• 한국식품영양학회지
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• 제29권3호
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• pp.371-381
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• 2016

The present study investigated the effects of processing parameters such as time (10, 20, 30, 40 min), pressure (25, 50, 75, 100 MPa), and the salinity of brine (0~10%(w/v)) on jacopever (Sebastes schlegeli Hilgendorf) in order to establish optimization of the three factors using a high hydrostatic pressure (HHP) machine. To do so, it analyzed the quality characteristics of volatile basic nitrogen (VBN), trimethylamine (TMA), total bacterial counts, dynamic viscoelasticities, and differential scanning calorimetry (DSC) properties. First, when the time increased to 40 mins, by 10 min intervals, the total bacterial counts in HHP groups under $25^{\circ}C$, 100 MPa, and 4%(w/v) brine were significantly decreased except for the first 10 min in comparison to the control group. In regards to DSC properties, the onset temperature ($T_O$) of the first endothermal curve was significantly reduced. Second, when the pressure level increased up to 100 MPa by 25 MPa increments, the total bacterial counts in the HHP samples significantly decreased for 20 min at 50 MPa or higher. As the pressure increased, G', G" and the slope of tan ${\delta}$ decreased (except for 50 MPa). Third, in regards to the salinities of brine, when the HHP processing was treated at 100 MPa, $25^{\circ}C$ for 20 min, the total bacterial counts of all the HHP groups significantly decreased in comparison to those of the control group. A significant difference was found in the enthalpy of the second endothermic curve in the 6~10%(w/v) (except 7%(w/v)) HHP groups. Therefore, the salinity of the immersion water under the HHP condition was appropriate when it was lower than 6%(w/v). The present study demonstrated that the optimum parameter condition according to/under the condition of the microbial inhibition and economic effects using an HHP would be the reaction time for 20 min, reaction pressure at 100 MPa, and the salinity of 4%(w/v) brine.

• Food Science and Biotechnology
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• 제15권1호
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• pp.63-69
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• 2006

The primary objective of this study is to determine whether a diet supplemented with brown rice koji (BRK) results in a reduced stress response in rats and mice. BRK, which has been suggested as a candidate for use as a stress- and fatigue-fighting supplement, was compared with red ginseng extract (RG) for its stress-reducing potential. The animals in this study were divided into no-stress, stress, RG, and BRK groups of 8 to 10 animals each. Stress was induced by means of immobilization (being restrained in plastic tubes for 30 min and electroshock (0.5 mA in mice or 2 mA in rats for 5 min). The no-stress group was not exposed to stress. Rats in the RG group received oral doses of 200 mg RG extract/kg body weight daily. The BRK group was fed a 30% BRK diet and exposed to stress. Animals were given supplements for 7 days before being exposed to stress, and then were given supplements for 5 days with exposure to stress. When the stress exposure ended, the animals were observed for stress-related changes in behavior and their plasma corticosterone levels were measured. BRK supplementation was associated with a partial blockade of the effects of stress on locomotion and elevated plus-maze test results in rats and mice. It was also associated with a partial reduction in stress-induced behaviors such as freezing, burrowing, smelling, face-washing, and rearing. BRK supplementation did not have a significant effect on plasma corticosterone levels, which were increased in the animals exposed to stress (p<0.01). The mice in the RG group received RG in water (2 mg RG/ mL $H_2O$), and the BRK group received a 30% BRK diet (weight) for 7 days. Both groups were evaluated for signs of fatigue. BRK supplementation increased endurance, as indicated by time on the rota-rod, in cold water, and on the horizontal wire. These results suggest that BRK supplementation partially protects the animal from the effects of stress and may also contribute to resistance to fatigue on physical exertion.

