416 research outputs found

    Scrub Typhus Presenting as Acute Mastoiditis.

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    Scrub typhus, a zoonosis, is known to present with varied clinical presentation. We present a case of acute mastoiditis who did not respond to conventional antibiotic therapy. The detailed repeat clinical examination revealed lymphadenopathy with eschar and IgM antibodies for scrub typhus by ELISA were positive. Patient had dramatic response to doxycycline therapy

    Doping-induced spin Hall ratio enhancement in A15-phase, Ta-doped β-W thin films

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    As spintronic devices become more and more prevalent, the desire to find Pt-free materials with large spin Hall effects is increasing. Previously it was shown that β-W, the metastable A15 structured variant of pure W, has charge-spin conversion efficiencies on par with Pt, and it was predicted that β-W/Ta alloys should be even more efficient. Here we demonstrate the enhancement of the spin Hall ratio (SHR) in A15-phase β-W films doped with Ta (W4-xTax where x = 0.34 ¹ 0.06) deposited at room temperature using DC magnetron co-sputtering. In close agreement with theoretical predictions, we find that the SHR of the doped films was ~9% larger than pure β-W films. We also found that the SHR's in devices with Co2Fe6B2 were nearly twice as large as the SHR's in devices with Co4Fe4B2. This work shows that by optimizing deposition parameters and substrates, the fabrication of the optimum W3Ta alloy should be feasible, opening the door to commercially viable, Pt-free, spintronic devices

    Determinants of the dynamic cerebral critical closing pressure response to changes in mean arterial pressure

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    Objective. Cerebral critical closing pressure (CrCP) represents the value of arterial blood pressure (BP) where cerebral blood flow (CBF) becomes zero. Its dynamic response to a step change in mean BP (MAP) has been shown to reflect CBF autoregulation, but robust methods for its estimation are lacking. We aim to improve the quality of estimates of the CrCP dynamic response. Approach. Retrospective analysis of 437 healthy subjects (aged 18–87 years, 218 males) baseline recordings with measurements of cerebral blood velocity in the middle cerebral artery (MCAv, transcranial Doppler), non-invasive arterial BP (Finometer) and end-tidal CO2 (EtCO2, capnography). For each cardiac cycle CrCP was estimated from the instantaneous MCAv-BP relationship. Transfer function analysis of the MAP and MCAv (MAP-MCAv) and CrCP (MAP-CrCP) allowed estimation of the corresponding step responses (SR) to changes in MAP, with the output in MCAv (SRVMCAv) representing the autoregulation index (ARI), ranging from 0 to 9. Four main parameters were considered as potential determinants of the SRVCrCP temporal pattern, including the coherence function, MAP spectral power and the reconstruction error for SRVMAP, from the other three separate SRs. Main results. The reconstruction error for SRVMAP was the main determinant of SRVCrCP signal quality, by removing the largest number of outliers (Grubbs test) compared to the other three parameters. SRVCrCP showed highly significant (p < 0.001) changes with time, but its amplitude or temporal pattern was not influenced by sex or age. The main physiological determinants of SRVCrCP were the ARI and the mean CrCP for the entire 5 min baseline period. The early phase (2–3 s) of SRVCrCP response was influenced by heart rate whereas the late phase (10–14 s) was influenced by diastolic BP. Significance. These results should allow better planning and quality of future research and clinical trials of novel metrics of CBF regulation

    Spectroscopic analysis of LiTm F

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    The absorption spectra of Tm3+ in LiTmF4 have been measured at 2, 10, 30, and 50 K in the spectral interval 4000-25 000 cm-1. The energy levels of the ground-state configuration were calculated by diagonalizing the Hamiltonian of the electron-electron interaction, the spin-orbit coupling, and the crystal field in a basis of the whole configuration. The electrostatic parameter F2, the spin-orbit parameter Îś, and the crystal-field parameters Bkq were varied to obtain the best agreement with the experimentally observed levels. As the model does not account for configuration mixing and minor magnetic effects, it was necessary after optimizing F2 and Îś to match the centers of gravity for the multiplets before the final adjustment of the B parameters. When this was done, the standard deviation was lowered from 170 to 12 cm-1. The B parameters obtained for Tm3+ have been compared to those of Tb3+, Ho3+, and Er3+ in LiLnF4, and they follow a common trend. The intensities of the transitions from the ground state were calculated in the Judd-Ofelt scheme, fitting six complex intensity parameters A(kqÎť) for best agreement with the experimentally observed intensities. The model was only able to give a rough estimate of the transition probabilities. The obtained relative standard deviation was 1.1. Contrary to what was found in the case of the energy calculations, it was important for the intensity calculations that the B parameters were allowed to take complex values. The imaginary part of the A parameters was not important to the intensities

    Advances in exosome therapies in ophthalmology–From bench to clinical trial

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    During the last decade, the fields of advanced and personalized therapeutics have been constantly evolving, utilizing novel techniques such as gene editing and RNA therapeutic approaches. However, the method of delivery and tissue specificity remain the main hurdles of these approaches. Exosomes are natural carriers of functional small RNAs and proteins, representing an area of increasing interest in the field of drug delivery. It has been demonstrated that the exosome cargo, especially miRNAs, is at least partially responsible for the therapeutic effects of exosomes. Exosomes deliver their luminal content to the recipient cells and can be used as vesicles for the therapeutic delivery of RNAs and proteins. Synthetic therapeutic drugs can also be encapsulated into exosomes as they have a hydrophilic core, which makes them suitable to carry water-soluble drugs. In addition, engineered exosomes can display a variety of surface molecules, such as peptides, to target specific cells in tissues. The exosome properties present an added advantage to the targeted delivery of therapeutics, leading to increased efficacy and minimizing the adverse side effects. Furthermore, exosomes are natural nanoparticles found in all cell types and as a result, they do not elicit an immune response when administered. Exosomes have also demonstrated decreased long-term accumulation in tissues and organs and thus carry a low risk of systemic toxicity. This review aims to discuss all the advances in exosome therapies in ophthalmology and to give insight into the challenges that would need to be overcome before exosome therapies can be translated into clinical practice
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