jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Alessandro Longo | Ewoud J. J. de Boed | Nisha Mammen | Marte van der Linden | Karoliina Honkala | Hannu Häkkinen | Petra E. de Jongh | Baira Donoeva
Source: Chemistry - A European Journal (article, 2020-03-27)
Field: Materials Science — Materials Chemistry

Towards Atomically Precise Supported Catalysts from Monolayer‐Protected Clusters: The Critical Role of the Support Controlling the size and uniformity of metal clusters with atomic precision is essential for fine-tuning their catalytic properties, however for clusters deposited on supports, such control is challenging. Here, by combining X-ray absorption spectroscopy and density functional theory calculations, it is shown that supports play a crucial role in the evolution of monolayer-protected clusters into catalysts. Based on the acidic nature of the support, cluster-support interactions lead either to fragmentation of the cluster into isolated Au-ligand species or ligand-free metallic Au<sup>0</sup> clusters. On Lewis acidic supports that bind metals strongly, the latter transformation occurs while preserving the original size of the metal cluster, as demonstrated for various Au<sub>n</sub> sizes. These findings underline the role of the support in the design of supported catalysts and represent an important step toward the synthesis of atomically precise supported nanomaterials with tailored physico-chemical properties. Monolayer ; Cluster (spacecraft) ; Nanomaterials ; Catalysis ; Density functional theory ; Chemical physics ; Cluster size ; Metal ; Nanotechnology ; Materials science ; Ligand (biochemistry) ; Fragmentation (computing) ; Chemistry ; Computational chemistry ; Electronic structure ; Computer science ; Organic chemistry Nanocluster Synthesis and Applications ; Quantum Dots Synthesis And Properties ; Catalytic Processes in Materials Science
Authors: Elisa Cepeda‐Pérez | David Doblas | Tobias Kraus | Niels de Jonge
Source: Science Advances (article, 2020-05-13)
Field: Materials Science — Materials Chemistry

Electron microscopy of nanoparticle superlattice formation at a solid-liquid interface in nonpolar liquids Nanoparticle superlattice films form at the solid-liquid interface and are important for mesoscale materials, but are notoriously difficult to analyze before they are fully dried. Here, the early stages of nanoparticle assembly were studied at solid-liquid interfaces using liquid-phase electron microscopy. Oleylamine-stabilized gold nanoparticles spontaneously formed thin layers on a silicon nitride (SiN) membrane window of the liquid enclosure. Dense packings of hexagonal symmetry were obtained for the first monolayer independent of the nonpolar solvent type. The second layer, however, exhibited geometries ranging from dense packing in a hexagonal honeycomb structure to quasi-crystalline particle arrangements depending on the dielectric constant of the liquid. The complex structures formed by the weaker interactions in the second particle layer were preserved, while the surface remained immersed in liquid. Fine-tuning the properties of the involved materials can thus be used to control the three-dimensional geometry of a superlattice including quasi-crystals. Superlattice ; Electron microscope ; Nanoparticle ; Materials science ; Microscopy ; Nanotechnology ; Chemical engineering ; Optoelectronics ; Optics ; Physics Quantum Dots Synthesis And Properties ; Iron oxide chemistry and applications ; nanoparticles nucleation surface interactions
Authors: Tristan Giraud | Sabine Bouguet‐Bonnet | Philippe Marchal | Guillaume Pickaert | Marie‐Christine Averlant‐Petit | Loïc Stefan
Source: Nanoscale (article, 2020-01-01)
Field: Materials Science — Biomaterials

