74 research outputs found

    Domain Adaptive Video Semantic Segmentation via Cross-Domain Moving Object Mixing

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    The network trained for domain adaptation is prone to bias toward the easy-to-transfer classes. Since the ground truth label on the target domain is unavailable during training, the bias problem leads to skewed predictions, forgetting to predict hard-to-transfer classes. To address this problem, we propose Cross-domain Moving Object Mixing (CMOM) that cuts several objects, including hard-to-transfer classes, in the source domain video clip and pastes them into the target domain video clip. Unlike image-level domain adaptation, the temporal context should be maintained to mix moving objects in two different videos. Therefore, we design CMOM to mix with consecutive video frames, so that unrealistic movements are not occurring. We additionally propose Feature Alignment with Temporal Context (FATC) to enhance target domain feature discriminability. FATC exploits the robust source domain features, which are trained with ground truth labels, to learn discriminative target domain features in an unsupervised manner by filtering unreliable predictions with temporal consensus. We demonstrate the effectiveness of the proposed approaches through extensive experiments. In particular, our model reaches mIoU of 53.81% on VIPER to Cityscapes-Seq benchmark and mIoU of 56.31% on SYNTHIA-Seq to Cityscapes-Seq benchmark, surpassing the state-of-the-art methods by large margins.Comment: Accepted to WACV 202

    Stroke awareness decreases prehospital delay after acute ischemic stroke in korea

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    BACKGROUND: Delayed arrival at hospital is one of the major obstacles in enhancing the rate of thrombolysis therapy in patients with acute ischemic stroke. Our study aimed to investigate factors associated with prehospital delay after acute ischemic stroke in Korea. METHODS: A prospective, multicenter study was conducted at 14 tertiary hospitals in Korea from March 2009 to July 2009. We interviewed 500 consecutive patients with acute ischemic stroke who arrived within 48 hours. Univariate and multivariate analyses were performed to evaluate factors influencing prehospital delay. RESULTS: Among the 500 patients (median 67 years, 62% men), the median time interval from symptom onset to arrival was 474 minutes (interquartile range, 170-1313). Early arrival within 3 hours of symptom onset was significantly associated with the following factors: high National Institutes of Health Stroke Scale (NIHSS) score, previous stroke, atrial fibrillation, use of ambulance, knowledge about thrombolysis and awareness of the patient/bystander that the initial symptom was a stroke. Multivariable logistic regression analysis indicated that awareness of the patient/bystander that the initial symptom was a stroke (OR 4.438, 95% CI 2.669-7.381), knowledge about thrombolysis (OR 2.002, 95% CI 1.104-3.633) and use of ambulance (OR 1.961, 95% CI 1.176-3.270) were significantly associated with early arrival. CONCLUSIONS: In Korea, stroke awareness not only on the part of patients, but also of bystanders, had a great impact on early arrival at hospital. To increase the rate of thrombolysis therapy and the incidence of favorable outcomes, extensive general public education including how to recognize stroke symptoms would be important.ope

    Effect of pre-stroke statin use on stroke severity and early functional recovery: a retrospective cohort study

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Abstract Background Experimental studies suggest that pre-stroke statin treatment has a dual effect of neuroprotection during ischemia and neurorestoration after ischemic injury. The aim of this study was to evaluate the effect of pre-stroke statin use on initial stroke severity and early clinical outcome. Methods We used a prospective database enrolling patients with acute ischemic stroke from 12 hospitals in Korea between April 2008 and January 2012. Primary endpoint was the initial stroke severity as measured by the National Institutes of Health Stroke Scale (NIHSS) score. Secondary endpoints were good outcome (modified Rankin Scale [mRS], 0โ€“2) and overall mRS distribution at discharge. Multivariable regression model and propensity score (PS) matching were used for statistical analyses. Results Among the 8340 patients included in this study, 964 patients (11.6ย %) were pre-stroke statin users. The initial NIHSS score (mean [95ย % CI]) was lower among pre-stroke statin users vs. non-users in multivariable analysis (5.7 [5.2โ€“6.3] versus 6.4 [5.9โ€“6.9], pโ€‰=โ€‰0.002) and PS analysis (5.2 [4.7โ€“5.7] versus 5.7 [5.4โ€“6.0], pโ€‰=โ€‰0.043). Pre-stroke statin use was associated with increased achievement of mRS 0โ€“2 outcome (multivariable analysis: OR [95ย % CI], 1.55 [1.25โ€“1.92], pโ€‰<โ€‰0.001; PS matching: OR [95ย % CI], 1.47 [1.16-1.88]; pโ€‰=โ€‰0.002) and favorable shift on the overall mRS distribution (multivariable analysis: OR [95ย % CI], 1.29 [1.12-1.51], pโ€‰=โ€‰0.001; PS matching: OR [95ย % CI], 1.31 [1.11-1.54]; pโ€‰=โ€‰0.001). Conclusions Pre-stroke statin use was independently associated with lesser stroke severity at presentation and better early functional recovery in patients with acute ischemic stroke

