jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Evelynn Vergauwen | Michiel Tubeeckx | Annemie Houben | Sandra Van Vlierberghe | Marc Demolder | Guido R.Y. De Meyer | Patrick Pauwels | Tomas Menovsky
Source: Preprints.org (preprint, 2023-11-08)
Field: Materials Science — Biomaterials

Electrospun Polyurethane Vascular Grafts for Cerebral Revascularization: A Pilot Study on Rats Background: The current standard technique for vascular grafting in cerebral revascularization surgery is through the interposition of an autologous blood vessel. Technical complications have necessitated the development of a synthetic alternative, but classical biomaterials are not suited for small caliber vascular grafting due to neointimal hyperplasia and thrombosis. Electrospinning of polymers is a promising technique for the development of small vascular grafts. The in vivo performance and efficacy of electrospun polyurethane (ePU) grafts with an internal diameter of &amp;lt; 1.5 mm have thus far not been evaluated. &#x0D; Methods: We developed a novel ePU graft with a diameter of 1.25 mm for implantation into the infrarenal aorta of rats. &#x0D; Results: Patency rates of grafts after a four-month-period were equal to those reported in other studies with larger ePU graft diameters, and equal or higher than in studies with other biomaterials. We observed some loss in flow velocity throughout the grafts, which suggests a decreased elasticity of the graft compared to native rat aorta. However, the grafts demonstrated good neo-endothelialization and minimal neointimal hyperplasia. Their porosity promoted cellular infiltration, as shown on tissue slide examination. &#x0D; Conclusion: Our results show that ePU vascular grafts with internal diameter of &amp;lt; 1.5 mm are promising candidates for vascular grafting in cerebral revascularization surgery. Neointimal hyperplasia ; Revascularization ; Medicine ; Intimal hyperplasia ; Surgery ; Aorta ; Grafting ; Materials science ; Internal medicine ; Stent ; Polymer Electrospun Nanofibers in Biomedical Applications
Authors: Samuel Hjorth-Jensen | David B. Konrad | E.M. Quistgaard | Line Hansen | A. Novák | Hang Chu | Michal Jurášek | Tomáš Zimmermann | Jacob Lauwring Andersen | Phil S. Baran | Poul Nissen | Dirk Trauner
Source: ChemRxiv (preprint, 2023-09-29)
Field: Materials Science — Materials Chemistry

Photoswitchable Inhibitors of the Sarco(endo)plasmic Calcium Pump Targeting the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) offers a promising strategy for treating drug-resistant cancers. However, as SERCA activity is essential for all cells types, specific inhibitors such as thapsigargin (TG) possess general toxicity. We explored the potential for developing SERCA inhibitors controllable with light by synthesizing TG derivatives containing an azobenzene photoswitch. These compounds (AzTG derivatives) were assessed by their ability to inhibit SERCA ATPase activity. We have identified cis-active and trans-active derivatives and our results reveal a ~2-fold difference in IC50 in response to photoisomerization, demonstrating an effect of the incorporated photoswitch. Furthermore, X-ray structures of SERCA in complex with two AzTG derivatives were obtained, revealing two different binding modes for the photoswitch group of these compounds. Taken together, we have developed photo-activatable SERCA inhibitors that can serve as tools to study the function of their target protein, and our results build the foundation for the design of improved, next-generation photoswitchable inhibitors. SERCA ; Thapsigargin ; Photoswitch ; Chemistry ; Endoplasmic reticulum ; Calcium ATPase ; ATPase ; Photoisomerization ; Biochemistry ; Biophysics ; Enzyme ; Biology Photochromic and Fluorescence Chemistry ; Advanced biosensing and bioanalysis techniques ; Photoreceptor and optogenetics research
Authors: M. Wagner | Rafał Ołdziejewski | Félix Rose | Verena Köder | Clemens Kuhlenkamp | Ataç Îmamoğlu | Richard Schmidt
Source: arXiv (Cornell University) (preprint, 2023-10-12)
Field: Materials Science — Materials Chemistry

