The annual cycle of forest trees : The Sarvas approach revisited

Peer reviewe

Titaanista valmistetun hammasimplantin pinnoittaminen antimikrobiaaliseksi ja osseointegraatiota edistäväksi

Hammasimplanttien käyttö on yleistynyt hampaiden korvaamisessa. Implanttien materiaalina käytetään titaania ja titaaniseoksia näiden mekaanisten ominaisuuksien, vähäisen toksisuuden ja korroosioresistenttiyden vuoksi, minkä lisäksi kyseisten materiaalien on todettu olevan bioyhteensopivia luusolujen kanssa. Implantit ovat kuitenkin alttiita infektioille, jotka voivat johtaa implantin menettämiseen. Antifouling-materiaalit estävät mikrobien kiinnittymistä pintoihin kosteissa oloissa, kuten suussa. Tässä kirjallisuustutkimuksen muotoisessa tutkielmatyössä esitellään titaanista valmistetuille hammasimplanteille suunniteltuja potentiaalisia antifouling-pinnoitemateriaaleja, jotka myös edistävät osseointegraatiota eli implantin luutumista. Lisäksi määritellään näiden materiaalien yleisimmät analysointimenetelmät, implantointiin vaikuttavia tekijöitä, keskeinen anatomia ja fysiologia. Opinnäytetyön viitteet haettiin suurimmaksi osaksi Scopus-tietopankin ja Google Scholarin kautta. Tutkimustulosten ja artikkelien valintakriteereinä olivat muun muassa sekä luutumisen että antimikrobiaalisuuden huomioiminen pinnoitettujen, titaanista valmistettujen hammasimplanttien in vivo - tai in vitro -tutkimuksissa. Useimmissa hakusanoilla löydetyissä artikkeleissa nimittäin vain toista tekijää tutkittiin: joko luutumista tai antimikrobiaalisuutta, muttei molempia. Artikkelien rajaamiseen käytettyjä hakusanoja olivat muun muassa titanium, dental, implant, coating, antifouling, antimicrobial, biocompatibility ja osseointegration. Hammasimplantointiin liittyvän keskeisen anatomian ja fysiologian esittämiseksi lähteinä käytettiin parodontologiaan ja suu- ja leukakirurgiaan keskittyvää kirjallisuutta. Useita eri potentiaalisia pinnoitemateriaaleja on kehitetty. Johtopäätöksenä voidaan kuitenkin todeta, ettei yhtä tutkielmassa esitellyistä hammasimplantin pinnoitemateriaaleista voida asettaa ylitse muiden, sillä materiaaleja ei ole vertailtu keskenään. Harvoista pinnoitteista oli tehty kliinisiä tai pitkäkestoisia tutkimuksia, mikä myös esti pinnoitteiden paremmuusvertailun tekemistä

Significance of the root connection on the dormancy release and vegetative bud burst of Norway spruce (Picea abies) seedlings in relation to accumulated chilling

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Sub-Arctic alpine Vaccinium vitis-idaea exhibits resistance to strong variation in snowmelt timing and frost exposure, suggesting high resilience under climatic change

In tundra ecosystems, snow cover protects plants from low temperatures in winter and buffers temperature fluctuations in spring. Climate change may lead to reduced snowfall and earlier snowmelt, potentially exposing plants to more frequent and more severe frosts in the future. Frost can cause cell damage and, in combination with high solar irradiance, reduce the photochemical yield of photosystem II (phi(PSII)). Little is known about the natural variation in frost exposure within individual habitats of tundra plant populations and the populations' resilience to this climatic variation. Here, we assessed how natural differences in snowmelt timing affect microclimatic variability of frost exposure in habitats of the evergreenVaccinium vitis-idaeain sub-Arctic alpine Finland and whether this variability affects the extent of cell damage and reduction in phi(PSII). Plants in early melting plots were exposed to more frequent and more severe frost events, and exhibited a more pronounced decrease in phi(PSII), during winter and spring compared to plants in late-melting plots. Snowmelt timing did not have a clear effect on the degree of cell damage as assessed by relative electrolyte leakage. Our results show that sub-Arctic alpineV. vitis-idaeais currently exposed to strong climatic variation on a small spatial scale, similar to that projected to be caused by climate change, without significant resultant damage. We conclude thatV. vitis-idaeais effective in mitigating the effects of large variations in frost exposure caused by differences in snowmelt timing. This suggests thatV. vitis-idaeawill be resilient to the ongoing climate change.Peer reviewe

Influence of grain size distribution on the Hall–Petch relationship of welded structural steel

The strength of polycrystalline metals increases with a decrease in grain size according to the Hall-Petch relationship. However, heterogeneous microstructures deviate from this relationship dependingon the distribution of grain sizes. This paper introduces a rule of mixtures based approach fordetermining the characteristic length of the microstructure for heterogeneous weld metal. Theproposed grain size parameter, the volume-weighted average grain size, is measured experimentallyfor nine structural steel weld metals and two base materials. The weld metals are found to have alarge variety of grain size distributions that are noticeably broader than those of the base material dueto differences in phase contents. The results show that the volume-weighted average grain size is ableto capture the influence of grain size distribution on the strength of welded structural steel. Based onthe experimental results, a modified Hall-Petch relationship is formulated for the strength predictionof heterogeneous microstructures. The modified relationship is also found to be applicable to datafrom the literature.Peer reviewe

