76 research outputs found

    Thermal Kinetic Inductance Detector (TKIDs) Camera: A Pathfinder mm-Wave Polarimeter

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    Thermal kinetic inductance detectors (TKIDs) are novel, superconductive, frequency-multiplexed bolometric detectors that promise the same noise performance as traditional transition-edge superconducting bolometers, but with ease of scalability to large array formats. This research starts with TKIDs being in the early stage of development. Readout hardware and strategies were developed to characterize the first batches of devices, still in the chips form containing a few detectors. The success of the TKIDs chips lead to a more in-depth exploration of the detector physics and the possibility to scale from chips containing tens of detectors to tiles counting hundreds. Novel characterization techniques were developed to deal with the testing of the arrays in a laboratory environment. Finally, the characterization of a science grade tile is detailed

    A flexible GPU-accelerated radio-frequency readout for superconducting detectors

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    We have developed a flexible radio-frequency readout system suitable for a variety of superconducting detectors commonly used in millimeter and submillimeter astrophysics, including kinetic inductance detectors (KIDs), Thermal KID bolometers, and quantum capacitance detectors. Our system avoids custom FPGA-based readouts and instead uses commercially available software radio hardware for analog to digital converter chip/digital to analog converter chip and a GPU to handle real-time signal processing. Because this system is written in common C++/CUDA, the range of different algorithms that can be quickly implemented make it suitable for the readout of many others cryogenic detectors and for the testing of different and possibly more effective data acquisition schemes

    A flexible GPU-accelerated radio-frequency readout for superconducting detectors

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    We have developed a flexible radio-frequency readout system suitable for a variety of superconducting detectors commonly used in millimeter and submillimeter astrophysics, including kinetic inductance detectors (KIDs), Thermal KID bolometers, and quantum capacitance detectors. Our system avoids custom FPGA-based readouts and instead uses commercially available software radio hardware for analog to digital converter chip/digital to analog converter chip and a GPU to handle real-time signal processing. Because this system is written in common C++/CUDA, the range of different algorithms that can be quickly implemented make it suitable for the readout of many others cryogenic detectors and for the testing of different and possibly more effective data acquisition schemes

    Inhibitors of lactate dehydrogenase (hLDH5) from Polygala flavescens subsp. flavescens

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    The human isoform 5 of lactate dehydrogenase (hLDH5) is an enzyme up-regulated in tumor tissues since cancer cells depend mainly on anaerobic respiration and their glycolytic rate is up to 200 times higher than that of the normal tissue. hLDH5 inhibition should cause cancer cell death by starvation, without interfering with healthy cells that normally use oxidative phosphorylation for ATP generation. Inhibition of LDH is so considered as a promising target in cancer treatment, since it is possible to cause a starving of cancerous cells by reducing glycolysis or by inhibiting the conversion of glucose to lactate. In the course of our research program on the hLDH5 inhibitory activity of natural products [1], a chemical study of P. flavescens subsp. flavescens was carried out. Polygala L. genus (Polygalaceae) is well known to contain phenolic oligosaccharides, xanthones, lignans, and triterpenic saponins and it’s largely used in the traditional medicine [2]. Ten new compounds were isolated from the n-BuOH residue of the aerial parts through Sephadex and RP-HPLC separations, including four flavonol glycosides, two oligosaccharides, one α-ionone, and three triterpenoidic saponins, together with two known oligosaccharides and two flavonol glycosides. All structures were elucidated on the basis of their spectroscopic and spectrometric data. The isolates were assayed for their inhibitory activity against hLDH5 and 3,6'-di-O-sinapoylsucrose showed an IC50 value of 90.4 µM. Modeling studies were carried out to suggest the putative interaction mode of this compound in the enzyme active site. This analysis highlighted that 3,6'-di-O-sinapoylsucrose shows a high number of H-bonds and interacts with enzyme regions rarely explored by the known hLDH5 inhibitors

