jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Metka Benčina | Ita Junkar | Alenka Vesel | Miran Mozetič | Aleš Iglič
Source: Nanomaterials (review, 2022-08-25)
Field: Materials Science — Materials Chemistry

Nanoporous Stainless Steel Materials for Body Implants—Review of Synthesizing Procedures Despite the inadequate biocompatibility, medical-grade stainless steel materials have been used as body implants for decades. The desired biological response of surfaces to specific applications in the body is a highly challenging task, and usually not all the requirements of a biomaterial can be achieved. In recent years, nanostructured surfaces have shown intriguing results as cell selectivity can be achieved by specific surface nanofeatures. Nanoporous structures can be fabricated by anodic oxidation, which has been widely studied for titanium and its alloys, while no systematic studies are so far available for stainless steel (SS) materials. This paper reviews the current state of the art in the anodisation of SS; correlations between the parameters of anodic oxidation and the surface morphology are drawn. The results reported by various authors are scattered because of a variety of experimental configurations. A linear correlation between the pores' diameter anodisation voltage was deduced, while no correlation with other processing parameters was found obvious. The analyses of available data indicated a lack of systematic experiments, which are recommended to understand the kinetics of pore formation and develop techniques for optimal biocompatibility of stainless steel. Biocompatibility ; Nanoporous ; Materials science ; Biomaterial ; Titanium ; Anode ; Anodic oxidation ; Surface modification ; Nanotechnology ; Metallurgy ; Chemical engineering ; Electrode ; Chemistry Anodic Oxide Films and Nanostructures ; Corrosion Behavior and Inhibition ; Nanoporous metals and alloys
Authors: Cangjie Yang | Wei Zhang | Xin Pang | Fan Xiao | Sandeep Kumar Kalva | Yipeng Zhang | Manojit Pramanik | Leilei Tian | Gang Liu | Mingfeng Wang
Source: Aggregate (article, 2022-09-06)
Field: Materials Science — Materials Chemistry

Polyester‐tethered near‐infrared fluorophores confined in colloidal nanoparticles: Tunable and thermoresponsive aggregation and biomedical applications Abstract Intricate assembly of multiple molecular chromophores assisted by protein scaffolds is essential in tuning the optical absorption and energy transfer in the light‐harvesting complexes of the photosynthetic systems in nature. However, it remains a challenge to achieve such structural complexity and functionality in synthetic polymer‐chromophore systems. Here, we report a series of polyester‐tethered pyrrolopyrrole cyanine derivatives and their colloidal nanoparticles dispersed in water, which show tunable J ‐ or H ‐aggregation excitonic coupling and near‐infrared fluorescence by precise control of the polymer chain lengths, composition, and temperature. Moreover, the optimal fluorescence or photothermal effect of the J ‐aggregate nanoparticles enables broad applications in fluorescence or photoacoustic bioimaging and phototherapy. Cyanine ; Chromophore ; Nanoparticle ; Fluorescence ; Photothermal therapy ; Polymer ; Nanotechnology ; Materials science ; Polyester ; Förster resonance energy transfer ; Absorption (acoustics) ; Photochemistry ; Chemical engineering ; Chemistry Luminescence and Fluorescent Materials ; Photoreceptor and optogenetics research ; Hemoglobin structure and function
Authors: Sunny Gupta | Henry Yu | Boris I. Yakobson
Source: Nature Communications (article, 2022-06-03)
Field: Materials Science — Materials Chemistry

