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PURPOSE OF REVIEW: The gold standard for diagnosis and treatment of obstructive sleep apnea (OSA) is attended overnight polysomnography (PSG) in a sleep laboratory. Alternative diagnostic techniques are urgently needed for both diagnosis and treatment control when initiating positive airway pressure (PAP) in the home setting. Current PAP devices compute data such as residual AHI (apnea-hypopnea index) using their proprietary algorithms to provide an automatic event detection (AED). It was suggested that these should be labeled AHIFLOW. RECENT FINDINGS: The current study situation shows an acceptable agreement with the tendency of mildly overestimating the AHI by the PAP devices. But, the literature is still limited in terms of accuracy, especially when considering the lack of standardization and different detection algorithms. SUMMARY: A validation of PAP devices regarding the agreement of AHIFLOW compared to AHIPSG is extremely important, given that the device analysis is exclusively based on the measured flow. There are considerable concerns about assessing the PAP effectiveness in higher risk groups based on the AED function alone. Given these reservations, the use of PAP event detection can be an important addition to the diagnostic spectrum and, in combination with telemonitoring, offers promising potential.
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BACKGROUND: Pediatric headache is an increasing medical problem that has adverse effects on children's quality of life, academic performance, and social functioning. Children with primary headaches exhibit enhanced sensory sensitivity compared to their healthy peers. However, comprehensive investigations including multimodal sensory sensitivity assessment are lacking. This study aimed to compare sensory sensitivity of children with primary headaches with their healthy peers across multiple sensory domains. METHODS: The study included 172 participants aged 6 to 17 years (M = 13.09, SD = 3.02 years; 120 girls). Of these 80 participants were patients with migraine, 23 were patients with tension-type headache, and 69 were healthy controls. The following sensory measures were obtained: Mechanical Detection Threshold (MDT), Mechanical Pain Threshold (MPT), Mechanical Pain Sensitivity (MPS), detection and pain threshold for Transcutaneous Electrical Nerve Stimulation (TENS), olfactory and intranasal trigeminal detection threshold, and odor identification ability. Sensory sensitivity was compared between groups with a series of Kruskal-Wallis tests. Binomial regression models were used to compare the relative utility of sensory sensitivity measures in classifying participants into patients and healthy controls, as well as into patients with migraine and tension-type headache. RESULTS: Patients with migraine had lower MPT measured at the forearm than patients with tension-type headaches and healthy controls. MPS was higher in patients with migraine than in healthy controls. All patients with headaches had lower detection threshold of TENS and higher olfactory sensitivity. Healthy controls showed increased intranasal trigeminal sensitivity. Scores in MPS, TENS, and olfactory and trigeminal thresholds were significantly predicting presence of primary headaches. Additionally, scores in MPT, olfactory and trigeminal threshold were positive predictors of type of headache. CONCLUSIONS: Children with primary headaches exhibit different sensory profiles than healthy controls. The obtained results suggest presence of increased overall, multimodal sensitivity in children with primary headaches, what may negatively impact daily functioning and contribute to further pain chronification. TRIAL REGISTRATION: The study was registered in the German Registry of Clinical Trials (DRKS) DRKS00021062.
