jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tamsin O’Reilly | Kristina M. Holsgrove | Xinqiao Zhang | John J. R. Scott | Iaroslav Gaponenko | Praveen Kumar | Joshua Agar | Patrycja Paruch | Miryam Arredondo
Source: Advanced Science (article, 2023-08-21)
Field: Materials Science — Materials Chemistry

The Effect of Chemical Environment and Temperature on the Domain Structure of Free‐Standing BaTiO<sub>3</sub> via In Situ STEM Ferroelectrics, due to their polar nature and reversible switching, can be used to dynamically control surface chemistry for catalysis, chemical switching, and other applications such as water splitting. However, this is a complex phenomenon where ferroelectric domain orientation and switching are intimately linked to surface charges. In this work, the temperature-induced domain behavior of ferroelectric-ferroelastic domains in free-standing BaTiO<sub>3</sub> films under different gas environments, including vacuum and oxygen-rich, is studied by in situ scanning transmission electron microscopy (STEM). An automated pathway to statistically disentangle and detect domain structure transformations using deep autoencoders, providing a pathway towards real-time analysis is also established. These results show a clear difference in the temperature at which phase transition occurs and the domain behavior between various environments, with a peculiar domain reconfiguration at low temperatures, from a-c to a-a at ≈60 °C. The vacuum environment exhibits a rich domain structure, while under the oxidizing environment, the domain structure is largely suppressed. The direct visualization provided by in situ gas and heating STEM allows to investigate the influence of external variables such as gas, pressure, and temperature, on oxide surfaces in a dynamic manner, providing invaluable insights into the intricate surface-screening mechanisms in ferroelectrics. Ferroelectricity ; Phase transition ; Chemical physics ; Materials science ; Oxide ; In situ ; Scanning transmission electron microscopy ; Oxidizing agent ; Transmission electron microscopy ; Chemistry ; Nanotechnology ; Dielectric ; Optoelectronics ; Condensed matter physics ; Physics Ferroelectric and Piezoelectric Materials ; Electronic and Structural Properties of Oxides ; Multiferroics and related materials
Authors: Sai Chaitanya Chiliveri | Yang Shen | James L. Baber | Jinfa Ying | Vatsala Sagar | Graeme Wistow | Philip Anfinrud | Ad Bax
Source: Journal of the American Chemical Society (article, 2023-08-07)
Field: Materials Science — Materials Chemistry

Experimental NOE, Chemical Shift, and Proline Isomerization Data Provide Detailed Insights into Amelotin Oligomerization Amelotin is an intrinsically disordered protein (IDP) rich in Pro residues and is involved in hydroxyapatite mineralization. It rapidly oligomerizes under physiological conditions of pH and pressure but reverts to its monomeric IDP state at elevated pressure. We identified a 105-residue segment of the protein that becomes ordered upon oligomerization, and we used pressure-jump NMR spectroscopy to measure long-range NOE contacts that exist exclusively in the oligomeric NMR-invisible state. The kinetics of oligomerization and dissociation were probed at the residue-specific level, revealing that the oligomerization process is initiated in the C-terminal half of the segment. Using pressure-jump NMR, the degree of order in the oligomer at the sites of Pro residues was probed by monitoring changes in <i>cis</i>/<i>trans</i> equilibria relative to the IDP state after long-term equilibration under oligomerizing conditions. Whereas most Pro residues revert to <i>trans</i> in the oligomeric state, Pro-49 favors a <i>cis</i> configuration and three Pro residues retain an unchanged <i>cis</i> fraction, pointing to their local lack of order in the oligomeric state. NOE contacts and secondary <sup>13</sup>C chemical shifts in the oligomeric state indicate the presence of an 11-residue α-helix, preceded by a small intramolecular antiparallel β-sheet, with slower formation of long-range intermolecular interactions to N-terminal residues. Although none of the models generated by AlphaFold2 for the amelotin monomer was consistent with experimental data, subunits of a hexamer generated by AlphaFold-Multimer satisfied intramolecular NOE and chemical shift data and may provide a starting point for developing atomic models for the oligomeric state. Chemistry ; Oligomer ; Intramolecular force ; Monomer ; Antiparallel (mathematics) ; Isomerization ; Dissociation (chemistry) ; Chemical shift ; Nuclear magnetic resonance spectroscopy ; Random hexamer ; Kinetics ; Stereochemistry ; Residue (chemistry) ; Crystallography ; Polymer ; Organic chemistry Enzyme Structure and Function ; Protein Structure and Dynamics ; Biochemical effects in animals
Authors: G. Velmurugan | P. Karunakaran | P.S. Sampath | R. Varahamoorthi
Source: Journal of Natural Fibers (article, 2023-06-22)
Field: Materials Science — Polymers and Plastics

