Hot Firing Test of a Quadrature NEA SSD9103S1 Configuration

Ja-Chun Koo,Hee-Sung Park,Max Guba 항공우주시스템공학회 2022 International Journal of Aerospace System Engineer Vol.9 No.2

The NEA release mechanism is used to provide restraint and release functions with low shock for critical deployment operations on solar arrays after launch. The GK3 solar array consists of 2 wings and 6 hold down points per panel. The NEA SSD9103S1 is a part of the GK3 solar array hold-down and release mechanism. Each NEA unit is equipped with two Z-diodes which provide power to a NEA unit connected in series after actuation of the fuse wire. This paper presents the hot firing test results of a quadrature NEA SSD9103S1 configuration. One output powers a maximum of 4 NEA SSD9103S1 units simultaneously. The necessary actuation pulse duration has been determined to meet margin requirement for thermal energy of minimum 4. Actuation thermal energy difference is about 6.6% between each half of two fired serial NEAs. Thermal energy margin at worst case is minimum 5.9 in case of an actuation pulse duration of 500 ms. Two series Zener impedance depend on current applied has been characterized by an additional actuation after all fuse wires are open circuit. Total number of actuation commands to the GK3 NEA unit reduce drastically from 24 in case of single NEA configuration down to 8 in case of parallel and quadrature NEA configurations. It can be accommodated by the existing HP2U Pyro design without any impact.

Treatment with ionomycin improves pregnancy rates in poor responders

( Ja-seong Koo ),( Sung-eun Moon ),( Hyeyoung Lee ),( Hwa-sook Moon ),( Sung-hun Min ) 대한산부인과학회 2016 대한산부인과학회 학술대회 Vol.102 No.-

목적: Ionomycin can induce Ca2+ influx by altering the plasma membrane permeability or can act directly on intracellular organelles which release Ca2+. Studies in somatic cell nuclear transfer bovine oocytes showed that ionomycin is a more potent and more specific Ca2+ ionophore than A23187. When ionomycin is used as an assisted oocyte activation agent, the reported fertilization rates are usually higher than with the use of A23187. In humans, calcium fluctuations were detected with a peak shortly before cell division. Interestingly, these calcium oscillations disappeared in arrested embryos. 방법: This prospective study was performed between October 2014 and December 2015 at a reproductive center. All patients involved gave written consent, and institutional review board approval was granted. This study includes 21 non-treatment and 22 treatment couples. A prospective study was conducted including patients with a poor responders following conventional ICSI in our center. In the treatment cycles, all metaphase II-oocytes were exposed to a commercially available ready-to-use 0.5 μM ionomycin for 5 min immediately after ICSI. After a three-step washing procedure, in vitro culture was performed as in the control cycles, when possible up to 8-cell stage. Cleavage and clinical pregnancy rates were compared, p-value of <0.05 was considered statistically significant. 결과: The average female age, number of oocytes retrieved, embryo developmental stage and number of embryos transferred did not vary significantly amongst the groups. Fertilization rate did not differ (75.4 versus 73.2%); however, further cleavage to 8-cell stage was significantly higher (p<0.001) in the ionomycin group (98.5%) when compared with the control cycles (91.9%). Most importantly, clinical pregnancy rates were higher (p<0.01) in the ionomycin treatment group (44.4%) when compared to the control group (20.8%). 결론: The findings of this study indicate that ionomycin treatment improves the rates of cleavage to 8-cell stage and clinical pregnancy in poor responders. However, this treatment does not seem to completely resolve the poor responders. Further investigations are necessary to determine the effects of ionomycin treatment of the culture conditions.

Fresh versus frozen-thawed day 3 embryo transfer in poor responders

( Sung-hun Min ),( Ja-seong Koo ),( Sung-eun Moon ),( Hyeyoung Lee ),( Hwa-sook Moon ) 대한산부인과학회 2016 대한산부인과학회 학술대회 Vol.102 No.-

