jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Julie Gaubert-Boussarie | Soizic Prado | Cédric Hubas
Source: Frontiers in Marine Science (article, 2020-04-22)
Field: Materials Science — Biomaterials

An Untargeted Metabolomic Approach for Microphytobenthic Biofilms in Intertidal Mudflats Microphytobenthic (MPB) biofilms in intertidal muddy sediments play important ecological functions in coastal ecosystems. These biofilms are mainly composed of epipelic diatoms but also prokaryotes, with a dominance of bacteria, which excrete diverse extracellular polymeric substances (EPS) according to their environment. While numerous studies have investigated the main components of these EPS matrices via traditional colorimetric assays, their fine composition, notably in specialized metabolites, is still largely unknown. A better chemical characterization of these MPB biofilms is necessary, especially regarding the numerous functions their chemical components play for microorganisms (e.g. motility, cell protection, defense mechanisms, chemical communication), but also for coastal systems (e.g. primary production, sediment stabilization, larval settlement of some invertebrates with high economical value). An alternative approach to traditional analyses is the use of untargeted metabolomic techniques, which have not yet been applied to such MPB biofilms. The objectives of the present study were to (a) propose a protocol for metabolic fingerprinting by LC-MS and GC-MS for metabolites analysis in polar and non-polar fractions in MPB biofilms extracted from mudflat sediment and to (b) apply this protocol to a case study: the effect of light exposure on the metabolomic fingerprint of the MPB biofilm community. We compared three extraction methods using different mixes of solvents and selected a methanol/chloroform mix (1:1), which gave better results for both techniques and fractions. We then applied the selected protocol to our case study using a short-term light exposure experiment in aquaria (7 days). The present study is the first using a detailed untargeted metabolomic approach on MPB biofilms from mudflat sediment and will provide a solid baseline for further work in this area Biofilm ; Metabolomics ; Intertidal zone ; Extracellular polymeric substance ; Biology ; Dominance (genetics) ; Environmental chemistry ; Ecology ; Chemistry ; Bacteria ; Bioinformatics ; Biochemistry Diatoms and Algae Research ; Marine Biology and Environmental Chemistry ; Marine Biology and Ecology Research
Authors: Hiroki Fujisawa | Meguya Ryu | Stefan Lundgaard | Denver P. Linklater | Elena P. Ivanova | Yoshiaki Nishijima | Saulius Juodkazis | Junko Morikawa
Source: Micromachines (article, 2020-07-29)
Field: Materials Science — Materials Chemistry

Direct Measurement of Temperature Diffusivity of Nanocellulose-Doped Biodegradable Composite Films The thermal properties of novel nanomaterials play a significant role in determining the performance of the material in technological applications. Herein, direct measurement of the temperature diffusivity of nanocellulose-doped starch-polyurethane nanocomposite films was carried out by the micro-contact method. Polymer films containing up to 2 wt%. of nanocellulose were synthesised by a simple chemical process and are biodegradable. Films of a high optical transmittance T≈80% (for a 200 μm thick film), which were up to 44% crystalline, were characterised. Two different modalities of temperature diffusivity based on (1) a resistance change and (2) micro-thermocouple detected voltage modulation caused by the heat wave, were used for the polymer films with cross sections of ∼100 μm thickness. Twice different in-plane α‖ and out-of-plane α⟂ temperature diffusivities were directly determined with high fidelity: α‖=2.12×10-7 m2/s and α⟂=1.13×10-7 m2/s. This work provides an example of a direct contact measurement of thermal properties of nanocellulose composite biodegradable polymer films. The thermal diffusivity, which is usually high in strongly interconnected networks and crystals, was investigated for the first time in this polymer nanocomposite. Materials science ; Nanocellulose ; Thermal diffusivity ; Nanocomposite ; Composite material ; Polymer ; Composite number ; Polymer nanocomposite ; Nanomaterials ; Transmittance ; Nanotechnology ; Chemical engineering ; Optoelectronics ; Cellulose Thermal properties of materials ; Adhesion, Friction, and Surface Interactions ; Surface Roughness and Optical Measurements
Authors: Fred P. M. Jjunju | Deidre E. Damon | David Romero-Perez | Iain S. Young | Ryan J. Ward | Alan Marshall | Simon Maher | Abraham K. Badu‐Tawiah
Source: Scientific Reports (article, 2020-07-01)
Field: Chemistry — Spectroscopy

