Fatigue Research Articles

Bioregeneration of sulfate-laden anion exchange resin

Ion exchange technology removes ionic compounds from waters effectively but treatment of the spent regenerant is expensive. The bioregeneration of sulfate-laden strong base anion exchange resin was successfully tested using both pure and mixed sulfate-reducing bacterial cultures. The resin was first used for removal of sulfate from neutral (pH 6.7 ± 0.5) synthetic sodium sulfate solutions, after which the spent resin was regenerated by incubating with a viable sulfate-reducing bacterial culture in batch and column modes. In the batch bioregeneration tests, the achieved bioregeneration was 36–95% of the original capacity of the fresh resin (112 mg SO42−/g) and it increased with regeneration time (1–14 days). The capacity achieved in the column tests during 24 hours of bioregeneration was 107 mg SO42−/g after the first regeneration cycle. During the bioregeneration, sulfate was mainly reduced by the sulfate-reducing bacteria (approx. 60%), but part of it was only detached from the resins (approx. 30%). The resin-attached sulfate was most likely replaced with ions present in the liquid sulfate-reducing bacterial culture (e.g., HCO3−, HS−, and Cl−). During the subsequent exhaustion cycles with the bioregenerated resin, the pH of the treated sodium sulfate solution increased from the original 6.7 ± 0.5 to around 9. The study showed that biological sulfate reduction could be used for sulfate removal in combination with ion exchange, and that the exhausted ion exchange resins could be regenerated using a liquid sulfate-reducing bacterial culture without producing any brine.

A-135 Caregiver Anxiety and Sleep in the Postpartum Period in Term and Preterm Infants

Abstract Objective: Postpartum anxiety impacts 3-40% of caregivers (Glasheen et al., 2009) and caregivers report sleeping about 20% less compared to other periods (Deepika et al., 2007). Since sleep problems exacerbate anxiety symptoms, targeting sleep problems in postpartum may reduce caregiver psychopathology. We hypothesized anxiety would decline from 6- to 12-months and that better sleep would predict lower levels of anxiety especially for caregivers of preterm infants. Method: Caregivers provided data with PediaTracTM (Lajiness-O’Neill et al., 2021), an online tool, at 6-, 9-, and 12-months from a larger longitudinal study of term (n=299) and preterm (n=218) infants recruited from three academic hospitals. Caregivers were sociodemograhpically diverse (Black/African American=33%, White=56%, multiracial=6%, other=4%; census-based area deprivation ADI M=5.14, SD=3.32) with 2 children (SD=1.21) in the home. Caregivers self-reported anxiety (Brief Symptom Inventory; Derogatis, 1977) and sleep quality (average of 4 PediaTracTM items: difficulty falling asleep, night awakenings, sleep quality satisfaction, morning fatigue) with higher scores indicating better sleep quality. Results: A multilevel model, accounting for nested observations, (R^2 = .06) was significant with sleep quality predicting anxiety, beta= -.22, p<.001, 95% CI [-.28, -.17]. Neither time, term status, demographic covariates nor moderation of sleep by term status were significant predictors. Conclusion: Though anxiety did not decline over postpartum, those with better sleep reported lower anxiety symptoms suggesting sleep interventions may reduce anxiety symptoms. Surprisingly, neither psychosocial stressors nor term status predicted anxiety severity. Other factors, e.g., parenting stress, should be considered in understanding differences in postpartum anxiety.

Burnout and resilience during the COVID-19 outbreak: differences between male and female students

This research aims to determine the burnout levels of male and female students on the three subscales of Exhaustion (EX), Cynicism (CY), and Professional Efficacy (PE) and their resilience during the COVID-19 pandemic. This is a non-experimental quantitative, descriptive, and cross-sectional research conducted on students of Riau University. The snowball sampling method was used to obtain data from 131 students consisting of 69 female and 62 male through the distribution of an online questionnaire and analyzed using the independent sample t-test and Pearson Product Moment Correlation. The data distribution showed that burnout on the PE, EX, CY, and resilience is in the high, moderate, and low categories, respectively.The data analysis showed that the burnout variable for the PE and EX indicators in female was higher than for men. Meanwhile, male's CY and resilience indicators were higher than female. This indicates significant differences in burnout and resilience between male and female during the pandemic. The results also showed that there is no correlation between PE and resilience as well as CY and resilience, while EX and resilience show a correlation. This finding shows the psychological condition of students in using distance learning during the pandemic. There is a need for strategies to be implemented to reduce the impact of the pandemic on students for better mental health.

