A proton-conducting lanthanide metal-organic framework integrated with a dielectric anomaly and second-order nonlinear optical effect

National Basic 25 Research Program of China (973 Program) [2012CB821700]; National Natural Science Foundation of China [20831002, 20502024]; China Postdoctoral Science Foundation [20100481049]; Scientific Research Program from the Education Department of Shaanxi Provincial Government [2013JK0654]; Priming Scientific Research Foundation [BS1115]; Provincial Innovation Training Project [1399]A multifunctional metal-organic framework generated from chiral tricarboxylate ligands and gadolinium ions has been successfully synthesized and characterized. It shows proton conduction, dielectric anomalous behaviour and a second-order NLO effect

Preparation and property evaluation of vitamin A cyclodextrin inclusion complex

Hydroxypropyl-β-cyclodextrin (HP-β-CD) is widely used in drug encapsulation and cosolvent of insoluble drugs, modified HP-β-CD derivatives may to make pH sensitive by introducing functional groups. In this study, HP-β-CD derivative was prepared by oxidation cross-linking method with urea as the crosslinker agent. HP-β-CD derivatives and vitamin A (VA) inclusion complex were characterized using FT-IR, DSC, XRD and SEM. The solubilization effect, encapsulation efficiency (EE, %), loading content (LC, %) and in vitro release behavior of cyclodextrin derivatives on VA also investigated at different pH. The experimental results show that urea linked HP-β-CD can significantly increase the solubility of VA up to 32 times then pure water, the EE of the VA inclusion complex reach 66.88±4.56%, and the LC was 15.38±1.12%, The 24h in vitro cumulative release reaches 95.91%(pH=4.5) and 66.68%(pH=7.0) when the ratio of urea to HP-β-CD was 3:1. The HP-β-CD derivatives can increase the solubility of VA and the drug release has pH sensitivity

Molecular Fingerprint and Dominant Environmental Factors of Nitrite-Dependent Anaerobic Methane-Oxidizing Bacteria in Sediments from the Yellow River Estuary, China

<div><p>Nitrite-dependent anaerobic methane oxidation (n-damo) is performed by “<i>Candidatus Methylomirabilis oxyfera</i>” (<i>M</i>. <i>oxyfera</i>), which connects the carbon and nitrogen global nutrient cycles. In the present study, <i>M</i>. <i>oxyfera</i>-like bacteria sequences were successfully recovered from Yellow River Estuary sediments using specific primers for 16S rRNA and <i>pmoA</i> genes. A <i>M</i>. <i>oxyfera</i>-like sequences analysis based on the 16S rRNA gene revealed greater diversity compared with the <i>pmoA</i> gene; the 16S rRNA gene sequences retrieved from the Yellow River Estuary sediments belong to groups A as well as B and were mainly found in freshwater habitats. Quantitative PCR showed that 16S rRNA gene abundance varied from 9.28±0.11×10³ to 2.10±0.13×10⁵ copies g^-1 (dry weight), and the <i>pmoA</i> gene abundance ranged from 8.63±0.50×10³ to 1.83±0.18×10⁵ copies g^-1 (dry weight). A correlation analysis showed that the total organic carbon (TOC) and ammonium (NH₄⁺) as well as the ratio of total phosphorus to total nitrogen (TP/TN) influenced the <i>M</i>. <i>oxyfera</i>-like bacteria distribution in the Yellow River Estuary sediments. These findings will aid in understanding the n-damo bacterial distribution pattern as well as their correlation with surrounding environmental factors in temperate estuarine ecosystems.</p></div

High-Resolution Small RNAs Landscape Provides Insights into Alkane Adaptation in the Marine Alkane-Degrader <i>Alcanivorax dieselolei</i> B-5

Alkanes are widespread in the ocean, and Alcanivorax is one of the most ubiquitous alkane-degrading bacteria in the marine ecosystem. Small RNAs (sRNAs) are usually at the heart of regulatory pathways, but sRNA-mediated alkane metabolic adaptability still remains largely unknown due to the difficulties of identification. Here, differential RNA sequencing (dRNA-seq) modified with a size selection (~50-nt to 500-nt) strategy was used to generate high-resolution sRNAs profiling in the model species Alcanivorax dieselolei B-5 under alkane (n-hexadecane) and non-alkane (acetate) conditions. As a result, we identified 549 sRNA candidates at single-nucleotide resolution of 5′-ends, 63.4% of which are with transcription start sites (TSSs), and 36.6% of which are with processing sites (PSSs) at the 5′-ends. These sRNAs originate from almost any location in the genome, regardless of intragenic (65.8%), antisense (20.6%) and intergenic (6.2%) regions, and RNase E may function in the maturation of sRNAs. Most sRNAs locally distribute across the 15 reference genomes of Alcanivorax, and only 7.5% of sRNAs are broadly conserved in this genus. Expression responses to the alkane of several core conserved sRNAs, including 6S RNA, M1 RNA and tmRNA, indicate that they may participate in alkane metabolisms and result in more actively global transcription, RNA processing and stresses mitigation. Two novel CsrA-related sRNAs are identified, which may be involved in the translational activation of alkane metabolism-related genes by sequestering the global repressor CsrA. The relationships of sRNAs with the characterized genes of alkane sensing (ompS), chemotaxis (mcp, cheR, cheW2), transporting (ompT1, ompT2, ompT3) and hydroxylation (alkB1, alkB2, almA) were created based on the genome-wide predicted sRNA–mRNA interactions. Overall, the sRNA landscape lays the ground for uncovering cryptic regulations in critical marine bacterium, among which both the core and species-specific sRNAs are implicated in the alkane adaptive metabolisms

A neighbor-joining phylogenetic tree showing the phylogenetic affiliations of <i>M</i>. <i>oxyfera</i>-like bacteria <i>pmoA</i> gene sequences from the Yellow River Estuary.

<p>The bootstrap values were based on 1,000 replicates, the scale bar represents 10% sequence divergence, and only >50% values are shown. In brackets, the numbers preceding the slash represent the number of clones belong to the OTU, and the numbers following the slash represent the total number of clones in corresponding clone libraries.</p