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31.
WYETH Paul 《中国科学B辑(英文版)》2011,(6)
Silks are among the most precious ancient and historic artefacts worldwide. While washing removes the natural gum from the fibres during the fabrication of most silk textiles, for a small proportion of historic silks some or perhaps all of the sericin still remains. This paper investigated the effect of sericin coating on the aging of silk fibroin by means of ATR and tensile testing. The results show that sericin can provide some extent of protection from light and heat aging. However, in high humidity envi... 相似文献
32.
A methodology is proposed for predicting the effective thermal conductivity of dilute suspensions of nanoparticles (nanofluids) based on rheology.The methodology uses the rheological data to infer microstructures of nanoparticles quantitatively,which is then incorporated into the conventional Hamilton-Crosser equation to predict the effective thermal conductivity of nanofluids.The methodology is experimentally validated using four types of nanofluids made of titania nanoparticles and titanate nanotubes dispersed in water and ethylene glycol.And the modified Hamilton-Crosser equation successfully predicted the effective thermal conductivity of the nanofluids. 相似文献
33.
Young-Hee Lee Govinda Bhattarai Santosh Aryal Min-Ho Lee Eun-Chung Jhee Ho-Keun Yi 《Applied Surface Science》2010,256(20):5882-5887
This study examined the gelatin nano gold (GnG) composite for surface modification of titanium in addition to insure biocompatibility on dental implants or biomaterials. The GnG composite was constructed by gelatin and hydrogen tetrachloroaurate in presence of reducing agent, sodium borohydrate (NabH4). The GnG composite was confirmed by UV-VIS spectroscopy and transmission electron microscopy (TEM). A dipping method was used to modify the titanium surface by GnG composite. Surface was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The MC-3T3 E1 cell viability was assessed by trypan blue and the expression of proteins to biocompatibility were analyzed by Western blotting. The GnG composite showed well dispersed character, the strong absorption at 530 nm, roughness, regular crystal and clear C, Na, Cl, P, and Au signals onto titanium. Further, this composite allowed MC-3T3 E1 growth and viability compared to gelatin and pure titanium. It induced ERK activation and the expression of cell adherent molecules, FAK and SPARC, and growth factor, VEGF. However, GnG decreased the level of SAPK/JNK. This shows that GnG composite coated titanium surfaces have a good biocompatibility for osteoblast growth and attachment than in intact by simple and versatile dipping method. Furthermore, it offers good communication between cell and implant surfaces by regulating cell signaling and adherent molecules, which are useful to enhance the biocompatibility of titanium surfaces. 相似文献
34.
Warren R Hayes C Pointon L Hoff R Gilbert FJ Padhani AR Rubin C Kaplan G Raza K Wilkinson L Hall-Craggs M Kessar P Rankin S Dixon AK Walsh J Turnbull L Britton P Sinnatamby R Easton D Thompson D Lakhani SR Leach MO;UK MRC study of MRI screening for breast cancer in women at high risk 《Magnetic resonance imaging》2006,24(7):917-929
OBJECTIVES: The aim of this study was to assess the consistency and performance of radiologists interpreting breast magnetic resonance imaging (MRI) examinations. MATERIALS AND METHODS: Two test sets of eight cases comprising cancers, benign disease, technical problems and parenchymal enhancement were prepared from two manufacturers' equipment (X and Y) and reported by 15 radiologists using the recording form and scoring system of the UK MRI breast screening study [(MAgnetic Resonance Imaging in Breast Screening (MARIBS)]. Variations in assessments of morphology, kinetic scores and diagnosis were measured by assessing intraobserver and interobserver variability and agreement. The sensitivity and specificity of reporting performances was determined using receiver operating characteristic (ROC) curve analysis. RESULTS: Intraobserver variation was seen in 13 (27.7%) of 47 of the radiologists' conclusions (four technical and seven pathological differences). Substantial interobserver variation was observed in the scores recorded for morphology, pattern of enhancement, quantification of enhancement and washout pattern. The overall sensitivity of breast MRI was high [88.6%, 95% confidence interval (CI) 77.4-94.7%], combined with a specificity of 69.2% (95% CI 60.5-76.7%). The sensitivities were similar for the two test sets (P=.3), but the specificity was significantly higher for the Manufacturer X dataset (P<.001). ROC curve analysis gave an area under the curve of 0.85 (95% CI 0.79-0.92) CONCLUSIONS: Substantial variation in all elements of the scoring system and in the overall diagnostic conclusions was observed between radiologists participating in MARIBS. High overall sensitivity was achieved with moderate specificity. Manufacturer-related differences in specificities possibly occurred because the numerical thresholds set for the scoring system were not optimised for both equipment manufacturers. Scoring systems developed on one equipment software may not be transferable to other manufacturers. 相似文献
35.
