jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yakui Deng | Yuan Yuan | Yulan Chen
Source: CCS Chemistry (article, 2020-07-09)
Field: Chemistry — Organic Chemistry

Covalently Cross-Linked and Mechanochemiluminescent Polyolefins Capable of Self-Healing and Self-Reporting Compared with non-cross-linked and dynamically covalent polymers, covalently cross-linked networks are irreplaceable in many areas; however, they are difficult to repair once fractured, due to limited polymer chain diffusion after cross-linking. Herein, the authors have reported a new kind of permanently cross-linked polyolefin, which when attached with amide side groups, yield mechanically robust yet readily repairable materials. A key is to use low cross-linking density, which enables satisfactory elasticity and chain mobility for thermodynamically favored healing. Another key is to incorporate dense hydrogen bonds that can undergo reversible associations. These factors jointly promise polyolefin networks with good mechanical properties and self-healing performance (recovered spontaneously up to 96% of its original tensile strength). More importantly, by means of mechanochemiluminescence from 1,2-dioxetane, which serves as the cross-linker and built-in self-reporting stress probe, a microscopic evaluation of how the chain entanglement proceeds upon healing and how failure occurs in the network can be obtained. Polyolefin ; Covalent bond ; Polymer science ; Polymer ; Nanotechnology ; Chemistry ; Materials science ; Organic chemistry Antimicrobial agents and applications ; Polydiacetylene-based materials and applications ; Luminescence and Fluorescent Materials
Authors: Laís Ribovski | Qihui Zhou | Jiawen Chen | Ben L. Feringa | Patrick van Rijn | Inge S. Zuhorn
Source: Chemical Communications (article, 2020-01-01)
Field: Materials Science — Biomaterials

Light-induced molecular rotation triggers on-demand release from liposomes Controllable molecular release from delivery vehicles is essential to successfully reduce drug toxicity and improve therapeutic efficacy. Light-powered hydrophobic molecular motors were therefore incorporated in liposomes to use molecular rotation to facilitate on-demand release. The extent of the release was precisely controlled by irradiation times, providing a simple yet sophisticated responsive molecular nanocarrier. Liposome ; Rotation (mathematics) ; On demand ; Chemistry ; Biophysics ; Nanotechnology ; Materials science ; Computer science ; Biology ; Artificial intelligence Nanoparticle-Based Drug Delivery ; Supramolecular Chemistry and Complexes ; Dendrimers and Hyperbranched Polymers
Authors: Ikuro Abe
Source: Chemical and Pharmaceutical Bulletin (review, 2020-08-31)
Field: Chemistry — Inorganic Chemistry

Nonheme Iron- and 2-Oxoglutarate-Dependent Dioxygenases in Fungal Meroterpenoid Biosynthesis This review summarizes the recent progress in research on the non-heme Fe(II)- and 2-oxoglutarate-dependent dioxygenases, which are involved in the biosynthesis of pharmaceutically important fungal meroterpenoids. This enzyme class activates a selective C-H bond of the substrate and catalyzes a wide range of chemical reactions, from simple hydroxylation to dynamic carbon skeletal rearrangements, thereby significantly contributing to the structural diversification and complexification of the molecules. Structure-function studies of these enzymes provide an excellent platform for the development of useful biocatalysts for synthetic biology to create novel molecules for future drug discovery. Biosynthesis ; Hydroxylation ; Chemistry ; Drug discovery ; Heme ; Enzyme ; Chemical biology ; Synthetic biology ; Stereochemistry ; Molecule ; Biochemistry ; Biology ; Computational biology ; Organic chemistry Metal-Catalyzed Oxygenation Mechanisms ; Microbial Natural Products and Biosynthesis ; Enzyme-mediated dye degradation
Authors: Caleb D. Watson | Michela Martinelli | Donald C. Cronauer | A. Jeremy Kropf | Christopher L. Marshall | Gary Jacobs
Source: Applied Catalysis A General (article, 2020-04-19)
Field: Materials Science — Materials Chemistry

