• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.335-341
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• 2017

The complexity of the bacterial recombination system is a barrier for the construction of bacterial mutants for the further functional investigation of specific genes. Several protocols have been developed to inactivate genes from the genus Pseudomonas. Those protocols are complicated and time-consuming and mostly do not enable easy construction of multiple knock-ins/outs. The current study describes a single and double crossover-recombination system using an optimized vector-free allele-exchange protocol for gene disruption and gene replacement in a single species of the family Pseudomonadaceae. The protocol is based on self-ligation (circularization) for the DNA cassette which has been obtained by overlapping polymerase chain reaction (Fusion-PCR), and carries an antibiotic resistance cassette flanked by homologous internal regions of the target locus. To establish the reproducibility of the approach, three different chromosomal genes (ncRNA31, rpoN, rpoS) were knocked-out from the root-associative bacterium Pseudomonas stutzeri A1501. The results showed that the P. stutzeri A1501 mutants, which are free of any plasmid backbone, could be obtained via a single or double crossover recombination. In order to optimize this protocol, three key factors that were found to have great effect on the efficiency of the homologous recombination were further investigated. Moreover, the modified protocol does not require further cloning steps, and it enables the construction of multiple gene knock-in/out mutants sequentially. This work provides a simple and rapid mutagenesis strategy for genome editing in P. stutzeri, which may also be applicable for other gram-negative bacteria.

• Proceedings of the Microbiological Society of Korea Conference
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• 2006.05a
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• pp.105-107
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• 2006

Two kinds of nucleoside hydrolases (NHs) encoded by rih1 and rih2 were cloned from Corynebacterium ammoniagenes using deoD- and gsk-defective Escherichia coli. Sequence analysis revealed that NH 1 was a protein of 337 aa with a deduced molecular mass of 35,892 Da, whereas NH 2 consisted of 308 aa with a calculated molecular mass of 32,310 Da. Experiments with crude extracts of IPTG-induced E. coli CGSC 6885(pTNU23) and 6885(pTNI12) indicated that the Rihl enzyme could catalyse the hydrolysis of uridine and cytidine and showed pyrimidine-specific ribonucleoside hydrolase activity. Rih2 was able to hydrolyse both purine and pyrimidine ribonucleosides with the following order of activity-inosine>adenosine>uridine>guanosine>xanthosine>cytidine-and was classified in the non-specific NHs family. rih1 and rih2 deletion mutants displayed a decrease in cell growth on minimal medium supplemented with pyrimidine and purine/pyrimidine nucleosides, respectively, compared with the wild-type strain. Growth of each mutant was substantially complemented by introducing rih1 and rih2, respectively. Furthermore, disruption of both rih1 and rih2 led to the inability of the mutant to utilize purine and pyrimidine nucleosides as sole carbon source on minimal medium. These results indicated that rih1 and rih2 play major roles in the salvage pathways of nucleosides in this micro-organism.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1516-1523
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• 2006

The water extract of Danchunhwan(DCH) has been traditionally used for treatment of dementia damage in oriental medicine. However, little is known about the mechanism by which the water extract of DCH rescues cells from neurodegenerative disease such as Alzheimer's disease. This study was designed to investigate the protective mechanisms of DCH on ${\beta}$-amyloid or $H_2O_2$-induced cytotoxicity in SH-SY5Y neuronblastoma cells. ${\beta}$-amyloid and $H_2O_2$ markedly decreased the viability of SH-SY5Y cells, which was characterized with apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the water extract of DCH significantly reduced both ${\beta}$-amyloid or $H_2O_2$-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, the water extract of DCH prevented prevented the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition (MPT) and the perturbation in Bcl-2 family protein expressions in $H_2O_2$-treated SH-SY5Y cells.

• Korean Journal of Child Education & Care
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• v.19 no.2
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• pp.57-69
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• 2019

Objective: The purpose of this research was to examine the moderating effects of relationships on the association between temperament and peer play interaction. Methods: The participants were 606 four year olds who were recruited from day care centers and preschools located in Incheon and Gyeonggi province. Teacher-child relationship was measured with Student-Teacher Relationship Scale. Peer interactions were measured with Penn Interactive Peer Play Scale. Temperament was measured with Child Behavior Questionnaire (CBQ). The data was analysed using Pearson correlation and hierarchial regression. Results: Teacher-child intimacy moderated the associations between inhibitory control and play disruption as well as between emotionality and play disconnection. Moreover, Teacher-child conflict moderated the association between emotionality and play disconnection. Conclusion/Implications: The findings suggest that teacher-child relationships buffer risks conferred by temperament.

