Anion exchange membranes with a semi-interpenetrating polymer network using 1,6-dibromohexane as bifunctional crosslinker

An anion exchange membrane(AEM)is generally expected to possess high ion exchange capacity(IEC),low water uptake(WU),and high mechanical strength when applied to electrodialysis desalination.Among different types of AEMs,semi-interpenetrating polymer networks(SIPNs)have been suggested for their structural superiorities,i.e.,the tunable local density of ion exchange groups for IEC and the restrained leaching of hygroscopic groups by insolubility for WU.Unfortunately,the conventional SIPN AEMs still struggle to balances IEC,WU,and mechanical strength simultaneously,due to the lack of the compact crosslinking region.In this work,we proposed a novel SIPN structure of polyvinylidene difluoride/polyvinylimidazole/1,6-dibromohexane(PVDF/PVIm/DBH).On the one hand,DBH with two cationic groups of imidazole groups are introduced to enhance the ion conductivity,which is different from the conventional monofunctional modifier with only one cationic group.On the other hand,DBH has the ability to bridge with PVIm,where the mechanical strength of the resulting AEM is increased by the increase of crosslinking degree.Results show that a low WU of 38.1%to 62.6%,high IEC of 2.12—2.22 mmol·g^(-1),and excellent tensile strength of 3.54—12.35 MPa for PVDF/PVIm/DBH membrane are achieved.This work opens a new avenue for achieving the high-quality AEMs.

A novel PDZ domain-containing gene is essential for male sex differentiation and maintenance in yellow catfish(Pelteobagrus fulvidraco)

The sex-determining genes are found to be variable among different fish species. Yellow catfish(Pelteobagrus fulvidraco) is an important aquaculture fish species in China with XX/XY sex-determining type. Recently, YY super-male yellow catfish has been successfully produced by combining hormonalinduced sex reversal method with sex chromosome-linked markers. Here, we identified a novel PDZ domain-containing gene in yellow catfish designated as pfpdz1, in whose intron the sex-linked marker was located. The coding sequence of pfpdz1 in Y chromosome was identical to that in X chromosome except a missense SNP(A/T) that changes an amino acid(E8V) in the N-terminal region. Pfpdz1 displayed male-specific expression during sex differentiation. Overexpression of pfpdz1 using additive transgenesis induces XX ovary to differentiate into testis-like tissue, while the targeted inactivation of pfpdz1 in Y chromosome using CRISPR/Cas9-mediated mutagenesis triggers ovarian differentiation. Furthermore,we demonstrated that pfpdz1 initiates testicular differentiation through upregulating expression of amh, dmrt1 and sox9a1, as well as downregulating expression of cyp19a1, foxl2 and wnt4. Our data provide functional evidence that pfpdz1 is significant for male differentiation and maintenance in yellow catfish.

Essential roles of stat5.1/stat5b in controlling fish somatic growth

Signal transducer and activator of transcription 5b（STAT5b） has been identified as a key downstream mediator of growth hormone（GH） signaling in somatic growth of mammalian. However, the corresponding homologue gene of Stat5b is unknown in fish species. In this study, we generated loss-offunction mutants in stat5.1 and stat5.2, two stat5 homologues existing in zebrafish. In stat5.1-deficient zebrafish, a significant reduction of body length and body weight was detected in the embryos/larvae and adults compared with the wild-type control fish, and sexual size dimorphism in adult zebrafish was also eliminated. However, the stat5.2-deficient zebrafish displayed a normal developmental phenotype during all lifespan. Chromatin immunoprecipitation combined with deep sequencing（Ch IP-seq） method was adopted to further investigate the potential transcriptional targets of Stat5 protein and cast much light upon the biological function of Stat5. We identified more than 800 genes as transcriptional targets of Stat5 during zebrafish embryogenesis. KEGG analysis indicated that the Stat5 target gene network is predominantly linked to the metabolic pathways, neuroactive ligand-receptor interaction and JAK-STAT signaling pathways. Further validation studies suggested that Stat5.1 protein could directly regulate the expression of gh1, and stat5.1-mutated zebrafish showed a reduction of gh1 mRNA level. In the present study, stat5.1 was revealed as the corresponding homologue gene of Stat5b in fish species. Additionally,we found a novel molecular interaction between Stat5.1/Stat5b and GH, and unraveled a positive feedback loop Stat5.1-GH-Stat5.1 which is necessary for somatic growth and body development in zebrafish.

