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Acoustic manipulation is a non-contact process that applies acoustic waves to immobilize particles into a specific region for a variety of potential applications. This provides an alternative way to address air ventilation requirements where building systems are becoming smarter and more efficient. Development of such a process within confined spaces can incorporate microscopic interactions to filter aerosol-based particulate matter (PM). In real-engineering conditions, it is hard to filter sub-micron particles (0.25–1.0 μm) than super-micron particles (> 2.5 μm) by using low-grade filters. The objectives of this work are twofold. First, we propose a new acoustic-driven pre-filtering device (i.e., a U-shaped resonant acoustic chamber) that can improve the working efficiency of low-grade filters for capturing such particles. Second, the device can optimize spatial homogeneity to enhance the removal efficiency of airborne particles under lower sound intensity requirements. The U-shaped acoustic-driven device in the form of a resonant chamber allows PM to reside at the pressure node of a standing wave. Experimental studies are conducted to verify the present design. The results show that an overall filtration efficiency of up to 89% for 1.0-μm airborne particles can be achieved when the acoustic-driven device is coupled together with a low-grade MERV-6 coarse filter. As a standalone device, the acoustic effect works well for the sub-micron particles with a filtration efficiency of up to 61% under a lower sound pressure level (116 dB) than as previously reported in the literature. In the analysis, we also discuss the performance dependence on frequency, sound pressure level and flow rate in terms of particle size distribution. The relevance of this research is a major step towards engineering an acoustic-based pre-filtering technique for developing future innovative ventilation solutions.

Mei-Chun Cheung,1 Janelle SK Lai,1 Joanne Yip,2 Jason Pui Yin Cheung3 1Department of Social Work, The Chinese University of Hong Kong, Hong Kong SAR, China; 2Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong SAR, China; 3Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong SAR, ChinaCorrespondence: Mei-Chun CheungDepartment of Social Work, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, ChinaTel +852-39431862Fax +852-26035018Email meichun@swk.cuhk.edu.hkPurpose: This study aimed to investigate the effects of trunk asymmetry on the health-related quality of life of early adolescents and to identify daily activities that were associated with trunk asymmetry in this cohort.Methods: This study included 200 early adolescents (52 male and 148 female) aged 10 to 14 years in Hong Kong. Among them, 100 adolescents were considered to have trunk asymmetry with angle of trunk rotation ≥ 5° and one or more physical signs on visual inspection. The 36-Item Short Form Health Survey was used to measure the eight scales under the physical and mental domains of the health-related quality of life. The adolescents reported their average daily durations spent (1) using a computer; (2) using a smartphone; (3) watching television, videos or DVDs; (4) doing homework; and (5) doing physical exercise. Independent samples t-tests, chi-square (χ2) tests or Mann–Whitney U-tests were performed to compare the health-related quality of life and the average daily duration of daily activities between early adolescents with and without trunk asymmetry. Logistic regression was performed to investigate the odds ratios of daily activities for trunk asymmetry.Results: Compared with early adolescents without trunk asymmetry, those with trunk asymmetry had a lower health-related quality of life in some of the physical domains, namely, bodily pain and general health, and all mental domains, namely, vitality (energy/fatigue), social functioning, role limitation due to emotional problems and mental health (p < 0.05). Use of computer was found to be significantly associated with trunk asymmetry in early adolescents (OR = 1.63, 95% CI [1.23, 2.14]).Conclusion: Our results indicate that increased computer use is associated with trunk asymmetry, which negatively impacts the health-related quality of life in early adolescents.Keywords: trunk asymmetry, computer, smartphone, health-related quality of life, early adolescents

The development of the worldwide high-speed rail network is expanding at a rapid pace, imposing great challenges on the operation safety. Recent advances in wireless communications and information technology can integrate the Internet of Things and cloud computing to form a real-time monitoring platform of high-speed trains. To realize this system, a sustainable power source is indispensable. In this case, an ideal solution is to deploy a vibration-based energy harvester instead of batteries for the electrical supply of wireless sensors/devices, as vibrations induced by rail/wheel contact forces and vehicle dynamics are an abundant energy source. To address this challenge, a multi-stable, broadband and tri-hybrid energy harvesting technique was recently proposed, which can work well under low-frequency, low-amplitude, and time-varying ambient sources. In this work, we will introduce our idea, following the recently proposed energy harvester and the dynamic responses of a train vehicle, to design a self-sustained sensing system on trains. Supported by this self-powered system, accelerometers and microphones deployed on an in-service train (in axle boxes/bogie frames) can measure vibration and noise data directly. The correlation of the vibration and noise data can then be analyzed simultaneously to identify the dynamic behavior (e.g., wheel defects) of a moving train.

