jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Prerna Yadav | Marta Jakubaszek | Bernhard Spingler | Bruno Goud | Gilles Gasser | Felix Zelder
Source: Chemistry - A European Journal (article, 2020-01-28)
Field: Chemistry — Spectroscopy

Fe<sup>III</sup>–Salen‐Based Probes for the Selective and Sensitive Detection of E450 in Foodstuff Inorganic pyrophosphate (PPi) is considered as a diagnostic marker for various diseases such as cancer and vascular calcification. PPi also plays an important preservative role as an additive E450 in foodstuff. In this work, a selective Fe<sup>III</sup> -salen-based probe for PPi is described; this probe disassembles in the presence of the target analyte into its molecular blocks, 1,2-propanediamine and 3-chloro-5-formyl-4-hydroxybenzenesulfonic acid. The latter signaling unit leads to a fluorometric response. Compared with a related prototype, the new complex shows a 2.3-times stronger emission at 500 nm and a 155-times better selectivity of PPi over adenosine triphosphate (ATP). Importantly, the new probe was successfully applied for detecting E450 in foodstuff. Analyte ; Selectivity ; Chemistry ; Pyrophosphate ; Fluorescence ; Adenosine triphosphate ; Combinatorial chemistry ; Chromatography ; Biochemistry ; Enzyme ; Catalysis Molecular Sensors and Ion Detection ; Electrochemical sensors and biosensors ; Mass Spectrometry Techniques and Applications
Authors: Kirti Sankhala | Joachim Koll | Volker Abetz
Source: Membranes (article, 2020-04-28)
Field: Materials Science — Materials Chemistry

Facilitated Structure Formation in Isoporous Block Copolymer Membranes upon Controlled Evaporation by Gas Flow The conventional fabrication of isoporous membranes via the evaporation-induced self-assembly of block copolymers in combination with non-solvent induced phase separation (SNIPS) is achieved under certain environmental conditions. In this study, we report a modification in the conventional fabrication process of (isoporous) flat sheet membranes in which the self-assembly of block copolymers is achieved by providing controlled evaporation conditions using gas flow and the process is introduced as gSNIPS. This fabrication approach can not only trigger and control the microphase separation but also provides isoporous structure formation in a much broader range of solution concentrations and casting parameters, as compared to fabrication under ambient, uncontrolled conditions. We systematically investigated the structure formation of the fabrication of integral asymmetric isoporous membranes by gSNIPS. A quantitative correlation between the evaporation conditions (causing solvent evaporation and temperature drop) and the self-assembly of block copolymers beginning from the top layer up to a certain depth, orientation of pores in the top layer and the substructure morphology has been discussed empirically. Fabrication ; Copolymer ; Membrane ; Evaporation ; Materials science ; Nanotechnology ; Chemical engineering ; Solvent ; Layer (electronics) ; Chemistry ; Composite material ; Thermodynamics ; Organic chemistry ; Polymer Block Copolymer Self-Assembly ; Advanced Polymer Synthesis and Characterization ; Polymer Surface Interaction Studies
Authors: Min Kim | Seung-Cheol Jee | Jung‐Suk Sung | Avinash A. Kadam
Source: Nanomaterials (article, 2020-09-09)
Field: Materials Science — Biomaterials

