jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Daniela F. Báez | Eduardo Gallardo‐Toledo | María Paz Oyarzún | Eyleen Araya | Marcelo J. Kogan
Source: International Journal of Nanomedicine (review, 2021-03-01)
Field: Materials Science — Biomaterials

The Influence of Size and Chemical Composition of Silver and Gold Nanoparticles on in vivo Toxicity with Potential Applications to Central Nervous System Diseases The physicochemical and optical properties of silver nanoparticles (SNPs) and gold nanoparticles (GNPs) have allowed them to be employed for various biomedical applications, including delivery, therapy, imaging, and as theranostic agents. However, since they are foreign body systems, they are usually redistributed and accumulated in some vital organs, which can produce toxic effects; therefore, this a crucial issue that should be considered for potential clinical trials. This review aimed to summarize the reports from the past ten years that have used SNPs and GNPs for in vivo studies on the diagnosis and treatment of brain diseases and those related to the central nervous system, emphasizing their toxicity as a crucial topic address. The article focuses on the effect of the nanoparticle´s size and chemical composition as relevant parameters for in vivo toxicity. At the beginning of this review, the general toxicity and distribution studies are discussed separately for SNPs and GNPs. Subsequently, this manuscript analyzes the principal applications of both kinds of nanoparticles for glioma, neurodegenerative, and other brain diseases, and discusses the advances in clinical trials. Finally, we analyze research prospects towards clinical applications for both types of metallic nanoparticles. In vivo ; Toxicity ; Nanotechnology ; Glioma ; Colloidal gold ; Nanoparticle ; Central nervous system ; Materials science ; Medicine ; Biology ; Neuroscience ; Biotechnology ; Cancer research ; Internal medicine Nanoparticle-Based Drug Delivery ; Nanoparticles: synthesis and applications ; Graphene and Nanomaterials Applications
Authors: Peter Möller | Regitze Sølling Wils | Emilio Di Ianni | Claudia Andrea Torero Gutierrez | Martin Roursgaard | Nicklas Raun Jacobsen
Source: Mutation Research/Reviews in Mutation Research (review, 2021-07-01)
Field: Materials Science — Materials Chemistry

Genotoxicity of multi-walled carbon nanotube reference materials in mammalian cells and animals Carbon nanotubes (CNTs) were the first nanomaterials to be evaluated by the International Agency for Research on Cancer (IARC). The categorization as possibly carcinogenic agent to humans was only applicable to multi-walled carbon nanotubes called MWCNT-7. Other types of CNTs were not classifiable because of missing data and it was not possible to pinpoint unique CNT characteristics that cause cancer. Importantly, the European Commission's Joint Research Centre (JRC) has established a repository of industrially manufactured nanomaterials that encompasses at least four well-characterized MWCNTs called NM-400 to NM-403 (original JRC code). This review summarizes the genotoxic effects of these JRC materials and MWCNT-7. The review consists of 36 publications with results on cell culture experiments (22 publications), animal models (9 publications) or both (5 publications). As compared to the publications in the IARC monograph on CNTs, the current database represents a significant increase as there is only an overlap of 8 publications. However, the results come mainly from cell cultures and/or measurements of DNA strand breaks by the comet assay and the micronucleus assay (82 out of 97 outcomes). A meta-analysis of cell culture studies on DNA strand breaks showed a genotoxic response by MWCNT-7, less consistent effect by NM-400 and NM-402, and least consistent effect by NM-401 and NM-403. Results from other in vitro tests indicate strongest evidence of genotoxicity for MWCNT-7. There are too few observations from animal models and humans to make general conclusions about genotoxicity. Genotoxicity ; Carbon nanotube ; Nanotechnology ; Materials science ; Chemistry ; Toxicity Nanoparticles: synthesis and applications ; Microplastics and Plastic Pollution ; Animal testing and alternatives
Authors: Pravin Pathak | Mohammad Amin Zarandi | Xiao Zhou | Janarthanan Jayawickramarajah
Source: Frontiers in Chemistry (review, 2021-11-08)
Field: Chemistry — Organic Chemistry

