Cationic Oxidative Leaching Engineering Modulated In Situ Self-Reconstruction of Nickel Sulfide for Superior Water Oxidation.

Tuning the electroactive surface species of electrocatalysts remains a significant challenge for achieving highly efficient oxygen evolution reactions. Herein, we propose an innovative in situ leaching strategy, modulated by cationic oxidation, to achieve active self-reconstruction of these catalysts. Vanadium is introduced as a cation into Ni3S2 and oxidized under low oxidative potential, leading to subsequent leaching into the electrolyte and triggering self-reconstruction. The structural evolution from V-Ni3S2 to Ni(OH)2 and subsequently to NiOOH is identified by operando Raman as a three-step transition. In contrast, V-free Ni3S2 is unable to bypass the thermodynamically predicted nickel oxysulfide products to transform into active NiOOH. As a result, the self-restructured V-Ni3S2 only needs an ultralow overpotential of 155 mV at 10 mA cm-2, outperforming V-free Ni3S2 and many other advanced catalysts. This work provides new guidelines for manipulating in situ leaching to modulate the self-reconstruction of catalysts.

Yellow-Green Leaf 19 Encoding a Specific and Conservative Protein for Photosynthetic Organisms Affects Tetrapyrrole Biosynthesis, Photosynthesis, and Reactive Oxygen Species Metabolism in Rice.

Chlorophyll is the main photosynthetic pigment and is crucial for plant photosynthesis. Leaf color mutants are widely used to identify genes involved in the synthesis or metabolism of chlorophyll. In this study, a spontaneous mutant, yellow-green leaf 19 (ygl19), was isolated from rice (Oryza sativa). This ygl19 mutant showed yellow-green leaves and decreased chlorophyll level and net photosynthetic rate. Brown necrotic spots appeared on the surface of ygl19 leaves at the tillering stage. And the agronomic traits of the ygl19 mutant, including the plant height, tiller number per plant, and total number of grains per plant, were significantly reduced. Map-based cloning revealed that the candidate YGL19 gene was LOC_Os03g21370. Complementation of the ygl19 mutant with the wild-type CDS of LOC_Os03g21370 led to the restoration of the mutant to the normal phenotype. Evolutionary analysis revealed that YGL19 protein and its homologues were unique for photoautotrophs, containing a conserved Ycf54 functional domain. A conserved amino acid substitution from proline to serine on the Ycf54 domain led to the ygl19 mutation. Sequence analysis of the YGL19 gene in 4726 rice accessions found that the YGL19 gene was conserved in natural rice variants with no resulting amino acid variation. The YGL19 gene was mainly expressed in green tissues, especially in leaf organs. And the YGL19 protein was localized in the chloroplast for function. Gene expression analysis via qRT-PCR showed that the expression levels of tetrapyrrole synthesis-related genes and photosynthesis-related genes were regulated in the ygl19 mutant. Reactive oxygen species (ROS) such as superoxide anions and hydrogen peroxide accumulated in spotted leaves of the ygl19 mutant at the tillering stage, accompanied by the regulation of ROS scavenging enzyme-encoding genes and ROS-responsive defense signaling genes. This study demonstrates that a novel yellow-green leaf gene YGL19 affects tetrapyrrole biosynthesis, photosynthesis, and ROS metabolism in rice.

Systematic identification and characterization of circular RNAs involved in flag leaf senescence of rice.

MAIN CONCLUSION: Circular RNAs (circRNAs) identification, expression profiles, and construction of circRNA-parental gene relationships and circRNA-miRNA-mRNA ceRNA networks indicate that circRNAs are involved in flag leaf senescence of rice. Circular RNAs (circRNAs) are a class of 3'-5' head-to-tail covalently closed non-coding RNAs which have been proved to play important roles in various biological processes. However, no systematic identification of circRNAs associated with leaf senescence in rice has been studied. In this study, a genome-wide high-throughput sequencing analysis was performed using rice flag leaves developing from normal to senescence. Here, a total of 6612 circRNAs were identified, among which, 113 circRNAs were differentially expressed (DE) during the leaf senescence process. Moreover, 4601 (69.59%) circRNAs were derived from the exons or introns of their parental genes, while 2110 (71%) of the parental genes produced only one circRNA. The sequence alignment analysis showed that hundreds of rice circRNAs were conserved among different plant species. Gene Ontology (GO) enrichment analysis revealed that parental genes of DE circRNAs were enriched in many biological processes closely related to leaf senescence. Through weighted gene co-expression network analysis (WGCNA), six continuously down-expressed circRNAs, 18 continuously up-expressed circRNAs and 15 turn-point high-expressed circRNAs were considered to be highly associated with leaf senescence. Additionally, a total of 17 senescence-associated circRNAs were predicted to have parental genes, in which, regulations of three circRNAs to their parental genes were validated by qRT-PCR. The competing endogenous RNA (ceRNA) networks were also constructed. And a total of 11 senescence-associated circRNAs were predicted to act as miRNA sponges to regulate mRNAs, in which, regulation of two circRNAs to eight mRNAs was validated by qRT-PCR. It is discussed that senescence-associated circRNAs were involved in flag leaf senescence probably through mediating their parental genes and ceRNA networks, to participate in several well-studied senescence-associated processes, mainly including the processes of transcription, translation, and posttranslational modification (especially protein glycosylation), oxidation-reduction process, involvement of senescence-associated genes, hormone signaling pathway, proteolysis, and DNA damage repair. This study not only showed the systematic identification of circRNAs involved in leaf senescence of rice, but also laid a foundation for functional research on candidate circRNAs.

