cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6234923
title: Simultaneous Multienzymatic Screening with Fluorogenic Probes

description: The simultaneous screening of multiple enzyme activities in a single assay has numerous advantages over the traditional format, since it decreases sampling errors, allows savings in reagents and consumables and reduces the time and labor required to conduct the assays. In the present study, a direct and sensitive assay for the simultaneous detection of epoxide hydrolase and esterase (or lipase) activities was developed. Signal overlap is avoided by synthesizing fluorogenic probes with enzyme-specific alkyl linkers, connected to different fluorophores (resorfurin and umbelliferone), which exhibit emission spectra at different wavelengths. The simultaneous assays were conducted in microplate format with the fluorogenic probes monitored in the same well that uses microorganisms as enzyme source. Our results show that the fluorescent signal from each of the probes used here can be discriminated, allowing multiple enzyme activity detection and quantitation.
DOI: 10.6084/m9.figshare.6234923.v1
title: Simultaneous Multienzymatic Screening with Fluorogenic Probes

description: The simultaneous screening of multiple enzyme activities in a single assay has numerous advantages over the traditional format, since it decreases sampling errors, allows savings in reagents and consumables and reduces the time and labor required to conduct the assays. In the present study, a direct and sensitive assay for the simultaneous detection of epoxide hydrolase and esterase (or lipase) activities was developed. Signal overlap is avoided by synthesizing fluorogenic probes with enzyme-specific alkyl linkers, connected to different fluorophores (resorfurin and umbelliferone), which exhibit emission spectra at different wavelengths. The simultaneous assays were conducted in microplate format with the fluorogenic probes monitored in the same well that uses microorganisms as enzyme source. Our results show that the fluorescent signal from each of the probes used here can be discriminated, allowing multiple enzyme activity detection and quantitation.
DOI: 10.6084/m9.figshare.6234917
title: Murine intestinal organoids resemble intestinal epithelium in their microRNA profiles

description: Intestinal organoids were established as an <i>ex vivo</i> model of the intestinal epithelium. We investigated whether organoids resemble the intestinal epithelium in their microRNA (miRNA) profiles. Total RNA samples were obtained from crypt and villus fractions in murine intestine and from cultured organoids. Microarray analysis showed that organoids largely resembled intestinal epithelial cells in their miRNA profiles. <i>In silico</i> prediction followed by qRT-PCR suggested that six genes are regulated by corresponding miRNAs along the crypt-villus axis, suggesting miRNA regulation of epithelial cell renewal in the intestine. However, such expression patterns of miRNAs and their target mRNAs were not reproduced during organoids maturation. This might be due to lack of luminal factors and endocrine, nervous, and immune systems in organoids and different cell populations between <i>in vivo</i> epithelium and organoids. Nevertheless, we propose that intestinal organoids provide a useful <i>in vitro</i> model to investigate miRNA expression in intestinal epithelial cells.
DOI: 10.6084/m9.figshare.6234917.v1
title: Murine intestinal organoids resemble intestinal epithelium in their microRNA profiles

description: Intestinal organoids were established as an <i>ex vivo</i> model of the intestinal epithelium. We investigated whether organoids resemble the intestinal epithelium in their microRNA (miRNA) profiles. Total RNA samples were obtained from crypt and villus fractions in murine intestine and from cultured organoids. Microarray analysis showed that organoids largely resembled intestinal epithelial cells in their miRNA profiles. <i>In silico</i> prediction followed by qRT-PCR suggested that six genes are regulated by corresponding miRNAs along the crypt-villus axis, suggesting miRNA regulation of epithelial cell renewal in the intestine. However, such expression patterns of miRNAs and their target mRNAs were not reproduced during organoids maturation. This might be due to lack of luminal factors and endocrine, nervous, and immune systems in organoids and different cell populations between <i>in vivo</i> epithelium and organoids. Nevertheless, we propose that intestinal organoids provide a useful <i>in vitro</i> model to investigate miRNA expression in intestinal epithelial cells.
DOI: 10.6084/m9.figshare.6234911
title: Brazilian Bioluminescent Beetles: Reflections on Catching Glimpses of Light in the Atlantic Forest and Cerrado

