bluuebunny/crossref_metadata_2025 huggingface dataset:
O discurso anticomunista na revista eclesiástica brasileira 1960 a 1970
Authors: Cruz Edmilson Pereira
Published: December 2019

A Igreja Católica no final do século XIX e no início do século XX adotou um discurso contrário ao pensamento marxista e a forma prática da ação de suas ideias. O primeiro papa a realizar uma declaração sobre o comunismo foi Leão XIII (1878-1903), que condenou a forma de ação dos marxistas na Europa em sua encíclica Rerum Novarum, posteriormente temos Pio X (1903-1914) e Bento XV (1914-1922) que seguiram o posicionamento de Leão XIII. Já Pio XI (1922-1939), vai adotar o discurso mais duro contra o pensamento comunista, na sua encíclica Divinis Redemptoris. Por sequência, teremos Pio XII (1939-1958) e João XXIII (1958-1963), que também seguiram seus antecessores. Baseando-se no Concílio Vaticano II, surge a Teologia da Libertação (TL) na América Latina, que une a doutrina pastoral da Igreja Católica com o pensamento marxista. O objetivo do nosso trabalho é investigar qual o posicionamento da Igreja Católica no Brasil diante do comunismo mundial, a partir dos artigos e comunicações encontrados na Revista Eclesiástica Brasileira (REB) entre os anos de 1960-1970. Através dessa revista iremos analisar a forma de discurso usado pela Igreja Católica do Brasil, antes do Concílio Vaticano II e do surgimento da Teologia da Libertação, perante o pensamento marxista.
A perseguição política ao PCB e a fundação da Escola de Polícia de Pernambuco
Authors: Silva Elton Flor
Published: December 2019

Os embates entre o Estado e os integrantes do Partido Comunista Brasileiro – PCB determinam em muitos momentos as decisões das esferas públicas no tocante ao universo político pernambucano. Dessa forma, o presente artigo tem como objetivo analisar, a partir de documentos impressos, jornais e fotografias o trajeto de embates entre o PCB e as forças de segurança pública que levaram à tomada de decisões por parte do Estado que culminariam na instituição da Escola de Polícia de Pernambuco - EPP e no seu Laboratório de Polícia Técnica e o Instituto de Medicina Legal de Pernambuco no ano de 1962, buscando contribuir com a historiografia pernambucana relacionada aos fatos ocorridos nesse período.
História, ambiente e povos indígenas no extremo Norte do Brasil: Impactos da construção da BR-156 em Oiapoque, Amapá (1976-1981)
Authors: Silva Giovani José da , Rocha Anderson Luis Azevedo da
Published: December 2019

O artigo apresenta um estudo sobre o conflito causado pela construção da rodovia BR-156 onde, atualmente, é a Terra Indígena Uaçá, habitada por indígenas Palikur, Karipuna e Galibi Marworno em Oiapoque, Estado do Amapá, Brasil. O objetivo foi analisar as mobilizações desses povos em torno da proteção de seus territórios e as discussões com os agentes do Estado no período da Ditadura Civil-Militar, entre os anos de 1976 e 1981. Foi utilizado o conceito de conflito socioambiental, definido pela Antropologia como disputas entre grupos sociais que se relacionam de diferentes maneiras com o meio natural, envolvendo três dimensões básicas: o mundo biofísico e seus múltiplos ciclos naturais, o mundo humano e suas estruturas sociais e o relacionamento dinâmico e interdependente entre esses dois mundos. No caso da BR-156, o conflito se dá pela intervenção do Estado na região do Uaçá para atender a interesses desenvolvimentistas, enquanto os povos indígenas da região lidaram com os impactos diretos da obra. As principais fontes analisadas foram artigos dos periódicos Boletim do CIMI e Mensageiro, que apresentam forte defesa em relação às demandas indígenas. Assim, a partir do estudo, foi possível perceber que, durante a Ditadura, o processo de construção da BR-156 foi marcado por pressões, imposições e ameaças por parte do governo, que teve como resposta a organização e a resistência dos habitantes da TI Uaçá em defesa de seus territórios.
Mais Além do Socialismo
Authors: Melo Fernando Jader de Magalhães
Published: December 2019

O texto problematiza a polissemia presente na palavra “socialismo” e como a mesma foi interpretada historicamente. Em estudo célebre, Marx opõe dois tipos de socialismo: o primeiro, considerado utópico, designa as teorias dos franceses Saint-Simon e Fourier, e do inglês Robert Owen; o segundo designa a concepção materialista da história, fundamentado na análise científica das forças produtivas sociais. Também Engels reconhece a descoberta genial desses teóricos, ainda que descreva suas deficiências ao compará-las com o modelo de sociedade proposto por Marx desde a década de 1840. Reivindicado pelas mais variadas tendências, o socialismo prossegue em sua existência buscando, agora, caminhos alternativos àqueles julgados autoritários por fugirem ao esquema tradicional da democracia representativa. Mas não seria o socialismo, na concepção materialista da história, uma democracia no sentido mais legítimo da palavra? Neste sentido, defende-se que ir além do socialismo é forjar a construção do ainda não, mas do previsível topos: a concretização do comunismo integral, da democracia radical.
Pathway Complexity in Fuel-Driven DNA Nanostructures with Autonomous Reconfiguration of Multiple Dynamic Steady States
Authors: Deng Jie , Walther Andreas
Published: December 2019

