• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.1-12
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• 2009

In 2008, baby formula containing melamine was found to be responsible for a large outbreak of renal failure in infants in China. A total of 294,000 infants were hospitalized, and at least 6 babies died due to ingestion of the tainted formula. Melamine contains high levels of nitrogen (>60%), which is used as an indicator of protein content. Therefore, high levels of melamine in infant formula were thought to be the result of deliberate contamination m an attempt to increase its apparent protein content. Following inspections by China's national inspection agency, assorted products from at least 22 dairy manufacturers across China were found to have varied levels of melamine (range: 0.096196.61 mg/kg). Melamine co-exposure with cyanuric acid can induce acute melamine-cyanurate crystal nephropathy, which can lead to renal failure at much lower doses than if either compound were ingested alone. However, currently, there are very few data on melamine analogues other than cyanuric acid. At an expert meeting of the WHO and FAO held to review toxicological aspects of melamine and cyanuric acid on December 14, 2008, a new tolerable daily intake (TDI) of melamine was established that could be applied to the entire population, including infants. Therefore, a risk assessment of the various theoretical melamine contamination levels in infant formula and selected representative foods (other than infant formula and sole-source nutrition products) is urgently needed for Korean babies and children up to 7 years of age. Although the undetectable level regulation for infant formula may be low enough to guarantee the safety of babies under the age of 1 year (including premature babies), the melamine standard of 2.5 ppm for foods other than baby formula could be insufficient to protect the 95th percentile population aged 1~2 years because of this demographic's high consumption of milk, yogurt, and soy milk (hazard index = 1.79). Because TDIs are chronic values intended to protect an individual over his/her lifetime, occasional modest ingestion in excess of the TDI is not likely to be a health concern. However, children aged 1~2 years may have renal systems that are comparatively more sensitive to the crystallization of melamine and its analogues. Therefore, governmental jurisdictions may need to practice more prudent management of food items that could raise the melamine exposure for this population.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1574-1582
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• 2014

Bacteria recognize changes in their population density by sensing the concentration of signal molecules, N-acyl-homoserine lactones (AHLs). AHL-mediated quorum sensing (QS) plays a key role in biofilm formation, so the interference of QS, referred to as quorum quenching (QQ), has received a great deal of attention. A QQ strategy can be applied to membrane bioreactors (MBRs) for advanced wastewater treatment to control biofouling. To isolate QQ bacteria that can inhibit biofilm formation, we isolated diverse AHL-degrading bacteria from a laboratory-scale MBR and sludge from real wastewater treatment plants. A total of 225 AHL-degrading bacteria were isolated from the sludge sample by enrichment culture. Afipia sp., Acinetobacter sp. and Streptococcus sp. strains produced the intracellular QQ enzyme, whereas Pseudomonas sp., Micrococcus sp. and Staphylococcus sp. produced the extracellular QQ enzyme. In case of Microbacterium sp. and Rhodococcus sp., AHL-degrading activities were detected in the whole-cell assay and Rhodococcus sp. showed AHL-degrading activity in cell-free lysate as well. There has been no report for AHL-degrading capability in the case of Streptococcus sp. and Afipia sp. strains. Finally, inhibition of biofilm formation by isolated QQ bacteria or enzymes was observed on glass slides and 96-well microtiter plates using crystal violet staining. QQ strains or enzymes not only inhibited initial biofilm development but also reduced established biofilms.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.266-271
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• 2009

In the recently synthesized rare earth transition metal carbide $La_7O_{s4}C_9$ one finds one-dimensional organometallic $[O_{s4}C_9]^{21-}$ polymers embedded in a $La^{3+}$ ionic matrix. The electronic structure of the polymeric $[O_{s4}C_9]^{21-}$ chain was investigated by density of states (DOS) and crystal orbital overlap population (COOP), using the extended Huckel algorithm. A fragment molecular orbital analysis is used to study the bonding characteristics of the $C_2$ units in $La_7O_{s4}C_9$ containing $C_2$ units and single C atoms as well. The title compound contains partially filled Os and carbon bands leading to metallic conductivity. As the observed distances already indicated, the calculations show extensive Os-C interactions. The C-C bond distance in the diatomic $C_2$ units ($d_{C-C}$=131 pm) in the solid is significantly increased relative to $${C_2}^{2-}$$ or acetylene, because antibonding $1{\pi}_g$ orbitals are partially filled by the Os-$C_2(1\;{\pi}_g)$ bonding contribution found at and below the Fermi level.

