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Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and molybdenum-based polyoxometalates guest, mesoporous molybdenum carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts. There is extensive research into non-platinum electrocatalysts for hydrogen evolution. Here, the authors report a molybdenum carbide catalyst, prepared via the carburization of a copper metal-organic framework host/molybdenum-based polyoxometalates guest system, and demonstrate its catalytic activity.

Summary Fe deficiency is a widespread nutritional disorder in plants. The basic helix‐loop‐helix (bHLH) transcription factors (TFs), especially Ib subgroup bHLH TFs which are involved in iron uptake, have been identified. In this study, an IVc subgroup bHLH TF MdbHLH104 was identified and characterized as a key component in the response to Fe deficiency in apple. The overexpression of the MdbHLH104 gene noticeably increased the H+‐ATPase activity under iron limitation conditions and the tolerance to Fe deficiency in transgenic apple plants and calli. Further investigation showed that MdbHLH104 proteins bonded directly to the promoter of the MdAHA8 gene, thereby positively regulating its expression, the plasma membrane (PM) H+‐ATPase activity and Fe uptake. Similarly, MdbHLH104 directly modulated the expression of three Fe‐responsive bHLH genes, MdbHLH38, MdbHLH39 and MdPYE. In addition, MdbHLH104 interacted with 5 other IVc subgroup bHLH proteins to coregulate the expression of the MdAHA8 gene, the activity of PM H+‐ATPase and the content of Fe in apple calli. Therefore, MdbHLH104 acts together with other apple bHLH TFs to regulate Fe uptake by modulating the expression of the MdAHA8 gene and the activity of PM H+‐ATPase in apple.

Summary In this study, we characterized the role of an apple cytosolic malate dehydrogenase gene (MdcyMDH) in the tolerance to salt and cold stresses and investigated its regulation mechanism in stress tolerance. The MdcyMDH transcript was induced by mild cold and salt treatments, and MdcyMDH‐overexpressing apple plants possessed improved cold and salt tolerance compared to wild‐type (WT) plants. A digital gene expression tag profiling analysis revealed that MdcyMDH overexpression largely altered some biological processes, including hormone signal transduction, photosynthesis, citrate cycle and oxidation–reduction. Further experiments verified that MdcyMDH overexpression modified the mitochondrial and chloroplast metabolisms and elevated the level of reducing power, primarily caused by increased ascorbate and glutathione, as well as the increased ratios of ascorbate/dehydroascorbate and glutathione/glutathione disulphide, under normal and especially stress conditions. Concurrently, the transgenic plants produced a high H2O2 content, but a low O2·− production rate was observed compared to the WT plants. On the other hand, the transgenic plants accumulated more free and total salicylic acid (SA) than the WT plants under normal and stress conditions. Taken together, MdcyMDH conferred the transgenic apple plants a higher stress tolerance by producing more reductive redox states and increasing the SA level; MdcyMDH could serve as a target gene to genetically engineer salt‐ and cold‐tolerant trees.

Background Epidemiological literature regarding the effect of polycystic ovary syndrome (PCOS) as a risk factor for non-alcoholic fatty liver disease (NAFLD) remains inconsistent. Furthermore, it remains debatable whether NAFLD is associated with PCOS as a consequence of shared risk factors or whether PCOS contributes to NAFLD in an independent fashion. Therefore, this meta-analysis was conducted. Methods This meta-analysis was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Relevant studies published before May 2017 were identified and retrieved from PubMed and Web of Science databases. The data were extracted, and the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Results A total of 17 studies were included into the present analysis. Compared to the control group, the risk of NAFLD in the PCOS group was higher (OR = 2.25, 95% CI = 1.95–2.60). When stratified by BMI and geographic location, the results indicated that the frequency of NAFLD risk was significantly higher in obese subjects (OR = 3.01, 95% CI = 1.88–4.82), non-obese subjects (OR = 2.07, 95% CI = 1.12–3.85), subjects from Europe (OR = 2.00, 95% CI = 1.58–2.52), subjects from the Asia-Pacific Region, (OR = 2.32, 95% CI = 1.89–2.84) and subjects from America (OR = 2.96, 95% CI = 1.93–4.55). In addition, PCOS patients with hyperandrogenism (HA) had a significantly higher risk of NAFLD, compared with controls (OR = 3.31, 95% CI = 2.58–4.24). However, there was no association between PCOS patients without HA and higher risk of NAFLD (OR = 1.46; 95% CI =0.55–3.87). The results of this meta-analysis should be interpreted with caution due to the small number of observational studies and possible confounding factors. Conclusion The meta-analysis results suggest that PCOS is significantly associated with high risk of NAFLD. Although this association was independent of obesity and geographic region, it might be correlated with HA.