Experimental Study of Sugarcane Bagasse Fiber with Rice Husk and Wood Powder Polymer Matrix Composite This research examines the mechanical, morphological, and moisture assimilation of composite materials built up from sugarcane bagasse fiber (SBF), rice husk (RH), and wood powder (WP) filler. Regular threads are now regarded as eco-friendly materials because of their sustainability. This article’s goal is to choose between two polymer structures with fiber and matrix: case 1 has epoxy (50%) plus sugarcane bagasse fiber (30%–45%) and wooden powder (5%–20%); case 2 has epoxy (50%) plus sugarcane fiber (30%–45%) plus rice husk (5%–20%). The impact of the mechanical test is compared to obtaining the best fiber volume fraction (Vf), and the failure of cracked surfaces and interfacial bonding analysis is done using SEM as a consequence of matrix cracking, void content, and fiber pullout. In order to get the characterization of materials, Thermo-Gravimetric Analysis (TGA) and X-Ray Diffraction (XRD) analyses were also performed. However, Sugarcane Bagasse Fiber, a single fiber, combined with an epoxy composite matrix demonstrated a strength of 14 to 18 Mpa and 230 to 250 g of weight. Nevertheless, when SBF was combined with hybrid materials like Rice Husk and Wood Powder, it demonstrated superior strength, with an estimate of 16 to 20 Mpa and a weight of 220 to 240 g. Husk ; Bagasse ; Materials science ; Composite material ; Fiber ; Composite number ; Epoxy ; Natural fiber ; Pulp and paper industry ; Botany Natural Fiber Reinforced Composites ; Mechanical Engineering and Vibrations Research ; Advanced Cellulose Research Studies
Authors: Isabella Piga | Fulvio Magni | Andrew Smith
Source: FEBS Letters (article, 2023-12-23)
Field: Chemistry — Spectroscopy

The journey towards clinical adoption of <scp>MALDI‐MS</scp>‐based imaging proteomics: from current challenges to future expectations Among the spatial omics techniques available, mass spectrometry imaging (MSI) represents one of the most promising owing to its capability to map the distribution of hundreds of peptides and proteins, as well as other classes of biomolecules, within a complex sample background in a multiplexed and relatively high-throughput manner. In particular, matrix-assisted laser desorption/ionisation (MALDI-MSI) has come to the fore and established itself as the most widely used technique in clinical research. However, the march of this technique towards clinical utility has been hindered by issues related to method reproducibility, appropriate biocomputational tools, and data storage. Notwithstanding these challenges, significant progress has been achieved in recent years regarding multiple facets of the technology and has rendered it more suitable for a possible clinical role. As such, there is now more robust and extensive evidence to suggest that the technology has the potential to support clinical decision-making processes under appropriate circumstances. In this review, we will discuss some of the recent developments that have facilitated this progress and outline some of the more promising clinical proteomics applications which have been developed with a clear goal towards implementation in mind. Proteomics ; Data science ; Computer science ; MALDI imaging ; Mass spectrometry imaging ; Computational biology ; Nanotechnology ; Mass spectrometry ; Matrix-assisted laser desorption/ionization ; Chemistry ; Biology ; Materials science ; Desorption ; Chromatography Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications ; Metabolomics and Mass Spectrometry Studies
Authors: Konstantinos Zoupalis | Amirpiran Amiri | Kate Sugden | Michaela Kendall | Kevin Kendall
Source: Energy Conversion and Management (article, 2023-01-05)
Field: Materials Science — Materials Chemistry

