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Tietokonetomografia on päivystysaikana yksi merkittävimmistä kuvantamismodaliteeteista, mutta sen tuoma säderasitus on huomattava muihin radiologisiin kuvantamismenetelmiin verrattuna. Tämän vuoksi on erittäin tärkeää, että lähettävä lääkäri osaa tarkasti arvioida tutkimuksen tarpeellisuutta ja tuoda pyynnön esille selkeästi röntgenlä-hetteen muodossa. Opinnäytetyön tarkoituksena oli tehdä Kymenlaakson keskussairaalan Kuvantamiskeskukseen ohjeistus hyvästä päivystysröntgenlähetteestä tietokonetomografiatutkimuksiin lähettäville lääkäreille, ja tavoitteena oli auttaa heitä tekemään parempia röntgenlähetteitä sekä yhtenäistää käytäntöjä eri yksiköiden välillä. Kun lähetteisiin on kirjattu välttämättömät tiedot, saavat tutkimuksia suorittavat röntgenhoitajat ja röntgenlääkärit heti selkeän käsityksen lähettävän lääkärin haluamasta tutkimuksesta sekä kuvausindikaatiosta. Opinnäytetyö toteutettiin kehittämistyönä yhteistyössä Kymenlaakson keskussairaalan Kuvantamiskeskuksen kanssa. Työn tuotoksena tehtiin kaksipuolinen ohje. Opinnäytetyön toteuttamista varten koottiin teoriatietoa muun muassa päivystysajan tietokonetomografiatutkimuksista, varjoaineista sekä tietokonetomografialaitteesta. Tietoa etsittiin eri tietokantojen avulla lehti- ja verkkoartikkeleista, kirjoista, internetsivuilta sekä tietoa saatiin myös tilaajalta. Ohjeet lähettäville lääkäreille tehtiin tietoa keräämällä sekä tilaajan antamaa palautetta käyttäen. Kymenlaakson keskussairaalan Kuvantamiskeskuksen toiveiden mukaisesti ohjeisiin sisällytettiin ohjeita hyvästä päivystysajan tietokonetomografialähetteestä, tietoa varjoaineesta sekä yleisimpien tietokonetomografiatutkimusten sädeannoksia. Ohjeet pidettiin mahdollisimman selkeinä ja ytimekkäinä. Ohjeisiin sisällytettiin Kymenlaakson keskussairaalan logo, työn tekijät ja käytetyt lähteet. Ohjeet toimitettiin Kymenlaakson keskussairaalan Kuvantamiskeskukselle sähköisessä muodossa. Ohjeiden käyttö- ja muokkausoikeudet luovutettiin samalla Kymenlaakson keskussairaalan Kuvantamiskeskukselle. Röntgenhoitajat voivat testata ohjeiden toimivuutta pyytämällä niistä palautetta.
Tässä diplomityössä käsitellään betonirakenteen vahvistuksen rajapinnan toimintaa ja mitoitusta. Kirjallisuuskatsauksena tutkittiin rajapinnan teoreettista toimintaa, ja selvitettiin miten leikkausvoimat siirtyvät rajapinnan yli. Kirjallisuuskatsauksessa selvisi, että leikkausvoimat siirtyvät kolmen voimansiirtomekanismin yhteisvaikutuksesta. Voimansiirtomekanismit ovat: koheesio, joka koostuu adheesiosta ja mekaanisesta lukittumisesta, kitka, sekä vaarnavaikutus. Vahvistusten rajapintoja mitoitetaan Suomessa nykyisin pääasiassa neljällä eri mitoitusmenetelmällä. Mitoitusmenetelmät ovat: Eurokoodin mukainen menetelmä, vaarnatappimenetelmä, TR066:den mukainen menetelmä ja Hiltin menetelmä. Kukin näistä ottaa hieman eri tavalla leikkausvoiman siirtomekanismit huomioon, ja siksi ne tuottavat hieman erilaisia tuloksia rajapinnan leikkauskestävyydelle. Esimerkkilaskelmilla tutkittiin, minkälaisia leikkauskestävyyksiä mitoitusmenetelmät tuottavat, kun 250 mm paksua laattaa vahvistetaan 150 mm paksulla betonikerroksella. Lisäksi tutkittiin, missä roolissa voimansiirtomekanismit ovat kussakin mitoitusmenetelmässä. Laskelmien tulos oli, että vaikka voimansiirtomekanismien suhteelliset osuudet vaihtelivat rajusti menetelmien välillä, ne tuottivat silti samansuuntaisia tuloksia rajapinnan leikkauskestävyydelle. Loppupäätelmä oli, että mikäli vahvistuksen rajapinnassa käytetään ETA-hyväksyttyä vaarnaa, kuten HUS4-H betoniruuviankkuria, on TR066:den mukainen menetelmä paras. Mikäli rajapinnassa käytetään harjateräksiä, Hiltin menetelmä on sopivin. Mainitut menetelmät kuitenkin ovat työläitä ja siksi vaativat laskentaohjelmiston käyttöä. Eurokoodin menetelmä ja vaarnatappimenetelmä ovat yksinkertaisuutensa vuoksi helposti sovellettavia myös käsinlaskennassa