Designing 1D correlated-electron states by non-Euclidean topography of 2D monolayers Two-dimensional (2D) bilayers, twisted to particular angles to display electronic flat bands, are being extensively explored for physics of strongly correlated 2D systems. However, the similar rich physics of one-dimensional (1D) strongly correlated systems remains elusive as it is largely inaccessible by twists. Here, a distinctive way to create 1D flat bands is proposed, by either stamping or growing a 2D monolayer on a non-Euclidean topography-patterned surface. Using boron nitride (hBN) as an example, our analysis employing elastic plate theory, density-functional and coarse-grained tight-binding method reveals that hBN's bi-periodic sinusoidal deformation creates pseudo- electric and magnetic fields with unexpected spatial dependence. A combination of these fields leads to anisotropic confinement and 1D flat bands. Moreover, changing the periodic undulations can tune the bandwidth, to drive the system to different strongly correlated regimes such as density waves, Luttinger liquid, and Mott insulator. The 1D nature of these states differs from those obtained in twisted materials and can be exploited to study the exciting physics of 1D quantum systems. Condensed matter physics ; Physics ; Monolayer ; Anisotropy ; Boron nitride ; Materials science ; Nanotechnology ; Quantum mechanics Graphene research and applications ; Topological Materials and Phenomena ; 2D Materials and Applications
Authors: Jie-Yu Zheng | Larissa K. S. von Krbek | Tanya K. Ronson | Jonathan R. Nitschke
Source: Angewandte Chemie International Edition (article, 2022-10-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Host Spin‐Crossover Thermodynamics Indicate Guest Fit Spin-crossover (SCO) metal-organic cages capable of switching between high-spin and low-spin states have the potential to be used as magnetic sensors and switches. Variation of the donor strength of heterocyclic aldehyde subcomponents in imine-based ligands can tune the ligand field for a Fe<sup>II</sup> center, which results in both homoleptic and heteroleptic cages with diverse SCO behaviors. The tetrahedral SCO cage built from 1-methyl-1H-imidazole-2-carbaldehyde is capable of encapsulating various guests, which stabilize different cage spin states depending on guest size. Conversely, the SCO tetrahedron exhibits different affinities for guests in different spin states, which is inferred to result from subtle structural differences of the cavity caused by the change in metal center spin state. Examination of SCO thermodynamics across a series of host-guest complexes enabled sensitive probing of guest fit to the host cavity, providing information complementary to binding-constant determination. Crossover ; Thermodynamics ; Spin crossover ; Statistical physics ; Physics ; Spin (aerodynamics) ; Host (biology) ; Condensed matter physics ; Computer science ; Biology Magnetism in coordination complexes ; Advanced NMR Techniques and Applications ; Lanthanide and Transition Metal Complexes
Authors: Estelle Rascol | Anouk Dufourquet | Rim Baccouch | Pierre Soule | Isabel D. Alves
Source: Scientific Reports (article, 2022-03-30)
Field: Chemistry — Physical and Theoretical Chemistry

An original approach to measure ligand/receptor binding affinity in non-purified samples Several biochemical and biophysical methods are available to determine ligand binding affinities between a biological target and its ligands, most of which require purification, labelling or surface immobilisation. These measurements, however, remain challenging in regards to membrane proteins, as purification processes require their extraction from their native lipid environment, which may in turn impact receptor conformation and functionality. In this study, we have developed a novel experimental procedure using microscale thermophoresis (MST) directly from cell membrane fragments, to determine different ligand binding affinities to a membrane protein, the dopamine D2 receptor (D2R). In order to achieve this, two main challenges had to be overcome: determining the concentration of dopamine D2R in the crude sample; finding ways to minimize or account for non-specific binding of the ligand to cell fragments. Using MST, we were able to determine the D2R concentration in cell membrane fragments to approximately 36.8 ± 2.6 pmol/mg. Next, the doses-responses curves allowed for the determination of K<sub>D</sub>, to approximately 5.3 ± 1.7 nM, which is very close to the reported value. Important details of the experimental procedure have been detailed in this paper to allow the application of this novel method to various membrane proteins. Microscale thermophoresis ; Ligand (biochemistry) ; Affinities ; Membrane ; Membrane protein ; Microscale chemistry ; Chemistry ; Receptor ; Cell membrane ; Biophysics ; Lipid bilayer ; Biological membrane ; Chromatography ; Biochemistry ; Biology thermodynamics and calorimetric analyses ; Lipid Membrane Structure and Behavior ; Field-Flow Fractionation Techniques
Authors: S. Agnolin | Jon Meléndez | Luca Di Felice | Fausto Gallucci
Source: International Journal of Hydrogen Energy (article, 2022-07-16)
Field: Materials Science — Materials Chemistry

