jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Luis Castillo Henríquez | Jose Castro-Alpízar | Mary Lopretti-Correa | José Roberto Vega‐Baudrit
Source: Preprints.org (preprint, 2020-12-01)
Field: Materials Science — Biomaterials

Bioengineered Scaffolds for Thermo-responsive Drug Delivery in Wound Healing innate and adaptive immune responses lead to wound healing by regulating a complex series of events promoting cellular cross-talk. An inflammatory response is presented with its characteristic clinical symptoms: heat, pain, redness, and swelling. Some smart thermo-responsive polymers like chitosan can be used to create biocompatible and biodegradable scaffolds with 3D architectures similar to human structures, allowing their efficient and safe use as tissue engineering and drug delivery systems in chronic wounds. Locally heated tumors above polymer lower critical solution temperature can induce its conversion into a hydrophobic form, enhancing drug release until the thermal stimulus is gone, where a lower release is due to the swelling of the material. This paper integrates the relevant reported contributions of bioengineered scaffolds for thermo-responsive drug delivery in wound healing. Therefore, we present a comprehensive review that aims to demonstrate the capacity of these systems to provide spatially and temporally controlled release strategies for one or more drugs used in wound healing. In this sense, the novel manufacturing techniques of 3D-printing and electrospinning are explored for the tuning of their physicochemical properties to adjust therapies according to the patient’s convenience, as well as reduce drug toxicity and side effects. Drug delivery ; Wound healing ; Chitosan ; Biocompatible material ; Swelling ; Materials science ; Nanotechnology ; Scaffold ; Drug ; Biomedical engineering ; Tissue engineering ; Medicine ; Chemistry ; Pharmacology ; Surgery ; Composite material Electrospun Nanofibers in Biomedical Applications ; Wound Healing and Treatments ; 3D Printing in Biomedical Research
Authors: Aadithya Jeyaranjan
Source: Journal of International Crisis and Risk Communication Research (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Cerium Oxide based Nanocomposites for Supercapacitors Access to clean, and sustainable energy is one of the biggest challenges of our generation. With the rapid growth of renewable energy harvesters, developing electrochemical energy storage devices (EEDs) that respond well to them is of significant interest. Supercapacitors are a class of EEDs with exceptional power densities and ultra-long cycle life. These properties make them an attractive candidate as a replacement, or to be used in combination with batteries and other EEDs. In this dissertation, nano cerium oxide (nano CeO2) based materials are examined as an active material for supercapacitor applications. The first part of this work details how the morphology and selective crystal planes can lead to significantly improved charge storage; and how a combination of high surface area and exposure of high energy crystal planes ({110}, {100}) can lead up to 1.5 times higher charge storage capacity. The remainder of the thesis examines how nano CeO2 can effectively be used as an additive to improve the electrochemical properties of other supercapacitor materials. The second part describes a method to drastically improve the poor cycle life of conductive polymer-based materials by the addition of nano CeO2 and graphene through scalable spraydrying process. The ternary composite exhibits a high energy density (46.3 Wh Kg-1) and stable cycle life (92% capacitance retention after 6000 cycles). The third part details how nano CeO2 can be used as an active mechanical spacer for graphene aerogel based material. Here, nano CeO2 not only contributes towards charge storage but also prevents the restacking of graphene layers. The hybrid aerogels exhibit a high specific capacitance of 503 F g-1 and minimal capacitance fade after 10,000 cycles. This work highlights how engineering nanostructures beyond simple size reduction can lead to superior electrochemical properties and ultimately EEDs with improved safety, high power, and energy density. Cerium oxide ; Supercapacitor ; Nanocomposite ; Oxide ; Materials science ; Chemical engineering ; Nanotechnology ; Metallurgy ; Chemistry ; Capacitance ; Electrode ; Engineering Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Catalytic Processes in Materials Science
Authors: Zahra El-Schich | Yuecheng Zhang | Tommy Göransson | Nishtman Dizeyi | Jenny Persson | Emil Johansson | Rémi Caraballo | Mikael Elofsson | Sudhirkumar Shinde | Börje Sellergren | Anette Gjörloff Wingren
Source: Research Square (Research Square) (preprint, 2020-05-10)
Field: Chemistry — Analytical Chemistry