Analysis of non-conjugated steroids in water using paper spray mass spectrometry A novel strategy for the direct analysis of non-conjugated steroids in water using paper spray mass spectrometry (PS-MS) has been developed. PS-MS was used in the identification and quantification of non-conjugated (free) steroids in fish tank water samples. Data shown herein indicates that individual amounts of free steroids can be detected in aqua as low as; 0.17 ng/µL, 0.039 ng/µL, 0.43 ng/µL, 0.0076 ng/µL for aldosterone, corticosterone, cortisol, and β-estrone, respectively, and with an average relative standard deviation of ca. < 10% in the positive ion mode using PS-MS/MS. Direct detection of free steroids in a raw water mixture, from aquaculture, without prior sample preparation is demonstrated. The presence of free steroids released in fish water samples was confirmed via tandem mass spectrometry using collision-induced dissociation. This approach shows promise for rapid and direct water quality monitoring to provide a holistic assessment of non-conjugated steroids in aqua. Chemistry ; Conjugated system ; Chromatography ; Mass spectrometry ; Tandem mass spectrometry ; Steroid ; Biochemistry ; Organic chemistry ; Hormone ; Polymer Mass Spectrometry Techniques and Applications ; Ion-surface interactions and analysis ; Analytical chemistry methods development
Authors: Kristen Kaasbjerg
Source: Physical review. B./Physical review. B (article, 2020-01-31)
Field: Materials Science — Materials Chemistry

Atomistic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>T</mml:mi></mml:math>-matrix theory of disordered two-dimensional materials: Bound states, spectral properties, quasiparticle scattering, and transport In this work, we present an atomistic first-principles framework for modeling the low-temperature electronic and transport properties of disordered two-dimensional (2D) materials with randomly distributed point defects (impurities). The method is based on the $T$-matrix formalism in combination with realistic density-functional theory descriptions of the defects and their scattering matrix elements. From the $T$-matrix approximations to the disorder-averaged Green's function and the collision integral in the Boltzmann transport equation, the method allows calculations of, e.g., the density of states including contributions from bound defect states, the quasiparticle spectrum and the spectral linewidth (scattering rate), and the conductivity/mobility of disordered 2D materials. We demonstrate the method by examining these quantities in monolayers of the archetypal 2D materials graphene and transition metal dichalcogenides contaminated with vacancy defects and substitutional impurity atoms. By comparing the Born and $T$-matrix approximations, we also demonstrate a strong breakdown of the Born approximation for defects in 2D materials manifested in a pronounced renormalization of, e.g., the scattering rate by the higher-order $T$-matrix method. As the $T$-matrix approximation is essentially exact for dilute disorder, i.e., low defect concentrations (${c}_{\text{dis}}\ensuremath{\ll}1$) or density (${n}_{\text{dis}}\ensuremath{\ll}{A}_{\text{cell}}^{\ensuremath{-}1}$ where ${A}_{\text{cell}}$ is the unit-cell area), our first-principles method provides an excellent framework for modeling the properties of disordered 2D materials with defect concentrations relevant for devices. Quasiparticle ; Matrix (chemical analysis) ; Scattering ; Physics ; Mathematics ; Combinatorics ; Quantum mechanics ; Materials science Graphene research and applications ; 2D Materials and Applications ; Topological Materials and Phenomena
Authors: Parteek Prasher | Mousmee Sharma | Flavia C. Zacconi | Gaurav Gupta | Alaa A. A. Aljabali | Vijay Mishra | Murtaza M. Tambuwala | Deepak N. Kapoor | Poonam Negi | Terezinha de Jesus Andreoli Pinto | Inderbir Singh | Dinesh Kumar Chellappan | Kamal Dua
Source: Current Organic Chemistry (review, 2020-08-26)
Field: Chemistry — Organic Chemistry

