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Hierarchical porous ZnCo2O4 microspheres are successfully synthesized and display attractive supercapacitive performance in 2 M KOH.

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Temporin-1CEb shows antimicrobial activity against Gram-positive bacteria, but its therapeutic potential is limited by its haemolysis. In this study, eight temporin-1CEb analogues with altered cationicities and hydrophobicities were synthesized. Increasing cationicity and amphipathicity by substituting neutral and non-polar amino acid residues on the hydrophilic face of the a-helix by five or six lysines increased antimicrobial potency approximately 10-fold to 40-fold, although when the number of positive charges was increased from +6 to +7, the antimicrobial potency was not additionally enhanced. The substitution of an L-lysine with a D-lysine, meanwhile maintaining the net charge and the mean hydrophobicity values, had only a minor effect on its antimicrobial activity, whereas significantly led a decrease in its haemolytic activity. Of all the peptides, L-K6 has the best potential as an antimicrobial agent because its antimicrobial activity against both Gram-positive and Gram-negative bacteria is substantial, and its haemolytic activity is negligible. L-K6 adopts an a-helix in 50% trifluoroethanol ⁄ water and 30 mM SDS solutions. L-K6 killed 99.9% of E. coli and S. aureus at 4· MIC in 60 min, and its postantibiotic effect was >5 h. L-K6 affects the integrity of E. coli and S. aureus plasma membranes by rapidly inducing membrane depolarization.Key words: cationicity, depolarization, haemolytic activity, hydrophobicity, membrane integrity Received 23 May 2011, revised 9 January 2012 and accepted for publication 10 January 2012Antimicrobial peptides (AMPs) with broad-spectrum antibacterial activities are synthesized in the skins of frogs and components of the innate immune systems of frogs (1). These compounds have potential as therapeutic agents against microorganisms (2). To date, approximately 200 AMPs, belonging to more than 20 different families, have been identified from more than 40 different amphibians (3-5). Among the AMP families, the members of the temporin family are short (10-13 amino acids), hydrophobic and C-terminally amidated AMPs found in frog skin that have haemolytic activity as well as antimicrobial activity. The first temporin was identified in the skin of the Asian frog Rana erythraea on the basis of its haemolytic activity (6). More than 50 different temporins have subsequently been isolated from the skins of North American and Eurasian frogs of the genus Rana and display potent antimicrobial activity against bacteria, fungi and even certain viruses (7,8). The antimicrobial mechanism of temporins is thought to be based on the leakage of water and ions through pores in the bacterial cell membrane (9). Although the use of the naturally occurring temporin-1CEb as antibiotics is limited because of their substantial haemolytic activities against human erythrocytes, temporins modified according to amphipathicity, charge and secondary structure may still represent promising drug candidates.Temporin-1CEb is a naturally occurring 12-residue peptide derived from skin secretions of Rana amurensis (th...

Abstract. A motivational community visualization was designed to encourage users to participate more actively and to bring more contributions in an online community. The visualization is inspired by the theory of social comparison in social psychology. It evolved through two designs: a fixed and a customizable one for two different communities of students sharing papers -one of graduate students in a research lab and another one for students in an undergraduate class. The paper discusses the features of the two communities, each of the two visualization designs, their advantages and disadvantages.

Non-spherical Cu@CuS yolk–shell structures are successfully obtained using Cu2O cube templates in a process combining rapid surface sulfidation followed by disproportionation of the Cu2O core upon treatment with a hydrochloric acid solution. By employing the above method, Cu@CuS yolk–shell structures with different morphologies, including octahedral, truncated octahedral, and cuboctahedral shapes, can be synthesized. The void space within the hollow structures provides a unique confined space, where the metallic copper present in the core of a shell can be protected from agglomeration and oxidation. Furthermore, the presence of metal copper in these hollow structures contributes to improvement in the photocatalytic properties of these materials. The application of these Cu@CuS structures indeed shows clearly improved photocatalytic performance. Electronic supplementary materialThe online version of this article (doi:10.1007/s40820-017-0135-7) contains supplementary material, which is available to authorized users.

Constructing heterojunctions with face-to-face interface is a new avenue for accelerating the charge separation in semiconductor photocatalysts toward highly efficient solar water splitting systems. Here, a novel SnS 2 / TiO 2 2D−2D ultrathin nanosheet heterostructure was fabricated via a hydrothermal route in two steps. The obtained 2D−2D SnS 2 /TiO 2 nanojunction has not only provided large contact areas but also shortened the charge transport distance, resulting in significantly enhanced photocatalytic H 2 evolution property. The H 2 generation rate obtained for the optimized sample reaches 652.4 μmol h −1 g −1 , far exceeding (∼8 times) that of pristine TiO 2 and SnS 2 ultrathin nanosheets under simulated solar irradiation. Moreover, further analysis reveals a photoinduced carrier transfer from TiO 2 to SnS 2 at the interface junction, which causes a partial reduction of the SnS 2 cocatalyst to SnS in the nanocomposite during the photocatalytic reactions. These results not only demonstrate that the construction of 2D−2D heterojunction is a promising approach to improve the photocatalytic H 2 production activity of nanostructured semiconductor photocatalysts but also provide new understanding into the role and evolution of SnS 2 nanosheets during the photocatalytic reaction process in heterogeneous photocatalyst systems.

Hollow α-Fe2O3 hexagonal nanocolumn particles (HHCPs) with exposed (101[combining macron]0) and (112[combining macron]5) facets have been synthesized through a hydrothermal method in the absence of templates. The time-dependent experimental results demonstrate that the formation of HHCPs includes four main steps: (1) formation of nanowire precursors, (2) aggregation and conversion to Fe1.833(OH)0.5O2 solid ellipsoid particles (SEPs), (3) dehydration to form hollow ellipsoid particles (HEPs), and (4) recrystallization to HHCPs. Due to their advantages of the hollow structure and the exposed special external and internal surface on the pore structure, the HHCPs exhibit higher gas sensing ability than that of calcined SEPs (CSEPs) and HEPs.