追踪锂金属负极的压力与形貌变化

采用高载量氧化物正极(>4mAh·cm^(-2))和超薄锂金属负极(<50μm)可以构建高比能锂金属二次电池。然而,该类电池的循环寿命和安全性受到锂金属不可控沉积的严重制约。高比表面积的锂枝晶和锂“苔藓”导致了较低的库伦效率,前者有一定可能穿刺隔膜,造成电池内短路,是亟待解决的安全隐患。因此,提升锂金属二次电池的循环寿命和安全性的关键在于实现锂金属的致密沉积。文献中已有多种化学方法可达到这样的效果。由于锂金属较软,受力容易发生形变,对锂金属电池施加机械压力是另一种促进锂金属致密沉积和提高循环性能的方法。然而,机械压力、锂金属形态的演变、和循环性能之间的关系尚未被完全理解。本文报道了一种基于薄膜压力传感器的电池压力测量装置,可以实时跟踪纽扣型锂金属电池内部的压力变化,并且探究外加机械压力对电池循环性能的影响。研究发现,在纽扣电池和高比能的软包电池(5 Ah,>380 Wh·kg^(-1))中,一定程度的压力可以促进锂金属的致密沉积,改善电池循环性能;而过大的压力则会导致锂金属向负极内部沉积,造成负极变形和电池性能恶化。我们的研究结果凸显了压力控制对于锂金属沉积行为的重要作用,为进一步改善高比能锂金属电池的循环性能提供了指导。

Liquid Metal-Based Self-Healable and Elastic Conductive Fiber in Complex Operating Conditions

Flexible conductive fibers are essential for wearable electronics and smart electronic textiles.However,in complex operating conditions,conductive fibers will inevitably fracture or damage.Herein,we have developed an elastic conductive self-healable fiber(C-SHF),of which the electrical and mechanical properties can efficiently heal in a wide operating range,including room temperature,underwater,and low temperature.This advantage can be owed to the combination of reversible covalent imine bond and disulfide bond,as well as the instantaneous self-healing ability of liquid metal.The C-SHF,with stretchability,conductivity stability,and universal self-healing properties,can be used as an electrical signal transmission line at high strain and under different operating conditions.Besides,C-SHF was assembled into a double-layer capacitor structure to construct a self-healable sensor,which can effectively respond to pressure as a wearable motion detector.

Nutritional composition and antioxidant activity of twenty mung bean cultivars in China

Interest in mung bean(Vigna radiata L.) as a functional food is growing; however, studies on the nutritional composition of major mung bean cultivars planted in China are limited.Twenty Chinese mung bean cultivars were collected and their nutritional compositions including starch, fat, protein, and phytochemicals were analyzed. The cultivars were found to have a high amount of resistant starch, accounting for 16.1%–22.3% of total starch, and balanced amino acid constitutions. Palmitic acid and linoleic acid were the two dominant fatty acids, accounting for respectively 32.4% and 36.1% of all of the assayed fatty acids. Four bound phenolic acids(syringic, caffeic, p-coumaric, and ferulic acids) and two free phenolic acids(caffeic and ferulic acids) were identified by HPLC. The antioxidant activity of 70%ethanol extracts from the 20 mung bean cultivars was evaluated. Their DPPH and ABTS+free-radical-scavenging capacity ranged from 28.13 ± 2.24 to 35.68 ± 0.71 μmol g-1and from3.82 ± 0.25 to 13.44 ± 1.76 μmol g-1, respectively. Significant positive correlations of ABTS+free-radical-scavenging capacity with total phenolic acids and total flavonoid contents were observed. These results suggest that Chinese mung bean cultivars are rich in balanced nutrients and that their phytochemicals should be considered as potential sources of natural antioxidants.

Comparisons of phaseolin type and α-amylase inhibitor in common bean(Phaseolus vulgaris L.)in China

The objective of this study was to characterize the phaseolin type and a-amylase(αAI) level in common bean(Phaseolus vidgaris L.) accessions deposited in the Chinese National Genebank.The 40 accessions sampled were common varieties originating in Asia,North America,South America,Europe,and Africa.No Inca(I-) phaseolin was observed in the accessions.Only four accessions contained Tendergreen(T-) phaseolin and the remaining36 contained Sanilac(S-) phaseolin.aAI proteins extracted from nine accessions showed higher a-amylase inhibitory activity than the control(Phase 2,IC_(50) = 0.65 μg).These common bean accessions have potential use as nutraceutical ingredients.

