• Journal of Ginseng Research
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• v.35 no.2
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• pp.176-190
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• 2011

There seems to be some controversy about the effect of total ginseng saponin (TGS) on the secretion of catecholamines (CA) from the adrenal gland. Therefore, the present study aimed to determine whether TGS can affect the CA release in the perfused model of the adrenal medulla isolated from spontaneously hypertensive rats (SHRs). TGS (15-150 ${\mu}g/mL$), perfused into an adrenal vein for 90 min, inhibited the CA secretory responses evoked by acetylcholine (ACh, 5.32 mM) and high $K^+$ (56 mM, a direct membrane depolarizer) in a dose- and time-dependent fashion. TGS (50 ${\mu}g/mL$) also time-dependently inhibited the CA secretion evoked by 1.1-dimethyl-4 -phenyl piperazinium iodide (DMPP; 100 ${\mu}M$, a selective neuronal nicotinic receptor agonist) and McN-A-343 (100 ${\mu}M$, a selective muscarinic M1 receptor agonist). TGS itself did not affect basal CA secretion (data not shown). Also, in the presence of TGS (50 ${\mu}g/mL$), the secretory responses of CA evoked by veratridine (a selective $Na^+$ channel activator (50 ${\mu}M$), Bay-K-8644 (an L-type dihydropyridine $Ca^{2+}$ channel activator, 10 ${\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10 ${\mu}M$) were significantly reduced, respectively. Interestingly, in the simultaneous presence of TGS (50 ${\mu}g/mL$) and N${\omega}$-nitro-L-arginine methyl ester hydrochloride [an inhibitor of nitric oxide (NO) synthase, 30 ${\mu}M$], the inhibitory responses of TGS on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644, cyclopiazonic acid, and veratridine were considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of TGS-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of TGS (150 ${\mu}g/mL$) was greatly elevated compared to the corresponding basal released level. Taken together, these results demonstrate that TGS inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the isolated perfused adrenal medulla of the SHRs. It seems that this inhibitory effect of TGS is mediated by inhibiting both the influx of $Ca^{2+}$ and Na+ into the adrenomedullary chromaffin cells and also by suppressing the release of $Ca^{2+}$ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade, without the enhancement effect on the CA release. Based on these effects, it is also thought that there are some species differences in the adrenomedullary CA secretion between the rabbit and SHR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.985-992
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• 2011

The 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics and flow distribution for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. Three types of modifications such as i) changing the plenum shape, ii) orifice install in the exit part of cleaned gas, iii) increasing the plenum number were established. From the results of computational fluid dynamics, it was revealed that the changing of plenum shape and orifice install in the exit part of cleaned gas was more reasonable than the increasing the plenum number because of the difficulties of retrofit. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, save the installation area, save the operation fee, and management more convenient.

• Genomics & Informatics
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• v.8 no.3
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• pp.108-115
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• 2010

Hypertension is the most prevalent disease worldwide and is itself a risk factor for cerebral, cardiac, and renal diseases. The inconsistency of candidate genes suggested by previous genomewide association studies (GWASs) may be due to not only differences in study design and genetic or environmental background but also the difference in the power of analysis between continuous traits and discrete traits. We analyzed 352,228 single nucleotide polymorphisms (SNPs) in 8842 unrelated Koreans obtained from Ansan and Ansung cohorts. We performed a series of GWA analyses using three different phenotype models; young hypertensive cases (278 subjects) versus elderly normotensive controls (680 subjects); the upper 25% (2211 hypertensive cases) versus the lower 25% of the SBP distribution (2211 hypotensive controls); and finally SBP and DBP as continuous traits (8842 subjects). The numbers of young hypertensive cases and elderly normotensive controls were not large enough to achieve genomewide significance. The model comparing the upper 25% subjects to the lower 25% of subjects showed a power that was approximate to that of QTL analysis. Two neighboring SNPs of the ATP2B1 gene, rs17249754 (SBP, p=$2.53^{-10}$; DBP, p=$1.28{\times}10^{-8}$) and rs7136259 (SBP, p=$1.30{\times}10^{-9}$; DBP, p=$6.41{\times}10^{-8}$), were associated with both SBP and DBP. Interestingly, a SNP of the RPL6 gene, rs11066280, revealed a significant genomewide association with SBP in men only (p=$3.85{\times}10^{-8}$), and four SNPs located near the MAN2A1 gene showed a strong association with DBP only in elderly men aged 60-70 years (e.g., rs6421827, p=$4.86{\times}10^{-8}$). However, we did not observe any gene variant attaining genomewide significance consistently in the three phenotype models except for the ATP2B1 gene variants. In general, the association signal with blood pressure was stronger in women than in men. Genes identified in GWASs are expected to open the way for prevention, early diagnosis, and personalized treatment of hypertension.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.61-79
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• 2018

