jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Francisco Fábio Oliveira de Sousa | Aurora Pinazo | Zakaria Hafidi | M. Teresa García | Elena Bautista | M. Carmen Morán | Lourdes Pérez
Source: Molecules (article, 2023-09-11)
Field: Chemistry — Organic Chemistry

Arginine Gemini-Based Surfactants for Antimicrobial and Antibiofilm Applications: Molecular Interactions, Skin-Related Anti-Enzymatic Activity and Cytotoxicity The antimicrobial and antibiofilm properties of arginine-based surfactants have been evaluated. These two biological properties depend on both the alkyl chain length and the spacer chain nature. These gemini surfactants exhibit good activity against a wide range of bacteria, including some problematic resistant microorganisms such us methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) and <i>Pseudomonas aeruginosa</i>. Moreover, surfactants with a C<sub>10</sub> alkyl chain and C<sub>3</sub> spacer inhibit the (MRSA) and <i>Pseudomonas aeruginosa</i> biofilm formation at concentrations as low as 8 µg/mL and are able to eradicate established biofilms of these two bacteria at 32 µg/mL. The inhibitory activities of the surfactants over key enzymes enrolled in the skin repairing processes (collagenase, elastase and hyaluronidase) were evaluated. They exhibited moderate anti-collagenase activity while the activity of hyaluronidase was boosted by the presence of these surfactants. These biological properties render these gemini arginine-based surfactants as perfect promising candidates for pharmaceutical and biological properties. Antimicrobial ; Chemistry ; Biofilm ; Pseudomonas aeruginosa ; Hyaluronidase ; Cytotoxicity ; Microbiology ; Bacteria ; Collagenase ; Enzyme ; Staphylococcus aureus ; Alkyl ; Biological activity ; Biochemistry ; Organic chemistry ; In vitro ; Biology Antimicrobial agents and applications ; Antimicrobial Peptides and Activities ; Surfactants and Colloidal Systems
Authors: M.M. Salem | K. A. Darwish | O. M. Hemeda | Mohamed Ati | Anwer S. Abd El-Hameed | Di Zhou | Moustafa A. Darwish
Source: Applied Physics A (article, 2023-08-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Exploring the promising frontiers of barium hexaferrite and barium titanate composites for electromagnetic shielding applications Abstract This study provides a comprehensive synthesis and meticulous examination of barium hexaferrite (BHF), barium titanate (BT), and their respective nanocomposites, unveiling their potential in specific applications, including electromagnetic interference shielding. The successful formation of BHF and BT was confirmed through Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses, revealing distinct absorption peaks indicative of the tetragonal configuration of BT and the BHF’s crystal structure. Scanning electron microscopy (SEM) depicted the unique morphologies and dispersions of particles in the synthesized nanocomposites, with BHF appearing larger (~ 82 nm) than BT (~ 50 nm). Vibrating sample magnetometry (VSM) findings exhibited an increased resistance to demagnetization with the addition of BT, despite a slight decline at 75% BT concentration due to the non-magnetic nature of BT dominating. Uniquely, the study presented an in-depth analysis of the composites’ conductivity, detailing their non-monotonic behavior across a frequency range. A detailed investigation into the complex permittivity and permeability revealed the composite’s enhanced ability to store and dissipate both electrical and magnetic energy, a function influenced by the concentrations of BT and BHF. A pivotal highlight of this research was the significant achievement of a reflection loss (RL) value of − 45 dB at 9.3 GHz for the composite with 75% BHF, suggesting the composite’s potential as an effective microwave absorber. This study represents a significant step toward designing and optimizing nanocomposites for specific applications in the realm of electromagnetic materials. Barium titanate ; Materials science ; Nanocomposite ; Composite material ; Reflection loss ; Fourier transform infrared spectroscopy ; Composite number ; Electromagnetic shielding ; Scanning electron microscope ; Permittivity ; Dielectric ; Ceramic ; Optics ; Optoelectronics ; Physics Electromagnetic wave absorption materials ; Magnetic Properties and Synthesis of Ferrites ; Advanced Antenna and Metasurface Technologies
Authors: Masanori Wakizaka | Shraddha Gupta | Qingyun Wan | Shinya Takaishi | H. Noro | Kazunobu Sato | Masahiro Yamashita
Source: Chemistry - A European Journal (article, 2023-12-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Spin qubits of Cu(II) doped in Zn(II) metal–organic frameworks above microsecond phase memory time With the aim of creating Cu(II) spin qubits in a rigid metal-organic framework (MOF), this work demonstrates a doping of 5 %, 2 %, 1 %, and 0.1 % mol of Cu(II) ions into a perovskite-type MOF [CH<sub>6</sub> N<sub>3</sub> ][Zn<sup>II</sup> (HCOO)<sub>3</sub> ]. The presence of dopant Cu(II) sites are confirmed with anisotropic g-factors (g<sub>x</sub> =2.07, g<sub>y</sub> =2.12, and g<sub>z</sub> =2.44) in the S=1/2 system by experimentally and theoretically. Magnetic dynamics indicate the occurrence of a slow magnetic relaxation via the direct and Raman processes under an applied field, with a relaxation time (τ) of 3.5 ms (5 % Cu), 9.2 ms (2 % Cu), and 15 ms (1 % Cu) at 1.8 K. Furthermore, pulse-ESR spectroscopy reveals spin qubit properties with a spin-spin relaxation (phase memory) time (T<sub>2</sub> ) of 0.21 μs (2 %Cu), 0.39 μs (1 %Cu), and 3.0 μs (0.1 %Cu) at 10 K as well as Rabi oscillation between M<sub>S</sub> =±1/2 spin sublevels. T<sub>2</sub> above microsecond is achieved for the first time in the Cu(II)-doped MOFs. It can be observed at submicrosecond around 50 K. These spin relaxations are very sensitive to the magnetic dipole interactions relating with cross-relaxation between the Cu(II) sites and can be tuned by adjusting the dopant concentration. Microsecond ; Doping ; Phase (matter) ; Qubit ; Spin (aerodynamics) ; Metal ; Materials science ; Copper ; Condensed matter physics ; Chemistry ; Physics ; Quantum ; Quantum mechanics ; Thermodynamics ; Metallurgy Magnetism in coordination complexes ; Electron Spin Resonance Studies ; Lanthanide and Transition Metal Complexes
Authors: Nihan Sengokmen-Ozsoz | Samand Pashneh‐Tala | Frederik Claeyssens
Source: 3D Printing and Additive Manufacturing (article, 2023-02-03)
Field: Materials Science — Materials Chemistry

