Evaluation of CPAP mask performance during 3 years of mask usage: time for reconsideration of renewal policies?

BackgroundContinuous positive airway pressure (CPAP) mask renewal policies vary inside and between countries. There are no independent studies on the optimal mask renewal frequency. We aimed to evaluate CPAP mask function over time in a real-life clinical setting, and to compare the results against current renewal policies.MethodsDaily performance data of 1846 CPAP masks (65% nasal, 22% nasal pillows, 12% oronasal) were recorded from 450 participants (68% male, mean age 59 years) with obstructive sleep apnoea. The unintentional leak, Apnoea-Hypopnoea Index (CPAP-AHI) and usage data were exported from the CPAP device.ResultsOf 656 324 nights of CPAP usage, the mean renewal time was 497 days (SD 327), mean leak 5.7 L/min (SD 8.1) and CPAP-AHI 3.8 events/h (SD 3.6). The difference in mean leak between one (5.2 L/min, SD 7.5), 12 (6.0 L/min, SD 10.2) and 24 months (5.8 L/min, SD 7.5) was minimal (p=0.59). Mean CPAP-AHI remained normal and unchanged in nasal masks and pillows up to 30 months, and was highest in oronasal masks. Different mask manufacturers performed similarly. Masks’ daily or total usage did not affect the results. Shifting the mask renewal policy to 24 months could reduce the mask-related cost up to 50%–88%.ConclusionsNasal masks and pillows could be used at least 2 years without significant changes in unintentional leak and CPAP-AHI. We suggest updating the mask renewal policies of nasal masks and pillows; results on oronasal masks and other manufacturers CPAP devices need further verification.

Mask, the Drosophila Ankyrin Repeat and KH domain-containing protein, affects microtubule stability

Proper regulation of microtubule (MT) stability and dynamics is vital for essential cellular processes, including axonal transportation and synaptic growth and remodeling in neurons. Here, we demonstrate that Mask negatively affects MT stability in both fly larval muscles and motor neurons. In larval muscles, loss-of-function of mask increases MT polymer length, and in motor neurons, loss of mask function results in overexpansion of the presynaptic terminal at the larval neuromuscular junctions (NMJs). mask genetically interacts with stathmin (stai), a neuronal modulator of MT stability, in the regulation of axon transportation and synaptic terminal stability. Our structure/function analysis on Mask revealed that its Ankyrin Repeats domain-containing N-terminal portion is sufficient to mediate Mask's impact to MT stability. Furthermore, we discovered that Mask negatively regulates the abundance of the microtubule-associated protein Jupiter in motor neuron axons, and that neuronal knocking down of Jupiter partially suppresses mask loss-of-function phenotypes at the larval NMJs. Together, our studies demonstrated that Mask is a novel regulator for microtubule stability, and such a role of Mask requires normal function of Jupiter.

A Novel Computerized Method for Measuring the Length of the Aorta in Patients with Severe Kyphotic Deformity

Objective: This study aimed to explore a new method for measuring the length of the aorta in patients with severe kyphotic deformity.Methods: The computed tomography (CT) scan data of one patient with severe kyphotic deformity were retrospectively collected. The data were saved as Digital Imaging and Communications in Medicine (DICOM) format, and were imported into MIMICS software for processing. Then, the MASK function of the MIMICS software was used to mark the aorta in each slice of CT, and a three-dimensional (3D) reconstruction model of the aorta was established. After that, the length of the aorta was defined as the length of the centerline, which was calculated by the MIMICS. Besides, two points were fixed as anchor, and the length of aorta was acquired by measuring the distance between the two points. The proximal one was the origin of the left subclavian artery, and the fork was the distal of iliac artery. The length of the aorta was measured preoperatively and postoperatively as well. Results: The 3D reconstruction model of the aorta was successfully established. It was revealed that the length of aorta was 418.9 mm preoperatively, and 435.4 mm postoperatively. The patient also underwent pedicle subtraction osteotomy (PSO). After orthopedic surgery, the length of the aorta was stretched by 16.5 mm. Conclusion: In the present research, a 3D reconstruction model of the aorta was successfully established, and the length of the aorta was accurately measured without any invasive procedure. Using MIMICS software, the length of aorta in patients with severe kyphotic deformity could be effectively and precisely measured.