Micro solid oxide fuel cell thermal dynamics: Incorporation of experimental measurements and model-based estimations for a multidimensional thermal analysis Transient behaviour of solid oxide fuel cells during various stages of operation, such as warmup, startup, load fluctuations, and shutdown, must be understood and predicted in order to design an efficient controller and prevent degradation/failure of the cell. The difficulty of measuring and monitoring solid oxide fuel cell thermal features necessitates an evaluation of the solid oxide fuel cell thermal dynamics using a hybrid tool that integrates both experimental and numerical methods. In this study, a hybrid measurement tool consisting of a quasi-two-dimensional microscale model and a test rig was used to investigate the solid oxide fuel cell thermal dynamics. Through the hybrid experiment-model approach, steady-state temperature differences across Positive-Electrolyte-Negative and along fuel flow direction were captured. Additionally, the speed of temperature difference change was estimated in two dimensions, which is crucial when estimating transient thermal stresses. Several thermal measures were used to evaluate the thermal dynamics of solid oxide fuel cells. The impact of the operating voltage regime on solid oxide fuel cell thermal dynamics was studied using the varying operating voltage (Voltage Interrupted Measurement) characterisation approach. The outcomes revealed that optimising the performance of solid oxide fuel cells requires a trade-off between thermal management and fuel utilisation due to the exponential effect of fuel utilisation on steady-state temperature differences. The effects of fuel humidity and oxygen content of the oxidant flow on solid oxide fuel cell thermal dynamics were also examined. The results shed light on the new aspects of fuel cell thermal dynamics that are key in designing future smart controllers. Solid oxide fuel cell ; Microscale chemistry ; Materials science ; Oxide ; Thermal ; Nuclear engineering ; Proton exchange membrane fuel cell ; Transient (computer programming) ; Mechanical engineering ; Electrolyte ; Fuel cells ; Chemical engineering ; Chemistry ; Thermodynamics ; Engineering ; Computer science Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Catalysis and Oxidation Reactions
Authors: Ardita Kilaj | Silvan Käser | Jia Wang | Patrik Straňák | Max Schwilk | Lei Xu | O. Anatole von Lilienfeld | Jochen Küpper | Markus Meuwly | Stefan Willitsch
Source: Physical Chemistry Chemical Physics (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Conformational and state-specific effects in reactions of 2,3-dibromobutadiene with Coulomb-crystallized calcium ions Recent advances in experimental methodology enabled studies of the quantum-state- and conformational dependence of chemical reactions under precisely controlled conditions in the gas phase. Here, we generated samples of selected <i>gauche</i> and <i>s-trans</i> 2,3-dibromobutadiene (DBB) by electrostatic deflection in a molecular beam and studied their reaction with Coulomb crystals of laser-cooled Ca<sup>+</sup> ions in an ion trap. The rate coefficients for the total reaction were found to strongly depend on both the conformation of DBB and the electronic state of Ca<sup>+</sup>. In the (4p)<sup>2</sup>P<sub>1/2</sub> and (3d)<sup>2</sup>D<sub>3/2</sub> excited states of Ca<sup>+</sup>, the reaction is capture-limited and faster for the <i>gauche</i> conformer due to long-range ion-dipole interactions. In the (4s)<sup>2</sup>S<sub>1/2</sub> ground state of Ca<sup>+</sup>, the reaction rate for <i>s-trans</i> DBB still conforms with the capture limit, while that for <i>gauche</i> DBB is strongly suppressed. The experimental observations were analysed with the help of adiabatic capture theory, <i>ab initio</i> calculations and reactive molecular dynamics simulations on a machine-learned full-dimensional potential energy surface of the system. The theory yields near-quantitative agreement for <i>s-trans</i>-DBB, but overestimates the reactivity of the <i>gauche</i>-conformer compared to the experiment. The present study points to the important role of molecular geometry even in strongly reactive exothermic systems and illustrates striking differences in the reactivity of individual conformers in gas-phase ion-molecule reactions. Ion ; Coulomb ; Calcium ; Chemistry ; State (computer science) ; Chemical physics ; Crystallography ; Computational chemistry ; Physics ; Quantum mechanics ; Computer science ; Organic chemistry ; Electron Chemical Thermodynamics and Molecular Structure ; Chemical Reactions and Mechanisms ; Chemical Reaction Mechanisms
Authors: Shaimaa Maher | Haitham Kalil | Guiming Liu | Khalid Sossey‐Alaoui | Mekki Bayachou
Source: Frontiers in Molecular Biosciences (article, 2023-10-23)
Field: Materials Science — Materials Chemistry