Feshbach Resonances in Exciton-Charge-Carrier Scattering in Semiconductor Bilayers Feshbach resonances play a vital role in the success of cold atoms investigating strongly-correlated physics. The recent observation of their solid-state analog in the scattering of holes and intralayer excitons in transition metal dichalcogenides [Schwartz et al., Science 374, 336 (2021)] holds compelling promise for bringing fully controllable interactions to the field of semiconductors. Here, we demonstrate how tunneling-induced layer hybridization can lead to the emergence of two distinct classes of Feshbach resonances in atomically thin semiconductors. Based on microscopic scattering theory we show that these two types of Feshbach resonances allow to tune interactions between electrons and both short-lived intralayer, as well as long-lived interlayer excitons. We predict the exciton-electron scattering phase shift from first principles and show that the exciton-electron coupling is fully tunable from strong to vanishing interactions. The tunability of interactions opens the avenue to explore Bose-Fermi mixtures in solid-state systems in regimes that were previously only accessible in cold atom experiments. Exciton ; Condensed matter physics ; Heterojunction ; Semiconductor ; Scattering ; Electron ; Quantum tunnelling ; Physics ; Feshbach resonance ; Materials science ; Atomic physics ; Quantum mechanics Electronic and Structural Properties of Oxides ; 2D Materials and Applications ; Machine Learning in Materials Science
Authors: William T. Gallonde | Corentin Poidevin | Félix Houard | Elsa Caytan | Vincent Dorcet | Arnaud Fihey | Kévin Bernot | Stéphane Rigaut | Olivier Galangau
Source: Angewandte Chemie (article, 2023-10-23)
Field: Materials Science — Biomaterials

Kinetic Delay in Cooperative Supramolecular Polymerization by Redefining the Trade‐Off Relationship between H‐Bonds and Van der Waals/π–π Stacking Interactions Abstract We here present how rebalancing the interplay between H‐bonds and dispersive forces (Van der Waals/π–π stacking) may induce or not the generation of kinetic metastable states. In particular, we show that extending the aromatic content and favouring the interchain VdW interactions causes a delay into the cooperative supramolecular polymerization of a new family of toluene bis‐amide derivatives by trapping the metastable inactive state. Stacking ; van der Waals force ; Supramolecular chemistry ; Metastability ; Polymerization ; Chemistry ; Kinetic energy ; Chemical physics ; Amide ; Polymer ; Crystallography ; Molecule ; Crystal structure ; Organic chemistry ; Physics Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Luminescence and Fluorescent Materials
Authors: Nikolaos Kostopoulos | Viacheslav Shkirskiy | Catherine Combellas | Frédéric Kanoufi | Tony Breton | Jean‐Marc Noël
Source: Electrochimica Acta (article, 2023-02-10)
Field: Chemistry — Electrochemistry

Aryldiazonium reduction mechanism deciphered by scanning electrochemical microscopy through an EC’ process Scanning electrochemical microscopy ; Electrochemistry ; Reduction (mathematics) ; Mechanism (biology) ; Chemistry ; Microscopy ; Process (computing) ; Nanotechnology ; Chemical engineering ; Materials science ; Electrode ; Computer science ; Optics ; Physics ; Physical chemistry ; Engineering Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors ; Molecular Junctions and Nanostructures
Authors: Magalie Delecluse | Anne‐Doriane Manick | Bastien Châtelet | Sabine Chevallier‐Michaud | Delphine Moraléda | Innocenzo De Riggi | Jean‐Pierre Dutasta | Alexandre Martinez
Source: ChemPlusChem (article, 2023-11-11)
Field: Chemistry — Organic Chemistry

Ditopic Covalent Cage for Ion‐Pair Binding: Influence of Anion Complexation on the Cation Exchange Rate A new hemicryptophane host with a ditopic molecular cavity combining a cyclotriveratrylene (CTV) unit with a tris-urea moiety was synthesized. The complexation of halides, tetramethylammonium (TMA<sup>+</sup>) cation, and ion pairs was investigated. A positive cooperativity was observed, since halides display a higher binding constant when a TMA<sup>+</sup> cation is already present inside the cage. When TMA<sup>+</sup> was complexed alone, a decrease of temperature from 298 K to 230 K was required to switch from a fast to a slow exchange regime on the NMR time scale. Nevertheless, the prior complexation of a halide guest in the lower part of the host resulted in significant decrease of the exchange rate of the subsequent complexation of the TMA<sup>+</sup> cation. Under these conditions, the <sup>1</sup>H NMR signals characteristic of a slow exchange regime were observed at 298 K. Addition of an excess of salts, increases the ionic strength of the solution, restoring the fast exchange dynamics. This result provides insight on how the exchange rate of a cation guest can be modulated by the complexation of a co-guest anion. Chemistry ; Tetramethylammonium ; Halide ; Moiety ; Ion exchange ; Ion ; Inorganic chemistry ; Cooperativity ; Host–guest chemistry ; Ionic bonding ; Crystallography ; Supramolecular chemistry ; Physical chemistry ; Stereochemistry ; Organic chemistry ; Crystal structure Supramolecular Chemistry and Complexes ; Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials
Authors: Suhang He | Bing Huang | Bohuai Xiao | Shuai Chang | Marina Podalko | Werner M. Nau
Source: Angewandte Chemie (article, 2023-10-09)
Field: Chemistry — Organic Chemistry