Sialic acid as a biomarker studied in breast cancer cells using fluorescent molecularly imprinted polymers, MIPs Abstract Sialylations are post-translational modifications of proteins and lipids that play important roles in many cellular events, including cell-cell interactions, proliferation and migration. Tumor cells express high levels of sialic acid (SA), which are often associated with the increased invasive potential in clinical tumors correlating with poor prognosis. To overcome the lack of natural SA-receptors, such as antibodies and lectins with high enough specificity and sensitivity, we have used molecularly imprinted polymers (MIPs), or “plastic antibodies”, as nanoprobes. Since high expression of EpCAM in primary tumors often is associated with proliferation and a more aggressive phenotype, the expression and of epithelial cell adhesion molecule (EpCAM) CD44 was initially analyzed. The SA-MIPs were used here for the detection of SA on the cell surface of breast cancer cells. Lectins that specifically bind to the α-2,3 SA and α-2,6 SA variants, respectively, were used for analysis of SA expression with both flow cytometry and confocal microscopy. Here we show a correlation of EpCAM and SA expression when using the SA-MIPs for detection of SA. We also demonstrate the binding pattern of the SA-MIPs on the breast cancer cell lines using confocal microscopy. Pre-incubation of the SA-MIPs with SA-derivatives as inhibitors could reduce the binding of the SA-MIPs to the tumor cells, indicating the specificity of the SA-MIPs. In conclusion, the SA-MIPs may be a new powerful tool in the SA-analysis of breast cancer cells. Molecularly imprinted polymer ; Fluorescence ; Biomarker ; Breast cancer ; Chemistry ; Cancer ; Cancer research ; Sialic acid ; Biochemistry ; Medicine ; Internal medicine ; Selectivity ; Catalysis Analytical chemistry methods development
Authors: Paolo Cifani | Zhi Li | Danmeng Luo | Mark Grivainis | Andrew M. Intlekofer | David Fenyö | Alex Kentsis
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2020-06-20)
Field: Chemistry — Spectroscopy

Discovery of protein modifications using high resolution differential mass spectrometry proteomics Summary Recent studies have revealed diverse amino acid, post-translational and non-canonical modifications of proteins in diverse organisms and tissues. However, their unbiased detection and analysis remain hindered by technical limitations. Here, we present a spectral alignment method for the identification of protein modifications using high-resolution mass spectrometry proteomics. Termed SAMPEI for Spectral Alignment-based Modified PEptide Identification, this open-source algorithm is designed for the discovery of functional protein and peptide signaling modifications, without prior knowledge of their identities. Using synthetic standards and controlled chemical labeling experiments, we demonstrate its high specificity and sensitivity for the discovery of sub-stoichiometric protein modifications in complex cellular extracts. SAMPEI mapping of mouse macrophage differentiation revealed diverse post-translational protein modifications, including distinct forms of cysteine itaconatylation. SAMPEI’s robust parameterization and versatility are expected to facilitate the discovery of biological modifications of diverse macromolecules. SAMPEI is implemented as a Python package, and is available open-source from BioConda and GitHub ( https://github.com/FenyoLab/SAMPEI ). Proteomics ; Computational biology ; Mass spectrometry ; Posttranslational modification ; Python (programming language) ; Cysteine ; Peptide ; High resolution ; Identification (biology) ; Chemistry ; Computer science ; Biology ; Biochemistry ; Chromatography Advanced Proteomics Techniques and Applications ; Peptidase Inhibition and Analysis ; Mass Spectrometry Techniques and Applications
Authors: Congya Zhou | Xiaofeng Cai | Yuanyuan Zhang | Chunmiao Pan | Chuanzhen Wang | Suodi Zhai | Li Yang | Shuangpeng Zhu | Xianhua Zhang
Source: Journal of Analytical Science & Technology (article, 2020-06-23)
Field: Chemistry — Spectroscopy

