25 research outputs found
Supported metal oxides for catalytic combustion of CO and VOCs emissions: Preparation of titania overlayers on a macroporous support
TiO2 (anatase), SiO2 and gamma-Al2O3 were used as supports for Co-, Cu-, Fe- and Mn-oxide with a loading of active phase corresponding to one theoretical layer. The catalysts were tested for the combustion of CO and toluene, and the best combinations with active phase and support were submitted to a deactivation test in a waste gas incinerator for 50 days. The catalyst screening showed that CuOx/TiO2 was the most promising system. To design a catalyst with good activity and transport properties, a macroporous substrate was coated with TiO2 for use as a support for Cu-oxide, Titania overlayers were prepared by precipitation from oxychloride, tetrachloride and alkoxide, and stabilisation with ZrO2 and SiO2 was tried. The results show that precipitation from oxychloride gives the best properties and that addition of ZrO2 gives enhanced activity to the catalyst, while SiO2 addition produces increased stability
1980-talets lågenergihus: hur fungerar de efter tio år
Syftet med detta forskningsprojekt är att undersöka hur ett antal väl dokumenterade experimenthus har fungerat under en tioårsperiod. Undersökningen jämför i första hand uppgifter om energianvändning och de driftfrågor som hör till energianvändningen. Vidare har de boendes upplevda inomhusklimat studerats för att kunna se om, och i så fall hur, experimenthusens låga energianvändning har påverkat det upplevda inomhusklimatet
Xandarovula patula (Gastropoda: Ovulidae) new to Scandinavia
In August 2009 six specimens of the ovulid gastropod Xandarovula patula (Pennant, 1777) (formerly known as Simnia patula Pennant, 1777), were found in dredge samples from a locality west of Smögen in western Sweden (58°22′N 11°05′E). In June and November 2010 a total of three specimens of the same species were found in dredge samples from near Svelgen Bridge, Øygarden, Hordaland, western Norway (60°27 ′N 04°57 ′E). Several small colonies of the presumed prey species, Alcyonium digitatum Linnaeus, 1758 and Tubularia indivisa Linnaeus, 1758, were found in the same dredge hauls. Xandarovula patula has been recorded from the Atlantic coast of southern Spain to the western end of the English Channel, with scattered records from the west coasts of Ireland and Britain, as far north as the Orkneys. More recently it has been reported from most Irish coasts, several parts of the Scottish coast and also from some places in the North Sea. Until now there have been no confirmed records from Scandinavian waters. The specimens recorded here may indicate recent immigration of a southern species due to warmer water temperatures
Genome-wide linkage scan for breast cancer susceptibility loci in Swedish hereditary non-BRCA1/2 families: suggestive linkage to 10q23.32-q25.3.
The two breast cancer genes BRCA1 and BRCA2 were identified more than 10 years ago and, depending on population, mutations in these genes are responsible for a varying percentage of familial breast cancer. In more than half the families, the increased risk of breast cancer cannot be explained by mutations in these genes, and the goal of this study was to locate novel susceptibility genes. One of the main difficulties in identifying the cause of hereditary non-BRCA1/BRCA2 breast cancer is genetic heterogeneity, possibly due to multiple, incompletely penetrant susceptibility genes, along with ethnic and geographic differences. In this study, one large family and 13 small to medium-sized families with multiple cases of breast cancer were analyzed by genome-wide linkage analysis. The genome scan was performed by genotype analysis of 10,000 SNP markers on microarrays. The strongest evidence of linkage (HLOD 2.34) was obtained on chromosome region 10q23.32-q25.3. A further two regions were identified, with LOD scores above 2.10 on 12q14-q21 and 19p13.3-q12. In a subset of families of western Swedish origin, two regions generated LOD scores exceeding 1.8: 10q23.32-q25.3 and 19q13.12-q13.32. The large family in the study exceeded LOD 1.5 in three regions: 10q23.32-q25.3, 19q13.12-q13.32, and 17p13. Our results indicate that one or more of the suggested regions may harbor genes that are involved in the development of breast cancer
Distribution of Intraportally Implanted Microspheres and Fluorescent Islets in Mice
The aim of the study was to evaluate the distribution of intraportally transplanted islets in mice. We initially administered 2000 polystyrene microspheres with a diameter of 50 μm intraportally into normoglycemic C57BL/6 mice. In separate experiments other mice were injected similarly with 300 microspheres each with a diameter of 100 or 200 μm. One week later the animals were killed, and the lungs and livers were removed and divided into lobes. The number of microspheres in each individual liver lobe and in the lungs was counted using a stereomicroscope. In other experiments, athymic C57BL/6 mice were similarly implanted with 250 islets isolated from transgenic mice expressing the enhanced yellow fluorescent protein in the islet cells. The distribution of microspheres and islets was independent of size, and fairly homogenous within the liver, with the exception of the caudate lobe, which contained fewer microspheres and islets, respectively. Approximately one third of all microspheres and islets were present as aggregates. Eighty-five to 90% of the implanted microspheres were identified in the liver sections, whereas 60–65% of the implanted islets were recovered. Aggregates or single fluorescent cells were observed in the liver of islet-implanted mice. We conclude that islets and microspheres implanted into the liver distribute fairly homogenously and quite a few of them exist as aggregates or, with respect to islets, as fragments
Recommended from our members
Pancreatic islet function in a transgenic mouse expressing fluorescent protein
Polyamines in pancreatic islets of obese-hyperglycemic ( ob/ob
To further evaluate the role of polyamines in insulin production and cell replication in diabetic pancreatic islets, we have studied hyperplastic islets of obese-hyperglycemic mice of different ages and normal islets of the same strain. The aims of the study were to investigate the impact of the diabetic state and aging on polyamine contents and requirements in these islets. Cultured islets from lean and obese animals contained significantly less polyamines than freshly isolated islets. Spermine-to-spermidine ratio was elevated in freshly isolated islets from young obese mice compared with those from lean mice. In islets from old obese animals, spermidine content was decreased, whereas the content of spermine was not different from that of young obese mice. The physiological significance of polyamines was investigated by exposing islets in tissue culture to inhibitors of polyamine synthesis. This treatment caused a partial polyamine depletion in whole islets but failed to affect polyamine content of cell nuclei. Insulin content was not affected in polyamine-deficient islets of obese mice, irrespective of age, in contrast to decreased islet insulin content in polyamine-depleted young lean animals. Polyamine depletion depressed DNA synthesis rate in obese mouse islets; in lean mice it actually stimulated DNA synthesis. We concluded that important qualitative and quantitative differences exist between islets from obese-hyperglycemic and normal mice with respect to polyamine content and requirements of polyamines for regulation of insulin content and cell proliferation. The results suggest that spermine may be involved in mediating the rapid islet cell proliferation noted early in obese-hyperglycemic syndrome, but changes in spermine concentration do not seem to account for the decline in islet cell DNA synthesis in aged normoglycemic animals