• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.1
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• pp.53-62
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• 2007

목적: 1990년대 초반부터 시작된 우리나라의 산업 보건에 대한 사회적 관심의 증대와 시장의 요구에 따라 산업위생기관의 양적인 팽창이 이루어지긴 하였으나 실험실 관련 안전보건규정이 미비한 상태에서 추진되어 산업위생 실험실에서 다양한 유해 위험성 인자를 취급함에도 불구하고 사용되는 량이 소규모로 인해 안전보건과 관련된 사항은 대부분 간과하고 있으며, 산업위생 실험실의 안전보건관리 실태는 선진외국에 비해 상당히 낙후되어 있는 실정이다. 따라서 본 연구는 우리나라 산업위생 실험실과 관련한 안전보건관리 실태를 평가함으로써 향후 실험실의 안전보건관리 수준을 향상 시키는데 효과적인 자료로 활용하는데 기여하고자 한다. 방법: 산업위생실험실의 안전보건 실태를 파악하기 위해 설문조사를 수행하였으며, 설문은 실험실의 전반적인 안전보건, 화학물질 저장 및 용기, 가연성 및 인화성 화학물질, 가스 실린더, 의사전달, 응급처치 및 비상사태 장비, 정리정돈, 소방안전, 전기안전, 개인보호구, 흄후드 및 환기, 및 이황화탄소 취급 사례로서 12개 영역으로 구성되었다. 연구대상은 2001년 한국산업안전공단 정도관리프로그램에 참여한 기관으로서 총 대상은 119개 기관이었다. 연구기간은 2002년 7월 01일부터 8월 30일까지 약 60일 이었다. 설문은 반송봉투에 넣어 설문완성 후 연구자에게 보낼 수 있도록 배려하였으며, 1차 설문을 보낸 후 2주 후에 설문 참여를 독려하기 위해 엽서를 발송하였고, 다시 2주 후에 각 산업위생기관에 개별 전화 연락을 취하였다. 그 결과 63% (75개 기관)의 완성된 설문을 얻을 수 있었다. 설문의 총 조사항목은 79문항으로 구성되어 있으며, 산업위생실험실의 안전보건 수준을 정량적으로 평가하기 위해 안전보건 매뉴얼, 교육훈련프로그램 및 한국산업안전공단 실험실 지침서를 보유한 기관과 그렇지 않은 기관간의 차이는 선별된 67문항에 대해 각 문항에 합당하거나 적절할 경우 1점을 부여하는 방식으로 점수화하였다. 이들의 관련성을 파악하기 위하여 Microsoft-Excel 2000 프로그램을 이용하여 two-tailed t-test 분석을 실시하였다. 결과 1. 산업위생실험실 운영과 관련한 67개 항목(항목별로 각 1점 부여)에 대한 안전보건 성과지수화 (100점으로 점수 환산) 결과 안전보건 매뉴얼을 보유한 기관은 $42.98{\pm}13.36$(p<0.001)점, 교육훈련프로그램을 보유한 기관은 $50.75{\pm}14.12$(p<0.01)점, 한국산업안전공단 실험실 지침서를 보유한 기관은 $43.58{\pm}11.92$(p<0.01)점으로 그렇지 않은 기관에 비해 통계적으로 유의하게 높은 점수분포를 보였다. 2. 화학물질 보관 캐비닛이 있는 기관 중 64.8%의 기관은 화학물질을 알파벳 순으로, 27.8%는 분류 기준에 따라, 그리고 7.4%는 무작위로 보관하고 있었다. 3. 단지 8.0% (6개)의 기관만이 실험실내에 눈세정 분수(2 개), 샤워기(3개) 및 눈세정물병(3개, 2개 중복 응답 기관)과 같은 응급처치 장치 및 물품을 갖추고 있었다. 4. 89.0%의 기관이 흄후드내에 화학물질을 보관하고 있었다. 5. 물질안전보건자료, 흄후드 기록지, 비상사태 절차서 및 한국산업안전공단 실험실 지침서와 같은 문서관리는 부적절하게 관리 및 기록되고 있었다. 6. 대부분의 산업위생 실험실은 응급처치 장비, 화학물질 또는 가스용기 보관실과 같은 실험실 안전설비가 부족할 뿐만 아니라 정리정돈, 화학물질 저장 캐비닛, 안전보호구 및 흄후드와 같은 관리가 미비하였다. 결론: 이상의 결과에 근거하여 기관장은 실험실의 안전보건관리를 위하여 문서관리체계를 제공하고, 모든 실험실 종사자가 적절한 개인보호구를 착용할 수 있도록 하며, 비상 장비를 설치하고, 실험실과 관련한 적절한 규정을 제정하며, 교육훈련 프로그램을 제공하여야 한다. 또한 실험실 종사자는 실험 중 적절한 개인보호구의 착용하고, 비상장비 이용에 대한 교육훈련에 참여하며, 적절한 실험실 운영관리에 대한 책임감을 가져야 한다. 위의 권고사항 이행을 위해서 KOSHA는 KQCP 프로그램에 실험실 안전보건관리 항목을 삽입하여 주기적인 평가를 수행할 필요가 있다. 우리나라 실험실의 특성을 고려할 때 본 연구결과는 일반 실험실에도 적용될 수 있을 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.57-65
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• 1999

