• 정보보호학회논문지
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• 제32권2호
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• pp.255-266
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• 2022

메신저 애플리케이션은 서버로 메시지 노출을 방지하고자 종단간 암호화를 자체적으로 적용하였다. 안전하고 효율적인 메시지 통신을 위해 종단간 암호화가 적용된 그룹 메시징 프로토콜인 MLS (Message Layer Security)의 표준화가 진행 중이다. 본 논문은 MLS의 동작 과정과 보안 요구사항을 기반으로 안전성 점검을 수행한다. 메신저 통신에서 필수 보안 요구사항인 중앙 서버에 대한 기밀성은 서버 관리자에 의해 쉽게 위반될 수 있다. 그룹의 통신 내용이 궁금한 서버 관리자를 curious admin으로 정의하고 관리자가 MLS에서 그룹키를 획득하는 공격을 제시한다. 메신저 애플리케이션 사용자에게 서버가 언제든 통신 내용을 열람할 수 있다는 점을 상기시킨다. Curious admin 공격을 방지하기 위해 서버를 거치지 않고 사용자 간 인증하는 방안에 대해 논의한다.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.338-351
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• 2003

UV radiation is the most dangerous stress factor among permanent environmental impacts on human skin. Consequences of UV exposure are aberrant tissue architecture, alterations in skin cells including functional changes. Nowadays new kinds of outdoor leisure-time activities and changing environmental conditions make the question of sun protection more important than ever. It is necessary to recognize that self-confident consumers do not consider to change their way of life, they demand modern solutions on the basis of new scientific developments. In the past one fundamental principle of cosmetics was the use of physical and organic filter systems against damaging UV-rays. Today new research results demonstrate that natural protecting cell mechanisms can be activated. Suitable biological actives strongly support the protection function not from the surface but from the inside of the cell. A soy seed preparation (SSP) was proven to stimulate natural skin protective functions. The major functions are an increased energy level and the prevention of DNA damage. These functions can I be defined as biological UV protection. The tumor suppressor protein p53 plays a key role in the regulation of DNA repair. p53 must be transferred into the phosphorylated form to work as transcription factor for genes which are regulating the cell cycle or organizing DNA repair. A pretreatment with SSP increases the phosphorylation rate of p53 of chronically UV-irradiated human keratinocytes significantly. According to the same test procedure SSP induces a dramatic increase in the expression of the tumor suppressor protein p14$^{ARF}$ that is supporting the p53 activity by blocking the antagonist of p53, the oncoprotein Mdm2. Mdm2, a ubiquitin E3-ligase, downregulates p53 and at the same time it prevents phosphorylation of p53. The positive influence of the tumor suppressor proteins explains the stimulation of DNA repair and prevention of sunburn cell formation by SSP, which was proven in cell culture experiments. In vivo the increased skin tolerance against UV irradiation by SSP could be confirmed too. We have assumed, that an increased repair potential provides full cell functionality.y.

• International Journal of Oral Biology
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• 제48권1호
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• pp.1-7
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• 2023

Oral squamous cell carcinoma (OSCC), which accounts for approximately 90% of oral cancers, has a high rate of local recurrence and a poor prognosis despite improvements in treatment. Exosomes released from OSCC cells promote cell proliferation and metastasis. Although it is clear that the biogenesis of exosomes is mediated by the endosomal sorting complex required for transport (ESCRT) machinery, the gene expression pattern of ESCRT, depending on the cell type, remains elusive. The exosomal release from the human OSCC cell lines, HSC-3 and HSC-4, and their corresponding gefitinib-resistant sub-cell lines, HSC-3/GR and HSC-4/GR, was assessed by western blot and flow cytometry. The levels of ESCRT machinery proteins, including Hrs, Tsg101, and Alix, and whole-cell ubiquitination were evaluated by western blot. We observed that the basal level of exosomal release was higher in HSC-3/GR and HSC-4/GR cells than in HSC-3 and HSC-4 cells, respectively. Long-term gefitinib exposure of each cell line and its corresponding gefitinib-resistant sub-cell line differentially induced the expression of the ESCRT machinery. Furthermore, whole-cell ubiquitination and autophagic flux were shown to be increased in gefitinib-treated HSC-3 and HSC-4 cells. Our data indicate that the expression patterns of the ESCRT machinery genes are differentially regulated by the characteristics of cells, such as intracellular energy metabolism. Therefore, the expression patterns of the ESCRT machinery should be considered as a key factor to improve the treatment strategy for OSCC.