description: ABSTRACT Bioluminescence - visible and cold light emission by living organisms - is a worldwide phenomenon, reported in terrestrial and marine environments since ancient times. Light emission from microorganisms, fungi, plants and animals may have arisen as an evolutionary response against oxygen toxicity and was appropriated for sexual attraction, predation, aposematism, and camouflage. Light emission results from the oxidation of a substrate, luciferin, by molecular oxygen, catalyzed by a luciferase, producing oxyluciferin in the excited singlet state, which decays to the ground state by fluorescence emission. Brazilian Atlantic forests and Cerrados are rich in luminescent beetles, which produce the same luciferin but slightly mutated luciferases, which result in distinct color emissions from green to red depending on the species. This review focuses on chemical and biological aspects of Brazilian luminescent beetles (Coleoptera) belonging to the Lampyridae (fireflies), Elateridae (click-beetles), and Phengodidae (railroad-worms) families. The ATP-dependent mechanism of bioluminescence, the role of luciferase tuning the color of light emission, the “luminous termite mounds” in Central Brazil, the cooperative roles of luciferase and superoxide dismutase against oxygen toxicity, and the hypothesis on the evolutionary origin of luciferases are highlighted. Finally, we point out analytical uses of beetle bioluminescence for biological, clinical, environmental, and industrial samples.
DOI: 10.6084/m9.figshare.6234911.v1
title: Brazilian Bioluminescent Beetles: Reflections on Catching Glimpses of Light in the Atlantic Forest and Cerrado

description: ABSTRACT Bioluminescence - visible and cold light emission by living organisms - is a worldwide phenomenon, reported in terrestrial and marine environments since ancient times. Light emission from microorganisms, fungi, plants and animals may have arisen as an evolutionary response against oxygen toxicity and was appropriated for sexual attraction, predation, aposematism, and camouflage. Light emission results from the oxidation of a substrate, luciferin, by molecular oxygen, catalyzed by a luciferase, producing oxyluciferin in the excited singlet state, which decays to the ground state by fluorescence emission. Brazilian Atlantic forests and Cerrados are rich in luminescent beetles, which produce the same luciferin but slightly mutated luciferases, which result in distinct color emissions from green to red depending on the species. This review focuses on chemical and biological aspects of Brazilian luminescent beetles (Coleoptera) belonging to the Lampyridae (fireflies), Elateridae (click-beetles), and Phengodidae (railroad-worms) families. The ATP-dependent mechanism of bioluminescence, the role of luciferase tuning the color of light emission, the “luminous termite mounds” in Central Brazil, the cooperative roles of luciferase and superoxide dismutase against oxygen toxicity, and the hypothesis on the evolutionary origin of luciferases are highlighted. Finally, we point out analytical uses of beetle bioluminescence for biological, clinical, environmental, and industrial samples.
DOI: 10.6084/m9.figshare.6234908
title: Solution Treatment Behaviors of 6061 Aluminum Alloy Prepared by Powder Thixoforming

description: Powder thixoforming (PTF) was a promising processing technology that can be used to fabricate high strength particle reinforced aluminum matrix composites, and a pioneer 6061 matrix alloy was fabricated utilizing PTF to investigate its solution treatment behaviors. A comparison study with traditional permanent mold cast (PMC) 6061 alloy disclosed that PTF alloy showed significantly reduced pore amount with only 0.16% (3.50% for PMC alloy). During solution treatment, PTF alloy displayed a much quicker solutionization progress than PMC alloy because of coarse eutectic phases and primary dendrites in latter alloy, its peak values of 14.5%, 241 MPa and 195 MPa in elongation, ultimate tensile strength and yield strength were achieved at 560ºC, an enhancement of 81.3%, 33.9% and 97.0%, respectively, compared with as-fabricated alloy. The dissolution of eutectic phases plays a dominative role in the growth of the primary α phases and secondarily primary α phases within 535ºC. However, the coarsening after 535ºC is subject to a mixture model involving atom diffusion along grain boundaries and through the crystal lattice. The superior tensile strengths of PTF alloy than PMC alloy resulted from decreased grain size, enhanced solid solution strengthening, reduced porosities and decreased harmful effect of insoluble phases in PTF alloy.
DOI: 10.6084/m9.figshare.6234908.v1
title: Solution Treatment Behaviors of 6061 Aluminum Alloy Prepared by Powder Thixoforming

