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In the rockfall prevention and control project, the reinforced concrete (RC) slab and sand (gravel soil) soil cushion layer are commonly used to form the protection structure, thereby resisting the rockfall impact. Considering that the oversized deformation of the cushion layer under impact load using the finite element simulation cannot converge, this article establishes a numerical calculation model using smoothed particle hydrodynamics–finite-element method coupling (SPH–FEM). First, the standard Lagrange finite-element mesh is established for the whole model using ABAQUS, and then the finite-element mesh of the soil cushion layer is converted to SPH particle at the initial moment of the calculation, and finally the calculation results are solved and outputted. The results indicate that, compared with the results of the outdoor rockfall impact test, the relative errors of the rockfall impact force and the displacement of the RC slab are within 10%, which proves the rationality of the coupling algorithm; moreover, in terms of the numerical simulation, the SPH–FEM coupling algorithm is more practical than the finite element for reproducing the mobility of the rockfall impacting the sand and soil particles. In addition, at an impact speed of less than 12 m·s−1, the cushion layer is able to absorb more than 85% of the impact energy, which effectively ensures that the RC slab is in an elastic working state under small impact energy and does not undergo destructive damage under large impact energy; the peak impact force of the rockfall is approximately linear with the velocity, and the simulated value of the peak impact force is basically the same as that of the theoretical value of Hertz theory; the numerical simulation is good for reproducing the damage process of the RC slab in accordance with the actual situation. The SPH–FEM coupling algorithm is more justified than the FEM in simulating the large deformation problem, and it can provide a new calculation method for the design and calculation of the rockfall protection structure.

ObjectiveTo investigate the incidence and influencing factors of postpartum depression and anxiety in Urumqi during the coronavirus disease （COVID-19） epidemic period in 2020.MethodsResearch subjects were the parturients who underwent postpartum health checkups in a third class hospital in Urumqi from January 2020 to December 2020. The maternal socio demographic and obstetric information were collected， and PHQ-9 and GAD-7 scales were used for screening of PPD and PPA. Calcaneal bone mineral density of the parturients was measured by French Pegasus ultrasonic bone densitometer. After univariate analysis of the related influencing factors of PPD and PPA， multivariate binary logistic regression analysis was used to explore the relationship between mental disorders and various influencing factors.ResultsA total of 2 490 puerpera participated in the survey. The incidences of PPD and PPA in 2020 were 13.4 % and 10.8 %， respectively. Six factors with statistical differences after univariate analysis were included in multivariate binary logistic regression analysis. The final results suggested that age over 35 （OR=1.707，95%CI：1.142‒2.551）， unemployment （OR=1.478，95%CI：1.003‒2.205）， multipara （OR=1.340，95%CI：1.037‒1.733）， bone loss and osteoporosis （OR=1.434，95%CI： 1.076‒1.910） were the risk factors of PPD， while breastfeeding （OR=0.466，95%CI： 0.301‒0.721） was a protective factor. Ages between 18‒24 （OR=1.559，95%CI：1.282‒3.097） and cesarean section （OR=1.433，95%CI： 1.105‒1.859） were the risk factors of PPA， while ages between 30‒34 years old （OR=0.524，95%CI： 0.332‒0.827）， occupation as medical staff （OR=0.282，95%CI： 0.807‒0.919）， breastfeeding （OR=0.530，95%CI： 0.330‒0.850） were protective factors.ConclusionIncidences of PPD and PPA are in middle-low levels during COVID-19 epidemic period. Age， occupation， delivery mode， delivery times， feeding pattern and bone mineral density are the influencing factors. Screen coverage of PPD and PPA in special period should be strengthened， and measures should be taken to reduce the risk.

