• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.55-64
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• 2019

Stress is accompanied by changes in the responses of the autonomic nervous system, and the heart rate variability (HRV) index is a quantitative marker that reflects autonomic responses induced by stressors. In this study, we observed changes in the autonomic responses induced by combinations of 30% oxygen administration and color light for stress relaxation. In all, 42 participants produced stress symptoms over the preceding two weeks, as rated on the stress response scale. After stress assessment, they were exposed to three therapeutic conditions, and electrocardiogram (ECG) signals were recorded before, during, and after therapy. The three therapy conditions consisted of only 30% oxygen administration with white light, a combination of 30% oxygen and orange light, and a combination of 30% oxygen and blue light. The HRV indices extracted from ECG signals were heart rate (HR), the standard deviation of the RR interval (SDNN), the mean square root of consecutive RR interval difference values (RMSSD), the low frequency component of HRV (LF), the high frequency component (HF), and the LF/HF ratio. These indicators were used to compare mean values before and after therapy. The results showed that HR and the LF/HF ratio were significantly lower after therapy than before it. In particular, the condition with 30% oxygen and blue light yielded significantly greater RMSSD and HF increases, as well as decreases in LF/HF ratio than in other two conditions. Our results suggest that therapy with 30% oxygen and blue light is the most effective for the relaxation of stress, which implies autonomic balance by parasympathetic activation.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1336-1344
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• 2014

The effects of various packaging systems, vacuum packaging (VACP), medium oxygen-modified atmosphere packaging (50% $O_2/20%$ $CO_2/30%$ $N_2$, MOMAP), MOMAP combined with vacuum skin packaging (VSP-MOMAP), high oxygen-MAP (80% $O_2/20%$ $CO_2/30%$ $N_2$, HOMAP), and HOMAP combined with VSP (VSP-HOMAP), on the activity of antioxidant enzyme, and oxidation and color stabilities in sliced Hanwoo (Korean cattle) beef loin were investigated at $4^{\circ}C$ for 14 d. Higher (p<0.05) superoxide dismutase activity and total reducing ability were maintained in VSP-MOMAP beef than in HOMAP beef. Lipid oxidation (2-thiobarbituric acid reactive substances, TBARS) was significantly (p<0.05) retarded in MOMAP, VSP-MOMAP, and VSP-HOMAP beef compared with HOMAP beef. Production of nonheme iron content was lower (p<0.05) in VSP-MOMAP beef than in HOMAP beef. Red color ($a^*$) was kept higher (p<0.05) in VSP-MOMAP beef compared with MOMAP, HOMAP, and VSP-HOMAP beef. However, VACP beef was found to have the most positive effects on the antioxidant activity, oxidation and red color stabilities among the various packaged beef. These findings suggested that VSP-MOMAP was second to VACP in improving oxidation and color stabilities in sliced beef loin during chill storage.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.1
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• pp.47-56
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• 2018

Background: The purpose of this study is to investigate the effects of administration order when a sedative drug (midazolam) and an opioid analgesic drug (fentanyl) is applied for moderate intravenous (IV) sedation in dentistry. Methods: A retrospective chart review was conducted in one dental clinic during its transition from a midazolam-first to a fentanyl-first protocol for dental procedures requiring moderate IV sedation. Physiological parameters, drug administration times, patient recovery times, drug dosages, and patient recall and satisfaction were investigated for differences. Results: A total of 76 charts (40 midazolam-first and 36 fentanyl-first administrations), were used in the analysis. Administering midazolam first resulted in an average 4.38 min (52%) decrease in administration times (P < 0.001), and a decrease in procedural recollection immediately following the procedure (P = 0.03), and 24 to 48 hours later (P = 0.009). Administering fentanyl first required an average of 2.43 mg (29%) less midazolam (P < 0.001). No significant differences were found for change in vital signs, minimum oxygen saturation levels, recovery times, and patient satisfaction (P > 0.05). Oxygen saturation levels did not drop below 90% for either group; however, 5 cases in the fentanyl-first group fell to between 90% and 92%, compared with 0 cases in the midazolam-first group. Conclusions: The administration order of fentanyl and midazolam may have different effects on patients and the sedation procedure. Findings from this study should be used to facilitate discussion among dental practitioners and to guide additional research investigating this topic.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.853-860
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• 2010

