• Title/Summary/Keyword: random unit cell

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X-ray Analys is of the Thermotropic Liquid Crystalline Copolyester Poly(1 -phenylethylpphenylene-tere phthalate) (열방성 액정폴리에스터Poly(1-phenylethyl.p-phenyleneterephthalate)의 X-선 결정구조해석)

  • 홍성권
    • Korean Journal of Crystallography
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    • v.2 no.2
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    • pp.13-21
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    • 1991
  • X-ray methods have been used to determine the chain conformation and packing of the thermotropic liquid crystalline copolyester prepared from 50% tarephthaloyl chloride(TPA) and 50% (1-phenylethyl) hydroquinone(PEHQ). The x-ray patterns of annealed melt-spun fibers contain a series of annealed melt-Pointing to a well ordered crystalline structure, despite the random sense(2 or 3-) of the 1-phenylethyl substiuttion on the TPA-hydroquinone backbone. The crystalline fiber is monoclinic with space group P2l and the unit cell has dimensions 11=12.77 A, b=10.17 A (upique axis), c=12.58 h (fiber axis). and β=90.1° and contains TPA-PEHO units of to or chains. The random substitution of 1-phenylethyl groups was modelled by placing these groups at both the 2and 3 positions and giving each a weight of one-hal(. T he structure has been refined by linked a rom least square methods(LALS) against 16 observed and 21 unobserved reflections. and had a final R value of 0.20. Packing of the side chains is effected by staggering adjacent chains along the b axis by approximately c/2, so that the side chains are interleaved. The phenyl-COO and COO-phenyl torsion angles are -6.1 and 65.6, respectively, such that the main chain phenyls are mutually inclined at 59.5 (the ester groups are assumed to be planar). These torsion angles compare very well with those for the model compounds, notably phenylbenzoate, and can be used in future analyses of the structures of more complex random sequence copolyesters.

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Prognostic Impact of Histology in Patients with Cervical Squamous Cell Carcinoma, Adenocarcinoma and Small Cell Neuroendocrine Carcinoma

  • Intaraphet, Suthida;Kasatpibal, Nongyao;Siriaunkgul, Sumalee;Sogaard, Mette;Patumanond, Jayanton;Khunamornpong, Surapan;Chandacham, Anchalee;Suprasert, Prapaporn
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5355-5360
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    • 2013
  • Background: Clarifying the prognostic impact of histological type is an essential issue that may influence the treatment and follow-up planning of newly diagnosed cervical cancer cases. This study aimed to evaluate the prognostic impact of histological type on survival and mortality in patients with cervical squamous cell carcinoma (SCC), adenocarcinoma (ADC) and small cell neuroendocrine carcinoma (SNEC). Materials and Methods: All patients with cervical cancer diagnosed and treated at Chiang Mai University Hospital between January 1995 and October 2011 were eligible. We included all patients with SNEC and a random weighted sample of patients with SCC and ADC. We used competing-risks regression analysis to evaluate the association between histological type and cancer-specific survival and mortality. Results: Of all 2,108 patients, 1,632 (77.4%) had SCC, 346 (16.4%) had ADC and 130 (6.2%) had SNEC. Overall, five-year cancer-specific survival was 60.0%, 54.7%, and 48.4% in patients with SCC, ADC and SNEC, respectively. After adjusting for other clinical and pathological factors, patients with SNEC and ADC had higher risk of cancer-related death compared with SCC patients (hazard ratio [HR] 2.6; 95% CI, 1.9-3.5 and HR 1.3; 95% CI, 1.1-1.5, respectively). Patients with SNEC were younger and had higher risk of cancer-related death in both early and advanced stages compared with SCC patients (HR 4.9; 95% CI, 2.7-9.1 and HR 2.5; 95% CI, 1.7-3.5, respectively). Those with advanced-stage ADC had a greater risk of cancer-related death (HR 1.4; 95% CI, 1.2-1.7) compared with those with advanced-stage SCC, while no significant difference was observed in patients with early stage lesions. Conclusion: Histological type is an important prognostic factor among patients with cervical cancer in Thailand. Though patients with SNEC were younger and more often had a diagnosis of early stage compared with ADC and SCC, SNEC was associated with poorest survival. ADC was associated with poorer survival compared with SCC in advanced stages, while no difference was observed at early stages. Further tailored treatment-strategies and follow-up planning among patients with different histological types should be considered.

