jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Nizar B. Alsharif | Katalin Bere | Szilárd Sáringer | Gergely F. Samu | Dóra Takács | Viktória Hornok | István Szilágyi
Source: Journal of Materials Chemistry B (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

Design of hybrid biocatalysts by controlled heteroaggregation of manganese oxide and sulfate latex particles to combat reactive oxygen species The preparation of an antioxidant hybrid material by controlled heteroaggregation of manganese oxide nanoparticles (MnO2 NPs) and sulfate-functionalized polystyrene latex (SL) beads was accomplished. Negatively charged MnO2 NPs were prepared by precipitation and initially functionalized with poly(diallyldimethylammonium chloride) (PDADMAC) polyelectrolyte to induce charge reversal allowing decoration of oppositely charged SL surfaces via simple mixing. The PDADMAC-functionalized MnO2 NPs (PMn) aggregated with the SL particles leading to the formation of negatively charged, neutral and positively charged (SPMn) composites. The charge neutralization resulted in rapidly aggregating dispersions, while stable samples were observed once the composites possessed sufficiently high negative and positive charge, below and above the charge neutralization point, respectively. The antioxidant assays revealed that SL served as a suitable substrate and that the PDADMAC functionalization and immobilization of MnO2 NPs did not compromise their catalase (CAT) and superoxide dismutase (SOD)-like activities, which were also maintained within a wide temperature range. The obtained SPMn composite is expected to be an excellent candidate as an antioxidant material for the efficient scavenging of reactive oxygen species at both laboratory and larger scales, even under harsh conditions, where natural antioxidants do not function. Manganese ; Sulfate ; Chemical engineering ; Manganese oxide ; Oxygen ; Materials science ; Oxide ; Chemistry ; Organic chemistry ; Metallurgy ; Engineering Advanced Nanomaterials in Catalysis ; Electrochemical sensors and biosensors ; Advanced biosensing and bioanalysis techniques
Authors: Houssém Chabane | Sébastien Livi | Xavier Morelle | Rodolphe Sonnier | LoïcDumazert | Jannick Duchet‐Rumeau | Jean‐François Gérard
Source: Polymer (article, 2021-04-03)
Field: Materials Science — Materials Chemistry

Synthesis of new ionic liquid-grafted metal-oxo nanoclusters – Design of nanostructured hybrid organic-inorganic polymer networks Silsesquioxane ; Ionic liquid ; Materials science ; Nanocages ; Nanoclusters ; Ionic bonding ; Chemical engineering ; Thermal stability ; Polymer ; Thermosetting polymer ; Polymer chemistry ; Nanostructure ; Nanocomposite ; Epoxy ; Organic chemistry ; Nanotechnology ; Chemistry ; Composite material ; Ion ; Catalysis Silicone and Siloxane Chemistry ; Flame retardant materials and properties ; Synthesis and properties of polymers
Authors: Kamil Raczyński | Andrzej Pihut | Jarosław J. Panek | Aneta Jezierska
Source: Molecules (article, 2021-06-06)
Field: Chemistry — Organic Chemistry

Competition of Intra- and Intermolecular Forces in Anthraquinone and Its Selected Derivatives Intra- and intermolecular forces competition was investigated in the 9,10-anthraquinone (<b>1</b>) and its derivatives both in vacuo and in the crystalline phase. The 1,8-dihydroxy-9,10-anthraquinone (<b>2</b>) and 1,8-dinitro-4,5-dihydroxy-anthraquinone (<b>3</b>) contain Resonance-Assisted Hydrogen Bonds (RAHBs). The intramolecular hydrogen bonds properties were studied in the electronic ground and excited states employing Møller-Plesset second-order perturbation theory (MP2), Density Functional Theory (DFT) method in its classical formulation as well as its time-dependent extension (TD-DFT). The proton potential functions were obtained via scanning the OH distance and the dihedral angle related to the OH group rotation. The topological analysis was carried out on the basis of theories of Atoms in Molecules (AIM-molecular topology, properties of critical points, AIM charges) and