Changes in the expression of stress-related genes play crucial roles in response to environmental stress. Basic helix-loop-helix (bHLH) proteins are the largest superfamily of transcription factors and a large number of bHLH proteins function in plant responses to abiotic stresses. We identified a new bHLHm1 transcription factor from apple and named it MdSAT1. β-Glucuronidase (GUS) staining showed that MdSAT1 expressed in various tissues with highly expressed in leaves. Promoter analysis revealed that MdSAT1 contained multiple response elements and its transcription was induced by several environmental cues, particularly salt and drought stresses. Overexpression of MdSAT1 in apple calli and Arabidopsis resulted in a phenotype of increased tolerance to salt and drought. Altering abscisic acid (ABA) treatment increased the sensitivity of MdSAT1-OE Arabidopsis to ABA, and heavy metal stress, osmotic stress, and ethylene did not participate in MdSAT1 mediated plant development. These findings reveal the abiotic stress functions of MdSAT1 and pave the way for further functional investigation.

Background In plants, CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) is a key negative regulator in photoperiod response. However, the biological function of COP1-interacting protein 1 (CIP1) and the regulatory mechanism of the CIP1-COP1 interaction are not fully understood. Results Here, we identified the apple MdCIP1 gene based on the Arabidopsis AtCIP1 gene. Expression pattern analysis showed that MdCIP1 was constitutively expressed in various tissues of apple, and responded to stress and hormone signals at the transcriptional level. Ectopic expression of MdCIP1 complemented the phenotypes of the Arabidopsis cip1 mutant, and MdCIP1 inhibited anthocyanin biosynthesis in apple calli. In addition, the biochemical assay demonstrated that MdCIP1 could interact with MdCOP1 protein by their coiled-coil domain, and MdCIP1-OX/cop1–4 had a similar phenotype in photomorphogenesis with the cop1–4 mutant, suggesting that COP1 is epistatic to CIP1 . Furthermore, the transient transformation assay indicated that MdCIP1 repressed anthocyanin biosynthesis in an MdCOP1-mediated pathway. Conclusion Take together, this study finds that MdCIP1 acts as a repressor in regulating hypocotyl elongation and anthocyanin biosynthesis through MdCOP1 in apple.

Water splitting, an efficient approach for hydrogen production, is often hindered by unfavorable kinetics of oxygen evolution reaction (OER). In order to reduce the overpotential, noble metal oxides-based electrocatalysts like RuO 2 and IrO 2 are usually utilized. However, due to their scarcity, the development of cost-effective non-precious OER electrocatalysts with high efficiency and good stability is urgently required. Herein, we report a facile one-step annealing of metal-organic frameworks (MOFs) strategy to synthesize N-doped graphene layers encapsulated NiFe alloy nanoparticles (NiFe@C). Through tuning the nanoparticle size and calcination temperature, NiFe@C with an average size of around 16 nm obtained at 700 °C exhibits superior OER performance with an overpotential of only 281 mV at 10 mA cm −2 and high durability. The facile synthesis method and excellent electrochemical performance show great potential of NiFe@C in replacing the precious metal-based electrocatalysts in the OER.

