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THE CURRENT STATUS OF BIOMEDICAL ENGINEERING IN THE USA

  • Webster, John G.
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.27-47
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    • 1992
  • Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

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The Consideration about Heavy Metal Contamination of Room and Worker in a Workshop (공작실에서 실내 및 작업종사자의 중금속 오염도에 관한 고찰)

  • Kim Jeong-Ho;Kim Gha-Jung;Kim Sung-Ki;Bea Suk-Hwan
    • The Journal of Korean Society for Radiation Therapy
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    • v.17 no.2
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    • pp.87-94
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    • 2005
  • Purpose : Heavy metal use when producing the block from the workshop. At this time, production of heavy metal dust and fume gives risk in human. This like heavy metal to improve seriousness through measurement and analysis. And by the quest in solution is purpose of this thesis. Materials and Methods : Organization is Inductively Coupled Plasma Atomic Emission Spectrometer, and the object is Deajeon city 4 workshops in university hospital radiation oncology (Bismuth, Lead, Tin and cadmium). Method is the ppb the pumping it does at unit, comparison analysis. And the Calculation heavy metal standard level in air through heavy metal standard level in body and blood, so Heavy metal temporary standard set. Results : Subterranean existence room air quality the administration laws appointed Lead and Cadmium's exposure recommend that it is $3{\mu}g/m^3\;and\;2{\mu}g/m^3$. And Bismuth and Tin decides $7{\mu}g/m^3\;and\;6{\mu}g/m^3$ through standard level in air heavy metal and standard level in body and blood. Heavy metal measurement level of workshops in 4 university hospital Daejeon city compares with work existence and nonexistence. On work nonexistence almost measurement level is below the recommend level. But work existence case express high level. Also consequently in composition ratio of the block is continuous with the detection ratio. Conclusion : Worker's heavy metal contamination imbrued serious for solution founds basic part. In hospital may operation on local air exhauster and periodical efficiency check, protector offer, et al. And worker have a correct understanding part of heavy metal contamination, and have continuous interest, health control. Finally, learned society sphere administer to establishment standard level and periodical measurement. And it founds basic solution plan of periodical special health checkup.

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Evaluation of safety by skin dosimetry in Intraoperative Radiotherapy for breast cancer patients (유방암 환자의 수술 중 방사선치료 시 피부선량 측정을 통한 안전성 평가)

  • Jung, In Ho;Kim, Joon Won;Park, Kwang Woo;Ha, Jin Sook;Jeon, Mi Jin;Cho, Yoon Jin;Kim, Sei Joon;Kim, Jong Dae;Shin, Dong Bong
    • The Journal of Korean Society for Radiation Therapy
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    • v.27 no.1
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    • pp.13-22
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    • 2015
  • Purpose : We investigated the safety of Intrabeam$^{TM}$ system, X-ray unit for Intraoperative Radiotheray (IORT) by measuring surface dose using Optically Stimulated Luminescent Dosimeter(OSLD). Materials and Methods : 30 patients were selected, who were in breast cancer patients and had an operation of breast conserving surgery (BCS). At the inner surface of tumor bed, 20 Gy were described, and 5 Gy at 1cm depth from the inner surface. Along the size of tumor bed which could be decided after resection of tumor, the size of applicator were determined. Usual treatment time were from 18 to 40 minutes. For the measurement of surface doses, OSLD were placed at superior(U1,2), inferior(D1,2), lateral(L1,2) and medial(M1,2) directions from the center of applicator. Each direction, two OSLD were placed at 0.5 cm and 1.5 cm from the center. Mean, maximum, and minimum doses were analyzed to be compared. Results : Mean values were U1 $2.23{\pm}0.80Gy$, U2 $1.54{\pm}0.53Gy$, D1 $1.73{\pm}0.63Gy$, D2 $1.25{\pm}0.45Gy$, L1 $1.95{\pm}0.82Gy$, L2 $1.38{\pm}0.42Gy$, M1 $2.03{\pm}0.70Gy$, and M2 $1.51{\pm}0.58Gy$. Maximum values were 4.34 Gy at U1, and Minimum values were 0.45 Gy at M2. 13.3 % of patient (4pts out of 30) were reported that surface dose were over 4 Gy. Conclusion : The fact that skin dose of all patients were less than 5 Gy based on OSLD measurement showed the safety of Intrabeam$^{TM}$ system. In the relatively small breast volume, the tendency that surface dose was increased had been shown, which was analyzed by the data of patients who irradiated over 4Gy at skin surface. Therefore, for appropriate indication for IORT, it is suggested that breast volume as well as the size and position of tumor should be carfully considered.

