jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Petja Marinova | Kristina Dimova Tamahkyarova
Source: Preprints.org (review, 2024-02-19)
Field: Chemistry — Organic Chemistry

Synthesis and Biological Activities of Some Metal Complexes of Peptides: A Review Peptides, both natural and synthetic, are well suited for a wide range of purposes and offer versa-tile applications in different fields such as biocatalysts, injectable hydrogels, tumor treatment, and drug delivery. The rising prominence of therapeutic peptides encompasses anticancer, antiviral, antimicrobial, and anti-neurodegenerative properties. The metals Na, K, Mg, Ca, Fe, Mn, Co, Cu, Zn, and Mo are ten of the twenty elements that are considered essential for life. Crucial for under-standing the biological role of metals is the exploration of metal-bound proteins and peptides. Aside from essential metals, there are other, non-essential metals that also interact biologically, exhibiting either therapeutic or toxic effects. Irregularities in metal binding contribute to diseases like Alzheimer’s, neurodegenerative disorders, Wilson&amp;#039;s, and Menkes disease. Certain metal com-plexes have potential applications as radiopharmaceuticals. The examination of these complexes was done by preforming UV-Vis, IR, EPR, NMR spectroscopy, and X-ray analysis. Chemistry ; Combinatorial chemistry ; Computational biology ; Biology Ferrocene Chemistry and Applications ; Inorganic and Organometallic Chemistry ; Metal complexes synthesis and properties
Authors: Sandro Stal | Marie Cordier | Florian Massuyeau | Olivier Hernandez | Michaël Paris | Jean‐Yves Mevellec | Camille Latouche | Sandrine Perruchas
Source: Inorganic Chemistry (article, 2024-10-31)
Field: Chemistry — Inorganic Chemistry

Luminescence Thermochromism of a Noncluster Copper Iodide Complex Hybrid copper(I) halide materials are currently attracting significant attention due to their exceptional luminescence properties, offering great potential for the development of multifunctional emissive materials with, in addition, eco-friendly features. A binuclear copper iodide complex, based on the [Cu<sub>2</sub>I<sub>2</sub>L<sub>4</sub>] motif with phosphite derivatives as ligands, has been synthesized and structurally characterized. Photophysical investigations indicate that this complex displays luminescence thermochromic properties, which are characterized by a temperature-dependent change in the relative intensity of two emission bands. The high-contrast luminescence thermochromism, with an important color variation from purple to cyan, is ascribed to the thermal equilibrium of two different excited states. While thermochromism is relatively known for multimetallic complexes, the perfectly controlled thermochromism of the studied compound is unprecedented for a binuclear complex. From theoretical investigations, this original feature is due to the coordination of phosphite ligands, which induces a specific energy layout of the complex, presenting vacant orbitals of varying nature. This single-component, dual-emissive binuclear complex, displaying relevant sensitivity temperature response, presents great potential for luminescence ratiometric thermometry applications. This study underlines the relevance of the ligand engineering strategy in developing original, emissive, and sustainable copper-based materials. Thermochromism ; Luminescence ; Chemistry ; Iodide ; Copper ; Photochemistry ; Excited state ; Halide ; Inorganic chemistry ; Optoelectronics ; Organic chemistry ; Materials science Metal-Organic Frameworks: Synthesis and Applications ; Polyoxometalates: Synthesis and Applications ; Luminescence Properties of Advanced Materials
Authors: Reabetswe Maake | Ikechukwu Achilonu
Source: The Protein Journal (article, 2024-07-09)
Field: Materials Science — Materials Chemistry

