70 research outputs found

    Simulation techniques in energy analysis

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    Simulation is one of the most frequently used techniques in energy modelling. After some general remarks on the nature of simulation models, a more detailed description of a large scale dynamic energy simulation model for the Federal Republic of Germany is given. The paper continues with a discussion of some model results and concludes with some brief remarks on the limitations of the simulation approach

    Generation of Healthy Mice from Gene-Corrected Disease-Specific Induced Pluripotent Stem Cells

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    Using the murine model of tyrosinemia type 1 (fumarylacetoacetate hydrolase [FAH] deficiency; FAH−/− mice) as a paradigm for orphan disorders, such as hereditary metabolic liver diseases, we evaluated fibroblast-derived FAH−/−-induced pluripotent stem cells (iPS cells) as targets for gene correction in combination with the tetraploid embryo complementation method. First, after characterizing the FAH−/− iPS cell lines, we aggregated FAH−/−-iPS cells with tetraploid embryos and obtained entirely FAH−/−-iPS cell–derived mice that were viable and exhibited the phenotype of the founding FAH−/− mice. Then, we transduced FAH cDNA into the FAH−/−-iPS cells using a third-generation lentiviral vector to generate gene-corrected iPS cells. We could not detect any chromosomal alterations in these cells by high-resolution array CGH analysis, and after their aggregation with tetraploid embryos, we obtained fully iPS cell–derived healthy mice with an astonishing high efficiency for full-term development of up to 63.3%. The gene correction was validated functionally by the long-term survival and expansion of FAH-positive cells of these mice after withdrawal of the rescuing drug NTBC (2-(2-nitro-4-fluoromethylbenzoyl)-1,3-cyclohexanedione). Furthermore, our results demonstrate that both a liver-specific promoter (transthyretin, TTR)-driven FAH transgene and a strong viral promoter (from spleen focus-forming virus, SFFV)-driven FAH transgene rescued the FAH-deficiency phenotypes in the mice derived from the respective gene-corrected iPS cells. In conclusion, our data demonstrate that a lentiviral gene repair strategy does not abrogate the full pluripotent potential of fibroblast-derived iPS cells, and genetic manipulation of iPS cells in combination with tetraploid embryo aggregation provides a practical and rapid approach to evaluate the efficacy of gene correction of human diseases in mouse models

    Acquired resistance to oxaliplatin is not directly associated with increased resistance to DNA damage in SK-N-ASrOXALI4000, a newly established oxaliplatin-resistant sub-line of the neuroblastoma cell line SK-N-AS

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    The formation of acquired drug resistance is a major reason for the failure of anti-cancer therapies after initial response. Here, we introduce a novel model of acquired oxaliplatin resistance, a sub-line of the non-MYCN-amplified neuroblastoma cell line SK-N-AS that was adapted to growth in the presence of 4000 ng/mL oxaliplatin (SK-N-ASrOXALI4000). SK-N-ASrOXALI4000 cells displayed enhanced chromosomal aberrations compared to SK-N-AS, as indicated by 24-chromosome fluorescence in situ hybridisation. Moreover, SK-N-ASrOXALI4000 cells were resistant not only to oxaliplatin but also to the two other commonly used anti-cancer platinum agents cisplatin and carboplatin. SK-N-ASrOXALI4000 cells exhibited a stable resistance phenotype that was not affected by culturing the cells for 10 weeks in the absence of oxaliplatin. Interestingly, SK-N-ASrOXALI4000 cells showed no cross resistance to gemcitabine and increased sensitivity to doxorubicin and UVC radiation, alternative treatments that like platinum drugs target DNA integrity. Notably, UVC-induced DNA damage is thought to be predominantly repaired by nucleotide excision repair and nucleotide excision repair has been described as the main oxaliplatin-induced DNA damage repair system. SK-N-ASrOXALI4000 cells were also more sensitive to lysis by influenza A virus, a candidate for oncolytic therapy, than SK-N-AS cells. In conclusion, we introduce a novel oxaliplatin resistance model. The oxaliplatin resistance mechanisms in SK-N-ASrOXALI4000 cells appear to be complex and not to directly depend on enhanced DNA repair capacity. Models of oxaliplatin resistance are of particular relevance since research on platinum drugs has so far predominantly focused on cisplatin and carboplatin

