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Wildlife roadkill surveys in Brazil often focus on birds, as they are one of the main groups affected by road accidents. In addition roadkill, anthropogenic litter also contributes to a significant number of bird fatalities every year. The present study aimed to investigate the stomach contents and possible contamination by inorganic material of birds killed on a federal highway that crosses the Serra de Itabaiana National Park in the state of Sergipe, Brazil. Monitoring and data collection were carried out from January to June 2022, with a motorcycle at an average speed of 60 km/h. The collected animals were transported to the Institute of Technology and Research, located at the Tiradentes University, Sergipe, Brazil, and a plastic material was identified. The plastic material found was subjected to Fourier Transform Infrared Spectroscopy (FTIR), which showed a similar wavenumber to a polymer in the polypropylene chain, very common in plastic packaging. The presence of plastics and metals in the intestinal contents of Caracara plancus and Crotophaga ani is noteworthy, as they have a greater tendency to ingest plastics due to their generalist diet. Plastic contamination in Progne chalybea and Nyctidromus albicollis probably occurred through bioaccumulation, from the consumption of insects contaminated by microplastics. [ABSTRACT FROM AUTHOR]

Los macroútiles han sido habitualmente marginados de los estudios, debido al peso que ha tenido la industria lítica tallada para la observación de los cambios y continuidades cronológicos y culturales. Sin embargo, estos elementos aparecen en yacimientos arqueológicos asociados a diferentes contextos geográficos y cronológicos, lo cual les confiere un valor como marcadores de la adaptación y de la evolución técnica desarrollada por los grupos humanos. En este trabajo se presentan los resultados del análisis detallado de un objeto procedente del yacimiento de Hort de Cortés-Volcán del Faro (València), asociado a niveles gravetienses. La singularidad de su morfología, de la materia prima y la presencia de huellas de uso apreciables a nivel macroscópico motivaron la aplicación de diferentes metodologías de estudio sobre la pieza para su comprensión. El análisis de las huellas de uso apunta a que esta roca carbonatada fue utilizada en actividades asociadas con el tratamiento de la piel. La diferenciación de dos grupos de huellas de uso ha determinado la distinción de dos tareas desarrolladas con el objeto. La presencia de residuos que se pueden correlacionar con el uso de la pieza se ha evaluado aplicando una aproximación multianalítica y no destructiva. Además, se han aplicado técnicas de espectroscopía atómica y molecular junto con estadística multivariante, con el objetivo de identificar la potencial fuente de materia prima. El interés de este estudio reside en la combinación de aproximaciones para el estudio de un macroútil. Todo ello ha permitido ampliar la limitada información que se tiene sobre este tipo de materiales, y abrir el debate sobre el conocimiento del nivel tecnológico alcanzado por los grupos humanos.

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Copyright of @limentech: Ciencia y Tecnología Alimentaria is the property of Journal @limentech, University of Pamplona and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Em sistemas de produção baseados em pastagens, o conhecimento do potencial nutritivo das forrageiras é de grande importância para a tomada de decisão quanto à suplementação alimentar. Entretanto, as análises para avaliar a composição nutricional são dispendiosas. A espectroscopia no infravermelho próximo (NIRS) é um método rápido e econômico utilizado para quantificar os teores dos compostos orgânicos dos alimentos. No presente trabalho foram desenvolvidos modelos de calibração multivariada para a predição dos teores de proteína bruta (PB), fibra insolúvel em detergente neutro (FDN), fibra insolúvel em detergente ácido (FDA) e digestibilidade in vitro da matéria orgânica (DIVMO) do azevém utilizando a técnica NIRS, para serem utilizados em rotina laboratorial. O número de amostras utilizadas variou de 294 a 390, de acordo com o componente analisado. Os modelos foram selecionados utilizando o erro quadrático médio da predição (RMSEP), o viés, a razão de desempenho do desvio (RPD), a razão de intervalo de erro (RER) e coeficientes de determinação (R2) obtidos na validação externa. Para PB, FDN, FDA e DIVMO os modelos selecionados apresentaram os seguintes valores, respectivamente: R2 = 0,98; 0,94; 0,96; 0,91; RMSEP = 0,96; 1,35; 1,03; 1,58; viés = 0,21; 0,51; 0,70; 0,06; RPD = 6,33; 5,02; 4,08; 3,80; e RER = 26,33; 14,37; 14,61; 11,46. De acordo com as medidas de qualidade de ajuste obtidas, os modelos desenvolvidos para PB, FDN e FDA podem ser utilizados na rotina laboratorial para as análises dos valores nutricionais de azevéns. O modelo desenvolvido para DIVMO pode ser utilizado para triagens de azevéns em estudos de avaliação, seleção e melhoramento.

Introduction: mercury (Hg) accumulates in large predatory species in marine ecosystems, such as tuna, swordfish, or various sharks species. Objective: to validate, through additions, a method of atomic absorption spectroscopy with cold vapour and flow injection system for the measurement of total Hg in seafood products. Material and methods: a total of 18 samples of different seafood products were analysed, spiking them to 4 ranges: low (0.1 mg/ kg); intermediate (0.5 and 1.0 mg/kg) and high (2.0 mg/kg). These were digested in a microwave oven and analysed with an atomic absorption spectrometer. Results: the diversity of the samples and the good accuracy and precision of the results confirmed the selectivity of the method. The working range of the method was established between 0.10-0.32 mg/kg of Hg in the sample and the limit of quantification at 0.10 mg/kg. All calibration lines fitted the linear regression model with statistical significance (p < 0.05). The trueness was 4.28%; 3.20 %; 12.28 % and 0.84% respectively for the 0.1 mg/kg; 0.5 mg/kg; 1.0 mg/kg and 2.0 mg/kg ranges, respectively. The average recovery of the method was 102.54 %. Horrat reproducibility (HorratR) values were 0.41; 0.30; 0.37 and 0.66 and Horrat repeatability (Horratr) values were 0.48; 0.35; 0.11 and 0.47 for the 0.1 mg/kg; 0.5 mg/kg; 1.0 mg/kg and 2.0 mg/kg spiking ranges, respectively in each case. The relative uncertainty values in each range were lower than the fixed limit of 25 %. Conclusion: our method was validated by fulfilling the regulatory requirements and the previously established acceptance criteria. [ABSTRACT FROM AUTHOR]

