jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Fernando Martínez‐Plumed | Pablo Barredo | Seán Ó hÉigeartaigh | José Hernández‐Orallo
Source: Nature Machine Intelligence (article, 2021-05-17)
Field: Materials Science — Materials Chemistry

Research community dynamics behind popular AI benchmarks The widespread use of experimental benchmarks in AI research has created competition and collaboration dynamics that are still poorly understood. Here we provide an innovative methodology to explore these dynamics and analyse the way different entrants in these challenges, from academia to tech giants, behave and react depending on their own or others’ achievements. We perform an analysis of 25 popular benchmarks in AI from Papers With Code, with around 2,000 result entries overall, connected with their underlying research papers. We identify links between researchers and institutions (that is, communities) beyond the standard co-authorship relations, and we explore a series of hypotheses about their behaviour as well as some aggregated results in terms of activity, performance jumps and efficiency. We characterize the dynamics of research communities at different levels of abstraction, including organization, affiliation, trajectories, results and activity. We find that hybrid, multi-institution and persevering communities are more likely to improve state-of-the-art performance, which becomes a watershed for many community members. Although the results cannot be extrapolated beyond our selection of popular machine learning benchmarks, the methodology can be extended to other areas of artificial intelligence or robotics, and combined with bibliometric studies. Experimental benchmarks such as ImageNet and Atari games play an important part in advancing artificial intelligence research. An analysis of results and papers linked to 25 popular benchmarks shows that research dynamics beyond conventional co-authorship has developed in this area. Computer science ; Dynamics (music) ; Artificial intelligence ; Competition (biology) ; Abstraction ; Data science ; Institution ; Selection (genetic algorithm) ; Machine learning ; Sociology ; Social science ; Epistemology ; Ecology Machine Learning in Materials Science ; Explainable Artificial Intelligence (XAI) ; Complex Network Analysis Techniques
Authors: Andrea Baschieri | Riccardo Amorati
Source: Antioxidants (review, 2021-09-29)
Field: Chemistry — Organic Chemistry

Methods to Determine Chain-Breaking Antioxidant Activity of Nanomaterials beyond DPPH•. A Review This review highlights the progress made in recent years in understanding the mechanism of action of nanomaterials with antioxidant activity and in the chemical methods used to evaluate their activity. Nanomaterials represent one of the most recent frontiers in the research for improved antioxidants, but further development is hampered by a poor characterization of the ''antioxidant activity'' property and by using oversimplified chemical methods. Inhibited autoxidation experiments provide valuable information about the interaction with the most important radicals involved in the lipid oxidation, namely alkylperoxyl and hydroperoxyl radicals, and demonstrate unambiguously the ability to stop the oxidation of organic materials. It is proposed that autoxidation methods should always complement (and possibly replace) the use of assays based on the quenching of stable radicals (such as DPPH<sup>•</sup> and ABTS<sup>•+</sup>). The mechanisms leading to the inhibition of the autoxidation (sacrificial and catalytic radical trapping antioxidant activity) are described in the context of nanoantioxidants. Guidelines for the selection of the appropriate testing conditions and of meaningful kinetic analysis are also given. Autoxidation ; Hydroperoxyl ; Antioxidant ; Chemistry ; Context (archaeology) ; Radical ; ABTS ; DPPH ; Quenching (fluorescence) ; Organic chemistry ; Biology Free Radicals and Antioxidants ; Electrochemical Analysis and Applications ; Advanced Nanomaterials in Catalysis
Authors: Jan Belza | Ariana Opletalová | Kateřina Poláková
Source: Microchimica Acta (review, 2021-11-25)
Field: Materials Science — Materials Chemistry

