• Animal cells and systems
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• v.6 no.3
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• pp.239-245
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• 2002

Plasma melatonin, thyroid-stimulating hormone (TSH) and body temperature were measured simultaneously and continuously before and after the sleep-wake cycle was shifted in 4 healthy males and changes in the circadian rhythm itself and in the phase relationship among these circadian rhythms were determined. Normal sleep-wake cycle (sleep hours: 2300-0700) was delayed by 10 h (sleep hours: 0900-1700) during the experiment. Even after this shift the typical melatonin rhythm was maintained: low during daytime and high during night. The melatonin rhythm was gradually delayed day by day. The TSH rhythm was also maintained fundamentally during 3 consecutive days of altered sleep-wake cycle. The phase was also delayed gradually but remarkably. The daily rhythm of body temperature was changed by the alteration of sleep-wake cycle. The body temperature began to decrease at the similar clock time as in the control but the decline during night awake period was less steep and the lowered body temperature persisted during sleep. The hormonal profiles during the days of shifted sleep/wake cycle suggest that plasma melatonin and TSH rhythms are basically regulated by an endogenous biological clock. The parallel phase shift of melatonin and TSH upon the change in sleep-wake cycle suggests that a common unitary pacemaker probably regulates these two rhythms. The reversal phase relationship between body temperature and melatonin suggests that melatonin may have a hypothermic effect on body temperature. The altered body temperature rhythm suggests that the awake status during night may inhibit the circadian decrease in body temperature and that sleep sustains the lowered body temperature. It is probable but uncertain that there ave causal relationships among sleep, melatonin, TSH, and body temperature.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.47-57
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• 1984

Mathematically-rigorous time-volume averaged conservation equations were simplified to established the differential equations of THERMIT-6S, which is a two-fluid 3-D code. The difference equations of THERMIT-6S were obtained by discretizing the proceeding set of differential equations. The spatial discretization is characterized by a first-order spatial scheme, donor cell method, and staggered mesh layout. For time discretization, a first order semi-implicit scheme treats implictly sonic terms and terms relating to local transport phenomena and explicitly convective terms. The results were linearized by the Newton-Raphson method. In order to construct the reduced pressure equation, the linearized equations were manipulated so that all variables are coupled between mesh cells through only the pressure variable. By simulating numerically the OPERA-15 experiment, it was found that THERMIT-6S is a very powerful code in predicting reactor behavior after sodium boiling including flow coastdown, reversal flow and flow oscillation.

• The Journal of Korean Academy of Sensory Integration
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• v.1 no.1
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• pp.9-16
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• 2003

Objective : The experiment consists of measuring functional grasp ability of a child suffering from sensory defense disability of the hands as the child is treated with sensory integration therapy. Methods : We treated two-year-old child with developmental disability to set up the reversal design(ABAB design). We used treatment equipments, free activities, and toys for sensory integration therapy. Results : A child's functional grasp ability did not show anything before the sensory integration therapy, however, after the sensory integration was applied during the first treatment(Treatment 1), the five minutes before the treatment, it averaged 1.87 times(ranges=0 to 5 times), the five minutes after the treatment, it averaged 1.25 times(ranges=0 to 8 times) showing an increased. After ending the sensory integration therapy, the functional grasp ability averaged 2.5 times before the therapy and 4 times after the therapy, which showed a totally different tendency, when we reapplied the treatment during the second treatment(Treatment 2), it averaged 2.4 times(ranges=1 to 4 times) before the treatment, and it averaged 5.3 times(ranges=4 to 6 times) after the treatment, which showed a big improvement. Conclusion : The sensory integration therapy brought an increase in functional grasp ability along with improvement in daily life functions of the child. For this result, there should be more research to see more effects and results to help those in need.

• Nutrition Research and Practice
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• v.5 no.4
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• pp.294-300
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• 2011

