jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: H.B. Krop | Pim de Voogt | Christian Eschauzier | Steven T. J. Droge
Source: Environmental Science Processes & Impacts (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Sorption of surfactants onto sediment at environmentally relevant concentrations:<i>independent-mode as unifying concept</i> At low surfactant concentrations often non-linear sorption processes are observed when natural adsorbents like sediment or soil are involved. This sorption process is often explained by a Dual-Model (DM) model, which assumes sorption to an adsorbent to be based on a combined ionic-polar and non-polar sorption interaction term. An Independent-Mode (IM) model, however, could treat surfactant sorption as two independent sorption processes to which the non-polar and ionic-polar features of the surfactant molecule contribute differently. For both models the overall exact partition coefficient, K, and its corresponding total standard free enthalpy of adsorption, Δ<sub>s</sub>G, are derived. We tested the outcome of both models against multiple published experimental sorption data sets by, (i) varying the organic carbon fraction, (ii) constructing sorption and partition isotherms over different concentration ranges, (iii) removing the organic carbon fraction, (iv) applying different types of mixtures of surfactants, and (v) explaining sorption hysteresis in desorption studies based on either continuous and successive washing steps. It turned out that only the IM model was able to explain the reported sorption phenomena. We also show that when one interaction is dominating, e.g. non-polar over ionic-polar, the Δ<sub>s</sub>G of the IM model can be approximated by the sum of the different Δ<sub>s</sub>G<sup>0</sup> values, the Δ<sub>s</sub>G of the DM model. The exact partition coefficient, K<sub>p</sub>(C<sub>w</sub>) (L kg<sup>-1</sup>) = dC<sub>s</sub> (mmol kg<sup>-1</sup>)/dC<sub>w</sub> (mmol L<sup>-1</sup>), is turning each sorption isotherm into a partition isotherm that provides the K<sub>p</sub> values required in environmental risk assessment models. Sorption ; Sediment ; Mode (computer interface) ; Environmental chemistry ; Environmental science ; Chemical engineering ; Chemistry ; Geology ; Computer science ; Adsorption ; Organic chemistry ; Geomorphology ; Engineering ; Human–computer interaction Surfactants and Colloidal Systems ; Per- and polyfluoroalkyl substances research ; Spectroscopy and Quantum Chemical Studies
Authors: Sophie Le Caër | Marie‐Claire Pignié | Quentin Berrod | Veronika Grzimek | Margarita Russina | Cédric Carteret | Antoine Thill | Jean-Marc Zanotti | J. Teixeira
Source: Nanoscale Advances (article, 2020-12-21)
Field: Materials Science — Biomaterials

Dynamics in hydrated inorganic nanotubes studied by neutron scattering: towards nanoreactors in water Water dynamics in inorganic nanotubes is studied by neutron scattering technique. Two types of aluminosilicate nanotubes are investigated: one is completely hydrophilic on the external and internal surfaces (IMO-OH) while the second possesses an internal cavity which is hydrophobic due to the replacement of Si-OH bonds by Si-CH<sub>3</sub> ones (IMO-CH<sub>3</sub>), the external surface being still hydrophilic. The samples have internal radii equal to 7.5 and 9.8 Å, respectively. By working under well-defined relative humidity (RH) values, water dynamics in IMO-OH was revealed by quasi-elastic spectra as a function of the filling of the interior of the tubes. When one water monolayer is present on the inner surface of the tube, water molecules can jump between neighboring Si-OH sites on the circumference by 2.7 Å. A self-diffusion is then measured with a value (<i>D</i> = 1.4 × 10<sup>-5</sup> cm<sup>2</sup> s<sup>-1</sup>) around half of that in bulk water. When water molecules start filling also the interior of the tubes, a strong confinement effect is observed, with a confinement diameter (6 Å) of the same order of magnitude as the radius of the nanotube (7.5 Å). When IMO-OH is filled with water, the H-bond network is very rigid, and water molecules are immobile on the timescale of the experiment. For IMO-OH and IMO-CH<sub>3</sub>, motions of the hydroxyl groups are also evidenced. The associated relaxation time is of the order of 0.5 ps and is due to hindered rotations of these groups. In the case of IMO-CH<sub>3</sub>, quasi-elastic spectra and elastic scans are dominated by the motions of methyl groups, making the effect of the water content on the evolution of the signals negligible. It was however possible to describe torsions of methyl groups, with a corresponding rotational relaxation time of 2.6 ps. The understanding of the peculiar behavior of water inside inorganic nanotubes has implications in research areas such as nanoreactors. In particular, the locking of motions inside IMO-OH when it is filled with water prevents its use under these conditions as a nanoreactor, while the interior of the IMO-CH<sub>3</sub> cavity is certainly a favorable place for confined chemical reactions to take place. Nanoreactor ; Neutron scattering ; Materials science ; Small-angle neutron scattering ; Chemical engineering ; Nanotechnology ; Scattering ; Chemical physics ; Chemistry ; Optics ; Physics ; Nanoparticle Clay minerals and soil interactions ; Electrostatics and Colloid Interactions ; Nanopore and Nanochannel Transport Studies
Authors: S. Bordère | Stéphane Glockner
Source: Computational Materials Science (article, 2020-09-10)
Field: Materials Science — Materials Chemistry

