677 research outputs found

    Design and construction of a point-contact spectroscopy rig with lateral scanning capability

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    The design and realization of a cryogenic rig for point-contact spectroscopy measurements in the needle-anvil configuration is presented. Thanks to the use of two piezoelectric nano-positioners, the tip can move along the vertical (zz) and horizontal (xx) direction and thus the rig is suitable to probe different regions of a sample \textit{in situ}. Moreover, it can also form double point-contacts on different facets of a single crystal for achieving, e.g., an interferometer configuration for phase-sensitive measurements. For the latter purpose, the sample holder can also host a Helmholtz coil for applying a small transverse magnetic field to the junction. A semi-rigid coaxial cable can be easily added for studying the behavior of Josephson junctions under microwave irradiation. The rig can be detached from the probe and thus used with different cryostats. The performance of this new probe has been tested in a Quantum Design PPMS system by conducting point-contact Andreev reflection measurements on Nb thin films over large areas as a function of temperature and magnetic field.Comment: 7 pages, 7 figures, published in Rev. Sci. Instru

    A percutaneous needle biopsy technique for sampling the supraclavicular brown adipose tissue depot of humans.

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    Brown adipose tissue (BAT) has been proposed as a potential target tissue against obesity and its related metabolic complications. Although the molecular and functional characteristics of BAT have been intensively studied in rodents, only a few studies have used human BAT specimens due to the difficulty of sampling human BAT deposits. We established a novel positron emission tomography and computed tomography-guided Bergström needle biopsy technique to acquire human BAT specimens from the supraclavicular area in human subjects. Forty-three biopsies were performed on 23 participants. The procedure was tolerated well by the majority of participants. No major complications were noted. Numbness (9.6%) and hematoma (2.3%) were the two minor complications noted, which fully resolved. Thus, the proposed biopsy technique can be considered safe with only minimal risk of adverse events. Adoption of the proposed method is expected to increase the sampling of the supraclavicular BAT depot for research purposes so as to augment the scientific knowledge of the biology of human BAT

    Accidental Ingestion of Endodontic File: A Case Report

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    Ingestion of the endodontic instrument during root canal treatment is rare but can result in serious complications. The present paper reports a case in which endodontic file was accidentally swallowed by the patient undergoing root canal therapy, which entered digestive tract and passed uneventfully

    QUANTIFICATION USING ULTRAVIOLET SPECTROSCOPY METHOD AND IN VITRO STABILITY STUDY OF NANOVESICULAR SYSTEM CONTAINING PHYTIC ACID

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    Objective: The quantification of drug and stability of nanoparticulate delivery systems is one of the major apprehensions in biomedical applications. The present research work was attempted to quantify phytic acid by utilizing ultraviolet (UV) spectroscopy method and to evaluate the stability of nanovesicular (niosomes) system containing phytic acid.Methods: Niosomes containing phytic acid were developed by thin-film hydration method. Nanoformulation was subjected to stability testing as per the International Council for Harmonisation (ICH) guidelines. The formulation was stored at 30°C±2°C and 65%±5% RH, samples were withdrawn at 15th, 30th, 60th, 90th, 120th, and 180th day of analysis and examined for the integrity of vesicular/particle size, polydispersity index, zeta potential, and percent encapsulation efficiency.Results: Prepared nanoformulation displayed a straight line (y=mx+c) equation of y=−0.0309x+1.0413. Optimized batch of niosomes, which was prepared including dicetylphosphate showed zeta potential value of −36±0.36. Stability study showed that prepared niosomal formulation was stable up to 180 days at room temperature.Conclusion: Findings of the current research work suggested that UV spectroscopy method can be effectively used for the quantification of phytic acid and niosomal formulation of phytic acid. The formulation was found to be stable as per the ICH guidelines for stability testing

    Submitral aneurysm in children: A rare entity with varied presentation!

