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  • Author or Editor: D. Xiao x
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Abstract  

Electrothermomechanical analysis (ETMA) is effective for studying electrically conductive adhesive joints. Post curing of an electrically conductive adhesive (silver particle filled epoxy) by heating at an elevated temperature significantly enhances the thermal and mechanical stability of the conductive adhesive joint. The contact electrical resistivity and thickness of a joint tend to decrease cycle to cycle upon thermal cycling between 30 and 50°C and upon compression (up to 0.55 MPa). The effects of compression and thermal cycling are significant in the joint without post curing, but is insignificant after post curing.

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Abstract  

This project compares various bibliometric measures and scientists' own judgments. Publication and cittion data are compiled for two cohorts of chemists awarded Sloan Fellowships. Citation patterns differ substantially between most cited papers and those these authors identify as their best. Theoretical, empirical, and methodological papers are contrasted as well. In addition, temporal citation patterns show that recognition spreads beyond the research area of a particular paper to yield cross-disciplinary citation surprisingly rapidly. Results suggest the utility of studying citation patterns among the Institute for Scientific Information Subject Categories, but also caution against equating publication and citation counts with scientific progress.

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Abstract  

The inhibitory effects of three berberine alkaloids (BAs) from Coptis chinensis Franch on Bifidobacterium adolescentis growth were investigated by microcalorimetry. The growth rate constant (k) and maximum heat-output power (Pmax) decreased and peak time of maximum heat-output power (tp) prolonged with the increase of BAs concentration. Half inhibitory ratios (IC50) BAs were respectively 790.3 (berberine), 339.6 (coptisine) and 229.8 μL−1 (palmatine), which indicated the sequence of their antimicrobial activity: berberine<coptisine<palmatine. Combined with previous findings, the sequence which could show the bioactivity of Bacillus shigae and Escherichia coli was: berberine>coptisine>palmatine. The structure-function relationship of BAs indicated that the functional group methylenedioxy or methoxyl at C2 and C3 might be the major group inducing the activities of BAs on E. coli and B. adolescentis. Meanwhile, the substituent groups at C2, C3, C9 and C10 almost had equal effect on B. shigae.

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Abstract

The aim of this study is to investigate the melting/freezing characteristics of paraffin by adding Cu nanoparticles. Cu/paraffin composite phase change materials (PCMs) were prepared by a two-step method. The effects of Cu nanoparticles on the thermal conductivity and the phase change heat transfer of PCMs were investigated by the Hot Disk thermal constants analyzer and infrared monitoring methods, respectively. The maximum thermal conductivity enhancements up to 14.2% in solid state and 18.1% in liquid state are observed at the 2 wt% Cu/paraffin. The photographs of infrared monitoring suggest that the melting and freezing rates of Cu/paraffin are enhanced. For 1 wt% Cu/paraffin, the melting and freezing times can be saved by about 33.3 and 31.6%, respectively. The results provide that adding nanoparticles is an efficient way to enhance the phase change heat transfer of PCMs.

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Authors: D. E. Re, V. Coetzee, D. Xiao, D. Buls, B. P. Tiddeman, L. G. Boothroyd and D. I. Perrett

Abstract

Experience-dependent changes in mate choice preferences may confer an evolutionary benefit by shifting preferences towards traits that are advantageous for specific environments. Previous studies have demonstrated that prolonged exposure to one type of face biases perceptions of subsequently viewed faces and exposure to one type of body biases perceptions of subsequently viewed bodies. We tested whether preferences in facial adiposity were affected by viewing heavy or light bodies. We first assessed facial adiposity preferences by asking Caucasian participants (n = 59) to transform three-dimensional female Caucasian faces along a body mass index (BMI) continuum until they reached optimal attractiveness. Participants then viewed heavy- or light-bodied two-dimensional images with the faces cropped out before repeating the face preference task. Male and female participants who viewed heavy bodies shifted preferences toward significantly higher facial adiposity, while those who viewed the light bodies showed no significant overall shift. These results provide evidence that adaptation to certain body types affects subsequent preferences for facial adiposity, and suggest that adaptation to one body domain may affect preferences in other body domains.

