Einfluss des Calcium-aktivierten Kalium-Kanals KCa3.1 auf die Migration von Pankreas-Sternzellen

Pankreas-Sternzellen spielen eine zentrale Rolle in der Progression des Pankreaskarzinoms. Vermittelt durch Wachstumsfaktoren beeinflussen sie z.B. dessen Proliferation und Metastasierung und verursachen die charakteristische Desmoplasie des Tumors. Sternzellen waren hinsichtlich ihrer Ausstattung mit Ionenkanälen, die eine wichtige Rolle bei der Progression von Tumoren einnehmen, bislang vollkommen uncharakterisiert. In Rahmen dieser Arbeit wurde in den Sternzellen die Expression von KCa3.1-Kanälen nachgewiesen und deren Wirken auf den Ca2+-Haushalt und die Migrationsfähigkeit von Sternzellen untersucht. Zusammenfassend konnte gezeigt werden, dass KCa3.1-Kanäle durch ihren Einfluss auf den Calcium-Haushalt eine entscheidende Rolle in der Migration der Pankreas-Sternzellen einnehmen. Pancreatic stellate cells (PSCs) play a critical role in the progression of pancreatic ductal adenocarcinoma (PDAC): Once activated by carcinoma cells, PSCs support their proliferation and metastasis. Furthermore, they contribute to the excessive deposition of extracellular matrix proteins in the PDAC stroma, the so-called desmoplastic reaction. So far, there is no information about ion channels expressed in PSCs. It is known that calcium-activated K+ channels KCa3.1 are involved in cancer progression and cell migration. We therefore investigated the expression and function of KCa3.1 in a human PSC cell line. In summary, we showed that KCa3.1 channels are crucial for stimulated migration of PSCs, most likely via their impact on [Ca2+]i.<br

Engineering the semiconductor/oxide interaction for stacking twin suppression in single crystalline epitaxial silicon(111)/insulator/Si(111) heterostructures

The integration of alternative semiconductor layers on the Si material platform via oxide heterostructures is of interest to increase the performance and/or functionality of future Si-based integrated circuits. The single crystalline quality of epitaxial (epi) semiconductor-insulator-Si heterostructures is however limited by too high defect densities, mainly due to a lack of knowledge about the fundamental physics of the heteroepitaxy mechanisms at work. To shed light on the physics of stacking twin formation as one of the major defect mechanisms in (111)-oriented fcc-related heterostructures on Si(111), we report a detailed experimental and theoretical study on the structure and defect properties of epi-Si(111)/Y2O 3/Pr2O3/Si(111) heterostructures. Synchrotron radiation-grazing incidence x-ray diffraction (SR-GIXRD) proves that the engineered Y2O3/Pr2O3 buffer dielectric heterostructure on Si(111) allows control of the stacking sequence of the overgrowing single crystalline epi-Si(111) layers. The epitaxy relationship of the epi-Si(111)/insulator/Si(111) heterostructure is characterized by a type A/B/A stacking configuration. Theoretical ab initio calculations show that this stacking sequence control of the heterostructure is mainly achieved by electrostatic interaction effects across the ionic oxide/covalent Si interface (IF). Transmission electron microscopy (TEM) studies detect only a small population of misaligned type B epi-Si(111) stacking twins whose location is limited to the oxide/epiSi IF region. Engineering the oxide/semiconductor IF physics by using tailored oxide systems opens thus a promising approach to grow heterostructures with well-controlled properties. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

Structural and optical quality of GaN grown on Sc2O3/Y2O3/Si(111)

Thick (∼900 nm) GaN layers were grown by molecular beam epitaxy on cost-effective Sc2O3/Y2O3/Si(111) substrates and characterized by x-ray diffraction and photoluminescence. Samples grown in Ga-rich condition show superior structural and optical quality with reduced density of cubic GaN inclusions within the hexagonal matrix and a relatively strong photoluminescence emission at 3.45 eV at 10 K. Cubic inclusions are formed in the initial growth stage and their concentration is reduced with increasing film thickness and after rapid thermal annealing

Experimental quality in the experiments of competition of hybrid in function of the variability in morphologic variables

O objetivo do trabalho foi verificar a relação entre a diferença mínima significativa em percentagem da média (DMS%) da variável rendimento de grãos, com a média e erro experimental das características morfológicas observadas no decorrer do experimento, ciclo dos cultivares estudadas e número de tratamentos adotados. Com os dados dos ensaios estaduais de competição de cultivares de milho no estado do Rio Grande do Sul, utilizou-se a análise de trilha, tendo como variável principal a DMS% e como variáveis explicativas as demais variáveis observadas nos experimentos, mostrando que variáveis como rendimento de grãos, altura da planta, altura de inserção da primeira espigas e número final de plantas, com valores mais homogêneos dentro de cada experimento, proporcionam um menor quadrado médio do erro, fazendo com que a precisão do experimento seja melhorada.A study was performed to verify the relationship between the least significative difference in mean percentage (LSD%) of the variable grain yield and the mean and experimental error of the morphological characteristics observed throughout the experiment cultivar cicle, and the number of treatments in corn. Using data from a net of corn cultivars trials in the Rio Grande do Sul State, a pathy analysis was carried out, with LSD% as the main variable and as explaining variables some other variables measured in the trials. The results showed that variables such as grain yield, plant height, heigth of the ear and the final number of plants in corn, with more homogeneous values inside each trial, lead to a smaller mean square error, which reproved the experimental precision.Facultad de Ciencias Agrarias y Forestale

