jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Georgios Tsaparlis
Source: Israel Journal of Chemistry (article, 2018-11-09)
Field: Chemistry — Physical and Theoretical Chemistry

Teaching and Learning Electrochemistry Abstract Numerous conceptual difficulties and misconceptions have been reported in the science and chemistry education literature about electrochemistry concepts such as electrolytes, redox equations, and about electrochemical (galvanic and electrolytic) cells. Other studies have considered teaching approaches aimed at improving learning and at overcoming misconceptions. This paper reviews these studies and considers strategies and approaches for the effective teaching of electrochemistry. Then, the review focuses on problem solving in equilibrium electrochemistry, especially problems involving the Nernst equation. The main findings of four studies with Greek university chemistry students, dealing with: (i) algorithmic problem‐solving ability; (ii) practice on problem solving; (iii) the effect of the format of a problem; and (iv) the construction and evaluation of a website devoted to electrochemistry problem solving, are reported. Chemistry ; Nernst equation ; Electrochemistry ; Galvanic cell ; Electrolyte ; Mathematics education ; Management science ; Psychology ; Electrode ; Physical chemistry ; Engineering Various Chemistry Research Topics ; Science Education and Pedagogy ; Educational Strategies and Epistemologies
Authors: Maria Lykaki | Eleni Papista | Sónia A. C. Carabineiro | Pedro B. Tavares | Michalis Konsolakis
Source: Catalysis Science & Technology (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Optimization of N<sub>2</sub>O decomposition activity of CuO–CeO<sub>2</sub> mixed oxides by means of synthesis procedure and alkali (Cs) promotion The fine-tuning of CuO–CeO<sub>2</sub> mixed oxides by means of synthesis procedure (co-precipitation) and alkali promotion (1.0 at Cs per nm<sup>2</sup>) towards highly active deN<sub>2</sub>O catalysts is demonstrated. Alkali metal ; Catalysis ; Decomposition ; Precipitation ; Inorganic chemistry ; Promotion (chess) ; Mixed oxide ; Materials science ; Chemistry ; Physics ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Nanomaterials for catalytic reactions
Authors: Xiaoli Liu | Lingqian Kong | Hongmei Du | Yan Zhang | Jinsheng Zhao | Yu Xie
Source: Organic Electronics (article, 2018-10-24)
Field: Materials Science — Polymers and Plastics

Synthesis and electrochromic properties of electrochromic polymers based on propylenedioxythiophene, diketopyrrolopyrrole and benzodithiophene units Electrochromism ; Materials science ; X-ray photoelectron spectroscopy ; Copolymer ; Cyclic voltammetry ; Monomer ; Band gap ; Electrochromic devices ; Polymer ; Thermogravimetric analysis ; Stille reaction ; Acceptor ; Photochemistry ; Analytical Chemistry (journal) ; Electrochemistry ; Chemistry ; Physical chemistry ; Chemical engineering ; Organic chemistry ; Optoelectronics ; Electrode Conducting polymers and applications ; Transition Metal Oxide Nanomaterials ; Organic Electronics and Photovoltaics
Authors: Ufana Riaz | Sapana Jadoun | Prabhat Kumar | Raj Kumar | Nitin Yadav
Source: RSC Advances (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Microwave-assisted facile synthesis of poly(luminol-<i>co</i>-phenylenediamine) copolymers and their potential application in biomedical imaging Conjugated copolymers have attracted much attention because of their outstanding photo-physical properties. The present work reports for the first time, microwave-assisted copolymerization of <i>o</i>-phenylenediamine with luminol using different weight ratios of the two monomers. The composition of the copolymers was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (<sup>1</sup>H-NMR) while monomer reactivity ratios were determined using the Fineman-Ross method. Ultraviolet-visible spectroscopy revealed the variation in polaronic states upon copolymerization while X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses showed the morphology of the copolymers to be intermediate between that of the homopolymers. Confocal analysis and fluorescence studies revealed that the copolymers showed composition based blue as well as red emission which could be utilized for <i>in vivo</i> imaging of cancer cells. Luminol ; Copolymer ; Chemistry ; Combinatorial chemistry ; Polymer chemistry ; Nanotechnology ; Chemiluminescence ; Organic chemistry ; Materials science ; Polymer Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics ; Click Chemistry and Applications
Authors: Àlex Julià López | Daniel Ruiz‐Molina | Katharina Landfester | Markus B. Bannwarth | Claudio Roscini
Source: Advanced Functional Materials (article, 2018-05-29)
Field: Materials Science — Materials Chemistry

