jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yue Sun | Xi Wu | Jianguo Li | Chandra Verma | Jing Yu | Ali Miserez
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2024-10-23)
Field: Materials Science — Biomaterials

Peptide-Based Complex Coacervates Stabilized by Cation-π Interactions for Cell Engineering Abstract Complex coacervation is a form of liquid-liquid phase separation (LLPS), whereby two types of macromolecules, usually bearing opposite net charges, self-assemble into dense microdroplets driven by weak molecular interactions. Peptide-based coacervates have recently emerged as promising carriers to deliver large macromolecules (nucleic acids, proteins and complex thereof) inside cells. Thus, it is essential to understand their assembly/disassembly mechanisms at the molecular level in order to tune the thermodynamics of coacervates formation and the kinetics of cargo release upon entering the cell. In this study, we design histidine-rich peptides consisting of modular sequences in which we systematically incorporate cationic, anionic, or aromatic residues at specific positions along the sequence in order to modulate intermolecular interactions and the resulting coacervation stability. We show that cation-π interactions between arginine and aromatic side chains are particularly efficient in stabilizing complex coacervates, and these interactions can be disrupted in the protein-rich intracellular environment, triggering the disassembly of complex coacervates followed by cargo release. With the additional grafting of a disulfide-based self-immolative sidechain, these complex coacervates exhibit enhanced stability and can deliver proteins, mRNA, and CRISPR/Cas9 genome editing tools with tunable release kinetics into cells. This capability extends to challenging cell types, such as macrophages. Our study highlights the critical role of cation-π interactions in the design of peptide-based coacervates, expanding the biomedical and biotechnology potential of this emerging innovative intracellular delivery platform. Table of Content Tandem peptides designed from histidine-rich beak proteins are modified with either negative, positive, or aromatic residues that can undergo complex coacervation through cation- π rather than electrostatic interactions. These complex coacervates can effectively recruit various macromolecular cargos and deliver them intracellularly with controlled release kinetics, including in hard-to-transfect macrophages. Coacervate ; Peptide ; Chemistry ; Computer science ; Biophysics ; Biochemistry ; Biology Supramolecular Self-Assembly in Materials
Authors: Samia Elouali |  Ait Hamdan Youssef | Samira Benali |  Lhomme Patrick |  Gosselin Matthias | Jean-Marie Raquez | Mohammed Rhazi | Patrick Lhomme
Source: ORBi UMONS (article, 2024-12-03)
Field: Materials Science — Biomaterials

Extraction of chitin and chitosan from hermetica illucens breeding waste: a greener approach for industrial application Chitin ; Extraction (chemistry) ; Chitosan ; Hermetia illucens Nanocomposite Films for Food Packaging ; Studies on Chitinases and Chitosanases ; Advanced Cellulose Research Studies
Authors: Elia Turco | Fu‐Peng Wu | Gonçalo Catarina | Nils Krane | Ji Ma | Román Fasel | Xinliang Feng | Pascal Ruffieux
Source: arXiv (Cornell University) (preprint, 2024-06-30)
Field: Materials Science — Materials Chemistry

