Tallinn University of Technology

About: Tallinn University of Technology is a education organization based out in Tallinn, Estonia. It is known for research contribution in the topics: European union & Computer science. The organization has 3688 authors who have published 10313 publications receiving 145058 citations. The organization is also known as: Tallinn Technical University & Tallinna Tehnikaülikool.

RNA-Seq Analysis Reveals Different Dynamics of Differentiation of Human Dermis- and Adipose-Derived Stromal Stem Cells

Abstract: Background Tissue regeneration and recovery in the adult body depends on self-renewal and differentiation of stem and progenitor cells. Mesenchymal stem cells (MSCs) that have the ability to differentiate into various cell types, have been isolated from the stromal fraction of virtually all tissues. However, little is known about the true identity of MSCs. MSC populations exhibit great tissue-, location- and patient-specific variation in gene expression and are heterogeneous in cell composition. Methodology/principal findings Our aim was to analyze the dynamics of differentiation of two closely related stromal cell types, adipose tissue-derived MSCs (AdMSCs) and dermal fibroblasts (FBs) along adipogenic, osteogenic and chondrogenic lineages using multiplex RNA-seq technology. We found that undifferentiated donor-matched AdMSCs and FBs are distinct populations that stay different upon differentiation into adipocytes, osteoblasts and chondrocytes. The changes in lineage-specific gene expression occur early in differentiation and persist over time in both AdMSCs and FBs. Further, AdMSCs and FBs exhibit similar dynamics of adipogenic and osteogenic differentiation but different dynamics of chondrogenic differentiation. Conclusions/significance Our findings suggest that stromal stem cells including AdMSCs and dermal FBs exploit different molecular mechanisms of differentiation to reach a common cell fate. The early mechanisms of differentiation are lineage-specific and are similar for adipogenic and osteogenic differentiation but are distinct for chondrogenic differentiation between AdMSCs and FBs.

ZnO/TiO2/Sb2S3 Core–Shell Nanowire Heterostructure for Extremely Thin Absorber Solar Cells

Abstract: Extremely thin absorber (ETA) solar cells integrating ZnO nanowires have been receiving increasing interest owing to efficient light-trapping phenomena and charge-carrier management, but the chemical instability of ZnO in acidic conditions limits its combination with a variety of absorbing semiconducting shells grown by chemical deposition techniques. By covering the ZnO nanowires grown by chemical bath deposition with a protective, passivating, conformal, thin, anatase-TiO2 layer by atomic layer deposition, we show that a uniform Sb2S3 absorbing shell is formed by chemical spray pyrolysis without structural degradation of the ZnO. The Sb2S3 absorbing shell consists of a very thin, conformal layer together with homogeneously distributed small clusters from the bottom to the top of the ZnO/TiO2 core–shell nanowire arrays. The resulting ETA solar cells integrating these ZnO/TiO2/Sb2S3 core–shell nanowire heterostructures with an Sb2S3 absorbing shell less than 10 nm-thick and P3HT as the hole-transporting m...

Effect of Selenium Treatment on Mineral Nutrition, Bulb Size, and Antioxidant Properties of Garlic (Allium sativum L.)

Abstract: Foliar selenium (Se) treatment of garlic at concentrations of 10, 50, and 100 μg of Se/mL was carried out in open field conditions in 2008 and 2009 in Estonia. Bulb weight and yield structure, content of total Se, S, N, P, K, Ca, and Mg, ascorbic acid content (AAC), pungency, total phenolics, and total antioxidant capacity (TAC) were determined. The highest level of Se decreased total S, K, and Ca in both years; no negative impact on bulb weight was observed. In 2009 Se10 treatment had significantly more bulbs with the largest diameter compared to the other treatments. In 2008, the AAC was decreased by Se50 and the content of total phenolics by all Se treatments; however, TAC was increased. Foliar Se fertilization of garlic at rates of 10-50 μg of Se/mL can be recommended to increase the number of large bulbs and increase bulb antioxidant capacity.

A review of the harmonic and unbalance effects in electrical distribution networks due to EV charging

Abstract: For wide use of electric vehicles (EVs), there are different aspects of the electric power system to consider for making it ready for the increased load by battery charging. The topics include power production, peak load management, distribution transmission capacity but also distribution network power quality and many more. This paper presents an overview on the likely power quality impacts in the distribution networks associated with EV charging. Based on a literature review, focus is especially put on harmonics and load unbalance in the network. Most relevant papers observing these topics are presented summarizing their contribution. The power quality aspects in distribution networks discussed here are not often presented within analysis of permissible EV penetration levels. Harmonics or voltage unbalance and effects associated with these could introduce additional limits to the EV charging capacity for the distribution networks. Therefore the analysis on the EV charging influence on these power quality topics requires also high-priority discussions before drawing conclusions on the distribution networks capabilities.