Off/On Fluorescent Nanoparticles for Tunable High‐Temperature Threshold Sensing Abstract Herein, a versatile threshold temperature sensor based on the glass transition temperature‐triggered fluorescence activation of a dye/developer duo, encapsulated in polymeric nanoparticles is reported. The emission enhancement, detectable even by unaided eye is completed within a narrow temperature range and activates at adjustable threshold temperatures up to 200 °C. Fluorescence is chosen as sensing probe due to its high detection sensitivity together with an advanced spatial and temporal resolution. The strategy is based on nanoparticles prepared from standard thermoplastic polymers, a fluorescence developer, and the commercially available Rhodamine B base dye, a well‐known and widely used fluorescent molecule. By making nanoparticles of different thermoplastic polymers, fast, abrupt, and irreversible disaggregation induced fluorescence enhancement, with tunable threshold temperature depending on the nanoparticles polymer glass transition is achieved. As a proof‐of‐concept for the versatility of this novel family of NPs, their use for sensing the thermal history of environments and surfaces exposed to the threshold temperature is showed. Materials science ; Fluorescence ; Nanoparticle ; Polymer ; Rhodamine B ; Glass transition ; Rhodamine ; Nanotechnology ; Composite material ; Optics ; Organic chemistry Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Perovskite Materials and Applications
Authors: Kiat Hwa Chan | Wei Hao Lee | Ming Ni | Yihua Loo | Charlotte A. E. Hauser
Source: Scientific Reports (article, 2018-11-14)
Field: Materials Science — Biomaterials

C-Terminal Residue of Ultrashort Peptides Impacts on Molecular Self-Assembly, Hydrogelation, and Interaction with Small-Molecule Drugs Single molecular changes on a tripeptide can have dramatic effects on their self-assembly and hydrogelation. Herein, we explore C-terminal residue variation on two consistent ultrashort peptide backbones, i.e. acetylated-Leu-Ile-Val-Ala-Gly-Xaa and acetylated-Ile-Val-Xaa (Xaa = His, Arg, Asn). The objective of this study is to identify candidates that can form hydrogels for small-molecule drug (SMD) delivery. Haemolysis and cytotoxicity (with human adipose-derived mesenchymal stem cells) assays showed that the new soluble peptides (Xaa = His, Arg) are cytocompatible. Gelation studies showed that all but acetylated-Ile-Val-Arg could gel under physiological conditions. Longer peptidic backbones drive self-assembly more effectively as reflected in field emission scanning electron microscopy (FESEM) and circular dichroism spectroscopy studies. Rheological studies revealed that the resultant hydrogels have varying stiffness and yield stress, depending on the backbone and C-terminal residue. Visible spectroscopy-based elution studies with SMDs (naltrexone, methotrexate, doxorubicin) showed that besides the C-terminal residue, the shape of the SMD also determines the rate and extent of SMD elution. Based on the elution assays, infrared spectroscopy, and FESEM, we propose models for the peptide fibril-SMD interaction. Our findings highlight the importance of matching the molecular properties of the self-assembling peptide and SMD in order to achieve the desired SMD release profile. Self-healing hydrogels ; Peptide ; Tripeptide ; Chemistry ; Circular dichroism ; Residue (chemistry) ; Small molecule ; Acetylation ; Molecule ; Drug delivery ; Biophysics ; Combinatorial chemistry ; Biochemistry ; Polymer chemistry ; Organic chemistry Supramolecular Self-Assembly in Materials ; RNA Interference and Gene Delivery ; Polydiacetylene-based materials and applications
Authors: G.D. Soto | Cintia Meiorin | Daniel G. Actis | P. Mendoza Zélis | Oscar Moscoso Londoño | Diego Muraca | Mirna A. Mosiewicki | Norma E. Marcovich
Source: European Polymer Journal (article, 2018-08-27)
Field: Materials Science — Polymers and Plastics

Magnetic nanocomposites based on shape memory polyurethanes Superparamagnetism ; Materials science ; Nanocomposite ; Magnetization ; Magnetite ; Casting ; Composite material ; Polyurethane ; Small-angle X-ray scattering ; Composite number ; Magnetic nanoparticles ; Nanoparticle ; Magnetic field ; Nanotechnology ; Scattering ; Metallurgy Polymer composites and self-healing ; Transition Metal Oxide Nanomaterials ; Aerogels and thermal insulation
Authors: Benoît Jacques | M. Coincon | J. Sygusch
Source: Journal of Biological Chemistry (article, 2018-03-28)
Field: Materials Science — Materials Chemistry