Numerical modeling of diffusion-controlled phase transformation using the Darken method: Application to the dissolution/precipitation processes in materials Diffusion ; Materials science ; Mechanics ; Phase (matter) ; Dissolution ; Tracking (education) ; Mass transfer ; Conservation of mass ; Precipitation ; Displacement (psychology) ; Interface (matter) ; Thermodynamics ; Bubble ; Physics ; Chemistry Solidification and crystal growth phenomena ; Aluminum Alloy Microstructure Properties ; High Temperature Alloys and Creep
Authors: S. Sabooni | E. Galinmoghaddam | A. A. Turkin | Liqiang Lu | R.J. Westerwaal | Christiaan Boelsma | E. Zoestbergen | Yutao Pei
Source: Journal of Alloys and Compounds (article, 2020-05-03)
Field: Materials Science — Materials Chemistry

Tailoring vapor-deposited ZnMg–Zn bilayer coating for steels by diffusion-driven phase transformation This study reports a “high temperature fast annealing” approach to tailor the microstructure of ZnMg–Zn bilayer coatings through a diffusion-driven phase transformation and to improve the adhesion strength and corrosion resistance, simultaneously. Selection of the appropriate annealing condition, 250 °C for 3 min, promotes the formation of MgZn2 on the topmost surface of the coating and Mg2Zn11 at the interface of ZnMg/Zn. This results to an increase of the adhesion strength from 65 MPa in the as-deposited condition to 82 MPa after annealing as well as a reduction in the corrosion current density from 0.91 to 0.52 μA/cm2, indicating enhanced corrosion resistance. The diffusion of the elements at high temperatures is also modeled to predict the stability region of phases during the annealing treatment. An excellent correlation is obtained between simulation and the experimental results. Annealing (glass) ; Materials science ; Corrosion ; Bilayer ; Coating ; Microstructure ; Metallurgy ; Composite material ; Chemical engineering ; Chemistry ; Membrane Corrosion Behavior and Inhibition ; Metal and Thin Film Mechanics ; High-Temperature Coating Behaviors
Authors: Yongfeng Zhang | Yipeng Gao | Cheng Sun | Daniel Schwen | Chao Jiang | Jian Gan
Source: Materials Theory (article, 2020-05-24)
Field: Materials Science — Materials Chemistry

Symmetry breaking during defect self-organization under irradiation Abstract One of the most intriguing phenomena under radiation is the self-organization of defects, such as the void superlattices, which have been observed in a list of bcc and fcc metals and alloys when the irradiation conditions fall into certain windows defined by temperature and dose rate. A superlattice features a lattice parameter and a crystal structure. Previously, it has been shown that the superlattice parameter is given by the wavelength of vacancy concentration waves that develop when the uniform concentration field becomes unstable. This instability is driven thermodynamically by vacancy concentration supersaturation and affected by the irradiation condition. However, a theory that predicts the superlattice symmetry, i.e., the selection of superlattice structure, has remained missing decades after the first report of superlattices. By analyzing the nonlinear recombination between vacancies and self-interstitial-atoms (SIAs) in the discrete lattice space, this work establishes the physical connection between symmetry breaking and anisotropic SIA diffusion, allowing for predictions of void ordering during defect self-organization. The results suggest that while the instability is driven thermodynamically by vacancy supersaturation, the symmetry development is kinetically rather than thermodynamically driven. The significance of SIA diffusion anisotropy in affecting superlattice formation under irradiation is also indicated. Various superlattice structures can be predicted based on different SIA diffusion modes, and the predictions are in good agreement with atomistic simulations and previous experimental observations. Superlattice ; Condensed matter physics ; Vacancy defect ; Instability ; Void (composites) ; Anisotropy ; Materials science ; Irradiation ; Lattice (music) ; Self-diffusion ; Chemical physics ; Physics ; Optics ; Quantum mechanics Nuclear Materials and Properties ; Fusion materials and technologies ; Nuclear materials and radiation effects
Authors: Gregor N. C. Simm | Robert Pinsler | Gábor Cśanyi | José Miguel Hernández-Lobato
Source: arXiv (Cornell University) (preprint, 2020-11-25)
Field: Materials Science — Materials Chemistry

