jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Bjarke S. Jessen | Patrick R. Whelan | David M. A. Mackenzie | Birong Luo | Joachim Dahl Thomsen | Lene Gammelgaard | Timothy J. Booth | Peter Bøggild
Source: Scientific Reports (article, 2018-04-17)
Field: Materials Science — Materials Chemistry

Quantitative optical mapping of two-dimensional materials The pace of two-dimensional materials (2DM) research has been greatly accelerated by the ability to identify exfoliated thicknesses down to a monolayer from their optical contrast. Since this process requires time-consuming and error-prone manual assignment to avoid false-positives from image features with similar contrast, efforts towards fast and reliable automated assignments schemes is essential. We show that by modelling the expected 2DM contrast in digitally captured images, we can automatically identify candidate regions of 2DM. More importantly, we show a computationally-light machine vision strategy for eliminating false-positives from this set of 2DM candidates through the combined use of binary thresholding, opening and closing filters, and shape-analysis from edge detection. Calculation of data pyramids for arbitrarily high-resolution optical coverage maps of two-dimensional materials produced in this way allows the real-time presentation and processing of this image data in a zoomable interface, enabling large datasets to be explored and analysed with ease. The result is that a standard optical microscope with CCD camera can be used as an analysis tool able to accurately determine the coverage, residue/contamination concentration, and layer number for a wide range of presented 2DMs. Computer science ; Computational biology ; Information retrieval ; Biology Graphene research and applications ; Laser-Ablation Synthesis of Nanoparticles ; Graphene and Nanomaterials Applications
Authors: Albert Gandioso | Marta Palau | Roger Bresolí‐Obach | Alex Galindo | Anna Rovira | Manel Bosch | Santi Nonell | Vicente Marchán
Source: The Journal of Organic Chemistry (article, 2018-08-31)
Field: Chemistry — Organic Chemistry

High Photostability in Nonconventional Coumarins with Far-Red/NIR Emission through Azetidinyl Substitution Replacement of electron-donating N,N-dialkyl groups with three- or four-membered cyclic amines (e.g., aziridine and azetidine, respectively) has been described as a promising approach to improve some of the drawbacks of conventional fluorophores, including low fluorescent quantum yields (Φ<sub>F</sub>) in polar solvents. In this work, we have explored the influence of azetidinyl substitution on nonconventional coumarin-based COUPY dyes. Two azetidine-containing scaffolds were first synthesized in four linear synthetic steps and easily transformed into far-red/NIR-emitting fluorophores through N-alkylation of the pyridine moiety. Azetidine introduction in COUPY dyes resulted in enlarged Stokes' shifts with respect to the N,N-dialkylamino-containing parent dyes, but the Φ<sub>F</sub> were not significantly modified in aqueous media, which is in contrast with previously reported observations in other fluorophores. However, azetidinyl substitution led to an unprecedented improvement in the photostability of COUPY dyes, and high cell permeability was retained since the fluorophores accumulated selectively in mitochondria and nucleoli of HeLa cells. Overall, our results provide valuable insights for the design and optimization of novel fluorophores operating in the far-red/NIR region, since we have demonstrated that three important parameters (Stokes' shifts, Φ<sub>F</sub>, and photostability) cannot be always simultaneously addressed by simply replacing a N,N-dialkylamino group with azetidine, at least in nonconventional coumarin-based fluorophores. Azetidine ; Fluorescence ; Chemistry ; Aziridine ; Nile red ; Pyridine ; Coumarin ; Moiety ; Photochemistry ; Aqueous solution ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Ring (chemistry) Click Chemistry and Applications ; Radical Photochemical Reactions ; Luminescence and Fluorescent Materials
Authors: Zi‐Ling Xue | Anibal J. Ramirez‐Cuesta | Craig M. Brown | Stuart Calder | Huibo Cao | Bryan C. Chakoumakos | Luke L. Daemen | Ashfia Huq | А. И. Колесников | Eugene Mamontov | A. Podlesnyak | Xiaoping Wang
Source: European Journal of Inorganic Chemistry (article, 2018-11-25)
Field: Chemistry — Inorganic Chemistry

