CTIVA: Censored time interval variable analysis.

Traditionally, datasets with multiple censored time-to-events have not been utilized in multivariate analysis because of their high level of complexity. In this paper, we propose the Censored Time Interval Analysis (CTIVA) method to address this issue. It estimates the joint probability distribution of actual event times in the censored dataset by implementing a statistical probability density estimation technique on the dataset. Based on the acquired event time, CTIVA investigates variables correlated with the interval time of events via statistical tests. The proposed method handles both categorical and continuous variables simultaneously-thus, it is suitable for application on real-world censored time-to-event datasets, which include both categorical and continuous variables. CTIVA outperforms traditional censored time-to-event data handling methods by 5% on simulation data. The average area under the curve (AUC) of the proposed method on the simulation dataset exceeds 0.9 under various conditions. Further, CTIVA yields novel results on National Sample Cohort Demo (NSCD) and proteasome inhibitor bortezomib dataset, a real-world censored time-to-event dataset of medical history of beneficiaries provided by the National Health Insurance Sharing Service (NHISS) and National Center for Biotechnology Information (NCBI). We believe that the development of CTIVA is a milestone in the investigation of variables correlated with interval time of events in presence of censoring.

Analysis of the Status and Future Direction for Digital Therapeutics in Children and Adolescent Psychiatry.

Digital therapeutics based on software, such as artificial intelligence, virtual reality, games, and smartphone applications, are in the spotlight as new therapeutic alternatives in child and adolescent psychiatry. It draws attention to overcoming conventional therapeutics' limitations, such as toxicity, cost, and accessibility, and encourages patients to participate in the treatment attractively. The growth potential of the digital therapeutics market for psychiatric disorders in children and adolescents in Korea and abroad has been highlighted. Clinical studies and Food and Drug Administration approvals for digital therapeutics have increased, and cases approved by the Ministry of Food and Drug Safety have emerged in Korea. As seen above, digital transformation in child and adolescent psychiatry will change treatment paradigms significantly. Therefore, as this new field has just begun to emerge, it is necessary to verify the effectiveness and scope of the application of digital therapeutics and consider preparing a compensation system and institutional arrangements. Accordingly, this study analyzed the development trends and application status of digital therapeutics in children and adolescents and presented limitations and development directions from the perspective of application in healthcare. Further, the study is expected to identify the utility and limitations of digital therapeutics for children and adolescents and establish effective application measures.

Indirect Decompression of Osteoporotic Vertebral Compression Fracture Using Intraoperative Motor Evoked Potential Monitoring-Guided Ligamentotaxis.

Osteoporotic vertebral compression fractures have become common in aging societies and can lead to a decreased quality of life with severe back pain and neurological deficits. Traditional direct decompression and stabilization surgeries can produce sufficient decompression and provide good results. However, after surgical treatment, some elderly patients with numerous chronic diseases often experience severe postoperative complications owing to the long surgery duration and massive bleeding. Therefore, to prevent perioperative morbidity, other surgical methods that simplify the surgical process and reduce the operation time are required. Herein, we describe a case of indirect decompression using ligamentotaxis and sequential anabolic agents. To examine their effectiveness during surgery, we monitored intraoperative motor-evoked potentials. The patient's neurological symptoms improved postoperatively. After the operation, the anabolic agent "romosozumab" was injected monthly to treat osteoporosis, prevent additional fractures, and accelerate posterolateral fusion. On serial follow-up, the anterior body height of the fractured vertebra improved significantly, demonstrating the importance of osteoporosis treatment using anabolic agents. Indirect decompression surgery may have early effects, whereas sequential anabolic agent use may consolidate the long-term effects of surgical treatment.

Exploring the Potential of Pulse Transit Time as a Biomarker for Sleep Efficiency through a Comparison Analysis with Heart Rate and Heart Rate Variability.

