• 한국환경보건학회지
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• 제43권6호
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• pp.447-456
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• 2017

Objectives: Pregnant women and those of childbearing age are a well-known sensitive population for human mercury exposure. Therefore, this study was conducted to reveal and enrich basic information for effective risk communication to reduce the adverse health effects of mercury exposure. Methods: A self-administered questionnaire survey was conducted among 432 women aged 19-44 years, recruited conveniently from three different regions (Busan, Ulsan, and Gumi City). Questionnaires were developed by referring to the existing literature and through expert meetings. They consisted of questions on knowledge and awareness of mercury exposure risks, health information literacy, and relevant information. Results: The rank of perceived mercury health risk score was 5 out of 16 environmental risk factors, and 41.7% of participants thought that even a very little mercury could lead to an adverse health effect. Although 90.3% of participants had knowledge that childbearing age women must pay attention to fish intake, only 38.9% of participants knew the national fish intake guidelines for pregnant women. Conclusions: Although risk perception and knowledge of pregnancy-specific features of mercury were relatively high, the national fish intake guidelines were still not well recognized. It could be an effective strategy to provide evidence-based and targeted information articulated by professionals using internet based communication channels.

• Fisheries and Aquatic Sciences
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• 제13권2호
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• pp.167-181
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• 2010

To predict changes in the marine environment of the Beolgyo Stream Estuary in Jeonnam Province, South Korea, where cohesive tidal flats cover a broad area and a large bridge is under construction, this study conducted numerical simulations involving tidal flow and cohesive sediment transport. A wetting and drying (WAD) technique for tidal flats from the Princeton Ocean Model (POM) was applied to a large-scale-grid hydrodynamic module capable of evaluating the flow resistance of structures. Derivation of the eddy viscosity coefficient for wakes created by structures was accomplished through the explicit use of shear velocity and Chezy's average velocity. Furthermore, various field observations, including of tide, tidal flow, suspended sediment concentrations, bottom sediments, and water depth, were performed to verify the model and obtain input data for it. In particular, geologic parameters related to the evaluation of settling velocity and critical shear stresses for erosion and deposition were observed, and numerical tests for the representation of suspended sediment concentrations were performed to determine proper values for the empirical coefficients in the sediment transport module. According to the simulation results, the velocity variation was particularly prominent around the piers in the tidal channel. Erosion occurred mainly along the tidal channels near the piers, where bridge structures reduced the flow cross section, creating strong flow. In contrast, in the rear area of the structure, where the flow was relatively weak due to the formation of eddies, deposition and moderated erosion were predicted. In estuaries and coastal waters, changes in the flow environment caused by artificial structures can produce changes in the sedimentary environment, which in turn can affect the local marine ecosystem. The numerical model proposed in this study will enable systematic prediction of changes to flow and sedimentary environments caused by the construction of artificial structures.

• 한국수자원학회논문집
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• 제46권9호
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• pp.947-956
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• 2013

급경사 산지하천 수충부의 호안은 대부분 콘크리트 옹벽으로 되어있다. 표면이 매끄러운 콘크리트 옹벽호안은 유속을 더 강화시키기 때문에 수충부 홍수피해의 원인이 되기도 한다. 본 연구에서는 개수로의 한 측벽에 설치한 정사각형 단면의 세로돌출줄눈이 흐름저항에 미치는 영향을 파악하기 위해 수리실험을 수행하였다. 돌출줄눈의 설치간격은 무차원 돌출줄눈 간격 ${\lambda}_{nv}$를 기준으로 조도유형 d형과 k형을 포함하도록 설계하였다. 흐름의 Froude 수는0.81~1.12의 범위였다. 흐름저항은 돌출줄눈의 설치간격과 유량에 좌우되었다. ${\lambda}_{nv}$가 9일 때 흐름저항이 가장 큰 것으로 나타났다. 세로돌출줄눈은 유량이 증가하면 d형 조도에서는 흐름저항을 감소시켰으나 k형 조도에서는 흐름저항을 증가시켰다. 흐름저항의 증가폭은 ${\lambda}_{nv}$이 9~12의 범위에서 상대적으로 더 크게 나타났다. 세로돌출줄눈에 의한 흐름저항은 대부분 형상저항에 의한 것이며 그 등가조도높이는 수심규모로 발생할 수 있고 흐름저항에 미치는 영향이 매우 크다. 측벽의 세로돌출줄눈은 흐름저항을 증가시키고 최대유속의 발생위치를 수로의 횡단면 중앙방향으로 이동시키는 수단으로 사용될 수 있을 것이다.

