• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.615-624
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• 2013

In this study, the emission patterns of reduced sulfur compounds (RSC) were investigated using four different types of food samples (boiled egg, milk, canned meat and strawberry) between fresh and decaying stages. To this end, the concentrations of RSCs were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. Four sulfur compounds ($H_2S$, $CH_3SH$, DMS and DMDS) were selected as target compounds along with two reference compounds ($CS_2$ and $SO_2$). Their concentrations were quantified using GC-PFPD equipped with thermal desorption (TD) system. The boiled egg showed the highest concentration of $H_2S$ (3,655 ppb) at D-1, while $CH_3SH$ reached its maximum value of 64.4~78.5 ppb after 3 days. In milk samples, concentration of $CH_3SH$, DMS, and DMDS went up to 487, 16.3, and 578 ppb, respectively with the progress of decay (D-9). In case of canned meat, concentration of $H_2S$ and $CH_3SH$ peaked in the beginning (D-0) such as 345 and 66.6 ppb. In case of strawberry, $CH_3SH$ and DMDS showed the maximum concentrations 135 and 50.5 ppb at D-1, respectively. The olfactometry dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test showed similar patterns when sum of odor intensity (SOI) was derived via conversion of odorant concentration data. The results of this study confirm that the time of strong RSC emissions is distinguished for each food type between fresh (e.g., strawberries) and decaying conditions (e.g., milk).

• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.587-599
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• 2002

Extracellular single unit recordings were made from the ventral posteromedial thalamic (VPM) nociceptive neurons to determine mechanoreceptive field (RF) and response properties. A total of 44 VPM thalamic nociceptive neurons were isolated from rats anesthetized with urethane-chloralose. Based on responses to various mechanical stimuli including touch, pressure and pinch applied to the RF, 32 of 44 neurons were classified as nociceptive specific (NS) neuron. The other 12 neurons, classified as wide dynamic range (WDR), showed a graded response to increasingly intense stimuli, with a maximum discharge to noxious pinch. The VPM nociceptive neurons showed various spontaneous activity ranged from 0-6 Hz. They were located throughout the VPM, and had an contralateral RF including mainly intraoral (and perioral) regions. The RF size was relatively small, and very few neurons had a receptive field involving 3 trigeminal divisions. The NS neurons activated only by pressure and pinch stimuli had high mechanical thresholds compared to WDR neurons activated also by touch stimuli. The VPM nociceptive neurons were tested with suprathershold graded mechanical stimuli. Most of 21 NS and 8 WDR neurons showed a progressive increase in number of spikes as mechanical stimulus intensity was increased. In some neurons, the responses reached a peak before the highest intensity was given. Application of 5 mM $CoCl_2{\;}(10{\;}{\mu}\ell)$ solution to the trigeminal subnucleus caudalis did not produce any significant changes in the spontaneous activity, RF size, mechanical threshold, and response to suprathreshold mechanical stimuli of 9 VPM nociceptive neurons tested. 17 of 33 VPM nociceptive neurons responded to noxious heat as well as noxious mechanical stimuli applied to their RF. Application of the mustard oil, a small-fiber excitant and inflammatory irritant, to the right maxillary first molar tooth pulp induced an immediate but short-lasting neuronal discharges upto approximately 4 min in 16 of 42 VPM nociceptive neurons. These results suggest that VPM thalamic nucleus may contribute to the sensory discriminative aspect of orofacial nociception.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.487-498
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• 2010

Purpose : To investigate the immediate effects of transcutaneous electrical nerve stimulation(TENS) on the spasticity and the balance in the stroke patients. Methods : 26 subjects with spasticity over lower limbs were allocated randomly into two groups : (1) TENS group, (2) placebo-TENS group. TENS was applied on the both gastrocnemius for 60 minutes(100 Hz, 0.25 ms, 2 times sensory threshold). The modified Ashworth Scale(MAS) and Manual Muscle Tester were used to assess the spasticity of the ankle plantar flexors. Static balance under three conditions was measured by force-plate; in (1) the condition of standing with eyes opened, (2) with eyes closed and (3) the condition of standing on unstable surface with eyes opened. Results : When compared with the pre and post TENS application, TENS showed significant reduction of ankle spasticity in MAS and MMT measurement. Also, Application of high-frequency TENS improved the balance under three conditions. Conclusion : A single session of TENS to stroke patients could reduce spasticity and improve the balance.

