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1.
Sanchita Bandyopadhyay-Ghosh Robert Jeng Joydeep Mukherjee Mohini Sain 《Journal of Polymers and the Environment》2010,18(3):231-234
Amylose containing polysaccharides are one of the most abundant and inexpensive naturally occurring biopolymers. Therefore,
they are one of the most promising candidates to produce substitute plastics, especially in packaging applications. To determine
the suitability for packaging applications, cytotoxicity of a modified amylose based bioplastic was investigated using NIH
3T3 Fibroblast cells from observation of cell morphology and MTS assay. Chemical durability of the amylose based bioplastic
film was also studied by ion release and pH measurement after immersing the film into water. In vitro cytotoxicity (Cell morphology
study and MTS assay) showed that the amylose based bioplastic film has in vitro biocompatibility and can be used for packaging
applications. The ion release and pH measurement also supported the results. 相似文献
2.
Shaun A. Watmough Julian Aherne M. Catherine Eimers Peter J. Dillon 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):301-306
In response to reduced sulphur emissions, there has been a large decrease in sulphate (; −0.97 μeq l−1 year−1) and hydrogen (−1.18 μeq l−1 year−1) ion concentration in bulk precipitation between 1980 and 2000 at Plastic Lake in central Ontario. The benefit of this large
reduction in deposition on stream water chemistry was assessed using the gauged outflow from a conifer-forested catchment (PC1; 23.3 ha),
which is influenced by a small wetland located immediately upstream of the outflow. Sulphate concentrations declined, but
not significantly due to large inter-annual variation in concentration. Between 1980 and 2000, there were significant increases in dissolved organic carbon, ammonium and potassium
concentration likely reflecting increased mineralisation in the wetland. Calcium concentrations in PC1 decreased during the
two decade period (−2.24 μeq l−1 year−1), as a consequence there was no improvement in stream pH and the Ca:Al ratio in PC1 continued to decline. A similar response
was noted in an upland-draining sub-catchment of PC1-08 that has been monitored since 1987. Despite large reductions in deposition and almost complete retention of nitrogen in soil, there has been no improvement (in terms of pH) in stream water
at PC1 due to a combination of soil acidification and climatic (droughts, increased mineralisation) perturbations. 相似文献
3.
K. Pritsch D. Ernst F. Fleischmann S. Gayler T. E. E. Grams A. Göttlein W. Heller N. Koch H. Lang R. Matyssek J. C. Munch M. Olbrich H. Scherb S. Stich J. B. Winkler M. Schloter 《Water, Air, & Soil Pollution: Focus》2008,8(2):139-154
A lysimeter study was performed to monitor effects of elevated ozone on juvenile trees of Fagus sylvatica L. as well as on the plant–soil system. During a fumigation period over almost three growing seasons, parameters related
to plant growth, phenological development and physiology as well as soil functions were studied. The data analyses identified
elevated ozone to delay leaf phenology at early and to accelerate it at late developmental stages, to reduce growth, some
leaf nutrients (Ca, K) as well as some soluble phenolics (hydroxycinnamic acid derivatives, total flavonol glycosides). No
or very weak ozone effects were found in mobile carbon pools of leaves (starch, sucrose), and other phenolic compounds (flavans).
Altered gene expression related to stress and carbon cycling corresponded well with findings from leaf phenology and chemical
composition analyses indicating earlier senescence and oxidative stress in leaves under elevated ozone. Conversely in the
soil system, no effects of ozone were detected on soil enzyme activities, rates of litter degradation and lysimeter water
balances. Despite the fact that the three reported years 2003–2005 were climatically very contrasting including a hot and
dry as well as an extremely wet summer, and also mild as well as cold winters, the influence of ozone on a number of plant
parameters is remarkably consistent, further underlining the phytotoxic potential of elevated tropospheric ozone levels. 相似文献
4.
Kangjing Zhang Huiying Yang Zhaobin Qiu 《Journal of Polymers and the Environment》2018,26(4):1320-1327
In this research, the thermal properties and crystallization behavior of novel poly(hexamethylene succinate-co-6 mol% butylene succinate) (PHBS) and its homopolymer poly(hexamethylene succinate) (PHS) were extensively studied. With respect to PHS, the introduction of a small content of butylene succinate (BS) unit slightly reduces the melting point and equilibrium melting point but hardly influences the glass transition temperature of PHBS. Despite crystallization temperature, PHS and PHBS crystallize through the same crystallization mechanism. At the same crystallization temperature, PHBS crystallizes more slowly than PHS; furthermore, lowering crystallization temperature enhances the crystallization rates of PHBS and PHS. The spherulites morphologies were observed for both of them, with the spherulites nucleation density of the copolymer being smaller than that of the homopolymer. PHBS and PHS share the same crystal structures, indicative of the location of BS unit in the amorphous region. 相似文献