Low- or standard-dose edoxaban versus antiplatelet therapy for leaflet thrombus and cerebral thromboembolism after TAVR: A prespecified analysis of randomized ADAPT-TAVR trial.

BACKGROUND: The risks of leaflet thrombosis and the associated cerebral thromboembolism are unknown according to different anticoagulation dosing after transcatheter aortic valve replacement (TAVR). The aim was to evaluate the incidence of leaflet thrombosis and cerebral thromboembolism between low-dose (30 mg) or standard-dose (60 mg) edoxaban and dual antiplatelet therapy (DAPT) after TAVR. METHODS: In this prespecified subgroup analysis of the ADAPT-TAVR trial, the primary endpoint was the incidence of leaflet thrombosis on 4-dimensional computed tomography at 6-months. Key secondary endpoints were new cerebral lesions on brain magnetic resonance imaging and neurological and neurocognitive dysfunction. RESULTS: Of 229 patients enrolled in this study, 118 patients were DAPT group and 111 were edoxaban group (43 [39.1%] 60 mg vs 68 [61.3%] 30 mg). There was a significantly lower incidence of leaflet thrombosis in the standard-dose edoxaban group than in the DAPT group (2.4% vs 18.3%; odds ratio [OR] 0.11; 95% confidence interval [CI], 0.01-0.55; P = .03). However, no significant difference was observed between low-dose edoxaban and DAPT (15.0% vs 18.3%; OR 0.79; 95% CI, 0.32-1.81; P = .58). Irrespective of different antithrombotic regiments, the percentages of patients with new cerebral lesions on brain MRI and worsening neurological or neurocognitive function were not significantly different. CONCLUSIONS: In patients without an indication for anticoagulation after TAVR, the incidence of leaflet thrombosis was significantly lower with standard-dose edoxaban but not with low-dose edoxaban, as compared with DAPT. However, this differential effect of edoxaban on leaflet thrombosis was not associated with a reduction of new cerebral thromboembolism and neurological dysfunction.

Compatibility Review for Object Detection Enhancement through Super-Resolution.

With the introduction of deep learning, a significant amount of research has been conducted in the field of computer vision in the past decade. In particular, research on object detection (OD) continues to progress rapidly. However, despite these advances, some limitations need to be overcome to enable real-world applications of deep learning-based OD models. One such limitation is inaccurate OD when image quality is poor or a target object is small. The performance degradation phenomenon for small objects is similar to the fundamental limitations of an OD model, such as the constraint of the receptive field, which is a difficult problem to solve using only an OD model. Therefore, OD performance can be hindered by low image quality or small target objects. To address this issue, this study investigates the compatibility of super-resolution (SR) and OD techniques to improve detection, particularly for small objects. We analyze the combination of SR and OD models, classifying them based on architectural characteristics. The experimental results show a substantial improvement when integrating OD detectors with SR models. Overall, it was demonstrated that, when the evaluation metrics (PSNR, SSIM) of the SR models are high, the performance in OD is correspondingly high as well. Especially, evaluations on the MS COCO dataset reveal that the enhancement rate for small objects is 9.4% higher compared to all objects. This work provides an analysis of SR and OD model compatibility, demonstrating the potential benefits of their synergistic combination. The experimental code can be found on our GitHub repository.

Application of TSPO-Specific Positron Emission Tomography Radiotracer as an Early Indicator of Acute Liver Failure Induced by Propacetamol, a Prodrug of Paracetamol.

Acetaminophen overdose is a leading cause of acute liver failure (ALF), and effective treatment depends on early prediction of disease progression. ALF diagnosis currently requires blood collection 24-72 h after APAP ingestion, necessitating repeated tests and hospitalization. Here, we assessed earlier ALF diagnosis using positron emission tomography (PET) imaging of translocator proteins (TSPOs), which are involved in molecular transport, oxidative stress, apoptosis, and energy metabolism, with the radiotracer [18F]GE180. We intraperitoneally administered propacetamol hydrochloride to male C57BL/6 mice to induce ALF. We performed in vivo PET/CT imaging 3 h later using the TSPO-specific radiotracer [18F]GE180 and quantitatively analyzed the PET images by determining the averaged standardized uptake value (SUVav) in the liver parenchyma. We assessed liver TSPO expression levels via real-time polymerase chain reaction, Western blotting, and immunohistochemistry. [18F]GE180 PET imaging 3 h after propacetamol administration (1500 mg/kg) significantly increased liver SUVav compared to controls (p = 0.001). Analyses showed a 10-fold and 4-fold increase in TSPO gene and protein expression, respectively, in the liver, 3 h after propacetamol induction compared to controls. [18F]GE180 PET visualized and quantified propacetamol-induced ALF through TSPO overexpression. These findings highlight TSPO PET's potential as a non-invasive imaging biomarker for early-stage ALF.

