Excessive intake of high-energy diets is an important cause of most obesity. The intervention of rats with high-fat diet can replicate the ideal animal model for studying the occurrence of human nutritional obesity. The proteomics and bioinformatics analysis can help us to systematically and comprehensively study the effect of high-fat diet on rat liver. In this study, 4056 proteins were identified in rat liver by using tandem mass tag. A total of 198 proteins were significantly changed, of which 103 were significantly up-regulated and 95 were significantly down-regulated. These significant differentially expressed proteins are primarily involved in lipid metabolism and glucose metabolism processes. The intake of a high-fat diet forces the body to maintain physiological balance by regulating these key protein spots to inhibit fatty acid synthesis, promote fatty acid oxidation, and accelerate fatty acid degradation. This study enriches our understanding of metabolic disorders induced by high-fat diets at the protein level.

As a counterpart of energy cascade, turbulent momentum cascade (TMC) in the wall-normal direction is important for understanding wall turbulence. Here, we report an analytic prediction of non-universal Reynolds number ( $Re_{\unicode[STIX]{x1D70F}}$ ) scaling transition of the maximum TMC located at  $y_{p}$ . We show that in viscous units, $y_{p}^{+}$ (and $1+\overline{u^{\prime }v^{\prime }}_{p}^{+}$ ) displays a scaling transition from $Re_{\unicode[STIX]{x1D70F}}^{3/7}$ ( $Re_{\unicode[STIX]{x1D70F}}^{-6/7}$ ) to $Re_{\unicode[STIX]{x1D70F}}^{3/5}$ ( $Re_{\unicode[STIX]{x1D70F}}^{-3/5}$ ) in turbulent boundary layer, in sharp contrast to that from $Re_{\unicode[STIX]{x1D70F}}^{1/3}$ ( $Re_{\unicode[STIX]{x1D70F}}^{-2/3}$ ) to $Re_{\unicode[STIX]{x1D70F}}^{1/2}$ ( $Re_{\unicode[STIX]{x1D70F}}^{-1/2}$ ) in a channel/pipe, countering the prevailing view of a single universal near-wall scaling. This scaling transition reflects different near-wall motions in the buffer layer for small $Re_{\unicode[STIX]{x1D70F}}$ and log layer for large  $Re_{\unicode[STIX]{x1D70F}}$ , with the non-universality being ascribed to the presence/absence of mean wall-normal velocity  $V$ . Our predictions are validated by a large set of data, and a probable flow state with a full coupling between momentum and energy cascades beyond a critical $Re_{\unicode[STIX]{x1D70F}}$ is envisaged.

Maternal one-carbon metabolism during pregnancy is crucial for fetal development and programming by DNA methylation. However, evidence on one-carbon biomarkers other than folate is lacking. We, therefore, investigated whether maternal plasma methyl donors, that is, choline, betaine and methionine, are associated with birth outcomes. Blood samples were obtained from 115 women during gestation (median 26·3 weeks, 90 % range 22·7–33·0 weeks). Plasma choline, betaine, methionine and dimethylglycine were measured using HPLC-tandem MS. Multivariate linear and logistic regression models were used to estimate the association between plasma biomarkers and birth weight, birth length, the risk of small-for-gestational-age and large-for-gestational-age (LGA). Higher level of maternal betaine was associated with lower birth weight (–130·3 (95 % CI –244·8, –15·9) per 1 sd increment for log-transformed betaine). Higher maternal methionine was associated with lower risk of LGA, and adjusted OR, with 95 % CI for 1 sd increase in methionine concentration was 0·44 (95 % CI 0·21, 0·89). Stratified analyses according to infant sex or maternal plasma homocysteine status showed that reduction in birth weight in relation to maternal betaine was only limited to male infants or to who had higher maternal homocysteine status (≥5·1 µmol/l). Higher maternal betaine status was associated with reduced birth weight. Maternal methionine was inversely associated with LGA risk. These findings are needed to be replicated in future larger studies.

