• Title/Summary/Keyword: low leakage

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Seventeen Years' Experience with Ninety-six Esophageal Atresias (선천성 식도 폐쇄증 - 17년간의 96예 치험 분석 -)

  • Chun, Yong-Soon;Jung, Sung-Eun;Lee, Seong-Cheol;Park, Kwi-Won;Kim, Woo-Ki
    • Advances in pediatric surgery
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    • v.1 no.2
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    • pp.140-148
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    • 1995
  • To study the clinical profiles and outcome of surgery in infants with esophageal atresia, we reviewed 96 esophageal atresia cases who were treated from April, 1978 to June, 1995. There were 51 male and 45 female infants, a ratio of 1.1:1. The low birth weight(<2500g) patients were 32%. Clinical findings at the time of diagnosis included drooling in 57%, choking in 50%, cyanosis in 38%, respiratory distress in 27% and swallowing difficulty in 20%. Gross classification included 6 cases of type A esophageal atresia(6%), 79 cases of type C(82%), 3 cases of type E (3%) and 8 cases of type F(8%). Associated anomalies occurred in 34 infants(35%). Among them, cardiac anomalies were most common(60%). A primary repair of the defect was carried out in 76 patients with type A or C. A staged operation comprising a repair or gastric tube interposition after gastrostomy was performed in 8 patients. In all 3 infants with H-type, a division of fistula was performed. Esophageal resection and anastomosis was done in 8 infants with esophageal stenosis. In one infant, a gastrostomy was performed and he expired before staged operation. Anastomotic complications included leakage in 16 cases(17%), stricture in 37 cases(39%) and recurrent tracheoesopohageal fistula in 3 cases(3%). The mortality rate was 14% and the leading cause of death was pneumonia. The overall survival rate was 86%, and according to Waterston criteria, the survival rates were 93%, 85% and 58% in class A, Band C, respectively. 75 patients were followed up with median follow up 6.4 years. Among them, 93% were uneventful and 7% had frequent pneumonia.

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The Study on Thermal Shock Test Characteristics of Solar Cell for Long-term Reliability Test (장기 신뢰성 평가를 위한 태양전지의 열충격 시험 특성에 관한 연구)

  • Kang, Min-Soo;Kim, Do-Seok;Jeon, Yu-Jae;Shin, Young-Eui
    • Journal of Energy Engineering
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    • v.21 no.1
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    • pp.26-32
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    • 2012
  • This study has been performed Thermal Shock test for analyze the cause of Power drop in PV(Photovoltaic) Module. Thermal Shock test condition was performed with temperature range from $-40^{\circ}C{\sim}85^{\circ}C$. One cycle time is 30min. which are consist of low and high temperature 15min. each other. The test was performed with total 500cycles. EL, I-V were conducted every 100cycle up to 500cycles. Mono Cell resulted in 8% Power drop rates in Bare Cell and 9% in Solar Cell. In the case of Multi Cell resulted in 6% Power drop rates in Bare Cell and 13% in Solar Cell. After Thermal Shock test, Solar Cell's Power drop resulted from surface damages, but in the case of Bare Cell's Power drop had no surface damages. Therefore, Bare Cell's Power drop was confirmed as according to leakage current increase by analysis of Fill Factor after Thermal Shock test. Also, Solar Cell's Power drop rates are higher than that of Bare Cell because of surface damages and consuming electric power increase. From now on, it should be considered that analyzed the reasons of Fill Factor decrease and irregular Power drop in PV module and Cell level using cross section, various conditions and test methods.

Optimal Condition of Microporous Membrane for Bone Marrow Stromal Cell Allotransplantation to Stimulate Wound Healing in Vitro (창상치유목적의 골수기질세포 동종이식을 위한 고분자막의 조건)

