Comprehensive molecular evolutionary analysis of small heat shock proteins in five diploid Gossypium species.

The small heat shock proteins (sHSPs) are important components in plant growth and development, and stress response. However, a systematical understanding of the sHSP family is yet to be reported in five diploid Gossypium species. In this study, 34 GlsHSPs, 36 GrsHSPs, 37 GtsHSPs, 37 GasHSPs, and 38 GhesHSPs were identified in Gossypium longicalyx, Gossypium raimondii, Gossypium turneri, Gossypium arboreum, and Gossypium herbaceum, respectively. These sHSP members can be clustered into 10 subfamilies. Different subfamilies had different member numbers, motif distributions, gene structures, gene duplication events, gene loss numbers, and cis-regulatory elements. Besides, the paleohexaploidization event in cotton ancestor led to expanding the sHSP members and it was also inherited by five diploid Gossypium species. After the cotton ancestor divergence, the sHSP members had the relatively conserved evolution in five diploid Gossypium species. The comprehensive evolutionary history of the sHSP family was revealed in five diploid Gossypium species. Furthermore, several GasHSPs and GhesHSPs were important candidates in plant growth and development, and stress response. These current findings can provide valuable information for the molecular evolution and further functional research of the sHSP family in cotton.

Carbon-Extraction-Induced Biaxial Strain Tuning of Carbon-Intercalated Iridium Metallene for Hydrogen Evolution Catalysis.

Metallene materials with atomic thicknesses are receiving increasing attention in electrocatalysis due to ultrahigh surface areas and distinctive surface strain. However, the continuous strain regulation of metallene remains a grand challenge. Herein, taking advantage of autocatalytic reduction of Cu2+ on biaxially strained, carbon-intercalated Ir metallene, we achieve control over the carbon extraction kinetics, enabling fine regulation of carbon intercalation concentration and continuous tuning of (111) in-plane (-2.0%-2.6%) and interplanar (3.5%-8.8%) strains over unprecedentedly wide ranges. Electrocatalysis measurements reveal the strain-dependent activity toward hydrogen evolution reaction (HER), where weakly strained Ir metallene (w-Ir metallene) with the smallest lattice constant presents the highest mass activity of 2.89 A mg-1Ir at -0.02 V vs reversible hydrogen electrode (RHE). Theoretical calculations validated the pivotal role of lattice compression in optimizing H binding on carbon-intercalated Ir metallene surfaces by downshifting the d-band center, further highlighting the significance of strain engineering for boosted electrocatalysis.

Tailoring the p-Band Center of NS Pair for Accelerating High-Performance Lithium-Oxygen Battery.

The local coordination environment of catalytical moieties directly determines the performance of electrochemical energy storage and conversion devices, such as Li-O2 batteries (LOBs) cathode. However, understanding how the coordinative structure affects the performance, especially for non-metal system, is still insufficient. Herein, a strategy that introduces S-anion to tailor the electronic structure of nitrogen-carbon catalyst (SNC) is proposed to improve the LOBs performance. This study unveils that the introduced S-anion effectively manipulates the p-band center of pyridinic-N moiety, substantially reducing the battery overpotential by accelerating the generation and decomposition of intermediate products Li1-3 O4 . The lower adsorption energy of discharging product Li2 O2 on NS pair accounts for the long-term cyclic stability by exposing the high active area under operation condition. This work demonstrates an encouraging strategy to enhance LOBs performance by modulating the p-band center on non-metal active sites.

Conserved and divergent evolution of the bZIP transcription factor in five diploid Gossypium species.

MAIN CONCLUSION: 495 bZIP members with 12 subfamilies were identified in the five diploid cottons. Segmental duplication events in cotton ancestor might have led to primary expansion of the cotton bZIP members. The basic leucine zipper (bZIP) transcription factor is one of the largest and most diverse families in plants. The evolutionary history of the bZIP family is still unclear in cotton. In this study, a total of 495 bZIP members were identified in five diploid Gossypium species, including 100 members in Gossypium arboreum, 104 members in Gossypium herbaceum, 95 members in Gossypium raimondii, 96 members in Gossypium longicalyx, and 100 members in Gossypium turneri. The bZIP members could be divided into 12 subfamilies with biased gene proportions, gene structures, conserved motifs, expansion rates, gene loss rates, and cis-regulatory elements. A total of 239 duplication events were identified in the five Gossypium species, and mainly occurred in their common ancestor. Furthermore, some GabZIPs and GhebZIPs could be regarded as important candidates in cotton breeding. The bZIP members had a conserved and divergent evolution in the five diploid Gossypium species. The current study laid an important foundation on the evolutionary history of the bZIP family in cotton.

