• 제목/요약/키워드: C-14 methods

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Structure of a Copper(Ⅱ) Hexaazamacrotricyclic Complex : (1,3,6,9,11,14-Hexaazatricyclo[12.2.1.16,9]octadecane)-copper(Ⅱ) Perchlorate

  • Cheon Manseog;Suh Paik Myunghyun;Shin Whanchul
    • Bulletin of the Korean Chemical Society
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    • 제13권4호
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    • pp.363-367
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    • 1992
  • The crystal structure of (1,3,6,9,11,14-hexaazatricycol[12.2.1.$1^{6,9}$]octadecane)copper(Ⅱ) perchlorate, Cu($C_{12}H_{26}N_6$)$(ClO_4)_2$, has been determined by the X-ray diffraction methods. The crystal data are as follows: Mr=516.9, triclinic, ${\alpha}=8.572\;(2)$, b=8.499 (3), c=15.204 (3) ${\AA}$, ${\alpha}=80.42\;(5),\;{\beta}=73.57\;(3),\;{\gamma}=69.82\;(4)^{\circ},\;V=994.2\;{\AA}^3,\;D_C=1.726\;gcm^{-3}$, space group $P{\tilde{1}},\;Z=2,\;{\mu}=21.27\;cm^{-1}&, F(000)=534 and T=297 K. The structure was solved by direct methods and refined by full-matrix least-squares methods to and R value of 0.081 for 1608 observed reflections measured with graphite-mono-chromated Mo Ka radiation on a diffractometer. There are two independent complexes in the unit cell. The two copper ions lie at the special positions (1/2, 0, 0) and (0, 1/2, 1/2)and each complex possesses crystallographic center of symmetry. Each Cu ion is coordinated to four nitrogen donors if the hexaazamacrotricyclic ligand and weakly interacts with two oxygen atoms of the perchlorate ions to form a tetragonally distorted octahedral coordination geometry. The Cu_N (sec), Cu_N(tert) and Cu_O coordination distances are 1.985 (14), 2.055 (14) and 2.757 (13) ${\AA}$ for the complex A and 1.996 (10), 2.040 (11) and 2.660 (13) ${\AA}$ for the complex B, respectively. The macrocycles in the two independent cations assume a similar conformation with the average r.m.s. deviation of 0.073 ${\AA}$. Two 1,3-diazacyclopentane ring moieties of the hexaazamacrotricyclic ligand are placed oppositely and almost perpendicularly to the square coordination plane of the ruffled 14-membered macrocycle. The secondary N atoms are hydrogen-bonded to the perchlorate O atoms with distances of 3.017 (23) and 3.025 (19) ${\AA}$ for the complexes A and B, respectively.

The Immunohistochemical Changes of Skin during Hair Follicle Cycle after Depilation in Mice

  • ;이창현
    • 대한의생명과학회지
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    • 제16권4호
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    • pp.349-357
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    • 2010
  • We have examined the histological changes of skin during hair follicle growth after depilation in C57BL/6N mice. We first studied on histological changes of number of mast cells and thickness of skin during hair follicle growth periods (telogen, 1 day, 3 day, 5 day, 10 day, 14 day, 17 day and 21 day after depilation) by toluidine blue, Giemsa and H&E staining methods. We second studied immunoreactive density of cytokines and Brdu labeled cells in skin during hair follicle growth periods after depilation in C57BL/6N mice by immunohistochemical methods. The histological changes on skin thickness was increased from telogen to 14 day. The number of mast cells was decreased in 3,5 and 10 day and increased in 14, 17 and 20 day after depilation. Immunoreactive density of cytokines [protein kinase C-${\alpha}$ (PKC-${\alpha}$), c-kit, and vascular endothelial growth factor (VEGF)] in 1, 3, 5, 10, and 14 day after depilation was mildly stained in bulge and cutaneous trunci m., but immunoreactive density of cytokines in 17 and 21 day was heavily stained in epidermis, bulge, outer root sheath (ORS), inner root sheath (IRS) and cutaneous trunci m.. Immunoreactive density of Brdu labeled cells in skin in 1 and 3 day was heavily stained in bulge, epidermis and connective tissue under the cutaneous trunci m.. In all periods, immunoreactive density of Brdu labeled cells in skin was heavily stained in bulge, subcutaneous tissue, cutaneous trunci m, ORS and IRS. These experiments suggest that histological changes related to hair follicle growth elevated mast cell counts, skin thickness and epidermis thickness and heavily stained immunoreactive density of cytokines and Brdu labeled cutaneous trunci m. and connective tissue under the cutaneous trunci m. after depilation in C57BL/6N mice.

