15 research outputs found
High speed slurry-pot erosion wear testing with large abrasive particles
One of the testing methods used to simulate slurry erosion in laboratory conditions is the slurry-pot method. In this work, a novel high speed slurry-pot type erosion wear tester was constructed for testing of materials used in mining and other mineral handling applications. In the tester, the samples are attached to a vertical rotating shaft on four levels in a pin mill configuration. High speeds up to 20 m/s at the sample tip can be achieved also with large abrasive size up to 10 mm. In the tests, the equipment proved to be functional and durable even with the high loads created by the high speeds and large abrasive sizes. There are, however, variations in the slurry concentrations inside the pot during testing, leading to different wear rates at the different sample levels. Therefore, a sample rotation test method was developed. By rotating the samples evenly through all sample levels, the overall deviations between samples will be minimized. Furthermore, with the sample rotation method up to eight materials can be tested simultaneously. The slurry-pot is suitable for testing various materials, such as steels and rubbers
Mining tailings as a raw material for glass-bonded thermally sprayed ceramic coatings : Microstructure and properties
Magnesium aluminate, MgAl2O4, spinel powders for thermal spraying, were synthesized from secondary raw materials by spray drying and subsequent reaction sintering. Talc ore mining tailings and aluminium hydroxide precipitate from aluminium anodizing process were studied. A stoichiometric MgAl2O4 spinel coating was prepared as a reference using pure raw materials. Atmospheric plasma spraying resulted in the formation of ceramic coatings. Microstructural investigations revealed that the reference coatings exhibited crystalline lamellar microstructure of MgAl2O4 but secondary coatings contained amorphous areas between the crystalline MgAl2O4 clusters. Abrasive wear test results revealed considerably lower wear rate for secondary coatings. It is suggested that the different structure of coatings, particularly the high degree of amorphous phase between the isolated crystalline MgAl2O4 clusters caused the higher abrasive wear resistance by changing the wear mechanism. The dielectric breakdown strength of the secondary coatings were at the same level, 24 V/μm, as compared to reference coating, 23 V/μm.acceptedVersionPeer reviewe
National MEDigi project: systematic implementation of digitalization to undergraduate medical and dental education in Finland
MEDigi is a nationwide Finnish project that aims to develop and implement digital teaching, learning and assessment solutions and to provide possibilities for national harmonization of undergraduate medical and dental education in Finland. The MEDigi project will investigate the options and feasibility of a common national digital online platform and produce digital content and solutions for medical education. Furthermore, tools and support system for digital pedagogy training will be created to ensure that the teaching staff will achieve and retain appropriate digipedagogical skills. The project aims also to increase the competence related to the digital tools used in clinical practice (eHealth, digital health) of physicians and dentists. Furthermore, academic research will be carried out on various aspects of the project. All the universities in Finland that offer the Licentiate Degree in Medicine and Dentist programmes are involved: Universities of Eastern Finland, Helsinki, Oulu, Tampere and Turku. The project is coordinated by the University of Oulu. The project is carried out in close collaboration with the Finnish Medical Society Duodecim and the Finnish Dental Society Apollonia. The project lifespan is until the end of May 2021. MEDigi project is financed by the Finnish Ministry of Culture and Education and its total budget is over 4 million euros.</p
Sähköisten terveyspalveluiden opetus lääketieteessä
Vertaisarvioitu.Digitalisaation myötä terveydenhuollon toiminnot muuttuvat nopeasti, ja sähköiset työkalut sekä palvelut ovat jo arkipäivää. Vaikutukset näkyvät koulutustarpeena, koska terveydenhuollon ammattilaisten digiosaaminen tulee turvata. Lääkärien peruskoulutuksen tulisi sisältää etälääketiedettä ja sähköisen terveydenhuollon palveluja (e-health) koskevaa opetusta. Kansallisessa MEDigi-hankkeessa määriteltiin suomalaisen e-health-opetuksen aihealueet ja tehtiin niille ydinainesanalyysi. Työryhmän työn perusteella määräytyi kaksitoista e-health-opetukseen soveltuvaa aihealuetta lääketieteen ja hammaslääketieteen peruskoulutuksessa. Niiden sisältämien opetusaiheiden keskeisyys määriteltiin kolmiportaisesti. Tuloksia sovellettiin pilottina Oulun yliopistossa lääketieteen viidennen vuosikurssin opiskelijoille toteutettuun teemapäivään, jonka opetussisältö muokattiin vastaamaan ydinainesanalyysin tuloksia. Opetus toteutettiin koronapandemian takia kokonaan etäopetuksena. Jatkossa tavoitteena on kansallisesti integroida ydinainesanalyysiin perustuva e-health-opetus suomalaiseen lääkärikoulutukseen