Neutron Instruments for Research in Coordination Chemistry Neutron diffraction and spectroscopy offer unique insight into structures and properties of solids and molecular materials. All neutron instruments located at the various neutron sources are distinct, even if their designs are based on similar principles, and thus, they are usually less familiar to the community than commercial X-ray diffractometers and optical spectrometers. Major neutron instruments in the USA, which are open to scientists around the world, and examples of their use in coordination chemistry research are presented here, along with a list of similar instruments at main neutron facilities in other countries. The reader may easily and quickly find from this minireview an appropriate neutron instrument for research. The instruments include single-crystal and powder diffractometers to determine structures, inelastic neutron scattering (INS) spectrometers to probe magnetic and vibrational excitations, and quasielastic neutron scattering (QENS) spectrometers to study molecular dynamics such as methyl rotation on ligands. Key and unique features of the diffraction and neutron spectroscopy that are relevant to inorganic chemistry are reviewed. Neutron scattering ; Inelastic neutron scattering ; Chemistry ; Neutron diffraction ; Neutron spectroscopy ; Neutron ; Quasielastic neutron scattering ; Spectrometer ; Neutron reflectometry ; Neutron source ; Spectroscopy ; Small-angle neutron scattering ; Nuclear physics ; Crystallography ; Physics ; Crystal structure ; Optics Inorganic Fluorides and Related Compounds ; Advanced Condensed Matter Physics ; Nuclear Physics and Applications
Authors: David R. Needell | Ognjen Ilic | Colton R. Bukowsky | Zach Nett | Lu Xu | Junwen He | Haley Bauser | Benjamin G. Lee | John F. Geisz | Ralph G. Nuzzo | A. Paul Alivisatos | Harry A. Atwater
Source: IEEE Journal of Photovoltaics (article, 2018-08-10)
Field: Chemistry — Physical and Theoretical Chemistry

Design Criteria for Micro-Optical Tandem Luminescent Solar Concentrators Luminescent solar concentrators (LSCs) harness light generated by luminophores embedded in a light-trapping waveguide to concentrate onto smaller cells. LSCs can absorb both direct and diffuse sunlight, and thus can operate as flat plate receivers at a fixed tilt and with a conventional module form factor. However, current LSCs experience significant power loss through parasitic luminophore absorption and incomplete light trapping by the optical waveguide. Here, we introduce a tandem LSC device architecture that overcomes both of these limitations, consisting of a poly(lauryl methacrylate) polymer layer with embedded cadmium selenide core, cadmium sulfide shell (CdSe/CdS) quantum dot (QD) luminophores and an InGaP microcell array, which serves as high bandgap absorbers on the top of a conventional Si photovoltaic. We investigate the design space for a tandem LSC, using experimentally measured performance parameters for key components, including the InGaP microcell array, CdSe/CdS QDs, and spectrally selective waveguide filters. Using a Monte Carlo ray-tracing model, we compute the power conversion efficiency for a tandem LSC module with these components to be 29.4% under partially diffuse illumination conditions. These results indicate that a tandem LSC-on-Si architecture could significantly improve upon the efficiency of a conventional Si photovoltaic cell. Materials science ; Tandem ; Optoelectronics ; Absorption (acoustics) ; Optics ; Waveguide ; Photovoltaic system ; Luminescence Photochemistry and Electron Transfer Studies ; Organic Light-Emitting Diodes Research ; solar cell performance optimization
Authors: Laidson P. Gomes | Hiléia K.S. Souza | José M. Campiña | Paula B. Andrade | Fernando Silva | Maria P. Gonçalves | Vânia Margaret Flosi Paschoalin
Source: Molecules (article, 2018-12-31)
Field: Materials Science — Biomaterials

