• Journal of Menopausal Medicine
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• v.24 no.3
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• pp.196-203
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• 2018

Objectives: This study was aimed to establish the most effective premature ovarian failure (POF) mouse model using Cyclophosphamide (CTX), busulfan (Bu), and cisplatin considering treatment duration of anticancer drugs and natural recovery time. Methods: POF was induced by intraperitoneally injecting CTX (120 mg/kg)/Bu (12 mg/kg) for 1 to 4 weeks or cisplatin (2 mg/kg) for 3 to 14 days to C57BL/6 female mice aged 6 to 8 weeks. Controls were injected with equal volume of saline for the same periods. Body weight was measured every week, and ovarian and uterine weights were measured after the last injection of anticancer drug. To assess ovarian function, POF-induced mice were superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin, and then mated with male. After 18 hours, zygotes were retrieved and cultured for 4 days. Finally, the mice were left untreated for a period of times after the final injection of anticancer drug, and the time for natural recovery of ovarian function was evaluated. Results: After 2 weeks of CTX/Bu injection, ovarian and uterine weights, and ovarian function were decreased sharply. Cisplatin treatment for 10 days resulted in a significant decrease in ovarian and uterine weight, and ovarian function. When POF was induced for at least 2 weeks for CTX/Bu and for at least 10 days for cisplatin, ovarian function did not recover naturally for 2 weeks and 1 week, respectively. Conclusions: These results suggest that CTX/Bu should be treated for at least 2 weeks and cisplatin for at least 10 days to establish the most effective primary ovarian insufficiency mouse model.

• Explosives and Blasting
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• v.37 no.1
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• pp.14-23
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• 2019

It has been an always issue for the blasting or the impact analysis to consider the strength characteristics of the rock materials associate with loading rate dependency. Due to the nature of transient loading, the dynamic rock test requires a careful technique to achieve the stress equilibrium state of the specimen. In this study, to investigate the relationship between the rock dynamic strength and the stress equilibrium state, a series of dynamic uniaxial compression tests for Pocheon granite were performed. As a result, the unbalanced stress state on the specimen can lead to the premature failure on the specimen and the less estimation of dynamic strength characteristic as well as the overestimation of strain rate. Consequently, a careful consideration of rock fracture process to achieve the dynamic force balance on the specimen should be required to make an reasonable evaluation of rock dynamic strength.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.1
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• pp.130-140
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• 2007

Fiber-sheet and steel-plate strengthening methods have been mainly used for strengthening the RC structures. However, recently the application of these two methods have dramatically decreased due to premature debonding failure between concrete surface and fiber-sheet and heavy self-weight of steel-plate. This article presents experimental results of shear behavior in RC beams strengthened with GSP(Glass fiber-Steel composite Plate). The thin steel plate in GSP makes usage of the anchoring system possible, which could delay or prevent the premature debonding failure. Three reference beams and 60 strengthened beams with GSP were tested. The experimental results showed that strengthened beams with GSP considerably increased in shear capacity compared with the reference beams.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.781-790
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• 2011

This paper contains the experimental results on strengthening effect of RC beams strengthened with NSM CFRP reinforcement and various strengthening details. A total of 14 beams have been tested to analyze strengthening effects of NSMR with various reinforcement details. Variables were cross-sectional shape of CFRP reinforcements, strengthening areas, grooves the number and location etc. Test results revealed that failure modes of NSMR showed two types. One was bond failure at interface between concrete and filler and the other was CFRP rupture. Also, failure mode of specimens with two grooves occurred premature bond failure because of superposition of failure surfaces at concrete around grooves. failure mode of MI specimens considered the equivalent section have changed bond failure to CFRP rupture and CFRP efficiency has improved 83% to 100%.

• Development and Reproduction
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• v.12 no.3
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• pp.289-296
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• 2008

BPES (Blepharophimosis/Ptosis/Epicanthus inversus Syndrome) is an autosomal dominant disorder caused by mutations in FOXL2. Affected individuals have premature ovarian failure (POF) in addition to small palpebral fissures, drooping eyelids, and broad nasal bridge. FOXL2 is a member of the forkhead family transcription factors. In FOXL2-deficient ovaries, granulosa cell differentiation dose not progress, leading to arrest of folliculogenesis and oocytes atresia. Using yeast two-hybrid screening of rat ovarian cDNA library with FOXL2 as bait, we found that small ubiquitin-related modifier (SUMO)-conjugating E2 enzyme UBE2I protein interacted with FOXL2 protein. UBE2I also known as UBC9 is an essential protein for processing SUMO modification. Sumoylation is a form of post-translational modification involved in diverse signaling pathways including the regulation of transcriptional activities of many transcriptional factors. In the present study, we confirmed the protein-protein interaction between FOXL2 and UBE2I in human cells, 293T, by in vivo immunoprecipitation. In addition, we generated truncated FOXL2 mutants and identified the region of FOXL2 required for its association with UBE2I using yeast-two hybrid system. Therefore, the identification of UBE2I as an interacting protein of FOXL2 further suggests a presence of novel regulatory mechanism of FOXL2 by sumoylation.

