jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: F. Le Mardelé | Ivan Mohelský | J. Wyzula | M. Orlita | Philippe Turek | Filippo Troiani | A.K. Boudalis
Source: arXiv (Cornell University) (preprint, 2024-03-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Observation of spin-electric transitions in a molecular exchange qubit Electric fields represent an ideal means for controlling spins at the nanoscale and, more specifically, for manipulating protected degrees of freedom in multispin systems. Here we perform low-temperature magnetic far-IR spectroscopy on a molecular spin triangle (Fe3) and provide the first experimental evidence of spin-electric transitions in polynuclear complexes. The co-presence of electric- and magnetic-dipole transitions, allows us to estimate the spin-electric coupling. Based on spin Hamiltonian simulations of the spectra, we identify the observed transitions and introduce the concept of a generalized exchange qubit. This applies to a wide class of molecular spin triangles, and includes the scalar chirality and the partial spin sum qubits as special cases. Qubit ; Spins ; Spin engineering ; Physics ; Condensed matter physics ; Spin (aerodynamics) ; Hamiltonian (control theory) ; Scalar (mathematics) ; Electric dipole moment ; Dipole ; Quantum mechanics ; Spin polarization ; Quantum ; Electron ; Mathematics Magnetism in coordination complexes ; Electron Spin Resonance Studies ; Spectroscopy and Quantum Chemical Studies
Authors: Antonín Králík | Golam Haider | Vaibhav Varade | Martin Kalbáč | Jana Vejpravová
Source: The Journal of Physical Chemistry C (article, 2024-07-23)
Field: Materials Science — Materials Chemistry

Addressing Individual Layers and Their Optical Properties in Artificial MoS<sub>2</sub> Bilayers via Sulfur Isotope Labeling The physicochemical properties of van der Waals (vdW) heterostructures are driven by the delicate interactions between the individual layers in a multilayer stack. While addressing the monolayers of different compositions in the multilayer is feasible, exploring the intrinsic properties of the monolayers of the same composition within a multilayer is extremely challenging. This becomes of utmost importance in energy conversion and storage concepts based on layered vdW materials. For example, the charge distribution on the individual layers can be determined, and the behavior can be disentangled. We introduce sulfur isotope labeling as a powerful tool for separately addressing monolayers in vdW heterostructures composed of transition metal disulfides. Using chemical vapor deposition (CVD), we prepared monolayers of MoS<sub>2</sub> using natural sulfur (<sup>Nat</sup>S) and <sup>34</sup>sulfur (<sup>34</sup>S) as precursors. Artificial bilayers were then prepared by transferring Mo<sup>34</sup>S<sub>2</sub> onto Mo<sup>Nat</sup>S<sub>2</sub>. Thanks to the different masses of <sup>Nat</sup>S and <sup>34</sup>S, we were able to disentangle the spectral fingerprints of phonons and excitons in the two layers using Raman and photoluminescence microspectroscopy. Also, the charge distribution on the individual layers was revealed through Raman spectra analysis. Our work thus provides a different perspective for understanding the functionalities and optical properties of smart architecture based on transition metal chalcogenides. Sulfur ; Isotope ; Materials science ; Chemistry ; Nanotechnology ; Physics ; Organic chemistry 2D Materials and Applications ; MXene and MAX Phase Materials ; Advanced biosensing and bioanalysis techniques
Source: International Journal of Biology Pharmacy and Allied Sciences (article, 2024-04-30)
Field: Materials Science — Polymers and Plastics

