bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guerra « al margen del cable ». Anticipación de la Segunda Guerra Mundial en las crónicas de Roberto Arlt
Authors: Raič Monika 
Published: February 2019

En las crónicas Al margen del cable de los años 1937 y 1938 el escritor argentino Roberto Arlt anticipa la Segunda Guerra Mundial. ¿A través de qué recursos narratológicos y con qué fin anticipa un argentino una guerra que está preparándose en Europa ? Para abarcar esta problemática implicaré reflexiones sobre el fenómeno de la anticipación, la oposición entre guerra y paz, y la cuestión de subjetividad cosmopolita marginal. Los textos de Arlt exponen un afirmado interés por entender estructuras psicológicas, sociales, económicas y políticas entretejidas globalmente. Contrapongo la noción de historia universal de Kant con las reflexiones de Arlt sobre historia, guerra y paz. Leo las operaciones narrativas y la selección temática como táctica de inserción del sujeto cosmopolita marginal en el discurso global cuyo epicentro es Europa.
A Gel‐Based Model of Selective Cell Motility: Implications for Cell Sorting, Diagnostics, and Screening
Authors: Ivanir Eran , Shachaf Yonatan , Mironi‐Harpaz Iris , Yeheskely‐Hayon Daniella , Hazanov Lena , Harpaz‐Segev Shlomit , Birman Tamara , Minai Limor , Melino Sonia , Yelin Dvir , Seliktar Dror 
Published: February 2019

AbstractThe ability to precisely control cell‐loaded material systems is essential for in vitro testing of novel therapeutics poised to advance to clinic. In this report, unique patterns of cell migration are devised into an in vitro gel‐in‐gel model for the purpose of obtaining cell response data to potentially therapeutic chemical agonists. The model consists of co‐cultures in a cell‐loaded microgel invading an acellular “sorting” gel. Material properties including biophysical and chemical compositions of the sorting gel are carefully controlled to guide a desired cell‐specific behavior, leading to massive tumor cell invasion by amoeboid migration mechanisms. Optical transparency enables straightforward and high‐throughput measurements of outgrowth response in the presence of either chemical and photoradiation therapy. Important dosing and drug sensitivity information are obtained with the gel‐in‐gel model using no more than a light microscope, without further need for arduous genomic or proteomic screening of the tissue samples.
A Double‐Layer Mechanochromic Hydrogel with Multidirectional Force Sensing and Encryption Capability
Authors: Zhu Qingdi , Van Vliet Krystyn , Holten‐Andersen Niels , Miserez Ali 
Published: February 2019

AbstractHydrogel‐based soft mechanochromic materials that display colorimetric changes upon mechanical stimuli have attracted wide interest in sensors and display device applications. A common strategy to produce mechanochromic hydrogels is through photonic structures, in which mechanochromism is obtained by strain‐dependent diffraction of light. Here, a distinct concept and simple fabrication strategy is presented to produce luminescent mechanochromic hydrogels based on a double‐layer design. The two layers contain different luminescent species—carbon dots and lanthanide ions—with overlapped excitation spectra and distinct emission spectra. The mechanochromism is rendered by strain‐dependent transmittance of the top‐layer, which regulates light emission from the bottom‐layer to control the overall hydrogel luminescence. An analytical model is developed to predict the initial luminescence color and color changes as a function of uniaxial strain. Finally, this study demonstrates proof‐of‐concept applications of the mechanochromic hydrogel for pressure and contact force sensors as well as for encryption devices.
Progress and Perspectives of Thin Film Kesterite Photovoltaic Technology: A Critical Review
Authors: Giraldo Sergio , Jehl Zacharie , Placidi Marcel , Izquierdo‐Roca Victor , Pérez‐Rodríguez Alejandro , Saucedo Edgardo 
Published: February 2019

