• Title/Summary/Keyword: 최기형성

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A Study on DC Interruption Technology using a Transformer Type Superconducting Fault Current Limiter to Improve DC Grid Stability (DC 그리드 안정성 향상을 위해 변압기형 초전도 한류기가 적용된 직류 차단 기술에 관한 연구)

  • Hwang, Seon-Ho;Choi, Hye-won;Jeong, In-Sung;Choi, Hyo-Sang
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.4
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    • pp.595-599
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    • 2018
  • Interruption system with the transformer type superconducting fault current limiter(TSFCL) is proposed in this paper. The interruption system with a TSFCL is a technology that it maximizes the interruption function of a mechanical DC circuit breaker using a transformer and a superconducting fault current limiter. By a TSFCL, the system limits the fault current till the breakable current range in the fault state. Therefore, the fault current could be cut off by a mechanical DC circuit breaker. The Interruption system with a TSFCL were designed using PSCAD/EMTDC. In addition, the Interruption system with a TSFCL was applied to the DC test circuit to analyze characteristics of a current-limiting and a interruption operation. The simulation results showed that the Interruption system with a TSFCL interrupted the fault current in a stable when a fault occurred. Also, The current-limiting rate of the Interruption system with a TSFCL was approximately 69.55%, and the interruption time was less than 8 ms.

MRI Protocol of Female Pelvis (여성골반 MRI 프로토콜)

  • Shin, Yu-Ri;Rha, Sung-Eun
    • Investigative Magnetic Resonance Imaging
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    • v.14 no.1
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    • pp.1-9
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    • 2010
  • Although ultrasonography is the most commonly used first-line imaging modality of the female pelvis because of diagnostic accuracy, low cost and safety, MRI is the best imaging modality of choice for the evaluation of the female pelvis. The indication of female pelvis MRI is diverse and includes the evaluation of M$\ddot{u}$llerian duct anomaly, differential diagnosis and characterization of uterine and ovarian tumors, and staging of malignant uterine and ovarian tumors. Understanding of MR protocols according to the specific gynecologic pathology allows accurate diagnosis and proper patient management.

A Clinical Analysis of Neonatal Surgical Gastrointestinal Diseases in Daegu·Busan Area (대구·부산 지역에서 수술을 요하는 신생아 소화기 질환의 임상적 고찰)

  • Son, Seung Kook;Park, Jae Hong;Choi, Byung Ho;Choi, Kwang Hae;Lee, Kyoung Hoon
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.7 no.2
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    • pp.179-185
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    • 2004
  • Purpose: Perinatal mortality rates have been used as a summary statistic for evaluating child health and medical status. Neonatal mortality rates have decreased over the past 30 years in Korea. To understand the current status of neonatal surgical gastrointestinal diseases in Daegu Busan area, we have studied about neonatal gastrointestinal diseases with their clinical features, postoperative outcome, and mortality rates. Methods: A clinical analysis on 202 neonates who underwent neonatal surgery from January 1996 to July 2003 at Pusan National University, Kyungpook National University, Youngnam University, and Daegu Catholic University was carried out. Results: The main diseases of surgical conditions were anorectal malformation (23.8%), atresia/stenosis of midgut (13.4%) and pyloric stenosis (13.4%). The male to female ratio was 2.8 : 1. Thirty-five cases (17.0%) had one or more associated anomalies including congenital heart disease, cryptoorchidism, hydronephrosis, and chromosomal anomaly. Twenty cases (10.0%) were diagnosed by antenatal ultrasound. Patients with esophageal atresia had the longest hospitalization for 54.6 days. Postoperative complications occurred in 18 cases (8.9%). The main postoperative complications were wound infection (3.5%) and anastomotic leakage (2.5%). Overall mortality was 5.9%. Diaphragmatic hernia showed the highest mortality rate (37.5%), and esophageal atresia (28.6%) and omphalocele (20.0%) were followed. Conclusion: The current status of neonatal surgical gastrointestinal diseases in Daegu Busan area has improved because the disease categories are various, postoperative complications and mortality rates are decreased.

