2,821 research outputs found

    Predicting late anemia in critical illness

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    INTRODUCTION: Identifying critically ill patients most likely to benefit from pre-emptive therapies will become increasingly important if therapies are to be used safely and cost-effectively. We sought to determine whether a predictive model could be constructed that would serve as a useful decision support tool for the pre-emptive management of intensive care unit (ICU)-related anemia. METHODS: Our cohort consisted of all ICU patients (n = 5,170) admitted to a large tertiary-care academic medical center during the period from 1 July 2000 to 30 June 2001. We divided the cohort into development (n = 3,619) and validation (n = 1,551) sets. Using a set of demographic and physiologic variables available within six hours of ICU admission, we developed models to predict patients who either received late transfusion or developed late anemia. We then constructed a point system to quantify, within six hours of ICU admission, the likelihood of developing late anemia. RESULTS: Models showed good discrimination with receiver operating characteristic curve areas ranging from 0.72 to 0.77, although predicting late transfusion was consistently less accurate than predicting late anemia. A five-item point system predicted likelihood of late anemia as well as existing clinical trial inclusion criteria but resulted in pre-emptive intervention more than two days earlier. CONCLUSION: A rule-based decision support tool using information available within six hours of ICU admission may lead to earlier and more appropriate use of blood-sparing strategies

    Influence of Laser Modulation Frequency on the Performance of Terahertz Photoconductive Switches on Semi-Insulating GaAs Exhibiting Negative Differential Conductance

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    [EN]In typical terahertz time-domain spectroscopy systems, the use of the lock-in technique is necessary because of the low current induced at the receiver so that the laser pump beam must be modulated (chopped) at a frequency much lower than the laser repetition rate. This work shows that, in the case of semi-insulating GaAs (SI-GaAs) antennas, this modulation has an important effect on the antenna current and consequently, on the radiated electromagnetic pulse. There exists a threshold bias (whose value depends on the chopping frequency) where an abrupt increase in the current and consequently, in the terahertz emission takes place. The calculated energy of the pulse below and above the threshold shows that the energy doubles. The exact bias voltage at which this occurs changes with the laser modulation frequency when this is below 350 Hz, but at higher frequencies, the threshold remains almost constant. The experiments show that the responsibility for this behavior is the S-shape negative differential conductance exhibited by SI-GaAs originated by a slow field-enhanced charge trapping mechanism, which is also an important source of noise at the receiver of the system.SpanishMINECO and FEDER under Project TEC2017-83910-R and in Junta de Castilla y León and FEDER under Project SA254P1

    Atrial fibrosis identification with unipolar electrogram eigenvalue distribution analysis in multi-electrode arrays

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    Atrial fbrosis plays a key role in the initiation and progression of atrial fbrillation (AF). Atrial fbrosis is typically identifed by a peak-to-peak amplitude of bipolar electrograms (b-EGMs) lower than 0.5 mV, which may be considered as ablation targets. Nevertheless, this approach disregards signal spatiotemporal information and b-EGM sensitivity to catheter orientation. To overcome these limitations, we propose the dominant-to-remaining eigenvalue dominance ratio (EIGDR) of unipolar electrograms (u-EGMs) within neighbor electrode cliques as a waveform dispersion measure, hypothesizing that it is correlated with the presence of fbrosis. A simulated 2D tissue with a fbrosis patch was used for validation. We computed EIGDR maps from both original and time-aligned u-EGMs, denoted as R and RA, respectively, also mapping the gain in eigenvalue concentration obtained by the alignment, ΔRA. The performance of each map in detecting fbrosis was evaluated in scenarios including noise and variable electrode-tissue distance. Best results were achieved by RA, reaching 94% detection accuracy, versus the 86% of b-EGMs voltage maps. The proposed strategy was also tested in real u-EGMs from fbrotic and non-fbrotic areas over 3D electroanatomical maps, supporting the ability of the EIGDRs as fbrosis markers, encouraging further studies to confrm their translation to clinical settings