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    AbstractWe present echocardiographic images in two children with a diagnosis of submitral aneurysm. Both had absolutely different presentations. The diagnosis was established on echocardiography and no advanced imaging techniques were used

    A Comparative Review of Electrolytes for Organic-Material-Based Energy-Storage Devices Employing Solid Electrodes and Redox Fluids

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    Electrolyte chemistry is critical for any energy‐storage device. Low‐cost and sustainable rechargeable batteries based on organic redox‐active materials are of great interest to tackle resource and performance limitations of current batteries with metal‐based active materials. Organic active materials can be used not only as solid electrodes in the classic lithium‐ion battery (LIB) setup, but also as redox fluids in redox‐flow batteries (RFBs). Accordingly, they have suitability for mobile and stationary applications, respectively. Herein, different types of electrolytes, recent advances for designing better performing electrolytes, and remaining scientific challenges are discussed and summarized. Due to different configurations and requirements between LIBs and RFBs, the similarities and differences for choosing suitable electrolytes are discussed. Both general and specific strategies for promoting the utilization of organic active materials are covered.So solid storage : The use of organic redox‐active materials is a new tendency for rechargeable batteries, either as traditional solid‐state electrode materials in lithium‐ion batteries or as dissolved redox fluidic species in liquid electrolytes for redox flow batteries. The performance‐limiting scenarios and some illuminating improvements by formulating electrolytes are reviewed

    Regulation of the CRL4(Cdt2) ubiquitin ligase and cell-cycle exit by the SCF(Fbxo11) ubiquitin ligase

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    F-box proteins and DCAF proteins are the substrate binding subunits of the Skp1-Cul1-F-box protein (SCF) and Cul4-RING protein ligase (CRL4) ubiquitin ligase complexes, respectively. Using affinity purification and mass spectrometry, we determined that the F-box protein FBXO11 interacts with CDT2, a DCAF protein that controls cell-cycle progression, and recruits CDT2 to the SCF(FBXO11)complex to promote its proteasomal degradation. In contrast to most SCF substrates, which exhibit phosphodegron-dependent binding to F-box proteins, CDK-mediated phosphorylation of Thr464 present in the CDT2 degron inhibits recognition by FBXO11. Finally, our results show that the functional interaction between FBXO11 and CDT2 is evolutionary conserved from worms to humans and plays an important role in regulating the timing of cell-cycle exit.Fil: Rossi, Mario. University Of New York; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biomedicina de Buenos Aires; ArgentinaFil: Duan, Shanshan. University Of New York; Estados Unidos. Howard Hughes Medical Institute; Estados UnidosFil: Jeong, Yeon Tae. University Of New York; Estados UnidosFil: Horn, Moritz. Max Planck Institute for Biology of Ageing; Alemania. University of Cologne; AlemaniaFil: Saraf, Anita. The Stowers Institute for Medical Research; Estados UnidosFil: Florens, Laurence. The Stowers Institute for Medical Research; Estados UnidosFil: Washburn, Michael P.. The Stowers Institute for Medical Research; Estados Unidos. University of Kansas; Estados UnidosFil: Antebi, Adam. Max Planck Institute for Biology of Ageing; Alemania. University of Cologne; AlemaniaFil: Pagano, Michele. University Of New York; Estados Unidos. Howard Hughes Medical Institute; Estados Unido

    ONE-DIMENSIONAL CUTTING STOCK PROBLEM (1D-CSP): A STUDY ON DATA DEPENDENT TRIM LOSS

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    ABSTRACT A generalized approach is introduced for getting minimal trim in one-dimensional cutting stock problem (1D-CSP) which occurs extensively while manufacturing of different engineering objects. Our study is especially focused on transmission tower manufacturing industry. The concept of computing total trim by using the idea of pre-defined sustainable trim has been explored in previous work of authors. Given m stock lengths ܷ ଵ , ܷ ଶ , … , ܷ , the cutting plan consists of cutting of at most two order lengths at a time out of the demanded set of n order lengths ݈ ଵ , ݈ ଶ , … , ݈ . Considering the given data, the total trim has been computed corresponding to two different sustainable trims of order one (viz.‫ݐ‬ ௦ ଵ ) and order two (viz.‫ݐ‬ ௦ ଶ ). Introducing various values of sustainable trims as knots between ‫ݐ‬ ௦ ଵ and ‫ݐ‬ ௦ ଶ , the total trim has been computed corresponding to each knot, the linear approximation has been constructed which predict the total trim loss at any arbitrary point ‫ݐ‬ lying between ‫ݐ‬ ௦ ଵ and ‫ݐ‬ ௦ ଶ
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