Improving and fine-tuning the properties of peptide-based hydrogels <i>via</i> incorporation of peptide nucleic acids Peptide self-assemblies have attracted intense research interest over the last few decades thanks to their implications in key biological processes (e.g., amyloid formation) and their use in biotechnological and (bio)material fields. In particular, peptide-based hydrogels have been highly considered as high potential supramolecular materials in the biomedical domain and open new horizons in terms of applications. To further understand their self-assembly mechanisms and to optimize their properties, several strategies have been proposed with the modification of the constituting amino acid chains via, per se, the introduction of d-amino acids, halogenated amino acids, pseudopeptide bonds, or other chemical moieties. In this context, we report herein on the incorporation of DNA-nucleobases into their peptide nucleic acid (PNA) forms to develop a new series of hybrid nucleopeptides. Thus, depending on the nature of the nucleobase (i.e., thymine, cytosine, adenine or guanine), the physicochemical and mechanical properties of the resulting hydrogels can be significantly improved and fine-tuned with, for instance, drastic enhancements of both the gel stiffness (up to 70-fold) and the gel resistance to external stress (up to 40-fold), and the generation of both thermo-reversible and uncommon red-edge excitation shift (REES) properties. To decipher the actual role of each PNA moiety in the self-assembly processes, the induced modifications from the molecular to the macroscopic scales are studied thanks to the multiscale approach based on a large panel of analytical techniques (i.e., rheology, NMR relaxometry, TEM, thioflavin T assays, FTIR, CD, fluorescence, NMR chemical shift index). Thus, such a strategy provides new opportunities to adapt and fit hydrogel properties to the intended ones and pushes back the limits of supramolecular materials. Peptide ; Nucleic acid ; Self-healing hydrogels ; Self-assembling peptide ; Peptide nucleic acid ; Chemistry ; Combinatorial chemistry ; Nanotechnology ; Materials science ; Biochemistry ; Organic chemistry Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis ; Advanced biosensing and bioanalysis techniques
Authors: Emmanouil Vereroudakis | Minaspi Bantawa | René P. M. Lafleur | Daniele Parisi | Nicholas M. Matsumoto | Joris W. Peeters | Emanuela Del Gado | E. W. Meijer | Dimitris Vlassopoulos
Source: ACS Central Science (article, 2020-07-28)
Field: Chemistry — Organic Chemistry

Competitive Supramolecular Associations Mediate the Viscoelasticity of Binary Hydrogels Supramolecular polymers are known to form strong and resilient hydrogels which can take up large amounts of water while exhibiting ease of processing and self-healing. They also possess similarities with networks of biological macromolecules. The combination of these features makes supramolecular polymers ideal candidates for studying mechanisms and consequences of self-assembly, which are relevant to biological materials. At the same time, this renders investigations of mixed hydrogels based on different supramolecular compounds necessary, since this substantially widens their applicability. Here, we address unusual viscoelastic properties of a class of binary hydrogels made by mixing fibrillar supramolecular polymers that are formed from two compounds: 1,3,5-benzene-tricarboxamide decorated with aliphatic chains terminated by tetra(ethylene glycol) (BTA) and a 20 kg/mol telechelic poly(ethylene glycol) decorated with the same hydrogen bonding BTA motif on both ends (BTA-PEG-BTA). Using a suite of experimental and simulation techniques, we find that the respective single-compound-based supramolecular systems form very different networks which exhibit drastically different rheology. More strikingly, mixing the compounds results in a non-monotonic dependence of modulus and viscosity on composition, suggesting a competition between interactions of the two compounds, which can then be used to fine-tune the mechanical properties. Simulations offer insight into the nature of this competition and their remarkable qualitative agreement with the experimental results is promising for the design of mixed hydrogels with desired and tunable properties. Their combination with a sensitive dynamic probe (here rheology) offer a powerful toolbox to explore the unique properties of binary hydrogel mixtures. Self-healing hydrogels ; Supramolecular chemistry ; Supramolecular polymers ; Rheology ; Ethylene glycol ; Materials science ; Polymer ; Viscoelasticity ; Hydrogen bond ; Raft ; Nanotechnology ; Chemical engineering ; Chemical physics ; Polymer chemistry ; Molecule ; Chemistry ; Organic chemistry ; Composite material ; Polymerization Surfactants and Colloidal Systems ; Supramolecular Self-Assembly in Materials ; Hydrogels: synthesis, properties, applications
Authors: Celia Martinez de la Torre | Jasmine H. Grossman | Andrey A. Bobko | Margaret F. Bennewitz
Source: PLoS ONE (article, 2020-09-18)
Field: Materials Science — Biomaterials