This study investigated differences in blood oxygen saturation($SpO_2$) and heart rate(HR) according to flow rate, gender, and phase in males and females in their 60s when the supply of 93% highly concentrated oxygen administration was changed (1L/min, 3L/min, and 5L/min). It recruited totally 20 elderly subjects including 10 males($68.0{\pm}2.6$ years) and 10 females ($65.5{\pm}3.1$ years). The experiment consisted of three phages of Rest 1(5 min), Hyperoxia(10 min), and Rest 2(10 min), and $SpO_2$[%] and HR[bpm] were measured during all phages. $SpO_2$ was higher in Hyperoxia phase supplied with highly concentrated oxygen than in Rest phases. Higher flow rate was associated with more increase in $SpO_2$. HR was reduced in Hyperoxia phase compared to Rest phases. More supply of highly concentrated oxygen was associated with more decrease of HR. However, there were no differences in both $SpO_2$ and HR according to gender.

• YAKHAK HOEJI
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• v.32 no.4
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• pp.287-293
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• 1988

Oxygen free radical have recently been found to mediate cell injury after ischemia in the kidney. The purpose of our study was to determine whether selenium had an effect on damge mediated by oxygen free radical in inorganic mercury induced renal failure, toxic model of renal failure. Toxic renal failure model was produced by subcutaneous injection of mercuric chloride (4mg/kg) once a day for 7 consecutive days. In additionally, coadministration of sodium selenite (1mg/kg) was performed by the same condition. As a consequence of this study, we were able to detect partially unequivocal role of selenium as below dipicted. The combination of sodium selenite showed that markedly inhibited production of superoxide radical in mercuric chloride alone. On the other hand, combined sodium selenite was unable to enhance against significantly lowered superoxide dismutase activity after mercuric chloride insult. However, simultaneous administration of sodium selenite was inclined to induce mitochondrial superoxide dismutase and catalase.

• Neonatal Medicine
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• v.18 no.1
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• pp.130-136
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• 2011

Purpose: Chloral hydrate is a common drug frequently used for procedural sedation. But data on chloral hydrate use in the newborns are limited. This study examined the frequency of adverse effects of chloral hydrate and factors related to the adverse effects. We also examined if there were additional adverse effects when an additional sedative was used. Methods: The medical records of 104 patients admitted to neonatal intensive care unit of Seoul St. Mary's Hospital from March 2010 to February 2011 who used chloral hydrate for procedural sedation were retrospectively reviewed. Results: Adverse effects after administration of chloral hydrate were noted in 41.3% of the 104 patients. The adverse events included oxygen desaturation (18.8%), increase in apneic episodes (17.5%), increase in bradycardia (10%), and feeding intolerance (3.8%). Using oxygen at the time of chloral hydrate administration was independently associated with adverse effects (odds ratio [OR], 10.911: 95% confidence interval [CI], 2.082-57.178) and with the necessity for an additional sedative after administration of chloral hydrate (OR, 4.151: 95% CI, 1.455-11.840). Using one additional sedative agent after chloral hydrate showed no difference in adverse effects except feeding intolerance. Conclusion: Patients dependent on oxygen at the time of chloral hydrate administration may were found to be at higher risk for adverse effect of chloral hydrate and for an additional sedative. When an additional sedative is needed, it could be used with monitoring feeding intolerance after chloral hydrate administration.

• Journal of The Korean Dental Society of Anesthesiology
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• v.2 no.1 s.2
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• pp.1-6
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• 2002

The usage of nitrous oxide is increased for the anxious patient to dental treatment. There are two methods to induce the sedation during dental treatment. One is sedation with drugs the other no need of drugs. We discussed here about sedation with drugs. The methods of drug administration are oral, intramuscular, intravenous, inhalation. The method of oral administration of drugs are convenient to patient and doctor but poor controllability. Intramuscular method is a parenteral technique that maintains several advantages over the enteral technique. However its pales in comparison to other parenteral technique. Intravenous method represents most effective method of ensuring predictable and adequate sedation in all patients. But it has inability to reverse the action of drugs after they have been injected except some drugs (e.g., narcotics and benzodiazepine). A variety of gaseous agents may be administered by inhalation to produce sedation. In dental practice, the inhalation administration of gas means use of nitrous oxide. There are many advantages of nitrous oxide administration. First, very short latent period and rapid onset of drug action which lead to possible titration of drug concentration. With nitrous oxide, clinical effects may become noticeable as quickly as 15 to 30 seconds after inhalation. Recovery from inhalation sedation is also quite rapid. In out patient dental practice rapid recovery is very important because it permit to discharge the patient without escort and the patient return to their ordinary life without limit. To success the conscious sedation with nitrous oxide, the administrator should be keep the mind that always titration of nitrous oxide concentration during induction and treatment. Careful observation need during treatment to prevent oversedation because the adequate nitrous oxide concentration to patients changed by environmental stress. Always begins with 100% oxygen and ends with 100% oxygen to prevent diffusion hypoxia which rare in clinical practice.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.619-627
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• 1997