description: Powder thixoforming (PTF) was a promising processing technology that can be used to fabricate high strength particle reinforced aluminum matrix composites, and a pioneer 6061 matrix alloy was fabricated utilizing PTF to investigate its solution treatment behaviors. A comparison study with traditional permanent mold cast (PMC) 6061 alloy disclosed that PTF alloy showed significantly reduced pore amount with only 0.16% (3.50% for PMC alloy). During solution treatment, PTF alloy displayed a much quicker solutionization progress than PMC alloy because of coarse eutectic phases and primary dendrites in latter alloy, its peak values of 14.5%, 241 MPa and 195 MPa in elongation, ultimate tensile strength and yield strength were achieved at 560ºC, an enhancement of 81.3%, 33.9% and 97.0%, respectively, compared with as-fabricated alloy. The dissolution of eutectic phases plays a dominative role in the growth of the primary α phases and secondarily primary α phases within 535ºC. However, the coarsening after 535ºC is subject to a mixture model involving atom diffusion along grain boundaries and through the crystal lattice. The superior tensile strengths of PTF alloy than PMC alloy resulted from decreased grain size, enhanced solid solution strengthening, reduced porosities and decreased harmful effect of insoluble phases in PTF alloy.
DOI: 10.6084/m9.figshare.6234905
title: Determination of Target Pesticide Residues in Tropical Fruits Employing Matrix Solid-Phase Dispersion (MSPD) Extraction Followed by High Resolution Gas Chromatography

description: A simple method based on matrix solid-phase dispersion (MSPD) extraction and gas chromatography with electron-capture detection (GC-ECD) is employed to determine pesticide residues in the following tropical fruits: banana, mango, melon, papaya and pineapple. In the MSPD proposed method, C18, silica gel and ethyl acetate presented the best results in the extraction, clean-up and elution steps, respectively. Spiked blank samples were used to minimize the matrix effect in the chromatographic determination. The validation process was conducted at three different concentration levels of spiked samples (0.50-2.50 µg g-1) in within-a-day and in among days assays. The limits of detection for the pesticides ranged from 4.0 to 23 µg kg-1. The method showed acceptable selectivity, coefficients of correlation higher than 0.997, and recovery between 76-105%. The within-a-day precision was assessed through the relative standard deviation (2.8-19%) for the different levels of spiked samples tested.
DOI: 10.6084/m9.figshare.6234902
title: Flipped Classroom: the analysis of an experience in the discipline of Calculus I

description: Abstract This paper aims to present the results of a first-time experiment conducted using the concept of inverted classroom (or flipped classroom) in the discipline of Differential and Integral Calculus I, in Engineering courses at ITA (Instituto Tecnológico de Aeronáutica). The flipped classroom is characterized, according to Valente (2014), as a form of e-learning, in which the contents and instructions are studied online way before class time class, where practical activities will be carried out, such as problem solving and projects, group discussion, among others. This study highlights the potential, some of the problems faced, and the opinions of students in the methodology. This also shows that, regardless of the difficulties faced during the experience, there is a need for innovative approaches regarding Calculus teaching in higher education.
DOI: 10.6084/m9.figshare.6234905.v1
title: Determination of Target Pesticide Residues in Tropical Fruits Employing Matrix Solid-Phase Dispersion (MSPD) Extraction Followed by High Resolution Gas Chromatography

description: A simple method based on matrix solid-phase dispersion (MSPD) extraction and gas chromatography with electron-capture detection (GC-ECD) is employed to determine pesticide residues in the following tropical fruits: banana, mango, melon, papaya and pineapple. In the MSPD proposed method, C18, silica gel and ethyl acetate presented the best results in the extraction, clean-up and elution steps, respectively. Spiked blank samples were used to minimize the matrix effect in the chromatographic determination. The validation process was conducted at three different concentration levels of spiked samples (0.50-2.50 µg g-1) in within-a-day and in among days assays. The limits of detection for the pesticides ranged from 4.0 to 23 µg kg-1. The method showed acceptable selectivity, coefficients of correlation higher than 0.997, and recovery between 76-105%. The within-a-day precision was assessed through the relative standard deviation (2.8-19%) for the different levels of spiked samples tested.
DOI: 10.6084/m9.figshare.6234902.v1
title: Flipped Classroom: the analysis of an experience in the discipline of Calculus I

