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The thermal barrier coating method is applied using materials with low thermal conductivity to increase the efficiency and improve the emissions of internal combustion engines. However, coated surfaces may be damaged due to the high thermal and pressure stresses encountered by the piston surface in the combustion chamber during engine operation. In this study, experiments and analysis were carried out for four piston models to analyze the coating layer and increase its strength: two partially coated piston surface models, a fully coated model, and an uncoated piston model. The results of the transient thermal analysis revealed that the fully coated piston model exhibited the highest surface temperature. Additionally, heat losses were observed to be lower in the fully coated model compared to the other piston models. Partially coated piston models exhibited lower heat flux on the coated surface but higher heat flux on the uncoated combustion chamber surfaces. Combustion analysis indicated that the fully coated piston model exhibited the highest in-cylinder temperature and pressure values, while the uncoated model had the lowest values. When comparing heat transfer rates on the walls, the uncoated piston model exhibited the highest transfer, whereas the fully coated piston model exhibited the lowest. Finally, the fully coated piston demonstrated the highest combustion efficiency. [ABSTRACT FROM AUTHOR]

A quasi-explicit algebraic solution of the problem of quasi-steady water droplet heat- and mass-transfer with condensation or evaporation in a prescribed environment including radiation has been obtained. The solution is based on the mass-fraction form of Fick's law of species diffusive mass transport, which allows accounting for variation in gas density through the diffusion layer surrounding the droplet. A new term, the average vapor supersaturation through the diffusion layer, has been included that allows the model to be extended to environmental conditions significantly outside those for which it is theoretically derived (dilute or near-saturation), even to conditions of relatively high temperature, low relative humidity, and low pressure. The latter two have atmospheric significance because evaporative cooling can induce significant decrease in droplet temperature and possibly induce freezing. Basic modeling assumptions are confirmed by comparison with time-dependent temperature and evaporation-rate measurements of a laboratory laser-heated droplet. Accuracy of the new model is assessed by comparison with exact equations. For temperatures between −30 and 0°C and negligible radiation, relative-error magnitudes in droplet temperature and evaporation rate are less than 5%, even for relative humidity down to 10% and pressure down to 60 kPa. This represents an improvement in accuracy over the conventional model, in which property variations of density and supersaturation through the diffusion layer are not taken into account. Differences in predicted evaporation rates between the mass-fraction and the more common partial-density Fick's laws, which can be significant (>10% above 70% relative humidity) in coupled, implicit equations, are shown to be made negligibly small (<0.5%) by linearizing about the saturation state. [ABSTRACT FROM AUTHOR]

Abstract Background Chronic lung disease (CLD) is common among children with HIV (CWH) including in those taking antiretroviral therapy (ART). Azithromycin has both antimicrobial and anti-inflammatory effects and has been effective in improving lung function in a variety of lung diseases. We investigated lung function trajectories among CWH with CLD on ART enrolled in a randomized controlled trial of adjuvant azithromycin. We also investigated factors that modified the effect of azithromycin on lung function. Methods The study used data from a double-blinded placebo-controlled trial conducted in Malawi and Zimbabwe of 48 weeks on azithromycin (BREATHE: ClinicalTrials.gov NCT02426112) among CWH aged 6 to 19 years taking ART for at least six months who had a forced expiratory volume in one second (FEV1) z-score

This paper shows how clusters of radiation-stabilized water droplets levitated in an upward flow of air and water vapor above a heated water surface can be modeled using Spalding's self-similarity theory of heat and mass transfer and Stefan flow. The model describes equilibrium droplet states, including stability conditions, as well as nonequilibrium (quasi-steady) transient evolution. Equilibrium states are shown to exist when Stefan-flow supersaturation, which has a quadratic-like variation with height above the water surface, and radiation-stabilized equilibrium supersaturation, which is nearly constant with height, are equal. The latter can be predicted by a fundamentally derived function of absorbed radiant flux (linear), droplet radius (linear if opaque), continuum thermal conductivity, and thermodynamic properties. In fact, all of the experimentally observed droplet behavior can be predicted using simple analytical results based on quasi-steady droplet energy and continuum transport. Unsteady droplet energy, Knudsen-layer transport, numerical solutions, and curve-fitting of numerical computations, as used previously in modeling this behavior, are not necessary. An interesting reversal of the usual effect of mass transfer on droplet drag in low-Re flow when levitated droplets are irradiated asymmetrically by significant infrared radiation is also postulated, which relates to the relative importance of normal (pressure) and tangential (shear stress) drag. This theory of radiation-augmented droplet evaporation, condensation, and relative motion in a moving gas has application to conditions in clouds, wherein droplets can experience either net radiative heating or cooling and fluctuating updrafts or downdrafts. [ABSTRACT FROM AUTHOR]

