105 research outputs found

    Improvement of Information Transfer Rates Using a Hybrid EEG-NIRS Brain-Computer Interface with a Short Trial Length: Offline and Pseudo-Online Analyses

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    Electroencephalography (EEG) and near-infrared spectroscopy (NIRS) are non-invasive neuroimaging methods that record the electrical and metabolic activity of the brain, respectively. Hybrid EEG-NIRS brain-computer interfaces (hBCIs) that use complementary EEG and NIRS information to enhance BCI performance have recently emerged to overcome the limitations of existing unimodal BCIs, such as vulnerability to motion artifacts for EEG-BCI or low temporal resolution for NIRS-BCI. However, with respect to NIRS-BCI, in order to fully induce a task-related brain activation, a relatively long trial length (≥10 s) is selected owing to the inherent hemodynamic delay that lowers the information transfer rate (ITR; bits/min). To alleviate the ITR degradation, we propose a more practical hBCI operated by intuitive mental tasks, such as mental arithmetic (MA) and word chain (WC) tasks, performed within a short trial length (5 s). In addition, the suitability of the WC as a BCI task was assessed, which has so far rarely been used in the BCI field. In this experiment, EEG and NIRS data were simultaneously recorded while participants performed MA and WC tasks without preliminary training and remained relaxed (baseline; BL). Each task was performed for 5 s, which was a shorter time than previous hBCI studies. Subsequently, a classification was performed to discriminate MA-related or WC-related brain activations from BL-related activations. By using hBCI in the offline/pseudo-online analyses, average classification accuracies of 90.0 ± 7.1/85.5 ± 8.1% and 85.8 ± 8.6/79.5 ± 13.4% for MA vs. BL and WC vs. BL, respectively, were achieved. These were significantly higher than those of the unimodal EEG- or NIRS-BCI in most cases. Given the short trial length and improved classification accuracy, the average ITRs were improved by more than 96.6% for MA vs. BL and 87.1% for WC vs. BL, respectively, compared to those reported in previous studies. The suitability of implementing a more practical hBCI based on intuitive mental tasks without preliminary training and with a shorter trial length was validated when compared to previous studies

    CLOCIS:Cloud-based conformance testing framework for IoT devices in the future internet

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    In recent years, the Internet of Things (IoT) has not only become ubiquitous in daily life but has also emerged as a pivotal technology across various sectors, including smart factories and smart cities. Consequently, there is a pressing need to ensure the consistent and uninterrupted delivery of IoT services. Conformance testing has thus become an integral aspect of IoT technologies. However, traditional methods of IoT conformance testing fall short of addressing the evolving requirements put forth by both industry and academia. Historically, IoT testing has necessitated a visit to a testing laboratory, implying that both the testing systems and testers must be co-located. Furthermore, there is a notable absence of a comprehensive method for testing an array of IoT standards, especially given their inherent heterogeneity. With a surge in the development of diverse IoT standards, crafting an appropriate testing environment poses challenges. To address these concerns, this article introduces a method for remote IoT conformance testing, underpinned by a novel conceptual architecture termed CLOCIS. This architecture encompasses an extensible approach tailored for a myriad of IoT standards. Moreover, we elucidate the methods and procedures integral to testing IoT devices. CLOCIS, predicated on this conceptual framework, is actualized, and to attest to its viability, we undertake IoT conformance testing and present the results. When leveraging CLOCIS, small and medium-sized enterprises (SMEs) and entities in the throes of IoT service development stand to benefit from a reduced time to market and cost-efficient testing procedures. Additionally, this innovation holds promise for IoT standardization communities, enabling them to champion their standards with renewed vigor

    Accessory auricle: Classification according to location, protrusion pattern and body shape