Symmetry-Aware Actor-Critic for 3D Molecular Design Automating molecular design using deep reinforcement learning (RL) has the potential to greatly accelerate the search for novel materials. Despite recent progress on leveraging graph representations to design molecules, such methods are fundamentally limited by the lack of three-dimensional (3D) information. In light of this, we propose a novel actor-critic architecture for 3D molecular design that can generate molecular structures unattainable with previous approaches. This is achieved by exploiting the symmetries of the design process through a rotationally covariant state-action representation based on a spherical harmonics series expansion. We demonstrate the benefits of our approach on several 3D molecular design tasks, where we find that building in such symmetries significantly improves generalization and the quality of generated molecules. Computer science ; Reinforcement learning ; Graph ; Homogeneous space ; Generalization ; Representation (politics) ; Action (physics) ; Symmetry (geometry) ; Series (stratigraphy) ; Theoretical computer science ; Artificial intelligence ; Mathematics ; Physics ; Geometry Machine Learning in Materials Science ; Protein Structure and Dynamics ; Computational Drug Discovery Methods
Authors: Xuejun Jiang | Mei Lin | Jian‐Wen Huang | Mulan Mo | Houhe Liu | Yuan Jiang | Xiaowen Cai | Albert Wingnang Leung | Chuanshan Xu
Source: Frontiers in Chemistry (review, 2020-12-10)
Field: Materials Science — Biomaterials

Smart Responsive Nanoformulation for Targeted Delivery of Active Compounds From Traditional Chinese Medicine Traditional Chinese medicine (TCM) has been used to treat disorders in China for ~1,000 years. Growing evidence has shown that the active ingredients from TCM have antibacterial, antiproliferative, antioxidant, and apoptosis-inducing features. However, poor solubility and low bioavailability limit clinical application of active compounds from TCM. "Nanoformulations" (NFs) are novel and advanced drug-delivery systems. They show promise for improving the solubility and bioavailability of drugs. In particular, "smart responsive NFs" can respond to the special external and internal stimuli in targeted sites to release loaded drugs, which enables them to control the release of drug within target tissues. Recent studies have demonstrated that smart responsive NFs can achieve targeted release of active compounds from TCM at disease sites to increase their concentrations in diseased tissues and reduce the number of adverse effects. Here, we review "internal stimulus-responsive NFs" (based on pH and redox status) and "external stimulus-responsive NFs" (based on light and magnetic fields) and focus on their application for active compounds from TCM against tumors and infectious diseases, to further boost the development of TCM in modern medicine. Bioavailability ; Active ingredient ; Drug delivery ; Pharmacology ; Traditional Chinese medicine ; Drug ; Medicine ; Targeted drug delivery ; Traditional medicine ; Chemistry ; Nanotechnology ; Materials science ; Pathology ; Alternative medicine Nanoparticle-Based Drug Delivery ; Advanced Drug Delivery Systems ; Carbon and Quantum Dots Applications
Authors: Matthew Witman | Sanliang Ling | Vitalie Stavila | Pavithra Wijeratne | Hiroyasu Furukawa | Mark D. Allendorf
Source: Molecular Systems Design & Engineering (article, 2020-01-01)
Field: Chemistry — Inorganic Chemistry

Design principles for the ultimate gas deliverable capacity material: nonporous to porous deformations without volume change A rotating slit pore motif yields a non-porous to porous structural transition without a change in unit cell volume. Deliverable ; Porosity ; Porous medium ; Materials science ; Volume (thermodynamics) ; Composite material ; Engineering ; Thermodynamics ; Physics Metal-Organic Frameworks: Synthesis and Applications ; Methane Hydrates and Related Phenomena ; Inorganic Fluorides and Related Compounds
Authors: Xiaoyan Sun | Lingzi Liu | Hui Zou | Yao Caixia | Zhengyu Yan | Baofen Ye
Source: International Journal of Nanomedicine (article, 2020-07-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

