• 대한의생명과학회지
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• 제24권4호
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• pp.430-434
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• 2018

Candida glabrata is the second most prevalent causative agent for candidiasis following C. albicans. The opportunistic yeast, C. glabrata, is able to cause the critical bloodstream infections in hospitalized patients. Conventional identification methods for yeasts are often time consuming and labor intensive. Therefore, recent studies on sequence-based identification have been conducted. Recently, sequencing the D1/D2 domain of the large subunit ribosomal RNA gene and the internal transcribed spacers (ITS) 1 and ITS2 regions of the ribosomal DNA has proven useful for DNA-based identification of most species of fungi. In the present study, therefore, fungal ITS and D1/D2 domain regions were targeted and analyzed by DNA sequencing for the accurate identification of C. glabrata clinical isolates. A total of 102 C. glabrata clinical isolates from various clinical samples including bloodstream, catheterized urine, bile and other body fluids were used in the study. The results of the DNA sequence analysis showed that the mean standard deviation of species identity percent score between ITS and D1/D2 domain regions was $97.8%{\pm}2.9$ and $99.7%{\pm}0.46$, respectively. These results revealed that the D1/D2 domain region might be a better target for identifying C. glabrata clinical isolates based on DNA sequences than the ITS1 and ITS2 regions. However, in order to evaluate the usefulness of D1/D2 domain region for species identification of all Candida species, other Candida species such as C. albicans, C. tropicalis, C. dubliniensis, and C. krusei should be verified in further studies additionally.

• Journal of Gastric Cancer
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• 제24권1호
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• pp.108-121
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• 2024

Anastomotic leaks and fistulas are significant complications of gastric surgery that potentially lead to increased postoperative morbidity and mortality. Surgical intervention is reserved for cases with severe symptoms or hemodynamic instability; however, surgery carries a higher risk of complications. With advancements in endoscopic treatment options, endoscopic approaches have emerged as the primary choice for managing these complications. Endoscopic clipping is a traditional method comprising 2 main categories: through-the-scope clips and over-the-scope clips. Through-the-scope clips are user friendly and adaptable to various clinical scenarios, whereas over-the-scope clips can close larger defects. Another promising approach is endoscopic stent insertion, which has shown a high success rate for leak closure, although vigilant monitoring is required to monitor stent migration. Infection control is essential in post-surgical leakage cases, and endoscopic internal drainage provides a relatively safe and noninvasive means to manage fluids, contributing to infection control and wound healing promotion. Endoscopic suturing offers full-thickness wound closure, but requires additional training and endoscopic versatility. As a promising tool, endoscopic vacuum therapy potentially surpasses stent therapy by draining inflammatory materials and closing defects. Furthermore, the use of tissue sealants, such as fibrin glue and cyanoacrylate, has been reported to be effective in selected situations. The choice of endoscopic device should be tailored to individual cases and specific patient conditions, with careful consideration of the nature of the defect. Further extensive studies involving larger patient populations are required to provide more robust evidence on the efficacy of endoscopic approach in managing post-gastric anastomotic leaks.

• Clinical Endoscopy
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• 제55권3호
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• pp.401-407
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• 2022

Background/Aims: Surgeons and endoscopists have started to use endoscopically inserted double pigtail stents (DPTs) in the management of upper gastrointestinal (UGI) leaks, including UGI anastomotic leaks. We investigated our own experiences in this patient population. Methods: From March 2017 to June 2020, 12 patients had endoscopic internal drainage of a radiologically proven anastomotic leak after UGI surgery in two tertiary UGI centers. The primary outcome measure was the time to removal of the DPTs after anastomotic healing. The secondary outcome measure was early oral feeding after DPT insertion. Results: Eight of the 12 patients (67%) required only one DPT, whereas four (33%) required two DPTs. The median duration of drainage was 42 days. Two patients required surgery due to inadequate control of sepsis. Of the remaining 10 patients, nine did not require a change in DPT before anastomotic healing. Nine patients were allowed oral fluids within the 1st week and a soft diet in the 2nd week. One patient was allowed clear oral feeds on the 8th day after DPT insertion. Conclusions: Endoscopic internal drainage is becoming an established minimally invasive technique for controlling anastomotic leak after UGI surgery. It allows for early oral nutritional feeding and minimizes discomfort from conventional external drainage.

