jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Davut Laçin | Ayse Z. Aroguz
Source: SN Applied Sciences (article, 2020-11-27)
Field: Materials Science — Biomaterials

Kinetic studies on adsorption behavior of methyl orange using modified halloysite, as an eco-friendly adsorbent Halloysite ; Adsorption ; Freundlich equation ; Methyl orange ; Fourier transform infrared spectroscopy ; Langmuir ; Materials science ; Langmuir adsorption model ; Chemical engineering ; Thermogravimetry ; Chemistry ; Nuclear chemistry ; Inorganic chemistry ; Organic chemistry ; Composite material Clay minerals and soil interactions ; Iron oxide chemistry and applications ; Adsorption and biosorption for pollutant removal
Authors: Lucie Huart | Christophe Nicolas | Josiane A. Kaddissy | Jean‐Michel Guigner | A. Touati | Marie‐Françoise Politis | Pascal Mercère | B. Gervais | Jean‐Philippe Renault | Marie‐Anne Hervé du Penhoat
Source: The Journal of Physical Chemistry A (article, 2020-03-02)
Field: Materials Science — Surfaces, Coatings and Films

Soft X-ray Radiation and Monte Carlo Simulations: Good Tools to Describe the Radiation Chemistry of Sub-keV Electrons The description of the biological effects of ionizing radiation requires a good knowledge of the dose deposition processes at both the cellular and molecular scales. However, experimental studies on the energy deposition specificity of sub-keV electrons, produced by most radiations, including high-energy photons and heavy ions, are scarce. Soft X-rays (0.2-2 keV) are here used to probe the physical and physico-chemical events occurring upon exposure of liquid water to sub-keV electrons. Liquid water samples were irradiated with a monochromatic photon beam at the SOLEIL synchrotron. Hydroxyl radical quantification was conducted through HO<sup>•</sup> scavenging using benzoate to form fluorescent hydroxybenzoate. The yields of HO<sup>•</sup> radicals exhibit a minimum around 1.5 keV, in good agreement with indirect observation. Moreover, they are relatively independent of the benzoate concentration in the range investigated, which corresponds to scavenging times of 170 ns to 170 ps. These results provide evidence that sub-keV electrons behave as high linear energy transfer particles, since they are able to deposit tens to hundreds of electronvolts in nanometric volumes. Monte Carlo method ; Radiation ; Electron ; Physics ; Computational physics ; Statistical physics ; Atomic physics ; Nuclear physics ; Materials science ; Mathematics Electron and X-Ray Spectroscopy Techniques ; X-ray Spectroscopy and Fluorescence Analysis ; Ion-surface interactions and analysis
Authors: Juan Pablo Segovia-Gutiérrez | Manuel A. Escobedo-Sánchez | Erick Sarmiento‐Gómez | Stefan U. Egelhaaf
Source: Frontiers in Physics (article, 2020-01-10)
Field: Materials Science — Materials Chemistry

Diffusion of Anisotropic Particles in Random Energy Landscapes—An Experimental Study If a colloidal particle is exposed to an external field, its Brownian motion is modified. In the case of an anisotropic particle, the external potential might not only affect its translation but also its rotation. We experimentally investigate the dynamics of a trimer, which consists of three spherical particles, within a random potential energy landscape. This energy landscape has energy values drawn from a Gamma distribution, a spatial correlation length similar to the particle size and is realised by a random light field, that is a laser speckle pattern. The particle translation and rotation are quantified by the mean squared (angular) displacement, the van Hove function and other observable quantities. The translation shows an intermediate subdiffusive regime and a long-time diffusion that slows down upon increasing the modulation of the potential. In contrast, the mean squared angular displacement exhibits only small deviations from a linear time dependence but a more detailed analysis reveals discrete angular jumps reflecting the symmetry of the trimer. A coupling between the translation and rotation is observed and found to depend on the length scale. Brownian motion ; Physics ; Mean squared displacement ; Rotational diffusion ; Anisotropy ; Rotation (mathematics) ; Diffusion ; Correlation function (quantum field theory) ; Displacement (psychology) ; Particle (ecology) ; Translation (biology) ; Classical mechanics ; Optics ; Quantum mechanics ; Geometry ; Chemistry ; Molecular dynamics ; Mathematics Material Dynamics and Properties ; Ecosystem dynamics and resilience ; Plant and animal studies
Authors: Alexey V. Luzhetsky | В. А. Петров | S. V. Yudintsev | Viktor I. Malkovsky | Michael I. Ojovan | Maximilian S. Nickolsky | A. A. Shiryaev | S. S. Danilov | Е. Е. Ostashkina
Source: Sustainability (article, 2020-05-19)
Field: Materials Science — Materials Chemistry