• 생명과학회지
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• 제29권12호
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• pp.1393-1400
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• 2019

본 연구에서는 사람의 제대정맥 내피세포에서 고농도 당에 의해 유도되는 세포사멸과 연관된 미토콘드리아의 기능적 지표 변화에 미치는 diazoxide의 효과를 관찰하였다. 고농도 당에 노출된 내피세포에서 세포사멸이 시간에 따라 증가하였고, caspase 3와 8, 9의 활성 증가가 동반되었다. Caspase 3와 9의 억제제들이 세포사멸을 감소시킨 반면 caspase 8의 억제제는 효과가 없었다. 고농도 당에 노출된 세포에서 미토콘드리아 막전위의 탈분극과 막투과도의 증가, 치토크롬 C (cytochrome C)의 유리가 동반됨을 관찰할 수 있었다. Diazoxide는 고농도 당에 의한 미토콘드리아 의존성 세포사멸 신호의 활성화를 억제하였다. Diazoxide의 이러한 효과들은 미토콘드리아막의 ATP-억제성 칼륨통로 차단제인 5-hydroxydecanoate에 의해 차단되었다. 이상의 결과들을 종합하면 diazoxide가 미토콘드리아막의 ATP-억제성 칼륨통로 개방을 통해 미토콘드리아 의존성 세포사멸 신호기작의 활성화를 차단하여 고농도 당에 의해 유도되는 세포사멸을 억제하는 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.267-273
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• 2003

We have investigated the effect on inducing substate(s) of positively charged residues replaced in position 172 of the second transmembrane domain in murine inward rectifier potassium channels, formed by stable or transient transfection of Kir2.1 gene in MEL or CHO cells. Single channel recordings were obtained from either cell-attached patches or inside-out patches excised into solution containing 10 mM EDTA to rule out the effect of $Mg^{2+}$ on the channel gating. The substate(s) could be recorded with all mutants D172H, D172K and D172R. The unitary current-voltage (I-V) relation was not linear with D172H at $pH_i$ 6.3, whereas the unitary I-V relation was linear at $pH_i$ 8.0. The relative occupancy at $S_{LC}$ was increased from 0.018 at $pH_i$ 8.0 to 0.45 at $pH_i$ 5.5. In H-N dimer, that was increased from 0.016 at $pH_i$ 8.0 to 0.23 at $pH_i$ 5.5. The larger the size of the side chain or $pK_a$ with mutants (D172H, D172K and D172R), the more frequent the transitions between the fully open state and substate within an opening. The conductance of the substate also depended upon the pKa or the size of the side chain. The relative occupancy at substate $S_{LC}$ with monomer D172K (0.50) was less than that in K-H dimer (0.83). However, the relative occupancy at substate with D172R (0.79) was similar to that with R-N dimer (0.82). In the contrary to ROMK1, positive charge as well as negative charge in position 172 can induce the substate rather than block the pore in murine Kir2.1. The single channel properties of the mutant, that is, unitary I-V relation, the voltage dependence of the mean open time and relative occupancy of the substates and the increased latency to the first opening, explain the intrinsic gating observed in whole cell recordings.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.40-46
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• 1998

