• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.507-516
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• 2022

The purpose of this study was to investigate the effect of rotational preference on body stability based on COP and EMG analysis in an quiet standing after turn in the left and right directions. The subjects of this study were 16 subjects with a high lateral preference for the right hand and foot. The subjects of this study were 16 subjects with high unilateral preference for the right hand and foot, and three rotational direction conditions (QS: quiet standing, LT: 10 turns on the left, RT: 10 turns on the right) were performed. In order to evaluate the stability in an quiet standing after turning, the results were derived and analyzed using a COP plate and an EMG. As a result of the study, LT and RT were larger than QS for all COP variables, but there was no difference according to the direction of turning. In EMG, RT showed larger muscle activity than the QS according to the rotational direction in left and right gastrocnemius. In conclusion, although all subjects had a high right lateral preference, there was no effect of rotational preference in COP, and gastrocnemius showed the effect of rotational preference.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.825-832
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• 2014

Previous works for detecting arrhythmia have mostly used nonlinear method such as artificial neural network, fuzzy theory, support vector machine to increase classification accuracy. Most methods require accurate detection of P-QRS-T point, higher computational cost and larger processing time. Even if some methods have the advantage in low complexity, but they generally suffer form low sensitivity. Also, it is difficult to detect PVC accurately because of the various QRS pattern by person's individual difference. Therefore it is necessary to design an efficient algorithm that classifies PVC based on QRS pattern in realtime and decreases computational cost by extracting minimal feature. In this paper, we propose PVC classification based on QRS pattern using QS interval and R wave amplitude. For this purpose, we detected R wave, RR interval, QRS pattern from noise-free ECG signal through the preprocessing method. Also, we classified PVC in realtime through QS interval and R wave amplitude. The performance of R wave detection, PVC classification is evaluated by using 9 record of MIT-BIH arrhythmia database that included over 30 PVC. The achieved scores indicate the average of 99.02% in R wave detection and the rate of 93.72% in PVC classification.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.1
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• pp.23-29
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• 2020

The skin is colonized by a large number of microorganisms with a stable composition of species. However, disease states of skin such as acne vulgaris, psoriasis, and atopic dermatitis have specific microbiome compositions that are different from those of healthy skin. The target modulation of the skin microbiome can be a potential treatment for these skin diseases. Quorum sensing (QS), a bacterial cell-cell communication system, can control the survival of bacteria and increase cell density. Also, QS affects the pathogenicity of bacteria such as biofilm formation and protease production. In this study, we confirmed anti-QS activity of Amorepacific patented ingredients, which are Lactobacillus ferment lysate (using Lactobacillus plantarum APsulloc 331261, KCCM 11179P) through bio-reporter bacterial strain Chromobacterium violaceum. The purple pigment production of C. violaceum controlled by QS was reduced 27.3% by adding 10 ㎍/mL of Lactobacillus ferment lysate (freeze dried). In addition, the Lactobacillus ferment lysate increased growth of Staphylococcus epidermidis 12% and decreased growth of Pseudomonas aeruginosa 38.5% and its biofilm formation 17.7% at a concentration of 10 ㎍/mL compared to the untreated control group. Moreover, S. epidermidis was co-cultured with the representative dermatological bacterium Staphylococcus aureus in the same genus, the growth of S. epidermidis was increased 134 % and the growth of S. aureus was decreased 13%. These results suggest that fermented lysate using Lactobacillus plantarum APsulloc 331261 may be useful as a cosmetic ingredient that can control the balance of skin microbiome.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.240-247
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• 2010