We introduce pathway complexity on a multicomponent systems level in chemically fueled transient DNA polymerization system. The systems are based on a monomeric species pool that is fueled by ATP and orchestrated by an enzymatic reaction network (ERN) of ATP-powered ligation and concurrent cleavage. Such systems display autonomous evolution over multiple structural dynamic steady states from monomers to dimers, oligomer of dimers to ultimately randomized polymer structure before being ultimately degraded back to monomers once the fuel is consumed. The enabling key principle is to design monomer species having kinetically selected molecular recognition with respect to the structure-forming step (ATP-powered ligation) by encoding different sticky-end overhangs into the ligation area. However, all formed structures are equally degraded, and the orthogonal molecular recognition of the different starting species are harmonized during the constantly occurring restriction process, leading in consequence to a reconfiguration of the driven dynamic nanostructures on a higher hierarchical level. This non-equilibrium systems chemistry approach to pathway complexity provides new conceptual insights in fuel-driven automatons and autonomous materials design.
The Performance of Dunning, Jensen and Karlsruhe Basis Sets on Computing Relative Energies and Geometries
Authors: Kirschner Karl , Reith Dirk , Heiden Wolfgang
Published: December 2019

In an effort to assist researchers in choosing basis sets for quantum mechanical modeling of molecules (i.e. balancing calculation cost versus desired accuracy), we present a systematic study on the accuracy of computed conformational relative energies and their geometries in comparison to MP2/CBS and MP2/AV5Z data, respectively. In order to do so, we introduce a new nomenclature to unambiguously indicate how a CBS extrapolation was computed. Nineteen minima and transition states of buta-1,3-diene, propan-2-ol and the water dimer were optimized using forty-five different basis sets. Specifically, this includes one Pople (i.e. 6-31G(d)), eight Dunning (i.e. VXZ and AVXZ, X=2-5), twenty-five Jensen (i.e. pc-n, pcseg-n, aug-pcseg-n, pcSseg-n and aug-pcSseg-n, n=0-4) and nine Karlsruhe (e.g. def2-SV(P), def2-QZVPPD) basis sets. The molecules were chosen to represent both common and electronically diverse molecular systems. In comparison to MP2/CBS relative energies computed using the largest Jensen basis sets (i.e. n=2,3,4), the use of smaller sizes (n=0,1,2 and n=1,2,3) provides results that are within 0.11--0.24 and 0.09-0.16 kcal/mol. To practically guide researchers in their basis set choice, an equation is introduced that ranks basis sets based on a user-defined balance between their accuracy and calculation cost. Furthermore, we explain why the aug-pcseg-2, def2-TZVPPD and def2-TZVP basis sets are very suitable choices to balance speed and accuracy.
Photocatalytic Proton Reduction by a Computationally Identified, Molecular Hydrogen-Bonded Framework
Authors: Aitchison Catherine , Kane Christopher M. , McMahon David P. , Spackman Peter , Pulido Angeles , Wang Xiaoyan , Wilbraham Liam , Chen Linjiang , Clowes Rob , Zwijnenburg Martijn , Sprick Seb , Little Marc , Day Graeme , Cooper Andrew I.
Published: December 2019

For the first time, a hydrogen-bonded organic framework is shown to be an effective photocatalyst for the production of hydrogen from water. The crystal structure of this molecular material is found to be key to good activity with a chemically identical but amorphous version showing orders of magnitude lower proton reduction rates.
Metallic Nanodimers as Phototactic Thermoplasmonic Nanoswimmers
Authors: Bertoni Andres , Passarelli Nicolas , Bustos-Marún Raúl
Published: December 2019

We assess the potentiality of several geometries of metallic nanodimers (one of the simplest thermoplasmonic systems) as candidates for active particles (nanoswimmers) propelled and controlled by light (phototaxis).

The studied nanodimers are formed by two spherical nanoparticles of gold, silver, or copper with radii ranging from 20 to 100 nm. Contrary to most proposals, which assume the asymmetry of the systems as a requirement for self-propulsion, our results show that nanodimers made of identical nanoparticles are excellent candidates for phototactic self-thermophoretic systems. Nonsymmetrical nanodimers, although having a tunable effective diffusion, possess much lower or null average thermophoretic forces. We show that the effective diffusion and the net thermophoretic force in both types of systems depend strongly on the wavelength of the incident light, which makes these properties highly tunable. Our study may result useful for the design of simple-to-make but controllable self-propelled nanoparticles, which can find numerous applications.
Cross-Coupling Polymerization at Iodophenyl Thin Films Prepared by Spontaneous Grafting of a Diazonium Salt
Authors: Marshall Nicholas , Rodriguez Andres
Published: December 2019

Development of a method for the surface-initiated Kumada cross-coupling polymerization based on 4-iodophenyldiazonium salt thin films, and use of this method to make very thick polythiophene brushes.
Reactants, Products, and Transition States of Elementary Chemical Reactions Based on Quantum Chemistry
Authors: Grambow Colin , Pattanaik Lagnajit , Green William H.
Published: December 2019