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The effects of selenium on fetal growth and development in CD-1 mice exposed with mercury for the gestation period (임신 중 수은을 섭취한 CD-1 마우스 태아의 성장발육과 기형발생에 미친 셀레늄의 효과)

  • Kim, Jin-suk;Lee, Sang-mok;Choi, Seok-wha;Lee, Won-chang
    • Korean Journal of Veterinary Research
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    • v.34 no.2
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    • pp.361-368
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    • 1994
  • Teratogenic and embryotoxic effects of mercury have been reported, however, there is little information about possible antidotes against mercury exposure during gestation. In order to evaluate therapeutic effects of selenium as an antidote against mercury poisoning, pregnant CD-1 mice were exposed to methylmercury chloride(20ppm) through the drinking water with treatment of sodium selenite (1.0mg, 2.0mg or 3.0mg/kg b.w., subcutaneously) or BAL(5.0mg/kg b.w., subcutaneously) under the single or combination base as the therapeutic agents from day 6 to 15 of gestation. Fetal growth parameters such as body weight and crown-rump length in the mice exposed to mercury, were reduced as was placental weight compared to those in the control. Treatment of selenium(alone, combination with BAL) reduced the harmful effects induced by mercury on the fetal growth parameters even though no specific relationship between dose and therapeutic effect. The incidence of dead fetuses/resorptions and malformed fetuses(especially cleft palate) was also increased in the mercury only treated group. Selenium treatment demonostrated reduced the incidence of abnormal fetuses under the exposure of mercury. Relative maternal organ weights(liver, kidney, spleen) were increased significantly but relative brain weight was decreased as evidenced by decreased in the mercury treated mice compared to that in the control. A subtle indication of maternal mercury toxicity evidenced by changes of relative maternal organ weights, decreased water and feed consumption were also prevented efficiently by selenium treatment. The present study suggests that methylmercuric chloride is embrytoxic and teratogenic in CD-1 mice when exposured during organogenesis and that selenium administration may have therapeutic application for the treatment of mercury poisoning although more applicable study in human should be performed with caution in the future.

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Teratogenicity Study of KTC-1, a New Semisynthetic Rifamycin Derivative, in Rats (새로운 반합성 Rifamycin 유도체 KTC-1의 랫트 최기형 시험)

  • 김종춘;정문구;박종일;한상섭
    • Toxicological Research
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    • v.11 no.1
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    • pp.81-89
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    • 1995
  • A teratogenicity study of KTC-1, a new semisynthetic rifamycin antituberculous drug, was conducted in Sprague-Dawley rats. Dosages of KTC-1 0, 7, 21, and 63 mg/kg/day were administered to darns orally gayage from day 7 to day 17 of gestation. Two-third of dams per group were subjected to cesarean section on day 21 of pregnancy for examination of their fetuses, and the remaining one-third of darns per group were allowed to deliver naturally for postnatal examination of their offspring. At 21 mg/kg/day, an increase in the skeletal variations of F1 fetuses and a decrease in the body weight of F1 offspring were seen. At 63 mg/kg/day, a loss in body weight was observed in darns. An increase in fetal death rate, a decrease in litter size and body weight, and an increase in the incidence of visceral malforrnations and skeletal variations were found in F1 fetuses. In particular, lumar rib occurred at an incidence of 31%. In addition, an increase in the dead newborns at birth and neonatal deaths during the lactation period, a loss in body weight, and a decrease in spleen weight were observed in F1 offspring. There were no signs of maternal toxicity or embryotoxicity at 7 mg/kg/day. The results suggest that the no-effect dose level(NOEL)for dams is 21 mg/kg/day, and NOELs for F1 fetuses and offspring are 7 mg/kg/day.

