• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.385-396
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• 2001

The purpose of this experiment was to examine the histological changes and the pattern of expression of proliferating cell nuclear antigen(PCNA) and type I collagen in the elongated bone affected by osteodistraction of the mandibular body in an adult canine model. Seven adult male mongrel dogs weighing over 20kg were used for this experiment. The author excluded 3 animals because they died before the planned time of sacrifice. The custom-made linear extraoral device and 4 bicortical fixation screws 2.3mm in diameter, 50mm in total length, 15mm in screw length were used in each animal. The distal part of the distractor produced a 0.75mm gap between proximal and distal bony segments every $360^{\circ}$ turn of the rotation rod of the device. The mandibular body of the right side from each animal was experimental side and the left side was left intact and served as control. At the experimental side, the mandibular body was osteotomized. After 5-day latency period, the segments were distracted with a rate of 1.1mm/day and a rhythm of two/day for ensuing 7 days. The animals were sacrificed at the 4th. 17th, and 32th day after the end of the distraction. The bony specimens were decalcified, embedded in paraffin, sectioned $5{\mu}m$ thick and stained with Masson trichrome and examined under the light microscope. The immunohistochemical examinations using anti-PCNA antibody and anti-type-I collagen antibody were performed to examine the pattern of the expression of PCNA and type I collagen, respectively. Results : 1. The mean increment of the distance between the proximal and distal screw-holding parts of the distractor was 6.8mm. The average elongation of the mandible in the experimental side was 5.3mm. The loss of elongation was 1.5mm in average. 2. New bone was already observed at the 4th. day after the end of distraction. But, bony union was not completed in the distraction gap at the 32th. day after the end of distraction by radiographic and microscopic examinations. 3. The expression rate of PCNA positive cells in the distraction gap had a tendency of decrease from 35.1-68.8% initially, to 49.1%, and finally to 17.6-27.2%. But at the final period, the tissue of the elongated gap still had the ability of cell proliferation. On the other hand, the expression of PCNA positive cells in the control side were negligible through the experimental period. 4. PCNA positive cells were observed primarily both at the central fibrous zone and at the region of just adjacent to CFZ which initiated new bone formation. 5. The expression pattern of the type I collagen was not zone-specific. They were observed diffusely throughout the elongation gap. 6. The predominant mechanism of new bone formation in the distraction gap was intramembranous. But, some of the regenerated bone was formed by endochondral ossification.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.682-692
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• 2007

This study presents an automatic system to predict parturition time in the crated sows. The system relies on ultrasonic transducers mounted from above along the length of the crate. Using a 40 kHz time of flight (TOF) single envelope wave, the momentary distances between the sensors are measured. Therefore, the local momentary height of the sow and the momentary posture, i.e. standing posture (SDP), kneeling posture (KP), sitting posture (STP) and lateral lying posture (LLP) are determined. Crated sows change their postures from standing to lying and vice versa which follows a characteristic pattern. As parturition approaches, sows exhibit uneasiness, restlessness and the stand up sequence (SUS, the posture transition from LLP to SDP) rate increases because of labor pains. In time series, the SUS rate demonstrates a peak and it happens approximately 0-12 h before parturition. In this paper, the basic parturition threshold value method (BPTVM) and the same hour method (SHM) are proposed for predicting parturition, both of which are based on the SUS rate. The BPTVM mainly detects the peak of the SUS rate. As the SUS rate exceeds the threshold value, the parturition becomes predictable. Moreover, the SHM calculates the difference in the SUS rates between a particular time of day and the corresponding time of the preceding day. Compared to the BPTVM, the SHM can eliminate the circadian rhythm of the SUS rate influenced by feeding behavior. Using the SHM the parturition can be approximately predicted within hours. In an attempt to define the threshold parameters of predicting parturition, a data set with 32 sows of the SUS rate are used to estimate assumable predicting probability. The results show the assumable probability of the parturition prediction within 9 h is 96.9% for the SHM and 84.4% for the BPTVM. Moreover, the SHM can even reach a 75% probability of prediction within three hours of parturition. We conclude that the SHM is more accurate and is more useful for parturition time prediction. When parturition is detected, the proposed algorithm generates a warning signal which can inform human personnel to protect the mother and newborn piglets.

