• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

• Journal of the Mineralogical Society of Korea
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• v.23 no.1
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• pp.51-61
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• 2010

Ettringite $(Ca_6[Al(OH)_6]_2(SO_4)_3{\cdot}26H_2O)$ is a sulfate mineral that shows a complicate property in concrete. It is often called as "a cancer of concrete" because secondary ettringite formation in hardened concrete often cause expansion and cracking of concrete due to its expansive crystal structure. In the present study, we tested the possibility for crystal growth inhibition of secondary ettringite by crystallization inhibitors that are commercially used for scaling inhibitors in Korea. For the test, we developed a method of ettringite solution synthesis. Three types of crystallization inhibitors were selected and examined the effects On ettringite growth inhibition. The experimental results of ettringite solution synthesis indicated that ettringite was successfully synthesized under condition that the mass balance between calcium hydroxide saturated solution and aluminum sulfate solution was attained. Monosulfate and semisulfate were synthesized when the ratio of $Ca^{2+}$ ions to ${SO_4}^{2+}$ ions was increased. The induction time of ettringite crystallization was less than 2 min. and crystallization was almost completed within an hour. The experimental results of ettringite crystallization inhibition showed that organic PBCT (2-Phosphonobutane-1,2,4-Tricarboxylic Acid) and inorganic SHMP (Sodium Hexametaphosphate) were relatively less effective on ettringite crystallization inhibition under experimental conditions. However, organic HEDP (1-Hydoxyethylidene-1,1-Diphosphonic Acid) effectively prevented ettringite growth with producing amorphous gel phase materials up to inhibitor concentration 0.1 vol.% of aluminum sulfate solution.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.111-115
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• 2006

A feeding trial was conducted to test the use of marine yeasts isolated from seawaters and sediments as a dietary source in cultivating a Cladocera, Moina macrocopa which is available as an alternative live food for fish larvae. The marine yeast-fed M. macrocopa had similar essential amino acid profiles to the documented values for Rotifers and Artemia enriched in microalgae and commercial diets. Erythrobacter sp. $S{\pi}-1$ lacked ${\omega}-3$ high unsaturated fatty acids (HUFAs), $20:5{\omega}-3$ (EPA) and $22:6{\omega}-3$ (DHA), which were also poor but detected in both the marine yeasts. An increase in the $20:5{\omega}-3$ and $22:6{\omega}-3$ levels, compared with the levels in marine yeast strains themselves, was more pronounced in the $22:6{\omega}-3$ level of Moina fed the Candida sp. Y-16, resulting in a high DHA:EPA ratio. When the Moina diets were switched, their ${\delta}^{13}C$ values shifted gradually toward the values of the switched diets. Diet switch from Erythrobacter sp. $S{\pi}-1$to Candide sp. Y.16 resulted in a more rapid turnover of Moina tissue carbon than that in the inverse case. When fed a mixed diet, the ${\delta}^{13}C$ values of Moina tissue approached the value of marine yeasts immediately. These temporal changes in the ${\delta}^{13}C$ values of Moina tissue indicate the preferential ingestion of marine yeasts and a selective assimilation of the carbon originated from marine yeasts. These findings suggest that marine yeasts, particularly Candida sp. Y-16, are highly available to mass cultures of M. macrocopa, providing better nutritional and dietaty values than the commercial diet (Erythrobacter sp. $S{\pi}-1$).

• Korean Journal of Materials Research
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• v.9 no.3
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• pp.274-281
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• 1999

Usually sputtering and electroless plating methods were used for manufacturing metal-alloy thin film magnetic memory devices. Since electroless plating method has many merits in mass production and product variety com­pared to sputtering method, many researches about electroless plating have been performed in the United State of America and Japan. However, electroless plating method has not been studied frequently in Korea. In these respects the purpose of this research is manufacturing Co-Mn-P alloy thin film on the corning glass 2948 by electroless plating method using sodium hypophosphite as a reductant, and analyzing deposition rate, alloy composition, microstructure, and magnetic characteristics at various pH's and temperatures. For Co-P alloy thin film, the reductive deposition reaction 0$\alpha$urred only in basic condition, not in acidic condition. The deposition rate increased as the pH and temperature increased, and the optimum condition was found at the pH of 10 and the temperature of $80^{\circ}C$. Also magnetic charac­teristics was found to be most excellent at the pH of 9 and the temperature of $70^{\circ}C$, resulting in the coercive force of 8700e and the squareness of 0.78. At this condition, the contents of P was 2.54% and the thickness of the film was $0.216\mu\textrm{m}$. For crystal orientation, we could not observe fcc for $\beta$-Co. On the other hand,(1010), (0002), (1011) orientation of hcp for a-Co was observed. We could confirm the formation of longitudinal magnetization from dominant (1010) and (1011) orientation of Co-P alloy. For Co-Mn-P alloy deposition, coercive force was about 1000e more than that of Co P alloy, but squareness had no difference. For crystal orientation, (l01O) and (lOll) orientation of $\alpha$-Co was dominant as same as that of Co- P alloy. Likewise we could confirm the formation of longitudinal magnetization.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.229-234
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• 2012

