• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1401-1411
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• 2019

Mycobacterial cell walls comprise thick and diverse lipids and glycolipids that act as a permeability barrier to antibiotics or other chemical agents. The use of OH radicals from a non-thermal plasma jet (NTPJ) for the inactivation of mycobacteria in aqueous solution was adopted as a novel approach. Addition of water vapor in a nitrogen plasma jet generated OH radicals, which converted to hydrogen peroxide ($H_2O_2$) that inactivated non-pathogenic Mycobacterium smegmatis and pathogenic Mycobacterium tuberculosis H37Rv. A stable plasma plume was obtained from a nitrogen plasma jet with 1.91 W of power, killing Escherichia coli and mycobacteria effectively, whereas addition of catalase decreased the effects of the former. Mycobacteria were more resistant than E. coli to NTPJ treatment. Plasma treatment enhanced intracellular ROS production and upregulation of genes related to ROS stress responses (thiolrelated oxidoreductases, such as SseA and DoxX, and ferric uptake regulator furA). Morphological changes of M. smegmatis and M. tuberculosis H37Rv were observed after 5 min treatment with $N_2+H_2O$ plasma, but not of pre-incubated sample with catalase. This finding indicates that the bactericidal efficacy of NTPJ is related to the toxicity of OH and $H_2O_2$ radicals in cells. Therefore, our study suggests that NTPJ treatment may effectively control pulmonary infections caused by M. tuberculosis and nontuberculous mycobacteria (NTM) such as M. avium or M. abscessus in water.

• Journal of Yeungnam Medical Science
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• 제36권3호
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• pp.231-240
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• 2019

Background: We sought to determine the value of combining diffusion-weighted (DW) and perfusion-weighted (PW) sequences with a conventional magnetic resonance (MR) sequence to assess solid components of borderline ovarian tumors (BOTs) and stage I carcinomas. Methods: Conventional, DW, and PW sequences in the tumor imaging studies of 70 patients (BOTs, n=38; stage I carcinomas, n=32) who underwent surgery with pathologic correlation were assessed. Two independent radiologists calculated the parameters apparent diffusion coefficient (ADC), $K^{trans}$ (vessel permeability), and $V_e$ (cell density) for the solid components. The distribution on conventional MR sequence and mean, standard deviation, and 95% confidence interval of each DW and PW parameter were calculated. The inter-observer agreement among the two radiologists was assessed. Area under the receiver operating characteristic curve (AUC) and multivariate logistic regression were performed to compare the effectiveness of DW and PW sequences for average values and to characterize the diagnostic performance of combined DW and PW sequences. Results: There were excellent agreements for DW and PW parameters between radiologists. The distributions of ADC, $K^{trans}$, and $V_e$ values were significantly different between BOTs and stage I carcinomas, yielding AUCs of 0.58 and 0.68, 0.78 and 0.82, and 0.70 and 0.72, respectively, with ADC yielding the lowest diagnostic performance. The AUCs of the DW, PW, and combined PW and DW sequences were $0.71{\pm}0.05$, $0.80{\pm}0.05$, and $0.85{\pm}0.05$, respectively. Conclusion: Combining PW and DW sequences to a conventional sequence potentially improves the diagnostic accuracy in the differentiation of BOTs and stage I carcinomas.

• Composites Research
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• 제34권3호
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• pp.148-154
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• 2021

탄소/에폭시 복합재료 분리판(BP)은 높은 기계적 특성과 생산성으로 인해 바나듐 레독스 흐름전지(VRFB)의 기존 흑연 분리판을 대체할 가능성이 있는 BP이다. 다기능 구조인 탄소/에폭시 복합재료 BP는 계면접촉저항(ICR)을 줄이기 위해 흑연 코팅 또는 추가 표면 처리가 필요하다. 그러나 팽창 흑연 코팅은 VRFB 작동 조건에서 낮은 내구성을 가지며 별도의 표면 처리는 추가 비용이 발생한다는 단점이 있다. 본 연구에서는 폴리에스테르 직물을 적용하여 탄소/에폭시 복합재료 BP 표면의 잉여 수지층을 균일하게 제거하여 탄소섬유를 노출시키는 잉여 수지 흡수법을 개발하였다. 이 방법은 BP 표면에 탄소섬유를 노출하여 ICR을 감소시킬 뿐만 아니라 탄소 펠트 전극을 효과적으로 고정할 수 있는 고유한 도랑 패턴을 형성한다. 잉여 수지 흡수법에 의해 제작된 복합재료 BP의 산성 환경 내구성, 기계적 특성 및 기체 투과도에 대해 실험적으로 검증하였다.