Helicon Injected Inertial Plasma Electrostatic Rocket

The Helicon Injected Inertial Plasma Electrostatic Rocket (HIIPER) is a space propulsion system developed at the University of Illinois Urbana-Champaign. The HIIPER couples a helicon tube with an inertial electrostatic confinement (IEC) fusion system. Its operating principle involves a helicon ionization stage followed by an electrostatic grid (IEC cathode grid) extraction stage. The helicon setup used in the HIIPER is modified to include a helicon bias grid at the upstream end of the tube. This grid is applied with a positive direct-current voltage to increase the plasma potential and the most probable ion energy of the plasma injected into the IEC fusion chamber. The IEC cathode grid in the HIIPER uses an innovative asymmetric design, graphically depicted through a computational model, that ejects a stream of electrons that accelerate the exhaust ions and simultaneously neutralize the exhaust jet. The model is also used to plot ion trajectories inside the HIIPER to identify any wall collision losses. A separate numerical study was undertaken to show augmentation of plasma kinetic energy on adding a magnetic nozzle as the final propulsion stage of the HIIPER. Experimental results were used to establish a relation between the input parameters and the ion density of the resulting plasma. Langmuir probe measurements were performed at two locations to validate corresponding computational results, indicating ion losses due to ion-wall collisions inside the helicon-IEC coupling. The results in this study add to the proof of concept of the HIIPER and allow for designing an upgrade of the propulsion system. Increasing thrust while maintaining plasma densities between 1017 and 1018 throughout the system is the current aim of HIIPER research. This study summarizes the various performance parameters of the propulsion system, along with a discussion of ongoing research and future scope.

Life among Chinese fibromyalgia patients: a cross-sectional study.

This study is to examine the impact of age on the clinical characteristics, fibromyalgia-related symptom severity and quality of life (QOL) among Chinese fibromyalgia patients. A packet of questionnaires on demographics, medical history, and severity of six major symptoms of fibromyalgia (i.e., pain, fatigue, sleep quality, depression, stress, and QOL) was completed by 124 Chinese patients. The patients were stratified into three groups by age (32 (25.8%) "young" patients, ≤ 39years; 73 (58.9%) "middle-age" patients, 40-59years; and 19 (15.3%) "older" patients, ≥ 60years). Analysis of covariance was conducted and adjusted for body mass index and symptom fibromyalgia duration. The majority of patients in this study were women (107, 86.3%), and the mean age was 49.4years (SD 10.8years). Pairwise comparisons among the three age groups found that the young and middle-aged patients were significantly more troubled than the older patients by their symptoms in several categories: morning tiredness (P ≤ 0.012), depression (P ≤ 0.002), anxiety (P ≤ 0.004), mental health index (P ≤ 0.002), and mental component summary score (P ≤ 0.017). The middle-aged patients reported more trouble than the older patients with regard to social functioning (P = 0.008), emotional roles (P = 0.012), depression (P = 0.012), and sleep quality (P = 0.017). The young patients exhibited the highest levels of current experienced stress (young vs. old, P = 0.013). This study has identified that middle-aged Chinese fibromyalgia patients exhibited less compromise of their QOL than did their older peers. This discrepancy begs a logical explanation and deserves further study. Key Points • This is the first clinical study to show the potential effect of age on fibromyalgia patients in China. • Characteristics, symptom severity, and QOL differ in different age groups. • The younger patients are, the worse their quality of life.

