Historical development and novel concepts on electrolytes for aqueous rechargeable batteries

In battery systems, aqueous electrolytes are superior in ionic conductivity, interfacial wettability, safety and environmentally benign compared to organic liquids, polymers, inorganic solid-state and ionic liquid electrolytes

A symmetric direct ammonia fuel cell using ternary NiCuFe alloy embedded in a carbon network as electrodes

Recently, due to the high energy density of ammonia, low source-to-tank energy cost and carbon free fuel, low-temperature direct ammonia fuel cells (DAFCs) have attracted extensive attention and play an important role in ammonia economy. In DAFCs, Pt-based materials have been the most studied electrocatalysts for the anodic ammonia oxidation reaction (AOR) and cathodic oxygen reduction reaction (ORR) over the past decade. However, the high cost of precious metal has markedly inhibited the large-scale application of DAFCs. Herein, a bifunctional material of ternary Ni4Cu5Fex (x = 0, 0.5, 1, 3, 5) alloy embedded in a carbon network was prepared by a simple solvothermal approach, and showed superior activity and durability towards both AOR and ORR. The excellent bifunctional catalytic activity of the Ni4Cu5Fe1/C sample was analyzed by experimental and calculational methods. Utilizing the bifunctional activities of this alloy, a symmetric DAFC was assembled with Ni4Cu5Fe1/C as both the anode and cathode, with a commercial anion exchange membrane (AEM) as electrolyte. The symmetric DAFC-Ni4Cu5Fe1/C showed a maximum current density of 67 mA cm−2 at 80 °C. To the best of our knowledge, this is the first report on a symmetric DAFC. This work not only reports a new AOR/ORR bifunctional catalyst, but also moves towards the development of low-cost DAFCs with simple structure

Intrachromosomal Looping Is Required for Activation of Endogenous Pluripotency Genes during Reprogramming

SummaryGeneration of induced pluripotent stem cells (iPSCs) by defined factors is an extremely inefficient process, because there is a strong epigenetic block preventing cells from achieving pluripotency. Here we report that virally expressed factors bound to the promoters of their target genes to the same extent in both iPSCs and unreprogrammed cells (URCs). However, expression of endogenous pluripotentcy genes was observed only in iPSCs. Comparison of local chromatin structure of the OCT4 locus revealed that there was a cohesin-complex-mediated intrachromosomal loop that juxtaposes a downstream enhancer to the gene’s promoter, enabling activation of endogenous stemness genes. None of these long-range interactions were observed in URCs. Knockdown of the cohesin-complex gene SMC1 by RNAi abolished the intrachromosomal interaction and affected pluripotency. These findings highlight the importance of the SMC1-orchestrated intrachromosomal loop as a critical epigenetic barrier to the induction of pluripotency

A new chromosome-scale duck genome shows a major histocompatibility complex with several expanded multigene families

BACKGROUND: The duck (Anas platyrhynchos) is one of the principal natural hosts of influenza A virus (IAV), harbors almost all subtypes of IAVs and resists to many IAVs which cause extreme virulence in chicken and human. However, the response of duck's adaptive immune system to IAV infection is poorly characterized due to lack of a detailed gene map of the major histocompatibility complex (MHC).RESULTS: We herein reported a chromosome-scale Beijing duck assembly by integrating Nanopore, Bionano, and Hi-C data. This new reference genome SKLA1.0 covers 40 chromosomes, improves the contig N50 of the previous duck assembly with highest contiguity (ZJU1.0) of more than a 5.79-fold, surpasses the chicken and zebra finch references in sequence contiguity and contains a complete genomic map of the MHC. Our 3D MHC genomic map demonstrated that gene family arrangement in this region was primordial; however, families such as AnplMHCI, AnplMHCIIβ, AnplDMB, NKRL (NK cell receptor-like genes) and BTN underwent gene expansion events making this area complex. These gene families are distributed in two TADs and genes sharing the same TAD may work in a co-regulated model.CONCLUSIONS: These observations supported the hypothesis that duck's adaptive immunity had been optimized with expanded and diversified key immune genes which might help duck to combat influenza virus. This work provided a high-quality Beijing duck genome for biological research and shed light on new strategies for AIV control.</p

An efficient symmetric electrolyzer based on bifunctional perovskite catalyst for ammonia electrolysis

Ammonia is a natural pollutant in wastewater and removal technique such as ammonia electro‐oxidation is of paramount importance. The development of highly efficient and low‐costing electrocatalysts for the ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) associated with ammonia removal is subsequently crucial. In this study, for the first time, the authors demonstrate that a perovskite oxide LaNi0.5Cu0.5O3‐δ after being annealed in Ar (LNCO55‐Ar), is an excellent non‐noble bifunctional catalyst towards both AOR and HER, making it suitable as a symmetric ammonia electrolyser (SAE) in alkaline medium. In contrast, the LNCO55 sample fired in air (LNCO55‐Air) is inactive towards AOR and shows very poor HER activity. Through combined experimental results and theoretical calculations, it is found that the superior AOR and HER activities are attributed to the increased active sites, the introduction of oxygen vacancies, the synergistic effect of B‐site cations and the different active sites in LNCO55‐Ar. At 1.23 V, the assembled SAE demonstrates ≈100% removal efficiency in 2210 ppm ammonia solution and >70% in real landfill leachate. This work opens the door for developments towards bifunctional catalysts, and also takes a profound step towards the development of low‐costing and simple device configuration for ammonia electrolysers

Long-term effects of biochar application on the growth and physiological characteristics of maize