• 한국전산유체공학회지
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• 제15권2호
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• pp.7-13
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• 2010

Flight vehicles such as wheel wells and bomb bays have many cavities. The flow around a cavity is characterized as an unsteady flow because of the formation and dissipation of vortices brought by the interaction between the free stream shear layer and the internal flow of the cavity. The resonance phenomena can damage the structures around the cavity and negatively affect the aerodynamic performance and stability of the vehicle. In this study, a numerical analysis was performed for the cavity flows using the unsteady compressible three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equation with Wilcox's turbulence model. The Message Passing Interface (MPI) parallelized code was used for the calculations by PC-cluster. The cavity has aspect ratios (L/D) of 5.5 ~ 7.5 with width ratios (W/D) of 2 ~ 4. The Mach and Reynolds numbers are 0.4 ~ 0.6 and $1.6{\times}10^6$, respectively. The occurrence of oscillation is observed in the "shear layer and transient mode" with a feedback mechanism. Based on the Sound Pressure Level (SPL) analysis of the pressure variation at the cavity trailing edge, the dominant frequencies are analyzed and compared with the results of Rossiter's formula. The dominant frequencies are very similar to the result of Rossiter's formula and other experimental datum in the low aspect ratio cavity (L/D = ~4.5). In the high aspect ratio cavity, however, there are other low dominant frequencies of the leading edge shear layer with the dominant frequencies of the feedback mechanism.

• 한국전산유체공학회지
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• 제19권4호
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• pp.29-36
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• 2014

A computational study of a thermal striping in the upper plenum of PGSFR(Prototype Generation-IV Sodium-cooled Fast Reactor) being developed at the KAERI(Korea Atomic Energy Research Institute) is presented. The LES(Large Eddy Simulation) approach is employed for the simulation of thermal striping in the upper plenum of the PGSFR. The LES is performed using the WALE (Wall-Adapting Local Eddy-viscosity) model. More than 19.7 million unstructured elements are generated in upper plenum region of the PGSFR using the CFX-Mesh commercial code. The time-averaged velocity components and temperature field in the complicated upper plenum of the PGSFR are presented. The time history of temperature fluctuation at the eight locations of solid walls of UIS(Upper Internal Structure) and IHX(Intermediate Heat eXchanger) are additionally stored. It has been confirmed that the most vulnerable regions to thermal striping are the first plate of UIS. From the temporal variation of temperature at the solid walls, it was possible to find the locations where the thermal stress is large and need to assess whether the solid structures can endure the thermal stress during the reactor life time.

• 한국전산유체공학회지
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• 제18권2호
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• pp.85-92
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• 2013

In this study, we consider heat transfer enhancement in laminar channel flow by means of an infinite streamwise array of equispaced identical circular cylinders. This flow configuration can be regarded as a model representing a micro channel or an internal heat exchanger with cylindrical vortex generators. A numerical parametric study has been carried out by varying Reynolds number based on the bulk mean velocity and the cylinder diameter, and the gap between the cylinders and the channel wall. An immersed boundary method was employed to facilitate to implement the cylinders on a Cartesian grid system. No-slip condition is employed at all solid boundaries including the cylinders, and the flow is assumed to be periodic in the streamwise direction. Also, the Prandtl number is fixed as 0.7. For thermal boundary conditions on the solid surfaces, it is assumed that heat flux is constant on the channel walls, while the cylinder surfaces remain adiabatic. The presence of the circular cylinders arranged periodically in the streamwise direction causes a significant topological change of the flow, leading to heat transfer enhancement on the channel walls. The Nusselt number averaged on the channel wall is presented for the wide ranges of Reynolds number and the gap. A significant heat transfer enhancement is noticed when the gap is larger than 0.8, while the opposite is the case for smaller gaps. More quantitative results as well as qualitative physical explanations are presented to justify the effectiveness of varying the gap to enhance heat transfer from the channel walls.