Electron Localization Function (ELF-2D maps showing bonding patterns, calculation of electron populations in the hydrogen bonds). The Symmetry-Adapted Perturbation Theory (SAPT) was applied for the energy decomposition in the dimers. Finally, Car-Parrinello molecular dynamics (CPMD) simulations were performed to shed light onto bridge protons dynamics upon environmental influence. The vibrational features of the OH stretching were revealed using Fourier transformation of the autocorrelation function of atomic velocity. It was found that the presence of OH and NO2 substituents influenced the geometric and electronic structure of the anthraquinone moiety. The AIM and ELF analyses showed that the quantitative differences between hydrogen bonds properties could be neglected. The bridged protons are localized on the donor side in the electronic ground state, but the Excited-State Intramolecular Proton Transfer (ESIPT) was noticed as a result of the TD-DFT calculations. The hierarchy of interactions determined by SAPT method indicated that weak hydrogen bonds play modifying role in the organization of these crystal structures, but primary ordering factor is dispersion. The CPMD crystalline phase results indicated bridged proton-sharing in the compound <b>2</b>. Intermolecular force ; Dihedral angle ; Intramolecular force ; Chemistry ; Hydrogen bond ; Density functional theory ; Anthraquinone ; Computational chemistry ; Molecule ; Chemical physics ; Crystallography ; Stereochemistry Free Radicals and Antioxidants ; Photochemistry and Electron Transfer Studies ; Spectroscopy and Quantum Chemical Studies
Authors: Yuhang Qian | Dongge Ma | Junbo Zhong
Source: Frontiers in Chemistry (review, 2021-11-15)
Field: Chemistry — Inorganic Chemistry

Metal-Organic Frameworks With Variable Valence Metal-Photoactive Components: Emerging Platform for Volatile Organic Compounds Photocatalytic Degradation With their outstanding diversities in both structures and performances, newly emerging metal-organic frameworks (MOFs) materials are considered to be the most promising artificial catalysts to meet multiple challenges in the fields of energy and environment. Especially in absorption and conversion of solar energy, a variety of MOFs can be readily designed to cover and harvest the sun irradiation of ultraviolet (UV), visible and near-infrared region through tuning both organic linkers and metal nodes to create optimal photocatalytic efficiency. Nowadays, a variety of MOFs were successfully synthesized as powerful photocatalysts for important redox reactions such as water-splitting, CO<sub>2</sub> reduction and aqueous environmental pollutants detoxification. MOFs applications in indoor-air VOCs pollutants cleaning, however, are less concerned partially because of limited diffusion of both gaseous pollutant molecules and photo-induced active species in very porous MOFs structures. In this mini-review, we focus on the major breakthroughs of MOFs as photocatalysts for the effective removal of indoor-air VOCs such as aldehydes, aromatics and short-chain alcohols. According to their nature of photoactive centers, herein MOFs photocatalysts are divided into two categories to comment, that is, MOFs with variable valence metal nodes as direct photoactive centers and MOFs with non-variable valence metal nodes but after combining other photoactive variable valence metal centers as excellent concentrated and concerted electron-transfer materials. The mechanisms and current challenges of the photocatalytic degradation of indoor-air VOC pollutants by these MOFs will be discussed as deeply as possible. Photocatalysis ; Metal-organic framework ; Valence (chemistry) ; Pollutant ; Materials science ; Metal ; Redox ; Photoactive layer ; Nanotechnology ; Photochemistry ; Catalysis ; Chemistry ; Chemical engineering ; Energy conversion efficiency ; Organic chemistry ; Adsorption ; Optoelectronics Metal-Organic Frameworks: Synthesis and Applications ; Advanced Photocatalysis Techniques ; Covalent Organic Framework Applications
