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This work studies the detachment of a micron-sized spherical particle from a surface with concave roughness in a linear shear flow. The concave roughness is described as regularly spaced hollow hemispheres below a flat surface and is characterised by two dimensionless parameters, i.e. dimensionless asperity distance and asperity size ratio. The hydrodynamic force and torque on the particle are calculated by performing lattice Boltzmann simulations for particle Reynolds numbers ranging from 0.02 to 40. Empirical correlations of the drag, lift and torque coefficients of the particle as functions of the particle Reynolds number and the asperity size ratio are proposed. For detachment by lifting, sliding and rolling, a numerical approach to calculate the critical particle Reynolds number (i.e. above which the particle can detach from the surface) is proposed. It is found that the dimensionless asperity distance and the distribution of asperities on the rough surface have a minor influence on the hydrodynamic force and torque on the particle, and the detachment of the particle becomes more difficult as the particle sits deeper in a larger hole. Both the empirical correlations and the numerical approach can be implemented into Lagrangian particle tracking and can accurately predict the detachment of particles from the surface with concave roughness or the detachment of particles embedded in a flat surface.
The nutritional status experienced in the early development of life plays a vital role in the long-term metabolic state of the individual, which is known as nutritional programming. The present study investigated the long-term effects of vegetable oil (VO) nutritional programming during the early life of large yellow croaker. First, larvae were fed either a fish oil (FO) diet or a VO diet for 30 d. Subsequently, under the same conditions, all fish were fed a commercial diet for 90 d and thereafter challenged with an FO or VO diet for 30 d. The results showed that growth performance was significantly lower in larvae fed the VO diet than in those in fed the FO diet in the stimulus phase. Notably, VO nutritional history fish showed lower levels of liver lipids liver total triglycerides and serum nonesterified free fatty acids than the FO nutritional history fish when juveniles were challenged with the VO diet, which was consistent with the expression of lipogenesis-related genes and proteins. Moreover, the VO nutritional history fish showed lower liver damage and higher antioxidant capacity than FO nutritional history fish when challenged with the VO diet. In summary, this study showed that a short VO stimulus during the early life stage of large yellow croaker, had a long-term effect on lipid metabolism and the antioxidant system. Specifically, VO nutritional programming had a positive effect on alleviating abnormal lipid deposition on the liver, liver damage, and the reduction of hepatic antioxidant capacity caused by a VO diet.
During the last few decades, bed-elevation profiles from radar sounders have been used to quantify bed roughness. Various methods have been employed, such as the ‘two-parameter’ technique that considers vertical and slope irregularities in topography, but they struggle to incorporate roughness at multiple spatial scales leading to a breakdown in their depiction of bed roughness where the relief is most complex. In this article, we describe a new algorithm, analogous to wavelet transformations, to quantify the bed roughness at multiple scales. The ‘Self-Adaptive Two-Parameter’ system calculates the roughness of a bed profile using a frequency-domain method, allowing the extraction of three characteristic factors: (1) slope, (2) skewness and (3) coefficient of variation. The multi-scale roughness is derived by weighted-summing of these frequency-related factors. We use idealized bed elevations to initially validate the algorithm, and then actual bed-elevation data are used to compare the new roughness index with other methods. We show the new technique is an effective tool for quantifying bed roughness from radar data, paving the way for improved continental-wide depictions of bed roughness and incorporation of this information into ice flow models.
To obtain a fine-grained Mg matrix, the (submicron + micron) bimodal size SiC particle reinforced AZ91 (SiCp/AZ91) composite was subjected to forging followed by the extrusion process first. Then, the fine-grained bimodal size SiCp/AZ91 composite was compressed at 270–370 °C with 0.1–0.001 s−1. The result indicated that the refinement of the Mg matrix contributed to its deteriorated strength at high temperature. However, the grain size is not the only factor influencing flow stress but the SiCp also plays an important role. The effect of SiCp on the fine grained Mg matrix depends on grain size and dislocation density, both of which strongly depend on temperature and strain rate. As compared with the fine grained Mg matrix reinforced by single size SiCp, the one with bimodal size SiCp unusually exhibit lower flow stress during hot compression. The calculated activation energy of the bimodal size SiCp/AZ91 composite is higher than the micron SiCp/AZ91 composite; however, nearly the same as the submicron SiCp/AZ91 composite, and the deformation of which was thought to be controlled by ∼1 vol% submicron SiCp.
The present study aimed to translate the English version of the Nutritional Form For the Elderly into Simplified Chinese, as well as to test the reliability (homogeneity and stability) and validity (content and construct validity) of the Chinese version of the Nutritional Form For the Elderly (NUFFE-CHI).
The study adopted a cross-sectional design. The English version of the NUFFE was translated into Simplified Chinese and a questionnaire survey was conducted. The data were analysed with statistical methods to estimate the homogeneity, stability, content and construct validity.
Jinzhou City, China.
A total number of 701 community-dwelling older adults answered the questionnaire, including background variables and the NUFFE-CHI. A small group of the participants (n 50) completed the NUFFE-CHI twice for test–retest reliability.
Cronbach’s α was 0·65 and the split-half reliability was 0·67. Item-to-total correlation analyses showed that the scale has sufficient internal consistency. The test–retest reliability regarding the total scores of NUFFE-CHI was reflected in an intra-class correlation coefficient of 0·88. The intra-class correlation coefficients between the test and retest of the NUFFE-CHI items varied between 0·43 and 0·98. A content validity index of 0·83 explained good content validity. Construct validity was demonstrated in an exploratory factor analysis with a six-factor solution, explaining 57·65 % of the variance.
This first testing of the NUFFE-CHI indicates sufficient evidence for reliability, content and construct validity. Further testing studies regarding homogeneity, concurrent validity, sensitivity and specificity are required before the NUFFE-CHI can be used as a screening instrument in clinical settings and in research.
The cDNA of bovine interleukin-18 (BoIL-18) was subcloned into pGEX6P-1 vector and transformed into Escherichia coli BL21(DE3). The recombinant protein was successfully expressed in E. coli by induction of isopropyl β-d-1-thiogalactopyranoside (IPTG) at 0.3 mmol/l for 8 h. SDS-PAGE indicated that the BoIL-18 fusion protein, 44 kDa, was highly expressed. Densitometric scanning showed that the fusion protein expression was about 31.8% of the total bacterial protein. The biological activity of the chromatographically purified protein was assayed. The peripheral blood mononuclear cells (PBMC) proliferation test indicated that the BoIL-18 fusion protein could enhance PBMC proliferation when its concentration was more than 0.10 mg/l. Enzyme-linked immunosorbent assay (ELISA) showed that the BoIL-18 fusion protein could induce interferon (IFN)-γ production from spleen lymphocytes when it was at a concentration of more than 0.20 mg/l, and that the inducing effect of BoIL-18 fusion protein on IFN-γ was directly proportional to its concentration. This verified that the purified BoIL-18 fusion protein possessed a functional activity and could be applied in further studies.
To measure the Ag/Co interfacial free energies, biaxial zero creep experiments were performed on Ag/Co multilayer films deposited on the Si (111) wafers. As the samples were heated from room temperature to 450°C, the residual stress in films, which was in situ monitored by substrate curvature technique, decayed gradually to zero due to the increasing plastic deformation in films. After held for several hours at 450°C, they reached a zero creep state while the equilibrium stresses were measured. The annealed element layers were immiscible, and exhibited the column grain distribution and (111) preferred orientations. Based on the Josell model, the free energy of Ag/Co (111) interfaces at 450°C was found to be 1.02 ± 0.17 J/m2.
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