  • Lee, Eun-Sang;Kim, Myeong-Joo;Han, Seung-Kyu;Hong, Sung-Taek;Kim, Woo-Kyung
    • Archives of Plastic Surgery
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    • v.37 no.5
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    • pp.509-518
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    • 2010
  • Purpose: Major drawbacks of conventional bone marrow stromal cells (BSCs) transplantation method are mainly caused by direct transplanted cell to host cell interactions. We hypothesized that separation of the transplanted cells by a microporous membrane might inhibit most of the potential adverse effects and induce superior effect. The purpose of the study is to determine the optimal condition of the microporous membrane. Methods: First, BSCs were placed in polyethylene terephthalate (PET) transwell inserts with 3, 8, or $12{\mu}m$ pore size, and cultured in 24 well culture plates. After 5 days, bottoms of the plates were observed for presence of attached BSCs in monolayer and cell numbers were evaluated. Second, BSCs were placed PET, polycarbonate (PCT), and mixed cellulose esters (MCE) transwell inserts with 3 and $8{\mu}m$ pore size, and cultured in 24 well culture plates. After 3 days, the supernatants of the media left in culture plate were analyzed for collagen, vascular endothelial growth factor (VEGF), platelet derived growth factor BB (PDGF-BB), and basic fibroblast growth factor (bFGF). Third, BSCs were placed in 15% and 70% of the PET membrane with $3{\mu}m$ pore size. All the experimental conditions and methods were same as the second study. Results: The optimal pore sizes to prevent BSC leakage were $3{\mu}m$ and $8{\mu}m$. The amounts of type I collagen and three growth factors tested did not show significant differences among PET, PCT, and MCE groups. However, the collagen, VEGF, and bFGF levels were much higher in the high (70%) density group than in the low (15%) density group. Conclusion: This study revealed that the optimal pore size of membrane to prevent direct BSC to recipient cell contact is in between $3{\mu}m$ and $8{\mu}m$. Membrane materials and pore sizes do not influence the collagen and growth factor passage through the membrane. The most striking factor for collagen and growth factor transport is pore density of the membrane.

Preoperative short course radiotherapy with concurrent and consolidation chemotherapies followed by delayed surgery in locally advanced rectal cancer: preliminary results

  • Aghili, Mahdi;Sotoudeh, Sarvazad;Ghalehtaki, Reza;Babaei, Mohammad;Farazmand, Borna;Fazeli, Mohammad-Sadegh;Keshvari, Amir;Haddad, Peiman;Farhan, Farshid
    • Radiation Oncology Journal
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    • v.36 no.1
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    • pp.17-24
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    • 2018
  • Purpose: This study aimed to assess complications and outcomes of a new approach, that is, combining short course radiotherapy (SRT), concurrent and consolidative chemotherapies, and delayed surgery. Materials and Methods: In this single arm phase II prospective clinical trial, patients with T3-4 or N+ M0 rectal adenocarcinoma were enrolled. Patients who received induction chemotherapy or previous pelvic radiotherapy were excluded. Study protocol consisted of three-dimensional conformal SRT (25 Gy in 5 fractions in 1 week) with concurrent and consolidation chemotherapies including capecitabine and oxaliplatin. Total mesorectal excision was done at least 8 weeks after the last fraction of radiotherapy. Primary outcome was complete pathologic response and secondary outcomes were treatment related complications. Results: Thirty-three patients completed the planned preoperative chemoradiation and 26 of them underwent surgery (24 low anterior resection and 2 abdominoperineal resection). Acute proctitis grades 2 and 3 were seen in 11 (33.3%) and 7 (21.2%) patients, respectively. There were no grades 3 and 4 subacute hematologic and non-hematologic (genitourinary and peripheral neuropathy) toxicities and perioperative morbidities such as anastomose leakage. Grade 2 or higher late toxicities were observed among 29.6% of the patients. Complete pathologic response was achieved in 8 (30.8%) patients who underwent surgery. The 3-year overall survival and local control rates were 65% and 94%, respectively. Conclusion: This study showed that SRT combined with concurrent and consolidation chemotherapies followed by delayed surgery is not only feasible and tolerable without significant toxicity but also, associated with promising complete pathologic response rates.

