bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enamines and Dimethylamino Imines as Building Blocks in Heterocyclic Synthesis: Reactions of DMF‐DMA Reagent with Different Functional Groups
Authors: Gümüş Mehmet , Koca İrfan 
Published: October 2020

AbstractN,N‐Dimethylformamide dimethyl acetal (DMF‐DMA) reagent can react with different functional groups of organic compounds. Enamines and dimethylamino imines are obtained, when the DMF‐DMA reagent is reacted with methylene, methyl and amino groups. These products are formed in the intermediate step in the synthesis of many hetero rings. These compounds are especially used as a starting material in the synthesis of heterostructures such as pyrimidine, pyridine, pyrazole, etc. Therefore, DMF‐DMA has been particularly prominent as a reagent in targeted synthesis and designs of many heterocyclic compounds. Herein, the reactions of DMF‐DMA reagent with different functional groups are categorized in four classes (methylene, methyl, amino, other groups) and the reactions of obtained enamine and dimethylamino imine compounds are investigated in detail such as nucleophilic addition, intramolecular cyclization or condensation reactions. The synthesis and continuation reactions of the enamine and dimethylamino imine compounds are also examined in terms of experimental conditions and reagents used.
New PEG‐Modified Ladder‐Like Silsesquioxane as an Antifoaming Agent
Authors: Goodarzi Faranak , Karimi Ali Reza 
Published: October 2020

AbstractNew ladder‐like silsesquioxane modified with polyethylene glycol as an antifoaming agent based on silicone was synthesized. Silsesquioxane containing polyethylene glycol fragments was successfully fabricated through the reaction of silsesquioxane bearing cyanuric chloride as a linker molecule with polyethylene glycol groups. The structure of the modified silsesquioxane was characterized by middle infrared spectroscopy (MIR), proton nuclear magnetic resonance (1H‐NMR), field emission scanning electron microscopy (FE/SEM), energy‐dispersive X‐ray spectroscopy (EDX), and transmission electron microscopy (TEM). In addition, thermogravimetric analysis (TGA) showed that the new silsesquioxane had excellent thermal stability. This modified structure was used as antifoaming agent for prevention of carryover in boiler systems. Furthermore, the results indicate that the combination of silsesquioxane and polyethylene glycol groups tends to increase the antifoaming properties of the new silicone‐based agent.
Synthesis of 1,1,4,4‐Tetracyanobuta‐1,3‐Dienes using Tetracyanoethylene Oxide via [3+2]‐Cycloaddition‐Ring Opening Reaction
Authors: Dar Arif Hassan , Gowri Vijayendran , Neethu K. M. , Jayamurugan Govindasamy 
Published: October 2020

AbstractUnlike the [3+2] cycloadduct of electron‐donating group (EDG)‐free alkynes with tetracyanoethylene oxide (TCNEO), the EDG induced [3+2] cycloadduct underwent one‐pot ring‐opening and deoxygenation reactions to provide the established EDG‐substituted non‐planar 1,1,4,4‐tetracyanobuta‐1,3‐dienes (TCBDs) push‐pull chromophores. This is an alternate synthetic method that provides access to TCBDs other than the [2+2] cycloaddition–retroelectrocyclization reactions with tetracyanoethene.
Ultrafine CeO2 Nanodots Embedded in Porous ZrO2 for Efficient and Sustainable Chlorine Recycle through Hydrochloric Acid Catalytic Oxidation
Authors: Li Dunfei , Wang Zhicheng , Huang Jincan , Fei Zhaoyang , Cui Mifen , Qiao Xu 
Published: October 2020

AbstractCeria (CeO2) has been regarded as one of the most promising industrial catalysts for hydrochloric acid (HCl) oxidation to replace RuO2‐based catalysts. Thermal sintering and chlorination of CeO2 limit its large‐scale application. In this work, ultrafine CeO2 nanodots embedded in a porous ZrO2 matrix (CeO2@ZrO2) are successfully prepared by a spontaneous deposition method and evaluated in HCl catalytic oxidation for sustainable Cl2 recycle. The physicochemical properties of CeO2@ZrO2 catalysts are characterized by means of XRD, Raman, SEM, TEM, BET, XPS, H2‐TPR and oxygen storage capacity (OSC). The results reveal that all CeO2@ZrO2 catalysts display large specific surface area, pore volume, perfect low‐temperature reduction performance and oxygen storage‐release capacity. More importantly, the unique structure of the CeO2 nanodots isolated by amorphous ZrO2 improves the dispersion and inhibits the sintering of active sites. The optimized 40CeO2@ZrO2 catalyst reveals superior activity (1.90 gCl2 ⋅ gcat−1 ⋅ h−1) and good durability (100 h under 430 °C). Kinetic studies reveal that the adsorption of O2 and HCl is competitive at the active sites, and the desorption of surface Cl is the rate‐determining step.
Synthesis of Chalcone‐Derived Heteroaromatics with Antibacterial Activities
Authors: Jin Hui , Jiang Xia , Yoo Hyebin , Wang Tingshu , Sung Chul Gi , Choi Umji , Lee Chang‐Ro , Yu Haiyang , Koo Sangho 
Published: October 2020