목적: To compare the clinical outcomes after day 3 fresh and frozen-thawed embryo transfer (FET) in poor responder patients undergoing IVF/ICSI treatment. FET was the preferable strategy for the poor responder patients in IVF/ICSI cycles to obtain both desirable clinical outcome and lower multiple pregnancy rates. Studies found that frozen-thawed embryo transfers significantly improved the clinical pregnancy rate in normal patients, this outcome strongly suggested the impaired endometrial receptivity in fresh ET cycles after ovarian stimulation. So FET may be the preferable strategy for poor responders to decline multiple pregnancies and increase the chance of pregnancy. 방법: A prospective analysis of fresh and frozen-thawed Day 3 embryo transfer strategies for the poor responder patients in IVF/ICSI cycles. The 120 poor responder patients diagnosed as primary infertility with lower than 3 oocytes retrieved were recruited in Day 3 fresh ET group and 125 patients with lower than 3 oocytes retrieved in fresh cycle, first transferred with frozen-thawed Day 3 embryo were assigned in FET group. A p-value of <0.05 was considered statistically significant. 결과: The average female age, number of oocytes retrieved, embryo developmental stage and number of embryos transferred did not vary significantly amongst the groups. However, in the poor responder patients, the clinical pregnancy rate after day 3 FET was significantly higher than that of day 3 fresh ET (43.6% VS 20.2%, p<0.05). Furthermore, the implantation rate in FET cycles was markedly higher than that of day 3 ET (38.7% vs. 18.5%, p<0.05). 결론: This is the first evidence that FET was the optimal strategy for the poor responder patients in IVF/ICSI cycles to higher clinical pregnancy rates and improve implantation rate.

Pn-AMP1, a Plant Defense Protein, Induces Actin Depolarization in Yeasts

Koo, Ja-Choon,Lee, Boyoung,Michael E. Young,Koo, Sung-Chul,John A. Cooper,Baek, Dong-won,Lim, Chae-Oh,Lee, Sang-Yeol,Yun, Dae-Jin,Cho, Moo-Je Plant molecular biology and biotechnology research 2004 Plant molecular biology and biotechnology research Vol.2004 No.-

Pn-AMP1, Pharbitis nil antimicrobial peptide 1, is a small cysteine-rich peptide implicated in host-plant defense. We show here that Pn-AMP1 causes depolarization of the actin cytoskeleton in Saccharomyces cerevisiae and Candida albicans. Pn-AMP1 induces rapid depolarization of actin cables and patches within 15 min. Increased osmolarity or temperature induces transient actin depolarization and results in increased sensitivity to Pn-AMP1, while cells conditioned to these stresses show less sensitivity. Mutations in components of a cell wall integrity pathway (Wsc1p, Rom2p, Bck1p and Mpk1p), which regulate actin repolarization, result in increased sensitivity to Pn-AMP1. A genetic screen reveals that mutations in components of the α-1,6-mannosyltransferase complex (Mnn10p, Mnn11p and Och1p), which regulate mannosylation of cell wall proteins, confer resistance to Pn-AMP1. FITC-conjugated Pn-AMP1 localizes to the outer surface of the cell with no significant staining observed in spheroplasts. Taken together, these results indicate that cell wall proteins are determinants of resistance to Pn-AMP1, and the ability of a plant defense protein to induce actin depolarization is important for its antifungal activity.

Effect of Wood Material Type on Biocide Retention and Distribution Using Supercritical Fluid Impregnation

Sung Mo Kang,Doo Jin Jung,Ja Oon Koo,J. J. Morrell 한국목재공학회 2005 목재공학 Vol.33 No.5

Is propofol safe when administered to cirrhotic patients during sedative endoscopy?

( Sang Jun Suh ),( Hyung Joon Yim ),( Eileen L Yoon ),( Beom Jae Lee ),( Jong Jin Hyun ),( Sung Woo Jung ),( Ja Seol Koo ),( Ji Hoon Kim ),( Kyung Jin Kim ),( Rok Son Choung ),( Yeon Seok Seo ),( Jong 대한내과학회 2014 The Korean Journal of Internal Medicine Vol.29 No.1

Background/Aims: In patients with liver cirrhosis, drugs acting on the central nervous system can lead to hepatic encephalopathy and the effects may be pro-longed. Recently, misuse of propofol has been reported and the associated risk of death have become an issue. Propofol is commonly used during sedative endoscopy; therefore, its safety in high-risk groups must be further investigated. We performed a pilot study of the safety and effi cacy of propofol during endos-copy in Korean patients with cirrhosis. Methods: Upper gastrointestinal endoscopy was performed under sedation with propofol along with careful monitoring in 20 patients with liver cirrhosis and 20 control subjects. The presence or development of hepatic encephalopathy was as-sessed using the number connection test and neurologic examination. Results: Neither respiratory depression nor clinically significant hypotension were observed. Immediate postanesthetic recovery at 5 and 10 minutes after the procedure was delayed in the cirrhotic patients compared with the control group; however, at 30 minutes, the postanesthetic recovery was similar in both groups. Baseline psychomotor performance was more impaired in cirrhotic patients, but propofol was not associated with deteriorated psychomotor function even in cir-rhotic patients with a minimal hepatic encephalopathy. Conclusions: Sedation with propofol was well tolerated in cirrhotic patients. No newly developed hepatic encephalopathy was observed.