    Differential Pulse Voltammetric Electrochemical Sensor for the Detection of Etidronic Acid in Pharmaceutical Samples by Using rGO-Ag@SiO<sub>2</sub>/Au PCB

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    An rGO-Ag@SiO2 nanocomposite-based electrochemical sensor was developed to detect etidronic acid (EA) using the differential pulse voltammetric (DPV) technique. Rapid self-assembly of the rGO-Ag@SiO2 nanocomposite was accomplished through probe sonication. The developed rGO-Ag@SiO2 nanocomposite was used as an electrochemical sensing platform by drop-casting on a gold (Au) printed circuit board (PCB). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed the enhanced electrochemical active surface area (ECASA) and low charge transfer resistance (Rct) of the rGO-Ag@SiO2/Au PCB. The accelerated electron transfer and the high number of active sites on the rGO-Ag@SiO2/Au PCB resulted in the electrochemical detection of EA through the DPV technique with a limit of detection (LOD) of 0.68 ฮผM and a linear range of 2.0โ€“200.0 ฮผM. The constructed DPV sensor exhibited high selectivity toward EA, high reproducibility in terms of different Au PCBs, excellent repeatability, and long-term stability in storage at room temperature (25 ยฐC). The real-time application of the rGO-Ag@SiO2/Au PCB for EA detection was investigated using EA-based pharmaceutical samples. Recovery percentages between 96.2% and 102.9% were obtained. The developed DPV sensor based on an rGO-Ag@SiO2/Au PCB could be used to detect other electrochemically active species following optimization under certain conditions

    Validation of Minor Stroke Definitions for Thrombolysis Decision Making

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    Background: Patients with low National Institutes of Health Stroke Scale (NIHSS) scores are frequently excluded from thrombolysis, but more than 25% of them remain disabled. We sought to define a validated minor stroke definition to reduce the inappropriate treatment exclusion. Methods: From an outcome database, untreated patients with an NIHSS score of 5 or less presenting within a 4.5-hour window were identified and 3-month modified Rankin Scale (mRS) outcomes were analyzed according to individual isolated symptoms and total NIHSS scores. The validity of the following minor stroke definitions were assessed: (1) the National Institute of Neurological Disorders and Stroke Tissue Plasminogen Activator (NINDS-TPA) trials&apos; definition, (2) the total NIHSS score, varying a cutoff point from 0 to 4, and (3) our proposed definition that included an NIHSS score 5 0 or an NIHSS score 5 1 on the items of level of consciousness (LOC), gaze, facial palsy, sensory, or dysarthria. Results: Of 647 patients, 172 patients (26.6%) had a 3-month unfavorable outcome (mRS score 2-6). Favorable outcome was achieved in more than 80% of patients with an NIHSS score of 1 or less or with an isolated symptom on the LOC, gaze, facial palsy, sensory, or dysarthria item. In contrast, unfavorable outcome proportion was more than 25% in patients with an NIHSS score of 2 or more. When the NINDS-TPA trials&apos; definition, our definition, or the definition of an NIHSS score of 1 or less were applied, more than 75% of patients with an unfavorable outcome were defined as a non-minor stroke and less than 15% of patients with an unfavorable outcome were defined as a minor stroke. Conclusion: Implementation of an optimal definition of minor stroke into thrombolysis decision-making process would decrease the unfavorable outcomes in patients with low NIHSS scores.N

