• Journal of Life Science
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• v.19 no.11
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• pp.1672-1678
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• 2009

The purified antifungal substances produced by Bacillus amyloliquefaciens IUB158-03 was positive to ninhydrin but negative to aniline, suggesting that the antifungal substance could be a peptide. FAB-MS, UV adsorption spectrum, and amino acid composition analysis revealed that the molecular weight of the antifungal substance was 1042 and that maximal adsorption was at 220 nm and 277 nm. The antifungal substance was composed of $Asn_3$, $Gln_2$, $Ser_1$, $Gly_1$, and $Tyr_1$. The composition and structural characteristics of antifungal substance were analysed by $^1H$-NMR spectrum, $^1H$-COSY, HMQC, which revealed that the compound belongs to the iturin A family. Temperature and pH had little effect on the stability of the antifungal substance in the ranges of $-70{\sim}121^{\circ}C$ and pH 6.0~10.0, respectively. It showed strong antibiotic activity against fungi. An in vitro cytotoxicity test using NIH3T3 cell showed that the antifungal substance does not have cytotoxicity. The number of circulating leukocytes and the hematobiological analysis of the mice administered with the antifungal substances was similar to those of the control group, indicating no cytotoxicity in vivo. Therefore, the antifungal substances extracted from culture broth of Bacillus amyloliquefaciens IUB158-03 have future potential as biocontrol agents against plant diseases caused by fungi.

• Polymer(Korea)
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• v.32 no.3
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• pp.256-262
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• 2008

Copolyimides containing pendant trifluoromethyl ($CF_3$) groups were synthesized from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and bis[4-(3-aminophenoxy)phenyl]sulfone (BAPS) with various concentrations of 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane(BAPP) to poly(amic acid)(PAA), followed by thermal imidization. These copolyimides were readily soluble in N,N'-dimethylacetamide (DMAc) and could be solution-cast into a flexible and tough film. The thermomechanical properties, morphology and an optical transparency of the copolyimide films were determined using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide angle X-ray diffraction (XRD), scanning electron microscopy (SEM), universal tensile machine (UTM), and a UV-Vis spectrometer. The cast copolyimide films exhibited high optical transparency with a cut-off wavelength (${\lambda}_0$) of $275{\sim}319\;nm$ in UV-vis absorption and a low yellow index(YI) value of $3.65{\sim}10.37$. The thermo-mechanical properties of copolyimide films were enhanced linearly with increasing a BAPP content. In contrast, the optical transparency of the copolyimide films was found to get worse with increasing a BAPP content.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.157-163
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• 1988

The volatile compounds produced from the browning reaction of 0.5M DL-alanine and 0.5M D-glucose mixture using propylene glycol as a reaction medium were analysed by gas chromatography and gas chromatography-mass spectrometry and effects of temperature($100^{\circ}C,\;120^{\circ}C,\;140^{\circ}C$) and time(20min, 2hours) on the formation of volatile compounds were investigated. Browning reaction were rapidly increased as the reaction temperature and time increased. From methylene chloride extracts, twenty six compounds, including 7 alkyl pyrazines. 4 pyrroles, 3 furans, 1 furanone and 11 miscellaneous compounds were identified. The relative amounts of pyrazines, pyrroles and furans were markedly increased as reaction temperature and time increased. The results showed that caramel-like and burnt sugar-like aroma produced by alanine -glucose reaction must be mainly comprised of nitrogeneous heterocyclic such as pyrazines, pyrroles and oxygen heterocyclic compounds such as 2-hydroxy-3-methyl-2-cyclopenten-1-one and 2,5-dimethyl-4-hydroxy-3(2H)-furanone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.139-147
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• 1991

