• Neonatal Medicine
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• v.28 no.1
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• pp.59-63
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• 2021

An important, albeit rare, cause of fetal bradycardia is long QT syndrome (LQTS). Congenital LQTS is an ion channelopathy caused by mutations in genes encoding cardiac ion channel proteins. Fetal onset of LQTS imposes high risk of life-threatening tachyarrhythmias and sudden cardiac death. Here, we report the case of a female newborn with fetal onset of bradycardia and a 2:1 atrioventricular (AV) block. After birth, a 12-lead electrocardiogram (ECG) revealed bradycardia with QT prolongation of a corrected QT (QTc) interval of 680 ms and pseudo 2:1 AV block. Genetic testing identified a heterozygous Gly402Ser (c.1204G>A) mutation in CACNA1C, confirming the diagnosis of LQTS type 8 (LQT8). The patient received propranolol at a daily dose of 2 mg/kg. Mexiletine was subsequently administered owing to the sustained prolongation of the QT interval and pseudo 2:1 AV block. One week after mexiletine inception, the ECG still showed QT interval prolongation (QTc, 632 ms), but no AV block was observed. There were no life-threatening tachyarrhythmias in a follow-up period of 13 months.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.439-446
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• 2008

Background: The aim of this study was to investigate the relationship of the left ventricular (LV) systolic function, the LV dimension and the LV mass with the QT dispersion in patients with stable angina, and we also wanted to compare this relationship between patients with and without significant coronary stenosis on coronary angiography. Material and Method: 174 patients complained of typical angina and they had no associated ST segment or cardiac enzyme abnormalities. The patients were divided into 2 groups based on the results of coronary angiography: the patients with angiographic coronary stenosis ${\geq}50%$ made up group I (n=101), and the patients with angiographic coronary stenosis <50% made up group II (n=73). An echocardiogram for assessing the LV ejection fraction (EF), the LV dimension and the LV mass and a 12.lead electrocardiogram for assessing the QT dispersion were performed before the coronary angiography. Result: The QT dispersion was significantly greater in group I than that in group II (39.8 ms vs. 33.3 ms; p<0.05). For all the patients, all the parameters of LV dimension and LV mass had statistically positive correlation to the QT dispersion, but the LV mass was the only independently significant parameter that was correlated with the increased QT dispersion (p<0.05). For group I, none of the echocardiographic parameters had significant correlation with the QT dispersion. However, the LV dimension and LV mass had significantly positive correlation with the QT dispersion, and the LV mass was also the only independently significant parameter that was correlated with increased QT dispersion in group II (p<0.05). Conclusion: Our study demonstrated a significantly positive correlation of the QT dispersion to the LV dimension and the LV mass in patients with stable angina. These findings are present only in patients without significant coronary stenosis.

• Journal of Biomedical Engineering Research
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• v.11 no.1
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• pp.57-64
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• 1990

This study describes the design of the portable intelligent QT analyzer which can record and analyze the ambulatory ECG data. System hardware is consisted of the one chip microcomputer(80C31) , A/D, ROM, RAM, LCD display and preamplifier. ECG data were processed by the differentiator and the digital filter. The de- tection of the parameters-QT, QTP and RR interval-was accomplished by the software algorithm using the slope and the amplitude of the processed data. Using this system, the trends of the parameters obtained during the long term could be observed.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.352-358
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• 2016

Quercetin (QT) and taxifolin (TF) are structurally similar plant-derived flavonoids that have antioxidant properties and act as free radical scavengers. The objective of this study was to investigate effects of QT and TF on nuclear maturation of porcine oocytes. Effects of TF at 0, 1, 10, and $50{\mu}g/mL$ on oocyte nuclear maturation (polar body extrusion) were investigated. After incubation for 44 h, there were no significant differences between the treatment and control groups except in the $50{\mu}g/mL$ group which was significantly lower (59.2%, p<0.05) than the other groups (control: >80%). After parthenogenetic activation, further in vitro development of QT- or TF-treated vs control oocytes was investigated. A significantly higher proportion of QT-treated ($1{\mu}g/mL$) oocytes developed into blastocysts compared to controls (24.3% vs 16.8%, respectively); however, cleavage rate and blastocyst cell number were not affected. The TF-treated group was not significantly different from controls. Levels of reactive oxygen species (ROS) and intracellular glutathione (GSH) in oocytes and embryos in a culture medium supplemented with QT or TF were measured. Both treatment groups had significantly lower (p<0.05) levels of ROS than controls, however GSH levels were different only in QT-treated oocytes. We conclude that exogenous flavonoids such as QT and TF reduce ROS levels in oocytes. Although at high concentration ($50{\mu}g/mL$) both QT and TF appear to be toxic to oocytes.

