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A Study of Upper Airway Resistance Syndrome : Clinical and Polysomnographic Characteristics (상기도저항 증후군에 대한 연구 : 임상 및 수면다원검사 특징)

  • Yang, Chang-Kook;Clerk, Alex
    • Sleep Medicine and Psychophysiology
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    • v.3 no.2
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    • pp.32-42
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    • 1996
  • Objectives : Upper airway resistance syndrome(UARS) is a sleep-related breathing disorder characterized by abnormal negative intrathoracic pressure during sleep. Abnormally increased negative intrathoracic pressure results in microarousal and sleep fragmentation which underlay UARS-associated complaints of daytime fatigue and sleepiness. Although daytime dysfunction in patients with UARS is comparable to that of sleep apnea syndrome, UARS has been relatively unnoticed in clinical setting. That is why UARS is apt to be excluded in diagnosing of sleep-related breathing disorders since its respiratory disturbance index and arterial oxygen saturation are within normal limits. The current study presents a summary of clinical and polysomnographic characteristics found in patients with UARS. The present study aims (1) to explore characteristics of patients diagnosed with UARS, (2) to characterize the polysomnographic findings of UARS patients, and (3) to enhance the understanding of UARS through those clinical and laboratory characteristics. Methods : This was a retrospective study of 20 UARS patients (male 15, female 5) and 30 obstructive sleep apnea (OSA) patients (male 21, female 9) at the Stanford Sleep Disorders Clinic. We diagnosed patients as having UARS when they met critenia, RDI < 5 characteristic findings of an elevated esophageal pressure($<-10\;cmH_2O$), frequent arousals secondary to an elevated esophageal pressure, and symptoms of daytime fatigue and sleepiness. We used polysomnographic value, which is standardized by Williams et al(1974), as normal control. Statiotical test were done with student t-tests. Results : (1) Mean age of UARS was $41.0\;{\pm}\;14.8$ years and OSA was $50.9\;{\pm}\;12.0$ years. UARS subject was significantly younger than OSA subject (p<0.05). (2) The total score of Epworth Sleepiness Scale (ESS) was UARS $9.7\;{\pm}\;6.3$ and OSAS $11.2\;{\pm}\;6.3$. There was no significant difference between two groups. (3) The mean body mass index was UARS $28.1\;{\pm}\;5.7\;kg/m^2$ and OSAS $32.9\;{\pm}\;7.0\;kg/m^2$. UARS had significantly lower meen body man index than OSAS subjects (p<0.05). (4) The polysomnographic parameters of UARS were not significantly different from those of OSA except RDI(p<0.001), $SaO_2$ (p<0.001) and slow wave sleep latency (p<0.05). (5) Compared with normal control, Total sleep time in UARS subjects was significantly shorter (p<0.001), sleep efficiency index was significantly lower (p<0.001), total awakening percentage was significantly higher (p<0.001), and sleep stage 1 (p<0.001) were significantly higher. (6) OSA patients showed poor sleep quality and distinct abnormal sleep architectures compared with normal control. Conclusions : Conclusions from the above results are as follows : (1) UARS patients were younger and had lower body mass index when umpared with OSA patients. (2) The quality of sleep and sleep architectures of the UARS and OSA patients are significantly different from those of normal control. (3) ESS scores and awakening frequencies of UARS are similar with those of OSA, suggesting that daytime dysfunction of UARS patients may be comparable to those of OSA patients. (4) The RDI and the $SaO_2$ which are important indicators in diagnosing sleep-related breathing disorders, of UARS subjects are close to normal value. (5) According to the the above results, we unclude that despite the absence of $SaO_2$ drops and the absence of an elevated number of apnea and hypopnea, subjects developed clinical complaints which were associated with laborious breathing, elevated Pes nadir, and frequently snoring. (6) Accordingly, we suggest including LIARS in the differential diagnosis list when sleep related breathing disorder is suspected clinically and overnight polysomnographic findings except snoring and frequent microarousal are within normal limits.

