal mucosa in our 30 patients was 430.63 μm, ranging from 113 to 823 μm. Epithelial thickness was not associated with donor site or age, but there were significant differences between genders, with males having much thicker palates than females.Grant sponsor: Department of Periodontology, Kyung Hee University, Seoul, Korea

    The effect of Er:YAG laser irradiation on the scanning electron microscopic structure and surface roughness of various implant surfaces: an in vitro study

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    The purpose of this study was to evaluate the surface roughness (Ra) and microscopic change to irradiated dental implant surfaces in vitro and ultimately to determine the proper pulse energy power and application time for the clinical use of Er:YAG lasers. Anodic oxidized surface implants and sand-blasted, large-grit, and acid-etched (SLA) surface implants were used. Each experimental group of implant surfaces included ten implants. Nine implants were used for the laser irradiation test groups and one for the control group. Each test group was equally divided into three subgroups by irradiated pulse energy power. Using an Er:YAG laser, each subgroup of anodic oxidized surface implants was split into 60-, 100-, and 140-mJ/pulse groups, with each subgroup of SLA surface implants irradiated with a 100-, 140-, or 180-mJ/pulse. Three implants in every test subgroup were respectively irradiated for 1, 1.5, and 2 min. The Ra values for each specimen were recorded and every specimen was observed by SEM. Irradiation by Er:YAG laser led to a decrease in implant surface roughness that was not statistically significant. In anodic oxidized surfaces, the oxidized layer peeled off of the surface, and cracks appeared on implant surfaces in the 100- and 140-mJ/pulse subgroups. However, with SLA surfaces, no significant change in surface texture could be found on any implant surface in the 100- and 140-mJ/pulse subgroups. The melting and fusion phenomena of implant surfaces were observed with all application times with 180 mJ/pulse irradiation. The SLA implant surfaces are stable with laser intensities of less than 140 mJ/pulse and an irradiation time of less than 2 min. The anodic oxidized surfaces were not stable with laser intensities of 100 mJ/pulse when an Er:YAG laser was used to detoxify implant surfaces

    Reliability Properties of Solderable Conductive Adhesives with Low-Melting-Point Alloy Fillers

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    A solderable conductive adhesive (SCA) using low-melting-point alloy (LMPA) filler was developed to overcome the limitations of conventional electrically conductive adhesives (ECAs), which include their low electrical conductivity, increased contact resistance, and low joint strength. The SCA formed good metallurgical conduction path between the corresponding electrodes due to the rheology-coalescence-wetting behaviors of molten LMPA fillers in SCA. This study examined the reliability of SCA assembly through the thermal shock test (218 to 398K, 1000 cycles) and the high temperature and high humidity test (358K/85%RH, 1000 h). The electrical resistance of the SCA assembly with metallurgical interconnections was much more stable than those with conventional ICAs. Before the reliability tests, a scallop-type Cu6Sn5 (©-phase) intermetallic compound (IMC) layer was formed on the Sn-plated Cu lead/LMPA and LMPA/Cu metallization interface based on the results of interfacial microstructure observations of quad flat packages (QFPs) that were assembled with SCA. After the reliability tests, the thickness of IMC layer increased with time, and Cu6Sn5 (©-phase) and Cu3Sn (-phase) were formed. In addition, the fracture surface exhibited a cleavage fracture mode with the fracture propagating along the CuSn IMC/SnBi interface. These results demonstrate that SCA assembly with metallurgical interconnection has stable electrical and mechanical bonding characteristics. [doi:10.2320/matertrans.MB201207

    DEEPOMICS FFPE, a deep neural network model, identifies DNA sequencing artifacts from formalin fixed paraffin embedded tissue with high accuracy

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    Abstract Formalin-fixed, paraffin-embedded (FFPE) tissue specimens are routinely used in pathological diagnosis, but their large number of artifactual mutations complicate the evaluation of companion diagnostics and analysis of next-generation sequencing data. Identification of variants with low allele frequencies is challenging because existing FFPE filtering tools label all low-frequency variants as artifacts. To address this problem, we aimed to develop DEEPOMICS FFPE, an AI model that can classify a true variant from an artifact. Paired whole exome sequencing data from fresh frozen and FFPE samples from 24 tumors were obtained from public sources and used as training and validation sets at a ratio of 7:3. A deep neural network model with three hidden layers was trained with input features using outputs of the MuTect2 caller. Contributing features were identified using the SHapley Additive exPlanations algorithm and optimized based on training results. The performance of the final model (DEEPOMICS FFPE) was compared with those of existing models (MuTect filter, FFPolish, and SOBDetector) by using well-defined test datasets. We found 41 discriminating properties for FFPE artifacts. Optimization of property quantification improved the model performance. DEEPOMICS FFPE removed 99.6% of artifacts while maintaining 87.1% of true variants, with an F1-score of 88.3 in the entire dataset not used for training, which is significantly higher than those of existing tools. Its performance was maintained even for low-allele-fraction variants with a specificity of 0.995, suggesting that it can be used to identify subclonal variants. Different from existing methods, DEEPOMICS FFPE identified most of the sequencing artifacts in the FFPE samples while retaining more of true variants, including those of low allele frequencies. The newly developed tool DEEPOMICS FFPE may be useful in designing capture panels for personalized circulating tumor DNA assay and identifying candidate neoepitopes for personalized vaccine design. DEEPOMICS FFPE is freely available on the web ( http://deepomics.co.kr/ffpe ) for research

    Genome-informed investigation of the molecular evolution and genetic reassortment of severe fever with thrombocytopenia syndrome virus.

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    BackgroundSevere fever with thrombocytopenia syndrome virus (SFTSV) is a viral pathogen causing significant clinical signs from mild fever with thrombocytopenia to severe hemorrhages. World Health Organization has paid special attention to the dramatic increase in human SFTS cases in China, Japan, and South Korea since the 2010s. The present study investigated the molecular evolution and genetic reassortment of SFTSVs using complete genomic sequences.Methods/principal findingWe collected the complete genome sequences of SFTSVs globally isolated until 2019 (L segment, n = 307; M segment, n = 326; and S segment, n = 564) and evaluated the evolutionary profiles of SFTSVs based on phylogenetic and molecular selection pressure analyses. By employing a time-scaled Bayesian inference method, we found the geographical heterogeneity of dominant SFTSV genotypes in China, Japan, and South Korea around several centuries before and locally spread by tick-born spillover with infrequent long-distance transmission. Purifying selection predominated the molecular evolution of SFTSVs with limited gene reassortment and fixed substitution, but almost all three gene segments appeared to harbor at least one amino acid residue under positive selection. Specifically, the nonstructural protein and glycoprotein (Gn/Gc) genes were preferential selective targets, and the Gn region retained the highest number of positively selected residues.Conclusion/significanceHere, the large-scale genomic analyses of SFTSVs improved prior knowledge of how this virus emerged and evolved in China, Japan, and South Korea. Our results highlight the importance of SFTSV surveillance in both human and non-human reservoirs at the molecular level to fight against fatal human infection with the virus
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