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An ultrasonic reverse time migration imaging method, based on high-order singular value decomposition, is proposed in the study to solve the problems of low signal-to-noise ratio (SNR) and excessive artifacts in defect ultrasonic detection imaging results of materials with high noise levels. In this method, based on the 3D structural properties of the ultrasonic full-matrix capture data, higher-order singular value decomposition is directly performed with the 3D data. The method overcomes the difficulty in selecting the number of singular values in the original singular value decomposition noise-reduction algorithm and realizes the one-step noise reduction processing of all the signals. Subsequently, the reverse time migration imaging is performed in the frequency domain, and high-quality acoustic images are obtained. The effects of the number of array elements, the center frequency of the excitation signal, and the number of defects on the denoising effect of the algorithm are investigated. It was experimentally demonstrated that the method could suppress the interference of noise signals and significantly improve the imaging SNR compared with total focusing method and the reverse time migration.

Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) has excellent harmonic characteristics, but its nonlinear transcendental system of equations is difficult to be solved, and the practical application encounters a bottleneck. In this paper, a modulation optimization method for seven-level SHEPWM inverter based on the Evolutionary Particle Swarm Optimization (EPSO) algorithm is proposed to address this problem, so that the algorithm quickly converges to the global optimum solution. The EPSO algorithm incorporates a population optimization strategy in two phases to improve the population diversity in real time. In the initialization phase, the initialized population is optimized using Opposition-Based Learning (OBL) to improve the quality of the initial population. In the iterative stage, we combine the adaptive Particle Swarm Optimization (PSO) algorithm, Tunicate Swarm Algorithm (TSA), Adaptive Gaussian Variation, Quasi-Opposition-Based Learning (QOBL) and other optimization methods to solve the problem of insufficient population diversity in the process of searching for the optimal solution, to break through the local optimum, and to improve the convergence speed and accuracy of the algorithm. Experiments of the algorithm in 19 benchmark functions and seven-level SHEPWM inverter optimization modulation show that the optimization ability of the EPSO algorithm is ahead of TSA, INFO, MA (Mayfly Algorithm), EO (Equilibrium Optimizer) and other optimization algorithms. The solution speed is about three times that of PSO, which achieves fast and highly accurate convergence, with a small error in the output of inverter, and better harmonic distortion rate than the standard requirement.

The aim was to explore the alterations in growth traits, physiological and biochemical characteristics of Prunus sibirica seedlings raised from spaceflight seeds. The seedlings cultivated by the “Shenzhou XII” spacecraft carrying the seeds of superior clones of P. sibirica were used to observe their growth traits and determine physiological indicators. The results showed that plant height of Prunus sibirica seedlings raised from spaceflight seeds increased by 18–34% and internode length increased by 8–26%, but the number of primary branches, secondary branches, and leaves showed no significant change compared to the ground control. Leaf length and width of Prunus sibirica seedlings raised from spaceflight seeds were significantly higher than those of the ground control, with leaf length, width, and area increasing to 1.21–1.80 times higher than that of the ground control. Furthermore, the antioxidant and osmoregulatory capacities of P. sibirica seedlings raised from spaceflight seeds were altered. The peroxidase (POD) activity and Malondialdehyde (MDA) content were increased in ST28, ST207, and ST507, while they were reduced in ST1 and ST453. Compared with the ground control, the content of soluble sugar(SS), starch (St), and free proline (Pro) were significantly or highly significantly increased in all lines. The content of soluble protein (SP) was significantly increased in ST1, ST28, ST207, and ST507, while there was no significant change in ST453. P. sibirica seedlings raised from spaceflight seeds exhibited increased leaf pigment content, the interstitial CO 2 concentration (Ci), net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr). In conclusion, compared with the ground control, the growth indexes and physiological characteristics of Prunus sibirica seedlings raised from spaceflight seeds were changed, and the direction of change was different for different lines. This provided a foundation for subsequent germplasm improvement and variety selection.