P1725: OBSERVATIONAL STUDY TO EVALUATE PATIENT-REPORTED OUTCOMES IN PAROXYSMAL NOCTURNAL HEMOGLOBINURIA

Background: Paroxysmal Nocturnal Hematuria (PNH) is a rare acquired hematopoietic stem cell disorder with non-specific clinical features and onset prevalent at young adult age. Main symptoms are fatigue (80%) and dyspnea (64%). Treatment for symptomatic and/or predominantly haemolytic PNH patients is associated with an improvement in survival and quality of life (QoL). To date, cancer-specific patient-reported outcome (PRO) measures (PROMS) have been used in PNH. A novel PNH-specific PROM, EORTC QLQ-AA/PNH, consisting of 54 items has undergone initial Phase 2-3 evaluation. We present preliminary results of the first 31 cases enrolled. Aims: The aim of this observational non-interventional prospective multicenter Italian study is to evaluate whether PROMs can identify patients’ biological response to treatment and factors associated with health-related QOL. The primary endpoint is differences in EORTC QLQ-C30 scores between patients with versus without hemolysis. Secondary endpoints include further validation of EORTC QLQ-AA/PNH Italian version, differences in scale scores between patients experiencing hemolysis versus those not experiencing hemolysis and factors associated with PROs by EORTC QLQ-AA/PNH. Methods: 110 adult patients age ≥ 18 years with PNH will be included. Exclusion criteria consists of bone marrow failure, history of treatment for cancer within the last 5 years and clinically significant comorbidities that impact PROs. Patients complete both PROMs on the day of visit to the clinic for the scheduled treatment and re-test after 2 weeks. For EORTC QLQ-AA/PNH higher scores identified higher impact or symptoms. Demographics and disease features are collected at baseline. Hemolysis is defined by a lactate dehydrogenase (LDH) ≥ 1.5 times upper limit of normal (ULN) at baseline. Results: Patient characteristics are shown in the Table 1. The EORTC QLQ-C30 scores did not distinguish patients with or without hemolysis, probably due to the small sample size. Baseline Global Function was good with median score 83 (IQR 50-100). Fatigue and dyspnea were not frequently reported with median scores 33 (IQR 11-33) and 0 (0-33), respectively. The EORTC QLQ-AA/PNH showed good reliability with Chronbach alpha standardized scores for all domains except Body Image (BI), Infections (IN) and Social Support (SS), confirmed at retest. There were strong correlations between the 2 questionnaires. QLQ-AA/PNH Cognitive Functioning (CF) median score was 0 (IQR 0-25), Emotional Functioning 20 (IQR 5-35), Fatigue (FA) 20 (IQR 10-30), Illness Intrusiveness (II) 11 (IQR 4-32), other symptoms (OS) 11 (0-21), Physical Functioning (PF) 17 (0-33), Role Functioning (RF) 14 (9-32), Stigmatisation (ST) 12 (0-25) and Fear of Progression (PAF) 123 (4-29). Hemoglobin levels correlated with QLQ C30 physical function (R=0.505, P=0.006), role function (R=0.450, P= 0.014), Fatigue (R=-0.520, P=0.004), Dyspnea (R=-0.410, P=0.027) and Pain (R0-0.409, P0 0.028). They correlated with EORTC QLQ-AA/PNH PF (R=0.499, P=0.006), ST (R=0.395, P=0.034) and FA (r=-0.517, p=0.004). Image:Summary/Conclusion: The preliminary analysis confirms the validity of the EORTC QLQ-AA/PNH as a PROM for PNH. Hemoglobin is an important factor which correlates with many PRO domains. Further analyses at study completion will inform on the impact of PNH in patients’ lives.

Adapted physical activity in patients (Pts) with advanced pancreatic cancer (APACaP): Results from a prospective national randomized GERCOR trial.