Synthesis and Applications of Porphyrin-Biomacromolecule Conjugates With potential applications in materials and especially in light-responsive biomedicine that targets cancer tissue selectively, much research has focused on developing covalent conjugation techniques to tether porphyrinoid units to various biomacromolecules. This review details the key synthetic approaches that have been employed in the recent decades to conjugate porphyrinoids with oligonucleotides and peptides/proteins. In addition, we provide succinct discussions on the subsequent applications of such hybrid systems and also give a brief overview of the rapidly progressing field of porphyrin-antibody conjugates. Since nucleic acid and peptide systems vary in structure, connectivity, functional group availability and placement, as well as stability and solubility, tailored synthetic approaches are needed for conjugating to each of these biomacromolecule types. In terms of tethering to ONs, porphyrins are typically attached by employing bioorthogonal chemistry (e.g., using phosphoramidites) that drive solid-phase ON synthesis or by conducting post-synthesis modifications and subsequent reactions (such as amide couplings, hydrazide-carbonyl reactions, and click chemistry). In contrast, peptides and proteins are typically conjugated to porphyrinoids using their native functional groups, especially the thiol and amine side chains. However, bioorthogonal reactions (e.g., Staudinger ligations, and copper or strain promoted alkyne-azide cycloadditions) that utilize <i>de novo</i> introduced functional groups onto peptides/proteins have seen vigorous development, especially for site-specific peptide-porphyrin tethering. While the ON-porphyrin conjugates have largely been explored for programmed nanostructure self-assembly and artificial light-harvesting applications, there are some reports of ON-porphyrin systems targeting clinically translational applications (e.g., antimicrobial biomaterials and site-specific nucleic acid cleavage). Conjugates of porphyrins with proteinaceous moieties, on the other hand, have been predominantly used for therapeutic and diagnostic applications (especially in photodynamic therapy, photodynamic antimicrobial chemotherapy, and photothermal therapy). The advancement of the field of porphyrinoid-bioconjugation chemistry from basic academic research to more clinically targeted applications require continuous fine-tuning in terms of synthetic strategies and hence there will continue to be much exciting work on porphyrinoid-biomacromolecule conjugation. Bioorthogonal chemistry ; Porphyrin ; Chemistry ; Click chemistry ; Combinatorial chemistry ; Conjugate ; Conjugated system ; Peptide ; Solid-phase synthesis ; Organic chemistry ; Polymer ; Biochemistry Click Chemistry and Applications ; Porphyrin and Phthalocyanine Chemistry ; Advanced biosensing and bioanalysis techniques
Authors: Wenyao Chen | Junbo Cao | Jia Yang | Yueqiang Cao | Hao Zhang | Zheng Jiang | Jing Zhang | Gang Qian | Xinggui Zhou | De Chen | Weikang Yuan | Xuezhi Duan
Source: Nature Communications (article, 2021-11-25)
Field: Materials Science — Materials Chemistry

Molecular-level insights into the electronic effects in platinum-catalyzed carbon monoxide oxidation A molecular-level understanding of how the electronic structure of metal center tunes the catalytic behaviors remains a grand challenge in heterogeneous catalysis. Herein, we report an unconventional kinetics strategy for bridging the microscopic metal electronic structure and the macroscopic steady-state rate for CO oxidation over Pt catalysts. X-ray absorption and photoelectron spectroscopy as well as electron paramagnetic resonance investigations unambiguously reveal the tunable Pt electronic structures with well-designed carbon support surface chemistry. Diminishing the electron density of Pt consolidates the CO-assisted O<sub>2</sub> dissociation pathway via the O*-O-C*-O intermediate directly observed by isotopic labeling studies and rationalized by density-functional theory calculations. A combined steady-state isotopic transient kinetic and in situ electronic analyses identifies Pt charge as the kinetics indicators by being closely related to the frequency factor, site coverage, and activation energy. Further incorporation of catalyst structural parameters yields a novel model for quantifying the electronic effects and predicting the catalytic performance. These could serve as a benchmark of catalyst design by a comprehensive kinetics study at the molecular level. Catalysis ; Carbon monoxide ; Electronic structure ; Density functional theory ; Dissociation (chemistry) ; Kinetics ; Chemical physics ; Chemistry ; X-ray absorption spectroscopy ; X-ray photoelectron spectroscopy ; Platinum ; Materials science ; Photochemistry ; Physical chemistry ; Absorption spectroscopy ; Computational chemistry ; Chemical engineering ; Organic chemistry ; Physics Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Electrocatalysts for Energy Conversion
Authors: Eugene Kim | Juya Jeon | Yaguang Zhu | Ethan D. Hoppe | Young‐Shin Jun | Guy M. Genin | Fuzhong Zhang
Source: ACS Applied Materials & Interfaces (article, 2021-10-11)
Field: Materials Science — Biomaterials

