• BMB Reports
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• v.51 no.4
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• pp.165-166
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• 2018

Osteoarthritis (OA) is the most common form of arthritis and is a leading cause of disability with a large socioeconomic cost. OA is a whole-joint disease characterized by cartilage destruction, synovial inflammation, osteophyte formation, and subchondral bone sclerosis. To date, however, no effective disease-modifying therapies for OA have been developed. The estrogen-related receptors (ERRs), a family of orphan nuclear receptor transcription factors, are composed of $ERR{\alpha}$, $ERR{\beta}$, and $ERR{\gamma}$, which play diverse biological functions such as cellular energy metabolism. However, the role of ERRs in OA pathogenesis has not been studied yet. Among the ERR family members, $ERR{\gamma}$ is markedly upregulated in human and various models of mouse OA cartilage. Adenovirus-mediated overexpression of $ERR{\gamma}$ in the mouse knee joint tissue caused OA pathogenesis. Additionally, cartilage-specific $ERR{\gamma}$ transgenic (Tg) mice exhibited enhanced experimental OA. Consistently, $ERR{\gamma}$ in articular chondrocytes directly caused expression of matrix metalloproteinase (MMP) 3 and MMP13, which play a crucial role in cartilage destruction. In contrast, genetic ablation of Esrrg or shRNA-mediated Esrrg silencing in the joint tissues abrogated experimental OA in mice. These results collectively indicated that $ERR{\gamma}$ is a novel catabolic regulator of OA pathogenesis and can be used as a therapeutic target for OA.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.157-164
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• 1988

SCK tumor cells were exposed to heat shock or several sulihydryl-reacting agents such as iodoacetamide(IAA), zinc chloride(Zn), and 2-mercaptoethanol(ME). Stress proteins induced by these agents were examined and the relationship between the induction of stress proteins and the production of abnormal proteins was discussed. Based on the present experiments, two classes of intracellular pathways for the induction of stress proteins were defined; one dependent on and the other independent of protein synthesis. The presence of cycloheximide during the induction period blocked the formation of stress proteins in the cells exposed to Zn or ME, but not in those exposed to heat shock or IAA.Therefore, stress protein seems to be induced either by denaturation of pre-existing mature proteins (e.g., heat shock or IAA) or by newly synthesized abnormal proteins(e.g., Zn or ME). In conclusion, it is ilkely that the production of abnormal proteins by stresses triggers stress protein induction. In addition, it was found that the cells exposed to IISP and GRP inducers simultaneously responded to more strong stress among several stresses encountered.

• Molecules and Cells
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• v.37 no.5
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• pp.412-417
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• 2014

It has been reported that exogenously introduced micro-RNA (exo-miRNA) competes with endogenously expressed miRNAs (endo-miRNAs) in human cells, resulting in a detectable upregulation of mRNAs with endo-miRNA target sites (TSs). However, the detailed mechanisms of the competition between exo- and endo-miRNAs remain uninvestigated. In this study, using 74 microarrays that monitored the whole-transcriptome response after introducing miRNAs or siRNAs into HeLa cells, we systematically examined the derepression of mRNAs with exo- and/or endo-miRNA TSs. We quantitatively assessed the effect of the number of endo-miRNA TSs on the degree of mRNA derepression. As a result, we observed that the number of endo-miRNA TSs was significantly associated with the degree of derepression, supporting that the derepression resulted from the competition between exo- and endo-miRNAs. However, when we examined whether the site proficiency of exo-miRNA TSs could also influence mRNA derepression, to our surprise, we discovered a strong positive correlation. Our analysis indicates that site proficiencies of both exo- and endo-miRNA TSs are important determinants for the degree of mRNA derepression, implying that the derepression of mRNAs in response to exo-miRNA is more complex than that currently perceived. Our observations may lead to a more complete understanding of the detailed mechanisms of the competition between exo- and endo-miRNAs and to a more accurate prediction of miRNA targets. Our analysis also suggests an interesting hypothesis that long 3'-UTRs may function as molecular buffer against gene expression regulation by individual miRNAs.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.309-315
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• 2006

The protective effects of baicalein, one of the flavonoids in Scutellaria baicalensis Georgi, were evaluated against 6-hydroxydopamine (6-OHDA)-induced neuronal damage in mice and cultured human neuroblastoma cells. Nigrostriatal damage was induced by stereotaxically injecting 6-OHDA into the right striatum. Baicalein was administered intraperitoneally 30 min before and 90 min after lesion induction. Animals received a further daily injection of baicalein for 3 consecutive days. Two weeks after 6-OHDA injection, contralateral rotational asymmetry was observed by apomorphine challenge in lesioned mice. Tyrosine hydroxylase (TH) immunohistochemistry revealed a significant loss of terminals in lesioned striatum and the reduction of the numbers of TH-positive cell in the ipsilateral substantia nigra (SN). In addition, the levels of dopamine (DA) and DA metabolites were reduced and lipid peroxidation was increased in lesioned striatum. However, baicalein treatment reduced apomorphine-induced rotational behavior in 6-OHDA-lesioned mice, and increased TH immunoreactivity in the striatum and SN, and DA levels in lesioned striatum. Lipid peroxidation induced by 6-OHDA was also inhibited by baicalein treatment. Furthermore, when SH-SY5Y human neuroblastoma cells were treated with baicalein, 6-OHDA-induced cytotoxicity and reactive oxygen species (ROS) production were significantly reduced. These results indicate that baicalein effectively protects 6-OHDA-induced neuronal damage through antioxidant action.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.4 s.235
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• pp.485-494
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• 2005