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Migraine Disorders , Pain Threshold , Tension-Type Headache , Humans , Adolescent , Female , Male , Child , Tension-Type Headache/physiopathology , Tension-Type Headache/diagnosis , Migraine Disorders/physiopathology , Migraine Disorders/diagnosis , Pain Threshold/physiology , Sensory Thresholds/physiology , Headache Disorders, Primary/physiopathology , Headache Disorders, Primary/diagnosisABSTRACT
BACKGROUND: Women living in high-quality healthcare systems are more likely to use oral contraceptives at some point in their lives. Research findings have sparked controversial discussions about contraception in the scientific community and the media, potentially leading to higher rates of method discontinuation. Understanding the underlying motives for method discontinuation is crucial for reproductive health equity and future programming interventions. To address this question, this study aims to explore women's experiences of oral contraceptive use and discontinuation on YouTube. METHODS: A concurrent explanatory mixed-methods design was used to conduct content analysis of German YouTube videos. The information from 175 videos of 158 individuals was extracted through quantitative descriptive content analysis. Twenty-one individuals were included in the qualitative content analysis. FINDINGS: The body was a recurring theme in the pill biographies. Women described, for example, bodily sensations as reasons for taking and stopping the pill. They also described positive and negative side effects while taking the pill and after stopping. The most common side effects of taking the pill mentioned by YouTubers were mood swings (76/158), weight gain (45/158), headaches (33/158), and depressed mood (45/158). The symptoms after discontinuation reported most were facial skin impurities (108/158), decreased mood swings (47/158), hair loss (42/158), and weight loss (36/158). Overall, women overwhelmingly rated their discontinuation experience as positive (87/91). CONCLUSIONS: The study identified key symptoms of oral contraceptive initiation and discontinuation by portraying the experiences of female YouTubers, adding valuable insights to the understanding of method initiation and discontinuation. Further research is needed to explore women's personal experiences with method discontinuation beyond the YouTube platform.
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Contraceptives, Oral , Social Media , Humans , Female , Adult , Young Adult , Video Recording , Adolescent , Contraception Behavior/psychology , Contraception Behavior/statistics & numerical data , Middle AgedABSTRACT
Manganese antimonate (MnySb1-yOx) electrocatalysts for the oxygen-evolution reaction (OER) were synthesized via chemical vapor deposition. Mn-rich rutile Mn0.63Sb0.37Ox catalysts on fluorine-doped tin oxide (FTO) supports drove the OER for 168 h (7 days) at 10 mA cm-2 with a time-averaged overpotential of 687 ± 9 mV and with >97% Faradaic efficiency. Time-dependent anolyte composition analysis revealed the steady dissolution of Mn and Sb. Extended durability analysis confirmed that Mn-rich MnySb1-yOx materials are more active but dissolve at a faster rate than previously reported Sb-rich MnySb1-yOx alloys.
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Background: Health Behaviour in School-aged Children (HBSC) is one of the largest international studies on child and adolescent health and cooperates with the World Health Organization (WHO). In Germany, adolescents aged 11, 13 and 15 are surveyed every four years about their health, health behaviour and social conditions. This article describes the HBSC study and in particular the methodology of the current 2022 survey and prior surveys conducted between 2009/10 and 2017/18. Method: 174 schools with a total of 6,475 students participated in the 2022 survey. The survey was conducted using questionnaires and covered a wide range of topics (including mental health, physical activity, bullying experiences, social determinants of health and experiences related to COVID-19). The 2022 survey was complemented by a school principal survey (N = 160). In addition to the current sample, the samples of the three previous surveys with representative data for Germany are presented: 2009/10 (N = 5,005), 2013/14 (N = 5,961) and 2017/18 (N = 4,347). Discussion: The health of children and adolescents is of great public health importance. The HBSC study makes a substantial contribution by providing internationally comparable results, analysing trends, and providing stakeholders with comprehensive and representative health monitoring data.
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BACKGROUND: In 2001, the International Classification of Functioning and Disability (ICF) introduced participation as a main goal of rehabilitation processes. However, to date, a comprehensive concept of participation in the rehabilitative context is missing, particularly in German-speaking countries. We thus aimed to refine and extend the existing concepts of participation in this brief communication. METHODS: In preceding studies, we conducted semi-structured interviews with adolescents who either had chronic diseases and/or physical disabilities or had no impairments and focus groups with parents and experts. Based on these diverse perspectives and findings, we refine the term participation. RESULTS: Participation is a construct that is embedded in a social context and consists of objective (i.e., attendance) and subjective (i.e., satisfaction and involvement) dimensions. These dimensions are reflected in different domains and areas that are relevant to adolescents' lives. In addition, the subjective relevance of respective areas in life needs to be regarded as a weighing component when evaluating participation. CONCLUSION: Our results reflect international models on participation, refine the existing concept, and underline the multidimensional character of participation. These findings are urgently needed to develop appropriate instruments, for example, for assessing whether rehabilitative processes are effective regarding the goal of participation.
