The Directional Crystallization Process of Poly (triazine imide) Single Crystals in Molten Salts.

Poly (triazine imide) photocatalysts prepared via molten salt methods emerge as promising polymer semiconductors with one-step excitation capacity of overall water splitting. Unveiling the molecular conjugation, nucleation, and crystallization processes of PTI crystals is crucial for their controllable structure design. Herein, microscopy characterization was conducted at the PTI crystallization front from meso to nano scales. The heptazine-based precursor was found to depolymerize to triazine monomers within molten salts and KCl cubes precipitate as the leading cores that guide the directional stacking of PTI molecular units to form aggregated crystals. Upon this discovery, PTI crystals with improved dispersibility and enhanced photocatalytic performance were obtained by tailoring the crystallization fronts. This study advances insights into the directional assembling of PTI monomers on salt templates, placing a theoretical foundation for the ordered condensation of polymer crystals.

The phosphatase PTEN links platelets with immune regulatory functions of mouse T follicular helper cells.

Beyond a function in hemostasis and thrombosis, platelets can regulate innate and adaptive immune responses. Hyperactive platelets are frequently associated with multiple human autoimmune diseases, yet their pathogenic functions in these diseases have not been fully established. Emerging studies show an essential function of the phosphatase and tensin homolog (PTEN) in maintenance of immune homeostasis. Here, we show that mice with platelet-specific deletion of Pten, develop age-related lymphoproliferative diseases and humoral autoimmunity not seen in wildtype animals. Platelet-specific Pten-deficient mice have aberrant T cell activation, excessive T follicular helper (Tfh) cell responses and accumulation of platelet aggregates in lymph nodes. Transferred Pten-deficient platelets are able to infiltrate into the peripheral lymphoid tissues and form more aggregates. Moreover, Pten-deficient platelets are hyperactive and overproduce multiple Tfh-promoting cytokines via activation of the PDK1/mTORC2-AKT-SNAP23 pathway. Pten-deficient platelets show enhanced interaction with CD4+ T cells and promote conversion of CD4+ T cells into Tfh cells. Our results implicate PTEN in platelet-mediated immune homeostasis, and provide evidence that hyperactive platelets function as an important mediator in autoimmune diseases using mouse models.

Inhibition of LDHA to induce eEF2 release enhances thrombocytopoiesis.

Translation is essential for megakaryocyte (MK) maturation and platelet production. However, how the translational pathways are regulated in this process remains unknown. In this study, we found that MK/platelet-specific lactate dehydrogenase A (LdhA) knockout mice exhibited an increased number of platelets with remarkably accelerated MK maturation and proplatelet formation. Interestingly, the role of LDHA in MK maturation and platelet formation did not depend on lactate content, which was the major product of LDHA. Mechanism studies revealed that LDHA interacted with eukaryotic elongation factor 2 (eEF2) in the cytoplasm, controlling the participation of eEF2 in translation at the ribosome. Furthermore, the interaction of LDHA and eEF2 was dependent on nicotinamide adenine dinucleotide (NADH), a coenzyme of LDHA. NADH-competitive inhibitors of LDHA could release eEF2 from the LDHA pool, upregulate translation, and enhance MK maturation in vitro. Among LDHA inhibitors, stiripentol significantly promoted the production of platelets in vivo under a physiological state and in the immune thrombocytopenia model. Moreover, stiripentol could promote platelet production from human cord blood mononuclear cell-derived MKs and also have a superposed effect with romiplostim. In short, this study shows a novel nonclassical function of LDHA in translation that may serve as a potential target for thrombocytopenia therapy.

Engineering Hierarchical Co@N-Doped Carbon Nanotubes/α-Ni(OH)2 Heterostructures on Carbon Cloth Enabling High-Performance Aqueous Nickel-Zinc Batteries.

Searching for high-performance Ni-based cathodes plays an important role in developing better aqueous nickel-zinc (Ni-Zn) batteries. For this purpose, herein, we demonstrate the design and synthesis of ultrathin α-Ni(OH)2 nanosheets branched onto metal-organic frameworks (MOFs)-derived 3D cross-linked N-doped carbon nanotubes encapsulated with tiny Co nanoparticles (denoted as Co@NCNTs/α-Ni(OH)2), which are directly supported on a flexible carbon cloth (CC). An aqueous Ni-Zn battery employing the hierarchical CC/Co@NCNTs/α-Ni(OH)2 as the binder-free cathode and a commercial Zn plate as the anode is fabricated, which displays an ultrahigh capacity (316 mAh g-1) and energy density (540.4 Wh kg-1) at 1 A g-1 as well as excellent rate capability (238 mAh g-1 at 10 A g-1) and superior cycling performance (about 84% capacity retention after 2000 cycles at 10 A g-1). The impressive electrochemical performance might benefit from the rich active sites, rapid electron transfer, cushy electrolyte access, rapid ion transport, and robust structural stability. In addition, the quasi-solid-state CC/Co@NCNTs/α-Ni(OH)2//Zn batteries are also successfully assembled with polymer electrolyte, indicating the great potential for portable and wearable electronics. This work might provide important guidance for constructing carbon-based hybrid materials directly supported on conductive substrates as high-performance electrodes for energy-related devices.

