Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Dynamics of fast pattern formation in porous silicon by laser interference

Patterns are fabricated on 290 nm thick nanostructured porous silicon layers by phase-mask laser interference using single pulses of an excimer laser (193 nm, 20 ns pulse duration). The dynamics of pattern formation is studied by measuring in real time the intensity of the diffraction orders 0 and 1 at 633 nm. The results show that a transient pattern is formed upon melting at intensity maxima sites within a time 1-µs) upon melting induced by homogeneous beam exposure and related to the different scenario for releasing the heat from hot regions. The diffraction efficiency of the pattern is finally controlled by a combination of laser fluence and initial thickness of the nanostructured porous silicon layer and the present results open perspectives on heat release management upon laser exposure as well as have potential for alternative routes for switching applications

Modelling and diagnostic of pulsed laser-solid interactions : applications to laser cleaning

The present study concerns the cleaning of materials using pulsed laser irradiation and it summarises the most recent results obtained by the collaborative research of different European groups, within the framework of a European program for training and mobility of researchers. A series of pulsed lasers, which emit at various wavelengths (from UV to IR) wit11 short duration of pulse (few nano-, pico- or femto-seconds), is used for the removal of metallic, ceramic and organic pollutants from contaminated solid surfaces of different natures. The scientific results obtained so far are focused on the laser cleaning of silicon wafers from sub-micrometer particles, tile theoretical modelling of particles removal mechanism during dry laser cleaning, the removal of oxide layers from oxidised metals and alloys, as well as on the development of laser imaging as a diagnostic tool for the estimation of the efficiency of the proposed cleaning technique

A comparison of ns and ps steam laser cleaning of Si surfaces

We report a quantitative investigation on the efficiency of the steam laser cleaning process using ns and ps pulses. Well-characterized polymer particles with a diameter of 800 nm dispersed on commercial Si wafers were chosen as a modeling contaminant system. As a result of our investigation, we show for the first time the feasibility of performing efficient steam laser cleaning with ps laser pulses and compare the achieved efficiency with the one obtained for ns pulses. For ns pulses, we found a cleaning fluence threshold of 50 mJ/cm2 that is independent of the pulse durations (2.5 ns and 8 ns) and the wavelengths (532 nm and 583 nm) used. The application of ps pulses (FWHM=30 ps, h=583 nm) lowered this threshold to 20 mJ/cm2. Both cleaning thresholds are far below the melting thresholds for these laser parameters. Cleaning efficiencies > 90% were reached for both pulse durations

Translational diagnostics: an in-house pipeline to validate genetic variants in children with undiagnosed and rare diseases

Diagnosis is essential for the management and treatment of patients with rare diseases. In a group of patients, the genetic study identifies variants of uncertain significance or inconsistent with the phenotype; therefore, it is urgent to develop novel strategies to reach the definitive diagnosis. Herein, we develop the in-house Translational Diagnostics Program (TDP) to validate genetic variants as part of the diagnostic process with the close collaboration of physicians, clinical scientists, and research scientists. The first 7 of 33 consecutive patients for whom exome-based tests were not diagnostic were investigated. The TDP pipeline includes four steps: (i) phenotype assessment, (ii) literature review and prediction of in silico pathogenicity, (iii) experimental functional studies, and (iv) diagnostic decision-making. Re-evaluation of the phenotype and re-analysis of the exome allowed the diagnosis in one patient. In the remaining patients, the studies included either cDNA cloning or PCR-amplified genomic DNA, or the use of patients' fibroblasts. A comparative computational analysis of confocal microscopy images and studies related to the protein function was performed. In five of these six patients, evidence of pathogenicity of the genetic variant was found, which was validated by physicians. The current research demonstrates the feasibility of the TDP to support and resolve intramural medical problems when the clinical significance of the patient variant is unknown or inconsistent with the phenotype.Peer ReviewedPostprint (author's final draft

Imprinting the Optical Near Field of Microstructures with Nanometer Resolution

10th International Conference on Laser Ablation, Singapore, November 22-27, 2009N

A high-sensitivity in situ optical diagnostic technique for laser cleaning of transparent substrates

A differential optical transmission technique has been used to monitor in situ the efficiency of laser cleaning for the removal of sub-micrometer-sized particles on substrates transparent at the monitoring wavelength. This technique has been applied to the removal of sub-micrometer polystyrene particles on polyimide substrates using laser pulses of 30 ps duration at 292 nm while probing the material transmission at 633 nm. The sensitivity achieved -1/104 for the transmission changes induced upon single-pulse laser exposure allows us to monitor the removal of just a few sub-micron-sized particles from the probed region inside the irradiated area

Ultraviolet laser patterning of porous silicon

This work reports on the fabrication of 1D fringed patterns on nanostructured porous silicon (nanoPS) layers (563, 372, and 290nm thick). The patterns are fabricated by phase-mask laser interference using single pulses of an UV excimer laser (193nm, 20ns pulse duration). The method is a single-step and flexible approach to produce a large variety of patterns formed by alternate regions of almost untransformed nanoPS and regions where its surface has melted and transformed into Si nanoparticles (NPs). The role of laser fluence (5-80mJcm-2), and pattern period (6.3-16µm) on pattern features and surface structuring are discussed. The results show that the diameter of Si NPs increases with fluence up to a saturation value of 75nm for a fluence ˜40mJcm-2. In addition, the percentage of transformed to non-transformed region normalized to the pattern period follows similar fluence dependence regardless the period and thus becomes an excellent control parameter. This dependence is fitted within a thermal model that allows for predicting the in-depth profile of the pattern. The model assumes that transformation occurs whenever the laser-induced temperature increase reaches the melting temperature of nanoPS that has been found to be 0.7 of that of crystalline silicon for a porosity of around 79%. The role of thermal gradients across the pattern is discussed in the light of the experimental results and the calculated temperature profiles, and shows that the contribution of lateral thermal flow to melting is not significant for pattern periods =6.3µm

Laser fabrication of porous silicon-based platforms for cell culturing

Postprint (published version

Ultraviolet optical near-fields of microspheres imprinted in phase change films

We report an experimental method for directly imaging optical near-fields of dielectric microspheres upon illumination with ultraviolet nanosecond laser pulses. The intensity distribution is imprinted in chalcogenide films leaving behind a characteristic fingerprint with features below 200 nm in size, which we read out with high-resolution field emission scanning electron microscopy. The experimental results are well matched by a rigorous solution of Maxwell s equations. Compared to previous works using infrared femtosecond laser pulses, the use of ultraviolet nanosecond pulses is identified to be superior in terms of minimum recordable features size and surface roughness of the imprint