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Quercetin has been shown to have a wide range of beneficial effects, such as anti-inflammation, anti-oxidation and immunomodulation. The study was designed to explore the role and molecular mechanisms of quercetin on the protective effect of bone marrow-derived mesenchymal stem cells (BMSCs) under oxidative stress in vitro. BMSCs were isolated from 4-week-old male Sprague–Dawley rats. Upon H2O2 stimulation in vitro, the effects of quercetin on the proliferation, anti-oxidation and osteogenic differentiation of BMSCs were evaluated by Cell Counting Kit-8, reactive oxygen species analysis, Western blot (WB), real-time PCR (RT-PCR), alkaline phosphatase staining and alizarin red staining. Additionally, ferroptosis-related markers were examined by WB, RT-PCR and Mito-FerroGreen. Finally, PI3K/AKT/mTOR signaling pathway was explored in these processes. We found that quercetin significantly maintained BMSCs viability upon H2O2 stimulation. Quercetin upregulated protein (ALP, OPN and RUNX2) and mRNA (Alp, Opn, Ocn and Runx2) levels of osteogenic markers, downregulated ROS levels and upregulated antioxidative gene expressions (Nrf2, Cat, Sod-1 and Sod-2) compared with the H2O2 group. The ferroptosis in BMSCs was activated after H2O2 stimulation, and the phosphorylation level of PI3K, AKT and mTOR was upregulated in H2O2-stimulated BMSCs. More importantly, quercetin inhibited ferroptosis and the phosphorylation level of PI3K, AKT and mTOR were downregulated after quercetin treatment. We conclude that quercetin maintained the viability and the osteoblastic differentiation of BMSCs upon H2O2 stimulation, potentially via ferroptosis inhibition by PI3K/AKT/mTOR pathway.

Background and Aims Brassica napus is one of the most important oilseed crops worldwide. Seed yield of B. napus significantly correlates with the primary root length (PRL). The aims of this study were to identify quantitative trait loci (QTLs) for PRL in B. napus. Methods QTL-seq and conventional QTL mapping were jointly used to detect QTLs associated with PRL in a B. napus double haploid (DH) population derived from a cross between ‘Tapidor’ and ‘Ningyou 7’. The identified major locus was confirmed and resolved by an association panel of B. napus and an advanced backcross population. RNA-seq analysis of two long-PRL lines (Tapidor and TN20) and two short-PRL lines (Ningyou 7 and TN77) was performed to identify differentially expressed genes in the primary root underlying the target QTLs. Key Results A total of 20 QTLs impacting PRL in B. napus grown at a low phosphorus (P) supply were found by QTL-seq. Eight out of ten QTLs affecting PRL at a low P supply discovered by conventional QTL mapping could be detected by QTL-seq. The locus qPRL-C06 identified by QTL-seq was repeatedly detected at both an optimal P supply and a low P supply by conventional QTL mapping. This major constitutive QTL was further confirmed by regional association mapping. qPRL-C06 was delimited to a 0.77 Mb genomic region on chromosome C06 using an advanced backcross population. A total of 36 candidate genes within qPRL-C06 were identified that showed variations in coding sequences and/or exhibited significant differences in mRNA abundances in primary root between the long-PRL and short-PRL lines, including five genes involved in phytohormone biosynthesis and signaling. Conclusions These results both demonstrate the power of the QTL-seq in rapid QTL detection for root traits and will contribute to marker-assisted selective breeding of B. napus cultivars with increased PRL.

Oilseed rape (Brassica napus L.; B. napus) is one of the main oil crops in China as well as in the world. Genome-wide association studies (GWAS) have revolutionised the field of complex agronomic traits. In B. napus, these include seed yield and yield-related traits, seed oil content, and abiotic and biotic stress-tolerance traits over the past decade in which hundreds of thousands to millions of genetic variants across the genomes of hundreds of individuals have been tested to identify genotype–phenotype associations. In this review, we assess the current status of GWAS in terms of genotypes, phenotypes, statistical models, and candidate genes for these agronomic traits in B. napus. Post-GWAS, the combination of QTL mapping, transcriptomics, and new statistical methods, has allowed us to identify candidate genes associated with specific agronomic traits. In addition, we can use diverse populations, increase the population size, or look for rare variants and structural variations of B. napus by whole-genome sequencing to minimise the ‘missing heritability’ effects. These approaches are essential for uncovering the genetic mechanisms defining or regulating complex agronomic traits and the delivery of molecular marker-assisted breeding in B. napus to breed new varieties that are higher yielding but resilient to our changing climate.

Due to the non-uniform distribution of inorganic phosphate (Pi) in the soil, plants modify their root architecture to improve acquisition of this nutrient. In this study, a split-root system was employed to assess the nature of local and systemic signals that modulate root architecture of Brassica napus grown with non-uniform Pi availability. Lateral root (LR) growth was regulated systemically by non-uniform Pi distribution, by increasing the second-order LR (2°LR) density in compartments with high Pi supply but decreasing it in compartments with low Pi availability. Transcriptomic profiling identified groups of genes regulated, both locally and systemically, by Pi starvation. The number of systemically induced genes was greater than the number of genes locally induced, and included genes related to abscisic acid (ABA) and jasmonic acid (JA) signalling pathways, reactive oxygen species (ROS) metabolism, sucrose, and starch metabolism. Physiological studies confirmed the involvement of ABA, JA, sugars, and ROS in the systemic Pi starvation response. Our results reveal the mechanistic basis of local and systemic responses of B. napus to Pi starvation and provide new insights into the molecular and physiological basis of root plasticity.