We show ionically cross-linked, temperature-responsive reversible or irreversible hydrogels of anionic cellulose nanocrystals (CNCs) and methacrylate terpolymers by mixing them homogeneously in the initially charge-neutral state of the polymer, which was subsequently switched to be cationic by cleaving side groups by UV irradiation. The polymer is a random terpolymer poly(di(ethylene glycol) methyl ether methacrylate)-rnd-poly(oligo(ethylene glycol) methyl ether methacrylate)-rnd-poly(2-((2-nitrobenzyl)oxycarbonyl)aminoethyl methacrylate), that is, PDEGMA-rnd-POEGMA-rnd-PNBOCAEMA. The PDEGMA and POEGMA repeating units lead to a lower critical solution temperature (LCST) behavior. Initially, homogeneous aqueous mixtures are obtained with CNCs, and no gelation is observed even upon heating to 60 °C. However, upon UV irradiation, the NBOCAEMAs are transformed to cationic 2-aminoethyl methacrylate (AEMA) groups, as 2-nitrobenzaldehyde moieties are cleaved. The resulting mixtures of anionic CNC and cationic PDEGMA-rnd-POEGMA-rnd-PAEMA show gelation for sufficiently high polymer fractions upon heating to 60 °C due to the interplay of ionic interactions and LCST. For short heating times, the gelation is thermoreversible, whereas for long enough heating times, irreversible gels can be obtained, indicating importance of kinetic aspects. The ionic nature of the cross-linking is directly shown by adding NaCl, which leads to gel melting. In conclusion, the optical triggering of the polymer ionic interactions in combination with its LCST phase behavior allows a new way for ionic nanocellulose hydrogel assemblies.
Methylcellulose/cellulose nanocrystal (MC/CNC) nanocomposite fibers showing high ductility and high modulus of toughness were prepared by a simple aqueous wet-spinning from corresponding nanocomposite hydrogels into ethanol coagulation bath followed by drying. The hydrogel MC aq. concentration was maintained at 1 wt-% while the CNC aq. loading was systematically varied in the range 0–3 wt-%. This approach resulted in MC/CNC fiber compositions from 25/75 wt-%/wt-% to 95/5 wt-%/wt-%. The optimal mechanical properties were achieved with the MC/CNC composition of 80/20 wt-%/wt-% allowing high strain (36.1%) and modulus of toughness (48.3 MJ/m3), still keeping a high strength (190 MPa). Further, we demonstrate that the continuous spinning of MC/CNC fibers is potentially possible. The results indicate possibilities to spin MC-based highly ductile composite fibers from environmentally benign aqueous solvents.
Fiber spinning of anionic TEMPO-oxidized cellulose (TOCN) nanofibrils with polycations by interfacial polyelectrolyte complexation is demonstrated. The formed fibers were mostly composed of cellulose nanofibrils and the polycations were a minor constituent, leading to yield and ultimate strengths of ca. 100 MPa and ca. 200 MPa, and Young’s modulus of ca. 15 GPa. Stretching of the as-formed wet filaments of TOCN/polycation by 20% increased the Young’s modulus, yield strength, and ultimate tensile strength by approximately 45, 36, and 26%, respectively. Importantly, feasibility of compartmentalized wound bicomponent fibers by simultaneous spinning of two fibers of different compositions and entwining them together was shown. This possibility was further exploited to demonstrate reversible shape change of a bicomponent fiber directly by humidity change, and indirectly by temperature changes based on thermally dependent humidity absorption. The demonstrated route for TOCN-based fiber preparation is expected to open up new avenues in the application of nanocelluloses in advanced fibrous materials, crimping, and responsive smart textiles.