Reaction times, activation energies, branching ratios, yields, and many other quantitative attributes are important for precise organic syntheses and generating detailed reaction mechanisms. Often, it would be useful to be able to classify proposed reactions as fast or slow. However, quantitative chemical reaction data, especially for atom-mapped reactions, are difficult to find in existing databases. Therefore, we used automated potential energy surface exploration to generate 12,000 organic reactions involving H, C, N, and O atoms calculated at the ωB97X-D3/def2-TZVP quantum chemistry level. We report the results of geometry optimizations and frequency calculations for reactants, products, and transition states of all reactions. Additionally, we extracted atom-mapped reaction SMILES, activation energies, and enthalpies of reaction. We believe that this data will accelerate progress in automated methods for organic synthesis and reaction mechanism generation---for example, by enabling the development of novel machine learning models for quantitative reaction prediction.
Intrinsic Stacking Interactions of Natural and Artificial Nucleobases
Authors: Harding Drew P. , J. Kingsley Laura , Spraggon Glen , Wheeler Steven
Published: December 2019

The intrinsic (gas-phase) stacking energies of natural and artificial nucleobases were explored using density functional theory (DFT) and correlated ab initio methods. Ranking the stacking strength of natural nucleobase dimers revealed a preference in binding partner similar to that seen from experiments, namely G > C > A > T > U. Decomposition of these interaction energies using symmetry-adapted perturbation theory (SAPT) showed that these dispersion dominated interactions are modulated by electrostatics. Artificial nucleobases showed a similar stacking preference for natural nucleobases and were also modulated by electrostatic interactions. A robust predictive multivariate model was developed that quantitively predicts the maximum stacking interaction between natural and a wide range of artificial nucleobases using molecular descriptors based on computed electrostatic potentials (ESPs) and the number of heavy atoms. This model should find utility in designing artificial nucleobase analogs that exhibit stacking interactions comparable to those of natural nucleobases. Further analysis of the descriptors in this model unveil the origin of superior stacking abilities of certain nucleobases, including cytosine and guanine.
Supramolecular Tuning Enables Selective Oxygen Reduction Catalyzed by Cobalt Porphyrins for Direct Electrosynthesis of Hydrogen Peroxide
Authors: Smith Peter T. , Kim Younghoon , Benke Bahiru Punja , Kim Kimoon , Chang Christopher
Published: December 2019

We report a supramolecular design strategy for promoting the selective reduction of O2 for direct electrosynthesis of H2O2. Specifically, we utilized cobalt tetraphenylporphyrin (Co-TPP), a non-selective oxygen reduction reaction (ORR) catalyst, as a building block to assemble the permanently porous supramolecular cage Co-PB-1(6) bearing six Co-TPP subunits connected through twenty-four imine bonds. Reduction of these imine linkers to amines yields the more flexible porous cage Co-rPB-1(6). Both Co-PB-1(6) and Co-rPB-1(6) cages produce 90-100% H2O2 from electrochemical ORR catalysis in neutral pH water, and we attribute this high selectivity to site isolation of the discrete molecular units, as the analogous Co-TPP monomer generates only a 50% mixture of H2O2 and H2O from electrochemical ORR under the same conditions. The ability to control reaction selectivity in supramolecular structures beyond traditional host-guest interactions offers new opportunities for designing such architectures for a broader range of catalytic applications.
Comprehensive Survey of CDK Inhibitor Selectivity in Live Cells with Energy Transfer Probes
Authors: Wells Carrow , Vasta Jim , Corona Cesear R. , Wilkinson Jennifer , Zimprich Chad A. , Ingold Morgan R. , Pickett Julie E. , Drewry David , Pugh Kathryn Maria , Huber Kilian , Cong Mei , Meisenheimer Poncho , Willson Timothy M. , Robers Matthew B.
Published: December 2019

A panel of cell-permeable energy transfer probes has been developed to quantify target occupancy for all 21 CDKs in live, intact cells. Here we present the first comprehensive evaluation of intracellular isozyme potency and selectivity for a collection of 46 clinically-advanced CDKi’s and tool molecules. Here we provide a broadly applicable method for evaluating the selectivity of chemical matter for CDKs in living cells, and present a refined set of tool molecules to study CDK function.
A Multifunctional Chemical Agent as an Attenuator of Amyloid and Tau Burden and Neuroinflammation in Alzheimer’s Disease
Authors: Cho Hong-Jun , Sharma Anuj K. , Zhang Ying , Gross Michael L. , Mirica Liviu M.
Published: December 2019

Alzheimer’s disease (AD) is the most common neurodegenerative degenerative disease, and its main hallmark is the deposition of amyloid beta (Aβ) peptides. However, several clinical trials focusing on Aβ-targeting agents have failed recently, and thus new therapeutic leads are focusing on alternate targets such as tau protein pathology, Aβ-metal induced oxidative stress, and neuroinflammation. To address these different pathological aspects of AD, we have employed a multifunctional compound (MFC) L1 that integrates Aβ-interacting and metal-binding functional groups in a single molecular framework. By perturbing the interactions between the Aβ species and metal ions during the Aβ aggregation process, L1 alleviates the formation of neurotoxic Aβ oligomers and promotes the formation of nontoxic, amorphous Aβ aggregates. Furthermore, the significant antioxidant activity and strong metal chelating ability of L1 are operating cooperatively to rescue neuroblastoma N2A cells from Cu2+-induced Aβ neurotoxicity. Along with in vivo Aβ-binding and favorable BBB permeability properties, the treatment of transgenic 5xFAD mice with L1 significantly reduces the amount of both amyloid plaques and associated phosphorylated tau (p-tau) aggregates in the brain by 40–50% versus the vehicle-treated 5xFAD mice. Besides, L1 mitigates the neuroinflammatory response of the activated microglia during the Aβ-induced inflammation process. Overall, these results suggest that L1 not only efficiently attenuates the formation of amyloid plaques and p-tau aggregates in vivo, but also reduces the microgliamediated neuroinflammatory response, which is quite uncommon among the previously reported amyloid-targeting chemical agents, and thus L1 could be envisioned as a lead compound for the development of novel AD therapeutics.
Mesoporous Carbon Structure-Based Glass Nanopipettes as Micro pH Probes
Authors: He Haili , Zhao Dongyuan
Published: December 2019

