Evaluation of the Diagnostic Performance and Efficacy of Wearable Electrocardiogram Monitoring for Arrhythmia Detection after Cardiac Surgery.

Background: Postoperative atrial fibrillation (A-fib) is a serious complication of cardiac surgery that is associated with increased mortality and morbidity. Traditional 24-hour Holter monitors have limitations, which have prompted the development of innovative wearable electrocardiogram (ECG) monitoring devices. This study assessed a patch-type wearable ECG device (MobiCARE-MC100) for monitoring A-fib in patients undergoing cardiac surgery and compared it with 24-hour Holter ECG monitoring. Methods: This was a single-center, prospective, investigator-initiated cohort study that included 39 patients who underwent cardiac surgery between July 2021 and June 2022. Patients underwent simultaneous monitoring with both conventional Holter and patchtype ECG devices for 24 hours. The Holter device was then removed, and patch-type monitoring continued for an additional 48 hours, to determine whether extended monitoring provided benefits in the detection of A-fib. Results: This 72-hour ECG monitoring study included 39 patients, with an average age of 62.2 years, comprising 29 men (74.4%) and 10 women (25.6%). In the initial 24 hours, both monitoring techniques identified the same number of paroxysmal A-fib in 7 out of 39 patients. After 24 hours of monitoring, during the additional 48-hour assessment using the patch-type ECG device, an increase in A-fib burden (9%→38%) was observed in 1 patient. Most patients reported no significant discomfort while using the MobiCARE device. Conclusion: In patients who underwent cardiac surgery, the mobiCARE device demonstrated diagnostic accuracy comparable to that of the conventional Holter monitoring system.

Delayed aortic regurgitation after TEVAR procedure: a case report.

BACKGROUND: Acute aortic regurgitation (AR) is uncommon condition and usually results in an emergent situation because the left ventricle does not adapt quickly due to a sudden increase in end-diastolic volume caused by the regurgitant flow. Thoracic endovascular aortic repair (TEVAR) is a procedure that places a stent-graft on the lesion of thoracic aorta through a minimally invasive approach. CASE PRESENTATION: Here we report that a catheter-induced aortic valve injury associated with TEVAR can cause delayed AR, exemplified by the case of a patient who developed acute AR 42 months after TEVAR. For this, aortic valve replacement was performed and the patient was discharged without complications. CONCLUSION: Our results demonstrate that when a catheter-related procedure is performed around the aortic valve, slight injury of the valve can cause aortic insufficiency even 3 years after surgery. Consequently, when performing a catheter-related procedure around the aortic valve, special attention is always required.

Prognostic Impact of Postoperative Complications in High-Risk Operable Non-small Cell Lung Cancer.

BACKGROUND: Patients with high-risk (HR) operable non-small cell lung cancer (NSCLC) may have unique prognostic factors. This study aimed to evaluate surgical outcomes in HR patients and to investigate prognostic factors in HR patients versus standard-risk (SR) patients. METHODS: In total, 471 consecutive patients who underwent curative lung resection for NSCLC between January 2012 and December 2017 were identified and reviewed retrospectively. Patients were classified into HR (n=77) and SR (n=394) groups according to the American College of Surgeons Oncology Group criteria (Z4099 trial). Postoperative complications were defined as those of grade 2 or higher by the Clavien-Dindo classification. RESULTS: The HR group comprised more men and older patients, had poorer lung function, and had more comorbidities than the SR group. The patients in the HR group also experienced more postoperative complications (p≤0.001). More HR patients died without disease recurrence. The postoperative complication rate was the only significant prognostic factor in multivariable Cox regression analysis for HR patients but not SR patients. HR patients without postoperative complications had a survival rate similar to that of SR patients. CONCLUSION: The overall postoperative survival of HR patients with NSCLC was more strongly affected by postoperative complications than by any other prognostic factor. Care should be taken to minimize postoperative complications, especially in HR patients.

A Complication of Diaphragm Repair Using a Gore-Tex (Expanded Polytetrafluorethylene) Membrane: A Case Report.

