Search

Eveningness and insomnia are highly comorbid and closely related to psychopathology in adolescents. We aimed to prospectively investigate the trajectories and associations of eveningness and insomnia with daytime functioning, depression and suicidal risk in adolescents.A 3-year longitudinal study was conducted among 414 Chinese adolescents. The associations of eveningness and insomnia with daytime functioning, depression and suicidal ideation were analyzed using logistic regressions.The prevalence rates of eveningness were similar at baseline and follow-up (19.3% vs 22.5%; p = 0.27), while the prevalence of insomnia increased at follow-up (29.2% vs 40.8%; p0.001). Among those eveningness adolescents (n=80) at baseline, 46.2% remained as stable evening-type at follow-up, and among those insomnia adolescents (n=121) at baseline, 64.5% had persistent insomnia at follow-up. Logistic regressions showed that stable, incident, and resolved eveningness were associated with excessive daytime sleepiness (EDS) at follow-up, while only persistent and incident insomnia increased the risk of EDS. Persistent and incident insomnia, as well as stable eveningness were independently associated with depression at follow-up. Persistent and incident insomnia, but not eveningness, were associated with suicidal ideation.The outcome assessments were based on self-reported questionnaires and the sample size is modest.Persistent eveningness and insomnia are significantly associated with greater risks of EDS and depression in adolescents, while both persistent and incident insomnia, but not eveningness, increased the risk of suicidal ideation. These findings underscore the importance of addressing sleep and circadian factors in the management of adolescent mood and daytime functioning.

BACKGROUND AND OBJECTIVE This study aimed to investigate if childhood primary snoring (PS) was associated with adverse cardiovascular outcomes at 5-year follow-up. METHODS This was a prospective matched cohort study. Subjects were recruited from a hospital-based cohort established from years 2006 to 2012 and they were aged 6-18 years at baseline. Each subject with PS was gender, age and BMI z-score matched with a control who had normal sleep study (obstructive apnoea-hypopnoea index [OAHI]

Background and objective We evaluated inattention and behavioural outcomes following surgery versus watchful waiting (WW) in school-aged children with mild obstructive sleep apnoea (OSA). Methods A prospective randomized controlled study was performed in pre-pubertal children aged 6-11 years with polysomnography (PSG)-confirmed mild OSA. They were assigned randomly to early surgical intervention (ES) or WW. The surgical intervention consisting of tonsillectomy with or without adenoidectomy and turbinate reduction was carried out within 4-6 weeks after randomization. Both groups underwent PSG, attention and behavioural assessment and review by an otorhinolaryngologist at baseline and 9-month follow-up. The primary outcome was omission T score from Conners' continuous performance test (CPT). Secondary outcomes were parent-reported behaviours, quality of life, symptoms and PSG parameters. Results A total of 114 participants were randomized. Data of 35 subjects from the ES and 36 from the WW group were available for final analysis. No significant treatment effect could be found in all CPT parameters and behavioural outcomes. Nevertheless, significantly greater reductions were seen in PSG parameters (obstructive apnoea-hypopnoea index [-1.4 ± 2.0 cf. +0.3 ± 4.1/h, p = 0.038] and arousal index [-1.3 ± 4.4 cf. +1.4 ± 4.5/h, p = 0.013]) and OSA-18 total symptom score (-17.3 ± 19.7 cf. -3.6 ± 14.1, p = 0.001) in the ES group. Subjects who underwent surgery also had significantly greater weight gain (+3.3 ± 2.1 cf. +2.2 ± 1.5 kg, p = 0.014) and increase in systolic blood pressure (+5.1 ± 12.4 cf. -1.2 ± 8.7 mm Hg, p = 0.016). Conclusion Despite improvements in PSG parameters and parent-reported symptoms, surgical treatment did not lead to parallel improvements in objective attention measures in school-aged children with mild OSA.