The relationship between sleep dynamics and blood pressure (BP) changes is well established. Moreover, sleep efficiency and wakefulness during sleep (WASO) events have a significant impact on BP dipping. Despite this knowledge, there is limited research on the measurement of sleep dynamics and continuous blood pressure (CBP). This study aims to explore the relationship between sleep efficiency and cardiovascular function indicators such as pulse transit time (PTT), as a biomarker of CBP, and heart rate variability (HRV), measured using wearable sensors. The results of the study conducted on 20 participants at the UConn Health Sleep Disorders Center suggest a strong linear relationship between sleep efficiency and changes in PTT (r2 = 0.8515) and HRV during sleep (r2 = 5886). The findings of this study contribute to our understanding of the relationship between sleep dynamics, CBP, and cardiovascular health.

Evaluation of the regenerative capacity of stem cells combined with bone graft material and collagen matrix using a rabbit calvarial defect model.

PURPOSE: The purpose of this study was to evaluate the regenerative capacity of stem cells combined with bone graft material and a collagen matrix in rabbit calvarial defect models according to the type and form of the scaffolds, which included type I collagen matrix and synthetic bone. METHODS: Mesenchymal stem cells (MSCs) were obtained from the periosteum of participants. Four symmetrical 6-mm-diameter circular defects were made in New Zealand white rabbits using a trephine drill. The defects were grafted with (1) group 1: synthetic bone (ß-tricalcium phosphate/hydroxyapatite [ß-TCP/HA]) and 1×105 MSCs; (2) group 2: collagen matrix and 1×105 MSCs; (3) group 3: ß-TCP/HA, collagen matrix covering ß-TCP/HA, and 1×105 MSCs; or (4) group 4: ß-TCP/HA, chipped collagen matrix mixed with ß-TCP/HA, and 1×105 MSCs. Cellular viability and cell migration rates were analyzed. RESULTS: Uneventful healing was achieved in all areas where the defects were made at 4 weeks, and no signs of infection were identified during the healing period or at the time of retrieval. New bone formation was more evident in groups 3 and 4 than in the other groups. A densitometric analysis of the calvarium at 8 weeks post-surgery showed the highest values in group 3. CONCLUSIONS: This study showed that the highest regeneration was found when the stem cells were applied to synthetic bone along with a collagen matrix.

Comparison of low-density lipoprotein cholesterol estimation methods in individuals with insulin resistance: A cross-sectional study.

BACKGROUND AND AIMS: The Friedewald, Sampson, and Martin equations were developed to estimate low-density lipoprotein cholesterol levels; however, the validation data of these equations with and without insulin resistance are insufficient. MATERIALS AND METHODS: We collected data on low-density lipoprotein cholesterol and lipid profiles from the Korea National Health and Nutrition Examination Survey. Using the data on insulin requirement, insulin resistance was calculated for 4,351 participants (median age, 48 [36-59] years; 49.9% male) using the homeostatic model assessment for insulin resistance (n = 2,713) and quantitative insulin-sensitivity check index (n = 2,400). RESULTS: According to the mean and median absolute deviation, the Martin equation yielded more accurate estimates than other equations when the triglyceride level was < 400 mg/dL with insulin resistance; the Sampson equation yielded lower estimates when the direct low-density lipoprotein cholesterol level was < 70 mg/dL and triglyceride level was < 400 mg/dL without insulin resistance. However, the three equations yielded similar estimates when the triglyceride level was < 150 mg/dL with and without insulin resistance. CONCLUSION: The Martin equation yielded more appropriate estimates than the Friedewald and Sampson equations for triglyceride levels < 400 mg/dL with and without insulin resistance. If the triglyceride level was < 150 mg, the Friedewald equation could also be considered.

Grid-wise simulation acceleration of the electromagnetic fields of 2D optical devices using super-resolution.

The significance of simulation has been increasing in device design due to the cost of real test. The accuracy of the simulation increases as the resolution of the simulation increases. However, the high-resolution simulation is not suited for actual device design because the amount of computing exponentially increases as the resolution increases. In this study, we introduce a model that predicts high-resolution outcomes using low-resolution calculated values which successfully achieves high simulation accuracy with low computational cost. The fast residual learning super-resolution (FRSR) convolutional network model is a model that we introduced that can simulate electromagnetic fields of optical. Our model achieved high accuracy when using the super-resolution technique on a 2D slit array under specific circumstances and achieved an approximately 18 times faster execution time than the simulator. To reduce the model training time and enhance performance, the proposed model shows the best accuracy (R2: 0.9941) by restoring high-resolution images using residual learning and a post-upsampling method to reduce computation. It has the shortest training time among the models that use super-resolution (7000 s). This model addresses the issue of temporal limitations of high-resolution simulations of device module characteristics.