Authors: Corneliu Hamciuc | Mihai Asăndulesa | Elena Hamciuc | Tiberiu Roman | Marius Andrei Olariu | Aurel Pui
Source: Polymers (article, 2021-05-19)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Novel Polyimide/Copper-Nickel Ferrite Composites with Tunable Magnetic and Dielectric Properties Heat-resistant magnetic polymer composites were prepared by incorporating cerium-doped copper-nickel ferrite particles, having the general formula Ni<sub>1-x</sub>Cu<sub>x</sub>Fe<sub>1.92</sub>Ce<sub>0.08</sub>O<sub>4</sub> (x: 0.0, 0.3, 0.6, 1.0), into a polyimide matrix. The effects of particle type and concentration on the thermal, magnetic, and electrical properties of the resulting composites were investigated. The samples were characterized by FTIR, scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis, differential scanning calorimetry, vibrating sample magnetometer, and broadband dielectric spectroscopy. The composites exhibited high thermal stability, having initial decomposition temperatures between 495 and 509 °C. Saturation magnetization (<i>M<sub>s</sub></i>), magnetic remanence (<i>M<sub>r</sub></i>), and coercivity (<i>H<sub>c</sub></i>) were found in range of 2.37-10.90 emu g<sup>-1</sup>, 0.45-2.84 emu g<sup>-1</sup>, and 32-244 Oe, respectively. The study of dielectric properties revealed dielectric constant values of 3.0-4.3 and low dielectric losses of 0.016-0.197 at room temperature and a frequency of 1 Hz. Materials science ; Thermogravimetric analysis ; Composite material ; Dielectric ; Ferrite (magnet) ; Thermal stability ; Differential scanning calorimetry ; Polyimide ; Coercivity ; Remanence ; Scanning electron microscope ; Copper ; Analytical Chemistry (journal) ; Magnetization ; Metallurgy ; Chemical engineering ; Chemistry Electromagnetic wave absorption materials ; Synthesis and properties of polymers ; Dielectric materials and actuators
Authors: Jhon Puerres | Pablo Ortiz | Marı́a T. Cortés
Source: Polymers (article, 2021-07-23)
Field: Materials Science — Polymers and Plastics

Effect of Electrosynthesis Potential on Nucleation, Growth, Adhesion, and Electronic Properties of Polypyrrole Thin Films on Fluorine-Doped Tin Oxide (FTO) Polypyrrole (PPy) is one of the most attractive conducting polymers for thin film applications due to its good electrical conductivity, stability, optical properties, and biocompatibility. Among the technologies in which PPy has gained prominence are optoelectronics and solar energy conversion, where transparent electrodes such as fluorine-doped tin oxide (FTO) or indium tin oxide (ITO) are frequently used. However, FTO substrates have the notable advantage that their components are widely available in nature, unlike those of ITO. Recognizing the importance that the FTO/polypyrrole system has gained in various applications, here, we studied for the first time the nucleation and growth mechanism of electro-synthesized PPy on FTO. Additionally, the effect of the synthesis potential (0.9, 1.0, 1.1, and 1.2 V vs. Ag/AgCl) on the homogeneity, adhesion, conductivity, and HOMO energy levels of PPy films was determined. From current-time transients and scanning electron microscopy, it was found that films synthesized at 0.9 and 1.0 V exhibit 3D growth with progressive nucleation (as well as lower homogeneity and higher adhesion to FTO). In contrast, films synthesized at 1.1 and 1.2 V follow 2D growth with instantaneous nucleation. It was also evident that increasing the polymerization potential leads to polymers with lower conductivity and more negative HOMO levels (versus vacuum). These findings are relevant to encourage the use of electro-synthesized PPy in thin film applications that require a high control of material properties. Polypyrrole ; Materials science ; Electrosynthesis ; Tin oxide ; Nucleation ; Thin film ; Chemical engineering ; Indium tin oxide ; Conductive polymer ; Nanotechnology ; Doping ; Transparent conducting film ; Conductivity ; Polymerization ; Polymer ; Electrode ; Composite material ; Optoelectronics ; Chemistry ; Physical chemistry ; Electrochemistry ; Organic chemistry Conducting polymers and applications ; Advanced Sensor and Energy Harvesting Materials ; Organic Electronics and Photovoltaics