Backround : Pneumoconiosis is the parenchymal lung disease that results from the inhalation and deposition of dust, usually mineral dust of occupational or environmental origin. Most of the pneumoconiosis can be categorized to coal workers' pneumoconiosis (CWP) in Korea. No effective treatement is currently available, and the therapy for symptomatic CWP is limited to treatment of complication. Therefore authors analyzed and reviewed clinical features and radiological findings of 95 patients with pneumoconiosis for assessing the prognostic factors in disease progression. Method: We reviewed medical records of 95 cases with pneumoconiosis including history, chest X-ray, pulmonary function test, electrocardiography, AFB stain and culture of sputum, and routine blood examination between June 1995 and June 1997 in Seonam University Namkwang Hospital. Results: All of cases are male(mean age, 57.4 years), 91 cases out of them are miners. The mean duration of exposure to dust is 18.8 years. Major clinical symptoms are dyspnea (100%), sputum (71.6%), chest pain (55.8%), cough (23.2%), and hemoptysis (6.3%). 82 % of cases are over Morgan-Seaton Grade 2 in the degree of dyspnea. Small opacity on chest x-ray is 82.1 % and large opacity is 17.9%. Small opacity has tit type (37.2%), q/q type (25.6%) and r/r type (11.5%). B type is 42.2% in large opacity. For the pulmonary function test, restrictive type is 40.3%, mixed type 19.5% and obstructive type 8.3%. The more increasing chest Xray density, the more decreasing $FEV_1$ (p<0.01). 38% of patients show tuberculosis in chest X-ray, 15.8% positive smear of acid fast bacilli in sputum. The prevalence of pulmonary tuberculosis is high in patients with poor clinical condition. The cases with the active pulmonary tuberculosis have severe dyspnea. Expired cases show 100% and 75% of positive pulmonary tuberculosis in chest X-ray and sputum examination, respectively. 75% of expired cases show the chronic cor pulmonale, who died of acute respiratory failure. Conclusion: These findings indicate that tuberculoois infection has a decisive influence on the progress and prognoois of pneumoconioois.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1065-1070
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• 2008

Purpose : This study aims to determine whether early closure (within 7 d) of significant patent ductus arteriosus (PDA) with indomethacin or ligation reduces neonatal morbidity when compared with delayed closure (after 7 d). Methods : Fifty-eight extremely-low-birth-weight infants admitted to the NICU of Seoul National University Hospital from April 2005 to May 2007 with PDA were studied retrospectively. Results : The mean gestational age (GA) was $26{\pm}2weeks$ (range, 23-32 wk), and the birth weight was $782{\pm}146g$ (range, 430-990 g). The delayed closure group was associated with early GA ($25.7{\pm}1.7wk$ vs $27.1{\pm}2.0wk$, P=0.013), in vitro fertilization (IVF) (55% vs 24%, P=0.017), and the absence of preeclampsia (5% vs. 34%, P=0.013). There was no difference in ductal size between the early closure and delayed closure groups. The incidence of bronchopulmonary dysplasia (95% vs 65%, P=0.012) and intraventricular hemorrhage (70% vs. 39%, P=0.027) increased in the delayed closure group. Using regression analysis adjusted for gestational age, delayed closure correlated positively with the duration of ventilator support (P=0.008), hospitalization (P=0.020), time to full enteral feeding (P<0.001), and total parenteral nutrition (P=0.010). Conclusion : Delayed closure of the hemodynamically significant patent ductus arteriosus in extremely-low-birth-weight infants is significantly related to the development of various morbidities. Thus, early closure of PDA is needed within the first week of life.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.217-225
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• 2004