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Comparative Analysis of Price Sensitivity for Using Environmental-Friendly Agricultural Products in University Foodservices Between Jeonnam and Gyeongnam Areas in Korea (대학급식의 친환경 농산물 이용에 대한 전남.경남지역 대학생의 가격민감성 비교)

  • Lee, So-Jung;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.8
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    • pp.1220-1230
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    • 2010
  • The purposes of this study were to compare price sensitivity analysis for using environmental-friendly agricultural products in university foodservice between Jeonnam and Gyeongnam areas in Korea and to suggest the optimum guideline for price increase. The questionnaires were distributed to 600 university students respectively in Jeonnam and Gyeongnam area from July 15 to July 25, 2008; among them, 570 students from Jeonnam area and 490 students from Gyeongnam area responded. The results of this study were as follows. First, Indifference price (IDP) were 890 won (Jeonnam area) and 1,050 won (Gyeongnam area); Optimum price point (OPP) were 1,030 won (Jeonnam area) and 1450 won (Gyeongnam area). Price stress range were 140 won (890~1030 won) in Jeonnam area and 400 won (1050~1450 won) in Gyeongnam area. Second, point of marginal cheapness (PMC) were 500 won (Jeonnam area) and 790 won (Gyeongnam area) whereas point of marginal expensiveness (PME) were 1,170 won (Jeonnam area) and 1820 won (Gyeongnam area). Range of acceptable price (RAP) were 670 won (500~1170 won) in Jeonnam area and 1030 won (790~1820 won) in Gyeongnam area. Third, on the basis of IDP percentage and RAP, students in Jeonnam area were more sensitive to meal price increase than students in Gyeongnam area. In contrast, on the basis of Price Stress, students in Gyeongnam area were more sensitive to meal price increase than students in Jeonnam area. Hence, when using environmental-friendly agricultural products in university foodservice, in Jeonnam area, meal price increase should be recommended to be in RAP (500~1170 won), and in Gyeongnam area, meal price increase should be recommended to be in RAP (790~1820 won).

Assessment of Nutrient Intakes of Lunch Meals for the Aged Customers at the Elderly Care Facilities Through Measuring Cooking Yield Factor and the Weighed Plate Waste (조리 중량 변화 계수 및 잔반계측법을 이용한 노인복지시설 이용자의 점심식사 영양섭취평가)

  • Chang, Hye-Ja;Yi, Na-Young;Kim, Tae-Hee
    • Journal of Nutrition and Health
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    • v.42 no.7
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    • pp.650-663
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    • 2009
  • The purposes of this study were to investigate one portion size of menus served and to evaluate nutrient intake of lunch at three elderly care facility food services located in Seoul. A weighed plate method was employed to measure plate wastes and consumption of the menus served. Yield factors were calculated from cooking experiments based on standardized recipes, and were used to evaluate nutrient intake. One hundred elderly participated in this study for measuring plate waste and were asked to complete questionnaire. Nutrient analyses for the served and consumed meal were performed using CAN program. The yield factors of rice dishes after cooking are 2.4 regardless of rice dish types, 1.58 for thick soups, 0.60 to 0.70 for meat dishes, and 1.0 to 1.25 branched vegetable. Average consumption quantity of dishes were 235.97 g for rice, 248.53 g for soup, 72.83 g for meat dishes, 39.80 g for vegetables and 28.36 g for Kimchi. On average the food waste rate is 14.0%, indicating the second highest plate waste percentage of Kimchi (26.2%), and meat/fish dish (17.3%). The evaluation results of NAR (Nutrition Adequacy Ratio) showed that iron (0.12), calcium (0.64), riboflavin (0.80), and folic acid (0.97) were less than 1.0 in both male and female elderly groups, indicating significant differences of NAR among three facilities. Compared to the 1/3 Dietary Reference Intake (DRIs) for the elderly groups, nutrient intake analysis demonstrated that calcium (100%) and iron (100%), followed by riboflavin, vitamin A, and Vitamin B6 did not met of the 1/3 EAR (Estimated Average Requirement). For the nutritious meal management, a professional dietitian should be placed at the elderly care center to develop standardized recipes in consideration of yield factors and the elderly's health and nutrition status.

Studies on Lipids in Fresh-Water Fishes 8. Comparison of Lipid Components among Wild and Cultured Carp (Cyprinus carpio) and Israeli Carp (Cyprinus carpio nudus) (담수어의 지질에 관한 연구 8. 천연 및 양식 잉어와 이스라엘 잉어의 지질성분 비교)