Low temperature water-gas shift: Optimization of K loading on Pt/m-ZrO2 for enhancing CO conversion Formate ; Catalysis ; Dehydrogenation ; Chemistry ; Platinum ; Decomposition ; Inorganic chemistry ; Nanoparticle ; Photochemistry ; Materials science ; Nanotechnology ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Electrocatalysts for Energy Conversion
Authors: Rohan A. Shirwaiker | Matthew B. Fisher | B. E. Anderson | Karl G. Schuchard | Paul B. Warren | Benoît Mazé | Pierre Grondin | Frances S. Ligler | Behnam Pourdeyhimi
Source: Tissue Engineering Part C Methods (article, 2020-06-18)
Field: Materials Science — Biomaterials

High-Throughput Manufacture of 3D Fiber Scaffolds for Regenerative Medicine Engineered scaffolds used to regenerate mammalian tissues should recapitulate the underlying fibrous architecture of native tissue to achieve comparable function. Current fibrous scaffold fabrication processes, such as electrospinning and three-dimensional (3D) printing, possess application-specific advantages, but they are limited either by achievable fiber sizes and pore resolution, processing efficiency, or architectural control in three dimensions. As such, a gap exists in efficiently producing clinically relevant, anatomically sized scaffolds comprising fibers in the 1-100 μm range that are highly organized. This study introduces a new high-throughput, additive fibrous scaffold fabrication process, designated in this study as 3D melt blowing (3DMB). The 3DMB system described in this study is modified from larger nonwovens manufacturing machinery to accommodate the lower volume, high-cost polymers used for tissue engineering and implantable biomedical devices and has a fiber collection component that uses adaptable robotics to create scaffolds with predetermined geometries. The fundamental process principles, system design, and key parameters are described, and two examples of the capabilities to create scaffolds for biomedical engineering applications are demonstrated. Impact statement Three-dimensional melt blowing (3DMB) is a new, high-throughput, additive manufacturing process to produce scaffolds composed of highly organized fibers in the anatomically relevant 1-100 μm range. Unlike conventional melt-blowing systems, the 3DMB process is configured for efficient use with the relatively expensive polymers necessary for biomedical applications, decreasing the required amounts of material for processing while achieving high throughputs compared with 3D printing or electrospinning. The 3DMB is demonstrated to make scaffolds composed of multiple fiber materials and organized into complex shapes, including those typical of human body parts. 3D printing ; Electrospinning ; Scaffold ; Fiber ; Materials science ; Tissue engineering ; Fabrication ; Throughput ; Nanotechnology ; Process (computing) ; Computer science ; Polymer ; Biomedical engineering ; Composite material ; Engineering Electrospun Nanofibers in Biomedical Applications ; Tissue Engineering and Regenerative Medicine ; Additive Manufacturing and 3D Printing Technologies
Authors: Gaowa Naren | Shiming Li | Joakim Andréasson
Source: Chemical Communications (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

A simplicity-guided cocktail approach toward multicolor fluorescent systems A molecular cocktail containing two photochromic diarylethene derivatives that displays multicolor emission spanning blue-green to orange in a color-correlated fashion has been devised. The function does not rely on excited state communication such as energy transfer reactions, which is the typical case for similar systems. Instead, harnessing the intrinsic fluorescent and photochromic properties of the two individual diarylethene derivatives run in parallel is enough to realize the color changes. This offers an extremely flexible situation as for the choice of the fluorophores and their respective concentrations. The function is conveniently demonstrated in bulk solution at μM concentrations, where a single light source serves as the color changing stimulus. Fluorescence ; Simplicity ; Chemistry ; Computer science ; Biochemical engineering ; Nanotechnology ; Simple (philosophy) ; Combinatorial chemistry ; Biological system ; Materials science ; Biology ; Engineering ; Physics ; Philosophy ; Epistemology ; Optics Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Olfactory and Sensory Function Studies
Authors: Kae Ken Foo | Nathalie Lamoureux | Armelle Cessou | Corine Lacour | Pascale Desgroux
Source: Journal of Quantitative Spectroscopy and Radiative Transfer (article, 2020-08-13)
Field: Chemistry — Spectroscopy