• 생약학회지
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• 제53권2호
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• pp.87-95
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• 2022

Methicillin resistance Staphylococcus aureus (MRSA) is a gram-positive bacterium, the most commonly isolated bacterial human pathogen. JiYu-san is one of the natural products used to treat diseases in the folk recipe. In this study, we investigated the antimicrobial activity of EtOH 70% extracts of JiYu-san (JYS) against MRSA. The antibacterial activity of JYS against MRSA strain was evaluated using minimum inhibitory concentration (MIC), checkerboard dilution test, and time-kill assay. The effect of JYS on the immune mechanism of MRSA was confirmed through cell membrane permeability tests and energy metabolism tests, and the antibacterial activity mechanism was performed using qRT-PCR and western blot. As a result, in the antibacterial test of JYS, the MIC was measured to be 1.9~1000 ㎍/mL, and synergistic or showed a partial synergistic effect. In addition, JYS showed antibacterial activity in a combination test with DCCD or TX-100. In a study on the mechanism of action of antibacterial activity, it was found that JYS suppressed MRSA resistance genes and proteins. These results suggest that JYS has antibacterial activity and provides great potential as a natural antibiotic by modulating the immune mechanism against MRSA.

• 대한한의학방제학회지
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• 제31권3호
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• pp.171-182
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• 2023

Objectives : Saposhnikoviae Radix (SR) and Glehniae Radix (GR) have been frequently used in traditional medicine to treat diseases related to 'wind' syndrome, but there have been cases where it has been mixed in a state where the plant of origin is not clear. In this study, to select materials for conducting preclinical cerebral infarction research, the network pharmacology analysis method was used to select suitable medicinal materials for the study. Methods : In this study, a Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) based network pharmacology analysis method was used, and oral bioavailability (OB), drug likeness (DL), Caco-2 and BBB permeability were utilized to select compounds with potential activity. For the values of each variable used in this study, OB ≥ 20%, DL ≥ 0.18, Caco-2 ≥ 0, and BBB ≥ -0.3 were applied, then networks of bioactive compounds, target proteins, and target diseases was constructed. STRING database was used to construct a protein-protein interaction network. Results : It was confirmed that SR rather than GR has various target proteins and target diseases based on network pharmacological analysis using TCMSP database. And it was analyzed that the bioactive compounds only in SR act more on neurovascular diseases, and both drugs are expected to be effectively used for cardiovascular diseases. Conclusions : In our future study, SR will be used in an ischemic stroke mouse model, and the mechanism of action will be explored focusing on apoptosis and cell proliferation.

• 한국지반공학회논문집
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• 제25권4호
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• pp.31-38
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• 2009

최근의 압밀시험(표준압밀시험 또는 자중압밀시험)을 대신하여 성형되는 않은(또는 성형이 불가능한 상태의) 연약한 흙의 압밀거동을 연속적으로 빠르고 편리하게 결정할 수 있는 실험방법이 요구된다. 그래서 본 연구에서는 이와 같은 흙의 압밀 거동을 플로우 펌프에서 발생된 침투압을 이용하여 연속적으로 빠르게 획득할 수 있는 급속압밀실험을 제안하였다. 실험 장치는 삼축셀, 플로우 펌프, 변환기, 데이터처리장치 등으로 구성되고, 실험의 과정은 동일 시료에 대해 침투압에 의한 압밀, 하중재하에 의한 압밀, 압밀 후 투수시험 순으로 연속적으로 진행된다. 또한 본 실험법의 검증을 위해 기존의 표준압밀시험으로부터 얻은 결과와 비교 검토도 이루어졌다. 연구 결과 급속압밀실험법이 연약한 흙의 압밀 침하량 산정에 필요한 데이터를 쉽고 빠르게 산정할 수 있는 방법임을 알 수 있었다.