POLYMERIC MICELLES: A NOVEL APPROACH FOR TARGETTING NON-SMALL CELL LUNG CANCER USING NINTEDANIB The present work was to explore the ability of amphiphilic block copolymer poloxamine (TETRONICS) to form polymeric micelles which acts as an effective drug delivery and targeting system for cancer therapy.The practical disadvantage of poloxamine due to its high CMC & cloud point is overcome by adding inorganic salt such as NaCl .The fabrication of class II drug Nintedanib into polymeric micelle was done by direct dissolution method.The formulation parameters were optimized using design expert software.Compatibility studies for drug and excipients were carried out by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry the designed polymeric micelles were evaluated for its characteristic features like Cloud point, DLS, Entrapment efficiency and In vitro release studies.In vitro cytotoxic activity for its efficiency as a promising drug delivery system was established using MTT assay.The lyophilized form of micelles was examined for its surface morphology using scanning electron microscopy and phase contrast microscopy.The solubilization of anticancer drug nintedanib demonstrates improved controlled release kinetics and cytotoxicity.On the whole, modulation in micellar behaviour by NaCl opens enchanting possibility of using T1307 and T1107 micelles as nanoreservoirs for carrying poorly water soluble drugs. Nintedanib ; Micelle ; Lung cancer ; Chemistry ; Cancer research ; Biophysics ; Materials science ; Lung ; Medicine ; Internal medicine ; Biology ; Organic chemistry ; Aqueous solution Dendrimers and Hyperbranched Polymers ; Nanomaterials for catalytic reactions ; Nanoparticle-Based Drug Delivery
Source: Angewandte Chemie International Edition (article, 2024-07-17)
Field: Chemistry — Organic Chemistry

Julia Stauber "A good day at work starts with a cup of coffee and a clear plan… A turning point in my current research project was when I successfully synthesized a complex molecule that had been deemed too challenging to make…" Find out more about Julia Stauber in her Introducing… Profile. Chemistry Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Synthesis and Reactivity of Heterocycles
Authors: Biying Zhuang | Meiyu Zhang | Ang Li | Qianqian Zhang | Jingbing Liu | Zilong Zheng | Hao Wang
Source:  (preprint, 2024-02-23)
Field: Materials Science — Polymers and Plastics

Dynamic multicolour tuning in π-conjugated polymers towards flexible electrochromic displays Multicolour electrochromic materials have been considered as a promising alternative to achieve dynamic full-colour tuning towards next-generation electronic display technology. However, the development of electrochromics with wide color gamut and subtle multicolour tunability still remains challenging due to inflexible energy level structures in intrinsic active materials. Herein, the electrochromic π-conjugated polymers with rich and subtle colour tunability were designed and developed based on a fine adjustment on the energy level structures. The chromatic transition covers almost full-colour gamut, and each colour scheme has a rich variety of categories stemming from versatile hues, chromas and lightnesses. Moreover, the multicolour π-conjugated polymers also demonstrate superior overall electrochromic performance, including fast switching (~1.0 s), high colouration efficiency (160.4 cm2 C-1@550 nm) and good reversibility (over 90 % retention after 10,000 cycles). As a proof of concept, ultrathin and flexible prototype devices are developed by utilizing the multicolour π-conjugated polymers as electrochromic active layer, exhibiting a wide colour gamut and highly saturated multicolour tunability. The design principles proposed in this work may also be applicable to diverse optoelectronic applications. Electrochromism ; Conjugated system ; Polymer ; Electrochromic devices ; Materials science ; Nanotechnology ; Optoelectronics ; Computer science ; Chemistry ; Electrode ; Composite material Conducting polymers and applications ; Transition Metal Oxide Nanomaterials ; Polydiacetylene-based materials and applications
Authors: Antonia Iazzetti | Antonio Arcadi | Marco Chiarini | Giancarlo Fabrizi | Antonella Goggiamani | Federico Marrone | Andrea Serraiocco | Roberta Zoppoli
Source: Molecules (article, 2024-07-22)
Field: Chemistry — Organic Chemistry

Palladium-Catalyzed Tsuji–Trost-Type Reaction of 3-Indolylmethylacetates with O, and S Soft Nucleophiles The chemical valorization of widespread molecules in renewable sources is a field of research widely investigated in the last decades. In this context, we envisaged that indole-3-carbinol, present in different <i>Cruciferae</i> plants, could be a readily available building block for the synthesis of various classes of indoles through a palladium-catalyzed Tsuji-Trost-type reaction with O and S soft nucleophiles. The regiochemical outcome of this high-yielding functionalization shows that the nucleophilic substitution occurs only at the benzylic position. Interestingly, with this protocol, the sulfonyl unit could be appended to the indole nucleus, providing convenient access to new classes of molecules with potential bioactivity. Palladium ; Catalysis ; Nucleophile ; Chemistry ; Medicinal chemistry ; Organic chemistry Synthesis of Indole Derivatives ; Catalytic C–H Functionalization Methods ; Catalytic Cross-Coupling Reactions
Authors: Pablo M. Blanco | Peter Košovan
Source: arXiv (Cornell University) (preprint, 2024-01-25)
Field: Materials Science — Materials Chemistry