description: Abstract This paper aims to present the results of a first-time experiment conducted using the concept of inverted classroom (or flipped classroom) in the discipline of Differential and Integral Calculus I, in Engineering courses at ITA (Instituto Tecnológico de Aeronáutica). The flipped classroom is characterized, according to Valente (2014), as a form of e-learning, in which the contents and instructions are studied online way before class time class, where practical activities will be carried out, such as problem solving and projects, group discussion, among others. This study highlights the potential, some of the problems faced, and the opinions of students in the methodology. This also shows that, regardless of the difficulties faced during the experience, there is a need for innovative approaches regarding Calculus teaching in higher education.
DOI: 10.6084/m9.figshare.6234899
title: The teaching of spin: an approach integrated to tecnology and society

description: Abstract In this work I present an revised approach to the Spin for an introductory course of modern physics. This proposal is elaborated considering the point of view that oftenly the Spin is presented as a “strange object”; it suggests to the students that electrons are spinning basically in the same instant that those students are presented to ondulatory mechanics, where classical particles no longer exists. Here, I look for present the Spin regarding the cronological order as it was conceived, discussing the original articles and what though the main authors that collectivelly contributed to the theory. At the same time, this is made contextualizing the technological importance that is played by the Spin in our society.
DOI: 10.6084/m9.figshare.6234899.v1
title: The teaching of spin: an approach integrated to tecnology and society

description: Abstract In this work I present an revised approach to the Spin for an introductory course of modern physics. This proposal is elaborated considering the point of view that oftenly the Spin is presented as a “strange object”; it suggests to the students that electrons are spinning basically in the same instant that those students are presented to ondulatory mechanics, where classical particles no longer exists. Here, I look for present the Spin regarding the cronological order as it was conceived, discussing the original articles and what though the main authors that collectivelly contributed to the theory. At the same time, this is made contextualizing the technological importance that is played by the Spin in our society.
DOI: 10.6084/m9.figshare.6234896
title: Thermomechanical Modelling of FSW Process Using a Cylindrical Tool in an Aluminum Alloy Alclad AA 2024-T3

description: The Friction Stir Welding Process (FSW/P) is an innovative technique to join metals using the plasticity, not occurring the melting. It was initially applied in aluminum alloys, but recently it has been extended to other materials, for example, copper, steel alloys, polimers and others. In this work it is analyzed the thermo mechanical modelling of the energies involved in the FSW process, performed using AA2024-T3 Alclad aluminum alloy. The temperature of the process surface was also calculated in the interval where it was not measured by type k thermocouples, visual inspection, forging force and energy per weld length analysis were also performed. The equations developed in this work were able to describe the behavior found in the experimental data of temperature and energy per weld length, which allows concludes that can be used to define any temperature point in a region of interest.
DOI: 10.6084/m9.figshare.6234896.v1
title: Thermomechanical Modelling of FSW Process Using a Cylindrical Tool in an Aluminum Alloy Alclad AA 2024-T3

description: The Friction Stir Welding Process (FSW/P) is an innovative technique to join metals using the plasticity, not occurring the melting. It was initially applied in aluminum alloys, but recently it has been extended to other materials, for example, copper, steel alloys, polimers and others. In this work it is analyzed the thermo mechanical modelling of the energies involved in the FSW process, performed using AA2024-T3 Alclad aluminum alloy. The temperature of the process surface was also calculated in the interval where it was not measured by type k thermocouples, visual inspection, forging force and energy per weld length analysis were also performed. The equations developed in this work were able to describe the behavior found in the experimental data of temperature and energy per weld length, which allows concludes that can be used to define any temperature point in a region of interest.
DOI: 10.6084/m9.figshare.6234893
title: Can low-fusing glass application affect the marginal misfit and bond strength of Y-TZP crowns?