Strain-stiffening is one of the characteristic properties of biological hydrogels and extracellular matrices, where the stiffness increases upon increased deformation. Whereas strain-stiffening is ubiquitous in protein-based materials, it has been less observed for polysaccharide and synthetic polymer gels. Here we show that agarose, that is, a common linear polysaccharide, forms helical fibrillar bundles upon cooling from aqueous solution. The hydrogels with these semiflexible fibrils show pronounced strain-stiffening. However, to reveal strain-stiffening, suppressing wall slippage turned as untrivial. Upon exploring different sample preparation techniques and rheological architectures, the cross-hatched parallel plate geometries and in situ gelation in the rheometer successfully prevented the slippage and resolved the strain-stiffening behavior. Combining with microscopy, we conclude that strain-stiffening is due to the semiflexible nature of the agarose fibrils and their geometrical connectivity, which is below the central-force isostatic critical connectivity. The biocompatibility and the observed strain-stiffening suggest the potential of agarose hydrogels in biomedical applications.
One of the major, but often overlooked, challenges toward high end applications of nanocelluloses is to maintain their high mechanical properties under hydrated or even fully wet conditions. As such, permanent covalent cross-linking or surface hydrophobization are viable approaches, however, the former may hamper processability and the latter may have adverse effect on interfibrillar bonding and resulting material strength. Here we show a concept based on physical cross-linking of cellulose nanofibers (CNF, also denoted as microfibrillated cellulose, MFC, and, nanofibrillated cellulose, NFC) with chitosan for the aqueous preparation of films showing high mechanical strength in the wet state. Also, transparency (∼70–90% in the range 400–800 nm) is achieved by suppressing aggregation and carefully controlling the mixing conditions: Chitosan dissolves in aqueous medium at low pH and under these conditions the CNF/chitosan mixtures form easily processable hydrogels. A simple change in the environmental conditions (i.e., an increase of pH) reduces hydration of chitosan promoting multivalent physical interactions between CNF and chitosan over those with water, resulting effectively in cross-linking. Wet water-soaked films of CNF/chitosan 80/20 w/w show excellent mechanical properties, with an ultimate wet strength of 100 MPa (with corresponding maximum strain of 28%) and a tensile modulus of 4 and 14 GPa at low (0.5%) and large (16%) strains, respectively. More dry films of similar composition display strength of 200 MPa with maximum strain of 8% at 50% air relative humidity. We expect that the proposed, simple concept opens new pathways toward CNF-based material utilization in wet or humid conditions, which has still remained a challenge.
We show that composite hydrogels comprising methyl cellulose (MC) and cellulose nanocrystal (CNC) colloidal rods display a reversible and enhanced rheological storage modulus and optical birefringence upon heating, i.e., inverse thermoreversibility. Dynamic rheology, quantitative polarized optical microscopy, isothermal titration calorimetry (ITC), circular dichroism (CD), and scanning and transmission electron microscopy (SEM and TEM) were used for characterization. The concentration of CNCs in aqueous media was varied up to 3.5 wt % (i.e, keeping the concentration below the critical aq concentration) while maintaining the MC aq concentration at 1.0 wt %. At 20 °C, MC/CNC underwent gelation upon passing the CNC concentration of 1.5 wt %. At this point, the storage modulus (G′) reached a plateau, and the birefringence underwent a stepwise increase, thus suggesting a percolative phenomenon. The storage modulus (G′) of the composite gels was an order of magnitude higher at 60 °C compared to that at 20 °C. ITC results suggested that, at 60 °C, the CNC rods were entropically driven to interact with MC chains, which according to recent studies collapse at this temperature into ring-like, colloidal-scale persistent fibrils with hollow cross-sections. Consequently, the tendency of the MC to form more persistent aggregates promotes the interactions between the CNC chiral aggregates towards enhanced storage modulus and birefringence. At room temperature, ITC shows enthalpic binding between CNCs and MC with the latter comprising aqueous, molecularly dispersed polymer chains that lead to looser and less birefringent material. TEM, SEM, and CD indicate CNC chiral fragments within a MC/CNC composite gel. Thus, MC/CNC hybrid networks offer materials with tunable rheological properties and access to liquid crystalline properties at low CNC concentrations.