Objectives: The objective of this study was to examine the effect of non-thermal dielectric barrier discharge(DBD) plasma on decontamination of Staphylococcus aureus(S. aureus) and Escherichia coli(E. coli) as common pathogens. Methods: This experiment was carried out in a chamber($0.64m^3$)designed by the authors. The plasma was continuously generated by a non-thermal DBD plasma generator(Model TB-300, Shinyoung Air tech, Korea). Suspensions of S. aureus and E. coli of 0.5 McFarland standard($1.5{\times}10^8CFU/mL$) were prepared using a Densi-Check photometer(bio $M{\acute{e}}rieux$, France). The suspensions were diluted1:1000 in sterile PBS solutions(approximately$10^{4-5}CFU/mL$) and inoculated on tryptic soy agar(TSA) in Petri dishes. The Petri dishes(80mm internal diameter)were exposed to the non -thermal DBD plasma in the chamber. Results: The results showed that 95% of S. aureus colonies were killed after a six-hour exposure to the DBD plasma. In the case of E. coli, it took two hours to kill 100% of the colonies. The gram-negative E. coli had a greater reduction than the gram-positive S. aureus. This difference may be due to the structure of their cell membranes. The thickness of gram-positive bacteria is greater than that of gram-negative bacteria. The S. aureus is more resistant to DBD plasma exposures than is E. coli. It should be noted that average concentrations of ozone, a byproduct of the DBD plasma generator, were monitored throughout the experiment and the results were well below the criteria, 50 ppb, recommended by the Korean Ministry of the Environment. Thus, non-thermal DBD plasma is deemed safe for use in hospital and public facilities. Conclusions: There was evidence that non-thermal DBD plasma can effectively kill S. aureus and E. coli. The results indicate that DBD plasma technology can greatly contribute to the control of infections in hospitals and other public and private facilities.

• Asia pacific journal of information systems
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• v.23 no.4
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• pp.129-149
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• 2013

According to the development of new Information Technologies, firms consistently invest a significant amount of money in IT activities, such as establishing internal and external information systems. However, several anti-Information activities-such as hacking, leakage of information and system destruction-are also rapidly increasing, thus many firms are exposed to direct and indirect threats. Therefore, firms try to establish information security systems and manage these systems more effectively via an enterprise perspective. However, stakeholders or some managers have negative opinions about information security systems. Therefore, in this research, we study the relationship between multibusiness firms' performance and information security systems. Information security indicates physical and logical correspondence of information system department against threats and disaster. Studies on information security systems suggested frameworks such as IT Governance Cube and COBIT Framework to identify information security systems. Thus, this study define that information security systems is a controlled system on enterprise IT process and resource on IT Governance perspective rather than independent domain of IT. Thus, Information Security Systems should be understood as a subordinate concept of IT and business processes. In addition, this study incorporates information capability to information security system literature to show the positive relationship between Information Security Systems and Corporate Performance. The concept of information capability suggested that an interaction of human, information, technical and an effect on corporate performance using three types of capability (IT Practice, Information Management Practice, Information Behaviors and Values). Information capability is about firms' capability to manage IT infrastructure and information as well as individual employees who use IT infrastructure and information. Thus, this study uses information capability as a mediating variable for the relationship between information security systems and firms' performance. To investigate the relationship between Information Security Systems and multibusiness firms' performance, this study extends the IT relatedness concept into Information Security Systems. IT relatedness provides understanding of how corporations cope with conflicts between headquarters and business units to create a synergy effect and achieve high performance using IT resources. Based on the previous literature, this study develops the IT Security Relatedness model. IT Security Relatedness is our main independent variable, while Information Capability and Information Security Performance are mediating variables. To control for the common method bias, we collect each multibusiness firm's financial performance and use it as our dependent variable. We find that Information Security Systems influence Information Capability and Information Security Performance positively, and these two variables consequently influence Corporate Performance positively. In addition, this result indirectly shows that corporations under a multibusiness environment can obtain synergy effects using the integrated Information Security Systems. This positive impact of Information Security Systems on multibusiness firms' performance has an important implication to various stakeholders. Therefore, multibusiness firms need to establish Information Security Systems to achieve better financial performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4656-4663
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• 2010