Heterogeneous Structure Omnidirectional Strain Sensor Arrays With Cognitively Learned Neural Networks.

Mechanically stretchable strain sensors gain tremendous attention for bioinspired skin sensation systems and artificially intelligent tactile sensors. However, high-accuracy detection of both strain intensity and direction with simple device/array structures is still insufficient. To overcome this limitation, an omnidirectional strain perception platform utilizing a stretchable strain sensor array with triangular-sensor-assembly (three sensors tilted by 45°) coupled with machine learning (ML) -based neural network classification algorithm, is proposed. The strain sensor, which is constructed with strain-insensitive electrode regions and strain-sensitive channel region, can minimize the undesirable electrical intrusion from the electrodes by strain, leading to a heterogeneous surface structure for more reliable strain sensing characteristics. The strain sensor exhibits decent sensitivity with gauge factor (GF) of ≈8, a moderate sensing range (≈0-35%), and relatively good reliability (3000 stretching cycles). More importantly, by employing a multiclass-multioutput behavior-learned cognition algorithm, the stretchable sensor array with triangular-sensor-assembly exhibits highly accurate recognition of both direction and intensity of an arbitrary strain by interpretating the correlated signals from the three-unit sensors. The omnidirectional strain perception platform with its neural network algorithm exhibits overall strain intensity and direction accuracy around 98% ± 2% over a strain range of ≈0-30% in various surface stimuli environments.

Effects of radiofrequency catheter ablation for premature ventricular complexes originating from the right ventricular outflow tract on right ventricular function.

INTRODUCTION: This study aimed to elucidate the relationship between premature ventricular complexes (PVCs) and right ventricular (RV) dysfunction, and the effects of radiofrequency catheter ablation (RFCA) on RV function. METHODS: A total of 110 patients (age, 50.8 ± 14.4 years; 30 men) without structural heart disease who had undergone RFCA for RV outflow tract (RVOT) PVCs were retrospectively included. RV function was assessed using fractional area change (FAC) and global longitudinal strain (GLS) before and after RFCA. Clinical data were compared between the RV dysfunction (n = 63) and preserved RV function (n = 47) groups. The relationship between PVC burden and RV function was analyzed. Change in RV function before and after RFCA was compared between patients with successful and failed RFCA. RESULTS: PVC burden was significantly higher in the RV dysfunction group than in the preserved RV function group (p < .001). FAC and GLS were significantly worse in proportion to PVC burden (p < .001 and p < .001, respectively). The risk factor associated with RV dysfunction was PVC burden [odds ratio (95% confidence interval), 1.092 (1.052-1.134); p < .001]. Improvement in FAC (13.0 ± 8.7% and -2.5 ± 5.6%, respectively; p < .001) and GLS (-6.8 ± 5.7% and 2.1 ± 4.2%, respectively; p < .001) was significant in the patients with successful RFCA, compared to the patients in whom RFCA failed. CONCLUSIONS: Frequent RVOT PVCs are associated with RV dysfunction. RV dysfunction is reversible by successful RFCA.

Continuous physiological signal measurement over 24-hour periods to assess the impact of work-related stress and workplace violence.

Work-related stress has long been recognized as an essential factor affecting employees' health and wellbeing. Repeated exposure to acute occupational stressors puts workers at high risk for depression, obesity, hypertension, and early death. Assessment of the effects of acute stress on workers' wellbeing usually relies on subjective self-reports, questionnaires, or measuring biometric and biochemical markers in long-cycle time intervals. This study aimed to develop and validate the use of a multiparameter wearable armband for continuous non-invasive monitoring of physiological states. Two worker populations were monitored 24 h/day: six loggers for one day and six ICU nurses working 12-hr shifts for one week. Stress responses in nurses were highly correlated with changes in heart rate variability (HRV) and pulse transit time (PTT). A rise in the low-to high-frequency (LF/LH) ratio in HRV was also coincident with stress responses. HRV on workdays decreased compared to non-work days, and PTT also exhibited a persistent decrease reflecting increased blood pressure. Compared to loggers, nurses were involved in high-intensity work activities 45% more often but were less active on non-work days. The wearable technology was well accepted by all worker participants and yielded high signal quality, critical factors for long-term non-invasive occupational health monitoring.

