• 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.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.507-515
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• 1996

Background : Potassium channel opener (K-opener) opens ATP-sensitive K'-channel located at cell membrane and induces potassium efflux from cytosol, resulting in intracellular hyperpolarization. Newly synthesized K-opener is currently examined for pharmacologic potency by means of rubidium release test from smooth muscle strip pre-incubated with Rb-86. Since in-vivo behavior of thallium is similar to that of rubidium, we hypothesized that K-opener can alter T1-201 kinetics in vivo. Purpose : This study was prepared to investigate the effects of pinacidil (one of potent K-openers) on the T1-201 uptake and clearance in cultured myocyte, and in-vivo biodistribution in mice. Methods : Spontaneous contracting myocytes were prepared to imitate in-vivo condition from 20 hearts of 3-5 days old Sprague-Dawley rat and cultured for 3-5 days before use ($5{\times}10^5$ cells/ml). Pinacidil was dissolved in 10% DMSO solution at a final concentration of 100nM or l0uM and was co-incubated with T1-201 in HBSS buffer for 20-min to evaluate its effect on cellular T1-uptake, or challenged to cell preparation pre-incubated with T1-201 for washout study. Two, 40 or $100{\mu}g$ of pinacidil was injected intravenously into ICR mice at 10 min after $5{\mu}Ci$ T1-201 injection, and organ uptake and whole body retention rate were measured at different time points. Results : Co-incubation of pinacidil with T1-201 resulted in a decrease in T1-201 uptake into cultured myocyte by 1.6 to 2.5 times, depending on pinacidil concentration and activity of T1-201 used. Pinacidil enhanced T1-201 washout by 1.6-3.1 times from myocyte preparations pre-incubated with T1-201. Pinacidil treatment appears to be resulted in mild decreases in blood and liver activity in normal mice, in contrast, renal and cardiac uptake were mildly decreased in a dose dependent manner. Whole body retention ratios of T1-201 were lower at 24 hour after injection with $100{\mu}g$ of pinacidil than control. Conclusion : These results suggest that treatment with K-opener may affect the interpretation of T1-201 myocardial images, due to decreasing thallium accumulation and enhancing washout from myocardium.

• 한국해양학회지
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• v.10 no.1
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• pp.33-40
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• 1975

The ion exchange sorption and elution behavior of toxic heavy metal ions, such as Hg(II) and Zn(II), have been studied in aqueous and methanolic media of MCl (M: K, Na and NH$\_$4/). The ion exchange resins studied are Dowex 1-X8, Cl$\^$-/ (50-100 or 200-400 mesh) and Dowex 50W-X8, M$\^$+/ form (M: K, Na, NH$\_$4/ and H). the sorption and elution of metal ion on the resin is largely due to the formation of the anionic chlororocomplex of metal ion. The addition of methanol in the medium contributes markedly to the distribution data. In order to apply this work for the treatment of polluted sea water with toxic heavy metal ions, removal experiment of the metal ions from the synthetic sample solution was investigated.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.483-489
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• 2006

The behavior of rare earth compounds such as $La_{2}O_{3}$, $CeO_{2}$, and $Ca(OH)_{2}$ on the removal of fluoride and heavy metals in the steel wastewater has been investigated. The removal mechanism of fluoride by rare earth elements has been known to be the formation of insoluble compounds between $F^{-}$ and cations such as $La^{3+}$ and $Ce^{4+}$ produced by the dissociation of rare earth compounds (To reduce the running cost of the fluoride wastewater treatment facility, their fluoride removal efficiencies were compared with those of inexpensive rare earth minerals such as natural lanthanide and cerium compound used as a glass polishing agent). All of the rare earth oxides used in this study showed a higher removal efficiency of fluoride than $Ca(OH)_{2}$ in the wastewater. In the case of artificial HF solution, the removal efficiency of fluoride showed in the order: $CeO_{2}$-mineral < $CeO_{2}$ < $Ca(OH)_{2}$ < $La_{2}O_{3}$-mineral < $La_{2}O_{3}$. However, the removal efficiency of fluoride in the wastewater increased in the following order: $Ca(OH)_{2}$ < $CeO_{2}$ mineral < $CeO_{2}$ < $La_{2}O_{3}$ mineral < $La_{2}O_{3}$. All agents showed high efficiencies for the removal of Mn and total Cr in the rare earth compounds. In the case of $Ca(OH)_{2}$, fluoride removal decreased with increasing pH while. However, the rare earth compounds showed a higher fluoride removal in higher pH condition, the optimum pH condition seemed to be around 7 considering both water quality and fluoride removal. Under the pH 7 condition, the $Ca(OH)_{2}$ was superior to rare earth compounds in Mn removal and the lanthanide was superior to others in total Cr removal.

