364 research outputs found
Understanding the interactions of cellulose fibres and deep eutectic solvent of choline chloride and urea
This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.A deep eutectic solvent composed of choline chloride (ChCl) and urea has been recently introduced as a promising cellulose compatible medium that enables e.g. fibre spinning. This paper clarifies the influence of such a solvent system on the structure and chemical composition of the cellulosic pulp fibres. Special emphasis was placed on the probable alterations of the chemical composition due to the dissolution of the fibre components and/or due to the chemical derivatisation taking place during the DES treatment. Possible changes in fibre morphology were studied with atomic force microscopy and scanning electron microscopy. Chemical compositions of pulp fibres were determined from the carbohydrate content, and by analysing the elemental content. Detailed structural characterisation of the fibres was carried out using spectroscopic methods; namely X-Ray Photoelectron Spectroscopy, solid state Nuclear Magnetic Resonance and Raman Spectroscopy. No changes with respect to fibre morphology were revealed and negligible changes in the carbohydrate composition were noted. The most significant change was related to the nitrogen content of the pulp after the DES treatment. Comprehensive examination using spectroscopic methods revealed that the nitrogen originated from strongly bound ChCl residuals that could not be removed with a mild ethanol washing procedure. According to Raman spectroscopic data and methylene blue adsorption tests, the cationic groups of ChCl seems to be attached to the anionic groups of pulp by electrostatic forces. These findings will facilitate the efficient utilisation of DES as a cellulose compatible medium without significantly affecting the native fibre structure.The authors acknowledge the Finnish Funding Agency for Innovation (TEKES) for funding the work via Design Driven Value Chains in the World of Cellulose 2.0 project. The Academy of Finland (Project ID 300367) is acknowledged for enabling the research mobility of T.T. to the University of Exeter, UK. Unto Tapper (VTT) is thanked for the SEM imaging, Atte Mikkelson, Ritva Heinonen and Marita Ikonen (VTT) for the chemical analysis and Robertus Nugroho (Aalto University) for the AFM imaging
Winter climate signal in boreal clastic-biogenic varves: a comprehensive analysis of three varved records from 1890 to 1990 AD with meteorological and hydrological data from Eastern Finland
Varve Distribution Reveals Spatiotemporal Hypolimnetic Hypoxia Oscillations During the Past 200 Years in Lake Lehmilampi, Eastern Finland
We investigated 34 sediment cores to reconstruct spatiotemporal variations in hypolimnetic hypoxia for the past 200 years in Lehmilampi, a small lake in Eastern Finland. As hypoxia is essential for varve preservation, spatiotemporal changes in varve distribution were used as an indicator for hypolimnetic hypoxia oscillations. The hypoxic water volume was used as a variable reflecting hypolimnetic hypoxia and determined for each year by estimating the water volume beneath the water depth where shallowest varves were preserved. As a result, seven hypoxia periods, highlighting the variations in hypolimnetic hypoxia, are established. These periods may be influenced by bioturbation, lake infill, and lake level changes. Furthermore, we evaluated the relationship between hypolimnetic hypoxia oscillations and climatic factors. Diatom assemblage changes were also analyzed to estimate whether the hypoxia periods could be related to anthropogenic eutrophication. The diatom analyses suggest relatively stable nutrient conditions for the past 200 years in Lake Lehmilampi. Climate, on the other hand, seems to be an important driver of hypoxia oscillations based on correlation analysis. The role of individual forcing factors and their interaction with hypolimnetic hypoxia would benefit from further investigations. Understanding climatic and anthropogenic forcing behind hypolimnetic hypoxia oscillations is essential when assessing the fate of boreal lakes in a multi-stressor world.</p
Changes in BMI and physical activity from youth to adulthood distinguish normal-weight, metabolically obese adults from those who remain healthy
Highlights: Adults with MONW have a lower BMI during youth until young adulthood, but higher BMI after this than adults with metabolically healthy normal weight. Adults with MONW have a greater decrease in physical activity from youth to adulthood than other adults. Healthy lifestyle is important in the prevention of metabolic disorders, particularly in individuals who are slim in childhood. Background: Individuals with metabolically obese normal-weight (MONW) have higher risk of cardiovascular events than those with obesity but a metabolically healthy status. Etiological factors leading to MONW are not well known. We hypothesized distinct trajectories of changes in BMI and physical activity may modify metabolic risk and distinguish individuals with MONW from those who remain healthy. Methods: We compared the mean levels of BMI and physical activity at eight time points (1980, 1983, 