Hierarchical Nanoreactor with Multiple Adsorption and Catalytic Sites for Robust Lithium-Sulfur Batteries.

Developing high-performance cathode host materials is fundamental to solve the low utilization of sulfur, the sluggish redox kinetics, and the lithium polysulfide (LiPS) shuttle effect in lithium-sulfur batteries (LSBs). Here, a multifunctional Ag/VN@Co/NCNT nanocomposite with multiple adsorption and catalytic sites within hierarchical nanoreactors is reported as a robust sulfur host for LSB cathodes. In this hierarchical nanoreactor, heterostructured Ag/VN nanorods serve as a highly conductive backbone structure and provide internal catalytic and adsorption sites for LiPS conversion. Interconnected nitrogen-doped carbon nanotubes (NCNTs), in situ grown from the Ag/VN surface, greatly improve the overall specific surface area for sulfur dispersion and accommodate volume changes in the reaction process. Owing to their high LiPS adsorption ability, outer Co nanoparticles at the top of the NCNTs catch escaped LiPS, thus effectively suppressing the shuttle effect and enhancing kinetics. Benefiting from the multiple adsorption and catalytic sites of the developed hierarchical nanoreactors, Ag/VN@Co/NCNTs@S cathodes display outstanding electrochemical performances, including a superior rate performance of 609.7 mAh g-1 at 4 C and a good stability with a capacity decay of 0.018% per cycle after 2000 cycles at 2 C. These properties demonstrate the exceptional potential of Ag/VN@Co/NCNTs@S nanocomposites and approach LSBs closer to their real-world application.

A lightweight and low-cost electrode for lithium-ion batteries derived from paper towel supported MOF arrays.

Herein, Cu-doped Co-ZIF nanoplate arrays are uniformly grown on a commercial paper towel substrate first. After a subsequent annealing treatment, well-defined Cu-doped Co/CoO nanoparticles embedded in N-doped carbon hybrid nanoplate arrays supported on the carbon paper substrate (denoted as Cu-doped Co/CoO/NC NPAs@CP) are obtained, which exhibit excellent performance as a low-cost, lightweight and binder-free anode for lithium ion storage.

Resorcinol-Formaldehyde Resin-Coated Prussian Blue Core-Shell Spheres and Their Derived Unique Yolk-Shell FeS2@C Spheres for Lithium-Ion Batteries.

The practical applications of transition metal sulfides as electrode materials for lithium-ion batteries (LIBs) is greatly hindered by the fast capacity fading owing to the large volume expansion. To address this issue, construction of transition metal sulfide and carbon nanocomposites with unique yolk-shell structures is an effective strategy but also remains a great challenge. In this work, we reported a facile approach to synthesize the unique yolk-shell FeS2@carbon (FeS2@C) spheres via calcination treatment of the resorcinol-formaldehyde (RF) resin-coated Prussian blue (FeFe PB) core-shell spheres in Ar atmosphere and a subsequent sulfidation treatment. The synthetic method herein was quite simple and convenient. Such unique structure design could effectively prevent the large volume expansion and dissolution of the active materials in the electrolytes during lithiation. As expected, the yolk-shell FeS2@C spheres exhibited good electrochemical performance as anode materials for LIBs, which displayed a high discharge capacity of 560 mA h g-1 at 100 mA g-1 for 100 cycles. When the current density increased to 1000 mA g-1, a reversible discharge capacity of 269 mA h g-1 was still retained after 500 cycles. The present work demonstrated an extraordinary synthetic strategy to construct transition metal sulfide and carbon nanocomposites with unique yolk-shell structure. In addition, this RF resin coating strategy can be further extended to synthesize other RF resin-coated PB analogue (PBA) core-shell nanostructures, demonstrating the generality of this RF resin coating strategy.

Functional classification of long non-coding RNAs by k-mer content.

The functions of most long non-coding RNAs (lncRNAs) are unknown. In contrast to proteins, lncRNAs with similar functions often lack linear sequence homology; thus, the identification of function in one lncRNA rarely informs the identification of function in others. We developed a sequence comparison method to deconstruct linear sequence relationships in lncRNAs and evaluate similarity based on the abundance of short motifs called k-mers. We found that lncRNAs of related function often had similar k-mer profiles despite lacking linear homology, and that k-mer profiles correlated with protein binding to lncRNAs and with their subcellular localization. Using a novel assay to quantify Xist-like regulatory potential, we directly demonstrated that evolutionarily unrelated lncRNAs can encode similar function through different spatial arrangements of related sequence motifs. K-mer-based classification is a powerful approach to detect recurrent relationships between sequence and function in lncRNAs.

