• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.1
• /
• pp.33-40
• /
• 2006

The characteristics of the aluminum waste melting and the distribution of the radioactive nuclides have been investigated for the estimation on the volume reduction and the decontamination of the aluminum wastes from the decommissioning of the TRIGA MARK it and III research reactors at the Korea Atomic Energy Research Institute(KAERI). The aluminum wastes were melted with the use of the fluxes such as flux $A:NaCl-KCl-Na_3AlF_6$, flux B:NaCl-NaF-KF, flux $C:CaF_2$, and flux $D:LiF-KCl-BaCl_2$ in the DC graphite arc furnace. For the assessment of the distribution of the radioactive nuclides during the melting of the aluminum, the aluminum materials were contaminated by the surrogate nuclides such as cobalt(Co), cesium(Cs) and strontium(Sr). The fluidity of aluminum melt was increased with the addition of the fluxes, which has slight difference according to the type of fluxes. The formation of the slag during the aluminum melting added the flux type C and D was larger than that with the flux A and B. The rate of the slag formation linearly increased with increasing the flux concentration. The results of the XRD analysis showed that the surrogate nuclide was transferred to the slag, which can be easily separated from the melt and then they combined with aluminum oxide to form a more stable compound. The distribution ratio of cobalt in ingot to that in slag was more than 40% at all types of fluxes. Since vapor pressures of cesium and strontium were higher than those that of the host metals at the melting temperature, their removal efficiency from the ingot phase to the slag and the dust phase was by up to 98%.

• Reproductive and Developmental Biology
• /
• v.28 no.3
• /
• pp.203-207
• /
• 2004

The transgenic mice carrying human Interleukin-10 (hIL-10) gene in conjunction with bovine (3 -casein promoter express hIL-10 in milk during lactation. In this study, stability of germ line transmission and expression of hIL-10 transgene integrated into host chromosome were monitored up to generation F8 of transgenic mice. When male mouse of generation F8 was crossbred with normal females, approximately half of offspring (50.9±5.8%) were identified as transgenic mice. Generation F9 to F15 mice also showed similar transmission rates (66.0±20.1%, 61.5±16.7%, 41.1±8.4%, 40.7±20.3%, 61.3±10.8%, 49.2±18.8% and 43.8±25.9%, respectively), implying that hIL-10 transgene can be transmitted stably up to long term generation in the transgenic mice. Expression levels of human IL-10 from milk of generation F9 to F14 mice were 3.6± 1.2 mg/ml, 4.2±0.9 mg/ml, 5.7±1.5 mg/ml, 6.3±3.5 mg/ml, 6.8±4.5 mg/ml and 6.8±3.1 mg/ml, respectively, which was showed high-level expression compared with that of generation F1 (1.6 mg/ml) mice. In conclusion, our results suggest that transgenic mice can be continuously passed their transgenes to the progeny through the breeding program with the same productivity of human IL-10 protein in their milk.

• Reproductive and Developmental Biology
• /
• v.36 no.3
• /
• pp.147-154
• /
• 2012

This study was designed to determine whether low-density lipoproteins (LDL) from egg yolk and taurine, hypotaurine and trehalose as antioxidant in extender improve the freezability and fertility of Korean Jeju Black Bull semen. The semen was cryopreserved with tris egg yolk extenders containing 7% glycerol and treated 4% LDL, 20 mM taurine, hypotaurine and trehalose. Frozen-thawed sperm were evaluated motility, viability, membrane, and acrosome integrity and sperm penetration ability. The results were compared to semen cryopreserved in tris egg yolk extender only as control. Frozen-thawed semen evaluation cleary indicated that the addition of LDL and LDL-antioxidants (taurine, hypotaurine and trehalose) combination were significantly improved (p<0.05) the viability (%; with staining test using eosin-Y) compared to control spermatozoa. Also, in membrane integrity (%; with supravital hypo-osmotic swelling test), not only LDL-antioxiants combination but also LDL were significantly increased (p<0.05) the swelled sperm using HOST compared to control. Sperm acrosome integrity state was classified by CTC (chlortetracycline) staining test. F pattern was significantly increased in LDL-antioxidant combination than control (p<0.05) and B pattern was not significantly differences among all treatments and control. However, AR pattern was significantly decreased in LDL-antioxidants combination than control (p<0.05). Pronucleus formation and sperm penetration index (SFI) were significantly increased in LDL and LDL-antioxidants combination than control (p<0.05). Especially, LDL-taurine significantly improved pronucleus fomation and SFI than LDL (p<0.05). It was concluded that LDL and LDL-antioxidants in extender improved the freezability and fertility of Korean Jeju Black bull spermatozoa.

