Prediction of Apnea-Hypopnea Index Using Sound Data Collected by a Noncontact Device

OBJECTIVE

To predict the apnea-hypopnea index (AHI) in patients with obstructive sleep apnea (OSA) using data from breathing sounds recorded using a noncontact device during sleep.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral hospital.

SUBJECT AND METHODS

Audio recordings during sleep were performed using an air-conduction microphone during polysomnography. Breathing sounds recorded from all sleep stages were analyzed. After noise reduction preprocessing, the audio data were segmented into 5-second windows and sound features were extracted. Estimation of AHI by regression analysis was performed using a Gaussian process, support vector machine, random forest, and simple linear regression, along with 10-fold cross-validation.

RESULTS

In total, 116 patients who underwent attended, in-laboratory, full-night polysomnography were included. Overall, random forest resulted in the highest performance with the highest correlation coefficient (0.83) and least mean absolute error (9.64 events/h) and root mean squared error (13.72 events/h). Other models resulted in somewhat lower but similar performances, with correlation coefficients ranging from 0.74 to 0.79. The estimated AHI tended to be underestimated as the severity of OSA increased. Regarding bias and precision, estimation performances in the severe OSA subgroup were the lowest, regardless of the model used. Among sound features, derivative of the area methods of moments of overall standard deviation demonstrated the highest correlation with AHI.

CONCLUSION

AHI was fairly predictable by using data from breathing sounds generated during sleep. The prediction model may be useful not only for prescreening but also for follow-up after treatment in patients with OSA.

Temporal response of polymer waveguide beam scanner with thermo-optic phase-modulator array

Solid-state light detection and ranging, capable of performing beam scanning without using any mechanical moving parts, requires a phase-modulator array. Polymers facilitate the fabrication of efficient phase modulators with low drive power, owing to their high thermo-optic (TO) effect and low thermal conductivity. We designed and fabricated a polymeric phase-modulator array and analyzed the temporal response of the TO phase modulator. The frequency response of the phase modulator was measured for a Mach-Zehnder interferometer (MZI), and the transfer function was modeled in terms of multiple poles and zeros. The frequency response of a fabricated beam-scanning device incorporating the TO phase modulator was also measured. The temporal response of the beam scanner was confirmed to coincide well with that of the MZI modulator. The device exhibited a fast rise time of 12 ms, accompanied by slight power variations appearing for a long period (over hundreds of seconds), which originated from the inherent viscoelastic effect of the polymer materials.

Efficient Luminescence of Sr2Si5N8:Eu2+ nanophosphor and its film applications to LED and Solar cell as a downconverter

Here we present the synthesis of the efficient nanophosphor Sr₂Si₅N₈:Eu²⁺ (D₅₀ = 144 nm) by a simple milling approach, its strong Rayleigh scattering, and its film applications to white LED and silicon solar cell as a downshifting medium. The final nanophosphor product showed the quantum efficiency comparable to the bulk phosphor which is, to our knowledge, the highest record of nitride nanophosphors. Especially the nanophosphor showed the more tail emission at the shorter-wavelength side of the emission spectrum and the faster thermal quenching with the more spectral broadening along with the temperature due to Rayleigh scattering. Also the lowering in the excitation spectrum was observed due to lower absorbance. Finally, the nanophosphor-dispersed polyvinyl alcohol (PVA) film was made, and its applications to white LED and silicon solar cell as a downshifting medium demonstrated that it gave the high color rendering property in white LED in spite of still lower luminous efficiency, and it caused the increase in efficiency of silicon solar cell.

A chemically bonded supercapacitor using a highly stretchable and adhesive gel polymer electrolyte based on an ionic liquid and epoxy-triblock diamine network

