• Mycobiology
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• v.47 no.3
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• pp.335-339
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• 2019

Endophytic fungi have the ability to live inside the host plant tissues without causing neither symptoms of diseases/or harm. Opportunistic infections are accountable for majority of the outbreaks, thereby putting a burden on the health system. To investigate and characterize the bioactive compounds for the control of bacteria of clinical importance, extracts from endophytic fungi were isolated from indigenous South African medicinal plants. Extracts from endophytic fungi were isolated from 133 fungal strains and screened against Gram positive and negative bacteria namely Bacillus cereus, Escherichia coli, Enterococcus faecium, and E. gallinarum using disk diffusion. Furthermore, gas chromatography-mass spectrometry was performed to identify the bioactive compounds. Sixteen out of one hundred and thirty-three (12%) fungi extracts exhibited antibacterial properties against some of the selected bacteria. E. coli was found to be the most susceptible in contrast to E. faecium and E. gallinarum which were the most resistant. The isolate MHE 68, identified as Alternaria sp. displayed the greater spectrum of antibacterial activities by controlling selected clinical bacteria strains including resistant E. faecium and E. gallinarum. The chemical analysis of the extract from MHE 68 indicated that linoleic acid (9,12-octadecadienoic acid (Z,Z)) and cyclodecasiloxane could be accountable for the antibacterial activity. This is the first study conducted on the secondary metabolites produced by endophytic fungal strains isolated from the Pelargonium sidoides DC. possessing antibacterial properties.

• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.208-213
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• 2011

We calculated the EPR (electron paramagnetic resonance) line-shape function. The line-widths of a -doped single crystal was studied as a function of the temperature with 0.5 and 2 at. at a frequency of (X-band). The line-width decreases with increasing temperature, such temperature behavior of the line-width can indicate a motional narrowing of the spectrum, when impurity ions substitute for host ions in an off-center position, and thus there can be fast jumping of dipoles between several symmetrically equivalent configurations. Therefore, the present technique is considered to be more convenient to explain the resonant system as in the case of other optical transition problems.

• Childhood Kidney Diseases
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• v.23 no.1
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• pp.29-35
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• 2019

Purpose: We aimed to determine characteristics of host, causative organisms, and antibiotic susceptibility of bacteria in pediatric patients with UTI living in metropolitan area of Korea. Methods: Retrospective investigation was done for the causative organisms of UTI in 683 pediatric cases treated at Ajou University Hospital from 2012 to 2017. Patients were classified into Escherichia coli and non-E. coli group, where E. coli group was subdivided into ESBL(+) and ESBL(-) groups based on whether the bacteria could produce extended spectrum beta-lactamase (ESBL). Antibiotic susceptibility of the causative organism was also determined. Results: A total of 683 UTIs occurred in 550 patients, of which 463 (67.8%) were first-time infection and 87 (32.2%) were recurrent ones (2-7 recurrences, 2.52 average), and 64.9% were male and 35.1% were female. The most common causative organism was E. coli (77.2%) and ESBL(+) E. coli was found in 126 cases. The susceptibility of E. coli to 3rd or 4th generation cephalosporin was relatively higher than that to ampicillin or amoxicillin/clavulanic acid. ESBL(+) E. coli showed higher resistance rate to 3rd or 4th generation cephalosporin than ESBL(-) E. coli. Conclusion: New treatment guideline should be considered due to the incidence of ESBL(+) E. coli increased up to one quarter of UTI cases.

• Economic and Environmental Geology
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• v.52 no.4
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• pp.259-274
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• 2019

Using portable XRF and SWIR analyzer, the characteristics of element dispersion and wallrock alterations induced by interaction between hydrothermal fluids and host rocks were investigated and ore exploration factors were estimated for the orogenic-type Samgwang Au deposits. On this purpose, in-situ measurements were conducted for 804 spots at regular intervals with a total of 4,824 times for host rocks, consisting of schist and gneiss, and altered wallrocks contacted with quartz veins in the Bonhang adit of the deposit, and the results were compared with quantitative data obtained by XRF and ICP analysis. The regression coefficients are 0.88 for major elements and 0.56 for trace elements, excluding V. For polished rock slabs, better results came out for major elements, 0.97 and for trace elements, 0.65. In altered wallrocks contacted with quartz veins, elements such as Fe, Zn, and Rb exhibit positive correlations with As in concentrations, while V forms a negative trend. Contour maps demonstrate that As, Zn, Rb, Fe, Ti, Cr, and Ni are enriched together near quartz veins, showing similar elemental behaviors. In-situ analysis using portable SWIR analyzer represents that schist and gneiss contain mica, illite, chlorite, sericite, amphibole, and epidote, while illite, sericite, gypsum, and mica are present in the altered rocks contacted with quartz veins. In contour maps, chlorite occurs mostly in host rocks, while sericite is concentrated near quartz veins. These results are similar to those of previous studies for element dispersion and hydrothermal alteration, and support the possibility for application of in-situ analysis on the exploration of orogenic gold deposit.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.369-375
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• 2009