Active site remodeling during the catalytic cycle in metal-dependent fructose-1,6-bisphosphate aldolases Crystal structures of two bacterial metal (Zn<sup>2+</sup>)-dependent d-fructose-1,6-bisphosphate (FBP) aldolases in complex with substrate, analogues, and triose-P reaction products were determined to 1.5-2.0 Å resolution. The ligand complexes cryotrapped in native or mutant <i>Helicobacter pylori</i> aldolase crystals enabled a novel mechanistic description of FBP C3-C4 bond cleavage. The reaction mechanism uses active site remodeling during the catalytic cycle, implicating relocation of the Zn<sup>2+</sup> cofactor that is mediated by conformational changes of active site loops. Substrate binding initiates conformational changes triggered upon P1 phosphate binding, which liberates the Zn<sup>2+</sup>-chelating His-180, allowing it to act as a general base for the proton abstraction at the FBP C4 hydroxyl group. A second zinc-chelating His-83 hydrogen bonds the substrate C4 hydroxyl group and assists cleavage by stabilizing the developing negative charge during proton abstraction. Cleavage is concerted with relocation of the metal cofactor from an interior to a surface-exposed site, thereby stabilizing the nascent enediolate form. Conserved residue Glu-142 is essential for protonation of the enediolate form prior to product release. A d-tagatose 1,6-bisphosphate enzymatic complex reveals how His-180-mediated proton abstraction controls stereospecificity of the cleavage reaction. Recognition and discrimination of the reaction products, dihydroxyacetone-P and d-glyceraldehyde 3-P, occurs via charged hydrogen bonds between hydroxyl groups of the triose-Ps and conserved residues, Asp-82 and Asp-255, respectively, and are crucial aspects of the enzyme's role in gluconeogenesis. Conformational changes in mobile loops β5-α7 and β6-α8 (containing catalytic residues Glu-142 and His-180, respectively) drive active site remodeling, enabling the relocation of the metal cofactor. Chemistry ; Stereochemistry ; Active site ; Aldolase A ; Substrate analog ; Protonation ; Catalytic cycle ; Enzyme ; Biochemistry Enzyme Structure and Function ; Microbial Metabolites in Food Biotechnology ; Plant nutrient uptake and metabolism
Authors: Rd Roro Altrista Yusrina Kharismi | Sutriyo Sutriyo S | Herman Suryadi
Source: Journal of Young Pharmacists (article, 2018-07-13)
Field: Materials Science — Biomaterials

Preparation and Characterization of Microcrystalline Cellulose Produced from Betung Bamboo (Dendrocalamus asper) through Acid Hydrolysis Published on:July 2018 Journal of Young Pharmacists, 2018; 10(2s):S79-S83 Original Article | doi:10.5530/jyp.2018.2s.15 Authors: Rd Roro Altrista Yusrina Kharismi, Sutriyo, Herman Suryadi Faculty of Pharmacy, Universitas INDONESIA. Abstract: Introduction: Microcrystalline cellulose (MCC) is an excipient used in food, cosmetics and pharmaceutical industries especially in the manufacture of tablet. Dendrocalamus asper (betung bamboo) contains high cellulose Microcrystalline cellulose ; Cellulose ; Excipient ; Angle of repose ; Materials science ; Hydrolysis ; Acid hydrolysis ; Chromatography ; Nuclear chemistry ; Chemistry ; Chemical engineering ; Organic chemistry ; Composite material Advanced Cellulose Research Studies ; Engineering and Technology Innovations
Authors: Gözde Barım | Sara R. Smock | Priscilla D. Antunez | Daniela Glaser | Richard L. Brutchey
Source: Nanoscale (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Phase control in the colloidal synthesis of well-defined nickel sulfide nanocrystals Morphologically well-defined colloidal nanocrystals of Ni3S4, NiS, Ni9S8, and Ni3S2 were independently prepared through a solution-phase synthesis using N,N'-disubstituted thioureas as the sulfur precursor. Synthetic control over phase and composition of the resulting colloidal nickel sulfide nanocrystals was achieved by primarily adjusting the reactivity of substituted thioureas as well as tuning the key reaction parameters of temperature and precursor ratio. In general, the more reactive N,N'-diphenyl thiourea yields more sulfur-rich phases (Ni3S4 and NiS) while less reactive N,N'-dibutyl thiourea yields sulfur-poor phases (Ni9S8 and Ni3S2). This phase control can be further tuned through the use of 1-dodecanethiol as an important secondary reactivity-directing agent. In the presence of 1-dodecanethiol, nanocrystals of more sulfur-deficient phases are prepared, while in the absence of 1-dodecanethiol, more sulfur-rich phases are prepared. Under the most sulfur-rich synthetic conditions (i.e., with N,N'-diphenyl thiourea and no thiol) a phase progression from Ni3S4 to the α-NiS and β-NiS phases was observed upon an increase in reaction temperature and sulfur-to-nickel precursor ratio. This study establishes, for the first time, a systematic evaluation of factors that simultaneously control the phase and yield well-defined nickel sulfide nanocrystals. Nickel sulfide ; Phase control ; Nickel ; Sulfide ; Nanocrystal ; Colloid ; Materials science ; Phase (matter) ; Nanotechnology ; Nanoparticle ; Chemical engineering ; Metallurgy ; Chemistry ; Organic chemistry ; Engineering Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Matthew P. Sullivan | Michél K. Nieuwoudt | Graham A. Bowmaker | Nelson Y. S. Lam | Dianna Truong | David C. Goldstone | Christian G. Hartinger
Source: Chemical Communications (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