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Economic Feasibility of Hill Land Development (산지개발(山地開發)의 경제성)

  • Kim, Dong-Min
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.4
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    • pp.283-295
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    • 1979
  • A new Farmland Expansion and Development Promotion Law was enacted in 1975. This law authorizes the Government to undertake development within a declared "reclamation area", wherever the land owners are unable to do so. In order to give additional impetus to conversion of waste hilly land into productive farmland, these hilly land development projects were conducted as large scale scheme which include soil fertility improvements such as the application of lime and phosphate. Farmland Expansion and Development Promotion Corps has attempted to undertake annual farm surveys in order to obtain some information about hilly land agriculture and farming operations within the reclamation project areas since 1976. As survey data accumulates, more and more clear picture of hilly land farming come to appear and enable us to conduct in-depth study. Effects of such upland reclamation include converting of previously unproductive slopeland into cultivable farmland for lucrative and commercial farming or food production. Furthermore, idle or marginal resources such as farm labor, equipment and compost would be fully employed. Socio-economic effects would include increases in land value and attitude change of farmers. On the other hand the preservation of natural environments might be damaged to the some extend by the projects. As shown in Table 7, the average farm size increased from 3,156 pyeong($3.3m^2$) to 5,562 pyeong, a 76.2% increase. The proportion of small farms with less than I ha dropped from 59.8% to 34.4%, but that of the large farms over 2 ha rose from 13.1% to 32.0% (See Table 8). The survey results indicate that as the farming on reclaimed uplands become time-honored, the acreage devoted for food crop production decreases against the economic crop growing acreage (see Table 6). For example, in the case of uplands reclaimed in 1972, the ratio of food crop acreages decreased from 99.7% in 1972 to 62.5% in 1977, whereas that of economic crop acreages increased from 0.3% in 1972 to 37.5% in 1977. The government used to actively encourage the farmers to carry out food crop production in the reclaimed upland targting toward the realization of self-sufficiency in food grains. It is, however, apparent that the farmers did hardly take the government advises as far as their economic interest were concerned. Yield per 10a. of various crops from the reclaimed uplands by year were surveyed as seen in Table 12. On the average, barley production in the reclaimed areas achieved 83.3% of the average unit yield from the existing upland in its 5 th year. Soybean yields showed a modest increase from 64% in the first year to 95%, in the 5 th year. In contrast, economic crops such as red pepper, totacco and radish achieved their maximum target yields in 3 years from starting to cultivate on the reclaimed farms. In order to test the post economic viability, an economic analysis was performed for each of selected subprojects on the basis of the data obtained through survey. The average actual internal economic rate of return on upland reclamation investments was found to be 20.3% which exceeded other types of projects of land and water development such as tidal land reclamation, irrigation or paddy rearrangement. The actual IRRs of subcategories of upland reclamation projects varied from 17.9% to 21.4% depending upon the kinds of cropping system adopted in each reclaimed areas such as food, economic, fruit or forage crops.