Oilseed rape (Brassica napus L.; B. napus) is an important oil crop around the world. However, the genetic mechanism of B. napus adaptations to low phosphate (P) stress are largely unknown. In this study, a genome-wide association study (GWAS) identified 68 SNPs significantly associated with seed yield (SY) under low P (LP) availability in two trials. Among these SNPs, two, chrC07__39807169 and chrC09__14194798, were co-detected in two trials, and BnaC07.ARF9 and BnaC09.PHT1;2 were identified as candidate genes of them, respectively, by combine GWAS with quantitative reverse-transcription PCR (qRT-PCR). There were significant differences in the gene expression level of BnaC07.ARF9 and BnaC09.PHT1;2 between P -efficient and -inefficiency varieties at LP. SY_LP had a significant positive correlation with the gene expression level of both BnaC07.ARF9 and BnaC09.PHT1;2. BnaC07.ARF9 and BnaA01.PHR1 could directly bind the promoters of BnaA01.PHR1 and BnaC09.PHT1;2, respectively. Selective sweep analysis was conducted between ancient and derived B. napus, and detected 1280 putative selective signals. Within the selected region, a large number of genes related to P uptake, transport and utilization were detected, such as purple acid phosphatase (PAP) family genes and phosphate transporter (PHT) family genes. These findings provide novel insights into the molecular targets for breeding P efficiency varieties in B. napus.

In the road test of vehicle performance evaluation, real-time and accurate estimation of road slope is essential for objective evaluation. Using slope meter directly can bring many problems such as large randomness and errors in road test. Using complex road slope estimation algorithm often brings redundant sensors and reduces detection efficiency. Aiming at the above problems, this paper proposes a road slope estimation model based on IMU error calibration and multi-sensor signal fusion. First, the vehicle-road dynamics and kinematics models are established. Then, the error sources of IMU are analyzed, and the calibration and compensation methods are proposed. The acceleration signal of IMU is compensated by inertia through the vehicle velocity signal obtained by multi-sensors, and the projection of gravity acceleration vector in the vehicle coordinate is decoupled. Finally, the model fuses the decoupled result with IMU angular velocity value through Kalman filter algorithm, and outputs the estimated slope of the road. The road test results show that the model can effectively compensate the IMU installation error and accurately estimate the road slope. And the slope estimation error is less than 0.5%, which can meet the needs of the road test of vehicle performance evaluation.

Background and Aims Oilseed rape (Brassica napus) is one of the most important oil crops worldwide. Phosphorus (P) deficiency severely decreases the plant height and branch number of B. napus. However, the genetic bases controlling plant height and branch number in B. napus under P deficiency remain largely unknown. This study aims to mine candidate genes for plant height and branch number by genome-wide association study (GWAS) and determine low-P-tolerance haplotypes. Methods An association panel of B. napus was grown in the field with a low P supply (P, 0 kg ha−1) and a sufficient P supply (P, 40 kg ha−1) across 2 years and plant height and branch number were investigated. More than five million single-nucleotide polymorphisms (SNPs) were used to conduct GWAS of plant height and branch number at two contrasting P supplies. Key Results A total of 2127 SNPs were strongly associated (P < 6·25 × 10−07) with plant height and branch number at two P supplies. There was significant correlation between phenotypic variation and the number of favourable alleles of associated loci on chromosomes A10 (chrA10_821671) and C08 (chrC08_27999846), which will contribute to breeding improvement by aggregating these SNPs. BnaA10g09290D and BnaC08g26640D were identified to be associated with chrA10_821671 and chrC08_27999846, respectively. Candidate gene association analysis and haplotype analysis showed that the inbred lines carrying ATT at BnaA10g09290Hap1 and AAT at BnaC08g26640Hap1 had greater plant height than lines carrying other haplotype alleles at low P supply. Conclusion Our results demonstrate the power of GWAS in identifying genes of interest in B. napus and provided insights into the genetic basis of plant height and branch number at low P supply in B. napus. Candidate genes and favourable haplotypes may facilitate marker-based breeding efforts aimed at improving P use efficiency in B. napus.

Oilseed rape (Brassica napus L.) is an important oilseed crop worldwide and 1000-seed weight (SW) is the important determinant of seed yield of B. napus. To elucidate the genetic mechanism of SW and mining candidate genes, a panel of 403 diverse B. napus accessions was screened in a genome-wide association study (GWAS) using 1.60 million single-nucleotide polymorphisms (SNPs). This study identified 340 SNPs significantly associated with SW by general linear model (GLM) and mixed linear model (MLM). Through GWAS combined with transcriptome data, two significantly differentially expressed genes were identified as candidate genes (BnaA02g06870D and BnaC06g28920D). Candidate gene association analysis and haplotype analysis showed that the inbred lines carrying ACCC at BnaA02g06870Hap1 and TTGG at BnaC06g28920Hap1 had greater SW than lines carrying other haplotype alleles. Candidate genes and favourable haplotypes identified in this study will be useful for large-seed breeding of B. napus.

