• Natural Product Sciences
• /
• v.18 no.2
• /
• pp.67-75
• /
• 2012

Zizyphi Spinosi Semen (ZSS) have been widely used for the treatment of insomnia in Asia. This experiment was performed to investigate whether methanol extract of ZSS (MEZSS) has hypnotic effects through the ${\gamma}$-amino butyric acid (GABA)ergic systems. MEZSS inhibited the locomotor activity. MEZSS enhanced pentobarbital-induced sleep behaviors. However, MEZSS itself did not induce sleep at higher dose, similar to muscimol. On the other hand, both pentobarbital and MEZSS increased the non rapid eye move (NREM) sleep, especially reducing the -wave electroencephalogram (EEG) activity in REM sleep. MEZSS showed similar effects with muscimol on potentiating chloride influx induced by pentobarbital. MEZSS significantly increased GABAA receptors ${\gamma}$-subunit expression and slightly decreased ${\beta}$-subunit expression in hypothalamus and thalamus, showing that subunit-expression was similar to diazepam. In addition, MEZSS enhanced the expression of glutamic acid decarboxylase (GAD). In conclusion, it is suggested that MEZSS might augment pentobarbital-induced sleep behaviors through the modification of GABAergic systems.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.11a
• /
• pp.43-44
• /
• 2012

Deterioration factors such as CO₂ and chloride ions cause steel corrosion in RC structures. The diffusion of these factors depends on the water content in concrete. To examine the moisture condition of concrete, this research considers the availability of the steel effect ratio, which is calculated by Resistivity Estimation Model (REM). It is concluded that the steel effect ratio is expected to be available as a quantitative evaluation method in the assessment of concrete layer resistivity.

• Journal of Korean Society on Water Environment
• /
• v.22 no.2
• /
• pp.264-270
• /
• 2006

In this research, volume reduction of activated sludge using electrolysis was studied to find an optimum condition using lab scale experiments. Wasted sludge was treated by electrolysis with controlling current density, chloride concentration, electrode distance, and reaction time. Volume of return sludge was reduced by 9.79% in average while maximum was 16.7%. Sludge volume reduction efficiency was affected by current density and reaction time. It was reversely proportional to the electrode distance. Especially current density was effective on the system performance significantly. Electric conductivity, salinity and COD were increased by electrolysis implying sludge disintegrated and converted to COD in part. An empirical equation for total solid removal efficiency by electrolysis was proposed by multiple linear regression analysis as: $TS_{rem}$(%) = 5.534 ${\times}$ current density (A/l) + 0.178 ${\times}$ reaction time (m) + 2.758.

• Resources Recycling
• /
• v.30 no.2
• /
• pp.46-52
• /
• 2021

Off-grade Ti generated from smelting and mechanical processing has a high oxygen content. In this work, off-grade Ti was deoxidized using Mg and a chloride mixture as the reductant and flux, respectively. The experiments were conducted in the α-Ti temperature range (1,023~1,123 K) and the effects of the reaction time, reaction temperature, quantitiy of Mg and chloride ratio on deoxidation were investigated. Notably, when YCl3 is used as the flux to react with MgO, it is possible to reduce the activity of MgO. Therefore Ti can be deoxidized using Mg. In this study, the O content was decreased from 0.5 wt% to 0.1004 wt% at 1073 K, for 6 hours, with Mg=3.6 g and $X_{YCl_3}=0.22$.

• Natural Product Sciences
• /
• v.22 no.4
• /
• pp.263-269
• /
• 2016

Rhynchophylline (RP) is a major tetracyclic oxindole alkaloid of Uncariae Ramulus et Uncus which has been used to treat hypertension, seizures, pain and anxiety in the oriental countries. A recent report revealed that RP attenuated ischemia-induced neuronal damage and kainite-induced convulsions in animals. This study was performed to investigate whether RP enhances pentobarbital-induced sleep behaviors and modulates sleep architecture in mice. Locomotor activity was significantly inhibited by RP at 0.25 and 0.5 mg/kg, similar to 2 mg/kg diazepam (a benzodiazepine agonist) in mice. RP shortened sleep latency and increased total sleep time in a dose-dependent manner when administrated with pentobarbital (42 mg/kg, i.p.). RP also increased the number of sleeping mice and total sleep time by concomitant administration with the sub-hypnotic dosage of pentobarbital (28 mg/kg, i.p.). On the other hand, RP (0.25 mg/kg, p.o.) itself significantly inhibited sleep-wake cycles, prolonged total sleep time, and rapid eye movement in rats. In addition, RP also increased chloride influx in the primary cultured hypothalamic neuronal cells. In addition, we found that glutamic acid decarboxylase ($GAD_{65/67}$) was activated by RP. In conclusion, RP augments pentobarbital-induced sleeping behaviors, and can be a candidate for treating insomnia.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.6
• /
• pp.824-835
• /
• 1999

Background: Sleep-related breathing disorders are commonly found in patients with chronic renal failure and particularly, sleep apnea may have an influence on the long-term mortality rates in these patients. Maintenance hemodialysis is the mainstay of medical measures for correcting the metabolic derangements of chronic renal failure but it is uncertain whether it may alleviate sleep disorders including sleep apnea. Methods: Forty seven patients on maintenance hemodialysis were surveyed with the sleep questionnaire about their clinical symptoms related to sleep disorders. Among them, 15 patients underwent the polysomnography and their blood levels of urea nitrogen, creatinine, electrolytes and the arterial blood gases in the nights before and following hemodialysis were measured. Results: Forty(85.1%) of the 47 patients complained of the symptoms associated with sleep-wake cycle disturbances, 55.3% experienced snoring and 27.7% reported witnessed apneas. The duration of REM sleep increased significantly in the nights after hemodialysis compared to the nights without hemodialysis(p<0.05) and the percentage of total sleep time comprising NREM sleep decreased significantly in the nights following hemodialysis compared to the nights before hemodialysis(p<0.05). The percentage of total sleep time consisting of the stage 1 and 2 NREM sleep showed the trend for a decrease in the nights after hemodialysis(p=0.051), while the percentage of total sleep time comprising the stage 3 and 4 NREM sleep did not change between nights. The obstructive sleep apnea was more predominant type than the central one in both nights and there were no differences in the apnea index and the apnea-hypopnea index between the nights. The decrease in the blood level of urea nitrogen, creatinine, potassium and phosphorus was observed after hemodialysis(p<0.05), but the differences of parameters measured during polysomnography between the nights did not correlate with the changes of biochemical factors obtained on the two nights. Arterial blood gas analysis showed that pH was significantly greater in the nights after hemodialysis than in the nights before hemodialysis(p<0.05), but there were no correlations between the parameters examined during polysomnography and the parameters of arterial blood gas analysis(p<0.05). Conclusion: These results suggest that chronic renal failure is an important systemic disorder which is strongly associated with sleep disorders. Maintenance hemodialysis, although it is a widely accepted measure to treat chronic renal failure, did not significantly modulate the sleep architecture and the severity of sleep apnea. Thus, taking the patients with chronic renal failure into account, it is advisable to try not only to find a substantial way for correcting metabolic derangements but also to consider the institution of more effective treatments for sleep disorders.