• The Korean Journal of Physiology and Pharmacology
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• 제20권4호
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• pp.333-340
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• 2016

Edaravone, a synthetic-free radical scavenger, has been reported to reduce ischemia-reperfusion-induced renal injury by improving tubular cell function, and lowering serum creatinine and renal vascular resistance. The present study investigated the effect of edaravone in diabetes mellitus-induced nephropathy in rats. A single administration of streptozotocin (STZ, 55 mg/kg, i .p.) was employed to induce diabetes mellitus in rats. The STZ-administered diabetic rats were allowed for 10 weeks to develop nephropathy. Mean body weight, lipid alteration, renal functional and histopathology were analysed. Diabetic rats developed nephropathy as evidenced by a significant increase in serum creatinine and urea, and marked renal histopathological abnormalities like glomerulosclerosis and tubular cell degeneration. The kidney weight to body weight ratio was increased. Moreover, diabetic rats showed lipid alteration as evidenced by a significant increase in serum triglycerides and decrease in serum high-density lipoproteins. Edaravone (10 mg/kg, i .p., last 4-weeks) treatment markedly prevented the development of nephropathy in diabetic rats by reducing serum creatinine and urea and preventing renal structural abnormalities. In addition, its treatment, without significantly altering the elevated glucose level in diabetic rats, prevented diabetes mellitus-induced lipid alteration by reducing serum triglycerides and increasing serum high-density lipoproteins. Interestingly, the renoprotective effect of edaravone was comparable to that of lisinopril (5 mg/kg, p.o, 4 weeks, standard drug). Edaravone prevented renal structural and functional abnormalities and lipid alteration associated with experimental diabetes mellitus. Edaravone has a potential to prevent nephropathy without showing an anti-diabetic action, implicating its direct renoprotection in diabetic rats.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1881-1890
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• 2016

Manganese superoxide dismutase (MnSOD) is a vital enzyme that protects cells from free radicals through eliminating superoxide radicals ($O^{2-}$). Hirudin, a kind of small active peptide molecule, is one of the strongest anticoagulants that can effectively cure thrombus diseases. In this study, we fused Hirudin to the C terminus of human MnSOD with the GGGGS linker to generate a novel dual-feature fusion protein, denoted as hMnSOD-Hirudin. The hMnSOD-Hirudin gene fragment was cloned into the pET15b (SmaI, CIAP) vector, forming a recombinant pET15b-hMnSOD-Hirudin plasmid, and then was transferred into Escherichia coli strain Rosetta-gami for expression. SDS-PAGE was used to detect the fusion protein, which was expected to be about 30 kDa upon IPTG induction. Furthermore, the hMnSOD-Hirudin protein was heavily detected as a soluble form in the supernatant. The purification rate observed after Ni NTA affinity chromatography was above 95%. The hMnSOD-Hirudin protein yield reached 67.25 mg per liter of bacterial culture. The identity of the purified protein was confirmed by western blotting. The hMnSOD-Hirudin protein activity assay evinced that the antioxidation activity of the hMnSOD-Hirudin protein obtained was $2,444.0{\pm}96.0U/mg$, and the anticoagulant activity of the hMnSOD-Hirudin protein was $599.0{\pm}35.0ATU/mg$. In addition, in vitro bioactivity assay showed that the hMnSOD-Hirudin protein had no or little cytotoxicity in H9c2, HK-2, and H9 (human $CD_4{^+}$, T cell) cell lines. Transwell migration assay and invasion assay showed that the hMnSOD-Hirudin protein could suppress human lung cancer 95-D cell metastasis and invasion in vitro.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.1007-1021
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• 2018

Cancer represents one of the most significant threats to human health on a global scale. Hence, the development of effective cancer prevention strategies, as well as the discovery of novel therapeutic agents against cancer, is urgently required. In light of this challenge, this research aimed to evaluate the effects of several potent bioactive peptides and proteins contained in crocodile white blood cell extract (cWBC) against LU-1, LNCaP, PC-3, MCF-7, and CaCo-2 cancer cell lines. The results demonstrate that 25, 50, 100, and $200{\mu}g/ml$ cWBC exhibits a strong cytotoxic effect against all investigated cell lines ($IC_{50}$ $70.34-101.0{\mu}g/ml$), while showing no signs of cytotoxicity towards noncancerous Vero and HaCaT cells. Specifically, cWBC treatment caused a significant reduction in the cancerous cells' colony forming ability. A remarkable suppression of cancerous cell migration was observed after treatment with cWBC, indicating potent antimetastatic properties. The mechanism involved in the cancer cell cytotoxicity of cWBC may be related to apoptosis induction, as evidenced by typical apoptotic morphology features. Moreover, certain cWBC concentrations induced significant overproduction of ROS and significantly inhibited the $S-G_2/M$ transition in the cancer cell. The molecular mechanisms of cWBC in apoptosis induction were to decrease Bcl-2 and XIAP expression levels and increase the expression levels of caspase-3, caspase-8, and p53. These led to a decrease in the expression level of the cell cycle-associated gene cyclin-B1 and the arrest of cell population growth. Consequently, these findings demonstrate the prospect of the use of cWBC for cancer therapy.

