• Archives of Plastic Surgery
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• 제47권3호
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• pp.228-234
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• 2020

Background A patient's overall condition sometimes does not allow for the complete removal of a dead eschar or injured slough in cases involving a pressure-injury skin lesion. This frequently occurs in clinical practice, particularly in bedridden and older patients receiving home care or intensive care. Even after debridement, it is also difficult to manage open exudative wounds in these patients. Nevertheless, when a mature or immature eschar is treated without proper debridement, liquefaction necrosis underneath the eschar or slough tends to reveal a large, open wound with infectious exudates. We hypothesized that if the presence of any bacteria under the eschar can be evaluated and the progression of the presumed infection of the subeschar can be halted or delayed without creating an open wound, the final wound can be small, shallow, and uninfected. Methods Using a punch instrument, we performed 34 viable subeschar tissue cultures with a secure junction between the eschar and the normal skin. Results The bacterial study had 29 positive results. Based on these results and the patient's status, appropriate antibiotics could be selected and administered. The use of suitable antibiotics led to relatively shallow and small exposed wounds. Conclusions This procedure could be used to detect potentially pathogenic bacteria hidden under black or yellow eschars. Since subeschar infections are often accompanied by multidrug-resistant bacteria, the early detection of hidden infections and the use of appropriate antibiotics are expected to be helpful to patients.

• Korea-Australia Rheology Journal
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• 제17권2호
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• pp.47-62
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• 2005

The present study deals with a mathematical model describing the dynamic response of heat and mass transfer in blood flow through bifurcated arteries under stenotic condition. The geometry of the bifurcated arterial segment possessing constrictions in both the parent and the daughter arterial lumen frequently appearing in the diseased arteries causing malfunction of the cardiovascular system, is formulated mathematically with the introduction of the suitable curvatures at the lateral junction and the flow divider. The blood flowing through the artery is treated to be Newtonian. The nonlinear unsteady flow phenomena is governed by the Navier-Stokes equations while those of heat and mass transfer are controlled by the heat conduction and the convection-diffusion equations respectively. All these equations together with the appropriate boundary conditions describing the present biomechanical problem following the radial coordinate transformation are solved numerically by adopting finite difference technique. The respective profiles of the flow field, the temperature and the concentration and their distributions as well are obtained. The influences of the stenosis, the arterial wall motion and the unsteady behaviour of the system in terms of the heat and mass transfer on the blood stream in the entire arterial segment are high­lighted through several plots presented at the end of the paper in order to illustrate the applicability of the present model under study.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.216-217
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• 2008

Zinc-oxide films were deposited by pulsed laser deposition (PLD) technique using doped ZnO target (mixed $In_2O_3$ 0.1, 0.3, 0.6 at. % - atomic percentage) on the p-type Si(111) substrate. A little Indium has added at the n-ZnO films for the electron concentration control and enhanced the electrical properties. Also, post thermal annealed ZnO films are shown an enhanced structural and controled electron concentration by the annealing condition for the hetero junction diode of a better emitting characteristics. The electrical and the diode characteristics of the ZnO films were investigated by using Hall effect measurement and current-voltage measurement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.553-556
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• 1999

This paper presents a proper condition to achieve above 19 % conversion efficiency using PC1D simulator. Cast poly-Si wafers with resistivity of 1 $\Omega$-cm and thickness of 250 ${\mu}{\textrm}{m}$ were used as a starting material. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer, BSF thickness and doping concentration were investigated. Optimized cell parameters were given as rear surface recombination of 1000 cm/s, minority carrier diffusion length in the base region 200 ${\mu}{\textrm}{m}$, front surface recombination velocity 100 cnt/s, sheet resistivity of emitter layer 100 $\Omega$/$\square$, BSF thickness 5 ${\mu}{\textrm}{m}$, doping concentration 5$\times$10$^{19}$ cm$^3$ . Among the investigated variables, we learn that a diffusion length of base layer acts as a key factor to achieve conversion efficiency higher than 19 %. Further details of simulation parameters and their effects to cell characteristics are discussed in this paper.

