76 research outputs found
Correlation between resistance of eggplant and defense-related enzymes and biochemical substances of leaves
14 eggplant cultivars were inoculated by Verticillium dahliae to screen their resistance against verticillium wilt. The resistances were shown as the disease incidence and disease index, and eggplant cultivars were classified into resistant type (R), moderate resistant type (MR), tolerant type (T), moderate susceptible (MS) and susceptible type (S), according to the final disease index. To find out the correlated physiological and biochemical indexes for evaluating the resistance of eggplant to verticillium wilt, the activities of defense-related enzymes, and the contents of some biochemical substances of leaves were investigated. The results show that the activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were significantly positively correlated with resistance (P <0.01) and the resistance was significantly positively correlated with the activity of peroxidase (POD) and the content of total chlorophyll (P<0.05), but significantly negatively correlated with the relative electric conductivity and the content of malondialdehyde (MDA) (P<0.05). The correlations between resistance and catalase (CAT) activity, the contents of sucrose, soluble protein and proline, were not detected.Keywords: Verticillium wilt, eggplant, disease resistance, defense-related enzyme, biochemical substanc
Accumulation of cinnamic acid and vanillin in eggplant root exudates and the relationship with continuous cropping obstacle
The contents of cinnamic acid and vanillin in eggplant root exudates and soil were determined by HPLC. The results showed that cinnamic acid and vanillin might remain in soil after the root of eggplant is released. With the extending growth stage and planting year of eggplant, the contents in root exudates, rhizosphere and continuous cropping soil increased. In bioassay and field studies, the allelopathy of cinnamic acid and vanillin to the verticillium wilt (V. dahliae) and the eggplant was observed, and when the concentration of cinnamic acid or vanillin was at 1 and 4mmol ⇦ -1, it inhibited the eggplant growth, while the occurrence of verticillium wilt was promoted. A high concentration of cinnamic acid and vanillin caused eggplant autotoxicity and increased the risk of disease infection, which finally led to continuous cropping obstacle.Keywords: Cinnamic acid, vanillin, root exudates, soil, verticillium wilt, continuous cropping obstacl
Experimental study and mechanism analysis of spontaneous imbibition of surfactants in tight oil sandstone
The process of spontaneous imbibition is the basis of oil recovery from tight oil reservoirs. In this study, spontaneous imbibition experiments were conducted based on tight oil weakly hydrophilic sandstone cores from the Honghe oilfield in the Ordos Basin. Four different types of surfactants, such as nonionic Triton X-100, nonionic Tween-80, cationic dodecyl trimethyl ammonium bromide, and anionic sodium dodecyl benzene sulfonate, were separately dissolved in 30 g/L potassium chloride solution as simulated formation water. The effects of surfactant type on spontaneous imbibition were analyzed, and the results indicated that, because the nonions are adsorbed on the surface via Van der Waals force and adsorb H+ through hydrogen bonds, the two nonionic surfactants altered the wettability of the core from weakly hydrophilic to strongly hydrophilic, the recovery rate was relatively high. The Triton X-100 was selected for subsequent spontaneous imbibition experiments by changing the mass concentration to adjust interfacial tension. It was found that the maximum recovery rate was 32% when the Triton X-100 mass concentration was 0.1%, which indicates that the enhanced recovery rate of spontaneous imbibition requires a sufficiently low wettability factor and a suitably high interfacial tension factor. Finally, the surfactants mixed with 0.03% sodium dodecylbenzene sulfonate and 0.1% Triton X-100 were used for spontaneous imbibition, attaining an oil recovery of up to 45%, which was 21.6% higher than that of single-surfactant imbibition. It was established that the synergistic mechanism depends on the wettability alteration of nonionic surfactant facilitating the spontaneous imbibition, while the anion accelerates oil removal from the core by continuously encasing oil droplets in the aqueous phase. This paper provides a theoretical basis for the imbibition development of weakly hydrophilic tight sandstone with high-salinity formation water.Cited as:Â Zhang, X., Ye, Q., Deng, J., Zhu, W., Tian, W., Kuang, S. Experimental study and mechanism analysis of spontaneous imbibition of surfactants in tight oil sandstone. Capillarity, 2023, 7(1): 1-12. https://doi.org/10.46690/capi.2023.04.0