• Advances in Traditional Medicine
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• v.4 no.3
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• pp.215-218
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• 2004

We investigated the effect of Qi therapy (QT) on peripheral blood pressure (PBP), glucose, lactate dehydrogenase (LDH) and cortisol concentrations. Fourteen college students participated in receiving QT and placebo treatment. There were significant differences in embedding dimension of PBP. Plasma cortisol concentrations during QT were significantly lower than during control sessions (P

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.102-102
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• 2019

This study developed a HPLC analysis method for the determination of avicularin (AL) and quercitrin (QT) in Astilbe chinensis by HPLC. HPLC was performed on a Capcell Pak C18 MGII column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and acetonitrile at a flow rate of 1.0 mL/min at $30^{\circ}C$ and a UV detection wavelength of 254 nm. The analytical method was validated for its specificity, precision, accuracy, and linearity. The limits of detection and quantitation were AL 0.09 and 0.28 mg/mL, QT 0.03 and 0.09 mg/mL respectively. Calibration curves showed good linearity (AL r2 > 0.99990 and QT r2 > 0.99994), and the precision of analysis was satisfied (less than AL 0.59%, QT 0.63%). Recoveries of quantified compounds ranged from AL 100.57 to 102.08%, QT 99.94 to 100.64%. These results indicate that the developed HPLC method was applied successfully to the detection of AL and QT in A. chinensis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.55-58
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• 2008

RFID(Radio frequency IDentification) leader is collision of data, when recognizing the multiple tag the inside area. This collision became the cause which delays the tag recognition time of the leader. The protocol which prevents the delay of tag recognition time of the leader the place where representative it uses QT(Query Tree) algorithms, it uses a collision bit position from this paper and are improved QT-MTC(Query Tree with Multi-Tag Cognition) algorithms which it proposes. This algorithm stored the bit position which bit possibility and the collision where the collision happens occurs in the stack and goes round a tree the number of time which, it reduced could be identified two tags simultaneously in order, it was planned. A result of performance analysis, It compared in QT protocols and the this algorithm against the tag bit which is continued a tush efficiency improvement effect was visible.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.109-117
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• 2016

The most important mission of RFID reader is identify EPC (Electronic Product Code) of RFID tag of products that located within distinguishable range of RFID reader. RFID reader transmits query message to RFID tags through wireless channel and RFID tags send unique EPC to response its query message simultaneously. therefore tag collision occurred frequently. RFID tags collision resolution algorithm required to apply RFID technology to various industries. In this paper, we propose enhanced M-ary algorithm that collision bits location is used by not only RFID reader but also tags. the main feature of the proposed algorithm is that integrate multiple query message of M-ary QT algorithm to the single query message by analyze multiple response messages from tags. the simulation results show that the proposed algorithm give better performance than M-ary QT algorithm in terms of the number of query-response, identification efficiency and communication overhead.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.555-559
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• 2011

Oil hydraulic piston pumps are extensively used worldwide because of their simple design, light weight, and cost effectiveness. However, an oil hydraulic pump is likely to have high leakage, friction, and low energy efficiency after long-term use. In oil hydraulic piston pumps the clearance between the valve block and the piston plays an important role in the volumetric and overall efficiency. We studied the wear property of the SACM645 material used in hydraulic piston pumps via experiments with different heat treatments. We prepared three different specimens. The maximum tensile strengths of the QT and QT-nitration specimens are similar (about 820 MPa), but the strains are significantly different. However, the fatigue characteristic depended on the heat treatment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.999-1005
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• 2008

RFID(Radio Frequency IDintification) leader is collision of data, when recognizing the multiple tag the inside area. This collision became the cause which delays the tag recognition time of the leader. The protocol which prevents the delay of tag recognition time of the leader the place where representative it uses QT(Query Tree) algorithms, it uses a collision bit position from this paper and are improved QT-MTC(Query Tree with Multi-Tag Cognition) algorithms which it proposes. This algorithm stored the bit position which bit possibility and the collision where the collision happens occurs in the stack and goes round a tree the number of time which, it reduced could be identified two tags simultaneously in order, it was planned. A result of performance analysis, It compared in QT protocols and the this algorithm against the tag bit which is continued a high efficiency improvement effect was visible.