• 전기화학회지
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• 제11권1호
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• pp.59-63
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• 2008

Poly (vinylchloride) (PVC) membrane electrodes based on neutral carrier, tetracycline was prepared as an active sensor for Hg(II) ion, and tested in different contents of the potassium tetrakis (4-chlorophenyl) borate (KTpClPB) as lipophilic salt. Bis (2-ethylhexyl) sebacate (DOS), bis(l-butylpentyl) adipate (BBPA), 2-nitrophenyl octyl ether (NPOE) and dibutyl phthalate (DBP) were used as diverse plasticizing solvent mediators. This electrode shows excellent potentiometric response characteristics and display good linearity with log $[Hg^{+2}]$ versus EMF response, over a range of concentrations between $10^{-7}$ and $10^{-3}M$. With 30.8mV/decade Nernstian slope, the detection limit was $6.9{\times}10^{-9}M$ and the response time was less than 20s. The proposed electrode yields very good selectivity for mercury (II) ion over many cations such as alkali, alkaline earth, transition and heavy metal ions. And it shows a very stable potential values in a wide pH range. This reliable electrode prepared was kept at least a month without considerable alteration in their response to Hg (II) ion.

• The Korean Journal of Physiology and Pharmacology
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• 제27권6호
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• pp.533-540
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• 2023

Sweroside is a natural monoterpene derived from Swertia pseudochinensis Hara. Recently, studies have shown that sweroside exhibits a variety of biological activities, such as anti-inflammatory, antioxidant, and hypoglycemic effects. However, its role and mechanisms in high glucose (HG)-induced renal injury remain unclear. Herein, we established a renal injury model in vitro by inducing human renal tubular epithelial cell (HK-2 cells) injury by HG. Then, the effects of sweroside on HK-2 cell activity, inflammation, reactive oxygen species (ROS) production, and epithelial mesenchymal transition (EMT) were observed. As a result, sweroside treatment ameliorated the viability, inhibited the secretion of inflammatory cytokines (TNF-α, IL-1β, and VCAM-1), reduced the generation of ROS, and inhibited EMT in HK-2 cells. Moreover, the protein expression of SIRT1 was increased and the acetylation of p65 NF-kB was decreased in HK-2 cells with sweroside treatment. More importantly, EX527, an inhibitor of SIRT1, that inactivated SIRT1, abolished the improvement effects of sweroside on HK-2 cells. Our findings suggested that sweroside may mitigate HG-caused injury in HK-2 cells by promoting SIRT1-mediated deacetylation of p65 NF-kB.

• Animal Systematics, Evolution and Diversity
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• 제5권1호
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• pp.77-88
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• 1989

한국산 살모사속 (Agkistrodom) 2종의 유전적, 형태적 및 종간잡종 형성 유.무를 구명하기 위하여 남한의 7개 지역에서 147개체를 채집하여 전기영동 및 형태형질 분석을 실시한 결과는 다음과 같다. 1. 15개의 성소 및 단백질에서 19개의 유전자를 검출하여 유전적 변이를 조사한 바 5개 유전자(26.3%)는 종간 및 집단간에 전혀 차이가 없었고 나머지 14개의 유전자중 4개 유전자는 매우 높은 률의 유전적 변이를 나타내었다. 2. 각 집단의 유전적 변이정도를 산출한 결과 A. b. brevicaudus는 평균 A= 1.55, P=42.1%, HD=0.096 및 HG=0.1l5였고 A .ussuriensis는 A= 1.45, P=31.6%, HD=0.1l7 및 HG=0.122로서 타 파충류에 비하여 높은 유전적 변이를 나타냈으며 이는 이들 종의 집단이 크고 안정된 상태에 있다고 사료된다. 3. 형태적으로 2종의 중간형으로 여겨졌던 제주집단은 강릉집단의 A .ussuriensis와 동일종으로 확인되었으며 종간 잡종은 전혀 찾아볼 수 없었다. 4. 2종간의 유전적 근록치는 S=0.662로서 이들은 약 180만년전에 분화되었으리라 추산된다.