Authors: Libby J. Marshall | Olga Matsarskaia | Ralf Schweins | Dave J. Adams
Source: Soft Matter (article, 2021-01-01)
Field: Materials Science — Biomaterials

Enhancement of the mechanical properties of lysine-containing peptide-based supramolecular hydrogels by chemical cross-linking Exposure of lysine-containing peptide-based gelators to the cross-linking agent glutaraldehyde allows tuning of gel mechanical properties. The effect of cross-linking depends on the position of the lysine residue in the peptide chain, the concentration of gelator and the conditions under which cross-linking takes place. Through control of these factors, cross-linking leads to increased gel strength. Self-healing hydrogels ; Supramolecular chemistry ; Lysine ; Peptide ; Chemistry ; Polymer chemistry ; Chemical engineering ; Materials science ; Biochemistry ; Molecule ; Amino acid ; Organic chemistry Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Photochromic and Fluorescence Chemistry
Authors: Christine Frank | Tamara Hoffmann | Oskar Zelder | Max Fabian Felle | Erhard Bremer
Source: Frontiers in Microbiology (article, 2021-04-08)
Field: Materials Science — Materials Chemistry

Enhanced Glutamate Synthesis and Export by the Thermotolerant Emerging Industrial Workhorse Bacillus methanolicus in Response to High Osmolarity The thermotolerant methylotroph <i>Bacillus methanolicus</i> MGA3 was originally isolated from freshwater marsh soil. Due to its ability to use methanol as sole carbon and energy source, <i>B. methanolicus</i> is increasingly explored as a cell factory for the production of amino acids, fine chemicals, and proteins of biotechnological interest. During high cell density fermentation in industrial settings with the membrane-permeable methanol as the feed, the excretion of low molecular weight products synthesized from it will increase the osmotic pressure of the medium. This in turn will impair cell growth and productivity of the overall biotechnological production process. With this in mind, we have analyzed the core of the physiological adjustment process of <i>B. methanolicus</i> MGA3 to sustained high osmolarity surroundings. Through growth assays, we found that <i>B. methanolicus</i> MGA3 possesses only a restricted ability to cope with sustained osmotic stress. This finding is consistent with the ecophysiological conditions in the habitat from which it was originally isolated. None of the externally provided compatible solutes and proline-containing peptides affording osmostress protection for <i>Bacillus subtilis</i> were able to stimulate growth of <i>B. methanolicus</i> MGA3 at high salinity. <i>B. methanolicus</i> MGA3 synthesized the moderately effective compatible solute L-glutamate in a pattern such that the cellular pool increased concomitantly with increases in the external osmolarity. Counterintuitively, a large portion of the newly synthesized L-glutamate was excreted. The expression of the genes (<i>gltAB</i> and <i>gltA2</i>) for two L-glutamate synthases were upregulated in response to high salinity along with that of the <i>gltC</i> regulatory gene. Such a regulatory pattern of the system(s) for L-glutamate synthesis in Bacilli is new. Our findings might thus be generally relevant to understand the production of the osmostress protectant L-glutamate by those Bacilli that exclusively rely on this compatible solute for their physiological adjustment to high osmolarity surroundings. Osmotic concentration ; Osmolyte ; Osmoprotectant ; Biology ; Bacillus subtilis ; Osmotic shock ; Fermentation ; Biochemistry ; Cell wall ; Proline ; Bacteria ; Amino acid ; Gene Enzyme Structure and Function ; Bacterial Genetics and Biotechnology ; Amino Acid Enzymes and Metabolism
Authors: Kosmas Vamvakidis | Νikolaos Μaniotis | C. Dendrinou-Samara
Source: Nanoscale (article, 2021-01-01)
Field: Materials Science — Biomaterials