Edoxaban Versus Dual Antiplatelet Therapy for Leaflet Thrombosis and Cerebral Thromboembolism After TAVR: The ADAPT-TAVR Randomized Clinical Trial.

BACKGROUND: It is unknown whether the direct oral anticoagulant edoxaban can reduce leaflet thrombosis and the accompanying cerebral thromboembolic risk after transcatheter aortic valve replacement. In addition, the causal relationship of subclinical leaflet thrombosis with cerebral thromboembolism and neurological or neurocognitive dysfunction remains unclear. METHODS: We conducted a multicenter, open-label randomized trial comparing edoxaban with dual antiplatelet therapy (aspirin plus clopidogrel) in patients who had undergone successful transcatheter aortic valve replacement and did not have an indication for anticoagulation. The primary end point was an incidence of leaflet thrombosis on 4-dimensional computed tomography at 6 months. Key secondary end points were the number and volume of new cerebral lesions on brain magnetic resonance imaging and the serial changes of neurological and neurocognitive function between 6 months and immediately after transcatheter aortic valve replacement. RESULTS: A total of 229 patients were included in the final intention-to-treat population. There was a trend toward a lower incidence of leaflet thrombosis in the edoxaban group compared with the dual antiplatelet therapy group (9.8% versus 18.4%; absolute difference, -8.5% [95% CI, -17.8% to 0.8%]; P=0.076). The percentage of patients with new cerebral lesions on brain magnetic resonance imaging (edoxaban versus dual antiplatelet therapy, 25.0% versus 20.2%; difference, 4.8%; 95% CI, -6.4% to 16.0%) and median total new lesion number and volume were not different between the 2 groups. In addition, the percentages of patients with worsening of neurological and neurocognitive function were not different between the groups. The incidence of any or major bleeding events was not different between the 2 groups. We found no significant association between the presence or extent of leaflet thrombosis with new cerebral lesions and a change of neurological or neurocognitive function. CONCLUSIONS: In patients without an indication for long-term anticoagulation after successful transcatheter aortic valve replacement, the incidence of leaflet thrombosis was numerically lower with edoxaban than with dual antiplatelet therapy, but this was not statistically significant. The effects on new cerebral thromboembolism and neurological or neurocognitive function were also not different between the 2 groups. Because the study was underpowered, the results should be considered hypothesis generating, highlighting the need for further research. REGISTRATION: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT03284827.

Early Surgery or Conservative Care for Asymptomatic Aortic Stenosis.

BACKGROUND: The timing and indications for surgical intervention in asymptomatic patients with severe aortic stenosis remain controversial. METHODS: In a multicenter trial, we randomly assigned 145 asymptomatic patients with very severe aortic stenosis (defined as an aortic-valve area of ≤0.75 cm2 with either an aortic jet velocity of ≥4.5 m per second or a mean transaortic gradient of ≥50 mm Hg) to early surgery or to conservative care according to the recommendations of current guidelines. The primary end point was a composite of death during or within 30 days after surgery (often called operative mortality) or death from cardiovascular causes during the entire follow-up period. The major secondary end point was death from any cause during follow-up. RESULTS: In the early-surgery group, 69 of 73 patients (95%) underwent surgery within 2 months after randomization, and there was no operative mortality. In an intention-to-treat analysis, a primary end-point event occurred in 1 patient in the early-surgery group (1%) and in 11 of 72 patients in the conservative-care group (15%) (hazard ratio, 0.09; 95% confidence interval [CI], 0.01 to 0.67; P = 0.003). Death from any cause occurred in 5 patients in the early-surgery group (7%) and in 15 patients in the conservative-care group (21%) (hazard ratio, 0.33; 95% CI, 0.12 to 0.90). In the conservative-care group, the cumulative incidence of sudden death was 4% at 4 years and 14% at 8 years. CONCLUSIONS: Among asymptomatic patients with very severe aortic stenosis, the incidence of the composite of operative mortality or death from cardiovascular causes during the follow-up period was significantly lower among those who underwent early aortic-valve replacement surgery than among those who received conservative care. (Funded by the Korean Institute of Medicine; RECOVERY ClinicalTrials.gov number, NCT01161732.).

