Validity of Energy Expenditure Estimation Equation using Heart Rate in Swimming

PURPOSE The purpose of this study was to develop an estimation equation that predicts energy expenditure (EE) during swimming exercise based on heart rate (HR). And, we also evaluated the validation for field application and compare it with the existing speed-based swimming EE equation. METHODS A total of 63 healthy adults (ages 19-49 years) who could swim at various speeds were conveniently sampled. The experi-ment was conducted in an indoor 25 m pool. The protocol (measurement of individual best performance, 0.4, 0.6, 0.8, <1.0 m/s) was performed for 4 minutes each according to the level of the individual. EE was evaluated using a portable respiratory gas analyzer (K4b2, Cosmed, Italy) and a swimming snorkel (Aqua Trainer Snorkel, Cosmed, Italy). HR was measured using a waterproof HR chest strap (Polar Electro Oy, Polar V800, Finland). A dummy control regression analysis was performed with the EE measured by the respiratory gas analyzer as the dependent variables and sex, age, height, weight, and HR during exercise as independent variables. RESULTS The participants in this study were randomly divided into two groups; the equation development (n=42) and the validation group (n=21). The estimation of EE during swimming exercise is as follows; EEm=-18.197-1.966 (Gender: men=0, women=1)+.027 (Age, year)+.073 (Height, cm)+.008 (Weight, kg)+.092 (HR, bpm) R2 = 78% (adj. R2 = 77.2%). The HR-based swimming EE estimation equation (mean=0.7, difference=6.7) verified by the Bland & Altman plot showed the lowest error, followed by Monpetit (mean=1.6, difference=11.6) and Costill (Mean=0.4, difference=16.7). CONCLUSIONS The EE during swimming was developed using physical characteristics such as sex, age, height, weight and HR in this study. This swimming EE equation might be used for commercial wearable devices

Distinct features of B cell receptors in neuromyelitis optica spectrum disorder among CNS inflammatory demyelinating diseases

Background Neuromyelitis optica spectrum disorder (NMOSD) stands out among CNS inflammatory demyelinating diseases (CIDDs) due to its unique disease characteristics, including severe clinical attacks with extensive lesions and its association with systemic autoimmune diseases. We aimed to investigate whether characteristics of B cell receptors (BCRs) differ between NMOSD and other CIDDs using high-throughput sequencing. Methods From a prospective cohort, we recruited patients with CIDDs and categorized them based on the presence and type of autoantibodies: NMOSD with anti-aquaporin-4 antibodies, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) with anti-myelin oligodendrocyte glycoprotein antibodies, double-seronegative demyelinating disease (DSN), and healthy controls (HCs). The BCR features, including isotype class, clonality, somatic hypermutation (SHM), and the third complementarity-determining region (CDR3) length, were analyzed and compared among the different disease groups. Results Blood samples from 33 patients with CIDDs (13 NMOSD, 12 MOGAD, and 8 DSN) and 34 HCs were investigated for BCR sequencing. Patients with NMOSD tended to have more activated BCR features compare to the other disease groups. They showed a lower proportion of unswitched isotypes (IgM and IgD) and a higher proportion of switched isotypes (IgG), increased clonality of BCRs, higher rates of SHM, and shorter lengths of CDR3. Notably, advanced age was identified as a clinical factor associated with these activated BCR features, including increased levels of clonality and SHM rates in the NMOSD group. Conversely, no such clinical factors were found to be associated with activated BCR features in the other CIDD groups. Conclusions NMOSD patients, among those with CIDDs, displayed the most pronounced B cell activation, characterized by higher levels of isotype class switching, clonality, SHM rates, and shorter CDR3 lengths. These findings suggest that B cell-mediated humoral immune responses and characteristics in NMOSD patients are distinct from those observed in the other CIDDs, including MOGAD. Age was identified as a clinical factor associated with BCR activation specifically in NMOSD, implying the significance of persistent B cell activation attributed to anti-aquaporin-4 antibodies, even in the absence of clinical relapses throughout an individuals lifetime.This study was supported by grants from the National Research Foundation of Korea (NRF) (2023R1A2C2007798); Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HR18C0016, HR21C0198); and Asan Institute for Life Science (2022IF0019, 2019IP0853-1), Asan Medical Center, Seoul, South Korea. This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI22C0553). This study was supported by a Medical Scientist Training Program from the Ministry of Science & ICT of Korea

