• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.124-129
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• 2018

This study was conducted to investigate the penetration dose and shielding rates of tungsten shields used in apron material by changing the type of source used in the nuclear medicine department, thickness of shielding material and distance between the source and detector. For the experiment, the source, shield, and detector were arranged in a straight line and measured with an inspector at a height of 100 cm. The highest shielding effect of tungsten was measured for $^{201}Tl$, while $^{123}I$ showed a higher shielding effect than $^{99m}Tc$. For the sources used in the experiment, the penetration dose decreased with distance and the shielding rate was measured with thicker thickness. However, the shielding rate of $^{13}1I$ and $^{18}F$ sources was found to be lower than when there was no shielding at 0.25 mmPb shield. Therefore, even if the radiation shielding effect of tungsten is high, considering the characteristics according to the type of source and the thickness of the shielding material, it may be helpful to reduce the exposure.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.55-58
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• 2008

Alanine racemase, a bacterial enzyme belonging to the fold-type III group of pyridoxal 5'-phosphate (PLP)-dependent enzymes, has been shown to catalyze the interconversion between L- and D-alanine. The alanine racemase from the pathogenic bacterium Enterococcus faecalis v583 has been overexpressed in E. coli and was shown to crystallize an enzyme at 295 K, using polyethylene glycol (PEG) 8000 as a precipitant. X-ray diffraction data to $2.5{\AA}$ has been collected using synchrotron radiation. The crystal is a member of the orthorhombic space group, $C222_1$ with unit cell parameter of a=94.634, b=156.516, $c=147.878{\AA},\;and\;{\alpha}={\beta}={\gamma}=90{\AA}$. Two or three monomers are likely to be present in the asymmetric unit, with a corresponding $V_m\; of\;3.38{\AA}^3\;Da^{-1}\;and\;2.26{\AA}^3\;Da^{-1}$ and a solvent content of 63.7% and 45.5%, respectively.

• Journal of the Korean Society of Radiology
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• v.5 no.1
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• pp.5-10
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• 2011

Based on basic concept of detection limit, sample measurement time & background measurement time was considered, and MDA values according to background measurement time and sample measurement time in land samples(river soil, surface soil, drinking water, underground water, surface water, pine leaf, mugwort) analysis among environmental samples were compared. Seeing the water sample analysis result, it was shown that most of the samples were not detected, and most of the samples in land specimen analysis showed to be below the detection limit of "Ministry of Education, Science and Technology Announcement Je-2008-28-ho", but $^{137}Cs$ which is one of artificial radioactive nuclide was detected in some samples. It can be traced back to 1950s and 1960s when nuclear tests were carried out in atmosphere and catastrophic Chernobyl atomic power station accident that caused fallouts in the sky, and this is common level of detection that can be observed worldwide. Seeing the result that the $^{134}Cs$(which is a isotope of $^{137}Cs$, and it has relatively short half life) was not detected in all samples, it can be considered it doesn't affect to the operation of atomic power station.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.360-364
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• 1992

Treatment for the brain tumors consist of surgery, chemotherapy, and a variety of methods of irradiation. Therapy is aimed to destroy the tumor, but necrosis and edema occur concurrently. Conventional structural imaging techniques such as CT or MRI are unable to reliably distinguish persistent and recurrent tumor from necrosis or edema. T1-201 has been shown to be useful in the evaluation of the myocardial viability by comparing the early uptake and redistribution image. The aim of this study is to evaluate the clinical usefulness of the early uptake and delayed washout images of the T1-201 brain SPECT in the brain tumors. In the pathologically diagnosed various brain tumor patients, brain SPECT was done with rotating gamma camera 15 minutes and 3 hours after T1-201 injection, and the T1-201 uptake in the tumor was compared with the skull and scalp activity. In the glioblastoma multiforme, meningioma and metastatic tumor, the T1-201 uptake was higher than low grade glioma in both 15 minute and 3 hour images (p<0.02). In the low grade glioma,3 hour T1-201 uptake was significantly lower than 15 minute uptake (p<0.05) but in the glioblastoma, meningioma and metastatic tumor there was no significant difference. There was no significant difference in the T1-201 uptake among the glioblastoma, meningioma and metastatic tumors. In one matastatic tumor, T1-201 uptake was decreased after radiation therapy. T1-201 brain SPECT could distinguish the benign and malignancy, and seems to be useful in the follow-up after treatment. But one of the early or delayed SPECT seems not to be necessary for these purposes.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.477-485
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• 1999