Impact of new-onset arrhythmia on cardiac reverse remodeling following transcatheter aortic valve replacement: computed tomography-derived left ventricular and atrial strains.

OBJECTIVE: Patients who undergo transcatheter aortic valve replacement (TAVR) are at risk for new-onset arrhythmia (NOA) that may require permanent pacemaker (PPM) implantation, resulting in decreased cardiac function. We aimed to investigate the factors that are associated with NOA after TAVR and to compare pre- and post-TAVR cardiac functions between patients with and without NOA using CT-derived strain analyses. METHODS: We included consecutive patients who underwent pre- and post-TAVR cardiac CT scans six months after TAVR. New-onset left bundle branch block, atrioventricular block, and atrial fibrillation/flutter lasting over 30 days after the procedure and/or the need for PPM diagnosed within 1 year after TAVR were regarded as NOA. Implant depth and left heart function and strains were analyzed using multi-phase CT images and compared between patients with and without NOA. RESULTS: Of 211 patients (41.7% men; median 81 years), 52 (24.6%) presented with NOA after TAVR, and 24 (11.4%) implanted PPM. Implant depth was significantly deeper in the NOA group than in the non-NOA group (- 6.7 ± 2.4 vs. - 5.6 ± 2.6 mm; p = 0.009). Left ventricular global longitudinal strain (LV GLS) and left atrial (LA) reservoir strain were significantly improved only in the non-NOA group (LV GLS, - 15.5 ± 4.0 to - 17.3 ± 2.9%; p < 0.001; LA reservoir strain, 22.3 ± 8.9 to 26.5 ± 7.6%; p < 0.001). The mean percent change of the LV GLS and LA reservoir strains was evident in the non-NOA group (p = 0.019 and p = 0.035, respectively). CONCLUSIONS: A quarter of patients presented with NOA after TAVR. Deep implant depth on post-TAVR CT scans was associated with NOA. Patients with NOA after TAVR had impaired LV reserve remodeling assessed by CT-derived strains. CLINICAL RELEVANCE STATEMENT: New-onset arrhythmia (NOA) following transcatheter aortic valve replacement (TAVR) impairs cardiac reverse remodeling. CT-derived strain analysis reveals that patients with NOA do not show improvement in left heart function and strains, highlighting the importance of managing NOA for optimal outcomes. KEY POINTS: • New-onset arrhythmia following transcatheter aortic valve replacement (TAVR) is a concern that interferes with cardiac reverse remodeling. • Comparison of pre-and post-TAVR CT-derived left heart strain provides insight into the impaired cardiac reverse remodeling in patients with new-onset arrhythmia following TAVR. • The expected reverse remodeling was not observed in patients with new-onset arrhythmia following TAVR, given that CT-derived left heart function and strains did not improve.

A Pilot Study of Accelerometer-Based Biometric Data Collection among Patients Undergoing Locoregional Therapies.

This study evaluated the feasibility of measuring patient recovery after locoregional therapies (LRTs) using a wearable activity tracker (WAT). Twenty adult patients with cancer were provided with a WAT device to wear for a minimum of 7 days prior to their procedure (baseline) and for up to 30 days after their procedure (recovery). Daily step counts were continuously recorded. Patient responses to the Short Form 36-Item Health Survey (SF-36) were also collected before and after LRT. Analysis of WAT data demonstrated a mean of 4,850 daily steps taken at baseline, which decreased to 2,000 immediately after LRT and then rapidly increased to approximately 4,300 daily steps over an average of 10 days (P < .001). No significant changes were observed in SF-36 responses between baseline and follow-up assessments (P > .10). These results suggest that WAT devices capture dynamic periprocedural data not reflected in survey-based assessments and may be used to monitor patient recovery after interventional oncologic procedures.

Percutaneous Cryoablation Provides Disease Control for Extra-Abdominal Desmoid-Type Fibromatosis Comparable with Surgical Resection.