    Digital Education in the College of Humanities, Arts and Social Sciences: Discipline Discussions

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    CC BY-NC-ND Flinders UniversityThe research reported here was undertaken by the Digital Education Working Group (DEWG) to achieve the following four objectives, in line with the CHASS Digital Education Action Plan: 1. To better understand the perspectives on, experiences with and plans for digital education across the College to inform further strategy or changes in the College’s approach to digital education. 2. To scope the professional learning and resourcing needs in a systematic and robust way to ensure adequate support is being provided. 3. To gather insights on current discipline-based models of learning and teaching to inform recommendations on the scholarship of teaching, particularly online teaching models. 4. To synthesise current good practice examples. The DEWG research team worked with eight discipline groups across CHASS in 2021: Archaeology, English, Geography, History, Indigenous Studies, Languages, Philosophy, and Screen and Media. This report serves as a high-level synthetic overview of the results of in-depth focus group interviews conducted with staff and makes recommendations about ways forward for digital education, with relevant stakeholders identified at College and University levels. Here, DEWG and the College’s executive leadership team hold responsibility for understanding, driving, improving and supporting the digital education strategies in the College. The report summarises key findings across several key areas

    Incorporating Breast Asymmetry Studies into CADx Systems

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    Breast cancer is one of the global leading causes of death among women, and an early detection is of uttermost importance to reduce mortality rates. Screening mammograms, in which radiologists rely only on their eyesight, are one of the most used early detection methods. However, characteristics, such as the asymmetry between breasts, a feature that could be very difficult to visually quantize, is key to breast cancer detection. Due to the highly heterogeneous and deformable structure of the breast itself, incorporating asymmetry measurements into an automated detection system is still a challenge. In this study, we proposed the use of a bilateral registration algorithm as an effective way to automatically measure mirror asymmetry. Furthermore, this information was fed to a machine learning algorithm to improve the accuracy of the model. In this study, 449 subjects (197 with calcifications, 207 with masses, and 45 healthy subjects) from a public database were used to train and evaluate the proposed methodology. Using this procedure, we were able to independently identify subjects with calcifications (accuracy = 0.825, AUC = 0.882) and masses (accuracy = 0.698, AUC = 0.807) from healthy subjects

    Incidence, clinical characteristics, risk factors and outcomes of meningoencephalitis in patients with COVID-19

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    We investigated the incidence, clinical characteristics, risk factors, and outcome of meningoencephalitis (ME) in patients with COVID-19 attending emergency departments (ED), before hospitalization. We retrospectively reviewed all COVID patients diagnosed with ME in 61 Spanish EDs (20% of Spanish EDs, COVID-ME) during the COVID pandemic. We formed two control groups: non-COVID patients with ME (non-COVID-ME) and COVID patients without ME (COVID-non-ME). Unadjusted comparisons between cases and controls were performed regarding 57 baseline and clinical characteristics and 4 outcomes. Cerebrospinal fluid (CSF) biochemical and serologic findings of COVID-ME and non-COVID-ME were also investigated. We identified 29 ME in 71,904 patients with COVID-19 attending EDs (0.40‰, 95%CI=0.27-0.58). This incidence was higher than that observed in non-COVID patients (150/1,358,134, 0.11‰, 95%CI=0.09-0.13; OR=3.65, 95%CI=2.45-5.44). With respect to non-COVID-ME, COVID-ME more frequently had dyspnea and chest X-ray abnormalities, and neck stiffness was less frequent (OR=0.3, 95%CI=0.1-0.9). In 69.0% of COVID-ME, CSF cells were predominantly lymphocytes, and SARS-CoV-2 antigen was detected by RT-PCR in 1 patient. The clinical characteristics associated with a higher risk of presenting ME in COVID patients were vomiting (OR=3.7, 95%CI=1.4-10.2), headache (OR=24.7, 95%CI=10.2-60.1), and altered mental status (OR=12.9, 95%CI=6.6-25.0). COVID-ME patients had a higher in-hospital mortality than non-COVID-ME patients (OR=2.26; 95%CI=1.04-4.48), and a higher need for hospitalization (OR=8.02; 95%CI=1.19-66.7) and intensive care admission (OR=5.89; 95%CI=3.12-11.14) than COVID-non-ME patients. ME is an unusual form of COVID presentation (<0.5‰ cases), but is more than 4-fold more frequent than in non-COVID patients attending the ED. As the majority of these MEs had lymphocytic predominance and in one patient SARS-CoV-2 antigen was detected in CSF, SARS-CoV-2 could be the cause of most of the cases observed. COVID-ME patients had a higher unadjusted in-hospital mortality than non-COVID-ME patients

