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Background: Previous studies have indicated that despite adhering to current patient selection guidelines, there remains a 30% to 40% subset of patients who do not experience improvement in heart failure (HF) after receiving cardiac resynchronization therapy (CRT). We aim to utilize echocardiographic myocardial work parameters to serve as predictors of responsiveness to CRT in patients with heart failure and reduced ejection fraction (HFrEF). Methods: We prospectively recruited patients who underwent CRT at Sun Yat-sen Memorial Hospital from June 2019 to September 2022. Comprehensive preoperative information, clinical laboratory data, conventional echocardiographic parameters and myocardial work were collected for all participants, as well as follow-up data 6 months after CRT. Results: Twenty-five patients (67.6%) showed response to CRT treatment, while twelve patients (32.4%) had no response. Compared with the non-response group, the response group had larger region constructive work [RCW: the sum of constructive work (CW) in the 9 segments of the basal, mid, and apical segments of the anterior, lateral, and posterior walls], region wasted work [RWW: the sum of wasted work (WW) in the 6 segments of the basal and mid segments of the anterior septum, posterior septum and anterior walls], and the combination of RCW and RWW (RCW + RWW) in baseline (RCW: 9,695.68±2,955.40 vs. 5,219.50±2,207.68 mmHg%, P<0.001; RWW: 3,612.08±1,723.80 vs. 1,674.33±995.23 mmHg%, P=0.001; RCW + RWW: 13,307.76±3,857.71 vs. 6,893.83±2,592.83 mmHg%, P<0.001). Furthermore, global constructive work (GCW), global wasted work (GWW), GCW + GWW, RCW, RWW, and RCW + RWW had areas under the receiver operating characteristic curve (AUCs) of 0.870, 0.770, 0.860, 0.890, 0.870, and 0.910, respectively, for predicting CRT responsiveness. Conclusions: The global and regional myocardial work parameters are associated with CRT response in CRT candidates. Particularly regional myocardial work parameters appear to be promising parameters to improve selection for CRT of patients with HFrEF.
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Sodium-ion batteries (SIBs) is a promising technology for next-generation energy storage. However, their performance is limited at low temperatures due to the inferior bulk and interfacial resistance of current electrolytes. Here we present a systematic study to evaluate carboxylate ester-based electrolytes for SIB applications, due to their favorable properties (i.e., low melting point, low viscosity and high dielectric constant). The effects of salt, concentration and solvent molecular structure were systematically examined and compared with those of carbonate-based electrolytes. By combining electrochemical tests with spectroscopic characterization, the performance of selective carboxylate ester-based electrolytes in hard carbon/Na and Na3V2(PO4)3/Na half-cells was evaluated. We found carboxylates enable high electrolyte conductivities, especially at low temperatures. However, carboxylates alone are inadequate to form a stable interphase due to their high reactivity, which can be addressed by choosing a suitable anion and facilitating anion-rich Na+ solvation by increasing salt concentration. Fundamental knowledge on the chemistry-property-performance correlation of this new family of electrolytes was obtained, and their benefits and pitfalls were thoroughly discussed. These discoveries and knowledge will shed light on the potential of carboxylate ester-based electrolytes and provide the foundation for further electrolyte engineering.
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Aims: To investigate the correlation and predictive value of left atrial diameter and blood uric acid levels with the occurrence of left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate CHA2DS2-VASc scores. Methods and results: A total of 849 inpatients diagnosed with atrial fibrillation who had low to moderate CHA2DS2-VASc scores and complete transesophageal echocardiography were included in this study. Among them, 66 patients had left atrial thrombus or dense spontaneous echo contrast. When different models were used to correct other known risk factors, acid levels and abnormal left atrial diameter were identified as additional risk factors for left atrial thrombus or dense spontaneous echo contrast. The incidence of left atrial thrombus or dense spontaneous echo contrast was higher in patients with abnormal serum uric acid levels than in the control group (12.4% vs. 5.6%, p < 0.05), and this difference persisted after correcting the baseline data with propensity score matching (10.6% vs. 4.1%, p < 0.05). Abnormal left atrial diameter was another risk factor suggested by regression analysis, with an increased incidence of left atrial thrombus or dense spontaneous echo contrast in the abnormal left atrial diameter group compared to the control group, both before (18.0% vs. 3.5%, p < 0.05) and after (15.5% vs. 5.2%, p < 0.05) propensity score matching. The best predictive value was obtained by adding both abnormal serum uric acid levels and abnormal left atrial diameter. Conclusion: Left atrial enlargement and high uric acid levels increase the risk of left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate CHA2DS2-VASc scores.
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Castor (Ricinus communis L.) is a dicotyledonous oilseed crop that can have either spineless or spiny capsules. Spines are protuberant structures that differ from thorns or prickles. The developmental regulatory mechanisms governing spine formation in castor or other plants have remained largely unknown. Herein, using map-based cloning in 2 independent F2 populations, F2-LYY5/DL01 and F2-LYY9/DL01, we identified the RcMYB106 (myb domain protein 106) transcription factor as a key regulator of capsule spine development in castor. Haplotype analyses demonstrated that either a 4,353-bp deletion in the promoter or a single nucleotide polymorphism leading to a premature stop codon in the RcMYB106 gene could cause the spineless capsule phenotype in castor. Results of our experiments indicated that RcMYB106 might target the downstream gene RcWIN1 (WAX INDUCER1), which encodes an ethylene response factor known to be involved in trichome formation in Arabidopsis (Arabidopsis thaliana) to control capsule spine development in castor. This hypothesis, however, remains to be further tested. Nevertheless, our study reveals a potential molecular regulatory mechanism underlying the spine capsule trait in a nonmodel plant species.
