Publications by authors named "Rouquette J"

We report herein on the magneto-chiral dichroism (MChD), investigated through near infrared light absorption, of a chiral nanomagnet showing room temperature magneto-electric coupling. The MChD signal associated with the Yb center is driven by the magnetic dipole allowed character of the F ← F electronic transition (|Δ| = 1). Magnetic field and temperature dependence studies reveal an MChD signal that follows the material magnetization and persists at room temperature.

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We investigated the site-disorder and thermal expansion of O(BO) ( = Pr, Nd, Gd, Er, Tm) through a single crystal structural study conducted between 100 and 300 K. Additionally, a high-pressure synchrotron X-ray diffraction study at low temperatures was conducted to determine the compressibility of both ordered and disordered prototype oxyborate lanthanides, specifically NdCaO(BO) and ErCaO(BO). The study revealed distinct behaviors consistent with their respective ionic radii.

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Luminescence (nano)thermometry has exploded in popularity, offering a remote detection way to measure temperature across diverse fields like nanomedicine, microelectronics, catalysis, and plasmonics. A key advantage is its supposed immunity to strong electromagnetic fields, a crucial feature in many environments. However, this assumption lacks comprehensive experimental verification as most of the proposed luminescent thermometers rely on magnetic ions, such as lanthanides.

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  • Barium-cobaltate-based perovskites (BaCoO) are being researched for their promise in energy storage and conversion due to flexible oxygen levels and adjustable oxidation states of nonprecious metals.
  • This study focuses on synthesizing and characterizing BaCoO at its lowest cobalt oxidation state, revealing a unique crystal structure that allows for significant oxygen storage capacity.
  • The findings suggest that BaCoO can undergo reversible transformations, maintaining high electronic conductivity at elevated temperatures, highlighting its potential for advanced energy applications.
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Hydrogen and helium saturate the 1D pore systems of the high-silica (Si/Al>30) zeolites Theta-One (TON), and Mobile-Twelve (MTW) at high pressure based on x-ray diffraction, Raman spectroscopy and Monte Carlo simulations. In TON, a strong 22 % volume increase occurs above 5 GPa with a transition from the collapsed P2 to a symmetrical, swelled Cmc2 form linked to an increase in H content from 12 H/unit cell in the pores to 35 H/unit cell in the pores and in the framework of the material. No transition and continuous collapse of TON is observed in helium indicating that the mechanism of H insertion is distinct from other fluids.

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Low-dimensional boron nitride (BN) chains were prepared in the one-dimensional pores of the siliceous zeolites theta-one (TON) and Mobil-twelve (MTW) by the infiltration, followed by the dehydrocoupling and pyrolysis of ammonia borane under high-pressure, high-temperature conditions. High-pressure X-ray diffraction in a diamond anvil cell and in a large-volume device was used to follow in situ these different steps in order to determine the optimal conditions for this process. Based on these results, millimeter-sized samples of BN/TON and BN/MTW were synthesized.

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Traditional thin sectioning microscopy of large bone and dental tissue samples using demineralization may disrupt structure morphologies and even damage soft tissues, thus compromising the histopathological investigation. Here, we developed a synergistic and original framework on thick sections based on wide-field multi-fluorescence imaging and spectral Principal Component Analysis (sPCA) as an alternative, fast, versatile, and reliable solution, suitable for highly mineralized tissue structure sustain and visualization. Periodontal 2-mm thick sections were stained with a solution containing five fluorescent dyes chosen for their ability to discriminate close tissues, and acquisitions were performed with a multi-zoom macroscope for blue, green, red, and NIR (near-infrared) emissions.

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  • Researchers successfully synthesized polymer-guest/zeolite-host nanocomposites using liquid phenylacetylene in VFI at high pressure, providing a more practical approach than previous methods.
  • The resulting composite features disordered polyphenylacetylene chains within the zeolite's pores, characterized through advanced techniques like synchrotron X-ray diffraction and nuclear magnetic resonance spectroscopy.
  • The newly developed materials exhibited promising gas sensing capabilities, particularly for detecting water and butanol vapors, demonstrating their potential for future technological applications.
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  • High-pressure X-ray diffraction and Raman spectroscopy were used to investigate how ammonia borane, a hydrogen storage material, behaves when inserted into the pores of zeolite theta-1 under high temperature and pressure.
  • Heating ammonia borane to 300 °C at pressures up to 5 GPa releases a significant amount of hydrogen as it converts to polyaminoborane and polyiminoborane chains.
  • The process leads to a notable increase in the unit cell volume of the zeolite, surpassing normal thermal expansion, and involves a phase transition to a more symmetric structure with larger pores.
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Follicular lymphoma (FL) is an indolent B cell lymphoproliferative disorder of transformed follicular center B cells, which accounts for 20-30 percent of all non-Hodgkin lymphoma (NHL) cases. Great advances have been made to identify the most relevant targets for precision therapy. However, no relevant models for in vitro studies have been developed or characterized in depth.

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Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides, resulting in numerous compounds forming homologous series nFeOmFe_{2}O_{3} and the appearance of FeO_{2}. Here, based on the results of in situ single-crystal x-ray diffraction, Mössbauer spectroscopy, x-ray absorption spectroscopy, and density-functional theory+dynamical mean-field theory calculations, we demonstrate that iron in high-pressure cubic FeO_{2} and isostructural FeO_{2}H_{0.5} is ferric (Fe^{3+}), and oxygen has a formal valence less than 2.