Inhibition of C-terminal O-Methyltransferase by a Rat Liver Cytosolic Peptide

  • Park, Seung-Hee;Lee, Hyang-Woo
    • Archives of Pharmacal Research
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    • 제17권5호
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    • pp.354-359
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    • 1994
  • The activity of SD-framesylcysteine O-methyltransferase was assayed by incubating the enzyrne with a synthetic in vitro substrate, [N-acetyl-S-trans, trns-famesyl-L-cysteine (AFC)], together with S-adenosyl-L-[emthyl-$_{14}$C)ester(AFCME)], was then analyzed either directly on HPLC or by converting the AFC[$methyl^{14}C$]ME to [$methyl^{14}C$] aclcohol by basehydrolysis. Employing these two analytical methods, it was established that a peptide purifed from rat liver cytosol fraction [Int. J. Biochem., 25, 1157 919930] strongly inhibited the above enzyme activity with $IC_{50}\; of\; 7.1\times 10^{-8}$ M. Also, the S-famesylcysteine O-methyltransferase from several human colon cancer cells was equally inhibited by the peptide.

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The crystal and molecular structure of sulfisoxazole

  • Koo, Chung-Hoe;Shin, Hyun-So;Cho, Sung-Il
    • Archives of Pharmacal Research
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    • 제5권2호
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    • pp.79-86
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    • 1982
  • Sulfisoxazole, $C-{11}H_{13}N_{3}S$, crystallized in the orthohombic system, space group Pbca, with a = 14.492(1), b = 11.563(1), c = 14.900(2) $\AA$ and Z = 8. Intensities for 1867(1360 observed) unique reflections were measured on a four-circle diffractometer wirh CuKa radiation ($\lambda$ = 1.5418$\AA$). The structure was solved by heavy atom methods and refined by full-matrix least-squares procedures to a final R of 0.094. The benzene ring plane makes an angle of $68^{\circ}C$ with the plane of the isoxazole ring, which is plannar. The conformational angle formed by the torsional angle C(4)-S-N(2)-C(7) is $54^{\circ}C$. There are two intermolecular hydrogen bonds in the structure. One of them is of the type N-H...H with the length 2.915$\AA$. Thus two dimensional networks of hydrogen bonds form infinite moelcular sheets parallel to the (001) plane. Adjacent sheets are bound together by van der Waals forces.

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Outcome Assessment of Endodontic Treatment of Mandibular Second Molars with C-shaped Canals in Elderly Patients

  • Go, Yu-Ra;Kim, Mi-Yeon;Kim, Sun-Ho;Kim, Jeong-Hee;Kim, Ran-Ah
    • Journal of Korean Dental Science
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    • 제14권2호
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    • pp.61-68
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    • 2021
  • Purpose: The aim of this study was to investigate the outcomes of endodontic treatment of mandibular second molar with C-shaped canal in elderly patients and related factors affecting the survival of the tooth. Materials and Methods: From 2010 to 2015, the survival rate following endodontic treatment was evaluated in elderly patients over 60 years who visited the Veterans Health Service Medical Center for endodontic treatment. The presence of C-shaped canals was confirmed using clinical records and radiographic features. Patient's age, sex, systemic diseases, tooth location, vitality, signs and symptoms, fractures, caries, apical radiolucency, canal shaping methods, sealer leakage, filling voids, and restoration of prosthesis were included in the analyses as confounding variables. The survival rate of teeth was analyzed using Kaplan-Meire analysis and the relationship between the survival rate and variables was analyzed using Simple and Multiple Cox regression analysis. Result: In total, 107 teeth in elderly patients had C-shaped canal. The survival rate of teeth that received endodontic treatment was 63.70%. None of the factors investigated significantly influenced the survival rate (P>0.05). Conclusion: In elderly patients with C-shaped canal, the survival rate after root canal treatment was not significantly different from that of other mandibular molars.

