• Title/Summary/Keyword: $OH^-$

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Exposure Assessment and Effect of Hygienic Measures for Reducing Total Exposure for Workers Exposed to Polycyclic Aromatic Hydrocarbons by Using 1-OH-pyrene in Urine (요중 1-OH-pyrene을 이용한 PAH환경근로자들의 노출평가 및 위생조치에 의한 총 노출량 감소효과)

  • Lee, Song-Kwon;Nam, Chul-Hyun;Roh, Pyong-Ui;Lee, Young-Sei;Cho, Ki-Hyun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.7 no.2
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    • pp.264-278
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    • 1997
  • The average level of coke oven emissions in the work site was $0.04mg/m^3$, which was below the permissible exposure level($0.2mg/m^3$). The average level of 1-OH-pyrene in the urine of the wokers was $0.745{\mu}mol/mol$ creatinine which is far below the BEI($2.3{\mu}mol/mol$ creatinine). Correlation between airborne COE in working environment and urinary 1-OH-pyrene concentration was statistically significant. These results explain that exposure level by biological monitoring is much higher than that by environmental monitoring. The effect of hygienic measures for reducing internal exposure to polycyclic aromatic hydrocarbons was studied in 25 coke-oven workers. Their 1-OH-pyrene levels increased by $0.77{\mu}mol/mol$ creatinine, while working with ordinary protective measures. The average levels of the same workers with extra hygienic measures increased by $0.34{\mu}mol/mol$ creatinine. The average increase of the urinary 1-OH-pyrene concentration over the 5-day work week was 56.3%($0.43{\mu}mol/mol$ creatinine) lower when extra hygienic measures were taken(p=0.0001).

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Anti-microbial Effect on Streptococcus mutans and Anti-oxidant Effect of the Butanol Fractions of Sanguisorbae Radix (지유(地楡) 부탄올 분획물의 Streptococcus mutans 항균활성 및 항산화 효과)

  • Park, Geun-Hye;Lee, Jin-Tae;An, Bong-Jeun
    • The Korea Journal of Herbology
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    • v.27 no.3
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    • pp.23-29
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    • 2012
  • Objective : Sanguisorbae Radix(SO). that belong to Rosaceae is widely distributed in Asia including Korea, Japan and China. It has been used as traditional medicine from old times as a treatment for anti-inflammatory drugs. This study was designed to investigate the effects of n-BuOH fractions of SO on anti-oxidant effect and anti-microbial effect on $Streptococcus$ $mutans$ ($S.$ $mutans$). Methods : The anti-microbial effect of $n$-BuOH fractions of SO. was assessed by the paper disk diffusion method and anti-oxidant effect was assessed by the DPPH radical scavenging effect, Superoxide anion radical scavenging effect and SOD like ability. Results : DPPH radical scavenging of the $n$-BuOH fraction from SO in 50 ug/mL was shown to be Fr-2 (89.9%), Fr-3 (88.7%), Fr-4 (76.3%), Fr-1 (59.4%), Fr-5 (56.2%). Superoxside anion radical scavenging activity of the n-BuOH fraction from SO. in 50 ug/mL for Fr-3 was shown to be 78%. SOD-like activity of n-BuOH fraction from the SO in 1000 ug/mL for Fr-3 were shown to be 76.1% respectively. The $n$-BuOH fraction from the SO had high anti-microbial effect on $S.$ $mutans$. Conclusion : As a result, the $n$-BuOH fraction from SO. has good anti-microbial and anti-oxidant effects in a concentration-dependent manner.