Effect of Gamma Irradiation on Structural Features and Dissolution of Nuclear Waste Na–Al–P Glasses in Water Structural properties and water dissolution of six sodium–aluminum–phosphate (NAP) glasses have been investigated before and after irradiation by a gamma-ray source based on 60Co. Two of these samples were of simple composition, and four samples had a complex composition with radionuclide simulants representing actinides, fission, and activated corrosion products. Samples of the simple composition are fully vitreous, whereas samples of the complex composition contained up to 10 vol.% of aluminum–phosphate, AlPO4, and traces of ruthenium dioxide, RuO2. Based on the study of pristine and irradiated glasses, it was established that the radiation dose of 62 million Gray had practically no effect on the phase composition and structure of samples. At the same time, the rate of leaching of elements from the irradiated samples by water was decreased by about two times. Dissolution ; Radiochemistry ; Leaching (pedology) ; Irradiation ; Actinide ; Sodium phosphates ; Nuclear chemistry ; Radionuclide ; Radioactive waste ; Fission products ; Chemistry ; Sodium ; High-level waste ; Ruthenium ; Phosphate ; Composition (language) ; Selective leaching ; Spent nuclear fuel ; Materials science ; Metallurgy ; Physical chemistry Nuclear materials and radiation effects ; Glass properties and applications ; Luminescence Properties of Advanced Materials
Authors: Libing Duan | Xiangyang Ji | Yajie Yang | Sihang Yang | Xinjun Lv | Yanbo Xie
Source: RSC Advances (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Thickness-dependent fast wetting transitions due to the atomic layer deposition of zinc oxide on a micro-pillared surface Smart surfaces promote the fundamental understanding of wetting and are widely used in practical applications for energy and water collection. Light-induced switchable wettability facilitated by ZnO coatings, for instance, was developed for liquid manipulation at the surface. However, the transition of wetting states was reported to follow a hydrophobic-hydrophilic cycle in an hour, which is very long and may limit its future applications. We recently discovered that the cycle of the wetting state transitions on inorganic coatings can be shortened to less than 100 seconds by using ALD-coated ZnO on a pillared surface. However, the mechanisms are still unclear. Here, we investigated the effects of coating thickness on the transition speed and found that it significantly depended on the thickness of the coating with the optimal thickness less than 50 nm. We found that the minimum critical time for a wetting state transition cycle was less than 50 seconds with a thickness of 40 nm. Although the transition time of surfaces with coatings over 70 nm thickness remained constant at 10 min for a cycle, it was shorter than those of other deposition techniques for a coarse surface. Here, we propose a "penetration-diffusion" model to explain the fast and thickness-dependent wetting transitions. Our study may provide a new paradigm for fast wetting transition surfaces with cycle time within tens of seconds using a homogeneous thin layer coated on a rough surface. Wetting ; Zinc ; Atomic layer deposition ; Deposition (geology) ; Layer (electronics) ; Oxide ; Materials science ; Chemical engineering ; Chemistry ; Nanotechnology ; Inorganic chemistry ; Metallurgy ; Composite material ; Geology ZnO doping and properties ; Semiconductor materials and devices ; Fluid Dynamics and Thin Films
Authors: Marco Salvalaglio | Maximilian Selch | Axel Voigt | Steven M. Wise
Source: Mathematical Methods in the Applied Sciences (article, 2020-12-21)
Field: Materials Science — Materials Chemistry

Doubly degenerate diffuse interface models of anisotropic surface diffusion We extend the doubly degenerate Cahn–Hilliard (DDCH) models for isotropic surface diffusion, which yield more accurate approximations than classical degenerate Cahn–Hilliard (DCH) models, to the anisotropic case. We consider both weak and strong anisotropies and demonstrate the capabilities of the approach for these cases numerically. The proposed model provides a variational and energy dissipative approach for anisotropic surface diffusion, enabling large‐scale simulations with material‐specific parameters. Degenerate energy levels ; Anisotropy ; Isotropy ; Dissipative system ; Surface (topology) ; Anisotropic diffusion ; Yield (engineering) Solidification and crystal growth phenomena ; Advanced Mathematical Modeling in Engineering ; Block Copolymer Self-Assembly
Authors: Vanessa Prévot | Souad Touati | Christine Mousty
Source: Frontiers in Chemistry (article, 2020-12-02)
Field: Materials Science — Materials Chemistry

