Long-term Filter Efficiency of mobile Air Purifiers in Schools

The SARS-CoV-2 pandemic forced many restrictions upon the public, such as the closing of schools, affecting social development and education of children. Here we tested air purifiers with HEPA filters as a measure to reduce the infection risk via airborne transmission during classes. We evaluated the efficiency and long-term performance of three devices over six month of operation at two schools by monitoring the particle decay from 0.003 µm to 10 µm. We found that the particle concentration was reduced reliably and spatially homogenously by 85 – 95% throughout the whole observed particle spectrum within ∼20 minutes for air exchange rates between 4.8 h−1 and 6.7 h−1. During the study we did not observe a clear decline in efficiency or performance of the air purifiers. We complemented our particle measurements with model calculations to estimate the virus concentration and inhaled dose of a susceptible person, assuming one infectious person was present. We calculated that the additional use of air purifiers reduced the number of potentially inhaled viruses at the end of the day by a factor of 2.65 relative to the case without air purifiers. Further, school-wide surveys indicated that the disturbance by the noise level of the air purifiers is to be considered and that the acceptance of air purifiers can be improved when the noise level is reduced. Overall, our study suggests that a combination of air purifiers and venting is a well-suited measure to reduce the potential indoor viral-load while still introducing fresh air into the room.</p

Table1_Comparison of left ventricular deformation abnormalities by echocardiography with cardiac magnetic resonance imaging in patients with acute myocarditis and preserved left ventricular ejection fraction.docx

PurposeCardiac magnetic resonance imaging (cMRI) represents the gold standard to detect myocarditis. Left ventricular (LV) deformation imaging provides additional diagnostic options presumably exceeding conventional transthoracic echocardiography (TTE). The present study aimed to analyze the feasibility to detect myocarditis in patients (pts) with preserved LV ejection fraction (LVEF) by TTE compared to cMRI. It has been hypothesized that the number of pathological findings by deformation imaging correspond to findings in cMRI.Methods and resultsBetween January 2018 and February 2020 102 pts with acute myocarditis according to the modified Lake Louise criteria and early gadolinium enhancement (EGE) by cMRI were identified at the department of cardiology at the University Hospital Leipzig. Twenty-six pts were included in this retrospective comparative study based on specific selection criteria. Twelve pts with normal cMRI served as a control group. LV deformation was analyzed by global and regional longitudinal strain (GLS, rLS), global and regional circumferential and radial strain (GCS, rCS, GRS, rRS), and LV rotation (including layer strain analysis). All parameters were compared to findings of edema, inflammation, and fibrosis by cMRI according to Lake Louise criteria. All pts with acute myocarditis diagnosed by cMRI showed pathological findings in TTE. Especially rCS and LV rotation analyzed by regional layer strain exhibit a high concordance with pathological findings in cMRI. In controls no LV deformation abnormalities were documented. Mean values of GLS, GRS, and GCS were not significantly different between pts with acute myocarditis and controls.ConclusionThis retrospective analysis documents the feasibility of detecting regional deformation abnormalities by echocardiography in patients with acute myocarditis confirmed by cMRI. The detection of pathological findings due to myocarditis requires the determination of regional deformation parameters, particularly rCS and LV rotation. The assessment of global strain values does not appear to be of critical value.</p

Datasheet1_Comparison of left ventricular deformation abnormalities by echocardiography with cardiac magnetic resonance imaging in patients with acute myocarditis and preserved left ventricular ejection fraction.pdf

PurposeCardiac magnetic resonance imaging (cMRI) represents the gold standard to detect myocarditis. Left ventricular (LV) deformation imaging provides additional diagnostic options presumably exceeding conventional transthoracic echocardiography (TTE). The present study aimed to analyze the feasibility to detect myocarditis in patients (pts) with preserved LV ejection fraction (LVEF) by TTE compared to cMRI. It has been hypothesized that the number of pathological findings by deformation imaging correspond to findings in cMRI.Methods and resultsBetween January 2018 and February 2020 102 pts with acute myocarditis according to the modified Lake Louise criteria and early gadolinium enhancement (EGE) by cMRI were identified at the department of cardiology at the University Hospital Leipzig. Twenty-six pts were included in this retrospective comparative study based on specific selection criteria. Twelve pts with normal cMRI served as a control group. LV deformation was analyzed by global and regional longitudinal strain (GLS, rLS), global and regional circumferential and radial strain (GCS, rCS, GRS, rRS), and LV rotation (including layer strain analysis). All parameters were compared to findings of edema, inflammation, and fibrosis by cMRI according to Lake Louise criteria. All pts with acute myocarditis diagnosed by cMRI showed pathological findings in TTE. Especially rCS and LV rotation analyzed by regional layer strain exhibit a high concordance with pathological findings in cMRI. In controls no LV deformation abnormalities were documented. Mean values of GLS, GRS, and GCS were not significantly different between pts with acute myocarditis and controls.ConclusionThis retrospective analysis documents the feasibility of detecting regional deformation abnormalities by echocardiography in patients with acute myocarditis confirmed by cMRI. The detection of pathological findings due to myocarditis requires the determination of regional deformation parameters, particularly rCS and LV rotation. The assessment of global strain values does not appear to be of critical value.</p

Primers used for amplification of the 18S rRNA gene of <i>Sarcocystis</i> spp.

<p>Primers used for amplification of the 18S rRNA gene of <i>Sarcocystis</i> spp.</p

Sites of origin, python species, prevalence of infection with <i>Sarcocystis</i> spp., and size classes of sporocysts detected in faecal samples from pythons of Southeast Asia, New Guinea, and Australia.

<p>Sites of origin, python species, prevalence of infection with <i>Sarcocystis</i> spp., and size classes of sporocysts detected in faecal samples from pythons of Southeast Asia, New Guinea, and Australia.</p

Phylogram of selected taxa of the Sarcocystidae including the new <i>Sarcocystis</i> isolates and species examined in this study (black symbols).

<p>Selected taxa of the Eimeriidae and the fish-host species <i>Goussia janae</i> served as root. Branches A and B indicate the subfamilies Toxoplasmatinae and Sarcocystinae, respectively. In addition to snake-host taxa, branch D includes <i>Sarcocystis</i> spp. of ruminating mammals as intermediate hosts. The tree was reconstructed by Minimum Evolution (ME) algorithm with 1557 sites of the 18S rRNA gene under analysis. Bootstrap values ≥ 50% of 1000 iterations are indicated. See further explanations in the text. Key to generic name abbreviations as follows: <i>B</i> = <i>Besnoitia</i>, <i>C</i> = <i>Cystoisospora</i>, <i>E</i> = <i>Eimeria</i>, <i>G</i> = <i>Goussia</i>, <i>H</i> = <i>Hyaloklossia</i>, <i>N</i> = <i>Neospora</i>, <i>S</i> = <i>Sarcocystis</i>, <i>T</i> = <i>Toxoplasma</i>.</p