True ileal digestibility (TID) values of amino acid (AA) obtained using growing rats are often used for the characterisation of protein quality in different foods and acquisition of digestible indispensable amino acid scores (DIAAS) in adult humans. Here, we conducted an experiment to determine the TID values of AA obtained from nine cooked cereal grains (brown rice, polished rice, buckwheat, oats, proso millet, foxtail millet, tartary buckwheat, adlay and whole wheat) fed to growing Sprague–Dawley male rats. All rats were fed a standard basal diet for 7 d and then received each diet for 7 d. Ileal contents were collected from the terminal 20 cm of ileum. Among the TID values obtained, whole wheat had the highest values (P<0·05), and polished rice, proso millet and tartary buckwheat had relatively low values. The TID indispensable AA concentrations in whole wheat were greater than those of brown rice or polished rice (P<0·05), and polished rice was the lowest total TID concentrations among the other cereal grains. The DIAAS was 68 for buckwheat, 47 for tartary buckwheat, 43 for oats, 42 for brown rice, 37 for polished rice, 20 for whole wheat, 13 for adlay, 10 for foxtail millet and 7 for proso millet. In this study, the TID values of the nine cooked cereal grains commonly consumed in China were used for the creation of a DIAAS database and thus gained public health outcomes.

A recently developed symmetry-based theory is extended to derive an algebraic model for compressible turbulent boundary layers (CTBL) – predicting mean profiles of velocity, temperature and density – valid from incompressible to hypersonic flow regimes, thus achieving a Mach number ( $Ma$ ) invariant description. The theory leads to a multi-layer analytic form of a stress length function which yields a closure of the mean momentum equation. A generalized Reynolds analogy is then employed to predict the turbulent heat transfer. The mean profiles and the friction coefficient are compared with direct numerical simulations of CTBL for a range of $Ma$ from 0 (e.g. incompressible) to 6.0 (e.g. hypersonic), with an accuracy notably superior to popular current models such as Baldwin–Lomax and Spalart–Allmaras models. Further analysis shows that the modification is due to an improved eddy viscosity function compared to competing models. The results confirm the validity of our $Ma$ -invariant stress length function and suggest the path for developing turbulent boundary layer models which incorporate the multi-layer structure.

Instability evolution in a transitional hypersonic boundary layer and its effects on aerodynamic heating are investigated over a 260 mm long flared cone. Experiments are conducted in a Mach 6 wind tunnel using Rayleigh-scattering flow visualization, fast-response pressure sensors, fluorescent temperature-sensitive paint (TSP) and particle image velocimetry (PIV). Calculations are also performed based on both the parabolized stability equations (PSE) and direct numerical simulations (DNS). Four unit Reynolds numbers are studied, 5.4, 7.6, 9.7 and $11.7\times 10^{6}~\text{m}^{-1}$ . It is found that there exist two peaks of surface-temperature rise along the streamwise direction of the model. The first one (denoted as HS) is at the region where the second-mode instability reaches its maximum value. The second one (denoted as HT) is at the region where the transition is completed. Increasing the unit Reynolds number promotes the second-mode dissipation but increases the strength of local aerodynamic heating at HS. Furthermore, the heat generation rates induced by the dilatation and shear processes (respectively denoted as $w_{\unicode[STIX]{x1D703}}$ and $w_{\unicode[STIX]{x1D714}}$ ) were investigated. The former item includes both the pressure work $w_{\unicode[STIX]{x1D703}1}$ and dilatational viscous dissipation $w_{\unicode[STIX]{x1D703}2}$ . The aerodynamic heating in HS mainly arose from the high-frequency compression and expansion of fluid accompanying the second mode. The dilatation heating, especially $w_{\unicode[STIX]{x1D703}1}$ , was more than five times its shear counterpart. In a limited region, the underestimated $w_{\unicode[STIX]{x1D703}2}$ was also larger than $w_{\unicode[STIX]{x1D714}}$ . As the second-mode waves decay downstream, the low-frequency waves continue to grow, with the consequent shear-induced heating increasing. The latter brings about a second, weaker growth of surface-temperature HT. A theoretical analysis is provided to interpret the temperature distribution resulting from the aerodynamic heating.