A Biosynthetic Hybrid Spidroin-Amyloid-Mussel Foot Protein for Underwater Adhesion on Diverse Surfaces Strong underwater adhesives are attractive materials for biomedical healing and underwater repair, but their success in applications has been limited, owing to challenges with underwater setting and with balancing surface adhesion and cohesion. Here, we applied synthetic biology approaches to overcome these challenges through design and synthesis of a novel hybrid protein consisting of the zipper-forming domains of an amyloid protein, flexible spider silk sequences, and a dihydroxyphenylalanine (DOPA)-containing mussel foot protein (Mfp). This partially structured, hybrid protein can self-assemble into a semi-crystalline hydrogel that exhibits high strength and toughness as well as strong underwater adhesion to a variety of surfaces, including difficult-to-adhere plastics, tendon, and skin. The hydrogel allows selective debonding by oxidation or iron-chelating treatments. Both the material design and the biosynthetic approach explored in this study will inspire future work for a wide range of hybrid protein-based materials with tunable properties and broad applications. Materials science ; Nanotechnology ; Toughness ; Spider silk ; Adhesion ; Underwater ; Self-healing hydrogels ; SILK ; Composite material ; Polymer chemistry Silk-based biomaterials and applications ; Polymer Surface Interaction Studies ; Biochemical and Structural Characterization
Authors: Farheen F. Jaldurgam | Zubair Ahmad | Farid Touati
Source: Nanomaterials (review, 2021-03-31)
Field: Materials Science — Materials Chemistry

Low-Toxic, Earth-Abundant Nanostructured Materials for Thermoelectric Applications This article presents recent research directions in the study of Earth-abundant, cost-effective, and low-toxic advanced nanostructured materials for thermoelectric generator (TEG) applications. This study's critical aspect is to systematically evaluate the development of high-performance nanostructured thermoelectric (TE) materials from sustainable sources, which are expected to have a meaningful and enduring impact in developing a cost-effective TE system. We review both the performance and limitation aspects of these materials at multiple temperatures from experimental and theoretical viewpoints. Recent developments in these materials towards enhancing the dimensionless figure of merit, Seebeck coefficient, reduction of the thermal conductivity, and improvement of electrical conductivity have also been discussed in detail. Finally, the future direction and the prospects of these nanostructured materials have been proposed. Thermoelectric effect ; Thermoelectric materials ; Materials science ; Thermal conductivity ; Seebeck coefficient ; Engineering physics ; Nanotechnology ; Figure of merit ; Thermoelectric generator ; Viewpoints ; Composite material ; Optoelectronics ; Physics Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; Thermal Radiation and Cooling Technologies
Authors: Matthew D. Ward | Jessica Wade | Xingyuan Shi | Jenny Nelson | Alasdair J. Campbell | Matthew J. Fuchter
Source: Advanced Optical Materials (article, 2021-11-02)
Field: Chemistry — Organic Chemistry

Highly Selective High‐Speed Circularly Polarized Photodiodes Based on π‐Conjugated Polymers Abstract Chiral π‐conjugated molecular systems that are intrinsically sensitive to the handedness of circularly polarized (CP) light potentially allow for miniaturized, low‐cost CP detection devices. Such devices promise to transform several technologies, including biosensing, quantum optics, and communication of data encrypted by exploiting the spin angular momentum of light. Here a simple, bilayer organic photodiode (CP OPD) comprising an achiral π‐conjugated polymer–chiral additive blend as the electron donor layer and an achiral C 60 electron acceptor layer is realized. These devices exhibit considerable photocurrent dissymmetry g ph , with absolute values as high as 0.85 and dark currents as low as 10 pA. Impressively, they showcase a linear dynamic range of 80 dB, and rise and fall times of ≈7 µs, which significantly outperforms all previously reported CP selective photodetectors. Mechanistically, it is shown that the g ph is sensitive to the thickness of both the chiral donor and achiral acceptor layers and that a trade‐off exists between the external quantum efficiency and g ph . The fast‐switching speeds of these devices, coupled with their large dynamic range and highly selective response to CP light, opens up the possibility of their direct application in CP sensing and optical communications. Photodiode ; Materials science ; Photocurrent ; Photodetector ; Optoelectronics ; Conjugated system ; Quantum efficiency ; Acceptor ; Polymer ; Optics ; Physics Synthesis and Properties of Aromatic Compounds ; Perovskite Materials and Applications ; Luminescence and Fluorescent Materials
Authors: Zhen Bi | Liang Fu
Source: Nature Communications (article, 2021-01-28)
Field: Materials Science — Materials Chemistry