Tuning the size and composition of manganese oxide nanoparticles through varying temperature ramp and aging time Manganese oxide (MnO) nanoparticles (NPs) can serve as robust pH-sensitive contrast agents for magnetic resonance imaging (MRI) due to Mn2+ release at low pH, which generates a ~30 fold change in T1 relaxivity. Strategies to control NP size, composition, and Mn2+ dissolution rates are essential to improve diagnostic performance of pH-responsive MnO NPs. We are the first to demonstrate that MnO NP size and composition can be tuned by the temperature ramping rate and aging time used during thermal decomposition of manganese(II) acetylacetonate. Two different temperature ramping rates (10°C/min and 20°C/min) were applied to reach 300°C and NPs were aged at that temperature for 5, 15, or 30 min. A faster ramping rate and shorter aging time produced the smallest NPs of ~23 nm. Shorter aging times created a mixture of MnO and Mn3O4 NPs, whereas longer aging times formed MnO. Our results indicate that a 20°C/min ramp rate with an aging time of 30 min was the ideal temperature condition to form the smallest pure MnO NPs of ~32 nm. However, Mn2+ dissolution rates at low pH were unaffected by synthesis conditions. Although Mn2+ production was high at pH 5 mimicking endosomes inside cells, minimal Mn2+ was released at pH 6.5 and 7.4, which mimic the tumor extracellular space and blood, respectively. To further elucidate the effects of NP composition and size on Mn2+ release and MRI contrast, the ideal MnO NP formulation (~32 nm) was compared with smaller MnO and Mn3O4 NPs. Small MnO NPs produced the highest amount of Mn2+ at acidic pH with maximum T1 MRI signal; Mn3O4 NPs generated the lowest MRI signal. MnO NPs encapsulated within poly(lactide-co-glycolide) (PLGA) retained significantly higher Mn2+ release and MRI signal compared to PLGA Mn3O4 NPs. Therefore, MnO instead of Mn3O4 should be targeted intracellularly to maximize MRI contrast. Manganese ; Dissolution ; Nanoparticle ; Composition (language) ; Chemistry ; Thermal decomposition ; Manganese oxide ; Particle size ; Chemical engineering ; Materials science ; Nanotechnology ; Organic chemistry ; Physical chemistry Nanoparticle-Based Drug Delivery ; Lanthanide and Transition Metal Complexes ; Nanocluster Synthesis and Applications
Authors: Petra Bombicz | Nóra V. May | Dániel Fegyverneki | Avirmed Saranchimeg | Laura Bereczki
Source: CrystEngComm (article, 2020-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

Methods for easy recognition of isostructurality – lab jack-like crystal structures of halogenated 2-phenylbenzimidazoles Easy recognition and numerical description of isostructurality; how different the similar structures can be; supramolecular aspects of isostructurality. Supramolecular chemistry ; Crystal structure ; Chemistry ; Crystallography Crystallography and molecular interactions ; Crystal structures of chemical compounds ; Crystallization and Solubility Studies
Authors: Figen Selli | Ümit Halis Erdoğan | Rudolf Hufenus | Edith Perret
Source: Polymer (article, 2020-08-03)
Field: Materials Science — Biomaterials

Mesophase in melt-spun poly(ϵ-caprolactone) filaments: Structure–mechanical property relationship Fine poly(ϵ-caprolactone) (PCL) filaments (diameter: 59–92 μm) were successfully melt-spun with modified drawing setups to prevent draw instabilities. Depending on the production parameters, different mechanical properties were obtained (tensile strength: 302–456 MPa, elongation at break: 69–88%). These variations are related to subtle structural differences, which we have analyzed with wide-angle x-ray diffraction (WAXD) and small-angle x-ray scattering (SAXS). SAXS was used to determine crystal widths and the spacing between crystals along the filament axis. Additionally, 2D WAXD patterns were simulated and WAXD profiles were fitted. The detailed 2D WAXD analysis revealed that a highly-oriented non-crystalline mesophase is present in drawn PCL filaments, which is most-likely situated in-between PCL crystals. A large amount of this mesophase (>16%), combined with high crystalline orientation and perfect crystals, led to higher tensile strength values. We also confirmed that PCL chains pack with non-planar chain conformations in the unit cell. Mesophase ; Small-angle X-ray scattering ; Materials science ; Ultimate tensile strength ; Caprolactone ; Protein filament ; Elongation ; Composite material ; Crystallography ; Scattering ; Crystal structure ; Liquid crystal ; Polymer ; Polymerization ; Optics ; Chemistry biodegradable polymer synthesis and properties ; Polymer crystallization and properties ; Electrospun Nanofibers in Biomedical Applications
Authors: Alessandro Cannavale
Source: Clean Technologies (article, 2020-11-20)
Field: Materials Science — Polymers and Plastics