Confined Growth of NiAl-Layered Double Hydroxide Nanoparticles Within Alginate Gel: Influence on Electrochemical Properties NiAl Layered Double Hydroxide (LDH) alginate bionanocomposites were synthesized by confined coprecipitation within alginate beads. The NiAl based bionanocomposites were prepared either by impregnation by divalent and trivalent metal cations of pre-formed calcium cross-linked alginate beads or by using the metal cations (Ni<sup>2+</sup>, Al<sup>3+</sup>) as crosslinking cationic agents for the biopolymer network. The impregnation step was systematically followed by a soaking in NaOH solution to induce the LDH coprecipitation. Powder x-ray diffraction (PXRD), infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), thermogravimetry analysis (TGA), electron microscopies (SEM and TEM) confirmed the biotemplated coprecipitation of LDH nanoparticles ranging from 75 to 150 nm for both strategies. The drying of the LDH@alginate beads by supercritical CO<sub>2</sub> drying process led to porous bionanocomposite aerogels when Ca<sup>2+</sup> cross-linked alginate beads were used. Such confined preparation of NiAl LDH was extended to bionanocomposite films leading to similar results. The permeability and the electrochemical behavior of these NiAl@alginate bionanocomposites, as thin films coated on indium tin oxide (ITO) electrodes, were investigated by cyclic voltammetry, demonstrating an efficient diffusion of the K<sub>4</sub>Fe(CN)<sub>6</sub> redox probe through the LDH@alginate based films and the improvement of the electrochemical accessibility of the Ni sites. Coprecipitation ; Materials science ; Chemical engineering ; Nanoparticle ; Cyclic voltammetry ; Hydroxide ; Nial ; Electrochemistry ; Nuclear chemistry ; Thermogravimetric analysis ; Thermogravimetry ; Nanotechnology ; Metallurgy ; Chemistry ; Electrode Layered Double Hydroxides Synthesis and Applications ; Supercapacitor Materials and Fabrication ; Advanced Photocatalysis Techniques
Authors: Alessandra Benassi | Filippo Doria | Valentina Pirota
Source: Preprints.org (preprint, 2020-11-02)
Field: Chemistry — Organic Chemistry

Groundbreaking Anticancer Activity of Highly Diversified Oxadiazole Scaffolds Nowadays, an increasing number of heterocyclic-based drugs found application in medicinal chemistry and, in particular, as anticancer agents. In this context, oxadiazoles, five-membered aromatic rings, emerged for their interesting biological properties. Modification of oxadiazole scaffolds represents a valid strategy to increase their anticancer activity, especially on 1,2,4 and 1,3,4 regioisomers. In the last years, an increasing number of oxadiazole derivatives, with remarkable cytotoxicity for several tumor lines, were identified. Structural modifications, that ensure higher cytotoxicity towards malignant cells, represent a solid starting point in the development of novel oxadiazoles-based drugs. To increase the specificity of this strategy, outstanding oxadiazole scaffolds have been designed to selectively interact with biological targets, including enzymes, globular proteins and nucleic acids, showing more promising antitumor effects. In the present work, we aim to provide a comprehensive overview of the anticancer activity of these heterocycles, describing their effect on different targets and highlighting how their structural versatility has been exploited to modulate their biological properties. Context (archaeology) ; Cytotoxicity ; Oxadiazole ; Chemistry ; Nucleic acid ; Combinatorial chemistry ; Computational biology ; Nanotechnology ; Biochemistry ; In vitro ; Biology ; Materials science ; Organic chemistry Click Chemistry and Applications ; Synthesis and biological activity ; Synthesis and Biological Evaluation
Authors: Guilherme Nunes Lucena | Caio Carvalho dos Santos | Gabriel Pinto | Bruno Estevan Amantéa | Rodolfo Debone Piazza | Miguel Jafelicci | Rodrigo Fernando Costa Marques
Source: Medical Devices & Sensors (article, 2020-05-16)
Field: Materials Science — Biomaterials

