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Presents a study that determined the contributions of ABB Asea Brown Boveri Ltd. in Baden, Switzerland to the development of industrial gas turbines. History of the ABB Asea Brown Boveri Ltd.; Information on the contributions of scientists and industrial leaders to the development of compressors for gas turbines; Details on the development of gas turbines.

The Mössbauer Conversion (MBC) Spectroscopy and criteria for its useful application are discussed and compared with other MB-techniques. By help of the MBC spectroscopy the isomer shift of the first excited state inW was measured and a change in radius −0.05 · 10> Δ 〈 r〉/〈 r〉>−0.28 · 10 derived. The ratio of quadrupole moments of first excited states inW andW turns out to be Q/ Q=0.976 (30). Due to the excellent statistical quality of the spectra the interference parameter of the 100keV E2 transition inW could be determined to 2 β=0.0165(9) for the L-shell. The MB-effect for the 61 keV transition in the instablePm has been detected for the first time. A width Λ=2.15(58) mm/s was obtained. [ABSTRACT FROM AUTHOR]

The mammalian heart comprises mainly cardiomyocytes, fibroblasts, endothelial cells, and smooth muscle cells. Cardiomyocyte subtypes are characterized by differential expression of intracellular proteins like MLC-2a, Cx40 or ANF in atrial cardiomyocytes as well as MLC-2v, Hey2 or Irx4 in ventricular cardiomyocytes. Nevertheless, to date the expression of chamber-specific intracellular proteins could not be correlated to corresponding cell surface markers. Therefore, the selective, surface marker-based enrichment of atrial or ventricular cardiomyocytes from whole-heart preparations is currently not possible.In a proof-of-concept study we performed a semi-automated, antibody-based surface marker screen on neonatal mouse heart preparations. By that we were able to identify several candidate markers exclusively expressed by non-cardiomyocytes. Using a magnetic cell sorting approach, we could highly enrich for neonatal cardiomyocytes by efficiently removing non-cardiomyocytes. In a second step, we were able to identify surface markers differentially expressed on atrial and ventricular cardiomyocytes, thereby dividing the pure cardiomyocyte population into two subpopulations. Next, we established cell isolation strategies to specifically isolate atrial and ventricular cardiomyocytes from whole-heart cell preparations with high purities. Expression profiling of the isolated subpopulations confirmed high expression of atrial marker genes such as Nr2f2, Fgf12, Sln, Gja5 and Nppa in the putative atrial fraction as well as high expression of genes associated with a ventricular myocyte identity, e.g. Hey2, Irx4, Lbh, Myh7 in the putative ventricular fraction. The sorted cells were viable, could be cultivated and exhibited spontaneous contractions 24h after plating.For the first time, we found a set of cell surface markers that can be used to specifically isolate atrial and ventricular cardiomyocytes from mouse heart. As the markers were also expressed on mouse embryonic stem cell-derived cardiomyocytes, current work analyzes their relevance for the identification and isolation of pluripotent stem cell-derived cardiomyocyte subpopulations. [ABSTRACT FROM AUTHOR]

Pure cardiovascular cell lineages are a requisite for an unbiased and cell type specific investigation of (patho-) physiological mechanisms involved in heart failure. Moreover pure heart cells are needed as building blocks for engineered heart mimetics. The latter offers the possibility to replace infarcted myocardium and to investigate heart development and cardiomyogenesis in a simplified in vitro model. However, it has to be acknowledged that strategies capable to specifically purify heart cells are not well established. To overcome these experimental limitations we developed a rapid and automated neonatal heart dissociation protocol enabling an immunomagnetic enrichment of the three major heart cell types, namely cardiomyocytes (CMs), cardiac fibroblasts (Fibs) and endothelial cells (Endos) from both, mouse and rat neonatal hearts.First, we established an enzyme mix optimal for the dissociation of neonatal mouse and rat hearts (P0-P3) by screening our enzyme library. Next, we optimized the dissociation by utilizing our gentleMACS technology resulting in a fast (1h), robust, and fully automated heart dissociation protocol. Analysis of the dissociated mouse and rat heart cells showed: (i) high cell vitalities (>90%), (ii) high frequencies of α-Actinin-positive CMs (>60%) and (iii) vimentin-positive non-CMs with a frequency of >40% (P2). In order to selectively enrich various cell-types from these heterogenous cell populations, we performed a cell-surface marker screen. We identified several candidates for the composition of antibody cocktails enabling selective enrichment of mouse and rat CMs, Fibs or Endos with purities of up to 97%. CMs grown in 2D cultures showed spontaneous beating activity and the expression of sarcomeric proteins in a cross-striated pattern (α-Actinin and cTnT). Additionally, heart cells were cultured on organotypic decellularized (1% SDS) mouse heart slices. Analysis of the slice cultures after recellularization showed (i) partial restoration of synchronous contractions and (ii) orientated and elongated heart cells along the microfibrillar heart structure. Purified Fibs were highly proliferative and could be expanded 34-fold over an analyzed culture period of 15 days. Finally, functionality of the purified endothelial cells was proven by Dil-LDL endocytosis.In summary, we established an automated protocol for the dissociation of neonatal mouse and rat hearts, enabling the subsequent immunomagnetic enrichment of CMs, Fibs and Endos which can readily be utilized for 2D cell culture assays or to generate in vitro heart muscle models and surrogate tissue for myocardial repair. [ABSTRACT FROM PUBLISHER]