• 한국통신학회논문지
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• 제35권8B호
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• pp.1129-1140
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• 2010

무선 메쉬 네트워크는 기존 무선 네트워크의 단점을 해결하기 위한 차세대 기술로서 많은 연구가 이루어졌다. 특히 Mobile WiMAX 기반의 무선 메쉬 네트워크는 다양한 장점을 지녀 더욱 주목 받고 있다. Mobile WiMAX 표준에서는 MIP와 PMIP를 기반으로 하는 두 개의 3계층 핸드오버 방안을 제공한다. MIP 기반 핸드오버는 많은 핸드오버 메시지 유발로 인한 긴 핸드오버 지연 단점을 지닌 반면, PMIP 기반 핸드오버는 이동 노드가 자신의 핸드오버에 관여치 않아, 무선 구간의 핸드오버 메시지를 줄이는 장점을 지녀 Mobile WiMAX의 3계층 핸드오버에 좀 더 효과적이다. 하지만 Mobile WiMAX에서 제공하는 기존의 PMIP 기반 핸드오버는 2계층 핸드오버 완료 후에 바인딩을 수행하기 때문에 여전히 핸드오버 지연 발생 문제점을 가지고 있다. 따라서, 본 논문에서는 2계층 핸드오버 완료 전에 수행 되는 고속 바인딩 과정을 통해 핸드오버 지연을 줄이는 PMIP 기반 무선 메쉬 네트워크에서의 고속 3계층 핸드오버 방안을 제안한다. 제안 방안은 기존 PMIP 기반 핸드오버 방안의 문제점을 개선했으며 이는 시뮬레이션 결과를 통해 증명하였다.

• Journal of Ginseng Research
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• 제42권2호
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• pp.165-174
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• 2018

Background: Extended endoplasmic reticulum (ER) stress may initiate apoptotic pathways in cancer cells, and ER stress has been reported to possibly increase tumor death in cancer therapy. We previously reported that caspase-8 played an important role in compound K-induced apoptosis via activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation in HL-60 human leukemia cells. The mechanisms leading to apoptosis in A549 and SK-MES-1 human lung cancer cells and the role of ER stress have not yet been understood. Methods: The apoptotic effects of compound K were analyzed using flow cytometry, and the changes in protein levels were determined using Western blot analysis. The intracellular calcium levels were monitored by staining with Fura-2/AM and Fluo-3/AM. Results: Compound K-induced ER stress was confirmed through increased phosphorylation of $eIF2{\alpha}$ and protein levels of GRP78/BiP, XBP-1S, and $IRE1{\alpha}$ in human lung cancer cells. Moreover, compound-K led to the accumulation of intracellular calcium and an increase in m-calpain activities that were both significantly inhibited by pretreatment either with BAPTA-AM (an intracellular $Ca^{2+}$ chelator) or dantrolene (an RyR channel antagonist). These results were correlated with the outcome that compound K induced ER stress-related apoptosis through caspase-12, as z-ATAD-fmk (a specific inhibitor of caspase-12) partially ameliorated this effect. Interestingly, 4-PBA (ER stress inhibitor) dramatically improved the compound K-induced apoptosis. Conclusion: Cell survival and intracellular $Ca^{2+}$ homeostasis during ER stress in human lung cancer cells are important factors in the induction of the compound K-induced apoptotic pathway.

• 대한임상검사과학회지
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• 제54권3호
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• pp.179-191
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• 2022

