• The Korean Journal of Physiology and Pharmacology
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• 제6권4호
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• pp.225-233
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• 2002

Kanagawa hemolysin (KH), an exotoxin produced from Kanagawa phenomenon-positive Vibrio parahemolyticus, has been shown to possess various biological activities including hemolysis, enterotoxicity, cytotoxicity, and cardiotoxicity. The aim of this study was to investigate the effect of KH on the cardiovascular system and its mechanism, employing in vivo and in vitro experiments of the rat. Intracerebroventricular (icv) administration of 100 mHU KH produced a marked and continuous pressor effect (icv KH-pressor effect), and the icv pressor effect was not repeatable. However, intravenous (iv) injection of the same dose of KH induced a prominent depressor effect (iv KH-depressor effect). The icv KH-pressor effect was inhibited by acid-denaturation, while the iv KH-depressor effect was not. Simultaneous icv administration of the three agents (ouabain, diltiazem, or bumetanide: $10{\mu}g/kg$ each) significantly reduced the pressor effect. The icv KH-pressor effect was inhibited by treatment with iv phentolamine or chlorisondamine, but was not affected by iv candesartan. The iv KH-depressor effect was repeatable and was attenuated by treatment with iv NAME or methylene blue. In vitro experiments using isolated thoracic aorta, $10^{-6}$ M phenylephrine (PE) and 50 mM KCl produced a sustained contraction. In rings contracted with either agents, KH showed relaxant responses in a concentration- dependent fashion and the relaxation (KH-vasorelaxation) was not dependent on the existence of the endothelium. The KH-vasorelaxation in the endothelium-intact rings contracted by PE was abolished by methylene blue treatment. In summary, the present findings suggest that in the icv KH-pressor effect the cation leak-inducing action of KH is implicated, which leads to the increased central sympathetic tone, that the iv KH-depressor effect results from the vasorelaxation via NO-guanylate cyclase system, and that the KH-vasorelaxation is independent of the endothelium and the guanylate cyclase system is involved in it. In conclusion, the mechanism of KH producing the icv pressor effect may not be identical to that of KH producing the iv depressor effect.

• 한국수정란이식학회지
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• 제17권1호
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• pp.1-5
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• 2002

본 연구는 고능력 한우 공란우의 이용효율을 극대화하기 위하여 반복 과배란처리가 수정란회수율에 미치는 영향을 알아보고자 수행하였다 공란우의 선발은 DNA marker에 의한 고급육을 선발하였다. 선발된 공란우는 Folltropin-V와 PG$F_2$$\alpha$를 병용 처리하여 과배란을 유도하였고, FSH 처리 6회째 PG$F_2$$\alpha$를 처리하여 발정을 유도하였다. 발정유도된 공란우의 수정은 12시간 간격으로 3회, 1회당 2 straw식 인공수정을 실시하였다. 수정 후 7~8일째 비외과적인 관류방법으로 채란하여 이식 가능란 또는 비정상란 등으로 구분하였다. 이식 가능한 수정란은 발정동기화된 수란우에 수정란이식을 실시 하였다. 고능력 한우 공란우로부터 반복 과배란처리에 의한 체내수정란 회수는 1차부터 5차에 걸쳐 각각 14, 4, 10, 6, 9개(계 43개)의 수정란이 회수되었고 이식 가능 수정란은 각각 7, 4, 10, 3, 6개(계 30개, 평균 6.0$\pm$2.7개)가 회수되었다. 채란된 수정란의 이식 후 수태율은 총 24개의 수정란을 17두에 이식하여 10두가 임신됨으로써 58.8%의 수태율을 얻었다. 이상의 결과로 보아 고급육 한우 또는 고능력 젖소 공란우를 이용한 반복적인 과배란 처리에 의한 수정란의 태란 가능성을 확인할 수 있었으며, 이와 같은 방법으로 고능력 공란우의 이용효율을 극대화 시킬 수 있다면 수정란이식의 산업화에 크게 기여할 수 있을 것으로 판단된다

• 한국표면공학회지
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• 제35권6호
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• pp.357-362
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• 2002

