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A Realidade Aumentada (RA) está cada vez mais acessível ao grande público. O amadurecimento da tecnologia em combinação com o barateamento dos dispositivos móveis tornou popular a experiência com RA. Paulatinamente, essa tecnologia vem sendo usada para fins educativos. O presente trabalho apresenta um jogo com recursos de RA para apoiar o aprendizado de isomeria. O aplicativo está estruturado em um jogo de seis perguntas e respostas e mais três questões que solicitam ao aluno construir uma molécula. O jogo foi experimentado com 35 voluntários entre 17 e 60 anos. Devido às restrições sanitárias quanto ao COVID ainda não foi possível testar com alunos do ensino médio. Com a avaliação foi possível concluir a possibilidade de usar o jogo em sala de aula. A maior contribuição do trabalho é a ideia validada do jogo com possíveis aplicações em sala de aula, fomentando o uso desse tipo de aplicativo nas aulas de química.

High-resolution electrospray ionization ion mobility mass spectrometry has revealed a gas-phase isomer of the ubiquitous, extremely well-studied Au25(SR)18 cluster both in anionic and cationic form. The relative abundance of the isomeric structures can be controlled by in-source activation. The measured collision cross section of the new isomer agrees extremely well with a recent theoretical prediction (Matus, M. F.; et al. Chem. Commun. 2020, 56, 8087) corresponding to a Au25(SR)18– isomer that is energetically close and topologically connected to the known ground-state structure via a simple rotation of the gold core without breaking any Au–S bonds. The results imply that the structural dynamics leading to isomerization of thiolate-protected gold clusters may play an important role in their gas-phase reactions and that isomerization could be controlled by external stimuli. peerReviewed

Photoactivation of bacteriophytochrome involves a cis–trans photoisomerization of a biliverdin chromophore, but neither the precise sequence of events nor the direction of the isomerization is known. Here, we used nonadiabatic molecular dynamics simulations on the photosensory protein dimer to resolve the isomerization mechanism in atomic detail. In our simulations the photoisomerization of the D ring occurs in the counterclockwise direction. On a subpicosecond time scale, the photoexcited chromophore adopts a short-lived intermediate with a highly twisted configuration stabilized by an extended hydrogen-bonding network. Within tens of picoseconds, these hydrogen bonds break, allowing the chromophore to adopt a more planar configuration, which we assign to the early Lumi-R state. The isomerization process is completed via helix inversion of the biliverdin chromophore to form the late Lumi-R state. The mechanistic insights into the photoisomerization process are essential to understand how bacteriophytochrome has evolved to mediate photoactivation and to engineer this protein for new applications. peerReviewed

En este video se clasifican los distintos tipos de isomería, centrándose en la isomería estructural de cadena, función y posición., Introducción a la isomería en cualquier curso de iniciación a la química orgánica

Photoactivation in the Photoactive Yellow Protein, a bacterial blue light photoreceptor, proceeds via photo-isomerization of the double C=C bond in the covalently attached chromophore. Quantum chemistry calculations, however, have suggested that in addition to double bond photo-isomerization, the isolated chromophore and many of its analogues, can isomerize around a single C-C bond as well. Whereas double bond photo-isomerization has been observed with x-ray crystallography, experimental evidence for single bond photo-isomerization is currently lacking. Therefore, we have synthesized a chromophore analogue, in which the formal double bond is covalently locked in a cyclopentenone ring and carried out transient absorption spectroscopy experiments in combination with non-adiabatic molecular dynamics simulations to reveal that the locked chromophore isomerizes around the single bond upon photo-activation. Our work thus provides experimental evidence for single bond photo-isomerization in a photoactive yellow protein chromophore analogue and suggests that photo-isomerization is not restricted to the double bonds in conjugated systems. This insight may be useful for designing light-driven molecular switches or motors. peerReviewed

O uso de jogos lúdicos no ensino de Química constitui-se em uma metodologia que pode atrair e motivar os alunos. Estudos concluíram que o conteúdo de Química, ao se aproximar do cotidiano e trabalhado de maneira dinâmica, faz com que o discente melhore seu desempenho. Sendo assim, este trabalho apresenta uma prática de ensino de Química em que foi confeccionado e aplicado o jogo “Isomeria em Ação” para alunos de uma escola estadual localizada no município de Barbacena, Minas Gerais. Constatou-se que o uso de jogos didáticos no cotidiano escolar se mostra eficiente, pois os mesmos geram impactos positivos no tocante à socialização, à cooperação e, sobretudo, à aprendizagem. Portanto, é plausível considerar que o uso de jogos em sala de aula, desde que acompanhado de uma metodologia adequada, possibilita ao estudante participar ativamente do processo de construção do conhecimento, complementando o conteúdo teórico com o lúdico; ou seja, aliando teoria e prática.

Isomeric bis(aldiminium) salts with a 1,4-cyclohexylene framework were synthesized. The first isolable bis(CAAC) was prepared from the trans-stereoisomer and its ditopic ligand competency was proven by conversion to iridium(I) and rhodium(I) complexes. Upon deprotonation, the cis-isomer yielded an electron rich olefin via a classic, proton-catalyzed pathway. The C[double bond, length as m-dash]C bond formation from the desired cis-bis(CAAC) was shown to be thermodynamically very favorable and to involve a small activation barrier. Compounds that can be described as insertion products of the cis-bis(CAAC) into the E–H bonds of NH3, CH3CN and H2O were also identified. peerReviewed

The use of metal nanoclusters is strongly reliant on their size and configuration; hence, studying the potential isomers of a cluster is extremely beneficial in understanding their performance. In general, the prediction and identification of isomer structures and their properties can be challenging and computationally expensive. Our work describes an investigation to find local isomers for the previously experimentally characterized small gold cluster [Au6(NHC-S)4]2+ protected by bidentate mixed carbene-thiolate ligands. We employ the molecular dynamics simulation method where the interatomic forces are calculated from density functional theory. We find several isomers that are more stable than the isomer corresponding to the experimental crystal structure, as well as a significant impact of the finite-temperature atom dynamics on the electronic structure and optical properties. Our work highlights the growing need to investigate ligand-stabilized metal clusters to uncover isomerism and temperature effects on their properties. peerReviewed