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    Background Accessory auricles (AAs) are common congenital anomalies. We present a new classification according to location and shape, and propose a system for coding the classifications. Methods This study was conducted by reviewing the records of 502 patients who underwent surgery for AA. AAs were classified into three anatomical types: intraauricular, preauricular, and buccal. Intraauricular AAs were divided into three subtypes: intracrural, intratragal, and intralobal. Preauricular AAs were divided into five subtypes: precrural, superior pretragal, middle pretragal, inferior pretragal, and prelobal. Buccal AAs were divided into two subtypes: anterior buccal and posterior buccal. AAs were also classified according to their protrusion pattern above the surrounding surface: pedunculated, sessile, areolar, remnant, and depressed.Pedunculated and sessile AAs were subclassified as spherical, ovoid, lobed, and nodular, according to their body shape. Cartilage root presence and family history of AA were reviewed. A coding system for these classifications was also proposed. Results The total number of AAs in the 502 patients was 1,003. Among the locations, the superior pretragal subtype (27.6%) was the most common. Among the protrusion patterns and shapes, pedunculated ovoid AAs were the most common in the preauricular (27.8%) and buccal areas (28.0%), and sessile lobed AAs were the most common in the intraauricular area (48.7%). The proportion of AAs with a cartilage root was 78.4%, and 11% of patients had a family history. The most common type of preauricular AA was the superior pretragal pedunculated ovoid AA (13.2%) with a cartilage root. Conclusions This new system will serve as a guideline for classifying and coding AAs

    Simultaneous Acquisition of EEG and NIRS during Cognitive Tasks for an Open Access Dataset

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    We provide an open access multimodal brain-imaging dataset of simultaneous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) recordings. Twenty-six healthy participants performed three cognitive tasks: 1) n-back (0-, 2- and 3-back), 2) discrimination/selection response task (DSR) and 3) word generation (WG) tasks. The data provided includes: 1) measured data, 2) demographic data, and 3) basic analysis results. For n-back (dataset A) and DSR tasks (dataset B), event-related potential (ERP) analysis was performed, and spatiotemporal characteristics and classification results for “target” vs. “non-target” (dataset A) and symbol “O” vs. symbol “X” (dataset B) are provided. Time-frequency analysis was performed to show the EEG spectral power to differentiate the task-relevant activations. Spatiotemporal characteristics of hemodynamic responses are also shown. For the WG task (dataset C), the EEG spectral power and spatiotemporal characteristics of hemodynamic responses are analyzed, and the potential merit of hybrid EEG-NIRS BCIs was validated with respect to classification accuracy. We expect that the dataset provided will facilitate performance evaluation and comparison of many neuroimaging analysis techniques

    Usefulness of the Cytomegalovirus Antigenemia Assay in Patients With Ulcerative Colitis

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    Background/AimsPatients with ulcerative colitis (UC) are at high risk for cytomegalovirus (CMV) reactivation. The usefulness of the CMV antigenemia assay in active UC patients has rarely been studied. We assessed whether the assay detects CMV colitis and predicts clinical outcomes in patients with UC.MethodsWe retrospectively reviewed the medical records of patients hospitalized for moderate-to-severe UC from 2003 to 2012. Positive CMV antigenemia was defined as ≥1 pp65-positive cell per 2×105 polymorphonuclear neutrophils. CMV colitis was defined as the presence of inclusion bodies and/or positive immunohistochemistry in the colonic mucosa. The primary outcome was steroid refractoriness, defined as the absence of clinical improvement after intravenous high-dose steroid administration.ResultsA total of 43 patients were enrolled. CMV antigenemia was detected in 12 (27.9%) patients. Positive CMV antigenemia was significantly associated with CMV colitis (P =0.001). The sensitivity and specificity of positive CMV antigenemia for diagnosing CMV colitis were 66.7% and 87.1%, respectively. Steroid refractoriness was found in 11 of 12 (91.7%) and 12 of 31 (38.7%) patients with positive and negative CMV antigenemia, respectively (P =0.002). The independent predictors for steroid refractoriness were positive CMV antigenemia (adjusted odds ratio [OR], 7.73; 95% confidence interval [CI], 1.22-49.19; P =0.030) and a shorter duration from the diagnosis of UC (adjusted OR, 0.99; 95% CI, 0.98-0.99; P =0.025).ConclusionsThe CMV antigenemia assay shows low sensitivity but high specificity for detecting CMV colitis and may predict steroid-refractory UC. Early rescue therapy might be considered in UC patients positive for CMV antigenemia

    Cellular direct conversion by cell penetrable OCT4-30Kc19 protein and BMP4 growth factor