The efficacy of laser-assisted hatching (LAH) on pregnancy and implantation rates of frozen-thawed embryo transfer at the cleavage stage

( Sung-hun Min ),( Ja-seong Koo ),( Hyun-jung Kim ),( Yi-jo Jeung ),( Hwa-sook Moon ) 대한산부인과학회 2019 대한산부인과학회 학술대회 Vol.105 No.-

Objective: LAH was proposed to improve the implantation rate in FET cycles, but conflicting information exists in the literature with respect to the efficacy of AH in FET cycles. Methods: Embryo freezing was performed by vitrification at the cleavage stage 3 days after oocyte retrieval. Frozen embryos were thawed on the day of FET cycle. In the LAH group, zona thinning was performed by an experienced embryologist using a RI laser. During the operation, the outer half of the zona pellucida over a quarter of the diameter of the zona was removed. In the control group, embryos were replaced without LAH. Pregnancy and implantation rates were compared, p-value of <0.05 was considered statistically significant. Results: There were no differences in age of women at embryo freezing/thawing, body mass index, duration of infertility, primary/secondary infertility, cause of infertility, basal serum FSH concentration, cycle number, percentage of smokers or number of embryos frozen between the LAH group and the control group. The HMG dosage and duration and number of eggs retrieved/fertilized of the index stimulated cycle did not differ. However, pregnancy rates (43.5 vs 37.2%), and ongoing implantation rates (19.2 vs 16.3%) were higher in LAH treatment group compared to control, but these differences did not reach statistical significance. Conclusion: The findings of this study indicate that LAH treatment improves implantation and clinical pregnancy rates in women undergoing frozen-thawed embryo transfer. Furthermore, this treatment may be considered as a preferable strategy during the IVF treatment. However, this method does not seem to completely resolve the FET cycle.

Diagnostic Significance of Brainstem Auditory Evoked Potentials in Microvascular Decompression of Patients with Hemifacial Spasm or Trigeminal Neuralgia

( Sang-koo Park ),( Sung-hyuk Lim ),( Chan-woo Park ),( Jin-woo Park ),( Sung-ho Chang ),( Keun-hye Park ),( Hae-ja Park ),( Ji-hye Song ),( Dong-ok Uhm ),( Ki-bong Kim ) 대한임상검사과학회 2011 대한임상검사과학회지(KJCLS) Vol.43 No.1

The purpose of this study was to analyse brainstem auditory evoked potentials (BAEP) wave change data during microvascular decompression (MVD). The nerve function of Cranial Nerve VIII is at risk during MVD. Intraoperative monitoring of BAEP can be a useful tool to decrease the danger of hearing loss. Between January and December 2009, 242 patients had MVD for hemifacial spasm (HFS) and trigeminal neuralgia (TN). Among intraoperative BAEP changes, amplitude of V-V’ was the most frequently observed during cerebellar retraction and decompression step of the MVD procedure. 138 patients (57%) had no BAEP change while 104 patients (42.98%) had BAEP change. 69 patients (28.5%) had Type A-I, 16 patients (6.6%) had Type A-II, 5 patients (2.1%) had Type B, and 13 patients (5.37%) had Type C. MVD is a surgical procedure to relieve the symptoms (e.g. pain, muscle twitching) caused by compression of a nerve by an artery or vein. During BAEP intraoperative monitoring, the surgical step is important in interpreting the changes of wave V. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. Intraoperative BAEP monitoring may provide an early warning of hearing disturbance after MVD.

Effect of post-steaming on CCA fixation

( Sung Mo Kang ),( Seung Hun Shin ),( Shin Kwon Kang ),( Doo Jin Jung ),( Ja Oon Koo ) 韓國木材工學會 2006 한국목재공학회 학술발표논문집 Vol.2006 No.-

Transient Liquid Jet Breakup Model and Comparison with Phase Doppler Measurements

Sang Ku Chang,Ja Ye Koo,Hong Chul Chung 대한기계학회 1995 KSME International Journal Vol.9 No.1