    Difficult tracheal intubation in neonates and infants. NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE): a prospective European multicentre observational study

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    BACKGROUND: Neonates and infants are susceptible to hypoxaemia in the perioperative period. The aim of this study was to analyse interventions related to anaesthesia tracheal intubations in this European cohort and identify their clinical consequences. METHODS: We performed a secondary analysis of tracheal intubations of the European multicentre observational trial (NEonate and Children audiT of Anaesthesia pRactice IN Europe [NECTARINE]) in neonates and small infants with difficult tracheal intubation. The primary endpoint was the incidence of difficult intubation and the related complications. The secondary endpoints were the risk factors for severe hypoxaemia attributed to difficult airway management, and 30 and 90 day outcomes. RESULTS: Tracheal intubation was planned in 4683 procedures. Difficult tracheal intubation, defined as two failed attempts of direct laryngoscopy, occurred in 266 children (271 procedures) with an incidence (95% confidence interval [CI]) of 5.8% (95% CI, 5.1–6.5). Bradycardia occurred in 8% of the cases with difficult intubation, whereas a significant decrease in oxygen saturation (SpO2<90% for 60 s) was reported in 40%. No associated risk factors could be identified among co-morbidities, surgical, or anaesthesia management. Using propensity scoring to adjust for confounders, difficult anaesthesia tracheal intubation did not lead to an increase in 30 and 90 day morbidity or mortality. CONCLUSIONS: The results of the present study demonstrate a high incidence of difficult tracheal intubation in children less than 60 weeks post-conceptual age commonly resulting in severe hypoxaemia. Reassuringly, the morbidity and mortality at 30 and 90 days was not increased by the occurrence of a difficult intubation event

    Complete genome sequences of two plant-associated <em>Pseudomonas putida </em>isolates with increased heavy-metal tolerance.

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    We report here the complete genome sequences of two Pseudomonas putida isolates recovered from surface-sterilized roots of Sida hermaphrodita The two isolates were characterized by an increased tolerance to zinc, cadmium, and lead. Furthermore, the strains showed typical plant growth-promoting properties, such as the production of indole acetic acid, cellulolytic enzymes, and siderophores

    Oberflächen-Desoxidationsmechanismen von Edelstählen bei Vakuumlötprozessen

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    Zwei Edelstähle werden verglichen, zum einen 1.4301 (AISI 304), ein austenitischer Chrom-Nickel-Stahl, zum anderen 1.4762 (AISI 446), ein ferritischer Chrom-Stahl, der Aluminium enthält. 1.4301 ist leicht durch Vakuumlöten zu fügen, 1.4762 hingegen kaum, da sich während der Wärmebehandlung im Lötofen eine mehrere Mikrometer dicke Aluminiumoxidschicht bildet. Durch den Vergleich der Auswirkungen auf Ober-fläche und Volumen von Wärmebehandlungen bei Sauerstoffpartialdrücken zwischen 10-13 und 10-6 mbar können Rückschlüsse auf die ablaufenden Prozesse gezogen wer-den. Während 1.4301 in der beobachteten Spanne keine Abhängigkeit von Umgebungs- oder Sauerstoffpartialdruck aufweist, offenbart sich bei 1.4762 eine starke Abhängig-keit: Aluminiumoxid bildet sich nur bei Wärmebehandlungen im Hochvakuum, nicht im Ultrahochvakuum. Das Desorptionsverhalten beider Stähle wird untersucht und die Abhängigkeit vom Sauerstoffpartialdruck wird dargestellt. Darauf aufbauend wird ein Desoxidationsmechanismus vorgeschlagen
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