  • CHOI Jin-Ho;RHIM Chae-Hwan;BAE Tae-Jin;YOON Tai-Heon;LEE Kang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.5
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    • pp.447-454
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    • 1985
  • As a part of serial study for comparing lipid components in freshwater fishes, this work was undertaken to compare the lipid components among wild and cultured carp, Cyprinus carpio, and Israeli carp, Cyprinus carpio nudus. The lipid components of cultured carp were analyzed and compared with those of wild and Israeli carp. In the content of total lipid, the lipid content in cultured carp was slightly lower than that in wild one, but similar to that in Israeli carp. The lipid contents in viscera of wild and cultured carp were 2 times higher than those in edible portion, but the lipid content in viscera of Israeli carp showed a similar trend to that in edible portion. In the fatty acid composition of neutral lipid in edible portion, percentages of $C_{18:1},\;C_{18:2},\;C_{18:3},\;C_{22:5}\;and\;C_{22:6}$ in cultured carp wire higher than those in wild one, while percentages of $C_{16:0},\;C_{18:0},\;C_{16:1},\;C_{20:4}\;and\;C_{20:5}$ lower, and percentage of $C_{18:2}$ in Israeli carp was noticeably higher than that in wild and cultured carp. In the case of phospholipid in edible portion, percentages of $C_{18:0},\;C_{18:1},\;C_{18:2},\;C_{18:3}\;and\;_C{22:6}$ in cultured carp were higher than those in wild one, while percentages of $C_{16:0},\;C_{16:1},\;C_{20:4},\;C_{20:5}\;and\;C_{22:5}$ lower. The unsaturation (TUFA/TSFA) of neutral lipid in cultured carp was slightly higher than that in wild one, but slightly lower than that in Israeli carp. In the case of phospholipid, the unsaturation showed a similar trend to that of neutral lipid. The essential fatty acid content(TEFA) of neutral lipid in edible portion of cultured carp was higher than that of wild one, but that in viscera lower. In the case of phospholipid in edible portion, the essential fatty acid content in Israeli carp was slightly higher than that in wild and cultured carp, and that in wild one was higher than that in cultured one. The w3 highly unsaturated fatty acid contents(w3 HUFA) of neutral lipid almost showed a similar trend to the essential fatty acid contents in wild and cultured carp, and Israeli carp. In the case of phospholipid, the w3 HUFA in Israeli carp was considerably higher than those in cultured and wild carp. In the ratio (A/C) of fatty acid content(A) in cultured carp to that(C) in diet, the A/C ratios of $C_{20:5}\;w3(0.12),\;C_{22:5}\;w6(0.53),\;C_{22:5}\;w3(0.68)\;and\;C_{22:6}\;w3(0.26)$ were much lower and in the ratio (B/C) of fatty acid content (B) in Israeli carp, the B/C ratios of $C_{18:3}\;w3(0.61),\;C_{20:5}\;w3(0.11),\;C_{22:4}\;w6(0.16),\;C_{22:5}\;w6(0.07)\;and\;C_{22:6}\;w3(0.79)$ were also lower than the other fatty acid. Consequently, it is considered that the ratios of w3 HUFA is related to the biosynthesis of polyenoic acid and growth rates of cultured and Israeli carp.

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Estimation of Genetic Parameters for Litter Size and Sex Ratio in Yorkshire and Landrace Pigs (요크셔종과 랜드레이스종의 산자수 및 성비에 대한 유전모수 추정)

  • Lee, Kyung-Soo;Kim, Jong-Bok;Lee, Jeong-Koo
    • Journal of Animal Science and Technology
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    • v.52 no.5
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    • pp.349-356
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    • 2010
  • This study was conducted to estimate heritabilities, repeatabilities and rank correlation coefficients among breeding values for litter size and sex ratio of Yorkshire and Landrace pigs using various single trait animal models. The analyses were carried out the data comprising 26,390 litters of Yorkshire and 26,173 litters of Landrace collected from the year 1998 to 2008 at a private swine breeding farm located in central part of Korea. Five different analytical models were used for genetic parameter estimation. Model 1 was most simple basic model fitted with year-month contemporary group fixed effect, random additive genetic effect and random residual effect. Model 2 was similar to the model 1 but permanent maternal environmental effect added as random effect, and model 3 was similar with the model 2 but linear and quadratic effects of sow age were added as fixed covariate effect. Model 4 was similar as model 2 except that the parity was added as fixed effect and model 5 was similar to model 3 or model 4 but covariate of sow age was nested within parity effect. The results obtained in this study are summarized as follows: The means and standard error of total number of pigs born per litter (TNB) and number of pigs born alive per litter (NBA) were $11.35{\pm}0.02$ and $10.04{\pm}0.02$ for Yorkshire, $10.97{\pm}0.02$ and $9.98{\pm}0.02$ for Landrace, respectively. The sex ratio (percentage of female per litter) was $45.75{\pm}0.11%$ and $45.75{\pm}0.11%$ for Yorkshire and Landrace, respectively. The heritability estimates of TNB (0.243) and NBA (0.192) from model 1 tended to be higher than those from any other models in both breeds. Differences in heritability and repeatability for TNB were not large among models 3, 4 and 5 and same tendency of negligible differences among estimates by models 3, 4 and 5 were observed for NBA, where heritability and repeatability ranged from 0.096 to 0.099 and from 0.188 to 0.193, respectively, in Yorkshire; and ranged from 0.092 to 0.098 and from 0.193 and 0.196, respectively, in Landrace. The heritability estimates for sex ratio were close to zero which was ranged from 0.002 to 0.003 for TNB and from 0.001 to 0.003 for NBA over the models applied. The rank correlation coefficients of breeding values by model 1 with those from other models (model 2, 3, 4 and 5), and breeding values by model 2 with those from other models (model 1, 3, 4 and 5) were highly positive but lower than the coefficients among breeding values by model 3, model 4 and model 5 which were high of 0.99, approximately, for TNB and NBA of both breeds.