• Neonatal Medicine
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• v.25 no.4
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• pp.186-190
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• 2018

Esophageal atresia (EA) with proximal tracheoesophageal fistula (TEF; gross type B) is a rare defect. Although most patients have long-gap EA, there are still no established surgical guidelines. A premature male infant with symmetric intrauterine growth retardation (birth weight, 1,616 g) was born at 35 weeks and 5 days of gestation. The initial diagnosis was pure EA (gross type A) based on failure to pass an orogastric tube and the absence of stomach gas. A "feed and grow" approach was implemented, with gastrostomy performed on postnatal day 2. A fistula was detected during bronchoscopy for recurrent pneumonia; thus, we confirmed type B EA and performed TEF excision and cervical end esophagostomy. As the infant's stomach volume was insufficient for bolus feeding after reaching a body weight of 2.5 kg, continuous tube feeding was provided through a gastrojejunal tube. On the basis of these findings, esophageal reconstruction with gastric pull-up was performed on postnatal day 141 (infant weight, 4.7 kg), and he was discharged 21 days postoperatively. At 12 months after birth, there was no catch-up growth; however, he is currently receiving a baby food diet without any complications. In patients with EA, bronchoscopy is useful for confirming TEF, whereas for those with long-gap EA with a small stomach volume, esophageal reconstruction with gastric pull-up after continuous feeding through a gastrojejunal tube is worth considering.

• Journal of Chest Surgery
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• v.49 no.5
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• pp.379-382
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• 2016

With advancements in complex repairs in neonates with complicated congenital heart diseases, extracorporeal membrane oxygenation (ECMO) has been increasingly used as cardiac support. ECMO has also been increasingly used for low birth weight (LBW) or very low birth weight (VLBW) neonates. However, since prematurity and LBW are risk factors for ECMO, the appropriate indications for neonates with LBW, especially VLBW, are under dispute. We report a case of ECMO performed in a 1,360-g premature infant with VLBW due to cardiopulmonary bypass weaning failure after repairing infracardiac total anomalous pulmonary venous return.

• Journal of Genetic Medicine
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• v.17 no.1
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• pp.47-50
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• 2020

In Turner syndrome (TS), 45,X/47,XXX mosaicism is a rare genotype. Due to its low frequency, the clinical features and prognosis are not clearly known. A 10-year-old girl was diagnosed with 45,X/47,XXX mosaicism TS and presented with short stature. She did not show any other TS phenotypic features, except for short stature, and developed spontaneous puberty and menarche, although she had unilateral ovarian agenesis. She achieved a significant growth improvement following growth hormone treatment. Since 45,X/47,XXX mosaic TS shows different gonadal function from that of classic TS, it is necessary to conduct surveillance for premature ovarian insufficiency.

• The Journal of Korean Obstetrics and Gynecology
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• v.35 no.1
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• pp.12-33
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• 2022

Objectives: Since the importance of Korean Medicine (KM) treatment for Poor Ovarian Response (POR) is high, we intend to present appropriate treatment standards and methods by analyzing information on KM knowledge presented in related research papers and literature. Methods: First, research papers dealing with Diminished Ovarian Reserve (DOR) and POR are analyzed. In addition, we analyze and refer to research papers on Premature Ovarian Failure and Premature Menopause, which are closely related to DOR. Results: It is considered that the application of KM treatment alone for DOR should be based on the age that best reflects the ovarian reserve rather than the value of the ovarian reserve-related index centered on Anti-Müllerian Hormine (AMH). Accordingly, as a DOR woman under the age of 38, if normal sexual intercourse is achieved and the spouse factor is excluded, KM treatment, focusing on herbal medicine and acupuncture, can be applied. Conclusions: Korean Medicine treatment for infertility caused by decreased ovarian reserve is expected to be effective. However, research on specific treatments and targets will have to be added.

• Structural Engineering and Mechanics
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• v.63 no.6
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• pp.703-712
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• 2017

The composite blades of offshore wind turbines accumulate structural damage such as fatigue cracking due to harsh operation environments during their service time, leading to premature structural failures. This paper investigates various fatigue crack models for reproducing crack development in composite blades and proposes a stochastic approach to predict fatigue crack evolution and to analyse failure probability for the composite blades. Three typical fatigue models for the propagation of fatigue cracks, i.e., Miner model, Paris model and Reifsnider model, are discussed to reproduce the fatigue crack evolution in composite blades subjected to cyclical loadings. The lifetime probability of fatigue failure of the composite blades is estimated by stochastic deterioration modelling such as gamma process. Based on time-dependent reliability analysis and lifecycle cost analysis, an optimised maintenance policy is determined to make the optimal decision for the composite blades during the service time. A numerical example is employed to investigate the effectiveness of predicting fatigue crack growth, estimating the probability of fatigue failure and evaluating an optimal maintenance policy. The results from the numerical study show that the stochastic gamma process together with the proper fatigue models can provide a useful tool for remaining useful life predictions and optimum maintenance strategies of the composite blades of offshore wind turbines.