Nonglycosidic Agonists of Invariant NKT Cells for Use as Vaccine Adjuvants

Based on the crystal structures of human α‐GalCer–CD1d and iNKT–α‐GalCer–CD1d complexes, nonglycosidic analogues of α‐GalCer were synthesized. They activate iNKT cells resulting in dendritic cell maturation and the priming of antigen‐specific T and B cells. Therefore, they are attractive adjuvants in vaccination strategies for cancer and infectious diseases.

     

Expression of Connexin43 Stimulates Endothelial Angiogenesis Independently of Gap Junctional Communication In Vitro

Connexins (Cx) form gap junctions (GJ) and allow for intercellular communication. However, these proteins also modulate gene expression, growth, and cell migration. The downregulation of Cx43 impairs endothelial cell migration and angiogenetic potential. Conversely, endothelial Cx43 expression is upregulated in an in vivo angiogenesis model relying on hemodynamic forces. We studied the effects of Cx43 expression on tube formation and proliferation in HUVECs and examined its dependency on GJ communication. Expectedly, intercellular communication assessed by dye transfer was linked to Cx43 expression levels in HUVECs and was sensitive to a GJ blockade by the Cx43 mimetic peptide Gap27. The proliferation of HUVECs was not affected by Cx43 overexpression using Cx43 cDNA transfection, siRNA-mediated knockdown of Cx43, or the inhibition of GJ compared to the controls (transfection of an empty vector, scrambled siRNA, and the solvent). In contrast, endothelial tube and sprout formation in HUVECs was minimized after Cx43 knockdown and significantly enhanced after Cx43 overexpression. This was not affected by a GJ blockade (Gap27). We conclude that Cx43 expression positively modulates the angiogenic potential of endothelial cells independent of GJ communication. Since proliferation remained unaffected, we suggest that Cx43 protein may modulate endothelial cell migration, thereby supporting angiogenesis. The modulation of Cx43 expression may represent an exploitable principle for angiogenesis induction in clinical therapy.     

Dauerhaftigkeitspotentiale selbstverdichtender Betone

The Potential Durability of Self‐Compacting Concrete Owing to its exceptional fresh concrete properties, the use of self‐compacting concrete SCC offers numerous technological and economical advantages. However, during the planning of constructions the question arises as to whether the special composition of SCC affects durability. Thus the potential durability of different SCC compositions was investigated systematically at the Centre for Building Materials (cbm) of the Technical University of Munich. In a first series of tests, attention was focused on the effect of the powder fraction and viscosity agents often used in SCC on durability. In addition, the effect of the special composition of SCC on the susceptibility to damaging alkali silica‐reactions ASR was investigated. The effectiveness of fly ash as a secondary cementitious material in avoiding damaging ASR when using reactive aggregate was clarified.     

Effect of wet chemical substrate pretreatment on the growth behavior of Ta(N) films deposited by thermal ALD

The deposition of ultra thin Ta(N) films by ALD is a possibility to achieve conformal film thickness and suitable step coverage for microelectronic applications. Due to the sorption of a precursor molecule to the substrate surface, the chemical interface conditions are important. In the present study selected substrate pretreatments were investigated by in situ XPS and spectroscopic ellipsometry in reference to the amount of carbon containing contamination and oxygen and in reference to the ALD growth rate of Ta(N) films. Furthermore, surface roughness was measured by AFM and will be discussed in dependence on the individual pretreatment and the ALD Ta(N) cycle number.     

Retrieval of Total Column Ozone From Imagers Onboard Geostationary Satellites

Geostationary imagers such as the Advanced Baseline Imager (ABI) proposed for the next generation of Geostationary Operational Environmental Satellites (GOESs), i.e., GOES Series R and beyond, and the spinning enhanced visible and InfraRed Imager (SEVIRI) onboard METEOSAT 8 provide atmospheric total column ozone (TCO) with high temporal (better than 15 min) and spatial (better than 5 km) resolutions. The purpose of this paper is to present a method that evolved from the current GOES sounder TCO retrieval that can be applied to ABI, with SEVIRI serving as a proxy for ABI. Although ABI and SEVIRI have fewer infrared spectral bands than the current series of GOES (-8 to -P) sounders, ABI and SEVIRI can provide TCO with an accuracy that is comparable to the current GOES sounder by using forecast temperature profiles as additional a priori information. Despite the need for additional data, the greatest advantage of ABI and SEVIRI is their fast 15-min coverage of the full disk. The SEVIRI TCO demonstrates how well geostationary imagers can capture ozone transport and change at high temporal and spatial resolutions. The estimated TCO has very good agreement (R = 0.92 and root-mean-square error = 3.7%) with the total ozone measurements from the Ozone Monitoring Instrument (OMI) onboard the Earth Observing System aura platform.     

2 MeV ion irradiation effects on AlGaN/GaN HFET devices

AlGaN/GaN heterostructure field effect transistors (HFETs) were irradiated with 2 MeV protons, carbon, oxygen, iron and krypton ions with fluences ranging from 1 × 10⁹ cm^?2 to 1 × 10¹³ cm^?2. DC, pulsed I–V characteristics, loadpull and S-parameters of the AlGaN HFET devices were measured before and after irradiation. In parallel, a thick GaN reference layer was also irradiated with the same ions and was characterized by X-ray diffraction, photoluminescence, Hall measurements before and after irradiation. Small changes in the device performance were observed after irradiation with carbon and oxygen at a fluence of 5 × 10¹⁰ cm^?2. Remarkable changes in device characteristics were seen at a fluence of 1 × 10¹² cm^?2 for carbon, oxygen, iron and krypton irradiation. Similarly, remarkable changes were also observed in the GaN layer for irradiations with fluence of 1 × 10¹² cm^?2. The results found on devices and on the GaN layer were compared and correlated.     

Vom Hofbräuhaus zum Deutschen Museum – Münchner Bauten aus Eisenbeton 1890 bis 1914 (1)

From Hofbräuhaus to the German Museum – reinforced concrete buildings in Munich from 1890 to 1914. This year (2008) Munich celebrates its 850‐year anniversary and in appropriate publications the authors try to work out the special Munich style. Little attention will be paid to a special chapter of Munich's history – the beginning of construction with reinforced concrete about 1900. Munich can claim that city to have been first in the new building technology and important buildings in reinforced concrete were designed and erected. Unfortunately, today this extraordinary architectural and engineering development is widely forgotten.     

Deliqueszenz und Effloreszenz hygroskopischer Salzpartikeln in Partikel‐Wand‐ und Partikel‐Partikel‐Kontakten

In case of dust separation with surface filters, adhesive bonds at particle‐wall and particle‐particle contacts are of great importance. The deliquescence and efflorescence of hygroscopic salt particles can significantly influence the adhesive bonds at particle contacts with such salt particles. Therefore, to investigate these phenomena, various types of particle contacts were produced by the separation of aerosols on filtering collectors and subsequently observed in the chamber of an environmental SEM during the moisture‐induced deliquescence and efflorescence.