We demonstrate herein the capacity of simple carboxylate salts – tetrametylammonium and tetramethylguanidinium pivalate – to act as catalysts in the isomerization of β,γ-unsaturated thioesters to α,β-unsaturated thioesters. The carboxylate catalysts gave reaction rates comparable to those obtained with DBU, but with fewer side reactions. The reaction exhibits a normal secondary kinetic isotope effect ( k 1H / k 1D = 1.065±0.026) with a β,γ−deuterated substrate. Computational analysis of the mechanism provides a similar value ( k 1H / k 1D = 1.05) with a mechanism where γ-reprotonation of the enolate intermediate is rate determining. peerReviewed

Decay spectroscopy of the odd-proton nuclei $^{249}$Md and $^{251}$Md has been performed. High-K isomeric states were identified for the first time in these two nuclei through the measurement of their electromagnetic decay. An isomeric state with a half-life of 2.8(5) ms and an excitation energy $\ge 910$ keV was found in $^{249}$Md. In $^{251}$Md, an isomeric state with a half-life of 1.4(3) s and an excitation energy $\ge 844$ keV was found. Similarly to the neighbouring $^{255}$Lr, these two isomeric states are interpreted as 3 quasi-particle high-K states and compared to new theoretical calculations. Excited nuclear configurations were calculated within two scenarios: via blocking nuclear states located in proximity to the Fermi surface or/and using the quasiparticle Bardeen–Cooper–Schrieffer method. Relevant states were selected on the basis of the microscopic-macroscopic model with a deformed Woods–Saxon potential. The most probable candidates for the configurations of K-isomeric states in Md nuclei are proposed. Decay spectroscopy of the odd-proton nuclei $^{249}$Md and $^{251}$Md has been performed. High-$K$ isomeric states were identified for the first time in these two nuclei through the measurement of their electromagnetic decay. An isomeric state with a half-life of $2.8(5)$ ms and an excitation energy $\geq 910$ keV was found in $^{249}$Md. In $^{251}$Md, an isomeric state with a half-life of $1.4(3)$ s and an excitation energy $\geq 844$ keV was found. Similarly to the neighbouring $^{255}$Lr, these two isomeric states are interpreted as 3 quasi-particle high-$K$ states and compared to new theoretical calculations. Excited nuclear configurations were calculated within two scenarios: via blocking nuclear states located in proximity to the Fermi surface or/and using the quasiparticle Bardeen-Cooper-Schrieffer method. Relevant states were selected on the basis of the microscopic-macroscopic model with a deformed Woods-Saxon potential. The most probable candidates for the configurations of $K$-isomeric states in Md nuclei are proposed.

In this work, we sought to bring Larry Laudan's epistemology, which presupposes that scientific progress is based on Problem Solving, closer to the subject of Isomerism, a research carried out by Jacob Berzelius. This theme is relevant in the study of Organic Chemistry, as isomerism is a common phenomenon and portrays the diversity of organic molecules that have the same molecular formula, but different structural properties and characteristics. However, its teaching in the classroom has been occurring in a fragmented way due to the difficulty found by teachers and students in developing the necessary abstraction to understand its most diverse representations. This work aims from the understanding of the importance and effectiveness of the discovery made by Berzelius, related to Larry Laudan's epistemology, to provide that the subject Isomerism can be approached in the classroom in a more understandable way, seeking, in this way, to minimize the difficulties between teaching and learning. En este trabajo se buscó acercar la epistemología de Larry Laudan, que presupone que el progreso científico se basa en la Resolución de Problemas, al tema de Isomeria, un trabajo de investigación realizado por Jacob Berzelius. Este tema es relevante en el estudio de la Química Orgánica, ya que la isomería es un fenómeno común y retrata la diversidad de moléculas orgánicas que tienen la misma fórmula molecular, pero tienen diferentes propiedades y características estructurales. Sin embargo, su enseñanza en el aula se viene dando de forma fragmentada debido a la dificultad que encuentran docentes y alumnos para desarrollar la abstracción necesaria para comprender sus más diversas representaciones. El objetivo es desde la comprensión de la importancia y efectividad del descubrimiento hecho por Berzelius, relacionado con la epistemología de Larry Laudan, para proporcionar que el tema Isomeria pueda ser abordado en el aula de una manera más comprensible, buscando, de esta manera, minimizar las dificultades entre la enseñanza y el aprendizaje. Neste trabalho buscou-se aproximar a epistemologia de Larry Laudan, que traz como pressuposto que o progresso científico está baseado na Resolução de Problemas, ao assunto de Isomeria, trabalho de pesquisa realizado por Jacob Berzelius. Este tema tem relevância no estudo da Química Orgânica, pois a isomeria é um fenômeno comum e retrata a diversidade de moléculas orgânicas que apresentam a mesma fórmula molecular, mas com propriedades e características estruturais diferentes. No entanto, seu ensino em sala de aula vem ocorrendo de forma fragmentada devido à dificuldade encontrada por professores e alunos em desenvolver a abstração necessária para compreender as suas mais diversas representações. Objetiva-se, a partir da compreensão da importância e da efetividade da descoberta realizada por Berzelius, relacionada à epistemologia de Larry Laudan, proporcionar que o assunto Isomeria possa ser abordado em sala de aula de forma mais compreensível, procurando, desta forma, minimizar as dificuldades entre o ensino e a aprendizagem.