The preservative effect of cellophane film packing on the quality of semi-salted and dried mackerel was studied. The product(P) of semi-salted and dried mackerel was prepared from raw mackerel by filleting, cleaning, soaking in 15%9v/w) salt solution for 30min, draining, packing with cellophane film (PT# 300, thickness:$20{\mu}{\textrm}{m}$) and drying for 4 hrs at $40^{\circ}C$ in hot air dryer. The product (C) was also prepared without cellophane film packing after draining. The product (C) and (P) were stored at $5.0{\pm}0.5^{\circ}C$. After processing and during storage, moisture content of product (P) was higher than that of product (C), but contents of VBN(volatile basic nitrogen), amino nitrogen and TMA of product (P) on dry basis were lower than those of product (C). Viable cell count, TBA value, peroxide value and decreasing rate of polyenoic acid of product (P) were also lower than those of product (C). In sensory evaluation, the shelf life of product (C) was about 9 days and that of product (P) was about 14 days. From the results of chemical and sensory evaluation, it was concluded that cellophane film packing was a good condition for preserving the quality of semi-salted and dried mackerel.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.601-609
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• 2018

Microcystis aeruginosa, a freshwater cyanobacteria species known to be one of the most predominant species responsible for cyanobacterial harmful algal blooms (CyanoHABs). It has been frequently associated with the contamination of neurotoxins and peptide hepatotoxins, such as microcystin and lipopolysaccharides-LPSs. CyanoHABs control technologies so far put in place do not provide a fundamental solution and cause secondary pollution linked with the control measures. For this study, algicidal peptides, which have been reported to be non-toxic and to have antimicrobial properties, were employed for the development of novel eco-friendly control against CyanoHABs. The four peptides (CMA1, CMA2, HPA3P, and HPA3NT3) selected in this study showed significant algicidal effects against M. aeruginosa cells inducing cell aggregation and flotation. Moreover, the newly generated peptides (K160242-5) with certain modifications also displayed high algicidal activity. The algicidal activity of the peptides was found to depend on the concentrations and structures of each of amino acid. The results of this study suggested a novel possibility of CyanoHABs control using the non-toxic algicidal peptides.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.545-553
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• 1993

The metalaxyl seed-soaking treatment markedly increased the root-mat formation of the young rice seedling(8- to l0-day-old) for machine transplanting. This experiment was conducted to find out a possible rooting mechanism of the young rice seedling in relation to the exogenous metalaxyl seed-soaking treatment. The rice seeds of Hwaseongbyeo variety were soaked in the solution of metalaxyl for 24 hours at room temperature. Metalaxyl(25% wettable powder), a fungicide, was used at the concentration of 200ppm as a promoting substance on the root-mat formation of the young rice seedling. Seeding rate of the young rice seedling was 220g per seed tray(30${\times}$60${\times}$depth 3cm). Metalaxyl seed treatment was highly effective in root initiation and elongation of the young rice seedling in terms of root activity, the number and length of root, and amino acid content of roots. The exogenous metalaxyl application would also increase the chlorophyll content and photosynthetic rate in the young rice seedling. Those factors resulted in vigorous root-mat formation of the young rice seedling. In particular, alanine is a lead compound of metalaxyl which biochemically plays an important role in energy intermediate of the rice plant. Alanine conjugation with a glucose (N-${\beta}$-glucoside) is probably the mechanism in enhancement of initiation and elongation of rice roots of young rice seedling.

• Clean Technology
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• v.16 no.2
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• pp.117-123
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• 2010

In this study, we propose two methods able to recover different type of gold from gold-cyanide solutions: biosorption and desorption process for mono-valent gold recovery and biosorption and incineration process for zero-valent gold recovery. The waste bacterial biomass of Corynebacterium glutamicum generated from amino acid fermentation industry was used as a biosorbent. The pH edge experiments indicated that the optimal pH range was pH 2 - 3. From isothermal experiment and its fitting with Langmuir equation, the maximum uptake capacity of Au(I) at pH 2.5 were determined to be 35.15 mg/g. Kinetic tests evidenced that the process is very fast so that biosorption equilibrium was completed within the 60 min. To recover Au(I), the gold ions were able to be successfully eluted from the Au-loaded biosorbent by changing the pH to pH 7 and the desorption efficiency was 91%. This indicates that the combined process of biosorption and desorption would be effective for the recovery of Au(I). In order to recover zero-valent gold, the Au-loaded biosorbents were incinerated. The content of zero-valent gold in the incineration ash was as high as 85%. Therefore, we claim on the basis of the results that two suggested combined processes could be useful to recover gold from cyanide solutions and chosen according to the type of gold to be recovered.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.359-381
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• 1992

