• The Korean Journal of Physiology and Pharmacology
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• 제27권2호
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• pp.167-176
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• 2023

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

• Journal of the Korean Data and Information Science Society
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• 제28권2호
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• pp.271-286
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• 2017

본 논문은 우리나라 생명보험산업의 장수리스크에 대한 자연헤지가 충분히 이루어지고 있는가를 평가해 보았다. 연금보험과 종신보험 준비금 계산 시 사망률 모형으로는 Lee-Carter 모형을 적용하였다. 사망률 개선 시나리오로는 연금보험과 종신보험 사망률이 모두 10%와 20% 개선되는 경우, 50세 이하 저연령 사망률은 10% 개선되고, 50세 이상 고연령 사망률은 20% 개선되는 경우, 마지막으로 연금보험 사망률은 20% 개선되지만 종신보험 사망률은 10% 개선되는 등 네 가지 시나리오를 살펴보았다. 분석결과 연금보험과 종신보험에 동일한 사망률 충격을 가하는 경우와 고연령의 사망률 개선이 저연령에 비해 빠르게 나타나는 경우 모두 연금보험과 종신보험 준비금의 합은 감소하는 것으로 나타났다. 네 번째 시나리오에서만 전체 준비금은 증가하였으나, 이 경우에도 연금보험 준비금 증가의 60% 이상이 자연헤지에 의해 상쇄하는 것으로 나타났다. 따라서 우리나라 생명보험산업의 장수리스크는 자연헤지를 통해 충분히 관리되고 있다고 판단된다.

• Clinical and Experimental Reproductive Medicine
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• 제21권3호
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• pp.241-245
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• 1994

Despite increasing success rate of IVF, poor response to ovarian stimulation remains a problem. So, attempts to improve ovarian responses, for example, by using combined gonadotropin-releasing hormone analogue(GnRH-a) and human menopausal gonadotropin(hMG) have shown limited success. It is reported that response of granulosa cells in vitro to FSH is stimulated by co-incubation with IGF-l, and IGF-l production can be increased by growth hormone. This suggest that combination regimen of G.H. and hMG may augment follicle recruitment. In fifteen patients who had previous history of poor ovarian response to gonadotropin stimulation after pituitary suppression with mid -luteal GnRH-a, the effectiveness of cotreatment with G.H. in IVF program was evaluated using a combination regimen of G.R. and hMG at Korea University Hospital IVF Clinic. Ovarian responses to gonadotropin stimulation in control and GH-treated cycles assessed by total dose and duration of hMG treatment, follicular development and peak $E_2$ level, number of eggs retrieved, and fertilization rates were also assessed. In each group, serum and follicular fluid IGF-1 concentrations on day of egg collection were measured by RIA after acidification and extraction by reveresed phase chromatography. Patients receiving G.H. required fewer days and ampules of gonadotropins, developed more oocytes, and more embryos transferred. But, the differences were not statistically significant, except the duration of hMG treatment. Our data showed a significantly higher concentration of IGF-l in the serum, not in the follicular fluid, of patients treated with G.H. compared with control group. These data suggest that growth hormone treatment does not improve the ovarian response in women with limited ovarian reserve to gonadotropin stimulation for IVF.

• The Korean Journal of Ecology
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• 제13권3호
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• pp.203-214
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• 1990

The work reported here aims to assess how Knots, Calidris canutus, accumulate rapidly large energy and nutrient reserve at Red Car in England. Most of Knots in England belong to long billed, long winged population compare with subspecies in Korea. The rate of prey intake of Knot increases as a nearest neighbour distance decreases. Foraging rate and vigilance rate increases as flock size decreases. The calorific value of each sized of Common Mussel Mytilus edulis, main food species of Knot, are almost same each other but the calorific content of each size Mussels are quite different each other. The rate of daily energy intake of Knots have been estimated from 192 kcal to 270 kcal.