External electric fields (EEFs) have proven to be very efficient in catalysing chemical reactions, even those inaccessible via wet-chemical synthesis. At the single-molecule level, oriented EEFs have been successfully used to promote in situ single-molecule reactions in the absence of chemical catalysts. Here, we elucidate the effect of an EEFs on the structure and conductance of a molecular junction. Employing scanning tunnelling microscopy break junction (STM-BJ) experiments, we form and electrically characterize single-molecule junctions of two tetramethyl carotene isomers. Two discrete conductance signatures show up more prominently at low and high applied voltages which are univocally ascribed to the trans and cis isomers of the carotenoid, respectively. The difference in conductance between both cis-/trans- isomers is in concordance with previous predictions considering π-quantum interference due to the presence of a single gauche defect in the trans isomer. Electronic structure calculations suggest that the electric field polarizes the molecule and mixes the excited states. The mixed states have a (spectroscopically) allowed transition and, therefore, can both promote the cis-isomerization of the molecule and participate in electron transport. Our work opens new routes for the in situ control of isomerisation reactions in single-molecule contacts.

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues. Em 1831, o prestigiado químico Jacob Berzelius introduziu o conceito de isómeros: Compostos que possuem os mesmos átomos nas mesmas proporções, mas em que esses átomos se ligam uns aos outros de diferentes formas (diferentes arranjos entre eles). O exemplo discutido à época foi o ácido fulmínico (H-C=N-O) (sais deste ácido são usados como detonadores primários) e o ácido ciânico (H-O-C N) (líquido incolor e venenoso). O conceito de isomeria permanece como essencial em química tendo ao longo dos anos sido aprofundado e alargado, sendo possível encontrar na natureza e no laboratório um largo conjunto de exemplos de compostos isómeros com propriedades e aplicações práticas muito distintas. […]. info:eu-repo/semantics/publishedVersion

A new β-decaying state in 214Bi has been identified at the ISOLDE Decay Station at the CERN-ISOLDE facility. A preferred Iπ = (8−) assignment was suggested for this state based on the β-decay feeding pattern to levels in 214Po and shell-model calculations. The half-life of the Iπ = (8−) state was deduced to be T1/2 = 9.39(10) min. The deexcitation of the levels populated in 214Po by the β decay of this state was investigated via γ -γ coincidences and a number of new levels and transitions was identified. Shell-model calculations for excited states in 214Bi and 214Po were performed using two different effective interactions: the H208 and the modified Kuo-Herling particle interaction. Both calculations agree on the interpretation of the new β-decaying state as an Iπ = 8− isomer and allow for tentative assignment of shell-model states to several high-spin states in 214Po. peerReviewed

Não recebi financiamento Historically, the traditional approach about contents has been criticized for its limitations regarding to the scientific knowledge. In this conception, Science is decontextualized and uncritical. Therefore, the teaching and learning contribute just a little to keep the interest and motivation in students. In this sense, this research aimed to identify the evidence of learning about isomerism in organic compounds, based on the execution of the educational game called ISOGAMES, based on problem solving and interdisciplinarity. The interest in the study of the theme arose from the analysis of my own practice, because, several times, the students had difficulty understanding concepts related to isomerism. Thus, this research was guided by the following question: Which evidences of learning, about isomerism in organic compounds, can be identified, through the execution of the educational game ISOGAMES, based on problem solving and interdisciplinarity? To get to this, the qualitative research involved the participation of forty sophomore high students of the full time Chemistry course, in one of the Technical Schools (ETECs) in the state´s countryside of São Paulo. The game itself was used for obtaining and analyzing the datas themselves; it was used Concept Maps (MCs) to the themes like adrenaline, aspartame, trans fat and vitamin C; the speeches of the involved ones and the answers to the problem questions. To identify the evidence of learning were analyzed the MCs built by the participants and, using the same resource were created MCs for each of the themes. It was indentified three categories, namely: development of criticality; disciplinary conceptual understanding (isomerism; enantiomers) and, finally, construction of interdisciplinary and contextual meanings about isomerism in organic compounds. The results indicated that the educational game ISOGAMES revealed contribution and potential for learning concepts about isomerism in organic compounds, since it was conceived from an interdisciplinary and investigative perspective. As an educational product resulting from this Dissertation, this game reflects the relationship between theory and practice and the breaking of disciplinary boundaries. Historicamente, a abordagem tradicional dos conteúdos vem sendo criticada por sua limitação no que diz respeito ao conhecimento científico. Nessa concepção, a Ciência é descontextualizada e acrítica. Por isso, o processo de ensino e aprendizagem pouco contribui para gerar interesse e motivação nos estudantes. Nesse sentido, a presente pesquisa teve por objetivo identificar os indícios de aprendizagem sobre a isomeria em compostos orgânicos, a partir da execução do jogo didático ISOGAMES, fundamentado na resolução de problemas e na interdisciplinaridade. O interesse pelo estudo do tema surgiu a partir da análise da própria prática pela professora, pois, diversas vezes, os estudantes apresentaram dificuldade de entender conceitos relacionados à isomeria. Dessa forma, esta pesquisa foi balizada com a seguinte questão: Quais indícios de aprendizagem, sobre a isomeria em compostos orgânicos, podem ser identificados, por meio da execução do jogo didático ISOGAMES, fundamentado na resolução de problemas e na interdisciplinaridade? Para tanto, a pesquisa do tipo qualitativa, envolveu a participação de quarenta estudantes do segundo ano do curso de Química integrado ao ensino médio, em uma das Escolas Técnicas (ETECs) do interior do Estado de São Paulo. Utilizamos como instrumentos para obtenção e análise dos dados o próprio jogo; os Mapas Conceituais (MCs) sobre as temáticas adrenalina, aspartame, gordura trans e vitamina C; as falas dos participantes e as respostas das questões-problema. Para identificarmos os indícios de aprendizagem, analisamos os MCs construídos pelos participantes e, a partir do mesmo recurso, criamos MCs para cada uma das temáticas. Identificamos três categorias, a saber: desenvolvimento da criticidade; entendimento conceitual disciplinar (isomeria; enantiômeros) e, por fim, construção de significados interdisciplinares e contextuais sobre a isomeria em compostos orgânicos. Os resultados indicaram que o jogo didático ISOGAMES revelou contribuição e potencial para a aprendizagem de conceitos sobre a isomeria em compostos orgânicos, já que foi concebido a partir de uma perspectiva interdisciplinar e investigativa. Por ser um produto educacional decorrente desta Dissertação, este jogo reflete a relação teoria e prática e a quebra das fronteiras disciplinares.