• Clinical and Experimental Pediatrics
• /
• v.45 no.6
• /
• pp.719-726
• /
• 2002

Purpose : Neonates in neonatal intensive care units(NICU) have a high risk of acquiring nosocomial infection because of their impaired host defence mechanism and invasive procedures. Nosocomial infection result in considerable morbidity and mortality among neonates. This study was carried out to survey both the epidemiology of nosocomial infection in our NICU and the annual trends of pathogens. Methods : We retrospectively reviewed culture proven nosocomial infection which occurred in our NICU from January 1995 to December 1999. The data included clinical characteristics, site of infection, pathogens, and mortality. Results : Nosocomial infection rates was 9.0 per 100 NICU admissions during the five-year period. Major sites of infection were bloodstream(32.3%), skin(18.4%), endotracheal tube(17.2%), and catheter(10.6%). The most common pathogen was S. aureus(29.9%). and the others were coagulase- negative staphylococci(CONS)(14.8%), Enterobacter(12.4%), and Candida(9.0%). During the five-year period, nosocomial infection rates increased from 9.5 to 11.6 per 100 admissions with the increase of CONS, Candida, Klebsiella, and Acinetobacter baumannii. The infection rate of S. aureus decreased. Multiple episodes of nosocomial infection occurred in 26.1% of all nosocomial infections. Overall bloodstream infection rates were 3.6 per 100 NICU admissions during five years. CONS(29.1%) and S. aureus(27.1%) were the two most common pathogens. Increasing rates of bloodstream infection by CONS, Candida, Klebsiella, and Acinetobacter baumannii were observed. Bloodstream infection related mortality was 11.9%. Conclusion : The predominant pathogens of nosocomial infection in NICU were S. aureus and CONS. Bloodstream infection, the most frequent nosocomial infection, should be a major focus of surveillance and prevention efforts in NICU.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.10 no.1
• /
• pp.63-75
• /
• 2012

This paper gives some basic requirements and preferences of various geological environmental conditions for the final deep geological repository of spent nuclear fuel (SNF). This study also indicates how the requirements and preferences are to be considered prior to the selection of sites for a site investigation as well as the final disposal in Korea. The results of the study are based on the knowledge and experience from the IAEA and NEA/OECD as well as the advanced countries in SNF disposal project. This study discusses and suggests preliminary guideline of the disposal requirements including geological, mechanical, thermal, hydrogeological, chemical and transport properties of host rock with long term geological stabilities which influence the functions of a multi-barrier disposal system. To apply and determine whether requirements and preferences for a given parameter are satisfied at different stages during a site selection and suitability assessment of a final disposal site, the quantitative criteria in each area should be formulated with credibility through relevant research and development efforts for the deep geological environment during the site screening and selection processes as well as specific studies such as productions of safety cases and validation studies using a generic underground research laboratory (URL) in Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.16 no.3
• /
• pp.281-290
• /
• 2018

