• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.526-538
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• 2016

Fumigants are used worldwide for control of biological agents that damage wooden cultural property. To establish a policy for fumigant use, biological evaluation of insects and microorganisms considering many factors is required. This study was performed to evaluate biological sensitivity and wood penetration of three fumigants applied for control of biological agents that damage wooden cultural properties in Korea. Among these, methyl bromide and ethylene oxide can control insects and fungi when exposed directly. However, they were unable to completely control biological agents within deeper parts of wood. Ethanedinitrile, which was developed as an alternative fumigant, exhibited outstanding wood penetration and biocidal efficacy. Further research involving various environmental conditions is warranted.

• Biomedical Science Letters
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• v.22 no.3
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• pp.65-74
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• 2016

The critical aspects of biosafety and bio-containment have been increasingly important in recent years. Biological agents involved in biological research projects at the Nanyang Technological University (NTU) Singapore are usually those with low risks. Biosafety level 2 or BSL 2 laboratories are widely used. However, biosafety measures which refer to the implementation of laboratory practices and procedures, specific construction features of laboratory facilities and safety equipment must be in place to reduce the exposure of laboratory personnel, the public or the environment to potentially infectious agents or other biological hazards. It is also required to pay more attention to laboratory-acquired infections (LAIs) which may occur in research laboratories, clinical laboratories or animal facilities. BSL 2 audit and certification program is implemented as an internal exercise covering laboratories in the university where biological agents are handled or biological research works are carried out. We have put some efforts to raise biosafety standards university-wide in both laboratory infrastructure and laboratory practices to a higher level. Common audit findings are briefly discussed in this presentation.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.1
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• pp.68-80
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• 2021

An uncertified facility is a facility not certified, as defined in the Biological Agents and Toxins Act (BATA) in Singapore, but has met the requirements of the Ministry of Health to possess First and Fifth Schedule biological agents and toxins. This type of facility is also known as a Biosafety Level 2 Plus (BSL 2+) facility. Registration as an uncertified facility or a BSL 2+ facility requires a certain process and procedure to be sought with the Biosafety Branch of the ministry. This review, shares first-hand knowledge on the journey to achieving registration of the authors' facility. The procedure involved considerable preparation, setting up facility requirements, biosafety precautions, procedures and practices, and training and competence of laboratory users. The ministry conducted a thorough onsite facility audit to ensure that the facility requirements and biosafety procedures and practices were in place. It then issued an approval letter of possession for the first-time use of biological agents and registered the laboratory as an uncertified facility. The expectation is that the comprehensive information shared may be of great benefit to other facilities with similar interests.

• Journal of Applied Biological Chemistry
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• v.50 no.3
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• pp.136-143
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• 2007

Despite the increased interests in biological control of soilborne diesease for environmental protection, biological control of bacterial wilt caused by Ralstonia solanacearum have not provided consistent or satisfying results. To enhance the control efficacy and reducing the inconsistency and variability, combinations of specific strains of microorganisms, each having a specific mechanism of control, were applied in this study. More than 30 microorganisms able to reduce the activity of pathogen by specific mechanism of action were identified and tested for their disease suppressive effects. After in vitro compatibility examinations, 21 individual strains and 15 combinations were tested in the greenhouse. Results indicated three-way combinations of different mode of control, TS3-7+A253-16+SKU78 and TS1-5+A100-1+SKU78, enhanced disease suppression by 70%, as compared to 30-50% reduction for their individual treatments. This work suggests that combining multiple traits antagonizing the pathogen improve efficacy of the biocontrol agents against Ralstonia solanacearum.

• Macromolecular Research
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• v.15 no.7
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• pp.676-681
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• 2007

A process designed to synthesize rigid polyurethane foam (PUF) with insulative properties via the modulation of PUF cell size via the addition of clay and the application of ultrasound was assessed. The blowing agents utilized in this study include water, cyclopentane, and HFC-365mfc, all of which are known to be environmentally-friendly blowing agents. The rigid PUFs were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI) and polyether polyol with a density of $50kg/m^3$. In addition, rigid PUFs/clay nanocomposites were synthesized with clay modified by PMDI with and without the application of ultrasound. The PUF generated using water as a blowing agent evidenced the highest tensile strength. The tensile strength of the PUF/nanocomposites was higher than that of the neat PUF and the strength was even higher with the application of ultrasound. The cell size of the PUF/clay nanocomposites was less than that of the neat PUF, regardless of the type of blowing agent utilized. It appears that the higher tensile strength and lower cell size of the PUF/clay nanocomposites may be attributable to the uniform dispersion of the clay via ultrasonic agitation. The thermal conductivity of the PUF/clay nanocomposites generated with HCFC-141b evidenced the lowest value when PUF/clay nanocomposites were compared with other blowing agents, including HFC-365mfc, cyclopentane, and water. Ultrasound has also proven effective with regard to the reduction of the thermal conductivity of the PUF/clay nanocomposites with any of the blowing agents employed in this study. It has also been suggested that the uniformly dispersed clay particles in the PUF matrix function as diffusion barriers, which prevent the amelioration of the thermal insulation property.