A new conductive-plate-integrated inductive power transfer (IPT) system for automated guided vehicles with little output power variation according to air-gap changes between the transmitter (Tx) and receiver (Rx) is proposed. The inductance change of the ferrite core due to variations in the air gap is nullified by a corresponding change in an aluminum plate. Compared to conventional ferrite IPT systems, self-inductance of the proposed Tx coil is little changed against air-gap variations, which results in robust resonant frequency and output voltage. The self-inductance was experimentally verified to remain within 0.45% even when the air gap changes by fivefold from 10 to 50 mm. The output power variation became a twelfth of that of the conventional ferrite IPT for air-gap variations of 30 ∼ 50 mm, where the efficiency was found to be 96.0% when the output power was 1 kW.

An optimal ampere-turns design for a long-distance dipole-coil-based inductive power transfer (IPT) system for maximum power efficiency is proposed in this article. Assuming that specific requirements, which are the target load power, the physical size of the transmitting (Tx) and receiving (Rx) coils, and the distance between the Tx and Rx coils, are given, quantitative analyses on the optimal ampere-turns of loosely coupled Tx and Rx coils to satisfy the constraints with maximum power efficiency have been conducted in this article. With the proposed design process, the IPT system is expected to be designed and fabricated with minimal cost and time. The maximum experimental error is only 8.8% when the delivery power ranges from 20–200 W in the experiment results, thus demonstrating that the method proposed in this article can suggest a viable design direction of the IPT system.

In this article, a novel structure of a receiving (Rx) coil with only two coils, which enables omnidirectional wireless power transfer (WPT) for any type of transmitting (Tx) system, is proposed for the first time. The coil adopts each coils into plane cross-shaped ferrite core, with each leg of the ferrite core intersecting both coils. The intersecting direction of the ferrite core for one coil is identical to that of the other one when it is rotated 90 degrees. It is verified that voltage will be induced on at least one coil with any direction of magnetic flux. With an analysis of circuit diagram, it is shown that a high quality factor of each coil can guarantee an omnidirectional power transfer even when the coupling coefficient between two coils has a nonzero value. A simulation model and an experimental prototype is built to verify the omnidirectional WPT of the proposed Rx coil structure, with loop-type Tx coil as an example among various Tx types. Omnidirectional power transfer capability of the proposed coil was verified with a light emitting diode (LED) load. The superiority of the proposed coil was verified by comparison with other Rx coil structures also.

In this article, a simple and cost-effective symmetric sensing coil set to be used for the metal object detection (MOD) in a stationary wireless electric vehicle charger is newly proposed. Compared to the conventional nonoverlapping sensing coil using the magnetic field change detection method, the proposed symmetric sensing coil set design offers the considerable advantage of eliminating all blind zones, i.e., regions where metal is undetectable in the conventional method. Moreover, by reducing the number of layers to one, the fabrication of the proposed sensing coil is easier and more cost effective. The design of the proposed sensing coil is optimized for highly sensitive MOD based on a sensitivity equation and on the finite element method simulations. An experiment conducted with a metal object 40 × 40 mm2 in size and a 20 A transmitting (Tx) coil current verifies the reliability and the blind-zone elimination feature of the proposed sensing coil.

Association between asthma control and cardiovascular disease (CVD) remains highly plausible as the two are related to chronic systemic inflammation. Children with physician-diagnosed asthma and matched healthy controls underwent endothelial function assessment. Repeat measurements were performed in uncontrolled asthmatics after initiation or up-titration of inhaled corticosteroids (ICS), compared to those with well-controlled asthma without ICS therapy. We found that children with uncontrolled asthma had inferior endothelial function compared to matched healthy controls. Enhancement in endothelial function, lung function and symptom control was observed in uncontrolled asthmatics after initiation or up-titration of inhaled corticosteroids (ICS). These results provided further evidence of a likely relationship between asthma control and cardiovascular health.