Carbon dots for virus detection and therapy Recent experience with the COVID-19 pandemic should be a lesson learnt with respect to the effort we have to invest in the development of new strategies for the treatment of viral diseases, along with their cheap, easy, sensitive, and selective detection. Since we live in a globalized world where just hours can play a crucial role in the spread of a virus, its detection must be as quick as possible. Thanks to their chemical stability, photostability, and superior biocompatibility, carbon dots are a kind of nanomaterial showing great potential in both the detection of various virus strains and a broad-spectrum antiviral therapy. The biosensing and antiviral properties of carbon dots can be tuned by the selection of synthesis precursors as well as by easy post-synthetic functionalization. In this review, we will first summarize current options of virus detection utilizing carbon dots by either electrochemical or optical biosensing approaches. Secondly, we will cover and share the up-to-date knowledge of carbon dots' antiviral properties, which showed promising activity against various types of viruses including SARS-CoV-2. The mechanisms of their antiviral actions will be further adressed as well. Finally, we will discuss the advantages and distadvantages of the use of carbon dots in the tangled battle against viral infections in order to provide valuable informations for further research and development of new virus biosensors and antiviral therapeutics. Virus ; Virology ; Medicine Carbon and Quantum Dots Applications ; Advanced biosensing and bioanalysis techniques ; Nanocluster Synthesis and Applications
Authors: Meredith H. Barbee | Zoe M. Wright | Benjamin P. Allen | Hailey F. Taylor | Emily F Patteson | Abigail Knight
Source: Macromolecules (article, 2021-03-09)
Field: Materials Science — Biomaterials

Protein-Mimetic Self-Assembly with Synthetic Macromolecules Protein-mimetic amphiphiles have significant promise as a platform to access the complex functions of natural biological materials and incorporate the tunability and environmental resilience of synthetic materials. The fields of polymer chemistry and chemical biology have concurrently approached the development of biomimetic amphiphiles with materials ranging from random amphiphilic copolymers to peptide–lipid conjugates. In this Perspective, we incorporate strategies from diverse chemical arenas for controlling assembled morphologies and dynamics of protein-mimetic synthetic macromolecules. An overview of significant advances in peptide amphiphiles and single-chain polymer nanoparticles provides the foundation for comparing recent advances in the implementation of multiple intermolecular interactions and computational strategies to fine-tune the assembled structures. We aim to bridge these fields, combining insights from multiple disciplines to inspire new approaches for the development of protein-mimetic materials, as these assemblies have far-reaching applications including in the development of new sensors, catalysts, and therapeutics. Amphiphile ; Nanotechnology ; Macromolecule ; Biomimetic materials ; Synthetic biology ; Synthetic polymer ; Polymer ; Copolymer ; Chemistry ; Nanoparticle ; Materials science ; Polymer science ; Organic chemistry ; Computational biology ; Biology ; Biochemistry Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis ; Polydiacetylene-based materials and applications
Authors: Helena B. A. Sousa | Catarina S. M. Martins | João A.V. Prior
Source: Nanomaterials (review, 2021-03-01)
Field: Materials Science — Materials Chemistry

You Don’t Learn That in School: An Updated Practical Guide to Carbon Quantum Dots Carbon quantum dots (CQDs) have started to emerge as candidates for application in cell imaging, biosensing, and targeted drug delivery, amongst other research fields, due to their unique properties. Those applications are possible as the CQDs exhibit tunable fluorescence, biocompatibility, and a versatile surface. This review aims to summarize the recent development in the field of CQDs research, namely the latest synthesis progress concerning materials/methods, surface modifications, characterization methods, and purification techniques. Furthermore, this work will systematically explore the several applications CQDs have been subjected to, such as bioimaging, fluorescence sensing, and cancer/gene therapy. Finally, we will briefly discuss in the concluding section the present and future challenges, as well as future perspectives and views regarding the emerging paradigm that is the CQDs research field. Nanotechnology ; Carbon quantum dots ; Biocompatibility ; Quantum dot ; Drug delivery ; Computer science ; Characterization (materials science) ; Materials science ; Engineering ethics ; Engineering Carbon and Quantum Dots Applications ; Advanced biosensing and bioanalysis techniques ; Graphene and Nanomaterials Applications
Authors: Kwangrae Kim | Hoon Kim | Jonghwan Kim | Changil Kwon | Jun Sung Kim | B. J. Kim
Source: Nature Communications (article, 2021-03-30)
Field: Materials Science — Materials Chemistry

