• Journal of The Korean Astronomical Society
• /
• v.37 no.5
• /
• pp.597-600
• /
• 2004

A substantial number of processes have been suggested as possible contributors to the extragalactic $\gamma$-ray background (EGRB). Yet another contribution to this background will be emission produced in hadronic interactions of cosmic-ray protons with the cluster thermal gas; this class of cosmic rays (CRs) has been shown to be responsible for the EUV emission in the Coma Cluster of galaxies. In this paper we assume the CRs in the Coma Cluster is prototypic of all clusters and derive the contribution to the EGRB from all clusters over time. We examine two different possibilities for the scaling of the CR flux with cluster size: the number density of the CRs scale with the number density of the thermal plasma, and alternatively, the energy density of the CRs scale with the energy density of the plasma. We find that in all scenarios the EGRB produced by this process is sufficiently low that it will not be observable in comparison with other mechanisms that are likely to produce an EGRB.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.37.1-37.1
• /
• 2013

We present our study of analyzing the photometric properties of the globular cluster (GC) system which resides in the extended halo of the central bright Coma cluster galaxy NGC 4874. The core of the Coma cluster of galaxies (Abell 1656) was observed with both the HST Advanced Camera for Surveys (ACS) in the F475W (g475) and F814W (I814) and Wide Field Camera 3 IR Channel (WFC3/IR) in the F160W (H160) filters. The data analysis procedure and GC candidate selection criteria are briefly described. We investigate the interesting "tilt" features in color-magnitude diagrams for this GC system and their link to the nonlinear color-metallicity relation for GCs. The NGC 4874's GC system exhibits a bimodal distribution in the optical g475-I814 color and much more than half the GCs fall in the red side at g475-I814 ~ 1.1. This bimodality is weakened in the optical-IR I814-H160 color; the quantitative analysis on the features of both color distributions using the Gaussian Mixture Modeling code proves the bimodalities are different. Both colors, thus, cannot linearly reflect the bimodality of an underlying metallicity, supporting the suggestion that observed bimodalities in extragalactic GC colors are the metallicity-to-color projection effect.

• Journal of Korean Neurosurgical Society
• /
• v.40 no.4
• /
• pp.234-238
• /
• 2006

Objective : The operative indications on cerebellar hemorrhage have been controversial especially when the patient condition is grave. Therefore we investigated whether it can be justifiable if we perform the surgery in poor clinical grade. Methods : Clinical records and computerized tomography[CT] films of the 89 patients, who were undergone hospital treatment due to spontaneous cerebellar hemorrhage between May 1997 and May 2004, were retrospectively researched. Results : The study population consisted of 36 males and 53 female patients. The mean age was 65years [range $23{\sim}89$]. As a result of treatment, the patients, whose Glasgow coma scale[GCS] score were higher, showed better outcomes [p=0.001]. 13 patients [14.6%] were below 5 in GCS score and 10 patients of these were operated. Among 10 patients, 4 patients [40%] showed good outcome and 5 patients [50%] had been dead. 3 patients [60%] of these dead patients had the findings of intraventricular hemorrhage, fourth ventricular obliteration and hydrocephalus in CT scan. Conclusion : This study suggests that operation may be justifiable in clinically poor grade patient with spontaneous intra cerebellar hemorrhage.

• The Journal of Korean Medicine
• /
• v.16 no.2 s.30
• /
• pp.299-311
• /
• 1995