In this study, the 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics, flow distribution, air mean ages, and residence time for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. In addition, it showed the possibility that the velocity field and distribution characteristics of the residence time could be improved through a modification to inlet structure of the spray dryer reactor. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, the installation area, the operation fee, and management more convenient.

• Korean Journal of Play Therapy
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• v.21 no.4
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• pp.491-507
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• 2018

The purpose of this study is to validate the Play Participation Attitude Scale for parents of preschoolers, which was developed by the Delphi survey. 447 parents of 9 daycare centers in Seoul and Incheon were recruited for this study and, finally, data from 339 parents were used to perform exploratory factor analysis, confirmatory factor analysis, correlation analysis, multiple regression analysis, and reliability analysis. The results of the study are as follows. First, factor analyses revealed that the global fit of the sensitively play (7 items), responsively play (6 items), and delightfully play(7 items) three-factor model was good. Second, the internal consistency of the Play Participation Attitude Scale was good. Third, there was a statistically significant positive correlation between the current scale and the parents' playfulness scale, indicating concurrent validity. Finally, higher scores of the Play Participation Attitude Scale and its three factors significantly predicted lower scores of parenting stress and higher scores of the preschoolers' self-control ability. These findings revealed that this new measure to be both valid and reliable and specifically suggests what kind of attitude is appropriate for parents to adopt when participating in preschoolers' play.

• Korean Journal of Radiology
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• v.22 no.6
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• pp.994-1004
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• 2021

Objective: To extract pulmonary and cardiovascular metrics from chest CTs of patients with coronavirus disease 2019 (COVID-19) using a fully automated deep learning-based approach and assess their potential to predict patient management. Materials and Methods: All initial chest CTs of patients who tested positive for severe acute respiratory syndrome coronavirus 2 at our emergency department between March 25 and April 25, 2020, were identified (n = 120). Three patient management groups were defined: group 1 (outpatient), group 2 (general ward), and group 3 (intensive care unit [ICU]). Multiple pulmonary and cardiovascular metrics were extracted from the chest CT images using deep learning. Additionally, six laboratory findings indicating inflammation and cellular damage were considered. Differences in CT metrics, laboratory findings, and demographics between the patient management groups were assessed. The potential of these parameters to predict patients' needs for intensive care (yes/no) was analyzed using logistic regression and receiver operating characteristic curves. Internal and external validity were assessed using 109 independent chest CT scans. Results: While demographic parameters alone (sex and age) were not sufficient to predict ICU management status, both CT metrics alone (including both pulmonary and cardiovascular metrics; area under the curve [AUC] = 0.88; 95% confidence interval [CI] = 0.79-0.97) and laboratory findings alone (C-reactive protein, lactate dehydrogenase, white blood cell count, and albumin; AUC = 0.86; 95% CI = 0.77-0.94) were good classifiers. Excellent performance was achieved by a combination of demographic parameters, CT metrics, and laboratory findings (AUC = 0.91; 95% CI = 0.85-0.98). Application of a model that combined both pulmonary CT metrics and demographic parameters on a dataset from another hospital indicated its external validity (AUC = 0.77; 95% CI = 0.66-0.88). Conclusion: Chest CT of patients with COVID-19 contains valuable information that can be accessed using automated image analysis. These metrics are useful for the prediction of patient management.