Microwave-assisted synthesis of $Cu_2O$ and Cu from $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$ ($Cu_2(OH)_3(CH_3COO){\cdot}H_2O$로 부터 마이크로파를 이용한 $Cu_2O$와 Cu의 합성)

  • Song, Ha-Chul;Huh, Young-Duk
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.4
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    • pp.166-171
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    • 2006
  • [ $Cu_2O$ ] and Cu have been synthesized from the layered organic-inorganic hybrid, $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$, assisted by microwave irradiation. $Cu_2O$ is formed in aqueous glucose solution, while metallic Cu is formed in ethylene glycol by reduction of $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$. The influence of microwave irradiation time and concentration of glucose on $Cu_2O$ particles formation and growth has been examined. The morphologies of $Cu_2O$ particles change from spheres with a few fm size to nanowires with diameter of 40 nm as increasing the microwave irradiation times.

Dephosphorylation of an Organic Phosphinate by Nucleophile in Anionic and Cationic Micellar Solutions (음이온 및 양이온 미셀 용액에서 친핵체에 의한 유기 포스피네이트의 탈인산화반응)

  • Kim, Jeung-Bea
    • Journal of Environmental Science International
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    • v.15 no.5
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    • pp.485-491
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    • 2006
  • In the aqueous solutions the dephosphorylations of isopropyl phenyl-4-nitrophenyl phosphinate(IPNPIN) mediated by hydroxide$(OH^{\theta})$ and o-iodosobenzoate$(IB^{\theta})$ ions ate relatively slow, because of hydrophobicity of the substrate, and however it appears that $OH^{\theta}$ is inherently better nucleophile than $IB^{\theta}$, which is more soft ion. On the other hand, in cetyltrimetyiammonium bromide(CTABr) solutions which contain cationic micelles, the dephosphorylations of IPNPIN mediated by $OH^{\theta}$ or $IB^{\theta}$ ate very accelerated to 120 or 100,000 times as compared with those in the aqueous solutions. The values of pseudo first order rate constants reach a maximum with increasing. Such rate maxima are typical of micellar catalysed bimolecular reactions and the rise in rate constant followed by a gradual decrese is characteristic of reactions of hydrophobic substrates. In the cationic micellar solutions of CTABr, $IB^{\theta}$ accelerates the reactions much more than that $OH^{\theta}$ does. The reason seems that $IB^{\theta}$ which is more hydrophobic and soft ion than $OH^{\theta}$ is more easily moved into the Stern layer of the CTABr micelles than $OH^{\theta}$. In the anionic micellar solutions of sodium dodecyl sulfate(SDS), the dephosrhorylations of IPNPIN ate slower than those in aqeous solutions. It means that $OH^{\theta}$ or $IB^{\theta}$ cannot easily move and approach to the Stern layer of the micelle in which almost all the hydrophobic substrate are located and which has a negative circumstance.

Isolation and identification of secondary metabolites from the roots of Brassica rapa (순무(Brassica rapa) 뿌리로부터 이차대사산물의 분리 및 동정)

  • Bang, Myun-Ho;Lee, Dae-Young;Han, Min-Woo;Chung, Hae-Gon;Jeong, Tae-Sook;Choi, Myung-Sook;Lee, Kyung-Tae;Baek, Nam-In
    • Journal of Plant Biotechnology
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    • v.36 no.1
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    • pp.64-67
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    • 2009
  • In order to identify secondary metabolites, the root of Brassica rapa was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$. From the EtOAc and n-BuOH fractions, four secondary metabolites were isolated through the repeated silica gel and octadecyl silica gel (ODS) column chromatographies. From the result of spectroscopic data including NMR and MS, the chemical structures of the compounds were determined as 4-(methoxymethyl)phenol (1), ${\alpha}$-methoxy-2,5-furandimethanol (2), phenyl-${\beta}$-D-glucopyranoside (3), and 2-phenylethyl-${\beta}$-D-glucopyranoside (4). They were isolated for the first time from Brassica rapa.