Accurate quantification of EVT201 and its two metabolites in human urine using UHPLC-MS/MS method with solid phase extraction Abstract A sensitive and accurate ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of EVT201 and its two metabolites, Ro46-1927 and Ro18-5528, in human urine. Different sample preparation methods were compared, and solid-phase extraction (SPE) was finally employed. Separation conditions and mass spectrometry parameters were optimized to achieve complete separation and enough sensitivity. Finally, the three analytes were separated on an Acquity BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with a gradient mobile phase. The gradient elution consisted of acetonitrile (containing 0.1% formic acid) and 10 mM ammonium formate (containing 1% acetonitrile and 0.1% formic acid) at a flow rate of 0.50 mL/min. Detection was performed on an electrospray ionization (ESI) source in positive mode with multiple reaction monitoring (MRM). The method was fully validated in accordance with the bioanalysis guidance in Chinese Pharmacopoeia. It showed satisfying linearity, accuracy, and precision in the range of 0.2–200 ng/mL for all the three analytes. The mean extraction recoveries were 85.2%, 65.6%, 87.9%, and 86.4% for EVT201, Ro46-1927, Ro18-5528, and the IS, respectively. The method was successfully applied to the bioanalysis of 833 urine samples to determine the concentration of EVT201 and its two metabolites simultaneously. Chromatography ; Bioanalysis ; Ammonium formate ; Formic acid ; Chemistry ; Solid phase extraction ; Analyte ; Extraction (chemistry) ; Selected reaction monitoring ; Mass spectrometry ; Electrospray ionization ; Sample preparation ; Detection limit ; Acetonitrile ; Elution ; Tandem mass spectrometry Analytical Chemistry and Chromatography ; Lanthanide and Transition Metal Complexes ; Electrochemical Analysis and Applications
Authors: Jie Yang | Wenzhao Fu | Chaoqiu Chen | Wenyao Chen | Wugen Huang | Ruoou Yang | Qingqiang Kong | Baiyan Zhang | Ji‐Xiao Zhao | Cheng‐Meng Chen | Jun Luo | Fan Yang | Xuezhi Duan | Zheng Jiang | Yong Qin
Source: Research Square (preprint, 2020-10-06)
Field: Materials Science — Materials Chemistry

Atomic design and fine-tuning of sub-nanometric Pt catalysts to tame hydrogen generation Abstract Rational synthesis of sub-nanocatalysts with controllable electronic and atomic structures remains a challenge to break the limits of traditional catalysts for superior performance. Here we report the atomic-level precise synthesis of Pt/graphene sub-nanocatalysts (from single atom, dimer, and to cluster) by atomic layer deposition, achieved by a novel high temperature pulsed ozone strategy to controllably pre-create abundant in-plane epoxy groups on graphene as anchoring sites. The specific in-plane epoxy structure endows the deposited Pt species with outstanding uniformity, controllability and stability. Their size-depended electronic and geometric effects have been observed for ammonia borane hydrolysis, revealing a volcano-type dependence of intrinsic activity on their sizes. Their active site structures have been identified based on extensive characterizations, dynamic compensation effect, kinetic isotope experiments and density function theory simulation. The Pt dimers show the highest catalytic activity and good durability than Pt single atoms and nanoparticles, ascribed to the unique C-Pt-Pt-O (C5Pt2O, metal-metal bond dimer) active site structure. Our work provides new insights into the precise tailoring and catalytic mechanism in sub-nanometer level. Catalysis ; Hydrogen ; Materials science ; Nanotechnology ; Chemical engineering ; Chemistry ; Engineering ; Organic chemistry Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Machine Learning in Materials Science
Authors: Marek Brzeziński | Adam Michalski | Bartłomiej Kost | Marta Socka | Marcin Florczak | Grzegorz Łapienis | Tadeusz Biela
Source: Macromolecular Chemistry and Physics (article, 2020-03-23)
Field: Materials Science — Biomaterials

Simultaneous Stereocomplexation of Polylactides during Polymerization of <scp>d</scp>‐LA in the Presence of a PLLA Template Abstract Matrix polymerization is frequently used to obtain different materials with control over the microstructure and molecular weight of the final products; however, it is never employed to obtain stereoregular polylactide. Therefore, here, l‐ lactide polymerization is initiated with butanol or methoxy poly(ethylene glycol). Subsequently, the hydroxyl end groups of the obtained poly( l ‐lactides) (PLLAs) are blocked with acetic anhydride to avoid stereoblock formation during matrix polymerization in the presence of PLLA as a template. The polymerization is carried out in tetrahydrofuran at 80 °C under vacuum. During the course of the process, the simultaneous stereocomplexation of a PLLA matrix with growing poly( d ‐lactide) chains is observed, leading to the formation of petal‐in‐petal microparticles. This approach can provide a tool for designing stereocomplexed particles with different morphologies and allows for fine‐tuning of their properties. Polymerization ; Polymer chemistry ; Ring-opening polymerization ; Lactide ; Materials science ; Ethylene glycol ; Polymer ; Chemical engineering ; Chemistry ; Organic chemistry ; Composite material biodegradable polymer synthesis and properties ; Carbon dioxide utilization in catalysis ; Bone Tissue Engineering Materials
Authors: Suiying Ye | Tian tian | Andrew J. Christofferson | Sofia Erikson | Jakub Jagielski | Zhi Luo | Sudhir Kumar | Chih‐Jen Shih | Jean-Christophe Leroux | Yinyin Bao
Source: ChemRxiv (preprint, 2020-05-27)
Field: Materials Science — Materials Chemistry

