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651.
652.
AIMS: To examine the prognostic and pathobiological importance of DNA content in oesophageal squamous cell carcinomas in Hong Kong Chinese subjects; to evaluate its association with the immunohistochemical proliferative marker MIB-1. METHODS: Paraffin wax embedded tumour tissue and adjacent normal tissue (control tissue) samples from 45 resected stage III oesophageal squamous cell carcinomas were studied using flow cytometric analysis. The DNA content and the clinicopathological data of these patients were analysed together with the MIB-1 labelling index. RESULTS: DNA aneuploidy was present in 14 (31%) of the 45 cases. However, the DNA content did not correlate significantly with the age, sex, or survival of the patients, nor the length, location, differentiation and MIB-1 labelling index of the oesophageal carcinomas. The synthetic (S) phase fraction of diploid tumours bore no relation to the patients' survival or MIB-1 score. CONCLUSIONS: Flow cytometry was not as useful as the MIB-1 labelling index in predicting the biological characteristics of the tumours and the prognosis of patients with oesophageal squamous cell carcinomas. This study does not support the routine use of DNA flow cytometric analysis in oesophageal cancers. 相似文献
653.
A. K. Shukevich A. A. Lukhvich N. V. Kremen’kova A. L. Luk’yanov V. I. Sharando 《Russian Journal of Nondestructive Testing》2004,40(11):763-767
The level of internal stresses appears to be the main interfering factor in the magnetic measurement of the thickness of nickel deposits. The possibility of development of a probe with an informative zone close to magnetic saturation, which would substantially decrease the effect of stresses on measurement results, is demonstrated.Translated from Defektoskopiya, Vol. 40, No. 11, 2004, pp. 62–68.Original Russian Text Copyright © 2004 by Shukevich, Lukhvich, Kremenkova, Lukyanov, Sharando. 相似文献
654.
V. V. Luk’yanova Yu. I. Tarasevich S. V. Bondarenko G. N. Malysh A. I. Zhukova A. P. Kozhan 《Journal of Water Chemistry and Technology》2008,30(1):24-31
Based on the data on adsorption of vapors of nitrogen, n-hexane, water, and electrochemical measurements it has been shown that thermoexpanded graphite possesses a nonuniform-porous structure and a vividly expressed hydrophobic surface per 1 m2 of which there are ~1018 of active hydrophilic centers. We have carried out their identification. We have investigated adsorption of anionic (sulfonol, direct scarlet dye, fulvic acids), cationic (crystalline violet dye), and nonionogenic (i-OcPh(OE)10) organic matter on the surface of thermoexpanded graphite. It has been shown that the use of the sorbent under investigation in the processes of water purification of dissolved organic compounds has good prospects. 相似文献
655.
K.W.K. Yeung Y.L. Chan K.O. Lam X.M. Liu S.L. Wu X.Y. Liu C.Y. Chung W.W. Lu D. Chan K.D.K. Luk Paul K. Chu K.M.C. Cheung 《Materials science & engineering. C, Materials for biological applications》2008,28(3):454-459
This paper describes the corrosion resistance, surface mechanical properties, cyto-compatibility, and in-vivo performance of plasma-treated and untreated NiTi samples. Nickel–titanium discs containing 50.8% Ni were treated by nitrogen and carbon plasma immersion ion implantation (PIII). After nitrogen plasma treatment, a layer of stable titanium nitride is formed on the NiTi surface. Titanium carbide is also found at the surface after carbon plasma implantation. Compared to the untreated samples, the corrosion resistances of the plasma PIII samples are better by a factor of five and the surface hardness and elastic modulus are better by a factor of two. The concentration of Ni leached into the simulated body fluids from the untreated samples is 30 ppm, whereas that from the plasma-treated PIII are undetectable. Although there is no significant difference in the ability of cells to grow on either surface, bone formation is found to be better on the nitrogen and carbon PIII sample surfaces at post-operation 2 weeks. All these improvements can be attributed to the formation of titanium nitride and titanium carbide on the surface. 相似文献
656.