We investigated the influence of the root of Panax ginseng C. A. Meyer on the secretion of catecholamines from bovine adrenal chromaffin cells, which are used as a model of nervous systems. In two major parts extracted from the ginseng root, the crude saponin fraction, but not the non-saponin fraction, reduced the secretion from the cells, stimulated by acetylcholine (ACh). Ginseng saponins (ginsenosides) are classified into three groups, the panaxadiol, the panaxatriol and the oleanolic acid groups, on the basis of the chemical structures of their saponins. Both the panaxadiol and the panaxatriol saponins, excluding only one oleanolic acid saponin ginsenoside-Ro, generally reduced the ACh-evoked secretion. The inhibitory effects of the panaxatriol were much stronger than those of the panaxadiol. However, ginsenoside-Rg, and -Rh3 in the panaxadiol saponins were the potent inhibitors comparable to the panaxatriol saponins. Ginsenoside-Rg2 in the panaxatriol was the most effective. It is probable that the ginsenoside inhibition of the catecholamine secretion is due to the suppression of the function of the nicotinic ACh receptor-cation channels. On the other hand, ginsenoside-Rg2 did not affect the angiotensin II-, the bradykinin-, the histamine- and the neurotensin- induced catecholamine secretions from the chromaffin cells and the muscarine- and the histamine- induced contraction of the ileum in guinea-pigs. Ginsenoside-Rbl, a panaxadiol saponin, and ginsenoside-Ro had no or only a slight effect on them. On the contrary, ginsenoside-Rg3 not only competitively inhibited the muscarine-induced ileum contraction but also reduced the angiotensin R -, the bradykinin-, the histamine- and the neurotensin-induced catecholamine secretions. Thus, the ginseng root contains active ingredients, namely some ginsensides, which suppress the responses induced by receptor stimulation. The inhibitory effects of ginseng saponins may be one of the action mechanisms for the pharmacological effects of the Panax ginseng root.

• Archives of Pharmacal Research
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• 제26권10호
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• pp.868-873
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• 2003

Ginsenosides, major active ingredients of Panax ginseng, that exhibit various pharmacological and physiological actions are transformed into compound K (CK) or M4 by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. Recent reports shows that ginsenosides might playa role as pro-drugs for these metabolites. In present study, we investigated the effect of bovine serum albumin (BSA), which is one of major binding proteins on various neurotransmitters, hormones, and other pharmacological agents, on ginsenoside $Rg_{2-}$, CK-, or M4-induced regulation of $\alpha3\beta4$ nicotinic acetylcholine (ACh) receptor channel activity expressed in Xenopus oocytes. In the absence of BSA, treatment of ACh elicited inward peak current ($I_{Ach}$) in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor. Co-treatment of ginsenoside $Rg_2$, CK, or M4 with ACh inhibited IAch in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor with reversible and dose-dependent manner. In the presence of 1% BSA, treatment of ACh still elicited $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor and co-treatment of ginsenoside $Rg_2$ or M4 but not CK with ACh inhibited $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor with reversible and dose-dependent manner. These results show that BSA interferes the action of CK rather than M4 on the inhibitory effect of $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor and further suggest that BSA exhibits a differential interaction on ginsenoside metabolites.

• Journal of Ginseng Research
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• 제39권4호
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• pp.314-321
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• 2015

