Chicken Cecum Immune Response to Salmonella enterica Serovars of Different Levels of Invasiveness▿

Day-old chicks are very susceptible to infections with Salmonella enterica subspecies. The gut mucosa is the initial site of host invasion and provides the first line of defense against the bacteria. To study the potential of different S. enterica serovars to invade the gut mucosa and trigger an immune response, day-old chicks were infected orally with Salmonella enterica serovar Enteritidis, S. enterica serovar Typhimurium, S. enterica serovar Hadar, or S. enterica serovar Infantis, respectively. The localization of Salmonella organisms in gut mucosa and the number of immune cells in cecum were determined by immunohistochemistry in the period between 4 h and 9 days after infection. Using quantitative real-time reverse transcription (RT)-PCR, mRNA expression of various cytokines, chemokines, and inducible nitric oxide synthase (iNOS) was examined in cecum. As a result, all S. enterica serovars were able to infect epithelial cells and the lamina propria. Notably, serovar Enteritidis showed the highest invasiveness of lamina propria tissue, whereas serovars Typhimurium and Hadar displayed moderate invasiveness and serovar Infantis hardly any invasion capabilities. Only a limited number of bacteria of all serovars were found within intestinal macrophages. Elevated numbers of granulocytes, CD8+ cells, and TCR1+ cells and mRNA expression rates for interleukin 12 (IL-12), IL-18, tumor necrosis factor alpha factor, and iNOS in cecum correlated well with the invasiveness of serovars in the lamina propria. In contrast, changes in numbers of TCR2+ and CD4+ cells and IL-2 mRNA expression seemed to be more dependent on infection of epithelial cells. The data indicate that the capability of Salmonella serovars to enter the cecal mucosa and invade lower regions affects both the level and character of the immune response in tissue

Oberirdische Speicher in Segmentbauweise für Wärmeversorgungssysteme – OBSERW: Abschlussbericht zum Verbundvorhaben

Im Projekt wurde eine alternative Speicherkonstruktion im Bereich von 500 bis 6000 m3 für den Betrieb in Solar- und Fernwärmesystemen entwickelt. Ausgangspunkt bilden große Kaltwasserspeicher in Segmentbauweise. Die Bautechnologie bietet ein signifikantes Kostenreduktionspotenzial gegenüber geschweißten Flachbodentanks, konnte bisher aber nicht auf Wärmespeicher übertragen werden. Aufgrund der dünnwandigen Bauweise und der Projektziele musste eine Überarbeitung des Wandaufbaus, der Einbauten und der Peripherie erfolgen. Dieser Bericht liefert eine Beschreibung des Speicher-Systems und die Ergebnisse des Verbundvorhabens. Die Funktionsfähigkeit wurde mit einem dreistufigen Verfahren nachgewiesen. Das geplante Vorgehen mit Laborversuchen im kleinen Maßstab bis zum Test mit einem Demonstrator im Realmaßstab (100 m3) war notwendig und zielführend. Die Bearbeitung der Hauptaufgaben (z. B. Materialuntersuchungen, Konstruktion, Betrieb) erfolgte vernetzt durch die beteiligten Forschungsinstitutionen. Das grundlegende Potenzial für eine spätere Anwendung in solaren Nahwärmesystemen oder Sekundärnetzgebieten der klassischen Fernwärme sind gegeben. Vor allem im Bereich der Beladung und im Wandaufbau konnten große Verbesserungen erzielt werden. Weitere Optimierungen und die Umsetzung mit größeren Speichern stehen noch aus.In the project, an alternative construction for thermal energy stores in the range of 500 to 6000 m3 was developed for operation in solar and district heating systems. Large cold water storage tanks in segmental construction are the starting point. Their construction technology offers a significant potential for cost reduction compared to welded flat-bottom tanks, but could so far not be transferred to hot water storage tanks. Due to the new design and the project objectives, the wall structure, the internals and the periphery had to be completely revised. This report provides a description of the storage system and the results of the joint project. The functionality was proven with a three-stage procedure. The planned procedure with laboratory tests on a small scale up to the test with a demonstrator on a real scale (100 m3) was necessary and purposeful. The main tasks (e.g. material testing, design, operation) were carried out by the participating research institutions in a network. The basic potential for a later application in solar local heating systems or secondary network areas of conventional district heating is given. Significant improvements were realized, especially in regard of the charging system and the wall construction. However, further optimizations and the transfer to larger storage tanks is still pending