AbstractAn efficient synthetic method of medicinally important chalcone‐derived heteroaromatics was proposed, which comprised of conjugate addition of ethyl acetoacetate to chalcones, followed by MnIII/CoII‐catalyzed oxidative deacetylation. Paal‐Knorr reactions of the resulting 1,4‐dicarbonyl compounds containing various phenyl substituents produced the corresponding 2‐carboethoxy‐3,5‐diphenyl furans, pyrroles, and thiophenes. The scope, mechanism, and electronic requirements for the phenyl substituents of chalcones in the key radical‐medicated deacetylation reaction were fully elucidated. Antibacterial activities of the 21 chalcone‐derived heteroaromatics were screened for Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii. The parent pyrrole 5 a showed most effective inhibition for E. coli and one third of the heteroaromatics exhibited significant inhibition for S. aureus at the concentration of 64 μg/mL.
Simultaneous Determination of Cd2+, Cu2+, Pb2+ and Hg2+ Based on 1,4‐Benzenedithiol‐2,5‐diamino‐hydrochloride‐1,3,5‐triformylbenzene Covalent‐Organic Frameworks
Authors: Yu Jingguo , Han Jiajia , Li Pinghua , Huang Zhenzhong , Chen Shouhui 
Published: October 2020

AbstractIndustry wastewater without purification treatment might contain heavy metal ions (HMIs), and the HMIs in water can induce various diseases regional outbreaks. It is necessary to monitor trace heavy metal ions in water samples. Herein, a covalent‐organic frameworks (COFs), COFBTLP‐1, is synthesized via a solvothermal reaction between 1,3,5‐triformylbenzene and 2,5‐diamino‐1,4‐benzenedithiol dihydrochloride. Two‐dimensional (2D) COFs nanosheets can be easily ultrasonically peeled from the bulk COFs. The COFs nanosheets were porous and flexible. And there are 24 metal ions adsorption sites on every cyclical structure of the COFs, provided by 12 S atoms and 12 N atoms on it. The 2D COFs nanosheets can be directly modified on the glassy carbon electrode without adhesive reagent and conductive reagent. The modified electrode shows high accuracy, high sensitivity, and low limit of detection for the simultaneous determination of four kinds of HMIs, Cd2+, Cu2+ Pb2+, and Hg2+.
In‐Situ Synthesis Graphene Supported TiO2 Nanosheets with Superior Cyclic and Rate Performance for Lithium‐Ion Batteries
Authors: Deng Ding‐Rong , Wu Qi‐Hui 
Published: October 2020

AbstractAnatase‐TiO2/graphene nanosheets (TiO2/GNs) composite with 3D architecture was synthesized via an in‐situ method. The honeycomb‐like structure has a porous nature, high stability and abundant electron/lithium pathways. When the sample was used as an anode material for Li‐ion battery, it showed an excellent electrochemistry performance with superior rate and cyclic performance. The capacity can keep at 184 mA h g−1 at 50 C (16.5 A g−1) after 10000 cycles. While, when the rate increased to as high as 150 C (52.5 A g−1), the reversible capacity can still maintain at above 125 mA h g−1. These results demonstrate the enormous potential of the nanocomposite has great potential applied in long‐life LIBs.
The Improvement on One‐pot Preparation of CoMo/Al2O3‐TiO2 Catalysts with Citric Acid Post‐treatment for Hydrodesulfurization of Thiophene
Authors: Han Dezhi , Xie Wenpeng , Li Qinghong , Chen Guoliang , Zhao Qiang , Zhang Qinqin , Bing Liancheng , Fu Haitao , Wang Fang , Wang Guangjian 
Published: October 2020