4007 Background: The benefit of adapted physical activity (APA) on health-related quality of life (HRQoL) in Pts with advanced pancreatic ductal adenocarcinoma (aPDAC) treated by chemotherapy (CTx) has never been prospectively assessed. Methods: Pts with aPDAC and ECOG performance status (PS) 0–2 were randomized 1:1 to receive usual care (UC) including first-line CTx at the investigator’s choice (standard arm), or UC plus a home-based 16-week APA program (APA arm). The APA program consisted of personalized aerobic and resistance exercises, with a weekly remote supervision by an APA professional trainer, and unsupervised sessions with a family member or friend (APA partner). The primary objective was the effect on HRQoL at week 16 (W16) measured by 3 dimensions of the EORTC QLQ-C30, global health status (GHS), physical functioning (PF), and fatigue (FA), with a one-sided type I error of 0.016 for each dimension. The primary HRQoL analysis was performed in Pts with available baseline and W16 scores for the 3 targeted dimensions (mITT1). Secondary analyses of HRQoL changes by the mixed model for repeated measures (MMRM) and time until definitive deterioration (TUDD) methods included Pts with baseline and ≥1 follow-up score (mITT2). Differences > 5 points in scores were considered clinically significant. Results: A total of 313 Pts (median age: 64 years; men: 55%, ECOG PS 0-1: 93%; metastatic: 77%; FOLFIRINOX: 78%, gemcitabine-based: 13%) were included from 11/2014 to 10/2020 (standard arm: n = 157, APA arm: n = 156). In the mITT1 population (n = 172), mean differences in HRQoL at W16 adjusted from baseline were -0.98 (SD 23.87; p = 0.39), -2.08 (SD 21.34; p = 0.26), and 4.16 (SD 29.18; p = 0.18) for GHS, PF, and FA, respectively. In the mITT2 population (n = 259), APA was associated with significant improvements in 5 (GHS, PF, cognitive functioning [CF], social functioning [SF], appetite loss) and 8 (GHS, CF, emotional functioning [EF], SF, insomnia, constipation, pain, financial difficulties) dimensions of HRQoL by MMRM and TUDD, respectively (Table). Secondary endpoints, including overall survival, progression-free survival, and chemotherapy toxicity will be presented. Conclusions: APA in combination with usual care improved several dimensions of HRQoL in Pts with aPDAC receiving first-line CTx. Clinical trial information: NCT02184663. [Table: see text]

Depression trajectories among women undergoing chemotherapy.

e24144 Background: Depressive symptoms are common among women undergoing chemotherapy (CTX) for breast or gynecological cancer. Many studies have examined the prevalence of depressive symptoms (usually at the beginning or end of CTX). However, given that CTX unfolds over a number of cycles, there is a need to better understand patterns of change in depressive symptoms over the course of treatment, and to identify factors that may predispose individuals to worse symptom trajectories. The purpose of this study, among women who underwent CTX for breast or gynecological cancer, was to evaluate for interindividual differences in depressive symptoms over the course of two cycles of CTX, and to identify characteristics associated with both initial levels (i.e., at the beginning of the study) and trajectories of depressive symptoms. Methods: Patients undergoing CTX for breast (n = 530) or gynecologic (n = 233) cancer completed the Center for Epidemiological Studies-Depression (CES-D) questionnaire six times over two treatment cycles. Patient-reported measures were used to assess demographic, clinical, symptom, stress, and coping characteristics at enrollment. Using hierarchical linear modeling (HLM), we evaluated characteristics associated with initial levels and trajectories of depressive symptoms. Results: One demographic (marital status) and two clinical (number of comorbidities, functional status) characteristics predicted interindividual differences in initial levels of depressive symptoms. One demographic (education) and one clinical (MAX-2 score, a CTX toxicity metric) characteristic were associated with interindividual differences in depressive symptom trajectories. Several symptom characteristics predicted interindividual differences in initial levels (i.e., morning fatigue), trajectories (i.e., initial level of depression), or both initial levels and trajectories (i.e., sleep disturbance, attentional function) of depressive symptoms. Two stress-related variables (i.e., perceived stress, cancer-related distress) predicted interindividual differences in both initial levels and trajectories of depressive symptoms. Several coping variables predicted interindividual differences in initial levels (i.e., behavioral disengagement), trajectories (i.e., venting), or both initial levels and trajectories (i.e., self-blame) of depressive symptoms. Conclusions: The range of demographic, clinical, symptom, stress and coping characteristics associated with interindividual differences in depressive symptoms underscores the importance of evaluating risk and protective factors. These factors may serve as useful markers for both screening and intervention to address depressive symptoms during CTX.

