358 results match your criteria: "National Institute of Optics[Affiliation]"

The development of quantum simulators, artificial platforms where the predictions of many-body theories of correlated quantum materials can be tested in a controllable and tunable way, is one of the main challenges of condensed matter physics. Here we introduce artificial lattices made of lead halide perovskite nanocubes as a new platform to simulate and investigate the physics of correlated quantum materials. We demonstrate that optical injection of quantum confined excitons in this system realizes the two main features that ubiquitously pervade the phase diagram of many quantum materials: collective phenomena, in which long-range orders emerge from incoherent fluctuations, and the excitonic Mott transition, which has one-to-one correspondence with the insulator-to-metal transition described by the repulsive Hubbard model in a magnetic field.

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Synthesis of superconducting phase of LaCeHat high pressures.

J Phys Condens Matter

November 2023

Department of Physics and Texas Center for Superconductivity, University of Houston, Houston TX 77204, United States of America.

Clathrate hydrideFm3-m-LaHhas been proven as the most extraordinary superconductor with the critical temperatureabove 250 K upon compression of hundreds of GPa in recent years. A general hope is to reduce the stabilization pressure and maintain the highvalue of the specific phase in LaH. However, strong structural instability distortsFm3-mstructure and leads to a rapid decrease ofat low pressures.

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Sintering, Mechanical and Optical Properties of TiB Composites with and without High-Energy Milling.

Nanomaterials (Basel)

September 2023

Institute of Science, Technology and Sustainability for Ceramic, National Research Council of Italy, Via Granarolo 64, I-48018 Faenza, Italy.

TiB is a promising material for several fields including impact-resistant armor, wear-resistant coatings, cutting tools and crucibles given its physical, mechanical and chemical properties, especially due to the combination of high hardness and exceptional wear resistance. It is however very difficult to sinter below 2000 °C, even under mechanical pressure; moreover, the low fracture toughness limits the applicability of the ceramic material. By using sintering additives, it is possible to improve the sintering process and increase the mechanical properties since the additives react with oxidized layers and form secondary phases.

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A cellular resolution atlas of Broca's area.

Sci Adv

October 2023

Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.

Brain cells are arranged in laminar, nuclear, or columnar structures, spanning a range of scales. Here, we construct a reliable cell census in the frontal lobe of human cerebral cortex at micrometer resolution in a magnetic resonance imaging (MRI)-referenced system using innovative imaging and analysis methodologies. MRI establishes a macroscopic reference coordinate system of laminar and cytoarchitectural boundaries.

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-cells within the endocrine pancreas are fundamental for glucose, lipid and protein homeostasis. Gap junctions between cells constitute the primary coupling mechanism through which cells synchronize their electrical and metabolic activities. This evidence is still only partially investigated through models and numerical simulations.

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Water-lipid interface in lipidic mesophases with excess water.

Faraday Discuss

February 2024

Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland.

This study investigates the influence of excess water on the lipidic mesophase during the phase transition from diamond cubic phase (3̄) to reverse hexagonal phase (). Using a combination of small angle X-ray scattering (SAXS), broadband dielectric spectroscopy (BDS), and Fourier transform infrared (FTIR) techniques, we explore the dynamics of lipids and their interaction with water during phase transition. Our BDS results reveal three relaxation processes originating from lipids, all of which exhibit a kink during the phase transition.

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Alzheimer's disease (AD) is a debilitating neurological condition characterized by cognitive decline, memory loss, and behavioral skill impairment, features that worsen with time. Early diagnosis will likely be the most effective therapy for Alzheimer's disease since it can ensure timely pharmacological treatments that can reduce the irreversible progression and delay the symptoms. Amyloid β-peptide 1-42 (Aβ (1-42)) is considered one of the key pathological AD biomarkers that is present in different biological fluids.

