• 한국축산식품학회지
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• 제43권4호
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• pp.612-624
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• 2023

The gut-brain axis encompasses a bidirectional communication pathway between the gastrointestinal microbiota and the central nervous system. There is some evidence to suggest that probiotics may have a positive effect on cognitive function, but more research is needed before any definitive conclusions can be drawn. Inflammation-induced by lipopolysaccharide (LPS) may affect cognitive function. To confirm the effect of probiotics on oxidative stress induced by LPS, the relative expression of antioxidant factors was confirmed, and it was revealed that the administration of probiotics had a positive effect on the expression of antioxidant-related factors. After oral administration of probiotics to mice, an intentional inflammatory response was induced through LPS i.p., and the effect on cognition was confirmed by the Morris water maze test, nitric oxide (NO) assay, and interleukin (IL)-1β enzyme-linked immunosorbent assay performed. Experimental results, levels of NO and IL-1β in the blood of LPS i.p. mice were significantly decreased, and cognitive evaluation using the Morris water maze test showed significant values in the latency and target quadrant percentages in the group that received probiotics. This proves that intake of these probiotics improves cognitive impairment and memory loss through anti-inflammatory and antioxidant mechanisms.

• Restorative Dentistry and Endodontics
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• 제46권1호
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• pp.2.1-2.8
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• 2021

Objectives: New premixed bioceramic root repair materials require moisture for setting. Using micro-computed tomography (micro-CT), this study evaluated the filling ability and volumetric changes of calcium silicate-based repair materials (mineral trioxide aggregate repair high-plasticity [MTA HP] and Bio-C Repair, Angelus), in comparison with a zinc oxide and eugenol-based material (intermediate restorative material [IRM]; Dentsply DeTrey). Materials and Methods: Gypsum models with cavities 3 mm deep and 1 mm in diameter were manufactured and scanned using micro-CT (SkyScan 1272. Bruker). The cavities were filled with the cements and scanned again to evaluate their filling capacity. Another scan was performed after immersing the samples in distilled water for 7 days to assess the volumetric changes of the cements. The statistical significance of differences in the data was evaluated using analysis of variance and the Tukey test with a 5% significance level. Results: Bio-C Repair had a greater filling ability than MTA HP (p < 0.05). IRM was similar to Bio-C and MTA HP (p > 0.05). MTA HP presented the largest volumetric change (p < 0.05), showing more volume loss than Bio-C and IRM, which were similar (p > 0.05). Conclusions: Bio-C Repair is a new endodontic material with excellent filling capacity and low volumetric change. The gypsum model proposed for evaluating filling ability and volumetric changes by micro-CT had appropriate and reproducible results. This model may enhance the physicochemical evaluation of premixed bioceramic materials, which need moisture for setting.

• 한국추진공학회지
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• 제26권4호
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• pp.28-43
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• 2022

고에너지 물질의 노화로 인하여 성능 감소를 최소화하기 위해 현재 노화 연구가 활발하게 진행되고 있지만, 개별 재료에 집중한 연구가 대부분이며 일반적인 노화 메커니즘 파악에는 미흡한 상태이다. 본 연구에서는 이러한 맹점을 해결하기 위해서 금속(W, Ti, Zr)과 KClO₄ 산화제를 기반으로 하는 고에너지 물질에 대하여 열/표면 분석을 수행하였으며, 이를 통해 고습도-고온 조건하에 노화된 해당 물질에서 보인 열역학적 특성 및 화학반응인자의 변화를 확인하였다. 그 결과, 금속 원소의 상태가 화학반응인자의 상당한 변화를 결정하였다. 즉, 금속의 산화 및 산화막 두께의 증가는 활성화에너지 평균값의 상승을 초래하였으며, 금속 원자의 전기음성도는 활성화에너지 값의 표준편차의 변화를 이끌어냈다.

• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1057-1065
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• 2023

Inflammatory bowel disease (IBD), a chronic inflammatory disease, results from dysregulation of the immune responses. Some lactic acid bacteria (LAB), including Lactobacillus, alleviate IBD through immunomodulation. In this study, the anti-colitis effect of LAB isolated from human breast milk was investigated in a mouse model induced acute colitis with 2,4,6-trinitrobenzene sulfonic acid (TNBS). TNBS remarkably increased weight loss, colon shortening, and colonic mucosal proliferation, as well as the expression levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β. Oral administration of LAB isolated from human breast milk resulted in a reduction in TNBS-induced colon shortening, as well as induced cyclooxygenase (COX)-2, nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB). In addition, LAB suppressed inflammatory cytokines such as TNF-α, IL-6, and IL-1β, and thus showed an effect of suppressing the level of inflammation induced by TNBS. Furthermore, LAB alleviated gut microbiota dysbiosis, and inhibited intestinal permeability by increasing the expression of intestinal tight junction protein including ZO-1. Collectively, these results suggest that LAB isolated from human breast milk can be used as a functional food for colitis treatment by regulating NF-κB signaling, gut microbiota and increasing expression of intestinal tight junction protein.

• 센서학회지
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• 제32권5호
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• pp.290-294
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• 2023

Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillage and wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of less than 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanent brain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gases is extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors that have been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture and mass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemical sensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide, an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fast response time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensors depend on imports. Although domestic technologies and products exist, more research is required on their long-term stability and reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristic evaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivity of the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counter electrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was also deposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuring concentrations as low as 0.6 ppm was developed.

• Anatomy and Cell Biology
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• 제56권4호
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• pp.494-507
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• 2023

Vascular dementia (VaD) is characterized by progressive memory impairment, which is associated with microglia-mediated neuroinflammation. Polyphenol-rich natural plants, which possess anti-inflammatory activities, have attracted scientific interest worldwide. This study investigated whether Rubus fruticosus leaf extract (RFLE) can attenuate VaD. Sprague-Dawley rats were separated into five groups: SO, sham-operated and treated with vehicle; OP, operated and treated with vehicle; RFLE-L, operated and treated with low dose (30 mg/kg) of RFLE; RFLE-M, operated and treated with medium dose (60 mg/kg) of RFLE; and RFLE-H, operated and treated with high dose (90 mg/kg) of RFLE. Bilateral common carotid artery and hypotension were used as a modeling procedure, and the RFLE were intraorally administered for 5 days (preoperative 2 and postoperative 3 days). The rats then underwent memory tests including the novel object recognition, Y-maze, Barnes maze, and passive avoidance tests, and neuronal viability and neuroinflammation were quantified in their hippocampi. The results showed that the OP group exhibited VaD-associated memory deficits, neuronal death, and microglial activation in hippocampi, while the RFLE-treated groups showed significant attenuation in all above parameters. Next, using BV-2 microglial cells challenged with lipopolysaccharide (LPS), we evaluated the effects of RFLE in dynamics of proinflammatory mediators and the upstream signaling pathway. RFLE pretreatment significantly inhibited the LPS-induced release of nitric oxide, TNF-α, and IL-6 and upregulation of the MAPKs/NF-κB/iNOS pathway. Collectively, we suggest that RFLE can attenuate the histologic alterations and memory deficits accompanied by VaD, and these roles are, partly due to the attenuation of microglial activation.

• International Journal of Stem Cells
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• 제16권1호
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• pp.93-107
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• 2023