A 65-year-old man underwent right trisectionectomy of the liver and reconstruction of the chest wall and diaphragm with a 2-mm Gore-Tex membrane due to recurrent hepatocellular carcinoma. After 3 years, the Gore-Tex membrane in the diaphragm migrated to the abdominal cavity and perforated the colon. We report a rare complication of a Gore-Tex membrane after diaphragm repair.

Development of a Novel Gas-Sensing Platform Based on a Network of Metal Oxide Nanowire Junctions Formed on a Suspended Carbon Nanomesh Backbone.

Junction networks made of longitudinally connected metal oxide nanowires (MOx NWs) have been widely utilized in resistive-type gas sensors because the potential barrier at the NW junctions leads to improved gas sensing performances. However, conventional MOx-NW-based gas sensors exhibit limited gas access to the sensing sites and reduced utilization of the entire NW surfaces because the NW networks are grown on the substrate. This study presents a novel gas sensor platform facilitating the formation of ZnO NW junction networks in a suspended architecture by growing ZnO NWs radially on a suspended carbon mesh backbone consisting of sub-micrometer-sized wires. NW networks were densely formed in the lateral and longitudinal directions of the ZnO NWs, forming additional longitudinally connected junctions in the voids of the carbon mesh. Therefore, target gases could efficiently access the sensing sites, including the junctions and the entire surface of the ZnO NWs. Thus, the present sensor, based on a suspended network of longitudinally connected NW junctions, exhibited enhanced gas response, sensitivity, and lower limit of detection compared to sensors consisting of only laterally connected NWs. In addition, complete sensor structures consisting of a suspended carbon mesh backbone and ZnO NWs could be prepared using only batch fabrication processes such as carbon microelectromechanical systems and hydrothermal synthesis, allowing cost-effective sensor fabrication.

An mHealth App (Speech Banana) for Auditory Training: App Design and Development Study.

BACKGROUND: With the growing adult population using electronic hearing devices such as cochlear implants or hearing aids, there is an increasing worldwide need for auditory training (AT) to promote optimal device use. However, financial resources and scheduling conflicts make clinical AT infeasible. OBJECTIVE: To address this gap between need and accessibility, we primarily aimed to develop a mobile health (mHealth) app called Speech Banana for AT. The app would be substantially more affordable and portable than clinical AT; would deliver a validated training model that is reflective of modern techniques; and would track users' progress in speech comprehension, providing greater continuity between periodic in-person visits. To improve international availability, our secondary aim was to implement the English language training model into Korean as a proof of concept for worldwide usability. METHODS: A problem- and objective-centered Design Science Research Methodology approach was adopted to develop the Speech Banana app. A review of previous literature and computer-based learning programs outlined current AT gaps, whereas interviews with speech pathologists and users clarified the features that were addressed in the app. Past and present users were invited to evaluate the app via community forums and the System Usability Scale. RESULTS: Speech Banana has been implemented in English and Korean languages for iPad and web use. The app comprises 38 lessons, which include analytic exercises pairing visual and auditory stimuli, and synthetic quizzes presenting auditory stimuli only. During quizzes, users type the sentence heard, and the app provides visual feedback on performance. Users may select a male or female speaker and the volume of background noise, allowing for training with a range of frequencies and signal-to-noise ratios. There were more than 3200 downloads of the English iPad app and almost 100 downloads of the Korean app; more than 100 users registered for the web apps. The English app received a System Usability Scale rating of "good" from 6 users, and the Korean app received a rating of "OK" from 16 users. CONCLUSIONS: Speech Banana offers AT accessibility with a validated curriculum, allowing users to develop speech comprehension skills with the aid of a mobile device. This mHealth app holds potential as a supplement to clinical AT, particularly in this era of global telemedicine.

Spatio-temporal patterns of the minimum rest time for outdoor workers exposed to summer heat stress in South Korea.

