• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.43-47
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• 2018

Traditional electroencephalography (EEG)-based authentication systems generally use external stimuli that require user attention and relatively long time for authentication. The aim of this study is to investigate the feasibility of biometric authentication based on EEG without using any external stimuli. Seventeen subjects took part in the experiment and their EEGs were measured while repetitively closing and opening their eyes. For identifying each subject, we calculated inter- and intra-subject cross-correlation using changes in alpha activity (8-13 Hz) during eyes closed as compared to eyes open. In order to optimize the number of recording electrodes, we calculated authentication accuracy by progressively reducing the number of electrodes used in the analysis. Significant increase in alpha activity was observed for all subjects during eyes closed, focusing on occipital areas, and spatial patterns of changed alpha activity were considerably different between the subjects. A mean authentication accuracy of 92.45% was obtained, which was retained over 75% when using only 8 electrodes placed around occipital areas. Our results could demonstrate the feasibility of the proposed novel authentication method based on resting state EEGs.

• Archives of Pharmacal Research
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• v.29 no.4
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• pp.310-317
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• 2006

We investigated the effects of trinitrobenzene sulfonic acid (TNBS), an amino-group reagent, on the human ether-a-go-go-related gene (HERG) $K^+$ channels expressed in Xenopus oocytes. TNBS neutralizes the positively charged amino-groups of peptide N-terminal and lysine residues. External application of TNBS at 10 mM for 5 min irreversibly shifted the curves for currents at the end of the pulse and tail currents of HERG to a more negative potential and decreased the maximal amplitude of the $I_{tail}$ curve $(I_{tail,max})$. TNBS had little effect on either the activated current-voltage relationship or the reversal potential of HERG current, indicating that TNBS did not change ion selectivity properties. TNBS shifted the time constant curves of both activation and deactivation of the HERG current to a more hyperpolarized potential; TNBS's effect was greater on channel opening than channel closing. External $H^+$ is known to inhibit HERG current by shifting $V_{1/2}$ to the right and decreasing $I_{tail,max}$. TNBS enhanced the blockade of external $H^+$ by exaggerating the effect of $H^+$ on $I_{tail,max}$, not on $V_{1/2}$. Our data provide evidence for the presence of essential amino-groups that are associated with the normal functioning of the HERG channel and evidence that these groups modify the blocking effect of external $H^+$ on the current.

• Safety and Health at Work
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• v.13 no.2
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• pp.141-147
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• 2022

Background: On the basis of its role for the development of occupational health research, information, good practices, the International Commission on Occupational Health (ICOH) launched the present survey to collect information on public health and prevention policies put in place by the governments of the countries in the world to contain the pandemic. Methods: A cross-sectional study was conducted through an online questionnaire focused on COVID-19 data, public health policies, prevention measures, support measures for economy, work, and education, personal protective equipment, intensive care units, contact tracing, return to work, and the role of ICOH against COVID-19. The questionnaire was administered to 113 ICOH National Secretaries and senior OSH experts. Collected data refer to the period ranging from the beginning of the pandemic in each country to June 30, 2020. Results: A total of 73 questionnaires from 73 countries around the world were considered valid, with a 64.6% response rate. Most of the respondents (71.2%) reported that the state of emergency was declared in their country, and 86.1% reported lockdown measures. Most of the respondents (66.7%) affirmed that the use of face masks was compulsory in their country. As for containment measures, 97.2% indicated that mass gatherings (meetings) were limited. Regarding workplace closing, the most affected sector was entertainment (90.1%). Conclusion: The results of this survey are useful to gain a global view on COVID-19 policy responses at country level.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.4
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• pp.289-294
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• 2022