Takju is a Korean alcoholic beverage made from rice, and is brewed with the yeast Saccharomyces cerevisiae. This study was conducted to evaluate the effects of exercise training and moderate Takju consumption on learning ability in 6-week old Sprague-Dawley male rats. The rats were treated with exercise and alcohol for 4 weeks in six separate groups as follows: non-exercised control (CC), exercised control (EC), non-exercised consuming ethanol (CA), exercised consuming ethanol (EA), non-exercised consuming Takju (CT), and exercised consuming Takju (ET). An AIN-93M diet was provided ad libitum. Exercise training was performed at a speed of 10 m/min for 15 minutes per day. Ethanol and Takju were administered daily for 6-7 hours to achieve an intake of about 10 ml after 12 hours of deprivation, and, thereafter, the animals were allowed free access to deionized water. A Y-shaped water maze was used from the third week to understand the effects of exercise and alcohol consumption on learning and memory. After sacrifice, brain acetylcholinesterase (AChE) activity was analyzed. Total caloric intake and body weight changes during the experiment were not significantly different among the groups. AChE activity was not significantly different among the groups. The number of errors for position reversal training in the maze was significantly smaller in the EA group than that in the CA and ET groups, and latency times were shorter in the EA group than those in the CC, EC, CT, and ET groups. The latency difference from the first to the fifth day was shortest in the ET group. The exercised groups showed more errors and latency than those of the non-exercised groups on the first day, but the data became equivalent from the second day. The results indicate that moderate exercise can increase memory and learning and that the combination of exercise and Takju ingestion may enhance learning ability.

• The Journal of Internal Korean Medicine
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• v.26 no.4
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• pp.767-775
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• 2005

This study was carried out to investigate the preventive effect of Salviae Miltiorrhizae Radix, Rhei Rhizoma and Carthami Flos combined with Samgijiwhang-Tang(SJTSRC) on streptozotocin(STZ)-induced diabetic nephropathy. Rats were divided into a control group of rats with STZ-induced diabetic nephropathy, a sample group of those given SJTSRC, and a normal group. In the experiment diabetic nephropathy was induced by giving STZ(60mg/kg) to rats via the peritoneum, and effects were assessed with measures of serum creatinine, serum BUN, secretion content of albumin and glucose content of urine, malondialdehyde(MDA) and glutathione(GSH) content in cortex of kidney. When STZ was injected into sample rat, the value of creatinine and BUN increased validly and STZ did damage to the kidney. When applying SJTSRC to sample rats, the value of serum creatinine decreased validly but the value of serum BUN decreased invalidity. It was confirmed that SJTSRC had an effect on recovery after kidney damage and secretion content of albumin increasedafter administration of SJTSRC but there was no change in glucose content of urine compared with the control group. The decrease of secretion of albumin after injection of STZ was taken to mean progressive diabetic nephropathy, and that reversal of that trend after SJTSRC administration showed that kidney function had improved, not through decreasing blood sugar, but through other factors. Results suggest that diabetic nephropathy was induced by STZ, and SJTSRC was effective in restricting the extent of damage to the kidney and halting the progression of diabetic nephropathy with improvement in levels of serum creatinine and albumin secretion. More study is needed, particularity pertaining to anti-oxidative effects in the kidney cortex.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.792-795
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• 2005

The guide-ways of precision machine tools are one of important element of machine tools. It has usually a pair of surfaces for constraint of one direction with bearing. In the case of precision machine tools, non-contact bearing such as hydrostatic bearing and aerostatic bearing is adopted usually. In this case, profiles of rails has effect on straightness and the clearance of bearing has effect on stiffness of guide way, which changes to higher if clearance changes to smaller. The clearance is varied along moving table according to relative distance of pair of rails. The relative distance of pair of rail can be divided by three properties. First and second properties are straightness of each pair of rail and bearing pad. And, third is parallelism about pair of rails and pairs of bearing pad. There are several methods for measuring straightness of each surface such as reversal method, sequential two point method, and way straightness. These straightness measuring methods are always acquiring deviation of profile from eliminating linear fitted inclined line and don't have the information of parallelism. Therefore, to get the small clearance for high stiffness, the straightness of rail and bearing pad and parallelism about pair of rails and pair of bearing pads are measured for correction such as regrinding, reassembling and lapping. In this research, new and easy method for measuring parallelism of pair of rails is suggested. Two displacement probe and sensor stage, which is carry on the displacement sensor, are needed. The simulation and experiment was accomplished about pair of horizontal guide way to confirm the measurement of parallelism. And, the third probe is added to measure the straightness of each rails by sequential two point method. From the estimation of combined these two methods, it is confirmed that the profiles of a pairs of rails can be measured.