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The Impact of the Reclamation and Utilization of Idle Hillside Lands on Future Food Production in Korea (식량(食糧)의 안정적(安定的) 공급(供給)을 위한 산지개발이용의 필요성(必要性)과 전망(展望))

  • Park, Johng-Moon
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.4
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    • pp.213-233
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    • 1979
  • It is generally agreed that the country's population will grow up to the level of 52 million by the year of 2000 and that due the active growth of industry, urbanization and road constructions, sizable portion of existing arable lands will be utilized for other purposes than agriculture in near future. From 1966 to 1977, it was estimated that, the average annual conversion of arable lands to other uses, was 12,909 ha. If this trend persists, it is predicted that from 1978 to 1991 when the 6th Five Years Economic Development Plan will terminate, approximately 181,000 ha of arable lands will be converted for other uses again. On the other hand, it is certain that the increased population (39 million in 1981, 45 million in 1991, 52 million in 2001) and the changes in food pattern along with the enhancement of living standards will bring about the phenomenal increase in demands for not only the staple food but also the livestock products such as meat, milk and eggs, vegetables and fruits. These future increased demands for various foods, naturally mean the increased needs for the expansion of arable lands at the same time. It is predicted that, if more activities than present scale are not taken for the expansion of arable lands, the national food self sufficiency level will drop from 79% in 1977 down to 62% in 1991. To meet the increased food demands in future, there are several ways and means. These will include the increased land use intensity, elevation of unit area yield levels, minimization of conversion of arable lands to other uses and expansion of arable lands through the reclamations of idle hillside lands and tidal lands. Among these, the expansion of arable lands through reclamations of idle hillside lands and tidal lands are more positive measures to cope with the increased production of foods in future. The reclamation of hillside lands demands more attention because it needs more advanced technologies in agronomical and engineering aspects, larger scale fundings and integrated socioeconomic considerations. In agromical aspects, the thechniques for early improvement of chemical and physical properties of soils, proper soil conservation measures and rational cropping systems are of particular importance. As to the financial supports to encourage the farmings in hillside land, much bold fund inputs are essential for the construction of roads, installation of irrigation and drainage facilities, soil conservation mechanisms, which will ensure the stabilized farming with reasonable incomes in the newly reclaimed lands.

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Perceptions of Quality Nursing care of Patients and Families (질적 간호에 대한 환자와 가족의 지각)