• Journal of Navigation and Port Research
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• v.38 no.2
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• pp.105-110
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• 2014

Korean government sets up a goal that jumps up to the third ranked powerful nation of offshore wind in the world until 2020 and announced "The plan for 2.5-gigawatt wind farm off the south-west coast by 2019". Such above, according to green energy policy, offshore wind farms(OWF) will be increased continuously. The development of OWF should be taken account of wind volume as well as marine traffic environment. Specially aids to navigation of OWF play a significant role in preventing collision between vessels navigating near waters and structures. For purpose of distinguishing OWF, IALA recommendations define installation of lights on SPS and IPS. However, there is no mention of light character that plays important role in identification of lights as marking offshore wind farm. Also the research on selection of proper light character has been insufficient state. Therefore in this paper, we analyzed internal and external regulations concerned marking with light on SPS and IPS in OWF. And suggested patterns and rhythms of light having not only easily recognized feature but also no confusion with other light of aids to navigation. The proposed light characters were verified by simulation, and the results were analysed that synchronism flickering of "Fl Y(4) 12s(SPS)" and "Fl Y 6s(IPS)" would be useful in combination of both lights.

• The Korean Journal of Emergency Medical Services
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• v.8 no.1
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• pp.149-160
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• 2004

Background : To save out-of-hospital cardiac arrest cases is a major concern for Korea. Cardiac arrest is a very common problem, with > 18,000 cases dying each year in Korea. Overall, survival to hospital discharge remains poor. Resuscitation has become an important multidisciplinary branch of medicine, demanding a spectrum of skills and attracting a plethora of specialities and organizations. Since the "Utstein Style" was advocated in 1991, many reports about out-of-hospital cardiac arrest have been published based on this guideline. These differences prevent valid inter-hospital and international comparisons. However, we do not know the true effectiveness of resuscitation. There are no guideline for reviewing, reporting, conducting research on resuscitation in Korea. This study evaluated the out-of-hospital factor associated with survival discharge of out-of-hospital cardiac arrest, was especially to provide basic data for the unified reporting guideline of resuscitation in Korea. Methods : From January 1990 to July 2004, we collected data about out-of-hospital cardiac arrest at Wonju Christian Hospital(WCH-CAD), Ewha Women University Mokdong Hospital(Ewha-CAD), I used same record form based on the "Utstein Style". The "Utstein Style" is internationally recommended guidelines for reporting outcome data from resuscitation events. Results : Resuscitation was performed in 1443 out-of-hospital cardiac arrest patients at 2 hospitals. Five hundred eighty(40.25%) patients recovered the spontaneous circulation at least once and One hundred sixty eight(11.66%) patients discharged alive. Initial EKG showed Ventricular Tachycardia/Ventricular Fibrillation in One hundred thirty five(9.33%) patients, asystole in one thousand nine(69.73%) patients and other rhythms in one hundred thirty nine(20.94%) patients. Among one hundred two cardiogenic cardiac arrest patients, two(2.0%) patients was discharged alive. Conclusion : Overall survival rate of out-of-hospital cardiac arrest patients was 11.66% which was poorer than that of the western country. The proportion of the cardiogenic cause was 33.38% which was only half of the western country. VT/VF is relatively not common ac a initial EKG rhythm. These differences might be to due difference in the prevalence pattern of out-of-hospital cardiac arrest as well as prematurity of the EMSS. It is needed that the best survival can be achieved if all following links have been optimized : rapid access, early CPR, early defibrillation, early ACLS.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.3
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• pp.193-202
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• 2004

