The NAC TF family is widely involved in plant responses to various types of stress. Red clover (Trifolium pratense) is a high-quality legume, and the study of NAC genes in red clover has not been ...comprehensive. The aim of this study was to analyze the NAC gene family of red clover at the whole-genome level and explore its potential role in the Pb stress response.
In this study, 72 TpNAC genes were identified from red clover; collinearity analysis showed that there were 5 pairs of large fragment replicators of TpNAC genes, and red clover was found to be closely related to Medicago truncatula. Interestingly, the TpNAC genes have more homologs in Arabidopsis thaliana than in soybean (Glycine max). There are many elements in the TpNAC genes promoters that respond to stress. Gene expression analysis showed that all the TpNAC genes responded to Pb stress. qRT-PCR showed that the expression levels of TpNAC29 and TpNAC42 were significantly decreased after Pb stress. Protein interaction network analysis showed that 21 TpNACs and 23 other genes participated in the interaction. In addition, the TpNAC proteins had three possible 3D structures, and the secondary structure of these proteins were mainly of other types. These results indicated that most TpNAC members were involved in the regulation of Pb stress in red clover.
These results suggest that most TpNAC members are involved in the regulation of Pb stress in red clover. TpNAC members play an important role in the response of red clover to Pb stress.
Caucasian clover (Trifolium ambiguum M. Bieb.) is an excellent perennial plant in the legume family Fabaceae, with a well-developed rhizome and strong clonal growth. Auxin is one of the most ...important phytohormones in plants and plays an important role in plant growth and development. Auxin response factor (ARF) can regulate the expression of auxin-responsive genes, thus participating in multiple pathways of auxin transduction signaling in a synergistic manner. No genomic database has been established for Caucasian clover. In this study, 71 TaARF genes were identified through a transcriptomic database of Caucasian clover rhizome development. Phylogenetic analysis grouped the TaARFs into six (1–6) clades. Thirty TaARFs contained a complete ARF structure, including three relatively conserved regions. Physical and chemical property analysis revealed that TaARFs are unstable and hydrophilic proteins. We also analyzed the expression pattern of TaARFs in different tissues (taproot, horizontal rhizome, swelling of taproot, rhizome bud and rhizome bud tip). Quantitative real–time RT–PCR revealed that all TaARFs were responsive to phytohormones (indole-3-acetic acid, gibberellic acid, abscisic acid and methyl jasmonate) in roots, stems and leaves. These results helped elucidate the role of ARFs in responses to different hormone treatments in Caucasian clover.
Trifolium repens L. (T. repens) is considered a potential phytoremediation species due to its large biomass and ability to accumulate and tolerate heavy metals. Lead (Pb) is an important heavy metal ...pollutant that can affect plant growth, photosynthesis, and enzyme activity. However, response mechanism of microorganisms in three root niches of metal tolerant plants to Pb is not completely understood. Therefore, in this study, a Pb poisoning model of T. repens was established with a Pb gradient (0, 1000 mg/kg, 2000 mg/kg, and 3000 mg/kg), and was used to evaluate growth and physiological responses, as well as enrichment and transport coefficients in T. repens, and explore the characteristics of rhizosphere soil and microbial composition of three root niches. We found that Pb stress caused oxidative injury, and inhibited photosynthesis in T. repens. 16S rDNA sequencing analysis showed that the richness of microbial communities in bulk soil was higher than that in rhizosphere soil both under Pb stress and Pb nonstress conditions. Moreover, Proteobacteria was dominant phylum in bulk and rhizosphere soils, and Proteobacteria and Cyanobacteria were dominant phylum in endophytic bacteria. For the first time, we systematically investigated the response of Pb from bulk soil to plant leaves. The results showed that microbial interaction existed between bulk and rhizosphere soil. Rhizosphere bacterium Haliangium was positively correlated with urease activity and soil nutrients. Endophytic bacterium Pseudomonas was positively correlated with plant biomass and played an important role in Pb tolerance of T. repens. In addition, endophytic bacteria formed complex correlation networks with growth and physiological indexes of both root and shoot, moreover the network in root was more complicated. Taken together, Pb stress dose-dependently inhibited the growth of plants. This study provided a theoretical basis for the further development of microbial cooperation with plant remediation of heavy metal contaminated soil.