Assuntos
Óleo de Rícino , Ricinus communis , Óleo de Rícino/metabolismo , Ricinus/genética , Ricinus/metabolismo , Regulação da Expressão Gênica de Plantas , Ricinus communis/genética , Ricinus communis/metabolismoRESUMO
Xanthoceras sorbifolium (yellowhorn) is originated in China and is a unique tree in northern China. Yellowhorn is very popular because of the gradual color change of its flower at different flower developmental stages. During flowering development, the color at the base of yellowhorn flower petals gradually changes from yellow to purple. The mechanism of this miraculous phenomenon is still unclear. Here we show that anthocyanin accumulation during flowering development is the main reason for this color change. RT-PCR results show that the expression level of a variety of anthocyanin biosynthesis genes changes in different flower developmental stages. Realtime results show that the expression changes of these anthocyanin biosynthesis genes are positively regulated by a cluster of R2R3-MYB transcription factor genes, XsMYB113s. Furthermore, the DNA methylation analysis showed that CHH methylation status on the transposon element near the XsMYB113-1 influence its transcript level during flowering development. Our results suggest that dynamic epigenetic regulation of the XsMYB113-1 leads to the accumulation of anthocyanins during yellowhorn flower color change. These findings reemphasize the role of epigenetic regulation in flower development and provide a foundation for further studies of epigenetic regulation in long-lived woody perennials.
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To enable the mass adoption of electric vehicles, the charging performance of Li-ion batteries needs to be significantly enhanced. The development of electrolytes with enhanced transport properties and faster interfacial reaction is one critical approach to realize fast charging within 10 min. Most current electrolyte studies are focusing on ester-based electrolytes. In this work, an ether-based electrolyte is reported, which shows remarkably better charging performance than commercial carbonate electrolytes and other reported ester-based electrolytes in both half and full cells. Electrochemical and spectroscopic characterization shows that the superior charging performance of the reported electrolyte is due to significantly reduced SEI resistance and charge transfer resistance. Cycling tests show remarkable stability in Li||graphite (gr) half cells, suggesting the potential of the electrolytes to enhance battery charging performance. LiFePO4 (LFP)||gr full cells were further tested, and it is found that the resistance of cells builds up during cycling due to gelation of the electrolyte, which limits the cycling performance of full cells. Potential strategies to address this limitation are discussed.
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Iron (Fe) metal batteries, such as Fe-ion batteries and all Fe flow batteries, are promising energy storage technologies for grid applications due to the extremely low cost of Fe and Fe salts. Nonetheless, the cycle life of Fe metal batteries is poor primarily due to the low Coulombic efficiency of the Fe deposition/stripping reaction. Current aqueous electrolytes based on Fe chloride or sulfate salts can only operate at a Coulombic efficiency of <91% under mild operation conditions (<5 mA/cm2), largely due to undesired hydrogen evolution reaction (HER). This work reports a series of novel Fe electrolytes, Fe electrolytes reinforced with Mg ions (FERMI) and Ca ions (FERCI), which have remarkably better Coulombic efficiency, higher conductivity, and faster deposition/stripping kinetics. By the addition of 4.5 M MgCl2 or CaCl2 into the baseline FeCl2 electrolyte, the Fe deposition/stripping efficiency can be significantly improved to 99.1%, which greatly boosts the cycling performance of Fe metal batteries in both half-cells and full-cells. Mechanistic studies reveal that the remarkably improved efficiency is due to a reduced amount of "dead Fe" as well as suppressed HER. By the combination of experiments and molecular dynamics and density functional theory computation, the electrolyte structure is revealed, and the mechanism for enhanced water reduction resistance is elucidated. These novel electrolytes not only enable a highly reversible Fe metal anode for low-cost energy storage technologies but also have the potential to address the HER side reaction problem in other electrochemical technologies based on aqueous electrolytes, such as CO2 reduction, NH3 synthesis, etc.
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As an advanced nondestructive testing (NDT) technology, industrial computed tomography (ICT) has been widely applied to diversified areas. In modern industry, ICT is especially useful for analyzing inner defects of complex and close work pieces. The common defects of work pieces include gas cavities, slag inclusions, cracks and shrinking cavities. Only cracks are often caused by fatigue usage. Precisely extracting a crack is important to estimate the remaining secure service time of the work piece. This paper presents a crack surface extraction method of ICT volume data based on finite plane integral transform (FPIT) and planelet. FPIT and planelet, as new methods of multiscale geometric analysis (MGA), have distinct discrimination for different plane singularities. Within the paper, firstly the definitions of FPIT and planelet are introduced. Secondly, after analyzing the components and relationship of planelet at monoscale, a fast performance of planelet transform is designed. Thirdly, the steps of the proposed crack surface extraction method are described. In numeric experiment, compared with the method of 3D facet model, C-V model and 3D wavelet respectively, the proposed method can extract the crack surface full and continuously, which,is robust to noise.
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In cone beam industrial computed tomography (ICT), it is often required to inspect the large object using flat detector. If traditional helical scanning is used, the field of view (FOV) is limited due to the size of flat detector. As an alternative, a dual helical cone-beam scanning is proposed in this paper. Before each helical scanning, x-ray source and flat detector are horizontally translated a given distance, and part of the object is covered by x-ray at each view angle. Then the object function is reconstructed by use of the improved helical FDK algorithm, which does not rebin projection data. Simulations validate that the images, which are reconstructed by proposed scanning mode and improved algorithm with small flat detector, are similar to those from the conventional helical scanning and FDK algorithm with large flat detector. The improved FDK algorithm is not sensitive to translation step. Furthermore, the proposed scanning mode can extend the radius of FOV up to at least 1.7 times.