Saralees Nadarajah 《数学物理学报(B辑英文版)》2010,30(1):330-340
Two posterior distributions for the mean of the Laplace distribution are obtained by deriving the distributions of the product XY and the ratio X/Y when X and Y are Student's t and Laplace random variables distributed independently of each other. Tabulations of the associated percentage points are given along with computer programs for generating them. 相似文献
36.
Bo Xiao a Qingchun Yuan b a EaStChem School of Chemistry Purdie Building North Haugh University of St. rews Fife St. rews KY ST UK b Institute of Particle Science Engineering School of Processing Environmental & Mineral Engineering University of Leeds Houldworth Building Leeds LS JT UK 《中国颗粒学报》2009,7(2)
Hydrogen is expected to play an important role in future transportation as a promising alternative clean energy source to carbon-based fuels.One of the key challenges to commercialize hydrogen energy is to develop appropriate onboard hydrogen storage systems,capable of charging and discharging large quantities of hydrogen with fast enough kinetics to meet commercial requirements.Metal organic framework (MOF) is a new type of inorganic and organic hybrid nanoporous particulate materials.Its diverse networks can enhance hydrogen storage through tuning the structure and property of MOFs.The MOF materials so far developed adsorb hydrogen through weak disperston interactions,which allow significant quantity of hydrogen to be stored at cryogenic temperatures with fast kinetics.Novel MOFs are being developed to strengthen the interactions between hydrogen and MOFs in order to store hydrogen under ambient conditions.This review surveys the development of such candidate materials,their performance and future research needs. 相似文献
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Granovskii A. B. Soboleva E. A. Fadeev E. A. Dubenko I. S. Aryal A. Samassekou H. Pandey S. Stadler S. Mazumdar D. Ali N. Lähderanta E. 《Journal of Experimental and Theoretical Physics》2020,130(1):117-122
Journal of Experimental and Theoretical Physics - Magnetic Heusler alloys X2BZ (where X and B are 3d elements and Z belongs to the sp group) exhibit diverse magnetic and structural properties,... 相似文献
38.
Titanium dioxide metal oxide affinity chromatography (TiO2‐MOAC) is widely regarded as being more selective than immobilized metal‐ion affinity chromatography (IMAC) for phosphopeptide enrichment. However, the widespread application of TiO2‐MOAC to biological samples is hampered by conflicting reports as to which experimental conditions are optimal. We have evaluated the performance of TiO2‐MOAC under a wide range of loading and elution conditions. Loading and stringent washing of peptides with strongly acidic solutions ensured highly selective enrichment for phosphopeptides, with minimal carryover of non‐phosphorylated peptides. Contrary to previous reports, the addition of glycolic acid to the loading solution was found to reduce specificity towards phosphopeptides. Base elution in ammonium hydroxide or ammonium phosphate provided optimal specificity and recovery of phosphorylated peptides. In contrast, elution with phosphoric acid gave incomplete recovery of phosphopeptides, whereas inclusion of 2,5‐dihydroxybenzoic acid in the eluant introduced a bias against the recovery of multiply phosphorylated peptides. TiO2‐MOAC was also found to be intolerant of many reagents commonly used as phosphatase inhibitors during protein purification. However, TiO2‐MOAC showed higher specificity than immobilized gallium (Ga3+), immobilized iron (Fe3+), or zirconium dioxide (ZrO2) affinity chromatography for phosphopeptide enrichment. Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) was more effective in detecting larger, multiply phosphorylated peptides than liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS), which was more efficient for smaller, singly phosphorylated peptides. Copyright © 2009 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. 相似文献
39.
Gileva Olga Aryal Pabitra Karki Sujita Kim HongJoo Kim Yeongduk Milyutin Vitaly Park HyangKyu Shin KeonAh 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1695-1700
The presented study reports on the purification of molybdenum oxide, which is one of the important tasks of the Advanced Mo based Rare process Experiment in searching for the neutrinoless double beta (0νββ) decay of 100Mo. Purified MoO3 powder is used as initial material for further growth of radiopure monocrystals. As purification technique, double sublimation, co-precipitation with calcium chloride carrier, and precipitation of polyammonium molybdate from acidic media were used. Concentrations of impurities like Sr, Ba, Pb, Th and U were measured by ICP-MS and radioactive isotopes were checked by a HPGe detector at the YangYang underground Laboratory in Korea.
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