A metagenomic insight into the Yangtze finless porpoise virome.

The Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) inhabiting the Yantze River, China is critically endangered because of the influences of infectious disease, human activity, and water contamination. Viral diseases are one of the crucial factors that threatening the health of Yangtze finless porpoise. However, there are few studies which elaborate the viral diversity of Yangtze finless. Therefore, this study was performed to investigate the viral diversity of Yangtze finless by metagenomics. Results indicated that a total of 12,686,252 high-quality valid sequences were acquired and 2,172 virus reads were recognized. Additionally, we also obtained a total of 10,600 contigs. Phages was the most abundant virus in the samples and the ratio of DNA and RNA viruses were 69.75 and 30.25%, respectively. Arenaviridae, Ackermannviridae and Siphoviridae were the three most predominant families in all the samples. Moreover, the majority of viral genus were Mammarenavirus, Limestonevirus and Lambdavirus. The results of gene prediction indicated that these viruses play vital roles in biological process, cellular component, molecular function, and disease. To the best of our knowledge, this is the first report on the viral diversity of Yangtze finless porpoise, which filled the gaps in its viral information. Meanwhile, this study can also provide a theoretical basis for the establishment of the prevention and protection system for virus disease of Yangtze finless porpoise.

Selectively Coupling Ru Single Atoms to PtNi Concavities for High-Performance Methanol Oxidation via d-Band Center Regulation.

Single atom tailored metal nanoparticles represent a new type of catalysts. Herein, we demonstrate a single atom-cavity coupling strategy to regulate performance of single atom tailored nano-catalysts. Selective atomic layer deposition (ALD) was conducted to deposit Ru single atoms on the surface concavities of PtNi nanoparticles (Ru-ca-PtNi). Ru-ca-PtNi exhibits a record-high activity for methanol oxidation reaction (MOR) with 2.01 A mg-1 Pt . Also, Ru-ca-PtNi showcases a significant durability with only 16 % activity loss. Operando electrochemical Fourier transform infrared spectroscopy (FTIR) and theoretical calculations demonstrate Ru single atoms coupled to cavities accelerate the CO removal by regulating d-band center position. Further, the high diffusion barrier of Ru single atoms in concavities accounts for excellent stability. The developed Ru-ca-PtNi via single atom-cavity coupling opens an encouraging pathway to design highly efficient single atom-based (electro)catalysts.

π-Conjugation Induced Anchoring of Ferrocene on Graphdiyne Enable Shuttle-Free Redox Mediation in Lithium-Oxygen Batteries.

Soluble redox mediators (RMs), an alternative to conventional solid catalysts, have been considered an effective countermeasure to ameliorate sluggish kinetics in the cathode of a lithium-oxygen battery recently. Nevertheless, the high mobility of RMs leads to serious redox shuttling, which induces an undesired lithium-metal degeneration and RM decomposition during trade-off catalysis against the sustainable operation of batteries. Here, a novel carbon family of graphdiyne matrix is first proposed to decouple the charge-carrying redox property of ferrocene and the shuttle effects. It is demonstrated that a ferrocene-anchored graphdiyne framework can function as stationary RM, not only preserving the redox-mediating capability of ferrocene, but also promoting the local orientated three-dimensional (3D) growth of Li2 O2 . As a result, the RM-assisted catalysis in lithium-oxygen battery remains of remarkable efficiency and stability without the depletion of oxidized RMs or lithium degradation, resulting in a significantly enhanced electrochemical performance.

Unraveling the Promotion Effects of a Soluble Cobaltocene Catalyst with Respect to Li-O2 Battery Discharge.