Chromogenic Technologies for Energy Saving Chromogenic materials and devices include a wide range of technologies that are capable of changing their spectral properties according to specific external stimuli. Several studies have shown that chromogenics can be conveniently used in building façades in order to reduce energy consumption, with other significant effects. First of all, chromogenics influence the annual energy balance of a building, achieving significant reductions in consumption for HVAC and artificial lighting. In addition, these technologies potentially improve the indoor level of visual comfort, reducing the risks of glare and excessive lighting. This brief review points to a systematic discussion—although not exhaustive and mainly limited to recent results and investigations—of the main studies that deal with building-integrated chromogenics that have appeared, so far, in the scientific literature. Architectural engineering ; Computer science ; Energy consumption ; HVAC ; GLARE ; Risk analysis (engineering) ; Automotive engineering ; Engineering ; Air conditioning ; Business ; Mechanical engineering ; Electrical engineering ; Materials science Transition Metal Oxide Nanomaterials ; Color Science and Applications ; Impact of Light on Environment and Health
Authors: Fatemeh Hashemi | Fabio Grillo | Vikram R. Ravikumar | Dominik Benz | Ankit Shekhar | Matthew B. E. Griffiths | Seán T. Barry | J. Ruud van Ommen
Source: Nanoscale (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Thermal atomic layer deposition of gold nanoparticles: controlled growth and size selection for photocatalysis Gold nanoparticles have been extensively studied for their applications in catalysis. For Au nanoparticles to be catalytically active, controlling the particle size is crucial. Here we present a low temperature (105 °C) thermal atomic layer deposition approach for depositing gold nanoparticles on TiO2 with controlled size and loading using trimethylphosphino-trimethylgold(iii) and two co-reactants (ozone and water) in a fluidized bed reactor. We show that the exposure time of the precursors is a variable that can be used to decouple the Au particle size from the loading. Longer exposures of ozone narrow the particle size distribution, while longer exposures of water broaden it. By studying the photocatalytic activity of Au/TiO2 nanocomposites, we show how the ability to control particle size and loading independently can be used not only to enhance performance but also to investigate structure-property relationships. This study provides insights into the mechanism underlying the formation and evolution of Au nanoparticles prepared for the first time via vapor phase atomic layer deposition. Employing a vapor deposition technique for the synthesis of Au/TiO2 nanocomposites eliminates the shortcomings of conventional liquid-based processes opening up the possibility of highly controlled synthesis of materials at large scale. Materials science ; Atomic layer deposition ; Deposition (geology) ; Nanoparticle ; Layer (electronics) ; Photocatalysis ; Colloidal gold ; Nanotechnology ; Chemical engineering ; Thermal ; Layer by layer ; Catalysis ; Chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Gold and Silver Nanoparticles Synthesis and Applications ; Copper-based nanomaterials and applications
Authors: Л. Л. Вовченко | L. Yu. Matzui | V. V. Oliynyk | Yurii Milovanov | Yevgen Mamunya | Nadezhda Volynets | Artyom Plyushch | P. Kuzhir
Source: Materials (article, 2020-03-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Polyethylene Composites with Segregated Carbon Nanotubes Network: Low Frequency Plasmons and High Electromagnetic Interference Shielding Efficiency Polyethylene (PE) based composites with segregated carbon nanotubes (CNTs) network was successfully prepared by hot compressing of a mechanical mixture of PE and CNT powders. Through comparison with a composite comprising randomly distributed carbon nanotubes of the same concentration, we prove that namely the segregated CNT network is responsible for the excellent electrical properties, i.e. 10<sup>-1</sup> S/m at 0.5-1% and 10 S/m at 6-12% of CNT. The investigation of the complex impedance in the frequency range 1 kHz-2 MHz shows that the sign of real part of the dielectric permittivity changes from positive to negative in electrically percolated composites indicating metal-like behavior of CNT segregated network. The obtained negative permittivity and AC conductivity behavior versus frequency for high CNT content (3%-12%) are described by the Drude model. At the same time, in contrast to reflective metals, high electromagnetic shielding efficiency of fabricated PE composites in the frequency range 40-60 GHz, i.e. close to 100% at 1 mm thick sample, was due to absorption coursed by multiple reflection on every PE-CNT segregated network interface followed by electromagnetic radiation absorbed in each isolated PE granule surrounded by conductive CNT shells. Materials science ; Carbon nanotube ; Composite material ; Electromagnetic shielding ; Permittivity ; Drude model ; Polyethylene ; Reflection loss ; Electromagnetic radiation ; Dielectric ; Composite number ; Absorption (acoustics) ; Electrical conductor ; Nanocomposite ; Optoelectronics ; Optics Electromagnetic wave absorption materials ; Dielectric materials and actuators ; Natural Fiber Reinforced Composites
Authors: Mi Yang | Francesca Petralia | Zhi Li | Hongyang Li | Weiping Ma | Xiaoyu Song | Sunkyu Kim | Heewon Lee | Han Yu | Bora Lee | Seohui Bae | Eunji Heo | Jan Kaczmarczyk | Piotr Stępniak | Michał Warchoł | Thomas Yu | Anna Calinawan | Paul C. Boutros | Samuel Payne | Boris Reva | Tunde Aderinwale | Ebrahim Afyounian | Piyush Agrawal | Mehreen Ali | Alicia Amadoz | Francisco Azuaje | John A. Bachman | Sherry Bhalla | José Carbonell‐Caballero | Priyanka Chakraborty | Kumardeep Chaudhary | Yong-Hwa Choi | Yoonjung Choi | Cankut Çubuk | Sandeep Kumar Dhanda | Joaquı́n Dopazo | Laura L. Elo | Ábel Fóthi | Olivier Gevaert | Kirsi J. Granberg | Russell Greiner | Marta R. Hidalgo | Vivek Jayaswal | Hwisang Jeon | Minji Jeon | Sunil V. Kalmady | Yasuhiro Kambara | Jaewoo Kang | Keunsoo Kang | Tony Kaoma | Harpreet Kaur | Hilal Kazan | Devishi Kesar | Juha Kesseli | Daehan Kim | Keonwoo Kim | Sang‐Yoon Kim | Sajal Kumar | Yunpeng Liu | Roland Luethy | Swapnil Mahajan | Mehrad Mahmoudian | Arnaud Muller | Petr V. Nazarov | Hien Nguyen | Matti Nykter | Shujiro Okuda | Sung Soo Park | Gajendra P. S. Raghava | Jagath C. Rajapakse | Tommi Rantapero | Hobin Ryu | Francisco Salavert | Sohrab Saraei | Ruby Sharma | Ari Siitonen | Artem Sokolov | Kartik Subramanian | Veronika Suni | Tomi Suomi | Léon-Charles Tranchevent | Salman Sadullah Usmani | Tommi Välikangas | Roberto de la Vega | Hua Zhong | Emily S. Boja | Henry Rodriguez | Gustavo Stolovitzky | Yuanfang Guan | Pei Wang | David Fenyö | Julio Sáez-Rodríguez
Source: Cell Systems (article, 2020-07-24)
Field: Chemistry — Spectroscopy