The frequency and substantial morbimortality of invasive hospital infections caused by Candida spp. stimulate interest in the research of new antifungal drugs that may improve this scenario, which is partly a reflection of the ineffectiveness that current antifungals have shown in recent decades due to resistance mechanisms imposed by these yeasts. Terpenes consist of one of the natural product classes, precursor of numerous biologically active molecular compounds that have already led to the development of drugs. Of the monoterpenes, β-citronelol has shown numerous pharmacological properties that highlights it as a possible candidate for drugs for various therapeutic purposes. However, this compound presents optical isomery and little is studied about the behavior of its isomers in biological environments. In view of these premises, the antifungal, cytotoxic and mutagenic activity of monoterpenes R - (+) - β-citronellol and S - (-) - β-citronellol was evaluated. Several microbiological assays were performed in vitro against Candida albicans and Candida tropicalis strains to evaluate its antifungal performance. The tests used were: determination of the Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), growth kinetics, mechanism of action, association and inhibition of biofilm formation. For the in vitro study of toxic effects, the following were performed: analysis of cell hemolysis of the ABO system to verify cytotoxic behavior and quantification of nuclear alterations in human oral mucosa cells to analyze the performance of these isomers as genotoxic/mutagenic agents. In the anti-Candida spp. activity assays, both isomers presented MIC50% of 64 μg/mL and MFC50% of 256 μg/mL for Candida albicans. For Candida tropicalis strains, the isomers exhibited a MIC50% of 256 μg/mL and a MFC50% of 1024 μg/mL. The antifungal activity displayed was of fungicidal nature without any statistical difference between the results. Growth kinetics showed that the higher the concentration used of these monoterpenes, the lower the time required to prevent the colony formation. The isomers acted in these cells causing damage to the fungal membrane. The association with amphotericin B demonstrated different effects between the analyzed fungal strains. However, the synergism and aditivity found suggest that the compounds can be used to reduce the fungal resistance of planktonic cells and the formation of biofilm, since all subinhibitory concentrations inhibited the development of this mechanism of virulence and resistance. Regarding the toxic behavior, it was found that both isomers have low cytotoxicity on the erythrocytes of the ABO system. This low hemolytic activity is not due to any kind of protective mechanism in the surface of erythrocytes, but rather because of the simple fact that these substances are not toxic. In addition, isomers caused very few nuclear changes, which makes them compounds with little genotoxic/mutagenic capacity. Thus, due to the antifungal activity and low toxic potential that these isomers presented, these can be considered as candidates for the development of new antifungal therapeutic alternatives, provided that more detailed studies are carried out to make the bioactivity and toxicity profiles of R and S - β - citronellol more solid against Candida species Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES A frequência e a morbimortalidade substancial de infecções invasivas provocadas por Candida spp. em ambientes hospitalares, estimulam o interesse na pesquisa de novos fármacos antifúngicos que possam melhorar, este cenário, que em parte é o reflexo da ineficácia que os antifúngicos vem mostrando nas últimas décadas em decorrência a mecanismos de resistência impostos por essas leveduras. Os terpenos consistem em uma das classes de produtos naturais, precusora de inúmeros compostos moleculares biologicamente ativos que já conduziram ao desenvolvimento de fármacos. Dos monoterpenos, o β-citronelol vem mostrando uma série de inúmeras propriedades farmacológicas que o destaca como um possível candidato a fármaco com finalidades terapêuticas diversas. No entanto, este composto revela enantiomeria e pouco é estudado sobre o comportamento de seus isômeros em ambientes biológicos. Diante dessas premissas, buscou-se avaliar a atividade antifúngica, citotóxica e mutagênica dos monoterpenos R - (+) - β-citronelol e S - (-) - β-citronelol. Vários ensaios microbiológicos foram realizados in vitro contra linhagens de Candida albicans e Candida tropicalis para avaliar o desempenho como antifúngico. Os ensaios utilizados foram: determinação da Concentração Inibitória Mínima (CIM), Concentração Fungicida Mínima (CFM), cinética de crescimento, estudo de mecanismo de ação, associação e inibição da formação de biofilme. Já para o estudo in vitro dos efeitos tóxicos, foram realizados: análise de hemólise de células do sistema ABO para verificar o comportamento citotóxico e quantificação das alterações nucleares em células de mucosa oral humana, para analisar o desempenho desses isômeros como agentes genotóxicos/mutagênicos. Nos ensaios de atividade anti-Candida spp. ambos os isômeros, apresentaram CIM50% de 64 μg/mL e CFM50% de 256 μg/mL para as linhagens de Candida albicans e para Candida tropicalis, os isômeros exibiram um CIM50% de 256 μg/mL e um CFM50% de 1024 μg/mL. A atividade antifúngica exibida foi do tipo fungicida e sem diferença estatística entre eles. A cinética de crescimento mostrou que quanto maior a concentração utilizada desses monoterpenos menor é o tempo necessário para impedir o processo de formação de colônias. Os isômeros atuaram nessas células por provocar danos a membrana fúngica. A associação com anfotericina B demonstraram efeitos diferentes entre as linhagens fúngicas analisadas. No entanto, o sinergismo e a aditividade constatados sugerem que os compostos podem ser utilizados para reduzir a resistência fúngica de células planctônicas e a formação de biofilme, já que todas as concentrações subinibitórias inibiram o desenvolvimento desse mecanismo de virulência e resistência. No que diz respeito, ao comportamento tóxico, foram constatados que ambos os isômeros tem baixa capacidade citotóxica sobre os eritrócitos do sistema ABO. Sendo que a baixa atividade hemolítica, está por nenhum tipo de mecanismo protetivo a superfície dos eritrócitos, mas sim, pelo simples fato das substâncias não se mostrarem tóxicas. Além disso, os isômeros causaram poucas alterações nucleares, o que permitiu configurá-los como compostos com pouca capacidade genotóxico/mutagênica. Desta forma, em virtude da atividade antifúngica e baixo potencial tóxico que esses isômeros apresentaram, estes podem ser considerados como candidatos ao desenvolvimento de novas alternativas terapêuticas antifúngicas, desde que, estudos mais detalhados sejam realizados para tornar mais sólido os perfis de bioatividade e toxicidade do R e S - β - citronelol frente as espécies de Candida