Synthesis and Anticancer Properties of ‘<i>Azole</i>’ Based Chemotherapeutics as Emerging Chemical Moieties: A Comprehensive Review Azole frameworks serve as privileged scaffolds in the contemporary drug design paradigm owing to their unique physicochemical profile that promotes the development of highly selective, physiological benevolent chemotherapeutics. Several azole nuclei function as bioisostere in medicinal chemistry and prompt the development of tailored therapeutics for targeting the desired biological entities. Besides, the azole scaffold forms an integral part in the advanced drug designing methodologies, such as target template insitu drug synthesis, that assists in rapid identification of the hit molecules form a diverse pool of leads; and direct biomolecule-drug conjugation, along with bioorthogonal strategies that ensure localization, and superior target specificity of the directed therapeutic. Lastly, the structural diversity of azole framework and high yielding click synthetic methods provide a comprehensive Structure-Activity Relationship analysis for design optimization of the potential drug molecules by fine-tuning the placement of different substituents critical for the activity. This review provides a comprehensive analysis of the synthesis and anticancer potential of azole based chemotherapeutics. Azole ; Chemistry ; Bioorthogonal chemistry ; Combinatorial chemistry ; Pharmacophore ; Computational biology ; Drug ; Function (biology) ; Small molecule ; Drug discovery ; Click chemistry ; Pharmacology ; Antifungal ; Stereochemistry ; Biochemistry Click Chemistry and Applications ; Synthesis and biological activity ; Synthesis and Biological Evaluation
Authors: Jing Wang | Sen Ye | Xiang Liu | Teck‐Peng Loh
Source: ACS Sustainable Chemistry & Engineering (article, 2020-10-16)
Field: Chemistry — Inorganic Chemistry

Hydrazine as Facile Nitrogen Source for Direct Synthesis of Amines over a Supported Pt Catalyst Facile preparation of secondary amines from alcohols or aldehydes is achieved by using the hydrazine (N2H4) as an easy-to-handle nitrogen source. The anatase titania-supported Pt (Pt/TiO2-A) is discovered to be an efficient catalyst to enable the first alcohols/aldehydes to amines conversion with N2H4 as the only nitrogen and hydrogen source without any additional base or additives. Mechanistic studies suggest that this alcohol-to-amine transformation proceeds by the sequential alcohol dehydrogenation, aldehyde-N2H4 condensation, azine reduction, imine formation, and reduction processes in one pot. As N2H4 is a strong nucleophile that readily reacts with aldehyde, the unique catalytic property of Pt/TiO2-A ensures the high selectivity of amine products by providing multifunctional active sites for dehydrogenation and multiple reductions. This study highlights the considerable potential of hydrazine in direct synthesis of nitrogen-containing fine chemicals with a fine-tuned heterogeneous Pt catalyst, which is safe, green, and easy to handle. Catalysis ; Chemistry ; Dehydrogenation ; Hydrazine (antidepressant) ; Aldehyde ; Amine gas treating ; Nucleophile ; Imine ; Alcohol ; Selectivity ; Reducing agent ; Organic chemistry ; Azine ; Combinatorial chemistry Asymmetric Hydrogenation and Catalysis ; Nanomaterials for catalytic reactions ; Carbon dioxide utilization in catalysis
Authors: Aiswarya Pradeepkumar | D. Kurt Gaskill | Francesca Iacopi
Source: Applied Sciences (review, 2020-06-24)
Field: Materials Science — Materials Chemistry

Electronic and Transport Properties of Epitaxial Graphene on SiC and 3C-SiC/Si: A Review The electronic and transport properties of epitaxial graphene are dominated by the interactions the material makes with its surroundings. Based on the transport properties of epitaxial graphene on SiC and 3C-SiC/Si substrates reported in the literature, we emphasize that the graphene interfaces formed between the active material and its environment are of paramount importance, and how interface modifications enable the fine-tuning of the transport properties of graphene. This review provides a renewed attention on the understanding and engineering of epitaxial graphene interfaces for integrated electronics and photonics applications. Graphene ; Materials science ; Epitaxy ; Nanotechnology ; Electronics ; Optoelectronics ; Engineering ; Electrical engineering ; Layer (electronics) Graphene research and applications ; Graphene and Nanomaterials Applications ; Advancements in Battery Materials
Authors: Joscha Kruse | Stefan Merkens | Andrey Chuvilin | Marek Grzelczak
Source: ACS Applied Nano Materials (article, 2020-09-14)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Kinetic and Thermodynamic Hysteresis in Clustering of Gold Nanoparticles: Implications for Nanotransducers and Information Storage in Dynamic Systems Hysteresis is an essential attribute of many solid-state devices and biological processes, yet it is often overlooked in colloidal and soft-matter dynamic systems. Herein, we show that gold nanoparticles can remain dispersed or aggregated at the same temperature depending on the trajectory of applied stimulus, featuring hysteretic behavior. Aided by real-time analytics and fine-tuning of experimental parameters, such as salt concentration, nanoparticle diameter, and surface potential, we disentangled the kinetic (rate-dependent) and thermodynamic (rate-independent) components of hysteresis in cyclic clustering of nanoparticles. The hysteresis originates from the difference in the aggregation and disassembly temperatures. Our findings enrich the repertoire of the experimental framework with potential for stimuli-sensitive nanotransducers, information storage, switchable catalysis, or autonomous chemical networks with feedback loops. Hysteresis ; Nanoparticle ; Materials science ; Soft matter ; Cluster analysis ; Nanotechnology ; Colloid ; Biological system ; Colloidal gold ; Chemical physics ; Kinetic energy ; Computer science ; Chemistry ; Physics ; Artificial intelligence ; Physical chemistry ; Condensed matter physics Gold and Silver Nanoparticles Synthesis and Applications ; Spectroscopy and Quantum Chemical Studies ; Advanced Thermodynamics and Statistical Mechanics
Authors: Linan Xu | Yihe Zhang | Lili Feng | Xin Li | Qi An
Source: Advanced Materials Interfaces (article, 2020-04-02)
Field: Materials Science — Materials Chemistry