본 연구는 공중보건에 위협이 되고 있는 carbapenemase 유전자형 중 bla_KPC, bla_NDM, bla_IMP, bla_VIM, bla_OXA-48-like 유전자의 표현형적 검사 및 분자진단으로 검출하고 관련 유전자 분포 양상에 대해 알아보았다. 표현형적 검사결과 MHT는 41균주 모두에서 양성을 확인하고, CIT는 meropenem+PBA는 18균주 및 meropenem+EDTA에서 8균주의 양성을 확인하였다. PCR 결과 bla_KPC 28균주, bla_NDM 25균주, bla_IMP 5균주, bla_VIM 1균주, bla_OXA-48-like 13균주에서 증폭 산물을 확인하였다. 또한 bla_KPC+bla_NDM 7균주, bla_KPC+bla_IMP 1균주, bla_NDM+bla_OXA-48-like 1균주, bla_NDM+bla_VIM 1균주, bla_KPC+bla_NDM+bla_IMP 4균주, bla_KPC+bla_NDM+bla_OXA-48-like 4균주를 확인하였다. 실시간 중합효소 연쇄반응을 이용한 융해 곡선 분석결과는 PCR 결과와 100% 일치함을 확인하였다. 결론적으로 real-time PCR을 이용한 신속하고 특이성이 높은 CRE 조기진단을 통한 유전자 확인은 제한된 치료 옵션과 높은 사망률로 공중 보건 위협을 고조하는 CRE의 감시, 진단 및 치료를 개선할 수 있으며 전염을 방지하기 위한 효과적인 항균 치료 및 시기적절한 감염 통제가 가능할 것으로 사료된다.

• Journal of Preventive Medicine and Public Health
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• 제24권2호
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• pp.181-194
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• 1991

This study intended to obtain an useful information on the prevalence of subjective symptoms, and to clarify the interrelationships between blood lead and lead related symptoms in low level lead exposure. The 93 male workers exposed to lead and 56 male nonexposed workers were examined for their blood lead(PBB), Zinc-protoporphy(ZPP), hemoglobin(HB) and personnal history, and completed 15 questionnaires related to symptoms of lead absorption : also measured lead concentration in air (PBA) in the workplace. The results obtained were as follows ; 1. The means of blood lead (PBB), blood ZPP and hemoglobin (HB) among workers exposed to lead were $26.1{\pm}8.8{\mu}g/dl,\;28.3{\pm}26.0{\mu}g/dl$ and $16.2{\pm}1.2g/dl$ : whereas those of nonexposed workers were $18.7{\pm}5.1{\mu}g/dl,\;20.6{\pm}8.7{\mu}g/dl$ and $17.3{\pm}1.1g/dl$. The means of above three indicies between two groups showed significant difference statistically (p<0.05). 2. The means of blood lead (PBB), blood ZPP and hemoglobin of workers exposed .to different lead concentration in air were as follows : When it was below $25{\mu}g/m^3$, the indices were $24.7{\pm}79,\;26.1{\pm}26.8{\mu}g/dl\;and\;16.4{\pm}1.1g/dl$ respectively : These indices were $27.1{\pm}8.5,\;23.9{\pm}10.92{\mu}g/dl\;and\;16.2{\pm}1.3g/dl$ when the lead concentration in air was $25{\sim}50{\mu}g/m^3$ : and they were $3.4{\pm}9.3,\;42.3{\pm}31.3{\mu}g/dl\;and\;15.5{\pm}1.2g/dl$ when the concentration of lead was above $50{\mu}g/m^3$. Although there were statistical difference in blood lead and hemoglobin among three different lead concentration in air, there was no statistical difference of blood ZPP among the three groups with different exposure levels (p>0.05). 3. The most frequent by complained symptom was 'Generalized weakness and fatigue', and fewest symptom was 'Intermittent pains in abdomen' 4. Only two symptoms out of fifteen symptoms checked by themselves revealed significant difference between exposed and nonexposed groups. These were 'Intermittent pains of abdomen' and 'Joint pain or arthralgia' (p<0.05), No positive correlation was found between the levels of blood lead and symptom groups categorized as gastrointestinal, neuromuscular and constitutional symptoms, 5. Blood lead (r=0.3995) and ZPP (r=0.2837) showed statistically significant correlation with mean lead concentration in air, whereas correlations were not demonstrated between blood lead and lead related symptoms or blood ZPP and lead related symptoms. 6. Blood lead (PBB) and ZPP showed association (r=0.2466) and the equation PBB=23.75+0.0842 ZPP was derived. 7. On stepwise multiple regression, using blood lead level as a dependent variable and ZPP, hemoglobin (HB), age, work duration (WD) and symptom prevalence as a independent variables, only ZPP significantly contributed a lot to blood lead level. 8. While the ZPP measurement was found to be a good indicator in evaluating health effect of lead absorption in low level lead exposure, lead related symptoms were not sensitive enough to evaluate of lead absorption in low level exposure.