Optimization of a High Internal Phase Emulsion-Based Resin for Use in Commercial Vat Photopolymerization Additive Manufacturing High internal phase emulsions (HIPEs) are potential stereolithography-based resins for producing innovative lightweight porous materials; however, the use of these resins has only been shown in bespoke stereolithography setups. These studies indicated that HIPEs tend to scatter the light during structuring through stereolithography, and can produce poorly defined and low-resolution structures, but the inclusion of light absorbers can drastically increase the printing resolution. In this study, we focused on the inclusion of biocompatible light absorbers within the resin and the compatibility of those resins with a commercial vat photopolymerization additive manufacturing (or stereolithography) setup. A surfactant (hypermer)-stabilized water-in-oil emulsion based on 2-ethylhexyl-acrylate and isobornyl-acrylate was used. For the light absorbers, both hydrophobic (beta-carotene) and hydrophilic (tartrazine) molecules were used, which dissolve in the organic phase and aqueous phase, respectively. It was found that using a combination of both beta-carotene and tartrazine provided the best stereolithography-based 3D printing resolution. In addition, the emulsion was stable for the duration of the printing process and showed a porous polyHIPE structure with open surface porosity. The formulation of these HIPE-based resins permits them to be used in a wide range of applications since complex structures could be fabricated from HIPEs. Stereolithography ; Photopolymer ; Materials science ; Emulsion ; Acrylate ; Porosity ; Chemical engineering ; 3D printing ; Composite material ; Polymer Pickering emulsions and particle stabilization ; Proteins in Food Systems ; Polymer composites and self-healing
Authors: Yanchun Lin | Austin B. Moyle | V. Beaumont | Lucy L. Liu | Sharon Polleck | Haijun Liu | Heliang Shi | Jason C. Rouse | Hai‐Young Kim | Ying Zhang | Michael L. Gross
Source: Analytical Chemistry (article, 2023-11-07)
Field: Chemistry — Spectroscopy