• Journal of Physiology & Pathology in Korean Medicine
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• v.32 no.1
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• pp.35-42
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• 2018

TRPA1 and TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels. TRPA1 and TRPV1 are often co-expressed in sensory neurons and play an important role in mechanical hyperalgesia and allodynia during neuropathic pain. Scutellariae Radix was reported to possess anti-inflammation properties and similar patterns of therapeutic action against different diseases. also Baicalin(a known principal constituent of Scutellaria Radix) was shown to down-regulate the mRNA expression levels of TRPV1. In this study, we observed the effects of Scutellariae Radix extract(SRE) in neuropathic pain induced SD rats via modulation of TRPV1 and TRPA1. Oral administration of a Scutellaria Radix extract(in doses of 300mg/kg, SRE(300)) showed a meaningful increase in the withdrawal threshold of mechanical allodynia and showed a meaningful decrease in the expression of c-fos compared to the control group. SRE(100) and SRE(300) showed a meaningful decrease in the expression of TRPV1 level compared to the control group. These results suggest that Scutellariae Radix extract could decrease mechanical allodynia by down-regulate the TRPV1 on the model of neuropathic pain.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.1
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• pp.15-22
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• 2010

Purpose : This study examines the effects of pre-eccentric exercise and stretch ing to bicepsbrachii to prevent delayed onset muscle soreness and recovery of muscular function depending on the training intensity with 28 normal adults in their twenties. Methods : The subjects were divided into a control group, a group without any previous eccentric exercise, and a stretching group. Pre-eccentric exercise group conducted exercise with the intensity of 25% of maximal voluntary contraction. Pre-eccentric exercise and stretching was applied before to induce delayed onset muscle soreness and after, 24 hour post, 48 hour post, and 72 hour post. Measurements were conducted to examine pain and muscular function changes before, immediately after, and after inducing delayed onset muscle soreness. After inducing delayed onset muscle soreness, measurements were taken at the 24th hour, 48th hour, and 72nd hour. Results : The pre-eccentric exercise group and stretching group showed a significant difference from the control group by isometric contract ion power and mechanical pain threshold as a result of measuring delayed onset muscle soreness. Conclusion : From these results, electrical stimulation using presynaptic inhibition mechanism of transcutaneous electrical stimulation (TES) had positive effects for walking ability on inhibition of muscle tone in lower extremity. The motor level stimulation group experienced a more significant effect than the sensory level stimulation group. Therefore, the transcutaneous electrical stimulation (TES) is considered to be effective on walking ability increasing through inhibition of muscle tone in lower extremity for rehabilitation of post stroke hemiplegic patients.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.95-109
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• 2014

In this study, the concentration of odorants released from albumin (EA) and yolk (EY) portions of boiled egg samples were determined as a function of storage time. The concentrations were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. As such, odorants produced during both fresh and decay conditions were measured through time. A total of 19 compounds were selected as the main target odorants along with 12 reference compounds. GC-MS (for VOC) and GC-PFPD system (for sulfur gases) equipped with thermal desorption (TD) system were employed for odorant analysis in this work. The initial concentrations measured from the chamber system were converted into flux terms ($ng{\cdot}g^{-1}{\cdot}min^{-1}$). The EA showed the highest concentration of $H_2S$ (234 $ng{\cdot}g^{-1}{\cdot}min^{-1}$) at EA-0, and the concentrations of AT (Acetone) was also seen clearly in the range of 11.7 (EA-0) to 58.6 $ng{\cdot}g^{-1}{\cdot}min^{-1}$ (EA-9). The EY showed similar patterns. EtAl (Ethyl alcohol) increased 9.47 (EA-1) to 96.7 $ng{\cdot}g^{-1}{\cdot}min^{-1}$ (EA-9) in EA samples. Ketone, alcohol, sulfur groups generally exhibited high concentrations compared to other odorants. These data were also compared in relation to olfactometry related dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test and sum of odor intensity (SOI).