Supermagnetic Sugarcane Bagasse Hydrochar for Enhanced Osteoconduction in Human Adipose Tissue-Derived Mesenchymal Stem Cells Hydrothermally carbonized sugarcane bagasse (SCB) has exceptional surface properties. Looking at the huge amount of SCB produced, its biocompatible nature, cheap-cost for carbonization, and its easy functionalization can give impeccable nano-biomaterials for tissue engineering applications. Herein, sugarcane bagasse was converted into hydrochar (SCB-H) by hydrothermal carbonation. The SCB-H produced was further modified with iron oxide (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles (denoted as SCB-H@Fe<sub>3</sub>O<sub>4</sub>). Facile synthesized nano-bio-composites were characterized by SEM, HR-TEM, XRD, FT-IR, XPS, TGA, and VSM analysis. Bare Fe<sub>3</sub>O<sub>4</sub> nanoparticles (NPs), SCB-H, and SCB-H@Fe<sub>3</sub>O<sub>4</sub> were tested for cytocompatibility and osteoconduction enhancement of human adipose tissue-derived mesenchymal stem cells (hADMSCs). The results confirmed the cytocompatible and nontoxic nature of SCB-H@Fe<sub>3</sub>O<sub>4</sub>. SCB-H did not show enhancement in osteoconduction, whilst on the other hand, Fe<sub>3</sub>O<sub>4</sub> NPs exhibited a 0.5-fold increase in the osteoconduction of hADMSCs. However, SCB-H@Fe<sub>3</sub>O<sub>4</sub> demonstrated an excellent enhancement in osteoconduction of a 3-fold increase over the control, and a 2.5-fold increase over the bare Fe<sub>3</sub>O<sub>4</sub> NPs. Correspondingly, the expression patterns assessment of osteoconduction marker genes (ALP, OCN, and RUNX2) confirmed the osteoconductive enhancement by SCB-H@Fe<sub>3</sub>O<sub>4</sub>. In the proposed mechanism, the surface of SCB-H@Fe<sub>3</sub>O<sub>4</sub> might provide a unique topology, and anchoring to receptors of hADMSCs leads to accelerated osteogenesis. In conclusion, agriculture waste-derived sustainable materials like "SCB-H@Fe<sub>3</sub>O<sub>44</sub>" can be potentially applied in highly valued medicinal applications of stem cell differentiation. Bagasse ; Mesenchymal stem cell ; Surface modification ; Adipose tissue ; Chemical engineering ; Nanoparticle ; Materials science ; Tissue engineering ; Chemistry ; Nanotechnology ; Biomedical engineering ; Biotechnology ; Biochemistry ; Cell biology Electrospun Nanofibers in Biomedical Applications ; Graphene and Nanomaterials Applications ; Bone Tissue Engineering Materials
Authors: Haiwei Lu | Guoliang Yuan | Steven H. Strauss | Timothy J. Tschaplinski | Gerald A. Tuskan | Jin‐Gui Chen | Xiaohan Yang
Source: BioDesign Research (review, 2020-01-01)
Field: Materials Science — Biomaterials

Reconfiguring Plant Metabolism for Biodegradable Plastic Production For decades, plants have been the subject of genetic engineering to synthesize novel, value-added compounds. Polyhydroxyalkanoates (PHAs), a large class of biodegradable biopolymers naturally synthesized in eubacteria, are among the novel products that have been introduced to make use of plant acetyl-CoA metabolic pathways. It was hoped that renewable PHA production would help address environmental issues associated with the accumulation of nondegradable plastic wastes. However, after three decades of effort synthesizing PHAs, and in particular the simplest form polyhydroxybutyrate (PHB), and seeking to improve their production in plants, it has proven very difficult to reach a commercially profitable rate in a normally growing plant. This seems to be due to the growth defects associated with PHA production and accumulation in plant cells. Here, we review major breakthroughs that have been made in plant-based PHA synthesis using traditional genetic engineering approaches and discuss challenges that have been encountered. Then, from the point of view of plant synthetic biology, we provide perspectives on reprograming plant acetyl-CoA pathways for PHA production, with the goal of maximizing PHA yield while minimizing growth inhibition. Specifically, we suggest genetic elements that can be considered in genetic circuit design, approaches for nuclear genome and plastome modification, and the use of multiomics and mathematical modeling in understanding and restructuring plant metabolic pathways. Polyhydroxyalkanoates ; Polyhydroxybutyrate ; Metabolic engineering ; Synthetic biology ; Biochemical engineering ; Production (economics) ; Bioplastic ; Plant metabolism ; Biotechnology ; Computational biology ; Metabolic pathway ; Computer science ; Biology ; Metabolism ; Biochemistry ; Genetics ; Engineering ; Gene ; RNA ; Ecology biodegradable polymer synthesis and properties ; Biofuel production and bioconversion ; Microbial Metabolic Engineering and Bioproduction
Authors: J. T. Bridgham | M. R. Redinbo | J. W. Thornton | E. A. Ortlund
Source: UNC Libraries (article, 2020-11-08)
Field: Materials Science — Materials Chemistry

