Categorization of the effects of E. coli LF82 and mutants lacking the chuT and shuU genes on survival, the transcriptome, and metabolome in germ-free honeybee.

The precise etiology of inflammatory bowel diseases (IBDs) remains elusive. The Escherichia coli strain LF82 (LF82) is known to be associated with IBD, and we hypothesized that this association may be related to the chuT and shuU genes. Here we constructed a germ-free (GF) honeybee model to investigate the effects of LF82 chuT and shuU genes on the honeybee intestine and their mechanisms. The chuT and shuU gene deletion strains LF82∆chuT and LF82∆shuU were generated by CRISPR-Cas9. These strains, together with nonpathogenic E. coli MG1655 (MG1655) and wildtype LF82, were allowed to colonize the guts of GF honeybees to establish single bacterial colonization models. Intestinal permeability was assessed following the administration of a sterile Brilliant Blue (FCF) solution. Comprehensive transcriptomic and metabolomic analyses of intestinal samples indicated that MG1655 had few disadvantageous effects on honeybees. Conversely, colonization with LF82 and its gene-deletion mutants provoked pronounced activation of genes associated with innate immune pathways, stimulated defensive responses, and induced expression of genes associated with inflammation, oxidative stress, and glycosaminoglycan degradation. Crucially, the LF82∆chuT and LF82∆shuU strains perturbed host heme and iron regulation, as well as tryptophan metabolism. These findings suggest that the deletion of chuT and shuU genes in E. coli LF82 may alleviate intestinal inflammation by partially modulating tryptophan catabolism. Our study proposes that targeting iron uptake mechanisms could be a potential strategy to mitigate the virulence of IBD-associated bacteria.

PEDOT-embellished Ti3C2Tx nanosheet supported Pt-Pd bimetallic nanoparticles as efficient and stable methanol oxidation electrocatalysts.

Exploiting high-efficiency and durable electrocatalysts toward the methanol oxidation reaction (MOR) is crucial for the advancement of direct methanol fuel cells (DMFCs). Herein, we demonstrate the loading of platinum-palladium bimetallic nanoparticles (Pt-Pd NPs) onto poly(3,4-ethylenedioxythiophene) (PEDOT)-embellished titanium carbide (Ti3C2Tx) nanosheets as the electrocatalyst (Ti3C2Tx/PEDOT/Pt-Pd) via a facile and rapid chemical reduction-assisted one-pot hydrothermal process. The structural and morphological analyses of Ti3C2Tx/PEDOT/Pt-Pd indicate that the three-dimensional (3D) hybrid structure formed between PEDOT and Ti3C2Tx provides a sizable active surface and more active sites, which enhances the homogeneous dispersion of the Pt-Pd NPs and facilitates mass transfer. The Schottky junctions formed between PEDOT and Pt-Pd NPs contribute to charge transfer. The electronic effects and synergistic interactions between the support and catalyst favor the electrocatalytic activity of the catalyst. The electrochemical test results reveal that the Ti3C2Tx/PEDOT/Pt-Pd catalyst has prominent electrocatalytic capability for the MOR. Compared with Ti3C2Tx/Pt-Pd and commercial Pt/C catalysts, the Ti3C2Tx/PEDOT/Pt-Pd catalyst has a larger electrochemical activity surface area (ECSA = 122 m2 g-1) and higher mass activity (MA = 1445.4 mA mg-1), as well as better CO tolerance and more reliable long-term durability (a peak current density retention of 71% after 5200 s).

Ultraviolet Photodetector Based on Poly(3,4-Ethylenedioxyselenophene)/ZnO Core-Shell Nanorods p-n Heterojunction.

In this work, we successfully assembled an organic-inorganic core-shell hybrid p-n heterojunction ultraviolet photodetector by the electropolymerization deposition of poly(3,4-ethylenedioxyselenophene) (PEDOS) on the surface of zinc oxide nanoarrays (ZnO NRs). The structures of composite were confirmed by FTIR, UV-Vis, XRD and XPS. Mott-Schottky analysis was used to study the p-n heterojunction structure. The photodetection properties of ZnO NRs/PEDOS heterojunction ultraviolet photodetector were systematically investigated current-voltage (I-V) and current-time (I-t) analysis under different bias voltages. The results showed that PEDOS films uniformly grew on ZnO NRs surface and core-shell structure was formed. The p-n heterojunction structure was formed with strong built-in electric field between ZnO NRs and PEDOS. Under the irradiation of UV light, the device showed a good rectification behavior. The responsivity, detection rate and the external quantum efficiency of the ultraviolet photodetector reached to 247.7 A/W, 3.41 × 1012 Jones and 84,000% at 2 V bias, respectively. The rise time (τr) and fall time (τf) of ZnO NRs/PEDOS UV photodetector were obviously shortened compared to ZnO UV photodetector. The results show that the introduction of PEDOS effectively improves the performance of the UV photodetector.

Electrochemical sensor formed from poly(3,4-ethylenedioxyselenophene) and nitrogen-doped graphene composite for dopamine detection.

