No abstract available.
Fires ; Open Access Publishing

PURPOSE: The aim of this study was to investigate the effect of different numbers of heat treatments applied to superstructure porcelain on optical, thermal, and phase formation properties of zirconia.MATERIALS AND METHODS: Forty zirconia specimens were prepared in the form of rectangular prism. Specimens were divided into four groups (n = 10) according to the number of firing at heating values of porcelain. Color differences and translucency parameter were measured, and X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC) were performed. Data were analyzed with analysis of variance (ANOVA).RESULTS: There were no statistically significant differences in ΔE, TP, L, a, and b value changes of the zirconia specimens as a result of repetitive firing processes (P>.05).CONCLUSION: Although additional firing processes up to 4 increase peak density in thermal analysis, additional firing processes up to 4 times can be applied safely as they do not result in a change in color and phase character of zircon frameworks.
Calorimetry, Differential Scanning ; Dental Porcelain ; Fires ; Heating ; Hot Temperature ; X-Ray Diffraction

PURPOSE: To characterize associated reactions (ARs) in the contralateral arm across multiple muscles during unimanual tasks and to identify factors related to ARs in children with cerebral palsy (CP).MATERIALS AND METHODS: This was a prospective, cross-sectional study of 35 children with CP. The extent of ARs of the contra-lateral, non-task hand was assessed while performing three unimanual tasks (opening and clenching the fist, a finger opposition task, and tapping fingers). The occurrence of ARs in each trial was evaluated separately for each task using a four-point scale (total scores ranged from 0 to 12). Surface electromyography (SEMG) was used to measure the firing activity of the muscles of the opposite arm during the task. The Manual Ability Classification System and Melbourne Assessment 2 (MA-2) were used to evaluate upper limb function.RESULTS: AR scores were higher in the more-affected limb than in the less-affected limb. SEMG data on the non-task hand showed motor overflow up to the elbow muscles in the more-affected limb. Root mean square ratios of EMG signals were significantly higher in children with ARs than in children without ARs. Multiple regression analysis showed both age and MA-2 to be significant factors related to ARs in the more-affected limb.CONCLUSION: Children with visible ARs showed motor overflow in the non-task limb during unimanual hand tasks. Age and upper limb function were significantly related to the extent of ARs in the more-affected limb of children with CP.
Arm ; Cerebral Palsy ; Child ; Classification ; Cross-Sectional Studies ; Elbow ; Electromyography ; Extremities ; Fingers ; Fires ; Hand ; Humans ; Muscles ; Prospective Studies ; Upper Extremity

Cotinine ; Daegu ; Firefighters ; Fires ; Humans ; Male ; Sensitivity and Specificity ; Smoke ; Smoking ; Tobacco Use

PURPOSE: The Iri station explosion that occurred in 1977 was a major social disaster in Korea, caused by a fire in a train equipped with explosives. The purpose of this study was to investigate the social disaster adaptation experiences of railroad workers. METHODS: This study was based on qualitative research using phenomenological methodology. Participants were six railroad workers who experienced the Iri station explosion. Data were collected through in-depth interviews with individual workers from March to June, 2018. The data analysis method was based on Colaizzi's approach. RESULTS: Experiences of railroad workers were categorized into 12 themes and the following 6 theme clusters: (1) Anxiety due to the extreme vibration and crash, (2) Terror regarding the horrible situation that one cannot face, (3) Anger about the cause of the explosion and a sense of relief about survival, (4) Confusion regarding different rumors, (5) Various efforts to return to daily life, and (6) Trauma that continues to exist. CONCLUSION: The findings of this study recommend that railroad organizations and managers should pay attention to enhance disaster preparedness and develop organizational disaster coping guidelines for members. The results of this study can help us to better understand the various aspects of the Iri station explosion of 1977.
Anger ; Anxiety ; Disasters ; Explosions ; Explosive Agents ; Fires ; Korea ; Methods ; Qualitative Research ; Railroads ; Statistics as Topic ; Vibration

