• Journal of Life Science
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• v.26 no.2
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• pp.265-274
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• 2016

Toxin-antitoxin (TA) systems are ubiquitous genetic modules that are evolutionally conserved in bacteria and archaea. TA systems composed of an intracellular toxin and its antidote (antitoxin) are currently classified into five types. Commonly, activation of toxins under stress conditions inhibits diverse cellular processes and consequently induces cell death or reversible growth inhibition. These effects of toxins play various physiological roles in such as regulation of gene expression, growth control (stress response), programmed cell arrest, persister cells, programmed cell death, phage protection, stabilization of mobile genetic elements or postsegregational killing of plasmid-free cells. Accordingly, bacterial TA systems are commonly considered as stress-responsive genetic modules. However, molecule screening for activation of toxin in TA system is available as development of antimicrobial agents. In addition, cytotoxic effect induced by toxin is used as effective cloning method with antitoxic effect of antitoxin; consequently cells containing cloning vector inserted a target gene can survive and false-positive transformants are removed. Also, TA system is applicable to efficient single protein production in biotechnology industry because toxins that are site-specific ribonuclease inhibit protein synthesis except for target protein. Furthermore, some TA systems that induce apoptosis in eukaryotic cells such as cancer cells or virus-infected cells would have a wide range of applications in eukaryotes, and it will lead to new ways of treating human disease. In this review, we summarize the current knowledge on bacterial TA systems and their applications.

• The Korean Journal of Blood Transfusion
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• v.23 no.2
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• pp.169-172
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• 2012

Lutheran a antigen ($Lu^a$) is detected in 6 to 8% of Caucasians and Africans. In Korean and other Asian populations, it is very rare or nearly absent. Therefore, although $Lu^a$ has a considerable immunizing capacity, sensitization to $Lu^a$ is a rare event. Here we report on a rare case of anti-$Lu^a$ in a 70 year-old female patient with Lu (a-/b+) phenotype and review the relevant literature. Due to the paucity of $Lu^a$ positive panel cells in antibody screening and identification tests, detection of this rare antibody to $Lu^a$ antigen is not feasible. Therefore, we should keep in mind the possibility of the misleading false negative result in detection of antibody to this low incidence antigen.

• Journal of Breast Cancer
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• v.21 no.4
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• pp.433-4341
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• 2018

Purpose: This study aimed to evaluate the effects of sentinel lymph node biopsy (SLNB) on recurrence and survival after neoadjuvant chemotherapy (NAC) in breast cancer patients with cytology-proven axillary node metastasis. Methods: We selected patients who were diagnosed with invasive breast cancer and axillary lymph node metastasis and were treated with NAC followed by curative surgery between January 2007 and December 2014. We classified patients into three groups: group A, negative sentinel lymph node (SLN) status and no further dissection; group B, negative SLN status with backup axillary lymph node dissection (ALND); and group C, no residual axillary metastasis on pathology with standard ALND. Results: The median follow-up time was 51 months (range, 3-122 months) and the median number of retrieved SLNs was 5 (range, 2-9). The SLN identification rate was 98.3% (234/238 patients), and the false negative rate of SLNB after NAC was 7.5%. There was no significant difference in axillary recurrence-free survival (p=0.118), disease-free survival (DFS; p=0.578) or overall survival (OS; p=0.149) among groups A, B, and C. In the subgroup analysis of breast pathologic complete response (pCR) status, there was no significant difference in DFS (p=0.271, p=0.892) or OS (p=0.207, p=0.300) in the breast pCR and non-pCR patients. Conclusion: These results suggest that SLNB can be feasible and oncologically safe after NAC for cytology-determined axillary node metastasis patients and could help reduce arm morbidity and lymphedema by avoiding ALND in SLN-negative patients.