The explicit bonding Reaction ensemble Monte Carlo method We present the explicit bonding Reaction ensemble Monte Carlo (eb-RxMC) method, designed to sample reversible bonding reactions in macromolecular systems in thermodynamic equilibrium. Our eb-RxMC method is based on the Reaction ensemble method, however, its implementation differs from the latter by the representation of the reaction. In the eb-RxMC implementation, we are adding or deleting bonds between existing particles, instead of inserting or deleting particles with different chemical identities. This new implementation makes the eb-RxMC method suitable for simulating the formation of reversible linkages between macromolecules, which would not be feasible with the original implementation. To enable coupling of our eb-RxMC algorithm with Molecular Dynamics algorithm for sampling of the configuration space, we biased the sampling of reactions only within a certain inclusion radius. We validated our algorithm using a set of ideally behaving systems undergoing dimerization and polycondensation reactions, for which analytical results are available. For dimerization reactions with various equilibrium constants and initial compositions, the degree of conversion measured in our simulations perfectly matched the reference values given by the analytical equations. We also showed that this agreement is not affected by the arbitrary choice of the inclusion radius or the stiffness of the harmonic bond potential. Next, we showed that our simulations can correctly match the analytical results for the distribution of the degree of polymerization and end-to-end distance of ideal chains in polycondensation reactions. Altogether, we demonstrated that our eb-RxMC simulations correctly sample both reaction and configuration space of these reference systems, opening the door to future simulations of more complex interacting macromolecular systems. Monte Carlo method ; Statistical physics ; Molecular dynamics ; RADIUS ; Space (punctuation) ; Configuration space ; Chemistry ; Computational chemistry ; Thermodynamics ; Physics ; Mathematics ; Computer science ; Quantum mechanics ; Statistics Machine Learning in Materials Science ; Protein Structure and Dynamics ; Polymer crystallization and properties
Authors: Shimul Saha
Source: Journal of Scientific Research (article, 2024-01-01)
Field: Chemistry — Organic Chemistry

Synthesis of New Mn(II), Co(II) and Cu(II) Complexes Grabbed in Novel Functionalized Ionic Liquid Tagged Schiff base: Physico-chemical Properties and Antibacterial Applications An ionic liquid tagged schiff base, [1-{2-(2-hydroxybenzylideneamino)ethyl}-3-methylimidazolium]PF6 was synthesized from a functionalized ionic liquid (FIL) 2-aminoethyl-3-methylimidazolium hexafluorophosphate, [2-aemim]PF6 and salicylaldehyde without using any organic solvent. The Schiff base was used as a ligand to trap Mn(II), Co(II), Cu(II) ions from its corresponding metal acetates and to form the new transition metal complexes. The synthesized Mn(II), Co(II), Cu(II) complexes along with the Schiff base were characterized by ESI-MS, PXRD, UV-Visible, FT-IR, 1H NMR spectroscopic and analytical (elemental analysis and magnetic susceptibility measurements) methods. Based on these spectral analysis data tetra coordinated geometries were assigned for the newly synthesized metal(II) complexes. Antibacterial sensitivity of the Schiff base and the Mn(II), Co(II), Cu(II) complexes were evaluated against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria to assess their minimum zone of inhibition. Schiff base ; Ionic liquid ; Ionic bonding ; Chemistry ; Polymer chemistry ; Inorganic chemistry ; Ion ; Organic chemistry ; Catalysis Inorganic and Organometallic Chemistry ; Multicomponent Synthesis of Heterocycles ; Chemical Synthesis and Reactions
Authors: Anindya Sundar Datta | Md. Harun Al Rashid | Sanchita Das
Source: Journal of Pharmacognosy and Phytochemistry (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Role of medicinal plant in synthesis of green silver nanoparticles as antibacterial agent In this current era, the fasten antibiotic-resistant of pathogens towards traditional antibiotics, has accountable for major global health problem. Researchers are perceptive to investigate for unconventional non antibiotic antimicrobial agents to control escalating development of bacterial resistance by microorganisms to antimicrobial drugs for prevention of infections caused by resistance pathogens. Different strategies with guiding principles are tested to build up effectual successive antibacterial agents, as widely used traditional physical and chemical methods for the production of NPs are high-cost with along with toxic byproducts, as well as harmful for the environment. In this admiration, green syntheses of nanoparticles are unquestionably promising materials, to reduce the use of hazards chemicals in development of nanoparticles by substituting them with plant-based materials. Silver nanoparticles (GAgNPs) have ability to go through the cell wall by penetrating the membrane of bacteria to amend their virulence potential by interaction with crucial biomolecules making trouble in molecular mechanisms. In fusion with suitable antibiotics, AgNPs may show synergistic effect and help to prevent the increasing worldwide bacterial resistance. Furthermore, due to unique characteristics such as superior biocompatibility and biodegradability GAgNPs have become the researcher’s center of attention of new antibacterial materials due to their small particles, large surface to volume area, physical, mechanical and chemical properties. In this review, we investigated recent studies regarding the potential function of plant extract as a reducing/ capping /stabilizing agent and the antimicrobial activity of AgNPs, their potential for use in the medical and pharmaceutical field. Silver nanoparticle ; Nanoparticle ; Nanotechnology ; Antibacterial activity ; Chemistry ; Materials science ; Bacteria ; Biology Nanoparticles: synthesis and applications ; Diverse Scientific Research Studies ; Moringa oleifera research and applications
Authors: Darragh Buckley | Alex Lonergan | Colm O’Dwyer
Source: arXiv (Cornell University) (preprint, 2024-11-20)
Field: Materials Science — Materials Chemistry