Excitonic density wave and spin-valley superfluid in bilayer transition metal dichalcogenide Abstract Artificial moiré superlattices in 2 d van der Waals heterostructures are a new venue for realizing and controlling correlated electronic phenomena. Recently, twisted bilayer WSe 2 emerged as a new robust moiré system hosting a correlated insulator at moiré half-filling over a range of twist angle. In this work, we present a theory of this insulating state as an excitonic density wave due to intervalley electron–hole pairing. We show that exciton condensation is strongly enhanced by a van Hove singularity near the Fermi level. Our theory explains the remarkable sensitivity of the insulating gap to the vertical electric field. In contrast, the gap is weakly reduced by a perpendicular magnetic field, with quadratic dependence at low field. The different responses to electric and magnetic field can be understood in terms of pair-breaking versus non-pair-breaking effects in a BCS analog of the system. We further predict superfluid spin transport in this electrical insulator, which can be detected by optical spin injection and spatial-temporal imaging. Condensed matter physics ; Physics ; Van Hove singularity ; Superfluidity ; Exciton ; Pairing ; Magnetic field ; Electric field ; Heterojunction ; Fermi level ; Electron ; Superconductivity ; Quantum mechanics 2D Materials and Applications ; Perovskite Materials and Applications ; Graphene research and applications
Authors: Leonardo Velasco | Juan Sebastián Castillo | Mohana V. Kante | J.J. Olaya | Pascal Friederich | Horst Hahn
Source: Advanced Materials (article, 2021-09-12)
Field: Materials Science — Materials Chemistry

Phase–Property Diagrams for Multicomponent Oxide Systems toward Materials Libraries Exploring the vast compositional space offered by multicomponent systems or high entropy materials using the traditional route of materials discovery, one experiment at a time, is prohibitive in terms of cost and required time. Consequently, the development of high-throughput experimental methods, aided by machine learning and theoretical predictions will facilitate the search for multicomponent materials in their compositional variety. In this study, high entropy oxides are fabricated and characterized using automated high-throughput techniques. For intuitive visualization, a graphical phase-property diagram correlating the crystal structure, the chemical composition, and the band gap are introduced. Interpretable machine learning models are trained for automated data analysis and to speed up data comprehension. The establishment of materials libraries of multicomponent systems correlated with their properties (as in the present work), together with machine learning-based data analysis and theoretical approaches are opening pathways toward virtual development of novel materials for both functional and structural applications. Computer science ; Materials science ; Visualization ; Chemical space ; Phase diagram ; Property (philosophy) ; Nanotechnology ; Machine learning ; Artificial intelligence ; Phase (matter) ; Drug discovery Machine Learning in Materials Science ; High Entropy Alloys Studies ; Catalysis and Oxidation Reactions
Authors: Rasmus Kronberg | Heikki Lappalainen | Kari Laasonen
Source: The Journal of Physical Chemistry C (article, 2021-07-17)
Field: Materials Science — Materials Chemistry