In this study, the spatio-temporal characteristics of the minimum rest time for the safety of South Korean outdoor workers during hot summer months (June to August) are examined based on the hourly wet-bulb globe temperature (WBGT) across 27 weather stations in South Korea. The WBGT thresholds in the work-rest recommendation of the Korea Occupational Safety and Health Agency (KOSHA 2017) for the quantification of the minimum rest time are evaluated through a comparison of the given thresholds with the occurrences of occupational heat-related illness patients due to outdoor work during hot summer months in South Korea. The long-term (2009-2018) average of the hourly WBGT values during summer months shows that outdoor workers with a moderate workload are exposed to heat stress during approximately 30% of the entire daytime working hours (06:00-18:00). According to the WBGT thresholds modified from the KOSHA (2017) guidelines, the daily minimum rest time for a moderate workload noticeably increases up to 18% (11 min/h) in mid-summer (late July and early August). During mid-summer, the minimum rest time for a continuous moderate outdoor workload even increases up to 31% (18 min/h) between 12:00 and 13:00 and is regionally higher in the southwestern than in the southeastern regions of the Korean Peninsula. These results suggest that in summertime high-heat environments, a mandatory rest time must be provided according to appropriate heat management programs for the safety of workers.

V2X-Communication-Aided Autonomous Driving: System Design and Experimental Validation.

In recent years, research concerning autonomous driving has gained momentum to enhance road safety and traffic efficiency. Relevant concepts are being applied to the fields of perception, planning, and control of automated vehicles to leverage the advantages offered by the vehicle-to-everything (V2X) communication technology. This paper presents a V2X communication-aided autonomous driving system for vehicles. It is comprised of three subsystems: beyond line-of-sight (BLOS) perception, extended planning, and control. Specifically, the BLOS perception subsystem facilitates unlimited LOS environmental perception through data fusion between local perception using on-board sensors and communication perception via V2X. In the extended planning subsystem, various algorithms are presented regarding the route, velocity, and behavior planning to reflect real-time traffic information obtained utilizing V2X communication. To verify the results, the proposed system was integrated into a full-scale vehicle that participated in the 2019 Hyundai Autonomous Vehicle Competition held in K-city with the V2X infrastructure. Using the proposed system, the authors demonstrated successful completion of all assigned real-life-based missions, including emergency braking caused by a jaywalker, detouring around a construction site ahead, complying with traffic signals, collision avoidance, and yielding the ego-lane for an emergency vehicle. The findings of this study demonstrated the possibility of several potential applications of V2X communication with regard to autonomous driving systems.

Increased cerebral blood volume in small arterial vessels is a correlate of amyloid-ß-related cognitive decline.

The protracted accumulation of amyloid-ß (Aß) is a major pathologic hallmark of Alzheimer's disease and may trigger secondary pathological processes that include neurovascular damage. This study was aimed at investigating long-term effects of Aß burden on cerebral blood volume of arterioles and pial arteries (CBVa), possibly present before manifestation of dementia. Aß burden was assessed by 11C Pittsburgh compound-B positron emission tomography in 22 controls and 18 persons with mild cognitive impairment (MCI), [ages: 75(±6) years]. After 2 years, inflow-based vascular space occupancy at ultra-high field strength of 7-Tesla was administered for measuring CBVa, and neuropsychological testing for cognitive decline. Crushing gradients were incorporated during MR-imaging to suppress signals from fast-flowing blood in large arteries, and thereby sensitize inflow-based vascular space occupancy to CBVa in pial arteries and arterioles. CBVa was significantly elevated in MCI compared to cognitively normal controls and regional CBVa related to local Aß deposition. For both MCI and controls, Aß burden and follow-up CBVa in several brain regions synergistically predicted cognitive decline over 2 years. Orbitofrontal CBVa was positively associated with apolipoprotein E e4 carrier status. Increased CBVa may reflect long-term effects of region-specific pathology associated with Aß deposition. Additional studies are needed to clarify the role of the arteriolar system and the potential of CBVa as a biomarker for Aß-related vascular downstream pathology.

Multilevel States of Nano-Electromechanical Switch for a PUF-Based Security Device.