Morphological Changes Associated with the Antibacterial Action of Silver Ions against Bovine Mastitis Pathogens (은 이온의 항균효과에 대한 소 유방염 원인균의 형태학적 변화)

  • Kang, Seog-Jin;Seol, Jae-Won;Hur, Tai-Young;Jung, Young-Hun;Choe, Chang-Yong;Park, Sang-Youel
    • Journal of Veterinary Clinics
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    • v.28 no.6
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    • pp.576-580
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    • 2011
  • Silver has potent antibacterial activity against a variety of bacteria while maintaining low toxicity in mammalian cells. This study was conducted to investigate the possible mechanism underlying the bactericidal effects of silver ions against bovine mastitis pathogens using electron microscopy. We used two different bacterial strains, Escherichia coli and Staphylococcus aureus, which are primarily responsible for the majority of bovine mastitis cases. Interaction between the bacteria and silver ions (50 ${\mu}g/mL$, 2 hours) were studied using energy-filtering transmission electron microscopy (EFTEM). EFTEM images showed that E. coli and S. aureus cells treated with the silver ions had distorted plasma membranes, silver ions attached to the outer membranes, scattered electron-light material, and leakage of cell contents from disrupted cell membranes.

Genetic Consideration of Sericite Deposits Derived from Granitic Rocks in the Taebaegsan Region (태백산지역에 분포하는 화강암체 기원 견운모광상의 성인적 고찰)

  • Yoo, Jang-Han;Chi, Sei-Jeong
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.3
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    • pp.239-246
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    • 2008
  • Yeongweol sericite deposit of Gangwon Province is regarded as one of the sericite deposits derived from granitic rocks due to post-magmatic alkali metasomatism, and the other sericite deposit of the same origin is the Daehyun mine of Gyungbug Province. Sericite ores were originated from leucocratic granitic stocks of Cambrian-Triassic age which intruded the pegmatitic migmatite of the unknown age and granite of the Pre-cambrian age, respectivcly. Jangsan quartzite of the lowermost formations of the Paleozoic era, which played as the capping rock protected from the leakage of the hydrothermal solution. It is well known that those sericite deposits arc formed during formation of the geosyncline, and they are also situated in the margins of the Hambaeg Syncline. Leucocratic granites commonly contain pegmatites with tourmaline crystals, and are rich in potassium feldspars, and sodium plagioclase as well. Sericitized ores are mainly found as we go up to the higher elevations or to the margins of the stocks. And some of the Highest grade sericite ores show the monominerallic character composed of nearly pure sericite probably doc to the ultra greisenization. Chemical analysis shows higher $Na_{2}O$ and $K_{2}O$ contents $(2.00\sim7.03wt%)$ as the sericitizations arc preceded and they represent obvious greisenization. But low CaO contents $(0.05\sim4.51wt%)$ indicate that albitizations are so weak. Pyrophyllite of the Youngweol area is often accompanied by the sericite, indicating rather stronger thermal effect than the Daehyun mine. It is known that there are several Sn deposits originated from greisenization in the Taebaegsan region. And greisens are inclined to contain W, Mo and several REE's such as Be, Nb and Li, and so Taebaegsan region interbedded with lots of carbonate formations are still worthwhile to survey for those metallic deposits.

Controlled Release of Oxyfluorfen from the Variously Complexed Formulations V. Effect of Water Leakage on Injury and Efficacy of Selected Formulations (수종(數種)의 결합제형(結合劑型)으로부터 Oxyfluorfen의 방출제어연구(放出制御硏究) V. 감수심(減水深)에 따른 선발제형(選拔劑型) Oxyfluorfen의 약해(藥害).약효평가(藥效評價))

  • Guh, J.O.;Kwon, O.D.;Kuk, Y.I.;Chon, S.U.
    • Korean Journal of Weed Science
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    • v.11 no.3
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    • pp.167-173
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    • 1991
  • Various formulations of oxyfluorfen were tested to evaluate effect of weed control efficacy and rice injury as affected by different degrees of water leakages. Rice injury was increased with increased water leakages. The formulations of Elvan, Coal slag and Chitosan gave slight injury to rice under all conditions included in terms of visual ratings, plant height and fresh weight production. However, weed control of most formulations was decreased and increased with increased water leakages for annual weeds and perennial weeds, respectively, Annual weeds were controlled greater than 90~ by all treatments, but perennial weed control was relatively low. Scirpus juncoides was the most tolerant annual weed to Oxyfluorfen. Elvan formulation showed somewhat decreased control of barnyardgrass with increased water leakages. The promising formulations of Oxyfluorfen were Chitosan, Coal slag, Bentonite B and Elvan (if the first releasing rate increased), which injured rice slightly and controlled annual weeds excellently regardless of degrees of water leakages.