Edible Chitosan Films and Their Nanosized Counterparts Exhibit Antimicrobial Activity and Enhanced Mechanical and Barrier Properties Chitosan and chitosan-nanoparticles were combined to prepare biobased and unplasticized film blends displaying antimicrobial activity. Nanosized chitosans obtained by sonication for 5, 15, or 30 min were combined with chitosan at 3:7, 1:1, and 7:3 ratios, in order to adjust blend film mechanical properties and permeability. The incorporation of nanosized chitosans led to improvements in the interfacial interaction with chitosan microfibers, positively affecting film mechanical strength and stiffness, evidenced by scanning electron microscopy. Nanosized or blend chitosan film sensitivity to moisture was significantly decreased with the drop in biocomposite molecular masses, evidenced by increased water solubility and decreased water vapor permeability. Nanosized and chitosan interactions gave rise to light biobased films presenting discrete opacity and color changes, since red-green and yellow-blue colorations were affected. All chitosan blend films exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. The performance of green unplasticized chitosan blend films displaying diverse morphologies has, thus, been proven as a potential step towards the design of nontoxic food packaging biobased films, protecting against spoilage microorganisms, while also minimizing environmental impacts. Chitosan ; Materials science ; Chemical engineering ; Antimicrobial ; Solubility ; Food packaging ; Epichlorohydrin ; Composite material ; Chemistry ; Organic chemistry ; Food science Nanocomposite Films for Food Packaging ; Antimicrobial agents and applications ; Nanoparticles: synthesis and applications
Authors: Pere Ràfols | Dídac Vilalta | Sònia Torres | R. Calavia | Bram Heijs | Liam A. McDonnell | J. Brezmes | Esteban del Castillo | Óscar Yanes | Noelia Ramírez | Xavier Correig
Source: PLoS ONE (article, 2018-12-12)
Field: Chemistry — Spectroscopy

Assessing the potential of sputtered gold nanolayers in mass spectrometry imaging for metabolomics applications Mass spectrometry imaging (MSI) is a molecular imaging technique that maps the distribution of molecules in biological tissues with high spatial resolution. The most widely used MSI modality is matrix-assisted laser desorption/ionization (MALDI), mainly due to the large variety of analyte classes amenable for MALDI analysis. However, the organic matrices used in classical MALDI may impact the quality of the molecular images due to limited lateral resolution and strong background noise in the low mass range, hindering its use in metabolomics. Here we present a matrix-free laser desorption/ionization (LDI) technique based on the deposition of gold nanolayers on tissue sections by means of sputter-coating. This gold coating method is quick, fully automated, reproducible, and allows growing highly controlled gold nanolayers, necessary for high quality and high resolution MS image acquisition. The performance of the developed method has been tested through the acquisition of MS images of brain tissues. The obtained spectra showed a high number of MS peaks in the low mass region (m/z below 1000 Da) with few background peaks, demonstrating the ability of the sputtered gold nanolayers of promoting the desorption/ionization of a wide range of metabolites. These results, together with the reliable MS spectrum calibration using gold peaks, make the developed method a valuable alternative for MSI applications. Mass spectrometry imaging ; Mass spectrometry ; MALDI imaging ; Materials science ; Analyte ; Colloidal gold ; Analytical Chemistry (journal) ; Matrix-assisted laser desorption/ionization ; Desorption ; Sputtering ; Chemistry ; Nanotechnology ; Nanoparticle ; Thin film ; Chromatography ; Adsorption Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Advanced Proteomics Techniques and Applications
Authors: David Clases | Stefanie Fingerhut | Astrid Jeibmann | Michael Sperling | Philip Doble | Uwe Kärst
Source: Journal of Trace Elements in Medicine and Biology (article, 2018-11-01)
Field: Materials Science — Materials Chemistry

LA-ICP-MS/MS improves limits of detection in elemental bioimaging of gadolinium deposition originating from MRI contrast agents in skin and brain tissues Gadolinium ; Chemistry ; Inductively coupled plasma mass spectrometry ; Mass spectrometry ; Magnetic resonance imaging ; Resolution (logic) ; Nuclear magnetic resonance ; Analytical Chemistry (journal) ; Chromatography ; Radiology ; Medicine Lanthanide and Transition Metal Complexes ; Radioactive element chemistry and processing ; Analytical chemistry methods development
Authors: Stephen W. C. Walker | Ahdia Anwar | Jarrod M. Psutka | Jeff Crouse | Chang Liu | J. C. Yves Le Blanc | Justin I. Montgomery | Gilles H. Goetz | John Janiszewski | J. Larry Campbell | W. Scott Hopkins
Source: Nature Communications (article, 2018-11-26)
Field: Chemistry — Spectroscopy