Nanopore-based nanomaterials have been widely used to prepare the biosensor due to the unique structure, and the high sensitivity to the external stimuli under different environmental conditions. In this report, we ingeniously designed and prepared mesoporous carbon structure-based quartz nanopipettes. The mesoporous carbon was in situ grown in the tip working area of a single quartz nanopipette through the method of evaporation induced self-assembly (EISA). The mesoporous carbon could reduce the effective aperture of the nanopipette, while the surface area of nanopipette tip could be increased by the mesoporous carbon structure as well. The negative charges on the inner surface of the nanopipette increased significantly, which made the ionic current rectification of the nanopore more remarkable, with the ionic current rectification ratio increasing from 2.3 to 34.8. The mesoporous carbon-based glass nanopipette with good response to pH has been used for the probe of pH value of micro-volume solution. The test results were consistent with those obtained by using a commercial pH meter.
The Problem of Aspartimide Formation During Protein Chemical Synthesis Using SEA-Mediated Ligation
Authors: Bouchenna Jennifer , Sénéchal Magalie , Drobecq Hervé , Vicogne Jérôme , Melnyk Oleg
Published: December 2019

Aspartimide formation often complicates the solid phase synthesis of peptides. Much less discussed is the potential occurrence of this side-reaction during the coupling of peptide segments using chemoselective peptide bond forming reactions such as the native chemical ligation and extended methods. Here we describe how to manage this problem using bis(2-sulfenylethyl)amido (SEA)-mediated ligation and SUMO-2/SUMO-3 as protein targets.
On the Solvent and Temperature Driven Stereoselectivity of the Diels-Alder Cycloaddition Reactions of Furan with Maleic Anhydride and Maleimide
Authors: Yadav Veejendra , Prasad Dasari L V K , Yadav Arpita , Yadav Kedar
Published: December 2019

In quantum chemical calculations, the Diels-Alder cycloaddition reaction of maleic anhydride with furan favors the endo-isomer kinetically in the gas phase. This preference, however, changes in favor of the exo-isomer on inclusion of solvent effects. For example, in acetonitrile, the exo-isomer was calculated to form twice as fast as the endo-isomer at room temperature, an observation that corroborates well with the experiments. The free energy change of the reaction is such that it allows faster reversal of the endo-isomer to the reactants in an equilibrium process and, thus, the predominance of the more stable exo-isomer eventually. The reaction of maleimide with furan is similar to that of maleic anhydride. However, it favors predominantly endo selectivity at temperatures below 320 K which is in excellent agreement with the experimental studies of temperature dependence of this DA reaction. Further, a gedanken calculation of the DA reaction of cyclopropene with furan has been investigated to delineate the effect of the retro-pathway on the stereoselectivity.
Increasing the Affinity of an O-Antigen Polysaccharide Binding Site in Shigella Flexneri Bacteriophage Sf6 Tailspike Protein
Authors: Kunstmann R. Sonja , Engström Olof , Wehle Marko , Widmalm Göran , Santer Mark , Barbirz Stefanie
Published: December 2019

We analysed the tailspike from bacteriophage Sf6 in complex with the O-polysaccharide of the pathogen Shigella flexneri. The conformational space populated by the polyrhamnose backbone of the S. flexneri O-polysaccharide as studied by an octasaccharide in complex with Sf6TSP could be well described with 2D 1H,1H-trNOESY NMR, utilizing a combination of methine-methine and methine-methyl correlations. The results are in good agreement with the conformations obtained from molecular dynamics (MD) simulations. To examine the impact of amino acid exchanges in the glycan binding site of Sf6TSP, MD simulations were used to predict increased O-polysaccharide binding affinities. We used surface plasmon resonance on S. flexneri O-polysaccharide surfaces to measure affinity increases in the obtained mutants.
Deciphering the Oxygen Absorption Pre-Edge: Universal Map of Transition Metal Redox Potentials in Batteries
Authors: Qiao Ruimin , Roychoudhury Subhayan , Zhuo Zengqing , Li Qinghao , Lyu Yingchun , Kim Jung-Hyun , Liu Jun , Lee Eungje , Polzin Bryant J. , Guo Jinghua , Yan Shishen , Hu Yongsheng , Li Hong , Prendergast David , Yang Wanli
Published: December 2019

