Perusteos kanteleesta

Kirjallisuusarvostelu

Porous silicon optical filters in gas sensing applications

In this thesis, the gas sensing properties of porous silicon-based thin-film optical filters are explored. The effects of surface chemistry on the adsorption and desorption of various gases are studied in detail. Special emphasis is placed on investigating thermal carbonization as a stabilization method for optical sensing applications. Moreover, the possibility of utilizing the increased electrical conductivity of thermally carbonized porous silicon for implementing a multiparametric gas sensor, which would enable simultaneous monitoring of electrical and optical parameters, is investigated. In addition, different porous silicon-based optical filter-structures are prepared, and their properties in sensing applications are evaluated and compared. First and foremost, thermal carbonization is established as a viable method to stabilize porous silicon optical filters for chemical sensing applications. Furthermore, a multiparametric sensor, which can be used for increasing selectivity in gas sensing, is also demonstrated. Methods to improve spectral quality in multistopband mesoporous silicon rugate filters are studied, and structural effects to gas sorption kinetics are evaluated. Finally, the stability of thermally carbonized optical filters in basic environments is found to be superior in comparison to other surface chemistries currently available for porous silicon. The results presented in this thesis are of particular interest for developing novel reliable sensing systems based on porous silicon, e.g., label-free optical biosensors.

Vapauden suuri vankila

Kirjallisuusarvostelu

Äntligen en djupdykning i kantelens värld

Kirjallisuusarvostelu

Kaaleen laulua Joensuun seudulta

Musiikkiarvostelu

Pysy Suomessa pyhänä

Kirjallisuusarvostelu

Arvoympäristö ja arvokasvatus lentoreserviupseerikurssilla : laadullinen tutkimus lentoRUK:n arvoista ja arvokasvatuksen toteutusmahdollisuuksista

Tässä luonteeltaan kvalitatiivisessa tapaustutkimuksessa tutkitaan lentoreserviupseerikurssin oppilaiden, kouluttajien ja lennonopettajien välisiä mahdollisia arvoristiriitoja sekä - yhtäläisyyksiä, joiden lisäksi kartoitetaan arvokasvatuksen toteutusmahdollisuuksia lentoreserviupseerikurssin toimintaympäristössä. Tutkimuksen empiirisen osion perusteella pyritään selvittämään tutkimuskohteiden yksilöllisten arvokäsitysten suhdetta toisiinsa ja Ilmavoimien organisaation arvoihin. Empiirisen osuuden toisena tärkeänä tavoitteena on tarkastella arvokasvatuksen eri tekijöitä lentoreserviupseerikurssilla. Tutkimustyön aineistonkeruumenetelmänä on käytetty teemahaastattelua. Tutkimuksen pääasiallisena teoriana on käytetty Schwartzin (1992) teoriaa arvojen universaalista rakenteesta ja sisällöstä. Schwartz on muodostanut tutkitun tiedon avulla arvoympyrän, joka sisältää 10 arvoluokkaa. Arvoympyrää on hyödynnetty tässä tutkimuksessa useaan otteeseen. Tutkimustyön arvokasvatuksen osuudessa lähdekirjallisuutta on tutkittu laajalti erityisesti organisaation arvojen ja arvokasvatuksen näkökulmista. LentoRUK:n eri henkilöstöryhmien arvoja sekä Ilmavoimien organisaation arvoja tarkasteltaessa kävi ilmi, että kurssin kokonaisarvoympäristö on melko yhtenäinen ja lähellä Ilmavoimien arvomaailmaa. Tarvetta nähtiin kuitenkin arvojen yhteiselle sopimiselle. Kurssin arvokasvatuksesta haastattelujen avulla saadut näkemykset poikkesivat eri haastatteluryhmien välillä enemmän. Tärkeimmäksi arvokasvatuksen metodiksi nousi jokaisen yhteisön jäsenen oma esimerkki. Kurssin arvokasvatuksen kehittämisehdotuksia ovat muun muassa koulutusorganisaation yhteisten tilaisuuksien järjestäminen sekä mahdollinen arvokasvatuksen huoneentaulu.