Background: Childhood adverse effects and traumatic experiences increase the risk for several psychiatric disorders. We now investigated whether prospectively assessed childhood family environment per se contributes to increased risk for psychotic disorders in adulthood, and whether these family patterns are also relevant in the development of affective disorders. Methods: We used the Young Finns Data (n = 3502). Childhood family environment was assessed in 1980/1983 with previously constructed risk scores: (1) disadvantageous emotional family atmosphere (parenting practices, parents' life satisfaction, parents' mental disorder, parents' alcohol intoxication), (2) adverse socioeconomic environment (overcrowded apartment, home income, parent's employment, occupational status, educational level), and (3) stress-prone life events (home movement, school change, parental divorce, death, or hospitalization, and child's hospitalization). Psychiatric diagnoses (ICD-10 classification) over the lifespan were collected up to 2017 from the national registry of hospital care. Non-affective psychotic disorder and affective disorder groups were formed. Results: Frequent stress-prone life events predicted higher likelihood of non-affective psychotic disorders (OR = 2.401, p = 0.001). Adverse socioeconomic environment or emotional family atmosphere did not predict psychotic disorders. Only disadvantageous emotional family atmosphere predicted modestly higher likelihood of affective disorders (OR = 1.583, p = 0.013). Conclusions: Our results suggest that childhood family environment and atmosphere patterns as such contribute to the risk for developing adulthood mental disorders with relative disorder specificity. The results emphasize the importance of both individual and public health preventive initiatives, including family support interventions.
Abstract In this study, lignin-based carbon nanofibers were prepared by electrospinning, followed by carbonization at four different temperatures (800, 1,000, 1,200, and 1,400°C). The surface and bulk elemental compositions were analyzed by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy, respectively. In addition, the structure of the prepared carbon nanofibers was characterized by scanning electron microscopy, transmission electron microscopy, focused ion beam microscopy, and Raman spectroscopy. Results showed that all carbon nanofibers, irrespective of the carbonization temperature, had continuous and homogeneous structures. They were dense and no phase separation was observed. Moreover, the nanofibers carbonized at 800°C or 1,000°C predominately contained amorphous carbon and some non-carbon elements. When the carbonization was performed at a higher temperature (1,200°C or 1,400°C), non-carbon elements were effectively removed and nanocrystalline graphite was formed, indicating that high temperature carbonization facilitated the formation of ordered carbon structures.
Abnormal glucose and lipid metabolism is common in antipsychotic-naive first-episode patients with schizophrenia, but it is unclear whether these changes can already be seen in premorbid or prodromal period, before the first psychotic episode. We examined insulin, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride trajectories in children and adolescents (9–18 years old), who were later diagnosed with schizophrenia, any non-affective psychosis (NAP) or affective disorder (AD). The study population consisted of a general population-based cohort “The Cardiovascular Risk in Young Finns Study”, started in 1980 (n = 3596). Psychiatric diagnoses were derived from the Health Care Register up to the year 2018. Multivariate statistical analysis indicated no significant differences in insulin or lipid levels in children and adolescents who later developed schizophrenia (n = 41) compared to the cohort control group (n = 3202). In addition, no changes in these parameters were seen in the NAP (n = 74) or AD (n = 156) groups compared to the controls, but lower triglyceride levels in childhood/adolescence associated with earlier diagnosis of psychotic disorder in the NAP group. Taken together, our results do not support any gross-level insulin or lipid changes during childhood and adolescence in individuals with later diagnosis of schizophrenia-spectrum disorder. Since changes in glucose and lipid metabolism can be observed in neuroleptic-naive patients with schizophrenia, we hypothesize that the more marked metabolic changes develop during the prodrome closer to the onset of the first psychotic episode. The findings have relevance for studies on developmental hypotheses of schizophrenia.
A strong genetic background for psychoses is well-established. Most individuals with a high genetic risk for schizophrenia, however, do not develop the disorder. We investigated whether individuals, who have a high genetic risk for schizophrenia but no non-affective psychotic disorders, are predisposed to develop milder forms of deviant thinking in terms of magical thinking. Participants came from the population-based Young Finns Study (n = 1292). The polygenic risk score for schizophrenia (PRS) was calculated on the basis of the most recent genome-wide association study (GWAS). Psychiatric diagnoses over the lifespan were collected up to 2017 from the registry of hospital care. Magical thinking was evaluated with the Spiritual Acceptance Scale (e.g., beliefs in telepathy, miracles, mystical events, or sixth sense) of the Temperament and Character Inventory in 1997, 2001, and 2012 (participants were 20–50-year-olds). We found that, among those who did not develop non-affective psychotic disorders, high PRS predicted higher magical thinking in adulthood (p = 0.001). Further, PRS predicted different developmental courses: a low PRS predicted a steady decrease in magical thinking from age 20 to 50 years, while in individuals with high PRS the decrease in magical thinking ceased in middle age so that their level of magical thinking remained higher than expected for that age. These findings remained when controlling for sex, childhood family environment, and adulthood socioeconomic factors. In conclusion, if high PRS does not lead to a non-affective psychotic disorder, it predicts milder forms of deviant thinking such as elevated magical thinking in adulthood, especially in middle age. The finding enhances our understanding of different outcomes of high genetic psychosis risk.
