99 research outputs found

    Low-temperature plasmonically enhanced single-molecule spectroscopy of fluorescent proteins

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    Ideal bioimaging probes in fluorescence microscopy are bright, biocompatible, offer a large signal-to-noise ratio against autofluorescence, and can be specifically attached to target biomolecules of interest. Fluorescent proteins have been engineered towards this goal. However, a limitation of fluorescent proteins is the quantum yield; the low brightness of the probes limits the contrast between the structure of interest and the background. This limitation can be overcome using plasmonic enhancement by coupling the electronic resonances of the molecule to the plasmonic resonances of a metal nanoparticle with a dominant radiative broadening [1]. This allows an enhanced fluorescence emission of the molecule by increased absorption via near-field enhancement and increased radiative decay rate of the molecule by the Purcell effect, with photons emitted to the far field. Gold nanorods (GNRs) have a surface plasmon resonance which can be tuned by changing their aspect ratio to match the absorption and emission wavelengths of the fluorophore. Therefore, coupling GNRs to fluorescent proteins offers a route toward developing improved imaging probes. Moreover, understanding the photophysical properties of the fluorescent probe used is vital in their application. These properties can be probed at low temperatures where the coupling between the vibrations and electronic transitions is not masked by dominant homogenous broadening

    Morphological evaluation and clinical significance of the supracondylar process and supratrochlear foramen: an anatomic and radiological study

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    Background: In our literature review, we did not encounter any study examining the supracondylar process (SP) and the supratrochlear foramen (STF) with a three-dimensional (3D) reconstruction method. The present study aimed to evaluate SP and STF morphologically by employing the 3D reconstruction method and emphasize their clinical significance. Materials and methods: The research was carried out on dried human humeri of unknown sex and without pathological alterations. A total of 81 humeri (42 right, 39 left) were obtained from the Departments of Anatomy of Gazi University Faculty of Medicine and Lokman Hekim University Faculty of Medicine. The morphometric measurements of SP and STF were made with a digital vernier caliper. The computed tomography (CT) images acquired for radiological evaluation were analyzed with the 3D reconstruction method. Results: The narrower distal medullary canal widths of humeri with STF were found to be statistically significant. No statistically significant difference was found between the transverse diameters (TD), vertical diameters (VD), the distance of the medial edge to the medial epicondyle (ME), and the distance of the lateral edge to the lateral epicondyle (LE) of the supratrochlear foramen of the right and left humeri. Conclusions: The supracondylar process is often evaluated by mistake as a pathological condition of the bone, not as a normal anatomical variation. Knowing different shapes and dimensions, e.g., the TD and VD distance in which STF emerges, can assist in avoiding the misinterpretation of radiographs

    A High-Gradient Test of a 30 GHz Molybdenum-Iris Structure

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    The CLIC study is actively investigating a number of different materials in an effort to find ways to increase achievable accelerating gradient. So far a series of rf tests have been made with a set of identical-geometry structures: a W-iris 30 GHz structure, a Mo-iris 30 GHz structure (with pulses as long as 16 ns) and a scaled Mo-iris X-band structure. A second Mo-iris 30 GHz structure of the same geometry has now been tested in CTF3 with pulse lengths up to 350 ns. The structure was conditioned to a gradient of 140 MV/m with a 70 ns pulse length and a breakdown rate slope of 13 MV/m per decade has been measure

    A Large Hadron Electron Collider at CERN

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    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100) fb1^{-1}. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC

    Left ventricular speckle tracking-derived cardiac strain and cardiac twist mechanics in athletes: a systematic review and meta-analysis of controlled studies

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    Background: The athlete’s heart is associated with physiological remodeling as a consequence of repetitive cardiac loading. The effect of exercise training on left ventricular (LV) cardiac strain and twist mechanics are equivocal, and no meta-analysis has been conducted to date. Objective: The objective of this systematic review and meta-analysis was to review the literature pertaining to the effect of different forms of athletic training on cardiac strain and twist mechanics and determine the influence of traditional and contemporary sporting classifications on cardiac strain and twist mechanics. Methods: We searched PubMed/MEDLINE, Web of Science, and ScienceDirect for controlled studies of aged-matched male participants aged 18–45 years that used two-dimensional (2D) speckle tracking with a defined athlete sporting discipline and a control group not engaged in training programs. Data were extracted independently by two reviewers. Random-effects meta-analyses, subgroup analyses, and meta-regressions were conducted. Results: Our review included 13 studies with 945 participants (controls n = 355; athletes n = 590). Meta-analyses showed no athlete–control differences in LV strain or twist mechanics. However, moderator analyses showed greater LV twist in high-static low-dynamic athletes (d = –0.76, 95% confidence interval [CI] –1.32 to –0.20; p < 0.01) than in controls. Peak untwisting velocity (PUV) was greater in high-static low-dynamic athletes (d = –0.43, 95% CI –0.84 to –0.03; p < 0.05) but less than controls in high-static high-dynamic athletes (d = 0.79, 95% CI 0.002–1.58; p = 0.05). Elite endurance athletes had significantly less twist and apical rotation than controls (d = 0.68, 95% CI 0.19–1.16, p < 0.01; d = 0.64, 95% CI 0.27–1.00, p = 0.001, respectively) but no differences in basal rotation. Meta-regressions showed LV mass index was positively associated with global longitudinal (b = 0.01, 95% CI 0.002–0.02; p < 0.05), whereas systolic blood pressure was negatively associated with PUV (b = –0.06, 95% CI –0.13 to –0.001; p = 0.05). Conclusion: Echocardiographic 2D speckle tracking can identify subtle physiological differences in adaptations to cardiac strain and twist mechanics between athletes and healthy controls. Differences in speckle tracking echocardiography-derived parameters can be identified using suitable sporting categorizations

    HE-LHC: The High-Energy Large Hadron Collider – Future Circular Collider Conceptual Design Report Volume 4

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    In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries
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