In order to understand the long-term behavior of radionuclides in granite environments, geochemical behavior characteristics of uranium in granitic host rock of KURT (KAERI Underground Research Tunnel) were investigated by dissolution experiment with different reaction time and solutions. In the dissolution experiment, significantly increased dissolution levels of uranium from granite powder samples were identified during the reaction time of 0~10 days for reaction solutions ($UD-CO_3$ and UD-Bg) containing a large amount of $CO_3{^{2-}}$. On the other hand, significantly increased dissolution levels of uranium were also identified for reaction solutions containing Na and Ca after 60 days. Dissolution of uranium continuously increased in reaction solutions of $UD-CO_3$ ($44.61{\mu}g{\cdot}L^{-1}$), UD-Bg ($41.01{\mu}g{\cdot}L^{-1}$), UD-Na ($26.87{\mu}g{\cdot}L^{-1}$), UD-Ca ($20.26{\mu}g{\cdot}L^{-1}$), UD-CaSi ($17.03{\mu}g{\cdot}L^{-1}$), and UD-Si ($10.47{\mu}g{\cdot}L^{-1}$) in the experimental period of ~270 days. However, after day 270, dissolution of uranium showed a decreasing tendency. This is thought to have occurred because existing uranium in granite samples reached the limit of dissolution by interaction with reaction solutions. Concentrations of dissolved uranium and points of maximum concentration value were found to differ depending on the $CO_3{^{2-}}$ presence in the mixed reaction solution and on the geochemical type of the water. It is estimated that differences in the reaction rate between the granite sample and the reaction solution are due to the influence of dissolved ions in the reaction solution.

• Journal of Applied Biological Chemistry
• /
• v.54 no.4
• /
• pp.279-283
• /
• 2011

Toll-like receptors (TLRs) play an important role in induction of innate immune responses. The activation of TLRs triggers inflammatory responses that are essential for host defense against invading pathogens. Phenethyl isothiocyanate (PEITC) extracted from cruciferous vegetables has an effect on anti-inflammatory therapy. Dysregulated activation of nuclear factor-${\kappa}$B (NF-${\kappa}$B), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) has been shown to play important roles in the development of certain inflammatory disease. To evaluate the therapeutic potential of PEITC, NF-${\kappa}$B activation and COX-2 and iNOS expression induced by lipopolysaccharide (LPS, TLR4 agonist), polyinosinic-polycytidylic acid (Poly[I:C], TLR3 agonist), 2 kDa macrophageactivating lipopeptide (MALP-2, TLR2 and TLR6 agonist) or oligodeoxynucleotide 1668 (ODN1668, TLR9 agonist) were examined. PEITC inhibits the activation of NF-${\kappa}$B induced by LPS or Poly[I:C] but not by MALP-2 or ODN1668. PEITC also suppressed the iNOS expression induced by LPS or Poly[I:C]. However, PEITC did not suppress COX-2 expression induced by LPS, Poly[I:C], MALP-2, or ODN1668. These results suggest that PEITC has the specific mechanism for antiinflammatory responses.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.10
• /
• pp.1751-1760
• /
• 2015

Mucin2 (MUC2), an important regulatory factor in the immune system, plays an important role in the host defense system against bacterial translocation. Probiotics known to regulate MUC2 gene expression have been widely studied, but the interactions among probiotic, pathogens, and mucin gene are still not fully understood. The aim of this study was to investigate the role of MUC2 in blocking effects of probiotics on meningitic E. coli-induced pathogenicities. In this study, live combined probiotic tablets containing living Bifidobacterium, Lactobacillus bulgaricus, and Streptococcus thermophilus were used. MUC2 expression was knocked down in Caco-2 cells by RNA interference. 5-Aza-2'-deoxycytidine (5-Aza-CdR), which enhances mucin-promoted probiotic effects through inducing production of Sadenosyl-L-methionine (SAMe), was used to up-regulate MUC2 expression in Caco-2 cells. The adhesion to and invasion of meningitic E. coli were detected by competition assays. Our studies showed that probiotic agents could block E. coli-caused intestinal colonization, bacteremia, and meningitis in a neonatal sepsis and meningitis rat model. MUC2 gene expression in the neonatal rats given probiotic agents was obviously higher than that of the infected and uninfected control groups without probiotic treatment. The prohibitive effects of probiotic agents on MUC2-knockdown Caco-2 cells infected with E44 were significantly reduced compared with nontransfected Caco-2 cells. Moreover, the results also showed that 5-Aza-CdR, a drug enhancing the production of SAMe that is a protective agent of probiotics, was able to significantly suppress adhesion and invasion of E44 to Caco-2 cells by upregulation of MUC2 expression. Taken together, our data suggest that probiotic agents can efficiently block meningitic E. coli-induced pathogenicities in a manner dependent on MUC2.

