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Decay Rate and Nutrients Dynamics during Decomposition of Oak Roots (상수리나무 뿌리 분해 및 분해과정에 따른 영양염류 변화)

  • 문형태
    • The Korean Journal of Ecology
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    • v.27 no.3
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    • pp.165-171
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    • 2004
  • Weight loss and nutrients dynamics during decomposition of oak roots (diameter classes: R₁〈0.2㎝, 0.5㎝〈R₂〈1㎝, 1㎝〈R₃〈2㎝, 2㎝.〈R₄〈4㎝) (Quercus acutissima) were studied for 33-months in Kongiu, Korea. After 33-months, decomposition rate of R₁, R₂, R₃ and R₄ was 49.6%, 47.5%, 66.4% and 66.1%, respectively. The decomposition constant(k) for R₁, R₂, R₃, and R₄ was 0.249/yr, 0.234/yr, 0.397/yr and 0.393/yr, respectively. Larger diameter class of the root lost more weight than smaller diameter class. N concentration in decomposing oak roots increased in all diameter classes. After 33-months, remaining N in R₁, R₂, R₃ and R₄ was 66.5%, 80.7%, 84.4% and 44.4%, respectively. K concentration in decomposing oak roots decreased in early part of decomposition and then increased in later stage of decomposition. After 33-months, remaining P in R₁, R₂, R₃ and R₄ was 64.7%, 62.4%, 93.1% and 30.7%, respectively. K concentration in decomposing oak roots decreased rapidly in early stage of decomposition. Remaining K in R₁, R₂, R₃ and R₄ was 11.6%, 10.6%, 5.9% and 7.7%, respectively. Ca concentration in decomposing oak roots showed different among diameter classes. After 33-months, remaining Ca in R₁, R₂, R₃ and R₄ was 66.2%, 51.0%, 39.1% and 48.3%, respectively. Initial concentration of Mg in oak root was higher in smaller diameter class. After 33-months, remaining Mg in R₁, R₂, R₃ and R₄ was 15.3%, 29.9%, 24.5% and 69.4%, respectively.

A Study on the International Carriage of Cargo by Air under the Montreal Convention-With respect to the Air Waybill and the Liability of Air Carrier (몬트리올 협약상 국제항공화물운송에 관한 연구 - 항공화물운송장과 항공운송인의 책임을 중심으로 -)

  • Lee, Kang-Bin
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.49
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    • pp.283-324
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    • 2011
  • The purpose of this paper is to research the air waybill and the carrier's liability in respect of the carriage of cargo by air under the Montreal Convention of 1999. The Warsaw Convention for the unification of certain rules for international carriage by air was adopted in 1929 and modified successively in 1955, 1961, 1971, 1975 and 1999. The Montreal Convention of 1999 modernized and consolidated the Warsaw Convention and related instruments. Under the Montreal Convention, in respect of the carriage of cargo, the air waybill shall be made out by the consignor. If, at the request of the consignor, the carrier makes it out, the carrier shall be deemed to have done so on behalf of the consignor. The air waybill shall be made out in three orignal parts. Under the Montreal Convention, the consignor shall indemnify the carrier against all damages suffered by the carrier or any other person to whom the carrier is liable, by reason of the irregularity, incorrectness or incompleteness of the particulars and statement furnished by the consignor or on its behalf. The air waybill is not a document of title or negotiable instrument. Under the Montreal Convention, the air waybill is prima facie evidence of the conclusion of the contract, of the acceptance of the cargo and of the conditions of carriage. If the carrier carries out the instructions of the consignor for the disposition of the cargo without requiring the production of the part of the air waybill, the carrier will be liable, for any damage which may be accused thereby to any person who is lawfully in possession of the part of the air waybill. Under the Montreal Convention, the carrier is liable by application of principle of strict liability for the damage sustained during the carriage of cargo by air. The carrier is liable for the destruction or loss of, or damage to cargo and delay during the carriage by air. The period of the carriage by air does not extend to any carriage by land, by sea or by inland waterway performed outside an airport. Under the Montreal Convention, the carrier's liability is limited to a sum of 17 Special Drawing Rights per kilogramme. Any provision tending to relieve the carrier of liability or to fix a lower limit than that which is laid down in this Convention shall be and void. Under the Montreal Convention, if the carrier proves that the damage was caused by the negligence or other wrongful act or omission of the person claiming compensation, or the person from whom he derives his rights, the carrier shall be wholly or partly exonerated from ist liability to the claimant to the extent that such negligence or wrongful act or omission caused the damage. Under the Montreal Convention, any action for damages, however founded, whether under this Convention or in contract or in tort or otherwise, can only be brought subject to the conditions and such limits of liability as are set out in this Convention. Under the Montreal Convention, in the case of damage the person entitled to delivery must complain to the carrier forthwith after the discovery of the damage, and at the latest, within fourteen days from the date of receipt of cargo. In the case of delay, the complaint must be made at the latest within twenty-one days from the date on which the cargo has been placed at his disposal. if no complaint is made within the times aforesaid, no action shall lie against the carrier, save in the case of fraud on its part. Under the Montreal Convention, the right to damage shall be extinguished if an action is not brought within a period of two years, reckoned from the date of arrival at the destination, or from the date on which the aircraft ought to have arrived, or from the date on which the carriage stopped. In conclusion, the Montreal Convention has main outstanding issues with respect to the carrier's liability in respect of the carriage of cargo by air as follows : The amounts of limits of the carrier's liability, the duration of the carrier's liability, and the aviation liability insurance. Therefore, the conditions and limits of the carrier's liability under the Montreal Convention should be readjusted and regulated in detail.