• 한국전산유체공학회지
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• 제10권2호
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• pp.38-47
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• 2005

Substructuring methods are often used in finite element structural analyses. In this study a multi-level substructuring(MLSS) algorithm is developed and proposed as a possible candidate for finite element fluid solvers. The present algorithm consists of four stages such as a gathering, a condensing, a solving and a scattering stage. At each level, a predetermined number of elements are gathered and condensed to form an element of higher level. At the highest level, each sub-domain consists of only one super-element. Thus, the inversion process of a stiffness matrix associated with internal degrees of freedom of each sub-domain has been replaced by a sequential static condensation of gathered element matrices. The global algebraic system arising from the assembly of each sub-domain matrices is solved using a well-known iterative solver such as the conjugare gradient(CG) or the conjugate gradient squared(CGS) method. A time comparison with CG has been performed on a 2-D Poisson problem. With one domain the computing time by MLSS is comparable with that by CG up to about 260,000 d.o.f. For 263,169 d.o.f using 8 x 8 sub-domains, the time by MLSS is reduced to a value less than $30\%$ of that by CG. The lid-driven cavity problem has been solved for Re = 3200 using the element interpolation degree(Deg.) up to cubic. in this case, preconditioning techniques usually accompanied by iterative solvers are not needed. Finite element formulation for the incompressible flow has been stabilized by a modified residual procedure proposed by Ilinca et al.[9].

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4717-4724
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• 2012

본 연구는 한국전통발효음식과 미백치아의 색조변화와의 관련성을 알아보고자 시행하였으며, 연구방법은 전문가 치아미백을 시행한 자연치아를 한국전통발효음식에 일정기간 침전 후 치과용 측색기를 이용하여 치아색조변화의 정도를 객관적으로 측정하였다. 본 연구에 사용된 치아시편은 30개로 한 치아당 30회 측정되었으며, 전체 측정 횟수는 900회 실시되었다. 측정은 치과용 측색기 ShadeEye NCC$^{(R)}$ Dental Chroma Meter를 사용하였다. 수집된 자료는 PASW 18.0을 사용하여 분석한 결과, 미백 전, 후 명도와 황색채도에서 유의한 차이가 나타났으며(p<0.001), 용액침전 후 명도와 황색채도는 시간에 따라 변화하였다(p<0.001). 침전용액에 따른 색조변화량의 차이를 알아본 결과, 미백 후부터 1주 동안, 2주에서 3주까지의 기간 동안 각 침전용액에 따라 유의한 차이가 나타났다(p=0.001, p<0.001). 한국전통발효음식은 침전기간과 침전용액에 따라 미백치아의 색조변화에 영향이 있음을 알 수 있었다. 하지만 본 연구는 구강 내의 상태 그대로를 재연하지 못하였기에 구강 내 상태, 섭취빈도, 구강위생관리에 따라 차이가 있을 것이다.

• 대한수의학회지
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• 제31권4호
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• pp.411-418
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• 1991