AbstractThe latest progress and future perspectives of thin film photovoltaic kesterite technology are reviewed herein. Kesterite is currently the most promising emerging fully inorganic thin film photovoltaic technology based on critical raw‐material‐free and sustainable solutions. The positioning of kesterites in the frame of the emerging inorganic solar cells is first addressed, and the recent history of this family of materials briefly described. A review of the fast progress achieved earlier this decade is presented, toward the relative slowdown in the recent years partly explained by the large open‐circuit voltage (VOC) deficit recurrently observed even in the best solar cell devices in the literature. Then, through a comparison with the close cousin Cu(In,Ga)Se2 technology, doping and alloying strategies are proposed as critical for enhancing the conversion efficiency of kesterite. In the second section herein, intrinsic and extrinsic doping, as well as alloying strategies are reviewed, presenting the most relevant and recent results, and proposing possible pathways for future implementation. In the last section, a review on technological applications of kesterite is presented, going beyond conventional photovoltaic devices, and demonstrating their suitability as potential candidates in advanced tandem concepts, photocatalysis, thermoelectric, gas sensing, etc.
High‐Performance All‐Polymer Solar Cells Enabled by an n‐Type Polymer Based on a Fluorinated Imide‐Functionalized Arene
Authors: Sun Huiliang , Tang Yumin , Koh Chang Woo , Ling Shaohua , Wang Ruizhi , Yang Kun , Yu Jianwei , Shi Yongqiang , Wang Yingfeng , Woo Han Young , Guo Xugang 
Published: February 2019

AbstractA novel imide‐functionalized arene, di(fluorothienyl)thienothiophene diimide (f‐FBTI2), featuring a fused backbone functionalized with electron‐withdrawing F atoms, is designed, and the synthetic challenges associated with highly electron‐deficient fluorinated imide are overcome. The incorporation of f‐FBTI2 into polymer affords a high‐performance n‐type semiconductor f‐FBTI2‐T, which shows a reduced bandgap and lower‐lying lowest unoccupied molecular orbital (LUMO) energy level than the polymer analog without F or with F‐functionalization on the donor moiety. These optoelectronic properties reflect the distinctive advantages of fluorination of electron‐deficient acceptors, yielding “stronger acceptors,” which are desirable for n‐type polymers. When used as a polymer acceptor in all‐polymer solar cells, an excellent power conversion efficiency of 8.1% is achieved without any solvent additive or thermal treatment, which is the highest value reported for all‐polymer solar cells except well‐studied naphthalene diimide and perylene diimide‐based n‐type polymers. In addition, the solar cells show an energy loss of 0.53 eV, the smallest value reported to date for all‐polymer solar cells with efficiency > 8%. These results demonstrate that fluorination of imide‐functionalized arenes offers an effective approach for developing new electron‐deficient building blocks with improved optoelectronic properties, and the emergence of f‐FBTI2 will change the scenario in terms of developing n‐type polymers for high‐performance all‐polymer solar cells.
Improvement of the Electroluminescence Performance of Exciplex‐Based OLEDs by Effective Utilization of Long‐Range Coupled Electron–Hole Pairs
Authors: Yuan Peisen , Guo Xiaomin , Qiao Xianfeng , Yan Donghang , Ma Dongge 
Published: February 2019

AbstractAn effective method to utilize the radiation of long‐range coupled electron–hole pairs to improve the electroluminescence performance of exciplex‐based organic light‐emitting diodes (OLEDs) is realized by codoping an organic spacer into the bulk‐heterojunction exciplex emitter. The photoluminescence properties of the codoped films reveal that the fraction of delayed fluorescence will be clearly strengthened with an increasing codoping ratio, indicating that more triplet excitons can be utilized effectively, thus greatly enhancing the efficiency of exciplex‐based OLEDs. The maximum external quantum efficiency is improved by ≈105%, from 3.9% to 8.0%, and maintains 7.5% at a luminance of 1000 cd m−2; the codoped devices with the spacer also exhibit excellent spectrum stability under various applied voltages. Magneto‐electroluminescence properties are also investigated to verify the radiative process of long‐range coupled electron–hole pairs. Furthermore, based on this codoped system, low driving voltage, high efficiency, and low efficiency roll‐off are achieved in the orange phosphorescence OLEDs, indicating the advantage of this method in exciton regulation and utilization. This work can assist for further research to achieve high‐performance exciplex‐based OLEDs by adjusting the exciton behavior in device structure design.
Fabrication of Lyotropic Alignment Layers for Thermotropic Liquid Crystals Facilitated by a Polymer Template
Authors: Zhang Bingru , Schmidtke Jürgen , Kitzerow Heinz‐Siegfried 
Published: February 2019

