Uncontrolled dendrites growth and serious parasitic reactions in aqueous electrolytes, greatly hinder the practical application of aqueous zinc‐ion battery. On the basis of in situ‐chemical ...construction and performance‐improving mechanism, multifunctional fluoroethylene carbonate (FEC) is introduced into aqueous electrolyte to construct a high‐quality and ZnF2‐riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. Notably, FEC additive can regulate the solvated structure of Zn2+ to reduce H2O molecules reactivity. Additionally, the ZHS layer with strong Zn2+ affinity can avoid dendrites formation and hinder the direct contact between the electrolyte and anode. Therefore, the dendrites growth, Zn corrosion, and H2 evolution reaction on ZMA in FEC‐included ZnSO4 electrolyte are highly suppressed. Thus, ZMA in such electrolyte realize a long cycle life over 1000 h and deliver a stable coulombic efficiency of 99.1 % after 500 cycles.
Multifunctional FEC is introduced into aqueous electrolyte to produce a ZnF2‐riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. The hydrolysate of FEC can favorably regulate the solvated structure of Zn2+ to restrict the H2O‐related parasitic reactions. The in situ formed ZHS layer not only realize uniform Zn deposition, but also suppresses ZMA corrosion.
3D carbon hosts can enable low‐stress Li metal anodes (LMAs) with improved structural and interfacial stability. However, the uneven Li+ flux and large concentration polarization, resulting from ...intrinsically poor Li affinity and limited porosity of carbon scaffolds, make the precise control of Li plating/stripping still one the key challenges facing advanced LMAs. Here it is demonstrated that a lightweight carbon scaffold, featuring parallel‐aligned porous fibers, can work well for homogeneous Li+ flux distribution and reduced concentration gradient to form a stable solid electrolyte interphase, and then synergistically guide smooth Li nucleation/growth even at low temperatures. As a result, the obtained LMAs delivers a high areal capacity up to 15 mAh cm−2, ultralong lifespan (4800 cycles at 4 mA cm−2) with very low voltage hysteresis of ≈21 mV, a high practically available specific capacity of 863.9 mAh g−1 after 1000 cycles, and a long‐term stable behavior at low‐temperature operation. As coupling with the commercial LiNi1/3Co1/3Mn1/3O2 cathodes and common carbonate‐based electrolyte, the corresponding practical cells also possess an ultralong lifespan and outstanding low‐temperature functionality. This study not only presents an advanced carbon host candidate but also sheds new light on crucial design principles of carbon scaffolds for practically feasible rechargeable metal batteries.
A lightweight carbon scaffold with a parallel‐aligned pattern achieves homogeneous Li+ flux distribution and reduces the concentration gradient to guide smooth Li nucleation/growth even at high‐power output and extreme temperatures. Accordingly, the prepared lithium metal anodes deliver a high areal capacity, ultralong lifespan with very low voltage hysteresis of ≈21 mV, and long‐term stable behavior at low‐temperature operation.
Aqueous zinc metal batteries have garnered unprecedented attention owing to their high theoretical specific capacity, appropriate redox potential, and remarkable sustainability. Nevertheless, the ...intractable issues induced by the notorious Zn dendrite growth and serious interfacial side reactions significantly impede their large‐scale utilization. Inducing Zn to electrodeposit through parallel arrangement mode is critical to realizing dendrite‐free Zn metal anodes (ZMAs). To realize this purpose, a unique polymeric molecular design strategy through chemically grafting a thin polyanthraquinone (PAQ) overlayer on the Zn surface in the manner of spontaneous polymerization reaction of anthraquinone diazonium tetrafluoroborate (AQN2+BF4−) is proposed firstly. Impressively, thus‐derived PAQ overlayer as an artificial protective layer can constrain the Zn2+ ions 2D diffusion and homogenize the electric field and Zn2+ ions concentration distribution, further guiding preferential growth along the Zn(002) plane. Assisted by the PAQ overlayer, the dendrite growth, H2 evolution reaction, and Zn corrosion on ZMAs are suppressed effectively. Accordingly, such polymeric molecular modified ZMAs ensure a remarkably high Coulombic efficiency of 99.7% at 4 mA cm−2 and achieve a long cycling lifespan up to 1750 h at 1 mA cm−2 and superior rate capability. This work provides a new insight into designing an interface protective layer for achieving highly stable ZMAs.