AbstractThe preparation of the supported catalysts with the treatment of various chelating agents would significantly influence their physicochemical properties and corresponding catalytic performance. In the present work, three different methods such as the incipient wetness impregnation method, wet mixing method, and the one‐pot method were employed to prepare the CoMo/Al2O3‐TiO2 hydrodesulfurization (HDS) catalysts. After the comprehensive consideration of the characterization and catalytic performance results, the catalyst prepared by the one‐pot method (OP) was further post‐treated by citric acid (CA) with different concentrations. The thiophene conversion over the CA post‐treated catalysts was significantly improved in comparison with that of the parent catalyst, especially for the OP‐C1.5 catalyst (molar ratio of CA/Mo=1.5) with the thiophene conversion higher than 97.2 %. The CA with the appropriate addition amount in the post‐treatment solution can weaken the MoO3‐Al2O3 interaction for promoting the re‐dispersion of Mo species, which is responsible for the enhanced HDS performance over the CA post‐treated catalysts.
A Heart‐Breast Cancer‐on‐a‐Chip Platform for Disease Modeling and Monitoring of Cardiotoxicity Induced by Cancer Chemotherapy
Authors: Lee Junmin , Mehrotra Shreya , Zare‐Eelanjegh Elaheh , Rodrigues Raquel O. , Akbarinejad Alireza , Ge David , Amato Luca , Kiaee Kiavash , Fang YongCong , Rosenkranz Aliza , Keung Wendy , Mandal Biman B. , Li Ronald A. , Zhang Ting , Lee HeaYeon , Dokmeci Mehmet Remzi , Zhang Yu Shrike , Khademhosseini Ali , Shin Su Ryon 
Published: October 2020

AbstractCardiotoxicity is one of the most serious side effects of cancer chemotherapy. Current approaches to monitoring of chemotherapy‐induced cardiotoxicity (CIC) as well as model systems that develop in vivo or in vitro CIC platforms fail to notice early signs of CIC. Moreover, breast cancer (BC) patients with preexisting cardiac dysfunctions may lead to different incident levels of CIC. Here, a model is presented for investigating CIC where not only induced pluripotent stem cell (iPSC)‐derived cardiac tissues are interacted with BC tissues on a dual‐organ platform, but electrochemical immuno‐aptasensors can also monitor cell‐secreted multiple biomarkers. Fibrotic stages of iPSC‐derived cardiac tissues are promoted with a supplement of transforming growth factor‐β 1 to assess the differential functionality in healthy and fibrotic cardiac tissues after treatment with doxorubicin (DOX). The production trend of biomarkers evaluated by using the immuno‐aptasensors well‐matches the outcomes from conventional enzyme‐linked immunosorbent assay, demonstrating the accuracy of the authors’ sensing platform with much higher sensitivity and lower detection limits for early monitoring of CIC and BC progression. Furthermore, the versatility of this platform is demonstrated by applying a nanoparticle‐based DOX‐delivery system. The proposed platform would potentially help allow early detection and prediction of CIC in individual patients in the future.
Educational gender gaps
Authors: Lundberg Shelly 
Published: October 2020

AbstractCross‐country studies reveal two consistent gender gaps in education—underachievement in school by boys and low rates of participation in STEM studies by girls. Recent economics research has shown the importance of social influences on women's STEM avoidance, but male low achievement has been less‐studied and tends to be attributed to behavior problems and deficient non‐cognitive skills. I revisit the determinants of the gender gap in U.S. educational attainment with a relatively‐advantaged sample of young men and women and find that school behavior and measured skills are not very important drivers of gender differences, particularly in the transition to college. Educational aspirations, on the other hand, are strongly predictive of educational gaps and the gender difference in aspirations cannot be explained, even with rich adolescent data that includes parental expectations and school achievement indicators. These results suggest that gender identity concerns may influence (and damage) the educational prospects of boys as well as girls through norms of masculinity that discourage academic achievement.
Complex Langevin calculations in QCD at finite density
Authors: Ito Yuta , Matsufuru Hideo , Namekawa Yusuke , Nishimura Jun , Shimasaki Shinji , Tsuchiya Asato , Tsutsui Shoichiro 
Published: October 2020

