• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.1
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• pp.1-10
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• 2009

Recently, Shin and Park proposed an authentication protocol using the hash function and the XOR operation in RFID/USN environment. However, Shin and Park's proposed authentication protocol is vulnerable to spoofing attack and location tracking attack and tag key exposure attack, and it does not provide tag anonymity. In this paper, we propose an improved authentication protocol for the RFID/USN environment that can withstand those attacks. The proposed authentication protocol provides more improved secrecy and communication efficiency because it decreases the communication rounds compared with the Shin and Park's protocol.

• Journal of Preventive Medicine and Public Health
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• v.42 no.5
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• pp.293-297
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• 2009

Objectives : To evaluate the impact of the workplace smoking ban in South Korea, where the male smoking rate is high (57%), on smoking behavior and secondhand smoke exposure. Methods : A workplace smoking ban legislation implemented in April 2003 requires offices, meeting rooms, and lobbies located in larger than 3,000 square meter buildings (or 2,000 square meter multipurpose buildings) should be smoke free. A representative cross-sectional survey, the third wave (2005) of health supplements in the National Health Nutrition Survey of South Korea, was used to measure the impact of the 2003 workplace smoking ban implementation on smoking behavior. It contained 3,122 observations of adults 20 to 65 years old (excluding selfemployed and non-working populations). A multivariate statistical model was used. The self-reported workplace smoking ban policy (full workplace ban, partial workplace ban, and no workplace ban) was used as the key measure. Results : A full workplace smoking ban reduced the current smoking rate by 6.4 percentage points among all workers and also decreased the average daily consumption among smokers by 3.7 cigarettes relative to no smoking ban. Secondhand smoke showed a dramatic decrease of 86 percent (= -1.74/2.03)from the sample mean for full workplace ban. However, public anti-smoking campaign did not show any significant impact on smoking behavior. Conclusions : The full workplace ban policy is effective in South Korea. Male group showed bigger impact of smoking ban policy than female group. The public antismoking campaign did not show any effectiveness.

• Fire Science and Engineering
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• v.23 no.4
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• pp.59-66
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• 2009

This research aims to conduct a pilot study for the in-fire performance of headed studs, commonly used in composite structures over the world. The robustness of the shear studs in fire appears to be a key element to govern the composite behaviour after a sudden local instability developed in structures such as trusses and cellular beams. In order to experimentally evaluate the residual strength of studs in fire, the standard push-out test was modified for a half of the original set-up to be equipped with a furnace. The adjustments allow the steel section to have a 3-sided exposure against fire. Under the Standard ISO fire, the modified push-out tests under loading were conducted to identify the failure mechanism of the studs in relation to temperature developments.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.5-10
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• 2003

This paper explores not only emerging scientific problems but also the difficulties communicating air quality issues into an increasingly sensitive the public and policy arena. The public understanding and trust in air pollution information and indices may be very different to the notions of validity or accuracy that are important for a scientist. We operate in a world where openness requires us to reveal both the difficulties and disagreements in our understanding of the polluted atmosphere. Yet this can be confusing and increase complexity in situations where clear political and social decisions are required. I am going to examine these issues, starting with questions of what substances we regard as pollutants and the difficulties of getting the correct balance of concern given the broadening the base of chemicals emitted to the environment. There are also questions of exposure particularly in terms of vulnerable populations, who may spend large amounts of time indoors, where air is rarely monitored. In contemporary society there are pollution problems that extend far beyond urban areas and we have to consider regional issues such as windblown dusts, smoke from forest fires along with issues of the emission of green house gases and ozone depleting substances. Finally I will discuss the issues of communicating with a concerned public and sceptical politicians and the troubling interface between technological and sociological control. Such complexity is often missed in a maze of seemingly stronger political and social needs.

• Biomedical Science Letters
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• v.21 no.1
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• pp.15-22
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• 2015

Dexamethasone, a synthetic glucocorticoid (GC), is clinically administered to woman at risk for premature labor to induce fetal lung maturation. However, exposure to repeated or excess GCs leads to intrauterine growth restriction (IUGR) and subsequently increases risk of psychiatric and cardio-metabolic diseases in later life through fetal programming mechanisms. GCs are key mediators of stress responses, therefore, maternal nutrient restriction or psychological stress during pregnancy also causes negative impacts on birth and neurodevelopment outcome of fetuses, and other congenital defects, such as craniofacial and skeletal abnormalities. In this study, to examine the effect of prenatal stress on fetal skeletal development, dexamethasone (1 mg/kg [DEX1] or 10 mg/kg [DEX10] maternal body weight per day) was administered intraperitoneally at gestational day 7.5~9.5 and the skeletons were prepared from embryos at day 18.5. Seven out of eighteen (39%) embryos treated with DEX10 showed axial skeletal abnormalities in either the T13 or L1 vertebrae. In addition, examination of the sternum revealed that xiphoid process, the protrusive triangular part of the lower end of the sternum, was bent more outward or inward in DEX group embryos. In conclusion, our findings suggest a possible link to the understanding of the effect of uterine environment to the fetal skeletal features.

