• Archives of Pharmacal Research
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• 제20권1호
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• pp.68-71
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• 1997

Penicillin sensor was prepared by immobilizing penicillinase (Pcase) on $H^{+}$-selective carboxylated poly (vinyl chloride) (PVC-COOH) membrane or cellulose filter membrane. The immobilization techniques are as follows. Pcase was immobilized with GTH on $H^{+}$-selective PVC-COOH membrane or some amount of BSA was dropped on that membrane. Another method to make immobilization is to mix type I Pcase with GTH and drop on a cellulose filter membrane. According to immobilization techniques, there were some differences in response properties of enzyme electrodes, however, all electrodes responded to Pcase-resistant penicillin derivatives. Pcase immobilized on cellulose filter membrane with $H^{+}$-selective PVC membrane eletrode was more stable and more sensitive to penicillinase-resistant penicillin derivatives than any other immobilization techniques.

• 한국산업보건학회지
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• 제26권1호
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• pp.48-57
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• 2016

Objectives: This study was conducted to evaluate the accuracy and precision of airborne metal analysis using polyvinyl chloride(PVC) membrane filter by pretreatment methods. Methods: A total of 75 spiked PVC samples for Cr, Fe and Mn ranged from 6 ug/sample to 40 ug/sample were used to evaluate recovery rates for three pretreatment methods: acid extraction, hot plate ashing and microwave digestion. For Mn, an additional 75 spiked mixed cellulose ester(MCE) membrane filters were analysed to compare the recovery rates of PVC samples. All samples were analysed with an inductively coupled plasma optical emission spectrometer(ICP-OES) and manganese samples were additionally analyzed by atomic absorption spectrometer(AAS). Results: The overall mean recovery rates of PVC samples for Cr, Fe and Mn were 90% or higher regardless of pretreatment methods, but there were statistically significant differences in recovery rates for Cr(p<0.05) and Mn(p<0.01) samples by pretreatment methods. The biases and the coefficient variations of PVC samples for three metals pretreated with three kinds of pretreatment methods ranged from 1.7% to 4.7% and from 1.6% to 6.5%, respectively. The manganese PVC samples pretreated by microwave digestion and analyzed with ICP-OES had the lowest bias at 1.9% and also showed lower bias than the bias for MCE samples, 2.7%. Conclusions: In order to accurately analyze the metals sampled with PVC membrane filters, microwave digestion and ICP-OES can be recommended.

• 대한화학회지
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• 제25권4호
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• pp.253-262
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• 1981

AgI/PVC${\cdot}$THF막전극은 단일할로겐화이온과 할로겐화이온 혼합물을 질산은표준용액으로 전위차법적정할 때 지시전극으로 사용될 수 있다. 그러나 할로겐화이온혼합물을 단계적정할 때 오차가 매우 큼을 알 수 있었다. 그러나 적정용액에 $NaNO_3$나 $Ba(NO_3)_2$같은 뭉침제를 가하면 오차가 매우 감소한다. 또한 젤라틴과 거름종이의 효과 그리고 온도의 영향도 조사하였다.

• 한국산업보건학회지
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• 제23권4호
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• pp.393-401
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• 2013

Objectives: Endotoxins in dust generated in occupational settings is known to contribute to the occurrence of respiratory illness among workers. The relationship between the level of endotoxins in total dust or respirable particulates collected from swine farms and immunological markers related with respiratory allergy was evaluated among swine husbandry workers. Materials and Methods: Peripheral blood samples were collected from ten workers at ten swine farms at Gyeonggi province, Korea. Peripheral mononuclear cells were stimulated with phorbol 12-myristate 13-acetate and ionomycin for 48 hours. The levels of various cytokines produced at culture supernatants were determined using a commercially available ELISA kit. The concentration of particulate matter($PM_{10}$) in the indoor air of the swine farms was evaluated using a PVC membrane filter and mini volume air sampler, and endotoxin levels in the dust were measured by Limulus Amebocyte Lysate Kinetic QCL method. Results: Levels of endotoxins in the total dust were categorized into high(geometric mean: $109.35EU/m^3$) and low concentrations (geometric mean: $0.95EU/m^3$) for five swine farms. Interleukin-4 levels were higher in the high endotoxin group than in the low endotoxin group, while interferon-${\gamma}$ levels were lower in the high endotoxin group than in the low endotoxin group. The ratio (interferon-${\gamma}$ to interleukin-4), indicating immunologic skewedness against allergic reactivities, was lower in the high endotoxin group($1.15{\pm}0.60$) than the low endotoxin group($3.09{\pm}2.38$). In addition, the level of interleukin-13, another cytokine contributing to the occurrence of allergic responses, was significantly higher in the at the high endotoxin group($1.12{\pm}0.37ng/m{\ell}$) than in the low endotoxin group($0.37{\pm}0.04ng/m{\ell}$). Hematologic assessment showed significantly lower cellularity in the number of total leukocytes, neutrophils, and eosinophils in the high endotoxin group than in the low endotoxin group. Conclusions: Even though a sufficient number of swine workers and farms were not investigated, this study generlly suggests that the immunological function of swine farm workers exposed to high levels of endotoxin could be modulated toward allergic reactivities.