Development of an advanced composite system form for constructability improvement through a Design for Six Sigma process

System form is widely used when constructing concrete buildings and structures because it has high productivity and good concrete casting quality compared with traditional hand-set form. However, from a worker’s perspective, system form is still very harsh to handle because of its heavy weight, noise generation, and use of releasing agent, and it also attenuates the productivity of system formwork. Therefore, this study proposes the use of an advanced composite material-based concrete form for workers using a Design for Six Sigma (DFSS) process to improve constructability of system formwork. User requirements are systematically reflected in the technical characteristics of concrete form, and innovative principles are scientifically organized through the DFSS process that mainly consists of quality function deployment and theory of creative problem-solving methods. The proposed composite form showed improved performance in deriving high-quality formwork and worker-friendly working conditions compared with previous system forms. Additionally, this study demonstrated how the DFSS will be a valuable tool for technology development and systematic decision-making in building construction

Acute Severe Symptomatic Hyponatremia Following Coronary Angiography

Hyponatremia is a relatively common electrolyte disorder. Although severe acute hyponatremia following coronary angiography is rare, potentially lethal neurologic manifestations may result. We describe a patient with severe, symptomatic hyponatremia, an unusual complication of coronary angiography. Lack of familiarity with contrast media-related hyponatremia caused a delay in diagnosis and therapy in our case. The diagnosis of acute hyponatremia should be considered in any patient who develops behavioral or neurologic manifestations following coronary angiography. Prompt diagnosis and treatment is essential to avoid permanent neurologic damage or death

A fatal case report of invasive pulmonary aspergillosis and mucormycosis coinfection in an immunocompetent patient with coronavirus disease 2019 in Korea

Systemic glucocorticoid treatment is highly recommended in critically ill coronavirus disease 2019 (COVID-19) patients. However, secondary fungal infections are of concern in such patients. Here, we describe the first case of COVID-19-associated invasive pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) coinfection in a COVID-19 positive immunocompetent patient in Korea. A 69-year-old man was admitted to our hospital with COVID-19 pneumonia. He had no underlying comorbidities and was not taking medications. He received remdesivir, dexamethasone, and antibiotic therapy under mechanical ventilation. Although his condition improved temporarily, multiple cavities were observed on chest computed tomography, and Aspergillus fumigatus was cultured from tracheal aspiration culture. He was diagnosed with probable CAPA and received voriconazole therapy. However, his condition was not significantly improved despite having received voriconazole therapy for 4 weeks. After release from COVID-19 quarantine, he underwent bronchoscopy examination and was then finally diagnosed with CAPA and CAM coinfection on bronchoscopic biopsy. Antifungal treatment was changed to liposomal amphotericin B. However, his progress deteriorated, and he died 4 months after admission. This case highlights that clinical suspicion and active checkups are required to diagnose secondary fungal infections in immunocompetent COVID-19 patients who receive concurrent glucocorticoid therapy

Guided bone regeneration with beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone membrane in partial defects of canine humerus

This study was performed to evaluate the effect of beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone (TCP/PLGC) membrane in the repair of partial bone defects in canine proximal humerus. Three adult mixed-breed dogs were used during the experimental period. The length of the defect was quarter of the full length of humerus, and width of the defect was quarter of middle diameter of the lateral aspect of humerus. The humeri of each dog were divided into treatment (TCP/PLGC) and control groups. The defect was covered with TCP/PLGC membrane in treatment group. To evaluate regeneration of the bone, computerized tomography (CT) and histopathologic examination were performed. The radiopaque lines were appeared at the original defect sites in TCP/PLGC group but below the original site in control at 4th week. Radiopacity and thickness of the defect sites, and radiopaque lines were more increased at 8th week than those of 4th week. Histopathologic findings revealed fibrous connective tissue migration into the defect and the migration inhibited the structure of new cortex to be placed in the original level in control whereas new cortex growth was found in the level of original line in TCP/PLGC group. However, the new cortical bone in the TCP/PLGC group was thinner and less organized than the adjacent intact cortex, and the amount of new cancellous bones were also scanty. The result suggested that TCP/PLGC membrane is a good guided bone regeneration material to restore the original morphology of humerus in partial defect

Prediction of Obstructive Sleep Apnea Based on Respiratory Sounds Recorded Between Sleep Onset and Sleep Offset

Objectives To develop a simple algorithm for prescreening of obstructive sleep apnea (OSA) on the basis of respiratorysounds recorded during polysomnography during all sleep stages between sleep onset and offset. Methods Patients who underwent attended, in-laboratory, full-night polysomnography were included. For all patients, audiorecordings were performed with an air-conduction microphone during polysomnography. Analyses included allsleep stages (i.e., N1, N2, N3, rapid eye movement, and waking). After noise reduction preprocessing, data were segmentedinto 5-s windows and sound features were extracted. Prediction models were established and validated with10-fold cross-validation by using simple logistic regression. Binary classifications were separately conducted for threedifferent threshold criteria at apnea hypopnea index (AHI) of 5, 15, or 30. Prediction model characteristics, includingaccuracy, sensitivity, specificity, positive predictive value (precision), negative predictive value, and area under thecurve (AUC) of the receiver operating characteristic were computed. Results A total of 116 subjects were included; their mean age, body mass index, and AHI were 50.4 years, 25.5 kg/m2, and23.0/hr, respectively. A total of 508 sound features were extracted from respiratory sounds recorded throughoutsleep. Accuracies of binary classifiers at AHIs of 5, 15, and 30 were 82.7%, 84.4%, and 85.3%, respectively. Predictionperformances for the classifiers at AHIs of 5, 15, and 30 were AUC, 0.83, 0.901, and 0.91; sensitivity, 87.5%,81.6%, and 60%; and specificity, 67.8%, 87.5%, and 94.1%. Respective precision values of the classifiers were89.5%, 87.5%, and 78.2% for AHIs of 5, 15, and 30. Conclusion This study showed that our binary classifier predicted patients with AHI of ≥15 with sensitivity and specificityof >80% by using respiratory sounds during sleep. Since our prediction model included all sleep stage data, algorithmsbased on respiratory sounds may have a high value for prescreening OSA with mobile devices

Subdermal Flexible Solar Cell Arrays for Powering Medical Electronic Implants

A subdermally implantable flexible photovoltatic (IPV) device is proposed for supplying sustainable electric power to in vivo medical implants. Electric properties of the implanted IPV device are characterized in live animal models. Feasibility of this strategy is demonstrated by operating a flexible pacemaker with the subdermal IPV device which generates DC electric power of ≈647 μW under the skin