• 생명과학회지
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• 제30권3호
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• pp.285-290
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• 2020

구제역바이러스(FMDV)는 Picornaviridae 과의 Aphthovirus 속의 한 종류이며, 야생과 가축의 소와 돼지에 감염한다. FMDV는 감염 조직에서 중증의 염증반응을 포함한 다양한 임상적 증후들을 일으킨다. FMDV 게놈 RNA는 약 8.3 kb 길이의 양성-단일 가닥을 가지고 있으며, 하나의 긴 단백질 번역틀(ORF)을 만든다. 이 ORF는 바이러스의 단백질가수분해효소에 의해서 구조단백질과 비구조단백질로 나누어진다. FMDV의 FMDV 2C 단백질은 FMDV 유전자에서 만들어지는 비구조단백질로서 염증과 세포사를 포함한 FMD 병리 과정과 바이러스 복제에서 중요한 역할을 한다. 이 연구에서 우리는 FMDV 2C가 염증 유도 사이토카인인 tumor necrosis factor alpha (TNFα)의 세포내 발현을 유도하는 가능성을 검토하였다. FMDV 2C의 돼지 세포인 IBRS-2 세포내 발현은 TNFα의 유전자 발현 조절 부위인 프로모터의 활성화를 이용하여 전사수준에서 TNFα의 mRNA와 단백질 생성을 증가시켰다. 추가적으로, 소포체 스트레스를 감소시키는 화학물질인 4-phenylbutyric acid (4-PBA) 처리는 FMDV 2C에 의해 유도된 TNFα 발현을 감소시켰다. 소포체 스트레스 반응을 매개하는 전사인자의 한 종류인 ATF4는 TNFα 프로모터의 활성을 유도하고, TNFα의 mRNA와 단백질 발현을 증가시켰다. 하지만, ATF4의 기능 결핍 돌연변이체 단백질의 발현은 FMDV 2C에 의한 TNFα 생성을 유도하지 못하였다. 이들 결과들은 FMDV FMDV 2C 단백질이 ATF4-매개 TNFα 발현을 통해 임상적 염증반응을 증가시키고, 이는 소포체 스트레스의 유도와 연관되어있음을 제시한다.

• Journal of Preventive Medicine and Public Health
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• 제29권4호
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• pp.747-764
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• 1996