For the extensive investigation of local heat/mass transfer on the near-tip surface of turbine blade, experiments were conducted in a low speed stationary annular cascade. The turbine test section has a single stage composed of sixteen guide vanes and blades. The chord length and the height of the tested blade are 150 mm and about 125 mm, respectively. The blade has flat tip geometry and the mean tip clearance is about $2.5{\%}$ of the blade chord. Detailed mass transfer coefficient on the blade near-tip surface was obtained using a naphthalene sublimation technique. The inlet flow Reynolds number based on chord length and incoming flow velocity is changed from $1.0{\times}10^{5}\;to\;2.3{\times}10^{5}.$ Extremely complex heat transfer characteristics are observed on the blade surface due, to complicated flow patterns, such as flow acceleration, laminarization, transition, separation bubble and tip leakage flow. Especially, the suction side surface of the blade has higher heat/mass transfer coefficients and more complex distribution than the pressure side surface, which is related to the leakage flow. For all the tested Reynolds numbers, the heat/mass transfer characteristics on the turbine blade are the similar. The overall averaged $Sh_{c}$ values are proportional to $Re_{c}^{0.5}$ on the stagnation region and the laminar flow region such as the pressure side surface. However, since the flow is fully turbulent in the near-tip region, the heat/mass transfer coefficients are proportional to $Re_{c}^{0.8}.$

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.3
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• pp.207-216
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• 1999

A phased array is a multi-element piezoelectric device whose elements are individually excited by electric pulses at programmed delay time. One of the advantages of using phased array in nondestructive evaluation (NDE) application over conventional ultrasonic transducers is their great maneuverability of ultrasonic beam. There are some parameters such as the number and the size of the piezoelectric elements and the inter-element spacing of the elements to design phased array transducer. In this study, the characteristic of ultrasonic beam for phased array transducer due to the variation of the number of elements has been simulated for ultrasonic SH-wave on the basis of Huygen's principle. Ultrasonic beam directivity and focusing due to the change of time delay of each element were discussed due to the change of the number of piezoelectric elements. It was found that ultrasonic beam was much more spreaded and hence its sound pressure was decreased as steering angle of ultrasonic beam was increased. In addition, the ability of ultrasonic bean focusing decreased gradually with the increase of focal length at the same piezoelectric elements. However, the ability of beam focusing was improved as the number of consisting elements was increased.

• Resources Recycling
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• v.6 no.3
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• pp.28-35
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• 1997

Adsorption properities of hcavy metals (Cd, Cu, Fe, Mn, Pb, Zn) and organic compounds (Trichloroethylene and T Tetrachroethy len려 on sh$\xi$1I( oyster and ark shell) were investigated using wat$\xi$r treatment matenals, The shell powder (m띠or C crystal structurc is calcium hydroxide) showed the preference adsorption for heavy metals in order of Mn > Zn > Fe > Cd > eu > P Pb. The high removal capacities of heavy metals arc helicved to be largely due to precipitation by foonation of metal c carhonat,잃 and hydroxides at high pH caused by the $Ca(OH)_2$ component of sl1ell, immobilizatIon of heavy metals in a solid I matrix by calcium‘ and fixation by insoluble organic materials in the oystcr and ark shell. The use of sh려I in water treatment h has the potential to bc benefIcial as a source of inexpensive matcrials‘ moreover, not only treatment of waste but also e environmcntal business including environmental-purification ceramics could be better off by utili낌ng high-valued waste and d developed puri'fication ceramics and media.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.401-401
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• 2018

