• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.21-48
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• 1974

The studies were carried out to disclose the physical and chemical properties of sericin fraction obtained from silk cocoon shells and its characteristics of swelling and solubility. The following results were obtained. 1. The physical and chemical properties of sericin fraction. 1) In contrast to the easy water soluble sericin, the hard soluble sericin contains fewer amino acids include of polar side radical while the hard soluble amino acid sach as alanine and leucine were detected. 2) The easy soluble amino acids were found mainly on the outer part of the fibroin, but the hard soluble amino acids were located in the near parts to the fibroin. 3) The swelling and solubility of the sericin could be hardly assayed by the analysis of the amino acid composition, and could be considered to tee closely related to the compound of the sericin crystal and secondary structure. 4) The X-ray patterns of the cocoon filament were ring shape, but they disappeared by the degumming treatment. 5) The sericin of tussah silkworm (A. pernyi), showed stronger circular patterns in the meridian than the regular silkworm (Bombyx mori). 6) There was no pattern difference between Fraction A and B. 7) X-ray diffraction patterns of the Sericin 1, ll and 111 were similar except interference of 8.85A (side chain spacing). 8) The amino acids above 150 in molecular weight such as Cys. Tyr. Phe. His. and Arg. were not found quantitatively by the 60 minutes-hydrolysis (6N-HCI). 9) The X-ray Pattern of 4.6A had a tendency to disappear with hot-water, ether, and alcohol treatment. 10) The partial hydrolysis of sericin showed a cirucular interference (2A) on the meridian. 11) The sericin pellet after hydrolysis was considered to be peptides composed with specific amino acids. 12) The decomposing temperature of Sericin 111 was higher than that of Sericin I and II. 13) Thermogram of the inner portioned sericin of the cocoon shell had double endothermic peaks at 165$^{\circ}C$, and 245$^{\circ}C$, and its decomposing temperature was higher than that of other portioned sericin. 14) The infrared spectroscopic properties among sericin I, II, III and sericin extracted from each layer portion of the cocoon shell were similar. II. The characteristics of seriein swelling and solubility related with silk processing. 1) Fifteen minutes was required to dehydrate the free moisture of cocoon shells with centrifugal force controlled at 13${\times}$10$^4$ dyne/g at 3,000 R.P.M. B) It took 30 minutes for the sericin to show positive reaction with the Folin-Ciocaltue reagent at room temperature. 3) The measurable wave length of the visible radiation was 500-750m${\mu}$, and the highest absorbance was observed at the wave length of 650m${\mu}$. 4) The colorimetric analysis should be conducted at 650mu for low concentration (10$\mu\textrm{g}$/$m\ell$), and at 500m${\mu}$ for the higher concentration to obtain an exact analysis. 5) The absorbing curves of sericin and egg albumin at different wave lengths were similar, but the absorbance of the former was slightly higher than that of the latter. 6) The quantity of the sericin measured by the colorimetric analysis, turned out to be less than by the Kjeldahl method. 7) Both temperature and duration in the cocoon cooking process has much effect on the swelling and solubility of the cocoon shells, but the temperature was more influential than the duration of the treatment. 8) The factorial relation between the temperature and the duration of treatment of the cocoon cooking to check for siricin swelling and solubility showed that the treatment duration should be gradually increased to reach optimum swelling and solubility of sericin with low temperature(70$^{\circ}C$) . High temperature, however, showed more sharp increase. 9) The more increased temperature in the drying of fresh cocoons, the less the sericin swelling and solubility were obtained. 10) In a specific cooking duration, the heavier the cocoon shell is, the less the swelling and solubility were obtained. 11) It was considered that there are differences in swelling or solubility between the filaments of each cocoon layer. 12) Sericin swelling or solubility in the cocoon filament was decreased by the wax extraction.. 13) The ionic surface active agent accelerated the swelling and solubility of the sericin at the range of pH 6-7. 14) In the same conditions as above, the cation agent was absorbed into the sericin. 15) In case of the increase of Ca ang Mg in the reeling water, its pH value drifted toward the acidity. 16) A buffering action was observed between the sericin and the water hardness constituents in the reeling water. 17) The effect of calcium on the swelling and solubility of the sericin was more moderate than that of magnecium. 18) The solute of the water hardness constituents increased the electric conductivity in the reeling water.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.279-286
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• 2002