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Concept Formation , Disabled Persons , Humans , Adolescent , Disabled Persons/rehabilitation , Social Environment , Focus Groups , Chronic Disease , International Classification of Functioning, Disability and Health , Disability EvaluationABSTRACT
INTRODUCTION: People suffering from substance use disorders often live in social contexts with children or are parents themselves. Addicted parents show specific substance-related problems while raising their children, which often leads to various lifelong consequences for the children. The German rehabilitative treatment system allows bringing children to inpatient treatment centres. This mixed-methods study evaluates a newly developed intervention, called 'KontextSucht' or 'AddictionContext', for parents in rehabilitation treatment centres concerning the effectiveness of the intervention in parenting and abstinence outcome. METHODS AND ANALYSIS: The study uses a two-stage parallel mixed-methods design. A feasibility study (stage 1) and a benefit assessment (stage 2) will be conducted to evaluate the intervention. Both parts of the study will be carried out with qualitative and quantitative work packages. German-speaking parents of children 0-14 years will be included in this study. Qualitative data will be analysed using qualitative content analyses, whereas quantitative data will be analysed descriptively using regression analysis as well as linear mixed models. ETHICS AND DISSEMINATION: All participants will receive detailed information on the study and sign informed consent before data collection. The research team has obtained the approval of the Ethical Review Committee at the Technical University of Munich in Germany and will follow all legislation rules regarding data protection. The study results will be published in peer-reviewed national and international journals. Furthermore, the study results will be included in an intervention manual distributed to treatment centres. TRIAL REGISTRATION NUMBER: DRKS00030950.
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Parents , Substance-Related Disorders , Child , Humans , Germany , Parenting , Clinical Trials as Topic , AdultABSTRACT
BACKGROUND: In Germany, various preventive services are offered to children and adolescents. These include regular standardized examinations (so called U/J examinations) and several vaccinations. Although strongly recommended, most of them are not mandatory. Our aim is to identify factors associated with the use of U/J examinations and vaccination against diphtheria, hepatitis B, Hib, pertussis, polio, and tetanus. While previous research has focused on sociodemographic factors, we also include socioeconomic, behavioral, and psychosocial factors. METHODS: We analyzed cross-sectional data from 15,023 participants (aged 0-17 years) of the nationwide representative KiGGS Wave 2 Survey. Participation in U/J examinations was assessed using a questionnaire, filled out by participants and/or their parents. Information on vaccination status was drawn from the participants' vaccination booklets. To identify relevant determinants for the use of preventive examinations and vaccinations, unadjusted and adjusted logistic regression models were employed with up to 16 different independent variables. RESULTS: Various independent variables showed an association with the use of preventive services. Higher socioeconomic status, absence of migration background, and lower household size were associated with significantly higher utilization of U examinations. Parents' marital status, area of residence, behavioral and psychosocial factors yielded insignificant results for most U/J examinations. Higher vaccination rates were found for children with no migration background, with residence in eastern Germany, lower household size, and with married parents. CONCLUSION: This study attempted to depict the influence of sociodemographic, psychosocial, and behavioral factors on the use of several preventive services. Our results indicate that predominantly sociodemographic variables influence the use of preventive services. Further efforts should be made to investigate the interplay of different determinants of healthcare use in children and adolescents.
