Search results for "hapettuminen"
showing 10 items of 14 documents
Effects of alternative electron acceptors on the activity and community structure of methane-producing and consuming microbes in the sediments of two…
2017
The role of anaerobic CH4 oxidation in controlling lake sediment CH4 emissions remains unclear. Therefore, we tested how relevant EAs (SO42−, NO3−, Fe3+, Mn4+, O2) affect CH4 production and oxidation in the sediments of two shallow boreal lakes. The changes induced to microbial communities by the addition of Fe3+ and Mn4+ were studied using next-generation sequencing targeting the 16S rRNA and methyl-coenzyme M reductase (mcrA) genes and mcrA transcripts. Putative anaerobic CH4-oxidizing archaea (ANME-2D) and bacteria (NC 10) were scarce (up to 3.4% and 0.5% of archaeal and bacterial 16S rRNA genes, respectively), likely due to the low environmental stability associated with shallow depths.…
Pot-Economy Autooxidative Condensation of 2-Aryl-2-lithio-1,3-dithianes
2018
The autoxidative condensation of 2-aryl-2-lithio-1,3-dithianes is here reported. Treatment of 2-aryl-1,3-dithianes with n-BuLi in the absence of any electrophile leads to condensation of three molecules of 1,3-dithianes and formation of highly functionalized α-thioether ketones orthothioesters in 51-89% yields upon air exposure. The method was further expanded to benzaldehyde dithioacetals, affording corresponding orthothioesters and α-thioether ketones in 48-97% yields. The experimental results combined with density functional theory studies support a mechanism triggered by the autoxidation of 2-aryl-2-lithio-1,3-dithianes to yield a highly reactive thioester that undergoes condensation wi…
Associations of resting and peak fat oxidation with sex hormone profile and blood glucose control in middle-aged women.
2022
Background and Aims Menopause may reduce fat oxidation. We investigated whether sex hormone profile explains resting fat oxidation (RFO) or peak fat oxidation (PFO) during incremental cycling in middle-aged women. Secondarily, we studied associations of RFO and PFO with glucose regulation. Method and Results We measured RFO and PFO of 42 women (age 52–58 years) with indirect calorimetry. Seven participants were pre- or perimenopausal, 26 were postmenopausal, and nine were postmenopausal hormone therapy users. Serum estradiol (E2), follicle-stimulating hormone, progesterone, and testosterone levels were quantified with immunoassays. Insulin sensitivity (Matsuda index) and glucose tolerance (…
Di- and Tetrairon(III) μ-Oxido Complexes of an N3S-Donor Ligand: Catalyst Precursors for Alkene Oxidations
2019
The new di- and tetranuclear Fe(III) μ-oxido complexes [Fe 4 (μ-O) 4 (PTEBIA) 4 ](CF 3 SO 3 ) 4 (CH 3 CN) 2 ] (1a), [Fe 2 (μ-O)Cl 2 (PTEBIA) 2 ](CF 3 SO 3 ) 2 (1b), and [Fe 2 (μ-O)(HCOO) 2 (PTEBIA) 2 ](ClO 4 ) 2 (MeOH) (2) were prepared from the sulfur-containing ligand (2-((2,4-dimethylphenyl)thio)-N,N-bis ((1-methyl-benzimidazol-2-yl)methyl)ethanamine (PTEBIA). The tetrairon complex 1a features four μ-oxido bridges, while in dinuclear 1b, the sulfur moiety of the ligand occupies one of the six coordination sites of each Fe(III) ion with a long Fe-S distance of 2.814(6) A. In 2, two Fe(III) centers are bridged by one oxido and two formate units, the latter likely formed by methanol oxidati…
Fat oxidation at rest and during exercise in male monozygotic twins
2019
Abstract Purpose We aimed to investigate if hereditary factors, leisure-time physical activity (LTPA) and metabolic health interact with resting fat oxidation (RFO) and peak fat oxidation (PFO) during ergometer cycling. Methods We recruited 23 male monozygotic twin pairs (aged 32–37 years) and determined their RFO and PFO with indirect calorimetry for 21 and 19 twin pairs and for 43 and 41 twin individuals, respectively. Using physical activity interviews and the Baecke questionnaire, we identified 10 twin pairs as LTPA discordant for the past 3 years. Of the twin pairs, 8 pairs participated in both RFO and PFO measurements, and 2 pairs participated in either of the measurements. We quantif…