  • Chi, Sung-Ai;Kwon, Sung-Bok;Park, Eun-Hee
    • Journal of Korean Academy of Nursing Administration
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    • v.4 no.1
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    • pp.247-275
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    • 1998
  • The purpose of this study was to offer the results of content analysis and qualitative study that explored the perceptions about quality nursing care of patients and families as consumers and to identify the implications of this study for quality nursing care management and research. The data was collected from 12 adult patients and 9 families who were admmitted at medical and surgical nursing unit of one university hospital in Seoul from October, 1996 to January, 1997. Research participants were asked to response "what do you think quality nursing care?" and similar questions during the interviews was performed. Data were analyzed using open coding and content analysis with frequencies and percents of attributes of quality nursing care. Attributes of quality nursing care and meaning of quality nursing care that patients and families perceived were explored. 1. The attributes of quality nursing care that patient and families perceived were categorized into 56 attributes. The highest response rate among the attributes was 'one's heart at ease' (76.2%), and the next high response rates were ranked in order 'consideration' , 'care about' (each 61.9% 'expert skill' (57.1%), 'deal with problem promptly' , 'information offer' (42.9%), 'intimate feeling' (38.1%), 'smile' 'service spirit' , 'do one's best' (each 33.3%), 'frequent visit' (23.8%), 'observe the time' (23.8%), 'direct nursing care' , 'speaking warmly' , give a hope' , 'address kindly' , 'a sense of duty' , 'good facilities' (each 19.0%), 'inquire after a patient health' , 'patient-centered nursing care' , 'showing an example' , 'professional knowledge' , 'careless moraly patient' , 'give encourage to patients' , 'good answer a question' (each 14.3%), 'do not imprudently' , 'do not disregard' , 'broad knowledge' , 'emergency treatment skill' , 'dependability' ,'consolation' giving a sense of security' , 'a self sacrificing spirit' , 'a sense of responsibility' 'hard - working', 'enough disposition of nursing staff (each 9.5%), 'improve patient's pride' and the rest attributes exhibited 4.7%, respectively. 2. The attributes that were identified in patients' data only were 8 categories, 'service sprit' (58.3 %) 'expert knowledge' , 'good answer a question' (each 25.0%), 'hard working' (16.7%), 'a warm character', 'professional attainments', 'do without reserve', 'satisfaction' (each 8.3%), 3. The attributes were identified to families' data only were 31 categories, 'speaking warmly' , 'direct nursing care', 'adress kindly', 'patientcentered nursing care', 'showing an example' (each 33.3%). 'do not imprudently' , 'do not disregard' , 'consolation', 'giving a sense of security', 'broad knowledge' , 'emergency treatment skill', 'dependability' ,'a self - sacrificing spirit', 'a sense of responsibility' (each 22.2%), 'improve patient's pride' , 'without discrimination' , 'show kindness' , 'individual nursing care', 'being with patient' , 'helping' , 'accuracy' , 'without any mistake' , 'love' , 'self - confidence', 'self possession', 'a self - denying spirit' , 'a sense of duty' , 'tighten discipline' , 'disposed room with similar patient to diagnosis', 'compensatory relationship between me dical team' , 'role of connection' (each 11.1 %). 4. The attributes of quality nursing care were integrated into 11 categories that they were 'patientcentered nursing care' (25.1%), 'expertise' (22.1%), 'caring'(18.1%), 'kindness'(11.1%L 'nurse attainments(10.1%), 'sincerity' (7.5%), 'good environment' (2.0%), 'effective organizational management', 'coordination', 'enough nursing staff' ( each 1.0%), 'satisfaction' (0.5%) were showed in the order of the highest rate. 5. The concept of quality nursing care were defined as 'give a satisfaction to patients by patientcentered care based on professional skill and caring with kindness and sincerity'. The description of the meaning of quality nursing care provided by this research participants, patients and families can provide important information for quality nursing care management, medical marketing, education and researches of this field. On the basis of the above findings the following recommendations are made: to suggest to utilize this results for patient care in practice setting, development of quality assessment tool in nursing care, repeat study by the same subjects and method, and to a comparative study by the same method to nurse.

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Problems of administrative area system in Korea and reforming direction (한국 행정구역체계의 문제점과 개편의 방향)

  • ;Yim, Seok-Hoi
    • Journal of the Korean Geographical Society
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    • v.29 no.1
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    • pp.65-83
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    • 1994
  • Sevaral problems of administrative area sysem in Korea have been brought up for a long time. Because its frame has remained since Chosun and Japanese colonial period in spite of changing local administrative environment in accordance with rapid industrialization and urbanization. Recent reform of city (Shi)- county (Gun) integration is derived from this argument. But problems which permeate deeply overall system cannot be solved by partial reorganization of Shi-Gun. They may be rationalized only through the reform of the whole system. The aims of this study are to analyze problems of administrative area system entirelr and to discuss the direction of its reform from that point of view. Major problems of administrative area system are summed up into the followings. Firstly, it is found that administrative hierarchies are too many levels. Contemporary administrative hierarchical structure is 4 levels: regional autonomous government (Tukpyolshi, Jik'halshi, Do), local autonomous government (Shi, Gun), two leveis of auxiliary administrative area (Up, Myun and Ri). These hierarchies were established in late period of Chosun which transportation was undeveloped and residential activity space was confined. But today developing transportion and expanding sphere of life don't need administrative hierarchical structurl with many levels. Besides developing administrative technology reduces administrative space by degrees. Many levels of contemporary administrative hierarchical structure are main factor of administrative inefficency, discording with settlement system. Second problem is that Tukpyolshi and Jik'halshi - cities under direct control of the central government as metropolitan area - underbounded cities. Underbounded city discomforts residential life and increases external elects of local pulic services. Especially this problem is Seoul, Pusan and Daegu. Third problem is that Do-areas are mostly two larger in integrating into single sphere of life. In fact each of them consistes of two or three sphere of life. Fourth Problem is metropolitan government system that central city is seperated from complementary area, i.e. Do. It brings about weakening the economic force of Do. Fifth problem is that several cities divided single sphere of life. It is main factor of finantial inefficency and facing difficult regional administration. Finally necessity of rural parish (Myun.) is diminished gradually with higher order center oriented activty of rural residents. First of all administrative area system should corresponds with substantial sphere of life in order to solve these problems. Followings are some key directions this study proposes on the reform of administrative area system from that standpoint. 1. Principles of reorgnization -- integration of central dty with complementary area. -- correspondence of administrative hierarchical structure with settlement system. -- correspondence of boundary of administrative area with sphere of life. 2. Reform strategy -- Jik'halshi is integrated with Do and is under the contol of Do. -- Small Seoul shi (city) which have special functions as captal is demarcated in Seoul tukpyolshi and 22 autonomous distrcts of Seoul tukpyolshi is integrated into 3-4 cities. -- Neighboring cities (Shies) in single sphere of life are intrgrated into single city (Shj). -- Myun and Ri are abolished in rural region and new unit of local administrative area on the basis of lowest order sphere of life into which 3-4 Ries are integrated replaces them.