description: Abstract To evaluate the effect of different surface treatments on the marginal misfit and retentive strength between Y-TZP crowns and an epoxy resin. Forty (40) epoxy resin (G10) abutments (height: 5mm, conicity: 60, finish line: large chamfer) with equal dimensions were milled and included in polyurethane to simulate the periodontal ligament. Next, 40 Y-TZP crowns (thickness: 1mm) were milled (Cerec in Lab) and randomly divided into four groups (n=10) according to the surface treatment: GS(glaze spray), GP(glaze powder/liquid), P(zirconia primer) and RS(tribochemical silica coating). The conditioned surfaces were cemented with dual self-adhesive cement, light cured and submitted to thermomechanical cycling (2x106, 100N, 4Hz, 5°/55°C). Marginal misfit was analyzed by a stereomicroscope and SEM. Retentive strength test was performed (1mm/min) until crown debonding. Glaze layer thickness was also performed to GS and GP groups. Marginal misfit data were analyzed by Kruskal Wallis and Dunn tests; one-way ANOVA and Tukey (5%) analyzed the tensile strength data. The marginal misfit of the GS (48.6±19.9μm) and GP (65.4±42.5μm) were statistically lower than the RS (96±62.9μm) and P (156±113.3μm) (p=0.001). The retentive strength of the GP (470.5±104.1N) and GS (416.8±170.2N) were similar to the P (342.1±109.7N), but statistically higher than those of the RS (208.9±110N). The GS and GP glaze layer was 11.64μm and 9.73μm respectively. Thus, glaze application promoted lower marginal discrepancy and higher retentive strength values than conventional techniques.
DOI: 10.6084/m9.figshare.6234893.v1
title: Can low-fusing glass application affect the marginal misfit and bond strength of Y-TZP crowns?

description: Abstract To evaluate the effect of different surface treatments on the marginal misfit and retentive strength between Y-TZP crowns and an epoxy resin. Forty (40) epoxy resin (G10) abutments (height: 5mm, conicity: 60, finish line: large chamfer) with equal dimensions were milled and included in polyurethane to simulate the periodontal ligament. Next, 40 Y-TZP crowns (thickness: 1mm) were milled (Cerec in Lab) and randomly divided into four groups (n=10) according to the surface treatment: GS(glaze spray), GP(glaze powder/liquid), P(zirconia primer) and RS(tribochemical silica coating). The conditioned surfaces were cemented with dual self-adhesive cement, light cured and submitted to thermomechanical cycling (2x106, 100N, 4Hz, 5°/55°C). Marginal misfit was analyzed by a stereomicroscope and SEM. Retentive strength test was performed (1mm/min) until crown debonding. Glaze layer thickness was also performed to GS and GP groups. Marginal misfit data were analyzed by Kruskal Wallis and Dunn tests; one-way ANOVA and Tukey (5%) analyzed the tensile strength data. The marginal misfit of the GS (48.6±19.9μm) and GP (65.4±42.5μm) were statistically lower than the RS (96±62.9μm) and P (156±113.3μm) (p=0.001). The retentive strength of the GP (470.5±104.1N) and GS (416.8±170.2N) were similar to the P (342.1±109.7N), but statistically higher than those of the RS (208.9±110N). The GS and GP glaze layer was 11.64μm and 9.73μm respectively. Thus, glaze application promoted lower marginal discrepancy and higher retentive strength values than conventional techniques.
DOI: 10.6084/m9.figshare.6234881
title: Mosquito species occurrence in association with landscape composition in green urban areas

description: Abstract Aedes aegypti prefers densely populated habitats, but has been shown to explore less anthropogenic environments. We investigated composition of the abundance of mosquitoes in forested areas and assessed relationships between species occurrences and different types of land use and land cover at three spatial scales (100m, 500m and 1000m). Mosquitoes were collected from October 2012 to March 2013 using oviposition traps. We collected 4,179 mosquitoes in total including at least 10 species. Aedes albopictus and Limatus durhami were eudominant species, representing 90% of all collected individuals. We found intraspecific differences in response to land use and land cover, and species response patterns were similar at all spatial scales. Ae. albopictus relative abundance was associated with urbanized areas, while Li. durhami, Haemagogus leucocelaenus and Toxorhynchites sp., abundances were associated with native forest. Aedes aegypti were found in five of the eight areas studied, including in an Atlantic forest fragment at a considerable distance from the forest edge (370 m). Aedes aegypti occurrence was not influenced by type of land use or land cover.