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Management of Vascular Injuries to the Extremities after Trauma (외상 후 사지 혈관손상의 치료)

  • Kim, Han Yong;Park, Jae Hong;Kim, Myoung Young;Hwang, Sang Won
    • Journal of Chest Surgery
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    • v.42 no.1
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    • pp.46-52
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    • 2009
  • Background: Vascular injuries to the extremities are potentially devastating and they can lead to limb loss and mortality if they are not appropriately managed. The vascular trauma caused by traffic and industrial accidents has recently increased according to the developing industry and transport system in Korea. Early recognition and treatment of these injuries are mandatory to achieve satisfactory outcomes. Material and Method: We retrospective reviewed 43 patients with vascular injuries that were due to blunt and penetrating trauma and they underwent emergency operations from January of 1998 to December of 2006. Result: There were 38 men and 5 women patients with a mean age of $42.0{\pm}16.8$ years (range: 17~77). The cause of vascular injuries were 28 traffic accidents (65%), 6 industrial accidents (14%), 6 glass injuries (14%) and 3 knife injuries (7%). The average time from admission to the operating room was $319.0{\pm}482.2$ minutes (range: 27~2,400 minutes). The average time from admission to discharge was $53.1{\pm}56.0$ days (range: 2~265 days). The anatomic injuries included the femoral artery in 16 cases (37%), the popliteal artery in 8 cases (19%), the brachial artery in 8 cases (19%), and the subclavian and axillary arteries in 7 cases (16%). The associated injuries were 23 bone fractures (53%), 18 muscle injuries (42%) 5 nerve injuries (12%) and 11 vein injuries (26%). The operation methods were 20 end to end anastomoses (46%), 16 interposition grafts (36%), 2 repairs with using patches (5%) and 5 others (12%). The number of amputations and cases of mortality were 3 cases (7%) and 4 cases (9%), respectively. Conclusion: Minimizing ischemia is an important factor for maximizing salvage of extremities. Prompt diagnosis and treatment can reduce the amputation and mortality rates.

Degradation of Microcystin-LR, Taste and Odor, and Natural Organic Matter by UV-LED Based Advanced Oxidation Processes in Synthetic and Natural Water Source (UV-LED기반 고도산화공정을 이용한 수중 마이크로시스틴-LR, 이취미 물질, 자연유기물 분해)

  • Yang, Boram;Park, Jeong-Ann;Nam, Hye-Lim;Jung, Sung-Mok;Choi, Jae-Woo;Park, Hee-Deung;Lee, Sang-Hyup
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.5
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    • pp.246-254
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    • 2017
  • Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.