Summary Plant secondary metabolism represents an important and ancient form of defense against pathogens. Phytopathogens secrete effectors to suppress plant defenses and promote infection. However, it is largely unknown, how fungal effectors directly manipulate plant secondary metabolism. Here, we characterized a fungal defense‐suppressing effector CfEC28 from Colletotrichum fructicola. Gene deletion assays showed that ∆CfEC28‐mutants differentiated appressoria normally on plant surface but were almost nonpathogenic due to increased number of plant papilla accumulation at attempted penetration sites. CfEC28 interacted with a family of chloroplast‐localized 3‐deoxy‐d‐arabinose‐heptulonic acid‐7‐phosphate synthases (DAHPSs) in apple. CfEC28 inhibited the enzymatic activity of an apple DAHPS (MdDAHPS1) and suppressed DAHPS‐mediated secondary metabolite accumulation through blocking the manganese ion binding region of DAHPS. Dramatically, transgene analysis revealed that overexpression of MdDAHPS1 provided apple with a complete resistance to C. fructicola. We showed that a novel effector CfEC28 can be delivered into plant chloroplasts and contributes to the full virulence of C. fructicola by targeting the DAHPS to disrupt the pathway linking the metabolism of primary carbohydrates with the biosynthesis of aromatic defense compounds. Our study provides important insights for understanding plant–microbe interactions and a valuable gene for improving plant disease resistance. [ABSTRACT FROM AUTHOR]

Potassium (K) fertilisation has frequently been shown to enhance plant resistance against pathogens, though the mechanisms remain elusive. This study investigates the interaction dynamics between Nicotiana benthamiana and the pathogen Alternaria longipes under different planta K levels. On the host side, adding K activated the expressions of three NLR (nucleotide‐binding domain and leucine‐rich repeat‐containing proteins) resistance genes, including NbRPM1, NbR1B23 and NbNBS12. Silencing these NLRs attenuated resistance in high‐K (HK, 40.8 g/kg) plant, whereas their overexpression strengthened resistance in low‐K (LK, 23.9 g/kg) plant. Typically, these NLRs mainly strengthened plant resistance via promoting the expression of pathogenesis‐related genes (PRs), ROS burst and synthesis of antifungal metabolites in HK plant. On the pathogen side, the expression of effectors HKCSP1, HKCSP2 and LKCSP were shown to be related to planta K content. A. longipes mainly expressed effectors HKCSP1 and HKCSP2 in HK plant to interfere host resistance. HKCSP1 physically interacted with NbRPM1 to promote the degradation of NbRPM1, then attenuated related resistance in HK N. benthamiana. Meanwhile, HKCSP2 directly interacted with NbPR5 to suppress resistance in HK plant. In LK plant, A. longipes mainly deployed LKCSP that interacted with NbR1B23 to interfere reduce resistance in N. benthamiana. Overall, our research insights that both pathogen and host mobilise distinct strategies to outcompete each other during interactions in different K nutrient environments. Summary statement: The present study demonstrated that changes in planta K content could mediate the interaction pattern between host plants and pathogens, eventually leading different outcome of plant disease. Although the pathogen tries to suppress host immune by deploying different virulence factors, the host can benefit much more due to its sufficient resistance events under high K condition. Our results add to evidence that K fertilisation can be adjusted to optimise suppression of fungal diseases and thus has value as a disease management tool. [ABSTRACT FROM AUTHOR]

Colletotrichum fructicola shows morphological and genetic differences in plus and minus strains. However, the mechanism of the differentiation between two types of strains is still largely unclear. Our early transcriptome analysis revealed that CfHMG expression differed in plus and minus strains. To define the functions of the CfHMG gene, we constructed gene deletion mutants by homologous recombination. We found that a CfHMG deletion mutant of the minus strain, CfHMG-M, could lead to a reduction in perithecium sizes and densities on media and sterile perithecium formation compared with the minus wild type (WT), whereas there was no effect for the plus mutant CfHMG-P. In co-cultures between CfHMG-P and minus WT, CfHMG-M and plus WT, or CfHMG-P and CfHMG-M, the quantities of perithecia were all reduced significantly. When conidial suspensions were inoculated on non-wounded apple fruit, it was found that the virulence of the minus mutant decreased significantly but not for the plus one. Further, we found that the virulence decrease in minus mutants was caused by a decrease in the conidium germination rate. Our results indicate that CfHMG of C. fructicola plays an important role in the mating line formation between the plus and minus strain for both strains and differentially regulates the perithecium size, density, fertilization, and virulence of the minus strain. The results are significant for further detecting the differentiated mechanisms between the plus and minus strains in Colletotrichum fungi. [ABSTRACT FROM AUTHOR]