Image_1_Arginine Catabolic Mobile Elements in Livestock-Associated Methicillin-Resistant Staphylococcal Isolates From Bovine Mastitic Milk in China.TIF

<p>The arginine catabolic mobile element (ACME) facilitates colonization of staphylococci on skin and mucous membranes by improving their tolerances to polyamines and acidic conditions. ACME is inserted in tandem with the SCCmec element and Staphylococcus epidermidis has been proposed to be a reservoir of ACME for other staphylococci. In this study, we investigated the existence of ACME in 146 staphylococcal isolates from mastitic milk and found 21 of them carried ACME. Almost half of the investigated S. epidermidis isolates contained the element. The whole genome of a S. epidermidis strain Y24 with ACME was further sequenced and the ACME-SCCmec composite island was assembled. This composite island is 81.3 kb long and consisted of 77 ORFs including a methicillin resistance gene mecA, a type II’ ACME gene cluster, a virulence gene pls and eight heavy metal tolerance genes. Wide existence of ACME in livestock-associated staphylococci from this study and a potential risk of spreading ACME among different staphylococcal species warrant close monitoring and further studies.</p

Table_1_Arginine Catabolic Mobile Elements in Livestock-Associated Methicillin-Resistant Staphylococcal Isolates From Bovine Mastitic Milk in China.DOCX

<p>The arginine catabolic mobile element (ACME) facilitates colonization of staphylococci on skin and mucous membranes by improving their tolerances to polyamines and acidic conditions. ACME is inserted in tandem with the SCCmec element and Staphylococcus epidermidis has been proposed to be a reservoir of ACME for other staphylococci. In this study, we investigated the existence of ACME in 146 staphylococcal isolates from mastitic milk and found 21 of them carried ACME. Almost half of the investigated S. epidermidis isolates contained the element. The whole genome of a S. epidermidis strain Y24 with ACME was further sequenced and the ACME-SCCmec composite island was assembled. This composite island is 81.3 kb long and consisted of 77 ORFs including a methicillin resistance gene mecA, a type II’ ACME gene cluster, a virulence gene pls and eight heavy metal tolerance genes. Wide existence of ACME in livestock-associated staphylococci from this study and a potential risk of spreading ACME among different staphylococcal species warrant close monitoring and further studies.</p

Clarifying the Roles of Oxygen Vacancy in W‑Doped BiVO₄ for Solar Water Splitting

Most oxide semiconductor photoanode materials for water splitting are synthesized in ambient environment. Oxygen vacancy exists in these samples making them intrinsically n-type at the as-synthesized state. Oxygen vacancy has been widely reported for enhancing the performance of a photoanode by improving the electron conductivity. Besides the effect on the bulk materials properties, oxygen vacancy also plays an important role in the interfacial charge transfer to electrolyte, on which much less attention has been paid in the past. Herein, we found that although air-annealed W-doped BiVO₄ has a higher electron density, lower surface charge transfer resistance, and a slightly better light absorption than the O₂-annealed sample, the latter displays a higher photocurrent density. Experimentally we found that the enhanced performance comes from a better charge separation efficiency, despite that the presence of oxygen vacancy does lead to a better charge transfer efficiency. Theoretical calculation finds that there is a localized state formed inside the bandgap in W-doped BiVO₄ with oxygen vacancy, which serves as recombination center to reduce its charge separation efficiency. Oxygen vacancy on the V site activates two different kinds of V into reactive sites for improved surface catalysis. Oxygen vacancy also facilitates the adsorption of the OH_ads, O_ads, and OOH_ads involved in a water splitting process, which benefits the surface catalytic process. It is predicted from this study that better performance can be achieved by introducing oxygen vacancy on the surface of a doped BiVO₄ and simultaneously avoiding oxygen vacancy in the bulk. The current study provides an important understanding of the roles played by oxygen vacancy in doped photoanode materials

Data_Sheet_1_Identification and Characterization of a Cis Antisense RNA of the rpoH Gene of Salmonella enterica Serovar Typhi.DOC

<p>Antisense RNAs from complementary strands of protein coding genes regulate the expression of genes involved in many cellular processes. Using deep sequencing analysis of the Salmonella enterica serovar Typhi (S. Typhi) transcriptome, a novel antisense RNA encoded on the strand complementary to the rpoH gene was revealed. In this study, the molecular features of this antisense RNA were assessed using northern blotting and rapid amplification of cDNA ends. The 3,508 nt sequence of RNA was identified as the antisense RNA of the rpoH gene and was named ArpH. ArpH was found to attenuate the invasion of HeLa cells by S. Typhi by regulating the expression of SPI-1 genes. In an rpoH mutant strain, the invasive capacity of S. Typhi was increased, whereas overexpression of ArpH positively regulates rpoH mRNA levels. Results of this study suggest that the cis-encoded antisense RNA ArpH is likely to affect the invasive capacity of S. Typhi by regulating the expression of rpoH.</p

Solvent-Assisted Surface Engineering for High-Performance All-Inorganic Perovskite Nanocrystal Light-Emitting Diodes

