• Clinical and Experimental Reproductive Medicine
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• v.50 no.1
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• pp.19-25
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• 2023

Objective: Sleep deprivation (SD) is a common problem in today's stressful lifestyle and have physiological consequences, including reproductive dysfunction and infertility. As an antioxidant, olive oil may be effective in reducing testicular and spermatological damage by decreasing the production of free radicals. Methods: This study investigated the effects of olive oil on sperm quality and testicular structure using stereological methods to assess rats with SD. Results: When comparing SD group to grid floor+distilled water (GR) group, we found that the sperm count and motility, as well as the percentage of slow progressive sperm was significantly lower in SD group (p<0.05), but the percentage of immotile sperm was higher (p<0.01). However, no improvement was observed in sperm count or motility after concomitant treatment of SD group with olive oil. Stereological examinations revealed no significant change in the total volumes of the seminiferous tubules, interstitial tissue, and germinal epithelium in the study groups. Conversely, the total number of testicular cell types was significantly lower in SD group than in GR group. Although the total number of Sertoli and Leydig cells was significantly higher in the S +olive oil group than in the untreated SD group, no significant difference in the total number of other testicular cell types was observed between the two groups. Conclusion: SD potentially induced structural changes in testis that affected sperm count and motility. However, olive oil only improved the total number of Sertoli and Leydig cells in the animals with SD and did not improve sperm count and motility.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.81-87
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• 2008

High-rise building is taking a place as one of building types from apartment housings to commercial buildings. With taking in account of stability and durability, strength of used materials is increasing gradually in these high-rise buildings. According to this, frequency in use of SD500 re-bar is increasing gradually in high-rise buildings. However the study of SD500 re-bar is insufficient because SD500 re-bar started to be used for domestic buildings lately. Specially because there is no guide or study to refer to, people get into difficulties when to decide the method of re-bar connection in construction using SD500 re-bar. Accordingly in this study, it suggests the method of estimating the economical efficiency on SD500 re-bar connection, and conducts benefit/ cost analysis on lapped splice and coupler splice by applying AHP theory, and then presents its result. After to analyze re-bar diameter of D25, 29, and 32, finally we attained the result that the coupler splice is advantageous in all parts of benefit/ cost more than the lapped splice.

• Journal of Pharmaceutical Investigation
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• v.35 no.5
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• pp.349-353
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• 2005

This study reports the pharmacokinetics of a novel histone deacetylase inhibitor, SD-0542, in rats after i..v. and oral administration. SD-0542 was injected intravenously at doses of 10, 20, and 40 mg/kg. The terminal elimination half-life $(t_{1/2})$, systemic clearance (Cl), and steady-state volume of distribution $(V_{ss})$ remained unaltered as a function of dose, with their values ranging from 2.0-2.5 hr, 157.2-214.1 ml/min/kg, and 11.1-17.5 L/kg, respectively, whereas, the initial serum concentration $(C_0)$ and AUC increased linearly as the dose was increased. Renal excretion of SD-0542 was minimal. Oral pharmacokinetic studies were conducted in rats at a dose of 20 mg/kg. The $T_{max}$, Cl/F, $V_{z}/F$, and $t_{1/2}$ were 2.0 hr, 92864 ml/min/kg, 16331 L/kg, and 2.0 hr, respectively. Taken together, SD-0542 showed linear pharmacokinetics over the i.v. bolus dose range studied. SD-0542 was poorly absorbed, with the absolute oral bioavailability of 0.9%.

• Journal of Life Science
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• v.10 no.4
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• pp.422-430
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• 2000

In order to search for the effects of Shine-Dalgarno (SD) sequence and nucleotide sequence of spacer region (SD-ATG) on bGH expression, oligonucleotides containing random SD sequences and a spacer region were chemically synthesized. The distance between SD region and initiation codon (ATG) was fixed to 9 nucleotides in length. The expression vectors have been constructed using pT7-1 vector containing a T7 promoter. Positive clones were screened with colony hybridization and named pT7A or pT7B plasmid series. The selected clones were confirmed by DNA sequencing and finally, 19 clones having various SD combinations were obtained. When bovine growth hormone was induced by IPTG in E. coli BL21(DE3), all cells harboring these plasmids produced a detectable level of bGH in western blot analysis. However, various SD sequences did not affect on bGH expression, indicating that the sequences of SD and the spacer region did not sufficiently destabilize mRNA secondary structure of bGH gene. Therefore, these results indicate that the disruption of mRNA secondary structure might be a major factor for regulating bGH expression in the translational initiation process.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.83-95
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• 2017

