• Molecules and Cells
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• 제42권12호
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• pp.840-849
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• 2019

The spatiotemporal mitotic processes are controlled qualitatively by phosphorylation and qualitatively by ubiquitination. Although the SKP1-CUL1-F-box protein (SCF) complex and the anaphase-promoting complex/cyclosome (APC/C) mainly mediate ubiquitin-dependent proteolysis of mitotic regulators, the E3 ligase for a large portion of mitotic proteins has yet to be identified. Here, we report c-Cbl as an E3 ligase that degrades DDA3, a protein involved in spindle dynamics. Depletion of c-Cbl led to increased DDA3 protein levels, resulting in increased recruitment of Kif2a to the mitotic spindle, a concomitant reduction in spindle formation, and chromosome alignment defects. Furthermore, c-Cbl depletion induced centrosome over-duplication and centriole amplification. Therefore, we concluded that c-Cbl controls spindle dynamics and centriole duplication through its E3 ligase activity against DDA3.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (D)
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• pp.713-718
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• 2006

이전의 스캐터넷 관련 연구들은 특정 지역내의 모든 장치들을 단시간 내에, 또는 최적의 성능을 내도록 형성하는 방법을 제안하였다. 그러나 실제 응용에서는 같은 사회적 그룹에 속한 사람들간의 통신이 더 빈번하게 일어나기 때문에, 같은 사회적 그룹에 속하는 장치를 먼저 소규모의 스캐터넷으로 연결하고 이렇게 형성된 스캐터넷을 터널로 연결하는 것이 더 효율적이다. 기존 스캐터넷을 평가하기 위해 제안된 APC는 병목현상을 고려하지 않기 때문에 스캐터넷의 성능을 나타내는 평가 기준으로 부적절하다. 따라서 우리는 성능에 압도적인 영향을 미치는 트래픽을 제외한 나머지 트래픽의 전송 성능 평균을 스캐터넷을 평가하는 기준으로 제안하였다. 그리고 터널의 개수와 위치가 전체 네트워크에 어떤 영향을 미치는지 알아보았다.

• 대한전자공학회논문지
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• 제25권12호
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• pp.1663-1668
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• 1988

Ohmic contact process for the fabrication of GaAs integrated circuits is very important. Specific contact resistivities, assuming Rsm=Rs, were measured after the rapid and the conventional alloying process, respectively. The results show that the characteristics of ohmic contact through the rapid alloying process is much better (Apc=1.3~3.3x10**-7 \ulcorner-(m\ulcorner. This is probably due to intensive and compound energy densities during the rapid alloying process. New analysis method of TLM patterns viz. measurements of normlaized specific contact resistivities are proposed to reduce measurement errors that could occur when measuring the small contact end resistances. The adoption of rapid alloying process for the mass production of GaAs integrated circuits could greatly reduce the total processig time.

• 생명과학회지
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• 제9권3호
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• pp.308-313
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• 1999

Ocellar morphological abnormality was studied in Drosophila rdgA mutant. In the mutant, ocellar photoreceptor cells were generally affected by the defection of rdgA molecules. Among organelles of photoreceptor cell, rhabdomeres were remarkably degenerated. The rdgA molecule, diacylglycerol kinase, was localized around SRC just below the rhabdomeric region. As a secondary phenomenon of photoreceptor degeneration, rER, multivesicular body and multilamella body were appeared in cytoplasm and these were known as to clean the cellular debris. These morphological abnormality was generally observed in degenerating cells. In Drosophila mutant, the degeneration of ocellar photoreceptor cell was facilitated to time. More intense morphological defection was observed in rdgA^{ks60} rather than in yw;rdgApc47.

• Journal of Electrical Engineering and Technology
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• 제3권2호
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• pp.243-253
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• 2008

This paper deals with the analysis, design, and implementation of a single phase AC-DC Zeta converter with high frequency transformer isolation and power factor correction(PFC) in two modes of operation, discontinuous current mode of operation(DCM), and continuous current mode of operation(CCM). A Digital Signal Processor(DSP) based implementation is carried out for validation of the Zeta converter developed design in discontinuous mode of operation. A comparison of both modes of operation is presented for a 1kW power rating from the point of view of steady state and dynamic behavior, power quality, simplicity, control technique, device rating, and converter size. The experimental results of a developed prototype of Zeta converter are presented for validation of the developed design. It is observed that CCM is most suitable for higher power applications where it requires some complex control and sensing of the additional variables.

