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Teräsbetonilaatan mitoitukseen on olemassa useita menetelmiä. Tässä insinöörityössä keskityttiin suorakaiteen muotoisen, aukollisen laatan mitoitukseen myötöviivamenetelmällä. Myötöviivamenetelmä on plastisuusteorian ylärajalauseen mukainen menetelmä laattojen kuormankantokyvyn laskemiseen. Työssä tehtiin Mathcad-pohjainen mitoitustyökalu, jolla voidaan ratkaista neljältä sivulta tuetun, tasaisesti kuormitetun aukollisen laatan myötökuorma. Työssä tarkasteltiin aluksi myötöviivateorian yleisiä perusteita ja myötöviivojen muodostumista. Tämän jälkeen käsiteltiin aukollista laattaa ja sen myötökuorman laskentaa. Lopuksi työssä tarkasteltiin työkalun lähtötietojen syöttämistä ja niiden rajoituksia sekä laskentaprosessia. Laskennan tuloksista saatiin selville tuennan, raudoituksen ja aukon vaikutus myötöviivan muotoon ja laatan kestävyyteen. Myös laatan ja aukon koko sekä aukon sijainti vaikuttavat näihin asioihin. Mitoitustyökalua voidaan käyttää vanhan laatan kestävyyden analysointiin, uuden laatan raudoituksen mitoitukseen sekä kuormituksen ja mittojen muutoksen vaikutuksen arviointiin.
Verinäytteenotto on yksi bioanalyytikon ydinosaamisalueista, joka tulee olla jokaisella hallinnassa. Se on osa laboratoriotutkimusprosessin preanalytiikan osa-aluetta. Suurin osa laboratoriotutkimusten virheistä tapahtuu nimenomaan preanalytiikan alueella ja tämä korostuu eritysesti haastavien potilaiden kohdalla. Potilaan hoidon kannalta on erittäin tärkeää, että otettu verinäyte on laadukas ja vastaa potilaan todellista terveydentilaa riip-pumatta potilaan näytteenoton haasteellisuudesta. Paraskaan analysaattori ei saa huonosti tai väärin otetusta näytteestä varmaa ja luotettavaa tulosta. Lapset ovat haastava potilasryhmä myös kokeneemmallekin bio-analyytikolle, mutta erityisesti vasta-alkajille. Tämä opinnäytetyö sisältää kirjallisen raporttiosion lisäksi kuvallisen posterin, jonka sijoituspaikkana on Savonia ammattikorkeakoulun näytteenottotilat. Kuvalliset ohjeet tarjoavat erinomaisen mahdollisuuden koko näytteenottoprosessin läpikäyntiin helposti ymmärrettävässä muodossa. Kun asiasta muodostuu opiskelijalle selkeä prosessi, se helpottaa asian johdonmukaista käsittelyä ja kohtaamista. Opinnäytetyön raporttiosa avaa laajasti eri näkökulmat niin työntekijän, potilaan kuin lasten vanhempienkin näkökulmasta. Siinä käsitellään lasten näytteenotto tekniseltä näkökantilta esitellen eri näytteenottotekniikat, oikeanlaisen lasten käsittelyn sekä turvallisen työskentelyn. Raportissa käsitellään lisäksi myös lapsipotilaiden kohtaaminen psykologiselta puolelta, joka on äärimmäisen tärkeä osa näytteenottoa. Ilman oikeanlaista psykologista lähestymistapaa on lähes mah-doton tehdä yhteistyötä lasten kanssa. Heidän kokemuksensa näytteenotosta vaikuttavat heidän suhtautumiseen asiaan myös tulevaisuudessa, joten hyvillä kokemuksilla on kauaskantoinen merkitys. Vasta valmistuneen bioanalyytikon toimenkuva alkaa usein juuri näytteenottoon perehtymisestä. Lapset ovat päivittäin työssä eteen tuleva potilasryhmä. Perehtymistä helpottaa huomattavasti, mikäli asia on jo ennestään prosessina tuttu. Suuri osa ajasta menee potilaan ohjaamiseen ja esivalmisteluun, jonka aikana erityisesti lap-sipotilaan kohdalla on tärkeää olla varman ja luotettavan oloinen. Sillä on merkitystä potilaan rauhallisuuteen, yhteistyökykyyn ja näin toimimalla saadaan otettua laadukas verinäyte lapsipotilaasta.