Distraction osteogenesis(DO) is defined as a gradual mechanical process of mechanical stretching two vascularized bone surface apart with a critical rate and rhythm such that new bone forms within the expanding gap, reliably bridges the gap, and ultimately remodels to normal structure. DO has become a mainstay in bone tissue engineering and has significantly improved our armamentarium for reconstructive craniomaxillofacial procedures. But the molecular and biological mechanisms that regulate the formation of new bone during distraction osteogenesis are not completely understood. BMPs are potent osteoinductive agents. Our hypothesis was that BMPs, especially BMP-2 and BMP-4, might play an importent role in the signaling pathways that link the mechanical forces created by distraction to biological responses and in promting new bone formation. Using a rabbit's mandible, we investigated the expression of BMP-2, -4 at different time points during distraction osteogenesis. The purpose of this study is to research the pattern of expression of BMP-2, -4 in new bone formation during distraction osteogenesis of the rabbit mandible. The experimental group was applied gradual distraction (0.7mm a day by twice a day, 4.9mm in total, for 7 days) and the control group was carried out osteotomy alone. They were examined clinically, histologically, and by RT-PCR analysis. On 3 days after osteotomy, the high level of expression of BMP-2, -4 was detected. But, the expression of BMP-4 was decreased during latency period. As distraction was started, its expression was increased and maintained till postoperative 28days. In control group, the expression of BMP-4was remarkably decreased till postoperative 14 days. On the other hand, the expression of BMP-2 was no difference between experimental group and control group. The expression of BMP-4 was maintanined at high level during the entire experimental period in both group. These findings suggested that excellent bone formation during distraction osteogenesis is associated with enhanced expression of BMP-4 genes by mechanical tension stress.

• Journal of Dairy Science and Biotechnology
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• v.34 no.1
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• pp.37-41
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• 2016

Melatonin is a hormone produced by the pineal gland in dark conditions. It plays a major role in the regulation of the sleep-wake cycle. Melatonin synthesis is known to be suppressed by environmental light. Cortisol is a steroid hormone that is a major indicator of physiological alterations due to stressful stimuli. It also displays a circadian rhythm, like melatonin. The highest levels are encountered during early morning and the lowest levels are observed at around midnight. In the present study, the effects of milking time on the melatonin and cortisol concentrations of raw milk and milk powder at the summer and winter solstices were examined. The melatonin concentration in milk increased significantly if cows were milked in the dark at night (p<0.05). The melatonin concentration in milk powder showed the same pattern with respect to the milking time (p<0.05). However, no significant difference in the cortisol concentration was observed between day- and night-time milk. Although the time of day did not affect the level of milk cortisol, seasonal factors affected the release of cortisol in milk (p<0.05). In conclusion, night-time milk is rich in endogenous melatonin. In this respect, it has potential applications for the development of melatonin rich-dairy products, which serve as natural sources of melatonin.

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.599-608
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• 1997

We studied on change of lens accommodation and pupil light reflex caused by VDT work in six women and compared them with those of other office works. The results were as follows. 1. In VDT work the accommodation contraction velocity decreased during the first 2-hr VDT task, then recovered markedly by the end of the one-hour lunch break, and decreased again by the end of the 2nd 2-hr VDT task. Changes of relaxation velocity showed similar pattern although it was less typical than that of contraction velocity 2. There was no marked change in accommodation contraction velocity and amplitude of accommodation in general office work and near-distance office work, and in the near-distance office work accommodation relaxation velocity decreased according to work load without recovery after lunch break. 3. Initial pupil diameter, initial pupil area of light reflex decreased significantly during VDT task only in VDT work and didn't recover after lunch break. These results suggest possibility that changes of accommodation contraction velocity, accommodation relaxation velocity, near point distance, and pupil diameter and area are useful in evaluating characteristics of VDT work. For this, more research adjusted individual differences, circadian rhythm, emotional stress needs.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.724-729
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• 2016