La obra está orientada a la temática de la Química Orgánica aplicada a las Ciencias Forestales, Agrarias y Naturales desde una mirada integradora que involucra la resolución de problemas. Se presentan ejercicios y problemas sobre distintos aspectos de la Química Orgánica, nomenclatura, la estructura molecular, la isomería y las características y propiedades de las distintas familias de compuestos orgánicos., Facultad de Ciencias Agrarias y Forestales

The regioselective synthesis of cis and trans stereoisomers of variously functionalized octahydro[1,2,4]triazolo[4,3-a]quinazolin-5-ones was performed. The 2-thioxopyrimidin-4-ones used in the synthesis reacted with hydrazonoyl chlorides in a regioselective manner to produce the angular regioisomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones rather than the linear isomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones. The synthesis process took place with electronic control. The angular regiochemistry of the products was confirmed by X-ray experiments and two-dimensional NMR studies.

Submitted by Raphael Perini Caetano (raphaelpcaetano@gmail.com) on 2019-12-04T20:13:49Z No. of bitstreams: 1 Biodisponibilidade e efeitos da suplementação de L e DL-metionina na integridade intestinal e estado oxidativo de leitões na fase de creche.pdf: 1154423 bytes, checksum: 0f41eff6917add90ce35571f5c90a09c (MD5) Rejected by Adriana Helena Vitta Zoratti (adriana.zoratti@unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: 1 - Segundo a CAPES (Portaria nº 206, de 4 de setembro de 2018), o agradecimento deve conter exatamente a seguinte redação: O presente trabalho foi realizado com apoio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Código de Financiamento 001. 2- A ficha catalográfica foi gerada com o nome da Faculdade de Ciências Farmacêuticas, Araraquara. Favor alterar para Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal. 3- Nas últimas páginas retirar a numeração lateral. Agradecemos a compreensão. on 2019-12-05T19:40:56Z (GMT) Submitted by Raphael Perini Caetano (raphaelpcaetano@gmail.com) on 2019-12-05T20:27:33Z No. of bitstreams: 1 Biodisponibilidade e efeitos da suplementação de L e DL-metionina na integridade intestinal e estado oxidativo de leitões na fase de creche.pdf: 1145796 bytes, checksum: eed150b73b0a8aeeb8e1578d40cb4137 (MD5) Approved for entry into archive by Adriana Helena Vitta Zoratti (adriana.zoratti@unesp.br) on 2019-12-06T13:10:49Z (GMT) No. of bitstreams: 1 caetano_rp_me_jabo_par.pdf: 679732 bytes, checksum: 5b1c5b2d68ed6d0d3b4fa7a2b3d1a122 (MD5) Made available in DSpace on 2019-12-06T13:10:49Z (GMT). No. of bitstreams: 1 caetano_rp_me_jabo_par.pdf: 679732 bytes, checksum: 5b1c5b2d68ed6d0d3b4fa7a2b3d1a122 (MD5) Previous issue date: 2019-10-10 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Dois estudos foram conduzidos com objetivo de comparar a biodisponibilidade relativa de L-Met e DL-Met com base em ensaio de balanço de N e os efeitos promovidos por ambas as fontes na morfologia intestinal e no sistema antioxidante de suínos em fase inicial e final de creche. Em cada experimento foram utilizados 42 suínos machos castrados (Agroceres PIC, Rio Claro, SP, Brazil: CamboroughTM x AGPIC 337TM) com peso inicial de 10,7 ± 1,09 kg e 20,5 ± 1,55 kg, respectivamente para o experimento 1 e o experimento 2. Cada experimento foi dividido em dois períodos experimentais com 21 suínos. Cada período experimental correspondeu a um bloco. Três suínos foram distribuídos aleatoriamente em 7 dietas experimentais dentro de cada bloco, resultando em um total de 6 repetições por tratamento. As dietas basais (DB) foram formuladas com deficiência de 68% em metionina, porém adequadas para os demais aminoácidos. Três níveis graduados de DL-Met e L-Met (0,03, 0,06 e 0,09%) foram suplementados à dieta basal para criar as dietas 2-7 em ambos os estudos. No experimento 1, ambas as fontes de metionina reduziram linearmente o N excretado pela urina e aumentaram linearmente a retenção de N (% de absorvido) (P ≤ 0,03). A biodisponibilidade relativa estimada para L-Met em comparação a DL-Met foi de 106% (intervalo de confiança – IC de 95%: 39 a 173%) para retenção de N (% de absorvido) em uma base equi-molar. No experimento 2, a suplementação com ambas as fontes de Met diminuiu linearmente a excreção de N urinário e aumentou linearmente o total de N retido, a retenção de N (% de ingerido e % de absorvido) (P ≤ 0,04). A biodisponibilidade estimada de L-Met em comparação a DL-Met foi de 95% (IC 95%: 13 a 177%) para retenção de N (% da ingerido) e 94% (IC 95%: 20 a 167%) para retenção de N (% de N absorvido), respectivamente em uma base equi-molar. Em ambos os experimentos, houve concentrações semelhantes de proteína carbonil e MDA no plasma, duodeno e fígado de suínos alimentados com dietas contendo L-Met ou DL-Met (P > 0,05). Não houve diferenças estatísticas na altura das vilosidades, largura das vilosidades, profundidade da cripta e razão entre altura das vilosidades : profundidade da cripta de duodeno, jejuno e íleo para ambas as fontes de Met (P ≥ 0,07). Os resultados indicam que DL-Met e L-Met são igualmente biodisponíveis como fontes de metionina e impactam positivamente na morfologia intestinal e no sistema antioxidante de suínos em fase inicial e final de creche. Two studies were conducted to compare the relative bioavailability of L-Met and DL-Met based on N balance assay and the effects promoted by both sources on intestinal morphology and antioxidant system of weaned and growing pigs. In each experiment were used 42 barrows (Agroceres PIC, Rio Claro, SP, Brazil: CamboroughTM x AGPIC 337TM) with initial body weight of 10.7 ± 1.09 kg and 20.5 ± 1.55 kg, respectively for Experiment 1 and Experiment 2. Each experiment was divided into two batches with 21 pigs. Each batch corresponded to a block. Three pigs were randomly assigned to 7 experimental diets within each block, resulting in a total of 6 replicates per treatment. Basal diets (BD) were formulated with 68% methionine deficiency, but adequate for the other amino acids. Three graded levels of DL-Met and L-Met (0.03, 0.06 and 0.09%) were supplemented to the basal diet to create diets 2-7 in both studies. In experiment 1, both sources of methionine linearly reduced N excreted in the urine and linearly increased N retention (% absorbed) (P ≤ 0.03). The estimated relative bioavailability for L-Met compared to DL-Met was 106% (95% CI - confidence interval: 39 to 173%) for N retention (% absorbed) on an equi-molar basis. In experiment 2, supplementation with both Met sources linearly decreased urinary N excretion and linearly increased total N retention, N retention (% ingested and% absorbed) (P ≤ 0.04). The estimated bioavailability of L-Met compared to DL-Met was 95% (95% CI: 13 to 177%) for N retention (% of intake) and 94% (95% CI: 20 to 167%) for N retention (% absorbed N), respectively on an equi-molar basis. In both experiments, there were similar concentrations of carbonyl protein and MDA in plasma, duodenum and liver of pigs fed diets containing L-Met or DL-Met (P > 0.05). There were no statistical differences in villus height, villus width, crypt depth and villus height: crypt depth ratio of duodenum, jejunum and ileum for both Met sources (P ≥ 0.07). The results indicate that DL-Met and L-Met are equally bioavailable as methionine sources and positively impact on intestinal morphology and antioxidant system of weaned and growing pigs. FAPESP: 2017/10354-5 Financiamento 001