AbstractUniformly aligned layers made of disodium cromoglycate (DSCG) or double‐stranded deoxyribonucleic acid (DNA) are fabricated. For this purpose, a thin liquid layer of a lyotropic chromonic liquid crystal made of DSCG and water or an aqueous solution of DNA is sandwiched between a silica substrate and an anisotropic polyethylene terephthalate film. Removal of the polymer film and subsequent drying yields a highly birefringent solid layer made of DSCG or DNA, respectively. Substrates with these well‐aligned layers can in turn be used to manufacture uniformly aligned samples of a thermotropic liquid crystal. The quality of the alignment is tested by measuring the order parameter of a dye‐doped nematic liquid crystal.
β‐Nitroacrylates as Starting Materials of Thiophene‐2‐Carboxylates Under Continuous Flow Conditions
Authors: Chiurchiù Elena , Patehebieke Yeersen , Gabrielli Serena , Ballini Roberto , Palmieri Alessandro 
Published: February 2019

AbstractWe report herein a general and efficient continuous flow‐based protocol for synthesizing thiophene‐2‐carboxylates starting from ketal‐functionalized β‐nitroacrylates. The protocol involves (i) a promoter‐free conjugate addition of thioacetic acid to β‐nitroacrylates, (ii) a base‐induced elimination of nitrous acid, and (iii) a final acid‐promoted domino cyclization‐aromatization process to afford the title targets. Thanks to the means of the flow chemistry and the use of solid supported systems, the three steps were combined in a whole flow chemical process, by which the products were isolated in good to excellent overall yields (38–88%).magnified image
Metal–Organic Framework: A Novel Material for Triboelectric Nanogenerator–Based Self‐Powered Sensors and Systems
Authors: Khandelwal Gaurav , Chandrasekhar Arunkumar , Maria Joseph Raj Nirmal Prashanth , Kim Sang‐Jae 
Published: February 2019

AbstractThe triboelectric nanogenerator (TENG) offers a simple and cost‐effective method to harness waste energy and works on the principle of contact electrification and electrostatic induction. The performance and application of TENG depend to a great extent on the material used for fabrication. The most widely used materials include polymers and a few metals, well‐arranged in the triboelectric series so as to promote electrification upon contact. New triboelectric materials are important for extending the applications and specificity of the TENG. A TENG based on a metal–organic framework (MOF) of the zeolitic imidazole family is reported here. The zeolitic imidazole framework‐8 (ZIF‐8) and Kapton are used as the active materials for MOF–TENG fabrication. Surface potential, structural, morphological and electrical measurements reveals detailed characteristics of ZIF‐8, confirming the MOF as a potential candidate for TENG applications. The MOF–TENG generates a sustainable output of 164 V and 7 µA in vertical contact–separation mode. Finally, a self‐powered UV counterfeit system and a tetracycline sensor are successfully developed and demonstrated with the MOF–TENG. The sensor is highly selective and reusable simply by washing.
Empowering Change Agents: Youth Organizing Groups as Sites for Sociopolitical Development
Authors: Nicholas Celeste , Eastman‐Mueller Heather , Barbich Natalie 
Published: February 2019

AbstractIn addition to social action campaigns, some youth organizing groups provide formative learning experiences which engage youth in relevant sociopolitical issues through critical approaches. These groups support sociopolitical development (SPD), a self and socially‐oriented process which influences youth personally, politically, and professionally into adulthood. This study explored how youth organizing experiences influenced SPD in the professional domain, applying an empowerment lens. Phenomenologically‐based interviews were conducted with former sexual health education youth organizers and adult program staff. Former youth participants chose socially‐oriented career paths influenced by the group's empowering approach to sexual health education and advocacy. They related meaningful sociopolitical learning experiences (e.g., interpersonal, educational, and civic engagement) to empowerment outcomes (e.g., political efficacy, critical awareness, and participatory behaviors) which informed career decisions. Professionally, participants sought to empower others as the group empowered them, drawing upon youth organizing social and human capital as they worked toward this aim. Combining sociopolitical and empowerment theorizing, the study adds to what is known about how purposefully designed youth organizing experiences support long‐term development outcomes for individuals. Viewed as socially‐oriented career development sites, youth organizing groups build capacity for social change beyond the groups themselves. Implications for youth organizing scholars and practitioners are provided.
Asymmetric 1,3‐Dipolar Cycloaddition Reactions of Enones by Primary Amine Catalysis
Authors: Yang Qi , Zhang Jieyu , Jia Zongbin , Yang Chunming , Zhang Long , Luo Sanzhong 
Published: February 2019