• Advances in nano research
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• 제12권3호
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• pp.291-300
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• 2022

The behavior of hydrogen species on the surface of the catalyst during the Lewis acid transformation to form Brønsted acid sites over the spherical silica-supported WO_x catalyst was investigated. To understand the structure-activity relationship of Lewis acid transformation and hydrogen bonding interactions, we explore the potential of using the in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) with adsorbed ammonia and hydrogen exposure. From the results of in situ DRIFTS measurements, Lewis acid sites on surface catalysts were transformed into new Brønsted acid sites upon hydrogen exposure. The adsorbed NH₃ on Lewis acid sites migrated to Brønsted acid sites forming NH⁴⁺. The results show that the dissociated H atoms present on the catalyst surface formed new Si-OH hydroxyl species - the new Brønsted acid site. Besides, the isolated Si-O-W species is the key towards H-bond and Si-OH formation. Additionally, the H atoms adsorbed surrounding the Si-O-W species of mono-oxo O=WO₄ and di-oxo (O=)₂WO₂ species, where the Si-O-W species are the main species presented on the Inc-SSP catalysts than that of the IWI-SSP catalysts.

• Clinical and Experimental Reproductive Medicine
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• 제51권1호
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• pp.28-41
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• 2024

Objective: Chronic scrotal hyperthermia (SHT) can lead to serious disorders of the male reproductive system, with oxidative stress playing a key role in the onset of these dysfunctions. Thus, we evaluated the impact of caffeine, a potent antioxidant, on cellular and tissue disorders in mice with chronic SHT. Methods: In this experimental study, 56 adult male NMRI mice were allocated into seven equal groups. Apart from the non-treated control group, all were exposed to heat stress. Two groups, termed "preventive" and "curative," were orally administered caffeine. The preventive mice began receiving caffeine immediately prior to heat exposure, while for the curative group, a caffeine regimen was initiated 15 consecutive days following cessation of heat exposure. Each treated group was subdivided based on pairing with a positive control (Pre/ curative [Cur]+PC) or a vehicle (Pre/Cur+vehicle). Upon conclusion of the study, we assessed sperm characteristics, testosterone levels, stereological parameters, apoptosis, antioxidant and oxidant levels, and molecular markers. Results: Sperm parameters, testosterone levels, stereological parameters, biochemical factors (excluding malondialdehyde [MDA]), and c-kit gene expression were significantly elevated in the preventive and curative groups, especially the former, relative to the other groups. Conversely, expression levels of the heat shock protein 72 (HSP72) and nuclear factor kappa beta (NF-κβ) genes, MDA levels, and apoptotic cell density were markedly lower in both caffeine-treated groups relative to the other groups, with more pronounced differences observed in the preventive group. Conclusion: Overall, caffeine attenuated cellular and molecular abnormalities induced by heat stress in the testis, particularly in the mice treated under the preventive condition.