Producción Científica, The metallic cyanoacetylides LiC3N, NaC3N, MgC3N, and CaC3N have been investigated by combined spectroscopy measurements and theoretical calculations. The theoretical calculations predict for the four species that the linear isomer with the formula MCCCN (M = Li, Na, Mg, and Ca) is the most stable one. We used laser ablation molecular beam Fourier transform microwave (FTMW) spectroscopy to synthesize these species by the reaction of metal vapors, produced by laser ablation, and 3-bromo-2-propynenitrile (BrCCCN). Pure rotational spectra were observed by FTMW spectroscopy in the 2–18 GHz frequency region only for LiCCCN and NaCCCN, while no spectral signatures for MgCCCN and CaCCCN could be detected. Finally, we have searched for LiCCCN and NaCCCN species toward the carbon-rich evolved star IRC +10 216, but only upper limits to their abundances have been obtained., Consejo Europeo de Investigación a través del VII Programa Marco de Investigación y Desarrollo (grant 610256 NANOCOSMOS), Ministerio de Economía, Industria y Competitividad (grants CTQ 2013-40717-P / CTQ 2013-76393-P / AYA2017-87515-P / Consolider-Ingenio 2010 CSD2009-00038), Junta de Castilla y León (grants VA175U13 / VA010G18 / VA077U13)

Las Aulas virtuales basadas en recursos digitales son una de las aplicaciones más interesantes de las Tecnologías de la Información y Comunicación (TIC) en la educación. Su implementación requiere de una adecuada formación de los docentes en los contenidos científicos y el manejo de las TIC; así como una adecuada planificación, selección y diseño acertado de los recursos digitales a incluir. Es de especial interés su aplicación en la enseñanza de las ciencias, necesitada de métodos innovadores que motiven al alumnado para fomentar su interés y curiosidad por los contenidos científicos. En este trabajo nos centraremos en el interés de estos entornos de aprendizaje virtuales para la educación de personas adultas en modelos de enseñanza a distancia, ofreciendo dos propuestas concretas de Aula Virtual en sendas áreas de la Física y Química: el movimiento y la isomería de los compuestos del carbono. Para ello, utilizaremos recursos digitales abiertos y gratuitos disponibles en internet así como recursos diseñados ad-hoc para esta propuesta en base a aplicaciones y software científicos. Virtual classrooms based on digital resources are one of the most interesting applications of Information and Communication Technologies (ICT) in education. Its implementation requires an adequate training of teachers in scientific content and the management of ICT; as well as an adequate planning, selection and successful design of the digital resources to be included. Of special interest is its application in the teaching- learning of science, in need of innovative methods that motivate students to promote their interest and curiosity about scientific content. In this work we will focus on the interest of these virtual learning environments for adult education in distance learning models, offering two concrete proposals of Virtual Classroom in the different areas of Physics and Chemistry: the movement and the isomerism of the carbon compounds. To do this, we will use open and free digital resources available on the internet as well as resources designed ad-hoc for this proposal based on scientific applications and software. Máster Universitario en Profesorado de Educación Secundaria por la Universidad Pública de Navarra Bigarren Hezkuntzako Irakasletzako Unibertsitate Masterra Nafarroako Unibertsitate Publikoan

