• 한국세라믹학회지
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• 제28권12호
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• pp.961-968
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• 1991

The nature and composition of the surfaces of silicon nitride and β-Sialon powders were investigated using high voltage and high resolution transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). β-Sialon powder was produced from Hadong kaolin by the carbothermic reduction and simultaneous nitridation. XPS showed that Al was contained in the surface of β-Sialon powder besides Si, N and O components, which is different from that of silicon nitride. It was supposed that Al in the surface of β-Sialon was bonded with oxygen from the oxygen-nitrogen ratio and the measurement of Al 2p binding energies. After both silicon nitride and β-Sialon powders were oxidized at 800℃ for 24h in air, nitrogen didn't exist in the surfaces and the depth of the oxide layer increased. The measurement of Si 2p binding energies showed that the chemical shifts occurred from Si3N2O and/or Si2N2O to SiO2 phase.

• 한국세라믹학회지
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• 제25권2호
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• pp.136-142
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• 1988

β-Al2O3, which is used for solid electrolyte membrances in sodium-sulfur batteries, was prepared by sol-gel process. Sodium-n-propoxide NaOC3H7 and aluminum-isopropoxide Al(OC3H7)3 were hydrolyzated in the solution at pH 3, pH 7, pH 9 and pH 11, respectively. The sol-gel processed samples were calcined at several temperature steps, respectively and analysed by thermal analyser(DT-TGA), infrared spectrum analyser and X-ray diffraction analyser. The gelling rate of solution at pH 7 was much higher than that of the solution at pH 3. Thermal exchanging behavior of the gels at pH 3 were similar to Na2O·Al2O3·6H2O and, above pH 7, were similar to Na2O·Al2O3·3H2O. When samples' composition ratio was 9.13 : 90.87 [NaOC3H7:Al(OC3H7)3] at pH 7, β-Al2O3 was formed at 1100℃.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.66-73
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• 2006

Monoclonal antibodies are designed to bind specifically to certain antigen, give therapeutic effect to the target and to be produced in large scale with homogeneity. The monoclonal antibodies conjugated with radionuclide can deliver therapeutic irradiation to the target, and showed successful results in certain malignancies, which is known as radioimmunotherapy. The target-to-background ratio depends on the antigen expression in the target and normal tissues, which is related to the therapeutic efficacy and toxicity in radioimmunotherapy. For the solid tumor beta-ray energy should be high, but lower beta energy is better for the hematological malignancies. I-l31 is widely used in thyroid cancer with low cost and high availability. Labeling monoclonal antibody with I-131 is relatively simple and reproducible. Some preclinical data for the I-131 labeled monoclonal antibodies including acute toxicity and efficacy are available from already published literatures in KIRAMS, physician sponsored clinical trial protocols using Rituximab, KFDA approved anti-CD20 chimeric monoclonal antibody and I-131 were approved by KFDA and currently are ongoing.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.106-112
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• 2006

Tissue hyperplasia is one of the most frequently encountered complications when self-expanding metallic stents are placed in benign non-vascular luminal organ strictures, thus causing restenosis of the lumen. The investigators postulated that ionizing irradiation could be applied to prevent restenosis caused by tissue hyperplasia in non-vascular luminal organs as it reduced coronary or peripheral arterial narrowing successfully. The authors combined $\beta$-irradiation using $^{188}Re-MAG_3$ solution with balloon dilation for animal and clinical studies because this new treatment approach had the advantages such as low penetration depth of $\beta$-ray, self-centering irradiation, and mechanical effect of balloon dilation over using $\gamma$-irradiation with afterloading devices in this article, the concept and mechanism of radioisotope balloon dilation, and animal and clinical studies using radioisotope balloon dilation are reviewed.

• 한국세라믹학회지
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• 제39권1호
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• pp.57-67
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• 2002

본 연구에서는 Tetracalcium Phosphate(TTCP), Dicalcium Phosphate Anhydrate(DCPA)계 골 시멘트에 $\beta$-tricalcium Phosphate (TCP)와 Precipitated Hydroxy Apatite(PHA)를 첨가하였을 때, 골시멘트의 초기 응결시간과 강도에 미치는 영향 및 in vitro test후의 표면 미세구조의 변화를 관찰하고자 하였다. 골 시멘트에 사용된 TTCP와 $\beta$-TCP는 약 3-5$mu extrm{m}$으로 합성후 분쇄하였으며, DCPA는 0.9$\mu\textrm{m}$, 그리고 PHA는 4$\mu\textrm{m}$의 평균 입경을 가졌다. 각각의 조성으로 배합된 시멘트는 Vicat건에 의한 초기응결시간 측정과 압축강도 시험을 행하였고, 의사체액내에 침적 후 침전 생성물을 x-선 회절 분석과 주사전자현미경을 이용하여 분석, 관찰 하였다. 초기 응결시간은 $\beta$-TCP나 PHA의 존재 유무와 함량의 증가에 따라 크게 좌우되지 않았으나, 분말 : 액상의 비에 영향을 받았으며, 특히 PHA가 함유되는 경우 PHA의 비표면적으로 인하여 응결에 요구되는 액상의 양은 PHA가 없는 경우에 비하여 2배 이상 되었다. $\beta$-TCP PHA의 첨가로 인해 압축강도는 낮아졌고, 이는 수화 생성물인 HAP의 생성 정도가 낮았기 때문이었다. 이는 x-선 회절 분석과 주사전자 현미경 관찰을 통하여 확인할 수 있었다. 본 연구로부터 TTCP-DCPA계 골 시멘트에 $\beta$-TCP나 PHA의 첨가는 기계적 물성과 생체 반응성 향상에 효과적이지 못하다는 것을 확인 할 수 있었다.