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Changes in microbial population, pH, sugar, organic acid, anthocyanins, total soluble phenolics, and anti-glucosidase contents were measured during fermentation of mulberry juice at 30 °C by probiotic Leuconostoc mesenteroides showing rapid growth after an approximately 1-day lag phase and reaching a maximum of 8.6 log CFU ml−1 after 4 d. During the rapid growth phase, the main mulberry juice sugars, glucose and fructose, were largely consumed, and the acidic metabolites, lactic acid and acetic acid, were produced accordingly. A slow decrease in the concentration of the main organic acid, citric acid, was also observed during fermentation. After 4 d fermentation, anthocyanin content showed a 44.4% reduction, but the total amount of soluble phenolics and α-glucosidase inhibitory activity showed no significant changes (P>0.05). This suggests that L. mesenteroides fermentation of mulberry juice is a good strategy to enhance its probiotic value and to decrease the sugar content without changing the anti-glucosidase activity, which is required to reduce postprandial rise in blood glucose.

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Authors: F. Wang, H. Fan, D. Chen, H. Bai, Z. Chen and L. Xiao

Abstract  

Radiolabeled somatostatin analogue is a useful ligand for scintigraphic imaging of somatostatin receptor-bearing tumors. In this study, we investigated the effects of different radiolabeling conditions on labeling yield and ratio between mono-iodinated and di-iodinated125I-Tyr3-octreotide by HPLC analysis. In vitro and in vivo stabilities of125I-Tyr3-octreotide and111In-DTPA-D-Phe1-octreotide were also determined. Both radiolabeled compounds were relatively stable in vitro, but were decomposed to free125I− and111In-DTPA in vivo, respectively.

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Abstract  

Excess molar enthalpies of binary mixtures for tributyl phosphate (TBP)+methanol/ethanol were measured with a TAM air Isothermal calorimeter at 298.15 K and ambient. The results for xTBP+(1–x)CH3OH are negative in the whole range of composition, while the values for xTBP+(1–x)C2H5OH change from positive values at low x to small negative values at high x. The experimental results have been correlated with the Redlich–Kister polynomial. IR spectra of the mixtures were measured to investigate the effect of hydrogen bonding in the mixture.

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Biofortifying food crops with essential minerals would help to alleviate mineral deficiencies in humans. Detection of quantitative trait loci (QTLs) for mineral nutrient contents in rice was conducted using backcross inbred lines derived from an interspecific cross of Oryza sativa × O. rufipogon. The population was grown in Hangzhou and Lingshui, with the contents of Mg, Zn, Fe, Mn, Cu and Se in brown rice measured in both trials and that in milled rice tested in Hangzhou only. A total of 24 QTLs for mineral element contents were identified, including two for both the brown and milled rice, 17 for brown rice only, and five for milled rice only. All the seven QTLs detected for the mineral contents in milled rice and 13 of the 19 QTLs for the contents in brown rice had the enhancing alleles derived from O. rufipogon. Fifteen QTLs were clustered in seven chromosomal regions, indicating that common genetic-physiological mechanisms were involved for different mineral nutrients and the beneficial alleles could be utilized to improve grain nutritional quality by markerassisted selection.

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Authors: H. Chen-Mayer, V. Sharov, D. Mildner, R. Downing, R. Paul, R. Lindstrom, C. Zeissler and Q. Xiao

Abstract  

A neutron lens has been constructed to focus cold neutrons from the exit of a58Ni neutron guide, which delivers a beam to the Prompt-Gamma Activation Analysis (PGAA) station at the NIST Cold Neutron Research Facility. The lens compresses a neutron beam of cross section 50 mm× 45 mm onto a focal spot of diameter 0.53 mm (fwhm) wich an average gain of 80 in neutron current density. PGAA measurements have been performed to demonstrate the enhanced sensitivity and detection limits for various elements and the spatial resolution in one transverse dimension. For the two test particles (a gadolinium glass bead and cadmium metal of sizes less than 0.5 mm), the gain in the -count rate with the lens is a factor of 60, and the detection limit is improved by a factor of 20. The system can be used for two-dimensional mapping of samples on a sub-millimeter scale to complement other analytical techniques such as neutron depth profiling (NDP).

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