• Title/Summary/Keyword: 엽면적률

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Midterm Results of Mitral Valve Repair by the New Chordae Formation Technique (승모판막 폐쇄부전증에서 신건삭 형성술을 이용한 판막 성형술의 임상분석)

  • Lee, Jae-Won;Lim, Han-Jung;Jung, Sung-Ho;Kim, Kun-Il;Choo, Suk-Jung;Song, Hyun;Song, Meung-Gun
    • Journal of Chest Surgery
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    • v.34 no.4
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    • pp.329-337
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    • 2001
  • 배경: 승포판 전엽이나 교련 또는 여러 판엽에 걸쳐 광범위한 병변으로 인한 승모판 역류의 경우 수술수기에 대한 뚜렷한 정립이 되어 있지 않은 실정이다. 최근 이러한 병변의 승모판 역류의 경우 PTEE(Polytetrafluro-ethylene)을 이용한 신건삭 형성술의 시행이 점차 늘고 있다. 이에 저자들은 PTEE를 이용한 신건삭 형성술이 승모판 성형술에 어떠한 영향을 미치는지 알아보고자 하였다. 대상 및 방법: 1994년 1월부터 1999년 12월까지 승모판막 성형술을 시행 받은 322명의 환자 중에서 신건삭 형성술을 이용하여 승모판 성형술을 시행한 144례(I군)과 신건삭 형성술 이외의 방법으로 승모판 성형술을 시행한 178례(II군)를 대상으로 하였다. 두 군에서 수술 직후ㅘ 수술 후 6개월, 1년 및 1년 단위로 주기적인 심초음파를 시행하였고 이를 통계적 검정하였다. 결과: 같은 기간 승모판 성형술은 승모판막 폐쇄 부전증으로 내원한 환자의 95%(306)에서 추적 관찰이 가능하였다. 두 구난에 수술 전 혈류 역학적인 차이를 보이지 않았고, 수술 전 평균 승모판막 폐쇄 부전의 정도는 I군이 3.8$\pm$0.4, II군이 3.6$\pm$0.3였으나 수술 후 추적 관찰에서 각각 1.3$\pm$0.9와 1.1$\pm$0.7 정도의 양호한 판막 성형술의 결과를 보였고 승모판막 면적의변화나 승모판막에서의 평균 압력차이 등 혈류 역학적인 결과에도 차이를 보이고 있지 않았다. 술 후 3명(0.9%)의 조기 사망과 4명 (1.2%)의 후기 사망이 있었으나 두 군간의 차이는 보이지 않았다. 만기 생존율( 93.7$\pm$3.3 vs 88.0$\pm$1.95) 및 판막살패가 발생하기 않을 확률( 93.7$\pm$3.6 vs 93.3$\pm$3.4%) 과 재수술이 필요치 않을 활률(99.3$\pm$0.7 vs 96.0$\pm$1.9%), 색전증, 감염성 심내막염, 판막과 관련된 합병증 발생률 등에서 두 군간에 의미 있는 차이는 없었다. 전엽과 후엽에서 신건삭 형성술을 시행한 환자에서는 통계학적인 차이가 없었다(p=0.29) 결론: 신건삭 형성술을 이용한 승모판 성형술은 승모판 성형술의 증가(r=0.98, p<0.01)를 가져 왔을 뿐만 아니라 내구성과 안정성에 있어 기존의 안전화된 수술 수기와 견줄만하다. 특히 이러한 신건삭 형성술은 승모판 전엽에 병변이 있는 경우와 교련부 및 여러 엽에 광범위한 병변으로 인하여 재건술이 어려운 경우에도 승모판 재건을 가능하게 하는 우수한 수술 수리가 사료된다.