This work is based on a computational study at structural level of the systems C6-nBnH6(2-n) and C10-nBnH8(4-n). The aim of this study is to know better the compounds that contain one or more hexacoordinated carbon atoms through the comparison of the positions boron atoms occupy on the more corresponding structural. We begin from the hypothesis that hypercoordinated carbon compounds are possible because the ionization of some organic systems make these carbon atoms adopt the electronic configuration of boron and make them show geometries that are forbidden for the organic compounds. For this reason, a question was made. In a system with one or more hexacoordinated positions, composed for carbon, boron and hydrogen, are the isomers with boron occupying hypercoordinared positions show more stability that the other ones? Using computational tools, it was optimized every possible isomer for every number of boron atoms “n” that these complexes can show. During the data recollection, the isomers were observed one by one and the energies of those conserving the geometry without showing any negative frequencies were written down. Then, the energies were compared for every sequence of isomers with the same amount of substituted carbon atoms and the behaviour patterns were identified. The results show that for the system C6-nBnH6(2-n) it’s more suitable when the boron atoms occupy the top position of the pentagonal-pyramid and, also, when there is a more than a single boron atom on the base and they are distributed in a non-consecutive form, with at least a carbon atom between them. For the system C10-nBnH8(4-n) have shown more stability too when boron occupies both hexacoordinated positions. In addition, it is observed that the more stable isomers are the ones that show a perfect symmetry, referring to the number of boron atoms per ring, and the maximum number of non-consecutive boron atoms on the two fused cycles. When “n” is odd and a total symmetry is not possible, the stability depends of the patterns told before and that the number of atoms of each type per cycle remains the same or as close as possible. When n=1, and it’s not possible for boron to occupy both hypercoordinated positions simultaneously, the boron atom it’s located in a position shared by the two organic rings, giving more importance at the last pattern explained

High overtone excitation induced conformational isomerization of glycolic acid – nitrogen complex in an argon matrix was investigated by Raman spectroscopy. The interaction between glycolic acid and nitrogen change the green light (532 nm) induced isomerization processes compared to non-complexed glycolic acid. The 180° rotation around of the Csingle bondC bond and stabilization of carboxyl Odouble bondCsingle bondOsingle bondH dihedral angle to trans position were the main conformational changes observed in the complex of the lowest energy conformer and nitrogen. Interestingly, only one stable light-induced conformational product was observed, which isomerises back to the lowest energy conformer upon prolonged irradiation at 532 nm. The vibrational Raman spectrum of glycolic acid – nitrogen complex and the analysis of the isomerization kinetics are presented. peerReviewed

The 1,3-dipolar cycloaddition reaction is one of the most rapid, and efficient protocols to access, and construct highly divergent heterocycle chiral auxiliaries. Free catalyst synthesis of spirooxindole scaffold incorporating sulphone moiety via one pot&ndash, three component reaction of 6-chloro-isatin, L-proline, and the phenylvinylsulphone as dienophile is presented. The new regioisomer and diastereomer was isolated by precipitation without the tedious purification step, and then characterized via NMR and single crystal X-ray diffraction analysis. Using Hirshfeld analysis, the analysis of molecular packing was performed. It depended mainly on strong O&hellip, H and N&hellip, H interactions, and weak H&hellip, H, C&hellip, H, and Cl&hellip, H interactions as well. DFT calculations were used to optimize the experimental X-ray structure, which was found well matched with the calculated one. Reactivity descriptors based on the energies of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals were calculated. Additionally, the donor&ndash, acceptor interactions which stabilized the system via &sigma, &ndash, &sigma, *, &pi, &rarr, &pi, *, n&rarr, * and n&rarr, * electron delocalization processes were also computed using NBO calculations. The net interaction energies are 49.96, 235.38, 179.66 and 107.06 kJ/mol, respectively. Additionally, the calculated NMR chemical shifts correlated well with the experimental data (R2=0.99).

International audience; Origins of stereoselectivity in ROP of racemic chiral cyclic esters promoted by achiral yttrium complexes, resulting in the formation of highly heterotactic polylactide, and highly syndiotactic or, more uniquely, highly isotactic poly(3-hydroxybutyrate)s, are discussed. A close interplay between the nature of the cyclic ester, most particularly of the exocyclic functional chain installed on the chiral center of β-lactones, and the ortho-substituents installed on the phenolate rings of the ligand, results in various determining secondary interactions of steric and also electronic nature.

Data on fission yields and isomeric yield ratios (IYR) are tools to study the fission process, in particular the generation of angular momentum. We use the IGISOL facility with the Penning trap JYFLTRAP in Jyväskylä, Finland, for such measurements on 232Th and natU targets. Previously published fission yield data from IGISOL concern the 232Th(p,f) and 238U(p,f) reactions at 25 and 50 MeV. Recently, a neutron source, using the Be(p,n) reaction, has been developed, installed and tested. We summarize the results for (p,f) focusing on the first measurement of IYR by direct ion counting. We also present first results for IYR and relative yields for Sn and Sb isotopes in the 128-133 mass range from natU(n,f) based on γ-spectrometry. We find a staggering behaviour in the cumulative yields for Sn and a shift in the independent fission yields for Sb as compared to current evaluations. Plans for the future experimental program on fission yields and IYR measurements are discussed.

We describe the synthesis of three new manganese (II) complexes containing the bidentate ligands 2-(1-methyl-3-pyrazolyl)pyridine (pypz-Me) and ethyl 2-(3-(pyridine-2-yl)-1H–pyrazol-1-yl)acetate (pypz-CH2COOEt), with formula [MnX2(pypz-Me)2] (X = Cl−1, CF3SO3−2) and [Mn(CF3SO3)2(pypz-CH2COOEt)2] 3. Complexes 1–3 have been characterized through analytical, spectroscopic and electrochemical techniques, as well as by monocrystal X-ray diffraction analysis. The complexes show a six-coordinated Mn(II) ion though different stereoisomers have been isolated for the three compounds. Complexes 1–3, together with the previously described compounds [MnCl2(pypz-H)2] 4, [Mn(CF3SO3)2(pypz-H)2] 5, [Mn(NO3)2(pypz-H)2] 6, [MnCl2(H2O)2(pypz-H)2] 7 (pypz-H = 2-(3-pyrazolyl)pyridine) and ([Mn(CF3SO3)2((−)-L)2] 8, ((−)-L = (−)-pinene[5,6]bipyridine), were tested in vitro for cytotoxic activity against NCI-H460 and OVCAR-8 cancer cell lines. The geometry of a specific compound does not seem to influence its activity in a significant extent. However, among the tested compounds those that display hydrophobic substituents on the pyrazole ring and triflate ions as labile ligands show the best antiproliferative properties. Specifically, compound 8 containing the pinene-bipyridine ligand presents an antiproliferative activity similar to that of cisplatin and higher than that of carboplatin, and displays selectivity for tumour cells. Its antiproliferative effect is due to the generation of ROS species that allow the compound to interact with DNA This research has been financed by Ministerio de Economia y Competitividad (MINECO) Spain, through projects CTQ2015-66143-P and BIO2013-43517, by Universitat de Girona through projects MPCUdG2016-18 and MPCUdG2016/048 and by DGU, Generalitat de Catalunya through projects SGR2014-70 and SGR2014-149