Nanocarbon-based TEMPO as stable heterogeneous catalysts for partial oxidation of alcohols

Polymerized fullerene hollow spheres bonded with 2,2,6,6-tetramethylpiperidine-l-oxyl （TEMPO） have been successfully synthesized via amination of C6o with 4-amino-TEMPO in the presence of H202, and then cross- linked by 1,6-hexanediamine. The hollow spheres were analyzed by fourier transform infrared spectrometer, electron spin resonance and X-ray photoelectron spec- troscopy analysis, which indicated the presence of N-O free radicals in the products. When used as a typical heterogeneous catalyst for selective oxidation of alcohols to the corresponding aldehydes or ketones, it exhibited excellent activities, selectivity and recyclability. This synthesis route is convenient and effective, and may provide a new approach to developing immobilized full- erene based heterogeneous catalysts with high activity and recyclability.

Loss of stat3 function leads to spine malformation and immune disorder in zebrafish

STAT （Signal Transducers and Activators of Transcription） gene family members have been revealed to be involved in cell growth and differentiation in vertebrates. Despite their physiological importance, their functions are poorly studied at organ and systemic levels. In this study, we performed a genome-wide analysis using data from invertebrates to vertebrates to identify STAT genes and analyze their evolutionary history. Interestingly, the STAT gene family undergoes genome duplications during the evolutionary history with STAT3 homologues firstly appearing in the basal extant vertebrate, sea lamprey, suggesting its possible roles in spine formation. To investigate the functions of stat3 in fish species, TALEN technology was performed to generate mutant zebrafish lines, star3 mutant zebrafish showed no obvious defects at early developmental stage but displayed severe lateral and vertical curvature of the spine （scoliosis）, spine fracture and the incomplete bone joints with narrower junction between vertebrae at early juvenile stage, as indicated by Alizarin red and Alcian blue staining, radiography and micro-computed tomography （MicroCT） analysis. Transcriptome analysis reveals dramatic alterations in a number of genes involved in immune and infection response, skeletal development and somatic growth, especially downregulated expression of collagen gene family, in the juvenile stat3 mutant zebrafish. Moreover, most of the collagen genes were detected to have abnormal expression pattern during the formation of spine deformities in stat3 mutants. Our data reveal that stat3 is specially expressed in vertebrates and required for normal spine development and immune function in zebrafish.

Carbonaceous aerogel and CoNiAl-LDH@CA nanocomposites derived from biomass for high performance pseudo-supercapacitor

Conversion of waste biomass to valuable carbonaceous material is a sustainable and environmental benign method for energy and reduction of greenhouse gas emission. Herein, a two-step hydrothermal method was developed to fabricate high performance electrode material from pomelo peels. In the first step, the pomelo peels were transformed to carbonaceous aerogel （CA）, which constructed of three- dimensional, sponge-like brown monolith with hierarchical pores, low-density （0.032 g]cm3） and excel- lent mechanical flexibility. Then, the cobalt nickel aluminum layered double hydroxide （CoNiAI-LDH） was in situ loaded on the surface of CA to form exquisite core-shell structure （CoNiAI-LDH@CA） through the second hydrothermal step. When used as an electrode material for supercapacitor, CoNiA1-LDHOCA exhibited high specific capacitances of 1,134F/g at 1A/g and 902Fig at 10A/g, respectively. Furthermore, they displayed an excellent cycling stability without an obvious capacitance decrease after 4,000 cycles.