Objective: Prenatal sleep problems have been previously linked to poor birth outcomes. However, much less is known about the associations between poor prenatal maternal sleep and offspring outcomes after birth. The purpose of this systematic review was to synthesize the findings linking prenatal maternal sleep health and offspring health and development during infancy and childhood., Methods: A total of 4650 nonduplicate articles were identified via PsycInfo and PubMed databases. After screening and full-text review, 34 articles met the inclusion criteria and were extracted for information., Results: The bulk of studies in this review (n = 19; 76.5%) were published between 2019 and 2024. Measures of prenatal sleep included sleep timing, quality, sleep disorders and/or symptoms of disorders, and daytime sleepiness. Offspring outcomes were categorized as follows: a) sleep health (e.g., nighttime sleep duration, night wakings), b) physical health (e.g., body mass index, hospitalizations), c) child developmental outcomes (e.g., global development, negative affect, executive functioning), and d) brain structure and function (e.g., brain volume, event-related potentials). Evidence consistently links poor prenatal sleep health to poorer offspring sleep, higher body mass index, higher prevalence of physical health conditions, poorer global development, and more behavioral problems. Emerging evidence also links prenatal sleep to differences in offspring brain structure and function., Conclusions: Poor prenatal maternal sleep health may be an environmental signal that informs offspring health. Future studies are needed to fully understand the pervasive, intergenerational, and long-lasting effects of sleep across pregnancy., (Copyright © 2025 Society for Biopsychosocial Science and Medicine.)

Abstract: More than 50 years of high-quality data demonstrate that naloxone is an efficacious and cost-effective overdose reversal agent. Intranasal naloxone is now available in the United States as an over-the-counter and generic medication for the first time since the start of the overdose crisis more than 20 years ago. As the overdose crisis continues to contribute to substantial loss of life, there is an historic opportunity for jurisdictions to expand equitable and sustained access to intranasal naloxone. Further, through simultaneously enacting and expanding effective Naloxone Access and Good Samaritan laws, and equitably implementing these laws, there is the potential to maximize the population-level effectiveness of naloxone to sustainably reduce overdose mortality., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 American Society of Addiction Medicine.)

Background: Poor prenatal maternal sleep is a pervasive, yet modifiable, health concern affecting maternal and foetal wellbeing. Experimental rodent studies demonstrate that prenatal maternal sleep deprivation affects offspring brain development and leads to adverse outcomes, including increased anxiety-like behaviour. We examined the relation between prenatal maternal sleep quality and neonatal white matter development and subsequent infant negative emotionality., Methods: Participants included 116 mother-infant (53% female) dyads. Prenatal sleep quality was prospectively assessed three times during gestation (16, 29, and 35 gestational weeks) using the Pittsburgh Sleep Quality Index. Neonatal white matter, as indexed by fractional anisotropy (FA), was assessed via diffusion weighted magnetic resonance imaging. Negative emotionality was measured via behavioural observation and maternal report when the infant was 6-months of age., Findings: More prenatal sleep problems across pregnancy were associated with higher neonatal FA in the uncinate fasciculus (left: b = 0.20, p = .004; right: b = 0.15, p = .027). Higher neonatal uncinate FA was linked to infant negative emotionality, and uncinate FA partially mediated the association between prenatal maternal sleep and behavioural observation of infant negative emotionality., Interpretation: Findings highlight prenatal sleep as an environmental signal that affects the developing neonatal brain and later infant negative emotionality., Funding: National Institutes of Health (R01MH109662, R01HL155744, P50HD103573, K12AR084226, F32 Training fellowships MH125572, HL165844, MH106440, and diversity supplement R01HL155744-01S1)., Competing Interests: Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