Surface roughness improvement of Hastelloy X tubular filters for H2 selective supported Pd–Ag alloy membranes preparation Thin Pd–Ag layers have been successfully deposited on ceramic supports with controlled surface characteristics. The need for less fragile membranes and ease of sealing and connection leads to the study of metallic supports for thin Pd-based membrane development. Metallic supported membranes are prone to intermetallic diffusion issues so an interdiffusion barrier must be introduced. However, metallic supports with sufficient surface quality for direct membrane deposition are expensive and not readily available in the market. It is thus important to study how to improve surface roughness of commercially available rough metallic filters, in order to allow deposition of a smooth, delamination-free Pd–Ag layer. This work reports a first attempt towards a standardized preparation procedure for Pd-based membranes on cheap, rough, and unrefined Hastelloy X tubular filters. The focus is on surface roughness reduction, in order to allow the deposition of a smooth, uniform Pd–Ag selective layer. The surface roughness of the tubes is tuned via 1) polishing and 2) addition of a smoothening interdiffusion barrier layer based on a boehmite dip-coated dispersion. The polishing time was assessed by studying the average support's roughness variation, permeation behavior and ability to retain ceramic coating. It was found that the best trade-off between polishing extent and gas permeance of the support amounts to 6 h. Moreover, it was assessed that increasing the boehmite load in the interdiffusion barrier precursor solution leads to thicker layers and larger surface roughness reduction, but greater solution instability. 1,2%wt of boehmite load proved the best trade-off between layer reproducibility and support coverage. Different dipping-sintering routes were evaluated in order to improve surface's suitability for electroless plating: a single interdiffusion layer deposition route proved the most suitable for Pd–Ag deposition. The electroless plating performed onto the treated supports results in a continuous Pd–Ag layer, proving Pd–Ag deposition possible on the selected filters. Materials science ; Surface roughness ; Polishing ; Boehmite ; Ceramic ; Alloy ; Membrane ; Surface finish ; Permeance ; Intermetallic ; Layer (electronics) ; Electropolishing ; Composite material ; Permeation ; Metallurgy ; Chemical engineering ; Electrode ; Chemistry Advancements in Solid Oxide Fuel Cells ; Electrodeposition and Electroless Coatings ; Copper Interconnects and Reliability
Authors: Qiangsheng Lu | Congcong Le | Xiaoqian Zhang | Jacob Cook | Xiaoqing He | M. Zarenia | Mitchel Vaninger | P. F. Miceli | David J. Singh | Chang Liu | Hailang Qin | T.‐C. Chiang | Ching‐Kai Chiu | Giovanni Vignale | Guang Bian
Source: Advanced Materials (article, 2022-04-21)
Field: Materials Science — Materials Chemistry

Dirac Fermion Cloning, Moiré Flat Bands, and Magic Lattice Constants in Epitaxial Monolayer Graphene Tuning interactions between Dirac states in graphene has attracted enormous interest because it can modify the electronic spectrum of the 2D material, enhance electron correlations, and give rise to novel condensed-matter phases such as superconductors, Mott insulators, Wigner crystals, and quantum anomalous Hall insulators. Previous works predominantly focus on the flat band dispersion of coupled Dirac states from different twisted graphene layers. In this work, a new route to realizing flat band physics in monolayer graphene under a periodic modulation from substrates is proposed. Graphene/SiC heterostructure is taken as a prototypical example and it is demonstrated experimentally that the substrate modulation leads to Dirac fermion cloning and, consequently, the proximity of the two Dirac cones of monolayer graphene in momentum space. Theoretical modeling captures the cloning mechanism of the Dirac states and indicates that moiré flat bands can emerge at certain magic lattice constants of the substrate, specifically when the period of modulation becomes nearly commensurate with the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:mrow><mml:mo>(</mml:mo> <mml:msqrt><mml:mn>3</mml:mn></mml:msqrt> <mml:mtext> </mml:mtext> <mml:mo>×</mml:mo> <mml:mtext> </mml:mtext> <mml:msqrt><mml:mn>3</mml:mn></mml:msqrt> <mml:mo>)</mml:mo> <mml:mi>R</mml:mi> <mml:msup><mml:mn>30</mml:mn> <mml:mi>o</mml:mi></mml:msup> </mml:mrow> <mml:annotation>\[(\sqrt 3 \; \times \;\sqrt 3 )R{30^o}\]</mml:annotation></mml:semantics> </mml:math> supercell of graphene. The results show that epitaxial single monolayer graphene on suitable substrates is a promising platform for exploring exotic many-body quantum phases arising from interactions between Dirac electrons. Graphene ; Monolayer ; Condensed matter physics ; Dirac fermion ; Materials science ; Bilayer graphene ; Physics ; Topological insulator ; Quantum mechanics ; Nanotechnology Graphene research and applications ; Topological Materials and Phenomena ; 2D Materials and Applications
Authors: Ludovic Melly | Andrea Banfi
Source: Cell and Tissue Research (review, 2022-02-17)
Field: Materials Science — Biomaterials