Oxidation by the action of ozone takes place at high rates and involves the reaction of ozone molecules with fatty acid double bonds followed by the formation of stable oxidation products with biological activity. In the present work, a comparative study on sunflower oil oxidized by ultraviolet (UV) light and ozone was carried out. This study involved the chemical characterization of sunflower oil oxidized by UV irradiation and ozonation, in addition to assessing the germicidal activity of oxidized oils obtained under various conditions. The results indicated that under the conditions studied, the increase in the dose of UV irradiation did not produce significant changes in the level of oxidation of the oil. Ozonation promoted the formation of oxygenated compounds at higher rates, increasing in concentration as the applied dosage of ozone increased. The germicidal activity of the oils behaved similarly, with considerably higher activity found in the ozonized oils. [ABSTRACT FROM AUTHOR]

O presente artigo discute os resultados obtidos com as análises de imagens e espectroscópicas (para determinação dos elementos e compostos químicos) não invasivas realizadas em seis pinturas do artista alemão, naturalizado italiano, Massimo Campigli pertencentes ao acervo do Museu de Arte Contemporânea da Universidade de São Paulo (MAC USP). Os aspectos da trajetória do artista, as soluções plásticas das obras somadas às análises feitas com técnicas espectroscópicas de fluorescência de raios X por dispersão de energia (FRX-DE), Raman, e infravermelho com transformada de Fourier (FTIR), e com técnicas de imageamento como fotografia sob luz visível (VIS), luz rasante (RAS), luz transmitida (TRANS), fluorescência visível induzida por radiação ultravioleta (UV-VIS), reflectografia de infravermelho (RIV) e radiografia (RAD) fornecem importantes informações sobre o artista e sua obra. As técnicas analíticas não invasivas foram realizadas no próprio museu e com equipamentos portáteis do Laboratório de Arqueometria e Ciências Aplicadas ao Patrimônio Cultural (LACAPC) do Instituto de Física (IF) da USP. No geral, os resultados obtidos corroboram com os testemunhos de Campigli sobre o seu fazer artístico, assim como daqueles que o viram trabalhando no ateliê. A sua escolha de paleta, composta por pigmentos naturais e sintéticos, na sua maior parte brancos e tintas com tonalidades terrosas, e suas etapas produtivas de criar e recriar as pinturas, muitas vezes reutilizando telas, foram comprovadas através das investigações analíticas.

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Copyright of Universitas Scientiarum is the property of Pontificia Universidad Javeriana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Jules-Marie-Augustin Chautard (1826-1901), a French multifaceted scientist who started as a pharmacist and then turned physicist and coin collector. His main activities were related to phenomenon of light polarization, particularly in camphor and lavender, and the spectral study of chlorophyll. He showed that camphor appeared as dextro, levo, and racemic isomers, the same as tartaric acid, and demonstrated that these isomers could be obtained by chemical means. He postulated that a compound appearing in one isomeric form should also be present in the two other forms. He showed that the spectrum of chlorophyll possessed some typical lines, which allowed its detection down to one part in ten thousand, and also when mixed with other substances, fact that provided an important physiological and forensic tool. Together with Dessaignes they separated physalin, the active bitter component of the plant Chinese lantern (Physalis alkekengi). [ABSTRACT FROM AUTHOR]

Background: After more than half a century since the increase in the dumping of plastics in the oceans and other bodies of water, the damage caused by these products and their fractions has been verified. Its presence compromises the quality of the environment due to its prolonged permanence in the habitat and potential for the adsorption of substances and release of chemical compounds to the environment responsible for the durability of the plastic. Aims: This paper aims to gather information about the source, characterization, and interactions of micro- and nanoplastic in the environment and provide current material for those curious about this pollution. Methods: This review was conducted searching for papers on micro and nanoplastics on Science Direct, Springer, and Elsevier databases using keywords such as “microplastic”, “nanoplastic”, “sources”, “contamination”, “instruments”, “analysis,” and “ocean”. This review used only published works and comprise the last seven years of research on the topic from the date the review was initiated. The work is structured in the definition of micro and nanoplastics, main sources, levels of contamination, adsorption processes, and characterization techniques. Results: Degradation drives the main role in producing micro- and nanoplastic. Studies have reported interactions between microplastic and hydrophobic and hydrophilic compounds and demonstrated that microplastics can concentrate inorganic and organic compounds in several orders of magnitude, acting as vectors for co-pollutants in the environment. Discussion: Factors such as exposure time, pH, salinity, temperature, and adsorbate concentration directly affect MP-pollutant selection processes. The adsorption process might happen in presence of micro- and nanoplastic since organic pollutants have a high affinity with solid or particulate materials. Methodologies and quantification vary significantly among studies making it difficult to synthesize data. Conclusions: This study demonstrates that numerous techniques are being modified to characterize micro- and nanoparticles. However, standardizing analysis methodologies has proven challenging due to the nature of these particles and their nanometer-scale size. [ABSTRACT FROM AUTHOR]

