• Biomolecules & Therapeutics
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• v.13 no.2
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• pp.90-94
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• 2005

Prazosin hydrochloride is an antihypertensive drug with selective ${\alpha}_1$-adrenoreceptor blocking effects. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of prazosin in human plasma. A reversed-phase C18 column was used for the separation of prazosin and terazosin (internal standard) with a mobile phase composed of water, acetonitrile and triethylamine(75:25:0.1, V/V;pH5.0) at a flow rate of 1.5 ml/min. the fluorescence detector was set at excitation and emissionwavelengths of 250 and 370 nm, respectively. Intra-and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 0.5 ng/ml. Good recovery (>80%) was seen in plasma. Prazosin was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study in plasma after oral administration of a single 2-mg dose as prazosin base to 16 healthy volunteers. The maximum plasma concentration of prazosin was 23.1 ${\pm}$ 16.5 ng/ml at 2.1 h, and the mean area under the curve and elimination half-life were calculated to be 108.4 ${\pm}$ 74.2 ng ${\cdot}$hr/ml and 2.5 ${\pm}$ 0.6 h, respectively.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.307-311
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• 2020

Purpose: This study examined the effects of changes in the intensity of Functional Electrical Stimulation (FES) on CorticoMuscular Coherence (CMC) during action observation. This paper presents a neurophysiological basis for the effective intensity of FES. Methods: Twenty-seven healthy volunteers were asked to observed a video with FES. The FES was provided with a sensory stimulation level, nerve stimulation level, and motor stimulation level. Simultaneously, an electroencephalogram (EEG) of the sensorimotor cortex and electromyogram (EMG) from the wrist extensor muscle were recorded. The peak CMC and average CMC were analyzed to compare the differences caused by the FES intensity. Results: The peak CMC showed a significant increase in the alpha band during motor stimulation (p<0.05). The average CMC showed a significant increase in the beta band during motor stimulation (p<0.05). Conclusion: The intensity of FES, which causes actual movement, increased the CMC during action observation. These results show that the intensity of the FES can affect the functional connection between the sensorimotor cortex and muscle.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.85-92
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• 2007

In the present study, three-dimensional motion analyses were performed to determine biomechanics of the lower extremity in unexpected missing foot steps for ten healthy young volunteers. In unexpected missing foot steps, the whole plantar surface of the foot or the heel contacted to the ground. A rapid ankle dorsiflexion was found right after missing foot steps and an increased plantarflexion moment was noted during loading response. After the unexpected situation, the breaking force increased rapidly. At this time, both tibialis anterior and soleus were simultaneously activated. Moreover, the range of motion at ankle, knee and hip significantly decreased during stance. In pre-swing, rectus femoris and biceps femoris prevented the collapse of the lower limbs. During late stance, propulsive forces decreased and thus, both plantarflexion moment and power generation were significantly reduced. On the opposite side, hip extension and pelvic upward motion during terminal swing were significant. Due to the shortened pre-swing, the energy generation at the ankle to push sufficiently off the ground was greatly reduced. This preliminary study would be helpful to understand the biomechanics of unexpected dynamic perturbations and valuable to prevent frequent falling of the elderly and patients with gait disorders.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.24-29
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• 2015

Objectives: The objective of this study was to identify determine factors for blood VOCs levels in college students. Methods: Venous blood samples were collected from healthy 29 male and 25 female volunteers. The samples were analyzed with solid-phase microextraction gas chromatography and mass spectrometry. Results: Blood concentrations of benzene, toluene, ethylbenzene, m-,p-xylene, o-xylene were higher in smoking group than in non-smoking group. Geometric means of smoking group and non-smoking group were 0.45 and $0.36{\mu}g/L$ in benzene, 0.82 and $0.47{\mu}g/L$ in toluene, 0.44 and $0.41{\mu}g/L$ in ethylbenzene, 0.49 and $0.39{\mu}g/L$ in m-,p-xylene and 0.47 and $0.43{\mu}g/L$ in o-xylene, respectively. Gender, alcohol drinking, coffee, commuting time (30 minutes) by a car and adjacency between home and road were not associated with increasing blood VOCs concentrations of college students. Conclusion: Smoking habit was significantly associated with blood concentrations of benzene, toluene, ethylbenzene, o-,m-,p-xylene in college students.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.15 no.1
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• pp.95-110
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• 2011

Objectives: The aim of the present study is to define breath-holding in spontaneous respiration and to observe the difference of respiratory variables, EEG and HRV. Methods: 46 healthy young volunteers (M:F=31:15) were recruited in the study. By measuring and analysing respiration, EEG and HRV in the spontaneous respiration. We segment subjects by 100% of coefficient of variation in the breath-holding. Results & Conclusions: 1. There is a period of breath-holding after expiration and before endeavored inspiration, in the course of respiration. The greater coefficient of variation in the breath-holding, longer respiration period mean, inspiration period mean and breath-holding mean in respiratory variable. 2. There was no significant difference between HRV parameters. 3. The greater coefficient of variation in the breath-holding, the higher ${\beta}$ frequency and ${\gamma}$ frequency in the left prefrontal lobe.