The accuracy and precision of multi-line NO-LIF thermometry in a wide range of pressures and temperatures Narrowband ; Line (geometry) ; Spectral line ; Materials science ; Adiabatic process ; Temperature measurement ; Computational physics ; Range (aeronautics) ; Accuracy and precision ; Broadband ; Optics ; Physics Spectroscopy and Laser Applications ; Combustion and flame dynamics ; Chemical Thermodynamics and Molecular Structure
Authors: David Martínez‐López | Eduardo Santamaría‐Aranda | Marco Marazzi | Cristina García‐Iriepa | Diego Sampedro
Source: Chemistry - A European Journal (article, 2020-12-01)
Field: Materials Science — Materials Chemistry

π‐Bridge Substitution in DASAs: The Subtle Equilibrium between Photochemical Improvements and Thermal Control** Donor-acceptor Stenhouse adducts (DASAs) are playing an outstanding role as innovative and versatile photoswitches. Until now, all the efforts have been spent on modifying the donor and acceptor moieties to modulate the absorption energy and improve the cyclization and reversion kinetics. However, there is a strong dependence on specific structural modifications and a lack of predictive behavior, mostly owing to the complex photoswitching mechanism. Here, by means of a combined experimental and theoretical study, the effect of chemical modification of the π-bridge linking the donor and acceptor moieties is systematically explored, revealing the significant impact on the absorption, photocyclization, and relative stability of the open form. In particular, a position along the π-bridge is found to be the most suited to redshift the absorption while preserving the cyclization. However, thermal back-reaction to the initial isomer is blocked. These effects are explained in terms of an increased acceptor capability offered by the π-bridge substituent that can be modulated. This strategy opens the path toward derivatives with infra-red absorption and a potential anchoring point for further functionalization. Absorption (acoustics) ; Substituent ; Chemistry ; Acceptor ; Photochemistry ; Isomerization ; Materials science ; Catalysis ; Stereochemistry ; Organic chemistry Photochromic and Fluorescence Chemistry ; Porphyrin and Phthalocyanine Chemistry ; Photoreceptor and optogenetics research
Authors: Marcel Krug | Nina Fröhlich | Dominik Fehn | Alexander L. Vogel | Frank Röminger | Karsten Meyer | Timothy Clark | Milan Kivala | Dirk M. Guldi
Source: Angewandte Chemie International Edition (article, 2020-12-11)
Field: Chemistry — Physical and Theoretical Chemistry

Pre‐Planarized Triphenylamine‐Based Linear Mixed‐Valence Charge‐Transfer Systems Three linear dimers with two redox-active planarized triphenylamines were synthesized and their structures verified by X-ray crystallography. Their radical cations, which exhibit electron self-exchange between the two redox centers, are of great interest. This process was thoroughly investigated by means of electron paramagnetic resonance spectroscopy, absorption spectroscopy, and (time-dependent) density functional theory calculations. A comparison of the key parameters of electron transfer with non-planarized nitrogen-centered building blocks emphasizes the impact of using redox centers with low internal reorganization energies. However, the distance-dependence attenuation factor of the super-exchange mechanisms remains similar. Redox ; Density functional theory ; Electron transfer ; Electron paramagnetic resonance ; Triphenylamine ; Spectroscopy ; Chemistry ; Valence (chemistry) ; Absorption spectroscopy ; Electron ; Materials science ; Photochemistry ; Chemical physics ; Computational chemistry ; Nuclear magnetic resonance ; Inorganic chemistry ; Physics Photochemistry and Electron Transfer Studies ; Molecular Junctions and Nanostructures ; Synthesis and Properties of Aromatic Compounds
Authors: Daichi Kato | Kazuhiko Kuroki
Source: Physical Review Research (article, 2020-05-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Many-variable variational Monte Carlo study of superconductivity in two-band Hubbard models with an incipient band The authors adopt a multivariable variational Monte Carlo technique to study bilayer and two-leg ladder Hubbard models from the weakly correlated to strongly correlated regimes. Conditions for superconductivity to be strongly enhanced are presented, and the underlying physics for this enhancement is revealed Hubbard model ; Superconductivity ; Monte Carlo method ; Variational Monte Carlo ; Quantum Monte Carlo ; Variational method Iron-based superconductors research ; Physics of Superconductivity and Magnetism ; Superconductivity in MgB2 and Alloys
Authors: Ryan Muzzio | Alfred J. H. Jones | Davide Curcio | Deepnarayan Biswas | Jill A. Miwa | Philip Hofmann | Kenji Watanabe | Takashi Taniguchi | Simranjeet Singh | Chris Jozwiak | Eli Rotenberg | Aaron Bostwick | Roland J. Koch | Søren Ulstrup | Jyoti Katoch
Source: Physical review. B./Physical review. B (article, 2020-05-26)
Field: Materials Science — Materials Chemistry

