• Journal of the Mineralogical Society of Korea
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• v.3 no.1
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• pp.1-6
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• 1990

Clacic amphiboles along the tremolite (Tr)-tschermakite(Ts) joint were synthesized using a piston-cylinder appratus. At 750-85$0^{\circ}C$and 12-2 kb, amphibole+corundum coexist with zoisite($\pm$talc, chlorite, and Mg-staurolite), but with anorthite($\pm$cholorite, spinel, pyroxenes, and sapphirine) at lower P. At 90$0^{\circ}C$, amphibole+corundum+clinopyroxene($\pm$anorthite, forsterite, sapphirine, and garnet) are stable over the P range 12-18 kb. These amphibole-bearing assemblages are replaced at high P by clcinopyroxene+talc+chlorite+zoisite at 650-75$0^{\circ}C$, and at higher temperatures by garnet+clinopyroxene($\pm$zoisite, orthopyroxene, and Mg-staurolite). Synthetic amphiboles with Ts>~45 mol% contain as much as 0.15 excess cations per formula unit(pfu) based on 23 oxygens(anhydrous formula), whereas less tschermakitic ones are deficient in cation occupancy by up to 0.18 pfu. This trend is attributed to the 야/trioctahedral substitution in Ca-amphiboles. Compositions of synthetic amphiboles display systematic changes with P and T governed by coexisting mineral assemblages. The Ts content (=[8-Si-Na]/2) increases with increasing T( Ts/ T=~0.1 nik% K-1) in the range 750-85$0^{\circ}C$, but remains nearly constant at 850-90$0^{\circ}C$. Pressure dramatically affects the Ts content of Ca-amphiboles:it increases with P at 8-12 kb( Ts/ T=2-3 mol% K-1), but significantly decreases at 12-21 kb( Ts/ P=-2.5 mol% Kb-1). Hence, the most tschermakitic amphiboles, containing 60$\pm$5 mol % Ts, or 1.2$\pm$0.1 tetrahedral Al, occur at 12 kb and 850-90$0^{\circ}C$. Compositions of Ca-amphiboles defined by a simple reaction, 3 Tr+2 zoisite+7 corundum+H2O=5 Ts, are reversed and used to estimate thermodynamic parameters of tschermakite assuming ideal mixing of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$=566.9$\pm$13.7 J mol-1K, -1and H$^{\circ}$=-12518.36$\pm$15.17 kJ mol.-1

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.5
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• pp.362-366
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• 2000

$Li_{0.44}MnO_2$cathode material has high reversibility during lithium insertion processes and is not easily damaged through over-charging or over-discharging. $Mn_2O_3$is often present as an impurity phase, and reduce the electrochemical capacity of electrode because this phase is electrochemically inert. Adding of excess NaOH reduced the $Mn_2O_3$to the content under undetectable by X-ray diffraction. Because the capacity can be increased in the cathode materials with larger unit cell, some of the manganese was replaced with titanium having larger ion size, and powders with the formula $Li_{0.44}T_{iy}Mn_{1-y}O_2$(where y = 0.11, 0.22, 0.33, 0.44, and 0.55) was synthesized and characterized. A maximum reversible capacity of 150 mAh/g was obtained for $Li/P(EO)_8$LiTFSI/$Li_{0.44}Ti_{0.22}Mn_{0.78}O_2$cells in electrochemical potential spectroscopy (ECPS) experiments. Cells with the titanium-doped manganese oxides exhibited a fade rate of 0.12 % or less per cycle.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.285-288
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• 2016

Proteolytic enzymes perform hydrolysis of the peptide bonds in the protein and most commonly use in the industry. Pseudoxanthomonas sp. WD12 and WD32 were previously isolated as protease producers from a rotten wood sample. Here, we report the secreted proteolytic enzymes. The optimum enzyme reaction temperature for the secreted crude enzyme from the strain WD12 and WD32 were $50^{\circ}C$ at pH 9.0 and $45^{\circ}C$ at pH 8.0, respectively. The enzyme activities of both strains were increased by addition of KCl, NaCl, $CaCl_2$ or $MnSO_4$, and decreased by addition of $AgNO_3$, $CuSO_4$, $FeCl_3$ or $AlCl_3$. Secreted enzymes of both strains were most strongly inhibited by addition of $FeCl_3$ or $CuSO_4$. Taken together these results, WD12 could be a candidate strain of industrial alkaline protease production.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3253-3256
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• 2015