Background: Orofacial pain is defined as pain felt in the soft or hard tissues of the head, face, mouth, and neck. Chronic orofacial pain is often challenging to diagnose and difficult to treat. Due to the lack of available information about the prevalence and clinical form of orofacial pain, this study aimed to evaluate the characteristics of chronic orofacial pain in patients presenting at the Department of Oral Medicine of Shahid Beheshti Dental School between 2012 and 2022. Methods: In this retrospective study, we evaluated the files of 121 patients at the Department of Oral and Maxillofacial Diseases of Shahid Beheshti Dental School, which were completed during 2012-2022. We extracted the required information from these files. Results: In total, 121 files were included in the study (30 male, 91 female). The mean age of the patients was 43.68 ± 16.79 years. The most common diagnosis in patients with chronic orofacial pain was temporomandibular disorders (TMD) (55.3%). Among pain-related factors, psychological factors showed the highest frequency (30.5%). Opening and closing (43.8%) had the highest frequency among factors that increased pain, and the rest (6.6%) had the highest frequency among the factors that reduced pain. Most patients experienced unilateral pain over the masseter area. Most patients reported their pain intensity to be greater than 7 in the verbal analog scale (VAS). The most common symptom associated with pain was joint noise (37.1%). Conclusion: A ten-year retrospective evaluation of patient files showed that more than half of the patients with chronic orofacial pain had TMD.

• Journal of Preventive Medicine and Public Health
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• v.28 no.3 s.51
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• pp.563-575
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• 1995

In order to investigate the prevalence and the factors related to the depression and burnout among private practice physicians, a SDS(self-rating depression scale) and MBI(Maslach burnout inventory) -based questionnaire study was performed on 344 private practice physicians in Kwangju and Chonnam area. The results were summarized as follows. 1. Mean SDS score was 38.3 in total subjects and the prevalence rate of depression was 48.8%. As for the frequency order of the items of the SDS, decreased libido, diurnal variation and hopelessness were relatively high, and suicidal rumination, constipation and agitation were noted low. 2. Noticeable factors related with depression were smoking, coffee use, sleeping time and satisfaction with income. 3. As a result a factor analysis with the MBI data, five factors named as emotional exhaustion, depersonalization, personal accomplishment, involvement and self-interest were extracted. Statistical analysis of the data demonstrated that 48.8% of the physician sample reported high scores on emotional exhaustion, and 45.3% scored high on depersonalization. Personal accomplishment scores remained high with 45.3% reporting high personal accomplishment. 4. Variables related to the burnout were age, sleeping time, family size religion, medical speciality, duration of practice setting, visiting patient number, closing day per month and job satisfaction. 5. In the relationship with depression, burnout was closely related to depression. Above results showed that the high percentage of private practice physicians experiencing depression and burnout suggests the need for further research to establish trends, to identify causal factors, and to develop avenues to reduce stress.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.659-663
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• 2000

The motality rate of acute subdural hematoma(ASDH) associated with closed head injury is high in spite of recent advances in neurosurgery. Many variables in regard to outcome of ASDH have been assessed. But among them, intracranial pressure(ICP) control and the time interval between injury and operative evacuation are the only things that can be affected by doctor. We introduced a simple method to the management of ASDH for reducing the time interval between injury and operation. When the immediate decompressive operation of ASDH was impossible by any causes, we made a burr hole at the center of hematoma, usually on 2-3cm above temporal squama and 1-2cm behind coronal suture under local anesthesia before main operation. Partial hematoma evacuation was achieved through the burr hole and it was effective in preventing further worsening of patients neurological status before main operation. Prompt hematoma evacuation through the burr hole seemed to be effective in delaying secondary ischemic brain damage and made easy to closing the dura opening and replacement of the bone flap at the end of main decompressive operation. This easy method may reduce the time interval between injury and operation. We represent surgical technique with two cases of ASDH managed with this simple method.

• Clinical and Experimental Pediatrics
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• v.56 no.4
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• pp.176-181
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• 2013

Purpose: Apical muscular ventricular septal defects (MVSDs), especially in small infants, can be difficult to manage using surgical and percutaneous closure. An intraoperative perventricular procedure is a good option for closing apical MVSDs in small children with or without associated cardiac anomalies. We evaluated the results of hybrid perventricular closure of apical MVSDs performed using an Amplatzer duct occluder (ADO). Methods: We retrospectively reviewed the medical records of 5 patients who underwent hybrid perventricular closure of MVSDs with ADOs, from March 2006 to May 2011. The median patient age at the time of the procedure was 12 months (range, 25 days to 25 months), and the median body weight was 9.1 kg (range, 4.3 to 15 kg). Two patients had multiple ventricular septal defects (VSDs; additional perimembranous VSD in 1 patient and multiple MVSDs in the other) and 3 patients had associated cardiac anomalies; complete transposition of the great arteries in 1 patient and an atrial septal defect in 2 patients. All the procedures were performed on beating hearts, exception in 1 case. The ADO selected for the aortic side was at least 1 to 2 mm larger than the largest VSD in the left ventricle side. Results: The procedure was successful in all patients and each device was well positioned. During the median follow-up of 2.4 years, a small residual VSD was noted in 2 patients who had multiple VSDs and no leakage was seen in the other 3 patients. Conclusion: Perventricular closure of MVSD with an ADO is a good option for patients with apical MVSD. However, careful manipulation is important, especially in the case of small infants.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.271-279
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• 1985

The authors treated a case of bimaxillary dentoalveolar protrusion corrected by anterior segmental osteotomies: As presurgical treatment & process, closing of the upper anterior spacing with fixed appliances was worked out, cephalometric predicition & model surgery was done, and fabrication of intra-arch acrylic resin splints were made. It was not necessary to make an intermaxillary fixation with wire after surgery. Only intramaxillary fixation of anterior retracted mobile segment with resin plate was required for 8 weeks. After surgical treatment, leveling of the upper and lower arch with rectangular arch wire were accomplished as the Intrusion of anterior teeth proceeded. We will continue to improve the class II molar relationship by using class II elastics and have a good occlusiion through the orthodontic treatment.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.627-637
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• 2020

Purpose: This experimental study was conducted to find out whether a water-mist fire suppression system can be applied to C.E.P., a representative combustible material of a rack storage. Method: First, it was confirmed whether the water-mist fire-extinguishing system used in this experiment was capable of extinguishing oil fires. After that, the C.E.P. boxes were loaded in the same small space as used in the oil fire experiment, and then the experiment was conducted on three scenarios; door opening, door closing, and door closing and increasing the internal load. The scenario was set considering the opening and space size conditions, which are important factors for the water-mist fire suppression. Result: Oil fire suppression tests have shown that fires are well extinguished in both the door open and closed conditions. In case of a fire of C.E.P. boxes in the same space condition as an oil fire, the fire was not extinguished in the door open condition. Fires were extinguished in the case with the door closed condition, but the afterglow was confirmed. Conclusion: In the oil fire suppression test, a water-mist fire suppression system extinguished a fire in both the door open and closed conditions. However, for the C.E.P fire, it was possible to extinguish only under the door closed condition, and there was a possibility of re-ignition.

• Journal of Life Science
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• v.34 no.6
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• pp.426-433
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• 2024

The environmental stress that plants are most susceptible to is water stress. Abscisic acid (ABA) is a plant hormone synthesized by plants to counteract environmental stress. The role of stomata in plants is to allow the synthesis of sucrose by absorbing CO₂, which greatly affects photosynthetic activity. In addition, stomata are pathways for transpiration, which releases H₂O and help establish a water potential gradient that allows plant roots to continuously absorb water and inorganic substances from the soil. Plants have a mechanism to minimize water loss by closing their stomata when exposed to water-stressed environments. The most well-studied hypothesis concerning the mechanism of stomatal closure is the response to water stress. When a plant receives sufficient water, its stomata open during the day and close at night due to its circadian rhythm. In addition, stomatal closure occurs when the concentration of CO₂ in the intercellular space increases. However, the mechanism of stomatal closure due to circadian rhythm and increased CO₂ concentration in the intercellular space is not well understood. When plants undergo water stress, the increased concentration of ABA in the guard cell cytoplasm induces an increase in Ca²⁺ concentration, resulting in cytoplasmic depolarization. As a result, the outward K⁺-channel of the tonoplast and the slow-type anion channels SLAC1 and SLAH3 are activated, releasing K⁺, Cl^-, and malate^2-, causing the stomata to close. Therefore, in this paper, the mechanism of stomatal closure caused by water stress was investigated.