Tampere University of Technology

About: Tampere University of Technology is a based out in . It is known for research contribution in the topics: Laser & Context (language use). The organization has 6802 authors who have published 19787 publications receiving 431793 citations. The organization is also known as: Tampereen teknillinen yliopisto.

Gene Expression Profiling of Immune-Competent Human Cells Exposed to Engineered Zinc Oxide or Titanium Dioxide Nanoparticles

Abstract: A comprehensive in vitro assessment of two commercial metal oxide nanoparticles, TiO2 and ZnO, was performed using human monocyte-derived macrophages (HMDM), monocyte-derived dendritic cells (MDDC), and Jurkat T cell leukemia-derived cell line. TiO2 nanoparticles were found to be non-toxic whereas ZnO nanoparticles caused dose-dependent cell death. Subsequently, global gene expression profiling was performed to identify transcriptional response underlying the cytotoxicity caused by ZnO nanoparticles. Analysis was done with doses 1 µg/ml and 10 µg/ml after 6 and 24 h of exposure. Interestingly, 2703 genes were significantly differentially expressed in HMDM upon exposure to 10 µg/ml ZnO nanoparticles, while in MDDCs only 12 genes were affected. In Jurkat cells, 980 genes were differentially expressed. It is noteworthy that only the gene expression of metallothioneins was upregulated in all the three cell types and a notable proportion of the genes were regulated in a cell type-specific manner. Gene ontology analysis revealed that the top biological processes disturbed in HMDM and Jurkat cells were regulating cell death and growth. In addition, genes controlling immune system development were affected. Using a panel of modified ZnO nanoparticles, we obtained an additional support that the cellular response to ZnO nanoparticles is largely dependent on particle dissolution and show that the ligand used to modify ZnO nanoparticles modulates Zn2+ leaching. Overall, the study provides an extensive resource of transcriptional markers for mediating ZnO nanoparticle-induced toxicity for further mechanistic studies, and demonstrates the value of assessing nanoparticle responses through a combined transcriptomics and bioinformatics approach.

User Experience Evaluation Methods in Academic and Industrial Contexts

Abstract: In this paper, we investigate 30user experience (UX) evaluation methods that were collected during a special interest group session at the CHI2009 Conference. We present a categorization of the collected UX evaluation methods and discuss the range of methods from both academic and industrial perspectives.

Online grid impedance measurement using discrete-interval binary sequence injection

Abstract: Grid impedance affects the stability and control performance of grid-connected power electronic devices such as inverters used to integrate wind and solar energy. Adaptive control of such inverters to guarantee stability under different grid conditions requires real-time measurement of the grid impedance performed online by the inverters themselves. Existing online measurement methods based on broadband excitations such as maximum-length binary sequence (MLBS) require relatively high injection that may interfere with normal grid control functions, or degrade inverter output current quality, especially when the grid impedance is low and a high current needs to be injected in order to produce sufficient voltage perturbation. This paper proposes the use of a discrete-interval binary sequence (DIBS) for such cases. The DIBS is a computer-optimized binary sequence where the energy is maximized at specified harmonic frequencies to minimize the required level of signal injection. Experimental results based on a three-phase grid-connected inverter are presented to demonstrate the effectiveness of the proposed methods.

PDMS and its suitability for analytical microfluidic devices.

Abstract: Poly(dimethylsiloxane) also known as PDMS is used in a wide range of biomedical applications. These range from implants through catheters to soft contact lenses. Therefore, it is understandable that PDMS has been extensively tested for these purposes. In past years, the microfluidics has moved from predominantly silicon and glass structures towards polymers due to their ease of manufacturing and moderate cost. PDMS has gained a lot of attention in various analytical applications. However, the testing of its suitability for such applications has not been as thorough as in the biomedical applications, perhaps relying on the experiments from that field. Microfluidic PDMS structures are more and more popular in various analytical devices. Such devices consume less reagents and can work with lower sample volumes. On the other hand, the surface-to-sample-volume ratio becomes larger. That increases the influence of material properties on the actual measurement. Some of the challenges include adsorption, diffusion, surface roughness, permeability and elasticity of PDMS, which are discussed in this paper.