Surface engineering of magnetic nanoparticles for hyperthermia and drug delivery Abstract Magnetic nanoparticles (MNP) have emerged as a relevant material for biomedical applications based on drug delivery systems and magnetic hyperthermia. When carefully tailored, their surface properties can enhance the solubility, bioavailability, permeability, metabolism, excretion, cell internalization and recognition of many medicines, which are parameters highly desired when one think in the development and efficiency increasing of several therapies. Allied to it, an interesting synergism can be achieved by the use of magnetic fields as trigger of drug release from thermosensitive polymer‐modified MNP or as a tool to increase accumulation of medicine in specific site. Faced it, here it shows how surface engineering of MNP can improve its biomedical relevance due to enhancement of cellular recognition, biocompatibility and drug release of several medicines. Furthermore, particular attention will be paid to the use of magnetic hyperthermia, which has acted synergic to improve MNP effects of many drug delivery systems. Drug delivery ; Biocompatibility ; Internalization ; Nanotechnology ; Magnetic nanoparticles ; Bioavailability ; Magnetic hyperthermia ; Drug ; Nanoparticle ; Targeted drug delivery ; Materials science ; Surface engineering ; Hyperthermia ; Biomedical engineering ; Pharmacology ; Chemistry ; Medicine ; Cell ; Biochemistry Nanoparticle-Based Drug Delivery ; Characterization and Applications of Magnetic Nanoparticles ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Patrick M. McCosker | Nicholas M. Butler | Alireza Shakoori | Michel Volland | Matthew J. Perry | Jesse W. Mullen | Anthony C. Willis | Timothy Clark | John B. Bremner | Dirk M. Guldi | Paul A. Keller
Source: Chemistry - A European Journal (article, 2020-09-04)
Field: Chemistry — Organic Chemistry

The Cascade Reactions of Indigo with Propargyl Substrates for Heterocyclic and Photophysical Diversity The synthesis of structurally diverse heterocycles for chemical space exploration was achieved via the cascade reactions of indigo with propargylic electrophiles. New pyrazinodiindolodione, naphthyridinedione, azepinodiindolone, oxazinoindolone and pyrrolodione products were prepared in one pot reactions by varying the leaving group (-Cl, -Br, -OMs, -OTs) or propargyl terminal functionality (-H, -Me, -Ph, -Ar). Mechanistic and density functional theory studies revealed that the unsaturated propargyl moiety can behave as an electrophile when aromatic terminal substitutions are made, and therefore competes with leaving group substitution for new outcomes. Selected products from the cascade reactions were investigated for their absorption and fluorescence properties, including transient absorption spectroscopy. This revealed polarity dependent excited state relaxation pathways, fluorescence, and triplet formation, thus highlighting these reactions as a means to access diverse functional materials rapidly. Propargyl ; Moiety ; Electrophile ; Chemistry ; Photochemistry ; Fluorescence ; Indigo ; Combinatorial chemistry ; Functional group ; Organic chemistry ; Catalysis Catalytic C–H Functionalization Methods ; Radical Photochemical Reactions ; Catalytic Alkyne Reactions
Authors: Changqiang Wu | Tian‐wu Chen | Lihua Deng | Xia Qian | Chuan Chen | Lan Mu | Yu Pu | Hongjie Tang | Ye Xu | Jiang Zhu | Chenjie Xu | Chengyi Shen | Xiao Ming Zhang
Source: Nanoscale Advances (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Mn(<scp>ii</scp>) chelate-coated superparamagnetic iron oxide nanocrystals as high-efficiency magnetic resonance imaging contrast agents In this communication, a paramagnetic bifunctional manganese(ii) chelate ([Mn(Dopa-EDTA)]<sup>2-</sup>) containing a catechol group is designed and synthesized. The catechol can bind iron ions on the surface of superparamagnetic iron oxide (SPIO) nanocrystals to form core-shell nanoparticles. Both 4 and 7 nm SPIO@[Mn(Dopa-EDTA)]<sup>2-</sup> show good water solubility, single-crystal dispersion, and low cytotoxicity. The study of the interplay between the longitudinal and transverse relaxation revealed that 4 nm SPIO@[Mn(Dopa-EDTA)]<sup>2-</sup> with lower <i>r</i> <sub>2</sub>/<i>r</i> <sub>1</sub> = 1.75 at 0.5 T tends to be a perfect <i>T</i> <sub>1</sub> contrast agent while 7 nm SPIO@[Mn(Dopa-EDTA)]<sup>2-</sup> with a higher <i>r</i> <sub>2</sub>/<i>r</i> <sub>1</sub> = 15.0 at 3.0 T tends to be a <i>T</i> <sub>2</sub> contrast agent. Interestingly, 4 nm SPIO@[Mn(Dopa-EDTA)]<sup>2-</sup> with an intermediate value of <i>r</i> <sub>2</sub>/<i>r</i> <sub>1</sub> = 5.26 at 3.0 T could act as <i>T</i> <sub>1</sub>-<i>T</i> <sub>2</sub> dual-modal contrast agent. <i>In vivo</i> imaging with the 4 nm SPIO@[Mn(Dopa-EDTA)]<sup>2-</sup> nanoparticle shows unique imaging features: (1) long-acting vascular imaging and different signal intensity changes between the liver parenchyma and blood vessels with the CEMRA sequence; (2) the synergistic contrast enhancement of hepatic imaging with the <i>T</i> <sub>1</sub>WI and <i>T</i> <sub>2</sub>WI sequence. In summary, these Fe/Mn hybrid core-shell nanoparticles, with their ease of synthesis, good biocompatibility, and synergistic contrast enhancement ability, may provide a useful method for tissue and vascular MR imaging. Superparamagnetism ; Nanocrystal ; Chelation ; Magnetic resonance imaging ; Contrast (vision) ; Iron oxide ; Nuclear magnetic resonance ; Materials science ; MRI contrast agent ; Chemistry ; Nanotechnology ; Nanoparticle ; Inorganic chemistry ; Magnetization ; Metallurgy ; Medicine ; Magnetic field ; Optics ; Physics ; Radiology Lanthanide and Transition Metal Complexes ; Nanoparticle-Based Drug Delivery ; Characterization and Applications of Magnetic Nanoparticles
Authors: Sén Takeda | Kentaro Yoshimura | Hiroshi Tanihata
Source: Journal of Visualized Experiments (article, 2020-02-19)
Field: Chemistry — Spectroscopy