Dual antiplatelet therapy after percutaneous coronary intervention for left main coronary artery disease.

INTRODUCTION AND OBJECTIVES: There are scarce data on the optimal duration and prognostic impact of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with second-generation drug-eluting stents for left main coronary artery (LMCA) disease. The aim of this study was to investigate the practice pattern and long-term prognostic effect of DAPT duration in patients undergoing PCI with second-generation drug-eluting stents for LMCA disease. METHODS: Using individual patient-level data from the IRIS-MAIN and KOMATE registries, 1827 patients undergoing PCI with second-generation drug-eluting stents for LMCA disease with valid information on DAPT duration were included. The efficacy outcome was major adverse cardiovascular events (MACE, a composite of cardiac death, myocardial infarction, and stent thrombosis) and the safety outcome was TIMI major bleeding. RESULTS: DAPT duration was <6 months (n=273), 6 to 12 months (n=477), 12 to 24 months (n=637), and ≥ 24 months (n=440). The median follow-up duration was 3.9 [interquartile range, 3.01-5.00] years. Prolonged DAPT duration was associated with lower incidences of MACE. In multigroup propensity score analysis, adjusted HR for MACE were significantly higher for DAPT <6 months and DAPT 6 to 12 months than for DAPT 12 to 24 months (HR, 4.51; 95%CI, 2.96-6.88 and HR 1.92; 95%CI, 1.23-3.00). There was no difference in HR for major bleeding among the assessed groups. CONCLUSIONS: DAPT duration following PCI for LMCA disease is highly variable. Although the duration of DAPT should be considered in the context of the clinical situation of each patient, <12 months of DAPT was associated with higher incidence of MACE. Registration identifiers: NCT01341327; NCT03908463.

Charge Injection Enhancement Comparisons of Iridium Oxide Microelectrodes In Vitro and In Vivo Using a Portable Neurostimulator.

Microelectrodes are desired to deliver more charges to neural tissues while under electrochemical safety limits. Applying anodic bias potential during neurostimulation is a known technique for charge enhancement. Here, we investigated the levels of charge enhancement with anodic bias potential in vitro and in vivo using a custom-designed portable neurostimulator. We immersed our custom microelectrode probe in saline and measured voltage transients in response to constant current stimulation with and without a 500 mV anodic bias potential. We then inserted the same microelectrode probe into the primary motor cortex of the rat brain and measured voltage transients with the same electronics. Results showed that the charge injection capacity of the activated iridium oxide microelectrode site (with 2000 µm2 geometric surface areas (GSAs)) increased by the use of the anodic bias potentials in both in vitro and in vivo: from 10 nC/phase to 32 nC/phase for 200 µs pulse widths, and from 2 nC/phase to 8 nC/phase, respectively. Thus, the order of charge injection capacities of the four cases tested in this study is as follows (from the lowest to the highest): in vivo without anodic bias, in vivo with anodic bias, in vitro without anodic bias, and in vitro with anodic bias. This work also validated in vivo use of our new portable neurostimulator which received stimulation waveforms wirelessly.

Effects of left atrial function on pulmonary arterial pressure in acute myocardial infarction, hypertrophic and dilated cardiomyopathy.