Fibrin-based factor delivery for therapeutic angiogenesis: friend or foe? Therapeutic angiogenesis aims at promoting the growth of blood vessels to restore perfusion in ischemic tissues or aid tissue regeneration. Vascular endothelial growth factor (VEGF) is the master regulator of angiogenesis in development, repair, and disease. However, exploiting VEGF for therapeutic purposes has been challenging and needs to take into account some key aspects of VEGF biology. In particular, the spatial localization of angiogenic signals within the extracellular matrix is crucial for physiological assembly and function of new blood vessels. Fibrin is the provisional matrix that is universally deposited immediately after injury and supports the initial steps of tissue regeneration. It provides therefore several ideal features as a substrate to promote therapeutic vascularization, especially through its ability to present growth factors in their physiological matrix-bound state and to modulate their availability for signaling. Here, we provide an overview of fibrin uses as a tissue-engineering scaffold material and as a tunable platform to finely control dose and duration of delivery of recombinant factors in therapeutic angiogenesis. However, in some cases, fibrin has also been associated with undesirable outcomes, namely the promotion of fibrosis and scar formation that actually prevent physiological tissue regeneration. Understanding the mechanisms that tip the balance between the pro- and anti-regenerative functions of fibrin will be the key to fully exploit its therapeutic potential. Angiogenesis ; Fibrin ; Therapeutic angiogenesis ; Regeneration (biology) ; Extracellular matrix ; Vascular endothelial growth factor ; Cell biology ; Tissue engineering ; Regenerative medicine ; Fibrosis ; Neovascularization ; Growth factor ; Immunology ; Biology ; Medicine ; Biomedical engineering ; Pathology ; Cancer research ; VEGF receptors ; Stem cell ; Internal medicine Electrospun Nanofibers in Biomedical Applications ; Angiogenesis and VEGF in Cancer ; Blood properties and coagulation
Authors: Matthew J. Hamer | Alessio Giampietri | Viktor Kandyba | Francesca Genuzio | Tevfik Onur Menteş | Andrea Locatelli | Roman Gorbachev | Alexei Barinov | Marcin Mucha‐Kruczyński
Source: ACS Nano (article, 2022-01-24)
Field: Materials Science — Materials Chemistry

Moiré Superlattice Effects and Band Structure Evolution in Near-30-Degree Twisted Bilayer Graphene In stacks of two-dimensional crystals, mismatch of their lattice constants and misalignment of crystallographic axes lead to formation of moiré patterns. We show that moiré superlattice effects persist in twisted bilayer graphene (tBLG) with large twists and short moiré periods. Using angle-resolved photoemission, we observe dramatic changes in valence band topology across large regions of the Brillouin zone, including the vicinity of the saddle point at <b><i>M</i></b> and across 3 eV from the Dirac points. In this energy range, we resolve several moiré minibands and detect signatures of secondary Dirac points in the reconstructed dispersions. For twists θ > 21.8°, the low-energy minigaps are not due to cone anticrossing as is the case at smaller twist angles but rather due to moiré scattering of electrons in one graphene layer on the potential of the other which generates intervalley coupling. Our work demonstrates the robustness of the mechanisms which enable engineering of electronic dispersions of stacks of two-dimensional crystals by tuning the interface twist angles. It also shows that large-angle tBLG hosts electronic minigaps and van Hove singularities of different origin which, given recent progress in extreme doping of graphene, could be explored experimentally. Bilayer graphene ; Condensed matter physics ; Brillouin zone ; Superlattice ; Graphene ; Band gap ; Materials science ; Scattering ; Electronic band structure ; Twist ; Topological insulator ; Physics ; Optics ; Nanotechnology ; Geometry Graphene research and applications ; 2D Materials and Applications ; Topological Materials and Phenomena
Authors: Rohit Pachat | Djoudi Ourdani | Maria‐Andromachi Syskaki | Alessio Lamperti | Subhajit Roy | Song Chen | Adriano Di Pietro | Ludovic Largeau | Roméo Juge | Maryam Massouras | Cristina Balan | Johannes W. van der Jagt | Guillaume Agnus | Y. Roussigné | M. S. Gabor | S. M. Chérif | Gianfranco Durin | Shimpei Ono | J. Langer | Damien Querlioz | D. Ravelosona | M. Belmeguenai | Liza Herrera Diez
Source: Advanced Materials Interfaces (article, 2022-07-11)
Field: Materials Science — Materials Chemistry