• Journal of Trauma and Injury
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• 제32권1호
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• pp.60-65
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• 2019

Pelvic fractures are associated with life-threatening injuries and high rates of morbidity and mortality. Management of internal blood loss associated with unstable pelvic ring injuries is paramount during the initial period. The reconstruction of the pelvic ring is of importance because it is a major contributor to the stability of the pelvic ring. We report the case of a 25-year-old man who had an unstable pelvic ring fracture combined with rupture of an obturator artery and had a successful and satisfactory treatment using minimally invasive surgery with percutaneous antegrade screw fixation.

• Genomics & Informatics
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• 제16권4호
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• pp.35.1-35.3
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• 2018

Biliary tract cancer (BTC) is a rare cancer and is associated with a poor prognosis. To understand the genetic characteristics of BTC, we analyzed whole-exome sequencing data and identified somatic mutations in patients with BTC. Tumors and matched blood or normal samples were obtained from seven patients with cholangiocarcinoma who underwent surgical resection. We discovered inactivating mutations of tumor suppressor genes, including APC, TP53, and ARID1A, in three patients. Activating mutations of KRAS and NRAS were also identified. Our analyses identified somatic mutations in Korean patients with BTC.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.137.2-137.2
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• 2003

Dendritic cells (DCs) are known to professional antigen presenting cell (APC). Due to the role as an effective activator of cytotoxic T Lymphocytes by expressing MHC, adhesion and co-stimulatory molecules, DCs are now widely recognized to play an important role in the immune responses to tumors.We investigated the effect of cultured DCs in murine melanoma pulmonary metastasis model. To follow the metastasis protocol, syngenic melanoma cells were inoculated intra-venously into the mouse (B16F10 into the C57BL/6)8 days prior to the first DC injection (1$\times$106 DCs/ mouse, i.p.) and the autologous tumor cell lysate pulsed-DCs were injected as a therapeutic module twice in two weeks. (omitted)

• 대한미생물학회지
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• 제21권3호
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• pp.311-329
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• 1986