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Article Synopsis
  • The Brain Imaging Data Structure (BIDS) is a collaborative standard designed to organize various neuroscience data and metadata.
  • The paper details the history, principles, and mechanisms behind the development and expansion of BIDS, alongside the challenges it faces as it evolves.
  • It also shares lessons learned from the project to help researchers in other fields apply similar successful strategies.
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We investigate nonlinear THz generation from lithium niobate films and crystals of different thicknesses by optical rectification of near-infrared femtosecond pulses. A comparison between numerical studies and polarization-resolved measurements of the generated THz signal reveals a 2 orders of magnitude enhancement in the nonlinear response compared to optical frequencies. We show that this enhancement is due to optical phonon modes at 4.

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The use of sunglasses and polarized sunglasses is common in all aspects of life and is very popular in outdoor athletic activities. However, the choice of athletes regarding their sunglasses is often not dictated by the performance ensured by one model rather than another but by other factors such as look or wearability due also to the lack of technical data on cataloguess. A conscious choice of filters to use, also according to road and weather conditions, supported by quantitative data, would instead allow athletes to improve their visual comfort and sport experience.

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Circularly polarized luminescence (CPL) is increasingly gaining interest not only for its applicative potentialities but also for providing an understanding of the excited state properties of chiral molecules. However, applications of CPL are mainly in the field of materials science: special organic molecules and polymers, metal (lanthanide) complexes, and organic dyes are actively and intensely studied. So far natural compounds have not been investigated much.

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Systemic administration of Nogo-A-neutralizing antibody ameliorates experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, the blood-brain barrier (BBB) is a major obstacle limiting the passage of systemically applied antibody to the CNS. To bypass the BBB, in the present study we tested the intranasal route of administration by targeting the olfactory mucosa with the Nogo-A-blocking antibody 11C7 mAb in myelin oligodendrocyte glycoprotein-induced EAE.

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Brain-wide neuron quantification toolkit reveals strong sexual dimorphism in the evolution of fear memory.

Cell Rep

August 2023

European Laboratory for Non-linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy; Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy; National Institute of Optics - National Research Council (CNR-INO), Sesto Fiorentino, Italy. Electronic address:

Fear responses are functionally adaptive behaviors that are strengthened as memories. Indeed, detailed knowledge of the neural circuitry modulating fear memory could be the turning point for the comprehension of this emotion and its pathological states. A comprehensive understanding of the circuits mediating memory encoding, consolidation, and retrieval presents the fundamental technological challenge of analyzing activity in the entire brain with single-neuron resolution.

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Natural aminosterols are promising drug candidates against neurodegenerative diseases, like Alzheimer and Parkinson, and one relevant protective mechanism occurs via their binding to biological membranes and displacement or binding inhibition of amyloidogenic proteins and their cytotoxic oligomers. We compared three chemically different aminosterols, finding that they exhibited different (i) binding affinities, (ii) charge neutralizations, (iii) mechanical reinforcements, and (iv) key lipid redistributions within membranes of reconstituted liposomes. They also had different potencies (EC) in protecting cultured cell membranes against amyloid-β oligomers.

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Imaging Approaches to Investigate Pathophysiological Mechanisms of Brain Disease in Zebrafish.

Int J Mol Sci

June 2023

European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy.

Zebrafish has become an essential model organism in modern biomedical research. Owing to its distinctive features and high grade of genomic homology with humans, it is increasingly employed to model diverse neurological disorders, both through genetic and pharmacological intervention. The use of this vertebrate model has recently enhanced research efforts, both in the optical technology and in the bioengineering fields, aiming at developing novel tools for high spatiotemporal resolution imaging.

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Fiber-Based SERS-Fluidic Polymeric Platforms for Improved Optical Analysis of Liquids.

Bioengineering (Basel)

June 2023

European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy.

Downsizing surface-enhanced Raman spectroscopy (SERS) within microfluidic devices has opened interesting perspectives for the development of low-cost and portable (bio)sensors for the optical analysis of liquid samples. Despite the research efforts, SERS-fluidic devices still rely either on the use of expensive bulky set-ups or on polymeric devices giving spurious background signals fabricated via expensive manufacturing processes. Here, polymeric platforms integrating fluidics and optics were fabricated with versatile designs allowing easy coupling with fiber-based Raman systems.