A commercial egg parasitoid, Trichogramma sp. Nabis101, was released into agricultural cultivating areas in Korea due to its wide host spectrum against insect pests. Moreover, an application technique has been recently developed to enhance its control efficacy by mixture treatment with a microbial control agent. Despite its expansion of commercial availability, any genetic identification on this commercial strain was not determined. Also, to meet inconsistent demands from consumers, the live parasitoids need to be stored without significant loss of their survival and parasitic activity. This study determined nucleotide sequence of internal transcribed spacer (ITS) of the wasp species. The identified ITS sequences indicate that this wasp species is most similar to T brasiliensis. Optimal storage condition of this wasp required young parasitized stage at $10^{\circ}C$. Under these conditions, survival, sex ratio, longevity, and parasitic behavior were not much impaired for 5 weeks.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.737-743
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• 2015

In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans.

• Journal of agricultural medicine and community health
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• v.16 no.2
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• pp.154-164
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• 1991

Albendazole is a broad spectrum anthelmintics with high activity against intestinal nematodes as well as tremtodes and cestodes infections. But so far wormicidal effect of albendazole against Paragonimus westermani is uncertain. The present study undertaken to observe the morphological changes of Paragonimus westermani which was obtained from experimentally infected with metacercariae isolated from Cambaroides similis and 9 of them were given albendazole 2 doses of 25mg/kg daily for the 2 days and 4 days from the day of 20 weeks after infection. The Paragonimus werms were collected from the lung of the cats which were autopsied at 24 hours after treatment. The fine structures of the collected worms were studied by means of scanning and transmission electron microscopy. The findings of the observations were compared with those of untreated worms. The results are as follows : 1) In the scanning electron microscopic(SEM) observations, the worms obtained from 2 days treated group showed many blebs which were formed on the surface of damaged tegument in between two suckers. Protrusion of oral sucker typically observed and surrounding tegumental ridges were damaged. 2) The worms obtained from 4 days treated group showed marked contraction revealing half size of normal worms. 3) The transmission electronmicroscopic(TEM) observations indicated that large blebs of irregular shapes were formed by the destruction of tegumental ridge of tegumental syncytium and also showed degeneration of mitochondriae. 4) Destruction of tegumental syncytium formation of blebs were usually observed in the ventral side of the worms. 5) Differentiation of tegumental layer and basement layer muscular layer and parenchymal layer around two suckers of worms obtained at 4 days treated group was difficult. 6) Many host cells invaded and destroyed the degenerated tegument by the occurrence of blebs or the exposed muscular layer of the worm after exfoliation of the tegument.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.46-46
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• 2003

Interleukin-10 (IL-10) is a homodimeric protein with a wide spectrum of anti-inflammatory and immune activities. It inhibits cytokine production and expression of immune surface molecules in various cell types. The transgenic mice carrying the human IL-10 gene in conjunction with the bovine $\beta$-casein promoter produced the human IL-10 in milk during lactation. Transgenic mice were generated using a standard method as described previously. To screen transgenic mice, PCR was carried out using chromosomal DNA extracted from tail or toe tissues with a primer set. In this study, stability of germ line transmission and expression of IL-10 gene integrated into host chromosome were monitored up to generation F15 of a transgenic line. When female mouse of generation F9 was crossbred with normal male, generation F9 to F15 mice showed similar transmission rates (66.0$\pm$20.13%, 61.5$\pm$16.66%, 41.1$\pm$8.40%, 40.7$\pm$20.34%, 61.3$\pm$10.75%, 49.2$\pm$18.82%, and 43.8$\pm$25.91%, respectively), implying that the IL-10 gene can be transmitted stably up to long term generation in the transgenic mice. For ELISA analysis, IL-10 expression levels were determined with an hIL-10 ELISA and a mIL-10 ELISA kit in accordance with the supplier's protocol. Expression levels of human IL-10 from milk of generation F9 to F13 mice were 3.6$\pm$1.20 mg/ml, 4.2$\pm$0.93 mg/ml, 5.7$\pm$1.46 mg/ml, 6.3$\pm$3.46 mg/ml, and 6.8$\pm$4.52 mg/ml, respectively. These expression levels are higher than in generation F1 (1.6 mg/ml) mice. We concluded that transgenic mice faithfully passed the transgene on their progeny and successively secreted target proteins into their milk through several generations, although there was a little fluctuation in the transmission frequency and expression level between the generations.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.143-153
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• 2003