A 3D-Printed Millifluidic Platform Enabling Bacterial Preconcentration and DNA Purification for Molecular Detection of Pathogens in Blood

Molecular detection of pathogens in clinical samples often requires pretreatment techniques, including immunomagnetic separation and magnetic silica-bead-based DNA purification to obtain the purified DNA of pathogens. These two techniques usually rely on handling small tubes containing a few millilitres of the sample and manual operation, implying that an automated system encompassing both techniques is needed for larger quantities of the samples. Here, we report a three-dimensional (3D)-printed millifluidic platform that enables bacterial preconcentration and genomic DNA (gDNA) purification for improving the molecular detection of target pathogens in blood samples. The device consists of two millichannels and one chamber, which can be used to preconcentrate pathogens bound to antibody-conjugated magnetic nanoparticles (Ab-MNPs) and subsequently extract gDNA using magnetic silica beads (MSBs) in a sequential manner. The platform was able to preconcentrate very low concentrations (1&ndash;1000 colony forming units (CFU)) of Escherichia coli O157:H7 and extract their genomic DNA in 10 mL of buffer and 10% blood within 30 min. The performance of the platform was verified by detecting as low as 1 CFU of E. coli O157:H7 in 10% blood using either polymerase chain reaction (PCR) with post gel electrophoresis or quantitative PCR. The results suggest that the 3D-printed millifluidic platform is highly useful for lowering the limitations on molecular detection in blood by preconcentrating the target pathogen and isolating its DNA in a large volume of the sample

Good for Us? Good for Me? Government Intervention for Sustainability and Service Quality

Korean government???s recent policy prohibits lodging properties from offering disposable hotel amenities including shampoo, soaps, and toothbrushes. Lodging businesses in Korea have been forced to either remove amenities or offer substitutes. Government policies for social and environmental sustainability often force businesses to cease existing services and offer substitutes, which is likely to harm service quality and customer satisfaction. Therefore, the business needs to understand how customers respond to such interventions and possible service quality declines. This study examines whether and how types of substitutes (i.e., perfect substitutes, imperfect substitutes, and no substitutes) that a hotel provides to comply with the government sustainability policy influence customers??? policy acceptance and customer satisfaction with the service. We also propose that the influence of substitute types on customer satisfaction and policy acceptance be moderated by the communication messages of the hotel. More specifically, we employ regulatory focus theory to develop the communication message frame, namely prevention hope and promotion hope. Our results show that consumers offered perfect substitutes have greater policy acceptance and higher satisfaction than those offered imperfect substitutes and no substitutes. Interestingly, however, no significant differences in satisfaction and policy acceptance are found between imperfect substitutes and no substitute groups. In terms of communication messages, a message with a promotion hope frame is more effective than a prevention hope message to improve the satisfaction of the incomplete substitute group, while no significant differences in satisfaction between the two message frames are found for perfect substitutes and no substitute groups. With the findings, we provide meaningful insights into how businesses respond to government intervention for sustainability and offer useful managerial implications

Time-Continuous Real-Time Trajectory Generation for Safe Autonomous Flight of a Quadrotor in Unknown Environment

In this paper, we present an efficient global and local replanning method for a quadrotor to complete a flight mission in a cluttered and unmapped environment. A minimum-snap global path planner generates a global trajectory that comprises some waypoints in a cluttered environment. When facing unexpected obstacles, our method modifies the global trajectory using geometrical planning and closed-form formulation for an analytical solution with 9th-order polynomial. The proposed method provides an analytical solution, not a numerical one, and it is computationally efficient without falling into a local minima problem. In a simulation, we show that the proposed method can fly a quadrotor faster than the numerical method in a cluttered environment. Furthermore, we show in experiments that the proposed method can provide safer and faster trajectory generation than the numerical method in a real environment