The well-defined low-energy features, so-called pre-edges, of oxygen K-edge X-ray absorption spectra in transition metal (TM) oxides correspond to the highly hybridized states of TM 3d and O 2p orbitals. The evolution of these features have been broadly used for studying the oxygen oxidation states in battery electrodes; however, critical questions remain on the validity of such an application and the origin of the pre-edge evolution upon cycling is yet to be clarified. Here, combined with theoretical calculations, we investigated the O-K pre-edge collected from 14 groups of electrodes and a total of 55 oxides that cover all 3d TMs used in battery cathodes with different elements, structures and electrochemical states. We show conclusive evidences that the O-K pre-edge variation is dominated by the change of TM states. More importantly, the O-K pre-edge enables a unique opportunity to project the lowest unoccupied states of all TMs onto one common energy window, which corresponds to the relative potentials of TM reduction reactions (electron filling). The summary of all XAS analysis thus delivers a universal map of the relative TM redox potentials, which reveals an unusual Cr3+/6+ redox that is further confirmed by both experiments and theory. This work provides a critical clarification on how to correctly interpret O-K pre-edge of TM oxides, which also leads to a simple but effective method to determine the relative TM redox potentials of known or unknown, usual or novel electrode materials.
Tunable Flexibility and Porosity of the Metal-Organic Framework DUT-49 Through Post-Synthetic Metal Exchange
Authors: Garai Bikash , Bon Volodymyr , Krause Simon , Schwotzer Friedrich , Gerlach Martin , Senkovska Irena , Kaskel Stefan
Published: December 2019

As a prominent and representative example of flexible metal-organic frameworks (MOFs), DUT-49(Cu) has gained attention due to the unique phenomenon of Negative Gas Adsorption (NGA); originating from an unprecedented struc-tural contraction during the gas adsorption. Herein, post-synthetic metal exchange is demonstrated to afford DUT-49 frameworks with a wide variety of metal cations, e.g. Mn2+, Fe2+, Ni2+, Zn2+, Cu2+ and Cd2+. The single-crystal-to-single-crystal conversion allowed to characterize the new MOFs by single crystal X-ray diffraction, indicating identical struc-ture and topology, as that of previously explored DUT-49(Cu) framework. This approach is proven successful in achieving Mn-Mn and Cd-Cd dimers, which are rare examples of M-M paddle-wheel SBUs. The relative stability and flexibility of the resulted frameworks are observed to be highly sensitive to the metal ion of the framework, following the trends predicted by Irving-Williams series. DUT-49(Ni) was recognized as a second material from DUT-49 series showing adsorption-induced transitions. A sequential increase in framework flexibility from rigid to flexible and from flexible to NGA has been achieved through selective incorporation of metal centers into the structure. Finally, hetero-metallic structures are formed by selective and controlled exchange of metal ions to finely tune the flexibility and NGA phenomenon of the framework.
Melanogenesis: A Search for Pheomelanin and Also, What Is Lurking Behind Those Dark Colors?
Authors: Vercruysse Koen , Govan Venise
Published: December 2019

We investigated the synthesis of melanin-like materials from DOPA, dopamine, norepinephrine and epinephrine in the presence of L-cysteine. We observed that L-cysteine delayed the formation of pigment from these catecholamines and that the presence of L-cysteine yielded darker-colored reaction mixtures. No reddish pigment was observed that would indicate the synthesis of pheomelanin-like material. The reactions were performed in the presence of Na2CO3 and through the addition of CaCl2 at the end of the reaction; the black, eumelanin-like material was co-precipitated with CaCO3. The remaining supernatant solutions were observed to be light-yellow to rusty-orange in color depending on the catecholamine used in the reaction. Size exclusion chromatography (SEC) analyses indicated that the removal of the black pigment left behind an oligomeric material that exhibited a strong absorbance band around 280nm. Our experimental and analytical observations prompt us to raise a number of points of discussion or hypotheses. 1) The presence of L-cysteine during the air-mediated oxidation of catecholamines leads to darker-colored pigments; not reddish or lighter-colored pigments that would visually resemble pheomelanin-like pigments, 2) SEC analyses suggested that the black pigment generated during the air-mediated oxidation of catecholamines is not necessarily the main reaction product, 3) The pre-formed, dark-colored pigments obtained through the air-mediated oxidative melanogenesis process can readily be deposited on insoluble mineral surfaces using an in situ co-precipitation procedure, 4) The air-mediated oxidation of catecholamines leads to a binary product that contains an insoluble, melanin-like substance and a soluble, oligo- or polymeric substance containing unoxidized precursor units, 5) The melanogenesis process leads to a binary product involving a non-covalently bonded combination of dark-colored pigment and a lighter-colored or colorless substance; the latter being understudied or ignored in the in vitro or in vivo studies of the melanogenesis process, 6) The kinetics of the melanogenesis process may determine the balance between insoluble and soluble components of the binary product generated; the slower the reaction the more dark-colored, insoluble pigment generated, 7) One should consider the possibility of intermolecularly, N-to-C, bonded units of catecholamines when evaluating the structure of melanins, polydopamines, etc. and 8) There is a need for a systematic study of the effect of amino acids (beyond just L-cysteine) and amines in general on the melanogenesis process.
Subnano Surface Engineering of TiO2 Nanoparticles by PET Molecular Layer Deposition: Tuning Photoactivity and Dispersibility
Authors: La Zara Damiano , Bailey Maximilian R. , Hagedoorn Peter-Leon , Benz dominik , Quayle Michael J. , Folestad Staffan , Ommen J. Ruud van
Published: December 2019