Tuning Multicolor Emission from a Single Fluorophore via Controlled Radical Polymerization-Mediated Charge Transfer &lt;p&gt;Tuning emission color of molecular fluorophores is of fundamental interest as it directly reflects the manipulation of excited states at the quantum-mechanical level. Despite recent progress in molecular design and engineering on single fluorophores, a systematic methodology to obtain multicolor emission in aggregated or solid states, which gives rise to practical implications in different fields, remains scarce. This is due to the complex interplay between the charge-transfer (CT) and singlet excitons. In this study, we present a general strategy to tune the emission color of a single-fluorophore aggregate by controlled radical polymerization-mediated charge transfer. Using a library of well-defined styrenic donor (D) polymers grown from an acceptor (A) fluorophore by atom transfer radical polymerization (ATRP), we found that the solid-state emission color can be fine-tuned by varying three molecular parameters: (i) the monomer substituent, (ii) the end-groups of the polymer, and (iii) the polymer chain length. Experimental and theoretical investigations reveal that the color tunability originates from the structurally dependent through-space charge transfer (TSCT) process that regulates CT energy. We further demonstrate that the polymer systems can be processed into thin films enabling versatile photolithography.&lt;/p&gt; Fluorophore ; Atom-transfer radical-polymerization ; Polymerization ; Polymer ; Materials science ; Photochemistry ; Acceptor ; Monomer ; Excited state ; Photoluminescence ; Chemical physics ; Nanotechnology ; Fluorescence ; Optoelectronics ; Chemistry ; Optics ; Atomic physics ; Physics Luminescence and Fluorescent Materials ; Conducting polymers and applications ; Organic Electronics and Photovoltaics
Authors: Maciej Kozak | Wojciech M. Kwiatek | М. Кискинова | A. Marcelli | S. Pascarelli
Source: Radiation Physics and Chemistry (article, 2020-06-24)
Field: Materials Science — Materials Chemistry

Proceedings of the 17th International Conference on X-Ray Absorption Fine Structure (XAFS 2018) X-ray absorption fine structure ; Graphene ; Catalysis ; Oxide ; Methanol ; Materials science ; Substrate (aquarium) ; Chemical engineering ; Phenol ; Formaldehyde ; Absorption (acoustics) ; Chemistry ; Nuclear chemistry ; Nanotechnology ; Organic chemistry ; Metallurgy ; Composite material Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Catalysis and Hydrodesulfurization Studies
Authors: Suiying Ye | Tian tian | Andrew J. Christofferson | Sofia Erikson | Jakub Jagielski | Zhi Luo | Sudhir Kumar | Chih‐Jen Shih | Jean‐Christophe Leroux | Yinyin Bao
Source: ChemRxiv (preprint, 2020-05-27)
Field: Materials Science — Materials Chemistry

