Coming theses from other universities
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Physical activity in children and effects of maturation on exercise : with reference to training, biomarkers, anthropometrical factors, and methods
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-233054
Background: Regular physical activity during childhood and adolescence can positively affect overall cardiometabolic health, fundamental motor skill development, bone density, quality of life, and psychological well-being. Research on physical activity in children is growing continuously, and one area is focused on assessing children's physical activity. Advances in wearable technology have provided more reliable tools for assessing physical activity, particularly in young children. These wearables must be calibrated to age-specific groups, body positions, and epoch times. Furthermore, muscle strength is an important health indicator in children; however, little is known about how muscle strength is influenced by age, maturity, hormones, and cytokines in pediatric populations. This thesis aimed to examine methods to estimate physical activity in children, understand which factors are associated with muscular strength in trained male children, and increase our understanding of how exercise-related hormones and proinflammatory cytokines (IL-6 and TNF-α) adapt to acute and long-term training.
Methods: This thesis included four studies. Paper I aimed to calibrate two accelerometer devices, MotionWatch 8 (MW8) and ActiGraph GT3X ( GT3X), worn on the hip and wrist (n = 30), and to develop age-specific cut-offs for physical activity intensities in 3-year-old children. Paper II was a cross-sectional study that examined the associations of muscular strength measures with anthropometric factors, chronological age, maturation, and training experience in trained prepubertal and pubertal males (n = 41). Another aim of Paper II was to examine whether a handgrip strength test can predict the total muscle strength assessed with whole-body free-weight exercises. Paper III was an intervention study that examined acute hormonal and cytokine responses to free-weight resistance training in trained prepubertal and pubertal male children (n = 41). Paper IV was a systematic review and meta-analysis that assessed the evidence of the effects of exercise training and training type on hormone and cytokine adaptations in children and adolescents.
Results: There was a strong correlation between MW8 and the GT3X device (counts/30 s) at both hip and wrist levels (Paper I). The devices' cut-off scores for physical activity levels were classified with outstanding and excellent accuracy (Paper I). The cross-sectional study showed that muscular strength tests in trained male children are mostly associated with anthropometric factors, which differ depending on the exercise test chosen (Paper II). Furthermore, the handgrip strength test was strongly associated with total muscle strength in trained male children (Paper II). A single resistance training session induced greater acute post-exercise testosterone and IGF-I levels in pubertal children than in prepubertal male children (Paper III). Post-exercise IL-6 levels were significantly increased only in the prepubertal group. Lastly, the systematic review and meta-analysis showed that long-term exercise training had a small effect on resting hormonal concentrations. Resistance training, but not endurance training, increased resting testosterone levels in healthy children and adolescents (Paper IV).
Conclusions: Measuring and classifying physical activity levels in preschoolers can be achieved accurately using MW8 or the GT3X device (Paper I). Another finding was that anthropometric measures such as body mass and fat-free mass are important factors associated with muscle strength, and they may be used to scale muscle strength scores to provide a fair interpretation across children of different body sizes (Paper II). A simple handgrip strength test could be a quick and effective screening tool for practitioners and researchers to estimate total muscle strength in trained male children (Paper II). Furthermore, pubertal children were stronger than prepubertal children and had greater post-exercise IGF-I and testosterone responses following a single resistance training session (Paper III). Finally, the systematic review and meta-analysis suggested that exercise training had a small effect on hormonal concentrations in healthy children and adolescents (Paper IV).
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Optimized prediction of mortality by use of register-based information in an intensive care unit population
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-543744
The primary objective of this thesis was to explore the importance of comorbidity for long-term survival following admission to the intensive care unit (ICU). By use of routinely collected laboratory biomarkers and by utilising a more detailed analysis of the patient’s hospital discharge history, we aim to challenge traditional risk prediction models and measures of comorbidity. We also apply the more comprehensive prediction model to understand how preexisting comorbidities may interact with a critical illness in older ICU patients and compare long-term mortality with the general population. Finally, we aim to understand the importance of comorbidity in relation to socioeconomic status (SES) when the measurement of comorbidity is optimised.
The study was performed by linking data from the Swedish Intensive Care Register (SIR), a hospital clinical laboratory database and several national public authority registers. Routinely collected laboratory biomarkers and quantitative comorbidity measures were compared in Cox regression models adjusting for age, sex and baseline comorbidities with Charlson Comorbidity Index (CCI) and the Simplified Acute Physiology Score (SAPS) version 2 or 3. The mortality in older ICU patients was then compared with individuals from the general population with a landmark of one year. Also, associations between socioeconomic factors and mortality were estimated by using Cox regression models adjusting for age, sex, SAPS3 and baseline comorbidity.
Routinely collected biomarkers discriminate both short- and long-term mortality in general ICU patients, almost as well as the SAPS II. The more comprehensive comorbidity prediction model provides a separation of risk categories within strata of age, the CCI, and intermediate SAPS3 strata. Older patients admitted to the ICU, and who survive the first year after an ICU admission, return to close to the mortality rate of the general population having similar comorbidity. Low educational level was associated with an increased long-term mortality rate after ICU admission. In a Landmark analysis, the association was weaker during the first year after ICU admission than after the first year, suggesting that risk factors other than those specifically related to ICU admission may be important.
By utilising extensive population-based data, the project contributes to the development of methods within registry-based epidemiological research. The importance of specific comorbidities in defined subgroups of intensive care patients should be of interest not only to intensive care specialists but also in a broader healthcare perspective.
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Wireless optical and electrical sensors, and combinations thereof, for biomedical applications
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-72794
The studies explore advancements in wireless sensor technologies for medical applications, particularly for wireless detection of skin hydration, non-invasive glucose monitoring, and microbial detection. The first academic paper describes a capacitive humidity sensor for assessing relative humidity and skin hydration, utilizing the sensitive dielectric properties of the monoolein–water system. Tested across various humidity levels and temperatures, these novel double-functional sensors feature interdigitated electrodes covered with monoolein and show a promising potential for wireless detection of skin hydration. The second and third academic papers focus on a wireless potentiometric sensor designed to detect bacteria in urine and monitor microbial biofilm formation in wounds, respectively, using Bluetooth-enabled sensors to detect bacterial growth in vitro and ex vivo. The fourth paper assesses the development of fluid-less, non-invasive blood glucose monitoring devices, comparing their accuracy and challenges with traditional invasive methods. Despite some improvements, the study reveals that current devices like the BG20 glucometer need significant enhancements to meet clinical accuracy standards. Overall, the thesis emphasizes the potential of innovative wireless sensor technologies in improving medical diagnostics, while also addressing the limitations that must be overcome to ensure clinical reliability.