Environmental factors that affect the singing of cicadas have not been studied extensively, especially those affecting the cicadas' singing during the nighttime. Therefore, the objective of this study is to identify the effects of tropical night and light pollution on the cicadas' singing in a downtown area. The study sites were an apartment complex in Seocho-gu, Seoul, and the Chiaksan National Park in Wonju-si. The study subjects were Hyalessa fuscata and Cryptotympana atrata, which are the dominant species in Korea during summer. Cicada songs were recorded 24 hours a day, every day. The recording period was between July and August, lasting 25 days at the Seoul site and 14 days at the Chiaksan National Park. Temperature, precipitation, humidity, and amount of sunshine were selected as the environmental factors that potentially affect the cicadas' singing. Statistical analyses included correlations of meteorological factors with the cicadas' singing per hour, per 24 hours, and at nighttime (21:00~04:00). The results showed that: 1) H. fuscata began singing during the dawn hours, and the singing increased in intensity early in the morning. C. atrata's singing reached its peak in the morning and afternoon, ceased during sunset hours, thereby exhibiting a difference in the singing pattern of the two species. 2) The frequency of singing by H. fuscata decreased when C. atrata began to sing intensively in numbers, thereby exhibiting interspecific influence. 3) The results of the correlation analysis between meteorological factors and the singing of H. fuscata and C. atrata showed that both species tended to sing more when the temperature was higher and sang less on rainy days. 4) When limited to nighttime only, C. atrata showed a tendency of singing when the nighttime temperature was high ($24-30^{\circ}C$, average $27^{\circ}C$), whereas H. fuscata did not show a correlation with meteorological factors. However, since H. fuscata sang during the night in areas with artificial lighting, it was concluded that its singing was due to light pollution.

• The Korean Journal of Emergency Medical Services
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• v.9 no.2
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• pp.111-128
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• 2005