Purpose : Infection with Shiga-like toxin (SLT)-producing Escherichia coli, an emerging human pathogen found particularly in young children under 5 years of age, causes a spectrum of illnesses with high morbidity and mortality, ranging from diarrhea to hemorrhagic colitis and hemolytic uremic syndrome. Host mediators play an important role in the pathogenesis of SLT-I toxicity. The experiments described here were designed to investigate the effect of SLT-I on TNF-${\alpha}$ production and to understand the effect of TNF-${\alpha}$ on GB3 expression. We also further examine the relationship between the Gb3 level and the differential susceptibility of cells to the cytotoxic action of SLT-I. Methods : The effect of purified SLT-1 from E. coli O157 : H7 (ATCC 43890) on tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) production in Raw264.7 cells was investigated. Many mediators regulate endothelial cell membrane expression of the glycolipid globotriaosyleramide (Gb3), which serves as the toxin receptor, suggesting that the host response to the toxin or other bacterial products may contribute to pathogenesis by regulating target cell sensitivity to the toxins. Therefore, the relationships between Gb3 expression and cytotoxicity against SLT-I on three types of cells were evaluated. Results : Detectable levels of TNF-${\alpha}$ were produced as early as six hours after induction and continued to increase during 48 hours by SLT-I. It was also found that Vero cells and dendritic cells (DC2.4 cells) expressed high levels of Gb3, 83% and 68%, respectively, and that Raw264.7 cells had a low level of Gb3 (29%) and appeared refractory to cytotoxicity against SLT-I. Vero cells and DC2.4 cells expressing high levels of Gb3 were highly susceptible to SLT-I. Furthermore, macrophages showed a resistance to SLT-I cytotoxicity, despite the fact that Gb3 expression was enhanced. Conclusion : These results strongly suggest that the expression of Gb3 is necessary but not sufficient to confer sensitivity of macrophages to SLT-I and further underpin the important role of SLT-I and its Gb3 receptors in the pathogenesis of E. coli O157 infection.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.49-54
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• 2000

The new green $Al_3GdB_4O_{12}:Tb^{3+} and red Al_3GdB_4O_{12}:Eu_{3+}$ phosphors were synthesized and then characterized their optical properties for PDP application. And also the photoluminescence properties of these phosphors were compared with the commercial green $Zn_2SiO_4:Mn^{2+} and (Y,Gd)BO_3: Eu^{3+}$ red PDP phosphors. The phosphors were synthesized by solid state reaction at 115$0^{\circ}C$ for 4hr. It was found that the emitting brightness of $Al_3GdB_4O_{12}:Tb^{3+}$(15mol%) green phosphor under 147nm excitation was higher than that of commercial $Zn_2SiO_4: Mn^{2+}$ green PDP phosphor. However, the color coordinate of this new green phosphor was inferior to the commercial one. On the other hand, the emitting intensity of $Al_3GdB_4O_{12}:Eu^{3+}$(15mol%) red phosphor was smaller than the $commercial(Y,Gd)BO_3: Eu^{3+}$ red one, but the CIE coordinate was slightly improved. The excitation spectrum showed that $Al_3GdB_4O_{12}$ phosphors had a strong excitation band at $\lambda=160nm$ associated with the host absorption. And the photoluminance excitation (PLE) intensity in VUV range for $Al_3GdB_4O_{12}:Tb^{3+}$ green phosphor was higher than that of $Zn_2SiO_4: Mn^{2+}$, but the PLE intensity of $Al_3GdB_4O_{12}:Eu^{3+}$ red phosphor was smaller than $(Y,Gd)BO_3: Eu^{3+}$.