Bottom-up assembly of a bilayer structure of icosahedral viral nanoparticles.

The development of 2D and 3D structures on the nanoscale containing viral nanoparticles (VNPs) as interesting nanobuilding blocks has come into focus for a bottom-up approach as an alternative to the top-down approach in nanobiotechnology. Our research has focused on the plant Tomato Bushy Stunt Virus (TBSV). In a previous study, we reported the impact of the pH value on the 2D assembly of viral monolayers. Here, we extend these studies into the third dimension by using specific interactions between the layers in combination with selective side chains on the viral capsid. The virus bilayer structure is prepared by an alternating deposition of His-tagged TBSV (4D6H-TBSV, first layer), Ni-NTA nanogold (second layer) complexes and 4D6H-TBSV, respectively, and 6D-TBSV (6xaspartic acid TBSV) as the third layer, i.e., the second layer of VNPs. The formed layer structures were imaged by using scanning force and scanning electron microscopy. The data show that a virus bilayer structure was successfully built up by means of the interaction between Ni-NTA nanogold and histidine. By comparing 4D6H- with 6D-TBSV in the third layer, the importance of these specific interactions is shown. This work paves the way for 3D nanodevices based on VNPs.

Healthy Preterm Newborns Show an Increased Frequency of CD4(+) CD25(high) CD127(low) FOXP3(+) Regulatory T Cells with a Naive Phenotype and High Expression of Gut-Homing Receptors.

Treg cells are crucial to prevent immune dysregulation, but little is known about the frequency of these cells in neonates, particularly in very/moderate and late preterm newborns studied as separate groups. The CD4(+) CD25(hi) CD127(lo) FOXP3(+) Treg population was phenotypically characterized to assess maturation markers and gut-homing integrins by flow cytometry in the cord blood of healthy preterm newborns born at 30-33(6/7) gestation weeks (Group 1), at 34-36(6/7) gestation weeks (Group 2) and term newborns born at 37-41 gestation weeks (Group 3), compared to healthy adults. An inverse correlation of the Treg percentage and gestational age was found, with significantly higher frequencies in Group 1 compared to Groups 2 and 3 and in Group 2 compared to Group 3, and significantly higher Treg frequencies and numbers in the neonates compared to the adults. All of the newborns exhibited increased Treg frequencies with a naive phenotype compared to adults. Cytotoxic T-lymphocyte-associated protein 4 CTLA-4 expression in the naive Treg was decreased in both preterm groups compared with those from term newborns and adults, and in the memory Treg from Group 1 compared with the other groups. The frequencies of Treg expressing α4ß7 and α4ß1 integrins were higher in both preterm groups, but significantly different only in Group 1, when compared with those from the term newborns and the adults. In conclusion, although a high frequency of Treg is present in newborns, an immature phenotype with a higher expression of CD45RA and α4ß7/α4ß1 and a lower expression of CTLA-4 is found, particularly in the very preterm group.

Life cycle assessment and economic analysis of a low concentrating photovoltaic system.

Many new photovoltaic (PV) applications, such as the concentrating PV (CPV) systems, are appearing on the market. The main characteristic of CPV systems is to concentrate sunlight on a receiver by means of optical devices and to decrease the solar cells area required. A low CPV (LCPV) system allows optimizing the PV effect with high increase of generated electric power as well as decrease of active surface area. In this paper, an economic analysis and a life cycle assessment (LCA) study of a particular LCPV scheme is presented and its environmental impacts are compared with those of a PV traditional system. The LCA study was performed with the software tool SimaPro 8.0.2, using the Econinvent 3.1 database. A functional unit of 1 kWh of electricity produced was chosen. Carbon Footprint, Ecological Footprint and ReCiPe 2008 were the methods used to assess the environmental impacts of the LCPV plant compared with a corresponding traditional system. All the methods demonstrated the environmental convenience of the LCPV system. The innovative system allowed saving 16.9% of CO2 equivalent in comparison with the traditional PV plant. The environmental impacts saving was 17% in terms of Ecological Footprint, and, finally, 15.8% with the ReCiPe method.

Novel materials for biofilm reactors and their characterization.

The application of adherently growing microorganisms for biotechnological production processes is established, but it is still a niche technology with only a small economic impact. However, novel approaches are under development for new types of biofilm reactors. In this context, increasingly more microstructured metal surfaces are being investigated, and they show positive effects on the bacterial growth and the biofilm establishment. However, for comparison of the data, the different surface materials have to correspond in their different characteristics, such as wettability and chemical composition. Also, new materials, such as plastic composite supports, were developed. To understand the interaction between these new materials and the biofilm-producing microorganisms, different surface science methods have to be applied to reveal a detailed knowledge of the surface characteristics. In conclusion, microstructured surfaces show a high potential for enhanced biofilm growth, probably accompanied by an enhanced productivity of the microorganisms.