In this work, we report molecular layer deposition (MLD) of ultrathin poly(ethylene terephthalate) (PET) films on gram-scale batches of ultrafine particles for the first time. TiO2 P25 nanoparticles (NPs) are coated up to 50 cycles in an atmospheric-pressure fluidized bed reactor at 150 °C using terephthaloyl chloride and ethylene glycol as precursors. Ex-situ diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis and transmission electron microscopy show the linear growth at 0.05 nm/cycle of uniform and conformal PET films, which are unattainable with conventional wet-phase approaches. The subnano and nano PET films not only suppress the photocatalytic activity of TiO2 NPs by reducing the generation of hydroxyl radicals, but also improve the dispersibility of TiO2 NPs in both organic and aqueous media. Still, the bulk optical properties, electronic structure and surface area of TiO2 are essentially unaffected by the MLD process. This study demonstrates the industrial relevance of MLD to simultaneously tune the photoactivity and dispersibility of the commercial photocatalyst TiO2 P25. Moreover, by rapidly modifying the surface properties of particles in a controlled manner at the subnanometer scale, particle MLD can serve many applications ranging from nanofluids to emulsions to polymer nanocomposites.
Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces
Authors: Ewen James , Latorre Carlos Ayestaran , Khajeh Arash , Moore Joshua , Remias Joseph , Martini Ashlie , Dini Daniele
Published: December 2019

Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe3O4(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe3O4, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe3O4(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe3O4. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe3O4(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe3O4(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.
Macroscale Control of Reactivity using 3D Printed Materials with Intrinsic Catalytic Properties
Authors: Manzano Sebastián , Wang hsin , qi long , Slowing Igor
Published: December 2019

Catalytically active stirrers were 3D printed by stereolithography. The geometries of the stirrers were tailored to maximize the performance of an acidic catalyst for the hydrolysis of a disaccharide. Catalytic activity per unit of surface area varied depending on the number and tilt of the blades in the stirrers, proving that macroscopic shape can affect catalyst performance. Flow dynamics analysis indicated the topological effect on reactivity is due to the amount of non-zero pressure contact points between the solution and the stirrers.
Localization of Spiropyran Activation
Authors: Grady Martha , Birrenkot Cassandra , May Preston A. , White ScottR. , Moore Jeffrey S. , Sottos Nancy R.
Published: December 2019

Functionalization of planar and curved glass surfaces with spiropyran (SP) molecules and localized UV-induced activation of the mechanophore are demonstrated. Fluorescence spectra of UV-irradiated SP-functionalized surfaces reveal that increases in surface roughness or curvature produces more efficient conversion of the mechanophore to the open merocyanine (MC) form. Further, force-induced activation of the mechanophore is achieved at curved glass-polymer interfaces and not planar interfaces. Minimal fluorescence signal from UV-irradiated SP-functionalized planar glass surfaces precluded mechanical activation testing. Curved glass-polymer interfaces are prepared by SP functionalization of E-glass fibers, which are subsequently embedded in a poly(methyl methacrylate) (PMMA) matrix. Mechanical activation is induced through shear loading by a single fiber microbond testing protocol. In situ detection of SP activation at the interface is monitored by fluorescence spectroscopy.
Nanoengineered Light-Harvested Proteins for Optogenetics and Photopharmacology
Authors: Garrido-Charles Aida , Cabré Gisela , Gascón-Moya Marta , Busqué Félix , Alibés Ramon , Hernando Jordi , Gorostiza Pau
Published: December 2019

Chemical modification with nanometer precision can be used to probe and to improve the function of complex molecular entities, from organic materials to proteins and their assemblies. Using the pigment arrangement in photosynthetic light-harvesting as inspiration, we show that molecular photosensitizers can be located at well-defined distances from photoisomerizable units in proteins in order to enhance and spectrally shift their photoresponses. The approach is demonstrated in Channelrhodopsin-2 (ChR2) and in the light-gated ionotropic glutamate receptor (LiGluR), two archetypical actuators in optogenetics and photopharmacology that have been used both for fundamental and therapeutic purposes. These proof-of-concept experiments together with theoretical simulations predict that the photosensitivity can be increased several orders of magnitude using these means, thus providing a unique methodology to boost the performance of current optogenetic and photopharmacological toolboxes.
Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds
Authors: Hossain Mohammad Mosharraf , Atkinson Joshua , Hartley Scott
Published: December 2019

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.
A Universal Porous Adsorbent for the Selective Capture of Carbon Dioxide
Authors: Taheri Qazvini Omid , Telfer Shane G.
Published: December 2019