How do childhood abuse and neglect affect prosocial behavior? The mediating roles of different empathic components
BackgroundChildhood abuse and neglect are typically considered as two different forms of maltreatment. Previous international studies have found differential effects of abuse and neglect on prosocial behavior, but this and the mediating pathway underlying these associations have not been examined in a Chinese sample. Our study aims to examine the effects of childhood abuse and neglect on prosocial behavior in Chinese participants and test the unique mediating roles of different empathic components in these associations.MethodsA total of 1,569 young adults (average age = 18.17 years) were recruited from a college that enrolls students from all provinces of China. Participants completed a series of questionnaires, including the Childhood Trauma Questionnaire, Interpersonal Reactivity Index, and Prosocial Tendencies Measure. Path analysis was conducted to determine the mediational relationships.ResultsEmotional neglect had significant direct effect on prosocial behavior (β = −0.108, p < 0.001), and could also impact prosocial behavior through the mediating roles of perspective-taking and empathic concern (effect size = −0.091 and −0.097 respectively, p < 0.001). Emotional abuse affected prosocial behavior only through personal distress (effect size = −0.072, p < 0.001). Physical abuse, sexual abuse and physical neglect have little effect on prosocial behavior and empathy.ConclusionChildhood abuse and neglect have distinct influences on prosocial behavior. Emotional abuse and emotional neglect affect prosocial behavior through distinct pathways. This conclusion could help to establish precise interventions for improving prosocial behavior in maltreated individuals
Interkingdom multi-omics analysis reveals the effects of nitrogen application on growth and rhizosphere microbial community of Tartary buckwheat
Tartary buckwheat (Fagopyrum tataricum Gaertn.) is an important pseudocereal crop with excellent edible, nutritional and medicinal values. However, the yield of Tartary buckwheat (TB) is very low due to old-fashioned cultivation techniques, particularly unreasonable application of nitrogen fertilizer. To improve the understanding on the theories of nitrogen use in TB, the effects of nitrogen application on growth, as well as chemical properties and microbial community of rhizosphere soil were investigated in this study. Nitrogen application could promote the plant height, stem diameter, nitrogen accumulation and yield of TB. The relative abundance and diversity of bacteria and fungi in the rhizosphere soil of TB were improved by nitrogen fertilizer. Nitrogen application increased the abundance of beneficial bacteria such as Lysobacter and Sphingomonas in rhizosphere soil, and decreased the abundance of pathogenic fungi such as Fusarium and Plectosphaerella. The results indicated that nitrogen application changed the distribution of microbial communities in TB rhizosphere soil. Furthermore, the specific enriched or depleted microorganisms in the rhizosphere soil of four TB varieties were analyzed at OTU level. 87 specific nitrogen-responsive genes with sequence variation were identified in four varieties by integrating genomic re-sequencing and transcriptome analysis, and these genes may involve in the recruitment of specific rhizosphere microorganisms in different TB varieties. This study provided new insights into the effects of nitrogen application on TB growth and rhizosphere microbial community, and improved the understanding on the mechanisms of TB root–microbe interactions
Genome-Wide Association Study for Adult-Plant Resistance to Stripe Rust in Chinese Wheat Landraces (Triticum aestivum L.) From the Yellow and Huai River Valleys
Stripe rust (also known as yellow rust), caused by the pathogen Puccinia striiformis f. sp. tritici (Pst), is a common and serious fungal disease of wheat (Triticum aestivum L.) worldwide. To identify effective stripe rust resistance loci, a genome-wide association study was performed using 152 wheat landraces from the Yellow and Huai River Valleys in China based on Diversity Arrays Technology and simple sequence repeat markers. Phenotypic evaluation of the degree of resistance to stripe rust at the adult-plant stage under field conditions was carried out in five environments. In total, 19 accessions displayed stable, high degrees of resistance to stripe rust development when exposed to mixed races of Pst at the adult-plant stage in multi-environment field assessments. A marker–trait association analysis indicated that 51 loci were significantly associated with adult-plant resistance to stripe rust. These loci included 40 quantitative trait