Alginate-based hydrogel platform embedding silver nanoparticles and cisplatin: characterization of the synergistic effect on a breast cancer cell line <b>Introduction:</b> Breast cancer is a significant cause of mortality in women globally, and current treatment approaches face challenges due to side effects and drug resistance. Nanotechnology offers promising solutions by enabling targeted drug delivery and minimizing toxicity to normal tissues. <b>Methods:</b> In this study, we developed a composite platform called (Alg-AgNPs-CisPt), consisting of silver nanoparticles coated with an alginate hydrogel embedding cisplatin. We examined the effectiveness of this nanocomplex in induce synergistic cytotoxic effects on breast cancer cells. <b>Results and Discussion:</b> Characterization using various analytical techniques confirmed the composition of the nanocomplex and the distribution of its components. Cytotoxicity assays and apoptosis analysis demonstrated that the nanocomplex exhibited greater efficacy against breast cancer cells compared to AgNPs or cisplatin as standalone treatments. Moreover, the nanocomplex was found to enhance intracellular reactive oxygen species levels, further validating its efficacy. The synergistic action of the nanocomplex constituents offers potential advantages in reducing side effects associated with higher doses of cisplatin as a standalone treatment. Overall, this study highlights the potential of the (Alg-AgNPs-CisPt) nanocomplex as a promising platform embedding components with synergistic action against breast cancer cells. Cisplatin ; Cytotoxicity ; Chemistry ; Breast cancer ; Cancer cell ; Drug ; Cancer treatment ; Reactive oxygen species ; MCF-7 ; Nanotechnology ; Apoptosis ; Cancer ; Cancer research ; Human breast ; Pharmacology ; Materials science ; Biochemistry ; In vitro ; Medicine ; Chemotherapy ; Internal medicine Nanoparticles: synthesis and applications ; Graphene and Nanomaterials Applications ; Nanoparticle-Based Drug Delivery
Authors: K. M. Faridul Hasan | Péter György Horváth | Zsófia Kóczán | Miklós Bak | László Bejó | Tibor Alpár
Source: Cellulose (article, 2023-04-03)
Field: Materials Science — Polymers and Plastics

Flame-retardant hybrid composite manufacturing through reinforcing lignocellulosic and carbon fibers reinforced with epoxy resin (F@LC) Abstract Novel flame retardant hybrid composites were developed from lignocellulosic and carbon fibers reinforced with epoxy resin using hot pressing technology. The size of the lignocellulosic fibers was within 0.045 to 0.8 mm, and the carbon fibers ranged from 5 to 8 mm. The nominal thickness of the composites was 10 mm, whereas the nominal density was 730 kg/m 3 . The composite dimensions were 400 × 400 mm 2 . The developed panels were tested for internal bonding strength and flexural properties to investigate their mechanical performance. Furthermore, SEM (Scanning electron microscopy) test was conducted to examine the morphologies of the products before and after fracture and found substantial quantities of both types of fiber in the composite system. The EDX (Energy disruptive X-ray) analysis also displayed the chemical elements present in the developed products. Moreover, an FTIR (Fourier transform infrared spectroscopy) study showed strong chemical interactions among the lignocellulosic and carbon fibers with the thermosetting epoxy polymers. The flame retardancy tests of the composite materials also showed significant thermal stability, especially after loading carbon fibers in the composite system. Moreover, dimensional stability showed an improving trend with the increase of carbon fibers as the reinforcement. Overall, the composite materials developed using lignocellulosic and carbon fibers with epoxy resin are showing a novel route to develop composites with high mechanical performance and considerable flame retardancy. Graphical abstract Materials science ; Epoxy ; Composite material ; Composite number ; Thermosetting polymer ; Fourier transform infrared spectroscopy ; Thermal stability ; Flexural strength ; Fire retardant ; Scanning electron microscope ; Fiber ; Carbon fibers ; Chemical engineering Flame retardant materials and properties ; Natural Fiber Reinforced Composites ; Fiber-reinforced polymer composites
Authors: Jie Li | Haonan Zhang | Dongyu Li | Yajun Liu | Edward A. Bayer | Qiu Cui | Yingang Feng | Ping Zhu
Source: Nature Communications (article, 2023-10-13)
Field: Materials Science — Materials Chemistry