AbstractWe report herein a 1,3‐dipolar cycloaddition between enones and nitrones with good to excellent distereo‐ and enantioselectivities by a chiral primary amine catalyst, which furnishes an operationally simple synthetic protocol for the fused bicyclic isoxazolidine derivatives with multiple stereogenic centers.
Technical note: Comparing dental topography software using platyrrhine molars
Authors: Pampush James D. , Crowell Jordan , Karme Aleksis , Macrae Scott A. , Kay Richard F. , Ungar Peter S. 
Published: February 2019

AbstractObjectivesThere remain many idiosyncrasies among the values calculated for varying dental topography metrics arising from differences in software preferences among research groups. The aim of this work is to compare and provide potential conversion formulae for dental topography metrics calculated using differing software platforms.MethodsThree software packages: ArcGIS, Surfer Manipulator, and molaR were used to calculate orientation patch count rotated (OPCR), Dirichlet normal energy (DNE), occlusal relief (OR), slope (m), and angularity (a) on platyrrhine second upper molars. Values derived from the various software packages were compared for distributional consistency and correlation. Where appropriate, formulae for conversion between like measures calculated on different software platforms were developed.ResultsWhen compared with the same measurement across software, OPCR, OR, and slope were all highly correlated. However, only OR demonstrated distributional consistency (i.e., nearly consistent mean, median, max, and min). Slope and OPCR were both higher when calculated by molaR as compared to Surfer Manipulator and ArcGIS calculations, conversion formulae are provided for these measures. DNE is only weakly correlated with angularity; but is correlated with orientation patch count across taxa.DiscussionWe explore why there is variation in the dental topography values calculated among the various software packages. The conversion formulae provided in this work will make possible direct comparisons among studies conducted across multiple research groups.
A Redox‐Active Nickel Complex that Acts as an Electron Mediator in Photochemical Giese Reactions
Authors: van Leeuwen Thomas , Buzzetti Luca , Perego Luca Alessandro , Melchiorre Paolo 
Published: February 2019

AbstractWe report a simple protocol for the photochemical Giese addition of C(sp3)‐centered radicals to a variety of electron‐poor olefins. The chemistry does not require external photoredox catalysts. Instead, it harnesses the excited‐state reactivity of 4‐alkyl‐1,4‐dihydropyridines (4‐alkyl‐DHPs) to generate alkyl radicals. Crucial for reactivity is the use of a catalytic amount of Ni(bpy)32+ (bpy=2,2′‐bipyridyl), which acts as an electron mediator to facilitate the redox processes involving fleeting and highly reactive intermediates.
Platforms for Stable Carbon‐Centered Radicals
Authors: Kato Kenichi , Osuka Atsuhiro 
Published: February 2019

AbstractOrganic radicals can potentially play important roles in functional materials owing to an unpaired electron, but they are usually highly reactive and difficult to use. Therefore, stabilization of organic radicals is important. Among organic radicals, carbon‐centered radicals are promising because of their trivalent nature, which enables structural diversity and elaborate designs, but they are also less stable because of the reactivities towards carbon–carbon bond formation and atmospheric oxygen. Recently, stable carbon‐centered radicals across diverse molecular platforms have been increasingly explored. This Minireview highlights these newly explored, stable carbon‐centered radicals, with a focus on porphyrinoid‐stabilized radicals because of their remarkable spin delocalization abilities.
Opening up the Single‐Cell Toolbox for Microbial Natural Products Research
Authors: Cahn Jackson K. B. , Piel Jörn 
Published: February 2019

AbstractThe diverse microbes that produce natural products represent an important source of novel therapeutics, drug leads, and scientific tools. However, the vast majority have not been grown in axenic culture and are members of complex communities. While meta‐’omic methods such as metagenomics, ‐transcriptomics, and ‐proteomics reveal collective molecular features of this “microbial dark matter”, the study of individual microbiome members can be challenging. To address these limits, a number of techniques with single‐bacterial resolution have been developed in the last decade and a half. While several of these are embraced by microbial ecologists, there has been less use by researchers interested in mining microbes for natural products. In this review, we discuss the available and emerging techniques for targeted single‐cell analysis with a particular focus on applications to the discovery and study of natural products.
Catalytic Prenylation and Reverse Prenylation of Indoles with Isoprene: Regioselectivity Manipulation through Choice of Metal Hydride
Authors: Hu Yan‐Cheng , Ji Ding‐Wei , Zhao Chao‐Yang , Zheng Hao , Chen Qing‐An 
Published: February 2019