    Body mass index and waist circumference as predictors of recurrent vascular events after a recent ischemic stroke

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    Objectives: Although elevated body mass index (BMI) is a risk factor for stroke, it appears to protect against recurrent vascular events. We tried to evaluate BMI and waist circumference (WC) as predictors of recurrent stroke and vascular events in a cohort of stroke survivors who were followed for 12 months. Materials and methods: We analyzed the stroke registry database of 6 hospitals and recruited patients with a first-ever stroke who were admitted from January 2011 to Novem-ber 2019 and had their BMI and WC measured. Cox proportional hazards models were used to compare risks of recurrent stroke and major vascular events (a com-posite of stroke, myocardial infarction, or vascular death) between different BMI and WC quintiles. Reference categories were patients in the lowest quintiles. Results: A total of 14 781 patients were analyzed. Patients in the second quintile of BMI had the lowest risk of recurrent stroke (adjusted hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.58-0.91); patients in the highest quintile had the lowest risk or a major vascular event (adjusted HR 0.71; 95% CI 0.58-0.86). Patients in the fourth quintile of WC had the lowest risk of recurrent stroke (adjusted HR 0.73; 95% CI 0.59-0.91) and a major vascular event (adjusted HR 0.72; 95 % CI 0.60-0.86). Conclusions: Our results show favorable effects of excess body weight and intra-abdominal fat on avoidance of vascular events after stroke and a favor-able effect of intra-abdominal fat on avoidance of recurrent stroke.N

    Fasting and Non-Fasting Triglycerides in Patients With Acute Ischemic Stroke

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    Background: Clinical implications of elevated fasting triglycerides (FTGs) and non-fasting triglycerides (NFTGs) in acute ischemic stroke (AIS) remain unknown. We aimed to elucidate the correlation and clinical significance of FTG and NFTG levels in AIS patients. Methods: Using a multicenter prospective stroke registry, we identified AIS patients hospitalized within 24 hours of onset with available NFTG results. The primary outcome was a composite of stroke recurrence, myocardial infarction, and all-cause mortality up to one year. Results: This study analyzed 2,176 patients. The prevalence of fasting and non-fasting hypertriglyceridemia was 11.5% and 24.6%, respectively. Multivariate analysis revealed that younger age, diabetes, higher body mass index and initial systolic blood pressure were independently associated with both fasting and non-fasting hypertriglyceridemia (all P &lt; 0.05). Patients with higher quartiles of NFTG were more likely to be male, younger, ever smokers, diabetic, and have family histories of premature coronary heart disease and stroke (all P &lt; 0.05). Similar tendencies were observed for FTG. The composite outcome was not associated with FTG or NFTG quartiles. Conclusion: The fasting and non-fasting hypertriglyceridemia were prevalent in AIS patients and showed similar clinical characteristics and outcomes. High FTG and NFTG levels were not associated with occurrence of subsequent clinical events up to one year.Y

    Current Status of Recanalization Therapy in Acute Ischemic Stroke with Symptomatic Intracranial Arterial Occlusion in Korea

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    Background: Recent methodological advances in recanalization therapy may alter recanalization strategies and clinical outcomes in patients with symptomatic occlusion of intracranial cerebral arteries. However, few studies have analyzed these changes at a national level, with none conducted in Korea. Methods: On the basis of a prospective multicenter stroke registry database in Korea, 642 consecutive patients hospitalized within 12 hours of the onset with symptomatic occlusion of intracranial major cerebral arteries between March 2010 and November 2011 were identified. Recanalization therapy was used in 48% (n = 307) of patients; intravenous thrombolysis only (IVT) in 46%, intra-arterial thrombolysis only (IAT) in 16%, and combined thrombolysis (CMT) in 38%. Of the 166 patients treated by IAT or CMT, the Penumbra system or the Solitaire was used in 58% of patients. Results: Early neurologic improvement (ENI), 3-month modified Rankin scale (mRS) score of 2 or less, and symptomatic hemorrhagic transformation (SHT) were observed in 43%, 39%, and 9% of the patients in the IVT group; 52%, 27%, and 12% of the patients in the IAT group; and 54%, 39%, and 12% of the patients in the CMT group, respectively. Compared with no treatment, adjusted odd ratios (95% confidence intervals) of recanalization therapy were 1.59 (1.04-2.42) for ENI, 1.37 (.81-2.30) for 3-month mRS score of 2 or less, and 2.58 (1.12-5.91) for SHT. Conclusions: The variety and active use of endovascular approaches were quite noticeable. As a whole, recanalization therapy tended to contribute to favorable outcomes despite a significant increase of symptomatic hemorrhage.N

