• Advances in aircraft and spacecraft science
• /
• 제4권4호
• /
• pp.449-465
• /
• 2017

The aim of the present work is to present a computational study of the non-linear aero-elastic behavior of a multi-layered Thermal Protection System (TPS). The severity of atmospheric re-entry conditions is due to the combination of high temperatures, high pressures and high velocities, and thus the aero-elastic behavior of flexible structures can be difficult to assess. In order to validate the specific computational model and the overall strategy for structural and aerodynamics analyses of flexible structures, the simplified TPS sample tested in the 8' High Temperature Tunnel (HTT) at NASA LaRC has been selected as a baseline for the validation of the present work. The von $K{\acute{a}}rm{\acute{a}}n^{\prime}s$ three dimensional large deflection theory for the structure and a hybrid Raleigh-Ritz-Galerkin approach, combined with the first order Piston Theory to describe the aerodynamic flow, have been used to derive the equations of motion. The paper shows that a good description of the physical behavior of the fabric is possible with the proposed approach. The model is further applied to investigate structural and aero-elastic influence of the number of the layers and the stitching pattern.

• 대한임상검사과학회지
• /
• 제49권4호
• /
• pp.374-381
• /
• 2017

LAP 지수는 공복시 중성지방 농도와 허리둘레의 조합으로 과도한 지방축적을 평가하는 지표이다. 이 연구는 LAP 지수와 ALT간의 관련성과 LAP 지수가 ALT에 미치는 영향에 대해 알아 보고자 간질환의 병력이 없는 건강한 성인남성을 대상으로 횡단면 연구를 실시하였다. 2015년 1월부터 2017년 6월까지 경기지역 종합병원에서 건강검진을 시행한 20세 이상 70세 이하의 성인 남성 13,854명을 연구 대상자로 하였다. LAP 지수는 남성의 경우 [허리둘레(cm)-65]${\times}$[중성지방(mmol/L)]으로 산출하였으며, 혈청 ALT 농도의 이상치는 남성 40 IU/L 이상인 경우를 기준으로 설정하였다. 모든 대상자들은 인체측정학적 지표와 생리학적 검사를 실시하였다. LAP 분위수가 증가할수록 ALT는 통계적으로 유의한 증가를 보였다(p<0.001). LAP 지수는 ALT와 상관관계를 보였으며(r=0.238, p<0.001), 특히 인슐린(r=0.449, p<0.001) 및 HDL-콜레스테롤(r=-0.369, p<0.001)과 상관성이 높게 나타났다. 또한 LAP 지수는 ALT에 영향을 미치는 요인이었으며(p<0.001), LAP 지수가 높을수록 ALT가 상승할 위험이 높게 나타났다(p<0.001). 결론적으로 LAP 지수는 한국 성인남성에서 ALT 상승을 예측하는 지표로 나타났다.

• 한국산학기술학회논문지
• /
• 제17권6호
• /
• pp.449-458
• /
• 2016

본 연구는 700병상이상 병원의 3개 수술실 간호사를 대상으로 물품관리 업무역량(물품관리능력, 인식정도, 지식정도)과 업무 만족도를 파악한 후에, 3개 수술실 간에 결과의 차이가 있는지 여부와 물품관리 업무역량과 업무만족도의 상관성을 분석하고 관련된 영향요인을 파악하여 수술간호 업무역량과 업무만족도 향상을 위한 교육과 간호업무 개선활동의 기초자료를 제공하고자 실시되었다. 연구는 구조화된 설문지를 이용하여 자기기입식으로 시행되었고, 연구대상은 현재 6개월 이상 수술실에서 수술간호에 참여 중인 간호사로 하였고 연구 참여자는 181명이였다. 연구결과 물품관리능력의 평균평점은 4.2점(${\pm}0.56$), 인식정도 3.4점(${\pm}0.76$), 지식정도는 3.5점(${\pm}0.40$)이고 업무 만족도는 3.4점(${\pm}0.55$)이었다. 3개 수술실 간호사 그룹 간의 물품간호 업무역량과 업무만족도의 결과에 차이는 없었고, 물품관리능력과 지식정도는(r=.627, p<0.01)이고, 지식정도와 인식정도는(r=.663, p<0.01)이며, 인식정도와 만족도는 (r=.485, p<0.01)로 양의 상관관계가 있었다. 수술실 간호사의 일반적 특성이 물품관리 업무역량과 업무만족도에 미치는 관련요인으로는 연령이 물품관리 업무역량에 유의하게 영향을 미치는 요인이고, 그 외의 항목은 유의하지 않았다. 이와 같은 연구결과를 기반으로 병원 간호사들의 지속적인 인력관리와 교육, 병원간의 의사소통 채널의 효율적인 관리를 위한 자료로 활용하여 수술실 간호사 역량과 만족도의 유지 및 향상에 기초자료를 제공하고자 한다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제5권3호
• /
• pp.449-454
• /
• 1992