Despite significant advances in the development of flexible gel polymer electrolytes (GPEs), there are still problems to be addressed to apply them to flexible electric double layer capacitors (EDLCs), including interfacial interactions between the electrolyte and electrode under deformation. Previously reported EDLCs using GPEs have laminated structures with weak interfacial interactions between the electrode and electrolyte, leading to fragility upon elongation and low power density due to lower utilization of the surface area of the carbon material in the electrode. To overcome these problems, we present a new strategy for constructing an epoxy-based GPE that can provide strong adhesion between electrode and electrolyte. The GPE is synthesized by polymerization of epoxy and an ionic liquid. This GPE shows high flexibility up to 509% and excellent adhesive properties that enable strong chemical bonding between the electrode and electrolyte. Moreover, the GPE is stable at high voltage and high temperature with high ionic conductivity of ∼10⁻³ S cm⁻¹. EDLCs based on the developed GPE exhibit good compatibility between the electrode and electrolyte and work properly when deformed. The EDLCs also show a high specific capacitance of 99 F g⁻¹, energy density of 113 W h kg⁻¹, and power density of 4.5 kW g⁻¹. The excellent performance of the GPE gives it tremendous potential for use in next generation electronic devices such as wearable devices.

A chemically bonded supercapacitor using a stretchable and adhesive gel polymer electrolyte based on ionic liquid and epoxy for flexible devices.

Equilibrium structures of water molecules confined within a multiply connected carbon nanotube: a molecular dynamics study

Water confinement inside a carbon nanotube (CNT) has been one of the most exciting subjects of both experimental and theoretical interest. Most of the previous studies, however, considered CNT structures with simple cylindrical shapes. In this paper, we report a classical molecular dynamics study of the equilibrium structural arrangement of water molecules confined in a multiply connected carbon nanotube (MCCNT) containing two Y-junctions. We investigate the structural arrangement of the water molecules in the MCCNT in terms of the density of water molecules and the average number of hydrogen bonds per water molecule. Our results show that the structural rearrangement of the H2O molecules takes place several angstroms ahead of the Y-junction, rather than only at the CNT junction itself. This phenomenon arises because it is difficult to match the boundary condition for hydrogen bonding in the region where two different hydrogen-bonded structures are interconnected with each other.

Utilization of Phosphate Alternatives in Marinated Chicken Breast and Chunked and Formed Deli Ham

Experiments were conducted to determine the efficacy of replacing phosphates in marinated chicken and chunked and formed deli ham using alternative ingredient blends. For the marinated chicken study, broiler breasts were marinated with a 13% solution of 1.0% NaCl, water and either 0.35% sodium tripolyphosphate or a phosphate alternative. Treatment variables consisted of (1) 0.35% sodium tripolyphosphate (STP), (2) negative control (no phosphate, NP), (3) 0.83% Whey protein concentrate (WPC), (4) 0.83% Oat fiber (OF, marinated chicken only), or (5) 1.05% Oat fiber with dry vinegar (OFDV).The WPC, OF, and OF-DV treatments also included 1,000 ppm of a natural flavor that served as an antioxidant. The STP treatment yielded breast meat with less (P < 0.05) cooking loss and a higher pH (P < 0.05) than the NP and alternative ingredient treatments. On average, no differences were observed (P > 0.05) in consumer acceptability for chicken breast appearance, texture and overall acceptability. For the ham study, each treatment formulation consisted of approximately 77% pork, 20% water, common commercial curing ingredients, and the following treatment effects: STP (0.4% STP), NP (no phosphate, NP), 1.3% OF-DV, and 1.1% WPC. STP had less cooking loss than all other treatments (P < 0.05). The STP treatment had greater protein bind (P < 0.05) than all other treatments, and the OF-DV treatment had greater protein bind than the WPC and NP treatments. The NP, STP, and WPC treatments were preferred (P < 0.05) over the OF-DV treatment. Application of WPC or OF-DV may help meat processors meet current clean label trends if the decrease in yields for chicken breast and deli hams and the decrease in firmness of texture in deli hams is acceptable to processors and consumers.

Measurement of finger joint angle using stretchable carbon nanotube strain sensor

Strain sensors capable of monitoring complex human motions are highly desirable for the development of wearable electronic devices and healthcare monitoring systems. Excellent sensitivity and a wide working range of the sensor material are important requirements for distinguishing dynamic human motion. In this study, a highly stretchable strain sensor was fabricated via inkjet printing of single-walled carbon nanotube (SWCNT) thin films on a stretchable polydimethylsiloxane substrate. The sensor was attached to the metacarpophalangeal (MCP) joint of the hand in 12 healthy male subjects. The subjects placed their hands next to a conventional goniometer and flexed the MCP joint to predetermined angles. A linear relationship was found between the change in the length of the strain sensor and the intended angle of the MCP joint. The fabricated thin films showed high durability during repeated cycling (1,000 cycles) and good sensitivity with a gauge factor of 2.75. This study demonstrates that the newly developed stretchable CNT strain sensor can be used for effectively measuring MCP joint angles. This sensor may also be useful for the analysis of complex and dynamic hand motions that are difficult to measure using a conventional goniometer.

Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15  GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15  GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.

Facile Fabrication of Polyvinyl Alcohol/Edge-Selectively Oxidized Graphene Composite Fibers

Graphene derivatives are effective nanofillers for the enhancement of the matrix mechanical properties; nonetheless, graphene oxide (GO), reduced GO, and exfoliated graphene all present distinct advantages and disadvantages. In this study, polyvinyl alcohol (PVA) composite fibers have been prepared using a recently reported graphene derivative, i.e., edge-selectively oxidized graphene (EOG). The PVA/EOG composite fibers were simply fabricated via conventional wet-spinning methods; thus, they can be produced at the commercial level. X-ray diffractometry, scanning electron microscopy, and two-dimensional wide-angle X-ray scattering analyses were conducted to evaluate the EOG dispersibility and alignment in the PVA matrix. The tensile strength of the PVA/EOG composite fibers was 631.4 MPa at an EOG concentration of 0.3 wt %, which is 31.4% higher compared with PVA-only fibers (480.6 MPa); compared with PVA composite fibers made with GO, which is the most famous water-dispersible graphene derivative, the proposed PVA/EOG ones exhibited about 10% higher tensile strength. Therefore, EOG can be considered an effective nanofiller to enhance the strength of PVA fibers without additional thermal or chemical reduction processes.

Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

Measurements of anisotropic flow coefficients (v_{n}) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at sqrt[s]=13  TeV, p-Pb at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, Xe-Xe at sqrt[s_{NN}]=5.44  TeV, and Pb-Pb at sqrt[s_{NN}]=5.02  TeV recorded with the ALICE detector. The multiplicity dependence of v_{n} is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|<0.8 for the transverse momentum range 0.2<p_{T}<3.0  GeV/c. An ordering of the coefficients v_{2}>v_{3}>v_{4} is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v_{2} multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v_{2} measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between v_{n}^{2} and v_{m}^{2}, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v_{2} and v_{4}, while for v_{2} and v_{3} it is negative and changes sign for multiplicities below 100, which may indicate a different v_{n} fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems.

Burden and clinical characteristics of high grade tuberculosis destroyed lung: a nationwide study

Background

Little clinical information on high grade tuberculosis destroyed lung (TDL) is available. The aim of this study was to investigate the characteristics and healthcare utilization of high grade TDL patients, and compared the differences between acute exacerbation and healthcare burden according to inhaler compliance.

Methods

This was an observational retrospective cohort study using the Korean Health Insurance Review and Assessment (HIRA) service database (2011-2015). Patients diagnosed with high grade TDL in 2011 were enrolled and reviewed for 5 years. The patients were further divided into adherent and non-adherent groups. Their socioeconomic outcomes according to treatment adherence in 2012 were analyzed.

Results

Among the 13,346 patients diagnosed with high grade TDL, 3,637 were assigned to the adherent group and 9,709 to the non-adherent group. Overall, 65.91% of the enrolled patients were male and the mean age of the study population was 64.68±10.06 years. All patients visited a tertiary hospital, but 99.04% and 69.74% also visited primary and secondary hospitals, respectively. The mean number of hospital admissions per year was 1.38±2.03 times per patient. The average total annual per-patient cost was US$4,140.95±3,715.01 and each patient spent a total of 56.21±45.28 days per year using hospital services. The majority of the patients in the adherent group were male (80.09% vs. 60.60%, P<0.01), and were of older age (65.71±9.35 vs. 64.29±10.28, P<0.01) than the non-adherent group. The frequencies of visiting a tertiary hospital (96.87 vs. 90.12%, P<0.01), the total mean healthcare utilization costs (US$4,151.77±4,084.76 vs. US$3,592.54±4,229.93, P<0.01), and the frequencies of exacerbations (0.72±2.03 vs. 0.46±1.51, P<0.01) were higher in the adherent group. However, healthcare services were used on significantly fewer days in the adherent group (52.96±50.87 vs. 56.67±50.81, P<0.01).

