25 research outputs found

    The neuroanatomical basis of the Gambler's fallacy: A univariate and multivariate morphometric study

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    Human decision-making can be irrational, as in the case of the gambler's fallacy (GF). Converging evidence from behavioral and functional neuroimaging studies has suggested that a hyperactive cognitive system and a hypo-active affective system contribute to the false world model that generates the GF. However, the neuroanatomical basis underlying the GF remains unclear. The current study addressed this issue by collecting high-resolution magnetic resonance anatomical images from a large sample of 350 healthy Chinese adults. Univariate voxel-based morphometry (VBM) analysis suggested that the gray matter volume (GMV) in the anterior cingulate cortex (ACC) and medial temporal lobe (MTL) (two regions of the cognitive system) showed negative correlations with the degree of GF, while the GMV in the striatum and orbitofrontal cortex (OFC; two regions of the affective system) showed positive correlations. Further multivariate VBM analysis showed that the GMV in these regions could potentially predict the degree of GF. Moreover, a mediation analysis suggested that the GMV in MTL, ACC, and OFC mediated the relationships between the cognitive abilities or affective decision-making performance and the GF. Results of our study help us to understand the potential neural bases of the cognitive system's constructive role and the affective system's destructive role in decision making

    High-Cycle Fatigue Life and Strength Prediction for Medium-Carbon Bainitic Steels

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    High-cycle fatigue (HCF) behaviors of medium-carbon bainitic steels with various inclusion sizes and microstructural features were studied using the rotating–bending fatigue test. Here, the medium-carbon bainitic steels with different melting processes were treated by three heat treatment routes incorporating bainite formation, namely bainite-based quenching plus partitioning (BQ&P), bainite austempering (BAT) and “disturbed bainite austempering, DBAT”. The interior inclusion-induced crack initiation (IICI) and noninclusion-induced crack initiation (NIICI) modes were found after fatigue failure. The fracture surface of IICI is characterized by a “fish-eye” surrounding a “fine granular area, FGA” in the vicinity of an inclusion. In contrast, a microfacet, instead of an inclusion, is found at the center of FGA for the NIICI fracture surface. The predications of fatigue strength and life were performed on the two crack initiation modes based on fracture surface analysis. The results showed that a majority of fatigue life is consumed within the FGA for both the IICI and NIICI failure modes. The fatigue strength of the NIICI-fatigued samples can be conveniently predicted via the two parameters of the hardness of the sample and the size of the microfacet

    High-Cycle Fatigue Life and Strength Prediction for Medium-Carbon Bainitic Steels

    No full text
    High-cycle fatigue (HCF) behaviors of medium-carbon bainitic steels with various inclusion sizes and microstructural features were studied using the rotating–bending fatigue test. Here, the medium-carbon bainitic steels with different melting processes were treated by three heat treatment routes incorporating bainite formation, namely bainite-based quenching plus partitioning (BQ&P), bainite austempering (BAT) and “disturbed bainite austempering, DBAT”. The interior inclusion-induced crack initiation (IICI) and noninclusion-induced crack initiation (NIICI) modes were found after fatigue failure. The fracture surface of IICI is characterized by a “fish-eye” surrounding a “fine granular area, FGA” in the vicinity of an inclusion. In contrast, a microfacet, instead of an inclusion, is found at the center of FGA for the NIICI fracture surface. The predications of fatigue strength and life were performed on the two crack initiation modes based on fracture surface analysis. The results showed that a majority of fatigue life is consumed within the FGA for both the IICI and NIICI failure modes. The fatigue strength of the NIICI-fatigued samples can be conveniently predicted via the two parameters of the hardness of the sample and the size of the microfacet

    Mechanism of subsurface microstructural fatigue crack initiation during high and very-high cycle fatigue of advanced bainitic steels

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    Advanced bainitic steels with the multiphase structure of bainitic ferrite, retained austenite and marten-site exhibit distinctive fatigue crack initiation behavior during high cycle fatigue/very high cycle fatigue (HCF/VHCF) regimes. The subsurface microstructural fatigue crack initiation, referred to as "non-inclusion induced crack initiation, NIICI", is a leading mode of failure of bainitic steels within the HCF/VHCF regimes. In this regard, there is currently a missing gap in the knowledge with respect to the cyclic response of multiphase structure during VHCF failure and the underlying mechanisms of fatigue crack initiation during VHCF. To address this aspect, we have developed a novel approach that explicitly identi-fies the knowledge gap through an examination of subsurface crack initiation and interaction with the lo -cal microstructure. This was accomplished by uniquely combining electron microscopy, three-dimensional confocal microscopy, focused ion beam, and transmission Kikuchi diffraction. Interestingly, the study indi-cated that there are multiple micro-mechanisms responsible for the NIICI failure of bainitic steels, includ-ing two scenarios of transgranular-crack-assisted NIICI and two scenarios of intergranular-crack-assisted NIICI, which resulted in the different distribution of fine grains in the crack initiation area. The fine grains were formed through fragmentation of bainitic ferrite lath caused by localized plastic deformation or via local continuous dynamic recrystallization because of repeated interaction between slip bands and prior austenite grain boundaries. The formation of fine grains assisted the advancement of small cracks. An-other important aspect discussed is the role of retained austenite (RA) during cyclic loading, on crack ini-tiation and propagation in terms of the morphology, distribution and stability of RA, which determined the development of localized cyclic plastic deformation in multiphase structure. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology

    Electroacupuncture-Modulated MiR-106b-5p Expression Enhances Autophagy by Targeting Beclin-1 to Promote Motor Function Recovery After Spinal Cord Injury in Rats

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    Objective Electroacupuncture (EA) has a definite effect on the treatment of spinal cord injuries (SCIs), but its underlying molecular mechanism remains unclear. Meanwhile, MiR-106b-5p is an autophagy- and apoptosis-related microribonucleic acid, but whether it regulates the progression of autophagy and apoptosis in SCIs is yet undetermined. As such, this study aimed to elucidate the involvement of miR-106b-5p in the EA treatment of an SCI. Methods The miR-106b-5p level was detected by quantitative real-time polymerase chain reaction. In vitro, SH-SY5Y cells were transfected with miR-106b-5p mimics or inhibitors to regulate the miR-106b-5p expression, while in vivo, SCI rats were treated with EA for 7 days at the bilateral Zusanli (ST36) and Jiaji (EX-B2) acupoints. The motor function was evaluated using the Basso-Beattie-Bresnahan (BBB) criteria. Further, autophagic vacuoles, pathological damage, and neuronal cell morphology were observed by transmission electron microscopy, as well as by hematoxylin and eosin and Nissl staining, respectively. Results The miR-106b-5p level, which can interact directly with Beclin-1 by influencing its expression, as well as the expressions of P62, Caspase-3, and Bax, was upregulated after an SCI, but it decreased after EA. Moreover, the ratio of LC3-II to LC3-I was upregulated after EA. EA can enhance autophagy, reduce neuronal apoptosis, and minimize motor dysfunction and histopathological deficits after an SCI. More importantly, however, all the above effects induced by EA can be reversed after an injection of miR-106-5p agomir to produce an overexpression of miR-106b-5p. Conclusion EA treatment could downregulate miR-106b-5p to alleviate SCI-mediated injuries by promoting autophagy and inhibiting apoptosis

    A High Density Genetic Map Derived from RAD Sequencing and Its Application in QTL Analysis of Yield-Related Traits in Vigna unguiculata

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    Cowpea [Vigna unguiculata (L.) Walp.] is an annual legume of economic importance and widely grown in the semi-arid tropics. However, high-density genetic maps of cowpea are still lacking. Here, we identified 34,868 SNPs (single nucleotide polymorphisms) that were distributed in the cowpea genome based on the RAD sequencing (restriction-site associated DNA sequencing) technique using a population of 170 individuals (two cowpea parents and 168 F2:3 progenies). Of these, 17,996 reliable SNPs were allotted to 11 consensus linkage groups (LGs). The length of the genetic map was 1,194.25 cM in total with a mean distance of 0.066 cM/SNP marker locus. Using this map and the F2:3 population, combined with the CIM (composite interval mapping) method, eleven quantitative trait loci (QTL) of yield-related trait were detected on seven LGs (LG4, 5, 6, 7, 9, 10, and 11) in cowpea. These QTL explained 0.05–17.32% of the total phenotypic variation. Among these, four QTL were for pod length, four QTL for thousand-grain weight (TGW), two QTL for grain number per pod, and one QTL for carpopodium length. Our results will provide a foundation for understanding genes related to grain yield in the cowpea and genus Vigna

    High-Performance Photodetectors Based on Single All-Inorganic CsPbBr<sub>3</sub> Perovskite Microwire

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    In recent years, hybrid organic–inorganic perovskites have emerged as promising photosensing materials for next-generation solution-processed photodetectors, achieving high responsivity, fast speed, and large linear dynamic range. In particular, perovskite photoresistors possess low-cost fabrication and easy integration with low dimensional structures. However, a relatively large dark current is still limiting the further development of perovskite photoresistors. Herein, we introduce full-inorganic perovskite polycrystalline microwires for high-performance photodetection, in order to enhance the device stability. Furthermore, dark current and noise can be effectively suppressed by tuning the contacts. All-inorganic CsPbBr<sub>3</sub> microwires with a number of nanocrystals on the wire surface are prepared by a simple, low-cost, two-step, solution-processed method at room temperature. Photodetectors based on this CsPbBr<sub>3</sub> polycrystalline single microwire are assembled on indium tin oxide electrodes and demonstrate a decent responsivity up to 118 A/W and a fast response within 40 ms. In addition, such optimized photoresistors possess a fairly tiny dark current and noise, which result in an improved detectivity of >10<sup>12</sup> Jones and demonstrate excellent characteristics to detect weak light
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