Pink-flowered Prunus sibirica , of the genus Prunus , is an exceptional germplasm resource with high ornamental value. Understanding the mechanism behind petal coloration is crucial for cultivating ornamental P. sibirica varieties. This study utilized pink-flowered and white-flowered P. sibirica petals at different stages of flowering to explore the relationship between various physiological indicators, anatomical structures of petals, and flower coloration during flowering. Results indicated that anthocyanins, key pigment indicators in pink-flowered P. sibirica , directly influenced the a* values (redness). Increased activity of phenylalanine deaminase (4.43–29.69 U/g), chalcone isomerase (9.80–46.67 U/g), and soluble sugar content (29.25–35.28 mg/g) promoted anthocyanin synthesis and accumulation. These substances indirectly affected flower color by influencing anthocyanin content through physiological processes related to petal coloration. Structural changes in epidermal cells of pink and white flower petals during flowering were similar, with differences in pigment content and distribution impacting petal light absorption. Correlation analysis revealed that a* values were significantly and positively correlated with five factors, one of which was anthocyanin content, and significant negative correlations with soluble protein content and cytosol pH. This study examined the factors influencing petal coloration in pink-flowered P. sibirica from both physiological and anatomical perspectives, providing a theoretical foundation for breeding new varieties of ornamental flowering plants.

The optimization of guide vane closing schemes (OGVCS) of pumped storage hydro units (PSHUs) is a cooperative control and optimal operation research field in renewable energy power generation technology. This paper presents an OGVCS model of PSHUs considering the rise rate of the unit rotational speed, the specific node pressure of each hydraulic unit, as well as various complicated hydraulic and mechanical constraints. The OGVCS model is formulated as a multi-objective optimization problem to optimize conflicting objectives, i.e., unit rotational speed and water hammer pressure criteria. In order to realize an efficient solution of the OGVCS model, an enhanced multi-objective bacterial-foraging chemotaxis gravitational search algorithm (EMOBCGSA) is proposed to solve this problem, which adopts population reconstruction, adaptive selection chemotaxis operator of local searching strategy and elite archive set to efficiently solve the multi-objective problem. In particular a novel constraints-handling strategy with elimination and local search based on violation ranking is used to balance the various hydraulic and mechanical constraints. Finally, simulation cases of complex extreme operating conditions (i.e., load rejection and pump outage) of a ‘single tube-double units’ type PSHU system are conducted to verify the feasibility and effectiveness of the proposed EMOBCGSA in solving OGVCS problems. The simulation results indicate that the proposed EMOBCGSA can provide a lower rise rate of the unit rotational speed and smaller water hammer pressure than other methods established recently while considering various complex constraints in OGVCS problems.

Gibberellins (GAs) are important in the floral regulatory networks of angiosperm plants. Several lines of evidence suggest that GAs also play a pivotal role in conifer male and female cone development. To gain new insights into the GA metabolism pathway in conifer trees and the role of GA metabolism in male and female cone development, we identified GA metabolism genes in Pinus tabuliformis. These included one PtCPS gene, one PtKS gene, one PtKO gene, TWO PtKAO genes, one PtGA20ox gene, two PtGA3ox genes and 12 PtGA2ox genes. According to phylogenetic analysis, the GA biosynthesis pathway evolved after the divergence of mosses from ferns, but the GA-deactivating gene family underwent divided expansion after divergence of the angiosperms from gymnosperms. However, the active sites of all GA metabolism enzymes were conserved during the evolution of land plants. During male and female cone development of P. tabuliformis, the expression of most of the PtGA2ox genes, especially PtGA2ox10, was higher than GA biosynthesis genes. However, the expression of PtKAO1 in cones peaked at a very early developmental stage. The expression pattern of GA metabolism genes indicated that GAs play different roles at the early and late stages of cone development.