• Childhood Kidney Diseases
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• 제10권1호
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• pp.8-17
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• 2006

목적 : 생체 외 당뇨병 상태로서 고농도의 당을 포함하는 배양액과 후기당화합물을 적용하여 세포배양하고 이때에 나타나는 병리적 변화, 즉, 세포외 기질의 변화와 형태학적 변화와 함께 투과성(여과율)의 변화를 살펴보았고 동시에 당뇨병성 신증에서의 단백뇨의 기전을 설명하고자 하였다. 방법 : 후기당화합물의 준비를 위해 50mg/mL BSA(Fraction V, Sigma)와 pretense inhibitor를 포함한 PBS(pH 7.4)에 glucose-6-phosphate를 섞어 0.2 M의 용액을 만들었다. BSA를 대조군으로 하였으며, 후기당화합물과 BSA를 $5{\mu}g/cm^2$ surface area의 농도가 되도록 붓고 다음과 같은 비교 대상의 culture dishes를 만들었다(B5; BSA만 첨가 - 5 mM, B30; BSA만 첨가 - 30mM, A5; 후기당화합물만 첨가 - 5 mM, A30; 후기당화합물만 첨가 - 30 mM, A/B 25: osmotic control - 25 mM mannitol). 이틀 배양 후와 일 주 배양 후 각각의 culture dishes에 있는 heparan sulfate proteoglycan (HSPG)양을 ELISA를 이용하여 측정하고 B5를 대준군으로 하여 각각 비교하였다. 각각의 colture dishes에 있는 사구체 상피세포를 scanning EM(Hitachi S-570, Japan)을 이용하여 형태학적 관찰을 하였다. Cellulose semi-permeable membrane을 이용하여 각각의 culture dishes에서 두 시간 동안 apical chamber를 통해 여과되는 BSA양을 sandwich ELISA method로 측정하여 투과성에 대한 분석을 하였다. 결과 : 이틀 동안 배양 후 측정한 대조군을 포함한 다섯 culture dishes의 HSPG양은 통계학적 차이는 없었다. 일 주 배양 후에 이틀 동안 배양한 B5 dish에 비해서 일 주 배양한 A30 dish를 제외한 일 주 배양한 모든 dishes에서 10% 이상의 HSPG양의 증가를 보였다(P<0.05) 일 주 배양한 B5 dish에 비해선 일 주 배양한 A30과 B30 dish에서 각각 HSPG양이 각각 77.8%와 95.3%로 감소하였고(P>0.05), osmotic control group(A/B 25)에선 통계적으로 유의한 차이를 보이지 않았다(P>0.05). 후기당화합물이 첨가된 경우에 SEM상 분리된 세포사이이음(intercellular junction)과 융합된 미세융모를 관찰할 수 있었다. BSA의 투과성은 일 주 배양 후 A30 dish에서만 일 주 배양 후 B5 dish에 비해 19% 증가하는 소견을 보였으나 통계적인 유의성은 없었다(P>0.05). 결론 : 사구체 상피세포의 HSPG 형성의 감소에 고농도의 당과 후기당화합물은 서로 부가적인 역할을 하고 후기당화합물이 더 큰 역할을 함을 알 수 있다. HSPG 감소 소견과 더불어 SEM상 장기간 고혈당을 유지하면 사구체 여과기전에서 size-selective와 charge-selective 장벽에 결함을 유발할 수 있으며 당뇨병에서의 단백뇨의 기전 중 하나로 생각된다.

• 센서학회지
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• 제6권5호
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• pp.414-422
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• 1997

CSVT(close spaced vapor transport)법으로 CdS/CdTe 이종접합 태양전지의 창재에 적합한 낮은 비저항과 적절한 광투과도를 갖는 CdS막을 증착하였다. 기판온도, 분위기압, 소스온도 등의 증착조건에 따른 CdS막의 전기적 및 광학적 특성을 조사하였다. 최적 증착조건은 기판온도 $300^{\circ}C$, 분위기압 100mTorr 및 소스온도 $730^{\circ}C$였으며, 이 때 증착된 CdS 막의 비저항은 $7.21{\times}10^{3}{\Omega}cm$있으며 광투과도는 63%이상이었다. 일반적인 고진공증착법으로 제조된 CdS막에 비해서 결정성이 크게 향상되었고 비저항은 약 3승정도 감소하였으며 광투과도는 비슷하여 창재로서 우수한 특성을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1768-1771
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• 2015