Expression, Purification and Biophysical Characterisation of Klebsiella Pneumoniae Protein Adenylyltransferase: A Systematic Integration of Empirical and Computational Modelling Approaches Infections that are acquired due to a prolonged hospital stay and manifest 2 days following the admission of a patient to a health-care institution can be classified as hospital-acquired infections. Klebsiella pneumoniae (K. pneumoniae) has become a critical pathogen, posing serious concern globally due to the rising incidences of hypervirulent and carbapenem-resistant strains. Glutaredoxin is a redox protein that protects cells from oxidative stress as it associates with glutathione to reduce mixed disulfides. Protein adenylyltransferase (PrAT) is a pseudokinase with a proposed mechanism of transferring an AMP group from ATP to glutaredoxin. Inducing oxidative stress to the bacterium by inhibiting the activity of PrAT is a promising approach to combating its contribution to hospital-acquired infections. Thus, this study aims to overexpress, purify, and analyse the effects of ATP and Mg<sup>2+</sup> binding to Klebsiella pneumoniae PrAT (KpPrAT). The pET expression system and nickel affinity chromatography were effective in expressing and purifying KpPrAT. Far-UV CD spectroscopy demonstrates that the protein is predominantly α-helical, even in the presence of Mg<sup>2+</sup>. Extrinsic fluorescence spectroscopy with ANS indicates the presence of a hydrophobic pocket in the presence of ATP and Mg<sup>2+</sup>, while mant-ATP studies allude to the potential nucleotide binding ability of KpPrAT. The presence of Mg<sup>2+</sup> increases the thermostability of the protein. Isothermal titration calorimetry provides insight into the binding affinity and thermodynamic parameters associated with the binding of ATP to KpPrAT, with or without Mg<sup>2+</sup>. Conclusively, the presence of Mg<sup>2+</sup> induces a conformation in KpPrAT that favours nucleotide binding. Isothermal titration calorimetry ; Klebsiella pneumoniae ; Thermostability ; Biochemistry ; Glutaredoxin ; Pathogen ; Chemistry ; Glutathione ; Biology ; Microbiology ; Enzyme ; Gene ; Escherichia coli Enzyme Structure and Function ; Trace Elements in Health ; thermodynamics and calorimetric analyses
Authors: Kushani Attanayake | Sultan Mahmud | Chandrima Banerjee | Daud Sharif | Mohammad Ashiqur Rahman | Sandra Majuta | Anthony DeBastiani | Mst Nigar Sultana | Samira Hajian Foroushani | Chong Li | Peng Li | Stephen J. Valentine
Source: International Journal of Mass Spectrometry (article, 2024-03-07)
Field: Chemistry — Spectroscopy

Examining DNA structures with in-droplet hydrogen/deuterium exchange mass spectrometry Capillary vibrating sharp-edge spray ionization (cVSSI) combined with hydrogen/deuterium exchange-mass spectrometry (HDX-MS) has been utilized to characterize different solution-phase DNA conformers including DNA G-quadruplex topologies as well as triplex DNA and duplex DNA. In general, G-quadruplex DNA shows a wide range of protection of hydrogens extending from ~12% to ~21% deuterium incorporation. Additionally, the DNA sequences selected to represent parallel, antiparallel, and hybrid G-quadruplex topologies exhibit slight differences in deuterium uptake levels which appear to loosely relate to overall conformer stability. Notably, the exchange level for one of the hybrid sequence sub topologies of G-quadruplex DNA (24 TTG) is significantly different (compared with the others studied here) despite the DNA sequences being highly comparable. For the quadruplex-forming sequences, correlation analysis suggests protection of base hydrogens involved in tetrad hydrogen bonding. For duplex DNA ~19% deuterium incorporation is observed while only ~16% is observed for triplex DNA. This increased protection of hydrogens may be due to the added backbone scaffolding and Hoogsteen base pairing of the latter species. These experiments lay the groundwork for future studies aimed at determining the structural source of this protection as well as the applicability of the approach for ascertaining different oligonucleotide folds, co-existing conformations, and/or overall conformer flexibility. Chemistry ; Hydrogen–deuterium exchange ; Mass spectrometry ; Deuterium ; Hydrogen ; Chromatography ; Organic chemistry ; Nuclear physics Mass Spectrometry Techniques and Applications ; DNA and Nucleic Acid Chemistry ; RNA and protein synthesis mechanisms
Authors: Saleh M. Khalil | Xuan Qin | John M. Hakenjos | Jian Wang | Zhaoyong Hu | Xinli Liu | Jin Wang | Mirjana Maletić‐Savatić | Kevin R. MacKenzie | Martin M. Matzuk | Feng Li
Source: Drug Metabolism and Disposition (article, 2024-04-24)
Field: Chemistry — Spectroscopy