Conclusions

High grade TDL imposes a high socioeconomic burden in Korea. Estimated medical costs and exacerbation event rate were higher in the adherent group whereas number of days of healthcare usage was significantly lower.

P5350Atrial fibrillation prediction using P wave signal-averaged ECG in patients with embolic stroke of undetermined source

Background

Approximately 10–25% of ischemic strokes are of unknown origin. Determining their potential association with subclinical atrial fibrillation (SCAF) is important for proper secondary prevention. We investigated whether SCAF can be predicted by assessing the atrial substrate with signal-averaged electrocardiography (SAECG).

Methods

Between April 2015 and February 2018, we recruited 125 consecutive patients with embolic stroke of undetermined source (ESUS) and 125 patients with paroxysmal atrial fibrillation (AF) patients as control. All participants underwent P wave SAECG at baseline and ESUS patients were followed up with ECG and Holter ECG, at baseline, 3, 6, and 12 months after discharge, and every 12 months thereafter.

Results

In the ESUS group (69 males, 68.4±12.1 years), 32 (25.6%) patients were diagnosed with SCAF during follow-up. There were no significant differences between both groups in terms of P wave duration [PWD] (ESUS vs. AF, P=0.321). PWD demonstrated a significant predictive efficacy for SCAF detection during follow-up (C-index of standard PWD=0.657, 95% confidence interval (CI) 0.552–0.761, P=0.008).

Stroke recurrence occurred in 22 patients (17.6%) and was significantly associated with PWD but not SCAF (odds ratio 2.756, 95% CI 1.061–7.161, P=0.037).

Conclusion

PWD, an ECG biomarker associated with atrial substrate directly contributes to AF and ESUS, is useful for predicting SCAF. The potential for using this simple ECG biomarker for screening for SCAF amongst ESUS patients merits further exploration.

P3762The impact of type and burden of atrial fibrillation on stroke occurrence in patients with atrial fibrillation: from a prospective cohort of atrial fibrillation patients (CODE-AF Registry)

Background and purpose

Although several studies reported that stroke risk in patients with paroxysmal atrial fibrillation (AF) is similar to those with persistent or permanent AF, there is still controversy on the relationship of AF type and stroke occurrence. We investigated the effect of AF type on AF burden and stroke risk in patients with non-valvular AF.

Methods

Within the CODE-AF prospective, outpatient registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation), we identified 8,883 patients ≥18 years of age with non-valvular AF and eligible follow-up visits. We compared AF burden and stroke risk among patients with 3 types of AF: paroxysmal (n=5,808) or persistent (n=2,806) or permanent (n=269).

Results

The median age of the overall population was 68.0 (interquartile range, 60.0–75.0); 36.0% were female. Patients with persistent and permanent AF were older and had higher CHA2DS2-VASc scores and anticoagulation rate than those with paroxysmal AF. Compared with permanent AF (5.2±16.4%), the arrhythmic burden of AF on 24hrs Holter monitoring was significantly lower in paroxysmal AF (2.1±7.2%, p<0.001) and persistent AF (2.0±7.5%, p<0.001). During median follow-up period of 1.38 years (interquartile range: 0.96–1.67), total 82 (0.92%) patients experienced ischemic stroke with incidence rates of 0.51, 1.04 and 1.69 events per 100 person-years for paroxysmal, persistent and permanent AF, respectively. Compared with paroxysmal AF, the risk of ischemic stroke was increased in persistent AF with clinical variable adjusted hazard ratio (aHR) of 1.94 (95% confidence intervals [CI], 1.23–3.07; P=0.005) and permanent AF with aHR of 2.64 (95% CI, 1.09–6.41; P=0.03).

AF type and HR of stroke occurrence Paroxysmal (n=5,808) Persistent (n=2,806) Permanent (n=269) Stoke events 39 37 6 Person years (PYs) 7673 3544 356 /100 PYs 0.51 1.04 1.69 HR (95% CI), p-value HR (95% CI), p-value HR (95% CI), p-value Unadjusted HR 1 (Reference) 2.05 (1.27–3.31), 0.003 3.32 (1.15–7.90), 0.02 Clinical variables adjusted HR 1 (Reference) 1.94 (1.23–3.07), 0.005 2.64 (1.09–6.41), 0.03 PYs: Person years; HR: Hazard ratio.