Background: Cardiac arrest is one of the most critical diseases which can likely lead to severe cerebral disability or brain death when the cases can not recover their circulation within 10 minutes. Saving out-of-hospital cardiac arrest cases is a recent concern in Korea. Resuscitation has become an important multidisciplinary branch of medicine, demanding a spectrum of skills and attracting a plethora of specialities and organizations. The best survival can be achieved if all the following links have been optimized : rapid access, and early CPR, defibrillation and ACLS, Since the "Utstein Style" was advocated in 1991, many reports about out-of-hospital cardiac arrest have been published based on this guideline. These differences prevent valid inter-hospital and international comparisons. However, it is not known how effective resuscitation has become to the patients. In other words, there are no guidelines for reviewing, reporting, and conducting research on resuscitation in Korea. This dissertation aims to provide the basic data for a unified reporting guideline of resuscitation in Korea and evaluating the out-of-hospital factors associated with survival discharge of out-of-hospital cardiac arrest. Methods: As for this study, uses the collected data about Out-of-hospital cardiac arrests at 4 area, from January, 2005 to April. 2005. With a retrospective study, 174 cases were analyzed. The data was recorded based on the Out-of-Hospital Utstein Style. Results: Resuscitation was performed on 174 out-of-hospital cardiac arrest cases at the 4 area 14 patients(8.1%) recovered their spontaneous circulation. Overall, the ROSC of the out-of-hospital cardiac arrest patients was 8.1%, which was poorer than that of western countries. Gender distribution was 50 females(28.7%) and 124 males(71.3%), approximately twice as many males as females. ROSC of witnessed arrests was found out to be 97.7%. The ratio of the witnessed arrest groups showed higher results than that of unwitnessed arrest groups in the above-examined cases. Cardiac etiology consisted of cardiac(33.5%), non-cardiac(45.7%), trauma(20.1%), and unknown(6.0%). Cardiac was the best performance. Initial rhythm showed Ventricular Tachycardia/pulseless Ventricular Fibrillation in 8 patients(6.0%), asystole in 100(75.2%) and unknown in 25(18.8%). The results of the Ventricular Tachycardia/pulseless Ventricular Fibrillation showed higher results than the others cases, The proportion of the cardiogenic cause was 33.5%, which was only half of western countries. Ventricular Tachycardia/pulseless Ventricular Fibrillation is relatively rare. These differences were due to the prevalent pattern of Out-of-hospital cardiac arrest as well as prematurity of the EMSS. Bystander CPR was practiced on 13 patients(7.52%). ROSC was shown in 46.2% cases. CPR by EMT was carried out on 167 cases(96.5%). ACLS by EMf was rare. From collapse, 4 cases(2.6%) arrived to ED within 6 minutes. 13 (8.6%) within 10 minutes, and 49(32.5%) over 31 minutes. The sooner the patients arrived, the greater the ratio of ROSC and discharged alive became, and the same with collapse time to ROSC. As the results of the logistic regression analysis, ROSC was found out to be highly influenced by the time of ED arrival from collapse and Ventricular Tachycardia/pulseless Ventricular Fibrillation. Therefore, the ratio of ROSC depends on not any single factor but various intervention factors. Conclusion: This dissertation presents the following suggestions and directions of the study hereafter. First, the first step for a chain of survival should be taken to activate EMSS early with a phone as soon as cardiac arrests are witnessed. Second, it is keenly needed that emergency medical technicians should be increased through emergency education for living. Third, it is necessary to establish the emergency transportation system. Fourth, most of the Koreans have little understanding of EMT and the present operation systems have many problems, which should be fundamentally changed. Fifth, it is required to have an active medical control over Out-of-hospital CPR, And proper psychological supports should be given not only to patients themselves and their family but also individuals who are engaged in emergency situation. Finally, through studies hereafter on nationwide, comprehensive, and standard forms, it is needed to examine into the biological figures of human body, causes and trends of cardiac arrests, and then, to enhance the survival rate of Out-of-hospital cardiac arrests. Korean guidelines for Cardiopulmonary resuscitation need to be made.

• Progress in Medical Physics
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• v.21 no.2
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• pp.209-217
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• 2010

Retinal prostheses are being developed to restore vision for the blind with retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Since retinal prostheses depend upon electrical stimulation to control neural activity, optimal stimulation parameters for successful encoding of visual information are one of the most important requirements to enable visual perception. Therefore, in this paper, we focused on retinal ganglion cell (RGC) responses to different voltage stimulation parameters and compared threshold charge densities in normal and rd1 mice. For this purpose, we used in vitro preparation for the retina of normal and rd1 mice on micro-electrode arrays. When the neural network of rd1 mouse retinas is stimulated with voltage-controlled pulses, RGCs in degenerated retina also respond to voltage amplitude or voltage duration modulation as well in wild-type RGCs. But the temporal pattern of RGCs response is very different; in wild-type RGCs, single peak within 100 ms appears while in RGCs in degenerated retina multiple peaks (~4 peaks) with ~10 Hz rhythm within 400 ms appear. The thresholds for electrical activation of RGCs are overall more elevated in rd1 mouse retinas compared to wild-type mouse retinas: The thresholds for activation of RGCs in rd1 mouse retinas were on average two times higher ($70.50{\sim}99.87\;{\mu}C/cm^2$ vs. $37.23{\sim}61.65\;{\mu}C/cm^2$) in the experiment of voltage amplitude modulation and five times higher ($120.5{\sim}170.6\;{\mu}C/cm^2$ vs. $22.69{\sim}37.57\;{\mu}C/cm^2$) in the experiment of voltage duration modulation than those in wild-type mouse retinas. This is compatible with the findings from human studies that the currents required for evoking visual percepts in RP patients is much higher than those needed in healthy individuals. These results will be used as a guideline for optimal stimulation parameters for upcoming Korean-type retinal prosthesis.