Surface Studies of Thiolate Adsorbates on Some Metals

The results and discussions in this thesis are based on my studies about selfassembled thiol layers on gold, platinum, silver and copper surfaces. These kinds of layers are two-dimensional, one molecule thick and covalently organized at the surface. They are an easy way to modify surface properties. Self-assembly is today an intensive research field because of the promise it holds for producing new technology at nanoscale, the scale of atoms and molecules. These kinds of films have applications for example, in the fields of physics, biology, engineering, chemistry and computer science. Compared to the extensive literature concerning self-assembled monolayers (SAMs) on gold, little is known about the structure and properties of thiolbased SAMs on other metals. In this thesis I have focused on thiol layers on gold, platinum, silver and copper substrates. These studies can be regarded as a basic study of SAMs. Nevertheless, an understanding of the physical and chemical nature of SAMs allows the correlation between atomic structure and macroscopic properties. The results can be used as a starting point for many practical applications. X-ray photoelectron spectroscopy (XPS) and synchrotron radiation excited high resolution photoelectron spectroscopy (HR-XPS) together with time-offlight secondary ion mass spectrometry (ToF-SIMS) were applied to investigate thin organic films formed by the spontaneous adsorption of molecules on metal surfaces. Photoelectron spectroscopy was the main method used in these studies. In photoelectron spectroscopy, the sample is irradiated with photons and emitted photoelectrons are energy-analyzed. The obtained spectra give information about the atomic composition of the surface and about the chemical state of the detected elements. It is widely used in the study of thin layers and is a very powerful tool for this purpose. Some XPS results were complemented with ToF-SIMS measurements. It provides information on the chemical composition and molecular structure of the samples. Thiol (1-Dodecanethiol, CH3(CH2)11SH) solution was used to create SAMs on metal substrates. Uniform layers were formed on most of the studied metal surfaces. On platinum, surface aligned molecules were also detected in investigations by XPS and ToF-SIMS. The influence of radiation on the layer structure was studied, leading to the conclusion that parts of the hydrocarbon chains break off due to radiation and the rest of the layer is deformed. The results obtained showed differences depending on the substrate material. The influence of oxygen on layer formation was also studied. Thiol molecules were found to replace some of the oxygen from the metal surfaces.Siirretty Doriast

Muokatun vermikuliitin käyttö puhdistusmenetelmänä metallipitoisessa kaivosvalumavedessä

GeoTrap on hitaasti kuumennettu vermikuliitti, joka soveltuu ammoniumin absorbointiin jätevesistä. Vermikuliitin välikerroksessa on yleensä magnesiumioneja, jotka voidaan korvata esimerkiksi ammoniumioneilla.Tässä tutkimuksessa selvitetään GeoTrapin ominaisuuksia metallipitoisten kaivosvalumavesien hoitamisessa. Tutkimuskohteena ovat Kaavin kunnassa sijaitsevasta Luikonlahden rikastushiekka-altaasta suotavat lievästi happamat ja metallipitoiset vedet. Projektin aikana tutkittiin sekä vesi-, että kiinteitä näytteitä. Vesinäytteitä otettiin rikastushiekka-altaan suotovedestä ja suotokohteen alapuolisesta pintavedestä.Lopputuloksena selvisi, että GeoTrap-käsittely poisti tehokkaasti metalleja vedestä vertailunäytteisiin verrattuna. GeoTrapkäsittelyn aikana veden pH, alkaliteetti ja epäorgaanisen hiilen määrä kasvoivat. Nämä ovat metalleja saostaneet ja  suodatuksen kautta poistaneet mekanismit. Toisaalta myös metallien sitoutumisesta GeoTrapiin saatiin näyttöä

Site fertility and soil water-table level affect fungal biomass production and community composition in boreal peatland forests

A substantial amount of below-ground carbon (C) is suggested to be associated with fungi, which may significantly affect the soil C balance in forested ecosystems. Ergosterol from in-growth mesh bags and litterbags was used to estimate fungal biomass production and community composition in drained peatland forests with differing fertility. Extramatrical mycelia (EMM) biomass production was generally higher in the nutrient-poor site, increased with deeper water table level and decreased along the length of the recovery time. EMM biomass production was of the same magnitude as in mineral-soil forests. Saprotrophic fungal biomass production was higher in the nutrient-rich site. Both ectomycorrhizal (ECM) and saprotrophic fungal community composition changed according to site fertility and water table level. ECM fungal community composition with different exploration types may explain the differences in fungal biomass production between peatland forests. Melanin-rich Hyaloscypha may indicate decreased turnover of biomass in nutrient-rich young peatland forest. Genera Lactarius and Laccaria may be important in nutrient rich and Piloderma in the nutrient-poor conditions, respectively. Furthermore, Paxillus involutus and Cortinarius sp. may be important generalists in all sites and responsible for EMM biomass production during the first summer months. Saprotrophs showed a functionally more diverse fungal community in the nutrient-rich site.Peer reviewe