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The negative thermal expansion material potassium cadmium dicyanoargentate, KCd[Ag(CN)], is studied at high pressure using a combination of X-ray single-crystal diffraction, X-ray powder diffraction, infrared and Raman spectroscopy, and density functional theory calculations. In common with the isostructural manganese analogue, KMn[Ag(CN)], this material is shown to exhibit very strong negative linear compressibility (NLC) in the crystallographic direction due to structure hinging. We find increased structural flexibility results in enhanced NLC and NTE properties, but this also leads to two pressure-induced phase transitions-to very large unit cells involving octahedral tilting and shearing of the structure-below 2 GPa.

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We present a multi-disciplinary image-based blood flow perfusion modeling of a whole organ vascular network for analyzing both its structural and functional properties. We show how the use of Light-Sheet Fluorescence Microscopy (LSFM) permits whole-organ micro-vascular imaging, analysis and modelling. By using adapted image post-treatment workflow, we could segment, vectorize and reconstruct the entire micro-vascular network composed of 1.

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Magnetoelectric (ME) materials combine magnetic and electric polarizabilities in the same phase, offering a basis for developing high-density data storage and spintronic or low-consumption devices owing to the possibility of triggering one property with the other. Such applications require strong interaction between the constitutive properties, a criterion that is rarely met in classical inorganic ME materials at room temperature. We provide evidence of a strong ME coupling in a paramagnetic ferroelectric lanthanide coordination complex with magnetostrictive phenomenon.

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  • Chronic remodeling after a heart attack leads to changes like fibrosis, cell death, and mitochondrial issues, which can cause heart failure.
  • The study suggests that the enzyme monoamine oxidase-A (MAO-A) increases harmful levels of 4-HNE in mitochondria, contributing to heart dysfunction through reactive oxygen species (ROS) and other mechanisms.
  • Inhibiting MAO-A showed protective effects in a model of heart damage, reducing 4-HNE levels and preventing calcium overload, thus improving heart function and providing new insights into heart disease mechanisms.
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Objective: The main function of skin is to protect the body from external aggressions. Over time, normal skin ageing is accelerated by external stresses such as smoking, pollution, chemical products and radiation. UV light, in particular UVA, causes DNA damage, apoptosis and morphological modifications, which are responsible for both premature ageing and cancer.

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Adipose tissue, as the main energy storage organ and through its endocrine activity, is interconnected with all physiological functions. It plays a fundamental role in energy homeostasis and in the development of metabolic disorders. Up to now, this tissue has been analysed as a pool of different cell types with very little attention paid to the organization and putative partitioning of cells.

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  • The study combines spectrophotometry with a new statistical method to assess the virulence of bacteria, using Galleria mellonella (wax moth larva) as a model host.
  • This approach enables automated survival data collection from up to 96 samples at once, making the process efficient.
  • Additionally, it allows for tracking the growth of pathogens if genetically modified bacteria with GFP (green fluorescent protein) are utilized.
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Background: Human skin is composed of the superimposition of tissue layers of various thicknesses and components. Histological staining of skin sections is the benchmark approach to analyse the organization and integrity of human skin biopsies; however, this approach does not allow 3D tissue visualization. Alternatively, confocal or two-photon microscopy is an effective approach to perform fluorescent-based 3D imaging.

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Dopamine (DA) plays a fundamental role in insect behavior as it acts both as a general modulator of behavior and as a value system in associative learning where it mediates the reinforcing properties of unconditioned stimuli (US). Here we aimed at characterizing the dopaminergic neurons in the central nervous system of the honey bee, an insect that serves as an established model for the study of learning and memory. We used tyrosine hydroxylase (TH) immunoreactivity (ir) to ensure that the neurons detected synthesize DA endogenously.

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The mechanisms by which organs acquire their functional structure and realize its maintenance (or homeostasis) over time are still largely unknown. In this paper, we investigate this question on adipose tissue. Adipose tissue can represent 20 to 50% of the body weight.

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Objective: White and brown adipose tissues play a major role in the regulation of metabolic functions. With the explosion of obesity and metabolic disorders, the interest in adipocyte biology is growing constantly. While several studies have demonstrated functional differences between adipose fat pads, especially in their involvement in metabolic diseases, there are no data available on possible heterogeneity within an adipose depot.

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A synthetic high-silica mordenite (HS-MOR) has been compressed in both non-penetrating (silicone oil, s.o.) and penetrating [methanol : ethanol : water (16 : 3 : 1) (m.

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Purpose: Saliva is a reliable, noninvasive, and cost-effective alternative to biomarkers measured in other biological fluids. Within certain populations, saliva sampling may be difficult because of insufficient saliva flow, which may compromise disease diagnosis or research integrity. Methods to improve flow rates (eg, administering citric acid, chewing gum, or collecting cotton) may compromise biomarker integrity, especially if the methods involve the presence of a collection aid in the oral cavity.

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  • The study examined how water (H2O) is inserted into a material called AlPO4-54·xH2O using techniques like X-ray diffraction and molecular simulations.
  • It was found that water molecules tend to cluster near the walls of the material's pores and that their arrangement is quite disordered.
  • While adding water helps to prevent the material from collapsing, it also leads to the beginning of chemical bonds forming between water and aluminum, which can cause the material to amorphize (lose its crystalline structure).
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