Direct observation of excitonic instability in Ta2NiSe5 Coulomb attraction between electrons and holes in a narrow-gap semiconductor or a semimetal is predicted to lead to an elusive phase of matter dubbed excitonic insulator. However, direct observation of such electronic instability remains extremely rare. Here, we report the observation of incipient divergence in the static excitonic susceptibility of the candidate material Ta<sub>2</sub>NiSe<sub>5</sub> using Raman spectroscopy. Critical fluctuations of the excitonic order parameter give rise to quasi-elastic scattering of B<sub>2g</sub> symmetry, whose intensity grows inversely with temperature toward the Weiss temperature of T<sub>W</sub> ≈ 237 K, which is arrested by a structural phase transition driven by an acoustic phonon of the same symmetry at T<sub>C</sub> = 325 K. Concurrently, a B<sub>2g</sub> optical phonon becomes heavily damped to the extent that its trace is almost invisible around T<sub>C</sub>, which manifests a strong electron-phonon coupling that has obscured the identification of the low-temperature phase as an excitonic insulator for more than a decade. Our results unambiguously reveal the electronic origin of the phase transition. Instability ; Phonon ; Coulomb ; Exciton ; Raman scattering ; Phase (matter) ; Phase transition ; Semiconductor 2D Materials and Applications ; Organic and Molecular Conductors Research ; Topological Materials and Phenomena
Authors: Stefano Sanvito | Alessandro Lunghi
Source: Trinity's Access to Research Output (TARA) (Trinity College Dublin) (article, 2021-03-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Multiple spin?phonon relaxation pathways in a Kramer single-ion magnet We present a first-principles investigation of spin-phonon relaxation in a molecular crystal of Co2+ single-ion magnets. Our study combines electronic structure calculations with machine-learning force fields and unravels the nature of both the Orbach and the Raman relaxation channels in terms of atomistic processes. We find that although both mechanisms are mediated by the excited spin states, the low temperature spin dynamics is dominated by phonons in the THz energy range, which partially suppress the benefit of having a large magnetic anisotropy. This study also determines the importance of intra-molecular motions for both the relaxation mechanisms and paves the way to the rational design of a new generation of single-ion magnets with tailored spin-phonon coupling. Phonon ; Relaxation (psychology) ; Condensed matter physics ; Anisotropy ; Ion ; Spin (aerodynamics) ; Raman spectroscopy ; Magnet ; Spin engineering ; Excited state ; Coupling (piping) ; Materials science ; Physics ; Spin polarization ; Atomic physics ; Optics ; Quantum mechanics ; Electron Magnetism in coordination complexes ; Advanced NMR Techniques and Applications ; Electron Spin Resonance Studies
Authors: Yupeng Diao | Luchun Yan | Kewei Gao
Source: Journal of Material Science and Technology (article, 2021-10-09)
Field: Materials Science — Metals and Alloys

