• Title/Summary/Keyword: Peak-hour ratio

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Perfusion Techniques Using the Modified Isolated Working Rat Heart Model (흰쥐의 심장을 이용한 Modified Isolated Working Heart Perfusion Technique)

  • Lee, Chong-Kook;Choi, Hyeong-Ho
    • Journal of Chest Surgery
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    • v.13 no.4
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    • pp.338-345
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    • 1980
  • We have modified an isolated perfusion rat heart model of cardiopulmonary bypass, with which we are able to screen the effects of various cardioplegic solutions and hypothermia upon the ability of the heart to survivie during and recover from period of ischemic arrest. The modified experimental model was differed from the original as follow : a heat coil chamber of atrial and aortic reservoir provided temperature control, and the perfusate was gassed with each pure oxygen and pure carbon dioxide in 95:5 ratio. The Langendorff perfusion was initiated for a 10 minute period by introducing perfusate at $37^{\circ}C.$ into the aorta from the aortic reservoir located 100 cm above the heart. The isolated perfused working rat heart model was a left heart preparation in which oxygenated perfusion medium (at $37^{\circ}C.$) entered the cannulated left atrium at a pressure of 20 cm $H_{2}O$ and was passed to the ventricle, from which it was sponeously elected(no electrical pacing) via an aortic cannula, against a hydrostatic pressure of 100cm $H_{2}O$. during this working period various indices of cardiac functin were measured. The cardiac functions were stable for over 3 hour with perfusion of Krebs-Henseleit bicarbonate buffer solution containing only glucose (11.1 mM/L). The percentage of cardiac functins were maintained about 94% on heart rate, 80.6% on peak aortic pressure, 87.7% on coronary flow and 76.3% on aortic flow rate after 3 hour of working heart perfusion at a pressure of 20 cm $H_{2}O$. We believe this preparation to be a good biochemical model for the human heart which offers many advantages including economic, speed of preparation, reproducibility, and the ability to handle large numbers.

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five year experience of thoracic civilian injuries -481 cases- (최근 5년간의 흉부손상 경험 -481 예-)

  • Son, Gwang-Hyeon;Gu, Bon-Il;Kim, Tae-Yeong
    • Journal of Chest Surgery
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    • v.19 no.3
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    • pp.421-428
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    • 1986
  • From January 1981 through December 1985, 481 thoracic civilian injuries were reviewed in the Department of Thoracic Surgery, Paik Hospital in Seoul. Sixty two percent of the injuries were caused by traffic accident, 18% fall down, 15% blunt trauma, 2% crushing injury, 2% stab wound, and 0.4% gunshot wound. Peak incidence of the trauma victim was fourth and fifth decades revealing 22% and 27% respectively. Sex ratio was 3.5:1 with male predominance. Elapsed time before admission was less than one hour in 36% and one to six hour in 30%. The types of the injuries were as follows: Non-penetrating injuries were the most part of the wounded, 97.6%. Rib fracture was the most common lesion occupying 292 patient out of 481 [61%]. Of these 292 patients, 72% was multiple rib fracture. The incidence of hemothorax or hemopneumothorax was 19% [102 patients] [Table 4]. Most common associated condition was head injuries, 98 patients [14%]. Thoracoabdominal injuries were seen in 31 patients [0.6%]. Tube thoracostomy was the definitive measures in the 20% of the wounded. Open thoractomy was performed in 5%. Additional procedures for the associated condition were done in the 16% of the cases, for example, reduction of long bone fracture and trephination for the head injury. Among 481 wounded, fatal complication occurred in 13 patients [2.7%]. This paper has also compared two series of patients according to period; one from 1970 to 1980 and the present series [Table 8]. Conclusively, the fatal complications or trauma death may be reduced by the effort 1] rapid transport of the victim, 2] initial correction or resuscitative measures of the circulatory and ventilatory deficit 3] early decision of definitive thoracostomy or thoracotomy and 4] proper prioritizing for the care of the multiple critically injured patient.