A study of Brachytherapy for Intraocular Tumor (안구내 악성종양에 대한 저준위 방사선요법에 관한 연구)

  • Ji, Gwang-Su;Yu, Dae-Heon;Lee, Seong-Gu;Kim, Jae-Hyu;Ji, Yeong-Hun
    • The Journal of Korean Society for Radiation Therapy
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    • v.8 no.1
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    • pp.19-27
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    • 1996
  • I. Project Title A Study of Brachytherapy for intraocular tumor II. Objective and Importance of the project The eye enucleation or external-beam radiation therapy that has been commonly used for the treatment of intraocular tumor have demerits of visual loss and in deficiency of effective tumor dose. Recently, brachytherapy using the plaques containing radioisotope-now treatment method that decrease the demerits of the above mentioned treatment methods and increase the treatment effect-is introduced and performed in the countries, Our purpose of this research is to design suitable shape of plaque for the ophthalmic brachytherapy, and to measure absorbed doses of Ir-192 ophthalmic plaque and thereby calculate the exact radiation dose of tumor and it's adjacent normal tissue. III. Scope and Contents of the project In order to brachytherapy for intraocular tumor, 1. to determine the eye model and selected suitable radioisotope 2. to design the suitable shape of plaque 3. to measure transmission factor and dose distribution for custom made plaques 4. to compare with the these data and results of computer dose calculation models IV. Results and Proposal for Applications The result were as followed. 1. Eye model was determined as a 25mm diameter sphere, Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15mm, 17mm and 20mm in diameter, and 1.5mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within ${\pm}10\%$ and distance deviations are within 0.4mm Maximum error is $-11.3\%$ and 0.8mm, respectively. As a result of it, we can treat the intraocular tumor more effectively by using custom made gold plaque and Ir-192 seeds.

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Evaluation of Scattered Dose to the Contralateral Breast by Separating Effect of Medial Tangential Field and Lateral Tangential Field: A Comparison of Common Primary Breast Irradiation Techniques (유방암 접선조사 치료 방법에 대한 반대쪽 유방에서의 산란선량 평가)

  • Ban, Tae-Joon;Jeon, Soo-Dong;Kwak, Jung-Won;Baek, Geum-Mun
    • The Journal of Korean Society for Radiation Therapy
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    • v.24 no.2
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    • pp.183-188
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    • 2012
  • Purpose: The concern of improving the quality of life and reducing side effects related to cancer treatment has been a subject of interest in recent years with advances in cancer treatment techniques and increasing survival time. This study is an analysis of differing scattered dose to the contralateral breast using common different treatment techniques. Materials and Methods: Eclipse 10.0 (Varian, USA) based $30^{\circ}$ EDW (Enhanced dynamic wedge) plan, $15^{\circ}$ wedge plan, $30^{\circ}$ wedge plan, Open beam plan, FiF (field in field) plan were established using CT image of breast phantom which in our hospital. Each treatment plan were designed to exposure 400 cGy using CL-6EX (VARIAN, USA) and we measured scattered dose at 1 cm, 3 cm, 5 cm, 9 cm away from medial side of the phantom at 1 cm depth using ionization chamber (FC 65G, IBA). We carried out measurement by separating effect of medial tangential field and lateral tangential field and analyze. Results: The evaluation of scattered dose to contralateral breast, $30^{\circ}$ EDW plan, $15^{\circ}$ wedge plan, $30^{\circ}$ wedge plan, Open beam plan, FIF plan showed 6.55%, 4.72%, 2.79%, 2.33%, 1.87% about prescription dose of each treatment plan. The result of scattered dose measurement by separating effect of medial tangential field and lateral tangential field results were 4.94%, 3.33%, 1.55%, 1.17%, 0.77% about prescription dose at medial tangential field and 1.61%, 1.40%, 1.24%, 1.16%, 1.10% at lateral tangential field along with measured distance. Conclusion: In our experiment, FiF treatment technique generates minimum of scattered dose to contralateral breast which come from mainly phantom scatter factor. Whereas $30^{\circ}$ wedge plan generates maximum of scattered doses to contralateral breast and 3.3% of them was scattered from gantry head. The description of treatment planning system showed a loss of precision for a relatively low scatter dose region. Scattered dose out of Treatment radiation field is relatively lower than prescription dose but, in decision of radiation therapy, it cannot be ignored that doses to contralateral breast are related with probability of secondary cancer.