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A 2.4 GHz Bio-Radar System with Small Size and Improved Noise Performance Using Single Circular-Polarized Antenna and PLL (하나의 원형 편파 안테나와 PLL을 이용하여 소형이면서도 개선된 잡음 성능을 갖는 2.4 GHz 바이오 레이더 시스템)

  • Jang, Byung-Jun;Park, Jae-Hyung;Yook, Jong-Gwan;Moon, Jun-Ho;Lee, Kyoung-Joung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.12
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    • pp.1325-1332
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    • 2009
  • In this paper, we design a 2.4 GHz bio-radar system that can detect human heartbeat and respiration signals with small size and improved noise performance using single circular-polarized antenna and phase-locked loop. The demonstrated bio-radar system consists of single circular-polarized antenna with $90^{\circ}$ hybrid, low-noise amplifier, power amplifier, voltage-controlled oscillator with phase-locked loop circuits, quadrature demodulator and analog circuits. To realize compact size, the printed annular ring stacked microstrip antenna is integrated on the transceiver circuits, so its dimension is just $40\times40mm^2$. Also, to improve signal-to-noise-ratio performance by phase noise due to transmitter leakage signal, the phase-locked loop circuit is used. The measured results show that the heart rate and respiration accuracy was found to be very high for the distance of 50 cm without the additional digital signal processing.

Hot Air Injection/Extraction Method for the Removal of Semi-Volatile Organic Contaminants from Soils (토양내 저휘발성 유류오염물 제거를 위한 고온공기 주입/추출기술 연구)

  • Gu Chung-Wan;Ko Seok-Oh
    • Journal of Soil and Groundwater Environment
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    • v.10 no.1
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    • pp.6-12
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    • 2005
  • Contamination of soils and groundwater by leakage of petroleum compounds from underground storage tanks (USTs) has become great environmental issues. Conventional methods such as soil vapor extraction (SVE) used for the remediation of unsaturated soils contaminated with volatile organic compounds might not be applied for the removal of semi-volatile organic compounds such as diesel fuels and PCBs, which have low volatility and high hydrophobicity. The objective of this study is to develop a hot air injection method to remove semi-volatile compounds. Additionally, operation parameters such as temperature, air flow rate, and water content are evaluated. Experimental results show that diesel ranged organics (DROs) are removed in the order of volatility of organic compounds. As expected, removal efficiency of organics is highly dependent on the temperature. It is considered that more than $90\%$ of organic contaminants whose carbon numbers range between 17 and 22 can be removed efficiently by the hot air injection-extraction method (modified SVE) over the $100^{\circ}C$. It is also found that increased air flow rate resulted in high removal rate of contaminants. However, air flow rate over 40 cc/min is not effective for the operation aspects, due to mass transfer limitation on the volatilization rate of the contaminants. The effect of the water content on the decane removal is minimal, but some components show large dependence on the removal efficiency with increasing water content.

Plasma Polymerized Styrene for Gate Insulator Application to Pentacene-capacitor (유기박막트랜지스터 응용을 위해 플라즈마 중합된 Styrene 게이트 절연박막)

  • Hwang, M.H.;Son, Y.D.;Woo, I.S.;Basana, B.;Lim, J.S.;Shin, P.K.
    • Journal of the Korean Vacuum Society
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    • v.20 no.5
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    • pp.327-332
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    • 2011
  • Plasma polymerized styrene (ppS) thin films were prepared on ITO coated glass substrates for a MIM (metal-insulator-metal) structure with thermally evaporated Au thin film as metal contact. Also the ppS thin films were applied as organic insulator to a MIS (metal-insulatorsemiconductor) device with thermally evaporated pentacene thin film as organic semiconductor layer. After the I-V and C-V measurements with MIM and MIS structures, the ppS revealed relatively higher dielectric constant of k=3.7 than those of the conventional poly styrene and very low leakage current density of $1{\times}10^{-8}Acm^{-2}$ at electric field strength of $1MVcm^{-1}$. The MIS structure with the ppS dielectric layer showed negligible hysteresis in C-V characteristics. It would be therefore expected that the proposed ppS could be applied as a promising dielectric/insulator to organic thin film transistors, organic memory devices, and flexible organic electronic devices.