All-inorganic cesium halide perovskite nanocrystals have attracted much interest in optoelectronic applications for the sake of the readily adjustable band gaps, high photoluminescence quantum yield, pure color emission, and affordable cost. However, because of the ineluctable utilization of organic surfactants during the synthesis, the structural and optical properties of CsPbBr₃ nanocrystals degrade upon transforming from colloidal solutions to solid thin films, which plagues the device operation. Here, we develop a novel solvent-assisted surface engineering strategy, producing high-quality CsPbBr₃ thin films for device applications. A good solvent is first introduced as an assembly trigger to conduct assembly in a one-dimensional direction, which is then interrupted by adding a nonsolvent. The nonsolvent drives the adjacent nanoparticles connecting in a two-dimensional direction. Assembled CsPbBr₃ nanocrystal thin films are densely packed and very smooth with a surface roughness of ∼4.8 nm, which is highly desirable for carrier transport in a light-emitting diode (LED) device. Meanwhile, the film stability is apparently improved. Benefiting from this facile and reliable strategy, we have achieved remarkably improved performance of CsPbBr₃ nanocrystal-based LEDs. Our results not only enrich the methods of nanocrystal surface engineering but also shed light on developing high-performance LEDs

Data_Sheet_2_Identification and Characterization of a Cis Antisense RNA of the rpoH Gene of Salmonella enterica Serovar Typhi.DOCX

<p>Antisense RNAs from complementary strands of protein coding genes regulate the expression of genes involved in many cellular processes. Using deep sequencing analysis of the Salmonella enterica serovar Typhi (S. Typhi) transcriptome, a novel antisense RNA encoded on the strand complementary to the rpoH gene was revealed. In this study, the molecular features of this antisense RNA were assessed using northern blotting and rapid amplification of cDNA ends. The 3,508 nt sequence of RNA was identified as the antisense RNA of the rpoH gene and was named ArpH. ArpH was found to attenuate the invasion of HeLa cells by S. Typhi by regulating the expression of SPI-1 genes. In an rpoH mutant strain, the invasive capacity of S. Typhi was increased, whereas overexpression of ArpH positively regulates rpoH mRNA levels. Results of this study suggest that the cis-encoded antisense RNA ArpH is likely to affect the invasive capacity of S. Typhi by regulating the expression of rpoH.</p

Ultrasmall Metal–Organic Framework Zn-MOF-74 Nanodots: Size-Controlled Synthesis and Application for Highly Selective Colorimetric Sensing of Iron(III) in Aqueous Solution

Here, a novel colorimetric sensing platform for highly selective detection of Fe³⁺ in aqueous solutions was developed based on zero-dimensional Zn-MOF-74 [Zn₂(DOBDC), DOBDC = 2,5-dihydroxyterephthalic acid] nanodots. The first ultrasmall Zn-MOF-74 nanodots with the average size within 10 nm were successfully synthesized by manipulating the initial conditions with a diluted material system. It was found that the ultrasamll MOF nanodots had a highly selective interaction with Fe³⁺ and showed a specific blue colorimetric change in aqueous solution. The highly dispersive nature in aqueous solution and high surface-to-volume ratio help MOF-74 nanodots closely interact with the targeted Fe³⁺ ions with a low limit of detection of 1.04 μM and a fast response within seconds. Finally, we demonstrate that the selective Fe³⁺ sensing mechanism of Zn-MOF-74 nanodots is due to the selective framework disruption and the formation of Fe-DOBDC salt complex with blue color. It is the first report of nanoscale MOF based colorimetric Fe³⁺ sensor with low limit of detection (LOD) comparable even to fluorescent MOF based Fe³⁺ sensors, which could be easily observed by naked-eye without expensive fluorescence apparatuses. The good colorimetric stability in aqueous environment, low limit of detection, rapid response, and nanosize nature enable this MOF nanodot to be a good Fe³⁺ sensing probe for biological and environmental sensing applications

Probing the Performance Limitations in Thin-Film FeVO₄ Photoanodes for Solar Water Splitting

FeVO₄ is a potentially promising n-type multimetal oxide semiconductor for photoelectrochemical water splitting based on its favorable optical band gap of ca. 2.06 eV that allows for the absorption of visible light up to around 600 nm. However, the presently demonstrated photocurrent values on FeVO₄ photoanodes are yet considerably low when comparing with α-Fe₂O₃, although FeVO₄ can absorb comparable wavelengths of sunlight as α-Fe₂O₃. Donor-type doping and constructing nanoporous film morphology have afforded desirable (but far from satisfactory) improvements in FeVO₄ photoanodes, whereas the fundamental properties, such as absorption coefficients and the nature of optical transition, and a quantitative analysis of the efficiency losses for FeVO₄ photoanodes remain elusive. In the present study, we conduct a thorough experimental analysis of structural, optical, charge transport, and surface catalysis properties of FeVO₄ thin films to investigate and clarify how and where the efficiency losses occur. Based on the results, the charge recombination pathways and light-harvesting loss in FeVO₄ thin-film photoanodes are identified and quantitatively determined. Our study will deepen the understanding on the photoelectrochemical behaviors of FeVO₄ photoanodes and will also shed light on the optimization routes to engineer this material to approach its theoretical maximum

Additional file 1: of Sheng Jiang San, a traditional multi-herb formulation, exerts anti-influenza effects in vitro and in vivo via neuraminidase inhibition and immune regulation

Method of High-performance liquid chromatography (HPLC) analysis of SJS. HPLC method was used to analyze the chemical profile of SJS. The HPLC condition is described in this additional file and the profile is shown in Additional file 2: Figure S1. By comparing with reference compounds, rhein, chrysophanol, emodin, aloe emodin and curcumin were found. (DOCX 13 kb

Additional file 2: of Sheng Jiang San, a traditional multi-herb formulation, exerts anti-influenza effects in vitro and in vivo via neuraminidase inhibition and immune regulation

Figure S1. HPLC analysis of SJS (a) HPLC profile of SJS (b) Some constituents were denoted by standard compounds. (PPTX 128 kb