106 research outputs found

    Vitamin K2 and its Impact on Tooth Epigenetics

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    The impact of nutritional signals plays an important role in systemic-based «models» of dental caries. Present hypotheses now focus both on the oral environment and other organs, like the nervous system and brain. The tooth is subjected to shear forces, nourishing and cleansing, and its present “support system” (the hypothalamus/parotid axis) relays endocrine signaling to the parotid gland. Sugar consumption enhances hypothalamic oxidative stress (ROS), reversing dentinal fluid flow, thus creating an enhanced vulnerability to the oral bacterial flora. The acid, produced by the oral bacterial flora, then leads to erosion of the dentine, and an irreversible loss of dental enamel layers. This attack brings about inflammatory responses, yielding metalloproteinase-based “dissolution”. However, vitamin K2 (i.e. MK-4/MK-7) may come to the rescue with its antioxidant property, locally (mouth cavity) or systemically (via the brain), thus sustaining/preserving hormone-induced dentinal fluid flow (encompassing oxidative stress) and boosting/magnifying bodily inflammatory responses. However, sugars may also reduce the tooth’s natural defences through endocrine signaling, thus enhancing acid-supported enamel dentine erosion. Vitamin K2 sustains and improves the salivary buffering capacity via its impact on the secretion/flow of calcium and inorganic phosphates. Interestingly, primitive cultures’ diets (low-sugar and high-K2 diets) preserve dental health

    Developing a New Generation of Integrated Micro-Spec Far Infrared Spectrometers for the EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM)

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    The current state of far-infrared astronomy drives the need to develop compact, sensitive spectrometers for future space and ground-based instruments. Here we present details of the μ\rm \mu-Spec spectrometers currently in development for the far-infrared balloon mission EXCLAIM. The spectrometers are designed to cover the 555714 μ\rm 555 - 714\ \mum range with a resolution of $\rm R\ =\ \lambda / \Delta\lambda\ =\ 512atthe at the \rm 638\ \mumbandcenter.ThespectrometerdesignincorporatesaRowlandgratingspectrometerimplementedinaparallelplatewaveguideonalowlosssinglecrystalSichip,employingNbmicrostripplanartransmissionlinesandthinfilmAlkineticinductancedetectors(KIDs).TheEXCLAIMm band center. The spectrometer design incorporates a Rowland grating spectrometer implemented in a parallel plate waveguide on a low-loss single-crystal Si chip, employing Nb microstrip planar transmission lines and thin-film Al kinetic inductance detectors (KIDs). The EXCLAIM \rm \muSpecdesignisanadvancementuponasuccessful-Spec design is an advancement upon a successful \rm R = 64\ \muSpecprototype,andcanbeconsideredasubmmsuperconductingphotonicintegratedcircuit(PIC)thatcombinesspectraldispersionanddetection.Thedesignoperatesinasingle-Spec prototype, and can be considered a sub-mm superconducting photonic integrated circuit (PIC) that combines spectral dispersion and detection. The design operates in a single M{=}2gratingorder,allowingonespectrometertocoverthefullEXCLAIMbandwithoutrequiringamultiorderfocalplane.TheEXCLAIMinstrumentwillflysixspectrometers,whicharefabricatedonasingle150mmdiameterSiwafer.FabricationinvolvesaflipwaferbondingprocesswithpatterningofthesuperconductinglayersonbothsidesoftheSidielectric.Thespectrometersaredesignedtooperateat100mK,andwillinclude355AlKIDdetectorstargetingagoalofNEP grating order, allowing one spectrometer to cover the full EXCLAIM band without requiring a multi-order focal plane. The EXCLAIM instrument will fly six spectrometers, which are fabricated on a single 150 mm diameter Si wafer. Fabrication involves a flip-wafer-bonding process with patterning of the superconducting layers on both sides of the Si dielectric. The spectrometers are designed to operate at 100 mK, and will include 355 Al KID detectors targeting a goal of NEP {\sim}8\times10^{-19} \rm W/\sqrt{Hz}.Wesummarizethedesign,fabrication,andongoingdevelopmentofthese. We summarize the design, fabrication, and ongoing development of these \rm \mu$-Spec spectrometers for EXCLAIM.Comment: 9 pages, 5 figures, to appear in the Proceedings of the SPIE Astronomical Telescopes + Instrumentation (2022

    Experiment for cryogenic large-aperture intensity mapping: instrument design

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    The experiment for cryogenic large-aperture intensity mapping (EXCLAIM) is a balloon-borne telescope designed to survey star formation in windows from the present to z  =  3.5. During this time, the rate of star formation dropped dramatically, while dark matter continued to cluster. EXCLAIM maps the redshifted emission of singly ionized carbon lines and carbon monoxide using intensity mapping, which permits a blind and complete survey of emitting gas through statistics of cumulative brightness fluctuations. EXCLAIM achieves high sensitivity using a cryogenic telescope coupled to six integrated spectrometers employing kinetic inductance detectors covering 420 to 540 GHz with spectral resolving power R  =  512 and angular resolution ≈4  arc min. The spectral resolving power and cryogenic telescope allow the survey to access dark windows in the spectrum of emission from the upper atmosphere. EXCLAIM will survey 305  deg2 in the Sloan Digital Sky Survey Stripe 82 field from a conventional balloon flight in 2023. EXCLAIM will also map several galactic fields to study carbon monoxide and neutral carbon emission as tracers of molecular gas. We summarize the design phase of the mission
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