| 1. |
- Alakukku, Laura, et al.
(författare)
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Maatalouden ympäristötuen vaikuttavuuden seurantatutkimus (MYTVAS 3) : loppuraportti
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Since 1995, agri-environmental support partly funded by the EU has formed the core of Finland’s agri-environmental policy. This system has had a variety of impacts on the relationship between agriculture and the environment. Today’s agri-environmental support is one of the packages included in the Rural Development Programme for Mainland Finland (2007–2013/2014), which both in itself and through the underlying EU legislation requires monitoring of the impacts of the measures implemented. The study monitoring the impact of the 2nd Finnish agri-environmental scheme (MYTVAS 3), which ran from 2008 to 2013, forms part of this monitoring. The MYTVAS 3 monitoring study was also financed by the Ministry of the Environment. The monitoring study was carried out by a consortium coordinated by MTT Agrifood Research Finland and including the Finnish Environment Institute (SYKE), the University of Helsinki, the Finnish Game and Fisheries Research Institute and the University of Turku.The purpose of the MYTVAS 3 monitoring study was to find out how agri-environmental support and its various measures have affected the state of the environment in agricultural areas, how agri-environmental support has affected the potential for farming and how agri-environmental support should be developed to increase its impact. The monitoring focused on the impacts of agri-environmental support on the nutrient load from agriculture on the waterways and on biodiversity. When evaluating the findings presented, we should remember that while monitoring data shows that something happened, it does not necessarily explain what caused it. It is not always possible to show that particular developments were a specific outcome of the current agri-environmental support system and the implementation of its measures. The delay between a measure and its observed impact is often long, and the cause-and-effect relationships are complicated and partly unknown. Also, other agricultural policy and fluctuations on the market may affect the state of the agricultural environment directly or indirectly.The monitoring data show that agri-environmental support has not had a detrimental impact on the potential for farming. Despite a slight increase in the incidence of weeds, they do not cause problems of the kind that would require amendments to the content of agri-environmental measures. Carbon levels in the surface stratum of arable land seems to be continuing their slow decline, and there is still need for measures to preserve organic material in the soil.Compliance with the fertilisation limits in the agri-environmental support system would seem to have had very little impact on crop quality. Variations in the weight and protein content per hectolitre and per 1,000 seeds were of the same order between 2006 and 2012 as they were between 1995 and 2005. Crop quantities have also not been noticeably affected by compliance with the fertilisation limits. Average crop yields remained stable between 1986 and 2013, and no clearly different crop years were observed in the 2000s. It is possible, however, that the lower fertilisation levels could have lowered crop potential in the years with advantageous weather conditions in the 2000s and that protein contents have been lower in advantageous years.The monitoring data also show that the nutrient load potential of agriculture, measured by nutrient balances, has decreased continuously for nitrogen and particularly for phosphorus. The decrease in the nutrient load potential is due above all to a decrease in the use of synthetic fertilisers. The decline in nitrogen fertilisation has bottomed out in recent years, and low protein levels measured in high crop yield years show that there is no point in further reducing nitrogen fertilisation. Optimising nitrogen fertilisation according to how advantageous the growing season is and effectively using the soluble nitrogen in cattle manure are key measures in achieving reasonable nitrogen balances and good crop quality despite fluctuations in growing season conditions. New crop variants have been found to make more efficient use of nitrogen than old ones, and thus the introduction of new variants should be promoted. Despite the decrease in the nutrient balances, there are indications that nutrient loads in runoff water from domestic animal production sites are becoming an increasing problem. Indeed, the fundamental problem with the nutrient load from agriculture is the diversification of livestock farming and crop farming, which has made it more difficult to use nutrients appropriately. Therefore attention must be paid to measures that both boost the use of nutrients in manure and reduce the levels of nutrients that end up in manure. Based on nutrient load monitoring in the catchment areas of rivers, the phosphorus load per hectare of cropland has decreased in each programme period, being about 80% of the level of the first period (1995–1999) in the third period (2007–2013). Because of the increase in the area of cropland, the nitrogen load on waterways from agriculture continued to grow during the second programme period (2000–2006) but peaked in the third (2007–2013). A similar trend was found in the nitrogen load per hectare of cropland.The most important threat to biodiversity is caused by the development of landscape structure, typically involving a decrease in the number of open or half-open areas excluded from actual cultivation. The consequence of the clearing of margins and ecological islands located in crop fields, drainage measures aimed at increasing arable land and all rationalisation of cultivated areas is the diminishing of exactly those areas that are the most important from the perspective of the biodiversity of the agricultural environment. However, the measure-specific findings in the monitoring study show that biodiversity benefits have been locally achieved where measures have been implemented on a broad enough scale (biodynamic farming, traditional biotopes, wetlands, buffer zones, green fallow / nature management areas). Particular care should therefore be