• Title/Summary/Keyword: Leaflet

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Measurement of Flow Field Downstream of Polyurethane Artificial Heart Valve with Floating Valve Leaflet (열림판이 지지대에 고정되지 않은 폴리우레탄 인공판막 하류의 유동장 측정)

  • Kim, J.K.;Sung, J.;Chang, J.K.;Min, B.G.;Yoo, J.Y.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.247-248
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    • 1998
  • The effect of unattached valve leaflet on flow field downstream of a floating and flapping polyurethane heart valve prosthesis was investigated. With a triggering system and a time-delay circuit the instantaneous velocity field downstream of the valve was measured by particle image velocimetry (PIV) in conjunction with the opening posture of a flexible valve leaflet during a cardiac cycle. Reynolds shear stress distribution was calculated from the velocity fields and wall shear stress was directly measured by hot-film anemometry (HFA). The floating motion of the valve leaflet resulted in the reduction of pressure drop and recirculating flow region downstream of the valve.

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A study on Brand Images and Consumers' Buying Intentions by Fashion Leaflet Advertisements (패션전단 광고에 따른 브랜드이미지와 구매의도에 관한 연구)

  • 신초영;이승희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.5
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    • pp.475-484
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    • 2003
  • The objectives of this study were to investigate the consumers' general perceptions and attitudes in response to the leaflet fashion advertisements, and to examine how much differently the level of price and the advertisement type affect brand images and consumers' buying intentions. Subjects for this study were 192 female university students in the twenties. Through the pre-test, several casual brands with such various the level of price as high, middle. and low were selected. Stimuli consisted of 8 photographs of the advertisements types which were manipulated according to the price level(highㆍmiddle & low) and the advertisements type(generalㆍleaflet). The results showed that consumers got the information on the fashion products mostly from the advertisements in magazines. It was also found that consumers showed the highest interests on the design and the discount rate of prices in the leaflet fashion advertisements. The price range(highㆍmiddle & low) of casual brands had significantly affected on the brand image and the consumers' buying intention. And the higher the prices of casual brands were, the worse brand images were when products were advertised by fashion leaflets. The advertisements types(generalㆍleaflet) gave some influences only on the brand image. Based on these results, marketing strategies of fashion advertising would be ,suggested.

Effects of the Mitral Valve Replacement with Preservation of Posterior Mitral Leaflet and Chorda Tendinae for Mitral Valvular Disease (승모판막질환에서 승모판 대치술시 승모판 후엽 및 건삭 보존의 효과)

  • Jo, Gang-Rae;Kim, Jong-Won
    • Journal of Chest Surgery
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    • v.23 no.3
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    • pp.488-500
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    • 1990
  • Author compared the effect of surgical methods between 40 patients who received mitral valve replacement with complete excision of the mitral valve[resected group] and 41 patients who received mitral valve replacement with preservation of posterior chorda tendineae and posterior mitral leaflet[preserved group] from 1985. 2. to 1989. 4. at cardiothoracic department of Pusan National University Hospital.v 1. There was no significant difference between the preserved group and resected group in cardiopulmonary bypass time and aortic cross clamping time and NYHA classification. 2. In preserved group of Mitral stenosis and Mitral regurgitation, the left ventricular functions were much improved after mitral valve replacement than resected group, but there was not so difference between the preserved group and reserved group in Mitral steno-regurgitation. 3. There were remarkable decrease in complication rate in preserved group compared to resected group. And also the death rates were remarkably decreased in preserved group which was 4.9% compared to resected group which was 17.5%. As the preservation of the posterior mitral leaflet and chorda tendineae during mitral valve replacement in mitral valve disease showed significantly improved effects in the maintaining of left ventricular function and reducing the postoperative complication, I assume the preservation of posterior mitral leaflet and chordae during mitral valve replacement will bring better result.

