The genome and transcriptome of Japanese flounder provide insights into flatfish asymmetry

Flatfish have the most extreme asymmetric body morphology of vertebrates. During metamorphosis, one eye migrates to the contralateral side of the skull, and this migration is accompanied by extensive craniofacial transformations and simultaneous development of lopsided body pigmentation(1-5). The evolution of this developmental and physiological innovation remains enigmatic. Comparative genomics of two flatfish and transcriptomic analyses during metamorphosis point to a role for thyroid hormone and retinoic acid signaling, as well as phototransduction pathways. We demonstrate that retinoic acid is critical in establishing asymmetric pigmentation and, via cross-talk with thyroid hormones, in modulating eye migration. The unexpected expression of the visual opsins from the phototransduction pathway in the skin translates illumination differences and generates retinoic acid gradients that underlie the generation of asymmetry. Identifying the genetic underpinning of this unique developmental process answers long-standing questions about the evolutionary origin of asymmetry, but it also provides insight into the mechanisms that control body shape in vertebrates.National Natural Science Foundation of China [31130057, 31461163005, 31530078, 31472269, 31472262, 31472273]; State 863 High Technology R&D Project of China [2012AA092203, 2012AA10A408, 2012AA10A403-2]; Education and Research of Guangdong Province [2013B090800017]; Taishan Scholar Climb Project Fund of Shandong of China; Taishan Scholar Project Fund of Shandong of China for Young Scientists; Shanghai Universities First-class Disciplines Project of Fisheries; Program for Professor of Special Appointment (Eastern Scholar) at the Shanghai Institutions of Higher Learning; Shanghai Municipal Science, Special Project on the Integration of Industryinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/publishedVersio

Processing and Microstructural Characterization of Ultra-High Temperature Ceramics

Spark plasma sintering (SPS), also known as direct current sintering (DCS) is an advanced sintering technique that and uses a continuous pulsed direct current to rapidly process materials through Joule heating and offers significant advantages and versatility over conventional sintering methods. The technique features in energy saving owing to high heating rates and is very suitable for consolidation as well as diffusion bonding of electrical conductive advanced ceramic materials such as ultra high temperature ceramics (UHTCs). However, cooling rate in SPS also plays an important role as it directly influences the generation of residual stress especially for specimens consist of dissimilar phases such as composites and laminates primarily due to CTE mismatch. Therefore, in order to produce high quality materials, a zirconium diboride with addition of silicon carbide (ZrB2-SiC) ultra high temperature ceramic composite is selected to investigate the effect of cooling rate in SPS on microstructure and mechanical properties. After being densified at the target temperature, ZrB2-25vol%SiC specimens are cooled from 1800°C using controlled cooling rates of 10 °C/minute to ~225.5 °C/minute (free cooling). A time dependent finite element analysis (FEA) model is used to simulate the temperature gradients across the specimens at dwell times and during the cooling processes. The residual stress within the specimens are experimentally verified using X-ray diffraction (XRD) and Raman spectrometry, and found maximum residual stress within the specimen cooled at 225.5 °C/minute. Peak Hardness and moderate elastic modulus is found for specimen sintered at 1800 °C and cooled at 100 °C/minute, which make this temperature and cooling rate appropriate conditions for future fabrication of UHTCs with similar thermal and electrical properties. These materials are of great interest for their excellent high-temperature capabilities, wear and corrosion resistance, and are regarded as material candidates for engineering applications in extreme environments. Therefore, development of an effective joining technique is important since near-net shape fabrication is challenging, and joints formed by brazing or conventional solid-state diffusion bonding limit the mechanical strength and high temperature applications of the base materials. Using SPS we have rapidly and successfully joined ZrB2 to hafnium diboride (HfB2) at 1750 and 1800 °C within a minute through electric current assisted solid-state diffusion bonding. The electric current enables localized Joule heating as well as plastic deformation of the mating surface asperities, and enhances the elemental interdiffusion process at the HfB2/ZrB2 interfaces owing to electromigration, which leads to the formation of ZrxHf1-xB2 solid solution. A series of characterization and analytical techniques including scanning electron microscopy (SEM), wavelength dispersive spectroscopy (WDS), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (S/TEM) are employed to study the microstructure and chemical composition at of the HfB2/ZrB2 interfaces. Apart from enhanced diffusion as a result of electromigration, the applied electric current can also be use to promote plastic deformation in ZrB2, which does not go through gross plastic deformation due to its extremely high melting point and brittle nature even when elevated temperature and pressure are applied. Through “electroplastic effect” (an effect based on electromigration) the mobility and multiplication of the existing dislocations in ZrB2 is enhanced, and a “metal-like” primary recrystallization phenomenon in the ZrB2 is observed meaning the material has experienced a sufficient amount of plastic deformation and reached the critical dislocation density and configuration for nucleation of “strain-free” grains. The average grain size of the recrystallized grain is only ½ of its original value. These findings suggest great potentials in microstructural tailoring and grain refinement of conductive advanced ceramics using SPS, and provide promising ideas for future fabrications and applications.Release after 30-Dec-201