The discharge process of a nonaqueous Li-O2 battery at the cathode is the direct oxygen reduction reaction (ORR) with the formation of discharge product, e.g., Li2O2, deposits on the cathode surface. The aggressive superoxide intermediate generated during the ORR severely degrades the organic electrolyte and carbon-based cathodes. To avoid the formation of superoxide species and promote the growth of Li2O2 in the electrolyte solution, we employ a soluble cobaltocene [Co(C5H5)2, Cp2Co] as a homogeneous molecule catalyst to boost the discharge performance of Li-O2 batteries. Owing to the unique chemical reactivity of Cp2Co with molecular oxygen, the electrochemistry of the discharge process at the cathode is the (Cp2Co)2II-O22- adduct-mediated process rather than direct electrochemical oxygen reduction, thereby avoiding the formation of aggressive superoxide intermediate. In addition, the strong intermolecular attraction between Cp2Co and the newly formed Li2O2 promotes the solution phase growth of Li2O2, which effectively suppresses electrode passivation.

Perovskite LaCoxMn1-xO3-σ with Tunable Defect and Surface Structures as Cathode Catalysts for Li-O2 Batteries.

Rechargeable lithium-oxygen batteries have shown great potential as next-generation sustainable and green energy storage systems. The bifunctional catalyst plays an important role in accelerating the cathode kinetics for practical realization of the batteries. Herein, we employ the surface structure and defect engineering to introduce surface-roughened nanolayers and oxygen vacancies on the mesoporous hollow LaCoxMn1-xO3-σ perovskite catalyst by in situ cation substitution. The experimental results show that the O2-electrode with the LaCo0.75Mn0.25O3-σ catalyst exhibits an extremely high discharge capacity of 10,301 mA h g-1 at 200 mA g-1 for the initial cycle and superior cycling stability under a capacity limit of 500 mA h g-1 together with a low voltage gap of 1.12 V. Good electrochemical performance of LaCo0.75Mn0.25O3-σ can be attributed to the synergistic effect of the hierarchical mesoporous hollow structure and the abundant oxygen vacancies all over the catalyst surface. We reveal that the modified surface structure can provide more accessibility of active sites to promote electrochemical reactions, and the introduced oxygen vacancy can serve as an efficient substrate for binding intermediate products and decomposition reactions of Li2O2 during discharge and charge processes. Our methodology provides meaningful insights into the rational design of highly active perovskite catalysts in energy storage/conversion systems.

First evaluation of legacy persistent organic pollutant contamination status of stranded Yangtze finless porpoises along the Yangtze River Basin, China.

Yangtze finless porpoises (Neophocaena asiaeorientalis asiaeorientalis), inhabiting the Yangtze River, are an endangered species in China. They are threatened by various kinds of pollutants, among which persistent organic pollutants (POPs) are of special concern due to their toxicities, high persistency and bioaccumulation potential. To better understand the POP contamination status of Yangtze finless porpoises, an investigation of stranded porpoises along the Yangtze River and adjacent two major lakes in the Yangtze River basin was conducted; the concentrations of four groups of legacy POPs, i.e., hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyl (PCBs), were determined in the blubber samples. The mean concentrations of ΣHCHs (the sum of all congeners/isomers), ΣDDTs, ΣPBDEs and ΣPCBs, were 1670 ± 4210, 28,800 ± 52,300, 141 ± 174, and 1020 ± 1070 ng/g lipid weight, respectively; the high DDTs/PCBs ratio reflected a strong influence of agricultural pollution in the Yangtze River basin, and the high α/γ ratio of HCH isomers indicated the usage of lindane in the corresponding areas; the predominance of low-brominated congeners of PBDEs may be related to congruent patterns in the related environmental matrices. A hazard quotient risk assessment revealed that DDTs could pose a relatively high risk to Yangtze finless porpoises compared with the risks posed by the other POPs.

Discovery of the Streptoketides by Direct Cloning and Rapid Heterologous Expression of a Cryptic PKS II Gene Cluster from Streptomyces sp. Tü 6314.

Genome sequencing and bioinformatic analysis have identified numerous cryptic gene clusters that have the potential to produce novel natural products. Within this work, we identified a cryptic type II PKS gene cluster (skt) from Streptomyces sp. Tü 6314. Facilitated by linear plus linear homologous recombination-mediated recombineering (LLHR), we directly cloned the skt gene cluster using the Streptomyces site-specific integration vector pSET152. Direct cloning allowed for rapid heterologous expression in Streptomyces coelicolor, leading to the identification and structural characterization of six polyketides (three known compounds and new streptoketides), four of which exhibit anti-HIV activities. Our study shows that the pSET152 vector can be directly used for LLHR, expanding the Rec/ET direct cloning toolbox and providing the possibility for rapid heterologous expression of gene clusters from Streptomyces.