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Outcomes after Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia: A Single-Center Experience

  • Choi, Wooseok;Cho, Won Chul;Choi, Eun Seok;Yun, Tae-Jin;Park, Chun Soo
    • Journal of Chest Surgery
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    • v.54 no.5
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    • pp.348-355
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    • 2021
  • Background: Congenital diaphragmatic hernia (CDH) is a rare disease often requiring mechanical ventilation after birth. In severe cases, extracorporeal membrane oxygenation (ECMO) may be needed. This study analyzed the outcomes of patients with CDH treated with ECMO and investigated factors related to in-hospital mortality. Methods: Among 254 newborns diagnosed with CDH between 2008 and 2020, 51 patients needed ECMO support. At Asan Medical Center, a multidisciplinary team approach has been applied for managing newborns with CDH since 2018. Outcomes were compared between hospital survivors and nonsurvivors. Results: ECMO was established at a median of 17 hours after birth. The mean birth weight was 3.1±0.5 kg. Twenty-three patients (23/51, 45.1%) were weaned from ECMO, and 16 patients (16/51, 31.4%) survived to discharge. The ECMO mode was veno-venous in 24 patients (47.1%) and veno-arterial in 27 patients (52.9%). Most cannulations (50/51, 98%) were accomplished through a transverse cervical incision. No significant between-group differences in baseline characteristics and prenatal indices were observed. The oxygenation index (1 hour before: 90.0 vs. 51.0, p=0.005) and blood lactate level (peak: 7.9 vs. 5.2 mmol/L, p=0.023) before ECMO were higher in nonsurvivors. Major bleeding during ECMO more frequently occurred in nonsurvivors (57.1% vs. 12.5%, p=0.007). In the multivariate analysis, the oxygenation index measured at 1 hour before ECMO initiation was identified as a significant risk factor for in-hospital mortality (odds ratio, 1.02; 95% confidence interval, 1.01-1.04; p=0.05). Conclusion: The survival of neonates after ECMO for CDH is suboptimal. Timely application of ECMO is crucial for better survival outcomes.

Physicochemical and Functional Properties of Pepsin-modified Myofibrillar protein from Sardine, Sardinops melanostica (Pepsin으로 수식된 정어리 myofibrillar protein의 특성)

  • Kim, Byung-Mook;Kim, Byung-Ryul
    • Korean Journal of Food Science and Technology
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    • v.26 no.2
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    • pp.110-116
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    • 1994
  • In order to study the effects of enzyme modification on the physico-chemical and functional properties of myofibrillar protein prepared from the frozen sardine, Sardinops melanostica, the protein was hydrolyzed with pepsin under the enzyme-substrate ratio 1:100 at $37^{\circ}C$ and pH 1.65 for 1, 4, 8, 12, and 24 hr, respectively. The properties of pepsin-modified sardine myofibriliar protein were determined. The extents of proteolysis with pepsin as a fuction of time was showed a typical enzyme hydorlysis curve with an initial region of 4 hour period followed by plateau region. The SDS-acrylamide slab gel electrophoresis patterns of pepsin-modified proteins showed mainly disappearances of minor protein bands, but no changes of main protein bands. The gel filtration patterns through Sephadex G-75 of sardine myofibrillar protein showed two big peaks and three small peaks. All the small peaks were disappearanced by proteolysis with pepsin in one hour. and during the period of proteolysis the fast big peak became gradually smaller and the late big peak eluted more slowly. By proteolysis, the emulsifying activity and emulsifying capacity of sardine myofibrillar protein were all decreased. The effects of pepsin-modification on emulsifying capacity were greater than those on emulsifying activity of protein. The aeration capacity of the protein was increased about 1.9 folds and the foam stability decreased to 0.6 folds of control by pepsin-modification. The pepsin-modified sardine myofibrillar proteins showed about 0.6 folds of heat coagulation and 1.4 folds of viscosity of control. The pH dependence of solubilities of sardine myofibrillar protein showed two isoelectric areas of pH 5 and 9. The pepsin-modified protein showed more clear pH dependences at the early stage but not at the late stage of proteolysis.

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Different Types of Active Region EUV Bright Points by Hinode/EIS

  • Lee, Kyoung-Sun;Moon, Yong-Jae;Kim, Su-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.28.2-28.2
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    • 2010
  • We have investigated seven Extreme-Ultraviolet (EUV) bright points in the active region (AR 10926) on 2006 December 2 by the EUV imaging spectrometer (EIS) onboard Hinode spacecraft. We determined their Doppler velocities and non-thermal velocities from 15 EUV spectral lines (log T=4.7-7.2) by fitting each line profile to a Gaussian function. We present the Doppler velocity map as a function of temperature which corresponds to a different height. As a result, these active region bright points show two different types of characteristics. Type 1 bright point shows a systematic increase of Doppler velocity from -68 km/s (blue shift) at log T=4.7 to 27 km/s (red shift) at log T=6.7, while type 2 bright points have Doppler velocities in the range of -20 km/s and 20 km/s. Using MDI magnetograms, we found that only type 1 bright point was associated with the canceling magnetic feature at the rate of $2.4{\times}10^{18}$ Mx/hour. When assuming that these bright points are caused by magnetic reconnection and the Doppler shift indicates reconnection out flow, the pattern of the Doppler shift implies that type 1 bright point should be related to low atmosphere magnetic reconnection. We also determined electron densities from line ratio as well as temperatures from emission measure loci using CHIANTI atomic database. The electron densities of all bright points are comparable to typical values of active regions (log Ne=9.9-10.4). For the temperature analysis, the emission loci plots indicate that these bright points should not be isothermal though background is isothermal. The DEM analysis also show that while the background has a single peak distribution (isothermal), the EUV bright points, double peak distributions.