• Cartoon and Animation Studies
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• s.39
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• pp.1-25
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• 2015

"Magical girl" is one of many popular genres that are watched in Japanese animation. The characteristics of "Magical girl" genre shows that most main heroine as the girl in young age, and this young girl play her role as a character with supernatural power. The majority in population of Japanese animation consumers were men. However, women began to become this population of Japanese animation consumers with the beginning of "Magical girl" genre, which also became a cause for the birth of "Shojo anime". The first "Shojo anime", as well as the first animation of "Magical girl" genre in Japan was , and this piece made a great hit when it was broadcasted. Since the great hit of , new pieces of animation in "Magical girl" genre has broadcasted through television continually, making other great hits also with in 1982 and< Sailor Moon> in 1992. Discussing of which, made not only a great hit in Japan, but worldwide as well, that its new season of TV series, , is broadcasted in 2014. "Magical girl" genre was loved by viewers of Japanese animation for a long time, and it is still broadcasted regularly today. In observation of pieces in "Magical girl" genre, magical girls who appear as a main character either fight for the world they live in, or take on an adventure, or take an action according to their idealistic purpose. However, the magical girls who appear in take an action not for the peace of their world, but rather for their own benefits and purposes. In , magical girls fight against the witches and their familiar spirits, which end up in a horrible conclusion. The witches who magical girls fought against were not already the witches in the beginning, but in fact were the other magical girls who took their action in the past. It Magical girls in present time were having witch hunt against the witches, who were once another magical girls in the past. Unlike traditional "Magical girl" genre, where witches and magical girls were used to be an that magical girls end up turning into witches. Witches did not exist in the beginning, but rather someone had to be one, to be hunted down in witch hunt. The cause of witch hunt did not exist in the beginning, but rather the ones had to be tagged as witches to be hunted down. Therefore, this paper is written to discuss an existence of witch in research of its historic origin of witch hunt, and on the witches appear in .

• Radiation Oncology Journal
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• v.12 no.1
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• pp.27-31
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• 1994

There are a number of reports suggesting that there may be a correlation between the clinical response to radiotherapy in various tumors and the clonogenic survival of cell lines derived from these tumors following exposure to 2 Gy(SF2). Authors conducted this study to determine SF2 for cells in primary culture from surgical specimens. The tumor tissues with squamous cell carcinoma of uterine cervix and head and neck were obtained. The tumor tissues were disaggregated to single cells by incubating with collagenase type w for 2 hours with constant stirring. Single cell suspensions were inoculated in four 24-well plates precoated with cell adhesive matrix. After 24 hours of incubation at 37$ ^{\circ}C $, rows of four wells were then irradiated, consisting of control set and five other sets each receiving doses of 1,2,3,4, and 6 Gy. After incubation for a total of 13 days, the cultures were stained with crystal violet and survival at each dose was determined by quantitative image analysis system, To determine whether cell growth was of epithelial origin, immunocytochemical staining with a mixture of cytokeratin and epithelial monoclonal antibodies were performed on cell cultures. During the period of this study, we received 5 squamous cell carcinoma specimens of head and neck and 20 of uterine cervical carcinoma. Of these, 15 yielded enough cells for radiosensitivity testing. This resulted an overall success rate of 60$ \% $. The mean SF2 value for 15 tumours was 0.55$\pm$0.17 ranging from 0.20 to 0.79. These results indicate that there is a broad range of sensitivities to radiation in same histologic type. So with a large patient population, we plan to determine whether a different SF2 value is associated with tumours that are controlled with radiotherapy than those that are not.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.320-329
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• 1997

Neuroanatomic substrate of autism has been the subjects of continuing investigation. Because previous studies had not demonstrated consistent and specific neuroimaging findings in autism and most studies comprised adults and school-aged children, we performed a retrospective review in search of common functional and anatomical abnormalities with brain SPECT using Tc-99m ECD and correlative MRI The patient population was composed of 18 children aged 28 to 89 months(mean age : 55 months) who met the diagnostic criteria of autism as defined in the DSM-IV and CARS. Brain SPECT was performed after intravenous injection of 185-370MBq of Tc-99m ECD using brain dedicated annular crystal gamma camera. MRI was performed in all patients including T1, T2 axial and T1 sagittal sequences. SPECT data were visually assessed. Thirteen patients had abnormal SPECT scan revealing focal areas of decreased perfusion. Decreased perfusion of cerebellar vermis(12/18), cerebellar hemisphere(11/18), thalami(13/18), basal ganglia(4/18), posterior parietal(7/18), and temporal(4/18) area were noted on brain SPECT. Whereas, only 3 patients had abnormal MR findings which were subtle volume loss of parieto-occipital white matter in 3 and mild thinning of posterior body of corpus callosum in 2 and slightly decreased volume of cerebellar vermis in 1. Comparison of the numbers of abnormal findings revealed that regional cerebral blood flow (rCBF) abnormalities seen on SPECT were more numerous than anatomical abnormalities seen on MRI. In conclusion, extensive perfusion impairment involving cerebellum, thalami and parietal lobe were found in this study. SPECT may be more sensitive in reflecting pathophysiology of autism than MRI. However, further studies are mandatory to determine the significance of thalamic and parietal perfusion impairment in autism.