Stabilization of Guest Molecules inside Cation‐Lidded Cucurbiturils Reveals that Hydration of Receptor Sites Can Impede Binding Abstract Docking of alkali metal ions to water‐soluble macrocyclic receptors generally reduces the affinity of guest molecules due to competitive binding. The idea that solvation water molecules could display a larger steric hindrance towards guest binding than cations has not been considered to date. We show that the docking of large cations to cucurbit[5]uril (CB5) unexpectedly increases (by a factor of 5–8) the binding of hydrophobic guests, methane and ethane. This is due to the removal of water molecules from the carbonyl portals of CB5 during cation binding, which frees up space for hydrophobe encapsulation. In contrast, smaller cations like sodium protrude deeply into the cavity of CB5 and cause the expected decrease in binding, such that the rational selection of alkali cations allows for a variation of up to a factor of 20 in binding of methane and ethane. The statistical analysis of crystallographic data shows that the cavity volume of CB5 can be enlarged by placing large alkali ions (Rb + and Cs + ) centro‐symmetrically at the portals. The results reveal a hitherto elusive steric hindrance of solvation water molecules near receptor binding sites, which is pertinent for the design of supramolecular catalysts and the understanding of biological receptors. Cucurbituril ; Steric effects ; Chemistry ; Solvation ; Supramolecular chemistry ; Molecule ; Alkali metal ; Docking (animal) ; Solvation shell ; Crystallography ; Inorganic chemistry ; Stereochemistry ; Organic chemistry Supramolecular Chemistry and Complexes ; Crystallography and molecular interactions ; Mass Spectrometry Techniques and Applications
Authors: Judith P. Araújo | Maikel Y. Ballester | Mariana P. Martins | Rafael P. Silva | Isadora G. Lugão | I. B. Okon | C. A. Onate
Source: INTERMATHS Revista de Matemática Aplicada e Interdisciplinar (article, 2023-06-30)
Field: Chemistry — Physical and Theoretical Chemistry

A methodology to obtain accurate potential energy Functions for diatomic systems: mathematical point of view The mathematics used in physical chemistry has changed greatly in the past forty years and it will certainly continue to change more quickly. Theoretical chemists and physicists must have an acquaintance with abstract mathematics if they are to keep up with their field, as the mathematical language in which it is expressed changes. Thinking about it, in this article, we want to show some of the most important concepts of Mathematical Analysis involved in obtaining analytical functions to represent the potential energy interaction for diatomic systems. A basic guide for the construction of a potential based on Dunham's coefficients and an example of a new potential obtained from this methodology is also presented. Diatomic molecule ; Point (geometry) ; Field (mathematics) ; Potential energy ; Energy (signal processing) ; Computer science ; Mathematical problem ; Calculus (dental) ; Applied mathematics ; Management science ; Mathematics ; Theoretical physics ; Mathematics education ; Engineering ; Physics ; Quantum mechanics ; Geometry ; Pure mathematics Various Chemistry Research Topics ; Chemical Thermodynamics and Molecular Structure ; History and advancements in chemistry
Authors: R S Mrinaleni | E P Amaladass | S Amirthapandian | A. T. Sathyanarayana | P Jegadeesan | K Ganesan | R M Sarguna | P. N. Rao | P. D. Gupta | T. Geetha Kumary | S. K. Rai | Awadhesh Mani
Source: arXiv (Cornell University) (preprint, 2023-01-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Exploring the substrate-driven morphological changes in Nd0.6Sr0.4MnO3 thin films Manganite thin films are promising candidates for studying the strongly correlated electron systems. Understanding the growth-and morphology-driven changes in the physical properties of manganite thin films is vital for their applications in oxitronics. This work reports the morphological, structural, and electrical transport properties of nanostructured Nd0.6Sr0.4MnO3 (NSMO) thin films fabricated using the pulsed laser deposition technique. Scanning electron microscopy (SEM) imaging of the thin films revealed two prominent surface morphologies: a granular and a unique crossed-nano-rod-type morphology. From X-ray diffraction (XRD) and atomic force microscopy (AFM) analysis, we found that the observed nanostructures resulted from altered growth modes occurring on the terraced substrate surface. Furthermore, investigations on the electrical-transport properties of thin films revealed that the films with crossed-nano-rod type morphology showed a sharp resistive transition near the metal-to-insulator transition (MIT). An enhanced temperature coefficient of resistance (TCR) of up to one order of magnitude was also observed compared to the films with granular morphology. Such enhancement in TCR % by tuning the morphology makes these thin films promising candidates for developing oxide-based temperature sensors and detectors. Manganite ; Materials science ; Thin film ; Scanning electron microscope ; Substrate (aquarium) ; Pulsed laser deposition ; Nanotechnology ; Nanostructure ; Composite material ; Condensed matter physics ; Ferromagnetism Magnetic and transport properties of perovskites and related materials ; Transition Metal Oxide Nanomaterials ; Electrical and Thermal Properties of Materials
Source: NanoWorld Journal (article, 2023-10-11)
Field: Materials Science — Polymers and Plastics

