A novel theoretical model for bubble dynamics is established that simultaneously accounts for the liquid compressibility, phase transition, oscillation, migration, ambient flow field, etc. The bubble dynamics equations are presented in a unified and concise mathematical form, with clear physical meanings and extensibility. The bubble oscillation equation can be simplified to the Keller–Miksis equation by neglecting the effects of phase transition and bubble migration. The present theoretical model effectively captures the experimental results for bubbles generated in free fields, near free surfaces, adjacent to rigid walls, and in the vicinity of other bubbles. Based on the present theory, we explore the effect of the bubble content by changing the vapour proportion inside the cavitation bubble for an initial high-pressure bubble. It is found that the energy loss of the bubble shows a consistent increase with increasing Mach number and initial vapour proportion. However, the radiated pressure peak by the bubble at the collapse stage increases with decreasing Mach number and increasing vapour proportion. The energy analyses of the bubble reveal that the presence of vapour inside the bubble not only directly contributes to the energy loss of the bubble through phase transition but also intensifies the bubble collapse, which leads to greater radiation of energy into the surrounding flow field due to the fluid compressibility.

Vertically neutral collapse of a pulsating bubble occurs when the boundaries above or below the bubble balance the buoyancy effect over a pulsation. In this study, the vertically neutral collapse of a bubble near a vertical rigid wall below the free surface is investigated. The boundary integral method (BIM) is employed to model the bubble dynamics with an open-domain free surface. Moreover, this method is validated against several buoyant bubble experiments. Bubble dynamics in such conditions are associated with three dimensionless parameters: the bubble-free surface distance $\gamma _{{f}}$, bubble–wall distance $\gamma _{{w}}$ and buoyancy parameter $\delta$. We derive the Kelvin impulse of a spherical bubble and the algebraic relationship for vertically neutral collapse, which proves to be accurate for predicting vertically neutral collapse when the bubble is relatively far from the boundaries. Four patterns of the vertically neutral collapse of the bubble for different $\gamma _{{w}}$ and $\gamma _{{f}}$ are identified: (i) formally downward jet; (ii) annular collapse; (iii) horizontal jet; and (iv) weak jet. Despite the downward jet shape, the ‘formally downward jet’ is in the vertically neutral collapse state in terms of the profile of toroidal bubbles and the orientation of local high-pressure zones around the bubble at jet impact. A bulge with a high curvature above the bubble in the ‘annular collapse’ pattern is formed during bubble collapse under two local high-pressure zones at the left and right extremities of the bubble. The ‘horizontal jet’ pattern has the greatest potential to attack the wall, and the power laws of the moment of the jet impact, jet velocity and bubble displacement with respect to the theoretical Kelvin impulse are discussed. In particular, we quantitatively illustrate the role of the free surface on bubble migration towards the wall through the variational power-law exponents of the bubble displacement with respect to $\gamma _{{w}}$.

Polycarboxylate superplasticizer (PCE) is sensitive to the clay present in concrete aggregates. In particular, Montmorillonite (Mnt), an impurity inevitably contained in the aggregate, can significantly influence the performance of concrete. In an effort to improve the compatibility of PCE, a zwitterionic PCE with cationic amide groups and shorter side-chain lengths was synthesized via free radical copolymerization. The optimal synthesis condition was verified via Box-Behnken design. In addition to characterizing the PCE, the performance of PCE in cement pastes with or without Na-Mnt was examined and the underlying mechanism was explored. The results show that, compared with commercially available PCE, the required dosage of PCE for cements containing Na-Mnt decreased. Unlike commercially available PCE, no intercalation occured on the newly manufactured clay-tolerant PCE within the layers of Mnt, resulting in a greater sorption thickness and improved dispersion of the cements containing Na-Mnt.

Leucine plays an important role in promoting muscle protein synthesis and muscle remodelling. However, what percentage of leucine is appropriate in creep feed and what proteome profile alterations are caused by dietary leucine in the skeletal muscle of piglets remain elusive. In this case, we applied isobaric tags for relative and absolute quantitation to analyse the proteome profile of the longissimus dorsi muscles of weanling piglets fed a normal leucine diet (NL; 1·66 % leucine) and a high-leucine diet (HL; 2·1 % leucine). We identified 157 differentially expressed proteins between these two groups. Bioinformatics analysis of these proteins exhibited the suppression of oxidative phosphorylation and fatty acid β-oxidation, as well as the activation of glycolysis, in the HL group. For further confirmation, we identified that SDHB, ATP5F1, ACADM and HADHB were significantly down-regulated (P<0·01, except ATP5F1, P<0·05), whereas the glycolytic enzyme pyruvate kinase was significantly up-regulated (P<0·05) in the HL group. We also show that enhanced muscle protein synthesis and the transition from slow-to-fast fibres are altered by leucine. Together, these results indicate that leucine may alter energy metabolism and promote slow-to-fast transitions in the skeletal muscle of weanling piglets.

