• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.623-632
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• 2006

To find potential targets of novel antimicrobial agents, we identified essential genes of Staphylococcus aureus N315 by using comparative genomics and allele replacement mutagenesis. By comparing the genome of S. aureus N315 with those of Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Streptococcus pneumoniae, a total of 481 candidate target genes with similar amino acid sequences with at least three other species by >40% sequence identity were selected. of 481 disrupted candidate genes, 122 genes were identified as essential genes for growth of S. aureus N315. Of these, 51 essential genes were those not identified in any bacterial species, and 24 genes encode proteins of unknown function. Seventeen genes were determined as non-essential although they were identified as essential genes in other strain of S. aureus and other species. We found no significant difference among essential genes between Streptococcus pneumoniae and S. aureus with regard to cellular function.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.651-654
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• 2003

Non-destructive testing is essential in the inspection of alteration, repair and new construction in construction industry. This paper is to evaluate the strength variation of fire damaged concrete by non-destructive testing. Furthermore, It is to infer the recovery degree of residual strength of fire-damaged concrete. For this purpose, researchers are exploring the performance of non-destructive testing method using ultrasonic testing and Schmidt hammer in concrete specimens. Testing is performed four-times: before fire test, directly after fire test, after 20 days and after 60 days.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.80-80
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• 2002

This study was carried out that to investigate the effects of amino acids supplemented with culture medium on development of porcine embryos cultured in vitro. Cumulus oocyte complexes (COCs) were cultured in the maturation medium containing hormones (0.5$\mu\textrm{g}$/$m\ell$ LH, 0.5$\mu\textrm{g}$/$m\ell$ FSH and 1$\mu\textrm{g}$/$m\ell$ estradiol-17${\beta}$) for 20-22 h at 39$^{\circ}C$ in an atmosphere of 5% CO$_2$in air. Subsequently, COCs were cultured in hormone-free maturation medium for 20-22 h. After maturation for 40-44h, oocytes were removed cumulus cells by pipetting and cultured with epididymal sperm for 5 h in the mTBM. Embryos obtained were divided in 4 groups (1) cultured in NCSU 23 containing 0.4% BSA to blastocyst stage(Control), (2) essential amino acids (EA), (3) non-essential amino acids (NA), (4) mixture of essential and non essential amino acid (EA+NA). All treated groups(2-4) were used a glucose free NCSU 23 medium supplemented with pyruvate (0.33 mM), lactate (4.5 mM) to morula stage. From morula to blastocyst stage embryos of all treated groups were cultured in NCSU 23 containing 0.4% BSA. The rates of cleaved oocytes at 48 h after IVF were from 82% to 88% in the groups of control, EA, NA and EA+NA, respectively. The in vitro developmental rates into blastocysts in the groups of EA and EA+NA were significantly (P<0.05) higher than those of group of control (35.1, 35.4 vs. 19.4%, respectively), however, no significant (P<0.05) between control and NA. In conclusion, supplemented with essential amino acid or mixture of essential and non essential amino acid in the culture medium at morula stage increased the rate of development to blastocyst on in vitro produced porcine embryos.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1162-1168
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• 2004

In this study, based on SSOP (Sanitation Standard Operating Procedure) for HACCP in Food Sanitation Act, essential facility, equipment and documentary records for HACCP implementation were identified. Usage and adoption of these devices at Korea Food ＆ Drug Administration appointed HACCP foodservices ("Appointed"), voluntary HACCP applying foodservices ("Voluntary applying") and HACCP non-applying foodservices ("Non-applying") have been compared. Total 46 contract foodservices were surveyed： 13 "Appointed" (65％ of nation-wide all appointed food services in February, 2002),17 "Voluntary applying" and 16 "Non-applying". For usage and adoption of facility and equipment, 18 out of total 27 surveying items showed significant differences at the three foodservice groups (p＜0.01 or p＜0.05). Specifically, following items showed lower usage than 70％ in the "Appointed"： ′A trench including grease trap′, ′3-compartment sink with hot water′. Regarding CCP monitoring tool installation, 8 out of total 9 items showed significant differences among the groups (p＜0.01 or p＜0.05). For the usage of 10 documentary recording items for HACCP application log, 7 items showed significant differences among the groups (p＜0.01 or p＜0.05). Resultantly, most of those essential facilities, equipment and documentary records ;were used only in the "Appointed". The limited usages of those were showed for the "Voluntary applying" where the dietitian answered they applied HACCP voluntarily. The "Non-applying" didn′t have many surveyed items.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.149-155
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• 2022

The view of not fully denying the application of accomplice regulations to non-punishable opponents has fallen into a formal and logical circular argument that only provides formal grounds for non-punishment and has failed to provide practical grounds. In addition, it can be said that it has a criminal policy problem contrary to the legal sentiment of the general public by not punishing the active government travel activities of non-punishable accomplices. Therefore, in order to solve this problem, it is necessary to respect the legislator's intention that general non-punishment accomplices can be punished if they exceed the 'minimum government travel commission'. Therefore, if an unpunishable accomplice acts at least within the act required to realize the constituent requirements, the application of the accomplice regulations shall be excluded, and the accomplice regulations shall be applied only if they exceed that extent. In addition, if the indispensable counterparty is a protected person or has no responsibility (possibility of expectation), it can be said that it has provided a practical basis for the inability to punish, so it can be understood as impossible to punish. This interpretation method is thought to be able to present concrete validity in marginal cases where the counterparty is more responsible by substantially presenting the basis for an unpunishable accomplice.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.54-65
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• 2024