Impact of Si on the high-temperature oxidation of AlCr(Si)N coatings
2022
The resistance of wear protective coatings against oxidation is crucial for their use at high temperatures. Here, three nanocomposite AlCr(Si)N coatings with a fixed Al/Cr atomic ratio of 70/30 and a varying Si-content of 0 at.%, 2.5 at.% and 5 at.% were analyzed by differential scanning calorimetry, thermogravimetric analysis and X-ray in order to understand the oxidation behavior depending on their Si-content. Additionally, a partially oxidized AlCrSiN coating with 5 at.% Si on a sapphire substrate was studied across the coating thickness by depth-resolved cross-sectional X-ray nanodiffraction and scanning trans-mission electron microscopy to investigate the elemental composition, morphol…
Neuromuscular, hormonal and oxidative stress responses to endurance running exercises in well-trained runners
2007
The aim of this study was to investigate to which type of running exercises well trained endurance runners respond more favourably with regard to acute neuromuscular and endocrinological responses and exercise-induced oxidative stress. It was hypothesized that these responses depend on the type of running exercise and relate to the physical characteristics. Altogether nine different running exercises and a long walking exercise were performed by a total of 88 male athletes. An intermittent exercise consisting of progressive 20 s runs decreased vertical jump performance in middle distance runners (MID), but improved it in marathon runners (MAR). An 18 – 24 min exhaustive test run, a 40 min i…
Degradation of Antibiotic Vancomycin by UV Photolysis and Pulsed Corona Discharge Combined with Extrinsic Oxidants
2023
Antibiotics are the most frequently detected pharmaceuticals in the environment creating conditions for the development of resistant genes in bacteria. Degradation and mineralization of glycopeptide antibiotic vancomycin (VMN) were examined by UV photolysis, pulsed corona discharge (PCD), and their combinations with extrinsic oxidants, hydrogen peroxide (HP), peroxydisulfate (PDS), and peroxymonosulfate (PMS). Both combinations were effective in VMN degradation and faster at pH 11 than in acidic or neutral media. Combined with the UV photolysis, HP showed a higher oxidation rate than other oxidants, whereas PMS and PDS proved to be more efficient in combinations with PCD. In contrast to low…
Effects of insulin deficiency on exercise-induced acute responses in the regulation of fatty acid oxidation in mouse gastrocnemius muscles
2014
Insulin is a hormone that plays an important role in the regulation of the metabolism of all the main nutrients. Its main function is to stimulate glucose uptake and disposal or utilization by the cells and thus to decrease blood glucose concentration. However, it also inhibits breakdown of proteins and lipids and promotes their synthesis. Type 1 diabetes is a disease in which insulin secretion is impaired because of destruction of pancreatic β-cells. It is characterized by hyperglycemia and increased reliance on fat oxidation. This is seen also as altered gene expression patterns. The purpose of this study was to look into the effects of insulin deficiency on exercise-induced acute respons…
Biotic oxidation of methane in landfills in boreal climatic conditions
2010
This study focused on the biotic oxidation of methane in landfill covers as a technology for reducing greenhouse gas emissions from landfills, particularly those located in the boreal climatic zone. First, methane oxidation was studied in laboratory batch assays in a landfill cover soil consisting of a composted mixture of sewage sludge and chemical sludge which had been installed on the landfill surface 4-5 years earlier. Second, methane oxidation was studied using mechanically-biologically treated municipal solid waste (MBT residual) as a material for methane-oxidizing landfill covers both in continuously methane-sparged laboratory columns and in an outdoor pilot lysimeter. Finally, meth…