• Korean Journal of Health Education and Promotion
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• v.1 no.1
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• pp.57-71
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• 1983

Sex education is necessary for the youth that they should have an adequate sexual knowledge, attitudes and behaviors in their adolescent period. Four major objectives of this study are as follows; 1. To know the level of sexual knowledge of commercial girl's high school students in Seoul. 2. To know their actual state for the attitudes and behaviors toward sex. 3. To compare the sexual knowledge, attitudes and behaviors of day time school students with those of night time school students. 4. To compare the factors associated with their sexual knowledge, attitudes and behaviors with the individual level. Data were collected on 986 students in Seoul from April 1 to April 10, 1983. As the result of this survey, the following conclusions were obtained. 1. The level of sexual knowledge. (1) The level of knowledge of day time high school students about the physiology of female and pregnancy is shown higher than those of night time students. 64.2% of the respondents are aware of the organ producing ovum. 56.4% the ovulation period. 95.6% the cause of pregnancy. 74.5% the pregnantable period and 12.7% the place of fetilization. (2) Out of 986 respondents. 71.8% knew about contraceptive method correctly, and day time school students knew litter better than night time school students, by showing 73.9% and 69.7% respectively. They knew about contraceptive method with 'oral pills'. 'menstrual cycles', 'condoms'. and 'loops' in the same order. 3) Kinds of veneral disease was correctly known by 37.9%. Day time students knew much better than night time school students. by showing 67.8% and 7.9%. respectively. Transmission method of veneral disease was correctly known by 28.3%. Day time students knew much better than night time students, by showing 51.2% and 5.3%, respectively. (4) The major information source of sexual knowledge was 'book and magazine' (39.9%) and 'friends' (27.4%). 2. Actual state of attitudes and behaviors toward sex. (1) Out of 986 respondents, 84.0% answered that premarital purity should be kept. (2) Out of 986 respondents, 60.8% had an acquaintance of the opposite sex. 45.2% of students with opposite sex reported introduction of their friends as the main channel of making an acquaintance of the opposite sex. (3) Of those who responded to this study 13.8% reported having masturbation, 21.5% kissing, 6.2% petting and 3.7% sex intercourse. (4) 64.8% had sexual problems, which was mensturance (27.2%), aquaintance of the opposite sex (25.4%). The main method to solve the problems were consultation with 'friends' and 'books and magazine' percentage being 39.1% and 30.8%, respectively, whereas very small students discussed with 'teachers' and 'parents' percentages being 0.3% and 5.9%, respectively. (5) Out of 986 respondents, 62.2% had experience in educating about sex, the percentage of day time school was higher than that of night time school. (6) 88.2% of students wanted sex education in school, which were 'general information about sex' (35.4%), 'sexual morality and solution of sexual desire' (18.5%), 'aquaintance of the opposite sex' (13.3%) and 'marriage and role of man and woman' (12.4%) in the same order. They wanted to be instructed about sexes in the lecture of physical education, home economics, biology, military training (59.9%), regular curriculum (17.5%), special lecture (16.9%) and by the counselor or school nurse (5.7%). 3. Analyse concerning the factors about the knowledge, attitudes and behaviors. (1) The better school record was, the higher the level of sexual knowledge. (2) Those who have the religion considered the permarital purity more important than those who have not, the percentage showing 86.7% and 80.7%, respectively. (3) The result of dyad analysis of making acquaintance of the opposite sex in the friendship network showed that a high index of the acquaintance of the opposite sex tends to be a high adoption of making one at the individual level in the group, while the low index tends to be a low adoption of making one in the group.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.341-347
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• 2008