Aims: There is a lack of published evidence relating to the rate of nonunion seen in occult scaphoid fractures, diagnosed only after MRI. This study reports the rate of delayed union and nonunion in a cohort of patients with MRI-detected acute scaphoid fractures., Methods: This multicentre cohort study at eight centres in the UK included all patients with an acute scaphoid fracture diagnosed on MRI having presented acutely following wrist trauma with normal radiographs. Data were gathered retrospectively for a minimum of 12 months at each centre. The primary outcome measures were the rate of acute surgery, delayed union, and nonunion., Results: A total of 1,989 patients underwent acute MRI for a suspected scaphoid fracture during the study period, of which 256 patients (12.9%) were diagnosed with a previously occult scaphoid fracture. Of the patients with scaphoid fractures, six underwent early surgical fixation (2.3%) and there was a total of 16 cases of delayed or nonunion (6.3%) in the remaining 250 patients treated with cast immobilization. Of the nine nonunions (3.5%), seven underwent surgery (2.7%), one opted for non-surgical treatment, and one failed to attend follow-up. Of the seven delayed unions (2.7%), one (0.4%) was treated with surgery at two months, one (0.4%) did not attend further follow-up, and the remaining five fractures (1.9%) healed after further cast immobilization. All fractures treated with surgery had united at follow-up. There was one complication of surgery (prominent screw requiring removal)., Conclusion: MRI-detected scaphoid fractures are not universally benign, with delayed or nonunion of scaphoid fractures diagnosed only after MRI seen in over 6% despite appropriate initial immobilization, with most of these patients with nonunion requiring surgery to achieve union. This study adds weight to the evidence base supporting the use of early MRI for these patients., Competing Interests: B. J. F. Dean reports personal grants from AOUK and the British Medical Association (Doris Hillier grant), not related to this study. M. Brewster reports support in accessing data used from the University Hospitals Birmingham (UHB) site from the informatics team of UHB, related to this study. M. L. Costa reports personal grants from National Institute for Health and Care Research (NIHR) and the Wellcome Trust for research into musculoskeletal trauma, not related to this study., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Background: The rapid maturation of the fetal brain renders the fetus susceptible to prenatal environmental signals. Prenatal maternal sleep quality is known to have important health implications for newborns including risk for preterm birth, however, the effect on the fetal brain is poorly understood., Method: Participants included 94 pregnant participants and their newborns (53% female). Pregnant participants (M age = 30; SD age = 5.29) reported on sleep quality three times throughout pregnancy. Newborn hippocampal and amygdala volumes were assessed using structural magnetic resonance imaging. Multilevel modeling was used to test the associations between trajectories of prenatal maternal sleep quality and newborn hippocampal and amygdala volume., Results: The overall trajectory of prenatal maternal sleep quality was associated with hippocampal volume (left: b = 0.00003, p = 0.013; right: b = 0.00003, p = .008). Follow up analyses assessing timing of exposure indicate that poor sleep quality early in pregnancy was associated with larger hippocampal volume bilaterally (e.g., late gestation left: b = 0.002, p = 0.24; right: b = 0.004, p = .11). Prenatal sleep quality was not associated with amygdala volume., Conclusion: These findings highlight the implications of poor prenatal maternal sleep quality and its role in contributing to newborn hippocampal development., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