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Comparison of Rotational Strength in Shoulders with Anterior Instability and Normal Shoulders Using Isokinetic Testing (등속성 검사를 통한 견관절 전방 불안정 환자와 정상인의 회전력 비교)

  • Lee, Dong-Ki;Kim, Tae-Kwon;Lee, Jin-Hyuck;Lee, Dae-Hee;Jung, Woong-Kyo
    • Clinics in Shoulder and Elbow
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    • v.15 no.2
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    • pp.79-85
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    • 2012
  • Objective: It has been expected that patient with posttraumatic recurrent anterior shoulder dislocation might have limited daily life activity because of pain and apprehension of dislocation. But there have been only a small number of investigations regarding the rotator strength in this patient. The aim of this study is to find the characteristics about rotator strength of patient with posttraumatic recurrent anterior shoulder dislocation using an isokinetic testing. Method: We enrolled thirteen patients with posttraumatic recurrent anterior shoulder dislocation and fifteen sex, age-matched healthy nonathletic subjects in this controlled study. All participants were male and there were no significant differences between the two groups in age, height, weight, BMI. Isokinetic internal rotator and external rotator strength was evaluated with a Biodex Isokinetic Testing machine (Biodex Medical Systems, Shirley, NY, USA), tests were performed at 60 deg/sec and 180 deg/sec for both sides. Peak torque normalized to body weight, external rotator to internal rotator ratio, total work and fatigue were calculated for each angular velocity. The association between internal rotator and external rotator strength and shoulder instability was analyzed by comparisons with a control group. Results: Any notable differences could not be found between the two groups given all data from no symptomatic left shoulder. There were no significant differences between the two groups statistically in internal rotation strength of right shoulder. However, there has been a tendency that at all angular velocities, external rotator peak torque to body weight, total work and external rotator to internal rotator ratio were significantly lower in the anterior instability group than the control group at all angular velocities. There was no substantial difference between those groups with respect to the fatigue of external rotator and internal rotator in our study. Conclusion: The prominent characteristics of posttraumatic recurrent anterior shoulder dislocation are external rotator weakness and loss of balance with external rotator and internal rotator. Therefore selective training using this information rotator might be helpful in conservative treatment and rehabilitation.

Growth Efficiency, Carcass Quality Characteristics and Profitability of Finishing Pigs Slaughtered at 130 vs. 110Kg (110kg 대비 130kg에 도축된 비육돈의 성장효율, 도체 품질 특성 및 수익성)

  • 이철영;권오천;하덕민;신호원;이제룡;하영주;이진희;하승호;김원기;김광위;김두환
    • Journal of Animal Science and Technology
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    • v.48 no.4
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    • pp.493-502
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    • 2006
  • The slaughter weight (wt) is a most important economic factor in swine roduction. The present study was undertaken to determine if it is feasible to increase the slaughter wt of finishing pigs to 130kg without significantly affecting the growth efficiency and carcass quality. One hundred and sixty gilts and 160 barrows born from lean-type Yorkshire×Landrace (YL)-dam and Duroc (D)-sire lines, which are most widely used for terminal breeding for pork production in Gyeongsangnam-do, were randomly allocated into 16 pens under a 2 (sex)×2 (slaughter wt; 110 vs. 130kg) factorial arrangement of treatments. The animals were fed ad libitum a diet containing 3,200kcal DE/kg and 15.5% crude protein. After slaughter at the predetermined wt, yields of trimmed primal cuts and physicochemical characteristics of the longissimus dorsi muscle (LD) were measured or analyzed. Average daily gain was greater (P<0.01) in barrows than in gilts (0.86 vs. 0.79kg), but it was not different between the 110- and 130-kg slaughter wt groups (P>0.05). Backfat thickness was greater in the 130- vs. 110-kg group in both sexes (gilts: 21.6 vs. 17.6 mm, barrows: 25.1 vs. 20.8 mm). The yield percentage of belly was greater in barrows than in gilts (21.2 vs. 20.5%) and also in the 130-kg vs. 110-kg group (21.4 vs. 20.2%). Major physicochemical characteristics of LD including the color, percentage of 48-h drip loss, 24-h pH and percentages of crude protein and fat were not influenced by slaughter wt. Marginal profit of the 130-kg vs. 110-kg market pig was approximately 󰠏20,000 won/head, which resulted primarily from the heavy carcass weight of the former exceeding the upper limit of the A- or B-grade. However, if it had not been for the carcass weight limit of the current grading system, a 130-kg market pig would have had a potential marginal profit greater than 20,000 won. Results suggest that slaughter wt of lean-line finishing pigs can be increased to 130kg without significantly compromising the growth efficiency and carcass quality and accordingly, the upper weight limit of the ‘good-grade’ carcass needs to be increased or abolished to accommodate the larger market pigs.

