Base-assisted transmetalation enables gold-catalyzed oxidative Sonogashira coupling reaction.

The traditional transition metal catalyzed neutral C(sp)-C(sp) cross-coupling reaction between a nucleophile and an electrophile is a key technique for the formation of carbon-carbon bonds. Herein, we present a general gold-catalyzed oxidative Sonogashira cross-coupling of arylboronic acids and terminal arylalkynes at room temperature with excellent functional-group tolerance and good chemoselectivity. Moreover, our mechanistic studies suggested a third pathway involving a base-assisted transmetalation between the gold(I) catalyst and aryl boronic acid might predominate in our reaction conditions, rather than the previously assumed oxidation of the gold(I) complex or deprotonation of alkynes.

Enhancing Char Formation and Flame Retardancy of Ethylene-Vinyl Acetate Copolymer (EVA)/Aluminum Hydroxide (ATH) Composites by Grafting Ladder Phenyl/Vinyl Polysilsesquioxane (PhVPOSS).

The ladder phenyl/vinyl polysilsesquioxane (PhVPOSS) was used to improve the flame-retardancy performances of ethylene-vinyl acetate copolymer (EVA)/aluminum hydroxide (ATH) composites due to the reactivity of its vinyl groups. FTIR, XPS, H NMR, and SEM-EDS data demonstrated the PhVPOSS grafting onto EVA molecular chains. The PhVPOSS improved the thermal stability of EVA/ATH composites, as shown by the thermogravimetric analysis (TGA).

Flame Retardancy of Nylon 6 Fibers: A Review.

As synthetic fibers with superior performances, nylon 6 fibers are widely used in many fields. Due to the potential fire hazard caused by flammability, the study of the flame retardancy of nylon 6 fibers has been attracting more and more attention. The review has summarized the present research status of flame-retarded nylon 6 fibers from three aspects: intrinsic flame-retarded nylon 6, nylon 6 composites, and surface strategies of nylon 6 fibers/fabrics.

Fabrication of an Eco-Friendly Clay-Based Coating for Enhancing Flame Retardant and Mechanical Properties of Cotton Fabrics via LbL Assembly.

An eco-friendly clay-based synergistic flame-retardant coating was established on cotton fabrics via facile layer-by-layer assembly derived from polyethyleneimine (PEI), attapulgite clay (ATP), and phytic acid (PA). The fabricated flame-retardant (FR) cotton fabrics demonstrated improved thermal stability. Compared to untreated cotton fabrics, the limiting oxygen index of Cotton-8TL was improved to 27.

Photoinduced inverse Sonogashira coupling reaction.

Alkynes are widely used in chemistry, medicine and materials science. Here we demonstrate a transition-metal and photocatalyst-free inverse Sonogashira coupling reaction between iodoalkynes and (hetero)arenes or alkenes under visible-light irradiation. Mechanistic and computational studies suggest that iodoalkynes can be directly activated by visible light irradiation, and an excited state iodoalkyne acted as an "alkynyl radical synthetic equivalent", reacting with a series of C(sp)-H bonds for coupling products.

Preparation and Characterization of TCPP-CaMMT Nanocompound and Its Composite with Polypropylene.

Based on the molecular dynamics method, the tris-(1-chloropropan-2yl) phosphate (TCPP)/montmorillonite (MMT) molecular model was established to study the binding energy and microstructure changes in TCPP and MMT. The theoretical simulation results showed that TCPP can enter the MMT layer and increase the layer spacing. From this, an organic intercalated Ca-montmorillonite TCPP-CaMMT was prepared by a very simple direct mixing method using flame retardant TCPP as a modifier.

Micro-Nanometer Particle Composition and Functional Design of Surface Nano-Structured Ammonium Polyphosphate and Its Application in Intumescent Flame-Retardant Polypropylene.

A novel composite and functional micro-nanometer particle is designed by the hydrolysis of aluminium isopropoxide on the surface of ammonium polyphosphate (APP) to prepare surface nanostructured ammonium polyphosphate (NSAPP). NSAPP is characterised by XPS, XRF, SEM, water solubility tests, and TGA. Results indicate that nanosized aluminium hydroxide is deposited on the surface of NSAPP, which enhanced its water resistance and thermostability.

A cross-linked charring strategy for mitigating the hazards of smoke and heat of aluminum diethylphosphonate/polyamide 6 by caged octaphenyl polyhedral oligomeric silsesquioxanes.

Aluminum diethylphosphonate (ADP) is a highly efficient phosphorus-based flame retardant, widely used in polyamide 6 (PA6). However, ADP/PA6 releases large amounts of heat and smoke under high heat flux, which commonly means serious hazards to life and property. Octaphenyl polyhedral oligomeric silsesquioxanes (OPS) is an organic-inorganic hybrid silicon compound, playing flame retardant role in condensed phase.