1986, 1989, 1992, 2001, 2007, 2011) between MONW and healthy normal-weight adults using linear mixed-model analysis. The analyses included 1180 participants of the Cardiovascular Risk in Young Finns study, a population-based study that represents six different age cohorts 3, 6, 9, 12, 15 and 18 years of age at baseline. Results: Individuals with adult MONW had significantly lower BMI in childhood and young adulthood, but their BMI increased more than in other adults after this age (p<0.001for interaction between time and MONW status). Physical activity decreased relatively more since youth in individuals with adult MONW (p<0.001). Conclusions: Relative leanness in youth and subsequent weight gain in young adulthood, and a gradual decrease in physical activity levels from youth to adulthood, predispose normal-weight individuals to metabolic impairments. The results highlight the importance of a healthy lifestyle in the prevention of metabolic disorders, particularly in individuals who are slim in childhood.publishedVersionPeer reviewe
The association between physical fitness and depressive symptoms among young adults: results of the Northern Finland 1966 birth cohort study
Background The effect of physical activity on mental health has been the subject of research for several decades. However, there is a lack of studies investigating the association between physical fitness, including both cardiorespiratory and muscular fitness and depressive symptoms among general population. The aim of this study was to determine the association between physical fitness and depressive symptoms among young adults. Methods The study population consists of 5497 males and females, members of the Northern Finland birth cohort of 1966, who at age 31 completed fitness tests and filled in a questionnaire including questions about depressive symptoms (Hopkins’ Symptom Checklist-25) and physical activity. Cardiorespiratory fitness was measured by a 4-min step test and muscular fitness by tests of maximal isometric handgrip and isometric trunk extension. The odds ratios (OR) with 95% confidence intervals (95% CI) for having depressive symptoms were calculated for quintiles groups of physical fitness using the third, median quintile as reference group, and the results were adjusted for potential confounding variables. Results Depressive symptoms were most common among males and females in the lowest quintile group of trunk extension test (OR 1.58 and 95% CI 1.07-2.32 in males and OR 1.43 and 95% CI 1.03-2.0 in females) and among males in the lowest quintile group of handgrip strength (OR 1.64 95% CI 1.11-2.42) compared to the reference group. Level of self-reported physical activity was inversely associated with depressive symptoms both in males (OR 1.74 95% CI 1.25-2.36) and females (OR 1.36 95% CI 1.05-1.75). The cardiorespiratory fitness was not associated with depressive symptoms (OR 1.01 95% CI 0.68-1.49 in males and 0.82 95% CI 0.57-1.16 in females). Conclusions The results indicate that low level of isometric endurance capacity of trunk extensor muscles is associated with high level of depressive symptoms in both sexes. In males, also poor handgrip strength is associated with increased levels of depressive symptoms. The physical activity level is inversely associated with the prevalence of depressive symptoms among young adults
Nanocellulose: Recent Fundamental Advances and Emerging Biological and Biomimicking Applications
In the e'ort toward sustainable advanced functional materials, nanocellu- loses have attracted extensive recent attention. Nanocelluloses range from rod-like highly crystalline cellulose nanocrystals to longer and more entan- gled cellulose nanofibers, earlier denoted also as microfibrillated celluloses and bacterial cellulose. In recent years, they have spurred research toward a wide range of applications, ranging from nanocomposites, viscosity modi- fiers, films, barrier layers, fibers, structural color, gels, aerogels and foams, and energy applications, until filtering membranes, to name a few. Still, nanocelluloses continue to show surprisingly high challenges to master their interactions and tailorability to allow well-controlled assemblies for functional materials. Rather than trying to review the already extensive nanocellulose literature at large, here selected aspects of the recent progress are the focus. Water interactions, which are central for processing for the functional proper- ties, are discussed first. Then advanced hybrid gels toward (multi)stimuli responses, shape-memory materials, self-healing, adhesion and gluing, bio- logical sca'olding, and forensic applications are discussed. Finally, composite fibers are discussed, as well as nanocellulose as a strategy for improvement of photosynthesis-based chemicals production. In summary, selected per- spectives toward new directions for sustainable high-tech functional mate- rials science based on nanocelluloses are described. </div
Associations of Physical Activity and Sedentary Behavior With Adolescent Academic Achievement