The feasibility of commercializing the hydrothermal synthesis of Na-A type zeolite from siliceous mudstone has been conducted using a 50-liter bench-scale autoclave and the application of the zeolite as an environmental remediation agent. Siliceous mudstone, which is widely distributed around the Pohang area, was adopted as a precursor. The siliceous mudstone is favorable for the synthesis of zeolite because it contains 70.7% $SiO_2$ and 10.0% $Al_2O_3$, which are major ingredient of zeolite formation. The synthesis of zeolite was carried out under the following conditions that had been obtained from the previous laboratory-scale tests: 10hr reaction time, $80^{\circ}C$ reaction temperature, $Na_2O/SiO_2$ ratio = 0.6, $SiO_2/Al_2O_3$ ratio = 2.0 and $H_2O/Na_2O$ ratio= 98.6. The crystallinity and morphology of the zeolite formed were similar to those obtained from the laboratory-scale tests. The recovery and cation exchange ion capacity were 95% and 215 cmol/kg, respectively, which are slightly higher than those obtained in laboratory scale tests. To examine the feasibility of the zeolite as an environmental remediation agent, experiments for heavy metal adsorption to zeolite were conducted. Its removal efficiencies of heavy metals in simulated waste solutions decreased in the following sequences: Pb > Cd > Cu = Zn > Mn. In a solution of 1500 mg/L total impurity metals, the removal efficiencies for these impurity metals were near completion (> 99%) except for Mn whose efficiency was 98%. Therefore, the synthetic Na-A type zeolite was proven to be a strong absorbent effective for removing heavy metals.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.570-577
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• 1999

Intuitively, higher bond strengths should result in less leakage. However, the relationship between bond strengths and microleakage value is complex and not clearly understood. The purpose of this study was to evaluate the relationship between tensile bond strengths and microleakage values in the same restorations to understand the behavior of resin bonding to tooth structure. One-hundred and twenty enamel or dentin specimens from freshly extracted bovine mandibular incisors were used. The specimen was treated with 32% phosphoric acid for 15 seconds and rinsed for 20 seconds. the teeth were divided into four groups by means of wet bonding technique or dry bonding. One-Step$^{TM}$ adhesive were applied to the specimen. The specimens were immersed in 2% methylene blue solution for 7 days, and tensile bond strength and microleakage were measured. The results were as follows: 1. Significant negative correlation was found between bond strengths and micro leakage values. Hence, higher bond strengths seem to be associated with lower microleakage, and vice versa (r=-0 50, p<0.05). 2. The Enamel/Wet group showed significantly higher bond strength than Enamel/Dry one, and Dentin/Wet group showed higher strength than Dentin/Dry one (p<0.05). 3. Microleakage was significantly less ill wet bonding than in dry one at dentin (p<0.05), however, there was no significant difference between wet and dry bonding at enamel (p>0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.544-556
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• 2011

This study investigated how elementary schoolers (n=159, 9~11 years) and middle schoolers (n=176, 13~15 years) perceived maternal parenting style dimensions, both general and child-feeding related, and whether these dimensions are associated with the subject's food behaviors. The exploratory factor analysis resulted in a solution of 10 parenting dimensions (reasonable guidance, affection and involvement, achievement expectation, clear behavioral regulation, criticism and anger, overprotection, psychological punishment, harsh punishment, punish by withdrawal of child's privileges, and lack of punishment) and 8 child-feeding dimensions (portion control, restriction, pressure to eat, monitor, undesirable model, desirable model, discourage unhealthful eating, and encourage healthful eating) with 49 and 43 items, respectively. Three parenting styles, authoritarian, permissive, and authoritative, were extracted via a second factor analysis using the 10 parenting dimensions. The correlation analysis indicated that authoritarian style was positively correlated with 'restriction' and 'undesirable model', while permissive style was negatively correlated with 'encourage healthful eating' in both groups. Authoritative style was strongly associated with all of the child-feeding dimensions except for 'undesirable model'. For food behaviors, the more likely elementary schoolers and middle schoolers perceived their mothers as authoritarian and permissive, respectively, the more unhealthful foods were consumed. The consumption frequency of healthful foods increased as mothers were perceived to be authoritative. More elementary schoolers of authoritative mothers ate meals with parents. Findings suggest that maternal parenting styles and dimensions, child-feeding dimensions, and child's food behaviors are associated. It may be that authoritarian and permissive styles are more detrimental for elementary schoolers and middle schoolers, respectively, whereas authoritative style is beneficial for both groups in terms of subject's food behaviors.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.153-164
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• 1999