Construction of MOF-derived hollow Ni-Zn-Co-S nanosword arrays as binder-free electrodes for asymmetric supercapacitors with high energy density.

Mixed transition metal sulfides with hollow structures hold great promise for energy-related applications. However, most of them are in the powder form, which should be mixed with unwanted polymer binders and conductive agents. In this study, a facile two-step strategy has been developed to grow mesoporous and hollow Ni-Zn-Co-S nanosword arrays (NSAs) on a nickel foam (NF) substrate with robust adhesion, which involves the hydrothermal growth of bimetallic Zn-Co-ZIF NSAs on NF and subsequent transformation into hollow Ni-Zn-Co-S NSAs through the sulfurization process. Benefiting from the unique structural and compositional advantages as well as directly grown conductive substrate, the Ni-Zn-Co-S-0.33 NSAs/NF electrode exhibits the best electrochemical performance when investigated as a binder-free electrode for supercapacitors. Impressively, the Ni-Zn-Co-S-0.33 NSAs/NF electrode delivers a high areal capacity of 1.11 mA h cm-2 at the current density of 10 mA cm-2, and the corresponding specific capacity is as high as 358.1 mA h g-1. Moreover, an asymmetric supercapacitor (ASC) device based on the Ni-Zn-Co-S-0.33 NSAs/NF as the positive electrode and Bi2O3/NF as the negative electrode has been successfully fabricated, and can deliver a high energy density of 91.7 W h kg-1 at a power density of 458 W kg-1 and maintain the energy density of 66.9 W h kg-1 at a high power density of 6696 W kg-1. The electrochemical results suggest that the hollow Ni-Zn-Co-S NSAs would possess great potential for applications in high-performance supercapacitors.

Bimetallic CoNiSx nanocrystallites embedded in nitrogen-doped carbon anchored on reduced graphene oxide for high-performance supercapacitors.

Exploring high-performance and low-priced electrode materials for supercapacitors is important but remains challenging. In this work, a unique sandwich-like nanocomposite of reduced graphene oxide (rGO)-supported N-doped carbon embedded with ultrasmall CoNiSx nanocrystallites (rGO/CoNiSx/N-C nanocomposite) has been successfully designed and synthesized by a simple one-step carbonization/sulfurization treatment of the rGO/Co-Ni precursor. The intriguing structural/compositional/morphological advantages endow the as-synthesized rGO/CoNiSx/N-C nanocomposite with excellent electrochemical performance as an advanced electrode material for supercapacitors. Compared with the other two rGO/CoNiOx and rGO/CoNiSx nanocomposites, the rGO/CoNiSx/N-C nanocomposite exhibits much enhanced performance, including a high specific capacitance (1028.2 F g-1 at 1 A g-1), excellent rate capability (89.3% capacitance retention at 10 A g-1) and good cycling stability (93.6% capacitance retention over 2000 cycles). In addition, an asymmetric supercapacitor (ASC) device based on the rGO/CoNiSx/N-C nanocomposite as the cathode and activated carbon (AC) as the anode is also fabricated, which can deliver a high energy density of 32.9 W h kg-1 at a power density of 229.2 W kg-1 with desirable cycling stability. These electrochemical results evidently indicate the great potential of the sandwich-like rGO/CoNiSx/N-C nanocomposite for applications in high-performance supercapacitors.

Dendritic unzipped carbon nanofibers enable uniform loading of surfactant-free Pd nanoparticles for the electroanalysis of small biomolecules.

In this study, graphene nanofibers (GNF), which are a superior support material, are successfully synthesized via the dendritic unzipping of stacked-cup carbon nanofibers (SCNF). Ultrasmall Pd nanoparticles are uniformly dispersed on the GNF (Pd/GNF) via chemical reduction under mild conditions without any surfactant involved. The components and structure of Pd/GNF are evaluated via scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman spectra and X-ray photoelectron spectroscopy (XPS). The characterization results indicate that the Pd nanoparticles have a uniform size of 3-6 nm without significant aggregation and the overall Pd content is about 11.2 wt% in the Pd/GNF composite. Moreover, a modified electrochemical sensor based on the Pd/GNF composite is successfully fabricated. In the two investigated redox probes (IrCl6 2- and [Fe(CN)6]3-), Pd/GNF shows a superior electrochemical response compared to the Pd nanoparticles loaded on SCNF and bare glass carbon electrode. For the detection of small biomolecules, Pd/GNF could individually or simultaneously detect ascorbic acid (AA), dopamine (DA) and uric acid (UA) through differential pulse voltammetry. The linear concentration ranges of UA, DA and AA are 0.1-1200 µM, 1-180 µM and 0.1-6000 µM, respectively.