This study was designed to investigate the effect of diazepam on the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus. Female rat(Sprague-Dawley) pretreated with oophorectomy and 4 days administration of estrogen, weighing about 200 g, was sacrificed by cervical dislocation, and the uteruses were isolated. A longitudinal muscle strip was placed in temperature controlled($37^{\circ}C$) muscle chamber containing Locke's solution and myographied isometrically. Diazepam inhibited the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus in a concentration-dependent manner. GABA, muscimol, a GABA A receptor agonist, bicuculline, a competitive GAGA A receptor antagonist, picrotoxin, a non competitive GABA A receptor antagonist, baclofen, a GABA B receptor agonist, and delta-aminovaleric acid, a GABA B receptor antagonist, did not affect on the spontaneous and oxytocin induced contraction of the isolated rat uterus. The inhibitory actions of diazepam on the spontaneous and oxytocin induced contraction were not affected by all the GABA receptor agonists and antagonists, but exceptionally potentiated by bicuculline. This potentiation-effect by bicuculline was not antagonized by muscimol. In normal calcium PSS, addition of calcium restored the spontaneous contraction preinhibited by diazepam and recovered the contractile of oxytocin preinhibited by diazepam. A23187, a calcium inophore, enhanced the restoration of both the spontaneous and oxytocin induced contraction by addition of calcium. In calcium-free PSS, diazepam suppressed the restoration of spontaneous motility by addition of calcium but allowed the recovery of spontaneous motility to a considerable extent. Diazepam could not inhibit some development of contractility by oxytocin in calcium-free PSS, but inhibited the increase in contractility by subsequent addition of calcium. These results suggest that the inhibitory action of diazepam on the rat uterine motility does not depend on or related to GABA receptors and that diazepam inhibits the extracellular calcium influx to suppress the spontaneous and oxytocin induced contractilities.

• The Korean Journal of Mycology
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• v.4 no.1
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• pp.31-44
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• 1976

The studies were carried out to examine the effects of supplementation of nutritional substances and physical conditions in substrate on the mycelial growth and yield of fresh sporophores of winter mushroom, Flammulina velutipes(Curt. ex Fr.) Sing. and to obtain further informations on the nutritional requirements of the fungus with reference to improvement of substrate through [analysis of chemical composition of the substrates during the cultivation period. The results obtained are summarized as follows: 1. The best yield of fresh sporophores, 84.4 g per 280 g substrate in a bottle, was obtained from the mixture of poplar sawdust 10 and rice bran 3 by volume when Flammulina velutipes was cultivated on the poplar sawdust supplemented by rice bran, wheat bran, cattle manure and various combinations of these materials as nutrient sources. The substrates of poplar sawdust 10 plus rice bran 3 and 2 or wheat bran 3 with a higher yield of fresh sporophores showed a comparatively higher content of total nitrogen. total sugar, and potassium. 2. The mycelial growth of the fungus was compared on the substrates of poplar sawdust supplemented by the several nutrient sources and poplar sawdust alone. The fastest linear growth occurred on substrates of poplar sawdust alone and poplar sawdust plus cattle manure deficient in sugar and nitrogen sources, but mycelial density was more sparse on the substrates. Also, growth in a solution extracted from these substrates was very meager. 3. In the substrates which varied with bulk density and moisture content optimum bulk density and moisture content for mycelial growth was 0.2g/cc and 72% on a dry weight basis, respectively, but the highest yield of fresh sporophores was obtained at the bulk density of 0.3g/cc and moisture content of 67%. 4. By increasing the ratio of rice bran in poplar sawdust the loss of total weight and ash, content at each stage was increased, and during the cultivation period of 75 days, loss of total weight of the substrates at inoculation was 17.8 to 28.8% and ash content increased about 12%. 5. 11 to 14% of the cellulose and 3 to 4% of the lignin content per original substrate were decreased without a great difference depending of the mixing ratio of rice bran. The soluble glucose concentration in the substrates was increased during the same period. 6. In the process of vegetative and reproductive growth of the fungus upon the substrates, the total nitrogen was increased in quantity per dry weight of sample but was reduced in absolute quantity to a minute extent. There is no great changes in content of organic nitrogen including amino acid nitrogen, and hydrolysable ammonium nitrogen during the vegetative growth period, but occurrence of sporophores resulted in a decrease in the nitrogen content of these forms. On the one hand, by an increase of additive amounts of rice bran, nitrogen contents of these forms were higher and the reduction range during the reproductive growth period became wider. 7. Mycelial growth of the fungus was accelerated in various liquid media supplemented with organic nitrogen sources such as peptone and yeast extract in comparison with addition of inorganic nitrogen sources. Furthermore, mycelial growth was mere vigorous in the media with higher content of organic nitrogen sources.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.1-31
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• 1962