• 통합자연과학논문집
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• 제9권2호
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• pp.94-102
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• 2016

The crystal structure of the potential active 6-ethoxy-3-phenyl-5a,9a-dihydro-3H-chromen[4,3-c][1,2]oxazole-3a(4H)-carbonitrile ($C_{19}H_{15}N_2O_3$) has been determined from single crystal X-ray diffraction technique. The title compound crystallizes in the monoclinic space group C2/c with unit cell dimension a= 29.3026(9) ${\AA}$, b= 6.7695(2) ${\AA}$ and c= 19.7597(6) ${\AA}$ [${\alpha}= 90^{\circ}$, ${\beta}= 125.709(10)^{\circ}$ and ${\gamma}= 90^{\circ}$]. Single crystals suitable for X-ray diffraction were obtained by slow evaporation method, the isoxazole and six membered pyran rings adopts envelope conformation. The crystal packing of the molecules is stabilized by the weak $C-H{\ldots}N$ hydrogen bond interaction.

• 통합자연과학논문집
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• 제9권2호
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• pp.103-112
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• 2016

The crystal structure of the potential active Methyl 8-bromo-3-phenyl-5a,9a-dihydro-3H-chromen [4,3-c][1,2] isoxazole-3a(4H)-carboxylate ($C_{18}H_{15}BrNO_4$) has been determined from single crystal X-ray diffraction technique. The title compound crystallizes in the triclinic space group Pī with unit cell dimension a=8.3129 (3) ${\AA}$, b=9.5847 (4) ${\AA}$ and c=11.1463(4) ${\AA}$ [${\alpha}=98.457(3)^{\circ}$, ${\beta}=102.806(2)^{\circ}$ and ${\gamma}=105.033(5)^{\circ}$]. Single crystals suitable for X-ray diffraction were obtained by slow evaporation method, the isoxazole and six membered pyran rings adopts envelope conformation. In the crystal, molecules are linked via pairs of inter molecular $C-H{\ldots}O$ hydrogen bonds to form dimmers.

• 통합자연과학논문집
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• 제8권1호
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• pp.30-39
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• 2015

The crystal structure of the potential active 2-amino-4-(4-hydroxy-3-methoxyphenyl)-7, 9-dimethyl-5-oxo-4, 5, 6, 7-tetrahydropyrano [2, 3-d] pyrazolo [3, 4-b] pyridine-3-carbonitrile ($C_{21}H_{22}N_5O_6S$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group P-1 with unit cell dimension a=8.1201(9)${\AA}$, b=12.2684(4)${\AA}$ and c=12.387(2)${\AA}$ [${\alpha}=69.573^{\circ}$, ${\beta}=12.168^{\circ}$ and ${\gamma}=76.060^{\circ}$]. In the structure the pyrazole, pyridine and pyran are almost coplanar each other. The crystal packing is stabilized by intermolecular C-H...O and N-H... O hydrogen bond interaction.

• 한국주조공학회지
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• 제30권3호
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• pp.100-110
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• 2010

The solidification sequence and formation of intermetallic phase of Fe-rich Al-Si-Cu alloy were investigated by using real-time imaging of synchrotron X-ray radiation. Effects of cooling rate during uni-directional solidification on the resultant solidification behavior was also studied in a specially constructed vacuum chamber in the SPring-8 facility. The series of radiographic images were complementarily analyzed with conventional analysis of OM and SEM/EDX for phase identification. Detailed solidification sequence and formation mechanisms of various phases were discussed based on real-time image analysis. The growth rates of $\alpha$-AlFeMnSi and ${\beta}-Al_5FeSi$ were measured in order to understand the growth behavior of each phase. It is suggested that real-time imaging technique can be a powerful tool for the precise understanding of solidification behavior of various industrial materials.

• 통합자연과학논문집
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• 제8권3호
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• pp.192-203
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• 2015

In view of the growing medicinal importance of pyrazole and its derivatives, the single crystal X-ray diffraction study was carried out for the potential active 2-Benzyl-3-[3-(4-bromo-phenyl)-1-phenyl-1H-pyrazol-4yl]-4,6-dioxo-5-phenyl-octahydro-pyrrolo[3,4-C]pyrrole-1-carboxylic acid ethyl ester ($C_{37}H_{31}BrN_4O_4$, H2O). In the title compound are two molecules exist in the asymmetric unit. It crystallizes in the monoclinic space group $P{\hat{i}}$ with unit cell dimension $a=13.361(18){\AA}$, $b=13.424(17){\AA}$ and $c=21.649(2){\AA}$ [${\alpha}=80.745(9)^{\circ}$, ${\beta}=79.770(10)^{\circ}$ and ${\gamma}=60.788(6)^{\circ}$]. The pyrazole ring adopts planar conformation. The sum of the bond angles at nitrogen atom of the pyrazole ring indicates the $Sp^2$ hybridized state. The crystal structure is stabilized by intramolecular C-H...O hydrogen bond interaction.