PURPOSES : The purpose of this study is to develop a regression model to predict the International Roughness Index(IRI) and Surface Distress(SD) for the estimation of HPCI using Expressway Pavement Management System(PMS). METHODS : To develop an HPCI prediction model, prediction models of IRI and SD were developed in advance. The independent variables considered in the models were pavement age, Annual Average Daily Traffic Volume(AADT), the amount of deicing salt used, the severity of Alkali Silica Reaction(ASR), average temperature, annual temperature difference, number of days of precipitation, number of days of snowfall, number of days below zero temperature, and so on. RESULTS : The present IRI, age, AADT, annual temperature differential, number of days of precipitation and ASR severity were chosen as independent variables for the IRI prediction model. In addition, the present IRI, present SD, amount of deicing chemical used, and annual temperature differential were chosen as independent variables for the SD prediction model. CONCLUSIONS : The models for predicting IRI and SD were developed. The predicted HPCI can be calculated from the HPCI equation using the predicted IRI and SD.

• Korean Journal of Construction Engineering and Management
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• v.8 no.2
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• pp.136-145
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• 2007

This study analyzes the current usage of SD500 high-strength re-bar in domestic construction sites. Also, an evaluation method was developed to measure economic efficiency of lap splice and coupler splice, which are most commonly used in connection SD500. The evaluation method was applied to construction sites in Seoul in December 2006, and the result revealed that coupler splice is relatively superior in terms of cost efficiency when the re-bar diameter is bigger and the concrete strength is lower.

• Clean Technology
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• v.14 no.4
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• pp.275-280
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• 2008

In this study, we carry out economic and technical feasibility study for treatment process of waste solvent such as SD waste solution and stripper solution from LCD manufacturing process. Extensive screening work has been done for selecting the best extraction solvent. As a result, it is shown that $CHCl_3$ is the most adequate extraction solvent for separation and recovery of both SD waste solvent and stripper waste. Rigorous simulation study has been carried out for extraction process and distillation process as a candidate of waste solvent treatment. The result shows that the solvent extraction process is more beneficial than the simple distillation process.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.3
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• pp.183-189
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• 2010

The purpose of this study was to examine the Industrial High Schools Technical Subjects teachers' perceptions and attitudes toward sustainable development(SD). The instrument consisted of totally 12 items. The subjects of this study were 98 Industrial High Schools Technical Subjects teachers. The period of survey is from June 23 to July 15 of 2010. The questionnaire included items asking whether they heard about terms such as sustainability or sustainable development, the source of information on SD, the level of understanding or the urgent task 2 for SD in Korea. Result of survey is following. First, Teacher thought that urgent task for SD is conservation of natural environment. Second, Most of the teacher consider the concept SD as 'pursuing the balance between environmental protection and economic development, and some of the teachers recognized the concept of SD in the paradigm of continuous economic development. Third, half of teachers have not heard terminology of SD .and 80% of them have not conducted ESD. Fourth, a few of teachers replied that obstacle of ESD is shortage of teacher's professionalism.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.2
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• pp.169-176
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• 2022

Laser ablation propulsion(LAP) is the method to create impulse by laser ablation. It can be used to deorbit the space debris(SD), as its long-range property and versatility on any material. In this paper, we find out several requirements of the LAP system(LAPS) to deorbit the SD by simple numerical calculations of the SD orbit and laser beam flux. As a result, minimum operable altitude angle turned out to be a crucial variable to the LAPS. Moreover, if minimum operable altitude angle is 10°, and if the minimum distance between the LAPS and the SD is below 450 km, 1 m/s² is sufficient to deorbit the SD by once. With 18 kJ/3 ns pulsed laser and cube shaped 100 kg SD, 1 m/s² acceleration can be achieved by increasing the pulse repetition rate over 34~53 Hz, depending on the size of the SD. This capability could compare with the conceptual design of the Japan Establishment for a Power-laser Community Harvest(J-EPoCH) facility, which include 8 kJ, 5 PW@100 Hz laser.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.415-425
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• 2022

Memory formation in the hippocampus is formed and maintained by circadian clock genes during sleep. Sleep deprivation (SD) can lead to memory impairment and neuroinflammation, and there remains no effective pharmacological treatment for these effects. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. In this study, we investigated the effects of MYR on memory impairment, neuroinflammation, and neurotrophic factors in sleep-deprived rats. We analyzed SD-induced cognitive and spatial memory, as well as pro-inflammatory cytokine levels during SD. SD model rats were intraperitoneally injected with 10 and 20 mg/kg/day MYR for 14 days. MYR administration significantly ameliorated SD-induced cognitive and spatial memory deficits; it also attenuated the SD-induced inflammatory response associated with nuclear factor kappa B activation in the hippocampus. In addition, MYR enhanced the mRNA expression of brain-derived neurotropic factor (BDNF) in the hippocampus. Our results showed that MYR improved memory impairment by means of anti-inflammatory activity and appropriate regulation of BDNF expression. Our findings suggest that MYR is a potential functional ingredient that protects cognitive function from SD.