PURPOSE: The aim of this study was to determine outcomes and prognostic factors for patients with primary and locally recurrent extra-abdominal desmoid tumors who underwent percutaneous cryoablation, and to compare with patients treated with surgery. METHODS: Group characteristics were compared using Fisher's exact test, and propensity score matching was performed using the nearest-neighbor approach. Kaplan-Meier and log-rank analyses were used to evaluate the variation in first local recurrence and disease control, while multivariate Cox regression was used to identify factors associated with first local recurrence. All statistical tests were two-sided and a p-value of 0.05 was considered statistically significant. RESULTS: Twenty-two cryoablation patients were matched with 33 surgical patients (n = 55). Median follow-up after cryoablation was 16.3 months versus 14.9 months after surgery. Two-year local recurrence-free survival (LRFS) was 59% after cryoablation and 71% after surgery, and median LRFS was 26.6 months after cryoablation but was not reached after surgery. Two-year disease control for all patients was 85%, however median disease control was not reached in either the cryoablation or surgery groups. There was no significant difference in LRFS or disease control between matched cryoablation and surgical patients. No local recurrences occurred after the first cryoablation in patients with zero or one of the following risk factors: tumor size > 5 cm, age ≤ 25 years, or locally recurrent disease. All patients with two or more of these risk factors recurred locally after the first cryoablation. CONCLUSION: Percutaneous cryoablation of primary and locally recurrent extra-abdominal desmoid tumors provides freedom from first local recurrence and long-term disease control comparable with surgery.

Different Clinical Features between Definite and Possible Takotsubo Syndrome in a Tertiary Referral Hospital.

BACKGROUND: Although imaging examination to exclude coronary artery disease (CAD) is an indispensable step for a definite diagnosis of takotsubo syndrome (TTS), this step may be overlooked in a substantial proportion of patients with secondary TTS admitted to a tertiary hospital. However, the clinical profiles and outcomes of these patients with "possible TTS" have rarely been investigated. METHODS: Among 420 consecutive TTS patients with characteristic transient ventricular ballooning on repeated echocardiography, 244 patients (58.1%) who underwent an imaging study for CAD were diagnosed with "definite TTS," whereas the remaining 176 were designated with "possible TTS." RESULTS: Overall, hypoxia (67.6%) and dyspnea (55.5%) were predominant presentations. The possible group was characterized by higher prevalence of male gender (46.6% vs. 35.2%, p = 0.019), secondary TTS (97.2% vs. 86.5%, p < 0.001), cancer (43.2% vs. 29.1%, p = 0.003), sepsis (46.0% vs. 32.0%, p = 0.003), and nonapical ballooning pattern (30.7% vs. 21.3%, p = 0.001) with less common ST-segment elevation on electrocardiogram (18.8% vs. 34.0%, p = 0.001). The possible group showed higher frequency of mechanical ventilation (56.2% vs. 40.2%, p = 0.001), pulmonary edema (72.2% vs. 61.5%, p = 0.023), and shock management (70.5% vs. 54.1%, p = 0.001) with similar in-hospital mortality (17.2% vs. 17.0%, p = 0.964). CONCLUSIONS: In real-world clinical practice, coronary evaluation for strict diagnosis of TTS is not frequently feasible. Addition of the possible group without coronary evaluation to the clinical spectrum of TTS would be helpful for fair estimation of clinical implication of TTS.

Analysis of older adults visiting the emergency department with fever as a suspected Covid-19 vaccine-related adverse reaction: A retrospective multicenter study.

INTRODUCTION: After COVID-19 vaccination was initiated, the number of patients visiting the emergency department (ED) with vaccine-related adverse reactions increased. We investigated the clinical features of older adults (aged 65 years and older) visiting the ED with self-reported COVID-19 postvaccination fever. METHODS: We conducted a retrospective observational study at three EDs between March 2021 and September 2021. Patients who reported adverse reactions, fever (≥37.5 °C) and/or febrile sensation or rigors following COVID-19 vaccination were included. The demographic and clinical data of these patients were collected by reviewing their medical records. RESULTS: A total of 562 patients were selected, and 396 (70.5%) were female. The older adult group included 155 (27.6%) patients, and the median age was 75 (69-79 years). The older adults less frequently had a fever (≥37.5 °C) upon ED presentation (75.5% vs. 85.7%, respectively), used more emergency medical services (43.9% vs. 18.7%, respectively), and visited an ED more frequently during early hours (00:00-06:00) (31% vs. 20.1%, respectively) compared to the younger adults (p = 0.004, p < 0.001 and p = 0.036). Fewer older adults visited an ED within 2 days of fever onset (73.5% vs. 84%) (p = 0.012), and more older adults were admitted for medical conditions other than vaccine-related adverse reactions (32.9% vs. 4.2%) (p < 0.001). Older adults received more thorough testing (laboratory and imaging tests). Among the older adults, the admission rate was associated with age (p = 0.003). CONCLUSION: Older adults presenting with fever as an adverse reaction following COVID-19 vaccination less frequently had a fever upon visiting the ED, required more ED testing, and had higher admission rates for non-vaccination-related medical conditions.

