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Crystal Structures of Dehydrated Partially $Sr^{2+}$-Exchanged Zeolite X, $Sr_{31}K_{30}Si_{100}A1_{92}O_{384}\;and\;Sr_{8.5}TI_{75}Si_{100}AI_{92}O_{384}$ (부분적으로 스트론튬이온으로 교환되고 탈수된, 제올라이트 X의 결정구조)

  • Kim Mi Jung;Kim Yang;Seff Karl
    • Korean Journal of Crystallography
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    • v.8 no.1
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    • pp.6-14
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    • 1997
  • The crystal structures of $Sr_{31}K_{30}-X\;(Sr_{31}K_{30}Si_{100}A1_{92}O_{384};\;a=25.169(5) {\AA}$) and $Sr_{8.5}Tl_{75}-X (Sr_{8.5}Tl_{75}Si_{100}A1_{92}O_{384};\;a=25.041(5) {\AA}$) have been determined by single-crystal X-ray diffraction techniques in the cubic space group $\=F{d3}\;at\;21(1)^{\circ}C$. Each crystal was prepared by ion exchange in a flowing stream of aqueous $Sr(ClO_4)_2\;and\;(K\;or\;T1)NO_3$ whose mole ratio was 1 : 5 for five days. Vacuum dehydration was done at $360^{\circ}C$ for 2d. Their structures were refined to the final error indices $R_1=0.072\;and\;R_w=0.057$ with 293 reflections, and $R_1= 0.058\;and\;R_w=0.044$ with 351 reflections, for which $I>2{\sigma}(I)$, respectively. In dehydrated $Sr_{31}K_{30}-X,\;all\;Sr^{2+}$ ions and $K^+$ ions are located at five different crystallographic sites. Six-teen $Sr^{2+}$ ions per unit cell are at the centers of the double six-rings (site I), filling that position. The remaining 15 $Sr^{2+}$ ions and 17 $K^+$ ions fill site II in the supercage. These $Sr^{2+}$ and $K^+$ ions are recessed ca $0.45{\AA}\;and\;1.06{\AA}$ into the supercage, respectively, from the plane of three oxygens to which each is bound. ($Sr-O=2.45(1){\AA}\;and\;K-O=2.64(1){\AA}$) Eight $K^+$ ons occupy site III'($K-O=3.09(7){\AA}\;and\;3.11(10){\AA}$) and the remaining five $K^+$ ions occupy another site III'($K-O=2.88(7){\AA}\;and\;2.76(7){\AA}$). In $Sr_{8.5}Tl_{75}-X,\;Sr^{2+}\;and\;Tl^+$ ions also occupy five different crystallographic sites. About 8.5 $Sr^{2+}$ ions are at site I. Fifteen $Tl^+$ ions are at site I' in the sodalite cavities on threefold axes opposite double six-rings: each is $1.68{\AA}$ from the plane of its three oxygens ($T1-O=2.70(2){\AA}$). Together these fill the double six-rings. Another 32 $Tl^+$ ions fill site II opposite single six-rings in the supercage, each being $1.48{\AA}$ from the plane of three oxygens ($T1-O=2.70(1){\AA}$). About 18 $Tl^+$ ions occupy site III in the supercage ($T1-O=2.86(2){\AA}$), and the remaining 10 are found at site III' in the supercage ($T1-O=2.96(4){\AA}$).

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TL Characteristics of CsI Single Crystal Scintillators and their Growth Conditions (CsI 단결정 섬광체의 열형광특성과 육성조건)

  • Doh, S.H.;Lee, W.G.;Hong, S.Y.;Bang, S.W.;Kang, K.J.;Kim, D.S.;Kim, W.;Kang, H.D.
    • Journal of Sensor Science and Technology
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    • v.7 no.4
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    • pp.234-242
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    • 1998
  • Changes in transmission and thermoluminescent characteristics were used in order to find out the optimum growth condition of CsI single crystal scintillators which were made relatively defect-free using Czochralski method. Impurity distribution in the crystals and the intensity and number of thermoluminescent glow peaks decreased as the process of crystallization was repeated. The direction of crystal growth turned out to be (110), the crystal structure of grown CsI was bee, and its lattice constant was found to be $4.568{\AA}$. The activation energy (trap depths) of CsI:3rd was 0.45 eV and its frequency factor was $5.18{\times}10^5\;sec^{-1}$.