This study was performed to provide the basic knowledge about the mushroom cultivation facilities. Classified current status of cultivation facilities in Gyeongnam province was investigated by questionnaire. The structure of Pleurotus eryngii cultivation facilities can be classified into the simple and permanent frame type. The simple frame structures were mostly single-span type, on the other hand, the permanent frame structures were more multi-span than simple structures. And the scale of cultivation facilities was very different regardless of structural type. But as a whole, the length, width and ridge height were prevailing approximately 20.0 m, $6.6\~7.0m$ and $4.6\~5.0m$ range, respectively. The floor area was about $132\~160\;m^2$, and floor was built with concrete to protect mushrooms from various harmful infection. The roof slope of the simple and permanent type showed about $41.5^{\circ}\;and\;18.6\~28.6^{\circ}$, respectively. The width and layer number of growing bed for mushroom cultivation were around $1.2\~1.6m$, 4 layers in common, respectively. Most of year round cultivation facilities were equipped with cooler, heater, humidifier, and ventilating fan. Hot water boiler was the most commonly used heating system, the next was electric heater and then steam boiler. The industrial air conditioner has been widely used for cooling. And humidity was controlled mostly by ultra-wave or centrifuging humidifier. But some farmers has been using nozzle system for auxiliary purpose. More then $90\%$ of the mushroom house had the independent environment control system. The inside temperature was usually controlled by sensor, but humidity and $CO_2$ concentration was controlled by timer for each growing stage. The capacity of medium bottle was generally 850 cc and 1100cc, some farms used 800 cc, 950 co and 1,250 cc. Most of mushroom producted has been usually shipped to both circulating company and joint market.

• Journal of Bio-Environment Control
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• v.3 no.2
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• pp.106-118
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• 1994

This study was conducted to analyze the effects of fluctuations in temperature, light intensity and soil temperature on the growth of red pepper seedlings in the nonheated plastic houses with various number of layers and in the open field. Relationship between the optimal environment and the growth of seedlings was discussed, and the maximum and minimum outdoor temperatures in Kwangju area from 1941 to 1985 were analyzed. The results obtained were as follows; 1. The minimum temperature in tunnel with quadruple coverings of P. E. film from December 20 to February 25 was decreased to 5$^{\circ}C$ mostly, where the exposure to chilling temperature could not be avoided during this period. The maximum temperature was increased to 33$^{\circ}C$ mostly and 42$^{\circ}C$ in peak, where some ventilation was needed. 2. The diurnal differences of inside temperature, increasing with number of layers, were 16 to 38$^{\circ}C$, while those of outside temperature were 5 to 1$0^{\circ}C$. 3. The cold injury in the quadruple coverings during winter occurred all the times below 12$^{\circ}C$ and as many as 200 times over 3$0^{\circ}C$, while effectiveness of thermal insulation in the multilayered nonheating plastic houses were clearly proved. 4. The inside light intensity was markedly reduced with the increment of layers and the minimum light intensity fallen down below the light compensation point for the growth of red pepper plants regardless of the number of layers. 5. Until 10 a. m., the temperature in the daytime during December 20 to mid - February showed below 10 to 12$^{\circ}C$ which was the limiting temperature for the growth of red pepper seedlings. After 4 p. m., the light intensity was sharply reduced despite of the air temperature kept over 12$^{\circ}C$. Therefore, limiting factors for the growth of red pepper seedlings were the temperature before 10 a. m. and the light intensity after 4 p. m. 6. The minimum soil temperature in quadruple coverings showed around 1$0^{\circ}C$ where the physiological damage for red pepper seedlings might be occurred. 7. The minimum outdoor temperatures from 1941 to 1985 was -19.4$^{\circ}C$, observed in the 5th January.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.52-61
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• 2020