In this study, an electrochemical sensor for dopamine (DA) detection has been developed by a composite of poly(3,4-ethylenedioxyselenophene) (PEDOS) and nitrogen-doped graphene (PEDOS/N-Gr) using an in situ polymerization method. Its structure and properties were then compared with those of the composites of poly(3,4-ethylenedioxythiophene) (PEDOT)/nitrogen-doped graphene (PEDOT/N-Gr), which were prepared by the same methods. FT-IR, Raman, UV-vis, XPS, mapping and SEM investigated the structure and morphology of these composites. These revealed that PEDOS/N-Gr had a higher conjugation degree than PEDOT/N-Gr. The synergetic effect between PEDOS and N-Gr was beneficial for the formation of a homogenous surface coating. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were conducted for electrochemical detection of DA. Compared with PEDOT/N-Gr, the PEDOS/N-Gr displayed an enhanced sensitivity and electrocatalytic performance for DA detection with linear ranges of 0.008-80 µM (PEDOT/N-Gr: 0.04-70 µM) and limits of detection (LOD) of 0.0066 µM (S/N = 3) (PEDOT/N-Gr: 0.018 µM (S/N = 3)).

Decode-seq: a practical approach to improve differential gene expression analysis.

Many differential gene expression analyses are conducted with an inadequate number of biological replicates. We describe an easy and effective RNA-seq approach using molecular barcoding to enable profiling of a large number of replicates simultaneously. This approach significantly improves the performance of differential gene expression analysis. Using this approach in medaka (Oryzias latipes), we discover novel genes with sexually dimorphic expression and genes necessary for germ cell development. Our results also demonstrate why the common practice of using only three replicates in differential gene expression analysis should be abandoned.

3D Hierarchically Structured CoS Nanosheets: Li+ Storage Mechanism and Application of the High-Performance Lithium-Ion Capacitors.

Lithium-ion capacitors possess excellent power and energy densities, and they can combine both of those advantages from supercapacitors and lithium-ion batteries, leading to novel generation hybrid devices for storing energy. This study synthesized one three-dimensional (3D) hierarchical structure, self-assembled from CoS nanosheets, according to a simple and efficient manner, and can be used as an anode for lithium ion capacitors. This CoS anode, based on a conversion-type Li+ storage mechanism dominated by diffusion control, showed a large reversible capacity, together with excellent stability for cycling. The CoS shows a discharge capacity ≈434 mA h/g at 0.1 A/g. The hybrid lithium-ion capacitor, which had the CoS anode as well as the biochar cathode, exhibits excellent electrochemical performance with ultrahigh energy and power densities of 125.2 Wh/kg and 6400 W/kg, respectively, and an extended cycling life of 81.75% retention after 40 000 cycles. The CoS with self-assembled 3D hierarchical structure in combination with a carbon cathode offers a versatile device for future applications in energy storage.

A facile strategy for the synthesis of three-dimensional heterostructure self-assembled MoSe2 nanosheets and their application as an anode for high-energy lithium-ion hybrid capacitors.

As energy storage devices, lithium-ion hybrid capacitors (LIHCs) are currently favored by researchers, because they combine the high energy density of lithium-ion batteries and the high power density as well as the long cycle life of electric double-layer capacitors. However, the reason that LIHCs are problematic for researchers and cannot be applied practically is the slow dynamic behavior of the battery type anode that leads to low magnification and cycle performance of the anode, furthermore, causing a dynamic imbalance between the Faraday embedded electrode and the capacitive electrode. Hence, it is imperative to find an anode material that can quickly intercalate/de-intercalate lithium. In this study, a novel anode material, MoSe2 nanoflowers, for LIHCs was incorporated through a facile solvothermal technique. The MoSe2 nanoflowers with a small volume change after Li+ insertion, conducive to a rapid kinetic layered heterostructure, result in extraordinary electrochemical performance. The prepared MoSe2 nanoflowers exhibit very good invertible capacity (641.4 mA h g-1 at 0.1 A g-1 after 200 cycles), superior velocity performance (380.3 mA h g-1 at 5 A g-1) and long-term cycling stability (214.6 mA h g-1 even after 1000 cycles at 1 A g-1) as anode materials for LIHCs. Benefiting from the reasonable nanometer size effect, locally fine charge transfers and low energy diffusion barriers, MoSe2 nanoflowers possess high rate pseudocapacitive behavior. In addition, the assembled MoSe2//AC (AC, activated carbon) LIHCs deliver a high energy density (78.75-39.1 W h kg-1) and high-power characteristic (150-3600 W kg-1). Besides, after 5000 cycles, the capacity retention rate is 70.28% under a broad potential window (0.5-3.5 V). This LIHC based on a transition metal selenide as an anode shows great potential for application in the fields of new energy electric vehicles and smart electronic products.

Complete genome sequence and genomic characterization of Microcystis panniformis FACHB 1757 by third-generation sequencing.

The cyanobacterial genus Microcystis is well known as the main group that forms harmful blooms in water. A strain of Microcystis, M. panniformis FACHB1757, was isolated from Meiliang Bay of Lake Taihu in August 2011. The whole genome was sequenced using PacBio RS II sequencer with 48-fold coverage. The complete genome sequence with no gaps contained a 5,686,839 bp chromosome and a 38,683 bp plasmid, which coded for 6,519 and 49 proteins, respectively. Comparison with strains of M. aeruginosa and some other water bloom-forming cyanobacterial species revealed large-scale structure rearrangement and length variation at the genome level along with 36 genomic islands annotated genome-wide, which demonstrates high plasticity of the M. panniformis FACHB1757 genome and reveals that Microcystis has a flexible genome evolution.