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991.
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993.
Feather,as a by-product of the poultry industry,has long been treated as a solid waste,which causes environmental and economic problems.In this work,the hydrolyzed feather keratin(HFK)was extracted from the chicken feather using a cost-effective method of alkali-extraction and acid-precipitation by applying urea and sodium sulfide.The aim was development and characterization of the eco-friendly films based on the HFK with variable glycerol contents by a thermoplastic process.The thermal analysis showed that high temperature and high pressure improved the compatibility between the glycerol and the HFK molecules.Also it was shown that the addition of water is necessary in the hot-pressing process of films.The FT-IR analysis indicated that the formation of the new hydrogen bonds between HFK and glycerol.By increasing the glycerol content,the film tensile strength(σ_b)decreases from 10.5 MPa to 5.7 MPa and the solubility increases from 15.3% to 20.9%,while the elongation at break(εb)achieves the maximum value of 63.8% for the film with 35% glycerol.The swelling was just below 16.9%at 25 °C for 24 h,suggesting a good stability of the films in water.The water vapor permeability(WVP)varied between 3.02 × 10~(-10)g · m~(-2)· s~(-1)· Pa~(-1)and 4.11 × 10~(-10)g · m~(-2)· s~(-1)· Pa~(-1)for the films with 20% and40% glycerol,respectively.The HFK film was uniform,translucent and tough,which could be used in packaging and agricultural field. 相似文献
994.
995.
Dual crosslinked carboxymethyl sago pulp/pectin hydrogel beads as potential carrier for colon‐targeted drug delivery 下载免费PDF全文
Hui Li Tan Li Shan Tan Yeon Yin Wong Saravanan Muniyandy Kamaruddin Hashim Janarthanan Pushpamalar 《应用聚合物科学杂志》2016,133(19)
Carboxymethyl sago pulp (CMSP)/pectin hydrogel beads were synthesized by calcium crosslinking and further crosslinked by electron beam irradiation to form drug carrier for colon‐targeted drug. Sphere‐shaped CMSP/pectin 15%/5% hydrogel beads is able to stay intact for 24 h in swelling medium at pH 7.4. It shows pH‐sensitive behavior as the swelling degree increases as pH increases. Fourier transform infrared spectroscopy analysis confirmed the absence of chemical interaction between hydrogel beads and diclofenac sodium. Differential scanning calorimetric and X‐ray diffraction studies indicate the amorphous nature of entrapped diclofenac sodium. The drug encapsulation efficiency is up to about 50%. Less than 9% of drug has been released at pH 1.2 and the hydrogel beads sustain the drug release at pH 7.4 over 30 h. This shows the potential of CMSP/pectin hydrogel beads as carrier for colon‐targeted drug. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43416. 相似文献
996.
Low n-6/n-3 PUFA Ratio Improves Lipid Metabolism,Inflammation, Oxidative Stress and Endothelial Function in Rats Using Plant Oils as n-3 Fatty Acid Source 下载免费PDF全文
Li Gang Yang Zhi Xiu Song Hong Yin Yan Yan Wang Guo Fang Shu Hui Xia Lu Shao Kang Wang Gui Ju Sun 《Lipids》2016,51(1):49-59
Lipid metabolism, inflammation, oxidative stress and endothelial function play important roles in the pathogenesis of cardiovascular disease (CVD), which may be affected by an imbalance in the n‐6/n‐3 polyunsaturated fatty acid (PUFA) ratio. This study aimed to investigate the effects of the n‐6/n‐3 PUFA ratio on these cardiovascular risk factors in rats fed a high‐fat diet using plant oils as the main n‐3 PUFA source. The 1:1 and 5:1 ratio groups had significantly decreased serum levels of total cholesterol, low‐density lipoprotein cholesterol, and proinflammatory cytokines compared with the 20:1 group (p < 0.05). Additionally, the 20:1 group had significantly increased serum levels of E‐Selectin, von Willebrand factor (vWF), and numerous markers of oxidative stress compared with the other groups (p < 0.05). The 1:1 group had a significantly decreased lipid peroxide level compared with the other groups (p < 0.05). Serum levels of malondialdehyde, reactive oxygen species and vWF tended to increase with n‐6/n‐3 PUFA ratios increasing from 5:1 to 20:1. We demonstrated that low n‐6/n‐3 PUFA ratio (1:1 and 5:1) had a beneficial effect on cardiovascular risk factors by enhancing favorable lipid profiles, having anti‐inflammatory and anti‐oxidative stress effects, and improving endothelial function. A high n‐6/n‐3 PUFA ratio (20:1) had adverse effects. Our results indicated that low n‐6/n‐3 PUFA ratios exerted beneficial cardiovascular effects, suggesting that plant oils could be used as a source of n‐3 fatty acids to prevent CVD. They also suggested that we should be aware of possible adverse effects from excessive n‐3 PUFA. 相似文献
997.
