• 공업화학
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• 제24권1호
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• pp.67-71
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• 2013

철, 구리, 알루미늄 등과 같은 금속의 에칭액으로 사용되는 $FeCl_3$ 용액의 에칭능력은 에칭 과정에서 $Fe^{3+}$이 $Fe^{2+}$로 환원되면서 감소하게 된다. 에칭능력의 감소는 에칭 속도에 영향을 주기 때문에 시간당 제거되는 금속의 양이 감소하여 에칭 효율이 저하되며, 폐 $FeCl_3$ 용액은 환경에 유해하며, 처리시 경제적인 문제점을 지니고 있다. 본 연구에서는 폐 $FeCl_3$ 에칭액에 HCl 첨가 후 $O_2$, $H_2O_2$ 등과 같은 강한 산화제를 이용한 에칭액 재생 방법과 재생된 에칭액을 이용한 금속 에칭시 산화-환원 전위(ORP) 및 에칭능력과의 관계를 조사하였다. 연구 결과 폐 $FeCl_3$ 에칭액 대비 2 vol%의 HCl과 미량의 $H_2O_2$를 이용하여 재생된 $FeCl_3$의 에칭 능력이 향상되었으며, 재생액을 이용한 에칭시 에칭액내의 $Fe^{2+}$, $Fe^{3+}$의 농도변화로 인하여 ORP를 기준으로 하는 방법보다 에칭시간을 일정하게 하는 것이 보다 효율적인 방법으로 제시되었다.

• 대한약리학회지
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• 제11권1호
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• pp.47-53
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• 1975

The metabolism of many drugs and also of steroid hormones is mediated by enzymes located in the microsomal fraction in smooth surfaced endoplasmic reticulum of mammalian liver. The duration and intensity of action of many drugs are largely determined by the speed at which they are metabolized in the body. Repeated administration of phenobarbital results in the induction of enzymes that metabolize a number of drugs. Lee et al. reported that daily administration of phenobarbital in rats significantly increased the activities of amylase in the pancreatobiliary juice, but the concentration of cholate in the bile was significantly lower in the treated group than that in the control group. After animals were treated with $CCl_4$, histological changes were shown in the endoplasmic reticulum, decreased microsomal enzyme activity and decreased hepatic protein synthesis were apparent. The purpose of the present report was to study the interaction between a 'microsomal-stimulating' agent such as phenobarbital and a 'microsomal- depressing' agent such as $CCl_4$ on hepatic and pancreatic functions in rats. The results obtained are summarized as follows: 1. The mortality rate of $CCl_4$ treated group was 34% and was decreased this figure to 15% with phenobarbital pretreatment. 2. In animals treated with phenobarbital the volume of biliary-pancreatic secretion was markedly elevated but the volume was decreased significantly in animals treated with $CCl_4$. 3. Total bilirubin output was elevated markedly in the $CCl_4$ treated group of rats pretreated with phenobarbital. The bilirubin concentration was increased in $CCl_4$ treated group and decreased in the group treated phenobarbital alone. 4. The concentration and total output of cholate in the bile were significantly lower in the all experimental group than control group. 5. In the animals treated with phenobarbital alone and phenobarbital plus $CCl_4$, the activity of lipase in pancreatobiliary juice was elevated, while in the animals treated with $CCl_4$ alone no change was observed. 6. The activity of amylase in the pancreatobiliary juice was decreased in the $CCl_4$ treated group, but elevated markedly in phenobarbital group and also elevated in phenobarbital-$CCl_4$ group. By the above results, it is concluded, when the liver was damaged by $CCl_4$, the exocrine function of pancreas and liver was decreased simultaneously. However, in the animals pretreated with phenobarbital, the toxicity of $CCl_4$ on the liver and pancreas was reduced.