Sähköisten terveyspalveluiden opetus lääketieteessä
Vertaisarvioitu.Digitalisaation myötä terveydenhuollon toiminnot muuttuvat nopeasti, ja sähköiset työkalut sekä palvelut ovat jo arkipäivää. Vaikutukset näkyvät koulutustarpeena, koska terveydenhuollon ammattilaisten digiosaaminen tulee turvata. Lääkärien peruskoulutuksen tulisi sisältää etälääketiedettä ja sähköisen terveydenhuollon palveluja (e-health) koskevaa opetusta. Kansallisessa MEDigi-hankkeessa määriteltiin suomalaisen e-health-opetuksen aihealueet ja tehtiin niille ydinainesanalyysi. Työryhmän työn perusteella määräytyi kaksitoista e-health-opetukseen soveltuvaa aihealuetta lääketieteen ja hammaslääketieteen peruskoulutuksessa. Niiden sisältämien opetusaiheiden keskeisyys määriteltiin kolmiportaisesti. Tuloksia sovellettiin pilottina Oulun yliopistossa lääketieteen viidennen vuosikurssin opiskelijoille toteutettuun teemapäivään, jonka opetussisältö muokattiin vastaamaan ydinainesanalyysin tuloksia. Opetus toteutettiin koronapandemian takia kokonaan etäopetuksena. Jatkossa tavoitteena on kansallisesti integroida ydinainesanalyysiin perustuva e-health-opetus suomalaiseen lääkärikoulutukseen
Characterization of diuron N-demethylation by mammalian hepatic microsomes and cDNAexpressed human cytochrome P450 enzymes.
ABSTRACT: Diuron, a widely used herbicide and antifouling biocide, has been shown to persist in the environment and contaminate drinking water. It has been characterized as a "known/likely" human carcinogen. Whereas its environmental transformation and toxicity have been extensively examined, its metabolic characteristics in mammalian livers have not been reported. This study was designed to investigate diuron biotransformation and disposition because metabolic routes, metabolizing enzymes, interactions, interspecies differences, and interindividual variability are important for risk assessment purposes. The only metabolic pathway detected by liquid chromatography/mass spectometry in human liver homogenates and seven types of mammalian liver microsomes including human was demethylation at the terminal nitrogen atom. No other phase I or phase II metabolites were observed. The rank order of N-demethyldiuron formation in liver microsomes based on intrinsic clearance (V max /K m ) was dog > monkey > rabbit > mouse > human > minipig > rat. All tested recombinant human cytochrome P450s (P450s) catalyzed diuron N-demethylation and the highest activities were possessed by CYP1A1, CYP1A2, CYP2C19, and CYP2D6. Relative contributions of human CYP1A2, CYP2C19, and CYP3A4 to hepatic diuron N-demethylation, based on average abundances of P450 enzymes in human liver microsomes, were approximately 60, 14, and 13%, respectively. Diuron inhibited relatively potently only CYP1A1/2 (IC 50 4 M). With human-derived and quantitative chemical-specific data, the uncertainty factors for animal to human differences and for human variability in toxicokinetics were within the range of the toxicokinetics default uncertainty/safety factors for chemical risk assessment
Metabolic profiling and in vitro-in vivo extrapolation of furathiocarb in mammalian hepatic microsomes
Abstract
Furathiocarb is a carbamate insecticide found in marine ecosystems as well as river water and sediments. The aim of this study was to characterize species differences in the in vitro metabolism of furathiocarb in seven mammalian species (human, monkey, minipig, rat, mouse, dog, rabbit) analyzed by LC-TOF-MS/MS, in order to provide qualitative and quantitative chemical-specific data to enhance toxicological risk assessment. Furathiocarb was mainly biotransformed to carbofuran metabolic pathway via (N-S) bond-cleavage. Two hydroxylated and sulfoxidated metabolites of furathiocarb were also detected (oxidation pathway). No unique human metabolites were detected. The carbofuran metabolic pathway was more predominant than the furathiocarb oxidation pathway in all species studied; differences based on hepatic clearance rates (CLH), were up to 9.4-fold in monkey and 7-fold in rats, while it was 4.3-fold in human. Animal to human differences in the carbofuran pathway are within the default toxicokinetic uncertainty factor, except for mouse (3.9-fold). Our findings on metabolic profiling and in vitro-in vivo extrapolations are helpful for the interpretation of toxicological findings and chemical risk assessment of furathiocarb