• Journal of Breast Cancer
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• v.21 no.4
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• pp.453-462
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• 2018

Purpose: This study aimed to compare the diagnostic performance of contrast-enhanced digital mammography (CEDM) and contrast-enhanced magnetic resonance imaging (CEMRI) in preoperative evaluations, and to evaluate the effect of each modality on the surgical management of women with breast cancer. Methods: This single-center, prospective study was approved by the Institutional Review Board, and informed consent was obtained from all patients. From November 2016 to October 2017, 84 patients who were diagnosed with invasive carcinoma (69/84) and ductal carcinoma in situ (15/84), and underwent both CEDM and CEMRI, were enrolled. Imaging findings and surgical management were correlated with pathological results and compared. The diagnostic performance of both modalities in the detection of index and secondary cancers (multifocality and multicentricity), and occult cancer in the contralateral breast, was compared. The authors also evaluated whether CEDM or CEMRI resulted in changes in the surgical management of the affected breast due to imaging-detected findings. Results: Eighty-four women were included in the analysis. Compared with CEMRI, CEDM demonstrated a similar sensitivity (92.9% [78/84] vs. 95.2% [80/84]) in detecting index cancer (p=0.563). For the detection of secondary cancers in the ipsilateral breast and occult cancer in the contralateral breast, no significant differences were found between CEDM and CEMRI (p=0.999 and p=0.999, respectively). Regarding changes in surgical management, CEDM resulted in similar changes compared with CEMRI (30.9% [26/84] vs. 29.7% [25/84], p=0.610). Regarding changes in surgical management due to false-positive findings, no significant differences were found between CEDM and CEMRI (34.6% [9/26] vs. 44.0% [11/25], p=0.782). Conclusion: CEDM demonstrated a diagnostic performance comparable with CEMRI in depicting index cancers, secondary cancers, and occult cancer in the contralateral breast. CEDM demonstrated similar changes in surgical management compared with CEMRI.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.231-239
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• 2021

The purpose of this study was to understand how a dental hygienist is viewed by students in terms of both image and job /employment perception using structural equations. This together with the incorporation of available online information would help in collating the necessary data for ensuring adequate manpower of dental hygienists' in the future. The collected data were analyzed using SPSS Statistics 24.0 and AMOS Graphics 21.0 statistics packages. It was found that students who perceive employment positively have a positive image of a dental hygienist even if a new infectious disease were to occur. They appreciate that a negative image of a dental hygienist's job during an epidemic could cause a negative perception of employment as a dental hygienist. Those who think negatively of the internet as a source of information believe that the internet has a lot of false information, is harmful, promotes anxiety, and has been shown to promote negative perceptions about employment as a dental hygienist. Those who think positively of internet information think that dental hygienists are susceptible to infection and can transmit infection, which has been shown to negatively affect their perception of employment. In conclusion, it is important to form an image of a dental hygienist through the recognition of the correct internet information in the period of new infectious diseases.

• The Journal of Korean Philosophical History
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• no.39
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• pp.85-114
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• 2013

Traditional values refer to one's attitudes or perspectives developed by negotiating with oneself, others, society, world, nature and universe, which include thoughts on what is right, desirable, and what is dos and don'ts. The purpose of this study was to investigate values which Korean people traditionally emphasized, and their changes by epochal situation focused on the Choson Era. Also, this study intended to assist in finding values and meaning which should be passed down and manifested in contemporary society based on the study results. In this context, I select some positive values in the background of the Joseon dynasty. As traditional values or ethics in Korea destroyed and distorted going through the period of Japanese colonialism, all the existing social culture and traditional culture were denied, which resulted in vanishing common value which led community for several hundred years. The loss of common value caused community destruction and collapse, and made Korean people seek to survival, success and advancement in life as suffering from severe conflict of values. Experience of hollow state of mind caused by historical and cultural severance left distorted and degenerated values to Korea people, which made them pursue false values without realizing true meaning of traditional values. The true meaning of traditional values should be universal no matter how society changes, and could be milestone to contemporary people wandering aimlessly. Realizing and reconsidering the meaning of traditional values to found comtemporary values of Korean people by reflecting on history can produce significant results beyond age-old debate about East or West, and tradition or modernity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.41-52
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• 2010