Characterization of altered mica from Sokli, northern Finland

Vermiculite is a mineral with many potential uses in various industrial areas, such as in insulation, horticulture, and environmental applications. The regolith of the Sokli carbonatite intrusion in northern Finland consists of weathered micas which reportedly contain vermiculite. The aim of the present study was to characterize the weathered mica in order to determine if the weathered regolith contains vermiculite. If so, the value of the apatite-rich Sokli intrusion may increase, because the vermiculite could be classified as an ore in Sokli. For the characterization, mica fractions were investigated using electron probe microanalysis (EPMA), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The EPMA results show that the potassium (K2O) content of the mica investigated varies between 6.20 and 0.31 wt.%. The XRD results provided evidence thatthe interlayer distances in the mica vary between 10.1 and 14.7 Å. The TGA shows that the dehydration of the samples varies between 6 and 12 wt.% for temperatures up to 170°C. Dehydroxylation takes place in three steps, as is characteristic for vermiculite. The results from this study revealed that mica in the weathered parts of the Sokli carbonatite is mostly vermiculite, and that the vermiculite was formed by the weathering of phlogopite. These results can be used to determine whether vermiculite is a possible future commodity at the Sokli carbonatite complex.</p

Early DNA methylation changes in children developing beta cell autoimmunity at a young age

Aims/hypothesis Type 1 diabetes is a chronic autoimmune disease of complex aetiology, including a potential role for epigenetic regulation. Previous epigenomic studies focused mainly on clinically diagnosed individuals. The aim of the study was to assess early DNA methylation changes associated with type 1 diabetes already before the diagnosis or even before the appearance of autoantibodies. Methods Reduced representation bisulphite sequencing (RRBS) was applied to study DNA methylation in purified CD4(+) T cell, CD8(+) T cell and CD4(-)CD8(-) cell fractions of 226 peripheral blood mononuclear cell samples longitudinally collected from seven type 1 diabetes-specific autoantibody-positive individuals and control individuals matched for age, sex, HLA risk and place of birth. We also explored correlations between DNA methylation and gene expression using RNA sequencing data from the same samples. Technical validation of RRBS results was performed using pyrosequencing. Results We identified 79, 56 and 45 differentially methylated regions in CD4(+) T cells, CD8(+) T cells and CD4-CD8- cell fractions, respectively, between type 1 diabetes-specific autoantibody-positive individuals and control participants. The analysis of pre-seroconversion samples identified DNA methylation signatures at the very early stage of disease, including differential methylation at the promoter of IRF5 in CD4(+) T cells. Further, we validated RRBS results using pyrosequencing at the following CpG sites: chr19:18118304 in the promoter of ARRDC2; chr21:47307815 in the intron of PCBP3; and chr14:81128398 in the intergenic region near TRAF3 in CD4(+) T cells. Conclusions/interpretation These preliminary results provide novel insights into cell type-specific differential epigenetic regulation of genes, which may contribute to type 1 diabetes pathogenesis at the very early stage of disease development. Should these findings be validated, they may serve as a potential signature useful for disease prediction and management.Peer reviewe

Early DNA methylation changes in children developing beta cell autoimmunity at a young age

Aims/hypothesis Type 1 diabetes is a chronic autoimmune disease of complex aetiology, including a potential role for epigenetic regulation. Previous epigenomic studies focused mainly on clinically diagnosed individuals. The aim of the study was to assess early DNA methylation changes associated with type 1 diabetes already before the diagnosis or even before the appearance of autoantibodies.Methods Reduced representation bisulphite sequencing (RRBS) was applied to study DNA methylation in purified CD4(+) T cell, CD8(+) T cell and CD4(-)CD8(-) cell fractions of 226 peripheral blood mononuclear cell samples longitudinally collected from seven type 1 diabetes-specific autoantibody-positive individuals and control individuals matched for age, sex, HLA risk and place of birth. We also explored correlations between DNA methylation and gene expression using RNA sequencing data from the same samples. Technical validation of RRBS results was performed using pyrosequencing.Results We identified 79, 56 and 45 differentially methylated regions in CD4(+) T cells, CD8(+) T cells and CD4-CD8- cell fractions, respectively, between type 1 diabetes-specific autoantibody-positive individuals and control participants. The analysis of pre-seroconversion samples identified DNA methylation signatures at the very early stage of disease, including differential methylation at the promoter of IRF5 in CD4(+) T cells. Further, we validated RRBS results using pyrosequencing at the following CpG sites: chr19:18118304 in the promoter of ARRDC2; chr21:47307815 in the intron of PCBP3; and chr14:81128398 in the intergenic region near TRAF3 in CD4(+) T cells.Conclusions/interpretation These preliminary results provide novel insights into cell type-specific differential epigenetic regulation of genes, which may contribute to type 1 diabetes pathogenesis at the very early stage of disease development. Should these findings be validated, they may serve as a potential signature useful for disease prediction and management.</p

