93 research outputs found

    Massive haemorrhagic pericardial effusion as the cardiac manifestation of Salmonella enteritidis infection in a severely immunocompromised patient

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    A 41-years-old gentleman was admitted for reduced effort tolerance with non-specific symptoms of weight loss and generalised body weakness. Chest X-ray (CXR) showed cardiomegaly. Echocardiography showed a large pericardial effusion with septation. Emergency pericardiocentesis was performed and pericardial fluid culture grew Salmonella enteritidis (S. enteritidis). He tested positive for the retroviral disease, with a CD4 count of 10 cells/µL. Intravenous (IV) ceftriaxone was administered. A pericardial drain was inserted due to the rapid re-accumulation of pericardial fluid after the initial pericardiocentesis. He also had drainage of his left pleural effusion. He had a guidewire exchange of pericardial drain around 2 weeks after admission, with flushing performed whenever the flow was poor. A repeat echocardiogram showed early signs of constrictive pericarditis with residual pericardial effusion in which intrapericardial fibrinolysis was considered. He was started on antiretroviral therapy (ART) and his condition remained stable. The pericardial drain was kept throughout his admission. Unfortunately, he developed severe sepsis and succumbed to it about a month post-admission

    Charge-coupled devices detectors with high quantum efficiency at UV wavelengths

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    We report on multilayer high efficiency antireflection coating (ARC) design and development for use at UV wavelengths on CCDs and other Si-based detectors. We have previously demonstrated a set of single-layer coatings, which achieve >50% quantum efficiency (QE) in four bands from 130 to 300 nm. We now present multilayer coating designs that significantly outperform our previous work between 195 and 215 nm. Using up to 11 layers, we present several model designs to reach QE above 80%. We also demonstrate the successful performance of 5 and 11 layer ARCs on silicon and fused silica substrates. Finally, we present a five-layer coating deposited onto a thinned, delta-doped CCD and demonstrate external QE greater than 60% between 202 and 208 nm, with a peak of 67.6% at 206 nm

    FIREBall-2: advancing TRL while doing proof-of-concept astrophysics on a suborbital platform

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    Here we discuss advances in UV technology over the last decade, with an emphasis on photon counting, low noise, high efficiency detectors in sub-orbital programs. We focus on the use of innovative UV detectors in a NASA astrophysics balloon telescope, FIREBall-2, which successfully flew in the Fall of 2018. The FIREBall-2 telescope is designed to make observations of distant galaxies to understand more about how they evolve by looking for diffuse hydrogen in the galactic halo. The payload utilizes a 1.0-meter class telescope with an ultraviolet multi-object spectrograph and is a joint collaboration between Caltech, JPL, LAM, CNES, Columbia, the University of Arizona, and NASA. The improved detector technology that was tested on FIREBall-2 can be applied to any UV mission. We discuss the results of the flight and detector performance. We will also discuss the utility of sub-orbital platforms (both balloon payloads and rockets) for testing new technologies and proof-of-concept scientific ideasComment: Submitted to the Proceedings of SPIE, Defense + Commercial Sensing (SI19

    Promoting deoxygenation of triglycerides via Co-Ca loaded SiO2-Al2O3 catalyst

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    Triglycerides and fatty acid derivatives can be converted to hydrocarbon-grade green diesel that are entirely fungible to the fossil fuels. In the present study, deoxygenation (DO) process of triolein was studied by using mesoporous SiO2-Al2O3 supported Co-Ca catalyst. The presence of active metals (Co-Ca) showed high DO activity exclusively via decarboxylation/decarbonylation (deCOx) pathways with maximum hydrocarbon n-(C8-C20) yield of 73%, and high selectivity of n-C15 and n-C17 fractions. This results suggested the acid-base active sites of catalyst provide selective deCOx pathway of triglycerides structure. In additional, the presence of high surface area of Co-Ca/ SiO2-Al2O3 enhance the metal dispersion for better accessment of large molecular reactant with catalyst during DO process. An optimum Co metal content (10 wt.%) for deCOx reaction was observed, while an excess Co content is not preferable due to tendency of cracking effect. The efficiency of Co-Ca/SiO2-Al2O3 was investigated by using non-edible feedstock (e.g. Ceiba oil and Sterculia oil) along with catalyst stability study were carried out. Resulst also indicated that degradation of DO activity was due to the formation of coke

    Detector Performance for the FIREBall-2 UV Experiment

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    We present an overview of the detector for the upcoming Faint Intergalactic Red-shifted Emission Balloon (FIREBall-2) experiment, with a particular focus on the development of device-integrated optical coatings and detector quantum efficiency (QE). FIREBall-2 is designed to measure emission from the strong resonance lines of HI, OVI, and CIV, all red-shifted to 195-225 nm window; its detector is a delta-doped electron multiplying charge coupled device (EM-CCD). Delta-doped arrays, invented at JPL, achieve 100% internal QE from the UV through the visible. External losses due to reflection (~70% in some UV regions) can be mitigated with antireflection coatings (ARCs). Using atomic layer deposition (ALD), thin-film optical filters are incorporated with existing detector technologies. ALD offers nanometer-scale control over film thickness and interface quality, allowing for precision growth of multilayer films. Several AR coatings, including single and multi-layer designs, were tested for FIREBall-2. QE measurements match modeled transmittance behavior remarkably well, showing improved performance in the target wavelength range. Also under development are ALD coatings to enhance QE for a variety of spectral regions throughout the UV (90-320 nm) and visible (320-1000 nm) range both for space-based imaging and spectroscopy as well as for ground-based telescopes