A Scalable Interfacial Engineering Strategy for a Finely Tunable, Homogeneous MoS<sub>2</sub>/rGO‐Based HER Catalytic Structure Abstract The electronic structures and catalytic efficacies of molybdenum disulfide (MoS 2 )‐based catalysts are sensitive to embedding environment. In order to develop a finely tunable strategy, a “layer‐by‐layer and Nafion capping” strategy for the scalable preparation of interfacial (MoS 2 )‐based catalytic structures is developed. The study shows that the assembly partner influences the electronic structures of the Zn&amp;N co‐doped (MoS 2 ) (Zn‐N‐(MoS 2 )) catalysts. Poly(allylamine hydrochloride) (PAH) decreases the catalytic efficacy, whereas when PAH‐rGO (rGO [reduced graphene oxide]) is the assembly partner, effective interfacial catalysts are prepared. The superior catalytic efficacy of (PAH‐rGO/Zn‐N‐(MoS 2 )) n can be attributed to the fact that rGO effectively activates the basal plane S 2− as the active sites. The catalytic efficacy of the multilayers at 16 assembly cycles due to a balance between the number of active sites and low resistance. After capping with Nafion layer, the interfacial catalysts exhibit high stability. Compared with the widely used drop‐casting methods, the layer‐by‐layer strategy possesses unique benefits, including fine‐tune the structures, free choice of the partner, and planar homogeneity. It is expected that this layer‐by‐layer catalyst immobilization strategy will benefit fundamental understandings regarding the finely controlled scalable interfacial immobilization of catalysts with superior efficacy, and assist in promoting the practical utilization of various catalysts. Catalysis ; Materials science ; Graphene ; Chemical engineering ; Molybdenum disulfide ; Nanotechnology ; Oxide ; Layer by layer ; Layer (electronics) ; Composite material ; Organic chemistry ; Chemistry ; Metallurgy MXene and MAX Phase Materials ; 2D Materials and Applications ; Advanced Photocatalysis Techniques
Authors: Anna Loiudice | Seryio Saris | Raffaella Buonsanti
Source: The Journal of Physical Chemistry Letters (article, 2020-04-15)
Field: Materials Science — Materials Chemistry

Tunable Metal Oxide Shell as a Spacer to Study Energy Transfer in Semiconductor Nanocrystals Colloidal semiconductor nanocrystals (NCs) are promising components in various optoelectronic and photocatalytic devices; however, the mechanism of energy transport in these materials remains to be further understood. Here, we investigate the distance dependence of the electronic interactions between CsPbBr<sub>3</sub> nanocubes and CdSe nanoplateles using an alumina (AlO<sub><i>x</i></sub>) shell as a spacer. CsPbBr<sub>3</sub>@AlO<sub><i>x</i></sub> core@shell NCs are synthesized via colloidal atomic layer deposition (c-ALD), which allows us to fine-tune the oxide thickness and thus the distance <i>d</i> between the two NCs. This versatile material platform shows that the electronic interactions between the CsPbBr<sub>3</sub> NCs and the CdSe nanoplatelets can be tuned from electron to energy transfer by increasing the shell thickness, whereas previous studies on the same system had been limited to the former. Considering the applicability of the c-ALD to different NCs, we suggest that metal oxide shell spacers synthesized by this approach can generally be used to study energy-transfer mechanisms at the nanoscale. Nanocrystal ; Materials science ; Oxide ; Semiconductor ; Atomic layer deposition ; Colloid ; Shell (structure) ; Metal ; Nanotechnology ; Electron transfer ; Nanoscopic scale ; Quantum dot ; Energy transfer ; Chemical engineering ; Layer (electronics) ; Optoelectronics ; Chemical physics ; Chemistry ; Physical chemistry ; Composite material ; Metallurgy Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Perovskite Materials and Applications
Authors: Vishwanath Hiremath | Bezawit T. Shiferraw | Jeong Gil Seo
Source: Journal of CO2 Utilization (article, 2020-08-31)
Field: Materials Science — Materials Chemistry

