• 설비공학논문집
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• 제13권9호
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• pp.827-835
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• 2001

In this study, condensation heat transfer characteristics were conducted with special heat transfer tubes of SH-C type. Experiments were carried out the saturated vapor temperature of 334K and the wall subcooling of 1.5-4.5K. The refrigerant was R-113 and the enhanced tubes used in the present study were SH-CDR, SH-CYR and SH-CHR. The experimental results showed that the condensation heat transfer coefficients of SH-C type tubes were about 23-66% higher than those of a low integral-fin tube. It was visualized that the condensed liquid on the outer surface of SH-C type tubes flowed continuously down unlike a low integral-fin tube and a plain tube, due to a 3-D extending fin on the outer surface of SH-C type tubes. As a result, the thermal resistance of the condensed liquid decreased and the heat transfer coefficient increased. Also, the enhancement ratio of SH-CDR tube was the highest, and it was about 9-11 times as compared to that of a plain tube.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.659-666
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• 2021

After Candida albicans, Candida glabrata is one of the most common fungal species associated with candidemia in nosocomial infections. Rapid acquisition of nutrients from the host is important for the survival of pathogens which possess the metabolic flexibility to assimilate different carbon and nitrogen compounds. In Saccharomyces cerevisiae, nitrogen assimilation is controlled through a mechanism known as Nitrogen Catabolite Repression (NCR). NCR is coordinated by the action of four GATA factors; two positive regulators, Gat1 and Gln3, and two negative regulators, Gzf3 and Dal80. A mechanism in C. glabrata similar to NCR in S. cerevisiae has not been broadly studied. We previously showed that in C. glabrata, Gln3, and not Gat1, has a major role in nitrogen assimilation as opposed to what has been observed in S. cerevisiae in which both factors regulate NCR-sensitive genes. Here, we expand the knowledge about the role of Gln3 from C. glabrata through the transcriptional analysis of BG14 and gln3Δ strains. Approximately, 53.5% of the detected genes were differentially expressed (DEG). From these DEG, amino acid metabolism and ABC transporters were two of the most enriched KEGG categories in our analysis (Up-DEG and Down-DEG, respectively). Furthermore, a positive role of Gln3 in AAA assimilation was described, as was its role in the transcriptional regulation of ARO8. Finally, an unexpected negative role of Gln3 in the gene regulation of ABC transporters CDR1 and CDR2 and its associated transcriptional regulator PDR1 was found. This observation was confirmed by a decreased susceptibility of the gln3Δ strain to fluconazole.

• IMMUNE NETWORK
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• 제12권4호
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• pp.155-164
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• 2012

It is well established that blocking the interaction of EGFR with growth factors leads to the arrest of tumor growth, resulting in tumor cell death. ER414 is a human monoclonal antibody (mAb) derived by guided selection of the mouse mAb A13. The ER414 exhibited a ~17-fold lower affinity and, as a result, lower efficacy of inhibition of the EGF-mediated tyrosine phosphorylation of EGFR when compared with mAb A13 and cetuximab. We performed a stepwise in vitro affinity maturation to improve the affinity of ER414. We obtained a 3D model of ER414 to identify the amino acids in the CDRs that needed to be mutated. Clones were selected from the phage library with randomized amino acids in the CDRs and substitution of amino acids in the HCDR3 and LCDR1 of ER414 led to improved affinity. A clone, H3-14, with a ~20-fold increased affinity, was selected from the HCDR3 randomized library. Then three clones, ER2, ER78 and ER79, were selected from the LCDR1 randomized library based on the H3-14 but did not show further increased affinities compared to that of H3-14. Of the three, ER2 was chosen for further characterization due to its better expression than others. We successfully performed affinity maturation of ER414 and obtained antibodies with a similar affinity as cetuximab. And antibody from an affinity maturation inhibits the EGF-mediated tyrosine phosphorylation of EGFR in a manner similar to cetuximab.