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En este estudio se utilizan imágenes ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) para proporcionar información sobre la composición mineral en zonas de cultivo sin vegetación en un sector del noroeste de la cuenca del Duero. Se han aplicado distintos cocientes de bandas al conjunto de imágenes multiespectrales correspondientes a longitudes de onda del visible e infrarrojo cercano (VNIR, visible and near-infrared) y del infrarrojo de onda corta (SWIR, short-wave infrared), para realzar la presencia de óxidos de hierro y de filosilicatos principalmente. Los resultados obtenidos permiten reconocer que en las zonas caracterizadas por rocas del sustrato paleozoico, sedimentos neógenos y pliocuaternarios, los minerales con contenido en hierro están más representados. Por otra parte, en las zonas caracterizadas por sistemas de terrazas fluviales es más patente la presencia de filosilicatos alumínicos. Estos resultados añaden información a la cartografía geológica y, fundamentalmente, litológica y de prospección mineral de extensas áreas con formas del relieve suaves en donde los afloramientos son muy escasos.

El síndrome de Melas es una enfermedad de herencia mitocondrial caracterizada por encefalopatía mitocondrial, acidosis láctica y eventos similares a ataque cerebrovascular, secundaria a una mutación en los genes que codifican las proteínas transportadoras de electrones, limitando la producción energética y generando disfunción multiorgánica, que afecta principalmente el sistema músculo esquelético y el sistema nervioso, lo que está en correlación con las características clínicas que presentan los pacientes. El diagnostico se basa en la sospecha clínica, los hallazgos paraclínicos e imagenológicos y la confirmación de la mutación a través del estudio genético. No existe tratamiento específico, se basa únicamente en el manejo sintomático y requiere apoyo multidisciplinario. Presentamos el caso de un paciente con antecedente de Melas, que ingresó por evento cerebrovascular isquémico bioccipital y correlación con hallazgos en neuroimágenes (espectroscopia y tractografía).

Objetivou-se desenvolver e avaliar modelos de regressão para a predição da composição química da cana-de-açúcar, farelo de soja e fubá de milho por NIR portátil aliado a técnicas quimiométricas. Foram utilizadas 95 amostras de cana-de-açúcar, 92 amostras de farelo de soja e 120 amostras de fubá de milho. Após a moagem das amostras, foi realizada aquisição dos espectros de cada amostra. Os valores referência foram obtidos através de análises químicas convencionais. Para construção dos modelos, foi utilizada a regressão por quadrados mínimos parciais e a validação cruzada leave one out. Os modelos com menor raiz quadrada do erro quadrático médio da validação cruzada foram submetidos a validação externa. Para avaliar a qualidade de ajuste dos modelos, os valores preditos foram comparados com os valores obtidos pelos métodos laboratoriais convencionais. Os modelos construídos estimaram corretamente todos os constituintes avaliados para a cana-de-açúcar, farelo de soja e fubá de milho (P ≥ 0,056). Os modelos construídos para predição dos teores de amostra seca em estufa a 55°C (ASA) e a 105°C (ASE), matéria seca total (MS), matéria orgânica (MO), fibra insolúvel em detergente neutro (FDN), FDN corrigida para cinzas e proteína (FDNcp), proteína insolúvel em detergente neutro (PIDN), fibra insolúvel em detergente ácido (FDA), proteína bruta (PB), carboidratos não fibrosos (CNF) e nutrientes digestíveis totais (NDT) da cana-de-açúcar; ASE, MO, FDN, FDA, FDN indigestível (FDNi), PB, NDT e amido de farelo de soja; e ASE, PB do fubá de milho apresentaram elevada acurácia e precisão (R2 ≥ 0,50 e CCC ≥ 0,60). Contudo os modelos construídos para predição dos teores de cinzas insolúveis em detergente neutro (CIDN) da cana-de-açúcar; extrato etéreo (EE) e CIDN do farelo de soja; e FDN, FDNi, CIDN, CNF e EE do fubá de milho foram acurados, porém pouco precisos (R2 ≥ -0,04 e CCC ≥ 0,03). Conclui-se que os modelos de regressão por NIR portátil estimaram acuradamente e, portanto, são recomendados para estimar a composição química da cana-de-açúcar, farelo de soja e fubá de milho.

As escolas públicas brasileiras estão passando por um período de transformações devido à baixa qualidade do ensino. De acordo com o Índice de Desenvolvimento da Educação Básica (IDEB), desde 2011 não há um crescimento educacional no país, refletindo consequentemente no Ensino de Ciências, no qual o Brasil se encontra nas últimas posições de acordo com os dados obtidos pelo Programa Internacional de Avaliação dos Estudantes (PISA), ficando atrás de países vizinhos como a Argentina, Chile, Uruguai e Colômbia. Diante dessa realidade, o presente estudo tem o objetivo de propor uma sequência de ensino investigativa pautada nos os pressupostos do Ensino de Ciências por Investigação (ENCI), bem como a contribuição de Vygotsky, relacionando a experimentação de baixo custo para abordar um conteúdo de Física Moderna e Contemporânea. Essa sequência didática será proposta como contexto da educação básica para alunos da 3º Série do Ensino Médio, abordando a Espectroscopia. A proposta busca utilizar a experimentação numa perspectiva investigativa a fim de possibilitar uma aula mais interativa para os alunos, permitindo desenvolver habilidades relacionadas a Alfabetização Científica. Desta forma espera-se que a partir dos pressupostos do ENCI encontrados na sequência didática, ofereça uma participação mais ativa promovendo a Alfabetização Científica dos alunos no Ensino de Física no âmbito escolar.