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Preventive Health Services , Vaccination , Child , Humans , Adolescent , Cross-Sectional Studies , Surveys and Questionnaires , Delivery of Health CareABSTRACT
INTRODUCTION: Rates of incapacity to work due to mental disorders have increased in many European countries. The consequences of persistent stress can impact individuals' physical and psychological well-being and gradually develop into chronic stress. Mental disorders or symptoms of burn-out syndrome can have severe consequences. Mental disorders leading to work incapacity significantly burden the health system. Prevention interventions can protect against burn-out, depression, anxiety and other mental health disorders. Digital health is a promising approach to increase the utilisation of effective prevention interventions. This mixed-methods study evaluates a newly developed app-supported psychosocial prevention intervention called 'RV Fit Mental Health' to strengthen participation in working life. METHODS AND ANALYSIS: The study uses a three-stage parallel mixed-methods design. This study accompanies the development (stage 1), piloting (stage 2) and evaluation (stage 3) of the new intervention. Within the stages, there is a quantitative as well as a qualitative research strand. Employed persons with an incipient mental disorder will be included. Additionally, experts within the project or connected areas will be included. Quantitative data will be analysed using multifactorial variance analyses in a pre-post design. Qualitative data will be analysed using qualitative content analysis. The study is a comprehensive research approach to investigate the development, piloting and evaluation of an app-supported psychosocial app-based prevention intervention. The rigour of the study will be achieved through data triangulation. ETHICS AND DISSEMINATION: All participants will receive detailed study information and give written informed consent before data collection. Ethical approval was obtained from the Technical University of Munich Ethics Committee. All data collection will follow all legislative rules regarding data protection, also following the Declaration of Helsinki. The study results will be disseminated in peer-reviewed journals and presented at international conferences. TRIAL REGISTRATION NUMBERS: DRKS00030818 and DRKS00033080.
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Mobile Applications , Psychotic Disorders , Humans , Mental Health , Anxiety , Research DesignABSTRACT
Research suggests that children of low-educated parents face greater health burdens during the passage from adolescence to young adulthood, as they are more likely to become low-educated themselves, establish behavioural and psychosocial disadvantages, or being exposed to unhealthy working conditions. However, studies examining the development and drivers of health inequalities during this particular life stage are limited in number and have produced varied results. This study investigates trajectories of self-rated health and overweight from 14 to 25 years of age, stratified by parental education, and explores the role of potential mediators (educational achievement, health behaviours, psychosocial factors, working conditions). We rely on prospective cohort data from the National Educational Panel Study (NEPS), a representative sample of 14,981 German ninth graders interviewed yearly from 2011 to 2021 (n = 90,096 person-years). First, we estimated random-effects growth curves for self-rated health and overweight over participants' age and calculated the average marginal effect of high versus low parental education. Second, a series of simulation-based mediation analyses were performed to test how much of health inequalities were explained by children's educational attainment (years of school education, years in university), health behaviours (smoking, alcohol, physical inactivity), psychosocial factors (number of grade repetitions, years in unemployment, chronic stress, self-esteem) and working conditions (physical and psychosocial job demands). We accounted for potential confounding by controlling for age, sex, migration background, residential area, household composition, and interview mode. Results show that higher parental education was related to higher self-rated health and lower probabilities of being overweight. Interaction between parental education and age indicated that, after some equalisation in late adolescence, health inequalities increased in young adulthood. Furthermore, educational attainment, health behaviours, psychosocial factors, and early-career working conditions played a significant role in mediating health inequalities. Of the variables examined, the level of school education and years spent in university were particular strong mediating factors. School education accounted for around one-third of the inequalities in self-rated health and one-fifth of the differences in overweight among individuals. Results support the idea that the transition to adulthood is a sensitive period in life and that early socio-economic adversity increases the likelihood to accumulate health disadvantages in multiple dimensions. In Germany, a country with comparatively low educational mobility, intergenerational continuities in class location seem to play a key role in the explanation of health inequalities in youth.
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Overweight , Parents , Child , Humans , Adolescent , Young Adult , Adult , Overweight/epidemiology , Prospective Studies , Educational Status , Parents/education , Health Inequities , Socioeconomic FactorsABSTRACT
Photoelectrochemical CO2 reduction (CO2R) is an appealing solution for converting carbon dioxide into higher-value products. However, CO2R in aqueous electrolytes suffers from poor selectivity due to the competitive hydrogen evolution reaction that is dominant on semiconductor surfaces in aqueous electrolytes. We demonstrate that functionalizing gold/p-type gallium nitride devices with a film derived from diphenyliodonium triflate suppresses hydrogen generation from 90% to 18%. As a result, we observe increases in the Faradaic efficiency and partial current density for carbon monoxide of 50% and 3-fold, respectively. Furthermore, we demonstrate through optical absorption measurements that the molecular film employed herein, regardless of thickness, does not affect the photocathode's light absorption. Altogether, this study provides a rigorous platform for elucidating the catalytic structure-property relationships to enable engineering of active, stable, and selective materials for photoelectrochemical CO2R.