Unexpected arene ligand exchange results in the oxidation of an organoruthenium anticancer agent: the first X-ray structure of a protein–Ru(carbene) adduct Correction for 'Unexpected arene ligand exchange results in the oxidation of an organoruthenium anticancer agent: the first X-ray structure of a protein-Ru(carbene) adduct' by Matthew P. Sullivan et al., Chem. Commun., 2018, 54, 6120-6123. Carbene ; Adduct ; Chemistry ; Ligand (biochemistry) ; Electron paramagnetic resonance ; Cleavage (geology) ; X-ray ; Ruthenium ; Stereochemistry ; Nuclear magnetic resonance spectroscopy ; Crystallography ; Medicinal chemistry ; Organic chemistry ; Catalysis ; Receptor ; Materials science ; Biochemistry N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Synthetic Organic Chemistry Methods ; Organometallic Complex Synthesis and Catalysis
Authors: Carsten Schmelter | Sebastian Funke | Jana Treml | Anja Beschnitt | Natarajan Perumal | Caroline Manicam | Norbert Pfeiffer | Franz H. Grus
Source: International Journal of Molecular Sciences (article, 2018-12-03)
Field: Chemistry — Spectroscopy

Comparison of Two Solid-Phase Extraction (SPE) Methods for the Identification and Quantification of Porcine Retinal Protein Markers by LC-MS/MS Proper sample preparation protocols represent a critical step for liquid chromatography-mass spectrometry (LC-MS)-based proteomic study designs and influence the speed, performance and automation of high-throughput data acquisition. The main objective of this study was to compare two commercial solid-phase extraction (SPE)-based sample preparation protocols (comprising SOLAµ<sup>TM</sup> HRP SPE spin plates from Thermo Fisher Scientific and ZIPTIP<sup>®</sup> C18 pipette tips from Merck Millipore) for analytical performance, reproducibility, and analysis speed. The house swine represents a promising animal model for studying human eye diseases including glaucoma and provides excellent requirements for the qualitative and quantitative MS-based comparison in terms of ocular proteomics. In total six technical replicates of two protein fractions [extracted with 0.1% dodecyl-ß-maltoside (DDM) or 1% trifluoroacetic acid (TFA)] of porcine retinal tissues were subjected to in-gel trypsin digestion and purified with both SPE-based workflows (<i>N</i> = 3) prior to LC-MS analysis. On average, 550 ± 70 proteins (1512 ± 199 peptides) and 305 ± 48 proteins (806 ± 144 peptides) were identified from DDM and TFA protein fractions, respectively, after ZIPTIP<sup>®</sup> C18 purification, and SOLAµ<sup>TM</sup> workflow resulted in the detection of 513 ± 55 proteins (1347 ± 180 peptides) and 300 ± 33 proteins (722 ± 87 peptides), respectively (FDR < 1%). Venn diagram analysis revealed an average overlap of 65 ± 2% (DDM fraction) and 69 ± 4% (TFA fraction) in protein identifications between both SPE-based methods. Quantitative analysis of 25 glaucoma-related protein markers also showed no significant differences (<i>P</i> > 0.05) regarding protein recovery between both SPE methods. However, only glaucoma-associated marker <i>MECP2</i> showed a significant (<i>P</i> = 0.02) higher abundance in ZIPTIP<sup>®</sup>-purified replicates in comparison to SOLAµ<sup>TM</sup>-treated study samples. Nevertheless, this result was not confirmed in the verification experiment using in-gel trypsin digestion of recombinant <i>MECP2</i> (<i>P</i> = 0.24). In conclusion, both SPE-based purification methods worked equally well in terms of analytical performance and reproducibility, whereas the analysis speed and the semi-automation of the SOLAµ<sup>TM</sup> spin plates workflow is much more convenient in comparison to the ZIPTIP<sup>®</sup> C18 method. Chromatography ; Solid phase extraction ; Sample preparation ; Proteomics ; Chemistry ; Mass spectrometry ; Quantitative proteomics ; Extraction (chemistry) ; Biochemistry Advanced Proteomics Techniques and Applications ; Identification and Quantification in Food ; Glaucoma and retinal disorders
Authors: Johannes Hachmann | Mohammad Atif Faiz Afzal | Mojtaba Haghighatlari | Yudhajit Pal
Source: Molecular Simulation (article, 2018-05-22)
Field: Materials Science — Materials Chemistry