Drag control using a newly developed spanwise opposed wall-jet forcing (SOJF) method is studied via direct numerical simulation of the incompressible Navier–Stokes equations in a turbulent channel flow (at the friction Reynolds numbers $Re_{\unicode[STIX]{x1D70F}}=180$ and 550). SOJF is characterized by three control parameters: the forcing amplitude $A^{+}$ , the spanwise spacing $\unicode[STIX]{x1D706}^{+}$ and the wall-jet height $y_{c}^{+}$ ( $+$ indicates viscous scaling). At $Re_{\unicode[STIX]{x1D70F}}=180$ , notable drag reduction is achieved for wide ranges of $A^{+}$ , $\unicode[STIX]{x1D706}^{+}$ and $y_{c}^{+}$ , with an optimal drag reduction of approximately 19 % found for $A^{+}\approx 0.015$ , $\unicode[STIX]{x1D706}^{+}\approx 1200$ and $y_{c}^{+}\approx 30$ . The drag reduction results from mergers of numerous low-speed typical individual streaks together by the wall jets, so that the slope of the merged streak envelope and hence the streak strength are reduced below the critical values required for streak instability as well as for transient growth; consequently, the generation of drag inducing near-wall streamwise vortices is suppressed. Through analysis using the FIK identity (Fukagata et al. Phys. Fluids, vol. 14 (11), 2002, pp. L73–L76) in combination with the triple decomposition and the spanwise wavenumber spectrum of the Reynolds shear stress, we find that the control significantly decreases skin friction due to the small scale random turbulent structures (from 75 to 23 % for the optimal case), but injects a dominant contribution at the forcing scale (approximately 34 %). As $A^{+}$ or $y_{c}^{+}$ increases, the drag reduction degrades due to the downwash near the initiation of the forcing wall jet. The energy input required for the excitation is found to be small, yielding a 17 % net power saving for the optimal control case. To determine the $Re$ dependence of the drag reduction, the control strategy is further validated at a higher $Re_{\unicode[STIX]{x1D70F}}=550$ . If the control parameters are kept the same as at $Re_{\unicode[STIX]{x1D70F}}=180$ (i.e. $A^{+}\approx 0.015$ , $\unicode[STIX]{x1D706}^{+}\approx 1200$ , $y_{c}^{+}\approx 30$ ), the drag reduction decreases to 10 %; however, interestingly, with modestly changed parameters ( $A^{+}\approx 0.018$ , $\unicode[STIX]{x1D706}^{+}\approx 1700$ , $y_{c}^{+}\approx 50$ ), drag reduction increases to about 15 %. This additional drag reduction results from the further suppression of turbulent structures in the buffer and log regions. This result, therefore, suggests prospects for drag reduction at even higher $Re$ via a proper choice of the SOJF parameters.

We present new scaling expressions, including high-Reynolds-number ( $Re$ ) predictions, for all Reynolds stress components in the entire flow domain of turbulent channel and pipe flows. In Part 1 (She et al., J. Fluid Mech., vol. 827, 2017, pp. 322–356), based on the dilation symmetry of the mean Navier–Stokes equation a four-layer formula of the Reynolds shear stress length $\ell _{12}$ – and hence also the entire mean velocity profile (MVP) – was obtained. Here, random dilations on the second-order balance equations for all the Reynolds stresses (shear stress $-\overline{u^{\prime }v^{\prime }}$ , and normal stresses $\overline{u^{\prime }u^{\prime }}$ , $\overline{v^{\prime }v^{\prime }}$ , $\overline{w^{\prime }w^{\prime }}$ ) are analysed layer by layer, and similar four-layer formulae of the corresponding stress length functions $\ell _{11}$ , $\ell _{22}$ , $\ell _{33}$ (hence the three turbulence intensities) are obtained for turbulent channel and pipe flows. In particular, direct numerical simulation (DNS) data are shown to agree well with the four-layer formulae for $\ell _{12}$ and $\ell _{22}$ – which have the celebrated linear scalings in the logarithmic layer, i.e. $\ell _{12}\approx \unicode[STIX]{x1D705}y$ and $\ell _{22}\approx \unicode[STIX]{x1D705}_{22}y$ . However, data show an invariant peak location for $\overline{w^{\prime }w^{\prime }}$ , which theoretically leads to an anomalous scaling in $\ell _{33}$ in the log layer only, namely $\ell _{33}\propto y^{1-\unicode[STIX]{x1D6FE}}$ with $\unicode[STIX]{x1D6FE}\approx 0.07$ . Furthermore, another mesolayer modification of $\ell _{11}$ yields the experimentally observed location and magnitude of the outer peak of $\overline{u^{\prime }u^{\prime }}$ . The resulting $-\overline{u^{\prime }v^{\prime }}$ , $\overline{u^{\prime }u^{\prime }}$ , $\overline{v^{\prime }v^{\prime }}$ and $\overline{w^{\prime }w^{\prime }}$ are all in good agreement with DNS and experimental data in the entire flow domain. Our additional results include: (1) the maximum turbulent production is located at $y^{+}\approx 12$ ; (2) the location of peak value $-\overline{u^{\prime }v^{\prime }}_{p}$ has a scaling transition from $5.7Re_{\unicode[STIX]{x1D70F}}^{1/3}$ to $1.5Re_{\unicode[STIX]{x1D70F}}^{1/2}$ at $Re_{\unicode[STIX]{x1D70F}}\approx 3000$ , with a $1+\overline{u^{\prime }v^{\prime }}_{p}^{+}$ scaling transition from $8.5Re_{\unicode[STIX]{x1D70F}}^{-2/3}$ to $3.0Re_{\unicode[STIX]{x1D70F}}^{-1/2}$ ( $Re_{\unicode[STIX]{x1D70F}}$ the friction Reynolds number); (3) the peak value $\overline{w^{\prime }w^{\prime }}_{p}^{+}\approx 0.84Re_{\unicode[STIX]{x1D70F}}^{0.14}(1-48/Re_{\unicode[STIX]{x1D70F}})$ ; (4) the outer peak of $\overline{u^{\prime }u^{\prime }}$ emerges above $Re_{\unicode[STIX]{x1D70F}}\approx 10^{4}$ with its location scaling as $1.1Re_{\unicode[STIX]{x1D70F}}^{1/2}$ and its magnitude scaling as $2.8Re_{\unicode[STIX]{x1D70F}}^{0.09}$ ; (5) an alternative derivation of the log law of Townsend (1976, The Structure of Turbulent Shear Flow, Cambridge University Press), namely, $\overline{u^{\prime }u^{\prime }}^{+}\approx -1.25\ln y+1.63$ and $\overline{w^{\prime }w^{\prime }}^{+}\approx -0.41\ln y+1.00$ in the bulk.