Premise of the study: A set of novel expressed sequence tag (EST) microsatellite markers was developed in Pinus sylvestris var. mongolica to promote further genetic studies in this species. Methods and Results: One hundred seventy-five EST–simple sequence repeat (SSR) primers were designed and synthesized for 31,653 isotigs based on P. tabuliformis EST sequences. The primer pairs were used to identify 25 polymorphic loci in 48 individuals. The number of alleles ranged from two to eight with observed and expected heterozygosity values of 0.0435 to 0.8125 and 0.0430 to 0.7820, respectively. Conclusions: These new polymorphic EST-SSR markers will be useful for assessing genetic diversity, molecular breeding and genetic improvement, and conservation of P. sylvestris var. mongolica.

Following the publication of the above paper, it was drawn to the Editors' attention by a concerned reader that various panels showing data from flow cytometric experiments in Figs. 2E, 5E and 6E, and the cell migration and invasion assay data shown in Fig. 2D and 6D, were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article were already under consideration for publication, or had already been published, elsewhere when it was submitted to , the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 38: 1569‑1578, 2017; DOI: 10.3892/or.2017.5810].

Hepatocellular carcinoma (HCC) is the fifth-most common cancer and third leading cause of cancer-related deaths worldwide. Increasing evidence indicates that dysregulation of microRNAs is often observed in HCC, and has been extensively investigated in terms of cancer formation, progression, diagnosis, therapy, and prognosis. Recently, microRNA-326 (miR-326) has been demonstrated to play important roles in multiple types of human cancer. However, the expression pattern, clinical significance, roles and regulatory mechanisms of miR-326 in HCC have yet to be elucidated. In this study, miR-326 was frequently downregulated in HCC tissues and cell lines. Low miR-326 expression was significantly associated with the TNM stage, differentiation and lymph node metastasis of HCC patients. Further functional assays demonstrated that the recovered miR-326 expression inhibited HCC cell proliferation and invasion and activated cell apoptosis in vitro. In addition, LIM and SH3 protein 1 (LASP1) was identified as a direct target gene of miR-326 in HCC. Furthermore, LASP1 was upregulated in HCC tissues and cell lines. The expression level of LASP1 mRNA was inversely correlated with that of miR-326 in HCC tissues. Moreover, LASP1 silencing elicited effects similar to miR-326 overexpression on HCC cells, and LASP1 upregulation markedly reversed the effects of miR-326 overexpression on HCC cells. These results revealed that miR-326 suppressed the progression of HCC by directly targeting LASP1. Therefore, miR-326 may be used as a potential therapeutic target for the treatment of patients with HCC.

Key messagePistil abortion in Prunus sibirica was associated with insufficient supply of nutrient, auxins, and gibberellins in flower buds, which promotes pistil development, and accumulation of cytokinins, which inhibits pistil development.Prunus sibirica is an important ecological and economic tree species with high utilization potential and broad application prospects. However, pistil abortion affects its fruit setting, yield, and quality, restricting its industrial development. In this study, the type and stage of pistil abortion in P. sibirica were identified using flower buds with abortive and fertile pistil. The effects of different nutrients and endogenous hormones on pistil abortion were analyzed. The pistil abortion type of P. sibirica clone belonged to abnormal style structure, and the key stage of pistil abortion was the dew white stage, characterized by pistil degeneration and dissolution at the dew white stage and complete pistil disintegration and disappearance at the full blooming stage. The soluble protein, soluble sugar, and total sugar contents of flower buds with abortive pistils were significantly lower than those of flower buds with fertile pistils at the dew white, initial blooming, and full blooming stages. Among the 44 hormones detected in flower buds of P. sibirica, majority were cytokinins (CKs 25), followed by auxins (13). At the dew white stage, the CK content in flower buds with abortive pistils was significantly higher than that in flower buds with fertile pistils. Pistil abortion in P. sibirica was mainly due to insufficient supply of soluble protein, soluble sugar, and total sugar in flower buds; insufficient supply of auxins and gibberellins, which promotes pistil development; and accumulation of cytokinins, which inhibits pistil development.