taken that all cultivated land continues to have a sufficient percentage of non-cultivated areas, whether they be natural meadows, nature management areas, biodiversity strips, buffer zones, filter strips, headlands, ecological islands, etc. Including the rather popular nature management areas as a new voluntary measure under basic measures was a significant contribution to biodiversity.Regarding the rural landscape, it may be noted that by visual inspection the area of cropland has remained largely unchanged, at the level of the landscape as a whole it is far more common for the landscape to become more closed than to become more open. This trend was also observed in the visual inspection of traditional biotopes, even if the openness of the meadows monitored largely remained unchanged.The only measures that directly address the reduction of gaseous emissions in the agri-environmental support system are the longterm grass cultivation on peat fields and special aid agreements for slurry injection in cropland. While other measures have indirectly affected gaseous emissions, the impact of agri-environmental support as a whole on reducing gaseous emissions from agriculture has been negligible. In general, we may conclude that the goals, content and support levels of agri-environmental support measures must be increasingly adapted and customised by region, by type of farming and by farm, because both the state of the agricultural environment and the needs of society differ greatly between different types of rural area.
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| 2. |
- Geißler, Sebastian, et al.
(författare)
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Deposition Kinetics of Bioinspired Phenolic Coatings on Titanium Surfaces
- 2016
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 32:32, s. 8050-8060
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Tidskriftsartikel (refereegranskat)abstract
- Polyphenols can form functional coatings on a variety of different materials through auto-oxidative surface polymerization in a manner similar to polydopamine coatings. However, the mechanisms behind the coating deposition are poorly understood. We report the coating deposition kinetics of the polyphenol tannic acid (TA) and the simple phenolic compound pyrogallol (PG) on titanium surfaces. The coating deposition was followed in real time over a period of 24 h using a quartz crystal microbalance with dissipation monitoring (QCM-D). TA coatings revealed a multiphasic layer formation: the deposition of an initial rigid layer was followed by the buildup of an increasingly dissipative layer, before mass adsorption stopped after approximately 5 h of coating time. The PG deposition was biphasic, starting with the adsorption of a nonrigid viscoelastic layer which was followed by layer stiffening upon further mass adsorption. Coating evaluation by ellipsometry and AFM confirmed the deposition kinetics determined by QCM-D and revealed maximum coating thicknesses of approximately 50 and 75 nm for TA and PG, respectively. Chemical characterization of the coatings and polymerized polyphenol particles indicated the involvement of both physical and chemical interactions in the auto-oxidation reactions.
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| 3. |
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| 4. |
- Katsaros, Ioannis
(författare)
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Silicon nitride-based materials for spinal and antipathogenic applications
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Silicon nitride (Si3N4) is a ceramic material that is well-established in industrial applications due to its stability in demanding environments. The mechanical properties and biocompatibility of the material have led to its approval for clinical use in spinal implants. The unique surface chemistry of Si3N4 has been shown to create a chemical environment that is supportive to bone regeneration while simultaneously reducing bacterial viability, both in vitro and in animal models in vivo. Thus, Si3N4 can be used in the spine to reduce patient recovery times while protecting the implant site from damaging and costly infections. However, results from clinical studies have not shown significant differences between silicon nitride and other spinal implant materials in terms of patient outcomes. Thus, the first aim of this thesis was to find ways to optimise the biological properties of the material and in turn create spinal implants that would exhibit significantly higher osteointegration while reducing the incidence of infections. To this end, a thermochemical surface modification was developed that changed the surface chemistry and roughness of the material resulting in increased in vitro bioactivity without affecting its antibacterial behaviour. Furthermore, the possibility of creating an osteoconductive, antibacterial bone cement to be used in vertebroplasties in the spine was explored. By adding up to 20%wt of a Si3N4 powder to poly methyl methacrylate (PMMA) cements, a significant (>90%) reduction of bacterial biofilm formation was achieved without affecting the compressive strength or biocompatibility of the modified bone cements in a negative way.A secondary objective of the study was to explore the antipathogenic properties of the material, fulfilling the growing need for a world where the spread of dangerous pathogens will be limited. The efficiency of the material against one of the most resilient DNA-viruses, the human adenovirus, was tested. It was found that contact with Si3N4 in both powder and bulk form rapidly reduced infectivity (>98% and >73%, respectively). Based on these results, a thermal modification of silicon nitride powders was developed, that would enhance their antiviral efficiency against SARS-CoV-2 and thus the applicability of the material. It was found that 10%wt modified-Si3N4 slurries rendered the coronavirus non-infectious after less than a minute of contact. The results of these studies proved that silicon nitride can also be used as an antipathogenic agent in environmental applications.Overall, in this thesis, steps were taken towards the development of Si3N4-based materials that can lead to faster healing, lower infection rates and that can be used to limit the spread of disease.