• 공업화학
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• 제5권6호
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• pp.1078-1091
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• 1994

기존의 자료로부터 얻을 수 있는 열역학적 계산에 의하면 금속 황화물을 염소가스에 의하여 금속 염화물로 얻을 수 있음을 알 수 있다. 실제로 AgS, $AS_2S_3$, CdS, CuS, $Cu_2S$, FeS, HgS, $MoS_2$, $Ni_3S_2$, PbS, $Sb_2S_3$, ZnS의 황화금속을 염소가스와 반응시켜 이를 열중량법에 의하여 고찰하였다. 이론적 계산이나 실험적 연구에서 황화물의 염소화 반응은 황화광물의 추출 야금 공정에 대한 좋은 대체 방법임을 알 수 있었다.

• 한국식품과학회지
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• 제36권4호
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• pp.523-526
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• 2004

본 연구는 우리나라에서 유통되는 과일류 중 유해중금속 함량을 파악하여 각국의 모니터링 및 기준과 비교함으로써 안전성을 평가하고자 하였다. 9종(386건)의 과일류에 대하여 4개 금속(Hg, Pb, Cd, As) 함량을 수은은 Mercury Analyzer로 납, 카드뮴, 비소는 습식분해 후 ICP 및 AAS로 분석하였다. 본 연구결과로부터 알아 낸 국내에서 유통되는 과일류 중 유해중금속 평균함량은 Hg 0.001 mg/kg, Pb 0.013 mg/kg, Cd 0.006 mg/kg, As 0.017 mg/kg으로 외국에서 보고된 결과와 유사한 수준이었다. 또한 우리나라 국민이 과일류를 통해 섭취하는 수은, 납, 카드뮴 등 유해중금속량은 FAO/WHO에서 설정한 잠정주간섭취허용량(PTWI)의 약 1-2% 수준으로 낮게 나타났다.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.260-260
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• 1999

We compared c-axis tunneling characteristics of small stacked intrinsic Josephson junctions prepared on the surface of pristine, I-, and HgI$_2$-intercalated Bi$_2Sr_2CaCu_2O_{8+x}$ (Bi2212) single crystals. The R(T) curves are almost metallic in I-Bi2212 specimens, but semiconducting in HgI$_2$-Bi2212 ones.· The transition temperatures were 82.0 K, 73.0 K, and 76.8 K for pristine Bi2212, I-Bi2212, and HgI2-Bi2212 specimens, respectively, consistent with p-T$_c$ phase diagram. Current-voltage (IV) characteristics of both kinds of specimens show multiple quasiparticle branches with well developed gap features, indicating Josephson coupling is established between neighboring CuO$_2$ planes. The critical current I$_c$ of I-Bi2212 is almost the same as of that of pristine crystals, but I$_c$ is much reduced in Hgl$_2$-Bi2212. In spite of expanded interlayer distances, the interlayer coupling is not significantly affected in I-Bi2212due to holes generated by iodine atoms. The coupling in HgI$_2$-Bi2212 is, however, weakened due to inertness of HgI$_2$ molecules and the expansion of interlayer distance. Relation between the superconducting transition temperature T$_c$ and the critical current I$_c$ seems to contradict Anderson's interlayer-pair-tunneling theory but agree with a modified version of it.

• 한국동물학회지
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• 제23권3호
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• pp.137-148
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• 1980

토끼 골격근 小胞體의 ATPase 活性에 미치는 $Hg^{2+}, Cu^{2+}, Pb^{2+}, Cd^{2+}, Mn^{2+}$ 등 2價 陽이온을 영향을 비교 측정하였다. 이들 陽이온은 $Mn^{2+}$을 제외하고 모두 이 酵素의 活性을 阻害하였다. $Mn^{2+}$은 低濃度 (12.5-100 $\mu$M)에서는 오히여 活性을 증가시켰고, 그 보다 高濃度에서는 극히 약하게 阻害하였다. $Mn^{2+}$을 제외한 위의 2價 陽이온들의 阻害龍은 $Hg^2$가 가장 컸고 (阻害係數 Ki = 10$\mu$M), rm 다음이 $Cu^{2+}$ (Ki = 30$\mu$M), $Pb^{2+}$ (Ki = 120$\mu$M), $Cd^{2+}$ (Ki = 320$\mu$M)의 순이었다. 위의 4종의 陽이온들의 ATPase에 대한 阻害作用을 可逆的 非競爭的 阻害로 판정되었다.

