Cellular reactions to long-term volatile organic compound (VOC) exposures

Investigations of cellular processes initiated by volatile organic compounds (VOCs) are limited when modelling realistic long-term exposure scenarios at low concentrations. Exposure to indoor VOCs is associated with a range of adverse effects, but data on molecular changes at regulatory threshold limits are lacking. Activity analysis of VOC in vitro can be a valuable complement to inhalation toxicological evaluations. We developed an exposure platform that generates a stable VOC atmosphere and allows the exposure of cells for longer periods. Using formaldehyde as a model analyte, air-liquid interface cultured A549 lung epithelial cells were exposed to critical concentrations of 0.1 and 0.5 ppm for 3 days. Owing to the lack of known exposure biomarkers, we applied a genome-wide transcriptional analysis to investigate cellular responses at these sublethal concentrations. We demonstrate a minor overlap of differentially expressed transcripts for both treatment concentrations, which can be further analyzed for their use as exposure biomarkers. Moreover, distinct expression patterns emerge for 0.1 and 0.5 ppm formaldehyde exposure, which is reflected in significant enrichment of distinct biological processes. More specifically, metabolism of specific compound classes, lipid biosynthesis and lung-associated functions are affected by lower exposure levels and processes affecting proliferation and apoptosis dominate the higher exposure levels

The Potential Role of Cannabinoids in Modulating Serotonergic Signaling by Their Influence on Tryptophan Metabolism

pharmaceutical

Enhancements to Statistical Protocol IDentification (SPID) for Self-Organised QoS in LANs

Since most real-time audio and video applications lack of QoS support, QoS demand of such IP data streams shall be detected and applied automatically. To support QoS in LANs, especially in home environments, a system was developed, which enables self-organised QoS for unmanaged networks through host implementations - in contrast to traditional solutions without network support. It supports per-link reservation and prioritisation and works without a need for application support. One part of this system is an automated traffic identification and classification system, which is subject of this paper. An efficient set of attribute meters, based on the Statistical Protocol IDentification (SPID), was investigated, enhanced and evaluated. We improved the performance, added support for UDP protocols and real-time identification. It is shown that using our implementation efficient near real-time protocol identification on per-flow basis is possible to support self-organised resource reservation

Quantitative Ethylene Measurements with MOx Chemiresistive Sensors at Different Relative Air Humidities

The sensitivity of two commercial metal oxide (MOx) sensors to ethylene is tested at different relative humidities. One sensor (MiCS-5914) is based on tungsten oxide, the other (MQ-3) on tin oxide. Both sensors were found to be sensitive to ethylene concentrations down to 10 ppm. Both sensors have significant response times; however, the tungsten sensor is the faster one. Sensor models are developed that predict the concentration of ethylene given the sensor output and the relative humidity. The MQ-3 sensor model achieves an accuracy of ±9.2 ppm and the MiCS-5914 sensor model predicts concentration to ±7.0 ppm. Both sensors are more accurate for concentrations below 50 ppm, achieving ±6.7 ppm (MQ-3) and 5.7 ppm (MiCS-5914)