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Effects of Nitric Oxide Scavenger and Inhibitor on the Development of Bovine IVM/IVF Embryos (Nitric Oxide 화합물 첨가가 소 체외수정란의 체외발육에 미치는 효과)

  • Jang H. Y.;Kim J. T.;Park C. K.;Cheong H. T.;Kim C. I.;Yang B. K.
    • Reproductive and Developmental Biology
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    • v.28 no.3
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    • pp.161-166
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    • 2004
  • This study was designed to evaluate the effects of nitric oxide scavenger (hemoglobin) and inhibitor (L-nitro-L-arginine methyl ester; L-NAME) with or without cumulus cell on the development of bovine IVM/IVF embryos. When CR/sub 1aa/ medium were supplemented with different dosage (lug/m, 5ug/m and 10ug/ml) of hemoglobin at 48hrs for in vitro culture, the proportion of embryos developing beyond morulae stage in 0, 1ug/ml and 5ug/ml with or without cumulus cell were 23.8%, 33.3 % and 26.8%, and 39.5%, 54.8% and 48.8%, respectively. There was a significantly difference the developmental rate of 1ug/ml hemoglobin intact cumulus cells to any other groups (P<0.05). On the other hand, when added to hemoglobin at 96 hrs, 1 ug/ml hemoglobin with cumulus cell group was significantly increased the percentage of developing into morulae and blastocysts to any other groups (P<0.05), and similar trend that of added at 48hrs. The overall means of the percentage of developing into morulae and blstocysts in 1ug/ml hemoglobin group was significantly increased than those of any other groups (P<0.05) and cumulus co-culture with hemoglobin was increased the in vitro developing rate of IVM/IVF embryos. In CR/sub 1aa/ medium treated with L-NAME 0, 10, 50 and 100mM, the developmental rate of morula plus blastocysts were 55.6%, 64.9%, 58.8% and 66.7%, respectively. The L-NAME did not affect the developmental rate and the cell numbers of blastocysts in all treated groups. These results indicate that hemoglobin and cumulus co-culture can increase the proportion of embryos that developed into morulae and blastocysts, but cell numbers of blastocysts were not affect in all groups.

Suppressive effects of ethanol extract of Aralia elata on UVB-induced oxidative stress in human keratinocytes (자외선 B를 조사한 인간유래각질세포에서 두릅순 에탄올추출물의 산화적 스트레스 억제효과)

  • Kwak, Chung Shil;Yang, Jiwon
    • Journal of Nutrition and Health
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    • v.49 no.3
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    • pp.135-143
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    • 2016
  • Purpose: Ultraviolet (UV)-induced oxidative stress contributes to several adverse biological effects on skin. Many phenolic phytochemicals have been shown to have antioxidant properties and protect skin cells from UV-induced oxidative damage. In this study, we investigated whether or not Aralia elata (AE) has a protective effect against UVB-induced reactive oxygen species (ROS), ultimately leading to photoaging. Methods: Phenolic content of dried AE and antioxidant properties of AE extract in 70% ethanol weredetermined by measuring DPPH and ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP). The effect of AE extract on cellular ROS generation and expression levels of oxidative stress-response proteins such as superoxide dismutase (SOD)-1, catalase, nuclear factor-erythroid 2-related factor (Nrf)-2, and heme oxygenase (HO)-1 in UVB-irradiated ($75mJ/cm^2$) human keratinocytes (HaCaT) were further determined by 2'-7'-dichlorofluoresceine diacetate assay and Western blotting, respectively. Results: The total phenolic and flavonoid contents of dried AE were 20.15 mg tannic acid/g and 18.75 mg rutin/g, respectively. The $IC_{50}$ of AE extract against DPPH radical was $98.5{\mu}g/mL$, and ABTS radical scavenging activity and FRAP upon treatment with $1,000{\mu}g/mL$ of AE extract were $41.8{\mu}g\;ascorbic\;acid\;(AA)\;eq./mL$ and $29.7{\mu}g\;AA\;eq./mL$,m respectively. Pretreatment with AE extract significantly reduced (p < 0.05) ROS generation compared to that in UVB-irradiated control HaCaT cells. Pretreatment with AE extract reversed reduction of Nrf-2 and SOD-1 protein expression and induction of HO-1 protein expression caused by UVB exposure in HaCaT cells, whereas it did not affect catalase expression. Conclusion: AE extract in 70% ethanol demonstrated a protective effect against UVB-induced oxidative stress and decreased expression of Nrf-2 and SOD-1 in human keratinocytes. These findings suggest that AE ethanol extract might have potential as a natural resource for a skin anti-photoaging product in the food and cosmetic industry.