Characterization of Higher Order Structural Changes of a Thermally Stressed Monoclonal Antibody via Mass Spectrometry Footprinting and Other Biophysical Approaches Characterizing changes in the higher order structure (HOS) of monoclonal antibodies upon stressed conditions is critical to gaining a better understanding of the product and process. One single biophysical approach may not be best suited to assess HOS comprehensively; thus, the synergy from multiple, complementary approaches improves characterization accuracy and resolution. In this study, we employed two mass spectrometry (MS )-based footprinting techniques, namely, fast photochemical oxidation of proteins (FPOP)-MS and hydrogen-deuterium exchange (HDX)-MS, supported by dynamic light scattering (DLS), differential scanning calorimetry (DSC), circular dichroism (CD), and nuclear magnetic resonance (NMR) to study changes to the HOS of a mAb upon thermal stress. The biophysical techniques report a nuanced characterization of the HOS in which CD detects no changes to the secondary or tertiary structure, yet DLS measurements show an increase in the hydrodynamic radius. DSC indicates that the stability decreases, and chemical or conformational changes accumulate with incubation time according to NMR. Furthermore, whereas HDX-MS does not indicate HOS changes, FPOP-MS footprinting reveals conformational changes at residue resolution for some amino acids. The local phenomena observed with FPOP-MS indicate that several residues show various patterns of degradation during thermal stress: no change, an increase in solvent exposure, and a biphasic response to solvent exposure. All evidences show that FPOP-MS efficiently resolves subtle structural changes and novel degradation pathways upon thermal stress treatment at residue-level resolution. Chemistry ; Footprinting ; Hydrogen–deuterium exchange ; Mass spectrometry ; Circular dichroism ; Differential scanning calorimetry ; Dynamic light scattering ; Nuclear magnetic resonance spectroscopy ; Protein tertiary structure ; Protein secondary structure ; Biophysics ; Chromatography ; Crystallography ; Biochemistry ; Stereochemistry ; Nanotechnology ; DNA Mass Spectrometry Techniques and Applications ; Protein purification and stability ; Analytical Chemistry and Chromatography
Authors: Emil H. Jensen | Loris Lombardo | Alessandro Girella | Matylda N. Guzik | Andreas Züttel | Chiara Milanese | Pamela S. Whitfield | Dag Noréus | Sabrina Sartori
Source: Molecules (article, 2023-04-27)
Field: Materials Science — Materials Chemistry

The Effect of Y Content on Structural and Sorption Properties of A2B7-Type Phase in the La–Y–Ni–Al–Mn System Metal hydrides are an interesting group of chemical compounds, able to store hydrogen in a reversible, compact and safe manner. Among them, A<sub>2</sub>B<sub>7</sub>-type intermetallic alloys based on La-Mg-Ni have attracted particular attention due to their high electrochemical hydrogen storage capacity (∼400 mAh/g) and extended cycle life. However, the presence of Mg makes their synthesis via conventional metallurgical routes challenging. Replacing Mg with Y is a viable approach. Herein, we present a systematic study for a series of compounds with a nominal composition of La<sub>2-<i>x</i></sub>Y<sub><i>x</i></sub>Ni<sub>6.50</sub>Mn<sub>0.33</sub>Al<sub>0.17</sub>, x = 0.33, 0.67, 1.00, 1.33, 1.67, focusing on the relationship between the material structural properties and hydrogen sorption performances. The results show that while the hydrogen-induced phase amorphization occurs in the Y-poor samples (x < 1.00) already during the first hydrogen absorption, a higher Y content helps to maintain the material crystallinity during the hydrogenation cycles and increases its H-storage capacity (1.37 wt.% for x = 1.00 vs. 1.60 wt.% for x = 1.67 at 50 °C). Thermal conductivity experiments on the studied compositions indicate the importance of thermal transfer between powder individual particles and/or a measuring instrument. Hydrogen storage ; Intermetallic ; Sorption ; Crystallinity ; Materials science ; Hydrogen ; Phase (matter) ; Metal ; Electrochemistry ; Electrical resistivity and conductivity ; Chemical engineering ; Inorganic chemistry ; Metallurgy ; Chemistry ; Physical chemistry ; Adsorption ; Organic chemistry ; Alloy ; Composite material ; Electrode ; Physics Hydrogen Storage and Materials ; Ammonia Synthesis and Nitrogen Reduction ; Catalysis and Hydrodesulfurization Studies
Authors: Péter Kisszékelyi | Radovan Šebesta
Source: Beilstein Journal of Organic Chemistry (review, 2023-05-04)
Field: Chemistry — Inorganic Chemistry