The solubilization of BTEX was evaluated in aqueous surfactant solutions with and without several additives. Anionic surfactant(Sodium Dodecyl Sulfate, SDS) and nonionic surfactants (NEODOL(equation omitted)25-3 and $SOFTANOL\circledR-90$ were used as test surfactants. The effects of surfactant HLB(Hydrophile-Lipophile Balance) Number and hydrocarbon molar volume and polarity of BTEX on the MSR(Molar Solubilization Ratio), micelle-water partition coefficient of BTEX, and CMC(C,itical Micelle Concentration) were investigated. Optimizing treatment conditions applicable to enhanced solubilization was also studied by manupulating salinity or electrolyte control with additives of ethyl alcohol, hydrotrope, and electrolyte solution. The most effective surfactant for solubilization was found $SOFTANOL\circledR-90$, since HLB number of 13.6 is similar to those values of BTEX ranging between 11.4 and 12.2, which was also proved experimentally. Ethyl alchohol of 3% was the most effective additives in reducing CMC and improving solubilization among the conditions using SDS, NEODOL(equation omitted)25-3, and $SOFTANOL\circledR-90$ with three additives. The partitioning of BTEX between surfactant micelles and aqueous solutions was characterized by a mole fraction micelle-phase/aqueous phase partion coefficient, $K_m$. Values of log $K_m$. for BTEX compounds in surfactant solutions of this study range from 2.95 to 3.76(100mM SDS) and 2.95 to 3.49(117mM $SOFTANOL\circledR-90$. Log $K_m$ appears to be a linear function of log $K_{ow}$ for SDS and $SOFTANOL\circledR-90$. A knowledge of partitioning of BTEX in aqueous surfactant system can be a prerequisite for the understanding of the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in remediation of contaminated soil and facilitated transport.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.83-89
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• 2010

We investigated the growth of cucumber plants, the uptake and use of mineral nutrients, such as $NO_3$-N, $NH_4$-N, $K^+$, $Ca^{+}^{+}$, $Mg^{+}^{+}$ and $Na^+$, absorbed from media solution, and the synthesis and distribution of soluble sugars under nutrient-deficient condition. Difference in plant growth revealed after 20 days of treatment. Nitrate uptake in nutrient-deficient condition was significantly reduced compared with nutrient-normal treatment, and its distribution was primarily in petioles, stem, roots and less in leaves. In contrast, ammonium content was markedly predominated in fast growing organs, and it was significantly different in growing leaves, expanded leaves, and roots under similar growth conditions. $K^+$, lack by deficient nutrient condition, was found in growing leaves. The $Ca^{+}^{+}$ content did not show significant difference between treatments and a substantial portion of $Ca^{+}^{+}$ remained in petioles. The $Mg^{+}^{+}$ content was significantly higher in the leaves of nutrient-normal condition compared with nutrient-deficient condition while significantly lower in stem and roots. The behavior of $Na^+$ in plant was similar to $K^+$ although its content was relatively little. The highest $CO_2$ assimilation was observed in fully expanded leaves of nutrient-normal condition, which was 1.7 times higher compared with nutrient-deficient condition. The instantaneous water use efficiency (A/E) and the A/gsratio, which is an index of leaf intrinsic water use efficiency for individual leaves, was 1.2 and 1.1 times higher, respectively. The total soluble sugar (TSS) contents were highest in leaves followed by petioles, stems and roots, and in younger leaves. The growing leaves contained about 7,200 mg $kg^{-1}$ of TSS in nutrient-normal condition whereas the TSS contents in nutrient-deficient condition were not significantly different between leaves. The $Mg^{+}^{+}$ and $NH_4$- N were positively correlated with the TSS whereas $NO_3$ - N was negatively correlated.