A nano-electromechanical (NEM) switch using multilevel states based on the high security physical unclonable function (PUF) is proposed and experimentally demonstrated. Using the asymmetric random stiction of a silicon nanowire (SiNW), the conventional binary state is simply expanded to a quaternary-state encryption key without increasing chip area. The multiple states are determined by the asymmetrically bent direction and stiction of the SiNW. The experimental results show that the fabricated NEM-PUF with multistates retains unique, random, and robust characteristics, while the key capacity is doubled, even with the same array size footprint.

Designing Surface Chemistry of Silver Nanocrystals for Radio Frequency Circuit Applications.

We introduce solution-based, room temperature- and atmospheric pressure-processed silver nanocrystal (Ag NC)-based electrical circuits and interconnects for radio frequency (RF)/microwave frequency applications. We chemically designed the surface and interface states of Ag NC thin films to achieve high stability, dc and ac conductivity, and minimized RF loss through stepwise ligand exchange, shell coating, and surface cleaning. The chemical and structural properties of the circuits and interconnects affect the high-frequency electrical performance of Ag NC thin films, as confirmed by high-frequency electromagnetic field simulations. An all solution-based process is developed to build coplanar structures, in which Ag NC thin films are positioned at both sides of the substrates. In addition, we fabricated flexible transmission lines and broadband electrical circuits for resistors, interdigitated capacitors, spiral and omega-shaped inductors, and patch antennas with maximum inductance and capacitance values of 3 nH and 2.5 pF at frequencies up to 20 GHz. We believe that our approach will lead to a cost-effective realization of RF circuits and devices in which sensing and wireless communication capabilities are combined for internet-of-things applications.

Effects of climate change-related heat stress on labor productivity in South Korea.

This study assessed the potential impact of heat stress on labor productivity in South Korea; as such, stress is expected to increase due to climate change. To quantify the future loss of labor productivity, we used the relationship between the wet-bulb globe temperature and work-rest cycles with representative concentration pathways (RCPs) 4.5 and 8.5 as the climate change scenarios. If only climate factors are considered, then future labor productivity is expected to decline in most regions from the middle of the twenty-first century onwards (2041-2070). From the late twenty-first century onwards, the productivity of heavy outdoor work could decline by 26.1% from current levels under the RCP 8.5 climate scenario. Further analysis showed that regional differences in labor characteristics and the working population had noteworthy impacts on future labor productivity losses. The heat stress caused by climate change thus has a potentially substantial negative impact on outdoor labor productivity in South Korea.

Transition States of Nanocrystal Thin Films during Ligand-Exchange Processes for Potential Applications in Wearable Sensors.

Ligand exchange is an advanced technique for tuning the various properties of nanocrystal (NC) thin films, widely used in the NC thin-film device applications. Understanding how the NC thin films transform into functional thin-film devices upon ligand exchange is essential. Here, we investigated the process of structural transformation and accompanying property changes in the NC thin films, by monitoring the various characteristics of silver (Ag) NC thin films at each stage of the ligand-exchange process. A transition state was identified in which the ligands are partially exchanged, where the NC thin films showed unexpected electromechanical features with high gauge factors up to 300. A model system was established to explain the origin of the high gauge factors, supported by the observation of spontaneously formed nanocracks and metal-insulator transition from the structural analysis and charge transport study, respectively. Taking advantages of the unique electromechanical properties of the NC thin films, we fabricated flexible strain gauge sensor devices with high sensitivity, reliability, and stability. We introduce a one-step fabrication process, namely, "the time- and spatial-selective ligand-exchange process", for the design of low-cost and high-performance wearable sensors that effectively detect human motion, such as finger or neck muscle movement. This study provides a fundamental understanding of the ligand-exchange process in NCs, as well as an insight into the functionalities of the NC thin films for technological applications.

A Three-Step Resolution-Reconfigurable Hazardous Multi-Gas Sensor Interface for Wireless Air-Quality Monitoring Applications.