In this paper, the peak pressure, stiffness, flow rate, and temperature rise of the oil film in the stepped cavity of the hybrid bearing are investigated. The pressure and flow equations for the central section of the stepped cavity and the axial section of the deep and shallow cavity are derived using the simplified Navier-Stokes equations and the boundary conditions of a liquid bearing. Using the control variable method, the influence of the geometrical parameters of the stepped cavity and the process parameters on the oil film characteristics was simulated, and the correctness of the pressure and flow equations was verified. The results show that: the spindle speed is positively correlated with the peak oil film pressure and flow rate; the oil film thickness is negatively correlated with the peak oil film pressure and positively correlated with the flow rate; the depth and width of the shallow cavity are correlated with the peak oil film pressure, but the correlation with the flow rate is low; the maximum error between the theoretical calculation and the simulation analysis is less than 7.3%. The pressure equation and the flow equation are used to establish the objective function with the maximum oil film stiffness, load-bearing capacity, and minimum temperature rise, and the ideal point evaluation function method is used to do a multi-target optimization design to optimize the ladder cavity and obtain the optimal oil cavity geometric parameters. And an 8.75% increase in peak pressure and a 4.1% reduction in temperature rise for the same process parameters.

Both surge and bore impacts could lead to the failure of coastal structures. Nevertheless, differences between the surge- and bore-induced hydrodynamic impact processes on a vertical wall are still unclear. Meanwhile, investigation of the bed pressure features during the wall impact is also rare. In this study, a series of dam-break experiments were conducted to specify the hydrodynamic characteristics of the surge and bore impact pressure on a vertical wall and its foundation. In the experiment, same initial water head was applied with five different initial downstream water levels (IDWLs). Temporal variations of the surge/bore impact pressures at four elevations on the wall and four positions along the bed were recorded. The surge induced maximum water height on the wall is larger than the bore-induced one, which decreases with the increase in the IDWL. With the increase in the IDWL, the initial peak impact pressure gradually decays owing to the slowing down of flow velocity and the significant air entrainment at the bore front. Regarding the initial peak pressure and its rise time, it is confirmed that the initial surge impact pressure is sensitive to the wall elevation, whereas it is relatively uniform along the wall bottom region for the bore impact pressure. As for the measured bed pressure, the initial impact zone induced by the secondary flow near the wall and the falling impact zone caused by the falling down of water mass from the splash-ups away from the wall are identified, showing different hydrodynamic features.

In this study, the impact process on a vertical wall due to the dam-break-induced surge was investigated experimentally. The entire surge impact process is classified into three stages, i.e. the in...

The information security rate of wireless sensor network with multiple eavesdroppers and multiple relays has been a research hotspot in recent years. In the scene of channel state information varies slowly, prior state information of the channel can be used to get beamformer vector which maximize information security under the constrains of power. When the channel state information varies rapidly, above method is unsuitable. To tackle this problem, a stochastic beamforming algorithm is proposed in this paper. It introduces maximum time-varying information security as the objective function and takes the power expectation of the weight vector as the constraint, using variable relaxation techniques and the Charnes–Cooper transform to convert the non-convex optimization into a convex form. Furthermore, performance of proposed method using two kinds of time-varying weight vector, namely complex Gaussian distribution and elliptical distribution, is deeply evaluated. Finally, numerical results are presented to demonstrate the performance of our proposed schemes.

Cnoidal wave and its extreme case, the solitary wave, can be described by the KdV equation, which was first derived by Korteweg and de Vires with the first-order accuracy. Subsequently, different a...

In endodontics, fracturing of the instrument in the root canal can arise as an inevitable problem for the dentist, especially during the application of the metal-nickel-titanium devices to the root canal. What is more, the broken parts of the instruments may be beyond the point of the apex, which can produce a range of symptoms and cause additional physical and mental pain to the patients that must be relieved as fast as possible. A few cases are available, in which the separated endodontic instruments beyond the apex are addressed with surgical approaches, indicating that some cases can be resolved by surgical management. However, it is difficult to achieve the ideal results often due to bleeding, a lack of clinic experience, and an inability to accurately comprehend soft tissue activities. The best way, then, is to prevent the occurrence entirely if possible.

Future information technologies for low-dissipation quantum computation, high-speed storage, and on-chip communication applications require the development of atomically thin, ultracompact, and ultrafast spintronic devices in which information is encoded, stored, and processed using electron spin. Exploring low-dimensional magnetic materials, designing novel heterostructures, and generating and controlling ultrafast electron spin in 2D magnetism at room temperature, preferably in the unprecedented terahertz (THz) regime, is in high demand. Using THz emission spectroscopy driven by femtosecond laser pulses, optical THz spin-current bursts at room temperature in the 2D van der Waals ferromagnetic Fe