Thermoplastic polycarbonate modified polyether-polyurethane (PEPU) elastomers were prepared by transurethane polycondensation method using poly(oxytetramethylene) glycol of M n 5 2000 and dimethyl-hexane-1,6-dicarbamate as the main raw materials, 1,4-butanediol as a chain extender and polycarbonate diol (PCDL) as an additive in the presence of dibutyltin oxide as a catalyst. The effect of the PCDL on the PEPUs' structure, intrinsic viscosity, molecular weight, mechanical, optical, and thermal properties, and water resistance were studied. The polycarbonate modified PEPUs showed better mechanical and thermal properties, but lower molecular weight and optical properties than the PEPUs. The PEPUs modified by PCDL1000 exhibited better performance, including mechanical, optical, and thermal properties, than those by PCDL2000.

Coastal saltern and aquaculture are vital components of human-made coastal areas and they have immense influence on the coastal water environment in China. Hyperspectral space-borne remote sensing is a significant technology in remote sensing, enabling in-depth identification and discrimination of the spectra from water features on shore. The study uses CHRIS/PROBA images to identify water-bodies and classify six optical water types from artificial and natural water in three sites across regions along China’s coastline. Most of the offshore waters are affected by the inflow of land source materials. The fluorescence peaks appearing at 675 nm can be observed by 5 water types. In addition to Class 1 water which is far from the shore and the Class 4 water whose signals are mainly affected by the algae at its bottom, the other 4 kinds of water show backscattering peak after 800 nm, suggesting that particles are playing an important role in coastal water. For coastal waters in Liushagang, the mangrove forest will transfer the water body signal received by the satellite into the vegetation signal; pools in coastal saltern have rather shallow water during production period when the benthic signal will seriously interfere the reflected signal. In the intertidal area, the hyperspectral characteristics in the same sample also change periodically due to the ebb and flow. The Class 2 and Class 3 water bodies alternately occur in the intertidal zone in the Lianyungang research area. Therefore, it is concluded that optical classification approaches reflect the advantages of remote sensing from Satellite-bone, and our study can be helpful and conductive for follow-up sensors.

IntroductionNon-viral gene vectors have attracted much attention in the last few decades, because of its potential activity and less side effects. Headgroup chemistry is a key aspect in lipid design. MethodsIn this study, a group of sulfonium lipids were designed and constructed by combining tetrahydrothiophene or tetrahydrothiopyran with an ethoxy linker and carbon aliphatic chains. 12 sulfonium lipids were synthesized and characterized by 1H NMR, 13C NMR, and Mass. The compounds were evaluated in terms of their ability as potential gene vectors. Condensates of sulfonium lipids (SL) and DNA were examined by gel electrophoresis and particle size and zeta potential were measured. Sulfonium compounds were tested on HepG2 cells for cytotoxicity. SL/DNA condensates were studied incellular uptake and distribution using fluorescent microscopy.ResultsThe results showed that sulfonium cation can effectively interact with phosphorous in DNA. Compounds containing a longer lipid chains can effectively retard DNA at S/P ratio higher than 10/1 and can condense DNA into a nanosize particles with particle size in the range 150 nm ~ 300 nm, zeta potential in the range of +20~+40. Sulfonium compounds were calculated IC50s on HepG2 cells in the range of 3.52 ng/mL to 1.64 μg/mL. The intra-cellular uptake experiments revealed that SL/DNA nano particle was taken into the cell at low efficiency.ConclusionSulfonium headgroup can interact with phosphate of DNA. The structural environment of sulfonium ion influences the DNA bonding effect. The designed cyclic sulfonium ion was buried in the middle of structure, and thus was hindered interaction with DNA. This type of molecule is worthy of further modification to increase DNA capacity and to reduce cell cytotoxicity.

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