This paper presents a resolution-reconfigurable wide-range resistive sensor readout interface for wireless multi-gas monitoring applications that displays results on a smartphone. Three types of sensing resolutions were selected to minimize processing power consumption, and a dual-mode front-end structure was proposed to support the detection of a variety of hazardous gases with wide range of characteristic resistance. The readout integrated circuit (ROIC) was fabricated in a 0.18 µm CMOS process to provide three reconfigurable data conversions that correspond to a low-power resistance-to-digital converter (RDC), a 12-bit successive approximation register (SAR) analog-to-digital converter (ADC), and a 16-bit delta-sigma modulator. For functional feasibility, a wireless sensor system prototype that included in-house microelectromechanical (MEMS) sensing devices and commercial device products was manufactured and experimentally verified to detect a variety of hazardous gases.

Chemically Designed Metallic/Insulating Hybrid Nanostructures with Silver Nanocrystals for Highly Sensitive Wearable Pressure Sensors.

With the increase in interest in wearable tactile pressure sensors for e-skin, researches to make nanostructures to achieve high sensitivity have been actively conducted. However, limitations such as complex fabrication processes using expensive equipment still exist. Herein, simple lithography-free techniques to develop pyramid-like metal/insulator hybrid nanostructures utilizing nanocrystals (NCs) are demonstrated. Ligand-exchanged and unexchanged silver NC thin films are used as metallic and insulating components, respectively. The interfaces of each NC layer are chemically engineered to create discontinuous insulating layers, i.e., spacers for improved sensitivity, and eventually to realize fully solution-processed pressure sensors. Device performance analysis with structural, chemical, and electronic characterization and conductive atomic force microscopy study reveals that hybrid nanostructure based pressure sensor shows an enhanced sensitivity of higher than 500 kPa-1, reliability, and low power consumption with a wide range of pressure sensing. Nano-/micro-hierarchical structures are also designed by combining hybrid nanostructures with conventional microstructures, exhibiting further enhanced sensing range and achieving a record sensitivity of 2.72 × 104 kPa-1. Finally, all-solution-processed pressure sensor arrays with high pixel density, capable of detecting delicate signals with high spatial selectivity much better than the human tactile threshold, are introduced.

Euphorbia kansui Attenuates Insulin Resistance in Obese Human Subjects and High-Fat Diet-Induced Obese Mice.

BACKGROUND: Obesity is a main cause of insulin resistance (IR), metabolic syndrome, and fatty liver diseases. This study evaluated Euphorbia kansui radix (Euphorbia) as a potential treatment option for obesity and obesity-induced IR in obese human and high-fat diet- (HFD-) induced obese mice. METHODS: In the human study, we analyzed the body weight change of 14 patients who took a single dose of 6 g of Euphorbia powder. In the animal study, male mice were divided into three groups: normal chow, HFD, and Euphorbia (high-fat diet and 100 mg/Kg Euphorbia once per week). Body weight, epididymal fat pad weight, fasting blood glucose, fasting insulin, HOMA-IR, and oral glucose tolerance test were measured. Also, macrophage infiltration and expression of CD68, tumor necrosis factor- (TNF-) α, interferon- (IFN-) γ, and interleukin- (IL-) 6 genes in the liver and adipose tissue were analyzed. RESULTS: The human study showed that Euphorbia has a potential effect on body weight loss. In the in vivo study, body weight, epididymal fat weight, glucose level, IR, expression of CD68, TNF-α, IFN-r, and IL-6 genes, and macrophages in liver and adipose tissue were significantly reduced by Euphorbia. CONCLUSIONS: These results suggest that Euphorbia attenuates obesity and insulin resistance via anti-inflammatory effects.

Nano-electromechanical Switch Based on a Physical Unclonable Function for Highly Robust and Stable Performance in Harsh Environments.