Background: Environmental tobacco smoke (ETS) exposure in children ranks one of the major public health problems in our time. Poor parental knowledge, attitude, and practice (KAP) on ETS often contribute to worse exposure of the kids. Thus, we aimed to document parental KAP regarding tobacco use, smoking cessation and children's ETS exposure, and to analyse how knowledge and attitude relate to practice.Methods: Self-administered KAP questionnaires were distributed to smoking parents recruited from the pediatric unit at the Prince of Wales Hospital, which provides pediatric service to a population of 1.2 million in Hong Kong. The 60-item questionnaire had a range of 0–38 for knowledge, 0–44 for attitude, and 0–40 for practice. Descriptive analyses were performed for KAP response, regression analyses were performed for the exploration of associations and identification of predictive indicators.Results: 145 smoking parents (mean age: 38.0 ± 6.7 yrs.; male: 85.5%) were included. Less than half (39.3%) of them reported a smoke-free policy at home. Among those parents who had private cars, less than half (45.2%) of them had smoke-free policy in their car that they never smoked in the car. Only 25.5% of the participants correctly answered ≥70% of the knowledge questions, and 11.8 % of the participants gave favorable responses to ≥70% of the attitude questions. The total knowledge and the total attitudes score were positively associated (r = 0.49, 95% CI: 0.35–0.79, p < 0.001), yet they were only modestly correlated with parental practice on children's ETS exposure. By multivariate regressions, potential predictive factors for more favorable parental KAP included higher household income, lower parental nicotine dependence level and breastfeeding practice.Conclusions: Parental KAP related to tobacco use and children's ETS exposure needs improvement to address the significant gap between recommended and actual practice. The weak association between knowledge and practice suggested that parental education alone is not adequate to combat ETS exposure in children.

Study Objectives:Previous studies suggest the presence of familial aggregation of obstructive sleep apnea (OSA) in adults. However, similar data on childhood OSA are limited. This family study aime...

In this paper, a novel loop coil structure for synthesized magnetic field focusing (SMF) technology and two current distribution calculating algorithms in the structure are proposed. The proposed structure enables field focusing in two-dimensional (2-D) space for the first time. The loop coil structure with a rectangular formation is adopted for a 2-D SMF system to minimize the volume and weight of the transmitting (Tx) coil array considering that conventional SMF systems inevitably have a volumetric design due to their dipole-based structure. Two algorithms to calculate the current distribution so as to focus the magnetic field at the target point are proposed. The first algorithm applies the Biot–Savart law to a loop-coil-based 2-D SMF system to calculate the distribution. The second algorithm utilizes a time-efficient synthesis method which reduces the matrix dimensions used in current distribution calculation. The second algorithm shows synthesis results with similar synthesis resolution compared with the first algorithm. Although the magnetic field distribution with the second algorithm has a little difference with that of first algorithm, its synthesis result focuses the magnetic field on the target point successfully, and it becomes more powerful as the number of coils increases. Synthesis results using two algorithms were compared with a finite-element method simulation with 100 Tx coils and 25 receiving (Rx) points. The synthesis resolution, as determined by –3 dB points, was enhanced by 4.45 times and 6.15 times for the first and the second algorithm, respectively, when compared to nonfocused case. An experimental prototype with 36 Tx coils and 9 Rx points with each coil 10 × 10 cm in size was built to demonstrate field focusing with current distributions calculated by the second algorithm at a frequency of 145 kHz. The experimental results were in good agreement with the simulated results, including a case in which the magnetic field was focused at Rx point other than center.