    Acute decompensated heart failure in a non cardiology tertiary referral centre, Sarawak General Hospital (SGH‑HF)

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    Abstract Background: Data on clinical characteristics of acute decompensated heart failure (ADHF) in Malaysia especially in East Malaysia is lacking. Methods: This is a prospective observational study in Sarawak General Hospital, Medical Department, from October 2017 to September 2018. Patients with primary admission diagnosis of ADHF were recruited and followed up for 90 days. Data on patient’s characteristics, precipitating factors, medications and short-term clinical outcomes were recorded. Results: Majority of the patients were classified in lower socioeconomic group and the mean age was 59 years old. Hypertension, diabetes mellitus and dyslipidaemia were the common underlying comorbidities. Heart failure with ischemic aetiology was the commonest ADHF admission precipitating factor. 48.6% of patients were having preserved ejection fraction HF and the median NT-ProBNP level was 4230 pg/mL. Prescription rate of the evidencebased heart failure medication was low. The in-patient mortality and the average length of hospital stay were 7.5% and 5 days respectively. 43% of patients required either ICU care or advanced cardiopulmonary support. The 30-day, 90-day mortality and readmission rate were 13.1%, 11.2%, 16.8% and 14% respectively. Conclusion: Comparing with the HF data from West and Asia Pacific, the short-term mortality and readmission rate were high among the ADHF patients in our study cohort. Maladaptation to evidence-based HF prescription and the higher prevalence of cardiovascular risk factors in younger patients were among the possible issues to be addressed to improve the HF outcome in regions with similar socioeconomic background. Keywords: Acute decompensated heart failure, Epidemiology, Sarawak, Southeast Asia, Malaysi

    Clinical Outcome Predictor using Killip Scoring in Acute Decompensated Heart Failure (ADHF): A Non-Cardiac Centre Pilot Experience

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    Background: Physicians in tertiary centers face a constant challenge in selecting patient with ADHF to be admitted from district healthcare centre, especially with limited resources. Appropriate risk stratification of patients with ADHF would improve the efficiency of our healthcare delivery system. Objective: We aim to find potential relationship between Killip clinical scoring with clinical outcome of ADHF, including in-patient mortality and requirement of advanced cardiorespiratory support. Methods: 35 consecutive cases with a discharge diagnosis of ADHF and admission creatinine clearance of more than 30 were randomly reviewed. Cases were analyzed retrospectively for their Killip score, in-patient mortality, requirement of advance cardiorespiratory care or ICU admission. Results: There were 21 male patients (60%) and 14 female patients. Mean age was 61±19 years old. Mean duration of ward-stay was 6±4 days. Comorbidities were 14 (40%) with history of coronary artery diseases and 17 (49%) with diabetes mellitus. 15 patients (43%) were on at least a single type of guideline directed medication for heart failure. The cohort was almost evenly distributed between those with a Killip score of 2 and above 2. A Killip score of 3 and above was found to have good positive predictive value (87%) for advanced cardio-respiratory care and negative predictive value of 78%. No in-patient death was observed for the group with Killip 2 while 5 deaths were recorded in the group scoring more than 2. A Killip score of 3 had excellent (100%) negative predictive value for in-patient mortality but poor positive predictive value (33%). Significant relationship (p<0.001) was observed for Killip scoring on both outcomes. Conclusion: Killip scoring may be useful for on-call physician to decide the need on tertiary care among patient with ADHF and mortality outcome. However, more prospective studies and patients should be recruited to validate the study

    Charge-coupled devices detectors with high quantum efficiency at UV wavelengths

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    We report on multilayer high efficiency antireflection coating (ARC) design and development for use at UV wavelengths on CCDs and other Si-based detectors. We have previously demonstrated a set of single-layer coatings, which achieve >50% quantum efficiency (QE) in four bands from 130 to 300 nm. We now present multilayer coating designs that significantly outperform our previous work between 195 and 215 nm. Using up to 11 layers, we present several model designs to reach QE above 80%. We also demonstrate the successful performance of 5 and 11 layer ARCs on silicon and fused silica substrates. Finally, we present a five-layer coating deposited onto a thinned, delta-doped CCD and demonstrate external QE greater than 60% between 202 and 208 nm, with a peak of 67.6% at 206 nm

    FIREBall-2: The Faint Intergalactic Medium Redshifted Emission Balloon Telescope

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    The Faint Intergalactic Medium Redshifted Emission Balloon (FIREBall) is a mission designed to observe faint emission from the circumgalactic medium of moderate redshift (z~0.7) galaxies for the first time. FIREBall observes a component of galaxies that plays a key role in how galaxies form and evolve, likely contains a significant amount of baryons, and has only recently been observed at higher redshifts in the visible. Here we report on the 2018 flight of the FIREBall-2 Balloon telescope, which occurred on September 22nd, 2018 from Fort Sumner, New Mexico. The flight was the culmination of a complete redesign of the spectrograph from the original FIREBall fiber-fed IFU to a wide-field multi-object spectrograph. The flight was terminated early due to a hole in the balloon, and our original science objectives were not achieved. The overall sensitivity of the instrument and telescope was 90,000 LU, due primarily to increased noise from stray light. We discuss the design of the FIREBall-2 spectrograph, modifications from the original FIREBall payload, and provide an overview of the performance of all systems. We were able to successfully flight test a new pointing control system, a UV-optimized, delta-doped and coated EMCCD, and an aspheric grating. The FIREBall-2 team is rebuilding the payload for another flight attempt in the Fall of 2021, delayed from 2020 due to COVID-19.Comment: 23 Pages, 14 Figures, Accepted for Publication in Ap
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