A study exploring the chemical behavior of some dihydroxylated β-amino ester stereo- and regioisomers, derived from unsaturated cyclic β-amino acids is described. The nucleophilic fluorinations involving hydroxy–fluorine exchange of some highly functionalized alicyclic diol derivatives have been carried out in view of selective fluorination, investigating substrate dependence, neighboring group assistance and chemodifferentiation.

CcmK proteins are major constituents of icosahedral shells of β-carboxysomes, a bacterial microcompartment that plays a key role for CO2 fixation in nature. Supported by the characterization of bidimensional (2D) layers of packed CcmK hexamers in crystal and electron microscopy structures, CcmK are assumed to be the major components of icosahedral flat facets. Here, we reassessed the validity of this model by studying CcmK isoforms from Synechocystis sp. PCC6803. Native mass spectrometry studies confirmed that CcmK are hexamers in solution. Interestingly, potential pre-assembled intermediates were also detected with CcmK2. Atomic-force microscopy (AFM) imaging under quasi-physiological conditions confirmed the formation of canonical flat sheets with CcmK4. Conversely, CcmK2 formed both canonical and striped-patterned patches, while CcmK1 assembled into remarkable supra-hexameric curved honeycomb-like mosaics. Mutational studies ascribed the propensity of CcmK1 to form round assemblies to a combination of two features shared by at least one CcmK isoform in most β-cyanobacteria: a displacement of an α helical portion towards the hexamer edge, where a potential phosphate binding funnel forms between packed hexamers, and the presence of a short C-terminal extension in CcmK1. All-atom molecular dynamics supported a contribution of phosphate molecules sandwiched between hexamers to bend CcmK1 assemblies. Formation of supra-hexameric curved structures could be reproduced in coarse-grained simulations, provided that adhesion forces to the support were weak. Apart from uncovering unprecedented CcmK self-assembly features, our data suggest the possibility that transitions between curved and flat assemblies, following cargo maturation, could be important for the biogenesis of β-carboxysomes, possibly also of other BMC., PLoS ONE, 12 (9), ISSN:1932-6203

A new tetradentate dinucleating ligand [1,1'-(4-methyl-1H-pyrazole-3,5-diyl)bis(1-(pyridin-2-yl)ethanol)] (Hpbl) containing an O/N mixed donor set of atoms has been synthesized and characterized by analytical and spectroscopic techniques. The Ru-Cl and Ru-aqua complexes containing this ligand of general formula [(RuX)-X-II(Hpb1)-(trpy)](Y+) (trpy = 2,2':6',2''-terpyridine; X = Cl, y = 1; X = H2O, y = 2) have been prepared and thoroughly characterized by spectroscopic and electrochemical techniques. The Ru aqua complex 2 undergoes N -> O linkage isomerization as observed electrochemically, and the related thermodynamic and kinetic parameters are extracted from cyclic voltammetry experiments together with DIGISIM, a CV simulation package. Under basic conditions an additional isomer is observed where the pyrazolyl group in the Hpbl ligand is replaced by the geminal pyridyl group. Further structural and electronic characterization of all the isomers has been carried out by means of DFT calculations Support from MINECO (CTQ2011-26440, CTQ-2013-49075-R, and CTQ2011-23156-C02-02) is gratefully acknowledged. L.F. is grateful for the award of a PIF doctoral grant from UAB. A.P. is grateful to the European Commission (CIG09-GA-2011-293900) and the Spanish MINECO (Ramon y Cajal contract RYC-2009-05226)

We have studied the XYYX and X2YY isomers of the X 2Y2 species (X = H, Li, Na, F, Cl, Br, I; Y = O, S, Se, Te) using density functional theory at the ZORA-BP86/QZ4P level. Our computations show that, over the entire range of our model systems, the XYYX isomers are more stable than the X2YY forms except for X = F and Y = S and Te, for which the F2SS and F2TeTe isomers are slightly more stable. Our results also point out that the Y-Y bond length can be tuned quite generally through the X-Y electronegativity difference. The mechanism behind this electronic tuning is the population or depopulation of the π* in the YY fragment We thank the following organizations for financial support: the HPC-Europa program of the European Union, The Netherlands Organization for Scientific Research (NWO), the Ministerio de Ciencia e Innovacion (MICINN, project numbers CTQ2011-23156/BQU and CTQ2011-25086/BQU, Ramon y Cajal contract to J.P., and FPI fellowship to M.E-H.), the Catalan Departament d'Innovacio, Universitats i Empresa (DIUE, project no. 2009SGR637 and Xarxa de Referenda en Quimica Teorica i Computacional), the FEDER fund (European Fund for Regional Development) for the grant UNGI08-4E-003, and the National Research School Combination Catalysis (NRSC-C). Support for the research of M.S. was received through the ICREA Academia 2009 prize for excellence in research funded by the DIUE of the Generalitat de Catalunya. Excellent service by the Stichting Academisch Rekencentrum Amsterdam (SARA), the Centre de Serveis Cientifics i Academics de Catalunya (CESCA), and the Barcelona Supercomputing Center Centro Nacional de Supercomputacion (BSC-CNS) is gratefully acknowledged