State ownership is an important phenomenon in the world economy, especially in transition economies. Previous research has focused on how state ownership influences organizational performance, but few studies have been conducted on how state ownership influences employees. I propose that different ownership structures trigger different relational models among employees who pay attention to organizational justice consistent with their model to guide their extra-role behavior. Specifically, state-owned organizations reinforce employees’ relational concern and direct employees’ attention to procedural justice, whereas privatized organizations highlight employees' instrumental concern and direct their attention to distributive justice. I leverage a sample of organizations in China to explore how different ownership structures activate different relational models among employees and alter the relationship between organizational justice and employees’ extra-role behaviors. I find that state ownership attenuates and even reverses the positive relationship between distributive justice and extra-role behaviors. Conversely, state ownership exaggerates the positive relationship between a critical procedural justice dimension (participation in decision making) and employee extra-role behaviors. Implications for the micro-foundations of corporate governance and institutional change, organizational justice literature, and cross-cultural research are developed. This study also generates new insights for transition economies such as China.

We numerically investigate the mechanism leading to the entrapment of spheres at the gas–liquid interface after impact. Upon impact onto a liquid pool, a hydrophobic sphere is seen to follow one of the three regimes identified in the experiment (Lee & Kim, Langmuir, vol. 24, 2008, pp. 142–145): sinking, bouncing or being entrapped at the interface. It is important to understand the role of wettability in this process of flow–structure interaction with dynamic wetting, and in particular, to what extent the wettability can determine whether the sphere is entrapped at the interface. For this purpose, a diffuse-interface immersed boundary method is adopted in the numerical simulations. We expand the parameter space considered previously, provide the phase diagrams and identify the key phenomena in the impact dynamics. Then, we propose the scaling models to interpret the critical conditions for the occurrence of sphere entrapment, accounting for the wettability of the sphere. The models are shown to provide a good correlation among the impact inertia of the drop, the surface tension, the wettability and the density ratio of the sphere to the liquid.

A new band-reject frequency-selective surface (FSS) based on dual-band near-zero refractive index metamaterial (ZIM) design is presented in this paper. Consisting of a planar array of complementary dual-layer symmetry resonant ring, the proposed FSS exhibits a high-selective band-reject filtering response. From the viewpoint of effective medium, the subwavelength FSS is characterized by near-zero effective magnetic permeability and near-zero effective electric permittivity in two different operational bands, respectively. The corresponding resonant behavior and E-field distributions are analyzed in detail. A prototype of the proposed FSS working in X-band is fabricated and measured. The simulation and experiment results verify the effectiveness and correctness of the ZIM-based design method.