• Natural Product Sciences
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• v.27 no.2
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• pp.86-98
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• 2021

This study was designed to characterize the effect of ginsenoside-Rg2 (Rg2), one of panaxatriol saponins isolated from Korean ginseng root, on the release of catecholamines (CA) in the perfused model of the rat adrenal medulla, and also to establish its mechanism of action. Rg2 (3~30 µM), administered into an adrenal vein for 90 min, depressed acetylcholine (ACh)-induced CA secretion in a dose- and time-dependent manner. Rg2 also time-dependently inhibited the CA secretion induced by 3-(m-chloro-phenyl-carbamoyl-oxy)-2-butynyltrimethyl ammonium chloride (McN-A-343), 1.1-dimethyl-4-phenyl piperazinium iodide (DMPP), and angiotensin II (Ang II). Also, during perfusion of Rg2, the CA secretion induced by high K⁺, veratridine, cyclopiazonic acid, methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoro-methyl-phenyl)-pyridine-5-carboxylate (Bay-K-8644) depressed, respectively. In the simultaneous presence of Rg2 and N^ω-nitro-L-arginine methyl ester hydrochloride ʟ-NAME), the CA secretion induced by ACh, Ang II, Bay-K-8644 and veratridine was restored nearly to the extent of their corresponding control level, respectively, compared to those of inhibitory effects of Rg2-treatment alone. Virtually, NO release in adrenal medulla following perfusion of Rg2 was significantly enhanced in comparison to the corresponding spontaneous release. Also, in the coexistence of Rg2 and fimasartan, ACh-induced CA secretion was markedly diminished compared to the inhibitory effect of fimasartan-treated alone. Collectively, these results demonstrated that Rg2 suppressed the CA secretion induced by activation of cholinergic as well as angiotensinergic receptors from the perfused model of the rat adrenal gland. This Rg2-induced inhibitory effect seems to be exerted by reducing both influx of Na⁺ and Ca²⁺ through their ionic channels into the adrenomedullary cells as well as by suppressing Ca²⁺ release from the cytoplasmic calcium store, at least through the elevated NO release by activation of NO synthase, which is associated to the blockade of neuronal cholinergic and AT₁-receptors. Based on these results, the ingestion of Rg2 may be helpful to alleviate or prevent the cardiovascular diseases, via reduction of CA release in adrenal medulla and consequent decreased CA level in circulation.

• Clean Technology
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• v.27 no.1
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• pp.85-92
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• 2021

A solar water battery is a system that generates power using solar energy. It is a combination of photoelectrochemical cells and an energy storage system. It can simultaneously convert and store solar energy without additional external voltage. Solar water batteries consist of photoelectrodes, storage electrodes and counter electrodes, and their properties and combination are important for the performance and the efficiency of the system. In this study, we tried to find the effect that changing the components of solar water batteries has on its system. The effects of the counter electrode during discharge, the kinds of photoelectrode and storage electrode materials, and electrolytes on the solar energy conversion and storage capacitance were studied. The optimized composition (TiO2 : NaFe-PB : Pt foil) exhibited 72.393 mAh g-1 of discharge capacity after 15 h of photocharging. It indicates that the efficiency of solar energy conversion and storage is largely affected by the configuration of the system. Also, the addition of organic pollutants to the chamber of the photoelectrode improved the battery's photo-current and discharge capacity by efficient photoelectron-hole pair separation with simultaneous degradation of organic pollutants. Solar water batteries are a new eco-friendly solar energy conversion and storage system that does not require additional external voltages. It is also expected to be used for water treatment that utilizes solar energy.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.246-256
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• 2022

The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 µM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.480-493
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• 2021

Since the generalized Hoek-Brown criterion (GHB) provides an efficient way of identifying its strength parameter values with the consideration of in-situ rock mass condition via Geological Strength Index (GSI), this criterion is recognized as one of the standard rock mass failure criteria in rock mechanics community. However, the nonlinear form of the GHB criterion makes its mathematical treatment inconvenient and limits the scope of its application. As an effort to overcome this disadvantage of the GHB criterion, the explicit approximate analytical equations for the minimum principal stress, which is associated with the maximum principal stress at failure, are formulated based on the Taylor polynomial approximation of the original GHB criterion. The accuracy of the derived approximate formula for the minimum principal stress is verified by comparing the resulting approximate minimum principal stress with the numerically calculated exact values. To provide an application example of the approximate formulation, the equivalent friction angle and cohesion for the expected plastic zone around a circular tunnel in a GHB rock mass are calculated by incorporating the formula for the approximate minimum principal stress. It is found that the simultaneous consideration of the values of mi, GSI and far-field stress is important for the accurate calculation of equivalent Mohr-Coulomb parameter values of the plastic zone.

• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.67-75
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• 2022

The purpose of this study is to present an appropriate management plan as a supplement to the scientific evidence of the currently operated distancing system for preventing COVID-19. The currently being used mathematical models are expressed as simultaneous ordinary differential equations, there is a problem in that it is difficult to use them for the management of entry and exit of small business owners. In order to supplement this point, in this paper, a method for quantitatively expressing the risk of infection by people who gather is presented in consideration of the allowable risk given to the gathering space, the basic infection reproduction index, and the risk reduction rate due to vaccination. A simple quantitative model was developed that manages the probability of infection in a probabilistic level according to a set of visitors by considering both the degree of infection risk according to the vaccination status (non-vaccinated, primary inoculation, and complete vaccination) and the epidemic status of the virus. In a given example using the model, the risk was reduced to 55% when 20% of non-vaccinated people were converted to full vaccination. It was suggested that management in terms of quarantine can obtain a greater effect than medical treatment. Based on this, a generalized model that can be applied to various situations in consideration of the type of vaccination and the degree of occurrence of confirmed cases was also presented. This model can be used to manage the total risk of people gathered at a certain space in a real time, by calculating individual risk according to the type of vaccine, the degree of inoculation, and the lapse of time after inoculation.

• Korean Journal of Social Welfare Studies
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• v.42 no.2
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• pp.179-203
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• 2011

The purpose of the study is 1) to investigate the reciprocal relationship between cognitive functioning and depressive symptoms and 2) to examine whether there is gender difference in this mutual relationship. The uniqueness of the current study is in its investigation on the simultaneous reciprocal relationship between cognitive functioning and depressive symptoms, which is different from previous studies examining unidirectional relationship. Subjects were 3,511 individuals aged 65 and over who participated in the first and second wave of Korean Longitudinal Study of Ageing. Non-recursive structural equation modeling identified the reciprocal relationship between cognitive functioning and depressive symptoms, with poorer cognitive functioning leading to higher depressive symptoms and higher depressive symptoms resulting in poorer cognitive functioning. Multi-group analysis showed the gender difference in the relationship between cognitive functioning and depressive symptoms. Specifically, cognitive functioning was the significant predictor of depressive symptoms for females, whereas the depressive symptoms was the significant predictor of cognitive functioning for males. These findings indicate that the reciprocal relationship and gender difference should be considered when we development practice implications for prevention and treatment related to depression and cognitive functioning. Based on these findings, implications for theory and practice were discussed.

• Journal of the Daesoon Academy of Sciences
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• v.46
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• pp.33-68
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• 2023

Simwudo (尋牛圖), known as Ox Seeking Pictures, originated in the 11th-12th century and have consistently played a guiding role in the teachings of various religions in East Asia. Some Korean religions that emerged during modern times conveyed their teachings through depictions of ox seeking or herding. Among them, Daesoon Jinrihoe stands out as a representative religion. The belief system of this particular religion elucidates its distinct doctrine and worldview by reimagining Simwudo, into a new set of six panels (seven or nine panels in some variations). The Simwudo of Daesoon Jinrihoe differs from that of Buddhism, particularly in its treatment of meditation (禪), both in terms of context and significance. While they share similarities in the aspect of ox-seeking, the Buddhist Simwudo symbolizes human nature, whereas the Simwudo of Daesoon Jinrihoe represents the great Dao of Heaven and Earth propagated by Kang Jeungsan and brought into completion by Jo Jeongsan. In the Buddhist context, the subject of the search is the Ox, signifying the restoration of a deluded human's pure nature in order to achieve personal salvation and in some version of Simwudo, reenter society to perform salvific actions for others. On the other hand, in the Simwudo of Daesoon Jinrihoe depicts the process of a human attaining immortality and following the teachings of Jeungsan and Jeongsan. This culminates in the final image which is the redemption of the world. The final phase of the Buddhist Simwudo, depending on the version, is either enlightenment (personal salvation) or reentering society to perform salvific actions (as a bodhisattva), whereas the Simwudo of Daesoon Jinrihoe show the simultaneous achievement of the perfection of humanity and the redemption of the world. This distinction highlights the fundamental differences between the Simwudo of these two distinctly different religious traditions. These differences arise from the contrasting purposes pursued by Buddhism and Daesoon Jinrihoe.

• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.162-172
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• 2021

Purpose We retrospectively evaluated the technical success rate and long-term efficacy of fluoroscopy-guided synovial cyst rupture followed by an intra-articular steroid injection at the post-laminectomy lumbar facet. Materials and Methods We selected subjects who had undergone a fluoroscopy-guided synovial cyst rupture with simultaneous intra-articular steroid injection within 6 months of MRI and demonstrated a symptomatic facet joint synovial cyst at the level of a previous lumbar laminectomy. Fourteen patients were enrolled, and we determined whether cyst rupture and symptom improvement were achieved after each procedure. The degrees of symptom improvement were categorized into 4: 1) symptoms improved (30% or more reduction, based on pre-procedural and post-procedural Numerical Pain Rating Scale scores), 2) symptoms not improved, 3) patient underwent surgery after injection, and 4) loss of follow-up. Results The success rate of percutaneous synovial cyst rupture decreased with repeated procedures (62.5% for the first procedure and 0% to 33.3% for additional procedures). However, 80% of the patients had symptom improvement with the procedures, overall. The surgery rate was 14.3% in 14 patients. Conclusion For patients with post-laminectomy symptomatic lumbar facet joint synovial cysts, fluoroscopy-guided synovial cyst rupture with intra-articular steroid injection may be an effective and less invasive treatment before considering a surgical approach.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.3
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• pp.103-107
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• 2024

In this study, nickel, a pure metal material, was proposed as a saggar for synthesizing NCM [Li(Ni_xCo_yMn_z)O₂] cathode active material. Nickel is known as a metal that is resistant to oxidation and has a high melting point. Nickel is one of the main components of NCM cathode material and was expected to be free from problems with contamination from saggar during cathode material synthesis. We sought to confirm the possibility of nickel as a saggar for synthesizing NCM cathode active materials. When a Ni metal crucible and Ni_0.8Co_0.1Mn_0.1(OH)₂ (NCM 811) precursor material were reacted at 900℃ for a long time, the change in the reaction layer on the surface of the crucible over time was analyzed. The nickel crucible reaction layer formed during heat treatment at 900℃ was nickel oxide, and is thought to have been created by simultaneous oxygen diffusion from the cathode precursor oxide and reaction with oxygen in the atmosphere. The change in thickness of the oxide layer appears to slow down after 480 hours, which suggests that the rate of oxygen diffusion from the precursor is reduced. It remained combined without falling out of the crucible until 480 hours. However, it was confirmed that the oxide layer falls off after 720 hours, so it is thought that it can be used as saggar for NCM synthesis only for a certain period of time.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.705-712
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• 2023

Common femoral artery pseudoaneurysm is a potentially serious complication of peripheral angiography. There have been few prior reports of simultaneous pseudoaneurysm in both common femoral arteries after percutaneous access. Here we report the case of a 58-year-old male patient who presented with phlegmon or abscess a few days after bilateral femoral access, after which newly developed bilateral femoral pseudoaneurysm with wide neck was observed on CT angiography 2 months after infection treatment. Because the patient refused surgery for pseudoaneurysm, a stent-graft was inserted in the left side, and percutaneous thrombin injection under US guidance with balloon occlusion was performed for the right side. Most pseudoaneurysms occur immediately after the causative procedure. However, there have been some cases in which pseudoaneurysms may occur several weeks or months later; it is therefore necessary to check the risk factors and to carefully observe the hemostasis site.