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Necrotizing Enterocolitis - A Survey by the Korean Association of Pediatric Surgeons - (괴사성 장염 - 대한소아외과학회회원 대상 전국조사 -)

  • Lee, Suk-Koo;Kim, D.Y.;Kim, S.G.;Kim, W.K.;Kim, I.K.;Kim, S.Y.;Kim, S.C.;Kim, J.E.;Kim, J.C.;Park, K.W.;Park, W.H.;Seo, J.M.;Song, Y.T.;Oh, S.M.;Oh, J.T.;Lee, N.H.;Lee, D.S.;Lee, S.C.;Jun, Y.S.;Chung, S.Y.;Chung, S.E.;Choi, K.J.;Choi, S.O.;Choi, S.H.;Han, S.J.
    • Advances in pediatric surgery
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    • v.12 no.1
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    • pp.70-85
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    • 2006
  • A nationwide survey on necrotizing enterocolitis (NEC) was undertaken among members of the Korean Association of Pediatric Surgeons. The members were required to complete a questionnaire and the case registration form for each patient during the three-year period from July 2001 to June 2004. Eighty one patients were included in the questionnaire, but only 71 patients were registered from 22 members in 16 hospitals. At the same time survey on focal intestinal perforation (FIP) was undertaken and 17 patients were registered from 11 members in 10 hospitals. Total 19,041 newborns were admitted to neonatal intensive care unit during the study period. Eighty one patients (17.27 %) were underwent surgery among 469 babies who were managed under the impression of NEC. The male to female ratio was 2.1:1. The premature were 60.6 %. The most common site of involvement was ileum. Overall and operation survival of NEC were 72 % and 79 %, respectively. The survival was lower in smaller babies, multiple segments involvement and involvement of both the small and large intestine. But there was no difference in survival according to sex or prematurity. The FIP showed very similarity with NEC in terms of incidence, and the age of diagnosis and operation. But the survival was much better and 100 %. The results showed the clinical characteristics of NEC and the trend of management in NEC in Korea. In the future we hope we can discuss about this topic in prospective manner.