ZnO-based Semiconductors and Structures for Transistors, Optoelectronic Devices and Sustainable Electronics Metal oxide thin films are of great interest in scientific advancement, particularly semiconductor thin films in transistors and in a wide range of optoelectronic applications. Many metal oxide thin films attract interest for their electronic bandgap, charge carrier mobility, optical opacity, luminescence, low cost, relative abundance and environmentally-friendly production. Additionally, these properties are often tuneable via particle size, film density, surface morphology, film deposition, growth method, hetero-interface engineering or ion-doping. Zinc oxide as a n-type semiconducting metal oxide is material of great interest owing to its intrinsically wide direct bandgap, high electron mobility, relatively high exciton binding energy, high optical transparency, demonstrated metal-ion doping optoelectronic effects, a range of different particle morphologies and deposition methods, photoluminescence ability, low cost and a variety of existing green synthesis methods. Here, these aspects of zinc oxide and some related oxides are reviewed, focusing on how the unique properties of this metal oxide make it suitable for a range of different applications from thin film transistors, high mobility oxide interfaces, transparent conductive oxides, photoanodes photodetectors, chemical sensors, photocatalysts, superlattice electronics and more. The properties and deposition methods and their impact on functionality will be discussed alongside their role in sustainable optoelectronics for future devices. Electronics ; Transistor ; Semiconductor ; Optoelectronics ; Materials science ; Engineering physics ; Nanotechnology ; Electrical engineering ; Engineering ; Voltage ZnO doping and properties
Authors: Ram Prakash Pandeya | Konstantin P. Shchukin | Yannic Falke | Gregor Mußler | Jalil Abdur Rehman | Nicolae Atodiresei | Alexander Fedorov | Boris V. Senkovskiy | Daniel Jansen | Giovanni Di Santo | L. Petaccia | A. Grüneis
Source: arXiv (Cornell University) (preprint, 2024-05-15)
Field: Materials Science — Materials Chemistry