Background: There is growing international recognition of the need for improvements to national chemical management systems for hazardous chemicals. The European Union has recently introduced the concept of 'essential uses' as a new approach to the management hazardous chemicals by limiting their uses. Objectives: This paper examines the concept of essential uses in chemical management and how to apply it through a case study of essential use. This approach is distinct from the current chemical management system, but seeks to improve its potential benefits by effectively restricting or gradually decreasing the use of hazardous substances. Methods: The concept of essential uses was introduced by reviewing the Montreal Protocol on Substances that Deplete the Ozone Layer, Cousins's three essentiality categories applied to PFAS, restriction options assessed in the PFAS restriction proposal under REACH, and the California Safer Consumer Products regulations prioritizing 6PPD in motor vehicle tires. Based on these essential uses concepts for PFAS and 6PPD, uses of benzene were classified in accordance with the essential uses approach for products using benzene in South Korea. Results: The essential use concept is able to manage the restriction and authorization of substances of concern through essential uses and non-essential uses and the feasible substitution of uses and substances. Conclusions: If the concept and methodology of essential uses are clearly established, they can be expected to shift the national chemical management paradigm from regulating substances to limiting uses under the existing substance management system.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.234-247
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• 2021

We used a heterozygous gene deletion library of fission yeasts comprising all essential and non-essential genes for a microarray screening of target genes of the antifungal terbinafine, which inhibits ergosterol synthesis via the Erg1 enzyme. We identified 14 heterozygous strains corresponding to 10 non-essential [7 ribosomal-protein (RP) coding genes, spt7, spt20, and elp2] and 4 essential genes (tif302, rpl2501, rpl31, and erg1). Expectedly, their erg1 mRNA and protein levels had decreased compared to the control strain SP286. When we studied the action mechanism of the non-essential target genes using cognate haploid deletion strains, knockout of SAGA-subunit genes caused a down-regulation in erg1 transcription compared to the control strain ED668. However, knockout of RP genes conferred no susceptibility to ergosterol-targeting antifungals. Surprisingly, the RP genes participated in the erg1 transcription as components of repressor complexes as observed in a comparison analysis of the experimental ratio of erg1 mRNA. To understand the action mechanism of the interaction between the drug and the novel essential target genes, we performed isobologram assays with terbinafine and econazole (or cycloheximide). Terbinafine susceptibility of the tif302 heterozygous strain was attributed to both decreased erg1 mRNA levels and inhibition of translation. Moreover, Tif302 was required for efficacy of both terbinafine and cycloheximide. Based on a molecular modeling analysis, terbinafine could directly bind to Tif302 in yeasts, suggesting Tif302 as a potential off-target of terbinafine. In conclusion, this genome-wide screening system can be harnessed for the identification and characterization of target genes under any condition of interest.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.87-100
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• 2015

It is well known that dietary protein affects the growth performance and carcass composition of poultry. Over the last several decades, numerous studies have been carried out to investigate to optimize the level of dietary protein since the protein is an important and expensive constituent in poultry feed. It is generally accepted that dietary protein should represent a balance of amino acids supporting the requirements for growth and maintenance of birds. A protein with balanced essential amino acids that matches a bird's requirement and sufficient non-essential amino acid nitrogen to enable the synthesis of all of the non-essential amino acids, is referred to as an 'ideal protein'. Feeding of excess protein or amino acids may result in an amount of nitrogen emission. Most common method to reduce nitrogen emission is using diet formulation which has lower dietary crude protein level and higher concentration of amino acid supplements. However, there are conflicting reports whether low protein diets supplemented with synthetic amino acids can obtain the growth performance equal to high protein diets. Excessive nitrogen excretion caused by amino acid imbalance also may influence the environment of poultry house due to ammonia production from uric acid. These environmental conditions may increase the incidence of skin problem or respiratory diseases of chickens. Various strategies based on comprehensive understanding should be tested to optimize nitrogen utilization and reduce nitrogen emission while maintaining the performance in poultry production.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.2
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• pp.9-16
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• 2004

Recently, lattice conditional independence models(LCIMs) have been introduced for the analysis of non-monotone missing data patterns and of non-nested dependent regression models. This approach has been successfully applied to solve various problems in data pattern analysis, however, it suffers from computational burden to search LCIMs. In order to cope with this drawback, we propose a new scheme for finding LCIMs based on the essential graph. Also, we show that the class of LCIMs coincides with the class of all transitive acyclic directed graph(TADG) models which are Markov equivalent to a specific acyclic directed graph(ADG) models.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.1-11
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• 1997

The purpose of this study was to describe the protein nutritional status of female collegians between nonvegetarian diet groups(14) and vegetarian diet groups(19). Daily intake, protein were calculated from food direct measurement. Urea/creatinine, muscle mass, fatique conditions and hematological parameter were calculated. Blood samples were analyzed for total protein, albumin ammonia, urea, uric acid, creatinine, BUN contents. The results obtained are summarized as following : 1) On total dietary intake, especially Fe, vitamin C, niacin intake, vegetarian groups were higher than non vegetarian groups. 2) On composition of EAA(essential amino acids), vegetarians were highter than non vegetarian of leucine contents, but were lower lysine and threonine contents. 3) On urea / creatinine excretion, vegetarians were higher than non begetarians. Muscle mass were non signicant, fatique condition, vegetarians were normal state. 4) Non vegetarians were increased serum albumin total protein, uric acid, ammonia but vegetarians were decreased BUN, ammonia after experimental diet intake. 5) In process of time after meal, non vegetarians were increased serum albumin total protein, BUN, but vegetarians were decreased ammonia.