MALDI Imaging Mass Spectrometry Visualizes the Distribution of Antidepressant Duloxetine and Its Major Metabolites in Mouse Brain, Liver, Kidney, and Spleen Tissues Duloxetine ; Mass spectrometry imaging ; Kidney ; Chemistry ; Pharmacology ; Spleen ; Phosphocholine ; Distribution (mathematics) ; Toxicity ; Pathology ; Internal medicine ; Medicine ; Biochemistry ; Mass spectrometry ; Chromatography Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Forensic Toxicology and Drug Analysis
Authors: Tim Silies | Nikos L. Doltsinis | Constantin G. Daniliuc | Fabio Rizzo
Source: ChemPhotoChem (article, 2024-09-12)
Field: Materials Science — Materials Chemistry

Fluorene vs. Spirobifluorene: Effect of the <i>π</i> ‐System on TADF Properties Abstract There are many options to design a molecular structure that could result in thermally activated delayed fluorescence (TADF). One promising strategy is to use the donor‐π‐acceptor motive where an electron‐donating unit is linked to an electron‐acceptor via an aryl moiety like phenyl. While this approach is widely used and well understood, the performance of the chromophores can be limited by different energy loss pathways, e. g. internal conversion, or by π‐stacking. To circumvent these problems rigid structures with sterically demanding substituents are applied. In this work, we designed two TADF emitters based on phenothiazine and nitrile linked via spiro‐9,9’‐bi[fluorene] or 9,9‐dimethylfluorene and compared the effect of the linker on the physical properties of the dyes. This work emphasizes the importance of careful design of conjugated spacer for efficient TADF emitters. Fluorene ; Materials science ; Chemistry ; Organic chemistry ; Polymer Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Lanthanide and Transition Metal Complexes
Authors: Sophie M. Pearce | Neil A. Cross | David P. Smith | Malcolm R. Clench | Lucy Flint | Grégory Hamm | Richard J. A. Goodwin | James Langridge | Emmanuelle Claude | Laura M. Cole
Source: Metabolites (article, 2024-05-29)
Field: Chemistry — Spectroscopy

Multimodal Mass Spectrometry Imaging of an Osteosarcoma Multicellular Tumour Spheroid Model to Investigate Drug-Induced Response A multimodal mass spectrometry imaging (MSI) approach was used to investigate the chemotherapy drug-induced response of a Multicellular Tumour Spheroid (MCTS) 3D cell culture model of osteosarcoma (OS). The work addresses the critical demand for enhanced translatable early drug discovery approaches by demonstrating a robust spatially resolved molecular distribution analysis in tumour models following chemotherapeutic intervention. Advanced high-resolution techniques were employed, including desorption electrospray ionisation (DESI) mass spectrometry imaging (MSI), to assess the interplay between metabolic and cellular pathways in response to chemotherapeutic intervention. Endogenous metabolite distributions of the human OS tumour models were complemented with subcellularly resolved protein localisation by the detection of metal-tagged antibodies using Imaging Mass Cytometry (IMC). The first application of matrix-assisted laser desorption ionization-immunohistochemistry (MALDI-IHC) of 3D cell culture models is reported here. Protein localisation and expression following an acute dosage of the chemotherapy drug doxorubicin demonstrated novel indications for mechanisms of region-specific tumour survival and cell-cycle-specific drug-induced responses. Previously unknown doxorubicin-induced metabolite upregulation was revealed by DESI-MSI of MCTSs, which may be used to inform mechanisms of chemotherapeutic resistance. The demonstration of specific tumour survival mechanisms that are characteristic of those reported for in vivo tumours has underscored the increasing value of this approach as a tool to investigate drug resistance. Mass cytometry ; Cancer research ; In vivo ; Mass spectrometry imaging ; Doxorubicin ; Osteosarcoma ; Drug resistance ; Immunohistochemistry ; Chemistry ; Chemotherapy ; Medicine ; Pathology ; Biology ; Mass spectrometry ; Internal medicine ; Phenotype ; Biochemistry Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications ; Advanced biosensing and bioanalysis techniques
Authors: Yuying Ma | Long Zhou | Jingyun Tan | Wang Sun | Yingping Zou | Yunbin Hu
Source: Advanced Optical Materials (article, 2024-12-16)
Field: Chemistry — Organic Chemistry