A key molecule in the pathogenesis of Alzheimer's disease (AD) is the ${\beta}$-amyloid peptide ($A{\beta}$) generated by ${\beta}$-secretase activity, an aspartic protease. This study was designed to evaluate inhibitory effect of the high-molecular weight water-soluble polysaccharides (Et-P) isolated and purified from Phellinus linteus fruiting body on ${\beta}$-secretase activity. The Et-P was purified from the hot water extract of Phellinus linteus fruiting body mainly by 75% ethanol precipitation and DEAE-Cellulose column chromatography. From the DEAE-Cellulose chromato-gram and molecular weight analysis, the Et-P was shown to be a mixture of three polysaccharides with molecular mass of 1,629, 1,294, and 21 kDa, respectively. The monosaccharide composition of Et-P was determined to be glu-cose, galactose, and mannose as major sugars, glucose being the most prominent one (48% in mole percentage). The elemental analysis and FT-IR analysis suggested that Et-P is typical polysaccharides having at least partially ${\beta}$-linkages and possible existing as complex with phenolic compounds. The laminarinase digestion and HPAEC-PAD analysis suggested that Et-P is a variant of beta-(1,3)-glucans. The Et-P showed DPPH radical scavenging activity and, especially, a significant inhibitory activity on ${\beta}$-secreatase activity (48% inhibitin at 100 ${\mu}g/mL$), suggesting that they may inhibit the formation of $A{\beta}$ which is the major causative of Alzheimer's disease. The results of this study suggest that the water soluble polysaccharides of Phellinus linteus fruiting body can be a potent material for the development of preventive or therapeutic agents for AD.

• Neonatal Medicine
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• v.15 no.1
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• pp.80-83
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• 2008

Purpose : Inguinal hernias are common in children and sometimes are associated with dangerous complications, such as incarceration. There are no established management guidelines for ovarian hernias. We have reviewed the clinical course of ovarian hernias in infants. Methods : We reviewed the medical records of female infants diagnosed with ovarian hernias by ultrasonogram at Kwandong University College of Medicine, Cheil General Hospital, and the Women's Healthcare Center between March 2001 and August 2007. We analyzed the patients gestational age, birth weight, age at the time of detection of the inguinal mass, the patients chief complaints, operative time, post-operative complications, and ultrasonographic findings. Results : Eight female infants had ovarian hernias, four of whom were born prematurely. Seven infants had left-sided ovarian hernias, and one infant had a right-sided ovarian hernia. Five infants underwent surgery and there were no postoperative complications or recurrences. Three girls did not have surgery, and the ovarian hernias regressed spontaneously, with no recurrences or complications. The regression time of inguinal masses ranged from 70-161 days after birth. Conclusion : Physical examination to detect movable masses within the labium major in premature female infants is important because the incidence of premature inguinal hernias is much higher than in term infants. No rational medical treatment plans for female ovarian hernias have been published to date. We cared for three girls with spontaneous regression of ovarian hernias. Pediatricians should be aware whether emergent surgery for ovarian hernias is indicated.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.307-315
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• 1988

This experiment was conducted to find out the effects of fertilizer-N and co-inoculation of the Rhizobium japonicum and the Azospirillum lipoferum on nodulation, $N_2$-fixation, and growth of soybean under in situ conditions. The results obtained were summarized as follows: 1. The yield of soybean dry matter was significantly greater in the R. japonicum alone, and the mixed inoculation of R. japonicum and A. lipoferum than those of un-inoculation. But inoculum applied by different strains did not significant effect on plant growth. The effects of nitrogen applied on soybean dry matter were higher in the ammonium sulfate than potassium nitrate, and decreased with increasing rates of two forms of nitrogen applied regardless of nitrogen source. 2. Acetylene redution activity was more increased in a single inoculation of R. japonicum than those of the mixed inoculation of the R. japonicum and the A. lipoferum, in cases of Danyeup cultivar, regardless of the form of combined nitrogen used. 3. Nodule mass and total nitrogenase activity per plant showed the positively significant effect in the interrelationship between dry matter of soybean and some factors related to nitrogen fixation efficiency. 4. The highest symbiotic effect in Danyeup cultivar was obtained when a single R. japonicum 84 Dy-1 strain was inoculated and fertilized with 18 mM potassium nitrate.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.1
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• pp.39-47
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• 2006

