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Maize, a monoecious crop, is a model plant for studying the regulation of floral organ development. In a previous study, we found that ZmMYB150 is significantly downregulated in sterile anthers by analyzing transcriptome data of the cytoplasmic male sterility (CMS) line C48-2 and its maintainer line 48-2. To elucidate the functional mechanism of ZmMYB150 in maize reproductive development, we cloned ZmMYB150, and sequence analysis showed it is a typical R2R3-MYB transcription factor (TF). Tissue-specific analysis revealed ZmMYB150 to be specifically highly in anthers. The subcellular localization in tobacco leaves proved that ZmMYB150 is located in the nucleus. Co-expression analysis identified 876 genes that may be coexpressed with ZmMYB150, and sequence alignment analysis showed that the coexpressed genes ZmMYB116 and ZmPIP5K6 are homologous to Arabidopsis male fertility-related genes. Furthermore, a yeast two-hybrid (Y2H) assay revealed that ZmMYB150 interacts with ZmPIP5K6. qRT-PCR analysis showed that ZmMYB150 is specifically highly expressed at the late stage of normal anther development, but no expression during the whole stages of sterile anther development. Tobacco transient expression system was used to confirm that ZmMYB150 can be regulated by miR159e-3p at the translational level. Our results lay a foundation for further understanding of the regulatory mechanism of MYB TFs in maize reproductive development.

OsEAT1 (DTD), a stamen-specific bHLH transcription factor, is a master regulator in rice male reproduction. To elucidate its functional mechanism in maize male reproduction, the maize orthologue ZmbHLH122 of OsEAT1 was isolated in this study. Sequence analysis revealed that the ZmbHLH122 coding sequence consists of 1422 bp which encode a protein of 473 amino acids. Bioinformatic analysis confirmed that ZmbHLH122 belongs to the bHLH TF family. The subcellular localization of ZmbHLH122-eGFP in rice protoplasts showed that ZmbHLH122 is a nuclear-localized protein. Yeast one-hybrid assays demonstrated that ZmbHLH122 exhibits weak transactivation ability. Genome-wide coexpression analysis identified 751 potential collaborators of ZmbHLH122, most of which are highly expressed in maize anthers and tassels, and sequence alignment analysis revealed that 43 coexpressed genes are homologous to Arabidopsis male fertility-related genes. Expression pattern analysis confirmed that ZmbHLH122 and its potential collaborators Ms23 (ZmbHLH16), ZmbHLH51, ZmbHLH66 (Ms32) and ZmMYB74 are preferentially expressed in the maize male reproductive organs, especially those at the uninucleate and early binucleate stages. Yeast two-hybrid assays revealed that ZmMYB74 directly interacts with two maize stamen development regulators, Ms23 (ZmbHLH16) and ZmbHLH51, and indirectly collaborates with ZmbHLH122. Our study lays the foundation for further understanding of the ZmbHLH122 molecular function in maize male reproduction.

A 3D finite element model (FEM) with realistic field measurements of temperature distributions is proposed to investigate the thermal stress variation in the steel–concrete composite bridge deck system. First, a brief literature review indicates that traditional thermal stress calculation in suspension bridges is based on the 2D plane structure with simplified temperature profiles on bridges. Thus, a 3D FEM is proposed for accurate stress analysis. The focus is on the incorporation of full field arbitrary temperature profile for the stress analysis. Following this, the effect of realistic temperature distribution on the structure is investigated in detail and an example using field measurements of Aizhai Bridge is integrated with the proposed 3D FEM model. Parametric studies are used to illustrate the effect of different parameters on the thermal stress distribution in the bridge structure. Next, the discussion and comparison of the proposed methodology and simplified calculation method in the standard is given. The calculation difference and their potential impact on the structure are shown in detail. Finally, some conclusions and recommendations for future bridge analysis and design are given based on the proposed study.

To clone and characterize the squalene synthase from Siraitia grosvenorii (SgSQS). The gene encoding SgSQS was cloned. SgSQS has 417 amino acid residues with an pI of 7.3. There are 32 phosphorylation sites in its sequence: S48 as well as S196 play important roles in regulation of enzyme activity. The enzyme is a monomeric protein with a cave-like active center formed by α helixes and has two transmembrane domains at its C-terminus. SgSQS mRNA expression in stem and root were about twice as much as that in leaf and peel. Full-length SgSQS with measurable catalytic activity was expressed in Escherichia coli. SgSQS activity was optimal at 37 °C and pH 7.5 respectively. SgSQS gene was cloned, and the molecular structure and biochemical function of SgSQS were characterized.

In the original version of this Article, there was an error in the legend for Figure 2, whereby the descriptions of panels a, b and c were presented in a different order to the corresponding figure panels. The text ‘a GWAS of duck plumage color, including 76 colored ducks and 30 white Pekin ducks. The gray horizontal dashed lines indicate the Bonferroni significance threshold of the GWAS (1 × 10−9). b Fixation index (FST) of all SNPs along chromosome 13 between mallards and Pekin ducks. Red dots indicate fixed SNPs. c The nucleotide diversity (π) of mallards (blue line) and Pekin ducks (red line) from 16.0 to 17.0 Mb on chromosome 13.’ should have read ‘a Fixation index (FST) of all SNPs along chromosome 13 between mallards and Pekin ducks. Red dots indicate fixed SNPs. b The nucleotide diversity (π) of mallards (blue line) and Pekin ducks (red line) from 16.0 to 17.0 Mb on chromosome 13. c GWAS of duck plumage color, including 76 colored ducks and 30 white Pekin ducks. The gray horizontal dashed lines indicate the Bonferroni significance threshold of the GWAS (1 × 10−9).’ This has been corrected in both the PDF and HTML versions of the Article.