The Role of Intestinal Bacteria and Gut-Brain Axis in Hepatic Encephalopathy.

Hepatic encephalopathy (HE) is a neurological disorder that occurs in patients with liver insufficiency. However, its pathogenesis has not been fully elucidated. Pharmacotherapy is the main therapeutic option for HE.

MegaPath: sensitive and rapid pathogen detection using metagenomic NGS data.

Background: Next-generation sequencing (NGS) enables unbiased detection of pathogens by mapping the sequencing reads of a patient sample to the known reference sequence of bacteria and viruses. However, for a new pathogen without a reference sequence of a close relative, or with a high load of mutations compared to its predecessors, read mapping fails due to a low similarity between the pathogen and reference sequence, which in turn leads to insensitive and inaccurate pathogen detection outcomes.

Results: We developed MegaPath, which runs fast and provides high sensitivity in detecting new pathogens.

Functional analysis of the agnH gene involved in nicotine-degradation pathways in Agrobacterium tumefaciens strain SCUEC1.

Agrobacterium tumefaciens strain SCUEC1 is a nicotine-degrading bacterium, which has been recently isolated from the tobacco waste-contaminated field soil. However, the mechanism for nicotine degradation in this strain remains unclear. Here, we analyze the function and biological properties of the agnH gene in the strain SCUEC1.

Potential utility of metagenomic sequencing for improving etiologic diagnosis of infective endocarditis.

To explore potential utility of metagenomic sequencing for improving etiologic diagnosis of infective endocarditis (IE) caused by fastidious bacteria. Plasma and heart valves of two patients, who were diagnosed with IE caused by and species, were sequenced by using Illumina MiSeq and Nanopore MinION. For patient 1, was detected in the plasma pool collected 4 days before valvular replacement surgery.

Study on Interaction between Propargyl-Terminated Polybutadiene and Plasticizers Based on Simulation and Experiments.

Molecular dynamics (MD) simulation and experimental methods are used to explore the interaction between the propargyl-terminated polybutadiene (PTPB) binder and plasticizers bis(2,2-dinitropropyl) formal/acetal (BDNPF/A) and dioctyl sebacate (DOS). Flory-Huggins parameters, radial distribution functions, and binding energies between PTPB and plasticizers are calculated using MD simulations. The solubility parameters of PTPB and the plasticizers are calculated by both MD and group contribution method.

AC-DIAMOND v1: accelerating large-scale DNA-protein alignment.

Summary: AC-DIAMOND (v1) is a DNA-protein alignment tool designed to tackle the efficiency challenge of aligning large amount of reads or contigs to protein databases. When compared with the previously most efficient method DIAMOND, AC-DIAMOND gains a 6- to 7-fold speed-up, while retaining a similar degree of sensitivity. The improvement is rooted at two aspects: first, using a compressed index of seeds with adaptive-length to speed-up the matching between query and reference sequences; second, adopting a compact form of dynamic programing to fully utilize the parallelism of the SIMD capability.

MegaGTA: a sensitive and accurate metagenomic gene-targeted assembler using iterative de Bruijn graphs.

Background: The recent release of the gene-targeted metagenomics assembler Xander has demonstrated that using the trained Hidden Markov Model (HMM) to guide the traversal of de Bruijn graph gives obvious advantage over other assembly methods. Xander, as a pilot study, indeed has a lot of room for improvement. Apart from its slow speed, Xander uses only 1 k-mer size for graph construction and whatever choice of k will compromise either sensitivity or accuracy.

MEGAHIT v1.0: A fast and scalable metagenome assembler driven by advanced methodologies and community practices.

The study of metagenomics has been much benefited from low-cost and high-throughput sequencing technologies, yet the tremendous amount of data generated make analysis like de novo assembly to consume too much computational resources. In late 2014 we released MEGAHIT v0.1 (together with a brief note of Li et al.

MEGAHIT: an ultra-fast single-node solution for large and complex metagenomics assembly via succinct de Bruijn graph.

MEGAHIT is a NGS de novo assembler for assembling large and complex metagenomics data in a time- and cost-efficient manner. It finished assembling a soil metagenomics dataset with 252 Gbps in 44.1 and 99.

Evaluation of meat as a first complementary food for breastfed infants: impact on iron intake.

The rationale for promoting the availability of local, affordable, non-fortified food sources of bioavailable iron in developing countries is considered in this review. Intake of iron from the regular consumption of meat from the age of 6 months is evaluated with respect to physiological requirements. Two major randomized controlled trials evaluating meat as a first and regular complementary food are described in this article.