Adolescent idiopathic scoliosis (AIS) is characterized by uneven shoulders, spinal curvature, and uneven hips, and asymmetry in paraspinal muscle activities is common in AIS. This pilot study was aimed at examining the use of a surface electromyography (sEMG) biofeedback posture training program in adolescents with mild scoliosis ( Cob b ’ s angle < 30 ° ) to attenuate asymmetry in paraspinal muscle activities and control the curve progression. Seven female adolescents (age, 12–14 years) with mild scoliosis ( Cob b ’ s angle < 30 ° ) were recruited. The participants received 30 tailor-made sessions of sEMG biofeedback posture training at a rate of one to two sessions per week for approximately 6 months. The activities of the paraspinal muscles (the trapezius, latissimus dorsi, thoracic erector spinae, and lumbar erector spinae) measured by sEMG during habitual sitting postures and spinal deformity evaluated by 3D ultrasound imaging were compared before and after training. The mean values of the root-mean-square sEMG ratio, an index of symmetry in paraspinal muscle activities of the muscle pairs between the concave and convex sides of the spinal curve, revealed significant asymmetry over the trapezius and lumbar erector spinae before the training (p p < 0.05 ). In two adolescents, the spinal curvature decreased by 5.7° and 5.6°, respectively, whereas the remaining adolescents showed a minimal curve progression with changes in the spinal curvature controlled under 5°. To conclude, sEMG biofeedback posture training can reduce asymmetry in paraspinal muscle activities and control curve progression in adolescents with mild scoliosis and can potentially be considered an alternative early intervention for muscle reeducation in this cohort.

Background Coxsackievirus A6 (CV-A6) represents the predominant enterovirus serotype in Hong Kong, but its epidemiology in our population was unknown. Objectives To examine the clinical and molecular epidemiology of CV-A6 and detect emerging recombinant strains in Hong Kong. Study design Nasopharyngeal aspirates (NPAs) from patients with febrile or respiratory illness were subject to RT-PCR for CV-A6 and sequencing of 5′-NCR and VP1. CV-A6-positive samples were further subject to 2C and 3D gene sequencing. Complete genome sequencing was performed on potential recombinant strains. Results Thirty-six (0.35%) NPAs were positive for CV-A6 by 5′-NCR RT-PCR and sequencing, 28 of which confirmed by partial VP1 gene sequencing. Among the 28 patients (mainly young children) with CV-A6 infection, hand-foot-and-mouth disease (HFMD) (43%), herpangina (18%) and tonsillitis (11%) were the most common diagnoses. Seven (25%) patients had neurological manifestations, including febrile seizures, encephalitis and meningitis. VP1 gene analysis showed that 24 CV-A6 strains circulating in Hong Kong belonged to genotype D5, while 4 strains belonged to D4. Further 2C and 3D gene analysis revealed eight potential recombinant strains. Genome sequencing of five selected strains confirmed four recombinant strains: HK459455/2013 belonging to recombination group RJ arisen from CV-A6/CV-A4, HK458288/2015 and HK446377/2015 representing novel group RL arisen from CV-A6/CV-A4, and HK462069/2015 representing novel group RM arisen from CV-A6/EV-A71. Recombination breakpoints located at 3D were identified in the latter three recombinant strains, with HK462069/2015 (from a child with encephalitis) having acquired 3D region from EV-A71. Conclusions We identified novel recombinant CV-A6 strains in Hong Kong, with 3D being a common recombination site.

Summary Autism susceptibility candidate 2 (AUTS2), a risk gene for autism spectrum disorders (ASDs), is implicated in telencephalon development. Because AUTS2 is also expressed in the cerebellum where defects have been linked to ASDs, we investigated AUTS2 functions in the cerebellum. AUTS2 is specifically localized in Purkinje cells (PCs) and Golgi cells during postnatal development. Auts2 conditional knockout (cKO) mice exhibited smaller and deformed cerebella containing immature-shaped PCs with reduced expression of Cacna1a. Auts2 cKO and knock-down experiments implicated AUTS2 participation in elimination and translocation of climbing fiber synapses and restriction of parallel fiber synapse numbers. Auts2 cKO mice exhibited behavioral impairments in motor learning and vocal communications. Because Cacna1a is known to regulate synapse development in PCs, it suggests that AUTS2 is required for PC maturation to elicit normal development of PC synapses and thus the impairment of AUTS2 may cause cerebellar dysfunction related to psychiatric illnesses such as ASDs., Graphical Abstract, Highlights • Loss of Auts2 leads to the reduction of cerebellar size • AUTS2 promotes the dendritic maturation of Purkinje cells • AUTS2 participates in PF and CF synapse development of Purkinje cells • Auts2 cKO mice exhibit the impaired motor learning and vocal communications, Molecular Neuroscience; Developmental Neuroscience; Cellular Neuroscience