The grafting of 2,3-epoxypropylmethacrylate (GMA) onto polypropylene fabric was carried out by the $\gamma$-ray preirradiation grafting technique. Subsequently, the GMA-grafted polypropylene fabric was reacted with iminodiacetic acid (IDA) in different mixed solvents to prepare the fibrous metal adsorbent. The grafting extent was found to be dependent on the reaction time, temperature, preirradiation dose and dose rate. The effects of various mixed solvents on the IDA amination onto GMA-grafted polypropylene fabric were investigated. Compared with other mixed solvents, the extent of amination was highest in the dimethylsulfoxide (DMSO)/water, but the reaction did not occur in the water. The adsorption characteristics of various metal ions by the prepared adsorbent were examined when it was immersed in the 100 ppm metal ion solution. The amount of adsorption followed the order:$Pb^{2+}>Co^{2+}>Fe^{2+}$.

• Analytical Science and Technology
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• v.23 no.2
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• pp.165-171
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• 2010

Glucose oxidase ($GOD_{ox}$) immobilized biosensor was fabricated by two methods. In one of the methods, gold nanoparticles (Au-NPs) prepared by ${\gamma}$-irradiation were loaded into the poly(maleic anhydride)-grafted multi-walled carbon nanotube, PMAn-g-MWCNT electrode via physical entrapment. In the other method, the Au-NPs were prepared by electrochemical reduction of Au ions on the surface of PMAn-g-MWCNT electrode and then GODox was immobilized into the Au-NPs. The $GOD_{ox}$ immobilized biosensors were tested for electrocatalytic activities to sense glucose. The sensing range of the biosensor based on the Au-NPs physically modified PMAn-g-MWCNT electrode was from $30\;{\mu}M$ to $100\;{\mu}M$ for the glucose concentration, and the detection limit was $15\;{\mu}M$. Interferences of ascorbic acid and uric acid were below 7.6%. The physically Au deposited PMAn-g-MWCNT paste electrodes appear to be good sensor in detecting glucose.

• Journal of Ginseng Research
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• v.30 no.3
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• pp.106-111
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• 2006

Adverse changes in individual's biochemistry under heavy metal stress are directly linked with its metabolic activity and health status. The present investigation highlights the differences in protecting role of Panax ginseng extract against mercuric chloride induced alterations in serum proteins. The assessment was based on dividing fifty albino rats into two sets, one for acute and the other for sub-acute study. All the sets had five groups with five albino rats in each i.e. control group, mercuric chloride treated group, Panax ginseng extract treated group, mercuric chloride followed by Panax ginseng extract treated group and Panax ginseng extract followed by mercuric chloride treated group. Mercuric chloride was given orally 0.926 mg/kg body weight for acute set and 0.044 mg/kg body weight for sub-acute set after LD50 (9.26 mg/kg body weight) determination by probitt analysis. 10 mg/kg body weight Panax ginseng extract was given in both acute and sub-acute sets after incorporating safety trials. The control group received tween-20 and distilled water only. The result exhibited significantly reduction (P<0.01) in serum protein, albumin and globulin following mercuric chloride intoxication whereas significant (P<0.01) enhancement in other groups with Panax ginseng extract as an ingredient confirming its protective role. All serum samples were also electrophoresed in 10% SDS with standard marker using discontinuous buffering system. Gradual disappearance of alpha-2 and beta-1 globulin bands from electrophoretic pattern was observed, while a single sharp band was observed between beta-2 and gamma globulin in serum protein pattern of acutely mercuric chloride treated rats. However, this band could not be visualized in sub-acute studies. Panax ginseng extract exhibits a better protection after acute intoxication.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.531-538
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• 2004