It is known that 2-methyl-1,4-naphtoquinone(menadione, MD) induces hepatotoxicities both in vivo and in vitro. These toxic effects are believed to result from oxidative damages to hepatocytes by "active oxygen" species via one-electron reduction of the naphtoquinone. The ginsenoside(GS) is a complex mixture of individual ginsenosides which is known to produce a range of effects on the cardiovascular and central nervous systems. In particular, GS has an antioxidant effect. In this experiment we studied the effect of GS from red panax ginseng(red ginseng total saponin, RGTS) on free radical-induced liver injuries by MD. Administration of MD($150{\mu}M$) caused an increase in aspartate aminotransferase(AST) activities and lipid peroxidation, decrease in alkaline phosphatase(ALP) activities and total bilirubin levels in blood, caused depletion of GSH and changes of antioxidant enzyme(superoxide dismutase, catalase) activities are shown in liver tissue. Administration of RGTS restored the AST levels that increased by MD, but catalase showed no significant changes. RGTS also had an effect of restoring the GSH level and had some synergistic effects with SOD. These data suggest that RGTS may have some protective effects on liver injury which is related with the oxygen free radical.

• Tuberculosis and Respiratory Diseases
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• v.84 no.3
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• pp.217-225
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• 2021

Background: Despite the proven benefits of dexamethasone in hospitalized coronavirus disease 2019 (COVID-19) patients, the optimum time for the administration of dexamethasone is unknown. We investigated the progression of COVID-19 pneumonia based on the timing of dexamethasone administration. Methods: A single-center, retrospective cohort study based on medical record reviews was conducted between June 10 and September 21, 2020. We compared the risk of severe COVID-19, defined as the use of a high-flow nasal cannula or a mechanical ventilator, between groups that received dexamethasone either within 24 hours of hypoxemia (early dexamethasone group) or 24 hours after hypoxemia (late dexamethasone group). Hypoxemia was defined as room-air SpO₂ <90%. Results: Among 59 patients treated with dexamethasone for COVID-19 pneumonia, 30 were in the early dexamethasone group and 29 were in the late dexamethasone group. There was no significant difference in baseline characteristics, the time interval from symptom onset to diagnosis or hospitalization, or the use of antiviral or antibacterial agents between the two groups. The early dexamethasone group showed a significantly lower rate of severe COVID-19 compared to the control group (75.9% vs. 40.0%, p=0.012). Further, the early dexamethasone group showed a significantly shorter total duration of oxygen supplementation (10.45 days vs. 21.61 days, p=0.003) and length of stay in the hospital (19.76 days vs. 27.21 days, p=0.013). However, extracorporeal membrane oxygenation and in-hospital mortality rates were not significantly different between the two groups. Conclusion: Early administration of dexamethasone may prevent the progression of COVID-19 to a severe disease, without increased mortality.

• Fire Science and Engineering
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• v.32 no.5
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• pp.1-5
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• 2018

Curtains are used for shading in windows. Since most curtains are made of flammable materials and are installed vertically, curtains can be an important factor in fire spreading. Accordingly, it is important to predict fire behaviors in studies on the combustion characteristics of flammable interior decorations, such as curtains. In this study, to analyze the combustion characteristics of six kinds of curtains, which are widely used interior decorations, the oxygen index was measured at room temperature and higher temperature. As a result of the experiment, the oxygen index at higher temperature of all specimens was about 3%~7.5% lower than that at room temperature and difference of 0.2% of oxygen index show big differences in combustion phenomenon of specimens. Therefore, when flame retardancy is evaluated with the oxygen index value of flammable interior decorations, the oxygen index value at higher temperature should be sufficiently considered.