Pre-Hospital Delay in Patients With Acute Stroke During the Initial Phase of the Coronavirus Disease 2019 Outbreak.

BACKGROUND: When a sudden outbreak of an infectious disease occurs, emergency medical services (EMS) response could be negatively affected. The poor prognosis of acute stroke may be largely attributed to delays in treatment. This study aimed to identify the impact of the sudden outbreak of coronavirus disease 2019 (COVID-19) on EMS response for patients with acute stroke. METHODS: This comparative cross-sectional study was conducted in 25 safety centers in Seoul, Korea. We enrolled patients with acute stroke who were transferred to the emergency department by EMS. The study period was from February-April 2020 and the same period in 2019. Patients were divided into two groups, pre-COVID-19 period and early-COVID-19 period, and previously collected patient data were analyzed. We performed comparative analyses of EMS response and clinical outcomes between the groups. RESULTS: Of 465 patients, 231 (49.7%) had an acute stroke during the study period. There was no significant difference between clinical characteristics of patients with acute stroke before and after the COVID-19 outbreak. EMS response times increased significantly during the early COVID-19 outbreak. The intensive care unit admission rate and mortality rate increased during the early COVID-19 outbreak. CONCLUSION: In the initial phase after the sudden COVID-19 outbreak, EMS response times for acute stroke were delayed and the clinical outcomes of patients with acute stroke deteriorated.

CFX: Contention-Free Channel Access for IEEE 802.11ax.

Orthogonal frequency-division multiple access (OFDMA) has attracted great attention as a key technology for uplink enhancement for Wi-Fi, since it can effectively reduce network congestion and channel access delay. Unfortunately, the traditional random access protocol of Wi-Fi seldom allows these benefits to be achieved, especially in dense network environments, as the access point (AP) rarely gains the channel access needed to trigger OFDMA uplink transmissions due to severe frame collisions. To address this problem, we propose a new channel access scheme called Contention-Free Channel Access for 802.11ax (CFX). In the proposed scheme, users can access the channel without contention, since they are guaranteed a transmission opportunity immediately after another user's transmission. To realize CFX on top of the existing Buffer Status Report/BSR Poll (BSR/BSRP) exchange protocol of 802.11ax, we develop an additional scheme based on shared channel access that helps the AP to obtain the buffer status of users and manage a contention-free channel access schedule. In addition, in order to appropriately utilize the savings from the reduced frame collisions, we conduct sum throughput maximization using an actor-critic proximal policy optimization (PPO)-based deep reinforcement learning approach. The results of an extensive evaluation show that CFX not only significantly improves the uplink performance of Wi-Fi in terms of throughput and channel access delay but can also dynamically adjust the parameters in response to changes in the network status.

Percutaneous Lymphatic Embolization as Primary Management of Pelvic and Retroperitoneal Iatrogenic Lymphoceles.