Diagnosis of Irrigation Time Based on Microchange of Stem Diameter in Greenhouse Tomato (온실재배 토마토의 농직경 변화에 의한 관개시기 진단)

  • 이변우
    • Journal of Bio-Environment Control
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    • v.6 no.4
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    • pp.250-257
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    • 1997
  • Stem diameter and shoot fresh weight of tomato grown in greenhouse were measured non-destructively at 10 minutes interval from 1 to 16 July, 1996 with displacement detector using strain gauges and with suspension-type load cell, respectively, and simultaneously were measured soil water potential, transpiration and solar radiation. Ample water was irrigated before experiment, and thereafter, irrigations were made on the next morning when visual symptoms of wilting appeared. Shoot fresh weight and stem diameter showed very similar patterns in diurnal changes which are characterized by predawn maximum and afternoon minimum and in long- term evolutions, suggesting that stem diameter shrinkage and expansion are closely related to plant water content and growth, respectively, Shoot weight and stem diameter reached minimum values a little later than the time on which transpiration showed maximum. The daily net gains of fresh weight(DG) and stem diameter(DI) showed significantly Positive correlations with solar radiation in those days on which plants were not water-stressed. However, Dl and DG on those days of water stress showed much lower values than expected from the relationships between solar radiation and them. Transpiration was much lower than the expected potential transpiration on 10 July, implying that plants were water-stressed. In this case water stress was not detected from visual symptom of wilting and/or soil water potential, but was able to be identified by the lower DI and DG than the expected. The maximum contraction of stem diameter(MC) and the maximum loss of fresh weight(ML) during daytime showed significantly positive correlations with solar radiation in those days on which plants were not water-stressed and were observed greater than expected from the relationships on severely water-stressed days. But mild water stress could not be discernable by ML and MC. It would be concluded that the daily net gains of fresh weight and/or stem diameter could be used as criteria for diagnosing the water status of tomato and for triggoring the onset of irrigation in automatic system.

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Role of Catecholamines in Ventricular Fibrillation (Catecholamines에 관(關)하여 -제4편(第四編) : 심실전동발생(心室顫動發生)에 있어서의 catecholamines의 의의(意義)-)