Eight healthy Holstein bulls, 4-6 years old were used to study the effect of season of the year on the incidence of the morphologically abnormal spermatozoa. Semen was collected twice a week by A. V. over one-year period. The percentage of total abnormal spermatozoa was $14.1{\pm}0.5$. Ejaculates collected during hot summer season had significantly higher incidence of abnormal spermatozoa than those collected during winter time. Warm spring had moderate semen abnormality. In addition to its effect on the total number of morphologically abnormal spermatozoa, season affected significantly the primary as well as the secondary types of abnormalities. The differences between incidence of primary and secondary types of abnormalities were not significant for all seasons and seasons pooled together. The ratio between the total forms of abnormality in the head, mid-piece and tail of spermatozoa was as 1:1.5:1. Head and mid-piece had defected more during summer compared with both winter and spring. There was no variation in tail abnormalities due to season. The significant effect of season on head was observed by large, pyriform, free and detached heads, while that on mid-piece was by swollen, coiled mid-pieces and protoplasmic droplets.

• 한국융합학회논문지
• /
• 제8권5호
• /
• pp.79-85
• /
• 2017

본 연구는 만성 B형 바이러스성 감염 환자의 간 기능 혈액 검사 수치와 간 섬유화 스캔 검사(FibroScan(R))의 비교 분석을 통한 간 섬유화 스캔 검사의 임상적, 기기적 융합 유용성을 평가하고자 하였다. 2015년 7월 1일부터 2016년 2월 28일까지 대전시 B내과에 내원한 만성 B형 바이러스성 감염 환자 75명의 간 섬유화 스캔 검사 결과와 간 기능 혈액검사 수치를 분석 하고 ROC곡선을 작성하였다. 알라닌 아미노전이요소, 아스파르테이트 아미노전이요소 수치가 각각 0.572, 0.502로 섬유화 수치와 가장 높은 상관관계를 보였다(p<0.000). 감마지티피, 총 빌리루빈, 알칼리성 인산분해효소 수치도 비교적 유의한 상관관계를 보였으나 알파태아단백과 총 단백정량은 통계적으로 유의하지 않았다. 또한 알부민(-0.449)과 혈소판치(-0.373)도 섬유화 수치와 상관관계가 없었다(p<0.000). 간 섬유화 정도가 높은 등급일수록 ROC 곡선의 정확도가 증가하였으며 F4의 간 경변 단계에서 가장 큰 AUROC값을 나타냈다. 따라서 간 섬유화 스캔 검사는 만성 간질환 환자의 간 기능 수치인 알라닌 아미노전이요소, 아스파르테이트 아미노전이요소 수치와 유의한 상관관계를 보여 간의 염증 검사 및 만성 간질환 진단에 매우 유용한 것으로 판단된다.

• Journal of Microbiology and Biotechnology
• /
• 제12권5호
• /
• pp.773-779
• /
• 2002

A gene (hap) encoding aminopeptidase from the chromosomal DNA of Bacillus licheniformis was cloned. The gene is 1,347 bp long and encodes a 449 amino acid preproprotein with a major mature region of 401 amino acids (calculated molecular mass 43,241 Da). N-Terminal sequence of the purified protein revealed a potential presence of N-terminal propeptide. The deduced primary amino acid sequence and the mass analysis of the purified protein suggested that a C-terminal peptide YSSVAQ was also cleaved off by a possible endogeneous protease. Tho amino acid sequence displayed 58% identity with that of the aminopeptidase from alkaliphilic Bacillus halodurans. This bacterial enzyme was overexpressed in recombinant Escherichia coli and Bacillus subtilis cells. Clones containing the intact hap gene, including its own promoter and signal sequence, gave rise to the synthesis of extracellular and thrmostable enzyme by B. subtilis transformants. The secreted protein exhibited the same biochemical properties and the similar apparent molecular mass as the B. lichenzyormis original enzyme.

• 한국분말재료학회지
• /
• 제18권5호
• /
• pp.449-455
• /
• 2011

In this study, p-type $(AgSbTe_2)_{15}(GeTe)_{85}$: TAGS-85 compound powders were prepared by gas atomization process, and then their microstructures and mechanical properties were investigated. The fabricated powders were of spherical shape, had clean surface, and illustrated fine microstructure and homogeneous $AgSbTe_2$ + GeTe solid solution. Powder X-ray diffraction results revealed that the crystal structure of the TAGS-85 sample was single rhombohedral GeTe phase, which with a space group $R_{3m}$. The grain size of the powder particles increased while the micro Vickers hardness decreased with increasing annealing temperature within the range of 573 K and 723 K due to grain growth and loss of Te. In addition, the crystal structure of the powder went through a phase transformation from rhombohedral ($R_{3m}$) at low-temperature to cubic ($F_{m-3m}$) at high-temperature with increasing annealing temperature. The micro Vickers hardness of the as-atomized powder was around 165 Hv, while it decreased gradually to 130 Hv after annealing at 673K, which is still higher than most other fabrication processes.