Synthesis of novel pyridinium N-chloramine precursors and its antimicrobial application on cotton fabrics

To control pathogenic microbial contamination on polymeric material surface, it is pivotal to develop materials with efficacious antimicrobial activity. Two pyridinium N-chloramine precursors containing a siloxane handle were synthesized, characterized, and grafted onto cotton fabrics. The attenuated total reflectance spectra and scanning electron microscope photo analysis indicated that the cotton fabric surface was successfully modified. The resultant chlorinated fabric samples were challenged against bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Results showed that: (1) the surface modified cotton fabrics displayed satisfactory biocidal efficacy; (2) the precursor structure played a major role on surface grafting and antibacterial activity. This work provides two promising pyridinium N-chloramine precursors which hold potential application for preparing antibacterial textile materials. (C) 2017 Wiley Periodicals, Inc

Mixed anionic surfactant-templated mesoporous silica nanoparticles for fluorescence detection of Fe3+

This work demonstrates a novel method for the synthesis of large pore mesoporous silica nanoparticles (MSNs) with a pore diameter of 10.3 nm and a particle diameter of ∼50 nm based on the incorporation of mixed anionic surfactants sodium dodecyl benzene sulfonate (SDBS) and sodium dodecyl sulphate (SDS) as the template in the synthesis process. The dispersity, morphology, pore structure and size of mesoporous nanoparticles were adjusted by changing the molar ratio of two anionic surfactants, the concentration of the co-structure-directing agent (3-aminopropyltrimethoxysilane) and the reaction temperature. The results of synthesis experiments suggested that the formation of large pore MSNs involved a nucleation and growth process. MSNs were post-grafted with a Schiff base moiety for fluorescence sensing of Fe3+ in water. The applicability of functionalized MSNs was demonstrated by selective fluorescence detection of Fe3+ in aqueous media.Validerad; 2016; Nivå 2; 20151207 (andbra)</p

Novel N-chloramine precursors for antimicrobial application: synthesis and facile covalent immobilization on polyurethane surface based on perfluorophenyl azide (PFPA) chemistry

To control the pathogen cross contaminations on medical material surface, there is a pressing need to develop antimicrobial materials with highly efficacious surface biocidal activity. In this work, N-chloramine precursors containing a quaternary ammonium unit and perfluorophenyl azide unit were synthesized and covalently immobilized on inert polyurethane (PU) film upon UV light irradiation. The surface modification was confirmed by contact angle, Fourier transform infrared (ATR FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) analyses. After bleaching treatment, satisfactory biocidal activity was achieved for the surface-modified PU films. It was found that the introduced surface QA center contributed an even faster surface contact killing behavior and that precursors with a longer structural linker caused higher surface chlorine content and higher antimicrobial efficacy. This approach provides a novel and facile method that enables the covalent immobilization of N-chloramine precursors on inert polymeric surface to produce durable antimicrobial materials