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BACKGROUND: In addition to erectile dysfunction, urinary incontinence is the most common functional limitation after radical prostatectomy (RPE) for prostate cancer (PCa). The German S3 guideline recommends informing patients about possible effects of the therapy options, including incontinence. However, only little data on continence from routine care in German-speaking countries after RPE are currently available, which makes it difficult to inform patients. OBJECTIVE: The aim of this work is to present data on the frequency and severity of urinary incontinence after RPE from routine care. MATERIALS AND METHODS: Information from the PCO (Prostate Cancer Outcomes) study is used, which was collected between 2016 and 2022 in 125 German Cancer Society (DKG)-certified prostate cancer centers in 17,149 patients using the Expanded Prostate Cancer Index Composite Short Form (EPIC-26). Changes in the "incontinence" score before (T0) and 12 months after RPE (T1) and the proportion of patients who used pads, stratified by age and risk group, are reported. RESULTS: The average score for urinary incontinence (value range: 0-worst possible to 100-best possible) was 93 points at T0 and 73 points 12 months later. At T0, 97% of the patients did not use a pad, compared to 56% at T1. 43% of the patients who did not use a pad before surgery used at least one pad a day 12 months later, while 13% use two or more. The proportion of patients using pads differs by age and risk classification. CONCLUSION: The results provide a comprehensive insight into functional outcome 12 months after RPE and can be taken into account when informing patients.
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Erectile Dysfunction , Prostatic Neoplasms , Urinary Incontinence , Male , Humans , Urinary Incontinence/epidemiology , Erectile Dysfunction/epidemiology , Prostatic Neoplasms/surgery , Prostatectomy/adverse effectsABSTRACT
BACKGROUND: Girls and women are more frequently affected by headache than boys and men. The influence of gender on the effectiveness of headache therapies has so far been hardly investigated. We examined gender differences in the outpatient multimodal Dresden Child and Adolescent Headache Program DreKiP. METHODS: We treated 140 patients with primary headache in a 15-hour structured group program. At baseline (T0) and six (T1) and twelve months (T2) after the end of the program, data on headache-related limitation of daily activities (PedMIDAS) as well as headache frequency, intensity, and pain-related disability (P-PDI) were collected. Retrospectively, these data were analyzed separately for girls and boys. RESULTS: For 91 patients (9-19 years, medianâ¯= 15; 71.4â¯% female) data were available for at least two measurement time points. Girls showed significantly higher headache frequency than boys at all time points (median headache days/last three months at T0: â 43, â 20; T1: â 32, â 12; T2: â 28, â 9) as well as numerically higher headache-related limitation of daily life. There were significant effects over time with a decrease in headache frequency (F (2.88)â¯= 5.862; pâ¯= 0.004) and improvement in daily functioning (F (2.92)â¯= 5.340; pâ¯= 0.006). There was no gender-specific treatment response. DISCUSSION: The DreKiP therapy shows effects in girls and boys with primary headache. Higher headache frequencies and everyday life restrictions in girls may have hormonal but also psychosocial causes and should be addressed in educational measures.
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Headache , Pain , Male , Child , Humans , Female , Adolescent , Retrospective Studies , Headache/therapyABSTRACT
OBJECTIVE: Participation is one of the key goals of re/habilitative processes. Since participation impacts adolescents' social-emotional development and overall health, this goal is particularly important for them. However, to date, no German-speaking self-assessment tool for participation among adolescents is available. This study sought therefore to develop such a tool and to test its psychometric properties. METHODS: Based on a preliminary qualitative study, we developed 133 items for a pilot version of the Social Participation Inventory (SPI). The SPI assesses the objective dimension (i.e., attendance) and the subjective dimension (i.e., involvement and satisfaction) of participation. To test the psychometric properties of the SPI, we conducted a quantitative cross-sectional survey and applied the SPI to n = 151 adolescents with and without disabilities and/or chronic diseases. RESULTS: By using principal component analyses, we examined the SPI's consistency and verified the theoretical considerations regarding the two components of participation (i.e., objective and subjective dimensions). Items that did not load sufficiently on components were removed after careful theoretical-based consideration. The condensed version of the SPI consists of 39 items that assess participation and 18 items to assess the perceived importance of respective areas of life. The SPI shows very good overall reliability (Cronbach's α = .920) and good validity. CONCLUSION: This study provides a new psychometrically tested participation self-assessment scale for adolescence with and without disabilities and/or chronic diseases. Further research is needed to re-evaluate its psychometric properties and to evaluate the application of the SPI in clinical and scientific contexts.