Structure of the transcription open complex of distinct σI factors Bacterial σ<sup>I</sup> factors of the σ<sup>70</sup>-family are widespread in Bacilli and Clostridia and are involved in the heat shock response, iron metabolism, virulence, and carbohydrate sensing. A multiplicity of σ<sup>I</sup> paralogues in some cellulolytic bacteria have been shown to be responsible for the regulation of the cellulosome, a multienzyme complex that mediates efficient cellulose degradation. Here, we report two structures at 3.0 Å and 3.3 Å of two transcription open complexes formed by two σ<sup>I</sup> factors, SigI1 and SigI6, respectively, from the thermophilic, cellulolytic bacterium, Clostridium thermocellum. These structures reveal a unique, hitherto-unknown recognition mode of bacterial transcriptional promoters, both with respect to domain organization and binding to promoter DNA. The key characteristics that determine the specificities of the σ<sup>I</sup> paralogues were further revealed by comparison of the two structures. Consequently, the σ<sup>I</sup> factors represent a distinct set of the σ<sup>70</sup>-family σ factors, thus highlighting the diversity of bacterial transcription. Clostridium thermocellum ; Biology ; Clostridia ; Cellulosome ; Transcription factor ; Bacteria ; Promoter ; Genetics ; Transcription (linguistics) ; Computational biology ; Cell biology ; Gene ; Biochemistry ; Cellulase ; Cellulose ; Gene expression Enzyme Structure and Function ; Endoplasmic Reticulum Stress and Disease ; Protein Structure and Dynamics
Authors: Jenna Poonoosamy | Alexander Kaspor | Stefan Rudin | Gabriel L. Murphy | Dirk Bosbach | Guido Deissmann
Source: Minerals (article, 2023-05-02)
Field: Chemistry — Inorganic Chemistry

The Use of Microfluidic Platforms with Raman Spectroscopy for Investigating the Co-Precipitation of Metals and Radionuclides in Carbonates In the context of long-term safety assessments of deep geological repositories for radio-active wastes, a rigorous understanding of the retention of radionuclides such as 226Ra due to co-precipitation with carbonate and sulphate minerals is important for a realistic prediction of radionuclide migration behaviour in the repository near and far field. The co-precipitation of 226Ra in sulphate minerals, in particular barite, has been studied experimentally and numerically in detail throughout the last decade to establish the thermodynamic properties and mixing behaviour of its solid solutions over a wide range of temperatures. However, so far, few studies have been dedicated to the incorporation of 226Ra into carbonates, and little is known about the mixing behaviour of 226Ra and calcium carbonate phases such as calcite, aragonite, or vaterite. The aim of the work presented here was to develop and explore innovative microfluidic experiments in combination with in situ Raman spectroscopy that can be used to investigate co-precipitation processes of radionuclides in carbonate minerals, using stable Ba as a chemical analogue for 226Ra in the first step, due to their similar ionic radii. Different microfluidic set-ups were developed to address co-precipitation in bulk solution as well as in confinement or under diffusive flow regimes. It could be shown by XRD and SEM-EDX analyses that high amounts of Ba can be incorporated into the lattice of calcite when formed via an amorphous precursor phase, suggesting that the formation of calcium carbonates can contribute to the retention of 226Ra in the repository environment, which will be verified in future studies using the presented microfluidic platforms. Calcite ; Carbonate ; Vaterite ; Aragonite ; Calcium carbonate ; Precipitation ; Context (archaeology) ; Radionuclide ; Raman spectroscopy ; Mineralogy ; Chemical engineering ; Materials science ; Chemistry ; Geology ; Metallurgy Radioactive element chemistry and processing ; Chemical Synthesis and Characterization ; Nuclear materials and radiation effects
Authors: Marvin Treger | Carolin König | Peter Behrens | Andreas Schneider
Source: Physical Chemistry Chemical Physics (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

Fragment-based approach for the efficient calculation of the refractive index of metal–organic frameworks Increasing demands on materials in the field of optical applications require novel materials. Metal-organic frameworks (MOFs) are a prominent class of hybrid inorganic-organic materials with a modular layout. This allows the fine-tuning of their optical properties and the tailored design of optical systems. In the present theoretical study, an efficient method to calculate the refractive index (RI) of MOFs is introduced. For this purpose, the MOF is split into disjoint fragments, the linkers and the inorganic building units. The latter are disassembled until metal ions are obtained. The static polarizabilities are calculated individually using molecular density functional theory (DFT). From these, the MOF's RI is calculated. To obtain suitable polarizabilities, an exchange-correlation functional benchmark was performed first. Subsequently, this fragment-based approach was applied to a set of 24 MOFs including Zr-based MOFs and ZIFs. The calculated RI values were compared to the experimental values and validated using HSE06 hybrid functional DFT calculations with periodic boundary conditions. The examination of the MOF set revealed a speed up of the RI calculations by the fragment-based approach of up to 600 times with an estimated maximal deviation from the periodic DFT results below 4%. Metal-organic framework ; Density functional theory ; Hybrid functional ; Periodic boundary conditions ; Disjoint sets ; Materials science ; Fragment (logic) ; Chemistry ; Computational chemistry ; Boundary value problem ; Physical chemistry ; Computer science ; Physics ; Algorithm ; Mathematics Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; X-ray Diffraction in Crystallography