Microwave heating-assisted synthesis of ultrathin platinum-based trimetallic nanosheets as highly stable catalysts towards oxygen reduction reaction in acidic medium.

There are currently almost no ternary platinum-based nanosheets used for acidic oxygen reduction reactions (ORR) due to the difficulty in synthesizing ternary nanosheets with high Pt content. In this work, several ultrathin platinum-palladium-copper nanosheets (PtPdCu NSs) with a thickness of around 1.90 nm were prepared via a microwave heating-assisted method. Microwave heating allows a large number of Pt atoms to deposit into PdCu nanosheets, forming Pt-based ternary nanosheets with high Pt content. Among them, Pt38Pd50Cu12 NSs catalyst displays the highest mass activity (MA) measured in 0.1 M HClO4 of 0.932 A/mgPt+Pd which is 8.6 times of that Pt/C. Besides, Pt38Pd50Cu12 NSs catalyst also exhibits excellent stability with an extremely low MA attenuation after 80,000 cycles accelerated durability testing (ADT) tests. In the single cell tests, the Pt38Pd50Cu12 NSs catalyst manifests higher maximum power density of 796 mW cm-2 than Pt/C of 606 mW cm-2. Density functional theory (DFT) calculations indicate the weaker adsorption between Pt and O-species in Pt38Pd50Cu12 NSs leads to a significant enhancement of ORR activity. This study provides a new strategy to design and prepare ultrathin Pt-based trimetallic nanosheets as efficient and durable ORR catalysts.

Oxyanion Engineering Suppressed Iron Segregation in Nickel-Iron Catalysts Toward Stable Water Oxidation.

Nickel-iron catalysts represent an appealing platform for electrocatalytic oxygen evolution reaction (OER) in alkaline media because of their high adjustability in components and activity. However, their long-term stabilities under high current density still remain unsatisfactory due to undesirable Fe segregation. Herein, a nitrate ion (NO3 - ) tailored strategy is developed to mitigate Fe segregation, and thereby improve the OER stability of nickel-iron catalyst. X-ray absorption spectroscopy combined with theoretical calculations indicate that introducing Ni3 (NO3 )2 (OH)4 with stable NO3 - in the lattice is conducive to constructing the stable interface of FeOOH/Ni3 (NO3 )2 (OH)4 via the strong interaction between Fe and incorporated NO3 - . Time of flight secondary ion mass spectrometry and wavelet transformation analysis demonstrate that the NO3 - tailored nickel-iron catalyst greatly alleviates Fe segregation, exhibiting a considerably enhanced long-term stability with a six-fold improvement over FeOOH/Ni(OH)2 without NO3 - modification. This work represents a momentous step toward regulating Fe segregation for stabilizing the catalytic performances of nickel-iron catalysts.

Multiple chemical valences induced interface regulation in perovskite nickelate/carbon nitride for boosting photocatalytic hydrogen evolution.

Recent developments in transition metal-based photocatalysts have heightened the need for superior solar utilization. Evidence suggests that properly adjusting the chemical valence of the transition metal elements could simultaneously achieve broad-spectrum absorption and efficient charge separation for the photocatalysts. However, the understanding and application of this strategy remain a significant challenge. Herein, a series of La0.9Ni0.8Co0.2O3-α/g-C3N4 (LNCO/CN) composites were synthesized employing a mild reduction procedure in the H2/Ar atmosphere. Experimental studies reveal that the composites regulated by interfacial coordination unsaturation Ni2+ and metal Ni0 possess accelerated Z-scheme charge transfer through the interfacial bond between Ni2+ and N. Besides, the localized-surface-plasmon-resonance-induced "hot electrons" injection process of in situ grown Ni0 nanoparticle is confirmed, which can efficiently quench the photoinduced holes and create hole vacancies around the interface. Due to the synergistic effect between Ni2+ and Ni0, the lifetime of the photo-excited electrons is prolonged with inhibited recombination behavior. After modulation, optimal LNCO/CN Z-scheme hybrid exhibits 9-fold promotion of photocatalytic hydrogen evolution rate compared to pristine LNCO/CN. This study gives valuable insight into the purposeful utilization of the chemical valence modulating strategy, which alters the chemical valence of transition metal elements to enhance the performance of perovskite-based photocatalysts dramatically.