• Journal of Korean Neurosurgical Society
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• 제60권6호
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• pp.676-683
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• 2017

Objective : The purpose of this study is to evaluate the efficacy and safety of 3-level hybrid surgery (HS), which combines fusion and cervical disc replacement (CDR), compared to 3-level fusionin patient with cervical spondylosis involving 3 levels. Methods : Patients in the anterior cervical discectomy and fusion (ACDF) group (n=30) underwent 3-level fusion and the HS group (n=19) underwent combined surgery with fusion and CDR. Clinical outcomes were evaluated using the visual analogue scale for the arm, the neck disability index (NDI), Odom criteria and postoperative complications. The cervical range of motion (ROM), fusion rate and adjacent segments degeneration were assessed with radiographs. Results : Significant improvements in arm pain relief and functional outcome were observed in ACDF and HS group. The NDI in the HS group showed better improvement 6 months after surgery than that of the ACDF group. The ACDF group had a lower fusion rate, higher incidence of device related complications and radiological changes in adjacent segments compared with the HS group. The better recovery of cervical ROM was observed in HS group. However, that of the ACDF group was significantly decreased and did not recover. Conclusion : The HS group was better than the ACDF group in terms of NDI, cervical ROM, fusion rate, incidence of postoperative complications and adjacent segment degeneration.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.227-235
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• 2012

이 연구에서는 최근 국내에서 개발된 보행용 기능성 신발 중 걷기 효율성을 변화시키는 복합적 기능성 신발(double rocker sole;CDR)과 negative-heel rocker sole(NR)형태 신발의 근육 활성도를 비교하였다. 연구대상은 하지정형 외과적 질환이 없는 40-50대 중년여성 11명을 대상(연령 $47.33{\pm}4.4$, 신장 $158.00{\pm}3.3$cm, 체중 $59.50{\pm}6.1$, BMI $23.80{\pm}1.8kg/m^2$)으로 하였다. 연구결과 좌,우측의 내측광근, 비복근, 반건양근에서는 근활성도의 수준은 통계적으로 유의한 차이가 나타나지 않았지만, CDR신발이 전경골근에서 통계적으로 유의하게 높은 결과가 나타났다(p<.05). 걷기운 동시 동일한 조건속에 운동을 실시할 경우 신발 밑창의 변화를 통해 인위적으로 운동량을 증가시킬 수 있을 것이다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.44.3-44.3
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• 2009

The MIRIS (Multi-purpose IR Imaging System), as the main payload of Science and Technology Satellite-3 (STSAT-3), is being developed by KASI in collaboration with several institutes for wide-field space observation in near IR wavelength. The Engineering Qualification Model (EQM) of MIRIS has been designed and fabricated in the laboratory. The system performance tests have been made including opto-mechanics, vibration test, thermal-vacuum environmental test and passive cooling test down to 200K. Most of the performance test results were satisfied with system requirements. The results of MIRIS performance tests have been presented at Critical Design Review (CDR) on September 2009. Several revisions were also recommended for Flight Model (FM) design, and detailed plan to develop FM of MIRIS is discussed in this paper.

• Journal of Korean Neurosurgical Society
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• 제56권1호
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• pp.28-33
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• 2014

Objective : Postoperative delirium is a common complication in the elderly after surgery but few papers have reported after spinal surgery. We analyzed various risk factors for postoperative delirium after spine surgery. Methods : Between May 2012 and September 2013, 70 patients over 60 years of age were examined. The patients were divided into two groups : Group A with delirium and Group B without delirium. Cognitive function was examined with the Mini-Mental State Examination-Korea (MMSE-K), Clinical Dementia Rating (CDR) and Global Deterioration Scale (GDS). Information was also obtained on the patients' education level, underlying diseases, duration of hospital stay and laboratory findings. Intraoperative assessment included Bispectral index (BIS), type of surgery or anesthesia, blood pressure, fluid balance, estimated blood loss and duration of surgery. Results : Postoperative delirium developed in 17 patients. The preoperative scores for the MMSE, CDR, and GDS in Group A were $19.1{\pm}5.4$, $0.9{\pm}0.6$, and $3.3{\pm}1.1$. These were significantly lower than those of Group B ($25.6{\pm}3.4$, $0.5{\pm}0.2$, and $2.1{\pm}0.7$) (p<0.05). BIS was lower in Group A ($30.2{\pm}6.8$ compared to $35.4{\pm}5.6$ in group B) (p<0.05). The number of BIS <40 were $5.1{\pm}3.1$ times in Group A, $2.5{\pm}2.2$ times in Group B (p<0.01). In addition, longer operation time and longer hospital stay were risk factors. Conclusion : Precise analysis of risk factors for postoperative delirium seems to be more important in spinal surgery because the surgery is not usually expected to have an effect on brain function. Although no risk factors specific to spinal surgery were identified, the BIS may represent a valuable new intraoperative predictor of the risk of delirium.