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Effect of Thinning on Environmental Factors and Wild Mushroom Fruting in Quercus mongolica Forest (신갈나무림에서 솎아베기가 임내환경과 자연버섯 발생에 미치는 영향)

  • Park, Yong Woo;Koo, Chang Duck;Choi, Hyun Bin;Kim, Jin Gun;Lee, Hee Su;Lee, Hwa Yong
    • Journal of Korean Society of Forest Science
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    • v.107 no.1
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    • pp.1-15
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    • 2018
  • In order to determine the effects of thinning on mushroom fruiting, microclimate and air temperature in Quercus mongolica forests, this study investigated changes in crown density, soil temperature, air temperature and throughfall in the natural Q. mongolica forest which was thinned by approximately 45% four years ago. The results showed that crown density was smaller than control by 6% from April to October, The soil temperature and air temperature in the thinned stands were significantly higher than those of the control by $1{\sim}2^{\circ}C$ until August and differences in air and soil temperature. The average daily temperature difference was higher than control by $0.2{\sim}0.7^{\circ}C$ until October. Throughfall from July to September in the thinned was approximately 135 mm higher than in the control. The maximum difference in throughfall per unit time was 3.5 mm/h. Soil moisture in the thinned site increased by approximately 5% compared with the control and reduced to the normal moisture after 4 days in both sites. 55 mushroom species were found in the thinned area between July and September. The thinned site contained 10 mycorrhizal mushrooms more than the control and 1 saprophytic mushroom species more than the control. Shannon-Wiener Index was 3.2, approximately 0.5 higher than the control. Tylopilus neofelleus, etc., occurred in the thinned site more quickly, but Aaricus subrutilescens, Clitocybe sp, occurred later. In the thinned site, the dominance of Tylopilus neofellelus and Armillaria sp. increased approximately 6% and 30% and yield about 1.5 times and 20 times, respectively. In conclusion, thinning in the Q. mongolica forest increased the soil and air temperature, soil moisture, throughfall and the diversity of mushroom species, and advanced the period of occurrence, and increased dominance and yield of some mycorrhizal mushrooms and Amillaria sp.

Growth and Physiological Adaptations of Tomato Plants (Lycopersicon esculentum Mill) in Response to Water Scarcity in Soil (토양 수분 결핍에 따른 토마토의 생육과 생리적응)

  • Hwang, Seung-Mi;Kwon, Taek-Ryun;Doh, Eun-Soo;Park, Me-Hea
    • Journal of Bio-Environment Control
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    • v.19 no.4
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    • pp.266-274
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    • 2010
  • This study aim to investigate fundamentally the growth and physiological responses of tomato plants in responses to two different levels of water deficit, a weak drought stress (-25 kPa) and a severe drought stress (-100 kPa) in soil. The two levels of water deficit were maintained using a micro-irrigation system consisted of soil sensors for the real-time monitoring of soil water content and irrigation modules in a greenhouse experiment. Soil water contents were fluctuated throughout the 30 days treatment period but differed between the two treatments with the average -47 kPa in -25 kPa set treatment and the -119 kPa in -100 kPa set treatment. There were significant differences in plant height between the two different soil water statuses in plant height without differences of the number of nodes. The plants grown in the severe water-deficit treatment had greater accumulation of biomass than the plants in the weak water-deficit treatment. The severe water-deficit treatment (-119 kPa) also induced greater leaf area and leaf dry weight of the plants than the weak water-deficit treatment did, even though there was no difference in leaf area per unit dry weight. These results of growth parameters tested in this study indicate that the severe drought could cause an adaptation of tomato plants to the drought stress with the enhancement of biomass and leaf expansion without changes of leaf thickness. Greater relative water content of leaves and lower osmotic potential of sap expressed from turgid leaves were recorded in the severe water deficit treatment than in the weak water deficit treatment. This finding also postulated physiological adaptation to be better water status under drought stress. The drought imposition affected significantly on photosynthesis, water use efficiency and stomatal conductance of tomato plants. The severe water-deficit treatment increased PSII activities and water use efficiency, but decreased stomatal conductance than the weak water-deficit treatment. However, there were no differences between the two treatments in total photosynthetic capacity. Finally, there were no differences in the number and biomass of fruits. These results suggested that tomato plants have an ability to make adaptation to water deficit conditions through changes in leaf morphology, osmotic potentials, and water use efficiency as well as PSII activity. These adaptation responses should be considered in the screening of drought tolerance of tomato plants.