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles Metal enolates are useful intermediates and building blocks indispensable in many organic synthetic transformations. Chiral metal enolates obtained by asymmetric conjugate additions of organometallic reagents are structurally complex intermediates that can be employed in many transformations. In this review, we describe this burgeoning field that is reaching maturity after more than 25 years of development. The effort of our group to broaden possibilities to engage metal enolates in reactions with new electrophiles is described. The material is divided according to the organometallic reagent employed in the conjugate addition step, and thus to the particular metal enolate formed. Short information on applications in total synthesis is also given. Electrophile ; Conjugate ; Chemistry ; Reagent ; Combinatorial chemistry ; Tandem ; Metal ; Group 2 organometallic chemistry ; Organic chemistry ; Molecule ; Catalysis Asymmetric Hydrogenation and Catalysis ; Asymmetric Synthesis and Catalysis ; Advanced Synthetic Organic Chemistry
Authors: Dávid Kovács | András Deák | G. Radnóczi | Zsolt E. Horváth | Attila Sulyok | Róbert Schiller | Ottó Czömpöly | Dániel Zámbó
Source: Journal of Materials Chemistry C (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Position of gold dictates the photophysical and photocatalytic properties of Cu <sub>2</sub> O in Cu <sub>2</sub> O/Au multicomponent nanoparticles Decorating Cu 2 O nanooctahedra with small Au nanograins is a superior strategy to utilize photogenerated charge carriers without generating hot electrons. Photocatalytic activity in these heteronanoparticles is improved even upon low-power excitation. Photocatalysis ; Materials science ; Charge carrier ; Nanoparticle ; Excitation ; Copper ; Position (finance) ; Photochemistry ; Electron ; Nanotechnology ; Chemical engineering ; Optoelectronics ; Metallurgy ; Catalysis ; Chemistry Copper-based nanomaterials and applications ; ZnO doping and properties ; Advanced Photocatalysis Techniques
Authors: Amisha S. Raikar | Sushma Priya | Shilpa Bhilegaonkar | Sandesh Narayan Somnache | Deepak M. Kalaskar
Source: Preprints.org (review, 2023-10-09)
Field: Materials Science — Surfaces, Coatings and Films

Surface Engineering of Bioactive Coatings for Improved Stent Hemocompatibility: A Comprehensive Review Cardiovascular diseases continuing to be a major contributor to illness and death on a global scale and the implementation of stents has given rise to a revolutionary transformation in the field of interventional cardiology. The thrombotic and restenosis complications associated with stent implantation pose ongoing challenges. In recent years, bioactive coatings have emerged as a promising strategy to enhance stent hemocompatibility and reduce thrombogenicity. This review article provides an overview of the surface engineering techniques employed to improve the hemocompatibility of stents and reduce thrombus formation. It explores the mechanisms underlying thrombosis and discusses the factors influencing platelet activation and fibrin formation on stent surfaces. Various bioactive coatings, including anticoagulant agents, antiplatelet agents, and surface modifications, are discussed in detail, highlighting their potential in reducing thrombogenicity. Evaluation methods for assessing hemocompatibility and thrombogenicity are also reviewed, ranging from in vitro assays to animal models. Recent advances in the field, such as nanotechnology-based coatings and bioactive coatings with controlled drug release systems, are highlighted. Surface engineering of bioactive coatings holds great promise for enhancing the long-term outcomes of stent implantation by enhancing hemocompatibility and reducing thrombogenicity. Future research directions and potential clinical applications are discussed, underscoring the need for continued advancements in this field. Thrombogenicity ; Restenosis ; Stent ; Nanotechnology ; Thrombus ; Biomedical engineering ; Materials science ; Medicine ; Thrombosis ; Surgery Polymer Surface Interaction Studies ; Vascular Procedures and Complications ; Electrospun Nanofibers in Biomedical Applications
Authors: Cheng Ding | Jing Ma | Yingxue Teng | Shanshan Chen
Source: Materials (article, 2023-11-19)
Field: Materials Science — Biomaterials

The Effect of Plasma Treatment on the Mechanical and Biological Properties of Polyurethane Artificial Blood Vessel In recent years, the incidence of cardiovascular disease has increased annually, and the demand for artificial blood vessels has been increasing. Due to the formation of thrombosis and stenosis after implantation, the application of many materials in the human body has been inhibited. Therefore, the choice of surface modification process is very important. In this paper, small-diameter polyurethane artificial blood vessels were prepared through electrospinning, and their surfaces were treated with plasma to improve their biological properties. The samples before and after plasma treatment were characterized by SEM, contact angle, XPS, and tensile testing; meanwhile, the cell compatibility and blood compatibility were evaluated. The results show that there are no significant changes to the fiber morphology or diameter distribution on the surface of the sample before and after plasma treatment. Plasma treatment can increase the proportion of oxygen-containing functional groups on the surface of the sample and improve its wettability, thereby increasing the infiltration ability of cells and promoting cell proliferation. Plasma treatment can reduce the risk of hemolysis, and does not cause platelet adhesion. Due to the etching effect of plasma, the mechanical properties of the samples decreased with the extension of plasma treatment time, which should be used as a basis to balance the mechanical property and biological property of artificial blood vessels. But on the whole, plasma treatment has positive significance for improving the comprehensive performance of samples. Materials science ; Contact angle ; Ultimate tensile strength ; Polyurethane ; Surface modification ; Wetting ; Biomedical engineering ; Blood vessel ; Hemolysis ; Composite material ; Chemical engineering ; Medicine ; Immunology ; Internal medicine Electrospun Nanofibers in Biomedical Applications ; Reconstructive Surgery and Microvascular Techniques ; Tissue Engineering and Regenerative Medicine
Authors: Tanja Schmitt | Li‐Yun Hsu | Nils Oberhof | Debkumar Rana | Andreas Dreuw | Eva Blasco | Petra Tegeder
Source: Advanced Functional Materials (article, 2023-04-25)
Field: Materials Science — Materials Chemistry