Hydrogen Adsorption on Defective Nitrogen-Doped Carbon Nanotubes Explained via Machine Learning Augmented DFT Calculations and Game-Theoretic Feature Attributions Complex machine learning (ML) models applied within computational chemistry and materials science tend to be seen as black boxes, yielding property predictions given some input features. While the purpose of ML methods is often to circumvent computationally expensive first-principles calculations, the fact that the inner workings of the models are not understood conceals chemical insight and knowledge regarding the underlying data and physical correlations within it. Knowing what a model is learning from the data and how outputs are formed is also useful in facilitating the justification and wider adoption of ML solutions. Here, we present an important contribution in this direction by exploring and explaining the hydrogen adsorption properties of defective nitrogen-doped carbon nanotubes (NCNTs) through density functional theory simulations and machine learning-based data analysis. As the main highlight, we demonstrate the application of a recent game-theoretic approach to deconvolute and interrogate the trained ML models, revealing how various structural, chemical, and electronic features contribute toward the hydrogen affinities of roughly 6500 different NCNT adsorption sites. The employed method of Shapley additive explanations (SHAP) attributes locally accurate importances to the investigated features, unraveling high spin polarization, narrow highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gap, small dopant–adsorption site separation, and diverse angle and coordination effects as particularly impactful for increasing hydrogen adsorption strengths. The SHAP method is shown capable of promoting a deep understanding of complex feature–activity relationships, facilitating research efforts such as rational catalyst design for energy conversion applications. Adsorption ; Hydrogen ; Feature (linguistics) ; Carbon nanotube ; Nitrogen ; Attribution ; Doping ; Carbon fibers ; Materials science ; Chemistry ; Physical chemistry ; Nanotechnology ; Psychology ; Organic chemistry ; Social psychology ; Composite material ; Optoelectronics Machine Learning in Materials Science ; Hydrogen Storage and Materials ; Electrocatalysts for Energy Conversion
Authors: Kritesh Kumar Gupta | T. Mukhopadhyay | Aditya Roy | Lintu Roy | S. Dey
Source: Journal of Physics and Chemistry of Solids (article, 2021-04-20)
Field: Materials Science — Materials Chemistry

Sparse machine learning assisted deep computational insights on the mechanical properties of graphene with intrinsic defects and doping Graphene ; Scalability ; Computer science ; Molecular dynamics ; Artificial intelligence ; Nanotechnology ; Computational model ; Deep learning ; Statistical physics ; Machine learning ; Materials science ; Physics ; Chemistry ; Computational chemistry Graphene research and applications ; Machine Learning in Materials Science ; Thermal properties of materials
Authors: Jingbai Li | Rachel Stein | Daniel Adrion | Steven A. Lopez
Source: Journal of the American Chemical Society (article, 2021-11-17)
Field: Chemistry — Organic Chemistry

Machine-Learning Photodynamics Simulations Uncover the Role of Substituent Effects on the Photochemical Formation of Cubanes Photochemical [2 + 2]-cycloadditions store solar energy in chemical bonds and efficiently access strained organic molecular architectures. Functionalized [3]-ladderdienes undergo [2 + 2]-photocycloadditions to afford cubanes, a class of strained organic molecules. The substituents (e.g., methyl, trifluoromethyl, and cyclopropyl) affect the overall reactivities of these cubane precursors; the yields range from 1 to 48%. However, the origin of these substituent effects on the reactivities and chemoselectivities is not understood. We now integrate single and multireference calculations and machine-learning-accelerated nonadiabatic molecular dynamics (ML-NAMD) to understand how substituents affect the ultrafast dynamics and mechanism of [2 + 2]-photocycloadditions. Steric clashes between substituent groups destabilize the 4π-electrocyclic ring-opening pathway and minimum energy conical intersections by 0.72-1.15 eV and reaction energies by 0.68-2.34 eV. Noncovalent dispersive interactions stabilize the [2 + 2]-photocycloaddition pathway; the conical intersection energies are lower by 0.31-0.85 eV, and the reaction energies are lower by 0.03-0.82 eV. The 2 ps ML-NAMD trajectories reveal that closed-shell repulsions block a 6π-conrotatory electrocyclic ring-opening pathway with increasing steric bulk. Thirty-eight percent of the methyl-substituted [3]-ladderdiene trajectories proceed through the 6π-conrotatory electrocyclic ring-opening, whereas the trifluoromethyl- and cyclopropyl-substituted [3]-ladderdienes prefer the [2 + 2]-photocycloaddition pathways. The predicted cubane yields (H: 0.4% < CH<sub>3</sub>: 1% < CF<sub>3</sub>: 14% < cPr: 15%) match the experimental trend; these substituents predistort the reactants to resemble the conical intersection geometries leading to cubanes. Chemistry ; Conrotatory and disrotatory ; Steric effects ; Substituent ; Conical intersection ; Electrocyclic reaction ; Trifluoromethyl ; Ring (chemistry) ; Photochemistry ; Cubane ; Computational chemistry ; Electronic effect ; Antiaromaticity ; HOMO/LUMO ; Stereochemistry ; Molecule ; Aromaticity ; Organic chemistry Organic Chemistry Cycloaddition Reactions ; Photochromic and Fluorescence Chemistry ; Radical Photochemical Reactions