    Synthesis and Biological Evaluation of New Glycoconjugated LDH Inhibitors as Anticancer Agents

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    Conjugation of known biologically active molecules to carbohydrate frameworks represents a valuable option for the preparation of hybrid, structurally-related families of compounds with the aim of modulating their biological response. Therefore, we present here a study on the preparation of d-galacto, d-manno, d-gluco, and d-lactose glycoconjugates of an established N-hydroxyindole-based (NHI) inhibitor of lactated dehydrogenase (LDH). Structural variations involved the sugar stereochemistry and size as well as the anchoring point of the NHI on the carbohydrate frame (either C-1 or C-6). In the case of the galactose anomeric glycoconjugate (C-1), intriguing solvent-dependent eects were observed in the glycosylation stereochemical outcome. The biological activity of the deprotected glycoconjugates in contrasting lactate formation and cancer cell proliferation are described

    Thermal Kinetic Inductance Detectors for millimeter-wave detection

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    Thermal Kinetic Inductance Detectors (TKIDs) combine the excellent noise performance of traditional bolometers with a radio frequency multiplexing architecture that enables the large detector counts needed for the next generation of millimeter-wave instruments. In this paper, we first discuss the expected noise sources in TKIDs and derive the limits where the phonon noise contribution dominates over the other detector noise terms: generation-recombination, amplifier, and two-level system (TLS) noise. Second, we characterize aluminum TKIDs in a dark environment. We present measurements of TKID resonators with quality factors of about 10510^5 at 80 mK. We also discuss the bolometer thermal conductance, heat capacity, and time constants. These were measured by the use of a resistor on the thermal island to excite the bolometers. These dark aluminum TKIDs demonstrate a noise equivalent power NEP = 2×10−17W/Hz2 \times 10^{-17} \mathrm{W}/\mathrm{\sqrt{Hz}} , with a 1/f1/f knee at 0.1 Hz, which provides background noise limited performance for ground-based telescopes observing at 150 GHz.Comment: 15 pages, 12 figure

    Antenna-coupled thermal kinetic inductance detectors for ground-based millimeter-wave cosmology

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    We present our design for antenna-coupled thermal kinetic inductance detectors (TKIDs) designed for Cosmic Microwave Background (CMB) observations in the 150 GHz band. The next generation of telescopes studying the CMB will require large arrays of detectors on cryogenic focal planes to achieve high sensitivity at the cost of increased integration and readout complexity. TKIDs have demonstrated photon-limited noise performance comparable to traditional bolometers with a radiofrequency (RF) multiplexing architecture that enables the large detector counts needed. We characterize TKIDs fabricated for observing the CMB in a frequency band centered at 150 GHz and discuss the optical performance. These devices are a critical step towards fielding a Keck Array camera with 512 devices on the focal plane at the South Pole

    Adaptation strategies and neurophysiological response in early-stage Parkinson's disease: BioVRSea approach

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    Introduction: There is accumulating evidence that many pathological conditions affecting human balance are consequence of postural control (PC) failure or overstimulation such as in motion sickness. Our research shows the potential of using the response to a complex postural control task to assess patients with early-stage Parkinson's Disease (PD). Methods: We developed a unique measurement model, where the PC task is triggered by a moving platform in a virtual reality environment while simultaneously recording EEG, EMG and CoP signals. This novel paradigm of assessment is called BioVRSea. We studied the interplay between biosignals and their differences in healthy subjects and with early-stage PD. Results: Despite the limited number of subjects (29 healthy and nine PD) the results of our work show significant differences in several biosignals features, demonstrating that the combined output of posturography, muscle activation and cortical response is capable of distinguishing healthy from pathological. Discussion: The differences measured following the end of the platform movement are remarkable, as the induced sway is different between the two groups and triggers statistically relevant cortical activities in α and θ bands. This is a first important step to develop a multi-metric signature able to quantify PC and distinguish healthy from pathological response
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