Introduction: The hygiene hypothesis suggests that decrease in early life infections due to increased societal-level hygiene standards subjects one to allergic and autoimmune diseases. In this report, we have studied the effect of sterilized forest soil and plant-based material on mouse immune system and gut microbiome. Methods: Inbred C57Bl/6 mice maintained in normal sterile environment were subjected to autoclaved forest soil-derived powder in their bedding for 1 h a day for 3 weeks. Immune response was measured by immune cell flow cytometry, serum cytokine enzyme-linked immunoassay (ELISA) and quantitative polymerase chain reaction (qPCR) analysis. Furthermore, the mouse gut microbiome was analyzed by sequencing. Results: When compared to control mice, mice treated with soil-derived powder had decreased level of pro-inflammatory cytokines namely interleukin (IL)−17F and IL-21 in the serum. Furthermore, splenocytes from mice treated with soil-derived powder expressed less IL-1b, IL-5, IL-6, IL-13, and tumor necrosis factor (TNF) upon cell activation. Gut microbiome appeared to be stabilized by the treatment. Conclusions: These results provide insights on the effect of biodiversity on murine immune system in sterile environment. Subjecting mice to soil-based plant and microbe structures appears to elicit immune response that could be beneficial, for example, in type 2 inflammation-related diseases, that is, allergic diseases.
Background: In modern urban environments children have a high incidence of inflammatory disorders, including allergies, asthma, and type 1 diabetes. The underlying cause of these disorders, according to the biodiversity hypothesis, is an imbalance in immune regulation caused by a weak interaction with environmental microbes. In this 2-year study, we analyzed bacterial community shifts in the soil surface in day-care centers and commensal bacteria inhabiting the mouth, skin, and gut of children. We compared two different day-care environments: standard urban day-care centers and intervention day-care centers. Yards in the latter were amended with biodiverse forest floor vegetation and sod at the beginning of the study. Results: Intervention caused a long-standing increase in the relative abundance of nonpathogenic environmental mycobacteria in the surface soils. Treatment-specific shifts became evident in the community composition of Gammaproteobacteria, Negativicutes, and Bacilli, which jointly accounted for almost 40 and 50% of the taxa on the intervention day-care children's skin and in saliva, respectively. In the year-one skin swabs, richness of Alpha-, Beta-, and Gammaproteobacteria was higher, and the relative abundance of potentially pathogenic bacteria, including Haemophilus parainfluenzae, Streptococcus sp., and Veillonella sp., was lower among children in intervention day-care centers compared with children in standard day-care centers. In the gut, the relative abundance of Clostridium sensu stricto decreased, particularly among the intervention children. Conclusions: This study shows that a 2-year biodiversity intervention shapes human commensal microbiota, including taxa that have been associated with immune regulation. Results indicate that intervention enriched commensal microbiota and suppressed the potentially pathogenic bacteria on the skin. We recommend future studies that expand intervention strategies to immune response and eventually the incidence of immune-mediated diseases.
An agricultural environment and exposure to diverse environmental microbiota has been suggested to confer protection against immune-mediated disorders. As an agricultural environment may have a protective role, it is crucial to determine whether the limiting factors in the transfer of environmental microbiota indoors are the same in the agricultural and urban environments. We explored how sampling month, garden diversity and animal ownership affected the indoor-transfer of environmental microbial community. We collected litter from standardized doormats used for 2 weeks in June and August 2015 and February 2016 and identified bacterial phylotypes using 16S rRNA Illumina MiSeq sequencing. In February, the diversity and richness of the whole bacterial community and the relative abundance of environment-associated taxa were reduced, whereas human-associated taxa and genera containing opportunistic pathogens were enriched in the doormats. In summer, the relative abundances of several taxa associated previously with beneficial health effects were higher, particularly in agricultural areas. Surprisingly, the importance of vegetation on doormat microbiota was more observable in February, which may have resulted from snow cover that prevented contact with microbes in soil. Animal ownership increased the prevalence of genera Bacteroides and Acinetobacter in rural doormats. These findings underline the roles of season, living environment and lifestyle in the temporal variations in the environmental microbial community carried indoors. As reduced contact with diverse microbiota is a potential reason for immune system dysfunction, the results may have important implications in the etiology of immune-mediated, non-communicable diseases.