방사성탄소연대측정 (Radiocarbon Dating)

  • 이현주;황진주;백현주
    • 보존과학연구
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    • 통권23호
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    • pp.197-214
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    • 2002
  • It is very important to determine the age of the Cultural Properties in archeology. In about 1950, W.F. Libby and a team of scientists at the University of Chicago developed the Radiocarbon Dating technique. Radiocarbon($^14$C) Dating is probably one of the most widely used and best known absolute dating methods. Radiocarbon ages are conventionally specified to the year 1950. This year is 0 BP year. BP is the initial of Before Present. The $^14$C within an organism is continually decaying into stable carbon isotopes. When $^14$C decays, it emits a $\beta$ - particle with an energy content of 156 KeV and becomes 14N. Only the $\beta$ - particle is detected by Liquid Scintillation Counting. $^14$C has a half life of 5730 years. It has been used to date samples as old as 50,000 years. Radiocarbon determinations can be obtained on organic material : wood, charcoal, shell, etc. The results of radiocarbon dating using Benzene Synthesizer and Liquid Scintillation Counter are KCP539 $4030\pm60$BP year, KCP540 $3980\pm60$BP year, KCP575 $4870\pm50$, KCP576 $100\pm50$BP year, KCP577 $130\pm50$BP yea and KCP578 $210\pm70$BP year.

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A comparison of photosynthesis measurements by O2 evolution, 14C assimilation, and variable chlorophyll fluorescence during light acclimatization of the diatom Coscinodiscus granii

  • Trampe, Erik;Hansen, Per Juel;Kuhl, Michael
    • ALGAE
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    • 제30권2호
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    • pp.103-119
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    • 2015
  • Photosynthetic rates of the large centric diatom Coscinodiscus granii were measured by means of multicolor variable chlorophyll fluorescence imaging, single cell $^{14}C$ assimilation, and optical $O_2$ sensor measurements during light acclimatization of cultures grown at five different irradiances: 50, 150, 235, 332, and $450{\mu}mol$ photons $m^{-2}\;s^{-1}$. Photo-acclimatization was evident from changes of cellular chlorophyll a content, growth rates, and light response curves. Each of the applied methods evaluates different parts and reactions in the photosynthetic apparatus, which makes a direct quantitative comparison of rates difficult, although a different degree of correlation were found between all three methods. However, when used in combination, they provide information about the internal relationship of photosynthetic pathways as well as the variation in photosynthetic capacity between individual cells within a single algal culture.

국내 쇄석골재를 사용한 모르타르 봉 및 콘크리트 각주 시험편의 알칼리-실리카 반응성 비교 (Comparison of Alkali-Silica Reactivity for Mortar Bar and Concrete Prism Specimens Using Crushed Aggregates in Korea)

  • 김성권;윤경구;허인
    • 한국도로학회논문집
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    • 제14권5호
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    • pp.93-99
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    • 2012
  • PURPOSES: The purpose of this study is to compare the alkali-silica reactivity for mortar bar and concrete prism specimens using crushed aggregates of 5 types in Korea. And the alkali-silica reactivity for those aggregates are measured by chemical test method. METHODS: The alkali-silica reactivity for those aggregates was measured by chemical test method of KS F 2545, mortar-bar test of KS F 2546, accelerated mortar-bar test method of ASTM C 1260 and concrete prism test method of ASTM C 1293, relatively. RESULTS: The alkali-silica reactivity for those aggregates was verified by chemical test of KS F 2546 and accelerated mortar-bar test of ASTM C 1260. However, it was not by mortar-bar test of KS F 2546 and concrete prism test of ASTM C 1293. CONCLUSIONS: The above results showed that relationship among the four test methods were very low. The results from 3 types of test methods using cement-aggregate combinations appeared to be different. Because the environmental conditions of test methods for measuring the alkali-silica reactivity such as equivalent alkali content(external source), humidity, temperature, and times were different though the aggregates were same. Moreover, alkali-silica reactivity showed the biggest impact when alkalis were supplied form outside and exposed to environmental conditions. The accelerated mortar-bar test method seems to be most appropriate test method for concrete structures exposed to alkali environment.

C-14 요소호기검사의 정량치가 Helicobacter pylori 감염 정도를 반영할 수 있을까? (Can the C-14 Urea Breath Test Reflect the Extent and Degree of Ongoing Helicobacter pylori Infection?)