• Mycobiology
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• v.42 no.4
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• pp.376-384
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• 2014

Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.127-133
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• 2019

The study of the genus Streptomyces is of particular interest because it produces a wide array of clinically important bioactive molecules. The genomic sequencing of many Streptomyces species has revealed unusually large numbers of cytochrome P450 genes, which are involved in the biosynthesis of secondary metabolites. Many macrolide biosynthetic pathways are catalyzed by a series of enzymes in gene clusters including polyketide and non-ribosomal peptide synthesis. In general, Streptomyces P450 enzymes accelerate the final, post-polyketide synthesis steps to enhance the structural architecture of macrolide chemistry. In this review, we discuss the major Streptomyces P450 enzymes research focused on the biosynthetic processing of macrolide therapeutic agents, with an emphasis on their biochemical mechanisms and structural insights.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.3
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• pp.335-342
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• 2015

Laboratory facilities for biology are designed as biosafety level 1, biosafety level 2, biosafety level 3, and biosafety level 4. Biosafety level designations are based on a composite of the design features, construction, containment facilities, equipment, practice and operation procedures required for working with agents from the various risk groups. Generally, biosafety level 3 means the facility that is appropriate for the experiments using pathogens which can cause serious diseases by aerosol transmission. The biosafety level assigned for the specific work to be done is driven by professional judgement based on a risk assessment, rather than by automatic assignment according to the particular risk group designation of the pathogenic agents to be used. In this paper, we introduced the biosafety level 3 facility operated in ADD(Agency for defense development). It contains the overview of facility, microbiological experiment, animal experiment, decontamination and waste disposal. Biosafety level 3 laboratory in ADD has served the vital role in the research of biological agents and antidote development.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.14-37
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• 2014

Objectives: Since information on biological factors in the workplace are currently lacking, I wanted to create a handbook of these factors that would be viewable at a glance as a means to more effectively prevent occupationally-infected diseases. Proper information on biological hazards in the workplace allowing the appropriate recognition of the harmful factors is desperately needed. Methods and Results: In this study, I intended to create a high-utility handbook of biologically hazardous agents in the workplace. To ensure its effectiveness, information and references about biologically hazardous agents in the workplace were analyzed and classified and pathogen safety data sheets(PSDS) sourced from the Public Health Agency of Canada were included. I intended to make it accessible from the point of view of workers and their employers. A more effective classification system of occupational infectious diseases is presented, and biologically hazardous agents were classified according to occupations, industries, infectious diseases, and so on. The handbook consists of 60 major kinds of biologically infectious occupational factors that are expected to be generated in workplaces in Korea, and are focused on practical utility. The pathogen safety data sheets(PSDS) of 192 species were also included. To allow more effective management, domestic and foreign laws and regulations are presented. Conclusions: This case report presents general information on the history and contents of the handbook and PSDS, it will also be useful in workplaces if download from the homepage of OSHRI, KOSHA(oshri.kosha.or.kr/bridge?menuID=901).

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.699-706
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• 2013

We have previously reported that N-acetylcysteine (NAC) not only delayed apoptosis but also enhanced the production of recombinant erythropoietin (EPO) in Chinese hamster ovary (CHO) cell culture. To investigate the production enhancement mechanism, the effects of similar thiol-reducing agents were studied. Intriguingly, all mild reducing agents examined including mercaptoethanesulfonic acid (MESNA), thiolactic acid (TLA), and thioglycolate (TG) were shown to block apoptosis and increase EPO production. A pulse-chase study of EPO secretion revealed that all four thiol-reducing agents increased the EPO secretion rate; among them TLA showed the highest rate. In terms of product quality, the sialic acid content of the glycoprotein is one of the most important factors. It was reported that a number of glycoproteins produced by CHO cells often have incomplete sialylation, particularly under high-producing conditions. Human ${\alpha}2,3$-sialyltransferase (${\alpha}2,3$-ST) was introduced into EPO-producing CHO cells in order to compensate for the reduced sialylation during supplementation with NAC. When ${\alpha}2,3$-ST was expressed in the presence of NAC, reduced sialylation was restored and an even more sialylated EPO was produced. Thus, our study is significant in that it offers increased EPO production while still allowing the prevention of decreased sialylation of EPO.