Community Assessment of the Predictability of Cancer Protein and Phosphoprotein Levels from Genomics and Transcriptomics Cancer is driven by genomic alterations, but the processes causing this disease are largely performed by proteins. However, proteins are harder and more expensive to measure than genes and transcripts. To catalyze developments of methods to infer protein levels from other omics measurements, we leveraged crowdsourcing via the NCI-CPTAC DREAM proteogenomic challenge. We asked for methods to predict protein and phosphorylation levels from genomic and transcriptomic data in cancer patients. The best performance was achieved by an ensemble of models, including as predictors transcript level of the corresponding genes, interaction between genes, conservation across tumor types, and phosphosite proximity for phosphorylation prediction. Proteins from metabolic pathways and complexes were the best and worst predicted, respectively. The performance of even the best-performing model was modest, suggesting that many proteins are strongly regulated through translational control and degradation. Our results set a reference for the limitations of computational inference in proteogenomics. A record of this paper's transparent peer review process is included in the Supplemental Information. Predictability ; Phosphoprotein ; Genomics ; Transcriptome ; Biology ; Computational biology ; Genetics ; Gene ; Genome ; Gene expression ; Statistics ; Mathematics Advanced Proteomics Techniques and Applications ; Bioinformatics and Genomic Networks ; RNA modifications and cancer
Authors: Alain C. Vaucher | Federico Zipoli | Joppe Geluykens | Vishnu H Nair | Philippe Schwaller | Teodoro Laino
Source: ChemRxiv (preprint, 2020-04-09)
Field: Materials Science — Materials Chemistry

Automated Extraction of Chemical Synthesis Actions from Experimental Procedures Experimental procedures for chemical synthesis are commonly reported in prose in patents or in the scientific literature. The automatic extraction of the details necessary to reproduce and validate a synthesis in a chemical laboratory is quite often a tedious task, requiring extensive human intervention. We present a method to convert unstructured experimental procedures written in English to structured synthetic steps (action sequences) reflecting all the operations needed to successfully conduct the corresponding chemical reactions. To achieve this, we design a set of synthesis actions with predefined properties and a deep-learning sequence to sequence model based on the transformer architecture to convert experimental procedures to action sequences. The model is pretrained on vast amounts of data generated automatically with a custom rule-based natural language processing approach and refined on a smaller set of manually annotated samples. Predictions on our test set resulted in a perfect (100%) match of the action sequence for 60.8% of sentences, a 90% match for 71.3% of sentences, and a 75% match for 82.4% of sentences. Computer science ; Transformer ; Sequence (biology) ; Natural language processing ; Set (abstract data type) ; Artificial intelligence ; Test set ; Task (project management) ; Sequence labeling ; Action (physics) ; Programming language ; Chemistry ; Engineering Machine Learning in Materials Science ; Advanced Text Analysis Techniques ; Software Engineering Research