Crystal Structure of an Ancient Protein: Evolution by Conformational Epistasis The structural mechanisms by which proteins have evolved new functions are known only indirectly. We report x-ray crystal structures of a resurrected ancestral protein—the ∼450 million year-old precursor of vertebrate glucocorticoid (GR) and mineralocorticoid (MR) receptors. Using structural, phylogenetic, and functional analysis, we identify the specific set of historical mutations that recapitulate the evolution of GR’s hormone specificity from an MR-like ancestor. These substitutions repositioned crucial residues to create new receptor-ligand and intra-protein contacts. Strong epistatic interactions occur because one substitution changes the conformational position of another site. “Permissive” mutations—substitutions of no immediate consequence, which stabilize specific elements of the protein and allow it to tolerate subsequent function-switching changes—played a major role in determining GR’s evolutionary trajectory. Epistasis ; Protein crystallization ; Evolutionary biology ; Protein structure ; Crystal structure ; Protein evolution ; Computational biology ; Biology ; Genetics ; Chemistry ; Crystallography ; Gene ; Biochemistry ; Crystallization Enzyme Structure and Function
Authors: Saveh Djalali | Bradley D. Frank | Lukas Zeininger
Source: Soft Matter (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Responsive drop method: quantitative<i>in situ</i>determination of surfactant effectiveness using reconfigurable Janus emulsions Characterization of surfactant effectiveness and thus an evaluation of their performance in a wide range of emulsion technologies requires a precise determination of key parameters including their critical micelle concentrations as well as their ability to lower the surface tension at interfaces. In this study, we describe a new approach to quantify marginal variations in interfacial tension of surfactant stabilized fluid interfaces. The method is based on a unique chemical-morphological coupling inside bi-phasic oil-in-water Janus emulsions that undergo dynamic morphological transitions in response to changes in the surfactant type, concentration, ratio, and configuration. Variations in Janus droplet morphologies are readily monitored in situ using a simple side-view imaging setup, resulting in a fast, convenient, cost-effective, time-, and sample-saving technique for the characterization of classical surfactant systems. In addition, the reported method facilitates monitoring of triggered changes in surfactant effectiveness, e.g. invoked by external triggers, and thus proves particularly useful for the in situ analysis of stimuli-responsive surfactants and emulsions. Pulmonary surfactant ; Janus ; Surface tension ; Emulsion ; In situ ; Characterization (materials science) ; Drop (telecommunication) ; Materials science ; Micelle ; Nanotechnology ; Chemical engineering ; Chemistry ; Chromatography ; Computer science ; Thermodynamics ; Organic chemistry ; Aqueous solution Pickering emulsions and particle stabilization ; Surfactants and Colloidal Systems ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Alicia Weibel | Andréas Flaureau | Adeline Pham | Geoffroy Chevallier | Jérôme Esvan | Claude Estournès | Christophe Laurent
Source: Journal of the European Ceramic Society (article, 2020-06-10)
Field: Materials Science — Materials Chemistry

One-step synthesis of few-layered-graphene/alumina powders for strong and tough composites with high electrical conductivity Materials science ; Graphene ; Raman spectroscopy ; Composite material ; X-ray photoelectron spectroscopy ; Scanning electron microscope ; Chemical vapor deposition ; Percolation threshold ; Conductivity ; Grain boundary ; Electrical resistivity and conductivity ; Transmission electron microscopy ; Nanotechnology ; Chemical engineering ; Microstructure ; Optics Graphene research and applications ; Advanced ceramic materials synthesis ; Thermal properties of materials
Authors: Marina García‐Pardo | Eva Nieto‐Pinero | A. K. Petford‐Long | R. Serna | Johann Toudert
Source: SHILAP Revista de lepidopterología (article, 2020-02-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Active analog tuning of the phase of light in the visible regime by bismuth-based metamaterials The active and analog tuning of the phase of light by metamaterials is needed to boost the switching performance of photonic devices. However, demonstrations of this type of tuning in the pivotal visible spectral region are still scarce. Herein, we report the active analog tuning of the phase of visible light reflected by a bismuth (Bi)-based metamaterial, enabled by a reversible solid-liquid transition. This metamaterial, fabricated by following a lithography-free approach, consists of two-dimensional assemblies of polydisperse plasmonic Bi nanostructures embedded in a refractory and transparent aluminum oxide matrix. The analog tuning of the phase is achieved by the controlled heating of the metamaterial to melt a fraction of the nanostructures. A maximum tuning of 320° (1.8 π) is observed upon the complete melting of the nanostructures at 230°C. This tuning is reversible by cooling to 25°C. In addition, it presents a wide hysteretic character due to liquid Bi undercooling. This enables the phase achieved by this analog approach to remain stable over a broad temperature range upon cooling and until re-solidification occurs around 100°C. Therefore, Bi-based metamaterials are endowed with analog optical memory capabilities, which are appealing for a wide range of applications, including optical data storage with enhanced information density or bistable photonic switching with a tunable “on” state. Materials science ; Metamaterial ; Photonic metamaterial ; Photonics ; Optoelectronics ; Phase (matter) ; Nanophotonics ; Nanostructure ; Lithography ; Nanotechnology Metamaterials and Metasurfaces Applications ; Photonic Crystals and Applications ; Phase-change materials and chalcogenides
Authors: Stefan Langner | Florian Häse | José Darío Perea | Tobias Stubhan | Jens Hauch | Loı̈c M. Roch | Thomas Heumueller | Alán Aspuru‐Guzik | Christoph J. Brabec
Source: Advanced Materials (preprint, 2020-02-12)
Field: Materials Science — Materials Chemistry