• 동의신경정신과학회지
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• 제34권3호
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• pp.141-150
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• 2023

Objectives: This study aimed to comprehend the characteristics of Korean medicine patterns in relation to varying degrees of cognitive impairment in an elderly population. Methods: The dataset included 127 elderly individuals with cognitive impairment obtained from three Korean medicine hospitals between 2018 and 2021. The participants were categorized into two groups based on Clinical Dementia Rating-Sum of Boxes (CDR-SB) scores: those with questionable impairment (QI) and those with very mild dementia (VMD). A diagnostic framework for Korean medicine patterns encompassing Qi deficiency, Yin deficiency, Phlegm dampness, and Heat-fire was employed. Liver blood markers, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the AST/ALT ratio, were also analyzed. Results: The scores of the cognitive assessment tools (MoCA-K, MMSE-DS, and K-IADL) of the QI group significantly differed from those of the VMD group. CDR-SB exhibited a positive correlation with the scores of each pattern of Qi deficiency, Yin deficiency, Phlegm dampness, and Heat-fire, whereas ALT and AST values displayed negative correlations. Binomial logistic analysis, controlling for potential confounders, such as age, education years, body mass index, the presence of chronic disease, and the presence of medication, verified that the VMD group showed higher pattern scores and lower ALT and AST values than the QI group. Conclusions: Increases in pattern scores along with decreased AST and ALT levels might be indicative of more severe cognitive impairment.

• Korean Journal of Radiology
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• 제24권4호
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• pp.274-283
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• 2023

Objective: To compare the outcomes of digital breast tomosynthesis (DBT) screening combined with ultrasound (US) with those of digital mammography (DM) combined with US in women with dense breasts. Materials and Methods: A retrospective database search identified consecutive asymptomatic women with dense breasts who underwent breast cancer screening with DBT or DM and whole-breast US simultaneously between June 2016 and July 2019. Women who underwent DBT + US (DBT cohort) and DM + US (DM cohort) were matched using 1:2 ratio according to mammographic density, age, menopausal status, hormone replacement therapy, and a family history of breast cancer. The cancer detection rate (CDR) per 1000 screening examinations, abnormal interpretation rate (AIR), sensitivity, and specificity were compared. Results: A total of 863 women in the DBT cohort were matched with 1726 women in the DM cohort (median age, 53 years; interquartile range, 40-78 years) and 26 breast cancers (9 in the DBT cohort and 17 in the DM cohort) were identified. The DBT and DM cohorts showed comparable CDR (10.4 [9 of 863; 95% confidence interval {CI}: 4.8-19.7] vs. 9.8 [17 of 1726; 95% CI: 5.7-15.7] per 1000 examinations, respectively; P = 0.889). DBT cohort showed a higher AIR than the DM cohort (31.6% [273 of 863; 95% CI: 28.5%-34.9%] vs. 22.4% [387 of 1726; 95% CI: 20.5%-24.5%]; P < 0.001). The sensitivity for both cohorts was 100%. In women with negative findings on DBT or DM, supplemental US yielded similar CDRs in both DBT and DM cohorts (4.0 vs. 3.3 per 1000 examinations, respectively; P = 0.803) and higher AIR in the DBT cohort (24.8% [188 of 758; 95% CI: 21.8%-28.0%] vs. 16.9% [257 of 1516; 95% CI: 15.1%-18.9%; P < 0.001). Conclusion: DBT screening combined with US showed comparable CDR but lower specificity than DM screening combined with US in women with dense breasts.

• 전기전자학회논문지
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• 제10권1호
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• pp.10-15
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• 2006

본 논문에서는 기준동작 클럭없이 데이터만으로 구현되는 반주기의 4x 오버샘플링 위상/주파수검출기를 이용한 클럭 데이터 복원회로에 대하여 서술하였다. 위상 및 주파수검출기는 4x 오버샘플링 기법을 이용하여 설계되었다. 위상검출기는 뱅뱅 제어방법에 의해, 주파수검출기는 로테이션방법에 의해 동작한다. 위상 및 주파수 검출기로부터 발생된 6개의 신호들은 전하펌프로 들어갈 전하량을 결정한다. VCO단은 4개의 차동 지연단으로 구성되고 8개의 클럭신호를 생성한다. 제안된 회로는 공급전압 1.8V, 0.18um MOCS 공정으로 설계 시뮬레이션되었다. 제안된 구조의 PD와 FD를 사용하여 25%의 넓은 트래킹 주파수 범위를 가진다.