A strategy assisted machine learning to process multi-objective optimization for improving mechanical properties of carbon steels Ultimate tensile strength ; Charpy impact test ; Ductility (Earth science) ; Materials science ; Elongation ; Computer science ; Machine learning ; Artificial intelligence ; Algorithm ; Composite material Hydrogen embrittlement and corrosion behaviors in metals ; Microstructure and Mechanical Properties of Steels ; Corrosion Behavior and Inhibition
Authors: Xiangyu Meng | Lin Qiu | Guangcheng Xi | Xiaotian Wang | Lin Guo
Source: SmartMat (article, 2021-08-19)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Smart design of high‐performance surface‐enhanced Raman scattering substrates Abstract Surface‐enhanced Raman scattering (SERS) spectroscopy has renowned its fame for the ultra‐high sensitivity and single‐molecule detection ability, and listed as a fingerprint spectrum representative in various trace detection fields. Considerable efforts have been made by researchers to design high‐sensitive SERS‐active substrates ranging from noble metals to semiconductors. This review summarizes the fundamental theories for SERS technique, that is, the electromagnetic enhancement mechanism and chemical enhancement mechanism and the state‐of‐the‐art design strategies for noble metal and semiconductor substrates. It also sheds light on the effective approaches to improve the SERS activity for noble metal substrates, that is, tuning the localized surface plasmon resonance position, the assembling of hot spots, and precise controlling of nanogaps. Although charge transfer is considered as the main reason for the enhancement mechanism for semiconductors at the present stage, the underlying theoretical basis remains mysterious. This review summarized the critical points for SERS‐active substrates design and prospected the future development direction of SERS technology. Raman scattering ; Nanotechnology ; Semiconductor ; Materials science ; Plasmon ; Surface plasmon resonance ; Noble metal ; Surface-enhanced Raman spectroscopy ; Raman spectroscopy ; Optoelectronics ; Metal ; Nanoparticle ; Optics ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Advanced biosensing and bioanalysis techniques
Authors: Mustafa Ergin Şahın
Source: CPSS Transactions on Power Electronics and Applications (article, 2021-03-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Modelling of Supercapacitors Based on Simplified Equivalent Circuit The need for energy storage devices especially in renewable energy applications has increased the use of supercapacitors. Accordingly, several supercapacitor models have been proposed in previous researches. Nevertheless, most of them require an intensive test to obtain the model parameters. These may not be suitable for an initial simulation study, where a simple model based on the datasheet is required to evaluate the system performance before building the hardware prototype. A simplified electrical circuit model for a supercapacitor (SC) based on the voltage-current equation is proposed in this paper to address this issue. This model doesn’t need an intensive test for accuracy. The structural simplicity and decent modelling accuracy make the equivalent electrical circuit model very suitable for power electronic applications and real-time energy management simulations. The parameters of the proposed model can be obtained from the datasheets value with a minimum test requirement. The experimental method to provide the parameters of the supercapacitor equivalent circuit is described. Based on the proposed method, the supercapacitor model is built in Matlab/Simulink, and the characteristics of equivalent series resistance (ESR) measurement and cycle life are compared with datasheets. The simulation results have verified that the proposed model can be applied to simulate the behaviour of the supercapacitor in most energy and power applications for a short time of energy storage. A supercapacitor test circuit is given to test the charge and discharge of supercapacitor modules. The experimental results are suitable for simulation results. Supercapacitor ; Equivalent circuit ; Computer science ; Electrical engineering ; Capacitance ; Engineering ; Physics ; Voltage Supercapacitor Materials and Fabrication ; Electric and Hybrid Vehicle Technologies ; Advanced Battery Technologies Research
Authors: Rocio Camacho-Morales | Lei Xu | Nikolay Dimitrov | Lyubomir Stoyanov | Zhonghua Ma | Alexander A. Dreischuh | Hark Hoe H. Tan | Costantino De Angelis | Chennupati Jagadish | Andrey E. Miroshnichenko | Davide Rocco | Valerio F. Gili | Andrei Komar | Mykhaylo Lysevych | Fouad Karouta | Giuseppe Leo | Mohsen Rahmani | Dragomir N. Neshev
Source: Advanced Photonics (article, 2021-06-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Infrared upconversion imaging in nonlinear metasurfaces Infrared imaging is a crucial technique in a multitude of applications, including night vision, autonomous vehicle navigation, optical tomography, and food quality control. Conventional infrared imaging technologies, however, require the use of materials such as narrow bandgap semiconductors, which are sensitive to thermal noise and often require cryogenic cooling. We demonstrate a compact all-optical alternative to perform infrared imaging in a metasurface composed of GaAs semiconductor nanoantennas, using a nonlinear wave-mixing process. We experimentally show the upconversion of short-wave infrared wavelengths via the coherent parametric process of sum-frequency generation. In this process, an infrared image of a target is mixed inside the metasurface with a strong pump beam, translating the image from the infrared to the visible in a nanoscale ultrathin imaging device. Our results open up new opportunities for the development of compact infrared imaging devices with applications in infrared vision and life sciences. Infrared ; Photon upconversion ; Noise (video) ; Semiconductor ; Nonlinear system ; Thermography ; Wavelength ; Thermal infrared spectroscopy Metamaterials and Metasurfaces Applications ; Plasmonic and Surface Plasmon Research ; Thermal Radiation and Cooling Technologies
Authors: Ekaterina A. Kukushkina | Syed Imdadul Hossain | Maria Chiara Sportelli | Nicoletta Ditaranto | Rosaria Anna Picca | Nicola Cioffi
Source: Nanomaterials (review, 2021-06-27)
Field: Materials Science — Materials Chemistry