A physical unclonable function (PUF) device using a nano-electromechanical (NEM) switch was demonstrated. The most important feature of the NEM-switch-based PUF is its use of stiction. Stiction is one of the chronic problems associated with micro- and nano-electromechanical system (MEMS/NEMS) devices; however, here, it was utilized to intentionally implement a PUF for hardware-based security. The stiction is caused by capillary and van der Waals forces, producing strong adhesion, which can be utilized to design a highly robust and stable PUF. The probability that stiction will occur on either of two gates in the NEM switch is the same, and consequently, the occurrence of the stiction is random and unique, which is critical to its PUF performance. This uniqueness was evaluated by measuring the interchip Hamming distance (interchip HD), which characterizes how different responses are made when the same challenge is applied. Uniformity was also evaluated by the proportion of "1" or "0" in the response bit-string. The reliability of the proposed PUF device was assessed by stress tests under harsh environments such as high temperature, high dose radiation, and microwaves.

Designing Metallic and Insulating Nanocrystal Heterostructures to Fabricate Highly Sensitive and Solution Processed Strain Gauges for Wearable Sensors.

All-solution processed, high-performance wearable strain sensors are demonstrated using heterostructure nanocrystal (NC) solids. By incorporating insulating artificial atoms of CdSe quantum dot NCs into metallic artificial atoms of Au NC thin film matrix, metal-insulator heterostructures are designed. This hybrid structure results in a shift close to the percolation threshold, modifying the charge transport mechanism and enhancing sensitivity in accordance with the site percolation theory. The number of electrical pathways is also manipulated by creating nanocracks to further increase its sensitivity, inspired from the bond percolation theory. The combination of the two strategies achieves gauge factor up to 5045, the highest sensitivity recorded among NC-based strain gauges. These strain sensors show high reliability, durability, frequency stability, and negligible hysteresis. The fundamental charge transport behavior of these NC solids is investigated and the combined site and bond percolation theory is developed to illuminate the origin of their enhanced sensitivity. Finally, all NC-based and solution-processed strain gauge sensor arrays are fabricated, which effectively measure the motion of each finger joint, the pulse of heart rate, and the movement of vocal cords of human. This work provides a pathway for designing low-cost and high-performance electronic skin or wearable devices.

Herbal acupuncture for type 2 diabetes: A meta-analysis.

Herbal acupuncture (HA) is a modern adjunctive technique in which natural herbs or biologic substances are injected into acupuncture points. The objective of this systematic review was to evaluate evidence of the effectiveness of HA for type 2 diabetes mellitus (T2DM). Three databases were searched. The included randomized controlled trials (RCTs) evaluated HA in controls and patients with T2DM and reported at least one of the following: Fasting blood glucose (FBG), postprandial (PP2hr) glucose and glycated hemoglobin (HbA1c). In a meta-analysis of seven RCTs (n=598 patients), HA significantly reduced levels of FBG, PP2hr glucose and HbA1c (P<0.0001, P=0.0005 and P=0.004, respectively). There was no significant effect of HA on total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, or triglyceride level. High degrees of heterogeneity were present for all analyses except HDL-cholesterol and LDL-cholesterol. HA might have a beneficial effect on FBG, PP2hr glucose and HbA1c levels in patients with T2DM; however, because of several limitations, the results are inconclusive. Therefore, additional rigorous RCTs are warranted to overcome the limitations of previous studies.

Engineering the Charge Transport of Ag Nanocrystals for Highly Accurate, Wearable Temperature Sensors through All-Solution Processes.

All-nanocrystal (NC)-based and all-solution-processed wearable resistance temperature detectors (RTDs) are introduced. The charge transport mechanisms of Ag NC thin films are engineered through various ligand treatments to design high performance RTDs. Highly conductive Ag NC thin films exhibiting metallic transport behavior with high positive temperature coefficients of resistance (TCRs) are achieved through tetrabutylammonium bromide treatment. Ag NC thin films showing hopping transport with high negative TCRs are created through organic ligand treatment. All-solution-based, one-step photolithography techniques that integrate two distinct opposite-sign TCR Ag NC thin films into an ultrathin single device are developed to decouple the mechanical effects such as human motion. The unconventional materials design and strategy enables highly accurate, sensitive, wearable and motion-free RTDs, demonstrated by experiments on moving or curved objects such as human skin, and simulation results based on charge transport analysis. This strategy provides a low cost and simple method to design wearable multifunctional sensors with high sensitivity which could be utilized in various fields such as biointegrated sensors or electronic skin.