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.132-140
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• 2010

High sodium intake is one of the risk factors for the development of hypertension. According to 2007 Korean National Health and Nutrition Examination Survey, sodium intake of Korean was three times higher than adequate intake (1.5 g/day) recommended by Korean Dietary Reference Intakes. High sodium intake is related to high threshold and preference of salty taste. And zinc status is known to affect taste acuity. The hypothesis of this study is that zinc status is associated with salty taste acuity, preference, sodium intake and blood pressure. The subjects included in this study were 50 men and 41 women aged 20-29 y who did not smoke and not take supplements or medications regularly. Dietary intake data for 3 days were collected by 24-h recall for 1 day and dietary record for 2-days. Salty taste acuity and preference were determined by sensory test. Fasting serum concentration of zinc, height, weight, body composition and blood pressure data were collected. Salt taste preference in high zinc intake group ($\geq$ estimated average requirement, EAR; men-8.1 mg/day, women-7 mg/day) was higher than that in low zinc intake group (< EAR). Salty taste preference was inversely correlated with serum zinc concentration in people with low concentration of serum zinc (${\leqq}\;81\;{\mu}g/dL$)(r = -0.3520, p < 0.05). Diastolic blood pressure was higher in high sodium intake group than in low sodium intake group (p < 0.05), positively correlated with salty taste preference (r = 0.3866, p < 0.05) in subjects with daily zinc intake below the EAR. We conclude that low zinc status may be related to high salty taste preference and high blood pressure in Korean young adults.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.562-568
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• 1998

Various diagnostic methods, such as electric pulp test, cold test, test cavity etc., have been used to determine the pulp vitality. At least two or more methods should be used with supplemental information to diagnose each case because using one method doesn't provide sufficient accuracy. These conventional methods have depended on nervous responses, but Laser Doppler Flowmeter determines the pulp vitality by measuring pulpal blood flow. In this case, we tested the vitality of the traumatized teeth with incomplete root apices and autotransplanted teeth with conventional methods and Laser Doppler Flowmeter. Conventional methods, such as electric pulp test and cold test can produce various responses according to the development state of the pulpal nerve and the sensory threshold of the patient. But, Laser Doppler Flowmeter has a lower false response rate than any other pulp vitality test methods and it can determine the vitality somewhat earlier than the other method.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.711-716
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• 2012

The purpose of this study was to investigate how the modulation method affects the effectiveness of eliciting tactile sensations by electrical stimulation. Two methods were employed and the results were compared and analyzed; pulse amplitude modulation (PAM) and pulse width modulation (PWM). Thirty-five healthy subjects participated in the experiments to measure the stimulation intensity that began to elicit a tactile sensation - activation threshold (AT). Constant-current monophasic rectangular pulse trains were employed, and the stimulation intensity was varied from zero until the subject felt any uncomfortable sensation. The step size of the stimulation intensity was 100nC/pulse. After each experiment, the subject described the sensation both quantitatively and qualitatively. The two modulation methods did not make a significant difference as far as the AT values were concerned, but most of the subjects showed 'intra-individual' consistency. Also, it was confirmed that our range of the stimulation parameters enabled us to obtain three major tactile sensations; tickling, pressure and vibration. The results suggested that the stimulation parameters and the modulation type should be selected for each individual and that selective electrical stimulation of the mechanoreceptors needs more diversified researches on the electrode design, multi-channel stimulation protocol, waveforms of the pulse train, etc.

• Safety and Health at Work
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• v.2 no.4
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• pp.355-364
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• 2011

Objectives: Though sulfur dioxide (SO2) is used widely at workplaces, itseffects on humans are not known. Thresholds are reportedwithout reference to gender or age and occupational exposure limits are basedon effects on lung functioning, although localized effects in the upper airways can be expected. This study's aim is to determine thresholds with respect to age and gender and suggests a new approach to risk assessment using breathing reflexes presumably triggered by trigeminal receptors in the upper airways. Methods: Odor thresholds were determined by the ascending method of limits in groups stratified by age and gender. Subjects rated intensities of different olfactory and trigeminal perceptions at different concentrations of $SO_2$. During the presentation of the concentrations, breathing movements were measured by respiratory inductive plethysmography. Results: Neither age nor gender effects were observed for odor threshold. Only ratings of nasal irritation were influenced bygender. A benchmark dose analysis on relative respiratory depth revealed a 10%-deviation from baseline at about 25.27 mg/$m^3$. Conclusion: The proposed new approach to risk assessment appearsto be sustainable. We discuss whether a 10%-deviation of breathingdepth is relevant.