  • Lee, Woo-Choo
    • The Korean Journal of Pharmacology
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    • v.19 no.1
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    • pp.15-35
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    • 1983
  • Although it has been well known that ventricular fibrillation is the most important complication during hypothermia, much investigation has failed to show the exact nature of the etiology of ventricular fibrillation. Recently, there has been considerable research on the relationship between sympathetic activity and ventricular fibrillation under hypothermia. Cardiac muscle normally contains a certain amount of norepinephrine and the dramatic effect of this catecholamines on the cardiac muscle is well documented. It is, therefore, conceivable that cardiac catecholamines might exert an influence on the susceptibility of heart muscle to tachycardia, ventricular fibrillation and arrhythmia, under hypothermia. Hypothermia itself is stress enough to increase tonus of sympatheticoadrenal system. The normal heart is supplied by an autonomic innervation and is subjected to action of circulating catecholamines which may be released from the heart. If the reaction of the heart associated with a variable amount of cardiac catecholamines is. permitted to occur in the induction of hypothermia, the action of this agent on the heart has not to be differentiated from the direct effects of cooling. The studies presented in this paper were designed to provide further information about the cardio-physiological effects of reduced body temperature, with special reference to the role of catecholamines in ventricular fibrillation. Healthy cats, weighing about 3 kg, were anesthetized with pentobarbital(30 mg/kg) intraperitoneally. The trachea was intubated and the endotracheal tube was connected to a C.F. Palmer type A.C. respirator. Hypothermia was induced by immersing the cat into a ice water tub and the rate of body temperature lowering was $1^{\circ}C$ per 5 to 8 min. Esophageal temperature and ECG (Lead II) were simultaneously monitored. In some cases the blood pH and serum sodium and potassium were estimated before the experiment. After the experiment the animals were killed and the hearts were excised. The catecholamines content of the cardiac muscle was measured by the method of Shore and Olin (1958). The results obtained are summarized as follows. 1) In control animal the heart rate was slowed as the temperature fell and the average pulse rates of eight animals were read 94/min at $31^{\circ}C$, 70/min at $27^{\circ}C$ and 43/min at $23^{\circ}C$ if esophageal temperature. Ventricular fibrillation was occurred with no exception at a mean temperature of $20.3^{\circ}C(21-l9^{\circ}C)$. The electrocardiogram revealed abnormal P waves in each progressive cooling of the heart. there was, ultimately, a marked delay in the P-R interval, QRS complex and Q-T interval. Inversion of the T waves was characteristic of all animals. The catecholamines content of the heart muscle excised immediately after the occurrence of ventricular fibrillation was about thirty percent lower than that of the pre-hypothermic heart, that is, $1.0\;{\mu}g/g$ wet weight compared to the prehypothermic value of $1.41\;{\mu}g/g$ wet weight. The changes of blood pH, serum sodium and potassium concentration were not remarkable. 2) By the adrenergic receptor blocking agent, DCI(2-3 mg/kg), given intramuscularly thirty minutes before hypothermia, ventricular fibrillation did not occur in one of five animals when their body temperature was reduced even to $16^{\circ}C$. These animals succumbed at that low temperature, and the changes of heart rate and loss of myocardial catecholamines after hypothermia were similar to those of normal animals. The actual effect of DCI preventing the ventricular fibrillation is not predictable. 3) Administration of reserpine(1 mg/kg, i.m.) 24 hours Prior to hypothermia disclosed reduced incidence of ventricular fibrillation, that is, six of the nine animals went into fibrillation at an average temperature of $19.6^{\circ}C$. By reserpine myocardial catecholamines content dropped to $0.045\;{\mu}g/g$ wet weight. 4) Bretylium pretreatment(20 mg/kg, i.m.), which blocks the release of catecholamines, Prevented the ventricular fibrillation under hypothermia in four of the eight cats. The pulse rate, however, was approximately the same as control and in some cases was rather slower. 5) Six cats treated with norepinephrine(2 mg/kg, i.m.) or DOPA(50 mg/kg) and tranylcypromine(10 mg/kg), which tab teen proved to cause significant increase in the catecholamines content of the heart muscle, showed ventricular fibrillation in all animals under hypothermia at average temperature of $21.6^{\circ}C$ and the pulse rate increased remarkably as compared with that of normal. Catecholamines content of cardiac muscle of these animals markedly decreased after hypothermia but higher than control animals. 6) The functional refractory periods of isolated rabbit atria, determined by the paired stimulus technique, was markedly shortened by administration of epinephrine, norepinephrine and isoproterenol. 7) Adrenergic beta-blocking agents, such as pronethalol, propranolol and sotalol(MJ-1999), inhibited completely the shortening of refractory period induced by norepinephrine. 8) Pretreatment with either phenoxftenbamine or phentolamine, an adrenergic alphatlocking agent, did not modify the decrease in refractory period induced by norepinephrine. From the above experiment it is possible to conclude that catecholamines play an important role in producing ventricular fibrillation under hypothermia. The shortening of the refractorf period of cardiac muscle induced by catecholamines mar be considered as a partial factor in producing ventriculr fibrillaton and to be mediated by beta-adrenergic receptor.

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