Risk management of water systems in residential homes : The ‘process’ of Legionella prevention

In the present study data was collect and analysed to gain evidence for the present situation of Legionella risk management and prevention of water systems in different buildings in the Canton of Zurich, Switzerland. These buildings comprise retirement homes, care homes and dwellings for people with a disability. According to given legislation, standards and technical rules, duty holders are liable for the quality of drinking water distributed by the water system in a building. Showers represent a frequently used, aerosol-generating device in the domestic setting and have been proposed as a source of Legionnaires’ disease, caused by Legionella bacteria. This study investigated the prevalence of Legionella in showers which are recognised as a potential source of risk of contamination for users. During a field campaign, data from ten buildings were collected. Water was sampled from showers and analysed with reproducible sampling procedures. As a second source of data, information concerning technical specifications and operating parameters of the (hot) water systems and shower facilities was collected from the operating manager through a semi-structured questionnaire. Based on the microbiological results provided by the classical culture method, a Legionella contamination was detected in two objects. Three additional care facilities showed raised results according to a different method applied. Evaluation of the responses given in the questionnaire revealed that control functions and documentation seem to be either unsatisfactory within the institutions, or are missing completely. Although the small size of the sample in this study does not permit generalizable statements, the results provide a solid foundation upon which further investigations can be based

Influence of the geometry on the agglomeration of a polydisperse binary system of spherical particles

Within the context of the European Horizon 2020 project ACDC, we intend to develop a probabilistic chemical compiler, to aid the construction of three-dimensional agglomerations of artificial hierarchical cellular constructs. These programmable discrete units offer a wide variety of technical innovations, like a portable biochemical laboratory that e.g. produces macromolecular medicine on demand. For this purpose, we have to investigate the agglomeration process of droplets and vesicles under proposed constraints, like confinement. This paper focuses on the influence of the geometry of the initialization and of the container on the agglomeration

Paths in a network of polydisperse spherical droplets

We simulate the movement and agglomeration of oil droplets in water under constraints, like confinement, using a simplified stochastic-hydrodynamic model. In the analysis of the network created by the droplets in the agglomeration, we focus on the paths between pairs of droplets and compare the computational results for various system sizes

Biofilme in Trinkwasserinstallationen : Quantifizierung von Biofilmen in Kunststoffrohren

Kunststoffrohre für Trinkwasserleitungen können die Verkeimung und Biofilmbildung fördern. Die biofilmbildenden Bakterien werden mit Ultraschall von den Innenflächen der Rohre abgelöst und die Zellzahl mit der an der Eawag entwickelten Methode durchflusszytometrisch bestimmt. Diese Methoden wurden eingesetzt, um in einer Testanlage aus 50 m PEXc-Kunststoffrohr, die kontinuierlich mit Leitungswasser durchflossen wurde, die Biofilmbildung zu verfolgen

FM in der Spitalhygiene : past – present – future

Die Spitalhygiene stellt ein besonders komplexes Fachgebiet der Hygiene dar. Damit möglichst umfassend aufgezeigt werden kann, was bisher im Kontext Spitalhygiene als Standard galt, welche Schnittstellen zum FM vorliegen, und welche Veränderungen in diesem Bereich zu erwarten sind, ist es wichtig, verschiedene Sichtweisen und Einschätzungen auszuweisen. Für den vorliegenden Artikel wurden daher verschiedene Perspektiven und Aufgabenbereiche berücksichtigt. Die hier zu Wort kommenden Protagonisten der Spitalhygiene sind Akteure, die Schlüsselpositionen in unterschiedlichen Funktions- und Verantwortungs-bereichen bekleiden. Sie gehen in ihrer Arbeit und in ihren Aufträgen kollaborativ mit Aufgabenbereichen des FM um, und umgekehrt. Im konkreten Fall sind dies die Verantwortungsträger aus zwei Schweizer Spitälern, von national und global agierenden Dienstleistungs-Unternehmen aus dem Bereich Reinigung und Hygiene, von einem Beratungsunternehmen mit Mandats-Schwerpunkt Hygiene sowie von einer kantonalen Behörde, die im Auftrag der Gesundheitsdirektion ihre Arbeit verrichtet. Der vorliegende Beitrag soll Anforderungen, Bedürfnisse und Interessen zusammengetragen, und kann dadurch als aktuelles und weit gefasstes Stimmungsbild verstanden werden

Obstacles on the pathway towards chemical programmability using agglomerations of droplets

We aim at planning and creating specific agglomerations of droplets to study synergic communication using these as programmable units. In this paper, we give an overview of preliminary obstacles for the various research issues, namely of how to create droplets, how to set up droplet agglomerations using DNA technology, how to prepare them for confocal microscopy, how to make a computer see droplets on photos, how to analyze networks of droplets, how to perform simulations mimicking experiments, and how to plan specific agglomerations of droplets

Artificial chemistry performed in an agglomeration of droplets with restricted molecule transfer

Within the scope of the European Horizon 2020 project ACDC – Artificial Cells with Distributed Cores to Decipher Protein Function, we aim at the development of a chemical compiler governing the three-dimensional arrangement of droplets, which are filled with various chemicals. Neighboring droplets form bilayers with pores which allow chemicals to move from one droplet to its neighbors. With an appropriate three-dimensional configuration of droplets, we can thus enable gradual biochemical reaction schemes for various purposes, e.g., for the production of macromolecules for pharmaceutical purposes. In this paper, we demonstrate with artificial chemistry simulations that the ACDC technology is excellently suitable to maximize the yield of desired reaction products or to minimize the relative output of unwanted side products