• 한국균학회지
• /
• 제26권4호통권87호
• /
• pp.437-449
• /
• 1998

본 연구는 1990년부터 국내에서 채집하여 고려대학교 농생물학과 진균표본보관소(SMK)에 보존하고 있는 Cercospora 및 관련 속의 진균을 대상으로 분류학적 연구를 실시한 결과의 네 번째 보고이다. 이번에는 Cercospora 3종, Phacellium 1종 Pseudocercospora 2종, Pseudocercosporella 1종 및 Ramularia 3종에 대한 균학적 특징을 기재, 묘사하였다. 고추에서 Cercospora capsici, 꽃황새냉이에서 C. cardaminae, 느러진장대와 장대나물에서 C. nasturtii, 쇠별꽃과 별꽃에서 Phacellium episphaerium, 구기자나무에서 Pseudocercospora chengtuensis, 고욤나무에서 P. diospyri-morrisianae, 배추와 유채 및 냉이에서 Pseudocercosporella capsellae, 나도냉이에서 Ramularia armoraciae, 익모초에서 R. lamii var. lamii, 수영 및 소리쟁이에서 R. pratensis var. pratensis를 각각 동정하였다.

• 한국미생물·생명공학회지
• /
• 제49권3호
• /
• pp.449-457
• /
• 2021

The aim of the present study was to survey the frequency of inducible and constitutive phenotypes and inducible cross-resistant genes by regulating the methylation of 23S rRNA (ermA, ermB, and ermC) and macrolide efflux-related msrA gene in Staphylococcus aureus and S. epidermidis strains. A total of 172 bacterial isolates (identified based on standard tests), were examined in this study. Antibiotic susceptibility was determined by the disk diffusion method, and all isolates were evaluated with respect to inducible and constitutive phenotypes. The presence of ermA, ermB, ermC, and msrA genes was investigated by a PCR assay. The constitutive resistance phenotypes showed a higher distribution among the isolates. R phenotype was detected more among S. epidermidis isolates (46.25%). ermB, ermC, and msrA genes were detected more in methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. epidermidis (MRSE) isolates that had R and HD phenotypes (>77% strains). The ermA gene had the lowest frequency among MRSA, MRSE, MSSA, and MSSE strains (<14% isolates). Distribution of inducible resistance genes in MRSA and MRSE strains, and possibly other species, leads to increased constitutive resistance to erythromycin, clindamycin, and other similar antibiotics. Therefore, it can be challenging to treat infections caused by these resistant strains.

• International Journal of Oral Biology
• /
• 제36권3호
• /
• pp.109-116
• /
• 2011

Periodontitis results from the activation of host immune and inflammatory defense responses to subgingival plaque bacteria, most of which are gram-negative rods with lipopoly-saccharides (LPSs) in their cell walls. LPSs have been known to induce proinflammatory responses and recently it was reported also that they induce the expression of microRNAs (miRNAs) in host cells. In our current study therefore, we aimed to examine and compare the miRNA expression patterns induced by the LPSs of major periodontopathogens in the human gingival epithelial cell line, Ca9-22. The cells were treated with 1 ${\mu}g$/ml of E. coli (Ec) LPS or 5 ${\mu}g$/ml of an LPS preparations from four periodontopathogens Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Aggregatibacter actinomycetemcomitans (Aa), and Fusobacterium nucleatum (Fn) for 24 h. After small RNA extraction from the treated cells, miRNA microarray analysis was carried out and characteristic expression profiles were observed. Fn LPS most actively induced miRNAs related to inflammation, followed by Aa LPS, Pi LPS, and Ec LPS. In contrast, Pg LPS only weakly activated miRNAs related to inflammation. Among the miRNAs induced by each LPS, miR-875-3p, miR-449b, and miR-520d-3p were found to be commonly up-regulated by all five LPS preparations, although at different levels. When we further compared the miRNA expression patterns induced by each LPS, Ec LPS and Pi LPS were the most similar although Fn LPS and Aa LPS also induced a similar miRNA expression pattern. In contrast, the miRNA profile induced by Pg LPS was quite distinctive compared with the other bacteria. In conclusion, miR-875-3p, miR-449b, and miR-520d-3p miRNAs are potential targets for the diagnosis and treatment of periodontal inflammation induced by subgingival plaque biofilms. Furthermore, the observations in our current study provide new insights into the inflammatory miRNA response to periodontitis.