• Journal of Yeungnam Medical Science
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• v.34 no.2
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• pp.293-297
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• 2017

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor that is highly aggressive in nature and indolent in progression. The common risk factors for MCC are senility, prolonged exposure to sunlight, and immune deficient states. Moreover, Merkel cell polyomavirus has recently been characterized to be significantly associated with pathogenesis of MCC, including the expression of Cytokeratin 20 (CK20). Diagnosis is often difficult since histopathological results require a number of differential diagnoses through immunohistochemical (IHC) stains with other cutaneous malignancies. A 67-year-old man presented with a solitary dome-shaped erythematous round mass on the left upper arm for 2 months. Biopsy and IHC studies revealed findings consistent with Merkel Cell Carcinoma of neuroendocrine origin. Common IHC stains usually confirm positive findings for CK20, which is also recognized as the key component in making the diagnosis. We present a CK20 negative MCC in light of expanding the knowledge of unusually stained IHC results in MCC.

• The Journal of Korean Medicine
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• v.24 no.2
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• pp.159-165
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• 2003

Objectives : Coptidis rhizoma (CR) is an oriental medicine that has been used in many traditional prescriptions against diabetes mellitus in Korea for centuries. Our purpose was to determine the protective effect and its action mechanism of CR on the cytotoxicity of pancreatic -cell line (RINm5F cell). Methods : In this experiment, we used methods such as MTT assay for detection of cytotoxicity, DNA fragmentation assay for detection of apoptotic cell death, LDH activity assay for detection of necrotic cell death, and measurement of $DiOC_{6}$ (3) retention for detection of mitochondrial membrane potential (MMP). Background : Nitric oxide (NO) is believed to playa key role in the process of pancreatic -cell destruction leading to insulin-dependent diabetes mellitus (IDDM). Results : Exposure of RINm5F cells to chemical NO donor such as S-nitroso-N-acetylpenicillamine (SNAP) induced cytotoxic events such as DNA fragmentation and lactate dehydrogenase (LDH) release into medium. However, pretreatment of RINm5F cells with CR extract ($10~50{\mu\textrm{g}}/ml$) for 3 hours prevented SNAP-induced DNA fragmentation and LDH release into medium through the inhibition of MMP disruption. Conclusions : These results suggest that CR may be a candidate for a therapeutic or preventing agent against IDDM.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.103-108
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• 2009

Objective: Conventional pterional approach is a commonly used neurosurgical technique for the treatment of cerebral aneurysms. However, this technique requires more extensive brain exposure than other key hole approaches and is sometimes associated with surgical traumatization or cosmetic problems. The aim of this study was to compare the postoperative outcome between pterional and supraorbital keyhole approaches in the patients with anterior circulation aneurysms. Methods: The authors reviewed patients with anterior circulation aneurysms who underwent aneurysm clipping via pterional or supraorbital keyhole approach at a single institute over a period of 2 years. Ninety-eight patients harboring 108 aneurysms were included in this study. Various outcomes were recorded, which included clinical grade, cosmetic problems, patients' satisfaction and complications such as chewing discomfort, frontal muscle weakness, hyposmia, infection. Results: The supraorbital approach exhibited a shorter operation time compared with the pterional approach. Complications such as chewing discomfort occurred less frequently in the supraorbital approach group. Moreover, the cosmetic outcome was significantly better in the supraorbital group than in the pterional group. Conclusion: The supraorbital keyhole approach reduced intra- and postoperative complications, including chewing discomfort and cosmetic disturbances, compared with the conventional pterional approach.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.118-125
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• 2012

Heat shock proteins (Hsps) play a key role in the cellular defense response to diverse environmental stresses. Here, the role of Hsp genes in the acquisition of thermotolerance in the cyanobacterium Microcystis aeruginosa NIES-298 was investigated. Twelve Hsp-related genes were examined to observe their modulated expression patterns at different temperatures (10, 15, 25, and $35^{\circ}C$) over different exposure periods. HspA and HtpG transcripts showed an up-regulation of expression at low temperatures (10 and $15^{\circ}C$) and high temperature ($35^{\circ}C$), compared with the control ($25^{\circ}C$). To examine their effects upon thermotolerance, we purified recombinant HspA and HtpG proteins. During a thermotolerance study at $54^{\circ}C$, the HspA-transformed bacteria showed increased thermotolerance compared with the control. HtpG also played a role in the defense response to acute heat stress within 30 min. These findings provide a better understanding of cellular protection mechanisms against heat stress in cyanobacteria.

• Toxicological Research
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• v.31 no.1
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• pp.33-40
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• 2015

Bee venom (BV) has long been used in traditional Eastern and Western medicine for chronic inflammation, pain and skin therapy. Human exposure to BV, however, often causes unwanted adverse effects and is even fatal in some cases. Phospholipase $A_2$ ($PLA_2$) of BV is now suspected to play a key role in these adverse effects. We investigated the potential use of $PLA_2$-free bee venom (PBV) as a replacement for BV in cosmetic products. PBV prepared by molecular weight cut-off ultrafiltration exhibits a superior profile in comparison with regular BV, by inhibiting elastase activity and suppressing the induction of nitric oxide (NO) and metalloproteinase-9 (MMP-9), while retaining the effects of cell proliferation and protection against ultraviolet B (UVB)-induced damage in human dermal fibroblast cells. PBV thus appears to be more promising than BV as a cosmetic ingredient with a reduced potential for adverse reactions in the recipient.