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| 5. |
- Weber, Florian, et al.
(författare)
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Characterization of the foreign body response of titanium implants modified with polyphenolic coatings
- 2022
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Ingår i: Journal of Biomedical Materials Research. Part A. - : John Wiley & Sons. - 1549-3296 .- 1552-4965. ; 110:7, s. 1341-1355
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Tidskriftsartikel (refereegranskat)abstract
- The foreign body response is dictating the outcome of wound healing around any implanted materials. Patients who suffer from chronic inflammatory diseases and impaired wound healing often face a higher risk for implant failure. Therefore, functional surfaces need to be developed to improve tissue integration. For this purpose, we evaluated the impact of surface coatings made of antioxidant polyphenolic molecules tannic acid (TA) and pyrogallol (PG) on the host response in human blood. Our results showed that although the polyphenolic surface modifications impact the initial blood protein adsorption compared to Ti, the complement and coagulation systems are triggered. Despite complement activation, monocytes and granulocytes remained inactivated, which was manifested in a low pro-inflammatory cytokine expression. Under oxidative stress, both coatings were able to reduce intracellular reactive oxygen species in human gingival fibroblasts (hGFs). However, no anti-inflammatory effects of polyphenolic coatings could be verified in hGFs stimulated with lipopolysaccharide and IL-1 beta. Although polyphenols reportedly inhibit the NF-kappa B signaling pathway, phosphorylation of NF-kappa B p65 was observed. In conclusion, our results indicated that TA and PG coatings improved the hemocompatibility of titanium surfaces and have the potential to reduce oxidative stress during wound healing.
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| 6. |
- Weber, Florian, et al.
(författare)
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Silicate-Phenolic Networks : Coordination-Mediated Deposition of Bioinspired Tannic Acid Coatings
- 2019
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 25:42, s. 9870-9874
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Tidskriftsartikel (refereegranskat)abstract
- Surface modification with polyphenolic molecules has been pursued in biomedical materials owing to their antioxidant, anti-inflammatory, and antimicrobial characteristics. Recently, the use of silicic acid (Si-aq) as a mediator for efficient surface deposition of tannic acid (TA) was reported, but the postulated Si-TA polymeric networks were not characterized. Herein, we present unambiguous evidence for silicate-TA networks that involve Si-O-C motifs by using solid-state NMR spectroscopy, further supported by XPS and ToF-SIMS. By using QCM-D we demonstrate the advantages of Si-aq, compared to using transition-metal ions, to improve the coating efficiency under mildly acidic conditions. The presented homogenous coating buildup and validated applicability in inorganic buffers broadens the use of TA for surface modifications in technological and biomedical applications.
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| 7. |
- Wiedmer, David, et al.
(författare)
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Oxidative power of aqueous non-irradiated TiO2-H2O2 suspensions : Methylene blue degradation and the role of reactive oxygen species
- 2016
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Ingår i: Applied Catalysis B. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 198, s. 9-15
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the degradation of methylene blue in non-irradiated TiO2-H2O2 suspensions was investigated. Five commercially available catalysts were characterized (BET surface area, zeta potential, hydrodynamic diameter) and their oxidative power was assessed by means of the degradation of methylene blue. A subsequent EPR study was made to verify and identify potential oxidative radicals. The results showed that all suspensions could degrade methylene blue significantly stronger compared to hydrogen peroxide alone. A broad variation between the different catalysts in their capability to adsorb dye molecules was found which was essential for decomposition of methylene blue in darkness. The highest degradation rate of all samples was found for Degussa P25 at neutral pH. EPR studies of this sample verified the presence of oxygen centred radicals namely hydroxyl ((OH)-O-center dot) and superoxide radicals (O-2(-center dot)/(OOH)-O-center dot). Non-irradiated TiO2-H2O2 systems show great potential not only in dye removal applications but also in the field of disinfection where low concentrations of hydrogen peroxide are required and irradiation may not be feasible.
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