Magnetic Excitations in Ferromagnetically Coupled Spin-1 Nanographenes In the quest for high-spin building blocks to form covalently bonded 1D or 2D materials with controlled magnetic interactions, $π$-electron magnetism provides an ideal framework to engineer large ferromagnetic interactions between nanographenes. As a first step in this direction, we investigate the spin properties of ferromagnetically coupled triangulenes, triangular nanographenes with spin $S = 1$. Combining in-solution synthesis of rationally designed molecular precursors and on-surface synthesis, we achieve covalently bonded $S = 2$ triangulene dimers and $S = 3$ trimers on Au(111). Starting from the triangulene dimer, we thoroughly characterize its low-energy magnetic excitations using inelastic electron tunneling spectroscopy (IETS). IETS reveals conductance steps identified as a quintet to triplet excitation, and a zero-bias peak stemming from higher-order spin-spin scattering of the 5-fold degenerate ferromagnetic ground state. The Heisenberg picture captures the relevant parameters of inter-triangulene ferromagnetic exchange, and its successful extension to the larger $S = 3$ system confirms the model's accuracy. We expect that the addition of ferromagnetically coupled building blocks to the toolbox of magnetic nanographenes opens new opportunities to design carbon materials with complex magnetic ground states. Condensed matter physics ; Spin (aerodynamics) ; Ferromagnetism ; Physics Graphene research and applications ; Molecular Junctions and Nanostructures ; Magnetism in coordination complexes
Authors: Michael Verhage | Kees Flipse
Source: arXiv (Cornell University) (preprint, 2024-10-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Order in disorder: oxygen vacancy driven electronic phase separation of LaNiO3-x epitaxial thin film surface investigated by scanning probe microscopy Oxygen vacancies in nickelates are known to introduce a variety of emergent phenomena and are considered to significantly affect conductivity. Few studies have examined real-space evidence for oxygen vacancies on the surface, particularly using scanning probe microscopy. Understanding the surface composition, both structurally and chemically, is crucial for the application of nickelates, such as in electrochemical water splitting reactions as catalysts. In this study, we investigate a 20 nm epitaxial LaNiO3-x(LNO) film grown on SrTiO3 (STO) via pulsed laser deposition. We examine the surface of this film using scanning tunneling microscopy (STM) and reveal a complex surface morphology composed of densely packed crystalline nanometer-sized circular features with radius ranging from 10 to 20 nm. Scanning tunneling spectroscopy revealed an electronic inhomogeneity, or phase separation, in nanoscale islands of semi-conductive nature embedded within a metallic matrix. This change in the electronic density of the states was associated with increased concentration of oxygen vacancies. Further evidence for significant oxygen vacancies at the surface was inferred by examining scanning tunneling tip-induced surface degradation. The strong electric field between the tip and sample likely facilitates oxygen removal in a vacuum environment, increasing the formation of vacancies, which can lead to the breakdown of the crystal structure. This provides insight into the possible origin of the chemical surface transformation during the electrochemical water splitting reaction of this nickelate. Epitaxy ; Materials science ; Thin film ; Oxygen ; Vacancy defect ; Phase (matter) ; Analytical Chemistry (journal) ; Optoelectronics ; Nanotechnology ; Crystallography ; Chemistry ; Layer (electronics) Magnetic and transport properties of perovskites and related materials ; Electronic and Structural Properties of Oxides ; Catalytic Processes in Materials Science
Authors: Jacopo Scarfiello | Marco Rusconi | Alberto Lanfranco | Emanuele Azzi | Stefano Caracciolo | Giovanni Ghigo | Polyssena Renzi | Annamaria Deagostino
Source: European Journal of Organic Chemistry (article, 2024-04-18)
Field: Chemistry — Inorganic Chemistry

Catalyst‐free Chloroamination Cyclization Cascade with Sodium Hypochlorite: from <i>N</i>‐(Pentenyl)sulfonylamides to 2‐(1‐Chloromethyl)pyrrolidines Abstract A mild and catalyst‐free protocol to obtain several 2‐chloromethylpyrrolidines by the use of a commercial solution of sodium hypochlorite is here reported, without the need for a light source. The choice of the solvent revealed to be crucial in the success of the reaction. Mechanistic studies, both experimental and computational, confirmed a radical mechanism, where the deprotonation step, followed by the oxidation of a N ‐centered anion to the corresponding radical, allowed 2‐chloromethylpyrrolidines, by a very fast cyclization, to be obtained. Sodium hypochlorite plays the role of both the oxidant and the chlorine source. Chemistry ; Sodium hypochlorite ; Cascade ; Catalysis ; Organic chemistry ; Stereoselectivity ; Sodium ; Organocatalysis ; Enantioselective synthesis ; Chromatography Vanadium and Halogenation Chemistry ; Fluorine in Organic Chemistry
Authors: Anee Taj | Zhen Wang | Xiao‐Hui Yang
Source:  (preprint, 2024-07-16)
Field: Chemistry — Organic Chemistry

Recent Advances in Transition-Metal-Catalyzed Hydrothiolation of Alkenes to Access Organosulfurs The development of new efficient strategies for the construction of the C-S bond has attracted considerable interest due to its presence in various crucial biological systems and pharmaceutical compounds. Alkene hydrothiolation is one of the simplest and most atom-economic methods for organosulfur synthesis. This review focuses on transition-metal-catalyzed C-S bond formation via alkene hydrothiolation with thiols and is divided into three sections covering 3d, 4d, and 5d transition-metal-catalyzed hydrothiolation re-ported from 2013 to the present. Synthetic methods, substrate scope, and reaction mechanisms are discussed. We aim to provide a concise overview of recent advances in the hydrothiolation of alkenes and hopefully encourage further exploration to fill the gaps. The current landscape suggests considerable potential for future innovation and discovery in this field. Catalysis ; Transition metal ; Chemistry ; Organic chemistry Sulfur-Based Synthesis Techniques ; Chemical Synthesis and Reactions ; Catalytic C–H Functionalization Methods
Authors: Hoshang Sahib | Laurent Schlur | Kumara Cordero | N. Viart | David Pesquera | Daniele Preziosi
Source: arXiv (Cornell University) (preprint, 2024-05-17)
Field: Materials Science — Materials Chemistry