PURPOSE: To evaluate the efficacy of lymphatic embolization (LE) in decreasing catheter output and dwell time in iatrogenic lymphoceles after percutaneous catheter drainage. MATERIALS AND METHODS: Retrospective review of patients who underwent intranodal lymphangiography (INL) with or without LE for management of iatrogenic lymphoceles between January 2017 and November 2020 was performed. Twenty consecutive patients (16 men and 4 women; median age, 60.5 years) underwent a total of 22 INLs and 18 LEs for 15 pelvic and 5 retroperitoneal lymphoceles. Lymphatic leaks were identified in 19/22 (86.4%) of the INLs. Three patients underwent INL only because a leak was not identified or was identified into an asymptomatic lymphocele. One patient underwent repeat INL and LE after persistent high catheter output, and 1 patient underwent repeat INL with LE after the initial INL did not identify a leak. Catheter output was assessed until catheter removal, and changes in output before and after the procedure were reported. The patients were followed up for 2-30 months, and procedural complications were reported. RESULTS: The median catheter output before the procedure was 210 mL/day (50-1,200 mL/day), which decreased to a median of 20 mL/day (0-520 mL/day) 3 days after the procedure, with a median output decrease of 160 mL (0-900 mL). The median time between INL with LE and catheter removal was 6 days, with no recurrence requiring redrainage. Four patients experienced minor complications of low-grade fever (n = 2) and lower limb edema (n = 2). CONCLUSIONS: Lymphangiogram and LE are safe and effective methods for the management of lymphoceles.

Clinical impact of mild to moderate pulmonary hypertension in living-donor liver transplantation.

Severe pulmonary hypertension (PHT) is a contraindication to liver transplantation (LT); however, the prognostic implication of mild to moderate PHT in living-donor LT (LDLT) is unknown. The study cohort retrospectively included 1307 patients with liver cirrhosis who underwent LDLT. PHT was defined as a mean pulmonary artery pressure (PAP) of ≥25 mmHg, measured intraoperatively just before surgery. The primary endpoint was graft failure within 1 year after LDLT, including retransplantation or death from any cause. The secondary endpoints were in-hospital adverse events. In the overall cohort, the median Model for End-stage Liver Disease-Sodium (MELD-Na) score was 19, and 100 patients (7.7%) showed PHT. During 1-year follow-up, graft failure occurred in 94 patients (7.2%). Patients with PHT had lower 1-year graft survival (86% vs. 93.4%, P = 0.005) and survival rates (87% vs. 93.6%, P = 0.011). Mean PAP was associated with a high risk of in-hospital adverse events and 1-year graft failure. Adding the mean PAP to the clinical risk model improved the risk prediction. In conclusion, mild to moderate PHT was associated with higher risks of 1-year graft failure and in-hospital events, including mortality after LDLT in patients with liver cirrhosis. Intraoperative mean PAP can help predict the early clinical outcomes after LDLT.

Association of the COVID-19 Pandemic and Low-rescue Suicide Attempts in Patients Visiting the Emergency Department after Attempting Suicide.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic may increase the total number of suicide attempts and the proportion of low-rescue attempts. We investigated the factors affecting low-rescue suicide attempts using the risk-rescue rating scale (RRRS) among patients who visited the emergency department (ED) after attempting suicide before or during the COVID-19 pandemic. METHODS: We retrospectively investigated suicide attempts made by patients who visited our ED from March 2019 to September 2020. Patients were classified into two groups based on whether they attempted suicide before or during the COVID-19 pandemic. Data on demographic variables, psychiatric factors, suicide risk factors and rescue factors were collected and compared. RESULTS: A total of 518 patients were included in the study, 275 (53.1%) of whom attempted suicide during the COVID-19 pandemic. The proportion of patients who made low-rescue suicide attempts differed before and during the COVID-19 pandemic (37.1% vs. 28.8%) (P = 0.046). However, the proportions of patients who made high-risk suicide attempts and high-lethality suicide attempts did not significantly differ between the two periods. The independent risk factors for low-rescue suicide attempts were age and the COVID-19 pandemic (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.00-1.03; P = 0.006) (OR, 1.52; 95% CI, 1.03-2.25; P = 0.034). CONCLUSION: The COVID-19 pandemic was associated with low-rescue suicide attempts in patients visiting the ED after attempting suicide. Thus, we need to consider the implementation of measures to prevent low-rescue suicide attempts during similar infectious disease crises.

Cross-Layer Optimization for Heterogeneous MU-MIMO/OFDMA Networks.