While the synthesis of hollow structures of transition metal oxides is well established, it is extremely challenging to fabricate complex hollow structures for mixed transition metal sulfides. Here we report an anion exchange method to synthesize a complex ternary metal sulfides hollow structure, namely nickel cobalt sulfide ball-in-ball hollow spheres. Uniform nickel cobalt glycerate solid spheres are first synthesized as the precursor and subsequently chemically transformed into nickel cobalt sulfide ball-in-ball hollow spheres. When used as electrode materials for electrochemical capacitors, these nickel cobalt sulfide hollow spheres deliver a specific capacitance of 1,036 F g −1 at a current density of 1.0 A g −1 . An asymmetric supercapacitor based on these ball-in-ball structures shows long-term cycling performance with a high energy density of 42.3 Wh kg −1 at a power density of 476 W kg −1 , suggesting their potential application in high-performance electrochemical capacitors. While the synthesis of hollow structures of transition metal oxides is well established, the related sulfide chemistry remains challenging. Here, the authors report the synthesis of nickel cobalt sulfide ball-in-ball hollow spheres, via anion exchange, and evaluate their pseudocapacitive behaviour.

Apis laboriosa is the largest honeybee that lives mainly on cliff faces, with strong migratory ability. In this study, we firstly sequenced and assembled two complete mitochondrial genomes of A. laboriosa isolated from two distant locations in China (Chongqing and Shangri‐La regions). Combined with the published mitochondrial genome of A. laboriosa from Nepal, comparative genomic analyses were conducted to gain insight into the genetic diversity of giant honeybees from different geographical distributions. The mitochondrial genomes of A. laboriosa from Chongqing and Shangri‐La regions were 15,579 and 15,683 bp in length, respectively, both larger than that from Nepal with the length of 15,510 bp. Three mitochondrial genomes all harbor 37 common genes and present the same AT bias and the frequency of codon usage. However, the fragments including COX1, SSUrRNA, LSUrRNA, and the AT‐rich region of the mitochondrial genome from Shangri‐La region demonstrate distinctive insertions and deletions compared to those from Chongqing and Nepal regions. Phylogenetic trees of mitochondrial genomes show that A. laboriosa from Chongqing is most closely related to that from Nepal, rather than to Shangri‐La. Genetic distance between Shangri‐La and Chongqing or Nepal was even larger than that between the various subspecies of Apis mellifera. Overall, these results unmark that A. laboriosa in different geographical distributions can exhibit high genetic diversity at the mitochondrial genomic level, and therein, A. laboriosa from Shangri‐La may be the subspecies. All these studies will contribute to our understanding of the geographical distribution and genetic differentiation of black giant honeybee in Asian region. Overall, this study demonstrates that Apis laboriosa with different geographical distributions have rich genetic diversity at the mitochondrial level, where Apis laboriosa from Shangri‐La even reached the subspecies differentiation level. Meanwhile, our study also found that geographical distance is not the main reason for genetic differentiation, which provides a reference for further expanding research on the geographical distribution of Apis laboriosa and analyzing their mechanisms of genetic differentiation.

Aqueous zinc‐ion batteries have emerged as promising candidates for next‐generation energy storage due to their superior safety and lower cost. However, the sluggish desolvation kinetics of hydrated zinc ions at anode causes critical issues, including dendritic growth, hydrogen evolution reaction (HER), and anode corrosion. Herein, taking Sb single‐atoms (SAs) as a proof‐of‐concept, a F‐axial coordination engineering strategy is proposed to accelerate the desolvation kinetics and thus ensure robust cycling stability of Zn anode. Theoretical calculations reveal that the electron delocalization triggered by F‐axial coordination and p‐p orbital hybridization between Sb and F atoms strengthens the affinity for Zn. Electrochemical analysis and in situ/ex situ spectroscopy characterizations demonstrate that the introduction of F‐axial coordination can effectively reduce the energy barrier for the desolvation process of hydrated zinc ions, inhibit HER, uniform Zn2+ diffusion, and enable lateral Zn deposition. Consequently, the symmetric zinc battery based on F‐axial coordinated Sb SAs (F‐Sb SAs)‐modified Zn anode features unprecedented stability up to 6000 and 1200 h at 5 and 20 mA cm−2, respectively. Furthermore, the fabricated F‐Sb SAs@Zn||I2 battery exhibits remarkably long durability at a high current density of 10 A g−1, maintaining 94.3% of capacity even after 100 000 cycles. The F‐axial coordinated Sb SAs (F‐Sb SAs) can effectively reduce the desolvation energy of hydrated Zn2+ ions and greatly accelerate the migration kinetics of Zn2+ ions. The symmetric cell and Zn‐I2 batteries based on F‐Sb SAs@Zn anode exhibit outstanding stability.