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The structure, microstructure, thermal and mechanical properties of glasses and glass-ceramics in the LMAS (Li2O, MgO, Al2O3, SiO2) system and the effect of P2O5 and Al2O3 additives have been studied. The transition temperatures of both glasses and glass-ceramics increase with the P2O5 and Al2O3 concentration, but at high temperatures the melt viscosity decreases. The main crystalline phases formed are lithium aluminium silicate, enstatite and β-spodumene, being the growth of β-spodumene favoured by fluorine ions, P2O5 and the heat treatment temperature as well. Raman and FT-IR spectroscopies have shown the formation a silica-rich glass phase which acts as a matrix of the crystallites containing Al2O3 and P2O5 in its composition. The shape and aspect ratio of the crystallites depend on the Al2O3 concentration. For low Al2O3 concentration a variety of tubular, granular and plate-like crystals appear, while for high Al2O3 concentration the main shape of the crystals is spherical or globular. Hv, E and CTE properties are related to the crystalline phases formed during the crystallization treatment, and their variations are in accordance with the increase of the crystal aspect ratio. The CTE values of the GCs decrease as the P2O5 content increases up to 3%, while for the Al2O3 concentration of 16% the minimum CTE value is obtained. Hv and E values of the GCs are higher than those corresponding to their respective parent glasses. According to these values, these glasses and glass-ceramics are not appropriate for machining. Resumen: En este trabajo se ha estudiado el efecto del contenido en P2O5 y Al2O3 en vidrios y vitrocerámicos del sistema LMAS (Li2O, MgO, Al2O3, SiO2) en su estructura, microestructura y propiedades térmicas y mecánicas. La adición de estos dos óxidos produce el aumento de las temperaturas de transición tanto de los vidrios como de los vitrocerámicos correspondientes, sin embargo, la viscosidad a alta temperatura decrece. Las fases cristalinas que se forman son fundamentalmente silicato de litio-aluminio, enstatita y β-espodumena, donde el crecimiento de β-espodumena está favorecido por la presencia de iones F, P2O5 así como por la temperatura de tratamiento. Las espectroscopias Raman y FTIR han permitido detectar la formación de una fase vítrea rica en sílice que actúa como matriz de los cristales que contienen Al2O3 y P2O5 en su composición. La microestructura cristalina depende de la concentración de y Al2O3 en los vidrios. Para bajas concentraciones de Al2O3 se originan cristales con formas tubulares o con formas mientras que para altas concentraciones de Al2O3 los cristales tienen forma esférica o globular fundamentalmente. Los valores de HV, E y CTE están relacionados con las fases cristalinas formadas durante el tratamiento de cristalización, y sus variaciones están relacionados con el factor de forma de los cristales. Los valores de CTE de los vitrocerámicos disminuyen a medida que el contenido de P2O5 aumenta hasta un 3%, mientras que para la concentración de Al2O3 del 16% se obtiene el valor mínimo de CTE. Los valores Hv y E de los GC son más altos que los correspondientes a sus respectivos vidrios principales. Estos valores indican que estos materiales, tanto vidrios como vitrocerámicos, no son apropiados para ser mecanizados.

Objetivou-se, avaliar a similaridade espectral entre cultivares de sorgo em diferentes estádios de maturação dos grãos, visando o desenvolvimento de modelos utilizando espectroscopia de refletância no infravermelho próximo (NIRS). Para a ensilagem utilizou-se os sorgos BRS 658 e BRS Ponta Negra, em mini silos de PVC, nos estádios de maturação dos grãos leitoso, pastoso, farináceo e duro. As variáveis foram estudadas pela técnica de Análise de Componentes Principais (PCA), e classificação usando a Modelagem Independente por Analogia de Classe (SIMCA) utilizando o software Unscrambler. A similaridade de amostras da silagem do BRS 658 com o banco de dados do BRS Ponta negra foi de 5% e do BRS Ponta Negra em relação as do BRS 658 a similaridade foi de 65%. Os dados demonstram grande similaridade do BRS Ponta Negra entre os estádios dos grãos leitoso e pastoso. A análise da PCA, demonstrou uma semelhança entre as amostras no estádio leitoso das duas cultivares, no estádio leitoso com pastoso, farináceo e duro. A análise exploratória indica que é importante considerar a cultivar e os estádios de maturidade dos grãos para o desenvolvimento de modelos NIR de silagem de sorgo. A análise dos espectros NIR das cultivares BRS 658 e BRS Ponta Negra, bem como dos estádios de maturidade no momento da ensilagem indicam que as dissimilaridades observadas agregam variabilidade ao modelo, mas que, ao mesmo tempo, não são tão significativas a ponto de sugerirem desenvolvimento de modelos separados, permitindo a fusão dos dados para desenvolvimento de um único modelo NIR.