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Self-Assessment , Social Participation , Humans , Adolescent , Pilot Projects , Cross-Sectional Studies , Reproducibility of Results , Psychometrics/methods , Chronic Disease , Surveys and QuestionnairesABSTRACT
Objective.Gradient-based optimization using algorithmic derivatives can be a useful technique to improve engineering designs with respect to a computer-implemented objective function. Likewise, uncertainty quantification through computer simulations can be carried out by means of derivatives of the computer simulation. However, the effectiveness of these techniques depends on how 'well-linearizable' the software is. In this study, we assess how promising derivative information of a typical proton computed tomography (pCT) scan computer simulation is for the aforementioned applications.Approach.This study is mainly based on numerical experiments, in which we repeatedly evaluate three representative computational steps with perturbed input values. We support our observations with a review of the algorithmic steps and arithmetic operations performed by the software, using debugging techniques.Main results.The model-based iterative reconstruction (MBIR) subprocedure (at the end of the software pipeline) and the Monte Carlo (MC) simulation (at the beginning) were piecewise differentiable. However, the observed high density and magnitude of jumps was likely to preclude most meaningful uses of the derivatives. Jumps in the MBIR function arose from the discrete computation of the set of voxels intersected by a proton path, and could be reduced in magnitude by a 'fuzzy voxels' approach. The investigated jumps in the MC function arose from local changes in the control flow that affected the amount of consumed random numbers. The tracking algorithm solves an inherently non-differentiable problem.Significance.Besides the technical challenges of merely applying AD to existing software projects, the MC and MBIR codes must be adapted to compute smoother functions. For the MBIR code, we presented one possible approach for this while for the MC code, this will be subject to further research. For the tracking subprocedure, further research on surrogate models is necessary.
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Protons , Tomography, X-Ray Computed , Computer Simulation , Phantoms, Imaging , Tomography, X-Ray Computed/methods , Software , Algorithms , Monte Carlo MethodABSTRACT
OBJECTIVE: Few studies have investigated health inequalities among young workers. The objectives of this study are to assess the extent of health inequalities in a sample of job starters and to explore the contribution of job demands and organisational factors. METHODS: We analyze data from the BIBB/BAuA Youth Employment Survey 2012. The cross-sectional survey includes a representative sample of 3214 German employees, apprentices, and trainees aged 15-24 years. Individuals were grouped by their years of schooling into low (< 12 years) and high levels of education (≥ 12 years). Regression analysis estimated the link between education and four health outcomes: self-rated health, number of health events, musculoskeletal symptoms, and mental health problems over the last 12 months. Counterfactual mediation analysis tested for indirect effects of education via working conditions (i.e., physical and psychosocial job demands) and company characteristics (i.e., company size, health prevention measures, financial situation, downsizing). All analyses were adjusted for age, sex, nationality, region, working hours, job tenure, employment relationship, and economic sector. RESULTS: Highly educated workers reported better self-rated health (b = 0.24, 95% CI 0.18-0.31) and lower numbers of health events (Rate Ratio (RR) = 0.74, 95% CI 0.67-0.82), musculoskeletal symptoms (RR = 0.73, 95% CI 0.66-0.80) and mental health problems (RR = 0.84, 95% CI 0.76-0.93). Total job demands explained between 21.6% and 87.2% of the educational differences (depending on health outcome). Unfavourable company characteristics were associated with worse health, but showed no or only small mediation effects. CONCLUSIONS: Health inequalities are already present at the early working career due to socio-economically stratified working hazards. To enhance prevention measures that aim at reducing inequalities in workplace health, we propose shifting attention towards earlier stages of life.