• Clinical and Experimental Pediatrics
• /
• v.49 no.11
• /
• pp.1211-1215
• /
• 2006

Purpose : In this study, we analyzed the short term changes of thyroid function, incidence and risk factors of thyroid dysfunction soon after allogeneic hematopoietic stem cell transplantation (HSCT) in children. Methods : We enrolled 80 pediatric patients following allogeneic HSCT, at the Catholic HSCT center between January, 2004 and February, 2006. Serum TSH (thyroid stimulating hormone), total serum thyroxine and total serum triiodothyronine levels were systematically measured in 80 patients before the HSCT, and at 1 month, 6 months and 12 months after HSCT. Results : Thyroid function statistically decreased at 1 month after HSCT(P<0.001). Thyroid dysfunction at 1 month was observed in 43 (54 percent) of 80 patients, 31 (39 percent) of whom presented with euthyroid sick syndrome (ETS). Thyroid dysfunction was normalized within 1 year after HSCT. In univariate analysis, malignant disease and the presence of acute graft-versus-host disease (grade ${\geq}II$) were risk factors for ETS (P=0.04, 0.01 respectively). In multivariate analysis, we could not detect an independent risk factor for ETS (P=0.19, 0.06 respectively). Conclusion : The present study suggests that the incidence of thyroid dysfunction is high after allogeneic HSCT. Therefore, regular monitoring of thyroid hormone levels after HSCT is required.

• Ocean and Polar Research
• /
• v.37 no.1
• /
• pp.49-59
• /
• 2015

Spatial variation in the reproductive effort of Manila clam Ruditapes philippinarum is often closely associated with variation in the seawater temperature and food availability, which determines gonad maturity and the quantity of gamates produced during spawning. Previous studies also have reported that severe infection by the protozoan parasite Perkinsus olseni exerts a negative impact on clam reproduction, retarding gonad maturation or decreasing the reproductive effort. In the present study, we investigated impacts of P. olseni infection on the reproductive condition of Manila clam during a spawning season. Histology revealed that 54% of female clams in Wando off the south coast were in spawning, while only 10% of the female from Gomso and 0% of the female from Seonjaedo in Gyeonggi bay off the west coast were engaged in spawning at the end of May in 2004. Ray's fluid thioglycollate media (RFTM) assay was applied to assess P. olseni infection and indicated that the infection intensity in Wando ($3,608,000{\pm}258,000cells/g$ wet tissue) was significantly higher than the levels in Gomso ($1,305,000{\pm}106,000cells/g$ wet tissue) and Seonjaedo ($1,083,000{\pm}137,000cells/g$ wet tissue, p < 0.001). The size of the ripe female follicle determined from histology was significantly smaller in Wando ($0.032mm^2$) compared to the sizes in Gomso ($0.059mm^2$) and Seonjaedo ($0.052mm^2$, p < 0.05). Accordingly, the number of ripe eggs in the follicle was significantly fewer among clams in Wando (14) compared to the numbers determined in Gomso (23) and Seonjaedo (22). The absolute quantity of egg in ripe clams from Wando (31.01 mg) was also significantly smaller than Seonjaedo (61.79 mg) and Gomso (133.3 mg). Quantity of total protein, carbohydrate, and lipid in the tissue in the Wando samples was significantly smaller than the quantities determined in Gomso and Seonjaedo (p < 0.001). The observed poor reproductive condition and proximate tissue composition of the females in Wando were, in part, explained by the extremely high level of the parasites, sapping the ability to store energy in the host tissues, which is used in tissue growth and the egg production.