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•The richness of microbial communities in bulk soil was higher than that in rhizosphere soil both under Pb stress and Pb non stress conditions.•Proteobacteria and Cyanobacteria were dominant phylum in endophytic bacteria at all Pb levels.•Rhizosphere bacteria Haliangium was positively correlated with urease and soil nutrients under Pb pollution.•Endophytic bacterium Pseudomonas was positively correlated with plant biomass.•Correlation network formed between endophytic bacteria and growth physiological indexes in root was complex than that in shoot.
How to fabricate flexible thermoelectric (TE) films with excellent electrical transport properties remains a major bottleneck for high-performance flexible TE cooling devices. Herein, a simple and ...efficient method is developed to fabricate high-performance flexible TE cooling device by selecting Bi0.5Sb1.5Te3 as TE component and epoxy resin as adhesive. It is discovered that the (000l) preferential orientation of Bi0.5Sb1.5Te3 grains could be successfully realized in Bi0.5Sb1.5Te3/epoxy thick films by hot-pressing curing process, thus causing the remarkable enhancement in the electrical transport properties. The highest power factor of the (000l)-oriented Bi0.5Sb1.5Te3/epoxy thick films reached 0.84 mW m−1 K−2 at 300 K, increased by 250% and 223% as compared with that of our non-pressure thick film and the highest value by other groups, respectively. A prototype flexible TE cooling device had been fabricated with the Bi0.5Sb1.5Te3/epoxy thick films. The stable temperature difference of the prototype device reached 6.2 K under a working current of 0.06 A, increased by about 24% as compared with the highest temperature difference of 5 K reported by other groups. Our work demonstrates that the hot-pressing curing process provides an effective approach to fabricate high-performance flexible TE cooling devices with Bi0.5Sb1.5Te3/epoxy thick films through the (000l) preferential orientation.
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•High-performance Bi0.5Sb1.5Te3/epoxy films are fabricated by hot-pressing curing.•(000l) orientation, defects reduction and densification are simultaneously realized.•All the electrical properties parameters (μ, σ, α) are simultaneously increased.•High-performance TE cooling devices are fabricated with the (000 l)-oriented films.
Bi
2
Te
3
-Based alloys are the only thermoelectric material for commercial applications while their low performance is extremely difficult to improve. Herein, superparamagnetic Fe
3
O
4
...nanoparticles (Fe
3
O
4
-NPs) are incorporated into a commercial p-type Bi
0.5
Sb
1.5
Te
3
matrix to improve the thermoelectric and cooling performance near room temperature. It is discovered that the Seebeck coefficient of the Fe
3
O
4
/Bi
0.5
Sb
1.5
Te
3
nanocomposites remarkably increased while the thermal conductivity significantly decreased because of the carrier multiple scattering and the enhanced phonon scattering induced by the Fe
3
O
4
-NPs, respectively. The maximum
ZT
reaches 1.5 at 340 K for the nanocomposite with 0.15 wt% of Fe
3
O
4
-NPs, being 32% higher than that of the matrix. At near room temperature, the huge cooling temperature difference reaches 5.4 K for a single-leg device made with the nanocomposite, increased by about 3 times as compared with the 1.8 K of the device made with the Bi
0.5
Sb
1.5
Te
3
matrix. This work reveals that introducing superparamagnetic nanoparticles is a universal approach to simultaneously enhance the thermoelectric and cooling performance of p-type BiSbTe-based alloys.
Superparamagnetic Fe
3
O
4
nanoparticles remarkably enhance the room-temperature thermoelectric and cooling performance of BiSbTe alloys.
The ability to control chemical and physical structuring at the nanometre scale is important for developing high-performance thermoelectric materials. Progress in this area has been achieved mainly ...by enhancing phonon scattering and consequently decreasing the thermal conductivity of the lattice through the design of either interface structures at nanometre or mesoscopic length scales or multiscale hierarchical architectures. A nanostructuring approach that enables electron transport as well as phonon transport to be manipulated could potentially lead to further enhancements in thermoelectric performance. Here we show that by embedding nanoparticles of a soft magnetic material in a thermoelectric matrix we achieve dual control of phonon- and electron-transport properties. The properties of the nanoparticles-in particular, their superparamagnetic behaviour (in which the nanoparticles can be magnetized similarly to a paramagnet under an external magnetic field)-lead to three kinds of thermoelectromagnetic effect: charge transfer from the magnetic inclusions to the matrix; multiple scattering of electrons by superparamagnetic fluctuations; and enhanced phonon scattering as a result of both the magnetic fluctuations and the nanostructures themselves. We show that together these effects can effectively manipulate electron and phonon transport at nanometre and mesoscopic length scales and thereby improve the thermoelectric performance of the resulting nanocomposites.