• Restorative Dentistry and Endodontics
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• 제33권3호
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• pp.235-245
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• 2008

본 연구의 목적은 복합레진의 slumping resistance를 측정할 수 있는 방법을 개발하고, 그 유용성을 평가하기 위해 rheometer를 이용해 측정된 복합레진의 여러 유변학적 성질과 slumping resistance의 상호 관련성을 밝히고자 하였다. 상용되는 hybrid composites (Z100, Z250, DenFil, Tetric Ceram, ClearFil)와 nanofil composite (Z350)를 2 mm 두께의 디스크 모양의 시편으로 만들었다. 사각형의 단면을 가진 알루미늄 형판으로 레진 디스크를 눌러 표준화된 자국을 남겼다. 이것을 즉시 광중합하거나 (no-slump) $25^{\circ}C$ 에서 3 분간 방치한 후에 광중합 하였다 (slumped). 흰 경석고로 광중합된 레진을 복제한 후 laser 3-D profilometer 로 표면의 단면 영상을 얻었다. Slumping 전 후 홈의 깊이의 비를 구해 slumping resistance index (SRI)라 정의하였다. 각 복합레진의 중합 전 전단 점탄성을 측정하기 위해 회전형 rheometer 를 이용하여 동적회전전단실험과 squeeze test를 시행하였다. 더불어 flow test를 시행하였다. 동적회전전단실험 및 압착실험의 결과와 SRI의 상호관련성을 조사하기 위해 상관분석을 하였다. 여섯 가지의 재료의 SRI 값에는 차이가 있었다 (Z100 < DenFil < Z250 < ClearFil < Tetric Ceram < Z350). SRI 는 전단 점성(손실)계수 G"와 가장 큰 양의 상관관계를 보였으며 Tan ${\delta}$는 SRI와 상관관계가 없었다. SRI는 수직 가압에 대한 저항 보다 전단흐름에 대한 저항과 관련성이 높았다. 본 연구에서 도입된 imprint method와 SRI는 복합레진이 slumping 되는 경향을 정량화하였으며 복합레진 조작성의 평가방법으로 사용할 수 있었다.

• Journal of Ginseng Research
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• 제39권2호
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• pp.116-124
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• 2015

Background: Ginseng, the root of Panax ginseng (PG), is used widely as a herbal medicine to prevent and treat various diseases. Panax ginseng has pharmacological effects on neurodegenerative diseases such as Alzheimer's disease (AD). The present study evaluated the neuroprotective effects of PG and its possible neuroprotective mechanisms in advanced glycation end product (AGE)-induced AD in a rat model. Methods: Advanced glycation end products were injected bilaterally into the CA3 region of the rats' brains. The Morris water maze test and step-down type passive avoidance test were performed to evaluate their memory and cognitive abilities. The oxidation indexes in the hippocampus were detected. Immunohistochemistry was conducted to visualize the receptors for advanced glycation end products (RAGEs) and nuclear factor-kappa-light-chain-enhancer of activated B cell (NF-${\kappa}B$). Results: Behavioral results showed that PG (1 g/kg, 0.5 g/kg, and 0.25 g/kg) significantly shortened the escape latency, remarkably increased the number of crossing times, significantly decreased the number of errors, and prolonged the latency in rats with AGE-induced AD. Panax ginseng also significantly reduced the malondialdehyde level, increased the glutathione content, and increased superoxide dismutase activity in the hippocampus. Panax ginseng significantly decreased the expression of RAGE and NF-${\kappa}B$. The blockade of anti-RAGE antibody could significantly reduce AGE-induced impairments and regulate these expressions. Conclusion: Our results demonstrated that PG significantly inhibits AGE-induced memory impairment and attenuates Alzheimer-like pathophysiological changes. These neuroprotective effects of PG may be associated with the RAGE/NF-${\kappa}B$ pathway. Our results provided the experimental basis for applying PG in preventing and treating AD.