AB1214 VITAMIN D SUPPLEMENTATION IN FIBROMYALGIA: A SYSTEMATIC REVIEW

BackgroundFibromyalgia (FM) is a chronic disease characterized by diffuse pain associated with high levels of fatigue whose intensity is very variable. Similar symptoms are found in patients with low levels of vitamin D, a vitamin that behaves like a hormone with multiple receptors spread in several tissues. Although its role in the pathophysiology of FM remains unclear many studies point to a correlation between vitamin D deficiency and FM symptoms severity. (1)ObjectivesConduct a systematic review of the literature to determine the value of vitamin D supplementation in fibromyalgia.MethodsMedline, EMBASE, and Cochrane databases were searched, from January 2000 to January 2022, using the descriptors “Fibromyalgia”, “Fatigue” and “Vitamin D.” Randomized and clinical control trials including FM patients in whom supplementation of vitamin D was made were selected. Data comprised sociodemographic description, diagnosis criteria, fibromyalgia symptoms, Fibromyalgia Impact Questionnaire (FIQ), short-form 36 (SF36), and vitamin D supplementation protocol was collected.ResultsOf the initial 2480 articles, 4 were eligible for final analysis. One did not observe any significant improvement in FIQ scores with vitamin D supplementation. The remaining three observed significant improvements in SF-36 and FIQ scores but to different extents. One only demonstrated improvements in specific components of the SF-36, also demonstrating improvements concerning morning fatigue. Another demonstrates improvements in all SF-36parameters, except for pain level. Lastly, other observed improvements in the scores of both FIQ and SF-36 scales.ConclusionOur review shows conflicting results regarding the role of using vitamin D supplementation in the quality of life of patients with FM(S). These results can be explained by different supplementations protocols and also different baseline levels of vitamin D for which it was decided to supplement. Nevertheless, vitamin D supplementation appears to have a benefit in fatigue and quality of life in FM patients. Larger studies, which last longer and have a more uniform supplementation protocol, are needed to confirm the results of this review.

Allergic disease, sleep problems, and psychological distress in children recruited from the general community

BackgroundIt is not clear which allergic disease is most strongly related to which sleep problem and whether sleep problems may mediate the association between allergic disease and psychological distress. There is also a need for more community-based studies using nonreferred samples. ObjectiveTo evaluate the association between individual allergic diseases and sleep problems and test whether the association between allergic disease and psychological distress is mediated through sleep problems. MethodsParents of 1449 Australian children aged 6 to 10 years recruited from the general community, completed measures of sleep problems (Pediatric Sleep Survey Instrument), psychological distress (Strengths and Difficulties Questionnaire), and frequency of allergic diseases. ResultsSleep and psychological distress scores were in the reference range. After controlling for coexisting allergic diseases, allergic rhinitis was associated with sleep routine problems, morning tiredness, night arousals, sleep disordered breathing and restless sleep; asthma with sleep routine problems, sleep disordered breathing and restless sleep; and eczema with restless sleep. Path analyses revealed that sleep problems mediated the association between asthma and allergic rhinitis but not eczema with psychological distress. ConclusionIn this nonreferred community sample, the frequency of sleep problems and psychological distress was lower than that typically reported in children referred to specialized centers. However, allergic rhinitis was associated with a broad range of sleep problems and to a lesser extent in children with asthma and least in children with eczema. Path analysis revealed that the association between allergic disease and psychological distress was mediated through sleep problems, highlighting the importance of assessing sleep health in children with allergic disease.

Burnout and Online Medical Education: Romanian Students in Lockdown and Their Residency Choices.

The primary aim of the study was to investigate the prevalence of burnout in Romanian medical students during the COVID-19 pandemic using the Maslach Burnout Inventory-General Survey for Students (MBI-GS(S)). The presence of burnout was assessed based on Exhaustion (EX), Cynicism (CY) and Professional Efficacy (PE) subscales. The secondary aim of the study was to identify the presence of intentional shift in medical specialty compared to their initial pursued choice within the population investigated. Data was collected online at the end of 2020 and beginning of 2021 through a licensed, customized MBI-GS(S) questionnaire from a sample of 126 Romanian medical students at the two leading medical schools in the country, Iasi (N = 56) and Cluj Napoca (N = 70). Descriptive statistics and bivariate correlations were also applied to describe the data set (age and gender of participants) and the relationship between variables (EX, CY, PE). Subsequently, the MBI-GS(S) group report revealed that 36.5% of the medical students in the sample (46) experienced burnout, with problematic results both in Exhaustion and Cynicism. Exhaustion and Cynicism, which contribute to burnout, showed high scores compared to the average scale (EX = 3.5/2.4; CY = 2.8/1.8), while the Professional Efficacy score was relatively high (PE = 3.8/4.4), showing a protective effect and burnout reduction. One of the main conclusions is that the consequences of burnout in medical students plays a significant role in shaping the future healthcare practitioners’ perception of the medical profession and of patients’ wellbeing. Exhaustion and Cynicism are mainly associated with depersonalization and disconnection from the patient. Another conclusion of the study is that about one third of the respondents (30% Cluj students and 37.5% Iasi students) considered changing residency options. The pandemic has also revealed the limitations of and challenges facing current medical education, and that further research is required to assess the trends in prevalence of burnout in medical students.