• Journal of agricultural medicine and community health
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• v.41 no.1
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• pp.1-12
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• 2016

Objectives: In establishing policies for agricultural safety, evaluating injury burdens as well as investigating the rates and characteristics of work injury is important. This study investigated the types and characteristics of agricultural injury subjective burdens. Methods: By analyzing the injured farmers identified in the 2013 Korean Farmers' Occupational Injury Survey, the burdens caused by injuries were categorized using one direct cost item (medical costs) and five indirect cost items (including productivity decreases and wage increases). Statistical differences among the burden items were analyzed using logistic regression analysis according to the characteristics of the farmers and their farm injuries. Results: Among the subjective burdens indicated by the 457 injured farmers, disruption to work was most common. The major influences on each subjective burden item are as follows: for the item of disruption to work, age, time of injury occurrence, treatment period, and farming machine use were influential; for an increased family member's burden of farm works, the number of family members and treatment period were influential. Regarding cost burden of treatment, the results varied according to whether or not the patient was hospitalized and annual income. Conclusion: Subjective burdens induced by indirect costs rather than those induced by direct costs were found to be higher in ratio. In regard to each burden item, the results varied according to the characteristics of the farmers and their farm injuries. To support injured farmer, setting goals to reduce indirect cost burdens and preparing concrete methods is necessary.

• Journal of Life Science
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• v.30 no.4
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• pp.379-385
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• 2020

Phlojodicarpus sibiricus and Artemisia kruhsiana Besser are medicinal plants traditionally used in Russia. Phlojodicarpus sibiricus extracts (PSE) have been shown to have anti-obesity properties, and Artemisia kruhsiana Besser extracts (AKBE) contain terpenoid compounds that exert various medicinal effects. Here, we investigated the potential pro-apoptotic effects of PSE and AKBE in diffuse large B-cell lymphoma (DLBCL) and elucidated the underlying mechanism. PSE and AKBE treatment of six DLBCL cell lines with various genetic abnormalities effectively reduced cell viability in a dose-dependent manner, while having a minimal impact on the survival of normal murine bone marrow cells and splenocytes. This suggests that the cytotoxic effects of PSE and AKBE are specific to DLBCL cells. Therefore, we expect limited side effects when these plant extracts are administered to DLBCL patients. Our JC-1 assays demonstrate that the pro-apoptotic effects of these plant extracts are produced by a reduction of anti-apoptotic Bcl-2 family members and, thereby, disruption of the mitochondrial membrane potential. Moreover, PSE and AKBE induce cell death independently of Myc, whose abnormalities are frequently observed in patients with DLBCL and are associated with poor prognosis. Our findings reveal hitherto uncharacterized pro-apoptotic effects of PSE and AKBE in DLBCL. Isolation of single compounds with anti-lymphoma activities should be pursued further.

• 모자간호학회지
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• v.2 no.1
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• pp.45-54
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• 1992

The purpose of this study was to explore the stressors in pediatric intensive care unit and impaired psychological responses of children after open heart surgery. Sixteen children aged 6 to 11, who were admitted to the hospital for open heart surgery during the period from July, 1991 to February, 1992 were the subjects of the study. Observations, drawings, and interviews were used to collect data for study. Behavioral responses about intensive care unit phenomena were analyzed according to the 4 categories identified to assess children's perceived stressors in ICU. Impaired psychological responses were examined using observational and interview data. Drawings were analyzed by content and color by this researcher and validated by the psychologist. The findings were as follows : 1. The most frequently perceived stressors by children in ICU were the physical stressors causing pain and discomfort(68.5%). It was followed by social stressors which denote disruption of relationship with family and friends(13.0% ), environmental stressors which denote unfamiliar surroundings, noise, staff, and other patients (11.2%), and psychological stressors which denote factors affecting self-esteem such as inability to communicate and inadquate knowledge of the situation (7.3%). 2. 81.3% of the children showed of least one of the impaired psychological responses. Three children (18.8%) experienced time disorientation. An equal number of subject experienced perceptual illusion. Two children(12.5%) experienced hallucination. Vivid dream about ICU phenomena was reported by 2 children. Seven children(43.8%) were identified as having exaggerated fear. They feared about oxygen mask and ICU environment in general. Seven children(43.8%) experienced impairment of memory about treatments, procedures, and environment of ICU. 3. The analysis of children's drawing revealed that 56.3% of children experienced fear in the ICU. 75% of children included nurses in the drawings and 62.5% of children drew other children. 81.3% of children drew and identified himself in the drawing. The colors used most by children were green, purple, and brown. From this result, it is recommended to prepare children before open heart surgery to reduce their stressors and impaired psychological responses in ICU.