Hexabenzoperylene‐Cored Double Thiahelicenes with Strong Luminescence Abstract Thiahelicenes, an important subclass of helicenes, are renowned for their pronounced chiroptical properties, particularly circular dichroism. However, the exploration of their circularly polarized luminescence (CPL) has been hindered due to their inherently weak fluorescence, leaving a critical gap in the development of thiahelicenes as efficient CPL emitters. To address this limitation, a novel strategy for enhancing the luminescence of thiahelicenes by integrating thiophene‐containing units with a highly emissive hexabenzoperylene (HBP) core is presented. Two isomeric HBP‐cored double thiahelicenes are synthesized, which serve as proof of concept. These molecules exhibit exceptionally high fluorescence quantum yields ( Φ F = 83% and 91%), surpassing all previously reported thiahelicenes. Furthermore, their luminescence dissymmetry factors show a four‐fold enhancement compared to the parent HBP, resulting in a remarkable CPL brightness of up to 84.9 M −1 cm −1 . These findings not only address the fluorescence limitation of thiahelicenes but also establish a new pathway for developing high‐performance CPL materials. Materials science ; Luminescence ; Optoelectronics Synthesis and Properties of Aromatic Compounds ; Fullerene Chemistry and Applications ; Luminescence and Fluorescent Materials
Authors: Alexander V. Kildishev | Karim Achouri | Daria A. Smirnova
Source: Advanced Optical Materials (article, 2024-11-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

The Art of Finding the Optimal Scattering Center(s) Abstract The truncated spatial multipolar spectra enable efficient approximate solutions to acoustic, quantum‐mechanical, and electromagnetic problems. In photonics, the efficient multipole description of a general emitter or scatterer with controlled accuracy is complicated by the ambiguity in choosing the multipole expansion center—the multipole terms depend on the position of the expansion center and therefore are not unique. This study solves this fundamental problem by finding the optimal scattering centers for which the spatial multipole spectrum becomes unique. These optimal positions are derived separately for the electric and magnetic multipoles by minimizing the norms of the poloidal quadrupoles, employing the long‐wave approximation (LWA) ansatz. The ultimate positions are verified with idealized discrete emitters and realistic scatterers. The optimal multipoles, including the toroidal terms, are calculated for several distinct scatterers; their utility for fast, low‐cost numerical schemes is discussed. The number of optimal magnetic scattering centers, defined by the multiplicity of the problem, can serve as a new topological metric of a given emitter or scatterer. This finding hints at potential relations between nanoscale optomechanics and topological photonics. Expansion of the work beyond the LWA is possible, with the promise of more general foundational concepts for electrodynamics, acoustics, and quantum mechanics. Center (category theory) ; Materials science ; Scattering ; Optics ; Physics ; Crystallography Metamaterials and Metasurfaces Applications ; Electromagnetic Scattering and Analysis ; Photonic Crystals and Applications
Authors: Aqsa Asad | Hafiz Saad Khaliq | Minseok Kim | Jae‐Won Lee | Hak‐Rin Kim
Source: Materials Advances (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Realization of giant superstructural chirality at broadband optical wavelengths <i>via</i> perovskite dielectric metasurfaces This study presents a perovskite-integrated metasurface to realize exceptional chirality with maximum anisotropy of ∼1.55 and the CD of ∼42 934 (mdeg) at the broad visible regime with potential applications in chiral photonics and optoelectronics. Chirality (physics) ; Realization (probability) ; Perovskite (structure) ; Broadband ; Anisotropy ; Photonics ; Dielectric ; Wavelength ; Materials science ; Optoelectronics ; Optics ; Physics ; Chemistry ; Crystallography ; Quantum mechanics ; Mathematics Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Thermal Radiation and Cooling Technologies
Authors: Matthias Neumann | Phillip Gräfensteiner | E. Machado | Ulrich Hirn | André Hilger | Ingo Manke | Robert Schennach | Volker Schmidt | Karin Zojer
Source: Advanced Theory and Simulations (article, 2024-04-22)
Field: Materials Science — Materials Chemistry