    Therapeutic vaccine in chronically Hiv-1-infected patients

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    Therapeutic vaccinations aim to re-educate human immunodeficiency virus (HIV)-1specific immune responses to achieve durable control of HIV-1 replication in virally suppressed infected individuals after antiretroviral therapy (ART) is interrupted. In a double blinded, placebocontrolled phase IIa multicenter study, we investigated the safety and immunogenicity of intranodal administration of the HIVACAT T cell Immunogen (HTI)-TriMix vaccine. It consists of naked mRNA based on cytotoxic T lymphocyte (CTL) targets of subdominant and conserved HIV-1 regions (HTI), in combination with mRNAs encoding constitutively active TLR4, the ligand for CD40 and CD70 as adjuvants (TriMix). We recruited HIV-1-infected individuals under stable ART. Study-arms HTI-TriMix, TriMix or Water for Injection were assigned in an 8:3:3 ratio. Participants received three vaccinations at weeks 0, 2, and 4 in an inguinal lymph node. Two weeks after the last vaccination, immunogenicity was evaluated using ELISpot assay. ART was interrupted at week 6 to study the effect of the vaccine on viral rebound. The vaccine was considered safe and well tolerated. Eighteen percent (n = 37) of the AEs were considered definitely related to the study product (grade 1 or 2). Three SAEs occurred: two were unrelated to the study product, and one was possibly related to ART interruption (ATI). ELISpot assays to detect T cell responses using peptides covering the HTI sequence showed no significant differences in immunogenicity between groups. There were no significant differences in viral load rebound dynamics after ATI between groups. The vaccine was safe and well tolerated. We were not able to demonstrate immunogenic effects of the vaccine

    The oncolytic virus Delta-24-RGD elicits an antitumor effect in pediatric glioma and DIPG mouse models

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    Pediatric high-grade glioma (pHGG) and diffuse intrinsic pontine gliomas (DIPGs) are aggressive pediatric brain tumors in desperate need of a curative treatment. Oncolytic virotherapy is emerging as a solid therapeutic approach. Delta-24-RGD is a replication competent adenovirus engineered to replicate in tumor cells with an aberrant RB pathway. This virus has proven to be safe and effective in adult gliomas. Here we report that the administration of Delta-24-RGD is safe in mice and results in a significant increase in survival in immunodeficient and immunocompetent models of pHGG and DIPGs. Our results show that the Delta-24-RGD antiglioma effect is mediated by the oncolytic effect and the immune response elicited against the tumor. Altogether, our data highlight the potential of this virus as treatment for patients with these tumors. Of clinical significance, these data have led to the start of a phase I/II clinical trial at our institution for newly diagnosed DIPG (NCT03178032)

    LEMUR: Large European Module for Solar Ultraviolet Research

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    The solar outer atmosphere is an extremely dynamic environment characterized by the continuous interplay between the plasma and the magnetic field that generates and permeates it. Such interactions play a fundamental role in hugely diverse astrophysical systems, but occur at scales that cannot be studied outside the solar system. Understanding this complex system requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1 and 0.3), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 170 Angstrom and 1270 Angstrom. The LEMUR slit covers 280 on the Sun with 0.14 per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km s 1 or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission
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