Tomatoes are the most commonly used and consumed vegetables, being acceptable for fresh consumption as well as for industrialization. Despite the wide acceptance of tomatoes, the consumer presents quality as a requirement for the acquisition of the fruit, which is measured through parameters such as soluble solids (SS) and titratable acidity (TA). A chemical analysis technique, non-destructive and non-invasive and with fast response, is an absorption spectroscopy in the near infrared region that has been widely used in several industries, from agricultural to petrochemicals. Demanding large-scale production, the quality of tomatoes demanded by consumers and as it is a non-destructive and noninvasive technique of near infrared spectroscopy (NIR), it is still necessary to test models under commercial conditions, ensuring a near infrared model for tomatoes making sorting easy. An external and practical validation of the near infrared models for fresh tomatoes was carried out, comparing them with the destructive methods and checking the accuracy of the models in qualifying the fruit in terms of soluble solids and acidity. This paper presents project models obtained from 2018 to 2019, built from the Model Builder and The Unscrambler programs and selected from parameters such as calibration coefficient, cross validation coefficient, average error of the calibration set, and cross validation and calculation of the residual calibration deviation. The results obtained through the prediction of the model for the soluble solid attributes and titratable acidity, of the table tomato with greater production variability. The model for SS of table tomato has potential for commercial use, either in determining the harvest point, or quantifying the vegetable's quality. For AT or portable NIR, it did not produce an applicable model due to the wavelength limitation. [ABSTRACT FROM AUTHOR]

ZnAl2O4 doped with various concentration (x) of Fe3+ were prepared using the Pechini synthesis. In the first set of samples, Fe3+ substituted Al3+ to create a system of the form ZnAl(2−x)Fex3+O4 (x = 0–0.08). To study the effect of charge compensation, Fe3+ substituted Zn2+ to create Zn(1−x)Fex3+Al2O4 (x = 0.05) system. The structure and particle morphology of the phosphors were studied using X-ray diffractometer (XRD) and field emission scanning electron spectroscopy, respectively. From the XRD data, the oxygen parameter and the inversion degrees were estimated. The elemental composition and electronic states of the phosphors were analyzed using X-ray photoelectron spectroscopy (XPS). XPS results showed that part of the Fe3+ were reduced to Fe2+ in the doped samples. Both photoluminescence and cathodoluminescence properties of the phosphors were also studied. Luminescence excitations using a xenon lamp and X-ray showed two broad emission bands located around 470 and 730 nm, and were ascribed to Fe ions occupying the tetrahedral (tet) and the octahedral (oct) sites in ZnAl2O4, respectively. A change in the lifetime of these two emission bands upon Fe doping further confirmed the existence of Fe in the tet and oct sites in the ZnAl(2−x)Fex3+O4 matrix. Resumen: Se preparó ZnAl2O4 dopado con varias concentraciones (x) de Fe3+ usando la síntesis de Pechini. En el primer conjunto de muestras, Fe3+ sustituyó Al3+ para crear un sistema de la forma ZnAl(2−x)Fex3+O4 (x = 0 a 0,08). Para estudiar el efecto de la compensación de carga, Fe3+ sustituyó Zn2+ para crear el sistema Zn(1−x)Fex3+Al2O4 (x = 0,05). La estructura y la morfología de las partículas de los fósforos se estudiaron utilizando un difractómetro de rayos X (XRD) y espectroscopía electrónica de barrido de emisión de campo, respectivamente. A partir de los datos XRD se estimaron el parámetro de oxígeno y los grados de inversión. La composición elemental y los estados electrónicos de los fósforos se analizaron mediante espectroscopía de fotoelectrones de rayos X (XPS). Los resultados de XPS mostraron que parte de Fe3+ se redujo a Fe2+ en las muestras dopadas. También se estudiaron las propiedades de fotoluminiscencia y catodoluminiscencia de los fósforos. Las excitaciones de luminiscencia usando una lámpara de xenón y rayos X mostraron dos amplias bandas de emisión ubicadas alrededor de 470 y 730 nm, y se atribuyeron a iones Fe que ocupan los sitios tetraédricos (tet) y octaédrico (oct) en ZnAl2O4, respectivamente. Un cambio en la vida útil de estas dos bandas de emisión después del dopaje con Fe confirmó aún más la existencia de Fe en los sitios tet y oct en la matriz ZnAl(2−x)Fex3+O4.

Nanoparticles are materials that measure from 1 to 100 nm of length. Currently, the antimicrobial property of silver nanoparticles is used by industries for the manufacture of beauty products and medicines. Nanoparticles can be synthesized from plants, algae or microorganisms, and they can also be obtained from combustion products. In this study, extracts of rosemary leaves (Rosmarinus officinalis L.) were used for the synthesis of silver nanoparticles (NPs-Ag) in order to produce an antimicrobial compound to be used as a fruit preservative. NPs-Ag were characterized qualitatively and quantitatively by phytochemical analysis and UV-VIS spectroscopy, showing an absorption in the range of 389-418 nm, which corresponds to their surface plasmon resonance. Furthermore, Scanning Electronic Microscopy was used to determine the size and morphology of the NPs-Ag, observing a spherical shape of 10 nm of diameter. Two bacterial strains were used in the antimicrobial tests, the Gram-negative (Escherichia coli) and the Gram-positive (Staphylococcus aureus) to verify the antimicrobial activity of the NPs-Ag. For E. coli, a better antibacterial activity was obtained with an inhibition halo of 3.21 mm. Subsequently, the NPs-Ag were used in apples to determine their use as a preservative, using beeswax smeared on the surface of the fruit as control, observing that synthesized NPs-Ag prolonged the maturation time of the fruits. [ABSTRACT FROM AUTHOR]

The prediction of soil properties through spectral information is widely discussed in the current scientific literature. The objective of this review was to find algorithms with the highest predictive potential for soil physicochemical properties based on spectral information captured with different instruments. A systematic review was carried out in which 121 articles were found, and 19 of them were chosen which met a determination coefficient greater than 0.80 or a root mean square error close to 0. It was determined that the most used spectral range corresponds to the range from 350 to 2500 nm; the partial least squares, support vector machine, and adjusted support vector machine algorithms are suitable for predicting pH, organic matter, and organic carbon. Furthermore, linear regression is only effective in predicting calcium carbonate, organic matter, moisture, and water content using individual bands. [ABSTRACT FROM AUTHOR]