The improvement of daily fatigue in women following the intake of maca (Lepidium meyenii) extract containing benzyl glucosinolate

Background: Daily fatigue is a problem for many people because of its association with other illnesses. Maca has lately attracted considerable attention as a food for recovering from fatigue. Maca is high in benzyl glucosinolate which improves endurance capacity by preventing glycogen depletion. However, its effect on fatigue has not been investigated in clinical trials on humans.Objective: The main objective of this study is to investigate the effects of maca supplements on reducing fatigue.Methods: This study evaluated the effect of the consumption of maca extract containing benzyl glucosinolate (9.6 mg/day) on fatigue in adult women. This randomized, placebo–controlled, parallel–group double–blind study enrolled 60 subjects who were allocated to consume maca extract or placebo for 4 weeks. A visual analogue scale (VAS) for fatigue was used to evaluate the results. Blood variables and adverse events were used to assess safety.Results: In both groups, the VAS of fatigue was decreased after 4 weeks compared with that before consumption. On stratification analysis, in subjects younger than 45 years, the VAS was significantly lower in the maca group, and the change between before and after supplementation was significantly larger in this group. Conclusions: It was suggested that intake of maca extract containing benzyl glucosinolate may have anti–fatigue effects in young women. So, maca supplements containing benzyl glucosinolate represent a food and drug candidate for reducing fatigue.Keywords: maca, Lepidium meyenii, benzyl glucosinolate, daily fatigue, visual analogue scale

Weekday sleep duration and morning tiredness are independent covariates of breakfast skipping in adolescents.

Although regular breakfast consumption is associated with various health benefits, many adolescents skip this meal, particularly those with shorter sleep durations. In order to better understand the association between sleep duration and breakfast consumption among youth, we analyzed the association between weekday morning tiredness and daily breakfast consumption in adolescents, and explored the mediating role of morning tiredness in the association between sleep duration and daily breakfast consumption on weekdays. The "Health Behaviour in School-aged Children" survey conducted in 2018 in French-speaking Belgian schools provided data (n = 8444 11-20-year-old adolescents) on bed- and wake-up times, and on the frequency of breakfast consumption and morning tiredness on weekdays. Multivariable logistic regressions and mediation analyses assessed the association, on weekdays, of morning tiredness (≥4 school mornings a week vs. less) and sleep duration (hours), with daily breakfast consumption, and the mediating role of morning tiredness. Feeling tired ≥4 school mornings a week was associated with lower odds of daily breakfast consumption on weekdays (aOR = 0.77 (95% CI 0.69-0.86)). In turn, on weekdays, sleep duration was positively associated with daily breakfast consumption (aOR = 1.29 (95% CI 1.23-1.36)), even after adjustment for morning tiredness (aOR = 1.28 (95% CI 1.21-1.35)). Morning tiredness only explained 4.9% of the association between sleep duration and daily breakfast consumption. Our findings suggest that in adolescents, sleep duration and morning tiredness are independent correlates of daily breakfast consumption on weekdays.

Does face mask affects sleep quality in patients with nasal septal deviation: evaluated by mini sleep questionnarie

Objectives: The aim of this study was to investigate the effects of face mask usage on the sleep quality of patients with nasal septal deviation.
 Material and Method: Thirty-four patients with unilateral nasal septum deviation (Group 1) and 27 healthy subjects without septum deviation (Group 2, control) were included in the study. Mask usage time per day (hours) in the last week, weight, length and BMI values, smoking, and alcohol habits were asked. In both groups, the sleep quality of the patients was evaluated by Mini Sleep Questionnaire (MSQ). Sleep delay (SD), sleep awakenings (SA), sleep medications (SM), daytime sleep (DS), morning fatigue (MF), habitual snoring (HS), morning awakening (MA), morning headache (MH), chronic fatigue (CF), and restless sleep (RS); and total MSQ items were evaluated.
 Results: All subjects used surgical masks. In the nasal septal deviation group, the right-sided deviation was detected in 15 (44.1%) patients and left-sided deviation was detected in 19 (55.9%) patients. Deviation located was anterior deviation in 12 (35.3%) patients, posterior deviation in 13 (38.2%) patients and antero-posterior deviation in 9 (26.5%) patients. Sleep Medications (SM) and Morning Headache (MH) values of the deviation group (Group 1) were significantly lower than those in the control group (p0.05). In older patients with septal deviation, Sleep Awakenings (SA), Habitual Snoring (HS), Morning Awakening (MA), and Total MSQ scores increased (p

Modelling of Environmental Ageing of Polymers and Polymer Composites-Durability Prediction Methods.