Study Objective Working memory deficits in children with obstructive sleep apnea (OSA) have been reported in previous studies, but the results were inconclusive. This study tried to address this issue by delineating working memory functions into executive processes and storage/maintenance components based on Baddeley's working memory model. Methods Working memory and basic attention tasks were administered on 23 OSA children aged 8–12 years and 22 age-, education-, and general cognitive functioning-matched controls. Data on overnight polysomnographic sleep study and working memory functions were compared between the two groups. Associations between respiratory-related parameters and cognitive performance were explored in the OSA group. Results Compared with controls, children with OSA had poorer performance on both tasks of basic storage and central executive components in the verbal domain of working memory, above and beyond basic attention and processing speed impairments; such differences were not significant in the visuo-spatial domain. Moreover, correlational analyses and hierarchical regression analyses further suggested that obstructive apnea–hypopnea index (OAHI) and oxygen saturation (SpO 2 ) nadir were associated with verbal working memory performance, highlighting the potential pathophysiological mechanisms of OSA-induced cognitive deficits. Conclusions Verbal working memory impairments associated with OSA may compromise children's learning potentials and neurocognitive development. Early identification of OSA and assessment of the associated neurocognitive deficits are of paramount importance. Reversibility of cognitive deficits after treatment would be a critical outcome indicator.

The Gupta-type many-body potential was applied to describe the interactions between atoms in zinc nanoclusters. From the calculated ground state structures, obtained by Brownian-type molecular dynamic simulation, we investigated the temperature effect of zinc clusters. We studied in particular the constant volume specific heat CV which is a thermodynamic quantity and also the relative bond length Lindemann parameter δ which is a geometric quantity. Effort is devoted to revealing the anomalies observed in these quantities for Zn clusters and making a comparison with those of the typical sp-type metallic clusters. To this end, we have chosen to calculate the CV and δ of clusters Znn for 29, 33, and 53 which are judged to be less stable by the energy difference and the second energy difference as well as 6, 36, 42, and 49 which are judged by the same energy criteria to be relatively more stable. Our results of simulation show that the structures of CV and δ exhibit unusual phase transition behaviors which ar...

Floating gate memories are the mainstream of flash non volatile memories and have followed Moore's law scaling through multiple technology generations, representing one of the fastest growing memory segments. Looking forward, maintaining the pace of Moore's law scaling is increasingly difficult. The challenging areas include electrical, physical and reliability characteristics of the memory cell. However, through innovative device design, introduction of new materials and memory error management, we anticipate that floating gate flash memories are economically viable beyond 45 nm to 32 nm. In this paper, the physical and electrical scaling challenges as well as possible solutions are discussed. Further, more complex, structural innovations may be possible to maintain further scaling.

ETOX flash memory [1] was developed to give the lowest cost electrical reprogrammable memory. However, for some application, it is desirable to have low density of byte alterable FLOTOX memories [2].

The use of flash memories, which are based on the technology of either erasable programmable ROMs (EPROMs) or electrically erasable programmable ROMs (EEPROMs), as an alternative to both of the latter is discussed. Their properties are compared to those of EPROMs and EEPROMs. Quality and reliability issues are considered. The future of all three memory types is discussed. >

The temperature dependence of the electronic magnetic susceptibilities of liquid caesium metal is investigated using a full nonlocal pseudopotential theory. A notable feature of the present theory is that it incorporates a highly reliable Generalised Non-local Model Pseudopotential formfactor and a liquid structure factor determined self-consistently from the Monte Carlo technique

It is demonstrated that the anomalous temperature dependence of the electrical resistivity, as experimentally reported for liquid binary alloys of simple metals, arises primarily from the significant decrease in the partial localization of the valence electrons on the electronegative component.

Summarization: This paper presents a novel kinematics-based differential evolution (kDE) technique to minimize the energy of molecular conformations using both robotics and evolutionary concepts. The kDE model consists of two modules: the pre-computation and the DE-loop. During pre-computation, a molecule is represented as a kinematics chain that deforms and adopts different conformations. At the DE-loop, a differential evolution algorithm is used for directing the search towards low-energy molecular conformations. Preliminary results demonstrate the effectiveness of our approach in rapidly identifying low-energy molecular conformations while attaining good convergence performance. The proposed technique can be used in nanoscale design and molecular docking applications. Παρουσιάστηκε στο: IEE 2009 Industrial Engineering Research Conference

It is demonstrated that in a full nonlocal pseudopotential calculation of the density of states, the results from the standard formula, N(E) = N(E FE )k ( ∂E k ∂k ) −1 , do not differ significantly from those using the Green-function method and are reliable for simple liquid metals, despite the fact that there is an uncertainty in treating E k as a dispersion function.