The purpose of this treatise is to prove the presence of cystine in silk fiber through wide sampling throughout all the sericultural processes of Bombyx mori.; also to show that disulfide cross linkages exist in the silk fiber. The conclusions reached were as follows: 1. Crystalline cystine was obtained from silk fibroin using Folin's Method. 2. Analytical data showing the cystine content of silk fiber and its related materials were obtained using Sullvan's Method as follows: Material Percent Cystine A. Mulberry leaf protein 0.175 B. Silkworm egg 0.33 C. Silkworm Body, matured, fat extracted, without silk gland 0.41 D. Silk gland, matured 1.23 E. Silkworm feces none F. Silkworm pupa, fat extracted 0.30 G. Silkworm moth, fat extracted 0.60 H. Raw Silk 0.22 I. Fibroin 0.175 J. Sericin 0.30 3. The presence of cystine in the silkworm was substantiated the existence of 0.175 % methionine in mulberry leaves and 0.12% methionine in the silk gland. 4. Part of the sulfhydryl compounds in the silk gland is believed to transfer to serine and methionine, with the former being secreted into the liquid silk finally as silk fiber and the latter used for nutritive purposes in the growing of silk gland tissue. 5. The cystine content is variable by mulberry species, silkworm species, sex, breeding process, and other culturing environments. 6. Hybrid silkworms require more nutritive amino acids for effective growth than the original parents, and secrete less of them as silk fiber. 7. From such an observation, the amino acid composition of silk fiber is believed to be fairly flexible. Cystine if included in the amorphous part of the fiber, especially in sericin. 8. The result from enriching the silkworm diet with pure cystine or wool cystine did not result in any advantage, therefore it is believed that the natural cystine and methionine contents in the mulberry leafaregoodenoughforsilkwormnutrition. 9. The disulfide cross linkage in silk fiber was verified by using the Harris Method. Contraction took place following the treatment of the fiber with various salts and acids. Comparisons were made with wool fiber. 10. During these experiments, the fibrious structure of silk fiber and the net-globular liquid form were photographed microscopically. It is believed that the globules of liquid silk are net-formed by the inter attraction of the OH ion of the globular peptide and the H ion of water as shown by the hair cracking behavior of the film. The net-globular protein precipitation from the mulberry protein solution showed that mulberry is a proper diet for the formation of fibrous protein in the silk fiber. 11. The significance of the presence of cystine in silk fiber as emphasized in this paper should result in modification of the general conception that cystine is absent from this fiber. NOTICE: A part of this treatise was presented at the annual Korea Sericultural Society meeting held in 1961.