Purpose: We proposed a new classification of pediatric intussusception based on clinical and radiologic findings. Methods: Data from 88 consecutive patients with intussusception were reviewed. We retrospectively analyzed six factors; patient age, sites of intussusception, symptoms, therapeutic methods, existence of enlarged mesenteric lymph nodes, and ultrasonographic (US) findings from clinical records. Results: 1) There was one neonatal case (1.1%), the others (98.9%) were infants and children. 2) These 87 infant and child cases consisted of 14 cases (16.1%) of small bowel intussusception (SBI) and 73 cases (83.9%) of ileo-colic intussusception (ICI). Of the 14 SBI cases, 12 cases were symptomatic and 2 cases were asymptomatic. The symptomatic group comprised 8 transient cases (66.7%), 3 operative cases (25.0%), and 1 enema-reduction case (8.3%). Two asymptomatic cases were incidentally captured by computed tomography. Of the 73 ICI cases, 19 cases (26.0%) required operation, and 54 (74.0%) enema-reduction. 3) When transient SBI cases were compared with operated SBI cases, enema-reduced and operated ICI cases, the age ($38.0{\pm}22.9$ months) of transient SBI cases were significantly higher than those of the others (p=0.003). Mean mass size ($20.8{\pm}2.7mm$) in transient SBI was significantly smaller than in the others (p=0.0001). 4) No correlation was found between the existence of enlarged mesenteric lymph nodes and therapeutic method or concomitant illness. 5) Most of the target types observed by US were in transient SBI cases, the remainder were in the enema-reduced ICI cases. In terms of the doughnuts type, all 8 cases (34.8%) with an external hypoechoic rim thickness of >8.9mm were treated surgically. Conclusion: Pediatric intussusception may be classified based on clinical and radiologic findings, which are likely to indicate appropriate therapies.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.31-37
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• 2005

Puruose : Thin glomerular basement membrane disease(TGBMD) is found in patients with family history of hematuria. TGBMD is autosomal dominant and is known to be one of the commonest causes of asymptomatic hematuria. This study was conducted to evaluate the histological and clinical features of patients with TGBMD. Methods : 150 cases diagnosed with TGBMD by renal biopsy while admitted in the department of pediatrics, Kyungpook National University Hospital between January 1999 and December 2003 comprised the study group. The following parameters were retrospectively anaIyzed age of onset, hematuria pattern, existence of proteinuria, process of diagnosis, laboratory findings, thickness and character of basement membrane and family history. Results : The mean age at the time of diagnosis was 7.9 years. The male to female ratio was 65:77. 94 patients or 66% visited the hospital with a chief complaint of persistent microscopic hematuria. Gross hematuria accounted for 13 cases or 9%. 78 cases(55%) were found to have hematuria for the first time from a routine school urinalysis screening. The renal biopsy showed the thickness of basement membrane to be 186$\pm$36 nm. Focal lamellation of the basement membrane was found in eight cases. In the family history, hematuria was shown in 10 cases on the Paternal side, 13 on The maternal side and none on both sides. In seven cases, hematuria was shown among siblings. No significant differences were found among the laboratory test results which were conducted at an average interval of fifteen months. Conclusion : TGBMD is one of the major causes of asymptomatic hematuria in children, which was diagnosed in increasing numbers since school urinary mass screening test started in 1998. In cases with familial progressive renal disease or focal duplication in the basement membrane Alport syndrome should be considered.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.105-118
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• 2006

Isolation and Identification of fatty acid and volatile compounds in tuna fish oil were successfully carried out using supercritical carbon dioxide. Samples of the oil were extracted in a 56 ml semi-batch stainless steel vessel under conditions which ranged from 80 to 200 bar and 40 to $60^{\circ}C$ with carbon dioxide flows from 10 ml/min. Volatiles in the oil extracted from the samples with supercritical carbon dioxide were analyzed by gas chromatography, mass detector with canister system. The extracts were contained with various fatty acids, 57.0% of unsaturated fatty acids such as docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA), and 43.0% of saturated fatty acids. The aroma compounds in the oil showed over 129 peaks, of which 100 compounds were identified. Volatile components included 2,4-hepatadienal(fishy), dimethyldisulfide (unpleasant), dimethyltrisulfide (unpleasant) and 2-nonenal(fatty). The isolation efficiency of the volatile compounds from the samples was 99.4% at $50^{\circ}C$ and 200 bar.