• Natural Product Sciences
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• v.26 no.3
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• pp.252-258
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• 2020

This study investigated the biochemical and histological changes associated with the co-administration of cisplatin and methanolic extract of Portulaca oleracea (MEPO) in adult Wistar rats. Twenty-four (24) adult female Wistar rats were randomly divided into six (6) groups (A-F) (n = 4). Group A served as the control group for the experiment and received no treatment. Group B was given a single dose of cisplatin and served as the cisplatin control group. Group C and D received 400 mg/kg and 800 mg/kg of MEPO 6 hours after a single dose cisplatin injection respectively. Group E and F received 400 mg/kg and 800 mg/kg of MEPO 6 hours before cisplatin injection. The cisplatin injection was 2 mL/kg given intraperitoneally for all groups. There was a significant increase in the serum levels of ALT, ALP, AST, total bilirubin, and conjugated bilirubin following cisplatin treatment (p = 0.000, 0.000, 0.039, 0.000, 0.004 respectively) with a consequent reversal due to MEPO administration across all treated groups (p = 0.000, 0.000, 0.000, and 0.000) in a dose-dependent fashion. Cisplatin caused the expansion of the red and white pulp in the spleen which was attenuated by MEPO. MEPO demonstrated a protective effect against cisplatin-induced liver and spleen toxicity.

• Development and Reproduction
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• v.18 no.3
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• pp.127-131
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• 2014

We investigated the androgenic effects of $17{\alpha}$-methyltestosterone (MT) on gonadal sex reversal in juvenile red spotted grouper Epinephelus akaara. The fish were immersed in $17{\alpha}$-MT at 1 and 5 mg/L. Treatment method of $17{\alpha}$-MT was once weekly for 4 and 8 weeks. Fish were sampled at 12 months after end of the treatment period in order to histological analysis. At the initiation of an experiment (70 day after hatching), juvenile red spotted grouper have the paired primordial gonads with somatic cells bellow kidney in the posterior portion of the body cavity. Formation of ovarian cavity indicates that the ovarian differentiation beginning at 70 DAH in red spotted grouper. At 12 months after end of the treatment period, control group, $17{\alpha}$-MT 1 mg/L treatment group for 4 and 8 weeks, and $17{\alpha}$-MT 5 mg/L treatment group for 4 weeks were all female. However, sex-changed males without ovarian cavity were observed in the $17{\alpha}$-MT 5 mg/L treatment group for 8 weeks. In grouper, we firstly reported that the red spotted grouper be able to induce the primary males by hormone treatment prior to gonadal sex differentiation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.22-29
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• 2002

Usually, much harmonics are included and cause harmonic loss of motor, torque pulsation, electro-magnetic noise and shock etc. by switching function of inverter when drive induction motor variableness inside. It applied partial resonant Buck converter and three phase voltage type SPWM inverter circuit to induction motor driving system in this paper that see to solve such problem. Changed operation condition variously to do input current of circuit that propose sine-wave by unit power factor almost and capacitor supplied bringing back to life voltage by power supply arranging properly assistance diode and electric power switching. Power factor and efficiency improved as that minimize variation of input at power supply voltage polarity reverse by that add voltage reversal function. Also, by using output filter, reduced harmonic of output line to line voltage components, and introduce state space analysis and forecast operation of rectifier. Such all items confirmed validity through simulation and an experiment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.137-145
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• 2000

Carcinogenesis is a multi-stage process that generally consists of at least three steps; initiation, promotion, and progression. If one of these carcinogenic steps were suppressed or delayed, the cancer could be prevented. Cancer chemoprevention is defined to be inhibition or reversal of the carcinogenic process by the specific chemical agents and is a novel approach to cancer management alternative to conventional chemotherapy. Chlorophylln(CHL), a water-soluble derivative of chlorophyll, containing sodium and copper, has been known to be strong antimutagen in several test systems, but its mechanism of antimutagenic action is unknown. In the present experiment, the possibility of CHL as chemopreventive drugs on 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal pouch carcinogenesis was investigated by mutagenicity test, carcinogenicity test, and frequency or spectrum of H-ras mutations in the both of DMBA-induced and chlorophylln-pretreated-DMBA induced tumor by polymerase chain reaction and non-isotopic restriction fragment length polymorphism. The treatment of CHL reduced the yields and multiplicity of the 0.5% DMBA-induced tumor, 86% to 62.5% and $3.7{\pm}0.6$ to $1.4{\pm}0.3$, respectively. The occurrence of histidine revertant by $20{\mu}mole$ DMBA was inhibited 25.6 to 81.7% by 1 to $5{\mu}M$ CHL in a dose-dependent manner. The mutation rates of H-ras gene in DMBA-induced and CHL-pretreated-DMBA induced tumor were 96%, 94% of which the most mutations were in codon 12/13. These results suggest that CHL inhibits the carcinogenic action of DMBA by the formation of complex between CHL and DMBA or the inhibition of the activation of DMBA in vivo. But CHL did not affect the mutation rates or its spectrum in already formed tumor.