• 한국재료학회지
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• 제21권7호
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• pp.384-390
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• 2011

Ti-6Al-4V ELI (Extra Low Interstitial) alloy has been widely used as an alternative to bone due to its excellent biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity. Therefore, nontoxic biomaterials with a low elastic modulus should be developed. However, the fabrication of a uniform coating is challenging. Moreover, the coating layer on Ti and Ti alloy substrates can be peeled off after implantation. To overcome these problems, it is necessary to produce bulk Ti and Ti alloy with hydroxyapatite (HA) composites. In this study, Ti, Nb, and Zr powders, which are biocompatible elements, were milled in a mixing machine (24h) and by planetary mechanical ball milling (1h, 4h, and 6h), respectively. Ti-35%Nb-7%Zr and Ti-35%Nb-7%Zr-10%HA composites were fabricated by spark plasma sintering (SPS) at $1000^{\circ}C$ under 70MPa using mixed and milled powders. The effects of HA addition and milling time on the biocompatibility and physical and mechanical properties of the Ti-35%Nb-7%Zr-(10%HA) alloys have been investigated. $Ti_2O$, CaO, $CaTiO_3$, and $Ti_xP_y$ phases were formed by chemical reaction during sintering. Vickers hardness of the sintered composites increases with increased milling time and by the addition of HA. The biocompatibilty of the HA added Ti-Nb-Zr alloys was improved, but the sintering ability was decreased.

• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.19-26
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• 2022

The Comprehensive in vitro Proarrhythmic Assay(CiPA) project was launched for solving the hERG assay problem of being classified as high-risk groups even though they are low-risk drugs due to their high sensitivity. CiPA presented a protocol to predict drug toxicity using physiological data calculated based on the in-silico model. in this study, features calculated through the in-silico model are analyzed for correlation of changing action potential in the near future, and features are verified through predictive performance according to drug datasets. Using the O'Hara Rudy model modified by Dutta et al., Pearson correlation analysis was performed between 13 features(dVm/dtmax, APpeak, APresting, APD90, APD50, APDtri, Ca_peak, Ca_resting, CaD90, CaD50, CaDtri, qNet, qInward) calculated at 100 pacing, and between dVm/d_{tmax_repol} calculated at 1,000 pacing, and linear regression analysis was performed on each of the 12 training drugs, 16 verification drugs, and 28 drugs. Indicators showing high coefficient of determination(R²) in the training drug dataset were qNet 0.93, AP resting 0.83, APDtri 0.78, Ca resting 0.76, dVm/dt_max 0.63, and APD90 0.61. The indicators showing high determinants in the validated drug dataset were APDtri 0.94, APD90 0.92, APD50 0.85, CaD50 0.84, qNet 0.76, and CaD90 0.64. Indicators with high coefficients of determination for all 28 drugs are qNet 0.78, APD90 0.74, and qInward 0.59. The indicators vary in predictive performance depending on the drug dataset, and qNet showed the same high performance of 0.7 or more on the training drug dataset, the verified drug dataset, and the entire drug dataset.

• 대한본초학회지
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• 제32권5호
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• pp.27-38
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• 2017

Objective : In the present study, we examined whether Canavalia gladiata D.C. (CG) and Arctium lappa L., Redix (AL) mixture (CGAL), their components, lupeol and chicoric acid, regulate immune system and suppress the tumor in vitro and in vivo. Methods : LPS-induced reactive oxygen species (ROS) and nitric oxide (NO) were measured after treatment with CG extract (CGE), CGAL, lupeol, chicoric acid and lupeol and chicoric acid mixture (lupeol+CA) in Raw264.7 cell. To determine the effect of CGE on immune responses, immune cell population and IgG production were assessed in mice. To investigate the effect of CGAL and their component on anti-tumor activity, tumor volume and weight were measured, cell cycles and immune cell population were analyzed in MC38 injected tumor bearing mice. Also, NK cell activity was determined in splenocyte isolated from tumor bearing mice. Results : CGE, CGAL, lupeol, chicoric acid and lupeol+CA decreased the LPS-induced ROS and NO production without cell toxicity in RAW264.7 cells. CGE increased the immune cell populations of $CD4^+T$, $CD8^+T$ and macrophages in various immune organ of mice. In tumor bearing mice, CGAL, lupeol, chicoric acid and lupeol+CA suppressed tumor volume and weight. In cell cycle analysis, they decreased the percentages of S phase. In addition, CGAL, lupeol, chicoric acid and lupeol+CA immune cell populations of $CD4^+T$, $CD8^+Tcell$, NK cell and macrophage in tumor as well as NK cell activity. Conclusion : CGAL and its compounds may enhance immune responses and suppress tumor growth, and may be capable of developing health functional foods.