Findings from observational studies have suggested a possible relation between Ca and breast cancer risk. However, the results of these studies are inconclusive, and the dose–response relationship between Ca intake and risk of breast cancer remains to be determined. A meta-analysis of prospective studies was conducted to address these issues. PubMed and Embase databases were searched for relevant studies concerning the association between Ca intake and breast cancer up to March 2016. The summary relative risks (RR) with 95 % CI were calculated with a random-effects model. The final analysis included eleven prospective cohort studies involving 26 606 cases and 872 895 participants. The overall RR of breast cancer for high v. low intake of Ca was 0·92 (95 % CI 0·85, 0·99), with moderate heterogeneity (P=0·026, I2=44·2 %). In the subgroup analysis, the inverse association appeared stronger for premenopausal breast cancer (RR 0·75; 95 % CI 0·59, 0·96) than for postmenopausal breast cancer (RR 0·94; 95 % CI 0·87, 1·01). Dose–response analysis revealed that each 300 mg/d increase in Ca intake was associated with 2 % (RR 0·98; 95 % CI 0·96, 0·99), 8 % (RR 0·92; 95 % CI 0·87, 0·98) and 2 % (RR 0·98; 95 % CI 0·97, 0·99) reduction in the risk of total, premenopausal and postmenopausal breast cancer, respectively. Our findings suggest an inverse dose–response association between Ca intake and risk of breast cancer.

Carbon nanodots (CDs) have generated enormous excitement because of their superiority in water solubility, chemical inertness, low toxicity, ease of functionalization and resistance to photobleaching. Here we report a facile thermal pyrolysis route to prepare CDs with high quantum yield (QY) using citric acid as the carbon source and ethylene diamine derivatives (EDAs) including triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and polyene polyamine (PEPA) as the passivation agents. We find that the CDs prepared from EDAs, such as TETA, TEPA and PEPA, show relatively high photoluminescence (PL) QY (11.4, 10.6, and 9.8%, respectively) at λex of 465 nm. The cytotoxicity of the CDs has been investigated through in vitro and in vivo bio-imaging studies. The results indicate that these CDs possess low toxicity and good biocompatibility. The unique properties such as the high PL QY at large excitation wave length and the low toxicity of the resulting CDs make them promising fluorescent nanoprobes for applications in optical bio-imaging and biosensing.

Ecological evidence suggests that niacin (nicotinamide and nicotinic acid) fortification may be involved in the increased prevalence of obesity and type 2 diabetes, both of which are associated with insulin resistance and epigenetic changes. The purpose of the present study was to investigate nicotinamide-induced metabolic changes and their relationship with possible epigenetic changes. Male rats (5 weeks old) were fed with a basal diet (control group) or diets supplemented with 1 or 4 g/kg of nicotinamide for 8 weeks. Low-dose nicotinamide exposure increased weight gain, but high-dose one did not. The nicotinamide-treated rats had higher hepatic and renal levels of 8-hydroxy-2′-deoxyguanosine, a marker of DNA damage, and impaired glucose tolerance and insulin sensitivity when compared with the control rats. Nicotinamide supplementation increased the plasma levels of nicotinamide, N1-methylnicotinamide and choline and decreased the levels of betaine, which is associated with a decrease in global hepatic DNA methylation and uracil content in DNA. Nicotinamide had gene-specific effects on the methylation of CpG sites within the promoters and the expression of hepatic genes tested that are responsible for methyl transfer reactions (nicotinamide N-methyltransferase and DNA methyltransferase 1), for homocysteine metabolism (betaine–homocysteine S-methyltransferase, methionine synthase and cystathionine β-synthase) and for oxidative defence (catalase and tumour protein p53). It is concluded that nicotinamide-induced oxidative tissue injury, insulin resistance and disturbed methyl metabolism can lead to epigenetic changes. The present study suggests that long-term high nicotinamide intake (e.g. induced by niacin fortification) may be a risk factor for methylation- and insulin resistance-related metabolic abnormalities.

Our aim is to screen miRNAs and genes related to tetralogy of Fallot and construct a co-expression network based on integrating miRNA and gene microarrays. We downloaded the gene expression profile GSE35490 (miRNA) and GSE35776 (mRNA) of tetralogy of Fallot from the Gene Expression Omnibus database, which includes eight normal and 15 disease samples from infants, and screened differentially expressed miRNAs and genes between normal and disease samples (cut-off: p < 0.05; FDR < 0.05; and log FC > 2 or log FC < −2); in addition, we downloaded human miRNA and their targets, which were collected in the miRNA targets prediction database TargetScan, and selected ones that also appeared in our differentially expressed miRNAs and their predicted targets (score >0.9) and then made a relationship of diff_miRNAs and diff_genes of our results. Finally, we uploaded all the diff_target genes into String, constructed a co-expression network regulated by diff_miRNAs, and performed functional analysis with the software DAVID. Comparing normal and disease lesion tissue, we got 32 and 875 differentially expressed miRNAs and genes, respectively, and found hsa-miR-124 with 34 diff_target genes and hsa-miR-138 with two diff_target genes. Then we constructed a co-expression network that contains 231 pairs of genes. Genes in the network were enriched into 14 function clusters, and the most significant one is protein localisation. We screened the tetralogy of Fallot-related hsa-miR-124 and hsa-miR-138 with their direct and indirect differentially expressed target genes, and found that protein localisation is the significant cause affecting tetralogy of Fallot. Our approach may provide the groundwork for a new therapy approach to treating tetralogy of Fallot.