Freestanding perovskite and infinite-layer nickelate membranes Following the discovery of superconductivity in hole-doped NdNiO$_2$ infinite-layer thin films, extensive research has been conducted particularly to compare these materials with cuprates. Superconductivity has also been observed in nickelate thin films with other rare-earth elements like Pr and La, but not in their bulk forms, suggesting a critical role for substrate-induced strain/interface or dimensionality effects. In this study, we use water-soluble (Ca,Sr)$_3$Al$_2$O$_6$ sacrificial layers to fabricate freestanding perovskite nickelate membranes and explore topotactic reduction without the SrTiO$_3$ substrate as a template. NdNiO$_3$-based heterostructure membranes transferred from a LaAlO$_3$ substrate exhibit better metallic behavior and higher hysteresis than those transferred from SrTiO$_3$, owing to the different strain states that the NdNiO$_3$ layer experience when grown on these two substrates. Despite the expected X-ray diffraction shifts, membranes reduced with CaH$_2$ display insulating characteristics, similar to bulk infinite-layer nickelates. Our findings strongly indicate that a template is necessary to stabilize a coherent and robust infinite-layer phase with optimal transport properties. Perovskite (structure) ; Layer (electronics) ; Membrane ; Materials science ; Business ; Composite material ; Chemical engineering ; Chemistry ; Engineering Chemical and Physical Properties of Materials ; Magnetic and transport properties of perovskites and related materials ; Electronic and Structural Properties of Oxides
Authors: Huisi Li
Source: KTH Publication Database DiVA (KTH Royal Institute of Technology) (article, 2024-01-01)
Field: Materials Science — Biomaterials

Lignin-Rich Microfibrillated Cellulose Films : From Production to Application Lignocellulosic biomass, particularly wood-derived cellulose, offers an abundant and renewable resource for producing advanced bio-based materials. This thesis explores the development and application of lignin-rich microfibrillated cellulose (LMFC) films produced from high-kappa number kraft pulp, highlighting their potential as sustainable alternatives to petrochemical-based materials. The research focuses on understanding the influence of residual lignin and raw fiber characteristics on the properties of LMFC films. The effects of drying conditions on the physicochemical and mechanical properties of these films were also investigated. The study demonstrates that residual lignin enhances the thermal stability and hydrophobicity of the films while also improving their mechanical properties under optimized processing conditions. Furthermore, hardwood and softwood pulps exhibit distinct fibrillation behaviors, with softwood-derived LMFC films showing superior tensile strength due to the formation of more fiber joints within the fiber networks. The exceptional mechanical performance of LMFC films, comparable to chemically modified cellulose nanofibers, demonstrates their potential for industrial applications. These lignin-rich films show promise in high-value fields such as battery, organic dye adsorption, and proton exchange application. Notably, LMFC films are ideal candidates as separators in aqueous zinc-ion batteries, where their enhanced wet tensile strength, superior electrolyte uptake, and good ionic conductivity enable stable cycling performance. Additionally, the films' enhanced affinity for cationic organic dyes positions them as effective and eco-friendly adsorbents for water treatment. The findings of this thesis contribute to the sustainable development of bio-based cellulose materials by optimizing lignocellulosic resources for a wide range of applications. Cellulose ; Ultimate tensile strength ; Lignin ; Nanofiber ; Cellulose fiber ; Thermal stability ; Softwood ; Fiber Advanced Cellulose Research Studies ; Lignin and Wood Chemistry ; Wood Treatment and Properties
Authors: Gamal Eldein Fathy Abd-E llatef
Source: Journal of Clinical Research and Reports (article, 2024-09-30)
Field: Materials Science — Biomaterials

Nanotechnology as a New Revolution for Cancer Therapy Since cancer is one of the leading causes of death worldwide, research into cancer treatments is currently representing a top priority. Researchers from all over the world are looking for an effective treatment that will specifically target cancer while causing minimal morbidity. Nanotechnology can improve the potency and selectivity of biological, chemical, and physical methods for inducing the death of cancer cells while lowering collateral damage to non-cancerous cells. Many nanoparticle delivery systems as inorganic and organic materials have been used in the development of cancer therapy. In this review, the function of nanoparticles in cancer therapy among various cancer drug delivery techniques will be discussed as well as how it works to overcome cancer drug resistance. We provide an up-to-date discussion of the recent progress that has been made in the use of nanotechnology in cancer therapy. Cancer ; Nanotechnology ; Cancer therapy ; Medicine ; Materials science ; Internal medicine Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Graphene and Nanomaterials Applications
Authors: İlhan CANDAN | Serap Yi̇ği̇t Gezgi̇n | Hadice Budak Gümgüm | Hamdi Şükür Kılıç
Source: Middle East Journal of Science (article, 2024-12-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