Magneto-fluorescent nanocomposites: experimental and theoretical linkage for the optimization of magnetic hyperthermia Magneto-fluorescent nanocomposites have been recognized as an emerging class of materials displaying great potential for improved magnetic hyperthermia assisted by optical imaging. In this study, we have designed a series of hybrid composites that consist of zinc doped Zn<sub>x</sub>Fe<sub>3-x</sub>O<sub>4</sub> ferrites functionalized by polyethylene-glycol (PEG8000) and an orange-emitting platinum complex [Pt(phen)Cl<sub>2</sub>]. Experimental and theoretical studies on the optimization of their magnetically-mediated heating properties were conducted. PEG was assembled around particles' surface by two different approaches; in situ and post-PEGylation. PEGylation ensured the optimal distance between the magnetic core and Pt(ii)-complex to maintain significant luminescence in the composite. The successful inclusion of the complex to the organic matrix was confirmed by a variety of spectroscopic techniques. A theoretical model was developed, based on linear response theory, in order to examine the composites' power losses dependence on their properties. Within this model, inter-particle interactions were quantified by inserting a mean dipolar energy term in the estimation of Néel relaxation time, and consequently, the size and concentration that maximize power loss were derived (20 nm and 4 mg mL<sup>-1</sup>). Moreover, a decrease in the anisotropy of nanoparticles resulted in an increase in specific loss power values. Theoretical estimations are validated by experimental data when heating aqueous dispersions of composites in 24 kA m<sup>-1</sup>, 765 kHz AMF for various values of concentration and size. Magnetic hyperthermia results showed that the theory-predicted values of optimum concentration and size delivered the maximum-specific loss power which was found equal to 545 W g<sup>-1</sup>. By the present approach, a quantitative link between the particles' dipolar interactions and their heating properties is established, while opening new perspectives to nanotheranostic applications. Magnetic hyperthermia ; Nanocomposite ; Fluorescence ; Materials science ; Hyperthermia ; Magnetic nanoparticles ; Nanoparticle ; Magneto ; Nanotechnology ; Nuclear magnetic resonance ; Chemistry ; Optics ; Medicine ; Physical chemistry ; Combustion ; Physics Nanoparticle-Based Drug Delivery ; Magnetic Properties and Synthesis of Ferrites ; Characterization and Applications of Magnetic Nanoparticles
Authors: Gökberk Ünal | Jesse Jones | Sevana Baghdasarian | Naoki Kaneko | Ehsan Shirzaei Sani | Sohyung Lee | Shima Gholizadeh | Satoshi Tateshima | Nasim Annabi
Source: Bioengineering & Translational Medicine (article, 2021-07-02)
Field: Materials Science — Biomaterials

Engineering elastic sealants based on gelatin and elastin‐like polypeptides for endovascular anastomosis Abstract Cerebrovascular ischemia from intracranial atherosclerosis remains difficult to treat. Although current revascularization procedures, including intraluminal stents and extracranial to intracranial bypass, have shown some benefit, they suffer from perioperative and postoperative morbidity. To address these limitations, here we developed a novel approach that involves gluing of arteries and subsequent transmural anastomosis from the healthy donor into the ischemic recipient. This approach required an elastic vascular sealant with distinct mechanical properties and adhesion to facilitate anastomosis. We engineered two hydrogel‐based glues: an elastic composite hydrogel based on methacryloyl elastin‐like polypeptide (mELP) combined with gelatin methacryloyl (GelMA) and a stiff glue based on pure GelMA. Two formulations with distinct mechanical characteristics were necessary to achieve stable anastomosis. The elastic GelMA/mELP composite glue attained desirable mechanical properties (elastic modulus: 288 ± 19 kPa, extensibility: 34.5 ± 13.4%) and adhesion (shear strength: 26.7 ± 5.4 kPa) to the blood