BACKGROUND: To investigate the differential contribution of the left atrial (LA) function and left ventricular (LV) fibrosis to pulmonary arterial systolic pressure (PASP) in hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and reperfused acute myocardial infarction (AMI). METHODS: Data of 370 patients with HCM (n = 133), DCM (n = 114) and reperfused AMI (n = 123) who underwent both echocardiography and cardiovascular magnetic resonance (CMR) were comprehensively reviewed. Phasic LA volumes, LA-global longitudinal strain (GLS), LA stiffness index, defined as E/e'/LA-GLS and extracellular volume fraction (ECV) of LV were measured using CMR. RESULTS: E/e' was correlated with PASP in all groups; however, the predicted value was significantly attenuated after adjusting for LA volume and LA strain in HCM and DCM, but remained significant in AMI. The LA stiffness index was related to PASP in HCM (p = 0.01) and DCM (p = 0.03) independent of LA volume index and E/e', but not in AMI. In DCM, ECV was significantly related to PASP (p < 0.001) independent of LA volume index and E/e'. When subdivided according to the linear regression between PASP and E/e', patients in the discrepantly high PASP group had lower total emptying fraction and reservoir fraction of left atrium in HCM and DCM but not in AMI. CONCLUSIONS: The LA function in HCM and DCM and LV fibrosis in DCM correlated with PASP independent of E/e' and LA size, contrary to that in AMI. These results suggest the presence of LA dysfunction in non-ischemic cardiomyopathies and usefulness of ECV measurement in DCM for the comprehensive evaluation of LV diastolic function.

A portable neurostimulator circuit with anodic bias enhances stimulation injection capacity.

Objective.Electrochemically safe and efficient charge injection for neural stimulation necessitates monitoring of polarization and enhanced charge injection capacity of the stimulating electrodes. In this work, we present improved microstimulation capability by developing a custom-designed multichannel portable neurostimulator with a fully programmable anodic bias circuitry and voltage transient monitoring feature.Approach.We developed a 16-channel multichannel neurostimulator system, compared charge injection capacities as a function of anodic bias potentials, and demonstrated convenient control of the system by a custom-designed user interface allowing bidirectional wireless data transmission of stimulation parameters and recorded voltage transients. Charge injections were conducted in phosphate-buffered saline with silicon-based iridium oxide microelectrodes.Main results.Under charge-balanced 200µs cathodic first pulsing, the charge injection capacities increased proportionally to the level of anodic bias applied, reaching a maximum of ten-fold increase in current intensity from 10µA (100µC cm-2) to 100µA (1000µC cm-2) with a 600 mV anodic bias. Our custom-designed and completely portable 16-channel neurostimulator enabled a significant increase in charge injection capacityin vitro. Significance.Limited charge injection capacity has been a bottleneck in neural stimulation applications, and our system may enable efficacious behavioral animal study involving chronic microstimulation while ensuring electrochemical safety.

Assessment of the Appearance and Toxin Production Potential of Invasive Nostocalean Cyanobacteria Using Quantitative Gene Analysis in Nakdong River, Korea.

Invasive nostocalean cyanobacteria (INC) were first reported in tropical regions and are now globally spreading rapidly due to climate change, appearing in temperate regions. INC require continuous monitoring for water resource management because of their high toxin production potential. However, it is difficult to analyze INC under a microscope because of their morphological similarity to nostocalean cyanobacteria such as the genus Aphanizomenon. This study calculates the gene copy number per cell for each target gene through quantitative gene analysis on the basis of genus-specific primers of genera Cylindrospermopsis, Sphaerospermopsis, and Cuspidothrix, and the toxin primers of anatoxin-a, saxitoxin, and cylindrospermopsin. In addition, quantitative gene analysis was performed at eight sites in the Nakdong River to assess the appearance of INC and their toxin production potential. Genera Cylindrospermopsis and Sphaerospermopsis did not exceed 100 cells mL-1 at the maximum, with a low likelihood of related toxin occurrence. The genus Cuspidothrix showed the highest cell density (1759 cells mL-1) among the INC. Nakdong River has potential for the occurrence of anatoxin-a through biosynthesis by genus Cuspidothrix because the appearance of this genus coincided with that of the anatoxin-a synthesis gene (anaF) and the detection of the toxin by ELISA.

The association between cardiac involvement and long-term clinical outcomes in patients with Duchenne muscular dystrophy.