The experimental exposure of animals to sources of ultraviolet radiation (UVR) which emit their energy primarily in the UVB region (280-320nm) is known to result in a number of well-described changes in the recipient's immune competence. Two such changes include a depressed capacity to effectively respond immunologically to transplants of syngeneic UVR tumors and a markedly reduced responsiveness to known inducers of delayedtype (DTH) and contact hypersensitivity (CH) reactions. The results of experiments that were designed to elucidate the mechanisms responsible for UVR-induced immunomodulation have implicated: 1) an altered pattern of lymphocyte recirculation, 2) suppressor T cells(Ts), 3) deviations in systemic antigen presenting cell (APC) potential. 4) changes in the production of interleukin-1-like molecules, and 5) the functional inactivation of epidermal Langerhans cells in this process. The exposure of skin to UVR, therefore, causes a number of both local and systemic alterations to the normal host immune system. In spite of this seeming complexity and diversity of responses, our recent studies have established that each of the UVR-mediated changes is probably of equal importance to creating the UVR-induced immunocompromised state. Normal animals were exposed to low dose UVR radiation on their dorsal surfaces under conditions where a $3.0\;cm^2$ area of skin was physically protected from the light energy. Contact sensitization of these animals with DNFB, to either the irradiated or protected back skin, resulted in markedly reduced CH responses. This was observed in spite of a normal responsiveness following the skin sensitization to ventral surfaces of the UVR-exposed animals. Systemic treatment of the low dose UVR recipients with the drug indomethacin (1-3 micrograms/day) during the UVR exposures resulted in a complete reversal of the depressions observed following DNFB sensitization to "protected" dorsal skin while the altered responsiveness found in the group exposed to the skin reactive chemical through directly UVR-exposed sites was maintained. These studies implicate the importance of EC as effective APC in the skin and also suggest that some of the systemic influences caused by UVR exposure involve the production of prostaglandins. This concept was further supported by finding that indomethacin treatment was also capable of totally reversing the systemic depressions in CH responsiveness caused by high dose UVR exposure (30K joules/$m^2$) of mice. Attempts to analyze the cellular mechanisms responsible established that the spleens of all animals which demonstrated altered CH responses, regardless of whether sensitization was through a normal or an irradiated skin site, contained suppressor cells. Interestingly, we also found normal levels of T effector cells in the peripheral lymph nodes of the UVR-exposed mice that were contact sensitized through normal skin. No effector cells were found when skin sensitization took place through irradiated skin sites. In spite of such an apparent paradox, insight into the probable mechanisms responsible for these observations was provided by establishing that UVR exposure of skin results in a striking and dose-dependent blockade of the efferent lymphatic vessels in all peripheral lymph nodes. Therefore, the afferent phases of immune responses can apparently take place normally in UVR exposed animals when antigen is applied to normal skin. The final effector responses, however, appear to be inhibited in the UVR-exposed animals by an apparent block of effector cell mobility. This contrasts with findings in the normal animals. Following contact sensitization, normal animals were also found to simultaneously contain both antigen specific suppressor T cells and lymph node effector cells. However, these normal animals were fully capable of mobilizing their effector cells into the systemic circulation, thereby allowing a localization of these cells to peripheral sites of antigen challenge. Our results suggest that UVR is probably not a significant inducer of suppressor T-cell activity to topically applied antigens. Rather, UVR exposure appears to modify the normal relationship which exists between effector and regulatory immune responses in vivo. It does so by either causing a direct reduction in the skin's APC function, a situation which results in an absence of effector cell generation to antigens applied to UVR-exposed skin sites, inhibiting the capacity of effector cells to gain access to skin sites of antigen challenge or by sequestering the lymphocytes with effector cell potential into the draining peripheral lymph nodes. Each of these situations result in a similar effect on the UVR-exposed host, that being a reduced capacity to elicit a CH response. We hypothesize that altered DTH responses, altered alloresponses, and altered graft-versus-host responses, all of which have been observed in UVR exposed animals, may result from similar mechanisms.

• 한국동물위생학회지
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• 제35권4호
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• pp.313-319
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• 2012

Consumer's preference and microbial inspections on fresh raw beef were carried out to understand the actual market status in Gwanju, Korea. Over 15 questions on questionnaire by 1,111 randomly selected respondents between April and May in 2011, results showed 65.5% positive on eating fresh raw beef, 63.8% negative on good hygiene condition of fresh raw beef, and 72.5% positive on the secure of the hygiene-safety for priority program, respectively. For microbial inspections, a total of 302 samples were collected from fresh raw beef purchased from slaughterhouse (n=122), transport (n=69) and consumer (n=81) stage, from lettuce (n=30) at consumer stage. The aerobic plate count (APC), E. coli count and food borne bacteria such as Salmonella spp., Listeria monocytogenes, Staphylococcus(S.) aureus and E. coli O157:H7 were tested in the samples. As results, the level of count on APC of fresh raw beef ranged $6{\times}10^1{\sim}1.8{\times}10^5CFU/g$ from slaughterhouse, $2{\times}10^2{\sim}8.3{\times}10^5CFU/g$ from transport stage and $1{\times}10^2{\sim}4{\times}10^5CFU/g$ from consumer stage. The level of count on E. coli of fresh raw beef ranged $1{\sim}9{\times}10^1CFU/g$ from slaughterhouse, $1{\sim}7{\times}10CFU/g$ from transport stage and $1{\sim}5.5{\times}10CFU/g$ from consumer stage. In total, 26 S. aureus were isolated, 10 (14.5%) from fresh raw beef at transport stage, 12 (14.8%) from fresh raw beef and 4 (13.3%) from lettuce at consumer stage. Enterotoxin of S. aureus was not detected among 26 isolates. All S. aureus isolates were typed using a DiversiLab$^{TM}$ rep-PCR system for genetic similarity test, showing over 95% of genetic relationship amon isolates.