Publications by authors named "Christian Gloor"

3 Publications

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Protection Level and Reusability of a Modified Full-Face Snorkel Mask as Alternative Personal Protective Equipment for Healthcare Workers during the COVID-19 Pandemic.

Chem Res Toxicol 2021 01 17;34(1):110-118. Epub 2020 Dec 17.

Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich 8093, Switzerland.

The worldwide outbreak of COVID-19 has drastically increased pressure on medical resources and highlighted the need for rapidly available, large-scale, and low-cost personal protective equipment (PPE). In this work, an alternative full-face mask is adapted from a modified snorkel mask to be used as PPE with two medical-grade filters and a 3D-printed adapter. Since the mask covers the eyes, mouth, and nose, it acts as a full-face shield, providing additional protection to healthcare workers. The SARS-CoV-2 has a size between 60 nm and 140 nm, and airborne viral particles can be carried by larger droplets with sizes up to several millimeters. The minimum filtration efficiency of mechanical and electrostatic filters is usually reached between 30 nm and 300 nm. The filtration efficiency of different medical filters is measured for particles below 300 nm to cover the size of the SARS-CoV-2 and small virus-laden droplets, and determine the minimum efficiency. The filtration performance of the adapted full-face mask is characterized using NaCl particles below 500 nm and different fitting scenarios to determine the minimum protection efficiency. The mask is compared to a commercial respirator and characterized according to the EN 149 standard, demonstrating that the protection fulfills the requirements for the FFP2 level (filtering face-piece 2, stopping at least 94% of airborne particles). The device shows a good resistance to several cycles of decontamination (autoclaving and ethanol immersion), is easy to be produced locally at low cost, and helps to address the shortage in FFP2 masks and face shields by providing adequate protection to healthcare workers against particles <500 nm in size.
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http://dx.doi.org/10.1021/acs.chemrestox.0c00371DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7771246PMC
January 2021

Hydrosulfonylation Reaction with Arenesulfonyl Chlorides and Tetrahydrofuran: Conversion of Terminal Alkynes into Cyclopentylmethyl Sulfones.

Angew Chem Int Ed Engl 2017 10 25;56(43):13329-13332. Epub 2017 Sep 25.

Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.

An efficient and simple radical chain reaction to convert terminal alkynes into arenesulfonylmethylcyclopentanes is described. The reaction involves a radical addition-translocation-cyclization process and necessitates solely the use of readily available arenesulfonyl chlorides in tetrahydrofuran. Interestingly, this radical-mediated C-H activation process took place with a high level of retention of configuration when an enantiomerically pure starting material was used.
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http://dx.doi.org/10.1002/anie.201707791DOI Listing
October 2017

Memory of chirality in reactions involving monoradicals.

Free Radic Res 2016 Nov 25;50(sup1):S102-S111. Epub 2016 Oct 25.

a Department of Chemistry and Biochemistry , University of Bern , Bern , Switzerland.

The effects of memory of chirality (MoC) in reactions involving monoradical species are reviewed here. Reactions involving a nonracemic chiral starting material bearing a single stereogenic element such as a chiral center or chiral axis directly involved in the new bond formation are discussed. These reactions lead to a nonracemic product via an intermediate susceptible to rapid racemization. Memory of chirality has been observed in cyclic radicals, aryl, ester/amide substituted acyclic radicals, and benzylic radicals at temperatures up to 130 °C.
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http://dx.doi.org/10.1080/10715762.2016.1232485DOI Listing
November 2016