Efficient and sustainable methods for carbon dioxide (CO2) capture are essential. Its atmospheric concentration must be reduced to meet climate change targets, and its removal from sources such as chemical feedstocks is vital. While mature technologies involving chemical reactions that absorb CO2 exist, they have many drawbacks. Porous materials with void spaces that are complementary in size and electrostatic potential to CO2 offer an alternative. In these materials, the molecular CO2 guests are trapped by noncovalent interactions, hence they can be recycled by releasing the CO2 with a low energy penalty. Capacity and selectivity are the twin challenges for such porous adsorbents. Here, we show how a metal-organic framework, termed MUF-16 (MUF = Massey University Framework), is a universal adsorbent for CO2 that sequesters large quantities of CO2 from a broad palette of gas streams with record selectivities over competing gases. The crystallographically-determined position of the CO2 molecules captured in the framework pores illustrate how complementary noncovalent interactions envelop CO2 while repelling other guest molecules. The low affinity of the pore environment for other gases underpins the strikingly high selectivity of MUF-16 for CO2 over methane, nitrogen, hydrogen, acetylene, ethylene, ethane, propylene and propane. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver a repertoire of high-purity products. MUF-16 is an inexpensive, robust, recyclable adsorbent that is universally applicable to the removal of CO2 from sources such as natural gas, syngas, flue gas and chemical feedstocks.
Molecular Generation Targeting Desired Electronic Properties via Deep Generative Models
Authors: Yuan Qi , Santana-Bonilla Alejandro , Zwijnenburg Martijn , Jelfs Kim
Published: December 2019

The chemical space for novel electronic donor-acceptor oligomers with targeted properties was explored using deep generative models and transfer learning. A General Recurrent Neural Network model was trained from the ChEMBL database to generate chemically valid SMILES strings. The parameters of the General Recurrent Neural Network were fine-tuned via transfer learning using the electronic donor-acceptor database from the Computational Material Repository to generate novel donor-acceptor oligomers. Six different transfer learning models were developed with different subsets of the donor-acceptor database as training sets. We concluded that electronic properties such as HOMO-LUMO gaps and dipole moments of the training sets can be learned using the SMILES representation with deep generative models, and that the chemical space of the training sets can be efficiently explored. This approach identified approximately 1700 new molecules that have promising electronic properties (HOMO-LUMO gap <2 eV and dipole moment <2 Debye), 6-times more than in the original database. Amongst the molecular transformations, the deep generative model has learned how to produce novel molecules by trading off between selected atomic substitutions (such as halogenation or methylation) and molecular features such as the spatial extension of the oligomer. The method can be extended as a plausible source of new chemical combinations to effectively explore the chemical space for targeted properties.
(In)vestindo camisas de futebol: moda esportiva e agência na produção das emoções torcedoras
Authors: Toledo Luiz Henrique de
Published: December 2019

Camisas de futebol apontam para um duplo vínculo de uma experiência emocional, que tensiona a relação entre o indivíduo e o coletivo. A moda esportiva com seus ciclos, marcas e indumentárias aparece não somente como dispositivo estético e protético assentado nos valores do consumismo, mas também pode ser concebida como instância agentiva na fabricação da pessoa do torcedor. Este artigo procura articular moda e futebol de uma perspectiva antropológica, que trata corpo e suas projeções (corporalidades) como fundamentos simbólicos de comunicação e produção de relações, no caso, relações entre a cultura material expressa pela moda e o multiverso da sociabilidade torcedora a partir de uma modalidade esportiva, o futebol.
Baila Comigo: os esportes e a moda esportiva a partir da influência do audiovisual
Authors: Silva Elisabeth Murilho da
Published: December 2019

O presente trabalho aborda a popularização dos esportes e das práticas corporais no fim do século XX. Inicialmente tratados como forma de ocupação distintiva da elite, os diferentes esportes exigiam roupas específicas, que se caracterizavam como uniformes, e era impossível o intercâmbio de roupas entre as várias modalidades. A partir da influência do audiovisual, na década de 1980, há uma popularização das práticas corporais e esportivas, transformando o mercado de moda esportiva no Brasil. Analisa-se especificamente a telenovela Baila Comigo, exibida em 1981 pela Rede Globo, que refletiu na maior procura por academias de dança e na diversificação dos uniformes para tais práticas.
“A coreografia vestiu também um ‘maillot’” 1 : sobre ballet aquático e roupas de banho no Rio de Janeiro dos anos 1940 (1947-1949)
Authors: Gonçalves Michelle Carreirão
Published: December 2019

Nos anos finais da década de 1940, o Rio de Janeiro viu surgir uma nova prática corporal sob influência do cinema e da cultura dos Estados Unidos. O ballet aquático, precursor do que hoje conhecemos como nado artístico, figurou nas piscinas da capital federal, entre os anos 1947 e 1949, em eventos sociais e beneficentes com apresentações organizadas em torno das atividades dentro d’água, mas também fora dela, com destaque para os desfiles de moda, notadamente de roupa de banho. Carro-chefe desses eventos, o maillot aparece transitando entre vestimenta esportiva e vestimenta de lazer, compondo o mundo feminino da época com seus ideais de beleza, graça, harmonia e também sensualidade.
Entre uniformes e espartilhos – os trajes de ciclismo no século XIX, da Europa a Porto Alegre
Authors: Santucci Natália de Noronha
Published: December 2019

Este texto contém um panorama da relação entre as modas de vestuário e as modas de atividades físicas ligadas ao ciclismo. Serão comentados os momentos que draisianas, velocípedes e bicicletas estiveram em voga, e as soluções encontradas no vestuário para utilizá-los, assim como a codificação do uso de algumas peças de roupa e objeções enfrentadas. As práticas adotadas pelos clubes de ciclismo que existiram em Porto Alegre entre o fim do século XIX e o início do XX serão o alicerce para a elaboração de comparações entre o Brasil e a Europa.
Juventude “transada”: tensionamentos das normativas de gênero na moda promovida pela revista Pop (anos 1970)
Authors: França Maureen Schaefer , Santos Marinês Ribeiro dos
Published: December 2019