To improve the growth inhibition activities and selectivities for quinclorac family, novel 3-substituted phenyl-5-(3,7-dichloro-8-quinolinyl)-1,2,4-oxadiazole derivatives as the substrate were synthesized and their the activities ($pI_{50}$) against shoot and root of rice plant (Oryza sativa L.) and barn-yard grass (Echinochloa crus-galli) were measured. And the quantitative structure-activity relationships (QSARs) between physicochemical parameters of the substitutents (R) on phenyl group and the activities ($pI_{50}$) were analyzed quantitatively. According to the SAR analyses, the substrates of planar conformation showed higher herbicidal activities against barnyard grass than rice plant. The activities against rice plant depend on the electronic effect (shoots: ${\sigma}_{opt.}=0.49$ & root: $R_{opt.}=-0.15$) of substituents, whereas the activities against shoots and roots of barnyard grass depend on hydrophobicity (${\pi}_{opt.}=0.37{\sim}2.40$). There were conditions of selective growth inhibition activity against barnyard grass when such a ortho-substituted electron donating substituents showing the hydrophobicity value, ${\pi}=2.40$ were introduced on the phenyl ring. The 2-tolyl substituent predicted from SAR equations was expected to have better growth inhibition activity and selectivity (${\Delta}pI_{50}=1.26$) for barnyard grass.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.278-284
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• 2008

The X-linked inhibitor of apoptosis (XIAP) is a member of a novel family of inhibitors of apoptosis and has several BIR domains (BIR1, BIR2, and BIR3) and a carboxy-terminal RING zinc-finger. Since suppressionof apoptosis is fundamentally important for carcinogenesis and tumor growth, we investigated the expression and function of XIAP in DEN-induced carcinogenesis using rat model. Wistar rats were injected intraperitoneally with DEN at a dose of 50 mg/kg in twice a week for 12 weeks (Group II) and 16 weeks (Group III) followed by the recovery periods, respectively. The evaluation of DEN-induced carcinogenesis carried out the blood, RT-PCR, histopathological and western blot analysis. The level of blood chemistry including GOT/GPT, albumin, and total bilirubin were significantly exchanged comparing to control and Group I/Group II. The expression of albumin and collagen mRNA were significantly exchanged (P<0.05) in both groups. In addition, AFP mRNA expression decreased more after recovery periods than Group II. XIAP was expressed constitutively in normal rat liver as well as DEN-induced Groups I and Group II. In addition, XIAP expression increased more in Group I with 4 weeks recovery periods than Group I. However, XIAP expression shown to increase in Group lI, otherwise, it was decreased in Group II with 10 weeks repair periods. Taken together, these results suggest the alteration of XIAP expression could be involved in hepatocellular carcinogenesis.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.38.2-39
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• 2021

I will presents the analysis of the gas properties of the protoplanetary disk surrounding the young low-mass (about 1.2M_sun) triple star, GG Tau A. This work makes use of ALMA observations of rotational lines of CO (¹²CO, ¹³CO and C¹⁸O) together NOEMA observations of a few dozens of other molecules. While the CO emission gives information on the molecular layer close to the disk atmosphere, its less abundant isotopologues ¹³CO and C¹⁸O bring information much deeper in the molecular layer. I will present the analysis of the morphology and kinematics of the gas disk using the CO isotopologues. A radiative transfer model of the ring in CO isotopologues will also be presented. The subtraction of this model from the original data reveals the weak emission of the molecular gas lying inside the cavity. Thus, I am able to evaluate the properties of the gas inside the cavity, such as the gas dynamics, excitation conditions, and the amount of mass in the cavity. High angular resolution observations of CO reveals sprials induced by embedded planet(s) located near the 3:2:1 mean-motion resonance that help to explain the special morphology of the circumbinary disk. I also discuss some chemical properties of the GG Tau A disk. I report the first detection of H2S and C₂S in a protoplanetary disk. The molecule abundance relative to ¹³CO of about twenties other molecules will also be given. In GG Tau A, the detections of rare molecules such as H₂S and C₂S have been probably possible because the disk is more massive (a factor about 3-5) than other disks where the molecules was searched. Such a large disk mass makes the system suitable to detect rare molecules and to study cold-chemistry in protoplanetary disks.