Kinetic study of the nonthermal effect of the esterification of octenyl succinic anhydride modified starch treated by microwave radiation 下载免费PDF全文
With cassava starch as a raw material and octenyl succinic anhydride as an esterifying agent, octenyl succinic anhydride modified starch (OSA–starch) was prepared in an aqueous medium and treated by water‐bath heating and microwave radiation at a certain temperature, respectively. The reaction kinetics of esterification were studied. The structural analysis and synthesis mechanism of OSA–starch were investigated by means of scanning electron microscopy and Fourier transform infrared spectroscopy. The differences in the esterification reaction kinetics between starches treated with water‐bath heating and microwave radiation were observed. Under the condition of water‐bath heating, the apparent activation energy of the esterification reaction was 52.22 ± 1.21 kJ/mol, and the pre‐exponential factor was 9018.20/min?1. Under the condition of microwave radiation, the apparent activation energy of the esterification reaction was 50.13 ± 1.16 kJ/mol, and the pre‐exponential factor was 4510.21/min?1. We found that microwave radiation could reduce both the activation energy of the reaction and the pre‐exponential factor. The lowering effect of the apparent activation energy was greater than that of the pre‐exponential factor under the condition of microwave radiation, and this resulted in increased reaction rates. The change in the esterification reaction kinetics was a nonthermal effect of microwave radiation on the esterification of cassava starch. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43909. 相似文献
998.
Effect of the melting temperature on the crystallization behavior of a poly(l‐lactide)/poly(d‐lactide) equimolar mixture 下载免费PDF全文
Yongai Yin Yan Song Zujiang Xiong Xiuqin Zhang Sicco de Vos Ruyin Wang Cornelis A. P. Joziasse Guoming Liu Dujin Wang 《应用聚合物科学杂志》2016,133(10)
The effect of the final melting temperature (Tf) on the crystallization of poly(l ‐lactide) (PLLA)/poly(d ‐lactide) (PDLA) was studied via a combination of differential scanning calorimetry, wide‐angle X‐ray scattering, polarized optical microscopy, and Fourier transform infrared (FTIR) spectroscopy. We observed that a residual stereocomplex (SC) crystal induced the formation of SC crystals during cooling from a Tf (230°C) just above the melting peak of the SC crystals. On cooling from a Tf (240°C) just above the endset temperature of SC crystal melting [Tm(S)(E)], the possible order structure and the strong interchain interaction promoted the preferential crystallization of SC crystals; this enhanced the formation of α crystals. During cooling from a Tf (≥250°C) far above Tm(S)(E), the crystallization peaks of α and SC crystals converged. The FTIR results indicated that the residual SC crystals, possible ordered structure, and interchain interactions in the melt might have been the key factors for the different crystallization of PLLA/PDLA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43015. 相似文献
999.
Jun Wang Jian Zhang Kaijie Ning Dewei Luo Hao Yang Danlei Yin Dingyuan Tang Ling Bing Kong 《Journal of the American Ceramic Society》2016,99(5):1671-1675
Highly transparent 0.5 at.% Tm:Y2O3 ceramics were prepared by using solid‐state reaction combined with vacuum sintering method, with ZrO2 and Al2O3 as sintering aids. Doping amount of ZrO2 was fixed at 1 at.%, while the effect of Al2O3 on densification, microstructure evolution, and transmittance of the Y2O3 ceramics was carefully studied. It was found that the addition of Al2O3 was very effective in improving densification of Y2O3, due to the formation of an Al‐rich eutectic phase Y4Al2O9 (YAM) during the sintering process. As the content of Al2O3 was increased from 0 to 81.8 wt ppm, porosity of the ceramics was decreased and transmittance was increased. However, when the content of Al2O3 was increased to 137 wt ppm, a secondary phase began to segregate at grain junctions. Further increase in the amount of Al2O3 led to an increase in both amount and size of the secondary phase. At the optimized content of Al2O3 with 81.8 wt ppm, the Tm:Y2O3 ceramics sintered at 1860°C for 13 h exhibited an in‐line transmittance of 83.0% at 2000 nm and 76.5% at 600 nm. It is expected that this finding can be readily applied to other transparent ceramics. 相似文献
1000.
Makoto Hamanaka Kimie Imakawa Mizuki Yoshida Zhihuan Zhao Shu Yin Xiaoyong Wu Yunfang Huang Jihuai Wu Tsugio Sato 《Journal of Porous Materials》2016,23(5):1189-1196
The SnO2 particles with different morphologies of nanorod, nanosheet, nanoparticle and nanodot were synthesized by liquid-phase methods. In addition, Pt was loaded on each prepared SnO2 by dispersing SnO2 particles into PtCl4 2? aqueous solutions containing 0.67 vol% methanol, followed by UV light irradiation for 6 h. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller measurement. The gas sensing properties of the synthesized SnO2 were tested by detecting the change in electric resistivity in flowing aceton and methanol gases with nitrogen base. The gas sensing properties greatly changed depending on not only the specific surface area, but also the exposed crystal plane, i.e., the SnO2 nanorods exposing (111) planes showed the excellent sensitivity and quick response ability, indicating the excellent gas sensing ability of the (111) plane. Furthermore, the Pt loading exceedingly enhanced the gas sensing properties. 相似文献