Biomedical subjects

Jong-Woo Park

Publications and source records attributed to Jong-Woo Park.

6 recordsLinked to original sources

PubMed2006

Remediation of soil contaminated with 2,4-dichlorophenol by treatment of minced shepherd's purse roots.

This study investigated the applicability of minced shepherd's purse root containing high peroxidase activity as a catalytic agent instead of purified and immobilized peroxidase for the remediation of soil contaminated with phenolic pollutants, using 2,4-dichlorophenol (2,4-DCP) as a model pollutant. The removal of 2,4-DCP in the soil was extremely fast when treated with peroxide and minced shepherd's purse root, and maximal removal was achieved within 10 min. Increasing the reaction temperature did not significantly influence removal of 2,4-DCP incubated with shepherd's purse. The removal of 2,4-DCP was dependent on the amount of shepherd's purse and the soil moisture content. Increasing the amount of shepherd's purse and moisture mixed with soil caused an increased removal of 2,4-DCP. Calcium peroxide was more effective than hydrogen peroxide, and maximal removal was achieved in 20 mM of both peroxides. The efficiency of 2,4-DCP removal decreased with increasing 2,4-DCP concentration but was greater than 60% at 500 to 1000 mg kg(-1). Our results provide strong evidence that shepherd's purse can be used to remediate soil contaminated with phenolic pollutants.

Biodegradation, Environmental↗

PubMed2003

Biotransformation of an organochlorine insecticide, endosulfan, by Anabaena species.

This study assesses the role of the blue-green algal species present in the soil in the dissipation of endosulfan and its metabolites in the soil environment. Two Anabaena species, Anabaena sp. PCC 7120 and Anabaena flos-aquae, were used in this study. Anabaena sp. PCC 7120 produced three principal biotransformation compounds, chiefly endosulfan diol (endodiol), and minor amounts of endosulfan hydroxyether and endosulfan lactone. Trace amounts of endosulfan sulfate were detected. In comparison, the biotransformation of endosulfan by Anabaena flos-aquae yielded mainly endodiol with minor amounts of endosulfan sulfate. An unknown compound was produced up to 70% from endosulfan spiked in the medium inoculated by A. flos-aquae after 8 days of incubation. Therefore, the endosulfan fate was dependent on the species. Within 1 day of incubation, two Anabaena species produced low amounts of beta-endosulfan after application of alpha-endosulfan. These results suggest the presence of isomerase in the Anabaena species. Further studies using a fermentor to control the medium pH at 7.2 to minimize chemical hydrolysis of endosulfan revealed a major production of endodiol with minor amounts of endosulfan sulfate and the unknown compound. These results showed that the production of the unknown compound might be dependent on the alkaline pH in the medium and that the production of endodiol by A. flos-aquae might be biologically controlled. This study showed that two algal species could contribute in the detoxification pathways of endosulfan in the soil environment.

Anabaena↗

PubMed2002

Transformation of the fungicide chlorothalonil by Fenton reagent.

A modified Fenton reagent (Fe(3+)/H(2)O(2)) transformed the fungicide chlorothalonil within 60 min in aqueous solution at unadjusted pH. Transformation varied with ferric salt. Transformation was greatest with ferric nitrate and least when ferric sulfate was used. UV irradiation enhanced the transformation of chlorothalonil. The transformation of chlorothalonil was enhanced, which increased with ferric ion or hydrogen peroxide concentration. Maximum transformation was achieved at 2 mM ferric ion and 100 mM hydrogen peroxide. Additionally, chlorothalonil was more dechlorinated in the UV irradiation condition. The proposed reaction pathway includes reduction of chlorothalonil to trichloroisophthalonitrile, dichloroisophthalonitrile, and monochloroisophthalonitrile; oxidation of trichloroisophthalonitrile to trichloro-3-cyanobenzoic acid and 3-carbamyltrichlorobenzoic acid; and oxidation of hydroxychlorothalonil to trichloro-3-cyanohydroxybenzoic acid and trichlorocyanophenol.

Chlorine↗

PubMed2002

Formation of bound residues of 8-hydroxybentazon by oxidoreductive catalysts in soil.