OPTICAL, MORPHOLOGICAL, STRUCTURAL, AND PHOTOCATALYTICAL PROPERTIES OF PLASMONIC AU NPS PRODUCED BY PULSED LASER DEPOSITION Plasmonic Au NPs exhibit exceptional optical, morphological, and structural properties, making them promising materials for applications in photocatalysis, sensing, and energy conversion. This study explores the synthesis and characterization of plasmonic gold NPs produced by pulsed laser deposition, a versatile physical vapor deposition technique. Pulsed Laser Deposition enables precise control over NP formation through tunable parameters such as laser fluence, ambient gas environment, and deposition duration. The resulting NPs were systematically analyzed to evaluate their optical properties, including localized surface plasmon resonance, as well as their morphological and structural attributes. The localized surface plasmon resonance behavior of the synthesized Au NPs was found to be highly dependent on particle size, shape, and distribution, as revealed by UV-Vis spectroscopy and electron microscopy. Structural analysis via X-ray diffraction confirmed the crystalline nature of the NPs, with lattice parameters correlating to their stability and catalytic efficiency. Photocatalytic activity tests demonstrated that the gold NPs could effectively degrade organic pollutants under visible light, leveraging their strong LSPR-induced hot electron generation and charge transfer properties. In this study, gold NP thin film was produced on microscopic glass by Pulsed Laser Deposition system. Gold NPs thin film photocatalyst efficiency 95.00% and reaction rate constant 0.39 min-1 were calculated. At the end of 210 min, MB dye was degraded and turned into high transparency due to localized surface plasmon resonance property of gold NP. The findings may provide valuable insights into the design and application of plasmonic Au NPs in photocatalysis and other advanced technologies. Materials science ; Plasmon ; Deposition (geology) ; Pulsed laser deposition ; Laser ; Optoelectronics ; Nanotechnology ; Optics ; Thin film ; Physics ; Geology Gold and Silver Nanoparticles Synthesis and Applications ; Copper-based nanomaterials and applications ; Laser-Ablation Synthesis of Nanoparticles
Authors: Adela F. Dobre | Augustin M. Mădălan | Anamaria Hanganu | Petre Ioniță
Source: Chemistry (article, 2024-09-03)
Field: Chemistry — Organic Chemistry

Diazenium Betaines Derived from the Stable Free Radical DPPH with Diradicaloid Behavior Starting from the well known stable free radical DPPH (or its reduced counterpart, 2,2-diphenyl-1-picryl-hydrazine) and several amino derivatives, novel zwitterionic compounds (diazenium betaines) were obtained and characterized by different means, like NMR, IR, MS, and UV–Vis. These betaines are highly intense blue-colored compounds that can be easily reduced by ascorbic acid (vitamin C) or sodium ascorbate to their corresponding para-phenyl substituted derivatives of DPPH, which have a yellow color. Most of such redox processes were found to be reversible. However, the oxidation of 2-p-aminophenyl-2-phenyl-1-picryl-hydrazine led to an azo-derivative of DPPH diradical, and its structure was unveiled by X-ray monocrystal diffraction. Possible diradicaloid behavior is also discussed. DPPH ; Chemistry ; Organic chemistry Synthesis and Properties of Aromatic Compounds ; Luminescence and Fluorescent Materials ; Radical Photochemical Reactions
Authors: Tobias Werner | Tito Añazco | Paula Osses-Mendoza | Alejandro Castro‐Álvarez | Cristian O. Salas | Raquel Bridi | Holger Stark | Christian Espinosa‐Bustos
Source: Antioxidants (article, 2024-11-01)
Field: Chemistry — Organic Chemistry