A unique polymeric molecular design strategy through chemical grafting of a thin polyanthraquinone overlayer on the Zn anode surface in the manner of spontaneous polymerization reaction of anthraquinone diazonium tetrafluoroborate (AQN2+BF4−) is first proposed to constrain Zn2+ 2D diffusion and realize the oriented growth of (002) crystal plane, then successfully suppressing the dendrite growth and H2 evolution reaction.
The structures of RNA molecules are often important for their function and regulation, yet there are no experimental techniques for genome-scale measurement of RNA structure. Here we describe a novel ...strategy termed parallel analysis of RNA structure (PARS), which is based on deep sequencing fragments of RNAs that were treated with structure-specific enzymes, thus providing simultaneous in vitro profiling of the secondary structure of thousands of RNA species at single nucleotide resolution. We apply PARS to profile the secondary structure of the messenger RNAs (mRNAs) of the budding yeast Saccharomyces cerevisiae and obtain structural profiles for over 3,000 distinct transcripts. Analysis of these profiles reveals several RNA structural properties of yeast transcripts, including the existence of more secondary structure over coding regions compared with untranslated regions, a three-nucleotide periodicity of secondary structure across coding regions and an anti-correlation between the efficiency with which an mRNA is translated and the structure over its translation start site. PARS is readily applicable to other organisms and to profiling RNA structure in diverse conditions, thus enabling studies of the dynamics of secondary structure at a genomic scale.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objective Congenital hypothyroidism (CH), the most common neonatal metabolic disorder, is characterized by impaired neurodevelopment. Although several candidate genes have been associated with CH, ...comprehensive screening of causative genes has been limited. Design and methods One hundred ten patients with primary CH were recruited in this study. All exons and exon–intron boundaries of 21 candidate genes for CH were analyzed by next-generation sequencing. And the inheritance pattern of causative genes was analyzed by the study of family pedigrees. Results Our results showed that 57 patients (51.82%) carried biallelic mutations (containing compound heterozygous mutations and homozygous mutations) in six genes (DUOX2, DUOXA2, DUOXA1, TG, TPO and TSHR) involved in thyroid hormone synthesis. Autosomal recessive inheritance of CH caused by mutations in DUOX2, DUOXA2, TG and TPO was confirmed by analysis of 22 family pedigrees. Notably, eight mutations in four genes (FOXE1, NKX2-1, PAX8 and HHEX) that lead to thyroid dysgenesis were identified in eight probands. These mutations were heterozygous in all cases and hypothyroidism was not observed in parents of these probands. Conclusions Most cases of congenital hypothyroidism in China were caused by thyroid dyshormonogenesis rather than thyroid dysgenesis. This study identified previously reported causative genes for 57/110 Chinese patients and revealed DUOX2 was the most frequently mutated gene in these patients. Our study expanded the mutation spectrum of CH in Chinese patients, which was significantly different from Western countries.
As emerging two-dimensional materials, metal-organic framework (MOF) nanosheet composites possess many unique physical and chemical properties, thus being expected to be widely applied in gas ...separation and adsorption, energy conversion and storage, heterogeneous catalysis, sensing as well as biomedicine. In this review, we first introduce the methods for integrating MOF nanosheets with other materials to prepare multifunctional composites. Next, the applications of MOF nanosheet composites in versatile fields are summarized and discussed. We hope this review will be instructive for researchers in the aspects of designs, preparations and applications of MOF nanosheet composites.
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As new and better materials are implemented for organic electrochemical transistors (OECTs), it becomes increasingly important to adopt more economic and environmentally friendly synthesis pathways ...with respect to conventional transition‐metal‐catalyzed polymerizations. Herein, a series of novel n‐type donor–acceptor‐conjugated polymers based on glycolated lactone and bis‐isatin units are reported. All the polymers are synthesized via green and metal‐free aldol polymerization. The strong electron‐deficient lactone‐building blocks provide low‐lying lowest unoccupied molecular orbital (LUMO) and the rigid backbone needed for efficient electron mobility up to 0.07 cm2 V−1 s−1. Instead, polar atoms in the backbone and ethylene glycol side chains contribute to the ionic conductivity. The resulting OECTs exhibit a normalized maximum transconductance gm,norm of 0.8 S cm−1 and a μC* of 6.7 F cm−1 V−1 s−1. Data on the microstructure show that such device performance originates from a unique porous morphology together with a highly disordered amorphous microstructure, leading to efficient ion‐to‐electron coupling. Overall, the design strategy provides an inexpensive and metal‐free polymerization route for high‐performing n‐type OECTs.