Magneto‐Ionics in Annealed W/CoFeB/HfO<sub>2</sub> Thin Films Abstract The magneto‐ionic modulation of the Dzyaloshinskii–Moriya interaction (DMI) and the perpendicular magnetic anisotropy (PMA), in W/CoFeB/HfO 2 stacks annealed at different temperatures and for varying annealing times, are presented in this work. A large modulation of PMA and DMI is observed in the systems annealed at 390 and 350 °C, whereas no response to voltage is observed in the as‐grown samples. A strong DMI is only observed in the samples annealed at 390 °C for 1 h, while PMA is present for all annealing times at temperatures of 390 and 350 °C. Magnetic properties including domain wall velocity improve drastically with increasing the annealing temperature and time, while the magneto‐ionic reversibility is increasingly compromised. The changes in PMA and DMI induced by the gate voltages in the samples annealed at 390 °C are permanent, while partial reversibility is only observed for the samples annealed at 350 °C for short times. This dependence of reversibility on post‐grown annealing has been associated to the influence of crystallization on ion mobility. These results show that a compromise between the enhancement of the magnetic properties and the magneto‐ionic performance could be needed in systems requiring annealing to develop PMA and DMI. Annealing (glass) ; Materials science ; Crystallization ; Condensed matter physics ; Ionic bonding ; Ion ; Nuclear magnetic resonance ; Chemistry ; Metallurgy ; Thermodynamics ; Physics ZnO doping and properties ; Magnetic properties of thin films ; Advancements in Battery Materials
Authors: David Sebastian Walch | Yeseul Yun | Niranjan Ramakrishnegowda | Lutz Mühlenbein | Andriy Lotnyk | Cameliu Himcinschi | Akash Bhatnagar
Source: Advanced Electronic Materials (article, 2022-06-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Resistive Switching in Ferroelectric Bi<sub>2</sub>FeCrO<sub>6</sub> Thin Films and Impact on the Photovoltaic Effect Abstract The multiferroic character of Bi 2 FeCrO 6 (BFCO), that is, the coexistence of ferroelectricity and ferromagnetism, has been predicted and demonstrated in different studies. Intriguingly, the material system also exhibits a reduced band gap, in addition to bulk‐driven photovoltaic effect. The co‐existence of all these attributes in a single system is a rare occurrence and paves way to a multitude of practical applications, with ferroelectric solar cell as one of them. In this work, epitaxially grown BFCO thin films, deposited with pulsed laser deposition on single crystalline SrTiO 3 (STO) substrates, reveal a self‐ordered ionic arrangement which is proven with X‐ray and transmission electron micrcoscope (TEM) measurements. A lowered band gap and a higher conductivity lead to a superior photovoltaic performance compared to a BiFeO 3 (BFO) reference film. Scanning probe microscopy (SPM) is used to test locally the ferroelectric switching properties. Poling with electric field not only caused a reliable change in the state of polarization, but also resulted in substantial changes in the resistance of the regions. Macroscopic measurements using transparent In 2 O 3 :Sn (ITO) electrodes demonstrate a bi‐directional multi‐stage resistive switching, which in turn influences the photovoltaic performance of the heterostucture. Materials science ; Ferroelectricity ; Thin film ; Photovoltaic effect ; Optoelectronics ; Pulsed laser deposition ; Multiferroics ; Band gap ; Solar cell ; Photovoltaic system ; Poling ; Polarization (electrochemistry) ; Nanotechnology ; Electrical engineering ; Dielectric Multiferroics and related materials ; Ferroelectric and Piezoelectric Materials ; Dielectric properties of ceramics