Multiple sclerosis and pregnancy: clinical and immunological aspects

Background: Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system that affects most commonly young women in their childbearing age. Previous studies have shown that MS relapse rate usually reduces during pregnancy and increases again after delivery. Patients with MS and their treating physicians are interested to know more about the risks the disease can cause to pregnancy and how pregnancy affects the disease. The reasons for increased relapse rate after delivery are not entirely clear, but loss of pregnancy related immune tolerance and changes in the hormonal status at the time of delivery seem to be of relevance. Aims and methods: The aims of this study were to follow the natural course of MS during and after pregnancy, evaluate pregnancy related risks among MS patients, follow the inflammatory response of MS patients during and after pregnancy and clarify the risk of relevant co-morbidities known to affect other autoimmune diseases after pregnancy and compare these results to healthy controls. This study was a part of a prospective nation-wide follow-up study of 60 Finnish MS patients. All eligible MS patients were enrolled in the study during the years 2003-2005. A prospective followup continued from early pregnancy until six months postpartum. MS relapses, EDSS scores and obstetric details were recorded. Blood samples were obtained from the patients at early, middle, and late pregnancy, after delivery and one month, three months and six months postpartum. Results: MS patients were no more likely to experience pregnancy or delivery complications than the Finnish mothers in general. The need of instrumental assistance, however, was higher among mothers with MS. Disease activity followed the course seen in previous studies. The majority of mothers (90.2%) breastfed their babies. Contrary to previous results, breastfeeding did not protect MS patients from disease worsening after delivery in present study. Mothers with active pre-pregnancy disease chose to breastfeed less frequently and started medication instead. MS patients presented with higher prevalence of elevated thyroid autoantibodies postpartum than healthy controls, but the rate of thyroid hormonal dysfunction was similar as that of healthy controls. The mode of delivery nor the higher rate of tissue damage assessed with C-reactive protein concentration were not predictive of postpartum relapses. The prevalence of gestational diabetes was slightly higher among mothers with MS compared to Finnish mothers in general, but postpartum depression was observed in similar rates. MS patients presented with significantly lower serum concentrations of vitamin D during pregnancy and postpartum than healthy controls. Conclusions: Childbearing can be regarded as safe for mothers with MS as it is for healthy mothers in general. Breastfeeding can be recommended, but it should be done only after careful evaluation of the individual risk for postpartum disease activation. Considering MS patients tend to develop thyroid antibody positivity after delivery more often than healthy controls and that certain treatments can predispose MS patients to thyroid hormonal dysfunction, we recommend MS mothers to be screened for thyroid abnormalities during pregnancy and after delivery. Increased risk for gestational diabetes should be kept in mind when following MS mothers and glucose tolerance test in early pregnancy should be considered. Adequate vitamin D supplementation is essential for MS mothers also during pregnancy and postpartum period.

Hypertrophy of infected Peyer’s patches arises from global, interferon-receptor, and CD69-independent shutdown of lymphocyte egress

Lymphoid organ hypertrophy is a hallmark of localized infection. During the inflammatory response, massive changes in lymphocyte recirculation and turnover boost lymphoid organ cellularity. Intriguingly, the exact nature of these changes remains undefined to date. Here, we report that hypertrophy of Salmonella-infected Peyer's patches (PPs) ensues from a global "shutdown" of lymphocyte egress, which traps recirculating lymphocytes in PPs. Surprisingly, infection-induced lymphocyte sequestration did not require previously proposed mediators of lymphoid organ shutdown including type I interferon receptor and CD69. In contrast, following T-cell receptor-mediated priming, CD69 was essential to selectively block CD4+ effector T-cell egress. Our findings segregate two distinct lymphocyte sequestration mechanisms, which differentially rely on intrinsic modulation of lymphocyte egress capacity and inflammation-induced changes in the lymphoid organ environment.