Studies on Characteristics of Sprouting and Occurrence on paddy field of Water Chestnut(Eleocharis Kuroguwai Ohwi) (올방개 괴경(塊莖)의 맹아(萌芽) 특성(特性)과 본답(本畓)에서의 발생(發生)에 관한 연구(硏究))

  • Kim, H.D.;Park, J.S.;Park, K.Y.;Choi, Y.J.;Yu, C.J.;Rho, Y.D.;Kwon, Y.W.
    • Korean Journal of Weed Science
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    • v.16 no.4
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    • pp.264-281
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    • 1996
  • As a consequence of wide use of herbicides, Eleocharis kuroguwai Ohwi became a dorminant problem weed for rice cultivation in Korea. To understand the establishment of the weed, experiments on physio-ecological characteristics were carried out sprouting and occurrence, the results could be summarized as follows: Sprouting percentage remained 68 to 73% until the time of field emergence, indicating many of the them are still dormant. The proportion of the dormant tubers were greater for the smaller than the bigger tubers. Apical dominance was apparent in sprouting, with 84% of tuber sprouted from only one of the apical buds. Tubers sprouted from 2 or 3 buds were less than 20%, and were mostly from the bigger tubers. When the shoot growth was compared, by controlling the others, ones from apical and the next 3 buds showed similar vigorous growth, but the later ones showed poorer growth. For the longevity of tubers, deep soil storage appeared to be better than storage in temperature controlled room to 2~$3^{\circ}C$. Emergence of E. kuroguwai was better in clay soil than in sand, and the possible depth for emergence in clay soil appeared to be up to 21cm, but was 15cm in sand. When tubers were exposed to salt solutions before emergence tests, E. kuroguwai appeared to be much sensitive to salts than S.planiculmis. Among the tubers formed in previous year, 12.7% remained still viable until the end of next crop season, but with relatively strong dormancy. The first emergence was about 10 days after planting at ordinary cropping seasons, and the days to the maximum shoot number stage were 60~90 from planting. The duration was extended at early transplanting, and shoot number, leaves per shoot, and tubers developed per plant were also greater at early plantings. The 6th order offshoots were developing when E. kuroguwai was planted at early season. When planted at later seasons, generation and the number of offshoots was reduced planted at early season. When planted at later seasons, generation and the number of offshoots was reduced and the number of tubers, runner and rhizome lengths was also reduced.

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Synthesis and Preliminary Evaluation of $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$ Guanine $([^{18}F]FHBG)$ in HSV1-tk Gene Transduced Hepatoma Cell (9-(4-$[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine $([^{18}F]FHBG)$의 합성과 헤르페스 단순 바이러스 티미딘 키나아제 이입 간암 세포주에서의 기초 연구)

  • Moon, Byung-Seok;Lee, Tae-Sup;Lee, Myoung-Keun;Lee, Kyo-Chul;An, Gwang-Il;Chun, Kwon-Soo;Awh, Ok-Doo;Chi, Dae-Yoon;Choi, Chang-Woon;Lim, Sang-Moo;Cheon, Gi-Jeong
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.4
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    • pp.218-227
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    • 2006
  • Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Materials and Methods: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with $K[^{18}F]/K2.2.2.$ in acetonitrile using N2-monomethoxytrityl-9-14-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of $[^{18}F]FHBG$ were performed, and was analyzed correlation between $[^{18}F]FHBG$ uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. Results: $[^{18}F]FHBG$ was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiothemical yield was about 20-25%) (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 $GBq/{\mu}\;mol$. Specific accumulation of $[^{18}F]FHBG$ was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked $[^{18}F]FHBG$ was retained inside of cells. The uptake of $[^{18}F]FHBG$ was showed a highly significant linear correlation ($R^2=0.995$) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. Conclusion: $[^{18}F]FHBG$ appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.