Beyond Ternary OPV: High‐Throughput Experimentation and Self‐Driving Laboratories Optimize Multicomponent Systems Fundamental advances to increase the efficiency as well as stability of organic photovoltaics (OPVs) are achieved by designing ternary blends, which represents a clear trend toward multicomponent active layer blends. The development of high-throughput and autonomous experimentation methods is reported for the effective optimization of multicomponent polymer blends for OPVs. A method for automated film formation enabling the fabrication of up to 6048 films per day is introduced. Equipping this automated experimentation platform with a Bayesian optimization, a self-driving laboratory is constructed that autonomously evaluates measurements to design and execute the next experiments. To demonstrate the potential of these methods, a 4D parameter space of quaternary OPV blends is mapped and optimized for photostability. While with conventional approaches, roughly 100 mg of material would be necessary, the robot-based platform can screen 2000 combinations with less than 10 mg, and machine-learning-enabled autonomous experimentation identifies stable compositions with less than 1 mg. Ternary operation ; Component (thermodynamics) ; Bayesian optimization ; Throughput ; Stability (learning theory) ; Computer science ; Materials science ; Nanotechnology ; Artificial intelligence ; Machine learning ; Physics ; Operating system Machine Learning in Materials Science ; Modular Robots and Swarm Intelligence ; Electrowetting and Microfluidic Technologies
Authors: Lucas de Paula Santos Petri | Emanuel Antonio Moutinho | Rondinele Pinheiro Silva | Renato Massoni Capelini | Rogério Salustiano | Guilherme Martinez Figueiredo Ferraz | Estácio Tavares Wanderley Neto | Jansen Villibor | Suzana Silva Pinto
Source: Energies (article, 2020-12-15)
Field: Materials Science — Materials Chemistry

A Portable System for the Evaluation of the Degree of Pollution of Transmission Line Insulators Surface pollution is a major cause of partial discharges in high voltage insulators in coastal cities, leading to degradation of their surface and accelerating their aging process, which may cause visible arcing, flashovers and system faults. Thus, this work provides a methodology for the assessment of the condition of insulators based on an instrument which generates a severity degree to help the electric utility team schedule maintenance routines for the structures that really need it. The instrument uses a Raspberry Pi board as the processing core, a PicoScope oscilloscope for the data acquisition and an antenna as a partial discharge sensor. The algorithms are implemented in Python, and use artificial intelligence tools, such as a convolutional network and a fuzzy inference system. Laboratory test methods for the simulation of the field pollution conditions were successfully used for the validation of the instrument, which showed a good correlation between the pollution level and the severity degree generated. In addition to that, field collected data were also used for the evaluation of the proposed severity degree, which is demonstrated to be consistent when compared with the utility’s reports and the history of the selected areas from where data were collected. Oscilloscope ; Computer science ; Partial discharge ; Data acquisition ; Transmission line ; Arc flash ; Pollution ; Real-time computing ; Python (programming language) ; Simulation ; Reliability engineering ; Engineering ; Electrical engineering ; Voltage ; Detector ; Telecommunications High voltage insulation and dielectric phenomena ; Aerosol Filtration and Electrostatic Precipitation ; Non-Destructive Testing Techniques
Authors: Romana Zafar | Nandini Gupta
Source: IET Nanodielectrics (article, 2020-05-18)
Field: Materials Science — Materials Chemistry