Abstract
We demonstrate that the complex Langevin method (CLM) enables calculations in QCD at finite density in a parameter regime in which conventional methods, such as the density of states method and the Taylor expansion method, are not applicable due to the severe sign problem. Here we use the plaquette gauge action with β = 5.7 and four-flavor staggered fermions with degenerate quark mass ma = 0.01 and nonzero quark chemical potential μ. We confirm that a sufficient condition for correct convergence is satisfied for μ/T = 5.2 − 7.2 on a 83 × 16 lattice and μ/T = 1.6 − 9.6 on a 163 × 32 lattice. In particular, the expectation value of the quark number is found to have a plateau with respect to μ with the height of 24 for both lattices. This plateau can be understood from the Fermi distribution of quarks, and its height coincides with the degrees of freedom of a single quark with zero momentum, which is 3 (color) × 4 (flavor) × 2 (spin) = 24. Our results may be viewed as the first step towards the formation of the Fermi sphere, which plays a crucial role in color superconductivity conjectured from effective theories.
$$ \mathcal{N} $$ = 1 supersymmetric Double Field Theory and the generalized Kerr-Schild ansatz
Authors: Lescano Eric , Rodríguez Jesús A. 
Published: October 2020

Abstract
We construct the $$ \mathcal{N} $$
N
= 1 supersymmetric extension of the generalized Kerr-Schild ansatz in the flux formulation of Double Field Theory. We show that this ansatz is compatible with $$ \mathcal{N} $$
N
= 1 supersymmetry as long as it is not written in terms of generalized null vectors. Supersymmetric consistency is obtained through a set of conditions that imply linearity of the generalized gravitino perturbation and unrestricted perturbations of the generalized background dilaton and dilatino. As a final step we parametrize the previous theory in terms of the field content of the low energy effective 10-dimensional heterotic supergravity and we find that the perturbation of the 10-dimensional vielbein, Kalb-Ramond field, gauge field, gravitino and gaugino can be written in terms of vectors, as expected.
Spectral theories and topological strings on del Pezzo geometries
Authors: Moriyama Sanefumi 
Published: October 2020

Abstract
Motivated by understanding M2-branes, we propose to reformulate partition functions of M2-branes by quantum curves. Especially, we focus on the backgrounds of del Pezzo geometries, which enjoy Weyl group symmetries of exceptional algebras. We construct quantum curves explicitly and turn to the analysis of classical phase space areas and quantum mirror maps. We find that the group structure helps in clarifying previous subtleties, such as the shift of the chemical potential in the area and the identification of the overall factor of the spectral operator in the mirror map. We list the multiplicities characterizing the quantum mirror maps and find that the decoupling relation known for the BPS indices works for the mirror maps. As a result, with the group structure we can present explicitly the statement for the correspondence between spectral theories and topological strings on del Pezzo geometries.
Growth cone repulsion to Netrin-1 depends on lipid raft microdomains enriched in UNC5 receptors
Authors: Hernaiz-Llorens Marc , Roselló-Busquets Cristina , Durisic Nela , Filip Adam , Ulloa Fausto , Martínez-Mármol Ramón , Soriano Eduardo 
Published: October 2020

AbstractDuring brain development, Uncoordinated locomotion 5 (UNC5) receptors control axonal extension through their sensing of the guidance molecule Netrin-1. The correct positioning of receptors into cholesterol-enriched membrane raft microdomains is crucial for the efficient transduction of the recognized signals. However, whether such microdomains are required for the appropriate axonal guidance mediated by UNC5 receptors remains unknown. Here, we combine the use of confocal microscopy, live-cell FRAP analysis and single-particle tracking PALM to characterize the distribution of UNC5 receptors into raft microdomains, revealing differences in their membrane mobility properties. Using pharmacological and genetic approaches in primary neuronal cultures and brain cerebellar explants we further demonstrate that disrupting raft microdomains inhibits the chemorepulsive response of growth cones and axons against Netrin-1. Together, our findings indicate that the distribution of all UNC5 receptors into cholesterol-enriched raft microdomains is heterogeneous and that the specific localization has functional consequences for the axonal chemorepulsion against Netrin-1.
The Seismic Source Parameters of Tremors Provoked by Long-Hole Destress Blasting Executed During the Longwall Mining of a Coal Seam Under Variable Stress Conditions
Authors: Wojtecki Łukasz , Mendecki Maciej J. , Gołda Iwona , Zuberek Wacław M. 
Published: October 2020