A biomimetic hierarchical scaffold: natural growth of nanotitanates on three-dimensional microporous Ti-based metals 总被引:1,自引:0,他引:1
Wu S Liu X Hu T Chu PK Ho JP Chan YL Yeung KW Chu CL Hung TF Huo KF Chung CY Lu WW Cheung KM Luk KD 《Nano letters》2008,8(11):3803-3808
Nanophase materials are promising alternative implant materials in tissue engineering. Here we report for the first time the large-scale direct growth of nanostructured bioactive titanates on three-dimensional (3D) microporous Ti-based metal (NiTi and Ti) scaffolds via a facile low temperature hydrothermal treatment. The nanostructured titanates show characteristics of 1D nanobelts/nanowires on a nanoskeleton layer. Besides resembling cancelous bone structure on the micro/macroscale, the 1D nanostructured titanate on the exposed surface is similar to the lowest level of hierarchical organization of collagen and hydroxyapatite. The resulting surface displays superhydrophilicity and favors deposition of hydroxyapatite and accelerates cell attachment and proliferation. The remarkable simplicity of this process makes it widely accessible as an enabling technique for applications from engineering materials treatment including energy-absorption materials and pollution-treatment materials to biotechnology. 相似文献
657.
V. V. Sumin I. V. Papushkin O. A. Bannykh V. M. Blinov P. Lukáš 《The Physics of Metals and Metallography》2008,105(1):88-91
An austenitic-martensitic nitrogen steel 0Kh16N4AB has been studied under load using high-resolution neutron diffraction analysis on an FSD neutron diffractometer at an IBR-2 reactor (Dubna) and on a diffractometer with a focusing monochromator on a reactor of the Nuclear Physics Institute (Czech Republic). Young’s moduli calculated from different reflections of the martensite and austenite phases have been obtained. It has been found that the yield strength σ0.2 corresponding to the slip plane (111) of the austenite phase is anomalously low and that with increasing degree of uniaxial tension the width of lines (111)γ strongly grows. In the steel under consideration the plane (111) of the austenite phase appears to be an easy-slip plane that ensures the enhanced properties of the steel, i.e., the combination of a high ultimate strength (1600 MPa) with a high plasticity (δ = 16%). 相似文献
658.
659.
Dušan Kopecký Martin Vrňata Filip Vysloužil Přemysl Fitl Ondřej Ekrt Jaromír Seidl Vladimír Myslík Jaroslav Hofmann Josef Náhlík Jan Vlček Lukáš Kučera 《Synthetic Metals》2010,160(9-10):1081-1085
The contribution deals with synthesis and characterization of conductive polypyrrole (PPY), which should be suitable for depositions of thin layers by Matrix Assisted Pulsed Laser Evaporation (MAPLE) method. The samples of doped PPY containing various organic dopants – (i) p-toluenesulfonic acid, (ii) dodecyl-benzenesulfonic acid, (iii) dioctyl-sulfosuccinic acid and (iv) camphorsulfonic acid – were synthesized by polymerization of pyrrole in acidic or neutral solution. Solubility of synthesized PPY and settlement time of PPY particles in water and dimethylsulfoxide – parameters critical for MAPLE method – were investigated. The composition of prepared PPY was verified by FTIR spectroscopy. Conductivity of the polymer in solid state was determined to be in range from σ = 2.6 × 10?6 S cm?1 to σ = 6.0 × 10?2 S cm?1. The optimal material for MAPLE deposition is PPY containing organic dopants (ii)–(iv), dissolved in DMSO matrix (solubility from 4.1% to 6.5% by weight and settlement time 140–240 h). 相似文献
660.
King Kevin M.; Karyadi Kenny A.; Luk Jeremy W.; Patock-Peckham Julie A. 《Canadian Metallurgical Quarterly》2011,25(3):446
“Impulsivity” has been consistently identified as a key personality predictor of alcohol-related problems and subsequent alcohol use disorder. Multiple prior studies have demonstrated impulsivity is an individual difference factor that strengthens the effects of some risk factors, such as alcohol consumption and depressive symptoms, on alcohol problems. However, recent research indicated common measures of impulsivity actually reflect multiple dispositions toward rash action, and that alcohol problems were most consistently related to one of those dispositions, negative urgency. Little research has examined how specific dispositions to rash action may act as putative moderators of other risk factors for alcohol problems. The goal of the current study was to test which dispositions to rash action moderated the effects of concurrent alcohol use or depressive symptoms on alcohol problems. Using a large cross-sectional sample of college students (n = 573), the current study utilized semicontinuous regression models, which allow prediction of both the likelihood and level of alcohol problems. Negative urgency was found to be the main predictor of alcohol problems, above and beyond other dispositions to rash action, which replicates prior research. However, each of the other dispositions exhibited risk-enhancing effects on the relations between either depressive symptoms or alcohol use and concurrent alcohol problems. Specifically, lower levels of premeditation enhanced the association between depressive symptoms and alcohol problems, while lower perseverance and higher sensation seeking were related to more alcohol problems at higher levels of alcohol use. Results suggest that multiple dispositions to rash action were related to problematic alcohol use both directly and via their interaction with other risk factors. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献