• 접착 및 계면
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• 제15권3호
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• pp.100-108
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• 2014

본 연구에서는 비스페놀 A 에폭시 수지/경화제(YD-128/DDM) 조성물의 비율을 조절하여 $170^{\circ}C$의 경화온도에서 접착성능 최적화 조성비를 얻기 위한 실험을 진행하였다. DSC, TGA, DMA, TMA 열분석 장비를 사용하여 YD-128/DDM 혼합물의 당량비 변화가 경화물의 열적 특성에 미치는 영향에 대하여 조사하였으며, 조성물의 경화시간은 YD-128/DDM (1 : 1.1) 조성물을 동적 DSC를 이용하여 측정된 시간당 누적 발열량을 총 발열량으로 나누어 계산한 전환율을 토대로 결정하였다. TGA를 이용한 분해 활성화 에너지 분석에서는 경화물의 DDM 당량비가 증가할수록 열안정성과 열분해 활성화 에너지가 높게 나타났고, DMA와 TMA를 이용한 경화물의 열적 특성 조사 결과에서는 당량비 1 : 1에서 다른 당량비 조건에 비해 우수한 탄성률 및 열팽창성이 관찰되었다. 또한 각기 다른 당량비의 조성물을 $170^{\circ}C$에서 경화하여 중첩 전단 강도를 측정하였다.

• 한국인터넷방송통신학회논문지
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• 제15권3호
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• pp.169-173
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• 2015

이 논문은 사용한지 13년 지난 운전 중 22 kV 케이블시스템을, 7년 동안 절연저항을 측정하여 그 결과를 연구한 논문이다. 우리는 발전소에서 설치 운전 중인 고전압 케이블이 시간에 따라 성능이 악화되는 현상의 추세를 결정하는 수명지수를 파악하였다. 위한 논문이다. 케이블 시스템은 시간에 따라 절연 저항이 감소한다. 초기 케이블 시스템은 아레니우스 열화 곡선을 따른다. 초기에는 수명 지수 n값이 9로 설계하였고, 이후 n값을 상향하여 16으로 결정하였다. 이유는 고전압에서 케이블이 동작할 경우, n값이 클 때 파괴특성이 높지 않고, n값이 낮은 값에서 파괴특성이 높았기 때문이다. 그러나 전압열화에 의하여 와이블 프롯을 따른 v-t 특성에 의하여 n값은 10~11의 값을 갖는 것을 확인하였다. 과거 케이블 설계 시 정한 n=9의 이론적 근거와 n=16 으로 높아진 원인을 파악함으로써 누설 전류 및 절연 저항의 선형적인 변화를 확인하였다. 단기적으로는 운전 중 케이블 시스템의 진단 평가에 활용되며, 장기적으로는 발전소 부하에서 동작 중인케이블 시스템의 설치 및 운영에 있어서 원가를 절감하기 위한 노력에 기여하고자 한다.

• 한국응용곤충학회지
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• 제27권2호
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• pp.103-110
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• 1988

사육실조건($25pm$$1^{\circ}C$, 광주기 16L:8D, 상대습도 60%)에서 조사된 담배나방(Heliothis assclta Gueness)의 우화, 교미 및 산란의 행동과 일일리듬은 다음과 같다. 불꺼진 후 3시나 이내에 75% 이상이 우화하였으며, 우화된 날개확장과 경화까지는 약 33분이 소요되었다. 성충 수컷은 교미때까지 촉각 운동, 날개 진동, hairpencils확장 , 암컷 산란관 두드림등 일련의 행동을 보였으나, 암컷은 복부끝의 수죽과 이완, 날개 진동 등의 다소 단순한 행동을 보였다. 모든 교미는 암기간 전반기에 주로 일어났으며, 불꺼진 2시간 전후에서 최대 피크를 보였으나, 처녀 암컷의 경우 연령증가에 따라 빨라지는 경향을 보였다. 교미율은 24시간된 미교미암컷에 가장 높았으며, 연령증가에 따라 감소되는데 같은 경향이 미교미수컷에서도 나타났다. 교미지속기단은 평균 $77\pm$14분이었다. 산란 역시 암기간 전체를 통하여 일어났지만, 불꺼진 후 2시간 이내에 최적 피크를 보였으며, 산란수는 교미후 3일에서 가장 많았다. 교미율, 산란수, 수명은 성비에 따라 달랐으며, 교미한 성충의 수명이 교미하지 않은 것보다 더 짧았다.