Supercapacitors Based on Reduced Graphene Oxide Nanofibers Supported Ni(OH)2 Nanoplates with Enhanced Electrochemical Performance.

Pseudocapacitive materials are critical to the development of supercapacitors but usually suffer from poor conductivity and bad cycling property. Here, we describe the production of novel graphene oxide nanofibers (GONFs) via a partial oxidization and exfoliation method and concurrently report that highly crystallized Ni(OH)2 nanoplates uniformly grow on reduced GONFs' outer graphene nanosheets through the hydrothermal method. Because of their unique structure with high electric conductivity, the rGONF/Ni(OH)2 composite exhibits superior specific capacitance (SC), favorable rate capability and enhanced cycling stability relative to other composites or hybrids, e.g., 1433 F g(-1) at 5 mV s(-1) scan rate, 986 F g(-1) at 40 mV s(-1), and 90.5% capacitance retention after 2000 cycles, and as-fabricated rGONF/Ni(OH)2//active carbon asymmetric supercapacitor (ASC) exhibits a remarkable energy density and a 85.3% high retention (44.1 Wh kg(-1) at 467 W kg(-1) and 37.6 Wh kg(-1) at 3185 W kg(-1)) with a wide potential window of 0-1.7 V. Therefore, this study shows that rGONFs offers an exciting opportunity as substrate materials for supercapacior applications and opens up a new pathway for design and manufacture of novel supercapacitor electrode materials.

Light-Induced Reversible Self-Assembly of Gold Nanoparticles Surface-Immobilized with Coumarin Ligands.

A novel light-induced reversible self-assembly (LIRSA) system is based on the reversible photodimerization and photocleavage of coumarin groups on the surface of gold nanoparticles (AuNPs) in THF solution. Facilitated by coumarin groups, light irradiation at 365 nm triggers the stable assembly of monodisperse AuNPs; the resulting self-assembly system can be disassembled back to the disassembled state by a relatively short exposure to benign UV light. The reversible self-assembly cycle can be repeated 4 times. A specific concentration range of coumarin ligand and the THF solvent were identified to be the two predominant factors that contribute to the LIRSA of AuNPs. This is the first successful application of reversible photodimerization based on a coumarin derivative in the field of AuNP LIRSA. This LIRSA system may provide unique opportunities for the photoregulated synthesis of many adjustable nanostructures and devices.

[Corn straw composting in the field and in situ fertilizer effect].

According to the fact that corn straws remain or burned in the field in hilly and mountainous areas of Southwest China, which causes organic matter waste and serious atmospheric pollution, it is necessary to develop an efficient method to compost the corn straws. In the present experiment, corn straws were placed on the landside and land corner for composting with thermophilic cellulous bacteria inoculated, chemical nitrogen and nitrogen absorption agent added, and then covered with polyethylene film (bio-composting). Thereafter, flue-cured tobacco grown in the same land was fertilized with the compost to study the fertilizer effect. The results showed that the temperature in bio-compost increased quickly (over than 35 degrees C within 2 to 3 days) but decreased slowly compared to natural composting (control). In the bio-compost, temperature over than 50 degrees C lasted for about 15 days and the number of bacteria was 100 to 1000 times higher than in the control de- spite that microbial groups decreased in the high temperature period. After 90 days of bio-composting, corn straws contained water less than 25% with pH 6. 14 and showed brown or black color and fragmental or farinose physical state, indicating good decomposition and humification. Meanwhile, the active organic matter and nutrients, including N, P and K, were significantly increased. The yield, mean price, economical output of flue-cured tobacco leaves were increased and the leaf quality was improved by application of chemical fertilizers plus the compost at the ratio of 1:1. Therefore, bio-composting could utilize efficiently corn straws and eliminate air pollution, which is worth popularization in hilly and mountain areas.

Mildly alkaline preparation and methylene blue adsorption capacity of hierarchical flower-like sodium titanate.

The hydrothermal preparation of flower-like layered sodium titanate architectures in a weakly alkaline medium is reported. NaCl was used as a morphology-directing agent, and a growth mechanism was proposed. The hierarchical structure is assembled from one-dimensional nanoribbons and exhibits an excellent removal capacity toward methylene blue (MB). A pseudo-second-order kinetic model was found to well describe the adsorption kinetics. Kinetic studies demonstrated that the overall rate of MB adsorption was controlled by surface adsorption and intraparticle diffusion. Results of this work are of great significance for environmental applications of flower-like layered sodium titanate architectures as a promising adsorbent material used for water purification.