7,249 research outputs found

    Expression of Neurotrophins and Their Receptors Tropomyosin-related kinases (Trk) under Tension-stress during Distraction Osteogenesis

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    The localization and expression of neurotrophins and their receptors during distraction osteogenesis was investigated in 72 male rat femurs (11 weeks old) to further clarify the concurrence of cellular and molecular events of new bone formation. After osteotomy, a 7-day lag phase was followed by distraction at the rate of 0.25 mm/12 h for 21 days (distraction phase), and a 7-day consolidation phase. The localization of neurotrophins (NGF, BDNF and NT-3) and their receptors tropomyosinrelated kinases (TRKA, TRKB and TRKC) by immunostaining showed positive staining in bone forming cells in each stage, although the presence and staining intensity varied by cell type and phase. The expressions of NGF, BDNF and NT-3 by real-time polymerase chain reaction (real-time PCR) showed that the peak of the mRNA expression of NGF occurred 10 days after distraction. NT-3 increased during bone extension, but decreased when distraction stopped. In contrast, BDNF continued to increase gradually throughout the distraction and consolidation phases. These findings suggest that neurotrophins and their receptors may play different roles in endochondral and intramembranous ossification in distraction osteogenesis. The tension stress caused by distraction may stimulate the expression of neurotrophins and their receptors, and promote osteogenesis

    Development of an LCD-Based Visual Field System

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    Background: The present study investigated the diagnostic effectiveness of an LCD-based visual field testing system (LVF) in comparison with the standard automated perimetry Humphrey Field Analyzer II-750i (HFA). Methods: A randomized controlled crossover study was conducted with 202 normal and 128 glaucomatous eyes using both LVF and HFA. The visual field testing systems were compared in terms of mean deviation (MD), pattern standard deviation (PSD), and area under the receiver operating characteristics curve (AUC) of MD and PSD differentiating the normal and glaucomatous eyes. Results: Significant correlations were found between MD measurements from LVF and those from HFA for normal eyes (r = 0.342) and glaucomatous eyes (r = 0.796); slightly higher significant correlations were identified between PSD measurements from LVF and those from HFA for normal eyes (r = 0.363) and glaucomatous eyes (r = 0.828). Furthermore, high AUCs of MD were found as 0.786 for LVF and 0.868 for HFA and AUCs of PSD as 0.913 for LVF and 0.932 for HFA. Conclusion: The comparison results of the present study support the competence of LVF compared with HFA in visual field testing for early detection of glaucoma.11Ysciescopuskc

    Unexpected Sudden Death of a 19-Year-Old Female with Congenital Single Coronary Artery Ostium during Exertion

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    Coronary artery anomalies are associated often with myocardial ischemia or sudden cardiac death. A 19-year-old woman who participated in an exertive game lost consciousness upon one such exertion. She was taken to a hospital where she died on the same day. An autopsy revealed that she had bifurcated coronary arteries, which arose from one coronary ostium in the left sinus of Valsalva. The right coronary artery arose from the left sinus and traveled between the aorta and the pulmonary trunk. The heart as well as the cardiac conduction system depended exclusively on the single coronary artery ostium for oxygenated blood supply, and the unbalanced blood distribution on her exertion probably led to sudden cardiac death. The case highlights the medicolegal importance of unexpected sudden cardiac death related to an anomalous origin of the coronary arteries

    High-resolution embedding extractor for speaker diarisation

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    Speaker embedding extractors significantly influence the performance of clustering-based speaker diarisation systems. Conventionally, only one embedding is extracted from each speech segment. However, because of the sliding window approach, a segment easily includes two or more speakers owing to speaker change points. This study proposes a novel embedding extractor architecture, referred to as a high-resolution embedding extractor (HEE), which extracts multiple high-resolution embeddings from each speech segment. Hee consists of a feature-map extractor and an enhancer, where the enhancer with the self-attention mechanism is the key to success. The enhancer of HEE replaces the aggregation process; instead of a global pooling layer, the enhancer combines relative information to each frame via attention leveraging the global context. Extracted dense frame-level embeddings can each represent a speaker. Thus, multiple speakers can be represented by different frame-level features in each segment. We also propose an artificially generating mixture data training framework to train the proposed HEE. Through experiments on five evaluation sets, including four public datasets, the proposed HEE demonstrates at least 10% improvement on each evaluation set, except for one dataset, which we analyse that rapid speaker changes less exist.Comment: 5pages, 2 figure, 3 tables, submitted to ICASS

    Absolute decision corrupts absolutely: conservative online speaker diarisation

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    Our focus lies in developing an online speaker diarisation framework which demonstrates robust performance across diverse domains. In online speaker diarisation, outputs generated in real-time are irreversible, and a few misjudgements in the early phase of an input session can lead to catastrophic results. We hypothesise that cautiously increasing the number of estimated speakers is of paramount importance among many other factors. Thus, our proposed framework includes decreasing the number of speakers by one when the system judges that an increase in the past was faulty. We also adopt dual buffers, checkpoints and centroids, where checkpoints are combined with silhouette coefficients to estimate the number of speakers and centroids represent speakers. Again, we believe that more than one centroid can be generated from one speaker. Thus we design a clustering-based label matching technique to assign labels in real-time. The resulting system is lightweight yet surprisingly effective. The system demonstrates state-of-the-art performance on DIHARD 2 and 3 datasets, where it is also competitive in AMI and VoxConverse test sets.Comment: 5pages, 2 figure, 4 tables, submitted to ICASS
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