Huono-osaisuuden ja sairastavuuden kytkennästä diakonian asiakkailla

Pitkäaikaissairauksien yleisyys vaihtelee Suomessa johdonmukaisesti sosioekonomisen aseman mukaan yhtä lailla kuin kuolleisuus ja koettu terveys. Artikkelissa hahmotetaan miten sairaudet ja huono-osaisuus kytkeytyvät yhteen Suomen evankelisluterilaisen kirkon diakoniatyön asiakkaiden keskuudessa. Tavoitteena on tunnistaa niitä mekanismeja ja prosesseja, jotka kytkevät sairastavuuden ja huono-osaisuuden toisiinsa. Tutkimusaineisto muodostuu diakoniatyöntekijöiden teemahaastatteluista (N = 21) sekä diakonian asiakkaita koskevista Kirkon diakoniarahaston avustushakemuksista ja -päätöksistä vuosilta 2004–2006 (N = 170). Sairauden ja huono-osaisuuden yhteenkietoutumisen prosessia tutkittiin episodianalyysin avulla neljässä vaiheessa: huono-osaisten ihmisten erityisongelmat ennen sairastumista, hoitoon hakeutumisessa, hoidon riittävyydessä ja laadussa sekä jatkohoidossa. Tulosten mukaan terveydessä ja huono-osaisuudessa ei ole kyse toisistaan riippumattomista taustatekijöistä vaan yhden ja saman prosessin vipuvoimista. Köyhyys aineellisten elinehtojen puutteena sairastuttaa. Aineellinen ahdinko voi tarkoittaa sitä, että terveydenhoidosta tingitään esimerkiksi asiakasmaksujen tai matkakulujen takia

Autumn cold acclimation of shoots does not explain the northern distribution limit of three southern exotic tree species in Finland

Frost hardiness (FH) is one of the key traits that limits the distribution of tree species in the north. Different species and ecotypes respond differently to the drivers of frost hardening and may therefore have different survival capacities, especially in their northern distribution range. Several southern tree species such as pedunculate oak (Quercus robur L.), Norway maple (Acer platanoides L.), and mountain elm (Ulmus glabra Hudson) have their natural northern distribution limit in Southern Finland. Here, we examined whether insufficient frost hardening in the autumn limits the northwards distribution of these three species. To that end, we monitored phenological events and frost hardening in the autumn in these exotic species in Central Finland, further north from the natural distribution range of the three exotic species, and for the sake of comparison, in the native silver birch (Betula pendula Roth.). In all species, a timely growth cessation was observed. The water content of the stem decreased, and its dry mass content increased rapidly in August before the onset of frost hardening, after which no major changes were observed in these two traits. In the early phase of hardening, there were differences in leaf colouring between the four species. The values of the electrical impedance parameters of the stem changed during frost hardening, with a clear turning point after the first night frosts at the end of September. Depending on the species and hardening phase, the high temperature exotherm (HTE) of the stem was observed between -3 °C and -10 °C, but HTE did not indicate differences between the species in frost hardening. In all four species, frost hardening started at the beginning of September and proceeded first at equal rates, but the hardening was more rapid later in birch than in the other species. The damaging temperature range assessed by the controlled freezing tests became wider with increasing FH. The occurrence rate of the low temperature exotherm (LTE) varied between the species, and the LTE was observed at around -35 °C in the last sampling at the beginning of December (no LTE was observed in birch). We conclude that the hardening of all four species took place in a timely manner so that in each, the frost hardiness was sufficient to survive the autumn frosts at the experimental site in Central Finland. Further studies are needed to examine whether the exotic three species also tolerate temporarily occurring extreme winter conditions such as temperatures below -35 °C, and the high short-term temperature variations in winter and especially in spring.202

Granulocyte colony-stimulating factor- and chemotherapy-induced large-vessel vasculitis : six patient cases and a systematic literature review

Objective. Patients receiving chemotherapy are prone to neutropoenic infections, presenting with non-specific symptoms such as a high fever and elevated inflammatory parameters. Large-vessel vasculitis (LVV) may have a similar clinical presentation and should be included in differential diagnostics. A few published case reports and adverse event reports suggest a causal association between LVV and the use of granulocyte colony-stimulating factor (G-CSF) and chemotherapy. Our objective was to evaluate the relationship between LVV, G-CSF and chemotherapy. Methods. Between 2016 and 2018, we identified six patients in Finland with probable drug-induced LVV associated with G-CSF and chemotherapy. All six patients had breast cancer. A systematic literature review was performed according to PRISMA guidelines using comprehensive search terms for cancer, chemotherapy, G-CSF and LVV. Results. The literature search identified 18 similar published case reports, of which most were published after 2014. In all patients combined (n = 24), the time delay from the last drug administration to the LVV symptoms was on average 5 days with G-CSF (range = 1-8 days) and 9 days with chemotherapy (range = 1-21 days). Common symptoms were fever (88%), neck pain (50%) and chest pain (42%). Based on imaging, 17/24 (71%) had vascular inflammation in the thoracic aorta and supra-aortic vessels, but 5/24 (21%) reportedly had inflammation limited to the carotid area. Conclusion. This review suggests that LVV may be a possible serious adverse event associated with G-CSF and chemotherapy. Successful management of drug-induced LVV requires early identification, through diagnostic imaging, and discontinuation of the drug.Peer reviewe