The natural change of winter night temperature from 00:00 to 04:30 O'clock with the different height of thermal screen in a venlo type glasshouse (W59×L68×H5.9 m) was studied using computational fluid dynamics (CFD). At the early stage of CFD analysis, the room temperature decrease of glasshouse with the 5.9 m height of thermal screen were faster than it with the 4.1m height of thermal screen, but at 2 hr after analysis it was slower than in it with the 4,1m, the temperature difference was 0.6℃ after 4 hr. If we consider that turn on the heater when the temperature were decrease below 13℃ at 1hr after CFD analysis, it is good for energy saving in the glasshouse with the 4.1 m height of thermal screen rather than in it with the 5.9 m height, because of the temperature decrease were slow during 2 hrs after analysis. The airflow at the height of 2 m which were grown tomato were fast and wide in the glasshouse with the 5.9 m height thermal screen rather than in it with the 4.1 m, the speed difference was 0.034m·s^-1 at 1hr after CFD analysis. The effect of temperature decrease in summer season were compared with the different height of shading screen from 12:00 to 14:30 O'clock. The height of shading screen were 5.7, 3.9 m, the gap of it were 30%. The air-inflow quantity by the fan with duct at lower part of venlo glasshouse was 0.67 ㎥·s^-1 until 1hr and to increase 3 times of it from 1hr after analysis. The roof window were open 100%. Until 1hr of CFD analysis, the temperature in the 30% open of shading screen was 0.9℃ higher than in the none shading screen. From 13:00 O'clock when the air-inlet quantity to increase 3 times, the temperature in case 30% gap of shading screen were decreased compare with the none shading screen, the temperature difference was 0.5℃ at 14:30 O'clock. The temperature on the floor surface in case 30% gap of shading screen were lower with it's height increase, the temperature difference was 8℃ compare with none shading screen. The relative humidity difference were insignificant by the height and gap of shading screen.

• Neonatal Medicine
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• v.16 no.1
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• pp.47-54
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• 2009

Purpose: Present evidences suggest that Ureaplasma urealyticum is a cause of pneumonia, septicemia, and bronchopulmonary dysplasia (BPD) in newborn infants, particularly those born prematurely. The purpose of this work was to examine the relationship between Ureaplasma urealyticum in the tracheal aspirates and adverse outcomes, such as BPD and early onset neonatal sepsis in premature infants. Methods: A polymerase chain reaction (PCR) was performed on tracheal aspirates collected within 24 hour after birth in 176 premature infants less than 35 weeks of gestation and admitted to the neonatal intensive care unit of Bundang CHA Hospital. Results: U. urealyticum was detected in 37 of 176 preterm infants (21.0%). Gestational age ($29^{+5}{\pm}2^{+5}$ wk vs. $30^{+6}{\pm}2^+{-5}$ wk, P=0.0l3) and birth weight (1.39${\pm}$0.44 kg vs. 1.59${\pm}$0.55 kg, P=0.037) were lower in the U urealyticum-positive group compared to the control group. The incidence of early onset neonatal sepsis (16.2% vs. 6.5%, P=0.045) and BPD (45.9% vs. 29.5%, P=0.047) was higher in the U urealyticum-positive group compared to the control group, but the severity of BPD was not different between two groups. However, multiple logistic regression analysis revealed that the presence of U. urealyticum was not independently related to the development of early onset neonatal sepsis and BPD. Conclusion: The results suggest that colonization of the lower respiratory tract by U. urealyticum might not be related to the development of neonatal sepsis and BPD directly in preterm infants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.93-103
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• 2020