In this paper, an autotuning control system (ACS), which utilizes the variation of self-inductance of a transmitter (Tx) coil caused by a ferrite core of a receiver (Rx), is newly proposed for the dynamic wireless electric vehicle (EV) charging. A Tx module consists of only passive elements that include a Tx coil, a partially compensated capacitor in series with the Tx coil, and a parallel compensation capacitor. All Tx modules share an ac bus line that passes the output filter of an inverter in parallel without any active switches. The current of the coupled Tx coil increases automatically without any manipulations such as controlling the power switches, sensing, or communication when the Rx module is approaching. Not only the system efficiency is increased by the reduction of the conduction losses from the uncoupled Tx modules, but control also becomes simpler because sensors are not required for detecting EVs, and the constant output voltage characteristics can be obtained. Through experiments, it was found that the proposed ACS is suitable for applications such as a tram that runs along an orbit with a small air gap, such as a train. The results showed that the current of a coupled Tx coil increased 11.6 times larger than that of an uncoupled Tx coil, at which time the dc–dc efficiency achieved was 88.4% for an output power of 766 W (10 Ω of load resistance) at the laboratory scale.

New coreless transmitting (Tx) coils with a conductive material plate for wide-range ubiquitous inductive power transfer (IPT) zones, i.e., U-IPT zones, where electric devices can be wirelessly charged during operation, are proposed in this paper. Because commercialized IPT systems are only available for short distances of several centimeters and one-to-one charging, the demand is increasing for U-IPT zones in which long-distance wireless charging with three-dimensional (3-D) free-positioning and simultaneous charging of multiple receiving (Rx) coils can be achieved. To satisfy this demand, U-IPT zones should be constructed to have a uniform magnetic field distribution in a wide space, which also poses no risk to the human body. In addition, to generate a uniform magnetic field in a wide 3-D space, such as a single room, the system requires the installation of many Tx coils above the ceilings and behind the walls of the room, and these coils should be capable of high electrical performance to support the efficiency of the entire IPT system and should be of excellent mechanical quality. Therefore, a U-IPT zone should meet the following four criteria: human safety, free-positioning of Rx coils, magnetic field uniformity, and economization. By virtue of a conductive material plate that cancels out the undesired direction of magnetic flux generated from the return wires, the proposed coreless Tx coil does not need any heavy ferromagnetic cores, which can cause nonuniformity of the magnetic field distribution and difficult construction. A prototype coreless Tx coil with the dimensions of 1 m × 1 m × 10 cm was fabricated and experimentally verified for a 1 m × 1 m U-IPT zone. The experimental results showed that 74%, 83%, and 76% high magnetic field uniformity could be achieved for $z_{1}= {{25}}$ cm, 50 cm, and 75 cm, respectively, and a 3-D omnidirectional wireless power delivery was achieved, while the guideline of the International Commission on Non-Ionizing Radiation Protection for human safety was satisfied throughout the entire U-IPT zone. Moreover, the weight of the entire system was only 9 kg, enabling easy installation. In the multiple wireless charging experiments, 47 W of power was consumed in total by load resistors, each of them connected to nine Rx coils, respectively, with 32% power efficiency at $z_{1}= {{20}}$ cm.

Study Objectives Childhood obstructive sleep apnea (OSA) is an important and prevalent disease. A short lingual frenulum is a risk factor for OSA, but whether tongue mobility also plays a role in OSA etiology remains unknown. This study aimed to examine tongue mobility in children with and without OSA. We hypothesized that reduced tongue mobility was associated with OSA. We also evaluated the relationship between tongue mobility and craniofacial profile. Methods This was a cross-sectional case-control study. Prepubertal Chinese children aged 5–12 years, suspected to have OSA were recruited from our sleep disorder clinic. All subjects underwent overnight polysomnography. The lingual frenulum was evaluated based on tongue mobility and free tongue length. Craniofacial measurements were assessed by lateral cephalometry. Results Eighty-two subjects (mean age: 8.32 ± 1.70 years, 57 males) were recruited. The mean tongue mobility was 58.2 (±19)% and 67.4 (±15)% (p = 0.019) in subjects with and without OSA, respectively. Tongue mobility was inversely correlated with OAHI (r = −0.218, p = 0.049). In multivariate logistic regression, low tongue mobility was independently associated with a higher risk of OSA after adjustment for age, sex, body mass index z-score, presence of large tonsils and turbinates, and nocturnal oral breathing (odds ratio = 3.65, 95% CI = 1.22 to 11.8). Tongue mobility was found to correlate with the cranial base angle (Ba-S-N) (r = 0.262, p = 0.018), which determines the relative position of the mandible. Conclusions In prepubertal children, reduced tongue mobility is associated with the occurrence and severity of OSA. Assessing tongue mobility is recommended in childhood OSA management.