loci (QTL) regions for adult-plant resistance. Twenty identified resistance QTL were linked closely to previously reported yellow rust resistance genes or QTL regions, which were distributed across chromosomes 1B, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5B, 6B, 7A, 7B, and 7D. Six multi-trait QTL were detected on chromosomes 1B, 1D, 2B, 3A, 3B, and 7D. Twenty QTL were mapped to chromosomes 1D, 2A, 2D, 4B, 5B, 6A, 6B, 6D, 7A, 7B, and 7D, distant from previously identified yellow rust resistance genes. Consequently, these QTL are potentially novel loci for stripe rust resistance. Among the 20 potentially novel QTL, five (QDS.sicau-2A, QIT.sicau-4B, QDS.sicau-4B.2, QDS.sicau-6A.3, and QYr.sicau-7D) were associated with field responses at the adult-plant stage in at least two environments, and may have large effects on stripe rust resistance. The novel effective QTL for adult-plant resistance to stripe rust will improve understanding of the genetic mechanisms that control the spread of stripe rust, and will aid in the molecular marker-assisted selection-based breeding of wheat for stripe rust resistance
Research on the Equity and Influencing Factors of Medical and Health Resources Allocation in the Context of COVID-19: A Case of Taiyuan, China
COVID-19 has killed millions of people worldwide. As a result, medical and health resources continue to be strained, posing a great threat to people’s safety and economic and social development. This paper built the index system of influencing factors of medical and health resources containing the economy, population and society, and then classified Taiyuan into three types of regions by cluster analysis. The Gini coefficient, Theil index and agglomeration degree were then used to analyze the spatial distribution of medical and health resources allocation, and its influencing factors were studied by grey relational analysis. It was found that the population allocation of medical and health resources in Taiyuan was better than area allocation. Population has the greatest influence on the allocation of medical and health resources, followed by society and the economy. The more developed the regional economy, the more diversified the main influencing factors, and the more adjustment and control choices of medical and health resources allocation. Suggestions for optimal allocation were put forward in order to fully utilize the limited medical and health resources, effectively respond to the epidemic needs, promote the sustainable development of resources, protect the health of residents, and improve social benefits
The first complete chloroplast genome of Fagopyrum leptopodum (Diels) Hedberg (Caryophyllales: Polygonaceae) with phylogenetic implications
In the present study, we sequenced and assembled the complete chloroplast genome of Fagopyrum leptopodum (Diels) Hedberg. The chloroplast genome of F. leptopodum was composed of 85 protein-coding genes, 8 ribosomal RNA genes, and 37 transfer RNA genes. The F. leptopodum chloroplast genome is 159,375 bp in length, with a GC content of 37.81%. Phylogenetic analysis based on the combined chloroplast gene dataset indicated that the F. leptopodum exhibited a close relationship with Fagopyrum luojishanense
Bimodal Nanocrystallization of NiTi Shape Memory Alloy by Laser Shock Peening and Post-deformation Annealing
In this paper, surface nanocrystallization of NiTi intermetallic alloy by a novel method is reported. The NiTi alloy is processed by laser shock peening (LSP) and controlled annealing. The microstructure of the NiTi alloy after processing is characterized by transmission electron microscopy. At the top surface of the material, a nanostructure with bimodal grains is obtained. The mechanism of the formation of the bimodal microstructure is discussed. At the material subsurface, deformation twins are generated by LSP and retained after controlled annealing. Tensile test results showed that both strength and ductility are significantly improved through LSP and controlled annealing
Application of boundary collocation method to two-dimensional wave propagation
Boundary Collocation Method (BCM) based on Eigenfunction Expansion Method (EEM), a new numerical method for solving two-dimensional wave problems, is developed. To verify the method, wave problems on a series of beaches with different geometries are solved, and the errors of the method are analyzed. The calculation firmly confirms that the results will be more precise if we choose more rational points on the beach. The application of BCM, available for the problems with irregular domains and arbitrary boundary conditions, can effectively avoid complex calculation and programming. It can be widely used in ocean engineering
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