Biochar, as a soil conditioner, has been widely used to promote the growth of maize, but most of the current research is short-term experiments, which limits the research on the long-term effects of biochar, especially the physiological mechanism of biochar on maize growth in aeolian sandy soil is still unclear. Here, we set up two groups of pot experiments, respectively after the new biochar application and one-time biochar application seven years ago (CK: 0 t ha-1, C1: 15.75 t ha-1, C2: 31.50 t ha-1, C3: 63.00 t ha-1, C4: 126.00 t ha-1), and planted with maize. Subsequently, samples were collected at different periods to explore the effect of biochar on maize growth physiology and its after-effect. Results showed that the plant height, biomass, and yield of maize showed the highest rates of increase at the application rate of 31.50 t ha-1 biochar, with 22.22% increase in biomass and 8.46% increase in yield compared with control under the new application treatment. Meanwhile, the plant height and biomass of maize increased gradually with the increase of biochar application under the one-time biochar application seven years ago treatment (increased by 4.13%-14.91% and 13.83%-58.39% compared with control). Interestingly, the changes in SPAD value (leaf greenness), soluble sugar and soluble protein contents in maize leaves corresponded with the trend of maize growth. Conversely, the changes of malondialdehyde (MDA), proline (PRO), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) manifested an opposite trend to the growth of maize. In conclusion, 31.50 t ha-1 biochar application can promote the growth of maize by inducing changes in its physiological and biochemical characteristics, but excessive biochar application rates ranging from 63.00-126.00 t ha-1 inhibited the growth of maize. After seven years of field aging, the inhibitory effect of 63.00-126.00 t ha-1 biochar amount on maize growth disappeared and changed to promoting effect

Serum Starvation Induced Cell Cycle Synchronization Facilitates Human Somatic Cells Reprogramming

Human induced pluripotent stem cells (iPSCs) provide a valuable model for regenerative medicine and human disease research. To date, however, the reprogramming efficiency of human adult cells is still low. Recent studies have revealed that cell cycle is a key parameter driving epigenetic reprogramming to pluripotency. As is well known, retroviruses such as the Moloney murine leukemia virus (MoMLV) require cell division to integrate into the host genome and replicate, whereas the target primary cells for reprogramming are a mixture of several cell types with different cell cycle rhythms. Whether cell cycle synchronization has potential effect on retrovirus induced reprogramming has not been detailed. In this study, utilizing transient serum starvation induced synchronization, we demonstrated that starvation generated a reversible cell cycle arrest and synchronously progressed through G2/M phase after release, substantially improving retroviral infection efficiency. Interestingly, synchronized human dermal fibroblasts (HDF) and adipose stem cells (ASC) exhibited more homogenous epithelial morphology than normal FBS control after infection, and the expression of epithelial markers such as E-cadherin and Epcam were strongly activated. Futhermore, synchronization treatment ultimately improved Nanog positive clones, achieved a 15–20 fold increase. These results suggested that cell cycle synchronization promotes the mesenchymal to epithelial transition (MET) and facilitates retrovirus mediated reprogramming. Our study, utilization of serum starvation rather than additional chemicals, provide a new insight into cell cycle regulation and induced reprogramming of human cells

Deformation Performance Analysis of a Truss Structure Based on the Deformation Decomposition Method

Trusses are among the basic components of large-span bridges and large-space structures. A method is proposed to conduct a comprehensive deformation analysis of a truss in terms of the basic rigid body displacements and the tension and compression deformation based on complete mathematical orthogonality and mechanical equilibrium. The correctness of the proposed method is verified by comparison with a traditional strain analysis. Furthermore, a relative deformation decomposition of the mode shape is proposed to analyse in detail its relative displacement and deformation. The correctness and superiority of the proposed method are verified by comparison with the modal mass participation coefficient method and the animation from observation method. Additionally, the relative deformation decomposition of a plane truss structure is realized under any load conditions based on the superposition of mode shapes. The quantitative analysis of the basic deformation performance of a plane truss structure can also be conducted by countable mode shapes, which do not involve load conditions. Finally, the number of mode shapes that must be considered differs when using the maximum displacement and the tension and compression deformation analysis indicators

Novel SW\u3csub\u3e2\u3c/sub\u3e-based 3D electrode with protecting scaffold for efficient and stable hydrogen evolution

The synthesis of an efficient and stable WS2-based three-dimensional (3D) electrode remains a challenge. Herein, a novel WS2-based 3D electrode (WS2/graphite rods (GR)) with significantly advanced electrocatalytic hydrogen evolution activity and stability was demonstrated. Compared to the film electrode of powdery WS2, WS2/GR showed a much lowered contact resistance (∼1 Ω), leading to a 200 mV lowered overpotential and a Tafel slope (47.9 mV·dec–1) much closer to that of the Pt electrode. Meanwhile, the novel 3D electrode exhibited greatly improved stability with little current decay after 15 h reaction. Further investigation revealed three different morphologies of WS2 nanostructures on and into the graphite rod. While the vertically growing WS2 nanosheets and WS2 nanoparticles inside played essential roles in advanced activity, the densely stacked ball-like self-assemblies of WS2 nanosheets on the surface of the rod was of little importance for the hydrogen evolution reaction performance. The reasons were that the confinement effect and the well protection of the graphite scaffold allowed the WS2 nanostructures inside the rod with largely exposed active sites and less likely to be oxidized. The work not only achieved excellent WS2-based 3D electrode but also provided effective approach for synthesizing efficient and stable 3D electrodes