Optimum Harvest Stage of Italian Ryegrass 'Kowinearly' According to One and Two Harvests During Spring Season (이탈리안 라이그라스 '코윈어리'의 봄철 1회 및 2회 이용에 따른 수확적기 구명)

  • Seo, Sung;Kim, Meing Jooung;Kim, Won Ho;Lee, Sang Hak;Jung, Min Woong;Kim, Ki Yong;Ji, Hee Chung;Park, Hyung Soo;Kim, Jong Geun;Choi, Gi Jun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.33 no.1
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    • pp.15-20
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    • 2013
  • This study was carried out to determine the optimum harvest stage of Italian ryegrass (Lolium multiflorum Lam., IRG) for maximum forage production during the spring season in Suwon, 2010. The variety of IRG was the early maturity type, 'Kowinearly', and six harvest stages (treatments) were first heading (T1), heading (T2), late heading to early bloom (T3), bloom to late bloom (T4), ripeness (T5), and late ripeness stage (T6). The dates of the first heading and heading of 'Kowinearly' were seen on 4 to 5 May, and 14 May, respectively. Plant length and dry matter (DM) percentage at first harvest were from 69 cm and 14.8% at T1 stage to 103 cm and 35.0% at T6 stage, respectively. The content of crude protein (CP) and in vitro DM digestibility (IVDMD) of T1, T2, T3, T4, T5 and T6 at first harvest were 15.6%, 10.6%, 10.1%, 8.1%, 7.3% and 5.4%, and 81.8%, 72.1%, 64.8%, 63.8%, 61.4% and 59.0%, respectively. The content of neural detergent fiber (NDF) and acid detergent fiber (ADF) were increased continuously with delayed harvest. A significantly higher yield of DM, CP and in vitro digestible DM (IVDDM) were observed for T3, and T4 (p<0.05). DM yield of 3,526 kg, 6,278 kg, 7,842 kg, 8,984 kg, 8,346 kg and 8,008 kg/ha, CP yield of 549 kg, 665 kg, 795 kg, 725 kg, 608 kg and 430 kg/ha, and IVDDM of 2,883 kg. 4,526 kg, 5,083 kg, 5,728 kg, 5,124 kg and 4,722 kg/ha at first harvest were recorded in T1, T2, T3, T4, T5 and T6, respectively. Regrowth yield of DM, CP and IVDDM were shown to be higher at T1 and T2 (p<0.05). However, no significant differences were observed between the two stages. Daily DM and DDM production of regrowth IRG were higher at T2, followed by T1. The total yield (at first and at regrowth) of DM, CP and IVDDM were significant higher for T2, followed by T3, T4 and T1 in order. At T2 stage, the yield was 11,089 kg, 1,254 kg, and 7,669 kg/ha in DM, CP, and IVDDM. In conclusion, the late heading to bloom stage was determined to be the optimum harvest stage for a single harvest, while the heading stage was a suitable stage of first harvest of 'Kowinearly' where two harvests were sought in a single year.

Effect of Air Circulation Velocity on the Rate of Lumber Drying in a Small Compartment Wood Drying Kiln (소형 목재인공건조실에 있어서 공기순환속도가 목재건조율에 미치는 영향)