Background: Chronic hepatitis B virus (HBV) infection related hepatocellular carcinoma (HCC) is a major health problem in the Asia-Pacific region including Thailand. Several factors have been proposed as contributing to hepatocarcinogenesis. This study was aimed to investigate the impact of CYP2C19 genotypic polymorphism in HCC related to chronic HBV infection in Thailand. Materials and Methods: A cross-sectional study was performed between April 2014 and January 2015. Chronic HBV patients with HCC (n=50) and without HCC (n=50) were included. Clinical information and blood samples of all patients were collected. The CYP2C19 genotype was determined by polymerase chain reaction-restriction fragment length polymorphism method, and was classified as rapid metabolizer (RM), intermediate metabolizer (IM) or poor metabolizer (PM). Results: The CYP2C19 genotype frequencies of RM, IM and PM in HBV patients were found to be 19/50 (38%), 25/50 (50%) and 6/50 (12%), respectively. The CYP2C19 genotype frequencies of RM, IM and PM in HBV with HCC patients were 21/50 (42%), 25/50 (50%) and 4/50 (8%), respectively. The distribution of CYP2C19 genotype was not different between patients with and without HCC. Interestingly, among HBV with HCC patients, the RM genotype of CYP2C19 tended to increase risk of aggressive manifestation (OR=2.89, 95%CI=0.76-11.25, P-value=0.07), compared with non RM genotype carriers. Conclusions: CYP2C19 genotype IM was the most common genotype in Thai patients with chronic HBV infection. In addition, genotype RM could be an associated factor for aggressive presentation in HCC related to chronic HBV infection.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10957-10960
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• 2015

Background: The CYP2C19 genotype has been found to be an important factor for peptic ulcer healing and H. pylori eradication, influencing the efficacy of proton pump inhibitors (PPIs) and the pathogenesis of gastric cancer. The aim of this study was to investigate clinical correlations of the CYP2C19 genotype in patients with gastritis, peptic ulcer disease (PUD), peptic ulcer bleeding (PUB) and gastric cancer in Thailand. Materials and Methods: Clinical information, endoscopic findings and H. pylori infection status of patients were assessed between May 2012 and November 2014 in Thammasat University Hospital, Thailand. Upper GI endoscopy was performed for all patients. Five milliliters of blood were collected for H. pylori serological diagnosis and CYP2C19 study. CYP2C19 genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis (RFLP) and classified as rapid metabolizer (RM), intermediate metabolizer (IM) or poor metabolizer (PM). Results: A total of 202 patients were enrolled including 114 with gastritis, 36 with PUD, 50 with PUB and 2 with gastric cancer. Prevalence of CYP2C19 genotype was 82/202 (40.6%) in RM, 99/202 (49%) in IM and 21/202 (10.4%) in PM. Overall H. pylori infection was 138/202 patients (68.3%). H. pylori infection was demonstrated in 72% in RM genotype, 69.7% in IM genotype and 47.6% in PM genotype. Both gastric cancer patients had the IM genotype. In PUB patients, the prevalence of genotype RM (56%) was highest followed by IM (32%) and PM(12%). Furthermore, the prevalence of genotype RM in PUB was significantly greater than gastritis patients (56% vs 36%: p=0.016; OR=2.3, 95%CI=1.1-4.7). Conclusions: CYP2C19 genotype IM was the most common genotype whereas genotype RM was the most common in PUB patients. All gastric cancer patients had genotype IM. The CYP2C19 genotype RM might be play role in development of PUD and PUB. Further study in different population is necessary to verify clinical usefulness of CYP2C19 genotyping in development of these upper GI diseases.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.1946-1952
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• 2005

New group 15 organometallic compounds, M$(phenanthrenyl)_3$ (M = P (1), Sb (2), Bi (3)) have been prepared from the reactions of 9-phenanthrenyllithium with $MCl_3$. A reaction of 9-(diphenylphosphino)phenanthrene with 2,6-diisopropylphenyl azide led to the formation of (phenanthrenyl)${(Ph)}_2P$=N-(2,6-$^iPr_2C_6H_3$) (4). The crystal structures of 2 and 4 have been determined by single-crystal X-ray diffractions, both of which crystallize with two independent molecules in the asymmetric unit. Compound 2 shows a trigonal pyramidal geometry around the Sb atom with three phenanthrenyl groups being located in a screw-like fashion with an approximately $C_3$ symmetry. A significant amount of CH- -$\pi$ interaction exists between two independent molecules of 4. The phosphorus center possesses a distorted tetrahedral environment with P-N bond lengths of 1.557(3)$\AA$ (P(1) N) and 1.532(3)$\AA$ (P(2)-N), respectively, which are short enough to support a double bond character. One of the most intriguing structural features of 4 is an unusually diminished bond angle of C-N-P, attributable to the hydrogen bonding of N(1)-H(5A) [ca. 2.49$\AA$ between two adjacent molecules in crystal packing. The compounds 1-3 show purple emission both in solution and as films at room temperature with emission maxima ($\lambda_{max}$) at 349, 366, and 386 nm, respectively, attributable to the ligand centered $\pi$ $\rightarrow$ $\pi^\ast$ transition in phenanthrene contributed by the lone pair electrons of the Gp 15 elements. Yet the nature of luminescence observed with 4 differs in that it originates from $\pi$ (diisopropylbenzene)-$\pi^\ast$ (phenanthrene) transitions with the $\rho\pi$contribution from the nitrogen atom. The emission maximum of 4 is red-shifted ranging 350-450 nm due to the internal charge transfer from the phenanthrenyl ring to the N-arylamine group as deduced from the ab initio calculations.

• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.201-211
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• 2018

Objective : The purpose of this study was to analyze the variability of clopidogrel responses according to duration of a clopidogrel drug regimen after stent-assisted coil embolization (SAC), and to determine the correlation between the variability of clopidogrel responses and thromboembolic or hemorrhagic complications. Methods : A total of 47 patients who underwent SAC procedures to treat unruptured intracranial aneurysms were enrolled in the study. Preoperatively, patients received more than seven days of aspirin (100 mg) and clopidogrel (75 mg), daily. P2Y12 reaction unit (PRU) was checked with the VerifyNow test one day before the procedure (pre-PRU) and one month after the procedure (post-PRU). PRU variability was calculated as the difference between the initial response and the follow-up response. Patients were sorted into two groups based on their response to treatment : responsive and hypo-responsive. Results : PRU variability was significantly greater in the hypo-responsive group when compared to the responsive group (p=0.019). Pre-PRU and serum platelets counts were significantly correlated with PRU variation (p=0.005 and p=0.004, respectively). Although thromboembolic complication had no significant correlated factors, hemorrhagic complication was correlated with pre-PRU (p=0.033). Conclusion : In conclusion, variability of clopidogrel responses during clopidogrel medication was correlated to serum platelet counts and the initial clopidogrel response. Thromboembolic and hemorrhagic complications did not show correlation with the variability of clopidogrel response, or the clopidogrel response after one month of medication; however, hemorrhagic complication was associated with initial clopidogrel response. Therefore, it is recommended to test patients for an initial clopidogrel response only, as further tests would be insignificant.

• Macromolecular Research
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• v.12 no.1
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• pp.107-111
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• 2004

We have studied the polymerization kinetics of acrylamide in aqueous solution with potassium persulfate as an initiator by using quantitative real-time in situ IR spectroscopy and monitoring the profiles of peaks in the range 1900-850 cm$\^$-1/. The conversion of acrylamide was calculated from the disappearance of the peak at 988 cm$\^$-1/, which is the out-of-plane bending mode of the=C-H unit, normalized to the C=O stretching peak at 1675 cm$\^$-1/, as an internal standard. For reaction temperatures in the range 40-65$^{\circ}C$ and initiator and monomer concentrations of 0.9-2.6 mmol/L and 0.5-1.1 mol/L, respectively, we deduced that the rate of monomer consumption follows the relation R$\_$p/=k［K$_2$S$_2$O$\_$8/］$\^$0.5/ [Μ］$\^$1.35${\pm}$0.10/. In addition, we obtained activation parameters from an evaluation of the kinetic data.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1599-1605
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• 2005

The object of this study is to develop the method for differentiating fresh meat from frozen meat by using the measurement of the mitochondrial malate dehydrogenase in the Korean native cattle. The principle of this experiment is based on the fact that the enzyme proteins associated with mitochondrial membrane could be released by freezing. The methods of differentiating fresh meat from thawed, frozen meat were studied by measurements of mitochondrial malate dehydrogenase activity of meat press juice. Fresh and frozen beef were stored at 4, -4, -18 and -77$^{\circ}C$ for 15-day storage period. A meat press machine using air pressure was manufactured especially for these experiments, and sufficient amount of drip (about 0.15 mL/g) from 1.5 g of beef sample was efficiently obtained under a pressure of 8 kg/$cm^{2}$ generated by the meat pressing machine. The mitochondrial malate dehydrogenase activities of frozen meat drip i년ices stored at -18 and -77$^{\circ}C$ were significantly higher than those of fresh and frozen meat samples at -4$^{\circ}C$ (p < 0.05) during 10-min reaction period. However, the enzyme activities of the frozen meat drip juices (-18 and -77$^{\circ}C$) disappeared after 5 minutes of the reaction, which was not observed from the fresh and -4$^{\circ}C$ frozen meats. The enzyme activity maintained until 12 minutes for the fresh and -4$^{\circ}C$ frozen meats. From these results, the mitochondrial malate dehydrogenase could be considered as an indicator to differentiate fresh beef from frozen one.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.497-502
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• 1997

For the purpose of enzymatic production of galactooligosaccharides from soybean arabinogalactan (SAG) hydrolysis, the $\beta$-1, 4-D-arabinogalactanase($\beta$-1, 4-galactanase) from Bacillus sp. HJ-12 was used. The soybean galactooligosaccharides(SOS) were optimally produced in SAG 1%(w/v), pH 8.0, 5$0^{\circ}C$, $\beta$-1, 4-galactanase 20unit/g SAG and 24-40 hour reaction conditions. The produced galactooligosaccharides had visocity of 11,000 cp at 75%(w/v), $25^{\circ}C$. The viscosity of galactooligosaccharides was 80 fold increasing value than that of sucrose solution. Temperature dependence of viscosity of SOS was 4.6 fold higher value than surose solution below than 5$0^{\circ}C$. Less than 50 Brix, the viscosity of SOS was similar with sucrose solution(20-40 cp), but increasing of concentration, the difference of viscosity between SOS and sucrose solution was increased. And, SOS was very stable at pH and temperature.