Cytotoxic and Apoptotic-inducing Effects of Purple Rice Extracts and Chemotherapeutic Drugs on Human Cancer Cell Lines

  • Banjerdpongchai, Ratana;Wudtiwai, Benjawan;Sringarm, Korawan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6541-6548
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    • 2013
  • Pigmented rice is mainly black, red, and dark purple, and contains a variety of flavones, tannin, polyphenols, sterols, tocopherols, ${\gamma}$-oryzanols, amino acids, and essential oils. The present study evaluated the cytotoxic effects of purple rice extracts (PREs) combined with chemotherapeutic drugs on human cancer cells and mechanisms of cell death. Methanolic (MeOH) and dichloromethane (DCM) extracts of three cultivars of purple rice in Thailand: Doisaket (DSK), Nan and Payao (PYO), were tested and compared with white rice (KK6). Cytotoxicity was determined by 3-(4, 5-dimethyl)-2, 5-diphenyltetrazolium bromide (MTT) assay in human hepatocellular carcinoma HepG2, prostate cancer LNCaP and murine normal fibroblast NIH3T3 cells. MeOH-PYO-PRE was the most cytotoxic and inhibited HepG2 cell growth more than that of LNCaP cells but was not toxic to NIH3T3 cells. When PREs were combined with paclitaxel or vinblastine, they showed additive cytotoxic effects on HepG2 and LNCaP cells, except for MeOH-PYO-PRE which showed synergistic effects on HepG2 cells when combined with vinblastine. MeOH-PYO-PRE plus vinblastine induced HepG2 cell apoptosis with loss of mitochondrial transmembrane potential (MTP) but no ROS production. MeOH-PYO-PRE-treated HepG2 cells underwent apoptosis via caspase-9 and-3 activation. The level of ${\gamma}$-oryzanol was highest in DCM-PYO-PRE (44.17 mg/g) whereas anthocyanin content was high in MeOH-PYO-PRE (5.80 mg/g). In conclusion, methanolic Payao purple rice extract was mostly toxic to human HepG2 cells and synergistically enhanced the cytotoxicity of vinblastine. Human HepG2 cell apoptosis induced by MeOH-PYO-PRE and vinblastine was mediated through a mitochondrial pathway.

Vitamin D Sufficiency: How should it be defined and what are its functional indicators?

  • Hollis Bruce W.
    • Proceedings of the Korean Nutrition Society Conference
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    • 2004.11a
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    • pp.22-33
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    • 2004
  • It has been more than three decades since the first assay assessing circulating 25(OH)D in human subjects was performed. That publication as well as several that followed it defined 'normal' nutritional vitamin D status in human populations. Recently, the wisdom by which 'normal' circulating 25(OH)D levels in human subjects were assigned in the past has come under question. It appears that sampling human subjects, who appear to be free from disease, and assessing 'normal' circulating 25(OH)D levels by plotting a Gaussian distribution is grossly inaccurate. There are many reasons why this method is inaccurate, including race, lifestyle habits, sunscreen usage, age, latitude, and inappropriately low dietary recommendations for vitamin D. For instance, a 400IU/day. AI for vitamin D is insignificant when one considers that a 10-15 minute whole body exposure to peak summer sun will generate and release up to 20,000 IU vitamin $D_3$ into the circulation. Recent studies, which orally administered up to 10,000 IU/day vitamin $D_3$ to human subjects for several months, have successfully elevated circulating 25(OH)D levels to those observed in individuals from sun-rich environments. Further, we are now able to accurately assess sufficient circulating 25(OH)D levels utilizing specific biomarkers instead of guessing what an adequate level is. These biomarkers include intact parathyroid hormone (PTH), calcium absorption, bone mineral density (BMD), insulin resistance and pancreatic beta cell function. Using the data from these biomarkers, vitamin D deficiency should be defined as circulating levels of $25(OH)D{\leq}30ng/mL$. In certain cases, such as pregnancy and lactation, significantly higher circulating 25(OH)D levels would almost certainly be beneficial to both the mother and recipient fetus/infant.