Experimental quality in the experiments of competition of hybrid in function of the variability in morphologic variables

O objetivo do trabalho foi verificar a relação entre a diferença mínima significativa em percentagem da média (DMS%) da variável rendimento de grãos, com a média e erro experimental das características morfológicas observadas no decorrer do experimento, ciclo dos cultivares estudadas e número de tratamentos adotados. Com os dados dos ensaios estaduais de competição de cultivares de milho no estado do Rio Grande do Sul, utilizou-se a análise de trilha, tendo como variável principal a DMS% e como variáveis explicativas as demais variáveis observadas nos experimentos, mostrando que variáveis como rendimento de grãos, altura da planta, altura de inserção da primeira espigas e número final de plantas, com valores mais homogêneos dentro de cada experimento, proporcionam um menor quadrado médio do erro, fazendo com que a precisão do experimento seja melhorada.A study was performed to verify the relationship between the least significative difference in mean percentage (LSD%) of the variable grain yield and the mean and experimental error of the morphological characteristics observed throughout the experiment cultivar cicle, and the number of treatments in corn. Using data from a net of corn cultivars trials in the Rio Grande do Sul State, a pathy analysis was carried out, with LSD% as the main variable and as explaining variables some other variables measured in the trials. The results showed that variables such as grain yield, plant height, heigth of the ear and the final number of plants in corn, with more homogeneous values inside each trial, lead to a smaller mean square error, which reproved the experimental precision.Facultad de Ciencias Agrarias y Forestale

Microplastic in Surface Waters of Urban Rivers: Concentration, Sources, and Associated Bacterial Assemblages

The ecological dynamics of microplastic (\u3c5 mm) are well documented in marine ecosystems, but the sources, abundance, and ecological role of microplastic in rivers are unknown and likely to be substantial. Microplastic fibers (e.g., synthetic fabrics) and pellets (e.g., abrasives in personal care products) are abundant in wastewater treatment plant (WWTP) effluent, and can serve as a point source of microplastic in rivers. The buoyancy, hydrophobic surface, and long transport distance of microplastic make it a novel substrate for the selection and dispersal of unique microbial assemblages. We measured microplastic concentration and bacterial assemblage composition on microplastic and natural surfaces upstream and downstream of WWTP effluent sites at nine rivers in Illinois, United States. Microplastic concentration was higher downstream of WWTP effluent outfall sites in all but two rivers. Pellets, fibers, and fragments were the dominant microplastic types, and polymers were identified as polypropylene, polyethylene, and polystyrene. Mean microplastic flux was 1,338,757 pieces per day, although the flux was highly variable among nine sites (min = 15,520 per day, max = 4,721,709 per day). High-throughput sequencing of 16S rRNA genes showed bacterial assemblage composition was significantly different among microplastic, seston, and water column substrates. Microplastic bacterial assemblages had lower taxon richness, diversity, and evenness than those on other substrates, and microplastic selected for taxa that may degrade plastic polymers (e.g., Pseudomonas) and those representing common human intestinal pathogens (e.g., Arcobacter). Effluent from WWTPs in rivers is an important component of the global plastic “life cycle,” and microplastic serves as a novel substrate that selects and transports distinct bacterial assemblages in urban rivers. Rates of microplastic deposition, consumption by stream biota, and the metabolic capacity of microplastic biofilms in rivers are unknown and merit further research

New records of predation of Harpactorinae (Hemiptera: Reduviidae) over Euglossini and Xylocopini bees (Hymenoptera: Apidae) in Brazil.

Abstract. The predatory activities of Apiomerus duckei Costa Lima, Seabra & Hathaway, 1951, Apiomerus pilipes (Fabricius, 1787) and Apiomerus luctuosus Costa Lima, Seabra & Hathaway, 1951 (Hemiptera: Reduviidae: Harpactorinae: Apiomerini) on orchid bees (Hymenoptera: Apidae: Apinae: Euglossini) in odoriferous traps in the influence area of Santo Antônio Hydroelectric Power Plant, Rondônia State, Brazil, and of Cosmoclopius annulosus Stål, 1872 (Hemiptera: Reduviidae: Harpactorinae: Harpactorini) on the bee Ceratina rupestris Holmberg, 1884 (Hymenoptera: Apidae: Apinae: Xylocopini: Ceratinina), in an experimental area cultivated with canola in Passo Fundo, Rio Grande do Sul State, Brazil, are recorded by the first time. Resumen. Se registran por primera vez las actividades depredadoras de Apiomerus duckei Costa Lima, Seabra y Hathaway, 1951, Apiomerus pilipes (Fabricius, 1787) y Apiomerus luctuosus Costa Lima, Seabra y Hathaway, 1951 (Hemiptera: Reduviidae: Harpactorinae: Apiomerini) sobre abejas orquídeas (Hymenoptera: Apidae: Apinae: Euglossini) en trampas odoríferas ubicadas en el área de influencia de la Central Hidroeléctrica Santo Antônio (HEP), Estado de Rondônia, Brasil, y de Cosmoclopius annulosus Stål, 1872 (Hemiptera: Reduviidae: Harpactorinae: Harpactorini) sobre la abeja Ceratina rupestris Holmberg, 1884 (Hymenoptera: Apidae: Apinae: Xylocopini: Ceratinina), en un área experimental cultivada con canola en Passo Fundo, Rio Grande do Sul State, Brasil