Wood of trees:Cellular structure,molecular formation,and genetic engineering

Wood is an invaluable asset to human society due to its renewable nature,making it suitable for both sustainable energy production and material manufacturing.Additionally,wood derived from forest trees plays a crucial role in sequestering a significant portion of the carbon dioxide fixed during photosynthesis by terrestrial plants.Nevertheless,with the expansion of the global population and ongoing industrialization,forest coverage has been substantially decreased,resulting in significant challenges for wood production and supply.Wood production practices have changed away from natural forests toward plantation forests.Thus,understanding the underlying genetic mechanisms of wood formation is the foundation for developing high-quality,fast-growing plantation trees.Breeding ideal forest trees for wood production using genetic technologies has attracted the interest of many.Tremendous studies have been carried out in recent years on the molecular,genetic,and cell-biological mechanisms of wood formation,and considerable progress and findings have been achieved.These studies and findings indicate enormous possibilities and prospects for tree improvement.This review will outline and assess the cellular and molecular mechanisms of wood formation,as well as studies on genetically improving forest trees,and address future development prospects.

木栓层在水和溶质运输中的生理功能研究进展

植物的根可选择性地从土壤中吸收水分和养分,并运输至地上部供植物生长发育所需,这些功能与其解剖结构密切相关。根部吸收的水和溶质在根中的径向运输主要包括质外体、共质体和跨细胞3条途径。内皮层是包围中央维管系统的最内细胞层。长期以来,内皮层分化形成的凯氏带被认为在阻断水和溶质通过质外体途径运输中发挥决定性作用。然而,近年来,研究发现内皮层分化形成的木栓层对水和溶质的径向运输作用不亚于凯氏带,甚至称木栓化是内皮层细胞的第二次生命。该文综述了近年来木栓层在水和溶质运输中生理功能的最新进展,阐述了木栓层与作物抗旱、抗盐、抗重金属和抗养分胁迫之间的关系,以期为内皮层可塑性调控植物生理功能的理论和实践提供参考。

Recent advances on N-acetylneuraminic acid:Physiological roles,applications,and biosynthesis

N-Acetylneuraminic acid(Neu5Ac),the most common type of Sia,generally acts as the terminal sugar in cell surface glycans,glycoconjugates,oligosaccharides,lipo-oligosaccharides,and polysaccharides,thus exerting numerous physiological functions.The extensive applications of Neu5Ac in the food,cosmetic,and pharmaceutical industries make large-scale production of this chemical desirable.Biosynthesis which is associated with important application potential and environmental friendliness has become an indispensable approach for large-scale synthesis of Neu5Ac.In this review,the physiological roles of Neu5Ac was first summarized in detail.Second,the safety evaluation,regulatory status,and applications of Neu5Ac were discussed.Third,enzyme-catalyzed preparation,whole-cell biocatalysis,and microbial de novo synthesis of Neu5Ac were comprehensively reviewed.In addition,we discussed the main challenges of Neu5Ac de novo biosynthesis,such as screening and engineering of key enzymes,identifying exporters of intermediates and Neu5Ac,and balancing cell growth and biosynthesis.The corresponding strategies and systematic strategies were proposed to overcome these challenges and facilitate Neu5Ac industrial-scale production.

Resource utilization of high concentration SO_(2) for sulfur production over La-Ce-O_(x)@ZrO_(2) composite oxide catalyst

Sulfur dioxide is one of the main causes of air pollution such as acid rain and photochemical smog,and its pollution control and resource utilization become an important research direction of air pollution control,The active component La-Ce-O_(x) is loaded on SiO_(2),γ-Al_(2)O_(3),TiO_(2) and ZrO_(2),and the La-Ce-Ox@ZrO_(2)exhibits the best catalytic activity.By adjusting the loading amount of La-Ce-O_(x),La-Ce-Ox@ZrO_(2) with different mass fractions was prepared.The results show that the activity of 15%La-Ce-Ox@ZrO_(2)catalyst is the best.The SO_(2)conversion is 100%,and the S yield and S selectivity are more than 96% at 350℃.According to the analysis results of H_(2)-TPR,CO_(2)-TPD and NH_(3)-TPD,ZrO_(2) as a support not only reduces the acidity of the catalyst,but also improves the weak alkaline sites of the catalyst,which is conducive to the adsorption and activation of SO2molecules at low temperature.The incorporation of La and Ce increases the oxygen concentration adsorbed on the catalyst.The strong interaction between the support ZrO_(2) and the active component La-Ce-Oxis conducive to the electron transfer between the active component and the support,and improves the activity of the catalyst.For the 15%La-Ce-O_(x)@ZrO_(2),the main reaction intermediates are weakly adsorbed SO_(2)(SO_(3)^(2-)),bicoordinated CO_(3)^(2-),monodentate carbonate and CO in the gas phase.Therefore,the catalytic reaction follows both L-H and E-R mechanisms.