Sample Preparation for Probe Electrospray Ionization Mass Spectrometry Mass spectrometry (MS) is a powerful tool in analytical chemistry because it provides very accurate information about molecules, such as mass-to-charge ratios (m/z), which are useful to deduce molecular weights and structures. While it is essentially a destructive analytical method, recent advancements in the ambient ionization technique have enabled us to acquire data while leaving tissue in a relatively intact state in terms of integrity. Probe electrospray ionization (PESI) is a so-called direct method because it does not require complex and time-consuming pretreatment of samples. A fine needle serves as a sample picker, as well as an ionization emitter. Based on the very sharp and fine property of the probe tip, destruction of the samples is minimal, allowing us to acquire the real-time molecular information from living things in situ. Herein, we introduce three applications of PESI-MS technique that will be useful for biomedical research and development. One involves the application to solid tissue, which is the basic application of this technique for the medical diagnosis. As this technique requires only 10 mg of the sample, it may be very useful in the routine clinical settings. The second application is for in vitro medical diagnostics where human blood serum is measured. The ability to measure fluid samples is also valuable in various biological experiments where a sufficient volume of sample for conventional analytical techniques cannot be provided. The third application leans toward the direct application of probe needles in living animals, where we can obtain real-time dynamics of metabolites or drugs in specific organs. In each application, we can infer the molecules that have been detected by MS or use artificial intelligence to obtain a medical diagnosis. Electrospray ionization ; Ionization ; Mass spectrometry ; DART ion source ; Sample (material) ; Ambient ionization ; Sample preparation ; Analytical Chemistry (journal) ; Characterization (materials science) ; Chemistry ; Electrospray ; Nanotechnology ; Computer science ; Biological system ; Chromatography ; Materials science ; Chemical ionization ; Ion ; Electron ionization Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Advanced Proteomics Techniques and Applications
Authors: Hui Jin | Hong Xia | Yaqin Fu | Yiping Qiu | Qing‐Qing Ni
Source: Materials Letters (article, 2020-01-11)
Field: Materials Science — Polymers and Plastics

Benzoyl peroxide thermo-crosslinked poly(ethylene-co-vinyl acetate) foam with two-way shape memory effect Materials science ; Benzoyl peroxide ; Scanning electron microscope ; Porosity ; Ethylene-vinyl acetate ; Composite material ; Vinyl acetate ; Shape-memory alloy ; Polymer ; Chemical engineering ; Copolymer ; Polymerization Polymer composites and self-healing ; Advanced Materials and Mechanics ; Electrospun Nanofibers in Biomedical Applications