Pseudomonas aeruginosa is a Gram (-) opportunistic human pathogen causing a wide variety of infections on lung, urinary tract, eyes, and burn wound sites and quorum sensing (QS), a cell density-sensing mechanism plays an essential role in Pseudomonas pathogenesis. In order to investigate the importance of QS in the Pseudomonas infections of Korean patients, we isolated 189 clinical strains of P. aeruginosa from the patients in Pusan Paik Hospital, Busan, South Korea. The QS signal production of these clinical isolates was measured by signal diffusion assay on solid media using reporter strains. While most clinical strains (79.4%) produced the QS signals as similar level as a wild type strain, PAO1 did, where LasR, the initial QS signal sensor-regulator was fully activated, a minority of them (4.2%) produced much less QS signals at the level to which LasR failed to respond. Similarly, while 72.5% of the clinical isolates produced QS signals enough to activate QscR, an another QS signal sensor-regulator, some few of them (9%) produced the QS signals at much lower level where QscR was not activated. For further analysis, we selected 74 clinical strains that were obtained from the patients under suspicion of Pseudomonas infection and investigated the total protease activity that is considered important for virulence. Interestingly, significant portion of them showed very low protease activity (44.6%) or no detectable protease activity (12.2%). When the biofilm-forming ability that is considered very important in chronic infection was examined, most isolates showed lower biofilm-forming activity than PAO1. Similarly, significant portion of clinical isolates showed reduced motility (reduced swarming activity in 51.4% and reduced twitching activity in 41.9%), or non-detectable motility (swarming-negative in 28.4% and twitching-negative in 28.4%). Our result showed that the clinical isolates that produced QS signals at the similar level to wild type could have significantly reduced activities in the protease production, biofilm formation, and motility, and some clinical isolates had unique patterns of motility, biofilm formation, and protease production that are not correlated to their QS activity.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.73.2-73.2
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• 2008

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2159-2170
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• 2016

Many plant-pathogenic bacteria are dependent on quorum sensing (QS) to evoke disease. In this study, the population of QS and quorum quenching (QQ) bacteria was analyzed in a consecutive monoculture system of Pseudostellaria heterophylla. The isolated QS strains were identified as Serratia marcescens with SwrIR-type QS system and exhibited a significant increase over the years of monoculture. Only one QQ strain was isolated from newly planted soil sample and was identified as Bacillus thuringiensis, which secreted lactonase to degrade QS signal molecules. Inoculation of S. marcescens to P. heterophylla root could rapidly cause wilt disease, which was alleviated by B. thuringiensis. Furthermore, the expression of lactonase encoded by the aiiA gene in S. marcescens resulted in reduction of its pathogenicity, implying that the toxic effect of S. marcescens on the seedlings was QS-regulated. Meanwhile, excess lactonase in S. marcescens led to reduction in antibacterial substances, exoenzymes, and swarming motility, which might contribute to pathogensis on the seedlings. Root exudates and root tuber extracts of P. heterophylla significantly promoted the growth of S. marcescens, whereas a slight increase of B. thuringiensis was observed in both samples. These results demonstrated that QS-regulated behaviors in S. marcescens mediated by root exudates played an important role in replanting diseases of P. heterophylla.

• Journal of Life Science
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• v.26 no.12
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• pp.1487-1497
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• 2016

Bacterial cell to cell communication strategies called quorum sensing (QS) using small diffusible signaling molecules (auto-inducers) govern the expression of various genes dependent on their population density manner. As a consequence of synthesis and response to the signaling molecules, individual planktonic cells synchronized group behaviors to control a diverse array of phenotypes such as maturation of biofilm, production of extra-polymeric substances (EPS), virulence, bioluminescence and antibiotic production. Many studies indicated that biofilm formations are associated with QS signaling molecules such as acyl-homoserine lactones (AHLs) mainly used by several Gram negative bacteria. The biofilm maturation causes undesirable biomass accumulation in various surface environments anywhere water is present called biofouling, which results in serious eco-technological problems. Numerous molecules that interfere the bacterial QS called quorum quenching (QQ), have been discovered from various microorganisms, and their functions and mechanisms associated with QS have also been elucidated. To resolve biofouling problems related to various industries, the novel approach based on QS interference has been emerged attenuating multi-drug resisting bacteria appearance and environmental toxicities, which may provide potential advantages over the conventional anti-biofouling approaches. Therefore this paper presents recent information related to bacterial quorum sensing system, quorum quenching enzymes that can control the QS signaling, and lastly discuss the anti-biofouling approaches using the quorum quenching.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.405-413
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• 2021