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Chordae Tendineae Approximation Technique for Severe Tricuspid Regurgitation with Severe Leaflet Tethering Using a Totally Endoscopic Beating-Heart Strategy: A Case Report

  • Dong Hee Jang;Jae Suk Yoo
    • Journal of Chest Surgery
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    • v.56 no.1
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    • pp.56-58
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    • 2023
  • Untreated severe tricuspid regurgitation (TR) is associated with poor outcomes. Functional TR occurs secondary to dilatation of the annulus and tethering of the leaflets. Ring annuloplasty alone can correct most cases, but is insufficient in cases of severe annular dilatation due to severe leaflet tethering. In such cases, a tricuspid edge-to-edge technique may be an option. However, stitching of the leaflet tips alone is likely to result in tearing of the leaflets. Approximation of the durable chordae tendineae is considered helpful for this problem. Herein, we present the case of a 39-year-old man who had undergone open-heart surgery for acute type A aortic dissection 13 months earlier. A right mini-thoracotomy approach with a beating-heart strategy was used, which did not require unnecessary pericardial adhesiolysis and dissection. This technique had the advantage of reducing the operation time and the risk of bleeding. To summarize, we present a case of tricuspid valve repair in a high-risk patient with severe leaflet tethering that was successfully managed using these methods.

Development and Evaluation of Nutrition Education Program for Middle Aged Men at Worksite (중년 남성의 직장내 영양교육 프로그램 개발 및 평가)

  • 우미경;제갈성아;김성애
    • Korean Journal of Community Nutrition
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    • v.3 no.2
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    • pp.261-272
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    • 1998
  • The purpose of this study was to develop, implement and evaluate a nutrition education program for middle aged men at a worksite. To be read easily, induce interest, and selected at need, seven 6-page leaflet aets were developed, which was the most preferable from chosen by the subjects. The contents of leaflet set were [Changing life style], [Good food habit],[Weight control and diet],[Cardiovascualr disease and diet], [Alimentary disease and diet],[Diaabetes and diet],and [Liver disease and diet]. Nutrition education was provided for 61 middle aged men(30 professors, 31 office workers) at a worksite from 40 mins to one hour. And the level of nutrition knowledge and nutrition attitude were tested to evaluate the effects of the nutrition education program with a developed leaflet set before and after nutrition education. After the nutrition deucation. the nutrition knowledge score had increased significantly at p<0.001, from average 9.3 point to 11.4 point. The level of nutrition knowledge was increased significantly at p<0.001, and the prevalence of misconceptions and the uncertainty of knowledge were decreased significantly at p<0.05. There was a significant difference between professors and office workers both before and after the program. Also, there was a significant increase in the attitude about nutrition score after the program and this means that the subjects were flexibly more open minded about nutrition than before(from 39.9 point, at p<0.001). The difference in the nutrition attitude score between professors and office workers was not significant both before and after the nutrition deucation. The developed leaflet set was evaluated very positively in understanding, interest, timing, and usage by the subjects.

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Photosynthesis and Leaf Anatomical Morphology on Different Leaf Shape of Soybean (엽형에 따른 콩 품종의 광합성 능력과 잎의 해부형태 비교)

  • Moon-Hee Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.3
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    • pp.248-251
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    • 2003
  • To find ideal leaf types for soybean breeding program, we examined the relationships among leaf anatomical and morphological characteristics and $\textrm{CO}_2$ assimilation on the different leaflet shape of soybean (Glycine max). In anatomical characters of leaf, palisade and spongy cells were thicker in both small seed cultivars with narrow leaflet and large seed cultivars with wide leaflet than others. $\textrm{CO}_2$ uptake per plant and leaf thickness were significantly associated with seed yield per plant, showing difference among the soybean cultivars. Although the leaf area was lower for narrow leaflet cultivars, which had a significantly higher photosynthetic rate per plant comparable to the wide leaflet cultivars.

Developing and Evaluating a Drug Information Leaflet of Antidiabetics for Senior Citizens; Employing Performance-based User-testing (노인용 당뇨치료제 안전사용설명서 개발 및 평가: 수행능력 기반 사용자 평가 활용)

  • Kim, Jin;Shim, Haeri;Lee, Iyn-Hyang
    • Korean Journal of Clinical Pharmacy
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    • v.27 no.3
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    • pp.171-177
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    • 2017
  • Objective: The study purpose was to develop a drug information leaflet for the elderly and to evaluate it with performance-based user-testing. Methods: We performed a stratified randomized controlled trial. We recruited 62 elderly patients with age of 65 or above who were taking antidiabetic medications at the point of participating and excluded those who suffered illiteracy. We randomly allocated them into the intervention group with a leaflet for the elderly and the control group with a leaflet for the general public. Main outcome measures were to 'be able to find information' and to 'be able to understand information.' We measured outcome variables by employing performance-based user-testing and analyzed data to find any differences between two groups with t-tests, chi-squared tests or Fisher's exact tests accordingly. Results: More participants in the intervention group understood how to store their medications than those in the control group (intervention group 93% vs. control group 70%; p=0.02). There were no significant differences in other information items between two groups. Mostly 'being able to understand information' was lower than 'being able to find information.' The gaps between two outcome variables were about 10% in the intervention group and about 18% in the control group. The lowest understanding was observed in information relating to drug names and their potential adverse events. Conclusion: Without providing personalized drug information, it might be hard for the elderly to improve their drug knowledge even with leaflets that were developed specifically for the elderly.