Revolutionizing Polyester Composites Using Synergistic Effects of Flax Fiber and Silicon Oxide Nanoparticles Vettrivel Arul, Eugenia Naranjo, Shrinwantu Raha, Lidia Castro Cepeda, Miguel Escobar, Alugoju Uday Kumar and Venkatraman Vijayan In recent years, researchers have shifted their focus from traditional metals and alloys to composites in the search for lightweight, highly functional materials. Glass fibers are more durable, cost-effective, and fireproof than natural fibers. Composite material ; Materials science ; Polyester ; Nanoparticle ; Fiber ; Oxide ; Silicon ; Nanotechnology ; Optoelectronics Natural Fiber Reinforced Composites ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry ; Material Properties and Applications
Authors: Gourab Das | Anjali Anand | Balaraman Vedhanarayanan | Akhil Padmakumar | Vakayil K. Praveen | Ayyappanpillai Ajayaghosh
Source: Chemistry - A European Journal (article, 2023-07-27)
Field: Materials Science — Biomaterials

Controlling the Morphological Features, Aspect Ratio and Emission Patterns of Supramolecular Copolymers by Restricted Dimensional Growth One of the bottlenecks associated with supramolecular polymerization of functional π-systems is the spontaneous assembly of monomers leading to one- or two-dimensional (1D or 2D) polymers without control over chain length and optical properties. In the case of supramolecular copolymerization of monomers that are structurally too diverse, preferential self-sorting occurs unless they are closely interacting donor-acceptor pairs. Herein, it is established that the spontaneous 1D polymerization of a phenyleneethynylene (PE) derivative and the 2D polymerization of a Bodipy derivative (BODIPY) can be controlled by copolymerizing them in different ratios, leading to unusual spindle-shaped structures with controlled aspect ratio, as evident by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) studies. For example, when the content of BODIPY is 50 % in the BODIPY-PE mixture, the 1D polymerization of PE is significantly restricted to form elongated spindle-like structures having an aspect ratio of 4-6. The addition of 75 % of BODIPY to PE resulted in circular spindles having an aspect ratio of 1-2.5, thereby completely restricting the 1D polymerization of PE monomers. Moreover, the resultant supramolecular copolymers exhibited morphology and aspect ratio dependent emission features as observed by the time-resolved emission studies. BODIPY ; Polymerization ; Monomer ; Supramolecular chemistry ; Copolymer ; Materials science ; Supramolecular polymers ; Polymer chemistry ; Polymer ; Scanning electron microscope ; Transmission electron microscopy ; Crystallography ; Chemical engineering ; Fluorescence ; Chemistry ; Nanotechnology ; Crystal structure ; Optics ; Composite material Supramolecular Self-Assembly in Materials ; Luminescence and Fluorescent Materials ; Covalent Organic Framework Applications
Authors: Martin Trulsson
Source: Langmuir (article, 2023-05-24)
Field: Chemistry — Physical and Theoretical Chemistry

