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Mesocentrotus nudus is an important aquaculture species in East Asia, valued for its gonads as the only edible part. However, the molecular basis of gonadal differentiation in this species remains poorly understood. In this study, we determined that morphological gonadal differentiation occurs when individuals reach a test diameter of approximately 40 mm. Amino acid profiling revealed sex-specific differences between ovaries and testes, with higher levels of lysine, proline, alanine, and glutamic acid in testes, suggesting sexual dimorphism in metabolic demand. To investigate the regulatory mechanisms involved, we conducted integrated transcriptomic and metabolomic analyses between differentiated and undifferentiated gonads. Differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) including retinoic acid, linoleic acid, and arachidonic acid, were significantly enriched in retinol metabolism, steroid biosynthesis, and amino acid metabolic pathways. Several key genes, such as GATA4 , CYP17A1 , and HSD17B , were identified as potential markers for gonadal differentiation. Furthermore, components of the TGF-β signaling pathway ( Smads , Rbx1 , SKP ) and retinol metabolism genes ( CYP26 , CYP1A , CYP3A ) exhibited sex-biased expression patterns. This study provides novel insights into the molecular mechanisms underlying sex differentiation in sea urchins and lays a molecular foundation for the development of sex-control breeding strategies.

In the entrapment of enzymes by sol-gel method, the special procedures for obtaining the unique structure of xerogel are sometimes destructive to enzymes, while the internal structure of xerogels is easily broken. To solve the above problems, we present an economical, bio-friendly procedure for the entrapment of Candida antarctica lipase B in silica xerogel. In this procedure, an encapsulation-structured enzyme-carrying silica xerogel was produced by controlling the evaporation rate of the solvent at ambient pressure during drying, while tetramethoxysilane and methyltrimethoxysilane were used as the co-precursors. The xerogel synthesis was modified and optimized for improving the stability and reusability of the enzyme, while the xerogel characteristic structure was preserved. Moreover, the effects of the co-precursors amount on the mechanical strength, pore structure, hydrophobicity, enzyme loading, and enzyme stability of the enzyme-carrying silica xerogels were systematically investigated. And the best performance was observed at the co-precursors content of 30.28 wt%. Finally, the catalytic performance of the enzyme-carrying silica xerogels on the transesterification of n -butanol with ethyl acetate was demonstrated. Graphical abstract

This study focuses on the demand for rapid prediction of the flow field of aero-engine inlet free jet tests and explores the application of radial basis function interpolation (RBF) and backpropagation neural network (BPNN) methods. The proper orthogonal decomposition (POD) method was used for model order reduction of the full-order flow field results from numerical simulations. Two rapid prediction methods, namely POD-RBF and POD-BPNN, were constructed by utilizing radial basis function interpolation and a backpropagation neural network. These methods successfully achieved rapid prediction of the test flow field under different Mach numbers and angles of attack. To verify the accuracy of the numerical simulation and rapid prediction methods, a free jet test of the jet inlet was conducted under the same conditions. The test results show good agreement with both the CFD calculation results and the rapid prediction results. The research results show that the ninth-order mode can accurately reconstruct the flow field structure with a reconstruction error of 1.83%. Both methods can quickly and accurately predict the flow field under different conditions, and the prediction results are in good agreement with the numerical simulation results. Generally speaking, the prediction error of the POD-BPNN method is smaller than that of the POD-RBF method.

The signal recognition particle (SRP) system delivers approximately 30% of the proteome to the endoplasmic reticulum (ER) membrane. SRP receptor alpha (SRα) binds to SRP for targeting nascent secreted proteins to the ER membrane in eukaryotic cells. In this study, the SRα homologous gene was identified in the sea cucumber, Apostichopus japonicus ( AjSRα ). AjSRα codes for 641 amino acids and has 54.94% identity with its mammalian homologs. Like mammalian SRα , it is expected to contain the SRP-alpha N domain, SRP54_N domain, and SRP54 domain. In addition, AjSRα is ubiquitously expressed in adult tissues and exhibits a sexually dimorphic expression pattern, with significantly higher expression in ovaries compared to testes. As a maternal factor, AjSRα can be continuously detected during embryonic development. Importantly, we first attempted to investigate its function by using lentiviral vectors for delivering SRα gene-specific shRNA, and we revealed that lentiviral vectors do not induce an upregulation of immune-related enzymes in sea cucumbers. However, compared to the dsRNA-based RNA interference (RNAi) method, lentivirus-mediated RNAi caused dynamic changes in gene expression at a later time. This study supplied the technical support for studying the functional mechanism of SRα in sea cucumbers.