Building and deploying a cyberinfrastructure for the data-driven design of chemical systems and the exploration of chemical space The use of modern data science has recently emerged as a promising new path to tackling the complex challenges involved in the creation of next-generation chemistry and materials. However, despite the appeal of this potentially transformative development, the chemistry community has yet to incorporate it as a central tool in every-day work. Our research program is designed to enable and advance this emerging research approach. It is centred around the creation of a software ecosystem that brings together physics-based modelling, high-throughput in silico screening and data analytics (i.e. the use of machine learning and informatics for the validation, mining and modelling of chemical data). This cyberinfrastructure is devised to offer a comprehensive set of data science techniques and tools as well as a general-purpose scope to make it as versatile and widely applicable as possible. It also emphasises user-friendliness to make it accessible to the community at large. It thus provides the means for the large-scale exploration of chemical space and for a better understanding of the hidden mechanisms that determine the properties of complex chemical systems. Such insights can dramatically accelerate, streamline and ultimately transform the way chemical research is conducted. Aside from serving as a production-level tool, our cyberinfrastructure is also designed to facilitate and assess methodological innovation. Both the software and method development work are driven by concrete molecular design problems, which also allow us to assess the efficacy of the overall cyberinfrastructure. Cyberinfrastructure ; Data science ; Computer science ; Chemical space ; Workflow ; Scope (computer science) ; Analytics ; Chemistry ; Drug discovery Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Frerich J. Keil
Source: Annual Review of Chemical and Biomolecular Engineering (review, 2018-06-07)
Field: Chemistry — Inorganic Chemistry

Molecular Modelling for Reactor Design Chemical reactor modelling based on insights and data on a molecular level has become reality over the last few years. Multiscale models describing elementary reaction steps and full microkinetic schemes, pore structures, multicomponent adsorption and diffusion inside pores, and entire reactors have been presented. Quantum mechanical (QM) approaches, molecular simulations (Monte Carlo and molecular dynamics), and continuum equations have been employed for this purpose. Some recent developments in these approaches are presented, in particular time-dependent QM methods, calculation of van der Waals forces, new approaches for force field generation, automatic setup of reaction schemes, and pore modelling. Multiscale simulations are discussed. Applications of these approaches to heterogeneous catalysis are demonstrated for examples that have found growing interest over the last few years, such as metal-support interactions, influence of pore geometry on reactions, noncovalent bonding, reaction dynamics, dynamic changes in catalyst nanoparticle structure, electrocatalysis, solvent effects in catalysis, and multiscale modelling. Multiscale modeling ; van der Waals force ; Molecular dynamics ; Catalysis ; Nanotechnology ; Chemistry ; Force field (fiction) ; Heterogeneous catalysis ; Electrocatalyst ; Chemical physics ; Statistical physics ; Materials science ; Computational chemistry ; Physics ; Molecule ; Physical chemistry Zeolite Catalysis and Synthesis ; Catalysis and Oxidation Reactions ; Catalysts for Methane Reforming