A generalized 2D non-local lattice spring model, the Volume-Compensated Particle Model (VCPM), is proposed for the study of fracture phenomena of homogeneous isotropic solids in this paper. In the proposed VCPM, both the pairwise local and the multi-body non-local interaction forces among particles are considered. Special focus is on the investigation of the failure anisotropy or directional preference of the crack path while modeling fracture phenomena within the framework of regular lattice spring models. Different from random network models, a generalized regular lattice framework to include multiple non-local forces from neighboring particles is proposed to eliminate/reduce this well-known failure anisotropy issue. Several benchmarks are tested to assess the performance of the proposed methodology. Discussions and conclusions are drawn based on the current study.

A simple, environmentally friendly and high efficient extraction method was proposed for the determination of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector (GC-MS). When this method was adopted, samples were pretreated by modified QuEChERS(quick, easy, cheap, effective, rugged and safe) method. An environmentally friendly extractant(ethanol aqueous solution) replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin(BSA) with phthalates show that there was a high-affinity interaction between phthalate and protein, decreasing the extraction efficiency of phthalates from fish samples. However, in the 80%(volume fraction, φ) ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in φ(ethanol) 80% aqueous solution than in either φ(ethanol) 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the purification steps were greatly simplified. Overall recoveries were 81.77%–90.5% with limits of detection between 2.53 and 9.61 μg/L, and relative standard deviation values at 1.15%–4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.

A simple analytical approximation is proposed in this paper to calculate the crack tip opening displacement under general random variable amplitude loadings. This approximation is based on a modified Dugdale model for cyclic loadings. The discussion is first given under constant amplitude loading and is extended to several simple cases under variable amplitude loadings. Following this, a general algorithm is proposed under general random variable loadings. Numerical examples are verified with finite element simulations. Following this, hardening effect is included by including a hardening correction function. The proposed analytical approximation is very efficient compared to the direct finite element simulation. The solution can be used for detailed fatigue crack growth analysis under random variable amplitude loadings.

In this paper, a concurrent simulation framework for fatigue crack growth analysis is proposed using a novel small time scale model for fatigue mechanism analysis and the extended finite element method (X-FEM) for fatigue crack growth simulation. The proposed small time scale fatigue model does not require the cycle counting as those using the classical fatigue analysis methods and can be performed concurrently with structural/mechanical analysis. The X-FEM greatly facilitates crack growth simulation without remeshing requirements ahead of the crack tip as in the classical finite element method. The basic concept and theory of X-FEM was briefly introduced and numerical predictions of stress intensity factors are verified with reference solutions under both uniaxial and multiaxial loadings. The small time scale fatigue model is integrated into the numerical simulation algorithm for concurrent fatigue crack growth analysis. Model predictions are compared with available experimental observations for model validation.

A general framework for probabilistic fatigue damage prognosis using maximum entropy concept is proposed and developed in this paper. The fatigue damage is calculated using a physics-based crack growth model. Due to the stochastic nature of fatigue crack propagation process, uncertainties arising from the underlying physical model, parameters of the model and the response variable measurement noise are considered and integrated into this framework. Incorporating all those uncertainties, a maximum relative entropy (MRE) approach is proposed to update the statistical description of model parameters and narrow down the prognosis deviations. A Markov Chain Monte Carlo (MCMC) simulation is then employed to generate samples from updated posterior probability distributions and provide statistical information for the maximum relative entropy updating procedure. A numerical toy problem is given to demonstrate the proposed MRE prognosis methodology. Experimental data for aluminum alloys are used to validate model predictions under uncertainty. Following this, a detailed comparison between the proposed MRE approach and the classical Bayesian updating method is performed to illustrate advantages of the proposed prognosis framework.

The binding reaction between 10-hydroxycamptothecin (10-HCPT) and human serum albumins (HSA) is studied by means of fluorescence spectroscopy, UV-Vis absorption spectrum, 1H NMR spectrum, and molecular simulation. The results indicate that the binding reaction of 10-HCPT and HSA is a single static quenching process, and the binding equilibrium constant for 10-HCPT binding with HSA is estimated K0= 4.93×104 L · mol−1 at 25 °C with the molar ratio of 1:1. The distance (r) and energy transfer efficiency (E) between donor (HSA) and acceptor (10-HCPT) are obtained as follows, r =3.51 nm; E =0.27. The enthalpy change (ΔH⦵) and entropy change (ΔS⦵) are calculated at different temperatures, and the hydrophobic force and shidipole force are the functions in the reaction. The results show that 10-HCPT binds within the subdomain II A of HSA by the hydrophobic force, and the 10-OH and 20-OH of 10-HCPT bind with both residue Leu-238 of HSA and Ala 291 of HSA by hydrogen bonds.