최근 지구온난화에 따른 기후변화로 시공간적으로 매우 불규칙한 강우가 발생하고 있으며, 홍수피해 및 극심한 가뭄으로 수자원개발 및 관리 환경이 더욱 어려워지고 있는 실정이다. 특히 우리나라는 하천수사용허가 기준유량의 원천이 되는 강수량의 계절별 편차가 매우 크고 연 강수량의 2/3 이상이 여름철에 집중된다. 하천수사용허가 기준유량은 하천유지유량이 고시되지 않은 지점은 10년 빈도의 갈수량인 기준갈수량과 같고, 하천유지유량이 고시된 지점은 기준갈수량에서 하천유지유량을 감한 양이다. 하지만 하천 유량의 변동성이 계절에 따라 매우 큼에도 불구하고 갈수기의 한정적인 기준갈수량으로 연중 전 기간의 하천수사용허가 기준유량을 설정하면 가용한 하천수량을 과소 산정할 우려가 있다. 따라서 계절성을 고려하여 기간에 맞는 기준갈수량을 산정하는 것이 안정적인 하천수의 사용과 하천관리에 필요한 유량을 효율적으로 관리할 수 있을 것으로 판단된다.본 연구에서는 효율적인 하천수사용허가 기준유량을 검토하기 위해 지역별 계절성을 고려한 갈수량 검토를 실시하였다. 갈수량 산정을 위한 자연유량은 TANK모형을 이용하여 우리나라 112개 중권역에 대해 50년 간 일별 자연유량을 모의하였다. 모의된 자연유량을 바탕으로 112개 중권역에 대해 유황분석을 실시하여 평균갈수량과 기준갈수량을 검토하였으며, 계절별 갈수량을 검토하기 위해 기간을 여름철(5~10월)과 겨울철(11~4월) 두 개의 시기로 구분하여 여름과 겨울 갈수량을 산정하였다. 또한, 계절성 분석을 위해 세 가지 계절성 지표를 검토하였다. 첫째, 여름과 겨울 갈수량의 비율인 SR(Seasonality Ratio), 둘째, 갈수량의 평균시기를 나타내는 주기적 계절성 지수 SI(Seasonality Index), 셋째, 갈수량의 월간 분포를 나타내는 SH(Seasonality Histogram)이다. 이러한 계절성 지표를 바탕으로 공간적 패턴을 분석하고 여름과 겨울 갈수량의 기초가 되는 수문학적 근거를 판단하였다. 따라서 유역의 계절성 지표를 바탕으로 기간을 분리하고 기간별 갈수량 검토를 통해 보다 효율적인 하천수사용허가 기준유량을 검토할 수 있을 것으로 판단된다.

• Journal of Pharmacopuncture
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• v.22 no.3
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• pp.160-165
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• 2019

Objectives: The aim of this study was to evaluate the effect of Ribes khorasanicum (R. khorasanicum); a plant growing in north Khorasan of Iran; on cardiovascular and stress oxidative in acute hypertension induced by N-nitro-l-arginine methyl ester (L-NAME), anitric oxide synthase inhibitor. Methods: Rats were divided into Control, L-NAME (10 mg/kg), Sodium Nitroprusside (SNP) (50 mg/kg) + L-NAME and three treated groups with R. khorasanicum (4, 12 and 24 mg/kg) groups + L-NAME. L-NAME and SNP were injected intravenously and extract intraperitoneal. In R. khorasanicum groups, L-NAME was injected 30 min after injection of the extract. Systolic blood pressure (SBP), mean arterial pressure (MAP) and heart rate (HR) were recorded continuously using power lab software. At the end of study oxidative stress parameters including of total thiol content (SH), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) in heart and aorta of all groups were also measured. Results: In groups 4 and 24 mg/kg extract +L-NAME, there was a non-significant decrease in SBP and MAP compared to L-NAME group but dose 12 mg/kg significantly attenuate the effect of L-NAME(P < 0.05). In L-NAME group the heart and aorta tissues antioxidant enzymes levels decreased, while in treated rats these enzymes significantly increased. Conclusion: The extract of R. khorasanicum in dose 12 mg/kg show anti-hypertensive effect that is mediated by an effect on NO system or antioxidant parameters.

• Korean Journal of Acupuncture
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• v.38 no.3
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• pp.133-139
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• 2021

Objectives : Parkinson's disease is a neurodegenerative disease caused by a decrease in the dopaminergic neurons in the substantia nigra. The abnormal expression of solute carrier family 6 member 4 (Slc6a4) has been reported in patients with Parkinson's disease. Methods : In this study, we used MPTP to examine the changes in the expression of Slc6a4 in the brain of mice with Parkinson's disease and investigate its effect on dopaminergic neuronal cell death. Results : In the examination of the Slc6a4 expression in the substantia nigra of MPTP-treated mice for 4 weeks. The gene expression was increased compared to the normal group. To investigate the relationship between Slc6a4 and dopaminergic neurons, we performed a study using siRNA of Slc6a4 in the dopaminergic neuronal cell line SH-SY5Y. Using the siRNA of Slc6a4 to evaluate gene expression, it revealed that the tyrosine hydroxylase (TH) expression increases when Slc6a4 decreases. Moreover, this confirms its effects on the dopaminergic neurons. Additionally, through the evaluation of factors related to apoptosis, in particular, it was established that the value of bax/bcl2 decreased and was affected. These results suggest that a decreased Slc6a4 expression induces an increase in TH expression, providing a mechanism of action for dopaminergic neurons regulated by Slc6a4 expression. Conclusions : Slc6a4 is deemed to be involved in the regulation of dopaminergic neurons, suggesting that an increased Slc6a4 expression induced by MPTP may influence a reduction of dopaminergic neurons.