Construction Methods of Switching Network for a Small and a Large Capacity AMT Switching System (소용량 및 대용량의 ATM시스템에 적합한 스위칭 망의 구성 방안)

  • Yang, Chung-Ryeol;Kim, Jin-Tae
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.4
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    • pp.947-960
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    • 1996
  • The primary goal for developing high performance ATM switching systems is to minimized the probability of cell loss, cell delay and deterioration of throughput. ATM switching element that is the most suitable for this purpose is the shared buffer memory switch executed by common random access memory and control logic. Since it is difficult to manufacture VLIS(Very Large Scale Integrated circuit) as the number of input ports increased, the used of switching module method the realizes 32$\times$32, 150 Mb/s switch utilizing 8$\times$8, 600Mb/s os 16$\times$16, 150Mb/s unit switch is latest ATM switching technology for small and large scale. In this paper, buffer capacity satisfying total-memory-reduction effect by buffer sharing in a shared buffer memory switch are analytically evalu ated and simulated by computer with cell loss level at traffic conditions, and also features of switching network utilizing the switching module methods in small and large-capacity ATM switching system is analized. Based on this results, the structure in outline of 32$\times$32(4.9Gb/s throughput), 150Mb/s switches under research in many countries is proposed, and eventually, switching-network structure for ATM switching system of small and large and capacity satisfying with above primary goals is suggested.

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Parameter Effect on Elastic Modulus of Discontinuity Rock-mass Based on Homogenization Method (균질화 이론에 근거한 불연속성 암반의 탄성계수에 영향을 미치는 불연속면의 조사 인자에 관한 연구)

  • Baek, Yong
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.63-70
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    • 2000
  • The quantitative analyses and the mechanical interpretation of discontinuity planes are the most important factor for the study of strength and deformation properties of rock masses containing discontinuity planes. However, the relationship between the factors investigated in the field and the actual mechanical properties of discontinuity planes is not fully understood. The main purpose of this study is to investigate the effects of density, length, and spacing of joints on elastic modulus of rock masses as these values vary. A new parameter which has a direct relation with the elastic modulus of discontinuity planes is also preposed in this study. The combination of finite element methods and homogenization methods has been used for the numerical analyses of a uintcell with discontinuity planes, which is generated using random-number generation methods. The elastic modulus of the discontinuity plane is found from the numerical analyses. The final results propose not only the relation between the investigation parameters of discontinuity planes and the elastic modulus of rock masses but also a new parameter, an effect area ratio having a linear relation with the elastic modulus of rock masses.

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Expression of Hepatitis B Virus S Gene in Pichia pastoris and Application of the Product for Detection of Anti-HBs Antibody

  • Hu, Bo;Liang, Minjian;Hong, Guoqiang;Li, Zhaoxia;Zhu, Zhenyu;Li, Lin
    • BMB Reports
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    • v.38 no.6
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    • pp.683-689
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    • 2005
  • Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying ahexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5% of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100% with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.

The Preparation and Magnetic Properties in Ba-ferrite Film (Ba-ferrite 박막의 제조 및 자기적 특성에 관한 연구)

  • Sur, Jung-Chul;Kim, Dae-Sung;Ha, Tae-Yang;Lee, Jae-Gwang
    • Journal of the Korean Magnetics Society
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    • v.13 no.2
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    • pp.64-69
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    • 2003
  • Ba-ferrite thin films were prepared on Si substrate with ${\alpha}$-Fe$_2$O$_3$ underlayer by a pulsed laser deposition system and characterized by X-ray, SEM, Mossbauer spectroscopy and VSM. The appropriate conditions of pulsation in ${\alpha}$-Fe$_2$O$_3$ and Ba-ferrite were the oxygen pressure of 0.1 Torr at a substrate temperature of 400$^{\circ}C$. Ba-ferrite crystals had the forms of ellipsoidal or needle and the grains shaped the more lumps with increasing the film thickness. Mossbauer spectroscopy assured that the direction of atomic spin in Fe ion was not random but had the tendency of arrangement normal to the substrate. The coercive force and squareness of hysteresis were larger in normal than in plane to the substrate but, the magnetic saturation moment was contrary to them. The spin arrangement was strongly affected by ${\alpha}$-Fe$_2$O$_3$ underlayer and the high coercive force and squareness were influenced by this. The crystal structure was conformed to be a Magntoplumbite symmetry with the hexagonal unit cell and the lattice constant of a increased with increasing film thickness, while c decreased