MgO insertion endowed strong basicity in mesoporous alumina framework and improved CO2 sorption capacity Mesoporous material ; Amorphous solid ; Materials science ; Sorption ; Chemical engineering ; Specific surface area ; Thermal stability ; Composite number ; Desorption ; Hydrothermal circulation ; Kinetics ; Nanotechnology ; Composite material ; Adsorption ; Chemistry ; Physical chemistry ; Crystallography ; Catalysis ; Organic chemistry Catalytic Processes in Materials Science ; Layered Double Hydroxides Synthesis and Applications ; Carbon Dioxide Capture Technologies
Authors: Sergio Gámez‐Valenzuela | Marcelo Echeverri | Berta Gómez‐Lor | José I. Martínez | M. Carmen Ruiz Delgado
Source: Journal of Materials Chemistry C (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

<i>In silico</i> design of 2D polymers containing truxene-based platforms: insights into their structural and electronic properties A total of 27 different 2D truxene-based polymers were theoretically investigated. Our results provide interesting guidelines to design novel 2D materials with applications ranging from sensing to photocatalysis or electronics. Materials science ; Polymer ; Electronics ; In silico ; Photocatalysis ; Nanotechnology ; Ranging ; Rational design ; Computer science ; Composite material ; Organic chemistry ; Physical chemistry ; Telecommunications ; Chemistry ; Catalysis Covalent Organic Framework Applications ; Luminescence and Fluorescent Materials ; Graphene research and applications
Authors: Marissa Baptista | Habib Joukhdar | Cesar R. Alcala‐Orozco | Kieran Lau | Shouyuan Jiang | Xiaolin Cui | Steven He | Fengying Tang | Céline Heu | Tim B. F. Woodfield | Khoon S. Lim | Jelena Rnjak‐Kovacina
Source: Biomaterials Science (article, 2020-01-01)
Field: Materials Science — Biomaterials

Silk fibroin photo-lyogels containing microchannels as a biomaterial platform for <i>in situ</i> tissue engineering The biophysical properties of biomaterials are key to directing the biological responses and biomaterial integration and function in in situ tissue engineering approaches. We present silk photo-lyogels, a biomaterial format fabricated using a new combinatorial approach involving photo-initiated crosslinking of silk fibroin via di-tyrosine bonds followed by lyophilization to generate 3D, porous lyogels showing physical properties distinct to those of lyophilized silk sponges or silk hydrogels. This fabrication approach allowed introduction of microchannels into 3D constructs via biofabrication approaches involving silk crosslinking around an array of 3D printed photocurable resin pillars to generate parallel channels or around a 3D printed sacrificial thermosensitive gel to generate interconnected channels in a rapid manner and without the need for chemical modification of silk fibroin. The presence of interconnected microchannels significantly improved migration of endothelial cells into 3D photo-lyogels in vitro, and tissue infiltration, photo-lyogel integration, and vascularization when implanted in vivo in a mouse subcutaneous model. Taken together, these findings demonstrate the feasibility and utility of a new combinatorial fabrication approach for generation of silk biomaterials that support cell interactions and implant integration for in situ tissue engineering approaches. Fibroin ; SILK ; Biomaterial ; In situ ; Tissue engineering ; Template ; Materials science ; Nanotechnology ; Chemistry ; Polymer science ; Biomedical engineering ; Composite material ; Engineering Silk-based biomaterials and applications ; Surface Modification and Superhydrophobicity ; Advanced Materials and Mechanics