An intermediate phenotype of a disease is a trait in the path of pathogenesis from genetic predisposition to disease manifestation. Identifying intermediate phenotypes with high heritability is helpful in delineating the genetics of a disorder. In this study, we aimed to examine various traits with regards to obesity, cardiovascular risk and upper airway structure to identify potential intermediate phenotypes of childhood obstructive sleep apnea (OSA). Children aged between 6 and 18 years and their parents and siblings were recruited. All subjects underwent anthropometric measurements, cardiovascular risk assessment, sonographic measurement of lateral parapharyngeal wall (LPW) thickness, X-ray cephalometry and overnight polysomnography. A total of 34 phenotypes were examined. One hundred and one families consisting of 127 children (46 overweight) and 198 adults (84 overweight) were recruited. Heritability of obstructive apnea-hypopnea index (OAHI) was significant in overweight (h2 = 0.54) but not normal-weight individuals (h2 = 0.12). LPW thickness (h2 = 0.68) and resting blood pressure (h2 = 0.36 and 0.43 for systolic blood pressure [SBP] and diastolic blood pressure [DBP], respectively) were significantly heritable and associated with OAHI. Moreover, these traits were found to have shared genetic variance with OAHI in the overweight subgroup. Hyoid bone position also had significant heritability (h2 = 0.55) and association with OAHI but genetic correlation with OSA severity was not demonstrated. These findings suggest that LPW thickness and resting blood pressure are possible intermediate phenotypes of OSA independent of body mass index, especially in overweight patients. Identifying genes relevant to these phenotypes may help to elucidate the genetic susceptibility of OSA.

Objective During the COVID-19 pandemic, central venous access line teams were implemented at many hospitals throughout the world to provide access for critically ill patients. The objective of this study was to describe the structure, practice patterns, and outcomes of these vascular access teams during the COVID-19 pandemic. Methods We conducted a cross-sectional, self-reported study of central venous access line teams in hospitals afflicted with the COVID-19 pandemic. To participate in the study, hospitals were required to meet one of the following criteria: development of a formal plan for a central venous access line team during the pandemic; implementation of a central venous access line team during the pandemic; placement of central venous access by a designated practice group during the pandemic as part of routine clinical practice; or management of an iatrogenic complication related to central venous access in a patient with COVID-19. Results Participants from 60 hospitals in 13 countries contributed data to the study. Central venous line teams were most commonly composed of vascular surgery and general surgery attending physicians and trainees. Twenty sites had 2657 lines placed by their central venous access line team or designated practice group. During that time, there were 11 (0.4%) iatrogenic complications associated with central venous access procedures performed by the line team or group at those 20 sites. Triple lumen catheters, Cordis (Santa Clara, Calif) catheters, and nontunneled hemodialysis catheters were the most common types of central venous lines placed by the teams. Eight (14%) sites reported experience in placing central venous lines in prone, ventilated patients with COVID-19. A dedicated line cart was used by 35 (59%) of the hospitals. Less than 50% (24 [41%]) of the participating sites reported managing thrombosed central lines in COVID-19 patients. Twenty-three of the sites managed 48 iatrogenic complications in patients with COVID-19 (including complications caused by providers outside of the line team or designated practice group). Conclusions Implementation of a dedicated central venous access line team during a pandemic or other health care crisis is a way by which physicians trained in central venous access can contribute their expertise to a stressed health care system. A line team composed of physicians with vascular skill sets provides relief to resource-constrained intensive care unit, ward, and emergency medicine teams with a low rate of iatrogenic complications relative to historical reports. We recommend that a plan for central venous access line team implementation be in place for future health care crises.