Trace elements accumulation in the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) - A threat to the endangered freshwater cetacean.

As a freshwater cetacean with a population of only approximately 1000 individuals, the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is threatened by water pollution. However, studies of contaminants accumulated in the Yangtze finless porpoise remain limited. In this study, concentrations of 11 trace elements in different tissues sampled from 38 Yangtze finless porpoise individuals were determined. The elements V, Ni, Zn, and Pb were mostly accumulated in the epidermis, Cr, Mn, Cu, Se, and Hg were mostly accumulated in the liver, while As and Cd were mostly accumulated in the blubber and kidney, respectively. The results show that trace elements concentrations in the epidermis do not reliably indicate concentrations in internal tissues of the Yangtze finless porpoises. Positive correlations between different trace elements concentrations in tissues with the highest concentrations suggested the similar mechanism of metabolism or uptake pathway of those elements. Concentrations of As, Se, Cd, Hg, and Pb in the tissues with the highest concentrations were significantly positively correlated with the body length. Furthermore, significantly higher trace elements concentrations were measured in the reproductive organs of females (ovaries) than males (testis). However, no significant difference of trace elements concentrations between habitats was found. In consideration of higher Hg and Cd level in Yangtze finless porpoises compared to other small cetaceans, the potential risk of Hg (in particular) and Cd toxicity to Yangtze finless porpoises needs further attention.

Structures and biological activities of cycloheptamycins A and B.

The heptadepsipeptide cycloheptamycin A was isolated from the terrestrial Streptomyces sp. Tü 6314. Its constitution was elucidated on the basis of NMR spectroscopic experiments and mass spectrometric analysis. Its stereostructure was investigated by peptide hydrolysis and derivatization and firmly established by X-ray structure analysis. In addition to the parent compound, a new cycloheptamycin analog, cycloheptamycin B, was discovered and structurally assigned using comparative MS/MS experiments and NMR. The biological profile of both compounds was investigated, revealing a selective inhibitory potential of cycloheptamycins against Propionibacterium acnes.

A Nanostructured Si/SiOC Composite Anode with Volume-Change-Buffering Microstructure for Lithium-Ion Batteries.

Si/SiOC composites are promising high-capacity anode materials for lithium-ion batteries since the SiOC matrix can effectively buffer the volumetric change of Si during cycling. However, a structure of Si nanoparticles (NPs) enwrapped by a continuous SiOC phase typically shows poor cyclic stability and low charge/discharge rate due to structure failure of bulk SiOC shells derived from carbon-rich organosilicon. To address this issue, in this work, an Si/SiOC nanocomposite with volume-change-buffering microstructure, in which Si NPs are uniformly dispersed in a matrix of SiOC nanospheres, has been synthesized. Our results show that the space between Si and SiOC NPs can accommodate the large volume change of Si during cycling and facilitate infiltration of the electrolyte. The nanostructured SiOC skeleton serves as both a mechanically robust buffer to alleviate the intrinsic expansion of Si and an effective electron conductor. The Si/SiOC NP composite displays significantly increased capacity and cyclic stability compared with pure SiOC, and delivers reversible capacities of around 800 mA h-1 g-1 at a current density of 100 mA g-1 (approximately 100 % capacity retention after 100 cycles) and around 600 mA h-1 g-1 at 500 mA g-1 (capacity retention about 80 % after 500 cycles).

Juanlimycins A and B, ansamycin macrodilactams from Streptomyces sp.

Ansamycins are a family of macrolactams characterized by an aromatic chromophore with an aliphatic chain (ansa chain) connected back to a nonadjacent position through an amide bond. This family has shown a high degree of druggability exemplified by rifamycins, maytansinoids, and geldanamycins. In this study, the isolation of two novel ansamycin macrodilactams with unprecedented features, juanlimycins A (1) and B (2), from Streptomyces sp. LC6 were reported. The structures of 1 and 2 were assigned on the basis of analysis of NMR spectroscopic data and X-ray single crystal diffraction.