4,912 research outputs found
Amiodarone-Induced Pulmonary Toxicity - A Frequently Missed Complication.
IntroductionAmiodarone is often used in the suppression of tachyarrhythmias. One of the more serious adverse effects includes amiodarone pulmonary toxicity (APT). Several pulmonary diseases can manifest including interstitial pneumonitis, organizing pneumonia, acute respiratory distress syndrome, diffuse alveolar hemorrhage, pulmonary nodules or masses, and pleural effusion. Incidence of APT varies from 5-15% and is correlated to dosage, age of the patient, and preexisting lung disease.DescriptionA 56-year-old male with a past medical history of coronary artery disease and chronic obstructive pulmonary disease was admitted for a coronary artery bypass graft. Post-operatively, the patient was admitted to the ICU for ventilator management and continued to receive his home dose of amiodarone 400 mg orally twice daily, which he had been taking for the past 3 months. The patient was found to be hypoxemic with a PaO2 52 mmHg and bilateral infiltrates on chest x-ray. Patient also complained of new onset dyspnea. Physical exam found bilateral rhonchi with bibasilar crackles and subcutaneous emphysema along the left anterior chest wall. Daily chest x-rays showed worsening of bilateral interstitial infiltrates and pleural effusions. A chest high-resolution computed tomography on post-operative day 3 showed extensive and severe bilateral ground glass opacities. APT was suspected and amiodarone was discontinued. A course of oral prednisone without antibiotics was initiated, and after one week of treatment the chest film cleared, the PaO2 value normalized and dyspnea resolved.DiscussionAPT occurs via cytotoxic T cells and indirectly by immunological reaction. Typically the lungs manifest a diffuse interstitial pneumonitis with varying degrees of fibrosis. Infiltrates with a 'ground-glass' appearance appreciated on HRCT are more definitive than chest x-ray. Pulmonary nodules can be seen, frequently in the upper lobes. These are postulated to be accumulations of amiodarone in areas of previous inflammation. Those undergoing major cardiothoracic surgery are known to be predisposed to APT. Some elements require consideration: a baseline pulmonary function test (PFT) did not exist prior. APT would manifest a restrictive pattern of PFTs. In APT diffusing capacity (DLCO) is generally >20 percent from baseline. A DLCO was not done in this patient. Therefore, not every type of interstitial lung disease could be ruled out. Key features support a clinical diagnosis: (1) new dyspnea, (2) exclusion of lung infection, (3) exclusion of heart failure, (4) new radiographic features, (5) improvement with withdrawal of amiodarone. Our case illustrates consideration of APT in patients who have extensive use of amiodarone and new onset dyspnea
CIDPro: Custom Instructions for Dynamic Program Diversification
Timing side-channel attacks pose a major threat to embedded systems due to
their ease of accessibility. We propose CIDPro, a framework that relies on
dynamic program diversification to mitigate timing side-channel leakage. The
proposed framework integrates the widely used LLVM compiler infrastructure and
the increasingly popular RISC-V FPGA soft-processor. The compiler automatically
generates custom instructions in the security critical segments of the program,
and the instructions execute on the RISC-V custom co-processor to produce
diversified timing characteristics on each execution instance. CIDPro has been
implemented on the Zynq7000 XC7Z020 FPGA device to study the performance
overhead and security tradeoffs. Experimental results show that our solution
can achieve 80% and 86% timing side-channel capacity reduction for two
benchmarks with an acceptable performance overhead compared to existing
solutions. In addition, the proposed method incurs only a negligible hardware
area overhead of 1% slices of the entire RISC-V system
Gradient Echo Quantum Memory for Light using Two-level Atoms
We propose a quantum memory for light that is analogous to the NMR gradient
echo. Our proposal is ideally perfectly efficient and provides simplifications
to current 3-level quantum memory schemes based on controlled inhomogeneous
broadening. Our scheme does not require auxiliary light fields. Instead the
input optical pulse interacts only with two-level atoms that have linearly
increasing Stark shifts. By simply reversing the sign of the atomic Stark
shifts, the pulse is retrieved in the forward direction. We present analytical,
numerical and experimental results of this scheme. We report experimental
efficiencies of up to 15% and suggest simple realizable improvements to
significantly increase the efficiency.Comment: 4 pages, 4 figure
Nash Welfare and Facility Location
We consider the problem of locating a facility to serve a set of agents
located along a line. The Nash welfare objective function, defined as the
product of the agents' utilities, is known to provide a compromise between
fairness and efficiency in resource allocation problems. We apply this welfare
notion to the facility location problem, converting individual costs to
utilities and analyzing the facility placement that maximizes the Nash welfare.
We give a polynomial-time approximation algorithm to compute this facility
location, and prove results suggesting that it achieves a good balance of
fairness and efficiency. Finally, we take a mechanism design perspective and
propose a strategy-proof mechanism with a bounded approximation ratio for Nash
welfare
The Impact of Frequency Bands on Acoustic Anomaly Detection of Machines using Deep Learning Based Model
In this paper, we propose a deep learning based model for Acoustic Anomaly
Detection of Machines, the task for detecting abnormal machines by analysing
the machine sound. By conducting extensive experiments, we indicate that
multiple techniques of pseudo audios, audio segment, data augmentation,
Mahalanobis distance, and narrow frequency bands, which mainly focus on feature
engineering, are effective to enhance the system performance. Among the
evaluating techniques, the narrow frequency bands presents a significant
impact. Indeed, our proposed model, which focuses on the narrow frequency
bands, outperforms the DCASE baseline on the benchmark dataset of DCASE 2022
Task 2 Development set. The important role of the narrow frequency bands
indicated in this paper inspires the research community on the task of Acoustic
Anomaly Detection of Machines to further investigate and propose novel network
architectures focusing on the frequency bands
Precision spectral manipulation of optical pulses using a coherent photon echo memory
Photon echo schemes are excellent candidates for high efficiency coherent
optical memory. They are capable of high-bandwidth multi-pulse storage, pulse
resequencing and have been shown theoretically to be compatible with quantum
information applications. One particular photon echo scheme is the gradient
echo memory (GEM). In this system, an atomic frequency gradient is induced in
the direction of light propagation leading to a Fourier decomposition of the
optical spectrum along the length of the storage medium. This Fourier encoding
allows precision spectral manipulation of the stored light. In this letter, we
show frequency shifting, spectral compression, spectral splitting, and fine
dispersion control of optical pulses using GEM
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