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Reproductive Toxicity Study of LBO0014, A New Recombinant Human Erythropoietin: Teratogenicity Study in Rats (새로운 인체 재조합 적혈구 조혈인자 LB00014의 생식독성연구: 랫드 최기형성시험)

  • 정문기;양병철;김종춘;송시환;이상구
    • Biomolecules & Therapeutics
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    • v.6 no.1
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    • pp.82-88
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    • 1998
  • LBO0014, a new recombinant human erythropoietin, was at dose levels of 0, 120, 600, and 3,000 IU/kg/day administered intravenously to pregnant Sprague-Dawley rats during the organogenetic period. All dams were subjected to caesarean section on day 20 of pregnancy, Effects of test substance on dams and embryonic development of Fl fetuses were examined. No treatment-related changes in clinical signs, body weight, and food consumption were observed at all doses tested. At necropsy spleen enlargement was found at 3,000 lU/kg. There was an ulcrease in the spleen weight at 600 and 3,0007/kg. Developmental toxicity was evident as increased resorptions at 3,000 lU/kg. At 600 and 3,000 RJ/kg, retarded ossification of fetuses occurred at an incidence of 31.3% and 64.7%, respectively. In addition, there was a delay in ossification of sternebrae and sacrocaudal vertebrae at 600 and 3,000 lU/kg. A decrease in the number of metacarpi and metatarsi was also seen at 3,000 nJ/kg. The results show that the no observed adverse effect dose level (NOAEL) for material toxicity was over 3,000 IU/kg/day and the NOAEL for developmental toxicity was 120 IU/kg/day.

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Teratogenicity Study of SKI 2053R, a New Platinum Anticancer Agent, in Rabbits (새로운 백금착물 항암제 SKI 2053R의 토끼 최기형성시험)

  • 김종춘;김갑호;박종일;김형진;정문구
    • Biomolecules & Therapeutics
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    • v.7 no.3
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    • pp.292-299
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    • 1999
  • SKI 2053 R, cis-Malonato [(4R, 5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane] platinum(II), is a newly developed antitumor platinum complex derived from cisplatin. Preclinical studies suggest that it may have greater antitumor activity and lower toxicity than cisplatin. Effects of test agent on general toxicity of does and embryonic development of Fl fetuses were investigated in rabbits. Sixty eight New Zealand white rabbits were distributed among three treated groups and a control group. SKI 2053R was administered intravenously to pregnant rabbits from days 6 to 18 of gestation at dose levels of 0, 0.67, 2.0, or 6.0 mg/kg/day. The pregnant does were subjected to the caesarean section on day 28 of gestation. No treatment-related changes in clinical signs, body weight, food consumption, and necropsy findings were observed in all groups. Fl fetuses showed no changes related to the treatment of SKI 2053R, except that an increase in the incidence of skeletal variations were observed at 6.0 mg/kg. There were no signs of material toxicity or embryotoxicity at 0.67 and 2.0 mg/kg. The results show that the administration of 6.0 mg/kg SKI 2053R induces skeletal variations in fetuses and that the no observed adverse effect levels(NOAELS) of SKI 2053R are considered to be over 6.0 mg/kg for does and 2.0 mg/kg for Fl fetuses in rabbits.

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Correction of Secondary cleft lip-nasal deformity; secondary rhinoplasty in children and adults (구순열 이차비기형의 교정; 아동과 성인에서의 이차 비성형술)

  • Song Gin-Ah;Myung Hoon;Hwang Soon-Jung;Seo Byoung-Moo;Lee Jong-Ho;Choung Pill-Hoon;Kim Myung-Jin;Choi Jin-Young
    • Korean Journal of Cleft Lip And Palate
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    • v.6 no.1
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    • pp.17-25
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    • 2003
  • Correction of the cleft-lip nasal deformity is a difficult task that requires clear understanding of the associated complex anatomy and function as well as the operation time, the selection of an operation method, On the expectation that it helps enhance understanding the current trend of cleft-rhinoplasty, authors analyzed secondary rhinoplasty between 1999 and 2002, In both the unilateral and bilateral cleft lip rhinoplasty, we reviewed the timing of repair, site of correction and it's major technique, incision or approach method, autogenous cartilage graft method, All patients with a septal deviation did not have a septal surgery, We were active in alar and nasal tip surgery and passive in septal and dorsal deformity correction, And for children, we used a conservative method but for adults, we used radical approach, Most surgeries are focused on esthetic goal and we thought that objective evaluation for nasal obstruction was needed for bener and predictable outcome.