Molecular order induced charge transfer in a C$_{60}$-topological insulator moiré heterostructure We synthesize and spectroscopically investigate monolayer C$_{60}$ on the topological insulator (TI) Bi$_4$Te$_3$. This C$_{60}$/Bi$_4$Te$_3$ heterostructure is characterized by excellent translational order in a novel (4 x 4) C$_{60}$ superstructure on a (9 x 9) unit of Bi$_4$Te$_3$. We measure the full two-dimensional energy band structure of C$_{60}$/Bi$_4$Te$_3$ using angle-resolved photoemission spectroscopy (ARPES). We find that C$_{60}$ accepts electrons from the TI at room temperature but no charge transfer occurs at low temperatures. We unravel this peculiar behaviour by Raman spectroscopy of C$_{60}$/Bi$_4$Te$_3$ and density functional theory (DFT) calculations of the electronegativity of C$_{60}$. Both methods are sensitive to orientational order of C$_{60}$. At low temperatures, Raman spectroscopy shows a dramatic intensity increase of the C$_{60}$ Raman signal, evidencing a transition to a rotationally ordered state. DFT reveals that the orientational order of C$_{60}$ at low temperatures has a higher electron affinity than at high temperatures. These results neatly explain the temperature-dependent charge transfer observed in ARPES. Our conclusions are supported by the appearance of a strong photoluminescence from C$_{60}$/Bi$_4$Te$_3$ at low temperatures. Topological insulator ; Heterojunction ; Moiré pattern ; Charge (physics) ; Insulator (electricity) ; Physics ; Transfer (computing) ; Topology (electrical circuits) ; Materials science ; Condensed matter physics ; Optoelectronics ; Computer science ; Quantum mechanics ; Optics ; Engineering ; Electrical engineering Diamond and Carbon-based Materials Research ; Electronic and Structural Properties of Oxides ; Graphene research and applications
Authors: Nadine Kohlhuber | Irina Sulaeva | Tao Zou | Oliver Musl | Robert Mildner | Scott Renneckar | Monika Österberg | Thomas Rosenau | Antje Potthast
Source: ChemRxiv (preprint, 2024-12-20)
Field: Chemistry — Spectroscopy

Enhanced Characterization of Lignin Nanoparticles by Asymmetric Flow-Field Flow Fractionation The unique properties of lignin nanoparticles (LNPs)—uniform shape, surface properties and nanoscale—carry great potential for the desired material utilization of technical lignins. Especially, the particle size distribution and dispersity of LNPs are the key for their successful valorization. However, characterization of LNPs usually require a combination of light scattering and microscopy techniques which provide only average values, are often limited in sampling size and require tedious sample preparation. Here we introduce a method based on asymmetric flow field-flow fractionation (AF4) coupled with multi angle laser light scattering (MALLS), dynamic light scattering (DLS) and refractive index (RI) detection for the analysis of size and shape of LNPs. Exploiting the separation power of AF4 in combination with MALLS, DLS, and RI allowed to obtain more enhanced particle size distributions of LNP that are comparable to batch DLS and AFM measurements. Moreover, we discuss the influence of the particle size on the MALLS and DLS signal and determination of the shape factor of LNP. Characterization (materials science) ; Lignin ; Flow (mathematics) ; Nanoparticle ; Fractionation ; Field (mathematics) ; Nanotechnology ; Field flow fractionation ; Materials science ; Chemistry ; Chemical engineering ; Chromatography ; Organic chemistry ; Mechanics ; Engineering ; Physics ; Mathematics Diffusion Coefficients in Liquids ; Petroleum Processing and Analysis ; Field-Flow Fractionation Techniques
Authors: Mingxuan Zhang | Yan Sun | Faming Liang
Source: arXiv (Cornell University) (preprint, 2024-11-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Magnitude Pruning of Large Pretrained Transformer Models with a Mixture Gaussian Prior Large pretrained transformer models have revolutionized modern AI applications with their state-of-the-art performance in natural language processing (NLP). However, their substantial parameter count poses challenges for real-world deployment. To address this, researchers often reduce model size by pruning parameters based on their magnitude or sensitivity. Previous research has demonstrated the limitations of magnitude pruning, especially in the context of transfer learning for modern NLP tasks. In this paper, we introduce a new magnitude-based pruning algorithm called mixture Gaussian prior pruning (MGPP), which employs a mixture Gaussian prior for regularization. MGPP prunes non-expressive weights under the guidance of the mixture Gaussian prior, aiming to retain the model's expressive capability. Extensive evaluations across various NLP tasks, including natural language understanding, question answering, and natural language generation, demonstrate the superiority of MGPP over existing pruning methods, particularly in high sparsity settings. Additionally, we provide a theoretical justification for the consistency of the sparse transformer, shedding light on the effectiveness of the proposed pruning method. Magnitude (astronomy) ; Transformer ; Gaussian ; Pruning ; Mathematics ; Statistics ; Computer science ; Artificial intelligence ; Pattern recognition (psychology) ; Physics ; Horticulture ; Biology ; Astrophysics Magnetic Properties and Applications ; Image and Signal Denoising Methods ; Seismic Imaging and Inversion Techniques