In this study, to improve the effect of the surface treatment, the shape design of shot ball is proposed. The fatigue effects of shot peening by the cut wire shot ball and the rounded cut wire shot ball are compared. The rotary bending and tensile fatigue tests are conducted on a spring steel to evaluate fatigue lives. The residual compressive stresses by the rounded cut wire shot ball is higher than by the rounded cut wire shot ball. This consequently increase the fatigue life and the reliability of surface treatment. Thus, to obtain optimum, repeatable and reliable shot peening effect the shape of the shot ball must be round.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.877-880
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• 2008

In this article, in order to fabricate polymer based electrospray device with super hydrophobic nozzle we use PTFE(polyfluorotetraethylene) plate and PMMA(polymethylmethacrylate). To obtain the super hydrophobic surface nozzle, PTFE surface is treated by argon and oxygen plasma treatment process. And evaluate the treated surface, perform measuring contact angle, SEM(Scanning Electron Microscope) and AFM(Atomic Force Microscope). We compare the performance of the super hydrophobic PTFE surface nozzle with raw PTFE and PMMA surface nozzle. For the ion beam treated PTFE nozzle, the liquid doesn't overflow and it keeps initial position and meniscus shape. From these results, we expect in cease of superhydrophobic surface nozzle jetting becomes more stable and repeatable.

• 열처리공학회지
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• 제26권5호
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• pp.233-240
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• 2013

Rapid and homogeneous heating in heat treatment has been a challenging engineering issue throughout a heating temperature over $1,000^{\circ}C$. Induction heating has been widely used in field of heat treatment compared with conventional heating system. Advantages in homogeneous heating, simple fabrication, and repeatable use can be efficiently made with the induction heater. In this paper, numerical analysis of an induction coil system for heat flux gauge heating is performed. The effect of configuration on the heating performance was considered in various cases of the coil radius, distance between the winding, relative height difference between the heat flux gauge and the coil, and the applied current frequency. Temperature distribution within the heat flux gauge at frequency-steady state was calculated with a finite element method. Sensitivity analysis was also performed and the relative importance of 2 key parameters; coil radius, distance between the winding, were taken as main contributors for induction heating.

• Journal of Korean Dental Science
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• 제13권2호
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• pp.59-66
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• 2020

Purpose: The purpose of this study was to investigate the masseter muscle thickness before and after treatment using ultrasound sonography in patients with parafunctional habits. Materials and Methods: From September 2019 to March 2020, a total of 27 patients who visited the Department of Oral and Maxillofacial Surgery at Ewha Womans University Seoul Hospital were collected. The thickness of both masseter muscles was measured using a tablet ultrasound scanner. Statistical analysis was performed by using the IBM SPSS version 26.0 statistical package (IBM Corp) with significance level at 0.05. Result: According to the statistical results, the thickness of the masseter muscle was thicker on the right side than on the left, with no correlation with sex or age. The severity and duration of pain did not have a significant correlation with the thickness of the masseter muscle. Botulinum A toxin injection in the masseter muscle was the most effective way to reduce pain and reduce the thickness of the masseter muscle. Splint treatment also showed some effects in reducing the thickness of the masseter muscle. Conclusion: Based on the findings, it can be claimed that ultrasonography is simple, inexpensive and easily repeatable method to get real-time diagnosis and treatment results for masseter muscles.

• 대한치과보철학회지
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• 제38권6호
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• pp.821-828
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• 2000

Metal - ceramic restorations have been the standard of fixed oral rehabilitation for over 30 years, and while many advances have been made in materials and research, the esthetic challenges of the light reflective metal substructure will always put clinician in an esthetic dilemma, for only a very talented ceramist / dentist team can create esthetics that rival nature on a repeatable basis. All ceramic restorations have also been a choice in our restorative armamentarium, but in the past, the materials have also had their own limitation, number on being question-able strength to withstand occlusal forces generated during mastication. IPS Empress 2 offers dentistry a metal free alternative to traditional restorative techniques. This clinical report describes the treatment of patients with esthetic problem of anterior dentition using Empress 2 system.