This study was carried out to investigate the amino acid and protein concentrations in amniotic fluid and the potency of the teratogenic effect of ethylenethiourea(2-imidazolidinethione, ETU) in the fetuses due to different dose amounts of this compound. The S.P.F. Sprague-Dawley female rats(10 weeks) were used in this study and these animals were divided into four groups; control group(25pregnant female rats), group I (dosed ETU from day 7 to day 17 of gestation at 10mg/kg/day), group II (dosed ETU from day 7 to day 17 of gestation at 30mg/kg/day), group III (dosed ETU from day 7 to day 17 of gestation at 50mg/kg/ day). 250mg/100mg ETU in group I, 750mg/100ml ETU in group II and 1,250mg/100ml ETU in group III were administered 4ml/kg 13.W by oral route. The results obtained were summarized as follows; 1. The anomalies of the external examination werf meningocele in the head, kinky tail, clubfoot and sharp tail.(Meningocele, in group III, significantly increased from control value at p<0.001). 2. The skeletal variations and delayed ossification were Lumbar ribs, asymmetric sternebrae, asymmetric 13th rib and delayed ossification of skull. Asymmetric sternebrae(group III ) was significantly increased from control value at p<0.05 and delayed ossification of skull (group II and III ) were significantly increased from control value at p<0.05 and p<0.01, respectively. 3. The internal soft tissue anomalies were hydroencephaly of 3th lateral ventricle, dilatation of ureter, dilatation of renal pelvis and cleft palate. (Hydroencephaly, 28.1% in group I, 88.3% in group II and 100% in group III ). 4. Protein values in amniotic fluids are not significantly decreased in 10mg/kg group but significantly(p<0.05) decreased in 30mg/kg group and 50mg/kg group from control group. 5. In the levels of amino acid in amniotic fluids, the levels of glntamic acid, iso-lencine, leucine, tyrosine and phenylalanine of 10mg/kg group are significantly decreased from control group. In 50mg/kg group, except for glycine, valine and methionine, all amino acid levels are significantly(p<0.05) decreased from control group.

• Tuberculosis and Respiratory Diseases
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• 제40권1호
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• pp.35-42
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• 1993

연구배경 : 흉막삼출의 원인 규명을 위한 방법으로는 여출액과 삼출액을 감별하기 위한 흉막액 통상검사, 세균학적검사, 세포학적검사 및 흉막생검 등이 시행되고 있다. 그러나 상기한 여러가지 방법으로도 약 10~20% 에서는 그 원인을 정확히 진단하기 어려운 실정이다. 본 연구는 상기한 여러 가지 방법을 통해 확진된 흉막삼출 환자를 대상으로 흉막액의 adenosine deaminase (ADA) 활성도 및 carcinoembryonic antigen (CEA)을 측정함으로써 흉막삼출 원인질환의 감별진단에 있어서의 임상적 의의를 평가하고자 하였다. 방법 : 1984년 3월부터 1987년 3월까지 연세대학교 의과대학 세브란스 병원에 삼출성 흉막염으로 입원하였던 환자중, 진단이 확실한 결핵성 흉막염 환자 61예, 폐결핵에 동반된 흉막삼출 17예, 악성 흉막염으로 확진된 17예, 폐암 및 기타 장기암에 동반된 흉막삼출 22예, 부폐렴성 흉막삼출 7예로서 총 124예를 연구 대상으로 하여 흉막액 ADA 활성도 및 CEA 치를 병행 측정하였다. 결과: 1) 결핵성 흉막삼출의 ADA 활성도는 악성 흉막삼출에 비하여 의의있게 높았다. 2) 악성 흉악삼출의 CEA 치는 결핵성 흉막삼출에 비하여 의의있게 높았다. 3) 흉막액 ADA 활성도가 40U/L 이상이면서 CEA 치 12ng/mL 미만인 경우를 결핵성 흉막염의 진단 기준으로 삼으면 그 예민도는 86.9%, 특이도는 100%이었다. 흉막액 CEA 치가 12 ng/mL 이상이면서 ADA 활성도가 40U/L 미만인 경우를 악성 흉막염의 진단 기준으로 하면 그 예민도는 76.5%, 특이도는 100%이었다. 결론 : 흉막액 ADA 활성도 및 CEA 치의 병행 측정은 흉막삼출 원인질환의 감별진단에 매우 중요한 지표로 삼을 수 있으리라 생각된다.