Dielectric characterisation of epoxy nanocomposite with barium titanate fillers High permittivity materials are currently in use for mitigation of electrical stress in high‐voltage apparatus and energy storage systems. In this work, epoxy‐based high permittivity nanocomposites with Barium titanate (BaTiO 3 ) nanofillers are considered, for the purpose of stress mitigation. Uniform dispersion of the fillers in the polymer up to 10% by volume is achieved. Apart from the use of as‐received fillers, the effect of using surface‐functionalised nanoparticles (with 3‐glycidoxypropyltrimethoxy‐silane) before use is also investigated. The nanocomposite is characterised in terms of its complex permittivity, DC conductivity, short‐term AC breakdown strength and space charge accumulation, to gauge its suitability for use in high‐voltage insulation. Complex permittivity is measured using broadband dielectric spectroscopy over a broad frequency range of 1 mHz to 1 MHz. DC conductivity is studied from polarisation–depolarisation current measurements. Short‐term AC breakdown strength tests are performed at power frequency (50 Hz). Space charge density along the sample thickness is obtained using pulsed electro‐acoustic technique. A computational case‐study is presented to show the feasibility of using the high permittivity nanocomposite for electric stress control in high‐voltage equipment (viz., at mounting flanges of 69 kV bushings). Materials science ; Barium titanate ; Permittivity ; Composite material ; Nanocomposite ; Epoxy ; Space charge ; Dielectric ; Relative permittivity ; Conductivity ; Stress (linguistics) ; Polymer nanocomposite ; Ceramic ; Optoelectronics High voltage insulation and dielectric phenomena ; Dielectric materials and actuators ; Power Transformer Diagnostics and Insulation
Authors: Olivia Hanaa Raouf | Samy Selim | Hussein S. Mohamed | Omayma F. Abdel-Gawad | Ali El‐Zanaty | Sayed A. Ahmed
Source: Advanced Journal of Chemistry-Section A (article, 2020-03-02)
Field: Materials Science — Biomaterials

Synthesis, Characterization and Biological Activity of Schiff Bases Based on Chitosan and Acetophenone Derivatives Modification of chitosan any Schiff base reaction with acetophenone derivatives was done. Fourier transformer infrared analysis (FT-IR), scanning electron microscope (SEM), and X-ray diffraction (XRD) were used as the appropriate characterize the Schiff base derivatives. Thermal behavior of the prepared materials was also studied. Various biological activities were examined for the prepared materials antimicrobial activity including antibacterial (studied against Streptococcus sp. Bacillus subtilis and Sarcina lutea as an example for gram-positive bacteria and Pseudomonas aeruginosa and Escherichia coli as an example for Gram-negative bacteria), anti-fungal (against Candida albicans) and anti-protozoal (against Trypanosoma cruzi and Leishmania donovaniwas). Antioxidant activity of chitosan and its Schiff base derivatives was detected using the FRAP and DPPH techniques. Colon carcinoma (Colo 205), hepatocellular carcinoma (Hep G2), urinary bladder carcinoma (T24P) and embryonic kidney adenocarcinoma (293) used to examine the anticancer activity of chitosan and its modified derivatives. The new chitosan Schiff base derivatives showed superior anti-bacterial, antifungal, anti-protozoal and antioxidant activity than parent chitosan. But in case of anticancer test of HebG2 and T24P chitosan was more effective than the modified derivatives. Chitosan ; Schiff base ; Chemistry ; Antibacterial activity ; Klebsiella oxytoca ; Nuclear chemistry ; Antimicrobial ; Candida albicans ; Bacteria ; Escherichia coli ; Microbiology ; Biochemistry ; Organic chemistry ; Biology ; Stereochemistry Nanocomposite Films for Food Packaging ; Multicomponent Synthesis of Heterocycles ; Synthesis and biological activity
Authors: Tairan Wang | Jian-Cong Li | Shu Wu | Sulei Hu | Runhai Ouyang | Wei‐Xue Li
Source: Chinese Journal of Chemical Physics (article, 2020-07-24)
Field: Materials Science — Materials Chemistry

Machine-learning adsorption on binary alloy surfaces for catalyst screening Over the last few years, machine learning is gradually becoming an essential approach for the investigation of heterogeneous catalysis. As one of the important catalysts, binary alloys have attracted extensive attention for the screening of bifunctional catalysts. Here we present a holistic framework for machine learning approach to rapidly predict adsorption energies on the surfaces of metals and binary alloys. We evaluate different machine-learning methods to understand their applicability to the problem and combine a tree-ensemble method with a compressed-sensing method to construct decision trees for about 60000 adsorption data. Compared to linear scaling relations, our approach enables to make more accurate predictions lowering predictive root-mean-square error by a factor of two and more general to predict adsorption energies of various adsorbates on thousands of binary alloys surfaces, thus paving the way for the discovery of novel bimetallic catalysts. Bimetallic strip ; Adsorption ; Bifunctional ; Catalysis ; Binary number ; Computer science ; Materials science ; Scaling ; Decision tree ; Construct (python library) ; Alloy ; Linear scale ; Binary tree ; Machine learning ; Artificial intelligence ; Chemistry ; Mathematics ; Algorithm ; Physical chemistry ; Metallurgy ; Organic chemistry Machine Learning in Materials Science ; Electrocatalysts for Energy Conversion ; Advanced Photocatalysis Techniques