Conclusion

Persistent and permanent AF was associated with the increased risk of stroke than paroxysmal AF, after adjustment of clinical variables including age, sex, comorbidities and anticoagulation rate. These results suggest that AF type and burden might be related with the risk of ischemic stroke and should be considered in the stroke prevention of AF.

First Observation of an Attractive Interaction between a Proton and a Cascade Baryon

This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.

Management of a young patient with dextrocardia, atrial septal defect, and Eisenmenger syndrome with venous-venous extracorporeal membrane oxygenation and heart-lung transplantation

Dextrocardia is a rare congenital condition which presents important challenges for surgical management. We discuss a patient with dextrocardia, atrial septal defect, and Eisenmenger syndrome, which ultimately led to decompensated end-stage lung disease and heart-lung transplant. Venous-venous extracorporeal membrane oxygenation was an important strategy to bridge the patient until donor organs became available. Transplantation of a heart-lung block allowed for the treatment of the patient's underlying congenital heart defect, anatomic reversal of dextrocardia with appropriate venous and arterial connections, and management of pulmonary damage from pulmonary hypertension.

DSCR1-mediated TET1 splicing regulates miR-124 expression to control adult hippocampal neurogenesis

Whether epigenetic factors such as DNA methylation and microRNAs interact to control adult hippocampal neurogenesis is not fully understood. Here, we show that Down syndrome critical region 1 (DSCR1) protein plays a key role in adult hippocampal neurogenesis by modulating two epigenetic factors: TET1 and miR-124. We find that DSCR1 mutant mice have impaired adult hippocampal neurogenesis. DSCR1 binds to TET1 introns to regulate splicing of TET1, thereby modulating TET1 level. Furthermore, TET1 controls the demethylation of the miRNA-124 promoter to modulate miR-124 expression. Correcting the level of TET1 in DSCR1 knockout mice is sufficient to prevent defective adult neurogenesis. Importantly, restoring DSCR1 level in a Down syndrome mouse model effectively rescued adult neurogenesis and learning and memory deficits. Our study reveals that DSCR1 plays a critical upstream role in epigenetic regulation of adult neurogenesis and provides insights into potential therapeutic strategy for treating cognitive defects in Down syndrome.

Radiation exposure during videofluoroscopic swallowing studies in young children

OBJECTIVES

Swallowing difficulties are best assessed by videofluoroscopic swallowing studies (VFSS). However, limiting radiation exposure is important, especially in young children. The purpose was to evaluate radiation dose in young children during VFSS, and to investigate factors associated with it.

METHODS

Children with swallowing difficulty who underwent VFSS from February 2012 to July 2014 were recruited. Dose area product (DAP) and screening time were offered by the fluoroscopy machine, and effective dose was calculated from the DAP using a conversion coefficient published by the National Radiological Protection Board (NRPB-R262). The age, gender, height, weight, body mass index (BMI), body surface area (BSA), underlying disease of the subject children, and results of VFSS were investigated.

RESULTS

In 89 children (mean age 1.57 ± 2.17, 55 boys and 34 girls), mean effective dose was 0.29 ± 0.20 mSv, mean DAP was 2.41 ± 1.65 Gy cm², and mean screening time was 2.24 ± 0.99 min. The effective dose correlated with the screening time (r = 0.598, p < 0.001), age (r = 0.210, p = 0.049), height (r = 0.521, p < 0.001), weight (r = 0.461, p < 0.001), and BSA (r = 0.493, p < 0.001). There was no such correlation with gender, BMI, underlying disease, or the results of VFSS.

CONCLUSIONS

The effective dose during VFSS (0.29 mSv) in young children, which is affected by screening time, age, and body size, is considerably lower than the pediatric radiation exposure limit of 1 mSv per year. However more than 4 VFSS annually would exceed this limit. Our findings will help physicians to reduce the radiation exposure and provide a useful references for future pediatric VFSS guidelines.