OBJECTIVE: This study examined the clinical characteristics of suicide attempters who exposed their suicidal intension to suggest an active intervention strategy for suicide prevention based on the regional emergency medical service system. METHODS: A prospective database of suicide attempters who visited the emergency department of Chungbuk National University Hospital between October 2013 and December 2017 was used. All of the adult patients who provided consent for the initial assessment for suicidal attempters were eligible, excluding cases with unknown exposure of suicidal intension. The primary and secondary endpoints were the risk factors affecting exposure to the suicidal intension and characteristics of the exposure group. The adjusted odds ratios (AORs) of exposure to suicidal attempts after adjusting for potential confounders was calculated. RESULTS: Of a total 1,035 suicidal attempters enrolled, 332 (32.1%) were included in the exposure group. The exposure group was more likely to have an educational level above high school and no religion, and have suicidal characteristics at night time (18:00–08:00), under the influence of alcohol, suicidal plan before 1 week, and suicidal method involving asphyxia (P<0.05). The exposure group was more likely to have no guardian (AORs, 1.46; 95% confidence interval [CI], 1.00–2.12), use methods involving asphyxia (AORs, 2.07; 95% CI, 1.46–2.91), and attempt suicide at night (18:00 to 08:00) (AORs, 1.38; 95% CI, 1.05–1.83) compared to the no exposure group. CONCLUSION: Models need to be established, where regional mental health welfare center, local government, fire headquarter, and tele-communication companies can participate in the implementation of an active intervention strategy.
Adult ; Asphyxia ; Chungcheongbuk-do ; Emergency Medical Services ; Emergency Service, Hospital ; Fires ; Humans ; Local Government ; Mental Health ; Methods ; Odds Ratio ; Prospective Studies ; Risk Factors ; Suicidal Ideation ; Suicide ; Suicide, Attempted

PURPOSE: To evaluate an effect of additional firing process after sintering of monolithic zirconia crown on marginal and internal fit through three-dimensional analysis. MATERIALS AND METHODS: Ten monolithic zirconia crowns were fabricated using titanium abutment model. Monolithic zirconia crowns were designed, milled, and sintered as a control group, and additional firing with coloring was performed as a test group. Three dimensional analysis were performed by using triple-scan protocol, and cross-section analysis on mesio-distal and disto-lingual section was evaluated to measure marginal and internal fitness. Then, three-dimensional surface difference on between two groups was evaluated (α=.05). RESULTS: There was statistically significant difference between the control group (32.0 ± 24.3 µm) and the test group (17.0 ± 10.8 µm) in the mesial axial wall (P < .02) and the control group (60.2 ± 24.3 µm) and the test group (71.8 ± 21.5 µm) in the distal axial wall (P < .01). There was no statistically significant difference at the remaining point. CONCLUSION: There was no statistical significance on the deviation of inner surface of crown according to firing number, and the results of both group were considered clinically acceptable.
Crowns ; Fires ; Titanium

Confirming the direct link between neural circuit activity and animal behavior has been a principal aim of neuroscience. The genetically encoded calcium indicator (GECI), which binds to calcium ions and emits fluorescence visualizing intracellular calcium concentration, enables detection of in vivo neuronal firing activity. Various GECIs have been developed and can be chosen for diverse purposes. These GECI-based signals can be acquired by several tools including two-photon microscopy and microendoscopy for precise or wide imaging at cellular to synaptic levels. In addition, the images from GECI signals can be analyzed with open source codes including constrained non-negative matrix factorization for endoscopy data (CNMF_E) and miniscope 1-photon-based calcium imaging signal extraction pipeline (MIN1PIPE), and considering parameters of the imaged brain regions (e.g., diameter or shape of soma or the resolution of recorded images), the real-time activity of each cell can be acquired and linked with animal behaviors. As a result, GECI signal analysis can be a powerful tool for revealing the functions of neuronal circuits related to specific behaviors.
Animals ; Behavior, Animal ; Brain ; Calcium Channels ; Calcium ; Carisoprodol ; Endoscopy ; Fires ; Fluorescence ; Ions ; Microscopy ; Neuronal Calcium-Sensor Proteins ; Neurons ; Neurosciences ; Statistics as Topic

Cordycepin exerts neuroprotective effects against excitotoxic neuronal death. However, its direct electrophysiological evidence in Alzheimer's disease (AD) remains unclear. This study aimed to explore the electrophysiological mechanisms underlying the protective effect of cordycepin against the excitotoxic neuronal insult in AD using whole-cell patch clamp techniques. β-Amyloid (Aβ) and ibotenic acid (IBO)-induced injury model in cultured hippocampal neurons was used for the purpose. The results revealed that cordycepin significantly delayed Aβ + IBO-induced excessive neuronal membrane depolarization. It increased the onset time/latency, extended the duration, and reduced the slope in both slow and rapid depolarization. Additionally, cordycepin reversed the neuronal hyperactivity in Aβ + IBO-induced evoked action potential (AP) firing, including increase in repetitive firing frequency, shortening of evoked AP latency, decrease in the amplitude of fast afterhyperpolarization, and increase in membrane depolarization. Further, the suppressive effect of cordycepin against Aβ + IBO-induced excessive neuronal membrane depolarization and neuronal hyperactivity was blocked by DPCPX (8-cyclopentyl-1,3-dipropylxanthine, an adenosine A₁ receptor-specific blocker). Collectively, these results revealed the suppressive effect of cordycepin against the Aβ + IBO-induced excitotoxic neuronal insult by attenuating excessive neuronal activity and membrane depolarization, and the mechanism through the activation of A₁R is strongly recommended, thus highlighting the therapeutic potential of cordycepin in AD.
Action Potentials ; Adenosine ; Alzheimer Disease ; Fires ; Ibotenic Acid ; Membranes ; Neurons ; Neuroprotection ; Neuroprotective Agents ; Patch-Clamp Techniques ; Pyramidal Cells

OBJECTIVES: In the developing auditory cortex, maturation of electrophysiological properties and cell types before and after hearing onset has been reported previously. However, the exact timing of firing pattern change has not been reported. In this study, firing pattern change was investigated from postnatal day 3 (P3) to P12 in auditory cortical layer II/III neurons to investigate whether firing pattern changes dramatically after a specific point during development. METHODS: ICR mice pups aged from P3 to P12 were sacrificed to obtain 300-mm-thick brain slices containing the primary auditory cortex. From cortical layer II/III neurons, the patterns of action potential firing generated by current injection were examined using whole cell current clamp technique and the characteristics of Na⁺ currents involved in action potential firing were investigated using whole cell voltage clamp technique. RESULTS: From P3 to P6, most cells did not show action potential firing (29 of 46 cells), and some cells responding to current injection showed a single action potential at the initial depolarizing current step (17 of 46 cells). This firing pattern changes from P7. From P7 to P9, cells begin to show regular spiking to current injection. The spiking frequency increased after P10. In studying Na⁺ current with whole cell voltage clamp, Na⁺ current densities increased gradually (32.0±2.0 pA/pF [P3–P6, n=7], 51.2±2.0 pA/pF [P7–P9, n=13], and 69.5±3.7 pA/pF [P10–P12, n=13]) in low external [Na⁺] condition. Na⁺ current recovery was accelerated and inactivation curves shifted to hyperpolarization with age. CONCLUSION: As regular spiking cells were observed from P7 but never from P3 to P6, P7 might be regarded as an important milestone in the development of auditory cortical layer II/III neurons. This change might mainly result from the increase in Na⁺ current density.
Action Potentials ; Animals ; Auditory Cortex ; Brain ; Fires ; Hearing ; Mice ; Mice, Inbred ICR ; Neurons