This study intended to obtain an useful information for health management of lead exposed workers and determine biological monitoring interval in early period of exposure by measuring the lead exposure indices and work duration in all male workers (n=433 persons) exposed less than 1 year in 6 storage battery industries and in 49 males who are not exposed to lead as control. The examined variables were blood lead concentration (PBB), Zinc-protoporphyrin concentration (ZPP), Hemoglobin (HB) and personal history; also measured lead concentration in air (PBA) in the workplace. According to the geometric mean of lead concentration in the air, the factories were grouped into three categories: A; When it is below $0.05mg/m^3$, B; When it is between 0.05 and $0.10mg/m^3$, and C; When it is above $0.10mg/m^3$. The results obtained were as follows: 1. The means of blood lead concentration (PBB), ZPP concentration and hemoglobin(HB) in all male workers exposed to lead less than 1 year in storage battery industries were $29.5{\pm}12.4{\mu}g/100ml,\;52.9{\pm}30.0{\mu}g/100ml\;and\;15.2{\pm}1.1\;gm/100ml$. 2. The means of blood lead concentration (PBB), ZPP concentration and hemoglobin(HB) in control group were $5.8{\pm}1.6{\mu}g/100ml,\;30.8{\pm}12.7{\mu}g/100ml\;and\;15.7{\pm}1.6{\mu}g/100ml$, being much lower than that of study group exposed to lead. 3. The means of blood lead concentration and ZPP concentration among group A were $21.9{\pm}7.6{\mu}g/100,\;41.4{\pm}12.6{\mu}g/100ml$ ; those of group B were $29.8{\pm}11.6{\mu}g/100,\;52.6{\pm}27.9{\mu}g/100ml$ ; those of group C were $37.2{\pm}13.5{\mu}g/100,\;66.3{\pm}40.7{\mu}g/100ml$. Significant differences were found among three factory group(P<0.01) that was classified by the geometric mean of lead concentration in the air, group A being the lowest. 4. The mean of blood lead concentration of workers who have different work duration (month) was as follows ; When the work duration was $1\sim2$ month, it was $24.1{\pm}12.4{\mu}g/100ml$, ; When the work duration was $3\sim4$ month, it was $29.2{\pm}13.4{\mu}g/100ml$ ; and it was $28.9\sim34.5{\mu}g/100ml$ for the workers who had longer work duration than other. Significant differences were found among work duration group(P<0.05). 5. The mean of ZPP concentration of workers who have different work duration (month) was as follows ; When the work duration was $1\sim2$ month, it was $40.6{\pm}18.0{\mu}g/100ml$, ; When the work duration was $3\sim4$ month, it was $53.4{\pm}38.4{\mu}g/100ml$ ; and it was $51.5\sim60.4{\mu}g/100ml$ for the workers who had longer work duration than other. Significant differences were found among work duration group(P<0.05). 6. Among total workers(433 person), 18.2% had PBB concentration higher than $40{\mu}g/100ml$ and 7.1% had ZPP concentration higher than $100{\mu}g/100ml$ ; In workers of factory group A, those were 0.9% and 0.0% ; In workers of factory group B, those were 17.1% and 6.9% ; In workers of factory group C, those were 39.4% and 15.4%. 7. The proportions of total workers(433 person) with blood lead concentration lower than $25{\mu}g/100ml$ and ZPP concentration lower than $50{\mu}g/100ml$ were 39.7% and 61.9%, respectively ; In workers of factory group A, those were 65.5% and 82.3% : In workers of factory group B, those were 36.1% and 60.2% ; In workers of factory group C, those were 19.2% and 43.3%. 8. Blood lead concentration (r=0.177, P<0.01), ZPP concentration (r=0.135, P<0.01), log ZPP (r=0.170, P<0.01) and hemoglobin (r=0.096, P<0.05) showed statistically significant correlation with work duration (month). ZPP concentration (r=0.612, P<0.01) and log ZPP (r=0.614, P<0.01) showed statistically significant correlation with blood lead concentration 9. The slopes of simple linear regression between work duration(month, independent variable) and blood lead concentration (dependent variable) in workplace with low air concentration of lead was less steeper than that of poor working condition with high geometric mean air concentration of lead. The study result indicates that new employees should be provided with biological monitoring including blood lead concentration test and education about personal hygiene and work place management within $3\sim4$ month.

• 한국균학회지
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• 제35권2호
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• pp.81-84
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• 2007

균주보존기관에서 분양받은 버섯 원균은 선발된 한천배지 시험관에 배양한 다음 $4{\sim}10^{\circ}C$ 정도에서 간이보존하면서 일정기간 마다 계대배양하여 이용하고 있다 이때 일부 버섯균은 균사체 재생이 지연되어 어려움을 겪는 경우가 있다. 본 시험은 왕송이버섯(Tricholoma giganteum)균의 간이보존 방법을 구명하기 위하여 저장온도(4, 15, $25^{\circ}C$), 용기종류(시험관, 바이알), 저장기간(배양직후, 1, 2, 3, 6, 12개월)을 달리한 후 균사절편(코르크보러, 직경 8 mm)을 한천배지상에 옮겨 $30^{\circ}C$에서 7일간 배양하고 균사직경을 비교하였다. 왕송이버섯균은 저장온도 $4^{\circ}C$에서 한천배지에 $1{\sim}12$개월간 저장시는 모두 균사생장이 안되었으나, 톱밥배지에 저장 2개월까지는 균사생장이 양호하였고, 6개월 이후에는 재생이 안 되었다. 저장온도 $15^{\circ}C$에서는 한천배지의 용기종류, 톱밥배지 공히 6개월 저장까지는 균사생장이 되었으나 12개월에는 조금 낮아지는 경향이었다. 이에 비하여 느타리버섯(춘추2호)은 $4^{\circ}C$ 및 $15^{\circ}C$에서 6개월까지 배지종류에 상관하지 않고 균사생장이 잘 되었으며 12개월에는 조금 낮아지는 경향이었다. 따라서 왕송이버섯균은 저장온도에 민감하게 반응하는 것으로 판단되며, $15^{\circ}C$에서 저장하면서 6개월 이내에 계대 배양하는 것이 바람직하다고 생각된다.