First Report on Cationic Triphenylphosphonium Compounds as Mitochondriotropic H3R Ligands with Antioxidant Properties Neurodegenerative diseases are a major public health problem due to the aging population and multifaceted pathology; therefore, the search for new therapeutic alternatives is of the utmost importance. In this sense, a series of six 1-(3-phenoxypropyl)piperidines alkyl-linked to a triphenylphosphonium cation derivative were synthesized as H<sub>3</sub>R ligands with antioxidant properties to regulate excessive mitochondrial oxidative stress and contribute to potential new therapeutic approaches for neurodegenerative diseases. Radioligand displacement studies revealed high affinity for H<sub>3</sub>R with K<i>i</i> values in the low to moderate two-digit nanomolar range for all compounds. Compound <b>6e</b> showed the highest affinity (K<i>i</i> H<sub>3</sub>R = 14.1 nM), comparable to that of pitolisant. Antioxidative effects were evaluated as radical-scavenging properties using the ORAC assay, in which all derivatives showed low to moderate activity. On the other hand, cytotoxic effects in SH-SY5Y neuroblastoma cells were investigated using the colorimetric alamar blue assay, which revealed significant effects on cell viability with an unequivocally structure-toxicity relationship. Finally, docking and molecular simulation studies were used to determine the H<sub>3</sub>R binding form, which will allow us to further modify the compounds to establish a robust structure-activity relationship and find a lead compound with therapeutic utility in neurodegenerative diseases. Cationic polymerization ; Antioxidant ; Chemistry ; Stereochemistry ; Pharmacology ; Combinatorial chemistry ; Biochemistry ; Organic chemistry ; Biology Synthesis and biological activity ; Free Radicals and Antioxidants ; Synthesis and Reactivity of Sulfur-Containing Compounds
Authors: Theodoros D. Bouloumis | Hao Zhao | Nikolaos Kokkinidis | Yunbin Hu | Viet Giang Truong | Akimitsu Narita | Síle Nic Chormaic
Source: arXiv (Cornell University) (preprint, 2024-04-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Disruptive Forces in Metamaterial Tweezers for Trapping 20 nm Nanoparticles Based on Molecular Graphene Quantum Dots In recent years, plasmonic optical tweezers have been used to trap nanoparticles and study interactions with their environment. An unavoidable challenge is the plasmonic heating due to resonant excitation and the resulting temperature rise in the surrounding environment. In this work, we demonstrate trapping of custom-synthesized 20 nm nanoparticles based on molecular graphene quantum dots using metamaterial plasmonic tweezers. Superior trap stiffness values as high as 8.8 (fN/nm)/(mW/$μ\mbox{m}^2$) were achieved with optical intensities lower than 1 mW/$μ\mbox{m}^2$. By gradually increasing the laser intensity we identified a critical value beyond which the stiffness values dropped significantly. This value corresponded to a temperature rise of about 16$^o$C, evidently sufficient to create thermal flows and disrupt the trapping performance. We, therefore, identified a safe intensity regime for trapping nanoparticles without unwanted heat. Our platform can be used for efficient nanopositioning of fluorescent particles and quantum emitters in an array configuration, potentially acting as a single-photon source configuration. Trapping ; Nanoparticle ; Materials science ; Nanotechnology ; Power (physics) ; Physics ; Thermodynamics ; Ecology ; Biology Gold and Silver Nanoparticles Synthesis and Applications ; Molecular Communication and Nanonetworks ; Carbon Nanotubes in Composites
Authors: Ebenezer Baa | Rui W. M. Krause | Gareth M. Watkins | Vincent J. Smith
Source:  (preprint, 2024-01-30)
Field: Materials Science — Materials Chemistry

Selective adsorption of DMSO on two chlorinated calixarene type scaffolds The selective adsorption of DMSO vapor on calixarene scaffold from a mixture consisting of either DMSO and water or DMSO and methanol was studied. Two calixarene-type scaffolds based on 4-chlorobenzaldehyde were obtained by reacting the aldehyde with either resorcinol or pyrogallol and characterized by various techniques including NMR, FTIR, thermal, and XRD. These materials were then used as sorbent materials for separating vapors. Results from this investigation indicate the scaffolds show selectivity towards DMSO. The resorcinol-based scaffold showed a higher selectivity for DMSO compared to the pyrogallol counterpart. The influence of synthesis solvent on the conformation and structural changes resulting from the interaction of the guest molecules with the host was also investigated. Calixarene ; Resorcinol ; Pyrogallol ; Chemistry ; Adsorption ; Solvent ; Selectivity ; Selective adsorption ; Sorbent ; Fourier transform infrared spectroscopy ; Methanol ; Organic chemistry ; Aldehyde ; Polymer chemistry ; Inorganic chemistry ; Molecule ; Combinatorial chemistry ; Nuclear chemistry ; Chemical engineering ; Catalysis Carbon Nanotubes in Composites ; Molecular Junctions and Nanostructures ; Porphyrin and Phthalocyanine Chemistry