AbstractThe basic industrial feedstock isoprene was employed as a building block to install prenyl and reverse‐prenyl groups onto indoles. The regioselectivity can be manipulated by the choice of metal hydride. Reverse‐prenylated indoles were attained with high selectivity when using Rh−H. By switching to a Pd−H catalyst, selectivity toward prenylated indoles was achieved. This regiodivergent method also features high atom economy without stoichiometric byproduct formation.
Ecofriendly Autoxidation of Castor Oil/Ricinoleic Acid. Multifunctional Macroperoxide Initiators for Multi Block/Graft Copolymers
Authors: Hazer Baki , Eren Melike 
Published: February 2019

AbstractEcofriendly autoxidation is a reaction of air oxygen with unsaturated organic molecules at room temperature. Castor oil and ricinoleic acid were ecofriendly autoxidized for 5 months to obtain castor oil macroperoxide with a Mn of 1935 g mol−1 (Pcast5m) and the ricinoleic acid macroperoxide initiator (Prici5m) with a Mn of 1169 g mol−1. Peroxide groups thermally initiated the free radical polymerization of methyl methacrylate (MMA), n‐butyl methacrylate (nBMA), and styrene (S). Peroxide formation in the oxidized castor oil and ricinoleic acid was confirmed using iodometric analysis, elemental analysis, and differential scanning calorimetry technique. Peroxide decomposition in both macroperoxide initiators was observed at 166 °C for Prici5m and 170 °C for Pcast5m. Hydroxyl groups of Pcast5m were reacted with methacryloyl chloride to obtain methacrylated castor oil macroperoxide (PcastMA). The polymerization rates of the obtained macroinitiators were compared. The polymerization rate order is Pcast5m > Prici5m > PcastMA. Polymerization of styrene by PcastMA resulted in an increase in molar masses and an increase in the polymerization time while those of the styrene polymerization by Pcast5m and Prici5m remained constant. Carboxylic acid groups were reacted with amine‐terminated polyethylene glycol (PEG), polydimethyl siloxane (PDMS), and polytetrahydrofuran (PTHF) while the hydroxyl functionality initiated the ring‐opening polymerization of ε‐caprolactone (CL). Prici‐PEG‐PMMA, Prici‐PS‐PDMS, Prici‐PS‐PTHF, Pcast‐PS‐PCL, Pcast‐PCL‐PMMA, and Pcast‐PS‐PnBMA multiblock copolymers were prepared and characterized using spectrometric, thermal, and stress–strain measurement techniques.
Thermoplastic starch/whey protein isolate/rosemary essential oil nanocomposites obtained by extrusion process: Antioxidant polymers
Authors: Azevedo Viviane Machado , Carvalho Raissa Alvarenga , Borges Soraia Vilela , Claro Pedro Ivo Cunha , Hasegawa Fernando Ken , Yoshida Maria Irene , Marconcini José Manoel 
Published: February 2019

ABSTRACTActive substances are added to polymers to act as a barrier to external elements, protecting the product. This article evaluated the effect of the addition of sodium montmorillonite (MMT) nanoparticles and the antioxidant activity of rosemary essential oil (EO) in thermoplastic starch/whey protein isolate (TPS/WPI) nanocomposites obtained by extrusion. X‐ray diffractograms showed dispersion/exfoliation of the MMT in the TPS/WPI matrix. The nanocomposites presented rough surface with the presence of porosity as shown by scanning electron microscopy images. Thermogravimetric analysis revealed that the combination between MMT and rosemary EO increased thermal stability of nanocomposites. The addition of rosemary EO became the films less rigid, weaker and had an antioxidant effect as shown by mechanical properties and 2,2‐diphenyl‐1‐picrylhydrazyl assay. The optical properties showed in opaque greenish yellow nanocomposites. Therefore, the addition of rosemary EO in nanocomposites showed an alternative for use as antioxidant polymers in packaging material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47619.