Human Fen1 protein (hFen1) plays an important role in Okazaki fragment processing by cleaving the flap structure at the junction between single-stranded (ss) DNA and doublestranded (ds) DNA, an intermediate formed during Okazaki fragment processing, resulting in ligatable nicked dsDNA. It was reported that hChlR1, a member of the cohesion establishment factor family, stimulates hFen1 nuclease activity regardless of its ATPase activity. In this study, we found that cohesion establishment factors cooperatively stimulate endonuclease activity of hFen1 in in vivo mimic condition, including replication protein-A-coated DNA and high salt. Our findings are helpful to explain how a DNA replication machinery larger than the cohesion complex goes through the cohesin ring structure on DNA during S phase in the cell cycle.

• 한국산학기술학회논문지
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• 제15권6호
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• pp.3423-3428
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• 2014

본 연구는 폭설 및 강풍 시 조립식 비닐하우스의 구조안정성을 해석하였으며, 내재해 규격 중 가장 엄격한 기준인 적설량 40 cm, 풍속 40m/s를 재해 기준으로 고려하여 적설 하중 및 풍 하중이 비닐하우스 구조에 미치는 영향을 분석하였다. 풍 하중의 경우, 공기역학적 특성에 의해 비닐하우스의 형상에 따른 국부적인 압력 분포 특성이 상이하기 때문에 유체-고체연성 해석 기법을 적용하였다. 적설하중 및 풍하중 해석 결과에서 비닐하우스 하단지지 파이프와 지붕서까래 체결 부분 근처에서 가장 큰 응력 및 변형이 발생하며, 적설 하중에 비해 풍 하중 시 구조 안정성이 다소 취약함을 확인하였다. 따라서 본 연구 결과를 기반으로 지지 파이프의 변형을 최소화 하면서 설치 및 유지보수가 용이한 조립식 연결 클립 설계를 위한 기초자료로 활용할 예정이다.

• 소음진동
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• 제4권2호
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• pp.163-175
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• 1994

An analytical method for nautral frequencies of a partially liquid- filled circular cylindrical shell with various boundary conditions is developed by means of the Stokes's transformation and Fourier series expansion on the basis of Sanders' shell equation. The liquid-shell coupled system is divided into two regions for convenient formulation. One is the empty shell region in which the Sanders' shell equations are formulated without the lipuid effect, the other is wetted shell region in which the shell equations are formulated with consideration of the liquid dynamic effect. The shell equations for each regions are combined by the geometry and the force continuities at the junction of the two regions. For the vibration relevant to the liquid motion, the velocity potential of liquid is assumed as a sum of linear combination of suitable harmonic functions in axial direction. The unknown parameters are selected to satisfy the boundary condition along the wetted shell surface. The natural frequencies of the liquid filled cylindraical shells with the clamped- free and the clamped-clamped boundary conditions examined in the previous works, are obtained by this analytical method. The results are compared with the previous works, and excllent agreement is found for the natural frequencies of the shells.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.233-233
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• 2010

Magnetic random access memory (MRAM), based on magnetic tunnel junction (MTJ) and CMOS, is a prominent candidate among prospective semiconductor memories because it can provide nonvolatility, fast access time, unlimited read/write endurance, low operating voltage and high storage density. The etching of MTJ stack with good properties is one of a key process for the realization of high density MRAM. In order to achieve high quality MTJ stack, the use of CoFeB and IrMn magnetic films as free layers was proposed. In this study, inductively coupled plasma reactive ion etching of CoFeB and IrMn thin films masked with Ti hard mask was investigated in a $Cl_2$/Ar gas mix. The etch rate of CoFeB and IrMn films were examined on varying $Cl_2$ gas concentration. As the $Cl_2$ gas increased, the etch rate monotonously decreased. The effective of etch parameters including coil rf power, dc-bais voltage, and gas pressure on the etch profile of CoFeB and IrMn thin film was explored, At high coil rf power, high dc-bais voltage, low gas pressure, the etching of CoFeB and IrMn displayed better etch profiles. Finally, the clean and vertical etch sidewall of CoFeB and IrMn free layers can be achieved by means of thin Ti hard mask in a $Cl_2$/Ar plasma at the optimized condition.