• Health Policy and Management
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• v.14 no.1
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• pp.65-88
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• 2004

In general, empowerment is defined as the motivational concept of autonomy and self-efficacy. Recently, the concept of empowerment is applied to improve organizational staff's job satisfaction and organizational commitment in many organizations. Empower-ment in service organizations, i.e., hospitals, has certainly generated more publicity than any other organizations. The objectives of this study are, first, to measure the degree of hospital employees' empowerment using Spreitzer(1995)'s empowerment theory, second, to analyze the causal relationship of organizational and job characteristics, a degree of empowerment, and organizational performance(job satisfaction and organizational commitment), and third, to offer the strategy for the improvement of job satisfaction and organizational commitment. Spreitzer insists that the empowerment is composed of 4 dimensions(meaning, competence, self-determination, and impact). And he argues that various work-related characteristics is a direct cause of empowerment and the indirect cause of job satisfaction and organizational commitment, mediated by the empowerment latent variable. In order to perform this study, data were collected by self-administered questionnaires from hospital employees working in administrative department of 3 university hospitals in Inchon and Kyunggi-Do region. The number of cases is 181(response rate; 86%). The Collected data were analyzed with SPSS Ver. 10.0 and AMOSV Ver. 4.0. First, to test validity of variables, the factor analysis was used. Second, to test reliability, Cronbach's alpha coefficients was calculated. Cronbach's alpha of empowerment variable is 0.8323 showing that there's no problem in regard to the internal consistency. Also the Cronbach's alpha of other variables are 0.8301 of the degree of perceived control, 0.6705 of job characteristics, O.8787 of compensation, 0.9254 of job satisfaction, and 0.8389 of organizational commitment, respectively. Among the questions of job characteristics, two survey questions are deleted due to lowering the reliability. Third, to test multicollinearity and correlation of variables, the correlation analysis was performed. There was no problem of multicollinearity. Finally structural equation modelling (SEM) analysis was conducted to find the causal relationship of organizational and job Characteristics, empowerment, job satisfaction and organizational commitment. The 16 variables are included for the SEM analysis. The major results of this study are as follows: First, in the case of model fitness, the condition of x$^2$ statistic(92.187) is not fully satisfied, but the indices of GFI(0.912), AGFI(0.863), NFI(0.917) and CFI(0.928) are partially satisfied, which needs to upper 0.90. Second, in the result of hypotheses testing, all hypotheses are accepted and have a positive effect in 95% or 99% confidence interval(P<0.05 or P<0.001) except the effect of compensation variable on empowerment(P=0.082). Third, in regard to the direct, indirect, and total effect of variables, the direct effect of perceived control, task characteristics, and compensation on job satisfaction are 0.728, 2.264, 0.328 and on organizational commitment are 0.094, 1.411, 0.418, respectively. Also the indirect effect of perceived control, task characteristics, and compensation on job satisfaction are 0.311, 0.196, 0.028 and on organizational commitment are 0.210, 0.132, 0.019, respectively. Thus, these findings imply that various work-related factors are direct effect of empowerment and indirect effect of result variables, job satisfaction and organizational commitment. Also These results showed that the workplace empowerment is significant mediating factor of employee's job satisfaction and organizational commitment.

• International Area Studies Review
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• v.22 no.2
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• pp.163-186
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• 2018

The purpose of this study is to analyze the institutional conditions and problems for the transition to the North Korean economic system. As a research method, we first analyzed the legislative processes of 4th stage market reform policies (liberalization, privatization, privatization, and corporation) by major economic transition countries. And we found out the difference with North Korea. Based on this, it analyzed the process of institutionalization of North Korea's 4th stage economic reform policies (7.1 measures, comprehensive market policies, Currency reform, 6.28 policy). According to research, There are three important conditions that can not compare the changes of the North Korean market economy with those of the transition economies. First, the internal and external conditions and environment for the transition of the economic system and the role of the state and civil society are very different. Second, the means and objectives of the policy decision process and the implementation process are different. Third, it differs absolutely in terms of the nature and effectiveness of the nation's political and economic policies. Fourth, the priority, contents, and legislation process of economic policies for economic reform differ considerably from those of North Korea. Especially, when discussing the possibility of transition to the 'Chinese model', it is accompanied a considerable risk. It is because the purpose of market entry of control power in North Korea and their survival network are quite unique. In addition, China's domestic market size, population size, and type of control are quite different from North Korea. A necessary and sufficient condition for the transition of the North Korean economic system is the relaxation of physical control mechanisms and institutions in the market area. Next, it is necessary to make a legitimate institutionalization as well as an entire survey on the illegal ownership market. Based on this, it is necessary to gradually change the dependence of the domestic market on China to South Korea. In other words, this is a paradigm shift in the semi-controlled power exclusion, post-automation and domestic market.