Background and Objectives: Chronic periodontitis can lead to alveolar bone resorption and eventually tooth loss. Stem cells from exfoliated deciduous teeth (SHED) are appropriate bone regeneration seed cells. To track the survival, migration, and differentiation of the transplanted SHED, we used super paramagnetic iron oxide particles (SPIO) Molday ION Rhodamine-B (MIRB) to label and monitor the transplanted cells while repairing periodontal bone defects. Methods and Results: We determined an appropriate dose of MIRB for labeling SHED by examining the growth and osteogenic differentiation of labeled SHED. Finally, SHED was labeled with 25 ㎍ Fe/ml MIRB before being transplanted into rats. Magnetic resonance imaging was used to track SHED survival and migration in vivo due to a low-intensity signal artifact caused by MIRB. HE and immunohistochemical analyses revealed that both MIRB-labeled and unlabeled SHED could promote periodontal bone regeneration. The colocalization of hNUC and MIRB demonstrated that SHED transplanted into rats could survive in vivo. Furthermore, some MIRB-positive cells expressed the osteoblast and osteocyte markers OCN and DMP1, respectively. Enzyme-linked immunosorbent assay revealed that SHED could secrete protein factors, such as IGF-1, OCN, ALP, IL-4, VEGF, and bFGF, which promote bone regeneration. Immunofluorescence staining revealed that the transplanted SHED was surrounded by a large number of host-derived Runx2- and Col II-positive cells that played important roles in the bone healing process. Conclusions: SHED could promote periodontal bone regeneration in rats, and the survival of SHED could be tracked in vivo by labeling them with MIRB. SHED are likely to promote bone healing through both direct differentiation and paracrine mechanisms.

• 원예과학기술지
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• 제32권5호
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• pp.666-672
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• 2014

본 연구는 저온 저장된 키위과실의 상온 유통 중 에틸렌 발생 및 품질에 미치는 영향을 확인함으로써 유통기간 연장에 NO 처리 효과를 확인하기 위해서 수행하였다. 1개월 저장된 키위를 $200{\mu}L{\cdot}L^{-1}$ NO를 처리한 후 대조구와 함께 상온에 저장하면서 품질을 비교하였다. 상온에서 저장하는 동안 무게손실은 무처리구에 높았다. 에틸렌 생성은 NO 처리에 의해서 2일 지연되었으며, 호흡률은 대조구에 비해 2배이상 낮았다. 3개월 저장된 키위과실은 100, 200, 그리고 $500{\mu}L{\cdot}L^{-1}$ 농도로 NO를 처리하였다. 대조구는 NO를 처리하지 않은 무처리구와 $N_2$ 처리구를 두었다. 무게손실은 $100{\mu}L{\cdot}L^{-1}$에서 가장 많았으며, 1개월 저장된 과실에 비해서도 높은 손실률을 보였다. 에틸렌 생생은 대조구와 $100{\mu}L{\cdot}L^{-1}$ NO에서 높은 반면 $200{\mu}L{\cdot}L^{-1}$ NO와 $500{\mu}L{\cdot}L^{-1}$ NO에서는 상대적으로 낮았다. 경도는 무처리구와 $N_2$ 처리구는 저장일수가 경과 되면서 급격히 연화된 반면, NO 처리구에서는 6일까지 경도가 높게 유지되었으며, 특히 $200{\mu}L{\cdot}L^{-1}$ NO 처리구는 9일까지 유지되었다. 키위과실로부터 채취하여 배양된 Botrytis cinerea에 NO를 처리한 결과 처리 후 2일 경과될 때까지 무처리구와 $N_2$ 처리구에 비해서 NO 처리구는 곰팡이 번식이 적었다. 이상의 결과를 종합해 보면 저장된 과실을 상온에 유통하기 전에 NO 처리는 에틸렌 발생 및 호흡을 저지시키고, 연화를 지연시키는데 효과가 있다. NO의 적정 처리 농도는 $200{\mu}L{\cdot}L^{-1}$ NO을 기준으로 너무 낮거나 높으면 NO의 효과가 줄어든다.