Message authentication is an essential security element in vehicular ad-hoc network(VANET). For a secure message authentication, integrity, availability, privacy preserving skill, and also efficiency in various environment should be provided. RAISE scheme has been proposed to provide efficient message authentication in the environment crowded with lots of vehicles and generally considered to be hard to provide efficiency. However, as the number of vehicles communicating in the area increases, the overhead is also incurred in proportion to the number of vehicles so that it still needs to be reduced, and the scheme is vulnerable to some attacks. In this paper, to make up for the vulnerabilities in dense vehicular communication network, we propose a more secure and efficient scheme using a process that RSU(Road Side Unit) transmits the messages of neighbor vehicles at once with Bloom Filter, and timestamp to protect against replay attack. Moreover, by adding a handover function to the scheme, we simplify the authentication process as omitting the unnecessary key-exchange process when a vehicle moves to other area. And we confirm the safety and efficiency of the scheme by simulating the false positive probability and calculating the traffic.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.531-540
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• 2021

As cyber attacks and crimes increase exponentially and hacking attacks become more intelligent and advanced, hacking attack methods and routes are evolving unpredictably and in real time. In order to reinforce the enemy's responsiveness, this study aims to propose a method for developing an artificial intelligence-based security control platform by building a next-generation security system using artificial intelligence to respond by self-learning, monitoring abnormal signs and blocking attacks.The artificial intelligence-based security control platform should be developed as the basis for data collection, data analysis, next-generation security system operation, and security system management. Big data base and control system, data collection step through external threat information, data analysis step of pre-processing and formalizing the collected data to perform positive/false detection and abnormal behavior analysis through deep learning-based algorithm, and analyzed data Through the operation of a security system of prevention, control, response, analysis, and organic circulation structure, the next generation security system to increase the scope and speed of handling new threats and to reinforce the identification of normal and abnormal behaviors, and management of the security threat response system, Harmful IP management, detection policy management, security business legal system management. Through this, we are trying to find a way to comprehensively analyze vast amounts of data and to respond preemptively in a short time.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.235-241
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• 2022

According to the World Water Development Report 2015 released by the United Nations, drinking water is expected to decrease by 40% by 2030. This does not mean that the amount of water decreases, but rather that the water source is contaminated due to environmental pollution. Because microbes are deeply related to water quality, the analysis of microbe is very important for water quality management. While the most common method currently used for microbial analysis is microscopic examination of the shape and feature after cell culture, as the gene analysis technology advances, quantitative polymerase chain reaction (qPCR) can be applied to the microscopic microbiological analysis, and the application method has been studied. Among them, a reverse transcription (RT) step enables the analysis of RNA by RT-PCR. Integrated cell culture (ICC)-qPCR shortens the test time by using it with microbial culture analysis, and viability qPCR can reduce the false positive errors of samples collected from natural water source. Multiplex qPCR for improved throughput, and microfluidic qPCR for analysis with limited amount of sample has been developed In this paper, we introduce the case, principle and development direction of the qPCR method applied to the analysis of microorganisms.

• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.2
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• pp.32-36
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• 2022

Purpose There are reports that the COVID-19 vaccine causes false positive uptake of axillary lymph nodes. Therefore, this paper intends to evaluate the change in SUVmax of axillary lymph nodes with the period after the COVID-19 vaccination. Materials and Methods In 134 breast cancer patients who were tested for ¹⁸F-FDG PET/CT at Severance hospital, 3.7 MBq/kg of ¹⁸F-FDG was intravenously injected and scanned for 2 minutes per bed after 60 minutes. The equipment was Discovery 600 (GE Healthcare, MI, USA). The period was divided into four groups, 0 to 2 weeks, 3 to 6 weeks, 7 to 10 weeks, and 11 weeks or more. SUVmax was measured after checking the uptake of axillary lymph nodes on the ipsilateral side of vaccination and the Kruskal-Wallis test was performed using SPSS Statistics 28 (IBM Corp., Armonk, NY, USA). Results From 0 to 2 weeks groups to 11 weeks or more group, the average of SUVmax was measured in the order of 5.52, 2.85, 1.82, and 1.7. As a result of the Kruskal-Wallis test, there was a significant difference between 0 to 2 weeks group from all other groups (P < 0.05), and there was no significant difference between the remaining three groups. Conclusion The SUVmax of axillary lymph nodes decreased over the period after the COVID-19 vaccination and no significant difference was found after 3 weeks of vaccination. Therefore, it is recommended to record COVID-19 vaccination information before examination.