• Journal of Microbiology and Biotechnology
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• v.6 no.5
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• pp.331-335
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• 1996

The second $\beta$-Xylosidase gene (xylB) from Bacillus stearothermophilus was isolated from the genomic library, cloned into pBR322, and subsequently transferred into Escherichia coli HB101. Six out of 10, 000 transformants were selected from the selective LB medium supplemented with p-nitrophenyl-$\alpha$-L-arabinofuranoside (pNPAf) and ampicillin ($50\mu g$/ml) based on their ability to form a yellow ring around the colony. One of the clones was found to harbor the recombinant plasmid with 5.0 kb foreign DNA, which was identical to the $\alpha$-L-arabinofuranosidase gene (arfI) previously cloned in this lab, while the other five had 3.5 kb of the foreign DNA. Southern blotting experiments confirmed that the 3.5 kb insert DNA was from B. stearothermophilus chromosomal DNA. A zymogram with 4-methylumbelliferyl-$\alpha$-L-arabinofuranoside as the enzyme substrate revealed that the cloned gene product was one of the mutiple $\alpha$-L-arabinofuranosidases produced by B. stearothermophilus. Unlike the arfI gene product, the product of the gene on the insert DNA (xylB) showed an activity not only on pNPAf but also on oNPX suggesting that the cloned gene product could be a bifunctional enzyme having both $\alpha$-L-arabinofuranosidase and $\beta$-xylosidase activities.

• Journal of Korean Neurosurgical Society
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• v.57 no.4
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• pp.276-282
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• 2015

Objective : The purpose of this study was to investigate morphological change at the craniovertebral junction (CVJ) region using computed tomography. Methods : A total of 238 patients were included in this study, and mean age was $47.8{\pm}21.3months$. Spinal canal diameter, Power's ratio, McRae line, antero-posterior C1 ring height, atlantoaxial joint space, C2 growth, epidural space from the dens (M-PB-C2) and longitudinal distance (basion to C2 lower margin, B-C2) were measured. The mean value of each parameter was assessed for individual age groups. The cohorts were then divided into three larger age groups : infancy (I) (${\leq}2years$), very early (VE) childhood (2-5 years) and early (E) childhood ($5{\geq}years$). Results : Spinal canal diameter increased with age; however, this value did not increase with statistical significance after VE age. A significant age-related difference was found for all C2 body and odontoid parameters (p<0.05). Mean McRae line was 8.5, 8, and 7.5 mm in the I, VE, and E groups, respectively. The M-PB-C2 line showed up-and-down dynamic change during early pediatric periods. Conclusion : Expansion of the spinal canal was restricted to the very early childhood period (less than 5 years) in the CVJ region; however, the C2 body and odontoid process increased continuously with age. The above results induced a dynamic change in the M-PB-C2 line. Although C2 longitudinal growth continued with age, the McRae line showed relatively little change.

• Polymer(Korea)
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• v.36 no.3
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• pp.262-267
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• 2012

2-(1,3,3-Trimethyl-6-azabicyclo [3,2,1]-oct-6-yl)-4,5-dihydro-1,3-oxazoline (TAO) was polymerized at several conditions to clarify the influence of initiators, alkyl halide ($PhCH_2Br$, $PhCH_2Cl$, MeI) and sulfonate (MeOTf). The reactions were conducted at $100^{\circ}C$ for 24 h. The resultant polymer forms several kinds of structures with different combination of initiators. The sole MeOTf initiator caused chain transfer reaction to form the one-order structure for which the resultant polymer exclusively formed pendant structure, while alkyl halide and MeOTf formed two kinds of structures, pendant and main chain, which is caused by partly-proceeded double isomerization polymerization by highly reactive nucleophilic counter anion of halogen. Merrifield polymer was also utilized as an intiator and copolymerized with TAO, which produced a graft structure.