Momentum-resolved view of highly tunable many-body effects in a graphene/hBN field-effect device Integrating the carrier tunability of a functional two-dimensional material electronic device with a direct probe of energy- and momentum-resolved electronic excitations is essential to gain insights on how many-body interactions are influenced during device operation. Here, we use microfocused angle-resolved photoemission in order to analyze many-body interactions in back-gated graphene supported on hexagonal boron nitride. By extracting the doping-dependent quasiparticle dispersion and self-energy, we observe how these interactions renormalize the Dirac cone and impact the electron mobility of our device. Our results are not only limited to a finite energy range around the Fermi level, as in electron transport measurements, but describe interactions on a much wider energy scale, extending beyond the regime of hot carrier excitations. Graphene ; Field (mathematics) ; Materials science ; Momentum (technical analysis) ; Nanotechnology ; Optoelectronics ; Physics ; Engineering physics ; Business Graphene research and applications ; Quantum and electron transport phenomena ; Diamond and Carbon-based Materials Research
Authors: Thomas Boele | David E. J. Waddington | T. Gaebel | Ewa Rej | A. Hasija | Louise J. Brown | Dane R. McCamey | D. J. Reilly
Source: Physical review. B./Physical review. B (article, 2020-04-17)
Field: Materials Science — Materials Chemistry

Tailored nanodiamonds for hyperpolarized <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">C</mml:mi><mml:mprescripts/><mml:none/><mml:mn>13</mml:mn></mml:mmultiscripts></mml:math> MRI Nanodiamond is poised to become an attractive material for hyperpolarized $^{13}\mathrm{C}$ magnetic resonance imaging if large nuclear polarizations can be achieved without the accompanying rapid spin-relaxation driven by paramagnetic species. Here we report enhanced and long-lived $^{13}\mathrm{C}$ polarization in synthetic nanodiamonds tailored by acid-cleaning and air-oxidation protocols. Our results separate the contributions of different paramagnetic species on the polarization behavior, identifying the importance of substitutional nitrogen defect centers in the nanodiamond core. These results are likely of use in the development of nanodiamond-based imaging agents with size distributions of relevance for examining biological processes. Nanodiamond ; Paramagnetism ; Materials science ; Physics ; Nuclear magnetic resonance ; Algorithm ; Computer science ; Condensed matter physics Diamond and Carbon-based Materials Research ; Atomic and Subatomic Physics Research ; High-pressure geophysics and materials
Authors: Xuanyu Long | Shunhong Zhang | Fa Wang | Zheng Liu
Source: npj Quantum Materials (article, 2020-07-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A first-principle perspective on electronic nematicity in FeSe Abstract Electronic nematicity is an important order in most iron-based superconductors, and FeSe represents a special example, in which nematicity disentangles from spin ordering. A first-principle description of this order remains elusive. Here, we show that by carefully searching the paramagnetic energy landscape within the density functional theory, a nematic solution stands out at either the + U or hybrid functional level with the lowest energy. The band structure and Fermi surface can be well compared with the recent experimental results. Symmetry analysis assigns the dominant order parameter to the E u irreducible representations of the D 4h point group. Distinct from the B 1g Ising nematicity as widely discussed in the context of vestigial stripe antiferromagnetic order, the two-component E u vector order features mixing of the Fe d -orbitals and inversion symmetry breaking, which lead to striking experimental consequences, e.g., missing of an electron pocket. Antiferromagnetism ; Physics ; Condensed matter physics ; Fermi surface ; Superconductivity ; Order (exchange) ; Symmetry (geometry) ; Theoretical physics ; Mathematics Iron-based superconductors research ; Rare-earth and actinide compounds ; Advanced Condensed Matter Physics
Authors: Alejandro López‐Bezanilla | P. B. Littlewood
Source: MRS Communications (article, 2020-01-14)
Field: Materials Science — Materials Chemistry