Scene text detection and recognition： recent advances and future trends

Text, as one of the most influential inventions of humanity, has played an important role in human life, so far from ancient times. The rich and precise information embod- ied in text is very useful in a wide range of vision-based ap- plications, therefore text detection and recognition in natu- ral scenes have become important and active research topics in computer vision and document analysis. Especially in re- cent years, the community has seen a surge of research efforts and substantial progresses in these fields, though a variety of challenges （e.g. noise, blur, distortion, occlusion and varia- tion） still remain. The purposes of this survey are three-fold： 1） introduce up-to-date works, 2） identify state-of-the-art al- gorithms, and 3） predict potential research directions in the future. Moreover, this paper provides comprehensive links to publicly available resources, including benchmark datasets, source codes, and online demos. In summary, this literature review can serve as a good reference for researchers in the areas of scene text detection and recognition.

A 10-miRNA risk score-based prediction model for pathological complete response to neoadjuvant chemotherapy in hormone receptor-positive breast cancer

Patients with hormone receptor(HR)-positive tumors breast cancer usually experience a relatively low pathological complete response(p CR)to neoadjuvant chemotherapy(NAC).Here,we derived a 10-micro RNA risk score(10-mi RNA RS)-based model with better performance in the prediction of p CR and validated its relation with the disease-free survival(DFS)in 755 HRpositive breast cancer patients(273,265,and 217 in the training,internal,and external validation sets,respectively).This model,presented as a nomogram,included four parameters:the 10-mi RNA RS found in our previous study,progesterone receptor(PR),human epidermal growth factor receptor 2(HER2)status,and volume transfer constant(K).Favorable calibration and discrimination of 10-mi RNA RS-based model with areas under the curve(AUC)of 0.865,0.811,and 0.804 were shown in the training,internal,and external validation sets,respectively.Patients who have higher nomogram score(>92.2)with NAC treatment would have longer DFS(hazard ratio=0.57;95%CI:0.39–0.83;P=0.004).In summary,our data showed the 10-mi RNA RS-based model could precisely identify more patients who can attain p CR to NAC,which may help clinicians formulate the personalized initial treatment strategy and consequently achieves better clinical prognosis for patients with HRpositive breast cancer.

NEDD8-conjugating enzyme E2 UBE2F confers radiation resistance by protecting lung cancer cells from apoptosis

Lung cancer,which is exacerbated by environmental pollution and tobacco use,has become the most common cause of cancer-related deaths worldwide,with a five-year overall survival rate of only 19%(Siegel et al.,2020;Yang et al.,2020;Yu and Li,2020).Nearly 85%of lung cancers are non-small cell lung cancers,of which lung adenocarcinoma is the most common subtype accounting for 50%of non-small cell lung cancer cases.At present,radiotherapy is the primary therapeutic modality for lung cancer at different stages,with significant prolongation of survival time(Hirsch et al.,2017;Bai et al.,2019;Shi et al.,2020).

TwoMADS-boxgenes regulate vascularcambium activity and secondary growth by modulating auxin homeostasis in Populus

In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process.However,the underlying molecular mechanismfor the establishment of auxin concentration is not fully understood.In this study,we identified two function-unknown MADS-box genes,VCM1 and VCM2,which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin.Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation.Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression,which tuned the soluble auxin concentration in the vascular cambium area.This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.

Arabidopsis ROOT ELONGATION RECEPTOR KINASES negatively regulate root growth putatively via altering cell wall remodeling gene expression

Receptor-like kinases(RLKs)play key roles in regulating various physiological aspects in plant growth and development.In Arabidopsis thaliana,there are at least 223 leucine-rich repeat(LRR)RLKs.The functions of the majority of RLKs in the LRR XI subfamily were previously revealed.Only three RLKs were not characterized.Here we report that two independent triple mutants of these RLKs,named ROOT ELONGATION RECEPTOR KINASES(REKs),exhibit increased cell numbers in the root apical meristem and enhanced cell size in the elongation and maturation zones.The promoter activities of a number of Quiescent Center marker genes are significantly up-regulated in the triple mutant.However,the promoter activities of several marker genes known to control root stem cell niche activities are not altered.RNA-seq analysis revealed that a number of cell wall remodeling genes are significantly up-regulated in the triple mutant.Our results suggest that these REKs play key roles in regulating root development likely via negatively regulating the expression of a number of key cell wall remodeling genes.

Fabrication of complex,3D,branched hollow carbonaceous structures and their applications for supercapacitors

A unique“integrated hard-templating strategy”is described for facile synthesis of a carbonaceous material with a novel three-dimensional(3 D)branched hollow architecture.A set of steps,including template formation,surface coating and template removal,all occur in a spontaneous and orderly manner in the one-pot hydrothermal process.Investigations on structural evolution during the process reveal that pre-synthesized zeolitic imidazolate framework-8(ZIF-8)nanoparticles are first dissociated and then self-assembled into 3 D branched superstructures of ZnO as templates.Initial self-assembly is followed by coating of the glucose-derived carbonaceous materials and etching of interior ZnO by organic acids released in situ by hydrolysis of glucose.The 3 D-branched hollow architecture is shown to greatly enhance supercapacitor performance.The research described here provides guidance into the development of strategies for complex hollow carbonaceous architectures for a variety of potential applications.