• 한국식품과학회지
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• 제17권2호
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• pp.121-127
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• 1985

Ciguatoxin 구조 연구의 일환으로 파랑비늘돔 중에 서 독성분을 추출하였는데 Scarus sordidus만 근육과 내장에 독이 있었으나, S.frenatus, S.scaber and S.pectorlis에는 모두 독이 없었다. 실리스산컬럼에서 얻은 조독을 DEAE-셀루로즈 컬럼상에서 콜로로포름, 클로로포름-메타놀 (1 : 1) 및 메타놀로 전개하였더니 클로로포름 유출액(ST-1) 과 클로로포름-메타놀(1 : 1) 유출액에서 독성분이 발견되었고, 메타놀 유출액에서는 독성분이 검출되지 않았다. ST-1과 ST-2을 silica gel 60F-254에 spot하여 클로로포름-메타놀-물-식초산 (90 : 9.5 : 0.2 : 0.3)으로 전개하였더니, 그Rf값이 각각 0.60-0.75, 0.30-0.54였다. DEAE-셀루로즈 컬럼에서 얻은 ST-1을 재재크로마토그라피 하여도 역시 ST-1과 ST-2로 나누어졌다. 이렇게 얻은 ST-1과 ST-2는 세파텍스 LH-20에 흡착시켜, 클로로포름-메타놀(1 : 1) 용매로 전개할 때, 머무름시간이 모두 같았고, 역상 LiChrosorb RP-18를 이용한 HPLC상에서도 머무름시간이 동일하였다. 또 순수한 $ST-1\;(1.10\;{\mu}g)$ 그리고 이것을 1 N NaOH로 처리한 것 $(1.13\;{\mu}g)$을 활성도V인 알루미나 컬럼에 흡착시켜 클로로포름-메타놀 혼합액으로 전개하였더니 알카리처리를 하지 않는 경우는 $0.35\;{\mu}g)$가 클로로포름-메타놀의 9 : 1, 1 : 1 유출액에서, $(0.55\;{\mu}g)$가 메타놀-물 (1 : 1) 유출액에서 검출되었으나, 알카리처리를 한 경우는 처음 독성의 50%가 소실되어, 클로로포름-메타놀 (9 : 1) 유출액에서 $(0.21\;{\mu}g)$, 메타놀-물 (1 : 1) 유출액에서 $(0.80\;{\mu}g)$ 검출되었다. 하면 morey eel내장에서 얻은 독물질도 DEAE-셀루로즈에서 ST-1 과 ST-2로 나누어지며, 이 ST-1의 TLC, HPLC 및 알루미나 컬럼상의 거동이 파랑비늘돔에서 얻은 ST-1의 그것과 같으므로 scaritoxin으로 보고한 ST-1은 ciguatoxin의 형태인 less polar cigutoxin (LPCTX) 으로 생각된다.

• 공업화학
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• 제19권5호
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• pp.477-483
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• 2008

구연산법을 이용하여 $La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-{\delta}$ 산화물을 합성하였으며, 합성된 분말은 압축 성형 후 $1300^{\circ}C$에서 소결하여 치밀한 페롭스카이트 분리막을 제조하였다. 구연산법으로 제조한 $La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-{\delta}$의 전구물질은 TGA와 XRD로 분석하였다. $260{\sim}410^{\circ}C$ 온도 영역에서 전구물질의 금속-구연산 복합체가 분해되며 페롭스카이트 산화물이 얻어지나 XRD 분석결과 $900^{\circ}C$ 이하에서는 $SrCO_3$가 불순물로 존재하였다. 분리막의 전기전도도는 온도가 증가함에 따라 증가하다. 결정격자의 산소 손실로 인해 공기분위기에서는 $700^{\circ}C$ ($Po_2=0.2atm$)부터, 헬륨분위기에서는 $600^{\circ}C$ ($Po_2=0.01atm$) 부터 각각 감소하였다. 산소투과량은 온도가 증가할수록 증가하였고, 두께 1.6 mm의 $La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-{\delta}$ 분리막은 $950^{\circ}C$에서 $0.31cm^3/cm^2{\cdot}min$의 최대 투과도를 보였다. 산소투과에 대한 활성화 에너지는 $750{\sim}950^{\circ}C$ 온도 영역에서 88.4 kJ/mol이었다. 40 h의 투과실험 후에 분리막의 페롭스카이트 결정 구조는 변하지 않았으며 0.3 mol Sr doping 시 2차상이 생성되지 않고 안정하였다.