The practical application of Bi
2
Te
3
thermoelectric (TE) materials is constrained by their high orientation structure and limited service temperature range. In this work, non-textured Bi
0.5
Sb
1.5
...Te
3
(BST) TE materials were fabricated via a facile, low-cost, and commercially applicable method: cold-pressing combined with annealing. Cu impurity was added into a BST matrix to regulate the carrier concentration and expand the service temperature range. The effects of Cu impurity on the phase composition, microstructure, and TE properties of
x
Cu/BST (
x
= 0.000%, 0.025%, 0.050%, 0.075%, 0.100%, 0.200% in weight) composite TE materials were investigated. An excellent ZT
ave
value of 0.85 was achieved across the entire temperature range due to synergistic optimization of the electronic and thermal transport properties, which was larger than that of the BST matrix of 0.52 and comparable to that of BST materials prepared by costly and low-yield methods.
The improvement of thermoelectric properties of
p
-type iron-based skutterudites is limited due to the present of more iron-rich impurity phases induced by the inherent structural instability of ...Fe-containing skutterudites. How to reduce the content of the impurity phase in
p
-type Fe-based skutterudites is a key to obtain high
ZT
value. Ce
1.25
Fe
4
Sb
12
materials with different sintering temperatures (723 K, 773 K, 798 K, 823 K and 848 K) have been prepared by a traditional melting-quenching-annealing process coupled with spark plasma sintering (SPS) technique. The results of XRD and EPMA analysis indicate that all the SPSed samples consist of the main skutterudite phase and impurity phases of FeSb
2
, Sb, CeSb
2
and oxides of Ce and Sb. Compared with other SPSed samples, the SPS-773 K sample has the best thermoelectric properties due to the relatively fewer impurity phases, a large number of micro-nanoscale particles at the grain boundary and more voids. The SPS-773 K sample shows the largest
ZT
value over the entire test temperature range due to the higher power factor and lower lattice thermal conductivity. The maximum
ZT
value reaches 0.81 at 800 K. This indicates that thermoelectric properties of Ce-filled Fe
4
Sb
12
skutterudite materials can be effectively improved by reducing impurity phases induced by the optimization of the sintering temperature.
This review aimed to summarize the use of machine learning for predicting the potential benefits of stroke rehabilitation treatments, to evaluate the risk of bias of predictive models, and to provide ...recommendations for future models.
This systematic review was conducted in accordance with the PRISMA statement and the CHARMS checklist. The PubMed, Embase, Cochrane Library, Scopus, and CNKI databases were searched up to April 08, 2023. The PROBAST tool was used to assess the risk of bias of the included models.
Ten studies within 32 models met our inclusion criteria. The optimal AUC value of the included models ranged from 0.63 to 0.91, and the optimal R2 value ranged from 0.64 to 0.91. All of the included models were rated as having a high or unclear risk of bias, and most of them were downgraded due to inappropriate data sources or analysis processes.
There remains much room for improvement in future modeling studies, such as high-quality data sources and model analysis. Reliable predictive models should be developed to improve the efficacy of rehabilitation treatment by clinicians.
In this paper, we proposed a decentralized cooperative lane-changing decision-making framework for connected autonomous vehicles, which is composed of three modules, i.e., state prediction, candidate ...decision generation, and coordination. In other words, each connected autonomous vehicle makes cooperative lane-changing decision independently. In the state prediction module, we employed existing cooperative car-following models to predict the vehicles' future state. In the candidate decision generation module, we proposed incentive based model to generate a candidate decision. In the candidate decision coordination module, we proposed an algorithm to avoid candidate lane-changing decision that may lead to a vehicle collision or traffic deterioration to be final decision. Moreover, the effects of decentralized cooperative lane-changing decision-making framework on traffic stability, efficiency, homogeneity, and safety are investigated in a numerical simulation experiment. Some stability, efficiency, homogeneity, and safety indicators are evaluated and show the high potential of our proposed framework in traffic dynamics.
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