Surgical Treatment of Partial Atrioventricular Septal Defect (부분 방실중격결손증의 외과적 치료)

  • 최준영
    • Journal of Chest Surgery
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    • v.20 no.4
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    • pp.760-764
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    • 1987
  • Fifty seven patients underwent repair of a partial atrioventricular septal defect from January 1980 to December 1986. The ostium primum atrial septal defect was closed with autologous or bovine pericardium. The cleft in the anterior mitral leaflet was present in 53 cases, absent in 4 cases. Of the 53 cases with a cleft in the anterior mitral leaflet, 48 received suture repair of the cleft, 3 received mitral valve replacement. There was no hospital death and all the patients were followed-up for a mean period of 26.4 months. Four required permanent pacemaker implantation due to complete heart block, and one of them died of sudden malfunction of pacemaker. Two received reoperation due to significant residual mitral insufficiency. Suture repair of the cleft in the anterior mitral leaflet resulted in significant decrease in degree of mitral regurgitation. During follow-up period 49 patients were in NYHA class I, 7 patients were in NYHA class II. This report suggests that excellent result can be achieved from repair of the partial atrioventricular septal defect by managing the left A-V valve as a bileaflet structure.

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Source-Sink Relations in North American Ginseng Seedlings as Influenced by Leaflet Removal

  • T. A., John
    • Journal of Ginseng Research
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    • v.32 no.4
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    • pp.337-340
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    • 2008
  • Seedlings of North American ginseng (Panax quinquefolius L.) were grown to full canopy establishment and then leaflet or leaf removal at different times applied to determine the effects on plant growth and performance. Leaf removal at 47, 57, 69 and 78 days after seeding resulted in 82.1, 59.8, 41.3 and 29.8% reduction, respectively, in root dry matter (economic yield) ; this indicates that leaf removal during the early root growth period causes greatest reduction in root yield. Removal of 1, 2, and 3 leaflets at 42, 52, 62 and 70 days from seeding reduced root weight at harvest (80 days from seeding) linearly, particularly at earlier removal dates. The perennating bud formed on all roots and was not influenced by treatment. This would suggest that if leaf loss occurs after canopy establishment the plant will re-grow the next year after the obligatory dormancy period.

Exploring on the Defense Strategies Against Hervivory of Juglans regia and J. mandshurica (호두나무와 가래나무의 초식에 대한 방어전략 탐색)

  • Kim, Gab-Tae;Lyu, Dong-Pyo;Kim, Hoi-Jin
    • Journal of Korean Society of Forest Science
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    • v.99 no.3
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    • pp.298-303
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    • 2010
  • To explore on the defense strategies against hervivory of Juglans regia and J. mandshurica, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Mt. Chiak, Mt. Cheongtae, Mt. Jungwang, Namyangju-si and Wonju-si, were investigated from May to October, 2009. Domatia of J. mandshurica revealed tuft type, these of J. regia revealed pocket+tuft type. Domatia number per leaflet proved the higher figures, 28.3/leaflet for J. mandshurica, and the lower, 19.6/leaflet for J. regia. Leaf surface trichomes of J. regia revealed stellates only on the domatia structures, and that of J. mandshurica does dense stellates and glandular hairs on the leaf-blade and vein. Predatory mites' number per leaflet proved highly significant differences among tree species, and mean of predatory mites was higher values (4.8/leaflet) in J. mandshurica and lower values (3.5/leaflet) in J. regia. Small amount of nectar are found distal veinparts on the leaf margin of J. mandshurica. Dense glandular hairs on the lower leaf surfaces of J. mandshurica estimates useful strategy against herbivory. It may be possible to breed J. regia for better expression of leaf traits such as dense glandular hairs that increase predator populations and efficacy.