Ginsan, a polysaccharide isolated from Panax ginseng, has been shown to be a potent immunomodulator, producing a variety of cytokines such as TNF-a, IL-1$\beta$, IL-2, IL-6, IL-12, IFN-${\gamma}$ and GM-CSF, and stimulating lymphoid cells to proliferate. In the present study, we analyzed some immune functions 1$^{st}$-5$^{th}$ days after ginsan i.p. injection, including the level of non-protein thiols (NPSH) as antioxidants, heme oxygenase (HO) activity as a marker of oxidative stress, zoxazolamine-induced paralysis time and level of hepatic cytochrome P-450 (CYP450) as indices of drug metabolism system, and activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, and albumin level as indicators of hepatotoxicity. Ginsan in the dose of 100 mg/kg caused marked elevation (1.7-2 fold) of HO activity, decrease of total CYP450 level (by 20-34%), and prolongation of zoxazolamine-induced paralysis time (by 65-70%), and showed some differences between male and female mice. Ginsan treatment did not seem to cause hepatic injury, since serum AST, ALT, and ALP activities and levels of total bilirubin and albumin were not changed.d.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.37-41
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• 2012

Objective : The aim of this study was to describe a single center's experience in the management of craniopharyngiomas in children over a 15-year period. Methods : The clinical records of pediatric patients treated for craniopharyngiomas between December 1995 and February 2011 were reviewed. Thirty-five pediatric patients diagnosed with craniopharyngioma were treated, and their medical records and imaging data were analyzed retrospectively. Results : The mean follow-up duration was 76 months (range, 10-195). Overall survival and local control rates at 10 years were $94.7{\pm}5.1%$ and $37.1{\pm}11.9%$, respectively. The female-to-male ratio was 16 : 19, and the mean age was 8.6 years (range, 1-17). Initially, gross total resection (GTR) was performed in 30 patients; subtotal resection (STR) followed by radiotherapy was performed in 5 patients. Of the 14 cases that showed recurrence after GTR, 5 patients were treated with GTR, 1 with radiation therapy (RT), 4 with gamma knife radiosurgery (GKRS), and 4 with subtotal resection followed by RT. No patients who underwent RT or GKRS had recurrences. Two cases with recurrence after STR followed by RT were treated with GTR. One patient died of hormonal insufficiency 64 months after the first surgery. The overall median time progression was 51.2 months (range, 3-182) : 49.7 months in the patients who underwent GTR and 60.2 months in the patients who underwent STR followed by RT. Conclusion : If safe resection is possible, GTR at the initial treatment should be attempted to reduce the tumor recurrence. However, if the tumor recurs after the first surgery, RT or GKRS with/without reoperation may be an effective salvage treatment for recurrent craniopharyngioma.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.135-140
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• 2003

Bacillus sp. secretes high levels of extracellular enzymes into the culture medium. The signal recognition particle (SRP) and the SRP receptor play a central role in targeting pre secretory proteins to the translocase. By the analysis of the DNA microarray of B. lentimorbus WJ5, it was detected that WJ5m12, antifungal activity deficient mutant induced by gamma radiation, had a down-regulated expression of the SRP receptor gene (B. subtitis srb homologue, srbL). To determine the relationship of SRP receptor to antifungal activity, srbL of B. lentimorbus WJ5 was amplified by PCR and ligated into pQE30 vector, and then transferred into WJ5m12. The transformant, WJ5m12::srbL, recovered the antifungal activity. From the 2-DE analysis, the several presecretory proteins accumulated in the mutant cell and decreased to a level of the wild type in WJ5m12::srbL. It seems that the srbL could play an important role in the secretion of the antifungal activity related proteins of B. lentimorbus WJ5.