&lt;p&gt;Intelligent Drug Delivery Microparticles with Visual Stimuli-Responsive Structural Color Changes&lt;/p&gt; The multicolor microparticles have great potential in drug delivery systems because of its vivid reporting color, excellent photothermal effect, and the good stimuli responsivity. Dextran ; Materials science ; Fluorescence ; Cyan ; Scanning electron microscope ; Drug delivery ; Photothermal effect ; Biomedical engineering ; Biophysics ; Nanotechnology ; Photothermal therapy ; Chemistry ; Chromatography ; Optics Gold and Silver Nanoparticles Synthesis and Applications ; Nonlinear Optical Materials Studies ; Photochromic and Fluorescence Chemistry
Authors: Jing Gao | Yuncong Chen | Zijian Guo | Weijiang He
Source: Biophysics Reports (article, 2020-10-01)
Field: Chemistry — Spectroscopy

Recent Endeavors on Molecular Imaging for Mapping Metals in Biology Transition metals such as zinc, copper and iron play vital roles in maintaining physiological functions and homeostasis of living systems. Molecular imaging including two-photon imaging (TPI), bioluminescence imaging (BLI) and photoacoustic imaging (PAI), could act as non-invasive toolkits for capturing dynamic events in living cells, tissues and whole animals. Herein, we review the recent progress in the development of molecular probes for essential transition metals and their biological applications. We emphasize the contributions of metallostasis to health and disease, and discuss the future research directions about how to harness the great potential of metal sensors. Molecular imaging ; Two-photon excitation microscopy ; Photoacoustic imaging in biomedicine ; Nanotechnology ; Bioluminescence imaging ; Bioluminescence ; Computational biology ; Chemistry ; Biology ; Ecology ; Materials science ; Biotechnology ; Physics ; Biochemistry Molecular Sensors and Ion Detection ; Trace Elements in Health ; Advanced biosensing and bioanalysis techniques
Authors: Somayeh Ahadi | Shahid I. Awan | Daniel B. Werz
Source: Chemistry - A European Journal (article, 2020-02-24)
Field: Chemistry — Organic Chemistry

Total Synthesis of Tri‐, Hexa‐ and Heptasaccharidic Substructures of the O‐Polysaccharide of <i>Providencia rustigianii</i> O34 A general and efficient strategy for synthesis of tri-, hexa- and heptasaccharidic substructures of the lipopolysaccharide of Providencia rustigianii O34 is described. For the heptasaccharide seven different building blocks were employed. Special features of the structures are an α-linked galactosamine and the two embedded α-fucose units, which are either branched at positions-3 and -4 or further linked at their 2-position. Convergent strategies focused on [4+3], [3+4], and [4+2+1] couplings. Whereas the [4+3] and [3+4] coupling strategies failed the [4+2+1] strategy was successful. As monosaccharidic building blocks trichloroacetimidates and phosphates were employed. Global deprotection of the fully protected structures was achieved by Birch reaction. HEXA ; Fucose ; Chemistry ; Stereochemistry ; Polysaccharide ; Organic chemistry ; Biochemistry Carbohydrate Chemistry and Synthesis ; Synthetic Organic Chemistry Methods ; Glycosylation and Glycoproteins Research
Authors: Sunjie Ye | Arsalan A. Azad | Joseph E. Chambers | Alison J. Beckett | Lucien Roach | Samuel C. T. Moorcroft | Zabeada Aslam | Ian A. Prior | Alexander F. Markham | P. Louise Coletta | Stefan J. Marciniak | Stephen D. Evans
Source: Small (article, 2020-10-25)
Field: Materials Science — Materials Chemistry