Comparison of Color-developing Methods for Phosphorus Analysis in Various Extractants for Soil Phosphorus (몇가지 토양인산(土壤燐酸) 추출용액(抽出溶液)의 인산(燐酸) 발색방법(發色方法) 비교(比較))

  • Yoon, Jung-Hui;Park, Baeg-Gyoon;Hwang, Ki-Sung
    • Korean Journal of Soil Science and Fertilizer
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    • v.31 no.2
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    • pp.114-119
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    • 1998
  • Intensity and stability of the blue color of phospho-molybdate complex in P analysis are known to be influenced by the matrix, reducing regent and acidity of the extractants. Objective of this research was to compare the efficiency of the color-developing reagents for P concentrations in distilled water and extracts of Lancaster, Mehlich II, and Mehlich III methods. Efficiencies on which to base this study were evaluated by the optimum ranges of P, reproducibility of calibration curve and stability of the developed color. Color-developing reagents employed were ammonium molybdate-1,2,4- aminonaphtholsulfonic acid (ANS), ammonium molybdate-ascorbic acid-bismuth subcarbonate (AB), and ammonium molybdate-ascorbic acid-antimony potassium tartarate (AA). The ANS revealed the lowest sensitivity but the widest ranges for P concentrations in color development. On the other hand, the AA bore the narrowest color-developing ranges and its sensitivity was similar to AB. However, at P concentrations lower than $0.5mg\;L^{-1}$, AA was more sensitive than AB. Based on the data on the ranges of calibration curve, stability of color and reproducibility of analytical data. AA reagent was considered to be suitable for the determination of P in distilled water and AB reagent was practically recommendable for soil P analysis in extracts by Lancaster, Mehlich II, and Mehlich III procedures.

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The Metabolizable Energy Value, Standardized Ileal Digestibility of Amino Acids in Soybean Meal, Soy Protein Concentrate and Fermented Soybean Meal, and the Application of These Products in Early-weaned Piglets

  • Zhang, H.Y.;Yi, J.Q.;Piao, X.S.;Li, P.F.;Zeng, Z.K.;Wang, D.;Liu, L.;Wang, G.Q.;Han, X.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.5
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    • pp.691-699
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    • 2013
  • Three experiments were conducted to evaluate the metabolizable energy (ME) value, standardized ileal digestibility (SID) of amino acids (AA) of soybean meal (SBM), soy protein concentrate (SPC) and fermented soybean meal (FSBM), and the application of these products in early-weaned piglets. In Exp. 1, four barrows with initial body weight (BW) of $14.2{\pm}1.4$ kg were used in a $4{\times}4$ Latin square design. The diet 1 contained corn as the only energy source. The other three diets replaced 25% of corn in diet 1 with one of the three soybean products, and the digestable energy (DE) and ME contents were determined by difference. In Exp. 2, four barrows (initial BW of $18.2{\pm}1.5$ kg) were fitted with ileal T-cannulas and allotted to a $4{\times}4$ Latin square design. Three cornstarch-based diets were formulated using each of the soybean products as the sole source of AA. A nitrogen-free diet was also formulated to measure endogenous losses of AA. In Exp. 3, ninety six piglets (initial BW of $5.6{\pm}0.9$ kg) weaned at $21{\pm}2$ d were blocked by weight and assigned to one of three treatments for a 21-d growth performance study. The control diet was based on corn and SBM, the two treatments' diets contained either 10% SPC or FSBM and were formulated to same SID lysine to ME ratio of 3.6 g/Mcal. The results showed that the ME content of SPC was greater than SBM (p<0.05). The SID of most AA in SPC was greater than the SID of AA in SBM (p<0.05). For the essential AA, the SID of histidine, isoleucine, leucine, lysine and threonine in FSBM were greater than in SBM (p<0.05). Even though they were fed same SID lysine to ME ratio of 3.6 g/Mcal diets, pigs fed SPC and FSBM diets had greater weight gain, G:F (p<0.05) and better fecal score (p<0.05) than pigs fed SBM diet. In conclusion, SPC showed a higher ME content and SID of AA than the SBM. SID of some essential AA in FSBM was higher than SBM and was similar with SPC. But the lower antigenic proteins and anti-nutritional factors content in SPC and FSBM may be the main factors affecting the performance of early-weaned piglets rather than the increased ME content and SID of AA.