Polymers and polymer composites are negatively impacted by environmental ageing, reducing their service lifetimes. The uncertainty of the material interaction with the environment compromises their superior strength and stiffness. Validation of new composite materials and structures often involves lengthy and expensive testing programs. Therefore, modelling is an affordable alternative that can partly replace extensive testing and thus reduce validation costs. Durability prediction models are often subject to conflicting requirements of versatility and minimum experimental efforts required for their validation. Based on physical observations of composite macroproperties, engineering and phenomenological models provide manageable representations of complex mechanistic models. This review offers a systematised overview of the state-of-the-art models and accelerated testing methodologies for predicting the long-term mechanical performance of polymers and polymer composites. Accelerated testing methods for predicting static, creep, and fatig ue lifetime of various polymers and polymer composites under environmental factors’ single or coupled influence are overviewed. Service lifetimes are predicted by means of degradation rate models, superposition principles, and parametrisation techniques. This review is a continuation of the authors’ work on modelling environmental ageing of polymer composites: the first part of the review covered multiscale and modular modelling methods of environmental degradation. The present work is focused on modelling engineering mechanical properties.

Daily microbreaks in a self-regulatory resources lens: Perceived health climate as a contextual moderator via microbreak autonomy.

Grounded in self-regulatory resources and conservation of resources theories, the current research examines poor self-regulatory capacity as a precursor to microbreaks and their possible outcomes at work. Full-time employees completed multiple online surveys for 10 (n₁ = 779 daily observations) and 5 workdays (n₂ = 1,024 daily observations). In Study 1, multilevel path analysis results showed that on days when employees had poorer recovery at home (i.e., poor sleep quality), they experienced higher fatigue in the next morning (low self-regulatory capacity) and thus took microbreaks more frequently at work. In turn, their engagement in microbreaks was related to higher work engagement during the day and lower end-of-work fatigue. Furthermore, perceived health climate was found to moderate the path from morning fatigue to microbreaks. In Study 2, we replicated and confirmed the serial mediation paths found in Study 1 (poor sleep quality → morning fatigue → microbreaks → work engagement and end-of-work fatigue). Building on Study 1, Study 2 also identified microbreak autonomy as a mechanism by which perceived health climate moderates the path between morning fatigue and microbreaks (i.e., mediated moderation effect). Exploratory analyses discovered intriguing patterns of socialization microbreaks versus other microbreaks, providing further implications for the theoretical perspective. Overall, the findings support the theoretical resource perspective of microbreaks as an effective energy management strategy while at work. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Applying Data Mining Approaches for Analyzing Hazardous Materials Transportation Accidents on Different Types of Roads

With the increase in the demand for and transportation of hazardous materials (Hazmat), frequent Hazmat road transport accidents, high death tolls and property damage have caused widespread societal concern. Therefore, it is necessary to carry out risk factor analysis of Hazmat transportation; predict the severity of accidents; and develop targeted, extensive and refined preventive measures to guarantee the safety of Hazmat road transportation. Based on the philosophy of graded risk management, this study used a priori algorithms in association rule mining (ARM) technology to analyze Hazmat transport accidents, using road types as classification criteria to find rules that had strong associations with property-damage-only (PDO) accidents and casualty (CAS) accidents under different road types. The results indicated that accidents involving PDO had a strong association with weather (WEA), traffic signals (TS), surface conditions (SC), fatigue (FAT) and vehicle safety status (VSS), and that accidents involving CAS had a strong association with VSS, equipment safety status (ESS), time of day (TOD) and WEA when urban roads were used for Hazmat transportation. Among Hazmat transport incidents on rural roads, the incidence of PDO accidents was associated with intersections (IN), SC, WEA, vehicle type (VT), and segment type (ST), while the occurrence of CAS accidents was associated with qualification (QUA), ESS, TS, VSS, SC, WEA, TOD, and month (MON). Strong associations between the occurrence of PDO accidents and related items, such as IN, SC, WEA and FAT, and the occurrence of CAS accidents and related items, such as ESS, TOD, VSS, WEA and SC, were identified for Hazmat road transport accidents on highways. The accident characteristics exemplified by strongly correlated rules were used as the input to the prediction model. Considering the scarcity of these events, four prediction models were selected to predict the severity of Hazmat accidents on each road type employing four analyses, and the most suitable prediction model was determined based on the evaluation criteria. The results showed that extreme gradient boosting (XGBoost) is preferable for predicting the severity of Hazmat accidents occurring on urban roads and highways, while nearest neighbor classification (NNC) is more suitable for predicting the severity of Hazmat accidents occurring on rural roads.