Growing field of materials informatics: databases and artificial intelligence Data science ; Materials informatics ; Software deployment ; Computer science ; Field (mathematics) ; Informatics ; Big data ; Nanotechnology ; Materials science ; Health informatics ; Data mining ; Engineering ; Software engineering Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Catalysis and Oxidation Reactions
Authors: K. Colton Flynn | Amy E. Frazier | Sintayehu Admas
Source: Remote Sensing (article, 2020-09-04)
Field: Chemistry — Analytical Chemistry

Nutrient Prediction for Tef (Eragrostis tef) Plant and Grain with Hyperspectral Data and Partial Least Squares Regression: Replicating Methods and Results across Environments Achieving reproducibility and replication (R&amp;R) of scientific results is tantamount for science to progress, and it is also necessary for ensuring the self-correcting mechanism of the scientific method. Topics of R&amp;R have sailed to the forefront of research agenda in many fields recently but have received less attention in remote sensing in general and specifically for studies utilizing hyperspectral data. Given the extremely local environments in which many hyperspectral studies are conducted (e.g., agricultural field plots), purposeful attention to the repeatability of findings across study locales can help ensure methods are generalizable. This study undertakes an investigation of the nutrient content of tef (Eragrostis tef), an understudied plant that is growing in importance due to both food and forage benefits, but does so within the context of the replicability of methods and findings across two study sites situated in different international and environmental contexts. The aims are to (1) determine whether calcium, magnesium, and protein of both the plant and grain can be predicted using hyperspectral data with partial least squares (PLS) regression with waveband selection, and (2) compare the replicability of models across differing environments. Results suggest the method can produce high nutrient prediction accuracy for both the plant and grain in individual environments, but selection of wavebands for nutrient prediction was not comparable across study areas. The findings suggest that the method must be calibrated in each location, thereby reducing the potential to extrapolate methods to different areas. Our findings highlight the need for greater attention to methods and results replication in remote sensing, specifically hyperspectral analyses, in order for scientific findings to be repeatable beyond the plot level. Hyperspectral imaging ; Eragrostis ; Partial least squares regression ; Context (archaeology) ; Ordinary least squares ; Nutrient ; Environmental science ; Regression ; Computer science ; Agricultural engineering ; Statistics ; Soil science ; Agronomy ; Mathematics ; Ecology ; Machine learning ; Biology ; Artificial intelligence Spectroscopy and Chemometric Analyses ; Remote Sensing in Agriculture ; Soil Geostatistics and Mapping
Authors: Yongzhe Tang | Guanghui Ge | Yuxia Li | Liangsong Huang
Source: Materials (article, 2020-09-23)
Field: Materials Science — Materials Chemistry

Effect of Al2O3 with Different Nanostructures on the Insulating Properties of Epoxy-Based Composites High thermal conductivity insulating dielectrics with good electrical properties have received widespread attention due to the continuous development of power systems and power electronic technologies. In this paper, the effects of differently structured nano alumina fillers on the thermal conductivity and insulating properties of polymer-based composites were studied. It was found that all three types of Al<sub>2</sub>O<sub>3</sub> nano-fillers enhanced the thermal conductivity of the composites, and the thermal conductivity increased more dramatically with increasing filler particle size. It is worth noting that Al<sub>2</sub>O<sub>3</sub> nanowires (NWs) exhibited the most significant improvement in thermal conductivity. The volume resistivity of the composites first increased and then decreased with increasing mass fraction of fillers, and Al<sub>2</sub>O<sub>3</sub> nanoplates (NPLs) showed the most significant improvement in the insulation performance of the composites. The dielectric constants of the composites increased with increasing mass fraction of fillers, while the dielectric losses first decreased and then increased with the same trend, yet the mass fractions of fillers for the three materials were different when the dielectric loss reached a minimum. In addition, all three types of filler increased the AC breakdown strength of the composites, but Al<sub>2</sub>O<sub>3</sub>-NPLs showed the most significant improvement on the breakdown performance of the composites. Materials science ; Composite material ; Dielectric ; Thermal conductivity ; Mass fraction ; Epoxy ; Filler (materials) ; Nanocomposite ; Volume fraction ; Electrical resistivity and conductivity ; Dielectric loss ; Conductivity High voltage insulation and dielectric phenomena ; Dielectric materials and actuators ; Electromagnetic wave absorption materials