The studies were investigated in the coma time and the survival time induced by KCN, the duration of breathing after decapitation, the survival time following ligation of both common carotid arteries and the survival time after it is treated for normobaric bypoxia with a nitrogen gas, a carbon dioxide gas or a vaccum in mice. The results were as follows: 1. In histotoxic anoxia, Moschus(0.4mg／kg, p.o) demonstrated a protective effect on coma induced by a sublethal dose of KCN(1.8mg／kg, i.v.) in mice. 2. Mice subjected to a lethal dose of KCN(3.0mg／kg, i.v.) did not die by administration of Moschus. 3. Moschus was significantly extended the duration of breathing after decapitation in mice. 4. Moschus showed a significant extension of survival time in mice following ligation of both common carotid arteries. 5. In the normobaric hypoxia with a nitrogen gas, Moschus showed a significant extension of survival time in mice. 6. In the normobaric hypoxia with a carbon dioxide gas, Moschus showed a significant shortness of survival time in mice. 7. In the normobaric hypoxia with a vaccum, Moschus showed a significant extension of survival time in mice. From the above results, it is suggested that Moschus demonstrated protective effects on the brain damages induced by cerebral anoxia.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.11 no.1
• /
• pp.31-35
• /
• 2013

Acute organophosphate intoxication is important because of its high morbidity and mortality. The mortality is still high despite the use of atropine as specific antidotal therapy and oximes for reactivation of acetylcholinesterase. Inhibition of acetylcholinesterase by organophosphate can cause acute parasympathetic system dysfunction, muscle weakness, seizure, coma, and respiratory failure. Acute alteration in conscious state or a coma, which may occur following organophosphate intoxication, is an indication of severe intoxication and poorer prognosis. This acute decline in conscious state often reverses when the cholinergic crisis settles; however, it may be prolonged in some patients. We report on a case of a 60-year-old male who showed prolonged decline in conscious state due to of Central Nervous System (CNS) toxicity after a suicide attempt with organophosphate.

• Journal of Astronomy and Space Sciences
• /
• v.6 no.1
• /
• pp.57-72
• /
• 1989

A total of 80 photographs on 29 nights and another total of 44(22 each in B and V) photoelectric observations on 6 nights are secured for P/Halley(1982 ⅰ) for seven months before and after the perihelion passage. The photographic observations have been mode at different places depending on the position of the comet and the development of the tail, while the photoelectric observations were made only with 61-cm reflector at Yonsei University Observatory(YUO). Four most representative photographs are presented only to illustrate the remarkable features of the comet. The second one of these shows a coma with a possible flash activity on 1985 SEPT. 18.56 UT. The third one shows the largest tail recorded among our plates, and the last one prepresents unusual record made on northern hemisphere at a latitude as high as about $33^{circ}$12' N on the occasion of the comet's second perigee on 1976 APR. 11.6 UT. Photoelectric observations, on the other hand, determine the V and B-V of the total and the coma of the comet before its perihelion passage, and exhibit the light variations of 0m.6 in V in an hour and a half. Two new sets of m and n, one before and the other after the perihelion passage, determined based on the collected data, but the values are dissimilar one another significantly.

• Korean Journal of Optics and Photonics
• /
• v.4 no.1
• /
• pp.1-8
• /
• 1993

A design of four-mirror optical system with reduction magnification 5X for deep UV ($\lambda$=248 nm of KrF excimer laser) submicron lithography is presented. Initially by using the paraxial quantities, the domain of solution for $t=d_1+d_2+d_3$<0 (d;: distance between the mirror $c_i$ and $c_{i+1}$ is found for the system which is free from the four off-axial Seidel first order aberrations that are coma, astigmatism, field curvature, and distortion. The solution with $d_5$=2.95 (normalized with respect to $c_i$= -1) is choosen and the aspherization is carried out to the spherical mirror surfaces ($c_3$ and $c_4$ in order to reduce the axial and residual off-axial higher order aberrations. The numerical aperture of the final system is as large as 0.4, which gives Rayleigh resolution of 0.38 $\mu\textrm{m}$.

• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.2
• /
• pp.199-206
• /
• 2014

Purpose: The present study was aimed to investigate the correlation between higher-order aberration and myopic degree by the analysis of fluctuation of high-order aberration according to the change of myopic degree in certain ranges of myopia and astigmatism. Methods: The high-order aberration in a total of 992 eyes was analyzed by using a LADARWave device employing Hartmann-Shack system, and the relation between high-order aberration and myopia by the change of myopic degree through manifest refraction test. Results: In all subjects, spherical aberration and total coma aberration were significantly increased by the increase of myopic degree, however, trefoil aberration and astigmatic aberration and tetrafoil aberration were decreased. With the group of lower myopic degree, the change of coma aberration was greater by myopic degree and its change was significantly different. The change of spherical aberration by myopic degree was greatly large in the a group of -3.00 D or more and the group of -6.00 D or more where as its change was not large in the group of lower than -3.00 D. The significant decrease of coma aberration was observed only in the group of astigmatic degree of -1.00 D or less when analyzing the correlation between the higher-order aberrations and myopia in the certain groups of astigmatic degree. In the case of spherical aberration, the significant change was shown in all astigmatic groups, however, its increase was larger with the increase of myopic degree in lower degree of astigmatism. The consistent relationship in variations of horizontal and vertical coma aberration in certain myopic and astigmatic groups was neither established nor statistically significant. Conclusions: It is concluded that the correlation between the higher-order aberration and low-order aberration obtained from the results of the present study can help the understanding related to vision quality and the improvement of vision quality.

• The Journal of Internal Korean Medicine
• /
• v.22 no.4
• /
• pp.503-512
• /
• 2001

Objective : This study was carried out to investigate the effects of DDT on the brain damage and hypertension. Methods : We observed the effect of Dodamtang(DDT) extract on KCN-induced coma, focal brain ischemia by MCA occlusion, cytotoxicity and protection of PC12 cells and B103 cells induced by amyloid ${\beta}$ protein(25-35). To prove the effect of DDT as a blood pressure depressant, we measured aldosterone, renin activity, catecholamine, sodium and NO density using the seperated blood plasma. Results : DDT showed a protective effect on cytotoxicity of PC12 cells and B103 cells induced by amyloid ${\beta}$ protein(25-35) in a dose dependent manner and proved the significant abridgement of brain ischemic area and edema induced by MCA occlusion, a critical decrease of neurologic deficitic grade in the fore-limbs. DDT didn't reduce the duration of KCN(1.87mg/kg iv.)-induced coma and prolonged the survival rate in the case of KCN(3.0mg/kg iv.)-induced coma by the ratio of 20%. While DDT increased the value of NO in SHR, it significantly decreased the blood pressure of SHR and the value of aldosterone& epinephrine in SHR. Conclusions : These results suggested that DDT might be usefully applied for treatment of hypertension, cerebral infarction, and brain damage.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.4
• /
• pp.252-257
• /
• 2010

Objective : Barbiturate coma therapy (BCT) is a useful method to control increased intracranial pressure (IICP) patients. However, the complications such as hypotension and hypokalemia have caused conditions that stopped BCT early. The complications of low dose BCT with $Bispectral^{TM}$ index (BIS) monitoring and those of high dose BCT without BIS monitoring have been compared to evaluate the efficacy of low dose BCT with BIS monitoring. Methods : We analyzed 39 patients with high dose BCT group (21 patients) and low dose BCT group (18 patients). Because BIS value of 40-60 is general anesthesia score, we have adjusted the target dose of thiopental to maintain the BIS score of 40-60. Therefore, dose of thiopental was kept 1.3 to 2.6 mg/kg/hour during low dose BCT. However, high dose BCT consisted of 5 mg/kg/hour without BIS monitoing. Results : The protocol of BCT was successful in 72.2% and 38.1% of low dose and high dose BCT groups, respectively. The complications such as QT prolongation, hypotension and cardiac arrest have caused conditions that stopped BCT early. Hypokalemia showed the highest incidence rate in complications of both BCT. The descent in potassium level were $0.63{\pm}0.26$ in low dose group, and $1.31{\pm}0.48$ in high dose group. The treatment durations were $4.89{\pm}1.68$ days and $3.38{\pm}1.24$ days in low dose BCT and high dose BCT, respectively. Conclusion : It was proved that low dose BCT showed less severe complications than high dose BCT. Low dose BCT with BIS monitoring provided enough duration of BCT possible to control ICP.