Ultrafast Excited States Dynamics of Orthogonal Photoswitches and The Influence of the Environment Abstract Molecular photoswitches are widely used in material sciences, physics, chemistry, and biology. As needs grow more complex, materials have to react more than one‐dimensionally. The use of multiple photoswitches at once opens manifold opportunities for further improved and more complicated systems. However, this requires independent addressability, i.e., orthogonality, and reversible processes. Herein, the first study on ultrafast excited state dynamics of two orthogonal photoswitches, a push‐pull azobenzene and a donor‐acceptor Stenhouse adduct is reported. In order to gain detailed insight in their interactions and mutual influences on their photoswitching behavior, they are addressed individually and simultaneously via transient absorption spectroscopy supported by quantum chemical calculations. They show reversible photoswitchability and in addition, can be used in 4D printing to provide easy access to a plethora of functional devices. Furthermore, environmental influences on the excited state dynamics are examined using different solvents and thin films. Both compounds photoisomerize independently when addressed individually or simultaneously and only little impacts on the excited state dynamics are found. Especially the vibrational relaxation is affected by different surroundings changing the energy dissipation while hardly affecting the electronic states involved. The orthogonal and simultaneous addressability is thereby crucial for their usage in 4D printed microactuators. Excited state ; Chemical physics ; Ultrashort pulse ; Materials science ; Photoswitch ; Molecular dynamics ; Nanotechnology ; Relaxation (psychology) ; Photochemistry ; Computational chemistry ; Physics ; Chemistry ; Atomic physics ; Quantum mechanics ; Laser Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Supramolecular Self-Assembly in Materials
Authors: Kamil Ciesielski | Karol Synoradzki | Damian Szymański | Kazuki Tobita | Katarzyna Berent | Patryk Obstarczyk | Kaoru Kimura | D. Kaczorowski
Source: Scientific Reports (article, 2023-01-28)
Field: Materials Science — Materials Chemistry

Half-Heusler phase TmNiSb under pressure: intrinsic phase separation, thermoelectric performance and structural transition Half-Heusler (HH) phase TmNiSb was obtained by arc-melting combined with high-pressure high-temperature sintering in conditions: p = 5.5 GPa, [Formula: see text] = 20, 250, 500, 750, and 1000 [Formula: see text]C. Within pressing temperatures 20-750 [Formula: see text]C the samples maintained HH structure, however, we observed intrinsic phase separation. The material divided into three phases: stoichiometric TmNiSb, nickel-deficient phase TmNi[Formula: see text]Sb, and thulium-rich phase Tm(NiSb)[Formula: see text]. For TmNiSb sample sintered at 1000 [Formula: see text]C, we report structural transition to LiGaGe-type structure (P[Formula: see text]mc, a = 4.367(3) Å, c = 7.138(7) Å). Interpretation of the transition is supported by X-ray powder diffraction, electron back-scattered diffraction, ab-initio calculations of Gibbs energy and phonon dispersion relations. Electrical resistivity measured for HH samples with phase separation shown non-degenerate behavior. Obtained energy gaps for HH samples were narrow ([Formula: see text] 260 meV), while the average hole effective masses in range 0.8-2.5[Formula: see text]. TmNiSb sample pressed at 750 [Formula: see text]C achieved the biggest power factor among the series, 13 [Formula: see text]WK[Formula: see text]cm[Formula: see text], which proves that the intrinsic phase separation is not detrimental for the electronic transport. Thermoelectric effect ; Materials science ; Phase (matter) ; Condensed matter physics ; Phase transition ; Thermodynamics ; Physics ; Quantum mechanics Advanced Thermoelectric Materials and Devices ; Heusler alloys: electronic and magnetic properties ; Intermetallics and Advanced Alloy Properties