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Changes of the Flame Temperature and OH Radical in the Unsteady Extinction Process (비정상 소화 과정에서의 화염 온도 및 OH 라디칼의 변화)

  • Lee, Uen-Do;Lee, Ki-Ho;Oh, Kwang-Chul;Shin, Hyun-Dong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.12
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    • pp.1557-1566
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    • 2004
  • A flame extinction phenomenon is a typical unsteady process in combustion. Flame extinction is characterized by various physical phenomena, such as convection, diffusion, and the production of heat and mass. Flame extinction can be achieved by either increasing the strain rate or curvature, by diluting an inert gas or inhibitor, or by increasing the thermal or radiant energy loss. Though the extinction is an inherently transient process, steady and quasi-steady approaches have been used as useful tools for understanding the flame extinction phenomenon. Recently, unsteady characteristics of flames have been studied by many researchers, and various attempts have been made to understand unsteady flame behavior, by using various extinction processes. Representative parameters for describing flame, such as flame temperature, important species related to reactions, and chemi-luminescence of the flame have been used as criterions of flame extinction. In these works, verification of each parameter and establishing the proper criterions of the extinction has been very important. In this study, a time-dependent flame temperature and an OH radical concentration were measured using optical methods, and the instantaneous change of the flame luminosity was also measured using a high-speed ICCD (HICCD) camera. We compare the unsteady extinction points obtained by three different methods, and we discuss transient characteristics of maximum flame temperature and OH radical distribution near the extinction limit.

The Study of Effects of Variable Parameters on Flame Structure and NOx Emission in Methane/Air Laminar Partially Premixed Flames (메탄/공기 층류 부분 예혼합화염에서 예혼합 정도에 따른 화염구조와 질소산화물의 배출에 미치는 영향에 관한 연구)

  • Oh, Jeong-Seog;Jeong, Yong-Ki;Jeon, Chung-Hwan;Chang, Young-June
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.362-367
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    • 2003
  • It is shown that the effect of variable parameters on flame structures and NOx emissions in the laminar partially premixed methane-air flames with a co-axial Bunsen burner. Objectives of this paper is to understand the effects of flow variables on NOx emissions and the flame structure with OH chemiluminescence, including reconstructed image by abel inversion processing at each conditions. A fuel flowrate of 200 [cc/min] was fixed and the amount of air was varied from 400 to 1200 [cc/min]. The experimental variables were equivalence ratio(${\Phi}$ fuel split percentage(${\sigma}$ and inner tube recess(x/D). Flow conditions were ranged from $1.36{\sim}4.76$(equivalence ratio), $50{\sim}100$(fuel split percentage) and $0{\sim}20$(inner tube recess). NOx analyzer and ICCD camera with a OH filter were used as a main experimental apparatus. In addition, Abel inversion, which is a kind of tomography and valuable to estimate a two-dimensional structure of co-axial flames from cubical information, was employed for combustion diagnostics. Results from this study indicate that the main effects depend on equivalence ratio and next sigma, x/D for NOx production and OH formation. Throughout Abel inversion, we could affirm the maximum position and the tendency of OH radical intensity by variants at five axial heights above the burner exit.

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Study of 25-Hydroxyvitamin D3 concentration according to the Hepatitis B virus (Hepatitis B virus에 따른 25-Hydroxyvitamin D3 농도 영향 연구)

  • Kim, Jean-Soo;Lee, Dong-Yeop
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2743-2748
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    • 2013
  • The vitamin gets through food and the sun. But there is case that density alters by certain factor in vitamin. So this research analyzed effect of the liver function factor and change of $25OH-VIT.D_3$ density. Research target is a person who undergo health medical examination in the certain university hospital medical examination center from August, 2012 to December, 2012. Comparison classified to experiment group and control group. As a result, variable that influence in $25OH-VIT.D_3$ density showed by age and B type inflammation of the liver titer. Specially, B type inflammation of the liver titer displayed reverse corelation ($R^2$=0.40). Therefore, inflammation of the liver carrier must manage liver fuction test and density of $25OH-VIT.D_3$.