Background We investigated (a) whether polygenic risk for schizophrenia predicts different trajectories of social development among those who have not developed psychoses and (b) whether possible associations are PRSSCZ-specific or evident also for any polygenic risk for mental disorders, e.g. for major depression. Methods Participants came from the population-based Young Finns Study (n = 2377). We calculated a polygenic risk score for schizophrenia (PRSSCZ) and for major depression (PRSDEP). Diagnoses of psychotic disorders were derived from the hospital care register. Social development from adolescence to middle age was measured by (a) perceived social support from friends, family, and a close other, (b) perceived sociability, and (c) family structure (partnership status, number of children, age of first-time parenthood). Results Among those without manifest psychoses, high PRSSCZ predicted lower experienced support from friends (B = -0.04, p = 0.009-0.035) and family (B = -0.04, p = 0.009-0.035) especially after early adulthood, and also lower perceived sociability (B = -0.05, p = 0.010-0.026). PRSSCZ was not related to family structure. PRSDEP did not predict any domain of social development. Conclusions Individuals at high PRSSCZ (not converted to psychosis) seem to experience a lower preference to be with others over being alone. Individuals with high (v. low) PRSSCZ seem to have a similar family structure in terms of partnership status or number of children but, nevertheless, they experience less support from their family. Among those not converted to psychosis in a typical age period, high PRSSCZ may predict a 'later risk phase' and reduced functional resilience when approaching middle age.
We investigated whether individuals, who have a high polygenic loading for schizophrenia and major depression (PGL) but have not developed the respective disorders, are still susceptible to experience milder forms of ill-being in terms of job strain or exhaustion. We used the population-based Young Finns Study data (n = 928). PGL was assessed with a cumulative score of the polygenic risk scores for schizophrenia and depression. Participants (24–49-year-olds) evaluated their exhaustion levels and perceived job characteristics over a 10-year follow-up (2001, 2007, 2011). Participants with diagnosed psychotic or affective disorders were excluded. We found that high PGL did not predict less favorable perceptions of job environment (job strain, demands, control, satisfaction, social support at work) but high PGL predicted a higher trajectory of exhaustion in early adulthood and middle age. Additionally, high (vs. low) PGL predicted a stronger increase in exhaustion at increased levels of job strain. These findings remained after controlling for sex, socioeconomic factors, health behaviors, and cognitive performance. In conclusion, individuals with high PGL may have an elevated liability to experience exhaustion especially in early adulthood and middle age (despite they perceive their job environment similarly than others), and especially and at high levels of job strain.
Schizophrenia is often regarded as a disorder of premature aging. We investigated (a) whether polygenic risk for schizophrenia (PRSsch) relates to pace of epigenetic aging and (b) whether personal dispositions toward active and emotionally close relationships protect against accelerated epigenetic aging in individuals with high PRSsch. The sample came from the population-based Young Finns Study (n = 1348). Epigenetic aging was measured with DNA methylation aging algorithms such as AgeAccelHannum, EEAAHannum, IEAAHannum, IEAAHorvath, AgeAccelHorvath, AgeAccelPheno, AgeAccelGrim, and DunedinPACE. A PRSsch was calculated using summary statistics from the most comprehensive genome-wide association study of schizophrenia to date. Social dispositions were assessed in terms of extraversion, sociability, reward dependence, cooperativeness, and attachment security. We found that PRSsch did not have a statistically significant effect on any studied indicator of epigenetic aging. Instead, PRSsch had a significant interaction with reward dependence (p = 0.001–0.004), cooperation (p = 0.009–0.020), extraversion (p = 0.019–0.041), sociability (p = 0.003–0.016), and attachment security (p = 0.007–0.014) in predicting AgeAccelHannum, EEAAHannum, or IEAAHannum. Specifically, participants with high PRSsch appeared to display accelerated epigenetic aging at higher (vs. lower) levels of extraversion, sociability, attachment security, reward dependence, and cooperativeness. A rather opposite pattern was evident for those with low PRSsch. No such interactions were evident when predicting the other indicators of epigenetic aging. In conclusion, against our hypothesis, frequent social interactions may relate to accelerated epigenetic aging in individuals at risk for psychosis. We speculate that this may be explained by social-cognitive impairments (perceiving social situations as overwhelming or excessively arousing) or ending up in less supportive or deviant social groups.