Strengthened proximity effect at grain boundaries to enhance inter-grain supercurrent in Ba1-xKxFe2As2 superconductors

Iron-based superconductors have great potential for high-power applications due to their prominent high-field properties. One of the central issues in enhancing the critical current density of iron-based superconducting wires is to reveal the roles and limitations of grain boundaries in supercurrent transport. Here, we finely tuned the electronic properties of grain boundaries by doping Ba1-xKxFe2As2 superconductors in a wide range (0.25<x<0.598). It is found that the intra-grain Jcintra peaks near x~0.287, while the inter-grain Jcinter has a maximum at about x~0.458. Remarkably, the grain boundary transparency parameter defined as Jcinter/Jcintra rises monotonically with doping. Through detailed microscopic analysis, we suggest that the FeAs segregation phase commonly existing at grain boundaries and the adjacent grains constitute superconductor-normal metal-superconductor (SNS) Josephson junctions which play a key role in transporting supercurrent. A sandwich model based on the proximity effect and the SNS junction is proposed to well interpret our data. It is found that overdoping in superconducting grains largely strengthens the proximity effect and consequently enhances the intergrain supercurrent. Our results will shed new insights and inspirations for improving the application parameters of iron-based superconductors by grain boundary engineering.Comment: 22 pages, 6 figure

Overexpression of a Transcription Factor Increases Lipid Content in a Woody Perennial Jatropha curcas

Vegetable oil is an important renewable resource for dietary consumption for human and livestock, and more recently for biodiesel production. Lipid traits in crops are controlled by multiple quantitative trait loci (QTLs) and each of them has a small effect on lipid traits. So far, there is limited success to increase lipid yield and improve lipid quality in plants. Here, we reported the identification of a homolog of APETALA2 (AP2) transcription factor WRINKLED1 (JcWRI1) from an oleaginous plant Jatropha curcas and characterized its function in Jatropha and Arabidopsis thaliana. Using physical mapping data, we located JcWRI1 in a QTL region specifying high oleate and lipid content in Jatropha. Overexpression of JcWRI1 in Jatropha elevated seed lipid content and increased seed mass. Lipid profile in seeds of over-expression plants showed higher oleate content which will be beneficial to improve biodiesel quality. Overexpression of JcWRI1 activated lipid-related gene expression and JcWRI1 was shown to directly bind to the AW-box of promoters of some of these genes. In conclusion, we were able to increase seed lipid content and improve seed lipid quality in Jatropha by manipulating one key transcription factor JcWRI1

Transcriptome-Wide Identification of miRNA Targets under Nitrogen Deficiency in Populus tomentosa Using Degradome Sequencing

miRNAs are endogenous non-coding small RNAs with important regulatory roles in stress responses. Nitrogen (N) is an indispensable macronutrient required for plant growth and development. Previous studies have identified a variety of known and novel miRNAs responsive to low N stress in plants, including Populus. However, miRNAs involved in the cleavage of target genes and the corresponding regulatory networks in response to N stress in Populus remain largely unknown. Consequently, degradome sequencing was employed for global detection and validation of N-responsive miRNAs and their targets. A total of 60 unique miRNAs (39 conserved, 13 non-conserved, and eight novel) were experimentally identified to target 64 mRNA transcripts and 21 precursors. Among them, we further verified the cleavage of 11 N-responsive miRNAs identified previously and provided empirical evidence for the cleavage mode of these miRNAs on their target mRNAs. Furthermore, five miRNA stars (miRNA*s) were shown to have cleavage function. The specificity and diversity of cleavage sites on the targets and miRNA precursors in P. tomentosa were further detected. Identification and annotation of miRNA-mediated cleavage of target genes in Populus can increase our understanding of miRNA-mediated molecular mechanisms of woody plants adapted to low N environments

The Intersection of Non-Coding RNAs Contributes to Forest Trees’ Response to Abiotic Stress

Non-coding RNAs (ncRNAs) play essential roles in plants by modulating the expression of genes at the transcriptional or post-transcriptional level. In recent years, ncRNAs have been recognized as crucial regulators for growth and development in forest trees, and ncRNAs that respond to various abiotic stresses are now under intense study. In this review, we summarized recent advances in the understanding of abiotic stress-responsive microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) in forest trees. Furthermore, we analyzed the intersection of miRNAs, and epigenetic modified ncRNAs of forest trees in response to abiotic stress. In particular, the abiotic stress-related lncRNA/circRNA–miRNA–mRNA regulatory network of forest trees was explored

The Effects of Wenxin Keli on P-Wave Dispersion and Maintenance of Sinus Rhythm in Patients with Paroxysmal Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials

Objective. To evaluate the beneficial and adverse effects of Wenxin Keli (WXKL), alone or combined with Western medicine, on P-wave dispersion (Pd) and maintenance of sinus rhythm for the treatment of paroxysmal atrial fibrillation (PAF). Methods. Seven major electronic databases were searched to retrieve randomized controlled trials (RCTs) designed to evaluate the clinical effectiveness of WXKL, alone or combined with Western medicine, for PAF, with Pd or maintenance rate of sinus rhythm as the main outcome measure. The methodological quality of the included studies was assessed using criteria from the Cochrane Handbook for Systematic Review of Interventions, version 5.1.0, and analysed using RevMan 5.1.0 software. Results. Fourteen RCTs of WXKL were included. The methodological quality of the trials was generally evaluated as low. The results of meta-analysis showed that WXKL, alone or combined with Western medicine, was more effective in Pd and the maintenance of sinus rhythm, compared with no medicine or Western medicine alone, in patients with PAF or PAF complicated by other diseases. Seven of the trials reported adverse events, indicating that the safety of WXKL is still uncertain. Conclusions. WXKL, alone or combined with Western medicine, appears to be more effective in improving Pd as well as maintenance of sinus rhythm in patients with PAF and its complications

The Effects of Wenxin Keli on P-Wave Dispersion and Maintenance of Sinus Rhythm in Patients with Paroxysmal Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials

Objective. To evaluate the beneficial and adverse effects of Wenxin Keli (WXKL), alone or combined with Western medicine, on P-wave dispersion (Pd) and maintenance of sinus rhythm for the treatment of paroxysmal atrial fibrillation (PAF). Methods. Seven major electronic databases were searched to retrieve randomized controlled trials (RCTs) designed to evaluate the clinical effectiveness of WXKL, alone or combined with Western medicine, for PAF, with Pd or maintenance rate of sinus rhythm as the main outcome measure. The methodological quality of the included studies was assessed using criteria from the Cochrane Handbook for Systematic Review of Interventions, version 5.1.0, and analysed using RevMan 5.1.0 software. Results. Fourteen RCTs of WXKL were included. The methodological quality of the trials was generally evaluated as low. The results of meta-analysis showed that WXKL, alone or combined with Western medicine, was more effective in Pd and the maintenance of sinus rhythm, compared with no medicine or Western medicine alone, in patients with PAF or PAF complicated by other diseases. Seven of the trials reported adverse events, indicating that the safety of WXKL is still uncertain. Conclusions. WXKL, alone or combined with Western medicine, appears to be more effective in improving Pd as well as maintenance of sinus rhythm in patients with PAF and its complications

Author Correction: Transcriptome and functional analysis reveals hybrid vigor for oil biosynthesis in oil palm (vol 7, 439, 2017)

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Author Correction: Transcriptome and functional analysis reveals hybrid vigor for oil biosynthesis in oil palm

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