AbstractThe underground mining of coal seams in the Upper Silesian Coal Basin is carried out at great depths and mostly in the presence of remnants or edges of other surrounding coal seams, i.e. under the condition of high stress level in the rock mass. Therefore, this mining is accompanied by rockburst hazard and suitable preventive action is required. Long-hole destress blasting plays an important role and is commonly applied in rockburst prevention in underground hard coal mines. Estimated blasting effectiveness is important when designing rockburst prevention. It is commonly estimated on the basis of the seismic energy of a provoked tremor. The seismic source parameters have already been considered for this purpose. Additional information about the effects of long-hole destress blasting could be contemplated in the planning of active rockburst prevention. The seismic source parameters of tremors provoked by long-hole destress blasting have been calculated and are presented in this article. Destress blasts were performed during the longwall mining of coal seam no. 506 in one of the hard coal mines in the Upper Silesian Coal Basin. They were executed from the longwall face, in order to destress the rock mass ahead of it. Parameters of the blasts were variable and they were modified according to geological and mining conditions and the observed level of rockburst hazard. The seismic source parameters have been determined for tremors provoked directly after firing explosives and for tremors occurring in the waiting time, and they have been compared with each other.
Rekombinante Allergene, Peptide und Virus-like Particles in der Immuntherapie von Allergien
Authors: Holzhauser Thomas , Schuler Frank , Dudek Simone , Kaul Susanne , Vieths Stefan , Mahler Vera 
Published: October 2020

Zusammenfassung
Aktuell werden extraktbasierte Therapieallergene aus natürlichen Allergenquellen (z. B. Hausstaubmilben, Baum- und Gräserpollen) zur allergenspezifischen Immuntherapie (AIT) eingesetzt, dem einzigen kausalen Therapieansatz, der durch Toleranzentwicklung allergische Erkrankungen positiv verändern und langfristig eine Krankheitsprogression verhindern kann. Aufgrund von Schwankungen in der natürlichen Zusammensetzung der Ausgangsmaterialien und unterschiedlichen Herstellungsprozessen ergeben sich Varianzen in Proteingehalt, Allergenkomposition und allergener Aktivität gleichlautender Produkte, was spezifische Herausforderungen an ihre Standardisierung stellt. Die Aufklärung der Nukleotidsequenzen allergieauslösender Proteine führte zur Entwicklung molekularer AIT-Ansätze. Dies ermöglicht die Applikation von ausschließlich allergologisch relevanten Strukturen und schließt chemisch synthetisierte Peptide, rekombinante Einzelallergene und Therapiemoleküle mit hypoallergenen Eigenschaften ein, die potenziell eine Auftitration mit höheren Allergendosen ohne allergische Nebenwirkungen und schnelleres Erreichen der wirksamen kumulativen Dosis ermöglichen. Zudem lassen sich weitere Modifikationen der AIT-Ansätze zur Verbesserung der allergenen und immunogenen Eigenschaften, wie zum Beispiel durch Verwendung von Virus-like Particles (VLP), erreichen. Bis dato sind die hier beschriebenen AIT-Ansätze ausschließlich in der klinischen Erprobung. Dieser Artikel gibt eine Übersicht über die publizierten, in klinischen AIT-Studien eingesetzten molekularen Allergietherapeutika. Ihr Mehrwert sowie Herausforderungen gegenüber etablierten Therapieallergenen werden diskutiert. Ziel ist die Entwicklung hochwirksamer und verträglicher AIT-Präparate mit einer verbesserten Patientenakzeptanz und -adhärenz.
Torus-like Solutions for the Landau-de Gennes Model. Part I: The Lyuksyutov Regime
Authors: Dipasquale Federico , Millot Vincent , Pisante Adriano 
Published: October 2020

AbstractWe study global minimizers of a continuum Landau-de Gennes energy functional for nematic liquid crystals, in three-dimensional domains, under a Dirichlet boundary condition. In a relevant range of parameters (which we call theLyuksyutov regime), the main result establishes the nontrivial topology of the biaxiality sets of minimizers for a large class of boundary conditions including the homeotropic boundary data. To achieve this result, we first study minimizers subject to a physically relevant norm constraint (theLyuksyutov constraint), and show their regularity up to the boundary. From this regularity, we rigorously derive the norm constraint from the asymptotic Lyuksyutov regime. As a consequence, isotropic melting is avoided by unconstrained minimizers in this regime, which then allows us to analyse their biaxiality sets. In the case of a nematic droplet, this also implies that the radial hedgehog is an unstable equilibrium in the same regime of parameters. Technical results of this paper will be largely employed in Dipasquale et al. (Torus-like solutions for the Landau- de Gennes model. Part II: topology of$$\mathbb {S}^1$$S1-equivariant minimizers.https://arxiv.org/pdf/2008.13676.pdf; Torus-like solutions for the Landau- de Gennes model. Part III: torus solutions vs split solutions (In preparation)), where we prove that biaxiality level sets are generically finite unions of tori for smooth configurations minimizing the energy in restricted classes of axially symmetric maps satisfying a topologically nontrivial boundary condition.