Iron oxides, including maghemite (γ-Fe2O3) and magnetite (Fe3O4), have been widely applied in many fields. For technological advances in the future, further improvements of their ferromagnetic properties are desirable. The development of iron ferrites with a large coercive field (Hc) is one of issues of consequence. For ferrites, however, enlarging the Hc value is not easy because of their low magnetocrystalling anisotropy constant. Here we report single-crystalline Cu-doped γ-Fe2O3 nanowires in which the controlled diameter (70–100 nm) and the graded Cu dopant (7, 10, and 15%) are directly obtained by a simple chemical vapor deposition technique. In particular, the coercive value (over 2 T) of 10% Cu-doped γ-Fe2O3 nanowires is much higher than that (<80 Oe) of undoped γ-Fe2O3 nanowires at room temperature. On the basis of the experimental magnetization data, the achievement of such a higher coercive field of Cu-doped γ-Fe2O3 (10%) nanowires is tentatively suggested.

The statistical analysis of heating effect and the cross-correlation analysis of both electron temperature and loop voltage have been done during electron cyclotron resonance heating (ECRH). The behavior of runaway electrons in the flat-top phase during ECRH are analyzed using experimental data. It is shown that the runaway population is indeed suppressed or even quenched when the toroidal electric field ET is reduced below the threshold electric field Eth by high-power and long-duration ECRH. The physical mechanism of runaway suppression is explored by the resonant interaction between the electron cyclotron waves and the energetic runaway electrons.

A rapid real-time polymerase chain reaction (RT-PCR) for detecting West Nile virus (WNV) was established. Primers were designed according to the sequence of the capsid protein gene of WNV by Primer Premier 5.0. In this way, an inexpensive assay using the intercalating dye SYBR Green I was developed and validated. The amplifying curve showed that this method could successfully amplify 102 copies/μl of the WNV gene, while reference to Japanese encephalitis virus (JEV) and blank control were all negative. Tenfold successive dilutions of positive WNV DNA were used to measure the sensitivity of RT-PCR. The assay system showed high reproducibility with coefficient of variation (CV) <2%. Thus the newly established RT-PCR assay was shown to be a rapid, sensitive and specific test for detecting WNV.

Al2O3 films are grown by atomic layer deposition (ALD) using trimethylaluminum and water as precursors on HF-last and NH3 plasma pretreatment Si substrates. The thickness, surface roughness, and density of Al2O3 films as well as the nature of their interlayers with Si substrates are characterized by x-ray reflectivity and spectroscopic ellipsometry techniques. The growth rates of Al2O3 films are 1.1 Å/cycle and 1.3 Å/cycle, respectively, on HF-last and NH3-plasma-nitrided surfaces. Al2O3 layer densities are rather independent of the number of growth cycles in all cases. The interfacial film thickness increases with the number of ALD cycles when deposited on an HF-last Si substrate. However, because SiOxNy inhibits oxygen diffusion, the interfacial film thickness is independent of the number of ALD cycles on the nitrided Si substrate.

GbRac1 gene was cloned from Gossypium barbadense with degenerate primers and 3′-RACE. Northern blot analysis indicated that GbRac1 mRNA was expressed abundantly in G. barbadense seedlings inoculated with Verticillium dehliae compared with mock-inoculated plants. A plant constitutive expression vector pRac harbouring GbRac1 gene was constructed and leaf discs of tobacco (Nicotiana tabacum L. cv. NC89) were transformed with pRac by Agrobacterium-mediated transformation. Disease challenge test of detached leaves of the transgenic plants by inoculation with Alternaria alternata showed that resistance was enhanced dramatically compared with the non-transgenic plants. Results suggest that GbRac1 gene might have potential application in the genetic engineering of plants with enhanced disease resistance.

A 1009 bp promoter sequence of cab gene, which encodes chlorophyll a/b binding protein belonging to a class of light-inducible proteins, was cloned from Gossypium arboreum. Sequence analysis showed that it had no obvious homology with previously published cab promoters. The full-length Gacab promoter and 5′ deletions with length of 197, 504 and 779 bp were fused with gus (uid A) gene, respectively, and plant expression vectors were used for transformation of Nicotiana tabacum cv. NC89. β-Glucuronidase (GUS) histochemical assay of transgenic tobacco plants showed that GUS was expressed specifically in leaves and young green tissues. GUS was not detected in the leaves of transgenic plants grown in the dark for 6 days. However, it was highly expressed in the leaves of these plants after induction with light for another 6 days, demonstrating that the full-length Gacab promoter is a light-inducible promoter. Transient GUS expression in rice calli indicated that the expression level of Gacab504::gus was the highest and stronger than that of the CaMV 35S promoter, while expression was reduced for Gacab197::gus, Gacab779::gus and Gacab1009::gus constructs. This suggests that −197 bp to −1 bp is a basic promoter of Gacab, some positive regulatory elements may exist in −504 bp to −197 bp, and the fragment −1009 bp to −504 bp may contain negative elements.