To enable the full benefits from MU-MIMO (Multiuser-Multiple Input Multiple Output) and OFDMA (Orthogonal Frequency Division Multiple Access) to be achieved, the optimal use of these two technologies for a given set of network resources has been investigated in a rich body of literature. However, most of these studies have focused either on maximizing the performance of only one of these schemes, or have considered both but only for single-hop networks, in which the effect of the interference between nodes is relatively limited, thus causing the network performance to be overestimated. In addition, the heterogeneity of the nodes has not been sufficiently considered, and in particular, the joint use of OFDMA and MU-MIMO has been assumed to be always available at all nodes. In this paper, we propose a cross-layer optimization framework that considers both OFDMA and MU-MIMO for heterogeneous wireless networks. Not only does our model assume that the nodes have different capabilities, in terms of bandwidth and the number of antennas, but it also supports practical use cases in which nodes can support either OFDMA or MU-MIMO, or both at the same time. Our optimization model carefully takes into account the interactions between the key elements of the physical layer to the network layer. In addition, we consider multi-hop networks, and capture the complicated interference relationships between nodes as well as multi-path routing via multi-user transmissions. We formulate the proposed model as a Mixed Integer Linear Programming (MILP) problem, and initially model the case in which each node can selectively use either OFDMA or MU-MIMO; we then extend this to scenarios in which they are jointly used. As a case study, we apply the proposed model to sum-rate maximization and max-min fair allocation, and verify through MATLAB numerical evaluations that it can take appropriate advantage of each technology for a given set of network resources. Based on the optimization results, we also observe that when the two technologies are jointly used, more multi-user transmissions are enabled thanks to flexible resource allocation, meaning that greater use of the link capacity is achieved.

Factors Associated with Delay of Emergency Medical Services Activation in Patients with Acute Stroke.

BACKGROUND: The poor prognosis of acute stroke may be largely attributed to delays in treatment. Emergency medical services (EMS) usage is associated with a significant reduction in the delay in stroke treatment. The aims of this study were to identify factors associated with the delay in EMS activation for patients with acute stroke. METHODS: This study was conducted at 26 Fire Safety Centers in five districts of Seoul, Korea. Patients with acute stroke transferred by EMS and admitted to a tertiary referral hospital from January 2014 to December 2018 were enrolled. In this cross-sectional study, the dependent variable was the time from stroke onset to EMS activation time. Patients were divided into two groups, onset-to-alarm time ≤ 30 min and onset-to-alarm time > 30 min, and previously collected patient data were analyzed. We performed logistical regression analyses of characteristics differing significantly between groups. RESULTS: Out of 480 patients, 197 (41%) had onset-to-alarm times > 30 min. Significant variables in the logistical analysis were alert mental state (adjusted odds ratio [aOR]: 2.77; 95% confidence interval [CI]: 1.31-6.13), pre-stroke mRS ≥ 2 (aOR: 2.46; 95% CI: 1.26-4.95), onset occurrence at private space (aOR: 2.31; 95% CI: 1.23-4.41), recognizing symptoms between 0 and 8 am (aOR: 2.30; 95% CI: 1.25-4.31), ischemic stroke (aOR: 1.88; 95% CI: 1.04-3.43), and witnessed by others (aOR: 0.32; 95% CI: 0.18-0.55). CONCLUSIONS: Delay in EMS activation for acute stroke cases is possibly related to difficult situations to recognize stroke symptoms, such as alert mental state, pre-stroke mRS ≥ 2, onset occurrence at private space, recognizing symptoms between 0 and 8 am, and unwitnessed by others.

Potential mechanism of left ventricular spherical remodeling: association of mitral valve complex-myocardium longitudinal tissue remodeling mismatch.