Determining molecular properties with differential mobility spectrometry and machine learning The fast and accurate determination of molecular properties is highly desirable for many facets of chemical research, particularly in drug discovery where pre-clinical assays play an important role in paring down large sets of drug candidates. Here, we present the use of supervised machine learning to treat differential mobility spectrometry - mass spectrometry data for ten topological classes of drug candidates. We demonstrate that the gas-phase clustering behavior probed in our experiments can be used to predict the candidates' condensed phase molecular properties, such as cell permeability, solubility, polar surface area, and water/octanol distribution coefficient. All of these measurements are performed in minutes and require mere nanograms of each drug examined. Moreover, by tuning gas temperature within the differential mobility spectrometer, one can fine tune the extent of ion-solvent clustering to separate subtly different molecular geometries and to discriminate molecules of very similar physicochemical properties. Differential (mechanical device) ; Mass spectrometry ; Computer science ; Chemistry ; Physics ; Chromatography Mass Spectrometry Techniques and Applications ; Analytical Chemistry and Chromatography ; Metabolomics and Mass Spectrometry Studies
Authors: Narendra Kumar | Padmini Rajagopalan | Praveen Pankajakshan | Arnab Bhattacharyya | Suchismita Sanyal | Janakiraman Balachandran | Umesh V. Waghmare
Source: Chemistry of Materials (article, 2018-12-10)
Field: Materials Science — Materials Chemistry

Machine Learning Constrained with Dimensional Analysis and Scaling Laws: Simple, Transferable, and Interpretable Models of Materials from Small Datasets Machine learning (ML) from materials databases can accelerate the design and discovery of new materials through the development of accurate, computationally inexpensive models to predict materials properties. These models in turn enable rapid screening of large materials search space. However, materials datasets describing functional properties are typically small, which creates challenges pertaining to interpretability and transferability when exploring them with conventional ML approaches. Further, correlations within the dataset can lead to instability (nonunique functional models relating inputs to outputs) and overfitting. In this work, we address these issues by developing a new approach, in which ML with the Bootstrapped projected gradient descent algorithm is constrained with Buckingham Pi theorem-based dimensional analysis and scaling laws of relationships between different input descriptors (properties). This constrained learning model enables us to learn from small data and develop predictive models that are accurate, computationally inexpensive, and physically interpretable. We demonstrate this approach by developing a simple model to predict the intrinsic dielectric breakdown field based on an available dataset of 82 compounds. Our approach is generic in nature and is expected to work effectively with other sparse materials datasets. Interpretability ; Overfitting ; Computer science ; Machine learning ; Artificial intelligence ; Simple (philosophy) ; Field (mathematics) ; Stability (learning theory) ; Mathematics ; Artificial neural network Machine Learning in Materials Science ; Computational Drug Discovery Methods ; X-ray Diffraction in Crystallography
Authors: Ravi Anant Kishore | Roop L. Mahajan | Shashank Priya
Source: Energies (article, 2018-08-24)
Field: Materials Science — Materials Chemistry

Combinatory Finite Element and Artificial Neural Network Model for Predicting Performance of Thermoelectric Generator Thermoelectric generators (TEGs) are rapidly becoming the mainstream technology for converting thermal energy into electrical energy. The rise in the continuous deployment of TEGs is related to advancements in materials, figure of merit, and methods for module manufacturing. However, rapid optimization techniques for TEGs have not kept pace with these advancements, which presents a challenge regarding tailoring the device architecture for varying operating conditions. Here, we address this challenge by providing artificial neural network (ANN) models that can predict TEG performance on demand. Out of the several ANN models considered for TEGs, the most efficient one consists of two hidden layers with six neurons in each layer. The model predicted TEG power with an accuracy of ±0.1 W, and TEG efficiency with an accuracy of ±0.2%. The trained ANN model required only 26.4 ms per data point for predicting TEG performance against the 6.0 minutes needed for the traditional numerical simulations. Thermoelectric generator ; Artificial neural network ; Computer science ; Generator (circuit theory) ; Software deployment ; Power (physics) ; Finite element method ; Automotive engineering ; Thermoelectric effect ; Artificial intelligence ; Engineering Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; 2D Materials and Applications
Authors: Yngve Ögren | Pál Tóth | Attila Garami | Alexey Sepman | Henrik Wiinikka
Source: Applied Energy (article, 2018-06-07)
Field: Chemistry — Analytical Chemistry