AIMS: Despite advances in contemporary cardiopulmonary therapies, cardiomyopathy remains the leading cause of death in patients with Duchenne muscular dystrophy (DMD). Also, the long-term clinical outcomes of patients with DMD and cardiomyopathy is unknown. This study investigated long-term clinical outcomes and their associated factors in patients with late-stage DMD. METHODS AND RESULTS: A total of 116 patients with late-stage DMD (age > 15 years) were enrolled in this retrospective study. All enrolled patients were followed up at a single tertiary referral hospital. LV systolic dysfunction was dichotomously defined as reduced [left ventricular ejection fraction (LVEF) ≤ 40%] vs. preserved [>40%] based on the initial echocardiographic result. The primary endpoint was all-cause death. The secondary endpoint was a composite event defined as death or unexpected hospitalization due to cardiovascular reasons including chest pain, dyspnoea, and generalized oedema. The patients were divided into preserved (n = 84, 72.4%) and reduced LVEF groups (n = 32, 27.6%). The mean age was 20.8 ± 5.9 years, the mean disease duration, 8.8 ± 3.7 years, and the mean follow-up duration, 1708 ± 659 days. For primary endpoint, the reduced LVEF group showed a lower rate of overall survival (Reduced LVEF vs. Preserved LVEF; 81.3% vs. 98.8%, log-rank P = 0.005). In the multivariable Cox regression analysis, brain-natriuretic peptide (BNP) level (adjusted hazard ratio [HR] 1.088, 95% confidence interval [CI] 1.019-1.162, P = 0.011) and diuretic use (adjusted HR 9.279, 95%CI 1.651-52.148, P = 0.011) were significant predictors of all-cause death in patients with DMD. For the secondary endpoint, the reduced LVEF group had a lower rate of freedom from composite events than the preserved LVEF group (65.6% vs. 86.9%, log-rank P = 0.005). In the multivariable Cox regression analysis, BNP level (adjusted HR 1.057, 95%CI 1.005-1.112, P = 0.032) and diuretic use (adjusted HR 4.189, 95% CI 1.704-10.296, P = 0.002) were significant predictors of the composite event in patients with DMD. CONCLUSIONS: Patients with DMD and reduced LVEF had worse clinical outcomes than those with preserved LVEF. BNP level and diuretic use were associated with adverse clinical outcomes in patients with late-stage DMD, irrespective of LVEF.

Simulator acceleration and inverse design of fin field-effect transistors using machine learning.

The simulation and design of electronic devices such as transistors is vital for the semiconductor industry. Conventionally, a device is intuitively designed and simulated using model equations, which is a time-consuming and expensive process. However, recent machine learning approaches provide an unprecedented opportunity to improve these tasks by training the underlying relationships between the device design and the specifications derived from the extensively accumulated simulation data. This study implements various machine learning approaches for the simulation acceleration and inverse-design problems of fin field-effect transistors. In comparison to traditional simulators, the proposed neural network model demonstrated almost equivalent results (R2 = 0.99) and was more than 122,000 times faster in simulation. Moreover, the proposed inverse-design model successfully generated design parameters that satisfied the desired target specifications with high accuracies (R2 = 0.96). Overall, the results demonstrated that the proposed machine learning models aided in achieving efficient solutions for the simulation and design problems pertaining to electronic devices. Thus, the proposed approach can be further extended to more complex devices and other vital processes in the semiconductor industry.

Impact of aortic atheroma and distensibility on diastolic function and prognosis in patients with ischemic stroke.

BACKGROUND: Patients with ischemic stroke are vulnerable to heart failure with preserved ejection fraction (HFpEF) because these conditions share common risk factors. Although evaluation of the ascending aorta, aortic arch, and proximal descending thoracic aorta is an essential step to determine the source of the causative embolism, the relationship between the degree of aortic atheroma and left ventricular (LV) diastolic function has not been extensively investigated. METHODS: We analyzed the transesophageal and transthoracic echocardiography in ischemic stroke patients. Patients with previous coronary artery disease, valvular heart disease of more than moderate degree, and an LV ejection fraction of less than 50% were excluded. The relationships between the grade of the aortic atheroma, aortic stiffness indexes, and diastolic functional indexes were evaluated. RESULTS: In 295 patients, the atheroma grade was significantly correlated with aortic stiffness index, ratio of mitral annular and inflow velocities (E/e'), left atrial volume index, and LV diastolic elastance. With further adjustment for age, hypertension, diabetes, estimated glomerular filtration rate, left atrial volume index, and LV mass index, the significance of the atheroma grade was attenuated. In the subgroup analysis, the atheroma grade was significantly and independently related to E/e' in women (ß = 0.181, p = 0.032), but not in men. However, atheroma grade was not associated with poor clinical outcomes in either sex. CONCLUSIONS: Aortic atheroma grade was significantly and independently related to LV diastolic function, especially in women. This suggests that aortic atheroma is an index of arterial stiffness and a potential risk factor for HFpEF through ventricular-vascular interactions, especially in women.

