• Clean Technology
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• v.28 no.4
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• pp.285-292
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• 2022

Adsorption tower systems based on activated carbon adsorption towers have mainly been employed to reduce the emission of volatile organic compounds (VOCs), a major cause of air pollution. However, the activated carbon currently used in these systems has a short lifespan and thus requires frequent replacement. An approach to overcome this shortcoming could be to develop metal oxide photocatalysis-activated carbon composites capable of degrading VOCs by simultaneously utilizing photocatalytic activation and powerful adsorption by activated carbon. TiO₂ has primarily been used as a metal oxide photocatalyst, but it has low economic efficiency due to its high cost. In this study, ZnO particles were synthesized as a photocatalyst due to their relatively low cost. Silver nanoparticles (Ag NPs) were deposited on the ZnO surface to compensate for the photocatalytic deactivation that arises from the wide band gap of ZnO. A microfluidic process was used to synthesize ZnO particles and Ag NPs in separate reactors and the solutions were continuously supplied with a pack bed reactor loaded with activated carbon powder. This microfluidic-assisted pack bed reactor efficiently prepared a Ag-ZnO-activated carbon composite for VOC removal. Analysis confirmed that Ag-ZnO photocatalytic particles were successfully deposited on the surface of the activated carbon. Conducting a toluene gasbag test and adsorption breakpoint test demonstrated that the composite had a more efficient removal performance than pure activated carbon. The process proposed in this study efficiently produces photocatalysis-activated carbon composites and may offer the potential for scalable production of VOC removal composites.

• Journal of Food Hygiene and Safety
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• v.39 no.1
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• pp.1-8
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• 2024

Salmonella is widely prevalent in various environments and often detected in poultry. In this study, we investigated the effect of heat treatment on heat resistance via measuring the minimum inhibitory concentration (MIC) values of antibiotics after 3, 6, and 9 min of acclimatization to mild heat treatment (50℃) against 11 strains of Salmonella spp. Most strains were susceptible to chloramphenicol and their MIC values were maintained or decreased after heat treatment compared to the control. Most control and heat-treated strains showed susceptibility or intermediate resistance to ciprofloxacin. All isolates were susceptible to tetracycline, with the MIC increasing after heat treatment for S. Gaminara BAA 711. In the control, three, two, and six strains were susceptible, intermediate resistance, and resistant to gentamicin, respectively. Among them, S. Heidelberg ATCC 8326 had an intermediate MIC breakpoint of 8 ㎍/mL in the control; however, after 3 and 9 min of heat treatment, the MIC value increased to 16 ㎍/mL, indicating it to be resistant. The results of this study revealed the changes in antibiotic resistance in some of the 11 strains after heat treatment. MIC values of ciprofloxacin increased when S. Montevideo BAA 710 was heat treated for 3 and 6 min. MIC values of gentamicin increased after 3 min of heat treatment for S. Enteritidis 109 D1 and after 3 and 9 minutes of heat treatment for S. Heidelberg ATCC 8326. The MIC value of tetracycline increased when S. Gaminara BAA 711 was heat treated for 6 and 9 min.

• Journal of Genetic Medicine
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• v.4 no.2
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• pp.133-141
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• 2007

Purpose : Cri-du-Chat syndrome (CdCs) is a rare but clinically recongnizable condition with an estimated incidence of 1:50,000 live births. The clinical characteristics of the syndrome include severe psychomotor and mental retardation, microcephaly, hypertelorism, hypotonia, and slow growth. Also the size of the chromosome 5p deletion ranges were known from the region 5p13 to the terminal region. In this study, we report the spectrum of 5p deletion in Korean 20 pts. with CdCs and genotype-phenotype associations in CdCs. Methods : In order to delineate genotype-phenotype correlation, molecular cytogenetic studies including GTG banding and clinical characterization were performed on Korean 20 pts with CdCs including parents. CGH array and Fluorescence in situ hybridization (FISH) analysis were used to confirm a terminal deletion karyotype and map more precisely the location of the deletion breakpoint. Results : Molecular analysis of the spectrum of 5p deletion revealed 9 pts (45%) with a del (5)(p14), 7 pts. (35%) a del (5)(p13), 3 pts. (15%) a del (5)(p15.1) and 1 pt. (5%) a del (5)(p15.2) in 20 pts with CdCs. 4(20%)pts were identified to have additional chromosome abnormalites of deficiency and duplication involving chromosomes of 6, 8, 18, & 22. Parental study identified 3 familial case (2 paternal and 1 maternal origin) showing parents being a balanced translocation carrier. And the comparison study of the deletion break points among these 20 pts. with their phenotype has showed the varying clinical pheno-types in the CdCs critical region. Conclusion : The characterization of 5p deletion including parental study may help to delineate the genotypephenotype correlation in CdCs. Also these molecular cytogenetic analyses will be able to offer better information for accurate genetic diagnosis in CdCs and further make possible useful genetic counseling in pts. and family.

• Tuberculosis and Respiratory Diseases
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• v.54 no.3
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• pp.295-303
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• 2003

Backgroung : The incidence of penicillin-resistant streptococcus pneumoniae(PRSP) accounts for almost 70% of all pneumococcal pneumonia cases in Korea. It is still unclear as to whether the efficacy of penicillin or equally active beta-lactam agents is compromised in PRSP pneumonia. This study investigated the prevalence of PRSP in community-acquired pneumonia and its clinical course. Methods : A total of 42 patients with community-acquired pneumococcal pneumonia were evaluated from July 1999 to May 2001. The cultured strains of Streptococcus pneumoniae were divided into susceptible, intermediately resistant, and resistant strains by an E-test, and the effect of the clinical course was investigated. Results : From a total of 42 patients, 22 (52.4%) patients had an intermediate resistance (MIC $0.1-1{\mu}g/m{\ell}$) and six (14.3%) showed a high resistance ($MIC{\geq}2.0{\mu}g/m{\ell}$) with current penicillin susceptibility categories. However, according to the classification of the DRSPTWG (Drug Resistant Streptococcus pneumoniae Therapeutic Working Group), there were 11 cases (26.2%) of intermediate resistance and no case of high resistance. Under empirical antimicrobial treatment, there was no difference in the clinical outcome between the penicillin susceptible and resistant group. Conclusion : The clinical outcome of PRSP pneumonia with empirical therapy was acceptable. These results suggest that the current MIC breakpoint for penicillin resistance in Streptococcus pneumoniae has been set at a very low level and penicillin resistance according to the NCCLS classification does not significantly influence the outcome of the empirical treatment for pneumococcal pneumonia.