Nos anos 1970, conexões entre a contracultura e os movimentos feminista e gay resultaram em tensionamentos dos modelos normativos de feminilidades e masculinidades. Tais mudanças comportamentais reverberaram no figurino de artistas da cultura pop assim como no vestuário do cotidiano. Sendo assim, a partir de algumas imagens de um editorial veiculado em 1973 pela Pop, primeira revista destinada ao público jovem no Brasil, discutimos, sob a ótica de gênero, como o emprego da moda reiterou e regulou, mas também questionou e ampliou, os limites para a construção dos corpos. Para tanto, a discussão, que dialoga com outros periódicos da época, apoia-se, sobretudo, na articulação entre as áreas dos Estudos de Gênero e História da Moda. Nós compreendemos que a moda não é neutra, mas sim uma prática cultural, sendo produzida segundo visões de mundo particulares, podendo reforçar ou contestar desigualdades sociais. Nossa análise indica que a moda em questão, veiculada pela Pop, funcionou, em certa medida, como uma estratégia material de tensionamento do conservadorismo social, refutando padrões tradicionais de gênero e produzindo modelos de feminilidades e masculinidades mais libertários.
Moda no museu: os vestidos-objeto de Olly Reinheimer no MAM-RJ (1969)
Authors: Corrêa Clecius Campos
Published: December 2019

Este artigo apresenta a exposição da artista alemã-brasileira Olly Reinheimer, Vestidos-objeto, realizada no Museu de Arte Moderna do Rio de Janeiro, em 1969, como exemplo de mostra de roupas em um museu de arte que foi legitimada como arte pela crítica. Explora-se a referida exposição a partir de sua repercussão em jornais cariocas, cuja abertura em formato de desfile foi chamada pela crítica de “happening da nova moda”. Antes, menciona-se o desfile ocorrido em 1966 no Masp, mostrando que a roupa e a performance eram partes do projeto artístico de Olly. O objetivo é apontar como a configuração da exposição, a aceitação no museu e a repercussão nos jornais indicaram Olly como uma artista no vértice da arte e da moda, capaz de atravessar o tema roupa no museu com o apoio da crítica especializada.
Expertise e legitimidade: os bureaux de style e a moda contemporânea
Authors: Campos Amanda Queiroz
Published: December 2019

O estudo aborda as empresas de previsão de tendências de moda, bureaux de style, e a ampla rede de relacionamentos por elas organizada no sistema de moda, demonstrando sua centralidade na criação de valor para produtos de moda. Primeiramente, discute-se a perspectiva de Giddens sobre a modernidade e o desencaixe da experiência direta, cujo vácuo foi preenchido por instituições especializadas. No sistema de moda, uma das expertises mais valorizadas ao longo da cadeia é o conhecimento das tendências, cuja institucionalização se dá por meio dos bureaux de style nos anos 1960. O objetivo principal deste trabalho é analisar o papel dos bureaux de style no atual sistema de moda. Para esse fim, os representantesmais relevantes foram investigados para desvendar as modalidades e as estratégias de informação de tendências da moda – e de si mesmos como especialistas. A pesquisa documental envolveu a coleta de imagens e de textos das empresas de pesquisa de tendências: Peclers, Promostyl, Carlin, DMI, View, WGSN, Use Fashion, TrendsTop e TrendUnion. Os dados foram analisados com o auxílio do software MAXQDA e com base nos fundamentos da GroundedTheory. Os resultados levam a questionar a fé depositada nessas agências. Considera-se que as “grandes” casas de estilo sustentam sua legitimidade graças aos seus discursos e à circulação de representações específicas, que podem ser vistas como estratégia de marca. Os bureaux de style mantêm e reiteram seu status de especialistas à medida que continuam a articular demanda, produção e consumo na moda.
Entrevistando Joanne Entwistle...
Authors: Bonadio Maria Claudia , Figueredo Henrique Grimaldi , Andrade Rita Morais de
Published: December 2019

É uma pergunta muito boa. Meu interesse surgiu depois que terminei a minha graduação na Goldsmiths, em Comunicação e Sociologia, na qual tive a sorte de ser ensinada por Dick Hebdige, professor do Departamento de Comunicação e um dos fundadores dos Estudos Culturais na Grã-Bretanha. [...]
Interviewing Joanne Entwistle…
Authors: Bonadio Maria Claudia , Figueredo Henrique Grimaldi , Andrade Rita Morais de
Published: December 2019

It is a very good question and it arose after I finish my undergraduate degree in Goldsmiths, which was in Communications and Sociology, and I was lucky to be taught by Dick Hebdige, a professor in the department of communications and one of the founders of the British culture studies. It was a very exciting intellectual environment and when I left college I knew I wanted to go on and do some further research, and I counted on Elizabeth Wilson’s book “Adorned in Dreams” which, at that time, was one of the few studies of fashion that was not just a historical text with gorgeous photographs of historical garments or a biography of a designer; but it was a text trying to give an account of the emergence of fashion, locating it within debates about modernity and post-modernity which I have been studying on my undergraduate degree. So I kind of consumed this book in a day and I was very excited, and it got me thinking about what other things have been published in fashion and what about the way people dress. I asked many, many questions. [...]