The purpose of this in vivo study was to assess the clinical screening performance of a quantitative light-induced fluorescence (QLF) device in detecting proximal caries in primary molars. Fluorescence loss, red autofluorescence and a simplified QLF score for proximal caries (QS-proximal) were evaluated for their validity in detecting proximal caries in primary molars compared to bitewing radiography. Three hundred and forty-four primary molar surfaces were included in the study. Carious lesions were scored according to lesion severity assessed by visual-tactile and radiographic examinations. The QLF images were analyzed for two quantitative parameters, fluorescence loss and red autofluorescence, as well as for QS-proximal. For both quantitative parameters and QS-proximal, the sensitivity, specificity and area under receiver operating curve (AUROC) were calculated as a function of the radiographic scoring index at enamel and dentin caries levels. Both quantitative parameters showed fair AUROC values for detecting dentine level caries (△F = 0.794, △R = 0.750). QS-proximal showed higher AUROC values (0.757 - 0.769) than that of visual-tactile scores (0.653) in detecting dentine level caries. The QLF device showed fair screening performance in detecting proximal caries in primary molars compared to bitewing radiography.

• Korean Journal of Veterinary Research
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• v.56 no.4
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• pp.209-213
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• 2016

This study evaluated several known echocardiographic markers related to the assessment of severity in dogs with patent ductus arteriosus (PDA) after the closure of ductus arteriosus (DA). Forty-two dogs with patent ductus arteriosus were enrolled in this study. Evaluated echocardiographic markers were left atrial to aortic root ratio, left ventricular end-diastolic dimension to aortic root ratio, indexed left ventricular end-diastolic and end-systolic dimensions, end-diastolic and end systolic volume index, pulmonic flow to systemic flow (Qp/Qs) ratio, velocities of pulmonary regurgitant and systolic jets, pulmonary flow profiles and the presence of mitral regurgitation. Those markers were evaluated before, 1 day, and 30 days after the closure of DA. Statistically significant changes in some echocardiographic markers (i.e., Qp/Qs) were observed. Although several studies in human and dogs have evaluated the clinical outcome of PDA occlusion using several echocardiographic markers, this study has firstly evaluated all echocardiographic markers known to be useful for assessing the clinical outcome of PDA occlusion in human, and has demonstrated that those markers including the Qp/Qs and pulmonary flow profiles were useful in evaluating of clinical outcome of PDA in dogs and the reduction of LA and LV preload after ductal closure could dramatically reduce after successful ductal occlusion of PDA in dogs.

• Asia pacific journal of information systems
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• v.11 no.2
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• pp.121-139
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• 2001

VOQL* query language, recently proposed, is a visual language for object-oriented databases. It is based on Ven Diagram and graph, so that the underlying schema structure can be naturally implied in query expressions. In VOQL*, structural relationship among the objects used in a query expression is represented graphically and thus it has formal semantics that can be inductively defined, as well as it can be used with ease. In this paper, we proposed revised VOQL* and introduced its query processor, InQs(Intelligent Querying System). While retaining the merit of VOQL* that it allows the structural relationship among the objects to be represented visually, the revised VOQL* has another merit that users can formulate a query interactively using various forms supplied by InQs. As a query processor that translates queries in revised VOQL into those in ODMG OQL, InQs provides an environment in which users express queries in revised VOQL* and then the system automatically translates them into those in ODMG OQL. Translation algorithm of InQs is much simpler and intuitive than other algorithms used in QUIVER and other systems, since it reflects the formal semantics of VOQL*, which is defined inductively.