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Teratogenic Effects of Phenytoin on Rat Embryos in Culture (랫드에 있어서 배양배자에 대한 Phenytoin의 최기형성 효과)

  • Kim, Jong-Choon;Lim, Kwang-Hyeon;Chung, Moon-Koo;Roh, Jung-Koo
    • Toxicological Research
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    • v.14 no.3
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    • pp.357-363
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    • 1998
  • The teratogenic potential of the anticonvulsant drug phenytoin (PHT) has been well documented both in the human and in the experimental animals. However there are few reports on the effects of PHT on embryonic development in rats in vitro. The present study was performed to evaluate the teratogenic effects of PHT using whole-embryo culture system in rats. Sprague-Dawley rat embryos were explanted on gestational day (GD) 9.5 and cultured for 48 hrs in the immediately centrifuged and heat-inactivated rat serum containing 0,25,50, or $100{\mu}g$ PHT/mL. At the end of culture period the embryos were scored for morphological development according to the procedure of Van Maele-Fabry, and their total protein contents were determined. At 100 ${\mu}$g/mL of culture medium. PHT caused significant reduction in developmental score and protein content of embryos and a high incidence morphological abnormalities (100%). Characteristic malformations included altered yolk and embryonic circulation, craniofacial hypoplasia, neural tube schisis, branchial arch defects, abnormal ratation, and limb bud hypoplasia, among others. There were no adverse effects on embryonic growth and development at concentrations of 25 and 50 ${\mu}$g /mL of culture medium. The results indicated that the dysmorphogenic effect of PHT on cultured embryos is due to a direct interference with embryonic development.

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Teratogenicity Evaluation of 2-Bromopropane Using Rat Whole Embryo Culture (랫드 전배아배양법을 이용한 2-Bromopropane의 최기형성 평가)

  • Kim Jong-Choon;Shin Dong-Ho;Kim Sung-Ho;Yang Young-Soo;Oh Ki-Seok;Jiang Cheng-Zhe;Chung Moon-Koo
    • Toxicological Research
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    • v.22 no.2
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    • pp.127-133
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    • 2006
  • Recently, we have reported that the environmental pollutant 2-bromopropane (2-BP) induces a significant embryo-fetal developmental toxicity in rats. However, the cause of developmental toxicity and the relationship between maternal and developmental toxicities could not be elucidated because the developmental toxicity of 2-BP was observed only in the presence of maternal toxicity The in vitro teratogenicity study using whole embryo culture was carried out to understand the teratogenic properties and the possible mechanism of teratogenicity induced by 2-BP in rats. Rat embryos aged 9.5 days were cultured in vitro for 48 hrs at medium concentrations of 0, 1, 3, or 10 mg/ml of 2-BP. Embryos were evaluated for growth, differentiation, and morphological alterations at the end of the culture period. At 10 mg/ml, 2-BP caused a delay in the growth and differentiation of embryos and an increase in the incidence of morphological alterations, including altered yolk sac circulation, abnormal axial rotation, craniofacial hypoplasia, open neuropore, absent optic vesicle and kinked somites. At 3 mg/ml, only a delay in the growth and differentiation of embryos was observed. There were no adverse effects on embryonic growth and development at the concentration of 1 mg/ml. The results showed that the exposure of 2-BP to rat embryos results in a developmental delay and morphological alterations at dose levels of 3 mg/ml culture media or higher and that 2-BP can induce a direct developmental toxicity in rat embryos.