Polycyclic aromatic hydrocarbons (PAHs) are priority environmental pollutants that cause adverse health effects. PAHs belong to endocrine signaling disruptors to which children are sensitive to. Recent evidence suggests that PAH pollution alters the abundance of environmental bacteria that is associated with health outcomes. The alteration of environmental and commensal microbiota by PAH pollution has never been connected to endocrine signaling pathways. To estimate the risk of endocrine disruption in daycare children, we measured PAHs from soil and air of eleven urban daycare centres in Finland. We analyzed daycare yards' soil and children's gut and skin bacterial communities with 16S rRNA gene metabarcoding and used Kyoto Encyclopaedia of Genes and Genomes database to categorize endocrine signaling pathways. We also assessed the PAH hazard to children's health based on the current risk assesments. We observed associations between signaling pathways in endocrine system and gaseous PAH levels in ambient air. Peroxisome proliferator-activated receptor and adipocytokine signaling pathway decreased with higher chrysene concentration in the air. Soil PAH contamination was associated with altered Actinobacteria, Bacteoridetes and Proteobacteria communities on children's skin and in daycare yard soil. However, adjusted genera were not the same in soil and on skin, with the exception of Mycobacterium that was associated with higher PAH concentrations both in soil and on the skin. Even though fluoranhtene levels were above the current threshold values, total PAHs were below safety threshold values and based on current risk assessments there is a minor risk for child health. Our findings indicate that PAH concentrations that are considered safe may interfere with endocrine signaling by commensal microbiota and alter both environmental and commensal bacterial communities. The imbalance in human microbiota and the decrease in signaling pathways may contribute to emerging public health problems, including inflammatory disorders, obesity and diabetes. Therefore, the optimal risk assessments of PAHs and theoretically also other contaminants shaping commensal microbiota may need to take into account the possibility of the disruption of endocrine signaling pathways.
There is evidence that polycyclic aromatic hydrocarbons (PAHs) and human gut microbiota are associated with the modulation of endocrine signaling pathways. Independently, studies have found associations between air pollution, land cover and commensal microbiota. We are the first to estimate the interaction between land cover categories associated with air pollution or purification, PAH levels and endocrine signaling predicted from gut metagenome among urban and rural populations. The study participants were elderly people (65–79 years); 30 lived in rural and 32 in urban areas. Semi-Permeable Membrane devices were utilized to measure air PAH concentrations as they simulate the process of bioconcentration in the fatty tissues. Land cover categories were estimated using CORINE database and geographic information system. Functional orthologues for peroxisome proliferator-activated receptor (PPAR) pathway in endocrine system were analyzed from gut bacterial metagenome with Kyoto Encyclopaedia of Genes and Genomes. High coverage of broad-leaved and mixed forests around the homes were associated with decreased PAH levels in ambient air, while gut functional orthologues for PPAR pathway increased along with these forest types. The difference between urban and rural PAH concentrations was not notable. However, some rural measurements were higher than the urban average, which was due to the use of heavy equipment on active farms. The provision of air purification by forests might be an important determining factor in the context of endocrine disruption potential of PAHs. Particularly broad-leaved forests around homes may reduce PAH levels in ambient air and balance pollution-induced disturbances within commensal gut microbiota.
As the incidence of immune-mediated diseases has increased rapidly in developed societies, there is an unmet need for novel prophylactic practices to fight against these maladies. This study is the first human intervention trial in which urban environmental biodiversity was manipulated to examine its effects on the commensal microbiome and immunoregulation in children. We analyzed changes in the skin and gut microbiota and blood immune markers of children during a 28-day biodiversity intervention. Children in standard urban and nature-oriented daycare centers were analyzed for comparison. The intervention diversified both the environmental and skin Gammaproteobacterial communities, which, in turn, were associated with increases in plasma TGF-β1 levels and the proportion of regulatory T cells. The plasma IL-10:IL-17A ratio increased among intervention children during the trial. Our findings suggest that biodiversity intervention enhances immunoregulatory pathways and provide an incentive for future prophylactic approaches to reduce the risk of immune-mediated diseases in urban societies.