The Crystal Structure of Bis(1,2-diaminopropane)palladium(Ⅱ) Bis(oxalato)palladate(Ⅱ) (Bis(1,2-diaminopropane)palladium(Ⅱ) Bis(oxalato)palladate(Ⅱ)의 결정구조)

  • Kim Sei Hwan;NagGung Hae;Jeon, Ho Jung
    • Journal of the Korean Chemical Society
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    • v.37 no.6
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    • pp.599-603
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    • 1993
  • Crystal structure of bis(1,2-diaminopropane)palladium(II) bis(oxalato)palladate(II) has been determined by X-ray crystallography. Crystal data: $Pd_2C_{10}H_{10}N_{4}O_{8}$, $M_W$ = 573.09, orthorhombic, space group $P_{ccn}$ (No = 56), a = 16.178(5), b = 16.381(6), c = 6.685(2)$\{AA}$, V = 1771.6 $\{AA}^3$, $M_W$W = 573.09, $D_c$ = 2.014 g${\cdot}c\;m^{-3}$, Z = 4, T = 294K, F(000) = 1056.0 and $\mu$ = 20.466 c$m^{-1}$. The intensity data were collected with $Mo-K\alpha$ radiation (${\lambda}$ = 0.7107 $\AA)$ on an automatic four-circle diffractometer with a graphite monochromater. The structure was solved by Patterson method and refined by full matrix least-squares methods using Pivot weights. The final R and S values were R = 0.065, $R_W = 0.059, R_{all}$ = 0.065 and S = 4.315 for 605 observed reflections. Both cation and anion complexes are essentially planar and have dihedral angle of $18(l)^{\circ}$ between thier planes. In the crystal structure, they do not have the Magnus's salt type mixed stacks; instead, the complex anions form regular stacks along the c-axis with the M-M bond length of $3.343(5)\AA$ and their stacks are surrounded by the complex cations through hydrogen bonds with the nitrogen-oxygen distances of 2.94(3) and $3.31(4)\AA.$

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Anion Adsorption Properties of Organobentonites Modified by Cationic Polymers (양이온 폴리머를 이용한 유기벤토나이트의 음이온 흡착특성)

  • 윤지해;황진연;이효민;고상모;유장한
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.2
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    • pp.147-155
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    • 2004
  • Anion adsorption properties of organobentonites modified by two cationic polymers, hexadecyltrimmethylammonium (HDTMA) and cetylpyridinum (CP), were investigated. The organobentonites showed the significant expansion of basal spacing to 42.0 $\AA$ at room temperature. The adsorption experiments were conducted for the 0.2 g of organobentonites with 40 mL solutions of various concentrations of anions such as nitrate, sulfate and phosphate. As a result, the organobentonites showed excellent adsorption capacities for those anions whereas untreated bentonite showed very low adsorption capacity. Adsorption rate of HDTMA-bentonite was about 90% for 100 mg/L solutions of nitrate and phosphate, and that of CP-bentonite was 97% for 100 mg/L solution of nitrate. Adsorption behaviors were slightly different for the different organobentonites and anions. Both organobentonites showed relatively higher adsorption rate for nitrate and phosphate than sulfate. Therefore, these organobentonites showing high anion adsorption capacities can be used far the removal of deleterious anions in the treatment of environmental pollution.

Crystal Structures of Fully Dehydrated $Ca^{2+}$-Exchanged Zeolite X, $Ca_{46}-X$, and $Ca^{2+}$ and $K^+$-Exchanged Zeolite X, $Ca_{32}K_{28}-X$ ($Ca^{2+}$ 이온으로 완전히 치환된 제올라이트 X, $Ca_{46}-X$$Ca^{2+}$ 이온과 $K^+$ 이온으로 치환된 제올라이트 X, $Ca_{32}K_{28}-X$를 완전히 진공 탈수한 결정구조)