• 한국산업보건학회지
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• 제29권2호
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• pp.141-158
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• 2019

Objectives: An adverse outcome pathway is a biological pathway that disturbs homeostasis and causes toxicity. It is a conceptual framework for organizing existing biological knowledge and consists of the molecular initiating event, key event, and adverse output. The AOP concept provides intuitive risk identification that can be helpful in evaluating the carcinogenicity of chemicals and in the prevention of cancer through the assessment of chemical carcinogenicity predictions. Methods: We reviewed various papers and books related to the application of AOPs for the prevention of occupational cancer. We mainly used the internet to search for the necessary research data and information, such as via Google scholar(http://scholar.google.com), ScienceDirect(www.sciencedirect.com), Scopus(www.scopus. com), NDSL(http: //www.ndsl.kr/index.do) and PubMed(http://www.ncbi.nlm.nih.gov/pubmed). The key terms searched were "adverse outcome pathway," "toxicology," "risk assessment," "human exposure," "worker," "nanoparticle," "applications," and "occupational safety and health," among others. Results: Since it focused on the current state of AOP for the prediction of toxicity from chemical exposure at work and prospects for industrial health in the context of the AOP concept, respiratory and nanomaterial hazard assessments. AOP provides an intuitive understanding of the toxicity of chemicals as a conceptual means, and it works toward accurately predicting chemical toxicity. The AOP technique has emerged as a future-oriented alternative to the existing paradigm of chemical hazard and risk assessment. AOP can be applied to the assessment of chemical carcinogenicity along with efforts to understand the effects of chronic toxic chemicals in workplaces. Based on these predictive tools, it could be possible to bring about a breakthrough in the prevention of occupational and environmental cancer. Conclusions: The AOP tool has emerged as a future-oriented alternative to the existing paradigm of chemical hazard and risk assessment and has been widely used in the field of chemical risk assessment and the evaluation of carcinogenicity at work. It will be a useful tool for prediction, and it is possible that it can help bring about a breakthrough in the prevention of occupational and environmental cancer.

• 한국융합학회논문지
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• 제13권4호
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• pp.359-372
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• 2022

본 연구는 2021년 1년간의 유튜브 인기급상승 데이터를 활용하여 장/단기노출 20개 채널의 특징을 비교함으로 인기급상승에 장기 노출될 수 있는 유튜브 콘텐츠 전략을 도출하고자 하였다. 먼저 피어슨 상관분석을 통해 제목 글자 수, 태그 수와 같은 여러 요소들이 장기노출과 연관성이 있음을 파악하고 이를 지표로 설정해 콘텐츠 특징을 비교분석하였다. 분석 결과, 1)과도한 특수문자를 사용하지 않은 약 40-45글자 정도의 '영상 제목', 2)10분 이내의 '영상 길이', 3)2-3문장, SNS 정보 기입, 3개 정도의 핵심 태그를 포함한 '영상 설명' 등의 콘텐츠 전략을 활용할 때 인기급상승에 장기 노출될 수 있음을 알 수 있었다. 또한, 텍스트마이닝을 통해 (먹방, mukbang), (역대급, 레전드) 등의 핵심 태그 쌍을 도출하였고, 본 태그를 동시에 설정한다면 더욱 효과적이라는 결과를 얻었다. 이러한 전략을 통해 콘텐츠가 인기급상승에 장기노출 된다면 채널은 세계적으로 확산되어 구독자, 조회 수 확보 등 다방면의 이점을 가져올 것이며, 기업 측면에서는 채널의 글로벌성을 평가할 수 있는 지표로 활용될 수 있을 것이다.

• 대한임상독성학회지
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• 제16권2호
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• pp.131-140
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• 2018

Purpose: The National Emergency Medical Center has been running a project for the storage and delivery of antidotes for acute poisoning patients of the Department of Health and Welfare, Korea. This study analyzed the results of this project over the past two years. Methods: The requests received by the National Emergency Medical Center and the data on the delivery process were analyzed. Results: This study analyzed a total of 121 patients with acute poisoning, who were requested to receive an antidote reserved at 20 key hospitals in 2015-2017, and whose age was $52.3{\pm}23.5\;years$; old; 54 were women. Intentional poisoning were 58.7%, and the home was the most common place of exposure (66.9%). The toxic substances were chemicals (32.2%), pesticides (27.3%), medicines (24.8%), and snake venom (4.1%). The patient's poison severity score was $2.4{\pm}0.7$ (median 3) indicating moderate-to-severe toxicity. Antidote administration was the cases treated in key hospitals 67.8% (82/121), in which transferred patients accounted for 57.3% (47/82). After receiving an antidote request from a hospital other than the key hospitals, the median was 75.5 minutes (range 10 to 242 minutes) until the antidote reached the patient, and an average of 81.5 minutes was required. The results of emergency care were intensive care unit (70.3%), general wards (13.2%), death (10.7%), and discharge from emergency department (5.0%). Conclusion: This study showed that the characteristics of acute poisoning patients treated with an antidote were different from previous reports of poisoned patients in the emergency department, and basic data on the time required for delivery from key hospitals was different.