Background: According to the biodiversity hypothesis of immune-mediated diseases, lack of microbiological diversity in the everyday living environment is a core reason for dysregulation of immune tolerance and – eventually – the epidemic of immune-mediated diseases in western urban populations. Despite years of intense research, the hypothesis was never tested in a double-blinded and placebo-controlled intervention trial. Objective: We aimed to perform the first placebo-controlled double-blinded test that investigates the effect of biodiversity on immune tolerance. Methods: In the intervention group, children aged 3–5 years were exposed to playground sand enriched with microbially diverse soil, or in the placebo group, visually similar, but microbially poor sand colored with peat (13 participants per treatment group). Children played twice a day for 20 min in the sandbox for 14 days. Sand, skin and gut bacterial, and blood samples were taken at baseline and after 14 days. Bacterial changes were followed for 28 days. Sand, skin and gut metagenome was determined by high throughput sequencing of bacterial 16 S rRNA gene. Cytokines were measured from plasma and the frequency of blood regulatory T cells was defined as a percentage of total CD3 +CD4 + T cells. Results: Bacterial richness (P < 0.001) and diversity (P < 0.05) were higher in the intervention than placebo sand. Skin bacterial community, including Gammaproteobacteria, shifted only in the intervention treatment to resemble the bacterial community in the enriched sand (P < 0.01). Mean change in plasma interleukin-10 (IL-10) concentration and IL-10 to IL-17A ratio supported immunoregulation in the intervention treatment compared to the placebo treatment (P = 0.02). IL-10 levels (P = 0.001) and IL-10 to IL-17A ratio (P = 0.02) were associated with Gammaproteobacterial community on the skin. The change in Treg frequencies was associated with the relative abundance of skin Thermoactinomycetaceae 1 (P = 0.002) and unclassified Alphaproteobacteria (P < 0.001). After 28 days, skin bacterial community still differed in the intervention treatment compared to baseline (P < 0.02). Conclusions: This is the first double-blinded placebo-controlled study to show that daily exposure to microbial biodiversity is associated with immune modulation in humans. The findings support the biodiversity hypothesis of immune-mediated diseases. We conclude that environmental microbiota may contribute to child health, and that adding microbiological diversity to everyday living environment may support immunoregulation.
According to the hygiene and biodiversity hypotheses, increased hygiene levels and reduced contact with biodiversity can partially explain the high prevalence of immune-mediated diseases in developed countries. A disturbed commensal microbiota, especially in the gut, has been linked to multiple immune-mediated diseases. Previous studies imply that gut microbiota composition is associated with the everyday living environment and can be modified by increasing direct physical exposure to biodiverse materials. In this pilot study, the effects of rural-second-home tourism were investigated on the gut microbiota for the first time. Rural-second-home tourism, a popular form of outdoor recreation in Northern Europe, North America, and Russia, has the potential to alter the human microbiota by increasing exposure to nature and environmental microbes. The hypotheses were that the use of rural second homes is associated with differences in the gut microbiota and that the microbiota related to health benefits are more diverse or common among the rural-second-home users. Based on 16S rRNA Illumina MiSeq sequencing of stool samples from 10 urban elderly having access and 15 lacking access to a rural second home, the first hypothesis was supported: the use of rural second homes was found to be associated with lower gut microbiota diversity and RIG-I-like receptor signaling pathway levels. The second hypothesis was not supported: health-related microbiota were not more diverse or common among the second-home users. The current study encourages further research on the possible health outcomes or causes of the observed microbiological differences. Activities and diet during second-home visits, standard of equipment, surrounding environment, and length of the visits are all postulated to play a role in determining the effects of rural-second-home tourism on the gut microbiota.
Gut microbes play an essential role in the development and functioning of the human immune system. A disturbed gut microbiota composition is often associated with a number of health disorders including immune-mediated diseases. Differences in host characteristics such as ethnicity, living habit and diet have been used toexplain differences in the gut microbiota composition in inter-continental comparison studies. As our previous studies imply that daily skin contact with organic gardening materials modify gut microflora, here we investigated the association between living environment and gut microbiota in a homogenous western population along an urban-rural gradient. We obtained stool samples from 48 native elderly Finns in province Häme in August and November 2015 and identified the bacterial phylotypes using 16S rRNA Illumina MiSeq sequencing. We assumed that yard vegetation and land cover classes surrounding homes explain the stool bacterial community in generalized linear mixed models. Diverse yard vegetation was associated with a reduced abundance of Clostridium sensu stricto and an increased abundance of Faecalibacterium and Prevotellaceae. The abundance of Bacteroides was positively and strongly associated with the built environment. Exclusion of animal owners did not alter the main associations. These results suggest that diverse vegetation around homes is associated with health-related changes in gut microbiota composition. Manipulation of the garden diversity, possibly jointly with urban planning, is a promising candidate for future intervention studies that aim to maintain gut homeostasis.