• 환경생물
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• 제40권4호
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• pp.398-404
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• 2022

본 연구는 플라스틱 가소제인 DEHP가 식물 병원균 중 하나인 P. carotovorum SCC1 균주에 미치는 영향을 조사하였다. DEHP가 균주 생장과 대사에 미치는 영향을 조사한 결과, 개체군 변화에 유의한 영향을 주지 않았으며, 세포막 투과성, ATPase 활성에 유의한 변화가 없었지만 TCA cycle 에서 DEHP 첨가에 따라 Succinyl-CoA synthase 활성이 유의적으로 감소하였다. 병원성 관련 유전자 발현량을 관찰한 결과 pectate lyase 유전자 발현량이 상대적으로 증가한 반면, pectinase 유전자는 상대적으로 발현량이 감소하였다. 따라서 DEHP는 P. carotovorum SCC1의 개체군 변화나 대사에는 유의미한 영향을 미치지 않지만 병원성 관련 유전자 발현에 영향을 미치므로 본 연구 결과는 향후 실제 식물 재배 조건에서 DEHP가 존재할 때 P. carotovorum의 특성에 관한 기초연구 자료로 활용할 수 있을 것이라 사료된다.

• BMB Reports
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• 제56권5호
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• pp.314-319
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• 2023

Sepsis is a life-threatening multi-organ dysfunction with high mortality caused by the body's improper response to microbial infection. No new effective therapy has emerged that can adequately treat patients with sepsis. We previously demonstrated that interferon-β (IFN-β) protects against sepsis via sirtuin 1-(SIRT1)-mediated immunosuppression. Another study also reported its significant protective effect against acute respiratory distress syndrome, a complication of severe sepsis, in human patients. However, the IFN-β effect cannot solely be explained by SIRT1-mediated immunosuppression, since sepsis induces immunosuppression in patients. Here, we show that IFN-β, in combination with nicotinamide riboside (NR), alleviates sepsis by blocking endothelial damage via SIRT1 activation. IFN-β plus NR protected against cecal ligation puncture-(CLP)-induced sepsis in wild-type mice, but not in endothelial cell-specific Sirt1 knockout (EC-Sirt1 KO) mice. IFN-β upregulated SIRT1 protein expression in endothelial cells in a protein synthesis-independent manner. IFN-β plus NR reduced the CLP-induced increase in in vivo endothelial permeability in wild-type, but not EC-Sirt1 KO mice. IFN-β plus NR suppressed lipopolysaccharide-induced up-regulation of heparinase 1, but the effect was abolished by Sirt1 knockdown in endothelial cells. Our results suggest that IFN-β plus NR protects against endothelial damage during sepsis via activation of the SIRT1/heparinase 1 pathway.

• 한국축산식품학회지
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• 제43권4호
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• pp.594-611
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• 2023

Whey protein (WP) has nutritional value, but the presence of β-lactoglobulin (β-LG) and α-lactalbumin (α-LA) cause allergic reactions. In this study, hypoallergenic whey protein hydrolyate (HWPH) was prepared by decomposing β-LG and α-LA of WP using exo- and endo-type proteases. The enzyme mixing ratio and reaction conditions were optimized using response surface methodology (RSM). Degradation of α-LA and β-LG was confirmed through gel electrophoresis, and digestion, and absorption rate, and immunostimulatory response were measured using in vitro and in vivo systems. Through RSM analysis, the optimal hydrolysis conditions for degradation of α-LA and β-LG included a 1:1 mixture of Alcalase and Prozyme reacted for 10 h at a 1.0% enzyme concentration relative to substrate. The molecular weight of HWPH was <5 kDa, and leucine was the prominent free amino acid. Both in vitro and in vivo tests showed that digestibility and intestinal permeability were higher in HWPH than in WP. In BALB/c mice, as compared to WP, HWPH reduced allergic reactions by inducing elevated Type 1/Type 2 helper T cell ratio in the blood, splenocytes, and small intestine. Thus, HWPH may be utilized in a variety of low allergenicity products intended for infants, adults, and the elderly.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.673-681
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• 2023

Hydrocarbon-based polymer membranes to replace perfluorinated polymer membranes are being continuously researched. However, hydrocarbon-based membranes have a problem in that they are less durable than fluorine-based membranes. In this study, we sought to compare the annealing effect to improve the durability of sulfonated poly(ether ether ketone) (SPEEK). After membranes formation, thermogravimetric analysis and tensile strength were measured to compare changes in membranes properties due to annealing. After manufacturing the membrane and electrode assembly (MEA), the initial performance and chemical durability was compared with unit cell operation. During the 24-hour annealing process, the strength increased due to the increase in-S-O-S-crosslinking, and the sulfonic acid group decreased, leading to a decrease in I-V performance. By annealing, the hydrogen permeability was reduced to less than 1/10 of that of the nafion membrane, and as a result, open circuit voltage (OCV) and durability was improved. The SPEEK membranes annealed for 24 hours showed higher durability than the nafion 211 membranes of the same thickness.