The objective of the study was to investigate whether adverse and benevolent childhood experiences were associated with trajectories of sleep quality throughout pregnancy. The study was conducted at obstetrics and gynecology clinics in the Rocky Mountain region of the USA. The participants of the study were pregnant individuals ( N = 164). Sleep quality was measured with the Pittsburgh Sleep Quality Index at three gestational time points, and adverse childhood experiences (ACEs) and benevolent childhood experiences (BCEs) were assessed once. Multilevel models were conducted to examine the trajectory of sleep quality across gestation in relation to ACEs and BCEs. Sleep quality was similar in early to mid-pregnancy, with a worsening of sleep quality late in pregnancy, following a quadratic trajectory. Higher levels of ACEs predicted poorer prenatal sleep quality ( b = 0.36, SE = 0.13, p = .004) throughout pregnancy, while higher levels of BCEs predicted better sleep quality ( b = -0.60, SE = 0.17, p < .001) throughout pregnancy. Examination of ACEs subtypes revealed that childhood maltreatment predicted poor sleep quality ( b = 0.66, SE = 0.18, p < .001), while childhood household dysfunction was not significantly associated ( b = 0.33, SE = 0.21, p = .11). Associations remained after covarying for socioeconomic status and current stressful life events. Both adverse and benevolent childhood experiences predict sleep health during pregnancy. Prevention and intervention strategies targeting resilience and sleep quality during pregnancy should be implemented to promote prenatal health and well-being., Competing Interests: Conflict of Interest The authors declare no competing interests.

Though notable progress has been made in protections for LGBTQ people in the United States, they are still disproportionately victims of discrimination and harassment. Activism efforts on behalf of LGBTQ communities by heterosexual, cisgender people-known as cishet allies-are critical to maintaining and gaining civil rights. Social justice praxis encourages people with privileged identities, such as heterosexuals, to act on behalf of and in coalition with LGBTQ communities. The current study conducted a thematic qualitative content analysis of open-ended self-report data about activist behaviors and beliefs of 249 self-identified cishet allies. Results describe: types of activism, events that sparked activism, motivators for activism, and barriers to activism. Findings show that educating self and others are key activist behaviors while social media usage may mitigate barriers, such as perceived lack of social support and time. Findings are discussed in context of sample limitations and future research directions are outlined.

Objective: This study's purpose was to examine whether disclosures to friends or family post-victimization was associated with emotional and academic consequences (e.g. feeling detached from others, getting worse grades) among students grouped by sexual identity and race intersections. Participants and Methods: We analyzed data from an online survey that was distributed to students ( n  = 6,331) at a university in the Southeast. Results: Path analyses indicated disclosure to friends and family partially mediated the relationship between victimization and consequences, such that an increase in the number of disclosures was associated with an increase in the number of consequences. These paths were significant among White sexual minority victims, sexual minority victims of color, White heterosexual students, and heterosexual students of color. Conclusions: These findings indicate that disclosure to informal sources is associated with amplified consequences, which may be ameliorated by training friends and family to respond to disclosures in a supportive manner.

Abstract: During spring 2018, the U.S. Food and Drug Administration (FDA), Centers for Disease Control and Prevention, and state and local public health agencies responded to a multistate outbreak of gastrointestinal illnesses caused by multiple Salmonella serovars and associated with consumption of kratom, a product harvested from a tropical tree native to Southeast Asia. The outbreak included 199 case-patients reported by 41 U.S. states, with illness onset dates ranging 11 from January 2017 to 8 May 2018, leading to 54 hospitalizations and no deaths. Case-patients reported purchasing kratom products from physical and online retail points of service (POSs). Products distributed to 16 POSs where 24 case-patients from 17 states purchased kratom were selected for traceback investigation. Traceback revealed that the kratom was imported from several countries, the most common being Indonesia. Local and state officials collected product samples from case-patients and retail POSs. The FDA collected 76 product samples from POSs and distributors, of which 42 (55%) tested positive for Salmonella. The positive samples exhibited a range of pulsed-field gel electrophoresis patterns and whole genome sequence genetic heterogeneity, and 25 (60%) of 42 samples yielded at least one isolate indistinguishable from one or more outbreak-related clinical isolates. Although it does not exclude a possibility of a single contamination source, the extent of genetic diversity exhibited by the Salmonella isolates recovered from product samples and a lack of traceback convergence suggested that kratom was widely contaminated across multiple sites from which it was grown, harvested, and packaged. As a result of the contamination, kratom products were recalled by numerous firms (both voluntarily and mandatory). Epidemiologic, traceback, and laboratory evidence supported the conclusion that kratom products were associated with illnesses., (Published 2022 by the International Association for Food Protection. Not subject to U.S. Copyright.)