The average growth day of 11 maize varieties from planting to silking in the first cropping (FC) was 89.5 days and in the second cropping (SC) was 46.7 days, which was 43 days faster than in the FC. The average 100-kernel weight (100 KW) in the FC was 28.4 g and 18.3 g in the SC, which was approximately 36.4% lower than that in the FC. The average crude oil content of FC was 3.97% and SC was 3.08%, which was about 0.89% lower than that of FC. The composition of stearic and oleic acid was significantly higher in FC, whereas palmitic and linoleic acid were higher in SC; however, linolenic acid was not statistically different between the two crops. The crude oil content was negatively correlated with linoleic acid (FC -0.264^ns, SC -0.504**) and positively correlated with linolenic acid (0.526**). Unsaturated fatty acid (USFA) composition showed a significant difference between FC (83.48%) and SC (82.96%). Total phytosterol content was 598.3 mg/100 g and 701.9 mg/100 g in FC and SC, respectively, and showed significant difference by planting dates. The β-sitosterol content showed no statistical difference between the planting dates, but campesterol and stigmasterol were significantly higher in SC than in FC. Therefore, it was considered that the temperature condition during the ripening period affects the 100 KW of maize, and this leads to the variation in phytosterol content. However, among phytosterols, β-sitosterol was relatively little affected by the planting dates. USFA composition showed a significantly negative correlation with phytosterol content. Considering the results, the relatively high phytosterol content in SC was mainly because of the delay in progress of starch accumulation as daily air temperature decreased from the middle of the ripening period, whereas progress of phytosterol accumulation in the maize kernel was considered relatively faster than that of starch accumulation.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.488-494
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• 2005

Purpose : To outline the aspects of extubation by birth weight and find the predictors for success/failure at the first extubation in extremely low birth weight infants. Methods : One hundred thirteen extremely low birth weight infants(<1,000 g) who were admitted to NICU at Samsung Seoul Hospital between Jan. 2000 and Jun. 2004 were enrolled. Clinical characteristics that are thought to be related with extubation success or failure were compared with the success and the failure of the first extubation. Results : As the birth weight decreased, extubation success day was significantly delayed : $16{\pm}3day(d)$ in 900-999 g; $20{\pm}3d$ in 800-899 g; $35{\pm}4d$ in 700-799 g; $37{\pm}9d$ in 600-699 g; $49{\pm}12d$ in ${\leq}599g$. 25 out of 113 infants(22%) failed the first extubation. Preterm premature rupture of membrane was associated with extubation success, and air leak was associated with extubation failure, with a borderline significance. Postnatal and corrected age and body weight at the first extubation, nutritional status, and ventilator settings were not associated with extubation success or failure. Extubation success day was significantly delayed, and the incidence of late-onset sepsis and mortality was significant higher in the failure of the first extubation. Conclusion : We could not find significant predictors for success/failure at the first extubation. The failure of the first extubation had an increased risk of late-onset sepsis and death. Further studies are needed to find the predictors for extubation success/failure.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.953-959
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• 2005

Purpose : The administration of total parenteral nutrition(TPN) has become a standard procedure in the management of nutritionally deprived and critically low birth weight neonates. Sepsis remains the most frequent serious complication during TPN, resulting in increased morbidity, mortality and health care costs. This study was performed to evaluate the clinical efficacy and complications of percutaneous central venous catheterization(PCVC) in very low birth weight infants. Methods : A total of 56 very low birth weight infants below 1,500 g during the period from January 1998 to December 2003 were enrolled and their medical records reviewed. Study group(n=32) included the babies who had undergone PCVC and a control group(n=24) included babies who had not undergone PCVC. We compared the study group with the control group for factors such as subject characteristics and catheter-related complications. Results : There was no difference in subject characteristics, such as birth weight, gestational week, respiratory distress syndrome, duration of ventilator therapy, duration from tube to complete oral feeding, days at TPN and its total duration, body weight at discontinuation of TPN and the days taken to reach to 2,000 g. However, the morbidity rate due to patent ductus arterious, chronic lung disease, necrotizing enterocolitis, osteopenia, cholestasis, and sepsis showed no difference. The study group with infants below 1,000 g showed a higher incidence of sepsis compared to the control group of the same weight group. The study group with infants between 1,000 to 1,500 g showed significantly higher incidences of intraventricular hemorrhage and took longer reach the a body weight of 2,000 g. Conclusion : Considering the high incidence of sepsis in the PCVC group, every attempt should be made to minimize the length of TPN therapy and encourage early enteral feeding. We also recommend the use of PCVC carefully in patients requiring prolonged nutritional support.