• 한국약용작물학회지
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• 제22권6호
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• pp.504-509
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• 2014

Methicillin-resistant Staphylococcus aureus (MRSA) is a substantial contributor to morbidity and mortality. In search of a natural products capable of inhibiting this multidrug resistant bacteria, we have investigated the antimicrobial activity of brazilein (BRZ) isolated from Caesalpinia sappan L. (Leguminosae) against 8 different strains of Staphylococcus aureus (S. aureus). New antimicrobial activity was found using the minimum inhibitory concentrations (MICs), broth dilution as well as checkerboard method. Against the 8 strains, the minimum inhibitory concentrations of BRZ were in the range of $62.5-500{\mu}g/mL$. From those results we performed the checkerboard test to determine the synergism of BRZ in combination with Hygromycin-b (HgB) against 4 strains. The combined activity of BRZ and HgB against 4 strains resulted in a fractional inhibitory concentrations index (FICI) ranging from 0.18-0.5. The effect of BRZ with HgB was found to be synergistic. We found that BRZ reduced the MICs of HgB. BRZ and HgB could lead to the development of new combination antibiotics against MRSA infection.

• 대한의용생체공학회:의공학회지
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• 제29권5호
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• pp.371-375
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• 2008

In blood pressure measurement, the oscillometric method detects and analyzes the pulse pressure oscillation while deflating the cuff around the arm. For its principle, one has to inflate cuff pressure above the subject's systolic pressure and deflate below the diastolic pressure. Most of the commercialized devices inflate until the fixed target pressure and deflate until the fixed completion pressure because there is no way to know the systolic and diastolic pressure before measurement. Too high target pressure makes stress to the subject and too low target pressure makes big error or long measurement time because of re-inflation. There are similar problems for inadequate completion pressure. In this study, we suggest new algorithm to set proper target and completion pressure for each subject by analyzing pressure waveform while inflating period. We compared our proposed method and auscultation method to see the errors of estimation. The differences between the two measurements were -4.02$\pm$4.80mmHg, -10.50$\pm$10.57mmHg and -0.78$\pm$5.l7mmHg for mean arterial pressure, systolic pressure and diastolic pressure respectively. Consequently, we could set the target pressure by 30 mmHg higher than our estimation and we could stop at 20mmHg lower than our estimated diastolic pressure. Using this method, we could reduce the measurement time.

• 한국식품위생안전성학회지
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• 제4권1호
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• pp.21-27
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• 1989

1988년 11월~12월 사이에 서울시내 각 식당에서 구득한 설렁탕외 10종의 대중식사 66건에 대한 수은함량을 수은분석기와 원자흡광광도계에 의하여 분석한 결과 다음과 같은 결과를 얻었다. 1. 국물의 평균 수은 농도는 측정방법이나 기기의 종류에 따른 차를 인정할수 없었으며 그 농도는 0.002ppm 정도였다. 2. 고형물의 경우 평균 수은농도는 수은분석기의 분석치에 의하면 0.007ppm, 그리고 AAS 에 의한 분석결과는 0.027ppm~0.030ppm으로 나타났으며 분석방법에 따른 차이는 유의성이 인정되었다. (p<0.01). 3. 대중식사 3그릇으로부터 측정한 1일 평균 수은섭취율은 수은분석기에 의하면 $7.806\mu\textrm{g}/day$로 보사부에서 발표한 $12.6\mu\textrm{g}/day$보다 약간 낮았다. AAS에 의한 경우는 각기 $31.290\mu\textrm{g}/day$, $35.349\mu\textrm{g}/day$로 나타나 이 결과에 따른다 하더라도 FAO/WHO의 기준치인 $42.9\mu\textrm{g}/day$ 보다는 훨씬 낮았다.