Exploring High Aspect Ratio Gold Nanotubes as Cytosolic Agents: Structural Engineering and Uptake into Mesothelioma Cells The generation of effective and safe nanoagents for biological applications requires their physicochemical characteristics to be tunable, and their cellular interactions to be well characterized. Here, the controlled synthesis is developed for preparing high-aspect ratio gold nanotubes (AuNTs) with tailorable wall thickness, microstructure, composition, and optical characteristics. The modulation of optical properties generates AuNTs with strong near infrared absorption. Surface modification enhances dispersibility of AuNTs in aqueous media and results in low cytotoxicity. The uptake and trafficking of these AuNTs by primary mesothelioma cells demonstrate their accumulation in a perinuclear distribution where they are confined initially in membrane-bound vesicles from which they ultimately escape to the cytosol. This represents the first study of the cellular interactions of high-aspect ratio 1D metal nanomaterials and will facilitate the rational design of plasmonic nanoconstructs as cytosolic nanoagents for potential diagnosis and therapeutic applications. Nanomaterials ; Cytosol ; Nanotechnology ; Plasmon ; Rational design ; Vesicle ; Materials science ; Biophysics ; Chemistry ; Membrane ; Optoelectronics ; Biology ; Biochemistry Advanced Nanomaterials in Catalysis ; Graphene and Nanomaterials Applications ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Vinod K. Ahirrao | Rajiv A. Jadhav | Vipul P. Rane | Harshal R. Bhamare | Ravindra Yeole
Source: Journal of Analytical Science & Technology (article, 2020-06-17)
Field: Chemistry — Spectroscopy

Time-dependent selected reaction monitoring-based GC-MS/MS method for estimation of genotoxic impurities in new antibacterial agent: alalevonadifloxacin mesylate Abstract Alalevonadifloxacin mesylate (ALA), pro-drug of levonadifloxacin is a new antibiotic approved in India to treat infections caused by Gram-positive bacteria. Alkyl mesylates (AMs) are known genotoxic impurities (GTI’s) formed in drug substances isolated as mesylate salts. Time-dependent selected reaction monitoring (t-SRM)-based gas chromatography tandem mass spectrometry (GC-MS/MS) method has been developed for trace estimation of AMs, namely, methyl methane sulfonate (MMS), ethyl methane sulfonate (EMS) and isopropyl methane sulfonate (IMS) in ALA. Liquid-liquid extraction (LLE) procedure using dichloromethane (DCM) as an extracting solvent was employed to extract AMs from the drug substance. Automatic selective reaction monitoring (auto-SRM) tool was applied to identify the most intense SRM pair of the ions to achieve the highest sensitivity. The method was validated in terms of specificity, linearity, sensitivity, precision, and accuracy. The limit of quantitation (LOQ) for the MMS, EMS and IMS were 5, 10, and 20 ng/g of ALA, respectively. For all analytes, the correlation coefficient (R) were greater than 0.9975 in the concentration range of 3.0–260 ng/mL. Mean recovery of all analytes was in the range of 91.77 to 97.65%. Chromatography ; Chemistry ; Analyte ; Detection limit ; Mesylate ; Dichloromethane ; Methane sulfonate ; Extraction (chemistry) ; Solvent ; Mass spectrometry ; Organic chemistry Analytical Chemistry and Chromatography ; Antibiotics Pharmacokinetics and Efficacy ; Pesticide Residue Analysis and Safety
Authors: Ahmad Khalaf Alkhawaldeh
Source: Preprints.org (preprint, 2020-06-28)
Field: Chemistry — Electrochemistry

Platinum Nanoparticles for the Electrochemical Study of Heavy Metal ions Formed by the Sputtering Deposition of the ion beam Electrode An electrochemical sensing platinum nanoparticle in the tantalum electrode is provided by means of an Ion Beam Sputtering Deposition (IBSD). The electrode was made with a Pt solution, sputtered simultaneously with hydrochloric acid corrosion on tantalum substrate. In the study of heavy metal ions, for example, the platinum nanoparticle electrodes as prepared were used Square wavelength voltammetry (OSWV) Hg2+, Cu2+ and Ag2+. The porous electrodes were observed in a broader range by the Pt nanostructure electrode for heavy metal ions. Furthermore, the susceptibility to detection has been shown to be saturated as the thickness of the layer electrode exceeded 50 nm. For Hg2+ 0,003-1 M, for Cu2+ 0,005-3 M and for Ag2+ the linear detection scale is 0,009-4 M. There has also been good reusability and repeatability. In addition, a scan electron microscope (SEM) used to study platinum electrode forming process and nanostructure. This electrode will have interesting applications in sensing systems. Electrode ; Materials science ; Platinum ; Tantalum ; Sputtering ; Platinum nanoparticles ; Electrochemistry ; Working electrode ; Nanoparticle ; Focused ion beam ; Nanostructure ; Palladium-hydrogen electrode ; Analytical Chemistry (journal) ; Scanning electron microscope ; Inorganic chemistry ; Ion ; Thin film ; Nanotechnology ; Metallurgy ; Chemistry ; Composite material Electrochemical Analysis and Applications ; Analytical Chemistry and Sensors ; Analytical chemistry methods development