Chromophors for two-photon absorption

Ziel der Arbeit war die Entwicklung und Synthese von Farbstoffen mit der Befähigung zur Zweiphotonenabsorption. Die maßgeschneiderten Chromophore sollten in der Zweiphotonenlaserrastermikroskopie (TPLSM) einsetzbar sein. Dazu wurden Design-Kriterien aufgestellt und ausgewählte Vetreter von vier Substanzklassen (Pyrazolo[1,2-a]pyrazol-1,7-dione, Benzo[2,1-b:3,4-b´]dithiophene, Dibenzothiophene und Dibenzothiophen-S,S-dioxide) synthetisiert. Ihre linear und nichtlinear optischen Eigenschaften wurden anhand von Absorptions-, Fluoreszenz- und Zweiphotonenanregungsspektren umfassend untersucht. N,N,N´N´-Tetraaryldibenzothiophen-S,S-dioxid-3,7-diamine erwiesen sich für die TPLSM als besonders geeignet. Sie wurden vom Kooperationspartner in TPLSM- und Fluoreszenzlebensdauer (FLIM)-Aufnahmen von Pflanzenzellen und Humanhaut eingesetzt.Target of this work was the developement and synthesis of dyes with the ability to undergo two-photon absorption. The taylor-made chromophores should be used for Two-photon Laser scanning microscopy (TPLSM). Therefore, design criteria were determined and chosen molecules from four different classes (Pyrazolo[1,2-a]pyrazol-1,7-diones, Benzo[2,1-b:3,4-b´]dithiophenes, Dibenzothiophenes and Dibenzothiophen-S,S-dioxides) have been synthesized. Their linear and nonlinear optical properties were investigated intensively by using UV/Vis, fluorescence and two-photon excitation spectroscopy. Especially N,N,N´N´-Tetraaryldibenzothiophene-S,S-dioxide-3,7-diamines have been proved to be suitable for TPLSM. They were used by co-operators for TPLSM- and fluorescence lifetime imaging (FLIM) of plant cells and human skin

On discontinuous Galerkin approach for atmospheric flow in the mesoscale with and without moisture

We present and discuss discontinuous Galerkin (DG) schemes for dry and moist atmospheric flows in the mesoscale. We derive terrain-following coordinates on the sphere in strong-conservation form, which makes it possible to perform the computation on a Cartesian grid and yet conserves the momentum density on an f -plane. A new DG model, i.e. DG-COSMO, is compared to the operational model COSMO of the Deutscher Wetterdienst (DWD). A simplified version of the suggested terrain-following coordinates is implemented in DG-COSMO and is compared against the DG dynamical core implemented within the DUNE framework, which uses unstructured grids to capture orography. Finally, a few idealised test cases, including 3d and moisture, are used for validation. In addition an estimate of efficiency for locally adaptive grids is derived for locally and non-locally occurring phenomena.publishedVersio

Review of Hydrogen Production Techniques from Water Using Renewable Energy Sources and Its Storage in Salt Caverns

Hydrogen is becoming an increasingly important energy carrier in sector integration for fuel cell transportation, heat and electricity. Underground salt caverns are one of the most promising ways to store the hydrogen obtained from water electrolysis using power generation from renewable energy sources (RES). At the same time, the production of hydrogen can be used to avoid energy curtailments during times of low electricity demand or low prices. The stored hydrogen can also be used during times of high energy demand for power generation, e.g., with fuel cells, to cover the fluctuations and shortages caused by low RES generation. This article presents an overview of the techniques that were used and proposed for using excess energy from RES for hydrogen production from water and its storage techniques, especially in underground salt caverns, for the aforementioned purpose, and its feasibility. This paper compares and summarizes the competing technologies based on the current state-of-the-art, identifies some of the difficulties in hydrogen production and storage, and discusses which technology is the most promising. The related analysis compares cost and techno-economic feasibility with regard to hydrogen production and storage systems. The paper also identifies the potential, technical challenges and the limitations associated with hydrogen integration into the power grid

GATA2 deficiency in children and adults with severe pulmonary alveolar proteinosis and hematologic disorders

Background The majority of cases with severe pulmonary alveolar proteinosis (PAP) are caused by auto-antibodies against GM-CSF. A multitude of genetic and exogenous causes are responsible for few other cases. Goal of this study was to determine the prevalence of GATA2 deficiency in children and adults with PAP and hematologic disorders. Methods Of 21 patients with GM-CSF-autoantibody negative PAP, 13 had no other organ involvement and 8 had some form of hematologic disorder. The latter were sequenced for GATA2. Results Age at start of PAP ranged from 0.3 to 64 years, 4 patients were children. In half of the subjects GATA2-sequence variations were found, two of which were considered disease causing. Those two patients had the typical phenotype of GATA2 deficiency, one of whom additionally showed a previously undescribed feature – a cholesterol pneumonia. Hematologic disorders included chronic myeloic leukemia, juvenile myelo-monocytic leukemia, lymphoblastic leukemia, sideroblastic anemia and two cases of myelodysplastic syndrome (MDS). A 4 year old child with MDS and DiGeorge Syndrome Type 2 was rescued with repetitive whole lung lavages and her PAP was cured with heterologous stem cell transplant. Conclusions In children and adults with severe GM-CSF negative PAP a close cooperation between pneumologists and hemato-oncologists is needed to diagnose the underlying diseases, some of which are caused by mutations of transcription factor GATA2. Treatment with whole lung lavages as well as stem cell transplant may be successful