Development of a vision-based soft sensor for estimating equivalence ratio and major species concentration in entrained flow biomass gasification reactors Mean squared error ; Wood gas generator ; Pixel ; Combustion ; Image processing ; Mathematics ; Equivalence (formal languages) ; Combustor ; Statistics ; Biological system ; Artificial intelligence ; Computer science ; Engineering ; Chemistry ; Coal ; Image (mathematics) ; Waste management Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Advanced Chemical Sensor Technologies
Authors: Sharon E. Ashbrook | Paul Hodgkinson
Source: The Journal of Chemical Physics (article, 2018-07-23)
Field: Chemistry — Spectroscopy

Perspective: Current advances in solid-state NMR spectroscopy In contrast to the rapid and revolutionary impact of solution-state Nuclear Magnetic Resonance (NMR) on modern chemistry, the field of solid-state NMR has matured more slowly. This reflects the major technical challenges of much reduced spectral resolution and sensitivity in solid-state as compared to solution-state spectra, as well as the relative complexity of the solid state. In this perspective, we outline the technique developments that have pushed resolution to intrinsic limits and the approaches, including ongoing major developments in the field of Dynamic Nuclear Polarisation, that have enhanced spectral sensitivity. The information on local structure and dynamics that can be obtained using these gains in sensitivity and resolution is illustrated with a diverse range of examples from large biomolecules to energy materials and pharmaceuticals and from both ordered and highly disordered materials. We discuss how parallel developments in quantum chemical calculation, particularly density functional theory, have enabled experimental data to be translated directly into information on local structure and dynamics, giving rise to the developing field of "NMR crystallography." Solid-state nuclear magnetic resonance ; Nuclear magnetic resonance spectroscopy ; Spectroscopy ; Field (mathematics) ; Sensitivity (control systems) ; Biomolecule ; Resolution (logic) ; Solid-state ; Chemical physics ; Spectral resolution ; Chemistry ; Materials science ; Computational physics ; Nanotechnology ; Nuclear magnetic resonance ; Physics ; Computer science ; Spectral line ; Physical chemistry ; Mathematics ; Quantum mechanics Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; NMR spectroscopy and applications
Authors: Lucia Haverová | Renáta Oriňáková | Andrej Oriňák | Radka Gorejová | Matěj Baláž | Petr Vanýsek | Miriam Kupková | Monika Hrubovčáková | Pavol Mudroň | J Radoňák | Zuzana Orságová Králová | Andrea Morovská Turoňová
Source: Metals (article, 2018-06-28)
Field: Materials Science — Biomaterials

An In Vitro Corrosion Study of Open Cell Iron Structures with PEG Coating for Bone Replacement Applications Iron-based substrates with polyethylene glycol coating were prepared as possible materials for biodegradable orthopedic implants. Biodegradable materials that provide mechanical support of the diseased tissue at the time of implanting and then disappear gradually during the healing process are sometimes favored instead of permanent implants. The implant degradation rate should match the time of the tissue regrowth. In this work, the degradation behavior of iron-based foams was studied electrochemically during immersion tests in Hanks’ solution. The corrosion rate of the polyethylene glycol-coated samples increased and the corrosion potential shifted to more negative values. This indicates an enhanced degradation rate as compared to the uncoated material, fulfilling the goal of being able to tune the degradation rate. It is the interfacial interaction between the hydrophilic polymer layer and the iron surface that is responsible for the enhanced oxidation rate of iron. Coating ; Polyethylene glycol ; Corrosion ; Degradation (telecommunications) ; Materials science ; Polyethylene ; Polymer ; PEG ratio ; Layer (electronics) ; Surface modification ; Implant ; Polymer degradation ; Chemical engineering ; Composite material ; Metallurgy ; Biomedical engineering ; Surgery Magnesium Alloys: Properties and Applications ; Corrosion Behavior and Inhibition ; Orthopaedic implants and arthroplasty