Probabilistic Circuit Implementation Based on P-Bits Using the Intrinsic Random Property of RRAM and P-Bit Multiplexing Strategy.

Probabilistic computing is an emerging computational paradigm that uses probabilistic circuits to efficiently solve optimization problems such as invertible logic, where traditional digital computations are difficult to solve. This paper proposes a true random number generator (TRNG) based on resistive random-access memory (RRAM), which is combined with an activation function implemented by a piecewise linear function to form a standard p-bit cell, one of the most important parts of a p-circuit. A p-bit multiplexing strategy is also applied to reduce the number of p-bits and improve resource utilization. To verify the superiority of the proposed probabilistic circuit, we implement the invertible p-circuit on a field-programmable gate array (FPGA), including AND gates, full adders, multi-bit adders, and multipliers. The results of the FPGA implementation show that our approach can significantly save the consumption of hardware resources.

A 1T2C FeCAP-Based In-Situ Bitwise X(N)OR Logic Operation with Two-Step Write-Back Circuit for Accelerating Compute-In-Memory.

Ferroelectric capacitors (FeCAPs) with high process compatibility, high reliability, ultra-low programming current and fast operation speed are promising candidates to traditional volatile and nonvolatile memory. In addition, they have great potential in the fields of storage, computing, and memory logic. Nevertheless, effective methods to realize logic and memory in FeCAP devices are still lacking. This study proposes a 1T2C FeCAP-based in situ bitwise X(N)OR logic based on a charge-sharing function. First, using the 1T2C structure and a two-step write-back circuit, the nondestructive reading is realized with less complexity than the previous work. Second, a method of two-line activation is used during the operation of X(N)OR. The verification results show that the speed, area and power consumption of the proposed 1T2C FeCAP-based bitwise logic operations are significantly improved.

Sensing Circuit Design Techniques for RRAM in Advanced CMOS Technology Nodes.

Resistive random access memory (RRAM) is one of the most promising new nonvolatile memories because of its excellent properties. Moreover, due to fast read speed and low work voltage, it is suitable for seldom-write frequent-read applications. However, as technology nodes shrink, RRAM faces many issues, which can significantly degrade RRAM performance. Therefore, it is necessary to optimize the sensing schemes to improve the application range of RRAM. In this paper, the issues faced by RRAM in advanced technology nodes are summarized. Then, the advantages and weaknesses in the novel design and optimization methodologies of sensing schemes are introduced in detail from three aspects, the reference schemes, sensing amplifier schemes, and bit line (BL)-enhancing schemes, according to the development of technology in especially recent years, which can be the reference for designing the sensing schemes. Moreover, the waveforms and results of each method are illustrated to make the design easy to understand. With the development of technology, the sensing schemes of RRAM become higher speed and resolution, low power consumption, and are applied at advanced technology nodes and low working voltage. Now, the most advanced nodes the RRAM applied is 14 nm node, the lowest working voltage can reach 0.32 V, and the shortest access time can be only a few nanoseconds.

Decreased expression of serum miR-424 correlates with poor prognosis of patients with hepatocellular carcinoma.

BACKGROUND: MicroRNAs (miRNAs) play important roles in many important cellular processes and deregulation of miRNAs is linked to many human diseases including cancer. Although miR-424 has been demonstrated to inhibit progression of hepatocellular carcinoma (HCC), its expression level in serum samples and the potential clinical values remain unknown. MATERIALS AND METHODS: The expression level of miR-424 in the serum clinical samples from HCC patients and healthy volunteers were determined by qRT-PCR. Then the association of serum miR-424 expression level with various important clinicopathological parameters and survival rates was evaluated. Multivariate Cox regression analysis was used to identify the independent risk factors for HCC. RESULTS: The expression level of serum miR-424 was significantly decreased in patients with HCC compared with the healthy volunteers (P<0.01). Reduced expression of serum miR-424 was associated with serum AFP (P=0.048), vein invasion (P=0.006) and TNM stage (P=0.003). In addition, survival analysis showed that HCC patients with lower serum miR-424 expression suffered poorer overall survival (P=0.018) and disease free survival (P=0.008). Moreover, serum miR-424 was demonstrated to be an independent risk factor for HCC. CONCLUSIONS: Our findings provide the compelling evidence that the decreased expression of serum miR-424 may serve as a novel biomarker to predict the unfavorable prognosis of HCC patients.