• Clinical and Experimental Reproductive Medicine
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• 제45권1호
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• pp.31-37
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• 2018

Objective: To evaluate the pregnancy rate and time to pregnancy after timed coitus with or without superovulation in infertile young women younger than 35 years old with low serum $anti-M{\ddot{u}}llerian$ hormone (AMH) levels ( < 25th percentile). Methods: A total of 202 patients younger than 35 years old were recruited retrospectively between 2010 and 2012. Ninety-eight women had normal serum AMH levels (25-75th percentile), 75 women had low serum AMH levels (5th ${\leq}$ & < 25th percentile) and 29 women had very low serum AMH levels ( < 5th percentile), according to reference values for their age group. Results: The clinical pregnancy rate was positively associated with AMH levels, but this trend did not reach statistical significance (43.9% vs. 41.3% vs. 27.6% in the normal, low, and very low AMH groups, respectively). The time to pregnancy was longer in the very low AMH group than in the normal AMH group ($13.1{\pm}10.9months$ vs. $6.9{\pm}6.1months$, p= 0.030). The cumulative live birth rate over 18 months was lower in the very low AMH group than in the normal AMH group, with marginal significance (20.0% vs. 55.9%, p= 0.051). The duration of infertility was negatively correlated with achieving pregnancy (odds ratio, 0.953; 95% confidence interval, 0.914-0.994; p= 0.026). Conclusion: Conservative management, such as timed coitus with or without superovulation, should be considered in young patients who have low ovarian reserve without any infertility factors. However, for women with a long duration of infertility or very low serum AMH levels, active infertility treatment should be considered.

• 대한한의학회지
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• 제43권1호
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• pp.136-153
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• 2022

Objectives: The aim of this study was to find out whether east asian herbal medicine (EAHM) treatment alone is effective in improving pregnancy-related indicators compared to conventional medicine in women with Diminished Ovarian Reserve (DOR). Methods: We searched eligible studies from PubMed, Cochrane Library, EMBASE, Chinese National Knowledge Infrastructure Database, CiNii, Korean Medical Database, Korean Studies Information Service System, Oriental Medicine Advanced Searching Integrated System, ScienceOn. GRADE pro was used to evaluate the current evidence of the study. Result: A total of 5 studies, 325 women with DOR were included. EAHM showed a significant effect on improvement of pregnancy rate (n=270, RR 2.13 [95% CI 1.44 to 3.15], Z=3.78, p=0.0002, I2=0%) and Anti-Mullerian Hormone (AMH) level (n=211, SMD 0.82 [95% CI 0.40 to 1.25], Z=3.80, p=0.0001) compared to conventional medicine. In ovulation rate (n=156, RR 0.86 [95% CI 0.70 to 1.06], Z=1.43, p=0.15, I2=0%), Antral Follicle Count (n=245, SMD 0.27 [95% CI -0.25 to 0.79], Z=1.01, p=0.31), and follicle stimulating hormone (n=245, SMD 0.29 [95% CI -0.13 to 0.70], Z=1.36, p=0.17) level, EAHM showed similar effects to conventional medicine. In this study, the most frequently used herbal medicines were Cuscutae Semen, Dipsaci Radix, and Angelicae Gigantis Radix. Conclusion: This meta-analysis showed that EAHM could improve pregnancy rates and AMH levels in women with DOR. However, more well-designed RCTs will have to be performed further in the future.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2018년도 공동국제학술발표회
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• pp.171-171
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• 2018

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.339-342
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• 2006

The power outputs of renewable energy such as wind turbines and solar energy powers depend on natural sources. Accordingly, the power outputs of renewable energy is different from capacity rate at the time of peak load. Because of this gap, long term electricity power plan can have over-estimated reserve margin. So, this paper suggests the chronological approach to calculate the reliability assessment of renewable energy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.471-472
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• 2015

This paper proposes a generator maintenance scheduling (GMS) problem with due consideration of various objective functions. The objectives include leveling the reserve rate, maximizing reliability and minimizing production cost. The practicality and effectiveness of the proposed approach are demonstrated in the simulation for a real-size power system model in South Korea.

• KDI Journal of Economic Policy
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• 제41권2호
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• pp.1-39
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• 2019

This paper utilizes a life-cycle overlapping-generations model to quantify the welfare effects of plans to postpone the depletion of the National Pension Fund. In order for the model to incorporate the rapidly changing demographic structure of Korea fully, we build and calibrate a model in transition directly. The model is considered suitable for analyzing the effects of demographic changes on the Korean economy and the effects of plans to change the National Pension System. According to a simulation of the model, to postpone the depletion of the National Pension Fund for 30 years, the premium rate must be increased to 18.3% from the current rate of 9%. By postponing the depletion of the fund reserve, young and future generations gain significantly at the expense of the older generations. The simulation results should be, however, interpreted as meaning that the current system is unjustifiably partial to the older generations. Moreover, given the current premium rate, it is desirable to strengthen the income-redistribution function of the National Pension System.