The multispectral image analysis technique to detect chlorophyll fluorescence (CF) in soybean seeds was studied to assess the relationship between CF signals and seed physiological potential. Eight treatments, corresponding to 0%, 2%, 4%, 6%, 8%, 10%, 12%, and 14% green seeds, were used on two cultivars, BMX Desafio RR 8473 RSF and 96R10 IPRO, which passed through different seed quality tests. Initially, the CF of the seeds was determined using 660 nm and 730 nm spectra, and then the germination, electrical conductivity, accelerated aging with saturated NaCl solution, tetrazolium, and computerized seedling image analysis (Vigor-S) tests were performed on the same seeds. A completely randomized design was used, as well as replications of each treatment. Analysis of variance (ANOVA) was performed on the data from germination, vigor, and CF tests using the R® software, and the means were grouped by the Scott-Knott test (p = 0.05). Pearson's linear correlation coefficients (r) were calculated for all combinations among the evaluations with significance of the r values determined by the t-test (p = 0.05), and multivariate analysis of the principal components was performed. Proportional increases in green seeds contribute to an increase in chlorophyll fluorescence signals and have a negative correlation with seed physiological quality; levels above 4% green seeds in the samples result in marked losses in physiological potential. Therefore, the chlorophyll fluorescence detected through multispectral images is inversely related to the physiological potential of soybean seeds. [ABSTRACT FROM AUTHOR]

Amazonia contains the largest remnant of continuous forest on the planet. In Brazil, it represents nearly 45% of the territory but contributes little to the country's economy. This work discusses the use of jutaicica copal resin extracted from tree species of the genus Hymenaea (Fabaceae), which once represented a considerable part of the economy of Pará state. We present a review of its historical use, explore how and for what purpose the resin is extracted, and characterize it based on thermal and spectroscopic techniques. In western Pará state, jutaicica is gathered mainly from two species, H. courbaril and H. parvifolia, and in the past was used as a valuable source for varnish production. The resins from these species are distinctive according to thermal and spectroscopic methods. Thermal analysis shows H. courbaril might be a better source for polymer gathering. Infrared spectra can be accurately used to differentiate sources and demonstrate more uniformity in samples from H. courbaril, which is corroborated by the 13C-RMN spectra of the analyzed batches. Jutaicica is one of many non-timber forest products lacking investments for economic reintegration, an important contribution of income in extractive reserves, which play a key role in the conservation of Amazonia. [ABSTRACT FROM AUTHOR]

Urinary lithiasis has been reported as a problem that affects humankind since ancient times and has been described in several animal species. The condition is a consequence of other diseases that may be present in the urinary system or related to other body disorders. The stone composition needs to be analyzed to identify the possible causes that led to the formation and development of uroliths. For this, several techniques are currently available, some of which are promptly accessible, while others are not. Thus, this literature review aimed to perform a brief introduction on urolithiasis, present the most used techniques in the analysis of the composition of canine and feline uroliths and point out the advantages and disadvantages of each technique. [ABSTRACT FROM AUTHOR]

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O tomate é a hortaliça mais produzida e consumida, tendo aceitabilidade tanto para o consumo in natura quanto para a industrialização. Apesar da ampla aceitação dos tomates, o consumidor apresenta como exigência para aquisição do fruto a qualidade, mensurada através de parâmetros como sólidos solúveis (SS) e acidez titulável (AT). Uma técnica de análise química, não destrutiva e não invasiva e de resposta rápida, é a de espectroscopia de absorção na região do infravermelho próximo que tem sido bastante utilizada em várias indústrias, desde agrícola a petroquímica. Considerando a produção em alta escala, a qualidade do tomate exigida pelos consumidores e por se tratar de uma técnica não destrutiva e não invasiva da espectroscopia no infravermelho próximo (Near Infrared Spectroscopy – NIR), faz-se necessário modelos testados em condições comerciais garantindo um modelo de infravermelho próximo para tomate facilitando a classificação. Realizou-se a validação de forma externa e prática dos modelos de infravermelho próximo para tomate in natura, comparando com os métodos destrutivos e conferindo a acurácia dos modelos na qualificação do fruto quanto aos teores de sólidos solúveis e acidez. O presente trabalho apresenta modelos do projeto executado de 2018 a 2019, construídos através dos aplicativos Model Builder e The Unscrambler e selecionados a partir de parâmetros como coeficiente de calibração, coeficiente da validação cruzada, erro médio do conjunto de calibração, e da validação cruzada e cálculo do desvio do resíduo de calibração. Os resultados foram obtidos através da previsão do modelo para os atributos sólidos solúveis (SS) e acidez titulável (AT), do tomate de mesa com maior variabilidade de produção. O modelo para SS apresenta potencialidade para uso comercial, seja na determinação de ponto de colheita, seja na quantificação de qualidade do vegetal. Já para AT, o NIR portátil não produziu um modelo aplicável pela limitação do comprimento de onda.