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Performance Evaluation of the Runoff Reduction with Permeable Pavements using the SWMM Model (SWMM 분석을 통한 투수성 포장의 유출 저감 특성 평가)

  • Lin, Wuguang;Ryu, SungWoo;Park, Dae Geun;Lee, Jaehoon;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.17 no.4
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    • pp.11-18
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    • 2015
  • PURPOSES: This study aims to evaluate the runoff reduction with permeable pavements using the SWMM analysis. METHODS: In this study, simulations were carried out using two different models, simple and complex, to evaluate the runoff reduction when an impermeable pavement is replaced with a permeable pavement. In the simple model, the target area for the analysis was grouped into four areas by the land use characteristics, using the statistical database. In the complex model, simulation was performed based on the data on the sewer and road network configuration of Yongsan-Gu Bogwang-Dong in Seoul, using the ArcGIS software. A scenario was created to investigate the hydro-performance of the permeable pavement based on the return period, runoff coefficient, and the area of permeable pavement that could be laid within one hour after rainfall. RESULTS : The simple modeling analysis results showed that, when an impervious pavement is replaced with a permeable pavement, the peak discharge reduced from $16.7m^3/s$ to $10.4m^3/s$. This represents a reduction of approximately 37.6%. The peak discharge from the whole basin showed a reduction of approximately 11.0%, and the quantity decreased from $52.9m^3/s$ to $47.2m^3/s$. The total flowoff reduced from $43,261m^3$ to $38,551m^3$, i.e., by approximately 10.9%. In the complex model, performed using the ArcGIS interpretation with fewer permeable pavements applicable, the return period and the runoff coefficient increased, and the total flowoff and peak discharge also increased. When the return period was set to 20 years, and a runoff coefficient of 0.05 was applied to all the roads, the total outflow reduced by $5195.7m^3$, and the ratio reduced to 11.7%. When the return period was increased from 20 years to 30 and 100 years, the total outflow reduction decreased from 11.7% to 8.0% and 5.1%, respectively. When a runoff coefficient of 0.5 was applied to all the roads under the return period of 20 years, the total outflow reduction was 10.8%; when the return period was increased to 30 and 100 years, the total outflow reduction decreased to 6.5% and 2.9%, respectively. However, unlike in the simple model, for all the cases in the complex model, the peak discharge reductions were less than 1%. CONCLUSIONS : Being one of the techniques for water circulation and runoff reduction, a high reduction for the small return period rainfall event of penetration was obtained by applying permeable pavements instead of impermeable pavement. With the SWMM analysis results, it was proved that changing to permeable pavement is one of the ways to effectively provide water circulation to various green infrastructure projects, and for stormwater management in urban watersheds.

Design Hourly Factor Estimation with Vehicle Detection System (차량검지기자료를 이용한 고속도로 설계시간계수 산정 연구)

  • Baek, Seung-Geol;Kim, Beom-Jin;Lee, Jeong-Hui;Son, Yeong-Tae
    • Journal of Korean Society of Transportation
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    • v.25 no.6
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    • pp.79-88
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    • 2007
  • Design Hourly Volume (DHV) is the hourly volume used for designing a section of road. DHV is also used to estimate the expected number of vehicles to pass or traverse the relevant section of road in a future target year. The Design Hour Factor (DHF) is defined as the ratio of DHV to Average Annual Daily Traffic (AADT). In addition to high precision of predicted traffic volume, in order to design a roadway to be the proper scale, applying appropriate DHFs considering traffic flow characteristics and type of area which surrounds the relevant roadway is important. This study categorizes sections of expressway (Suh Hae An Expressway) according to their area type and estimates DHFs utilizing traffic data obtained from a vehicle detection system (VDS). This study shows that DHFs calculated using VDS data are different from those using traffic data acquired from a coverage survey. While AADTs from both data show similar values, peak hour volumes from both data show significant differences especially for recreational areas. DHFs from the coverage survey are quite different from the values provided by the Korean design guide or previous research results and DHFs for urban areas are higher than recreational areas. However, DHFs from VDS shows similar values to previous research results. The result of this study suggests that using VDS for estimating DHFs is more reliable than using a coverage survey.