Efficacy and Safety of Disinfectants for Decontamination of N95 and SN95 Filtering Facepiece Respirators: A Systematic Review

Background: Decontaminating and re-using filtering facepiece respirators (FFR) for healthcare workers is a potential solution to address inadequate FFR supply during a global pandemic.Aim: The objective of this review was to synthesize existing data on the effectiveness and safety of using chemical disinfectants to decontaminate N95 FFR. Methods: We conducted a systematic review on disinfectants to decontaminate N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined study eligibility and extracted and verified predefined data fields. Original research reporting on N95 FFR function, decontamination, physical appearance, safety, or mask fit following decontamination with a disinfectant was included. Findings and Conclusions: A single cycle of vaporized hydrogen peroxide successfully removes infectious pathogens without affecting mask function or fit, and with little change in FFR physical appearance. Residual hydrogen peroxide levels following decontamination were below the safety limit. More than one decontamination cycle of vaporized hydrogen peroxide may be possible but further information is required on how multiple cycles would affect mask fit in a real world setting before the upper limit can be established. Although immersion in liquid hydrogen peroxide does not appear to adversely affect mask function, there is no available data on its ability to remove infectious pathogens from FFRs or its impact on mask fit. Sodium hypochlorite, ethanol, isopropyl alcohol and EtO are not recommended due to safety concerns or negative effects on mask function.

Microwave- and Heat-Based Decontamination of N95 Filtering Facepiece Respirators: A Systematic Review

Final peer-reviewed article: https://doi.org/10.1016/j.jhin.2020.08.005Background: In pandemic situations such as COVID-19, shortages of proper protective equipment are common. One solution may be to decontaminate equipment such as facemasks for reuse.Aim: The aim of this review was to collect and synthesize existing information on decontamination of N95 filtering facepiece respirators (FFRs) using microwave and heat-based treatments, with special attention to impact on mask function (aerosol penetration, airflow resistance) and fit.Methods: A systematic review (PROSPERO ID pending) of literature available on Medline, Embase, Global Health, JISRP and JEFF was conducted. Records were screened independently by two reviewers, and data was extracted and analyzed from studies that reported on the effects of microwave- or heat-based decontamination on N95 FFR performance and/or microbial load. Results: All interventions successfully destroyed viral/bacterial contaminants. Other than autoclaving, which significantly increased aerosol penetration, moist and dry microwave and heat conditions did not significantly impact functional parameters or fit. However, several conditions caused physical damage to at least one N95 model. Conclusions: Microwave irradiation and heat provides safe and effective decontamination options for N95 FFR reuse during critical shortages. However, autoclaving masks is not recommended by the evidence in this review. Any mask disinfected using these methods should be inspected for physical degradation before reuse.NOTE: The experiments summarized in this manuscript are performed under specialized laboratory conditions. Household appliances should not be used for any purposes that are not indicated in their manufacturer-supplied guidelines, including mask decontamination. Doing so may lead to damage or injury.

Ground-roll attenuation using curvelet downscaling

We have developed a ground-roll attenuation strategy for seismic records that adopts the curvelet transform. The curvelet transform decomposes the seismic events based on their dip and frequency content information. The curvelet panels that contain only either reflection or ground-roll energy can be used to alter the curvelet panels with mixed reflection and ground-roll energies. We build a curvelet-domain mask function from the ground-roll-free curvelet coefficients (high frequencies) and downscale it to the ground-roll-contaminated curvelet coefficients (low frequencies). The mask function is used inside a least-squares optimization scheme to preserve the seismic reflections and attenuate the ground roll. Synthetic and real seismic data examples show the application of the proposed ground-roll attenuation method.

Phase-space analysis for ionization processes in the laser–atom interaction using Gabor transformation

In this paper, the ionization processes during laser–atom interaction are investigated in phase-space using Gabor transformation. Based on the time-dependent Schrödinger equation (TDSE), the depletion of the whole system caused by the mask function is taken into consideration in calculating the plasma density. We obtain the momentum distribution via the Gabor transformation of the escaping portions of the time-dependent wave packet at the detector-like points on the interior boundaries from which the kinetic energies carried by the escaping portions are calculated.

Extraction of Peak Feature Based on Synthetic Sinc Model in SAR images

Peak is an important feature in Synthetic Aperture Radar(SAR), which represents essence of scattering centre. There are two general approaches in the literature to extract peak. One way is to extract peak after speckle suppression filtering. Using this method, the extracted feature is in accurate, and the algorithm is more complicated. Another is that detecting the amplitude of the peak directly. In order to have a fast and accurate peak extraction, we proposed using the Sinc peak model algorithm in this paper. It directly extracts peak features from the original SAR image without any noise suppression filtering, which is instead of Gauss mask function. The estimation parameters of peaks use QE theorists. Finally, we can get accuracy three parameters to describe peak features. Analytic fluctuation of parameters is compared with Gauss model peaks using truth SAR images. Experimental demonstrate that the new algorithm is more effective than others for extracting peak features in SAR images.