This study was performed to determine which oxidoreductive catalysts were most efficient in catalyzing the binding of 8-hydroxybentazon to soil humic substances. 8-Hydroxybentazon was completely transformed by an oxidoreductive enzyme, laccase of Myceliophthora thermophila, at pH 3.0-7.0 within 30 min. When abiotic catalysts, manganese(IV), iron(III), and aluminum oxides were used in the same pH range, 8-hydroxybentazon was completely transformed only by manganese(IV) oxide (delta-MnO2), but a relatively small amount of 8-hydroxybentazon was transformed by iron(III) oxide and aluminum oxide. The adsorption of 8-hydroxybentazon in the soil showed an H-type and coincided well with the Langmuir isotherm. To better understand the factors involved in the rapid and strong binding of 8-hydroxybentazon with soil humic substances, 8-hydroxybentazon transformation by oxidoreductive catalysts was studied in various soil conditions: air-dried, preincubated, sterilized, and iron(III) oxide and manganese(IV) oxide free. 8-Hydroxybentazon was completely transformed within 24 h in the decreasing order of preincubated, air-dried, and sterilized soils. However, little transformation was observed in the iron(III) oxide and manganese(IV) oxide free soils. These results suggest that the major catalyst responsible for the rapid and strong binding of 8-hydroxybentazon to soil humic substances is a metal oxide, manganese(IV) oxide, not a soil oxidoreductive enzyme.

Adsorption↗

PubMed2002

Three-year experience in using total laboratory automation system.

We implemented a total laboratory automation (TLA) system, currently used in Chungnam National University Hospital (CNUH), designed around the A&T Corporation to perform the general and specific laboratory testing throughout the system in a timely and cost-effective manner. The system consists of two major lines: chemistry and hematology. The analyzers attached to the hematology line include one SE 9000 hematology analyzer (Sysmex Corporation, Kobe, Japan), one SP-100 slide maker (Sysmex), and one R9000 reticulocyte counter (Sysmex). The chemistry line consists of preanalytic system and linked analyzers. The analyzers attached to chemistry line are one Hitachi 747 chemistry analyzer (Hitachi, Ltd., Tokyo, Japan), one A&T 502X analyzer (A&T Corporation, Tokyo, Japan) and one Architect i2000 immunochemistry analyzer (Abbott Diagnostics Division, Santa Clara, USA). The preanaytic system including start stocker, centrifuge, de-cap unit and aliquoting unit were connected with analyzers. The turn around time (TAT) of all tests was shortened in comparison to manual systems. Consequently it makes feasible one-day care clinic and makes reduced inherent errors in sample identification, dispensing, and reporting. In addition, real-time re-run can make test quality more reliable. As many as 12 departments can be reduced to 7 departments. The subsidiary advantages of smaller size were incorporated into reduced working steps facilitating workflow. Overall, better qualified and quicker results can be provided to the clinicians, and proper cost-effectiveness and better quality services can be anticipated as a result of much easier system management and higher reliability. In conclusion, the TLA has been successful within our laboratory.

Automation↗

PubMed2002

Clinical pathologist in Korea--training program and its roles in laboratories.

A rapid development of practice of laboratory medicine in Korea owes its success to the clinical pathologists (CP), who have played a role of a pathfinder for laboratories. The Korean CP postgraduate education (residency) program is unique in that it is exclusively for laboratory medicine. The training program for clinical pathologists includes diagnostic hematology, diagnostic immunology, clinical microbiology, clinical chemistry, blood bank, diagnostic genetics, informatics and laboratory management. The program has produced a strong group of about 600 laboratory physicians, officially clinical pathologists since 1963. Most of Korean clinical pathologists work as laboratory directors, directors of university hospital laboratories or teaching faculty members in medical schools. The roles of clinical pathologists are laboratory management, interpretation of laboratory test results, clinical consulting services to clinicians and patients, ordering secondary tests after reviews of requested test results and utilization management. The clinical pathologists have developed clinical laboratories to be a main contributor for improved medical practice. During the last 40 years under the turbulent healthcare system, clinical pathologists have significantly contributed to safeguard the laboratory interests. The education program and the role of clinical pathologists are described.

Curriculum↗