  • 임석태;손명희;이승옥;이수택;정명자
    • 대한핵의학회지
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    • 제35권1호
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    • pp.61-68
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    • 2001
  • 목적: H. pylori는 현재 인체에서 매우 높은 감염률을 보이고 있고 세균의 위내 집락형성이 위염, 궤양성 질환 및 위암 등 많은 위장 질환의 발생과 관련이 있다고 알려져 있다. 본 연구는 비관혈적이고 편리하게 사용될 수 있는 C-14 요소호기검사의 진단성능을 알아보고 정량적 측정치가 내시경 생검에 의한 H. pylori 분포 정도와 상관관계가 있는지를 비교분석함으로써 치료후 추적관찰에 침습적인 내시경적 검사를 대체할 수 있는 유용성이 있는지를 알아보고자 하였다. 대상 및 방법: 최근 4주 이내에 H. pylori 박멸요법을 받지 않는 150명의 환자(남:녀=83:67, 나이, $48{\pm}11.2$세)를 대상으로 균박멸요법 시행전에 위십이지장내시경 및 생검, CLO 검사, C-14 요소호기검사를 시행하였다. 조직생검 결과를 금과옥조로 하여 침습적인 CLO 검사와 비침습적인 C-14 요소호기검사의 H. pylori 감염 진단성능을 비교분석 하였고 Wyatt법에 의한 조직검사의 등급(0-4)과 C-14 요소호기검사의 정량적 수치와의 상관관계를 분석하였다. 결과: H. pylori 감염에 대한 CLO 검사의 민감도 83.2%, 특이도 81.4%, 양성예측도 91.8%, 음성예측도 81.4%, 정확도는 82.7% 이었다. C-14 요소호기검사는 민감도 92.5%, 특이도 88.4%, 양성예측도 97.1%, 음성예측도 88.4%, 정확도는 91.3% 이었다. 병리조직검사에서 등급 0은 $45{\pm}27dpm$, 등급 1은 $707{\pm}584dpm$, 등급 2는 $1558{\pm}584dpm$, 등급 3은 $1851{\pm}604$, 등급 4는 $2719{\pm}892dpm$으로 조직검사의 등급이 높을수록 C-14 요소호기검사의 정량적 수치가 높게 측정되었다(r=0.848, p<0.01). 결론: C-14 요소호기검사는 H. pylori 감염을 진단하는데 CLO 검사에 비하여 높은 민감도와 정확도를 보이는 비침습적이고 간편한 임상적으로 유용한 검사 방법이며, 정량적 수치는 병리조직검사에 의한 H. pylori 분포와 유의한 상관관계를 보여 치료 후 추적관찰에 내시경적 검사와 더불어 균박멸 유무를 진단하는데 유용한 지표로 이용될 수가 있을 것으로 사료된다.

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백-밸브-마스크 환기 시 마스크 밀착방법에 따른 환기효과 비교 (Comparison of ventilation effects by mask-sealing methods during bag-valve-mask ventilation)

  • 이남종;백미례
    • 한국응급구조학회지
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    • 제22권1호
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    • pp.73-82
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    • 2018
  • Purpose: The purpose of this study was to compare the tidal volumes and airway pressures of 3 mask-sealing methods (one hand C-E, two hands C-E, and one hand O-E) for ventilation treatment. Methods: The study subjects were 45 paramedic students. Tidal volume was measured for the three sealing methods by setting a ventilator, connecting it to the masks for 2 minutes, and using Respi-trainer software. Results: Regarding general characteristics, the group of men, in upper grades, and with practical training experience and experience and experience in the implementation of bag-valve-mask ventilation provided higher tidal volumes. Regarding physical characteristics, larger hands and greater grip strength correlated with higher tidal volume. Two hands C-E generated the highest tidal volume of $483.78{\pm}34.14mL$, one hand O-E generated $449.59{\pm}51.09mL$ and one hand C-E generated $394.31{\pm}68.95mL$. Conclusion: Means of tidal volumes were statistically significantly different based on mask sealing methods (p<.001). Two hand C-E was performed by the two-persons task and was suggested as the most effective method. For the one-person task, one hand O-E was the more effective method compared to the previous one hand C-E.