Lactone building blocks are incorporated into the backbone of donor–acceptor (D–A) copolymers to combine a sustainable polymerization strategy with the high performance needed for n‐type organic electrochemical transistors (OECTs). All the polymers are synthesized via aldol polycondensation. Among them, p(C‐T)‐based OECT achieves a µC* of 6.7 F cm−1 V−1 s−1 and a normalized maximum transconductance gm,norm of 0.8 S cm−1.
This Research Commentary responds to the March 2022 issue of
JRME.
To discuss the four articles in the issue across their diverse approaches to equity, the authors propose a socio-ecological ...framework for mapping research in mathematics education. The framework focuses on the layers of social activity that each study addresses, both analytically and with respect to implications. Using their analysis of the articles in the issue, the authors identify strengths in mathematics education research and areas in which more work is needed.
Myopia, especially high myopia, would cause damage in the choroid, retina and sclera, thereby leading to vision loss. Although refractive error correction can help improve visual acuity, the ...pathology of myopia, a global issue, remains unclear and myopia progression, as well as concomitant fundus progression, remains uncontrolled. Under such circumstances, prevention of myopia is of great significance and thus should be prioritized.
To explore whether outdoor time has positive significance for myopia prevention.
Databases of Pubmed, Science Direct, the Cochrane Library, the Chinese National Knowledge Infrastructure and the Wanfang Database were searched. The following terms or their combinations were used: myopia, prevention, control, random, randomized, randomization, intervention, outdoor. The full search strategy was shown in the Appendix below. The databases were last searched on -October 24, 2018.
Randomized controlled trials (RCTs) that participants accepted outdoor activity as an intervention measure for myopia prevention were included.
Two review authors independently extracted data and assessed the risk of bias for included studies. A fixed-effects model was applied, given that the heterogeneity among included studies was small.
Five RCTs with 3,014 subjects were included. Subjects' age ranged from 6 to 12 years, and the follow-up duration ranged from 9 to 36 months. Spherical equivalent error (SER) of the outdoor group was larger than that of the control group, and the pooled mean difference (MD) was 0.15 (95% CI 0.06-0.23) diopter (D). The change in SER of the outdoor group was smaller than that of the control group, with a pooled MD of 0.17 (95% CI 0.16-0.18) D. New myopia cases in the outdoor group were fewer than that of the control group, and the pooled risk ratio was 0.76 (95% CI 0.67-0.87). The change in axial length of the outdoor group was smaller than that of the control group, and the pooled MD was -0.03 (95% CI -0.03 to -0.03) mm. For all analyzed outcomes, there was no heterogeneity across included studies (I2 = 0%) and there was no publication bias either.
Outdoor time helps slow down the change of axial length and reduce the risk of myopia.
The poor reversibility and stability of Zn metal anode (ZMA) caused by uncontrolled Zn deposition behaviors and serious side reactions severely impeded the practical application of aqueous Zn metal ...battery. Herein, a liquid‐dynamic and self‐adaptive protective layer (LSPL) was constructed on the ZMA surface for inhibiting dendrites and by‐products formation. Interestingly, the outer LSPL consists of liquid perfluoropolyether (PFPE), which can dynamically adapt volume change during repeat cycling and inhibit side reactions. Moreover, it can also decrease the de‐solvation energy barrier of Zn2+ by strong interaction between C–F bond and foreign Zn2+, improving Zn2+ transport kinetics. For the LSPL inner region, in‐situ formed ZnF2 through the spontaneous chemical reaction between metallic Zn and part PFPE can establish an unimpeded Zn2+ migration pathway for accelerating ion transfer, thereby restricting Zn dendrites formation. Consequently, the LSPL‐modified ZMA enables reversible Zn deposition/dissolution up to 2000 h at 1 mA cm−2 and high coulombic efficiency of 99.8% at 4 mA cm−2. Meanwhile, LSPL@Zn||NH4V4O10 full cells deliver an ultralong cycling lifespan of 100 00 cycles with 0.0056% per cycle decay rate at 10 A g−1. This self‐adaptive layer provides a new strategy to improve the interface stability for next‐generation aqueous Zn battery.
A liquid‐dynamic and self‐adaptive protective layer is constructed on the Zn metal surface to dynamically adapt the volume change and rapidly repair the cracks of Zn metal anode, thereby inhibiting dendrite and side reaction formation.
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