Charge transport characterization of the alternative low power hybrid ion engine (alphie) with particle-in-cell simulations

The Alternative Low Power Ion Engine (alphie) is a high specific impulse plasma thruster where both electrons and ions flow combined through the open spaces of its two-grids system. Ionizing electrons from its external cathode travel in toward the ionization chamber accelerated by the potential drop established between the grids, whereas ions exit toward the opposite direction and are later neutralized by electrons emitted from the cathode. In this configuration, the ion current is not space-charge limited, contrary to conventional gridded ion engines where only ions are transported through the grids. Since previous approaches that consider only one charged species are not valid for the alphie two-grids system, the characterization of geometrical parameters is studied using a fully particle-in-cell simulation. This numerical scheme calculates the velocities and positions of electrons and ions within a structured axial-symmetric mesh, which mimics one hole of the grids. The charged particle densities, currents, and their axial and radial mean velocities along the simulation domain are evaluated. Additionally, important reductions in the computational time have been obtained using different time scales for ions and electrons. Numerical results show that moderate changes in the thickness and separation of the grids with respect to the values employed in the prototype currently tested in the laboratory do not significantly affect the exhaust ion current or the ion beam collimation. Since the average velocity of the axial ions is essentially insensitive to small modifications of the geometric parameters, so will the specific impulse and thrust delivered.

Influence of Tobacco on Physical Fitness Recovery of College Students After Sports

Objectives: In this paper, the effects of tobacco on aerobic exercise ability and physical fitness recovery of college students were studied. Methods: University group sports intervention form: traditional characteristic project (basketball) + Taiji soft ball (R&D intervention project). Exercise time: 3 times/week; Activity duration: 30min; Activity intensity: the heart rate is controlled at 120-140 beats/min. All the college students in the experimental group are students who have never smoked, and the college students in the control group are students who have smoked for more than two years. The other conditions are the same. Results: The exercise time and endurance of experimental groups I and II were significantly lower than those of the control group, and the cardiopulmonary function was significantly lower than that of the control group. The indexes of experimental group II changed significantly compared with experimental group I, and the difference was statistically significant. Conclusion: Cigarette smoke can significantly reduce the aerobic exercise ability and anti fatigue ability. The longer the smoking time, the more serious the adverse effects. Therefore, tobacco smoke and nicotine will damage college students’ aerobic exercise ability and have a negative impact on the recovery of physical fitness after exercise.

The Effects of Whole-Body Vibration on Fatigue in Vertical Jump Performance and Isometric Mid-Thigh Pull Measures

The purpose of this study is to determine the effects of coupling WBV and acute muscular fatigue to determine its effects on countermovement vertical jump (CMVJ) performance and isometric mid-thigh pull (IMTP). Twenty-eight healthy active adults volunteered for five-day study. Testing sessions 2–5 included one of four conditions: No WBV and no fatigue (CON), WBV and fatigue (WBV + FAT), WBV and no fatigue (WBV), and no WBV and fatigue (FAT). WBV was performed using a frequency of 50 Hz and a low amplitude while performing quarter squats for a total of 4 min with a 30 s rest or work ratio. Lower-body fatigue induced using Bosco fatigue protocol. CMVJ and IMTP were performed on force plates. SPSS was used to perform a 2 × 2 Repeated Measures ANOVA. Significant main effects were found for fatigue in CMVJ-height and CMVJ-peak ground reaction force, no significant main effect for WBV, and no significant interactions. Lower-body fatigue decreases vertical jump performance, and WBV did not attenuate the detrimental effects of lower-body fatigue.