Clinical Implications of Poststent Optical Coherence Tomographic Findings: Severe Malapposition and Cardiac Events.

OBJECTIVES: This study sought to evaluate the impact of poststent optical coherence tomography (OCT) findings, including severe malapposition, on long-term clinical outcomes. BACKGROUND: Suboptimal OCT findings following percutaneous coronary intervention (PCI) are highly prevalent; however, their clinical implications remain controversial. METHODS: Of the patients registered in the Yonsei OCT registry, a total of 1,290 patients with 1,348 lesions, who underwent OCT immediately poststenting, were consecutively enrolled for this study. All patients underwent implantation of drug-eluting stents. Poststent OCT findings were assessed to identify predictors of device-oriented clinical endpoints (DoCE), including cardiac death, target vessel-related myocardial infarction (MI) or stent thrombosis, and target lesion revascularization (TLR). Significant malapposition criteria associated with major safety events (MSE) were also investigated, such as cardiac death, target vessel-related MI, or stent thrombosis. RESULTS: The median follow-up period was 43.0 months (interquartile range [IQR] 21.4 to 56.0 months). The incidence rates of stent edge dissection, tissue prolapse, thrombus, and malapposition after intervention were not associated with occurrence of DoCE. However, patients with significant malapposition (total malapposition volume [TMV] ≥7.0 mm3] exhibited more frequent MSE. A smaller minimal stent area (MSA) was identified as an independent predictor for DoCE (hazard ratio [HR]: 1.20 [95% confidence interval [CI]: 1.00 to 1.43]; p = 0.045). Malapposition with TMV ≥7.0 mm3 was found to be an independent predictor of MSE (HR: 6.12 [95% CI: 1.88 to 19.95]; p = 0.003). Follow-up OCT at 3, 6, or 9 months after PCI showed that poststent TMV ≥7.0 mm3 was related to a greater occurrence of late malapposition and uncovered struts. CONCLUSIONS: Although most suboptimal OCT findings were not associated with clinical outcomes, a smaller MSA was associated with DoCE, driven mainly by TLR, and significant malapposition with TMV ≥7.0 mm3 was associated with more MSE after PCI. (Yonsei OCT [Optical Coherence Tomography] Registry for Evaluation of Efficacy and Safety of Coronary Stenting; Yonsei OCT registry; NCT02099162).

Wide-Range Motion Recognition Through Insole Sensor Using Multi-Walled Carbon Nanotubes and Polydimethylsiloxane Composites.

High linearity/sensitivity and a wide dynamic sensing range are the most desirable features for pressure sensors to accurately detect and respond to external pressure stimuli. Even though a number of recent studies have demonstrated a low-cost pressure sensing device for a smart insole system by using scalable and deformable conductive materials, they still lack stretchability and desirable properties such as high sensitivity, hysteresis, linearity, and fast response time to obtain accurate and reliable data. To resolve this issue, a flexible and stretchable piezoresistive pressure sensor with high linear response over a wide pressure range is developed and integrated in a wearable insole system. The sensor uses multi-walled carbon nanotubes and polydimethylsiloxane (MWCNT/PDMS) composites with gradient density double-stacked configuration as well as randomly distributed surface microstructure (RDSM). The randomly distributed surface of the MWCNT/PDMS composite is easily and non-artificially generated by the evaporation of residual IPA solvent during a composite curing process. Due to two functional features consisting of the double-stacked composite configuration with different gradient MWCNT density and RDSM, the pressure sensor shows high linear sensitivity (∼82.5 kPa) and a pressure range of 0-1 MPa, providing extensive potential applications in monitoring human motions. Moreover, for a practical wearable application detecting the user's real-time motions, a custom-designed output signal acquisition system has been developed and integrated with the insole pressure sensor. As a result, the insole sensor can successfully detect walking, running, and jumping movements and can be used in daily life to monitor gait patterns by virtue of its long-term stability.