• The Journal of Korean Medicine
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• v.24 no.1
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• pp.100-109
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• 2003

Objectives : The purpose of this study is to 1. measure the skin resistance of jeong-acupuncture points using compound electrode, and 2. develop a database of skin resistance based on age and gender. Methods : The skin resistance of jeong-acupuncture points on the hands and feet of 191 healthy volunteers was measured using a specially designed compound electrode. A constant current of $5{\mu\textrm{A}}$ was applied to the measurement points and the skin resistance was obtained using amplifier, A/D converter and Acknowledge software program, Results : 1. ANOVA statistical analysis showed no significant differences between jeong-acupuncture points on hands and feet. 2. Paired samples t-test showed no significant differences between Yin-Yang meridian points, 3. When the data were sorted by gender, factor analysis showed statistically significant differences between male and female groups in all measured points except for left foot. 4. Based on the factor analysis, a significant relationship between the skin resistance and age was found in feet. However, no such relationship was found in hands. Conclusions : There are differences in skin resistance according to sex and age, Further clinical research is necessary using compound electrode method.

• The Journal of Korean Physical Therapy
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• v.29 no.1
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• pp.27-32
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• 2017

Purpose: Recent electrophysiological studies have shown that the sensorymotor cortex is activated during both actual action excuted by themselves and observation of action performed by other persons. Observation of action based on mirror neuron system can be used as a cognitive intervention to promote motor learning. The purpose of this study was to investigate the brain activity changes during action observation and action execution using EEG. Methods: Thirty healthy volunteers participated and were requested to perform hand action and to observe the video of hand action performed by another person. The EEG activity was evaluated by a method which segregated the time-locked for each condition. To compare the differences between action observation and execution, the Mu suppression and the relative band power were analysed. Results: The results showed significant mu suppression during the action observation and execution, but the differences between the two conditions were not observed. The relative band power showed a significant difference during the action observation and execution, but there were no differences between the two conditions. Conclusion: These results indicate that action execution and observation involve overlapping neural networks in the sensorymotor cortical areas, proposing positive changes on neurophysiology. We are expected to provide information related to the intervention of cognitive rehabilitation.

• The Journal of Internal Korean Medicine
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• v.38 no.1
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• pp.20-31
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• 2017

Objectives: This study investigated the effect of SM-2015 on blood alcohol clearance and hangover. We undertook this study to test whether SM-2015 is effective in decreasing blood alcohol concentration and preventing the symptoms of alcohol-induced hangover. Methods: Twenty healthy volunteers participated in this randomized crossover study. All participants were classified between an SM-2015 intake group (test group) and a non-intake group (control group). The primary outcome measure was the difference in blood alcohol concentration and hangover severity scores between the test and control groups. The secondary outcome measure was the difference in a liver function test (LFT) between the test and control groups. Results: After alcohol exposure, the sensitivity scores of blood alcohol concentration and hangover symptoms (sleepiness, dizziness, nausea, weakness, stomach pain, diarrhea, and concentration disorder) were significantly decreased in the SM-2015 intake group compared with the non-intake group. There were no differences in the LFT results between the SM-2015 intake group and the non-intake group. Conclusions: SM-2015 is effective in decreasing blood alcohol concentration and preventing the symptoms of alcohol-induced hangover. Larger studies are required to confirm these findings.

• Journal of Oriental Neuropsychiatry
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• v.25 no.3
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• pp.271-286
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• 2014

Objectives: The purpose of this study is to investigate the clinical trial research trends in regards to the neurofeedback training (NFT) in Korean journals. Methods: We researched articles published in Korean journals from 2000 up to 2013 and were related to the NFT. We searched six electronic databases to find relevant articles, using the term 'neurofeedback'. Results: 1) 6 single group comparative studies and 31 randomized controlled trials were found. 2) Healthy volunteers and students were most frequently studied with neurofeedback training. Other studies included attention deficit hyperactivity disorder (ADHD), Poststroke, panic disorder, premenstrual dysphoric disorder (PDD), temporomendibular disorder (TMD), and obesity. NFT interventions were attempted in diverse training protocols and assessed with many different outcome measurements. 3) Most studies showed effective results after NFT. Conclusions: NFT is increasingly studied and used in various clinical fields. Also, there have been efforts to adopt NFT in Korean medical clinics and researches, and more rigorous and innovative studies are needed in the future.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.2
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• pp.285-293
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• 2000

Objectives: We have accomplished a clinical research about counteracting the pesticides intoxication using oriental medical method and treatment. And we observed the preventive effect of Gamdu-tang(甘豆湯) to intoxication of Organophosphorus Insecticides. Material and Methods: The subjects were 8 volunteers who were healthy and not taking medications. we observed change of cholinesterase(ChE) activity in serum of them after exposed to pesticides Results and Conclusions : In this study of the preventive effects of Gamdu-tang(甘豆湯) on the intoxication of Organophosphate Insecticides, we evaluated that the decreasing value of ChE activity after spraying insecticides of Gamdu-tang medication group was smaller than non-medication group, but it was less significant(P>0.05 P<0.1). We had a difficult to gather participant in this study, so it's necessary for us to get together more larger group in the next study.