Lasten kengät ja sukat - kirjallinen ohje vanhemmille

Opinnäytetyön tavoitteena oli lasten jalkaterveyden edistäminen kehittämällä päiväkoti-ikäisten lasten vanhemmille kirjallinen ohje sopivien kenkien ja sukkien valintaa varten. Yhteistyökumppaniksi opinnäytetyössä valittiin päiväkoti Vantaalta. Opinnäytetyön lähestymistapa oli kvalitatiivinen eli laadullinen. Aineistonkeruumenetelminä käytettiin kattavaa kirjallisuuskatsausta, puolistrukturoitua teemahaastattelua ja puolistrukturoitua kyselylomaketta. Kirjallisuuskatsauksen aineisto kerättiin seuraavista tietokannoista: Medic, Cinahl, Medline ja Cochrane Library. Systemaattisen haun tuottamista tutkimuksista, tutkimusartikkeleista ja asiantuntija-artikkeleista valikoitui 11 käyttökelpoista osumaa. Haastattelujoukko koostui viidestä päiväkoti-ikäisen lapsen vanhemmasta. Artikkelit ja haastatteluaineisto analysoitiin teoriaohjaavan sisällönanalyysin avulla. Kyselylomakkeiden palaute analysoitiin aineistolähtöisesti. Tutkimusten mukaan lasten kenkien tulisi jäljitellä mahdollisimman tarkoin paljasjaloin kävelyä ja sallia jalkaterien toimia luonnollisesti. Kenkien tulisi olla kevyet, joustavat, hengittävät ja sopivat kooltaan. Vanhempien tietämys oikeanlaisista lasten kengistä ja sukista sekä niiden sopivuuden luotettavasta arvioinnista osoittautui haastattelujen perusteella puutteelliseksi ja osin virheelliseksi. Kengät valittiin yleensä ulkonäön perusteella. Sopivan koon arvioinnissa luotettiin liikaa kokonumerointiin. Vanhemmat olivat kiinnostuneita lasten jalkaterveydestä ja hyvistä kengistä, mutta tiedon saatavuudessa oli puutteita. Aiempien tutkimusten ja vanhempien haastattelujen pohjalta kehitettiin vanhemmille kirjallinen ohje apuvälineeksi lasten kenkien ja sukkien valintaan. Vanhempien lisäksi ohjetta voivat myös hyödyntää työssään eri ammattikuntien edustajat, kuten päiväkotien henkilökunta, terveydenhoitajat ja jalkaterapeutit. Ohje antaa tietoa lasten jalkaterveyttä tukevien kenkien ja sukkien valinnasta.The aim of the thesis was to improve children’s foot health by providing the parents of 2–6-year-old children with a written guideline for choosing appropriate shoes and socks for their children. A day-care center in Vantaa, Finland was chosen to be our partner in the thesis. The methodological approach of the thesis was qualitative. The methods of collecting data were a literature review, a half-structured themed interview and a questionnaire. The literature was gathered up from the following databases: Medic, Cinahl, Medline and Cochrane Library. After a systematic search of researches, research articles and expert interviews, 11 usable source materials were found. The interview group consisted of five parents of 2–6-year-old children. According to the research, children’s shoes should mimic barefoot walking and allow natural functions of the foot. Shoes should be light-weight, flexible, breathable and well-fitting. According to the interviews, the parents’ knowledge about children’s shoes and socks turned out to be inadequate and partially incorrect. Shoes were often selected on the grounds of appearance. When choosing the shoe size, the parents relied too much on the size number. Though parents were interested in children’s foot health and shoes, they lacked the correct information. Based on the previous researches and the interviews made, a written guideline was produced to help the parents to choose shoes and socks for their children. This guideline could also be used by a various professionals, e.g. day-care personnel, school nurses and podiatrists. The guideline provides information about choosing appropriate shoes and socks for children

Nanostructured Vermiculite A new material for recycling ammonium from different types of polluted matters

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