Developing a new treatment for superficial fungal infection using antifungal Collagen-HSAF dressing

Fungal pathogens are common causes of superficial clinical infection. Their increasing drug resistance gradually makes existing antifungal drugs ineffective. Heat stable antifungal factor (HSAF) is a novel antifungal natural product with a unique structure. However, the application of HSAF has been hampered by very low yield in the current microbial producers and from extremely poor solubility in water and common solvents. In this study, we developed an effective mode of treatment applying HSAF to superficial fungal infections. The marine-derived Lysobacter enzymogenes YC36 contains the HSAF biosynthetic gene cluster, which we activated by the interspecific signaling molecule indole. An efficient extraction strategy was used to significantly improve the purity to 95.3%. Scanning electron microscopy images revealed that the Type I collagen-based HSAF (Col-HSAF) has a transparent appearance and good physical properties, and the in vitro sustained-release effect of HSAF was maintained for more than 2 weeks. The effective therapeutic concentration of Col-HSAF against superficial fungal infection was explored, and Col-HSAF showed good biocompatibility, lower clinical scores, mild histological changes, and antifungal capabilities in animals with Aspergillus fumigatus keratitis and cutaneous candidiasis. In conclusion, Col-HSAF is an antifungal reagent with significant clinical value in the treatment of superficial fungal infections

Ligand-Stabilized Au13Cux (x=2, 4, 8) Bimetallic Nanoclusters: Ligand Engineering to Control the Exposure of Metal Sites

通讯作者地址: Zheng, NF (通讯作者) Xiamen Univ, Collaborat Innovat Ctr Chem Energy Mat, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China.Three novel bimetallic Au-Cu nanoclusters stabilized by a mixed layer of thiolate and phosphine ligands bearing pyridyl groups are synthesized and fully characterized by X-ray single crystal analysis and density functional theory computations. The three clusters have an icosahedral Au-13 core face-capped by two, four, and eight Cu atoms, respectively. All face-capping Cu atoms in the clusters are triply coordinated by thiolate or pyridyl groups. The surface ligands control the exposure of Au sites in the clusters. In the case of the Au13Cu8 cluster, the presence of 12 2-pyridylthiolate ligands still leaves open space for catalysis. All the 3 clusters are 8-electron superatoms displaying optical gaps of 1.8-1.9 eV. The thermal decomposition studies suggest that the selective release of organic ligands from the clusters is possible.MOST of China 2011CB932403 ,2011CB201301 ,2009CB930703 , NSFC 21227001 ,21131005 ,21021061 ,20925103 ,20923004 , Fundamental Research Funds for the Central Universities 201012104

Preparation and characterization of radiation-grafted poly (tetrafluoroethylene-co-perfluoropropyl vinyl ether) membranes for alkaline anion-exchange membrane fuel cells

Novel alkaline anion-exchange membranes (AAEMs) were synthesized by graft copolymerization of vinylbenzyl chloride onto pre-irradiated poly (tetrafluoroethylene-co-perfluoropropyl vinyl ether) film, followed by quaternization and alkalization. Two kinds of radiation modes, continuous radiation and dis-continuous radiation (with 15 min break in each hour's radiation), were conducted to the PFA films. The structure of the AAEMs was characterized by Fourier transform infrared (FT-IR). The performances of the AAEMs, including ion exchange capacity (IEC), ionic conductivity, water uptake (WU) and methanol permeability, were investigated systematically. The results showed that the degree of grafting of the film prepared by continuous irradiation is higher than the one prepared by discontinuous irradiation, which results in higher IEC, WU and ionic conductivity. The continuously irradiated membrane exhibited a maximum ionic conductivity of 0.05 S cm(-1) at 60 degrees C. A maximum power density of 16 mW cm(-2) for a direct methanol single cell was obtained at 60 degrees C with the continuously irradiated membrane as the electrolyte. MnO(2)/C and PtRu/C as the cathode and anode electrocatalysts, respectively. This result indicates that the direct alcohol alkaline anion-exchange membrane fuel cell is a promising system with further improvement on AAEMs. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.National Natural Science Foundation of China[20776139]; Hi-Tech Research and Development Program of China[2009AA05Z121, 2007AA05Z159

Middle and near ultraviolet spectrograph of the Scientific Experimental system in Near SpacE (SENSE)

The Scientific Experimental system in Near SpacE (SENSE) consists of different types of instruments that will be installed on a balloon-based platform to characterize near-space environmental parameters. As one of the main scientific payloads, the middle and near ultraviolet spectrograph (MN-UVS) will provide full spectra coverage from middle ultraviolet (MUV, 200−300 nm) to near ultraviolet (NUV, 300−400 nm) with a spectral resolution of 2 nm. Its primary mission is to acquire data regarding the UV radiation background of the upper atmosphere. The MN-UVS is made up of six primary components: a fore-optical module, an imaging grating module, a UV intensified focal plane module, a titanium alloy frame, a spectrometer control module, and a data processing module. This paper presents in detail the engineering design of each functional unit of the MN-UVS, as well as the instrument’s radiometric calibration, wavelength calibration, impact test, and low-pressure discharge test. Furthermore, we are able to report ground test and flight test results of high quality, showing that the MN-UVS has a promising future in upcoming near-space applications

Effects of phase-breaking on long-range charge transfer in DNA: Partially-coherent-tunneling model study

The mechanism of hole charge transfer in DNA of various lengths and sequences is investigated based on a partially coherent tunneling theory (Zhang et al., J Chem Phys 117:4578, 2002), where the effects of phase-breaking in adenine-thymine and guanine-cytosine base pairs are treated on equal foot. This work aims at providing a self-consistent microscopic interpretation for rate experiments on various DNA systems. We will also clarify the condition under which the simple superexchange-mediated-hopping picture is valid, and make some comments on the further development of present theory