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A passive flexible patch for human skin temperature measurement based on contact sensing and contactless interrogation is presented. The patch acts as an RLC resonant circuit embedding an inductive copper coil for magnetic coupling, a ceramic capacitor as the temperature-sensing element and an additional series inductor. The temperature affects the capacitance of the sensor and consequently the resonant frequency of the RLC circuit.

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Multi-Scale Femtosecond-Laser Texturing for Photothermal Efficiency Enhancement on Solar Absorbers Based on TaB Ceramics.

Nanomaterials (Basel)

May 2023

Institute of Structure of Matter, National Research Council (CNR-ISM), Montelibretti Section, Via Salaria km 29.300, I-00015 Monterotondo Scalo, Italy.

Tantalum boride is an ultra-refractory and ultra-hard ceramic known so far for its favorable high-temperature thermo-mechanical properties and also characterized by a low spectral emittance, making it interesting for novel high-temperature solar absorbers for Concentrating Solar Power. In this work, we investigated two types of TaB sintered products with different porosities, and on each of them, we realized four femtosecond laser treatments differing in the accumulated laser fluence. The treated surfaces were then characterized by SEM-EDS, roughness analysis, and optical spectrometry.

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Metasurfaces can be opportunely and specifically designed to manipulate electromagnetic wavefronts. In recent years, a large variety of metasurface-based optical devices such as planar lenses, beam deflectors, polarization converters, and so on have been designed and fabricated. Of particular interest are tunable metasurfaces, which allow the modulation of the optical response of a metasurface; for instance, the variation in the focal length of a converging metalens.

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Mechanisms underlying cardiac arrhythmias are typically driven by abnormalities in cardiac conduction and/or heterogeneities in repolarization time (RT) across the heart. While conduction slowing can be caused by either electrophysiological defects or physical blockade in cardiac tissue, RT heterogeneities are mainly related to action potential (AP) prolongation or abbreviation in specific areas of the heart. Importantly, the size of the area with altered RT and the difference between the short RT and long RT (RT gradient) have been identified as critical determinators of arrhythmogenicity.

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Luminescent solar concentrators (LSCs) are a class of optical devices able to harvest, downshift, and concentrate sunlight, thanks to the presence of emitting materials embedded in a polymer matrix. Use of LSCs in combination with silicon-based photovoltaic (PV) devices has been proposed as a viable strategy to enhance their ability to harvest diffuse light and facilitate their integration in the built environment. LSC performances can be improved by employing organic fluorophores with strong light absorption in the center of the solar spectrum and intense, red-shifted emission.

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Preserving and analytically examining daguerreotypes is particularly challenging because of their multi-material and multi-component structure. Various sensors have been exploited to examine mainly the image plates of the daguerreotypes even though the degradation goes beyond this component. Micro-analyses have been the preferred method due to the nanoscale structure of the image particles.

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High cholesterol levels are a risk factor for the development of Alzheimer's disease. Experiments investigating the influence of cholesterol on the proteolytic processing of the amyloid precursor protein (APP) by the β-secretase Bace1 and on their proximity in cells have led to conflicting results. By using a fluorescence bioassay coupled with flow cytometry we found a direct correlation between the increase in membrane cholesterol amount and the degree of APP shedding in living human neuroblastoma cells.

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A Guide to Perform 3D Histology of Biological Tissues with Fluorescence Microscopy.

Int J Mol Sci

April 2023

European Laboratory for Non-linear Spectroscopy, LENS, 50019 Sesto Fiorentino, Italy.

Article Synopsis
  • - The analysis of tissue alterations is essential in pathology for accurate diagnoses, and new techniques in tissue clearing and fluorescence microscopy have enabled 3D studies of biological tissues.
  • - Combining advanced fluorescence microscopy with classical staining methods like H&E has led to the development of 3D histology, allowing for more detailed observations of tissue structures.
  • - The use of fluorescence staining techniques allows for comparable results to traditional methods, making 3D imaging accessible for pathologists and opening up new possibilities in clinical pathology.
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