En la literatura científica actual se discute ampliamente acerca de la predicción de propiedades edáficas mediante información espectral. El objetivo de esta revisión fue encontrar algoritmos con el mayor potencial predictivo para las propiedades fisicoquímicas del suelo, basados en información espectral capturada con diferentes instrumentos. Se realizó una revisión sistemática en la cual se encontraron 121 artículos de los cuales se eligieron 19, que cumplieran con un coeficiente de determinación mayor a 0,80 o una raíz del error cuadrado medio cercana a 0. Se determinó que el rango espectral más utilizado corresponde al rango desde 350 hasta 2500 nm; los algoritmos mínimos cuadrados parciales, máquina de soporte vectorial y máquina de soporte vectorial ajustado son adecuadas para predecir pH, materia orgánica y carbono orgánico. Además, la regresión lineal solo es efectiva para predecir el carbonato de calcio, materia orgánica, humedad y contenido de agua mediante bandas individuales.

Las nanopartículas son materiales que pueden llegar a medir entre 1 a 100 nm de longitud, y en la actualidad la propiedad antimicrobiana de las nanopartículas de plata es aprovechada por las industrias para la fabricación de productos de belleza y medicamentos. Las nanopartículas pueden ser sintetizadas a partir de plantas, algas o microorganismos, y también pueden ser obtenidas como productos de combustión. En este estudio se utilizaron extractos de las hojas de romero (Rosmarinus officinalis L.) para la síntesis de nanopartículas de plata (NPs-Ag) con la finalidad de producir un compuesto antimicrobiano para usarse como conservante de frutas. Las NPs-Ag se caracterizaron cualitativa y cuantitativamente mediante análisis fitoquímicos y espectroscopia UV-VIS, presentando una absorción en el rango de 389-418 nm, que corresponde a la resonancia de su plasmón superficial. Además, se empleó la microscopía electrónica de barrido para determinar el tamaño y morfología de las NPs-Ag, observándose una forma esférica de 10 nm de diámetro. Se emplearon dos cepas bacterianas en los ensayos antimicrobianos realizados, la gramnegativa (Escherichia coli) y la grampositiva (Staphylococcus aureus) para comprobar la actividad antimicrobiana de las NPs-Ag. Para E. coli se obtuvo una mejor actividad antibacteriana con un halo de inhibición de 3,21 mm. Posteriormente se usaron las NPs-Ag en manzanas para determinar su uso como conservante, usando la cera de abeja como control untada en la superficie de las frutas, observándose que las nanopartículas sintetizadas alargaron el tiempo de maduración de la frutas.

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Eugène Anatole Demarçay (1852-1904), a French chemist who discovered the element europium and identified the presence of radium in a radioactive mixture provided by Marie and Pierre Curie; synthesized a variety of organic compounds of titanium and of tin, among them, those resulting from the reaction of titanium chloride with a variety of esters of organic monoacids. He proved that the essence of chamomile was a mixture of several esters, mainly butyl and amyl valerate and angelate, and not a mixture of aldehydes. He studied the compounds of nitrogen and sulfur, among them the nitrogen sulfide chlorosulfates, and described their properties. Developed an apparatus for determining the spectrum of rare earths and radioactive elements based on the spark produced by an induction coil provided with a short and thick platinum wire, and used it to propose a method for their separation by fractionation. He also determined the presence of molybdenum and vanadium in vegetables, etc. [ABSTRACT FROM AUTHOR]

Physicochemical interactions between a polymeric matrix and an anesthetic solution were investigated as a potential material for local dressings. Different types of hydrogels were synthesized: from polyacrylamide (PAAm), from modified PAAm with NaOH (forming polyelectrolytic networks, product of basic hydrolysis) and finally, hydrogels from semiinterpenetrated networks (semi-IPN) of PAAm/poly (vinyl alcohol), (synthesized in ratios PAAm/PVA 90/10 and 60/40 %m/m). The xerogels were loaded with the local anesthetic lidocaine hydrochloride, their chemical structure and the absorption of lidocaine was characterized by Fourier transform infrared spectroscopy (FTIR), while the hydrogels' ability to release anesthesia was monitored by UV spectrometry. The hydrolyzed hydrogels expanded three times more in lidocaine than the other hydrogels, the FTIR indicated that carboxylate groups formed during the hydrolysis process, which favored the expansion of the network. In the semi-IPN PAAm/PVA hydrogels the swelling decreased at higher concentrations of the fed PVA. Consequently, by increasing the concentration of PVA in the network from 10 to 40% m / m, the concentration of lidocaine released was lower and the elution rate was 5 times slower, achieving the release of 242.06 mg·L-1 after 240 min. [ABSTRACT FROM AUTHOR]

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Antecedentes: la ideación combina la creatividad y el análisis de pensamiento para el desarrollo acertado de un software. Su importancia radica en que encuentra el punto de equilibrio entre los usuarios potenciales‚ los desarrolladores y las necesidades de la empresa. La ideación es una etapa crucial cuando se deben generar análisis estadísticos con grandes volúmenes de datos (ej. datos hiperespectrales) y cuando hay diferentes niveles de usuarios (ej‚ investigadores‚ estudiantes‚ productores). Objetivo: idear una plataforma interactiva y escalable para la gestión de conocimiento en el uso de información hiperespectral para el análisis de diferentes tipos de muestras‚ insumos y productos agropecuarios. Métodos: para identificar las necesidades del proyecto‚ se realizó un estudio previo mediante una revisión bibliográfica para determinar la tecnología y herramientas más adecuadas para su desarrollo. Esto generó un paso a paso para la elaboración de una plataforma que permita cubrir las necesidades del proyecto. Resultados: se definió que Python es el lenguaje más apropiado para la elaboración de la plataforma. También se identificaron los pasos necesarios para el desarrollo de esta‚ como la recopilación de la información y materiales necesarios para la enseñanza de imágenes hiperespectrales de forma didáctica‚ el diseño de la interfaz y la programación de las funciones necesarias. Conclusión: los resultados obtenidos en la ideación indicaron que es posible generar un prototipado y evaluar una herramienta interactiva‚ escalable y adaptable que pueda crecer con el tiempo y permita a los usuarios aprender sobre imágenes hiperespectrales de forma interactiva y efectiva. [ABSTRACT FROM AUTHOR]