• Korean Journal of Radiology
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• 제20권5호
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• pp.773-780
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• 2019

Objective: To assess segmental liver stiffness (LS) with MRI before and after endovascular intervention in patients with Budd-Chiari syndrome (BCS). Materials and Methods: Twenty-three patients (13 males and 10 females; mean age, 42.6 ± 12.6 years; age range, 31-56 years) with BCS as a primary liver disease were recruited for this study. Two consecutive magnetic resonance elastography (MRE) examinations were performed before the endovascular treatment. Fifteen patients who underwent endovascular intervention treatment also had follow-up MRE scans within three days after the procedure. LS was measured in three liver segments: the right posterior, right anterior, and left medial segments. Inter-reader and inter-exam repeatability were analyzed with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Segmental LS and clinical characteristics before and after the intervention were also compared. Results: Within three days of the endovascular intervention, all three segmental LS values decreased: LS of the right posterior segment = 7.23 ± 0.88 kPa (before) vs. 4.94 ± 0.84 kPa (after), LS of the right anterior segment = 7.30 ± 1.06 kPa (before) vs. 4.77 ± 0.85 kPa (after), and LS of the left medial segment = 7.22 ± 0.87 kPa (before) vs. 4.87 ± 0.72 kPa (after) (all p = 0.001). There was a significant correlation between LS changes and venous pressure gradient changes before and after treatments (r = 0.651, p = 0.009). The clinical manifestations of all 15 patients significantly improved after therapy. The MRE repeatability was excellent, with insignificant variations (inter-reader, ICC = 0.839-0.943: inter-examination, ICC = 0.765-0.869). Bland-Altman analysis confirmed excellent agreement (limits of agreement, 13.4-19.4%). Conclusion: Segmental LS measured by MRE is a promising repeatable quantitative biomarker for monitoring the treatment response to minimally invasive endovascular intervention in patients with BCS.

• 구강회복응용과학지
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• 제25권4호
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• pp.337-347
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• 2009

심하게 마모된 치열의 경우 마모로 인해 교합평면의 이상과 보철물을 제작할 공간이 없는 경우가 많다. 이 경우 대개 reverse curve를 보이는 교합평면을 바로잡고 보철물을 제작하기 위해 고합교경을 높여주는 과정이 필요하다. 교합고경이란 상하악 치아가 최대 폐구위에서 감합하고 있을때 상악에 대한 하악의 수직적 위치를 나타낸다. McAndrew는 고경이 변한다해도 중심위에서 전체치궁의 균일한 접촉이 이루어 진다면 치조골내에서 일어나는 remodeling 에의한 고경의 변화에도 불구하고 수정된 교합개선상태는 유지된다고 하였다. 중심위는 치료를 위한 하악위치의 참고점으로 널리 사용되어 왔다. 중심위란 하악이 해부학, 생리학적으로 안정을 이룬 상태에서 반복재현 가능한 위치이다. 본 증례에서는 심하게 마모된 치열을 지녀 보철수복을 위한 공간을 상실한 환자에서 교합고경을 증가시켜 중심위를 이용하여 처치한 치험예를 문헌고찰과 함께 보고하고자 한다.

• Radiation Oncology Journal
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• 제16권3호
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• pp.351-355
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• 1998

혈관육종은 전체 악성종양의 빈도에서 약 1$\%$를 차지하는 매우 드문 종양이다. 이 중 반 수 정도는 두경부에 발생하며 특히 장년 층의 남자에서 두피에 호발하는 경향을 보인다. 권고되는 치료방법으로는 수술적 제거와 방사선치료가 있으나 넓은 범위의 종양이 전 두피에 퍼져있을 때는 수술적 방법이 적용되기 힘들다. 여기 방사선 치료만으로 완전 관해를 보인 두피 혈관육종의 경우를 보고하며 엑스선과 전자선을 이용하여 간단하면서도 재현성 있는 방사선치료방법을 소개한다. 볼루스는 표면선량을 증가시키고 뇌조직의 정상세포에 대한 방사선량을 최소화시키기 위하여 사용할 수 있지만 두경부와 같이 굴곡이 심한 환자의 표면에 밀착시키기는 어렵다 Thermoplastic과 파라핀을 이용하여 제작한 헬멧을 혈관육종의 방사선 치료에 사용한 결과 전체 두피에 대한 열형광선량계에 의해 측정한 방사선량은 7$\%$ 이내의 고른 선량분포를 얻을 수 있었다.