Highly stretchable multi-walled carbon nanotube/thermoplastic polyurethane composite fibers for ultrasensitive, wearable strain sensors

Here, we report a novel highly sensitive wearable strain sensor based on a highly stretchable multi-walled carbon nanotube (MWCNT)/Thermoplastic Polyurethane (TPU) fiber obtained via a wet spinning process. The MWCNT/TPU fiber showed the highest tensile strength and ultra-high sensitivity with a gauge factor (GF) of approximately 2800 in the strain range of 5-100%. Due to its high strain sensitivity of conductivity, this CNT-reinforced composite fiber was able to be used to monitor the weight and shape of an object based on the 2D mapping of resistance changes. Moreover, the composite fiber was able to be stitched onto a highly stretchable elastic bandage using a sewing machine to produce a wearable strain sensor for the detection of diverse human motions. We also demonstrated the detection of finger motion by fabricating a smart glove at the joints. Due to its scalable production process, high stretchability and ultrasensitivity, the MWCNT/TPU fiber may open a new avenue for the fabrication of next-generation stretchable textile-based strain sensors.

Channel Measurement and Feasibility Test for Wireless Avionics Intra-Communications

Wireless avionics intra-communication (WAIC) refers to a wireless communication system among electronic components (e.g., sensors and actuators) that are integrated or installed in an aircraft and it is proposed to replace heavy and expensive wired communication cables. Recently, the use of a frequency band (4.2⁻4.4 GHz) for the WAIC (so-called, WAIC band) has been approved by international telecommunication union (ITU). Accordingly, several existing wireless protocols such as IEEE 802.11 and IEEE 802.15 are being considered as candidate techniques for the intra-avionics sensor network. In this paper, we perform a real field experiment to investigate wireless channel characteristics in intra-avionics sensor networks at the WAIC bands by a software-defined radio platform (universal software radio peripheral, USRP) and self-produced monopole antennas for the WAIC band. Through the experiment, we validated the feasibility of IEEE 802.11 protocol for the intra-avionics sensor network at the WAIC band in real aircraft environments. Furthermore, based on the measurement data, we evaluated the bit error rate (BER) performance of multiple antenna techniques where we considered the maximum ratio combining (MRC) for the multi-antenna receiver and the space-time block coding (STBC) for the multi-antenna transmitter.

Soft Modular Electronic Blocks (SMEBs): A Strategy for Tailored Wearable Health-Monitoring Systems

Precise monitoring of human body signals can be achieved by soft, conformal contact and precise arrangement of wearable devices to the desired body positions. So far, no design and fabrication methodology in soft wearable devices is able to address the variations in the form factor of the human body such as the various sizes and shapes of individual body parts, which can significantly cause misalignments and the corresponding inaccurate monitoring. Here, a concept of soft modular electronic blocks (SMEBs) enabling the assembly of soft wearable systems onto human skin with functions and layouts tailored to the form factors of individuals' bodies is presented. Three types of SMEBs are developed as fundamental building blocks for functional modularization. The physical design of SMEBs is optimized for a mechanically stable island-bridge configuration. The prepared SMEBs can be integrated onto a target body part through rapid, room-temperature (RT) assembly (<5 s) using an oxygen plasma-induced siloxane bonding method. A soft metacarpophalangeal (MP) joints flexion monitoring system that is tailored to allow for accurate monitoring for multiple individuals with unique joint and hand sizes is demonstrated.

Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|η|<0.8) are measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV. The analysis is carried out for the 0%-20% (high) and 60%-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v_{2}) for heavy-flavor decay electrons in the transverse momentum interval 1.5<p_{T}<4  GeV/c in high-multiplicity events, with a significance larger than 5σ. The results are compared with those of charged particles at midrapidity and those of inclusive muons at forward rapidity. The v_{2} measurement of open heavy-flavor particles at midrapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems.