The Northern Finland Birth Cohort 1986 (N = 8,061) was used to investigated the joint associations of physical activity and sedentary behavior with academic achievement. Logistic regression analysis was used to evaluate how classes formed by latent class analysis (LCA) according to overall physical activity, sports club membership, viewing TV, using a computer, reading books and magazines, other sedentary activities, and sleep were associated with grade-point average. When adjusted for gender, self-rated health, and mother's education, physically active adolescents and generally active adolescents were about twice as likely to have high grade-point average compared with sedentary TV viewers.Peer reviewe
Life-course leisure-time physical activity trajectories in relation to health-related behaviors in adulthood : the Cardiovascular Risk in Young Finns study
BackgroundEvidence on whether leisure-time physical activity (LTPA) facilitates individuals' adoption of multiple healthy behaviors remains scarce. This study investigated the associations of diverse longitudinal LTPA trajectories from childhood to adulthood with diet, screen time, smoking, binge drinking, sleep difficulties, and sleep duration in adulthood.MethodsData were drawn from the Cardiovascular Risk in Young Finns Study. Participants were aged 9-18years (N=3553; 51% females) in 1980 and 33-49years at the latest follow-up in 2011. The LTPA trajectories were identified using a latent profile analysis. Differences in self-reported health-related behaviors across the LTPA trajectories were studied separately for women and men by using the Bolck-Croon-Hagenaars approach. Models were adjusted for age, body mass index, education level, marital status, total energy intake and previous corresponding behaviors.ResultsPersistently active, persistently low-active, decreasingly and increasingly active trajectories were identified in both genders and an additional inactive trajectory for women. After adjusting the models with the above-mentioned covariates, the inactive women had an unhealthier diet than the women in the other trajectories (p0.50). The low-active men followed an unhealthier diet than the persistently and increasingly active men (p0.50). Compared to their inactive and low-active peers, smoking frequency was lower in the increasingly active women and men (p0.20) and persistently active men (p0.20). The increasingly active men reported lower screen time than the low-active (p0.50) and persistently active (p0.20) men. The increasingly and persistently active women reported fewer sleep difficulties than the inactive (p0.80) and low-active (p0.50 and>0.80, respectively) women. Sleep duration and binge drinking were not associated with the LTPA trajectories in either gender, nor were sleep difficulties in men and screen time in women.ConclusionsNot only persistently higher LTPA but also an increasing tendency to engage in LTPA after childhood/adolescence were associated with healthier diet and lower smoking frequency in both genders, having less sleep difficulties in women and lower screen time in increasingly active men. Inactivity and low activity were associated with the accumulation of several unhealthy behaviors in adulthood. Associations were stronger in women.Peer reviewe
Changes in BMI and physical activity from youth to adulthood distinguish normal-weight, metabolically obese adults from those who remain healthy
HighlightsAdults with MONW have a lower BMI during youth until young adulthood, but higher BMI after this than adults with metabolically healthy normal weight. Adults with MONW have a greater decrease in physical activity from youth to adulthood than other adults. Healthy lifestyle is important in the prevention of metabolic disorders, particularly in individuals who are slim in childhood.BackroundIndividuals with metabolically obese normal-weight (MONW) have higher risk of cardiovascular events than those with obesity but a metabolically healthy status. Etiological factors leading to MONW are not well known. We hypothesized distinct trajectories of changes in BMI and physical activity may modify metabolic risk and distinguish individuals with MONW from those who remain healthy.MethodsWe compared the mean levels of BMI and physical activity at eight time points (1980, 1983, 1986, 1989, 1992, 2001, 2007, 2011) between MONW and healthy normal-weight adults using linear mixed-model analysis. The analyses included 1180 participants of the Cardiovascular Risk in Young Finns study, a population-based study that represents six different age cohorts 3, 6, 9, 12, 15 and 18 years of age at baseline.ResultsIndividuals with adult MONW had significantly lower BMI in childhood and young adulthood, but their BMI increased more than in other adults after this age (pConclusionsRelative leanness in youth and subsequent weight gain in young adulthood, and a gradual decrease in physical activity levels from youth to adulthood, predispose normal-weight individuals to metabolic impairments. The results highlight the importance of a healthy lifestyle in the prevention of metabolic disorders, particularly in individuals who are slim in childhood.</p
Associations of parental physical activity trajectories with offspring's physical activity patterns from childhood to middle adulthood : The Young Finns Study
Peer reviewe
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