  • Chung, Byung-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.2 no.2
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    • pp.5-7
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    • 1974
  • 1. This study indicates that above the fiber saturation point the drying rate can be increased with increasing the velocity of the air circutation, i.e., the drying rate of sample boards is proportional to the air velocity, but below the fiber saturation point, the effect of the velocity of air circulation is very low as shown in Figs. 1 and 2. 2. Under the controlled temperature and humidity in the kiln, the more the sample boards have moisture, the higher drying rate of it can be obtained. In other words, this means that even though in the case of drying various moisture content of wood, at the final drying stage, approximately the same percentage of moisture content of wood can be secured by employing the higher velocity of air circulation. 3. This study shows that the rate of drying in kiln changes distinctly at the fiber saturation point, i, e., above the fiber saturation point, the drying curve shows concave aginst the X axsis, but below the fiber saturation point, in the range from 30 percent of moisture content to 20 percent of moisture content, the curve shows convex as shown in Fig. 3. As the drying progresses, however, the drying curve shows concave again below 20 percent of moisture content. This means that inflection point of drying curve may be located clearly at the fiber saturation point, i.e., 30 percent of moisture content. As mentioned above, the 30 percent of moisture content of wood at which the inflectional point appears can be recognized as a critical point, i. e., the fiber saturation point at which all free water was removed from wood. The existence of inflectional point indicates that the evaporation of hygroscopic water in a cell wall is more difficult than the evaporation of free water in a cell cavity and the minor space of cell wall. The convex curve in the range of moisture content from 30 percent to 20 percent means that the evaporation of capillary condensed water has a tendency of the same rates of drying approximately, but as approaching to the 20 percent of moisture, the transfusion of moisture from wood becomes difficult because of having less moisture in cell wall. Below 20 percent of moisture content, the drying curve shows concave again, which means that it is difficult to remove the moisture located nearer to the surface of cellulose molecules and the surface bound water. These relations were revealed in Fig. 4. In comparison AC curve which does not have the two inflection points with BD curve which has two inflection points, i.e., Band D, they are mentioned already, by existence of the inflection points, the curve BD shows that the change of drying rate in the interval from 20 percent of moisture content to 30 percent of moisture content is not greater than in the case of the curve AC in the same interval. At the inflection point of 30 percent of moisture content, it can be noticed that the changing of the drying rate is very conspicuous. This phenomenon also can be recognized, as it is noticed by the Fig. 3, the drying rate from green to 30 percent of moisture content is very great. But the inclination of the curve is very slow from 30 percent of moisture content to 20 percent of moisture content, i.e., the inclination of the curve becomes almost horizontal lines. Acknowledgments Gratitude is expressed to Fred E. Dickinson, Professor of 'Wood Technology, School of Natural Resources, University of Michigan, USA for his suggestion to carry out this study.

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A Comparative Study of the Standard Uptake Values of the PET Reconstruction Methods; Using Contrast Enhanced CT and Non Contrast Enhanced CT (PET/CT 영상에서 조영제를 사용하지 않은 CT와 조영제를 사용한 CT를 이용한 감쇠보정에 따른 표준화섭취계수의 비교)

  • Lee, Seung-Jae;Park, Hoon-Hee;Ahn, Sha-Ron;Oh, Shin-Hyun;NamKoong, Heuk;Lim, Han-Sang;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.3
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    • pp.235-240
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    • 2008
  • Purpose: At the beginning of PET/CT, Computed Tomography was mainly used only for Attenuation Correction (AC), but as the performance of the CT have been increase, it could give improved diagnostic information with Contrast Media. But it was controversial that Contrast Media could affect AC on PET/CT scan. Some submitted thesis' show that Contrast Media could overestimate when it is for AC data processing. On the contrary, the opinion that Contrast Media could be possible to affect the alteration of SUV because of the overestimated AC. But it does not have a definite effect on the diagnosis. Thus, the affection of Contrast Media on AC was investigated in this study. Materials and Methods: Patient inclusion criteria required a history of a malignancy and performance of an integrated PET/CT scan and contrast- enhanced CT scan within a 1-day period. Thirty oncologic patients who had PET/CT scan from December 2007 to June 2008 underwent staging evaluation and met these criteria. All patients fasted for at least 6 hr before the IV injection of approximately 5.6 MBq/kg (0.15 mCi/kg) of $^{18}F$-FDG and were scanned about 60 min after injection. All patients had a whole body PET/CT performed without IV contrast media followed by a contrast-enhanced CT on the Discovery STe PET/CT scanner. CT data were used for AC and PET images came out after AC. The ROIs drew and measured SUV. A paired t-test of these results was performed to assess the significance of the difference between the SUV obtained from the two attenuation corrected PET images. Results: The mean and maximum Standardized Uptake Values (SUV) for different regions averaged over all Patients. Comparing before using Contrast Media and after using, Most of ROIs have the increased SUV when it did Contrast Enhanced CT compare to Non-Contrast enhanced CT. All regions have increased SUV and also their p value was under 0.05 except the mean SUV of the Heart region. Conclusion: In this regard, the effect on SUV measurements that occurs when a contrast-enhanced CT is used for attenuation correction could have significant clinical ramifications. But some submitted thesis insisted that the percentage change in SUV that can determine or modify clinical management of oncology patients is small. Because there was not much difference that could be discovered by interpreter. But obviously the numerical change was occurred and on the stage finding primary region, small change would be base line, such as the region of liver which has greater change than the other regions needs more attention.

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