vessel, while the pure GelMA glue exhibited superior adhesion (shear strength: 49.4 ± 7.0 kPa) at the cost of increased stiffness (elastic modulus: 581 ± 51 kPa) and reduced extensibility (13.6 ± 2.5%). The in vitro biocompatibility tests confirmed that the glues were not cytotoxic and were biodegradable. In addition, an ex vivo porcine anastomosis model showed high arterial burst pressure resistance of 34.0 ± 7.5 kPa, which is well over normal (16 kPa), elevated (17.3 kPa), and hypertensive crisis (24 kPa) systolic blood pressures in humans. Finally, an in vivo swine model was used to assess the feasibility of using the newly developed two‐glue system for an endovascular anastomosis. X‐ray imaging confirmed that the anastomosis was made successfully without postoperative bleeding complications and the procedure was well tolerated. In the future, more studies are required to evaluate the performance of the developed sealants under various temperature and humidity ranges. Elastin ; Biomedical engineering ; Materials science ; Gelatin ; Self-healing hydrogels ; Elastic modulus ; Ex vivo ; Anastomosis ; Biocompatibility ; In vivo ; Composite material ; Surgery ; Medicine ; Chemistry ; Pathology ; Polymer chemistry Electrospun Nanofibers in Biomedical Applications ; Bone Tissue Engineering Materials ; Intracranial Aneurysms: Treatment and Complications
Authors: Aaron D. Cabral | Tudor B. Radu | Elvin D. de Araujo | Patrick T. Gunning
Source: RSC Chemical Biology (review, 2021-01-01)
Field: Chemistry — Spectroscopy

Optical chemosensors for the detection of proximally phosphorylated peptides and proteins Proximal multi-site phosphorylation is a critical post-translational modification in protein biology. The additive effects of multiple phosphosite clusters in close spatial proximity triggers integrative and cooperative effects on protein conformation and activity. Proximal phosphorylation has been shown to modulate signal transduction pathways and gene expression, and as a result, is implicated in a broad range of disease states through altered protein function and/or localization including enzyme overactivation or protein aggregation. The role of proximal multi-phosphorylation events is becoming increasingly recognized as mechanistically important, although breakthroughs are limited due to a lack of detection technologies. To date, there is a limited selection of facile and robust sensing tools for proximal phosphorylation. Nonetheless, there have been considerable efforts in developing optical chemosensors for the detection of proximal phosphorylation motifs on peptides and proteins in recent years. This review provides a comprehensive overview of optical chemosensors for proximal phosphorylation, with the majority of work being reported in the past two decades. Optical sensors, in the form of fluorescent and luminescent chemosensors, hybrid biosensors, and inorganic nanoparticles, are described. Emphasis is placed on the rationale behind sensor scaffolds, relevant protein motifs, and applications in protein biology. Phosphorylation ; Posttranslational modification ; Protein phosphorylation ; Computational biology ; Chemistry ; Cell biology ; Biophysics ; Biology ; Biochemistry ; Protein kinase A Advanced Proteomics Techniques and Applications ; Chemical Synthesis and Analysis ; Peptidase Inhibition and Analysis
Authors: C. J. Butler | M. Yoshida | T. Hanaguri | Y. Iwasa
Source: Physical Review X (article, 2021-03-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Doublonlike Excitations and Their Phononic Coupling in a Mott Charge-Density-Wave System By injecting electrons into the Mott state of tantalum disulfide, experiments reveal new, unexpected electronic behaviors that could shed light on the underlying interactions that create this exotic state. Coupling (piping) ; Electron ; Mott insulator ; Tantalum ; State (computer science) ; Strongly correlated material Organic and Molecular Conductors Research ; 2D Materials and Applications ; Electronic and Structural Properties of Oxides