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Occupations , Working Conditions , Humans , Adolescent , Cross-Sectional Studies , Workplace/psychology , EmploymentABSTRACT
Objective.Proton therapy is highly sensitive to range uncertainties due to the nature of the dose deposition of charged particles. To ensure treatment quality, range verification methods can be used to verify that the individual spots in a pencil beam scanning treatment fraction match the treatment plan. This study introduces a novel metric for proton therapy quality control based on uncertainties in range verification of individual spots.Approach.We employ uncertainty-aware deep neural networks to predict the Bragg peak depth in an anthropomorphic phantom based on secondary charged particle detection in a silicon pixel telescope designed for proton computed tomography. The subsequently predicted Bragg peak positions, along with their uncertainties, are compared to the treatment plan, rejecting spots which are predicted to be outside the 95% confidence interval. The such-produced spot rejection rate presents a metric for the quality of the treatment fraction.Main results.The introduced spot rejection rate metric is shown to be well-defined for range predictors with well-calibrated uncertainties. Using this method, treatment errors in the form of lateral shifts can be detected down to 1 mm after around 1400 treated spots with spot intensities of 1 × 107protons. The range verification model used in this metric predicts the Bragg peak depth to a mean absolute error of 1.107 ± 0.015 mm.Significance.Uncertainty-aware machine learning has potential applications in proton therapy quality control. This work presents the foundation for future developments in this area.
Subject(s)
Proton Therapy , Uncertainty , Protons , Machine Learning , Neural Networks, ComputerABSTRACT
BACKGROUND: Alzheimer's disease (AD) is characterized by the intra- and extracellular accumulation of amyloid-ß (Aß) peptides. How Aß aggregates perturb the proteome in brains of patients and AD transgenic mouse models, remains largely unclear. State-of-the-art mass spectrometry (MS) methods can comprehensively detect proteomic alterations, providing relevant insights unobtainable with transcriptomics investigations. Analyses of the relationship between progressive Aß aggregation and protein abundance changes in brains of 5xFAD transgenic mice have not been reported previously. METHODS: We quantified progressive Aß aggregation in hippocampus and cortex of 5xFAD mice and controls with immunohistochemistry and membrane filter assays. Protein changes in different mouse tissues were analyzed by MS-based proteomics using label-free quantification; resulting MS data were processed using an established pipeline. Results were contrasted with existing proteomic data sets from postmortem AD patient brains. Finally, abundance changes in the candidate marker Arl8b were validated in cerebrospinal fluid (CSF) from AD patients and controls using ELISAs. RESULTS: Experiments revealed faster accumulation of Aß42 peptides in hippocampus than in cortex of 5xFAD mice, with more protein abundance changes in hippocampus, indicating that Aß42 aggregate deposition is associated with brain region-specific proteome perturbations. Generating time-resolved data sets, we defined Aß aggregate-correlated and anticorrelated proteome changes, a fraction of which was conserved in postmortem AD patient brain tissue, suggesting that proteome changes in 5xFAD mice mimic disease-relevant changes in human AD. We detected a positive correlation between Aß42 aggregate deposition in the hippocampus of 5xFAD mice and the abundance of the lysosome-associated small GTPase Arl8b, which accumulated together with axonal lysosomal membranes in close proximity of extracellular Aß plaques in 5xFAD brains. Abnormal aggregation of Arl8b was observed in human AD brain tissue. Arl8b protein levels were significantly increased in CSF of AD patients. CONCLUSIONS: We report a comprehensive biochemical and proteomic investigation of hippocampal and cortical brain tissue derived from 5xFAD transgenic mice, providing a valuable resource to the neuroscientific community. We identified Arl8b, with significant abundance changes in 5xFAD and AD patient brains. Arl8b might enable the measurement of progressive lysosome accumulation in AD patients and have clinical utility as a candidate biomarker.