Antecedentes: el método de espectroscopía de infrarrojo cercano (NIRS), es una alternativa para realizar análisis de suelo, ya que es un método rápido, no destructivo, sencillo y preciso, que relaciona la radiación infrarroja cercana difusamente reflejada con las propiedades físicas y químicas del suelo. Objetivo: desarrollar modelos estadísticos para predecir los parámetros de textura (T) y pH, con el uso de NIRS. Métodos: para ello se utilizaron 1880 muestras de suelos de sistemas de producción del departamento de Antioquia las cuales fueron analizadas por el método de Bouyoucos para T y el método potenciómetro con electrodo de vidrio y suelo para pH. Estas muestras también fueron escaneadas en un equipo NIRS modelo FOSS DS 2500 en un rango de longitud de onda de 850 a 2500 nm. Luego de obtener la información espectral se procedió a realizar el análisis estadístico de mínimos cuadrados parciales (PLS) y se aplicaron algunas transformaciones como señal multiplicativa corregida (MSC) la cual fue aplicada a los espectros, mientras que logaritmo y raíz cuadrada fueron aplicadas a las variables. Resultados: para el total de las muestras analizadas los resultados para el parámetro pH fueron positivos, obteniendo un coeficiente de determinación (R2) alto (0,69), siendo el mejor modelo PLS, mientras que para el parámetro textura (arcilla, limo y arena) se obtuvo resultados no favorables debido a que los R2 fueron bajos (de 0,46, 0,44 y 0,21) para arcilla, limo y arena, respectivamente). Conclusiones: se puede predecir con NIRS el pH del suelo, mientras que el parámetro textura requiere de otros modelos más avanzados o de otras técnicas. [ABSTRACT FROM AUTHOR]

The Danish physicist Niels Bohr (1885-1962) is known by physicists and chemists because of his atomic model, which was relevant to develop quantum theory and theoretical chemistry. His contributions are usually presented in a simplistic way in most of the science didactic materials, especially those aimed at basic school. Most of the time, the view of a history that is linear, elitist, neutral, naive, and producer of irrefutable evidence is reinforced through a single universal method. Such conceptions end up fostering a stereotyped and naive view of science, in contradiction with specialized literature recommendations and official documents that suggest a critical training about scientific knowledge and its development. With this in mind, in this article, we present an alternative approach to narratives present in didactic materials, especially in the context of initial teacher training. We emphasize little known atomic models, personal aspects of scientists, and some elements of spectroscopy development when elaborating some atomic models at the beginning of the 20th century, emphasizing Niels Bohr's contributions. We present the theoretical and methodological assumptions used to delimit a historical approach and to prepare a historiographic narrative. This result aims at offering elements to support teacher educators regarding the use of a historical approach to science, in order to promote, in their future professional practice, the teaching and learning of scientific concepts and reflections on scientific practice.

Objetivos: Revisar os achados de imagem característicos na doença de Tay-Sachs, um distúrbio autossômico recessivo raro. Metodologia: Relato de caso de um paciente do sexo masculino, de 1 ano e 6 meses de idade, com atraso no desenvolvimento neuropsicomotor e convulsões, que realizou exames de imagem no nosso serviço. Resultados: A tomografia computadorizada de crânio revelou, como principal achado, hiperdensidade espontânea nos tálamos, além de hipodensidade simétrica e difusa na substância branca supratentorial. A ressonância magnética de crânio mostrou alteração de sinal na substância branca nas imagens ponderadas em T2, com hipersinal na substância branca periventricular, profunda e subcortical, núcleos da base, cápsulas internas, externas e extremas, com preservação relativa do corpo caloso. Além disso, foi observado hipersinal espontâneo em T1 nos tálamos. Os corpos estriados exibiam volumes aumentados, com múltiplos focos puntiformes hipotensos em T2 (aparência manchada/salpicada). A espectroscopia de prótons revelou diminuição da razão N-acetil aspartato (NAA)/creatina (Cr) e aumento da proporção de mioinositol (mI)/Cr. A fundoscopia demonstrou manchas vermelhas maculares (cherry red spots). Conclusões: A doença de Tay-Sachs está associada a alterações de imagem fortemente sugestivas, podendo ser corroborado pela espectroscopia, devendo ser reconhecidas pelo médico radiologista para adequado diagnóstico diferencial das doenças neurológicas hipomielinizantes da infância.

El presente estudio da a conocer los resultados de los análisisno invasivosde colorimetría y espectroscopía de reflectancia visible llevados a cabo por primera vez sobre cinco ejemplos de escultura románica en mármol del Museo Arqueológico Nacional (Madrid) de procedencia gallega y leonesa. En concreto se han analizado dos columnas de San Paio de Antealtares (Santiago de Compostela), un parteluz de Vigo, y dos ejemplos procedentes del monasterio de San Benito de Sahagún (León). The present study reveals the results of the non-invasive analysis of colorimetry and visible reflectance spectroscopy, carried out for the first time to five examples of Spanish Romanesque marble sculpture from the National Archaeological Museum (Madrid, Spain) of Galician and Leonese origin. Specifically, two columns of San Paio de Antealtares (Santiago de Compostela), a mullion from Vigo, and two examples from the monastery of San Benito de Sahagún (León) have been analyzed.