R‐Vine Copulas for Data‐Driven Quantification of Descriptor Relationships in Porous Materials Abstract Local variations in the 3D microstructure can control the macroscopic behavior of heterogeneous porous materials. For example, the permittivity through porous sheets or membranes is governed by local high‐volume pathways or bottlenecks. Due to local variations, unfeasibly large amounts of microstructure data may be needed to reliably predict such material properties directly from image data. Here it is demonstrated that a vine copula approach provides parametric models for local microstructure descriptors that compactly capture the 3D microstructure including its local variations and efficiently probe it with respect to selected, measurable properties. In contrast to common methods of complexity reduction, the proposed approach creates parametric models for the multivariate probability distribution of high‐dimensional descriptor vectors that inherently contain the complex, nonlinear dependencies between these descriptors. Therein, material properties are offered in physically motivated distributions of microstructure descriptors rather than as normally distributed data. Applied to porous fiber networks (paper) before and after unidirectional compression, it is shown that the copula‐based models reveal material‐characteristic relationships between two or more microstructure descriptors. In this way, the presented modeling approach can provide deeper insight into the microscopic origin of effective macroscopic properties of heterogeneous porous materials. Vine copula ; Vine ; Porosity ; Porous medium ; Computer science ; Mathematics ; Artificial intelligence ; Copula (linguistics) ; Econometrics ; Geology ; Geotechnical engineering ; Biology ; Ecology Machine Learning in Materials Science ; Asphalt Pavement Performance Evaluation
Authors: Jaideep Ray | Jeffrey Horner | Ian Winter | David J. Kemmenoe | Edward R. Arata | Michael Chandross | Scott Alan Roberts | Anne Grillet
Source: Computers & Fluids (article, 2024-03-30)
Field: Materials Science — Materials Chemistry

A data-driven multiscale model for reactive wetting simulations Wetting ; Surface tension ; Molecular dynamics ; Materials science ; Contact angle ; Drop (telecommunication) ; Sessile drop technique ; Scale (ratio) ; Mechanics ; Statistical physics ; Biological system ; Thermodynamics ; Composite material ; Physics ; Chemistry ; Mechanical engineering ; Computational chemistry ; Engineering Block Copolymer Self-Assembly ; Lattice Boltzmann Simulation Studies ; nanoparticles nucleation surface interactions
Authors: Jafaar Fahad A. Rida
Source: Scalable Computing Practice and Experience (article, 2024-08-01)
Field: Materials Science — Materials Chemistry

The Employment of Carbon Nanotubes in Biomedical Applications Carbon nanotubes (CNTs), a prominent application of nanotechnology, find extensive use across various fields. Their electrical and optical characteristics, which are affected by the manufacturing process and any impurities introduced during production, are crucial in establishing their suitability for use. This research focuses on the utilization of carbon nanotubes in medical applications, exploring their properties both as electrical conductors and semiconductors, comparable to silicon used in precision medical equipment and devices. When functioning as electrical conductors, CNTs exhibit characteristics similar to traditional conductive materials. This property is harnessed in medical applications, particularly in targeted cancer treatments that minimize impact on healthy cells. CNTs’ efficient conduction of electrical current makes them valuable components in medical devices and equipment. Furthermore, CNTs showcase semiconductor properties akin to silicon. This characteristic is crucial for developing advanced medical equipment, enabling accurate diagnostics and medical imaging. The semiconductor behavior allows the creation of intricate medical devices with enhanced precision. The research underscores the significance of CNTs in shaping the future of medical technology, especially when integrated with artificial intelligence applications. The ability of CNTs to function both as conductors and semiconductors highlights their versatility in the medical field, promising advancements in healthcare technologies. Their use holds potential for targeted cancer treatments, accurate diagnostics, medical imaging, and enhanced performance through integration with artificial intelligence. Carbon nanotube ; Nanotechnology ; Semiconductor ; Materials science ; Electrical conductor ; Computer science ; Optoelectronics Carbon Nanotubes in Composites ; Nanotechnology research and applications ; Neuroscience and Neural Engineering