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Light Quality and Photoperiod Affect Growth of Sowthistle (Ixeris dentata Nakai) in a Closed-type Plant Production System (밀폐형 식물생산시스템에서 광질과 광주기에 따른 씀바귀의 생육)

  • Kim, Hye Min;Kang, Jeong Hwa;Jeong, Byoung Ryong;Hwang, Seung Jae
    • Horticultural Science & Technology
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    • v.34 no.1
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    • pp.67-76
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    • 2016
  • This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

Effect of the Elevated Carbon Dioxide on the Growth and Physiological Responses of Peach 'Mihong' (CO2 상승처리가 복숭아 '미홍'의 수체생육 및 생리반응에 미치는 영향)

  • Lee, Seul Ki;Cho, Jung Gun;Jeong, Jae Hoon;Ryu, Suhyun;Han, Jeom Hwa;Do, Gyung-Ran
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.312-319
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    • 2021
  • This study was conducted to investigate the effect of elevated carbon dioxide on the growth and physiological responses of peach 'Mihong' (Prunus persica). We simulated three different carbon dioxide conditions based on climate change scenarios RCP 8.5 in the sunlight phytotron rooms from April 22 to July 6, 2020; 400 µmol·mol-1(present condition), 700 µmol·mol-1 treatment(expecting carbon dioxide concentrations in mid-21st century), 940 µmol·mol-1 treatment (expecting carbon dioxide concentrations in late 21st century). The average of maximum photosynthesis rate at 700 µmol·mol-1(16.06 µmol·CO2·m-2·s-1) was higher than those at 400 µmol·mol-1(14.45 µmol·CO2·m-2·s-1) and 940 µmol·mol-1(15.96 µmol·CO2·m-2·s-1) from May 22 to July 2. However, stomatal conductances at 700 µmol·mol-1 and 940 µmol·mol-1 were lower than those at the control. Also, the carbon dioxide saturation point in all treatments was reduced from 1,200 µmol·mol-1 in the early stage of growth to 600-800 µmol·mol-1 in the late stage of growth. The stomatal densities were decreased as carbon dioxide increased. The shoot lengths were decreased while the carbon dioxide was increased, but the increase of trunk diameter and leaf areas, shoot numbers were not statistically different. The fruit weight at 700 µmol·mol-1(152.5 g) was higher than those at the control(141.8 g) and 940 µmol·mol-1(147.4 g). The soluble solids were higher at 700 µmol·mol-1, 940 µmol·mol-1 compared to the control. These results suggest that a carbon dioxide elevated to 700 µmol·mol-1 in the future may give a positive effect on the yield and fruit quality of peach 'Mihong' while a carbon dioxide elevated above 940 µmol·mol-1 may affect negatively such as early senescence and loss of fruit set.

Shading Effects on the Growth and Physiological Characteristics of Osmanthus insularis Seedlings, a Rare Species (희귀 식물 박달목서 유묘의 생장 및 생리적 특성에 대한 차광 효과)

  • Da-Eun Gu;Sim-Hee Han;Eun-Young Yim;Jin Kim;Ja-Jung Ku
    • Journal of Korean Society of Forest Science
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    • v.113 no.1
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    • pp.88-96
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    • 2024
  • This study was conducted to determine the optimal light conditions for the in situ and ex situ conservation and restoration of Osmanthus insularis, a rare plant species in South Korea. Evaluations included the growth performance, leaf morphological features, photosynthetic characteristics, and photosynthetic pigment contents of seedlings grown from April to November under different light conditions (100%, 55%, 20%, and 10% relative light intensity). The shoot lengths and root collar diameters did not differ significantly with relative light intensity. The dry weights of leaves, stems, and roots and the leaf number were highest at 55% relative light intensity. The leaf shape showed morphological acclimation to light intensity, with leaf area decreasing and thickness increasing as the relative light intensity increased. Several leaf parameters, including photosynthetic rate and stomatal conductance at light saturation point, net apparent quantum yield, and dark respiration, as well as chlorophyll a, chlorophyll b, and carotenoid contents, were all highest at 55% relative light intensity. Under full light conditions, the leaves were the smallest and thickest, but the chlorophyll content was lower than at 55% relative light intensity, resulting in lower photosynthetic ability. Plants grown at 10% and 20% relative light intensity showed lower chlorophyll a, chlorophyll b, and carotenoid contents, as well as decreased photosynthetic and dark respiration rates. In conclusion, O. insularis seedlings exhibited morphological adaptations in response to light intensity; however, no physiological responses indicating enhanced photosynthetic efficiency in shade were evident. The most favorable light condition for vigorous photosynthesis and maximum biomass production in O. insularis seedlings appeared to be 55% relative light intensity. Therefore, shading to approximately 55% of full light is suggested for the growth of O. insularis seedlings.