Leaf-Associated Shifts in Bacterial and Fungal Communities in Response to Chicken Rearing Under Moso Bamboo Forests in Subtropical China

Integrated bamboo-chicken farming (BCF) systems are a traditional agroforestry pattern with large economic benefits in subtropical China. However, little is known regarding the effect of this integration on the bamboo leaf-associated microbiome, which can be very important for disease control and nutrient turnover. In the present study, we compared the leaf-associated bacterial and fungal communities of moso bamboo (Phyllostachys edulis) in a BCF system and an adjacent moso bamboo forest (MBF). The results showed that Cyanobacteria and Ascomycota were the predominant microbial phyla associated with bamboo leaves. Chicken farming under the bamboo forest significantly increased the bacterial and fungal alpha diversity (observed operational taxonomic units (OTUs) and Simpson&rsquo;s index) associated with bamboo leaves. Principal components analysis (PCoA) further confirmed the shifts in the bacterial and fungal communities caused by chicken farming. Based on the observed relative abundances, the phyla Bacteroidetes, Actinobacteria, TM7, and Basidiomycota were significantly increased on BCF-associated leaves compared with MBF leaves, while Acidobacteria and Ascomycota were significantly decreased. An ecological function prediction analysis based on metabolic processes indicated that BCF could accelerate nutrient (C, N, and S) cycling but may increase the risk of fungal-associated diseases. Our findings suggest that shifts in leaf-associated bacterial and fungal communities can be important indicators for the scientific management of BCF systems

Changes of Root Endophytic Bacterial Community Along a Chronosequence of Intensively Managed Lei Bamboo (Phyllostachys praecox) Forests in Subtropical China

Endophytic bacteria widely exist inside plant tissues and have an important role in plant growth and development and the alleviation of environmental stress. However, little is known about the response of root-associated bacterial endophytes of Lei bamboo (Phyllostachys praecox) to intensive management, which is a common management practice for high bamboo shoot production in subtropical China. In this study, we comparatively investigated the root endophytic bacterial community structures in a chronosequence of intensively managed (5a, 10a, 15a, and 20a) and extensively managed plantations (as control, Con). The results showed that endophytic Proteobacteria was the dominant bacterial phylum in the bamboo roots. Intensive management significantly increased (p &lt; 0.05) the bacterial observed species and Chao1 (except 5a) indices associated with bamboo roots. The relative abundances of Firmicutes, Bacteroidetes, and Actinobacteria (except 15a) in the intensively managed bamboo roots significantly increased (p &lt; 0.05) compared with those in Con, while the relative abundance of Proteobacteria significantly decreased in intensively managed bamboo roots (p &lt; 0.05). The phyla Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were the biomarkers in Con, 5a, 15a, and 20a, respectively. Redundancy analysis (RDA) showed that soil alkali-hydrolysable N (AN), available phosphorus (AP), available K (AK), and total organic carbon (TOC) were significantly correlated (p &lt; 0.05) with the bacterial community compositions. Our results suggest that the root endophytic microbiome of Lei bamboo was markedly influenced by intensive management practices, and the available nutrient status could be the main driving factor for such shifts. Although heavy fertilization in the intensive management system increased the diversity indices, the rapid changes in root endophyte communities and their relevant functions might indicate a high risk for sustainable management

Synthesis of quaternary phosphonium N-chloramine biocides for antimicrobial applications

The recently developed quaternary ammonium (QA) N-chloramine has been proved to be a promising "composite" biocide with drastically boosted antibacterial efficacy afforded by the QA moiety. In this work, a series of quaternary phosphonium (QP) N-chloramine biocides, covalently combining an N-chloramine moiety and a QP moiety via varied aliphatic methylene units, were synthesized by means of multi-step chemical reactions. Preliminary antibacterial tests against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) showed that the synthetic QP N-chloramine exhibited distinctively higher biocidal efficacy than the QA counterpart. Furthermore, bactericidal tests also indicated that QP N-chloramine with a linker of -(CH2)(12)-showed the highest biocidal efficacy, suggesting synergistic action between the N-chloramine moiety and QP moiety