Since mitral valve (MV) complex (MVC) longitudinally bridges left ventricular (LV) base end and its middle, insufficient MVC longitudinal tissue length (TL) elongation relative to whole LV myocardial longitudinal TL elongation could limit LV-base-longitudinal-TL elongation, leading to predominant LV-base-transverse-TL elongation, constituting LV spherical remodeling. In 30 patients with dilated cardiomyopathy (DCM), 30 with aortic regurgitation (AR), and 30 controls, LV sphericity, LV-apex- or base-transverse- and longitudinal-TL, MVC-longitudinal-TL, and whole-LV-longitudinal-TL were measured by three-dimensional (3D) echocardiography. Ratio of each measure versus mean normal value (i.e., LV-apex-transverse-TL ratio) was considered to express the directional and regional tissue elongation. [LV-base-longitudinal-TL ratio/global-LV-TL ratio] and [MVC-longitudinal-TL ratio/whole-LV-longitudinal-TL ratio] were obtained as the degree of LV-base-longitudinal-TL or MVC-longitudinal-TL elongation relative to the whole LV elongation. LV-apex-transverse-, LV-apex-longitudinal-, and LV-base-transverse-TL ratios were significantly increased (1.27 to 1.42, P < 0.01) in both DCM and AR, while the LV-base-longitudinal-TL ratio was not increased in DCM [1.04 ± 0.19, not significant (ns)] and only modestly increased in AR (1.12 ± 0.21, P < 0.01). Whole-LV-longitudinal-TL ratio was significantly increased in both DCM and AR (1.22 ± 0.18 and 1.20 ± 0.16, P < 0.01), while MVC-longitudinal-TL ratio was not or only modestly increased in both groups (1.07 ± 0.15, ns, and 1.12 ± 0.17, P = 0.02, respectively). Multivariable analysis revealed that LV sphericity was independently related to a reduced [LV-base-longitudinal-TL ratio/global-LV-TL ratio] (standard ß = -0.42, P < 0.01), which was further related to a reduced [MVC-longitudinal-TL ratio/whole-LV-longitudinal-TL ratio] (standard ß = 0.72, P < 0.01). These are consistent with the hypothesis that relatively less MVC-longitudinal-TL elongation in the process of primary LV myocardial tissue elongation may limit LV-base-longitudinal-TL elongation, contributing to LV spherical remodeling.NEW & NOTEWORTHY Left ventricular (LV) spherical remodeling is associated with poor prognosis and less-effective cardiac performance, which commonly develops in dilated cardiomyopathy. However, its mechanism remains unclear. We hypothesized and subsequently clarified that less mitral valve complex (MVC) tissue longitudinal elongation relative to whole LV myocardial tissue longitudinal elongation is related to disproportionately less LV base longitudinal versus transverse myocardial tissue elongation, constituting spherical remodeling. This study suggests modification of MVC tissue elongation could be potential therapeutic targets.

Blood pressure levels and cardiovascular risk according to age in patients with diabetes mellitus: a nationwide population-based cohort study.

BACKGROUND: Little is known about age-specific target blood pressure (BP) in hypertensive patients with diabetes mellitus (DM). The aim of this study was to determine the BP level at the lowest cardiovascular risk of hypertensive patients with DM according to age. METHODS: Using the Korean National Health Insurance Service database, we analyzed patients without cardiovascular disease diagnosed with both hypertension and DM from January 2002 to December 2011. Primary end-point was composite cardiovascular events including cardiovascular death, myocardial infarction and stroke. RESULTS: Of 241,148 study patients, 35,396 had cardiovascular events during a median follow-up period of 10 years. At the age of < 70 years, the risk of cardiovascular events was lower in patients with BP < 120/70 mmHg than in those with BP 130-139/80-89 mmHg. At the age of ≥ 70, however, there were no significant differences in the risk of cardiovascular events between patients with BP 130-139/80-89 mmHg and BP < 120/70 mmHg. The risk of cardiovascular events was similar between patients with BP 130-139/80-89 mmHg and BP 120-129/70-79 mmHg, and it was significantly higher in those with BP ≥ 140/90 mmHg than in those with BP 130-139/80-89 mmHg at all ages. CONCLUSIONS: In a cohort of hypertensive patients who had DM but no history of cardiovascular disease, lower BP was associated with lower risk of cardiovascular events especially at the age of < 70. However, low BP < 130-139/80-89 mmHg was not associated with decreased cardiovascular risk, it may be better to keep the BP of 130-139/80-89 mmHg at the age of ≥ 70.

Diverging cyclic radial shearing interferometry for single-shot wavefront sensing.

In this investigation, we describe a simple cyclic radial shearing interferometer for single-shot wavefront sensing. Instead of using the telescope lens system used in typical radial shearing interferometry, a single lens is used to generate two diverging radial shearing beams. This simple modification leads to the advantages of conveniently adjusting the radial shearing ratio, compactness of the system, and practical ease of alignment. With the aid of a polarization pixelated CMOS camera, the spatial phase-shifting technique is used to extract the phase with a single image. The most important feature is the fringe contrast enhancement by reducing the aberrations caused by the complicated optical system even though an incoherent light is used. The experimental results show the fringe contrast enhancement is at least 0.1 better than that of the conventional method, and the wavefronts are properly reconstructed with less than 0.071λ root-mean-squared wavefront error regardless of the coherence of the light.