  • Jang, Se Bok;Song, Seong Hwan;Kim, Yang
    • Journal of the Korean Chemical Society
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    • v.39 no.1
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    • pp.7-13
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    • 1995
  • The crystal sructures of $X(Ca_{46}Al_{92}Si_{100}O_{384})$ and $Ca_{32}K_{28}-X(Ca_{32}K_{28}Al_{92}Si_{100}O_{384})$ dehydrated at $360^{\circ}C$ and $2{\times}10^{-6}$ Torr have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at $21(1)^{\circ}C.$ Their structures were refined to the final error indices, R_1=0.096,\;and\;R_2=0.068$ with 166 reflections, and R_1=0.078\;and\;R_2=0.056$ with 130 reflections, respectively, for which I > $3\sigma(I).$ In dehydrated $Ca_{48}-X,\;Ca^{2+}$ ions are located at two different sites opf high occupancies. Sixteen $Ca^{2+}$ ions are located at site I, the centers of the double six rings $(Ca(1)-O(3)=2.51(2)\AA$ and thirty $Ca^{2+}$ ions are located at site II, the six-membered ring faces of sodalite units in the supercage. Latter $Ca^{2+}$ ions are recessed $0.44\AA$ into the supercage from the three O(2) oxygen plane (Ca(2)-O(2)= $2.24(2)\AA$ and $O(2)-Ca(2)-O(2)=119(l)^{\circ}).$ In the structure of $Ca_{32}K_{28}-X$, all $Ca^{2+}$ ions and $K^+$ ions are located at the four different crystallographic sites: 16 $Ca^{2+}$ ions are located in the centers of the double six rings, another sixteen $Ca^{2+}$ ions and sixteen $K^+$ ions are located at the site II in the supercage. These $Ca^{2+}$ ions adn $K^+$ ions are recessed $0.56\AA$ and $1.54\AA$, respectively, into the supercage from their three O(2) oxygen planes $(Ca(2)-O(2)=2.29(2)\AA$, $O(2)-Ca(2)-O(2)=119(1)^{\circ}$, $K(1)-O(2)=2.59(2)\AA$, and $O(2)-K(1)-O(2)=99.2(8)^{\circ}).$ Twelve $K^+$ ions lie at the site III, twofold axis of edge of the four-membered ring ladders inside the supercage $(K(2)-O(4)=3.11(6)\AA$ and $O(1)-K(2)-O(1)=128(2)^{\circ}).$

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Synthesis and Rietveld Structure Refinement of Mn-Tourmalines (Tsilaisite) (Mn-전기석(Tsilaisite)의 합성 및 리트벨트 구조분석)

  • Grover John;Choi Jin-Beom
    • Journal of the Mineralogical Society of Korea
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    • v.19 no.1 s.47
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    • pp.15-29
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    • 2006
  • Synthetic Mn-tourmalines (tsilaisite) were obtained by hydrothermal synthesis under the condition of 2 Kbar, $375{\sim}700^{\circ}C$, and 50 day-run-time with complete substitution of Mg in dravite by Mn (Mn%=0, 25, 50, 75, and 100%). They are all 6 samples containing Mn-tourmaline with some amounts of albite, spessartine, rhodocrosite, phlogopite etc, showing different synthetic condition of temperature and Mn composition. Synthetic Mn-tourmalines are of site deficiency in X-site ($0.53{\sim}0.68$) more than that of natural ones (approx. $0.2{\sim}0.3$) and show Mn cations occupying Y-site less than expected with initial experiments, leading to failure in synthesis of end-member tsilaisite. Rietveld structural refinements reveal that $R_{wp}$ ($R_{p}/R_{exp}$) is in the range of 13.35 and 18.62%, $R_{B}$ and S (CofF) are $4.85{\sim}6.25%$ (S-18: 8.57%), $1.31{\sim}1.59$ (S-18: 1.81), respectively. Unit cell parameters (space group R3m, z=3) are ${\alpha}=15.8994\;{\AA}$ and $c=7.1846\;{\AA}$ in average (S-18: ${\alpha}=15.9491\;{\AA},\;c=7.1773\;{\AA}$). Average bond lengths of and are $2.67{\sim}2.69\;{\AA}$ (S-18: $2.65\;{\AA}$) and $2.00{\sim}2.02\;{\AA}$ (S-18: $1.96\;{\AA}$), respectively. Ditrigonality (${\delta}$) are in the range of 0.022 and 0.031 (S-18: 0.061), indicating degrading symmetry with increase of Mn content.