• 한국인터넷방송통신학회논문지
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• 제16권6호
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• pp.147-152
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• 2016

배선 작업이 어려운 공장 환경에서 설비의 상태를 모니터링하는 시스템을 구축하기위해 배포와 설치가 쉬운 무선센서 네트워크가 적합하다. 지그비는 다른 무선 통신 프로토콜에 비해 저가격, 저전력 특징을 가지고 있어 다수의 노드를 필요로 하는 모니터링 시스템에 적용하기 적합하다. 지그비 통신은 모든 프로토콜 계층이 서로 신뢰하는 OTM을 기반으로 하고 있기 때문에 디바이스 간에 암호화 보안이 필요하다. 각 노드간의 통신에 있어서 노드 인증을 보장하고, 각 노드가 관리하고 있는 비밀 정보의 노출을 최소화 해야 한다. 공장의 설비는 배포 위치가 규칙적이고 고정적이다. 공장 환경에서 센서로부터 수집되는 정보와 센서 노드에 연결되어 있는 엑츄에이터 제어 정보를 보호하기 위해 설비의 배포 환경과 유사한 이차원 그리드 기반 키 선분배 기법을 기반으로 하는 암호화 기법을 제안한다.

• 한국발생생물학회지:발생과생식
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• 제14권1호
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• pp.35-41
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• 2010

Mammalian reproduction is regulated by a feedback circuit of the key reproductive hormones such as GnRH, gonadotropin and sex steroids on the hypothalamic-pituitary-gonadal axis. In particular, the onset of female puberty is triggered by gain of a pulsatile pattern and increment of GnRH secretion from hypothalamus. Previous studies including our own clearly demonstrated that genistein (GS), a phytoestrogenic isoflavone, altered the timing of puberty onset in female rats. However, the brain-specific actions of GS in female rats has not been explored yet. The present study was performed to examine the changes in the activities of GnRH neurons and their neural circuits by GS in female rats. Concerning the drug delivery route, intracerebroventricular (ICV) injection technique was employed to eliminate the unwanted actions on the extrabrain tissues which can be occurred if the testing drug is systemically administered. Adult female rats (PND 100, 210-230 g BW) were anaesthetized, treated with single dose of GS ($3.4{\mu}g$/animal), and sacrificed at 3 hrs post-injection. To determine the transcriptional changes of reproductive hormone-related genes in hypothalamus, total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). ICV infusion of GS significantly raised the transcriptional activities of enhanced at puberty1 (EAP-1, p<0.05), glutamic acid decarboxylase (GAD67, p<0.01) which are known to modulate GnRH secretion in the hypothalamus. However, GS infusion could not change the mRNA level of nitric oxide synthase 2 (NOS-2). GS administration significantly increased the mRNA levels of KiSS-1 (p<0.001), GPR54 (p<0.001), and GnRH (p<0.01) in the hypothalami, but decreased the mRNA levels of LH-$\beta$ (p<0.01) and FSH-$\beta$ (p<0.05) in the pituitaries. Taken together, the present study indicated that the acute exposure to GS could directly activate the hypothalamic GnRH modulating system, suggesting the GS's disrupting effects such as the early onset of puberty in immature female rats might be derived from premature activation of key reproduction related genes in hypothalamus-pituitary neuroendocrine circuit.