In this paper, we present the weighted scale-free treelike networks controlled by the weight factor r and the parameter m . Based on the network structure, we study two types of weight-dependent walks with a highest-degree trap. One is standard weight-dependent walk, while the other is mixed weight-dependent walk including both nearest-neighbor and next-nearest-neighbor jumps. Although some properties have been revealed in weighted networks, studies on mixed weight-dependent walks are still less and remain a challenge. For the weighted scale-free treelike network, we derive exact solutions of the average trapping time (ATT) measuring the efficiency of the trapping process. The obtained results show that ATT is related to weight factor r , parameter m and spectral dimension of the weighted network. We find that in different range of the weight factor r , the leading term of ATT grows differently, i.e., superlinearly, linearly and sublinearly with the network size. Furthermore, the obtained results show that changing the walking rule has no effect on the leading scaling of the trapping efficiency. All results in this paper can help us get deeper understanding about the effect of link weight, network structure and the walking rule on the properties and functions of complex networks.

This paper has been retracted.

Understanding drop dispersion behavior is significant to the optimization of liquid dispersion devices. In this work, the drop dispersion behavior in the combined trapezoid spray tray was directly observed and analyzed with a high-speed camera. It was found that the fracture of the liquid neck is the main mode for the liquid column to generate drops. The dispersion behavior of the drops was simulated by CFD, and it was found that the liquid neck is caused by the surrounding vortex field and the uneven pressure distribution inside the liquid column. At the same time, the dispersion time of the drops was counted, and it was found that the drop dispersion time ranges from 5 to 60 ms, depending on the drop diameter and the gas kinetic energy factor in plate hole F0.

In this paper a family of weighted fractal networks, in which the weights of edges have been assigned to different values with certain scale, are studied. For the case of the weighted fractal networks the definition of modified box dimension is introduced and a rigorous proof for its existence is given. Then, the modified box dimension depending on the weighted factor and the number of copies is deduced. Assuming that the walker, at each step, starting from its current node, moves uniformly to any of its nearest neighbors. The weighted time for two adjacency nodes is the weight connecting the two nodes. Then the average weighted receiving time (AWRT) is a corresponding definition. The obtained remarkable result displays that in the large network, when the weight factor is larger than the number of copies, the AWRT grows as a power law function of the network order with the exponent, being the reciprocal of modified box dimension. This result shows that the efficiency of the trapping process depends on the modified box dimension: the larger the value of modified box dimension, the more efficient the trapping process is.

A fractal interpolation function on a p-series local field Kp is defined, and its p-type smoothness is shown by virtue of the equivalent relationship between the Hölder type space CσKp and the Lipschitz class Lipσ,Kp. The orders of the p-type derivatives and the fractal dimensions of the graphs of Weierstrass type function on local fields are given as an example. The α-fractal function on ℝ is introduced and the conclusion of its smoothness is improved in a more general case; some examples are shown to support the conclusion. Finally, a comparison between the fractal interpolation functions defined on ℝ and Kp is given.

We study a class of evolutionary pseudodifferential equations of the second order in t, (∂2u(t,x)/∂t2+2a2Tα/2(∂u(t,x)/∂t)+b2Tαu(t,x)+c2u(t,x)=q(t,x)), where t∈(0,z] and Tα is pseudodifferential operator in x∈Qp, which defined by Weiyi Su in 1992. We obtained the exact solutions to the equations which belong to mixed classes of real and p-adic functions.