Tuning Multicolor Emission from a Single Fluorophore via Controlled Radical Polymerization-Mediated Charge Transfer Tuning emission color of molecular fluorophores is of fundamental interest as it directly reflects the manipulation of excited states at the quantum-mechanical level. Despite recent progress in molecular design and engineering on single fluorophores, a systematic methodology to obtain multicolor emission in aggregated or solid states, which gives rise to practical implications in different fields, remains scarce. This is due to the complex interplay between the charge-transfer (CT) and singlet excitons. In this study, we present a general strategy to tune the emission color of a single-fluorophore aggregate by controlled radical polymerization-mediated charge transfer. Using a library of well-defined styrenic donor (D) polymers grown from an acceptor (A) fluorophore by atom transfer radical polymerization (ATRP), we found that the solid-state emission color can be fine-tuned by varying three molecular parameters: (i) the monomer substituent, (ii) the end-groups of the polymer, and (iii) the polymer chain length. Experimental and theoretical investigations reveal that the color tunability originates from the structurally dependent through-space charge transfer (TSCT) process that regulates CT energy. We further demonstrate that the polymer systems can be processed into thin films enabling versatile photolithography. Fluorophore ; Atom-transfer radical-polymerization ; Photochemistry ; Polymer ; Materials science ; Polymerization ; Acceptor ; Chemical physics ; Monomer ; Excited state ; Photoluminescence ; Radical polymerization ; Fluorescence ; Nanotechnology ; Chemistry ; Optoelectronics ; Optics ; Atomic physics ; Physics Luminescence and Fluorescent Materials ; Conducting polymers and applications ; Analytical Chemistry and Sensors
Authors: Yu. V. Levina | A. V. Plutalova | С. Д. Зайцев | Р. В. Томс | Н. С. Серхачева | Е. А. Лысенко | Е. В. Черникова
Source: Polymer Science Series B (article, 2020-05-01)
Field: Chemistry — Organic Chemistry

Amphiphilic Copolymers of Acrylic Acid and n-Butyl Acrylate with the Predetermined Microstructure: Synthesis and Properties Features of the synthesis of n-butyl acrylate copolymers with acrylic acid in 1,4-dioxane by free radical reversible addition-fragmentation chain transfer (RAFT) polymerization mediated by symmetric trithiocarbonates are considered. It is shown that the living mechanism of polymerization is realized in the studied systems. The chemical nature of the RAFT agent dictates different chain microstructures (random block or random) of the copolymers. The effect of chain microstructure on the properties of the copolymers containing about 90 mol % of acrylic acid units is studied by differential scanning calorimetry, contact angle measurements, turbidimetry, potentiometric titration, and dynamic light scattering. It is demonstrated that all the copolymers in the solid phase have similar properties: a single glass transition temperature close to the glass transition temperature of polyacid and a good water wettability. In dilute aqueous solutions, the properties of the copolymers are different: at the inherent pH, random copolymer macromolecules form large associates, while random block copolymers are dispersed into individual coils or micelles. All the copolymers are weaker polyacids compared with PAA; the random block copolymers are characterized by the compaction of macromolecules at small degrees of ionization. Our studies provide evidence that reversible addition-fragmentation chain transfer polymerization is an efficient tool for the targeted insertion of nonpolar units into a polyelectrolyte chain and it can be used for the fine-tuning of its properties. Copolymer ; Chain transfer ; Polymer chemistry ; Materials science ; Acrylate ; Acrylic acid ; Polymerization ; Chemical engineering ; Living polymerization ; Polyelectrolyte ; Raft ; Radical polymerization ; Butyl acrylate ; Polymer ; Composite material Advanced Polymer Synthesis and Characterization ; Photopolymerization techniques and applications ; Polymer Surface Interaction Studies
Authors: Daniel Bůžek | Soňa Ondrušová | Jan Hynek | Petr Kovář | Kamil Lang | Ján Rohlíček | Jan Demel
Source: ChemRxiv (preprint, 2020-01-13)
Field: Chemistry — Inorganic Chemistry

Robust Aluminium and Iron Phosphinate Metal-Organic Frameworks for Efficient Removal of Bisphenol A Herein, we introduce a new series of highly stable MOFs, constructed using Fe3+ and Al3+ metal ions and bisphosphinate linkers. The isoreticular design leads to ICR-2, ICR-4, ICR-6, and ICR-7 MOFs with a honeycomb arrangement of linear pores, surface areas up to 1360 m2 g-1, and high solvothermal stability. In most cases, their sorption capacity is retained even after 24 h reflux in water. The choice of the linkers allows fine tuning of the pore sizes and the chemical nature of the pores. This feature can be utilized for optimization of host-guest interactions between molecules and pore walls. Water pollution by various endocrine disrupting chemicals has been considered as a global threat to public health. In this work, we proved that the chemical stability and the hydrophobic nature of the synthesized series of MOFs result in remarkable sorption properties of these materials for neurodisruptor bisphenol A. Bisphenol A ; Sorption ; Bisphenol ; Chemical engineering ; Aluminium ; Chemical stability ; Chemistry ; Molecule ; Porosity ; Environmental remediation ; Metal ; Materials science ; Organic chemistry ; Adsorption ; Contamination ; Epoxy Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Membrane Separation and Gas Transport