Assessment of an in vitro whole cigarette smoke exposure system: The Borgwaldt RM20S 8-syringe smoking machine

<p>Abstract</p> <p>Background</p> <p>There have been many recent developments of <it>in vitro </it>cigarette smoke systems closely replicating <it>in vivo </it>exposures. The Borgwaldt RM20S smoking machine (RM20S) enables the serial dilution and delivery of cigarette smoke to exposure chambers for <it>in vitro </it>analyses. In this study we have demonstrated reliability and robustness testing of the RM20S in delivering smoke to <it>in vitro </it>cultures using an in-house designed whole smoke exposure chamber.</p> <p>Results</p> <p>The syringe precision and accuracy of smoke dose generated by the RM20S was assessed using a methane gas standard and resulted in a repeatability error of ≤9%. Differential electrical mobility particle spectrometry (DMS) measured smoke particles generated from reference 3R4F cigarettes at points along the RM20S. 53% ± 5.9% of particles by mass reached the chamber, the remainder deposited in the syringe or connecting tubing and ~16% deposited in the chamber. Spectrofluorometric quantification of particle deposition within chambers indicated a positive correlation between smoke concentration and particle deposition. <it>In vitro </it>air-liquid interface (ALI) cultures (H292 lung epithelial cells), exposed to whole smoke (1:60 dilution (smoke:air, equivalent to ~5 μg/cm²)) demonstrated uniform smoke delivery within the chamber.</p> <p>Conclusions</p> <p>These results suggest this smoke exposure system is a reliable and repeatable method of generating and exposing ALI <it>in vitro </it>cultures to cigarette smoke. This system will enable the evaluation of future tobacco products and individual components of cigarette smoke and may be used as an alternative <it>in vitro </it>tool for evaluating other aerosols and gaseous mixtures such as air pollutants, inhaled pharmaceuticals and cosmetics.</p

Neuartige GMR-Sensoren auf der Grundlage des Spin-Valve-Effekts. Teilvorhaben: Sensorintegration Abschlussbericht

It was investigated, whether the new GMR sensors are well suited for application in automobiles, what are the advantages with respect to the well-known AMR sensors, and whether they can stand to rough operation conditions to be encountered in automobiles. The results of this test project are very promising, i.e. it is recommended to pursue these developments in a main effort. This main project should have the aim to develop the GMR technology further in practical applications. As a prototypical application, the test project defined a high-resolution angle sensor. For its realization, an angle sensor test apparatus was set up suitable for investigations in the climate chamber from -20 C to appr. +80 C. The relevant sensor parameters were investigated, and the parameters of the angle sensor were set. An evaluation algorithm for the angle sensor was developed. The cooperation of the sub-contractor IMO (investigation of degradation, highly accurate magnetic scales) was a key factor for the success of the project. (orig.)Es wurde geprueft, ob sich die neuen GMR-Sensoren prinzipiell fuer die Verwendung im Automobil eignen, ob sie gegenueber den bereits bekannten AMR-Sensoren Vorteile besitzen und ob sie den rauhen Bedingungen des Automobileinsatzes standhalten. Die Ergebnisse des Vorprojekts waren so vielversprechend, dass es sich lohnt, die Untersuchungen dazu in einem Hauptprojekt weiterzutreiben mit konkreten Sensorentwicklungen als Zielsetzung. Prototypische Anwendung des Vorprojekts war ein hochaufloesender Winkelsensor. Zu dessen Realisierung wurde ein Winkelsensor-Testplatz aufgebaut, geeignet fuer Messungen im Klimaschrank von -20 C bis +80 C. Im einzelnen wurden die relevanten Sensorparameter untersucht sowie die Winkelsensor-Systemparameter eingestellt. Ein Auswertealgorithmus fuer die Winkelauswertung wurde entwickelt. Die Bearbeitung eines Unterauftrags durch die Fa. IMO (Degradationsuntersuchungen, hochgenaue magnetische Massstaebe) hat wesentlich zum Erfolg beigetragen. (orig.)SIGLEAvailable from TIB Hannover: F00B1070+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman