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Laser-accelerated metallic flyers can be used in microscale manufacturing processes by providing high-speed impact and shockwave to target materials. This study conducted microscale punching experiments using a laser-accelerated flyer for various mold sizes, workpiece thicknesses, and flyer thicknesses to investigate performance and failure characteristics of the punching process. In the case of a single flyer impact, punching was successful when the ratio of mold diameter to workpiece thickness exceeded 3. High-speed punching advantages, which improve punching quality as the shear zone increases and burrs become smaller, were validated. When flyer thickness was significantly reduced, punching performance deteriorated although higher speed could be realized, because the thinner flyer was difficult to maintain flatness during acceleration, resulting in inefficient forming pressure transfer to the workpiece. When the ratio of mold diameter to workpiece thickness was less than 3, punching was achieved through multiple flyer impacts. However, pressure transfer efficiency from the flyer to the workpiece was further reduced. Thus, punching performance could be improved by reducing the relative size of the flyer to the mold diameter.

Background/Aims Endoscopic submucosal dissection (ESD) has been an established treatment for indicated early gastric cancer (EGC) without deterioration of quality of life (QOL) compared with surgical resection. The aim of this study was to evaluate long-term QOL in patients undergoing ESD for EGC. Methods Patients scheduled to undergo curative ESD for EGC were prospectively enrolled from 12 institutions between May 2010 and December 2011. Assessments of QOL with Korean versions of the European Organization for Research and Treatment of Cancer (EORTC) QOL questionnaire-core (QLQ-C30) and a gastric cancer-specific questionnaire (STO22) were performed at baseline and at 7 days, 3 months, and 6 months after ESD. Results A total of 666 subjects were assessed for QLQ-C30 and QLQ-STO22. The mean QLQ-C30 score was 69.5 at baseline, 68.8 at 7 days, 73.1 at 3 months, and 73.2 at 6 months. The global health status on the EORTC QLQ-C30 was significantly improved after 3 and 6 months (p=0.0003 and p

Background/Aims Endoscopic submucosal dissection (ESD) is an effective treatment for early gastric cancer (EGC) that has demonstrated a minimal risk of lymph node metastasis in retrospective studies. We sought to prospectively evaluate the short-term outcomes of ESD treatment in EGCs. Methods A prospective multicenter cohort study of neoplasms 3 cm or less in diameter at endoscopic size evaluation was performed in 12 Korean ESD study group-related university hospitals and the National Cancer Center. Resected specimens were evaluated by the central pathologic review board. Results A patient cohort (n=712) with a total of 737 EGCs was analyzed. The margin-freeen bloc resection rate was 97.3%, and curative resection of 640 lesions (86.8%) was achieved. Lower curative resection rates were associated with lesions 2 to 3 cm in size prior to ESD compared with lesions 2 cm or less in size (78.6% vs 88.1%, respectively, p=0.009). Significant factors associated with noncurative resection were moderately or poorly differentiated histological type, posterior wall tumor location, tumor size larger than 3 cm, ulceration, and submucosal invasion. Delayed bleeding occurred in 49 patients (6.9%), and 12 patients (1.7%) exhibited perforations. Conclusions ESD is an effective treatment with a high curative resection rate for EGCs that meets relatively conservative pre-ESD indications. Long-term survival outcomes should be evaluated in follow-up studies.

Purpose The diagnostic criteria of gastric intraepithelial neoplasia (IEN) are controversial across the world. We investigated how many discrepancies occur in the pathologic diagnosis of IEN and early gastric carcinoma in endoscopic submucosal dissection (ESD) specimens, and evaluated the reasons of the discordance. Materials and methods We retrospectively reviewed 1,202 ESD specimens that were originally diagnosed as gastric IEN and early carcinoma at 12 institutions. Results The final consensus diagnosis of carcinoma were 756 cases, which were originally 692 carcinomas (91.5%), 43 high-grade dysplasias (5.7%), 20 low-grade dysplasias (2.6%), and 1 others (0.1%), respectively. High- and low-grade dysplasia were finally made in 63 and 342 cases, respectively. The diagnostic concordance with the consensus diagnosis was the highest for carcinoma (91.5%), followed by low-grade dysplasia (86.3%), others (63.4%) and high-grade dysplasia (50.8%). The general kappa value was 0.83, indicating excellent concordance. The kappa values of individual institutions ranged from 0.74 to 1 and correlated with the proportion of carcinoma cases. The cases revised to a final diagnosis of carcinoma exhibited both architectural abnormalities and cytologic atypia. The main differential points between low- and high-grade dysplasias were the glandular distribution and glandular shape. Additional features such as the glandular axis, surface maturation, nuclear stratification and nuclear polarity were also important. Conclusion The overall concordance of the diagnosis of gastric IEN and early carcinoma in ESD specimens was excellent. It correlated with the proportion of carcinoma cases, demonstrating that the diagnostic criteria for carcinoma are more reproducible than those for dysplasia.

Background The present multicenter retrospective study aimed to compare the outcome of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) among Korean patients with symptomatic extracranial carotid stenosis. Methods Between January 2008 and December 2011, 677 patients underwent either CAS (346, 51.1%) or CEA (331, 48.9%). The primary end point included the occurrence of major adverse cardiovascular events (MACEs), defined as fatal or nonfatal stroke and myocardial infarction, and all-cause mortality during the periprocedural period and within 4 years after CAS or CEA. Results Although patients undergoing CAS and CEA did not differ significantly in MACE incidence within 4 years (15.3% vs. 11.5%, P = 0.14), CEA showed lower periprocedural MACE incidence than CAS with clinical significance (6.1% vs. 3.0%, P = 0.06). During the periprocedural period, the incidence of any stroke was significantly higher in patients undergoing CAS (5.5% vs. 2.4%, P = 0.04) but not the incidence of myocardial infarction (0.6% vs. 0.3%, P > 0.99). Kaplan–Meier survival analysis showed similar MACE-free (P = 0.16), stroke-free (P = 0.24), and overall survival (P = 0.25) rates in both groups. On subgroup analysis, patients older than 70 years undergoing CAS had a significantly higher incidence of MACE at 4 years (22.7% vs. 13.7%, P = 0.03). Conclusions Although the risk of MACE did not differ significantly within 4 years in this Korean population undergoing CAS and CEA, there was a higher risk of stroke with CAS during the periprocedural period.

Background Discrepancies in the clinicopathologic parameters pre- and post-endoscopic submucosal dissection (ESD) sometimes necessitate additional surgical resection. The aim of this study was to assess such discrepancies in clinicopathologic parameters before and after ESD in the context of reducing the risk of failure of curative ESD. Methods Data on 712 early gastric cancer patients were prospectively collected from 12 university hospitals nationwide. The inclusion criteria were differentiated carcinoma

The present study compared event-related potential (ERP) patterns for two stimuli types, puff and suction, by applying these stimuli to the fingers; ERP patterns for the two stimuli were compared at C3, an area related to somatosensory perception, and at FC5, an area related to motor function. Participants were 12 healthy males in their 20s (mean age=23.1±2.0 years). One session consisted of a Control Phase (3s), a Stimulation Phase (3s), and a Rest Phase (9s). During the Stimulation Phase, a 4-psi suction or puff stimulus was applied to the first joint of the right index finger. After completion of the session, a subjective magnitude test was presented. In all phases, electroencephalography signals were recorded. We extracted maximum positive amplitude and minimum negative amplitude as well as relevant latency values for C3 and FC5 signals. Suction and puff stimuli had similar subjective magnitude scores. For both C3 and FC5, the maximum and minimum amplitude latency was reached earlier for the suction stimulus than for the puff stimulus. In conclusion, when suction and puff stimuli of the same intensity were applied to the fingers, the suction stimulus caused a more sensitive response in the somatosensory area (C3) and motor area (FC5) than did the puff stimulus.

Context Robotic partial nephrectomy (RPN) is rapidly increasing; however, the benefit of RPN over laparoscopic partial nephrectomy (LPN) is controversial. Objective To compare perioperative outcomes of RPN and LPN. Evidence acquisition We searched Ovid-Medline, Ovid-Embase, the Cochrane Library, KoreaMed, KMbase, KISS, RISS, and KisTi from their inception through August 2013. Two independent reviewers extracted data using a standardized form. Quality of the selected studies was assessed using the methodological index for nonrandomized studies. Evidence synthesis A total of 23 studies and 2240 patients were included. All studies were cohort studies with no randomization, and the methodological quality varied. There was no significant difference between the two groups regarding complications of Clavien-Dindo classification grades 1–2 ( p =0.62), Clavien-Dindo classification grades 3–5 ( p =0.78), change of serum creatinine ( p =0.65), operative time ( p =0.35), estimated blood loss ( p =0.76), and positive margins ( p =0.75). The RPN group had a significantly lower rate of conversion to open surgery ( p =0.02) and conversion to radical surgery ( p =0.0006), shorter warm ischemia time (WIT; p =0.005), smaller change of estimated glomerular filtration rate (eGFR; p =0.03), and shorter length of stay (LOS; p =0.004). Conclusions This meta-analysis shows that RPN is associated with more favorable results than LPN in conversion rate to open or radical surgery, WIT, change of eGFR, and shorter LOS. To establish the safety and effectiveness outcomes of robotic surgery, well-designed randomized clinical studies with long-term follow-up are needed. Patient summary Robotic partial nephrectomy (PN) is more favorable than laparoscopic PN in terms of lower conversion rate to radical nephrectomy, a favorable renal function indexed estimated glomerular filtration rate, shorter length of hospital stay, and shorter warm ischemia time.

In this study, a tactile stimulator that could separately or simultaneously display the vibrotactile and pressure sense was developed. The developed system consisted of a control unit, a drive unit, and an actuator, and can be operated with PC or manually. This system quantitatively controls the stimulation parameters such as the stimulation intensity, duration, frequency, and stimulation type. A preliminary electroencephalogram (EEG) experiment for three types of stimulation (vibrotactile, pressure sense, vibrotactile + pressure sense) highlights that the system could be used in complex tactile cognitive studies. An event-related desynchronization (ERD) and synchronization (ERS) were measured at the area of C3 and C4 for all three types of stimulation, and a clear response was identified in the contralateral somatosensory area from the brain topology. Therefore, it is expected that this system could be widely used in single and complex human tactile cognition and perception studies for vibrotactile and pressure sensation.

This study investigated neuronal activation differences under two conditions: driving only and distracted driving. Driving and distraction tasks were performed using a Magnetic Resonance (MR)-compatible driving simulator with a driving wheel and pedal. The experiment consisted of three blocks, and each block had both a Rest phase (1 min) and a Driving phase (2 min). During the Rest phase, drivers were instructed to simply look at the stop screen without performing any driving tasks. During the Driving phase, each driver was required to drive at 110 km/h under two conditions: driving only and driving while performing additional distraction tasks. The results show that the precuneus, inferior parietal lobule, supramarginal gyrus, middle frontal gyrus, cuneus, and declive are less activated in distracted driving than in driving only. These regions are responsible for spatial perception, spatial attention, visual processing and motor control. However, the cingulate gyrus and sub-lobar regions (lentiform nucleus and caudate), which are responsible for error monitoring and control of unnecessary movement, show increased activation during distracted driving compared with driving only.

The aim of this study was to investigate the effect of inhalation of Salvia sclarea (clary sage; clary) or Lavandula angustifolia (lavender) essential oil vapors on autonomic nervous system activity in female patients with urinary incontinence undergoing urodynamic assessment. STUDY DESIGN, LOCATION, AND SUBJECTS: This study was a double-blind, randomized, controlled trial carried out in 34 female patients with urinary incontinence.The subjects were randomized to inhale lavender, clary, or almond (control) oil at concentrations of 5% (vol/vol) each. Systolic blood pressure, diastolic blood pressure, pulse rate, respiratory rate, and salivary cortisol were measured before and after inhalation of these odors for 60 minutes.The clary oil group experienced a significant decrease in systolic blood pressure compared with the control (p=0.048) and lavender oil (p=0.026) groups, a significant decrease in diastolic blood pressure compared with the lavender oil group (p=0.034) and a significant decrease in respiratory rate compared with the control group (p0.001). In contrast, the lavender oil group tended to increase systolic and diastolic blood pressure compared with the control group. Compared with the control group, inhalation of lavender oil (p=0.045) and clary oil (p0.001) resulted in statistically significant reductions in respiratory rate.These results suggest that lavender oil inhalation may be inappropriate in lowering stress during urodynamic examinations, despite its antistress effects, while clary oil inhalation may be useful in inducing relaxation in female urinary incontinence patients undergoing urodynamic assessments.

A new Real-Time Subjective Emotionality Assessment (RTSEA) system was developed for this study. The system is composed of two parts: an emotionality input and evaluation parts. An experiment was conducted in order to investigate the effectiveness of the RTSEA system. The present study compared Galvanic Skin Response (GSR) with the RTSEA by presenting 28 subjects with pictures that aroused either positive or negative emotion. Following the experiment, a subjective assessment using a questionnaire was given to the same subjects. According to the correlation coefficients, changes of the RTSEA had strong correlations with the changes of the GSR. Also, the questionnaire results showed marked similarity to the average responses of the RTSEA. In conclusion, the most remarkable characteristic of the present system is that it not only assesses the average emotionality when stimuli are presented, but also shows the trend of change in emotionality over time.

This study aimed to investigate the hypothesis that administration of the air with 30% oxygen compared with normal air (21% oxygen) enhances verbal cognitive functioning through increased activation in the brain. Nine male college students participated in the study. The experiment consisted of two runs, one for verbal cognition task with normal air (21% oxygen) and the other for verbal cognition task with hyperoxic air (30% oxygen). Functional brain images were taken with a 3T MRI using the single-shot EPI method. From the results of the verbal behavioral analysis, the accuracy rate was enhanced with 30% oxygen administration when compared to 21% oxygen. The activities were observed at the occipital, parietal, temporal and frontal lobes during both 21% and 30% oxygen administration. There were more activations observed at the right middle frontal gyrus, right inferior frontal gyrus, right superior frontal gyrus, cingulate gyrus, left middle temporal gyrus, and left fusiform gyrus with 30% oxygen administration. These results suggest that a higher concentration of breathed oxygen increases saturation of blood oxygen in the brain, and facilitates verbal performance.

This study investigated the effects of 30% oxygen administration on visuospatial cognitive ability using time course data analysis of fMRI. A visuospatial task was presented while brain images were scanned by a 3T MRI system. The results showed that there was an improvement in performance and also increased BOLD intensity in the parietal lobe in the higher oxygen condition. There was positive relation between behavior performance and BOLD intensity in the right parietal lobe. This result supports the conclusion that the increase in the cognitive processing ability due to highly concentrated oxygen can be explained by the increase in the BOLD intensity.

The present study tried to investigate the simulator sickness objectively by observing the change of the simulator sickness for the different level of sickness groups (sick and non-sick group). The subjective evaluations using Simulator Sickness Questionnaire (SSQ) and physiological responses were measured every five minutes when they were driving as 60km/h in the driving graphic simulator. Response level of the subjective evaluation for all subjects on the simulator sickness was linearly increased with time for every item, and the response level of sick group was bigger than that of non-sick group. When the analysis on central nervous system was done separately on the sick and the non-sick group, there was significant difference in the parameter ϑ/total at Fz and Cz. Although the analysis on autonomic nervous system for all subjects showed the increased activation of sympathetic nervous system, there was no significant difference between the sick and non-sick group.

This study investigated the effect of 30% oxygen administration on memory cognitive performance, blood oxygen saturation, and heart rate. Ten healthy male and female college students participated in the study. The experiment consisted of two runs: one was a memory task, with normal air (21% oxygen) administered and the other was with hyperoxic air (30% oxygen) administered. The experimental sequence in each run consisted of Rest (1 min), Control Task (1 min), Word Presentation (1 min), Reaction Time Task (1 min), Distractor (2 min), and Word Recall (1 min). Blood oxygen saturation and heart rate were measured throughout the six phases. The results of the memory performance analysis reveal that word recall rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased and heart rate was decreased compared to that with 21% oxygen administration. This result supports the hypothesis that 30% oxygen administration would lead to increases in memory performance.

This study investigated the effect of 30% oxygen administration on visuospatial cognitive performance, blood oxygen saturation, and heart rate. Six male (25.8±1.0 years) and six female (23.8±1.9 years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of visuospatial cognition. The experiment consisted of two runs: one was a visuospatial cognition task, with normal air (21% oxygen) administered and the other was with hyperoxic air (30% oxygen) administered. The experimental sequence in each run consisted of Rest1 (1 min), Control (1 min), Task (4 min), and Rest2 (4 min). Blood oxygen saturation and heart rate were measured throughout the four phases. The results of the visuospatial behavioural analysis reveal that accuracy rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased and heart rate was decreased compared to that with 21% oxygen administration. It can be concluded that, during cognitive processing, 30% oxygen administration increased blood oxygen saturation and had a positive effect on visuospatial cognitive performance.

The study was done to check replication of changes in sensitivity with a simple simulator as had been obtained in an experiment using the real road situation. Another purpose was to control simulator sickness which could have confounded data from testing with a simulator or in actual driving. Sensitivity of the drivers (72 healthy young adults, M age=24 yr., SD=5) while performing the driving task was measured in terms of subjective ratings of simulator sickness and affect, and physiological measures (i.e., galvanic skin responses and skin temperature) at different driving speeds and in driving mode conditions, using a simple vehicle simulator. Analysis showed measures of drivers' state, including simulator sickness, physiological indices, and subjective reports, increased with driving speed (30→90→120 km/hr.) and driving mode change from the regular speed to sudden increasing to sudden decreasing speeds. Particularly, the results suggest that the increased autonomic nervous activation induces increase of rated simulator sickness. Based upon the same tendency in change of the simulator sickness and physiological state with driving speed and driving mode conditions, it was concluded that, if the results obtained from the simulator experiment can be generalized to the real situation, the simulator sickness must be considered a confounding factor. The results also suggest that the changes in human sensitivity are dependent upon aspects related to speed of a vehicle and driving mode.

This study aimed to investigate the hypothesis that a transient increase in oxygen level administered to subjects increases the BOLD effect in brain regions associated with verbal cognitive functioning and enhances performance accuracy. A verbal task was presented while brain images were scanned by a 3T fMRI system. The accuracy rate on the verbal task was enhanced during 30% oxygen administration compared to 21% oxygen administration. The neural activations were observed at the occipital, parietal, temporal and frontal lobes, during both 21% and 30% oxygen administration. Increased brain activations were observed in the right middle frontal gyrus, right inferior frontal gyrus, right superior frontal gyrus, cingulate gyrus, left middle temporal gyrus, and left fusiform gyrus with 30% oxygen administration. These results suggest that a higher concentration of breathed oxygen increases saturation of blood oxygen in the brain, and facilitates verbal cognitive performance.