    Comparative effectiveness of standard care with IV thrombolysis versus without IV thrombolysis for mild ischemic stroke

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    Background-One third of patients presenting with initially mild strokes have unfavorable outcomes, and the efficacy of intravenous thrombolysis (IVT) in this population has not been proven. This study aimed to evaluate the comparative effectiveness of standard care with IVT versus without IVT in mild stroke patients. Methods and Results-Using a multicenter stroke registry database, we identified patients with acute ischemic stroke who presented within 4.5 hours of symptom onset and had initial National Institutes of Health Stroke Scale scores &lt;= 5. Multivariable logistic analysis and propensity score matching were used to adjust for baseline imbalances between the patients who did and did not receive IVT. Adjusted odds ratios and 95% CIs of IVT were estimated for 3-month modified Rankin Scale scores of 0 to 1 and symptomatic. Of 13 117 patients with stroke who were hospitalized between April 2008 and May 2012, 1386 met the eligibility criteria, and 194 (14.0%) were treated with IVT. For a modified Rankin Scale of 0 to 1 at 3 months, the adjusted odds ratios were 1.96 (95% CI, 1.28 to 3.00; P=0.002) by multivariable logistic analysis and 1.68 (1.10 to 2.56; P=0.02) by propensity score matching analysis, respectively. There was a statistically nonsignificant excess of symptomatic hemorrhagic transformation (odds ratios=3.76 [0.95 to 16.42; P=0.06] and 4.81 [0.84 to 49.34; P=0.09]), respectively. Conclusions-In this observational registry-based study, standard care with IVT is more effective than not receiving IVT in mild ischemic stroke patients, and there is a statistically nonsignificant risk of symptomatic hemorrhagic transformation.Y

    Stroke awareness decreases prehospital delay after acute ischemic stroke in korea

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    Abstract Background Delayed arrival at hospital is one of the major obstacles in enhancing the rate of thrombolysis therapy in patients with acute ischemic stroke. Our study aimed to investigate factors associated with prehospital delay after acute ischemic stroke in Korea. Methods A prospective, multicenter study was conducted at 14 tertiary hospitals in Korea from March 2009 to July 2009. We interviewed 500 consecutive patients with acute ischemic stroke who arrived within 48 hours. Univariate and multivariate analyses were performed to evaluate factors influencing prehospital delay. Results Among the 500 patients (median 67 years, 62% men), the median time interval from symptom onset to arrival was 474 minutes (interquartile range, 170-1313). Early arrival within 3 hours of symptom onset was significantly associated with the following factors: high National Institutes of Health Stroke Scale (NIHSS) score, previous stroke, atrial fibrillation, use of ambulance, knowledge about thrombolysis and awareness of the patient/bystander that the initial symptom was a stroke. Multivariable logistic regression analysis indicated that awareness of the patient/bystander that the initial symptom was a stroke (OR 4.438, 95% CI 2.669-7.381), knowledge about thrombolysis (OR 2.002, 95% CI 1.104-3.633) and use of ambulance (OR 1.961, 95% CI 1.176-3.270) were significantly associated with early arrival. Conclusions In Korea, stroke awareness not only on the part of patients, but also of bystanders, had a great impact on early arrival at hospital. To increase the rate of thrombolysis therapy and the incidence of favorable outcomes, extensive general public education including how to recognize stroke symptoms would be important.</p
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