Background: Ginseng belongs to the genus Panax. Its main active ingredients are the ginsenosides. Interstitial cells of Cajal (ICCs) are the pacemaker cells of the gastrointestinal (GI) tract. To understand the effects of ginsenoside Re (GRe) on GI motility, the authors investigated its effects on the pacemaker activity of ICCs of the murine small intestine. Methods: Interstitial cells of Cajal were dissociated from mouse small intestines by enzymatic digestion. The whole-cell patch clamp configuration was used to record pacemaker potentials in cultured ICCs. Changes in cyclic guanosine monophosphate (cGMP) content induced by GRe were investigated. Results: Ginsenoside Re ($20-40{\mu}M$) decreased the amplitude and frequency of ICC pacemaker activity in a concentration-dependent manner. This action was blocked by guanosine 50-[${\beta}-thio$]diphosphate [a guanosine-5'-triphosphate (GTP)-binding protein inhibitor] and by glibenclamide [an adenosine triphosphate (ATP)-sensitive $K^{+}$ channel blocker]. To study the GRe-induced signaling pathway in ICCs, the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (a guanylate cyclase inhibitor) and RP-8-CPT-cGMPS (a protein kinase G inhibitor) were examined. Both inhibitors blocked the inhibitory effect of GRe on ICC pacemaker activity. L-NG-nitroarginine methyl ester ($100{\mu}M$), which is a nonselective nitric oxide synthase (NOS) inhibitor, blocked the effects of GRe on ICC pacemaker activity and GRe-stimulated cGMP production in ICCs. Conclusion: In cultured murine ICCs, GRe inhibits the pacemaker activity of ICCs via the ATP-sensitive potassium ($K^{+}$) channel and the cGMP/NO-dependent pathway. Ginsenoside Re may be a basis for developing novel spasmolytic agents to prevent or alleviate GI motility dysfunction.

• 대한인간공학회지
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• 제35권4호
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• pp.205-223
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• 2016

Objective:This study introduced the status of studies and the projects related with agricultural accident prevention carried out by the Rural Development Administration. This study was conducted to promote Korean farmers' agricultural safety activation by analyzing study trends on farmers' agricultural work safety. Background: Agriculture is one of the dangerous industries, and the agricultural accident rate is on the rise, due to recent serious aging and increased female work force. Such a phenomenon emerges as a serious problem from the social perspective, and therefore measures for farmers' healthy and safe agricultural activities and accident prevention are required. Method: This study conducted literature review related with domestic and international agricultural safety and health. This study also examined the hazard factors of agricultural labor and injuries, agricultural safety and health system and policy, support and education for farmers' safety practice, and the status of convenience tools and protection equipment, based on major study activities performed by the Rural Development Administration for recent four to five years. Results: Through the study results, the status of Korea's agricultural safety system, compensation support policy, safety education of farmers for actual practice, and diverse channels including media were confirmed. This study also presented the R&D implementation status on convenience equipment and protective gear to prevent agricultural diseases and safety accidents. Conclusion: This study found out that continuous monitoring and efforts are required to prevent accidents for the Korea's agricultural labor environment and agricultural safety, and that social bond of sympathy formation is demanded through effect analysis on the implemented projects including education and support projects. Furthermore, it can be understood that agricultural accident prevention should be carried out through shift from current government-led top down approach to bottom-up approach from itself. Application: The results of this study can be utilized as useful data for farmers' safety and health.

• 한국진공학회지
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• 제15권2호
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• pp.216-222
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• 2006

InGaAs/GaAs 양자 우물 내에 삽입된 InAs 양자점으로 구성된 5층의 흡수층과 $Al_{0.3}Ga_{0.7}As/GaAs$ SL (superlattice) 암전류 장벽층을 갖는 QDIP (quantum dot infrared photodetector) 구조에 대한 수소 RF 플라즈마에 의한 수소화 처리가 QDIP의 전기적. 광학적 특성에 미치는 영향에 대해 연구하였다. RF 플라즈마 수소화 처리는 양자점의 밴드구조에 영향을 미치지 않았으며 $Al_{0.3}Ga_{0.7}As/GaAs$ SL 암전류 장벽층 내의 결함 제거 및 QDIP 구조 내 결함 생성을 동시에 유도함으로써 QDIP의 전기적 특성 향상은 수소 플라즈마 처리시간의 함수임을 알았다. 20 W의 수소 RF 플라즈마를 사용했을 때, 10분간의 플라즈마 조사가 가장 좋은 전기적 특성을 제공하여 높은 암전류 때문에 원시료에서는 측정 할 수 없었던 광전류 신호를 측정 할 수 있었다.