Ion and Site Correlations of Charge Regulating Surfaces: A Simple and Accurate Theory Charge regulation is fundamental in most chemical, geochemical, and biochemical systems. Various mineral surfaces and proteins are well-known to change their charge state as a function of the activity of the hydronium ions, that is, the pH. Besides being modulated by the pH, the charge state is sensitive to salt concentration and composition due to screening and ion correlations. Given the importance of electrostatic interactions, a reliable and straightforward theory of charge regulation would be of utmost importance. This Article presents a theory that accounts for salt screening, site, and ion correlations. Our approach shows an impeccable agreement as compared to Monte Carlo simulations and experiments of 1:1 and 2:1 salts. We furthermore disentangle the relative importance of site-site, ion-ion, and ion-site correlations. Contrary to previous claims, we find that ion-site correlations for the studied cases are subdominant to the two other correlation terms. Ion ; Chemistry ; Charge (physics) ; Monte Carlo method ; Chemical physics ; Salt (chemistry) ; Hydronium ; Electrostatics ; Atomic physics ; Statistical physics ; Physics ; Physical chemistry ; Quantum mechanics Electrostatics and Colloid Interactions ; Geophysical and Geoelectrical Methods ; Minerals Flotation and Separation Techniques
Authors: William Schenken | Simon A. Meynell | Francisco Machado | Bingtian Ye | Claire A. McLellan | Maxime Joos | V. V. Dobrovitski | Norman Y. Yao | Ania C. Bleszynski Jayich
Source: arXiv (Cornell University) (preprint, 2023-09-27)
Field: Materials Science — Materials Chemistry

Long-lived coherences in strongly interacting spin ensembles Periodic driving has emerged as a powerful tool to control, engineer, and characterize many-body quantum systems. However, the required pulse sequences are often complex, long, or require the ability to control the individual degrees of freedom. In this work, we study how a simple Carr-Purcell Meiboom-Gill (CPMG)-like pulse sequence can be leveraged to enhance the coherence of a large ensemble of spin qubits and serve as an important characterization tool. We implement the periodic drive on an ensemble of dense nitrogen-vacancy (NV) centers in diamond and examine the effect of pulse rotation offset as a control parameter on the dynamics. We use a single diamond sample prepared with several spots of varying NV density, which, in turn, varies the NV-NV dipolar interaction strength. Counter-intuitively, we find that rotation offsets deviating from the ideal π-pulse in the CPMG sequence (often classified as pulse errors) play a critical role in preserving coherence even at nominally zero rotation offset. The cause of the coherence preservation is an emergent effective field that scales linearly with the magnitude of the rotation offset. In addition to extending coherence, we compare the rotation offset dependence of coherence to numerical simulations to measure the disorder and dipolar contributions to the Hamiltonian to quantitatively extract the densities of the constituent spin species within the diamond. Coherence (philosophical gambling strategy) ; Dipole ; Physics ; Diamond ; Offset (computer science) ; Hamiltonian (control theory) ; Qubit ; Quantum ; Statistical physics ; Condensed matter physics ; Quantum mechanics ; Chemistry ; Computer science ; Mathematics Diamond and Carbon-based Materials Research ; High-pressure geophysics and materials ; Atomic and Subatomic Physics Research
Authors: Eelis Kamula | Juha Vaara | Petr Štěpánek
Source: ChemRxiv (preprint, 2023-05-22)
Field: Chemistry — Spectroscopy

Characteristic nuclear spin-induced optical rotation in oxygen-containing organic molecules Nuclear spin-induced optical rotation (NSOR) is a nuclear magneto-optic effect that manifests itself as a rotation of the plane of polarization of linearly polarized light. The effect is induced by ordered nuclear magnetic moments within a molecule. NSOR is sensitive to specific, localized interactions. Hence, the connection between the local chemical environment and the corresponding NSOR signal is crucial to understand. Despite the fact that contributions to better understand the connection have been made, the general systematics still remain unknown. In this paper, NSOR in oxygen compounds is investigated systematically to better understand the impact of oxygen atoms on the NSOR signal. NSOR signals are computed using density-functional theory methods for five different classes of oxygen compounds. The ability of NSOR to distinguish different molecules and individual nuclei in the molecules is studied and the information provided by NSOR is compared to conventional NMR spectroscopy. The results reveal that NSOR is capable of chemical distinction between nuclei and molecules, and by using NMR and NSOR together it is possible to distinguish nuclei near the oxygen atom. Molecule ; Oxygen ; Polarization (electrochemistry) ; Spectroscopy ; Optical rotation ; Chemistry ; Density functional theory ; Nuclear magnetic resonance spectroscopy ; Chemical physics ; Spin (aerodynamics) ; Rotation (mathematics) ; Chemical shift ; Spin polarization ; Molecular physics ; Nuclear magnetic resonance ; Atom (system on chip) ; Physics ; Computational chemistry ; Physical chemistry ; Quantum mechanics Molecular spectroscopy and chirality ; Spectroscopy and Quantum Chemical Studies ; Quantum optics and atomic interactions