• Proceedings of the Korean Vacuum Society Conference
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• 1996.06a
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• pp.40-41
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• 1996

Nitridation technique has been receiving much attention for the formation of a thin nitrided buffer layer on which high quality nitride films can be formedl. Particularly, gallium nitride (GaN) has been considered as a promising material for blue-and ultraviolet-emitting devices. It can also be used for in situ formed and stable passivation layers for selective growth of $GaAs_2$. In this work, formation of a thin nitrided layer is investigated. Nitrogen electron cyclotron resonance(ECR)-plasma is employed for the formation of thin nitrided layer. The plasma source used in this work is a compact ECR plasma gun3 which is specifically designed to enhance control, and to provide in-situ monitoring of plasma parameters during plasma-assisted processing. Microwave power of 100-200 W was used to excite the plasma which was emitted from an orifice of 25 rnm in diameter. The substrate were positioned 15 em away from the orifice of plasma source. Prior to nitridation is performed, the surface of n-type (001)GaAs was exposed to hydrogen plasma for 20 min at $300{\;}^{\circ}C$ in order to eliminate a native oxide formed on GaAs surface. Change from ring to streak in RHEED pattern can be obtained through the irradiation of hydrogen plasma, indicating a clean surface. Nitridation was carried out for 5-40 min at $RT-600{\;}^{\circ}C$ in a ECR plasma-assisted molecular beam epitaxy system. Typical chamber pressure was $7.5{\times}lO^{-4}$ Torr during the nitridations at $N_2$ flow rate of 10 seem.(omitted)mitted)

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1789-1793
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• 2014

Pseudo-first-order rate constants ($k_{obsd}$) have been measured spectrophotometrically for the reactions of 5-nitro-8-quinolyl nicotinate (4) and 5-nitro-8-quinolyl isonicotinate (5) with alkali metal ethoxides (EtOM; M = K, Na and Li) in anhydrous ethanol at $25.0{\pm}0.1^{\circ}C$. The plots of $k_{obsd}$ vs. [EtOM] curve slightly upward for the reactions with EtOK and EtONa but are linear for the reactions with EtOLi and for those with EtOK in the presence of 18-crown-6-ether. Dissection of $k_{obsd}$ into $k_{EtO^-}$ and $k_{EtOM}$ (i.e., the second-order rate constants for the reactions with the dissociated $EtO^-$ and ion-paired EtOM, respectively) has revealed that the reactivity increases in the order $EtO^-{\approx}EtOLi$ < EtOK < EtONa for the reactions of 4 and EtOLi < $EtO^-$ < EtOK < EtONa for the reactions of 5. Comparison of the kinetic results for the reactions of 4 and 5 with those reported previously for the corresponding reactions of 5-nitro-8-quinolyl benzoate (2) and picolinate (3) has revealed that the esters possessing a pyridine ring (i.e., 3-5) are significantly more reactive than the benzoate ester 2 due to the presence of the electronegative N atom (e.g., 2 << 3 < 4 < 5). It has been concluded that $M^+$ ion catalyzes the reactions of 3-5 by increasing the electrophilicity of the reaction center through a five-membered cyclic transition state (TS) for the reaction of 3 and via a four-membered cyclic TS for the reactions of 4 and 5.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2082-2089
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• 1992

An experimental study on forging an axi-symmetric dome type of AISI4130 was carried out using modeling material. In order to verify the validity of the experimental data, a similarity study between plasticine and AISI4130 has been made. Friction conditions were characterized by ring test for the various lubricants. For the closed-die forging experiments of an axi-symmetric dome type of AISI4130 using the plasticine, various cylindrical billets with different aspect ratios were forged and different flash width to thickness(W/T) ratios were used in order to determine the optimum forging conditions. As W/T ratios decrease forging loads decrease while excess volumes increase. It was found out that the experimental results reproduce the similiar results available in the literature. As a result of these experiments, it was construed physical modeling is an excellent tool for forging process simulation at a practical level.