An Analysis on the Correlation between Types of Urban Railway Stations and Users' Travel Patterns (도시철도역사 유형과 통행패턴과의 상관관계 분석)

  • Kim, Hwang Bae;Oh, Dong Kyu;Lee, Sang Hwa;Jin, Sang Kyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.5
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    • pp.1553-1558
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    • 2014
  • The travel demand, peak hour ratio and forms of platform of urban railway stations are very different each other, also the users' behavior is. So the types of urban railway stations have to be classified according to these characteristics. However, the current methods of classification are arbitrary on the purpose of each studies and the legal standards are very simple; categorized by normal station vs. whistle station, types of trains, forms of platforms and shapes of architecture. This study clarifies the standards for classifying the types of urban railway stations, results the complete enumeration survey on all the urban railway stations in Seoul Metropolitan Area and makes the database based on the surveyed data, purposing on helping for making strategies and researching. On this study, utilizing the database which is established for this study, the correlation between the physical and geographical characteristics and users' travel patterns of urban railway stations is clarified by the statistical analysis. In the future, the statistical results will be helpful for making strategies and researching.

Study on the Diurnal Variation of the Plasma Immunoreactive Glucagon (정상 한국인의 혈중 Glucagon의 동태에 관한 연구)

  • Lee, Hong-Kyu;Chung, June-Key;Kim, Eui-Chong;Hong, Kee-Suk;Kim, Byoung-Kook;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.18 no.1
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    • pp.39-44
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    • 1984
  • It is well known that glucagon, like insulin, is very important in the moment-to-moment control of the homeostasis of glucose, and of amino acids. Glucagon has been shown to have potent glycogenolytic, gluconeogenic and lipolytic activities. Attention to its role in the pathogenesis of diabetes mellitus and hypoglycemia has been also advanced recently. To evaluate the diurnal variation of plasma glucagon concentration, we measured serum glucose, insulin, and plasma glucagon every 30 minutes or every hour in 7 normal Korean adults. Results were as follows: 1) Although plasma glucagon concentration showed wide individual variations, it had a tendency to decrease after meals. After lunch and dinner, plasma glucagon concentration had gradually declined and reached its nadir at postprandial 2-2.5 hours. The minimal level of plasma glucagon was at 4 A.M. 2) Serum insulin:plasma glucagon ratios were increased promptly after meals. Especially after lunch, its peak was prominent $(3.65{\pm}1.95)$. The minimal level of serum insulin:plasma glucagon ratio appeared at 6 A.M.

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Clinical Analysis of Patients Who Visited the Emergency Room of an Oriental Medical Center (한의과대학 부속 한방병원 한방응급실 내원환자에 대한 임상적 분석)

  • Ryu, Jae-Hwan;Kim, Young-Chul;Lee, Beom-Jun;So, Hyung-Jin
    • The Journal of Korean Medicine
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    • v.28 no.3 s.71
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    • pp.197-206
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    • 2007
  • Objectives : By recording basic data of patients visiting the emergency room of the oriental medicine center, we can understand their characteristics and gain better insight about them. Methods : We performed a retrospective study of 2,674 patients who visited the emergency room of Kyunghee Oriental Medical Center, from June 1, 2006 to May 31, 2007. Results : 1. Of 2,674 total patients, the male to female ratio was 0.94:1 and the 6th decade of life was the peak age group. 2. The majority of patients visited our emergency room between 06:00 and 24:00(midnight). 3. Most patients visited on a Saturday or Sunday. 4. By monthly distribution, the patients increased slightly during June, July, August and October. 5. The majority of patients visited the emergency room within 24 hours of onset. 6. The patients were categorized as follows: neurological diseases 71.15%, musculoskeletal diseases 16.02%, internal medical disease 9.04%, psychiatric and related disease 3.79%. 7. The average transit time was about 1 hour 30 minutes. 8. Admission rate was 48% and the rate of admission to the intensive care unit (ICU) was 5% of total visiting patients. Conclusion : Assuming that this research will continue adding patient's data continuously, this work will help us to understand the features of patients who visiting the emergency room of the oriental medical center.

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