Ag-Based Synergistic Antimicrobial Composites. A Critical Review The emerging problem of the antibiotic resistance development and the consequences that the health, food and other sectors face stimulate researchers to find safe and effective alternative methods to fight antimicrobial resistance (AMR) and biofilm formation. One of the most promising and efficient groups of materials known for robust antimicrobial performance is noble metal nanoparticles. Notably, silver nanoparticles (AgNPs) have been already widely investigated and applied as antimicrobial agents. However, it has been proposed to create synergistic composites, because pathogens can find their way to develop resistance against metal nanophases; therefore, it could be important to strengthen and secure their antipathogen potency. These complex materials are comprised of individual components with intrinsic antimicrobial action against a wide range of pathogens. One part consists of inorganic AgNPs, and the other, of active organic molecules with pronounced germicidal effects: both phases complement each other, and the effect might just be the sum of the individual effects, or it can be reinforced by the simultaneous application. Many organic molecules have been proposed as potential candidates and successfully united with inorganic counterparts: polysaccharides, with chitosan being the most used component; phenols and organic acids; and peptides and other agents of animal and synthetic origin. In this review, we overview the available literature and critically discuss the findings, including the mechanisms of action, efficacy and application of the silver-based synergistic antimicrobial composites. Hence, we provide a structured summary of the current state of the research direction and give an opinion on perspectives on the development of hybrid Ag-based nanoantimicrobials (NAMs). Antimicrobial ; Nanotechnology ; Materials science ; Noble metal ; Antibiotic resistance ; Biochemical engineering ; Combinatorial chemistry ; Chemistry ; Metal ; Antibiotics ; Organic chemistry Nanoparticles: synthesis and applications ; Advanced Nanomaterials in Catalysis ; Antimicrobial agents and applications
Authors: Fang Jiang | Na Song | Runhai Ouyang | Peng Ding
Source: ACS Applied Materials & Interfaces (article, 2021-02-02)
Field: Materials Science — Materials Chemistry

Wall Density-Controlled Thermal Conductive and Mechanical Properties of Three-Dimensional Vertically Aligned Boron Nitride Network-Based Polymeric Composites Polymeric composites with good thermal conductive and improved mechanical properties are in high demand in the thermal management materials. Construction of a three-dimensional (3D) structure has been proved to be an effective method to obtain polymeric composites with improved through-plane thermal conductivity (TC) for efficient thermal management of electronics. However, the TC enhancement of the obtained polymeric composites is limited, mainly due to poor control of the 3D thermal conductive network. Additionally, achieving high thermal conductive properties and enhanced mechanical properties simultaneously is of great challenge for polymeric composites. In this work, a 3D boron nitride framework (BNF) with a well-defined vertically aligned open structure and designed wall density fabricated by a unidirectional freezing technique was applied. The as-prepared BNF/polyethylene glycol (PBNF) composites exhibit enhanced through-plane TC, excellent thermal transfer capability (Δ<i>T</i><sub>max</sub> = 34 °C), and improved mechanical properties (Young's modulus enhancement up to 356%) simultaneously, making it attractive to thermal management applications. Strong correlation between the TC and mechanical properties of the PBNF composites and the wall density of the BNF scaffolds was found, providing opportunities to tune the TC and mechanical properties through the controlling of wall density. Furthermore, the models between TC and Young's modulus of PBNF composites were established by using the data-driven method "sure independence screening and sparsifying operator", which enables us to predict TC and Young's modulus of the polymeric composites for designing promising composite materials. The design principles and fabrication strategies proposed in this work could be important for developing advanced composite materials. Materials science ; Composite material ; Boron nitride ; Thermal conductivity ; Composite number ; Electrical conductor ; Modulus ; Thermal ; Fabrication Thermal properties of materials ; Thermal Radiation and Cooling Technologies ; Thermal Expansion and Ionic Conductivity