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    Background : The number of patients suffering from osteoporosis is increasing as the elderly population increases. The demand for investigating bone regeneration strategies naturally arises. One of the approaches to induce bone regeneration is somatic cell transdifferentiation. Among the transcriptional regulators for transdifferentiation, octamer-binding transcription factor 4 (OCT4) is famous for its role in the regulation of pluripotency of stem cells. Bone morphogenetic protein 4 (BMP4) is another factor that is known to have a significant role in osteogenic differentiation. Previous studies have achieved transdifferentiation of cells into osteoblasts using viral and plasmid deliveries of these factors. Although these methods are efficient, viral and plasmid transfection have safety issues such as permanent gene incorporations and bacterial DNA insertions. Herein, we developed a cell penetrating protein-based strategy to induce transdifferentiation of endothelial cells into osteoblasts via nuclear delivery of OCT4 recombinant protein combined with the BMP4 treatment. For the nuclear delivery of OCT4 protein, we fused the protein with 30Kc19, a cell-penetrating and protein stabilizing protein derived from a silkworm hemolymph of Bombyx mori with low cytotoxic properties. This study proposes a promising cell-based therapy without any safety issues that existing transdifferentiation approaches had. Methods : OCT4-30Kc19 protein with high penetrating activities and stability was synthesized for a protein-based osteogenic transdifferentiation system. Cells were treated with OCT4-30Kc19 and BMP4 to evaluate their cellular penetrating activity, cytotoxicity, osteogenic and angiogenic potentials in vitro. The osteogenic potential of 3D cell spheroids was also analyzed. In addition, in vivo cell delivery into subcutaneous tissue and cranial defect model was performed. Results : OCT4-30Kc19 protein was produced in a soluble and stable form. OCT4-30Kc19 efficiently penetrated cells and were localized in intracellular compartments and the nucleus. Cells delivered with OCT4-30Kc19 protein combined with BMP4 showed increased osteogenesis, both in 2D and 3D culture, and showed increased angiogenesis capacity in vitro. Results from in vivo subcutaneous tissue delivery of cell-seeded scaffolds confirmed enhanced osteogenic properties of transdifferentiated HUVECs via treatment with both OCT4-30Kc19 and BMP4. In addition, in vivo mouse cranial defect experiment demonstrated successful bone regeneration of HUVECs pretreated with both OCT4-30Kc19 and BMP4. Conclusions : Using a protein-based transdifferentiation method allows an alternative approach without utilizing any genetic modification strategies, thus providing a possibility for safer use of cell-based therapies in clinical applications.This work was fnancially supported by the Ministry of Science and ICT (NRF2021R1A2C2008821). The Institute of Engineering Research at Seoul National University provided research facilities for this work

    Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

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    Background/AimsThe efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.MethodsAmong patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.ResultsOverall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.ConclusionsCautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy

    Risk of acute exacerbations in chronic obstructive pulmonary disease associated with biomass smoke compared with tobacco smoke

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    Background Risk of exacerbations in chronic obstructive pulmonary disease (COPD) associated with biomass smoke has not been well addressed, although biomass smoke is similar in composition to tobacco smoke. Methods To investigate whether the risk of exacerbations in COPD associated with biomass smoke differs from that in COPD associated with tobacco smoke, we recruited patients with COPD from two Korean multicenter prospective cohorts. In a multiple linear regression model, the standardized regression coefficient (β) of biomass smoke exposure ≥25 years was most similar to that (β′) of tobacco smoke exposure ≥10 pack-years (β = − 0.13 and β′ = − 0.14). We grouped patients with COPD into four categories based on the above cut-offs: Less Tobacco-Less Biomass, Less Tobacco-More Biomass, More Tobacco-Less Biomass, and More Tobacco-More Biomass. The main outcome was the incidence of moderate or severe exacerbations. Results Among 1033 patients with COPD, 107 were included in Less Tobacco-Less Biomass (mean age: 67 years, men: 67%), 40 in Less Tobacco-More Biomass (mean age: 70 years, men: 35%), 631 in More Tobacco-Less Biomass (mean age: 68 years, men: 98%), and 255 in More Tobacco-More Biomass (mean age: 69 years, men: 97%). The incidence rates of exacerbations were not significantly different between Less Tobacco-More Biomass and More Tobacco-Less Biomass (adjusted incidence rate ratio, 1.03; 95% confidence interval, 0.56–1.89; P = 0.921). No interaction between sex and tobacco and biomass smoke was observed. When propensity score matching with available covariates including age and sex was applied, a similar result was observed. Conclusions Patients with COPD associated with biomass smoke and those with COPD associated with tobacco smoke had a similar risk of exacerbations. This suggests that patients with COPD associated with biomass smoke should be treated actively.None declared

    The trans-ancestral genomic architecture of glycemic traits

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    Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe
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