Thermal and Structural Stabilities of LixCoO2 cathode for Li Secondary Battery Studied by a Temperature Programmed Reduction

Temperature programmed reduction (TPR) method was introduced to analyze the structural change and thermal stability of LixCoO2 (LCO) cathode material. The reduction peaks of delithiated LCO clearly represented the different phases of LCO. The reduction peak at a temperature below 250 °C can be attributed to the transformation of CoO2–like to Co3O4–like phase which is similar reduction patterns of CoO2 phase resulting from delithiation of LCO structure. The 2nd reduction peak at 300~375 °C corresponds to the reduction of Co3O4–like phase to CoO–like phase. TPR results indicate the thermal instability of delithiated LCO driven by CoO2–like phase on the surface of the delithiated LCO. In the TPR kinetics, the activation energies (Ea) obtained for as-synthesized LCO were 105.6 and 82.7 kJ mol-1 for Tm_H1 and Tm_H2, respectively, whereas Ea for the delithiated LCO were 93.2, 124.1 and 216.3 kJ mol-1 for Tm_L1, Tm_L2 and Tm_L3, respectively. As a result, the TPR method enables to identify the structural changes and thermal stability of each phase and effectively characterize the distinctive thermal behavior between as-synthesized and delithiated LCO.

Megahertz-wave-transmitting conducting polymer electrode for device-to-device integration

The ideal combination of high optical transparency and high electrical conductivity, especially at very low frequencies of less than the gigahertz (GHz) order, such as the radiofrequencies at which electronic devices operate (tens of kHz to hundreds of GHz), is fundamental incompatibility, which creates a barrier to the realization of enhanced user interfaces and ‘device-to-device integration.’ Herein, we present a design strategy for preparing a megahertz (MHz)-transparent conductor, based on a plasma frequency controlled by the electrical conductivity, with the ultimate goal of device-to-device integration through electromagnetic wave transmittance. This approach is verified experimentally using a conducting polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), the microstructure of which is manipulated by employing a solution process. The use of a transparent conducting polymer as an electrode enables the fabrication of a fully functional touch-controlled display device and magnetic resonance imaging (MRI)-compatible biomedical monitoring device, which would open up a new paradigm for transparent conductors.

The emergence of applications requiring device-to-device interactivity has to the need to develop conducting electrodes with high optical transparency at low radiofrequencies. Here, the authors demonstrate conductive polymer electrodes with high transparency in the MHz-order frequency range.

Au decoration of a graphene microchannel for self-activated chemoresistive flexible gas sensors with substantially enhanced response to hydrogen

Graphene is one of the most promising materials for high-performance gas sensors due to its unique properties such as high sensitivity at room temperature, transparency, and flexibility. However, the low selectivity and irreversible behavior of graphene-based gas sensors are major problems. Here, we present unprecedented room temperature hydrogen detection by Au nanoclusters supported on self-activated graphene. Compared to pristine graphene sensors, the Au-decorated graphene sensors exhibit highly improved gas-sensing properties upon exposure to various gases. In particular, an unexpected substantial enhancement in H2 detection is found, which has never been reported for Au decoration on any type of chemoresistive material. Density functional theory calculations reveal that Au nanoclusters on graphene contribute to the adsorption of H atoms, whereas the surfaces of Au and graphene do not bind with H atoms individually. The discovery of such a new functionality in the existing material platform holds the key to diverse research areas based on metal nanocluster/graphene heterostructures.

Choroid Plexus Carcinoma in Adults: Two Case Reports

Choroid plexus tumors are uncommon brain tumors that primarily occur in children. Most of these tumors originate from the intraventricular area, and the most common clinicalpresentation is increased intracranial pressure. Dissemination through the cerebrospinal fluid space is the inevitable natural course of the disease. Here, we present 2 rare cases of adult choroid plexus carcinoma (CPC), each with distinct clinical presentation and progression. The first case was a 40-year-old male who presented with multiple intraventricular masses. After surgical biopsy, radiation and intrathecal chemotherapy failed to elicit any response. The patient progressed with spinal cord dissemination and expired 1 year later. The second case presented with visual disturbance, and brain MRI revealed a large ovoid juxtaventricular mass with peritumoral edema. This 49-year-old female patient underwent craniotomy for what was thought to be a high-grade glioma; however, the mass was connected to the choroid plexus at the operative field. Her pathology specimen was diagnosed as CPC, and adjuvant systemic chemotherapy was administered. She has now been free of recurrence for 10 months. The description of the presentation and progression of these rare adult-onset CPC provides insight for the diagnosis and treatment of other rare instances of choroid plexus tumors.