The aim of this study was to elucidate the optimized fabrication factors influencing the formation and properties of shellac(SHL) nanofibers loaded with an antimicrobial monolaurin(ML). The main and interaction effect...The aim of this study was to elucidate the optimized fabrication factors influencing the formation and properties of shellac(SHL) nanofibers loaded with an antimicrobial monolaurin(ML). The main and interaction effects of formulation and process parameters including SHL content(35%–40% w/w), ML content(1%–3% w/w), applied voltage(9–27 kV) and flow rate(0.4–1.2 ml/h) on the characteristic of nanofibers were investigated through a total of 19 experiments based on a full factorial design with three replicated center points. As a result, the SHL content was the major parameter affecting fiber diameter. Another response result revealed that the SHL content would be also the most significant negative impact on amount of beads. An increase in the concentration of SHL leaded to a reduction in the amount of beads. From the results of characterization study, it was proved that ML might be entrapped between the chains of SHL during the electrospinning process exhibiting an excellent encapsulation. According to the response surface area, small(?488 nm) and beadless(?0.48) fibers were obtained with the SHL and ML contents of 37.5% and 1.1% w/w respectively, at the applied voltage of 18 k V and the flow rate of 0.8 ml/h. In addition, the results of the kill-kinetic studies showed that SHL nanofibers loaded with ML exhibited an excellent antibacterial activity against Staphylococcus aureus, while Escherichia coli was less affected due to the hydrophilic structure of the its outer membrane. ML also exerted an antifun-gal activity by reducing the number of Candida albicans colonies. Based on their structural and antimicrobial properties, SHL nanofibers containing ML could be potentially used as a medicated dressing for wound treatment.展开更多
To improve the mechanical properties of fast-growing Chinese fir(Cunnighamia lanceolate),expand its range of application,increase its value,and avoid the environmental pollution caused by impregnation with synthetic r...To improve the mechanical properties of fast-growing Chinese fir(Cunnighamia lanceolate),expand its range of application,increase its value,and avoid the environmental pollution caused by impregnation with synthetic resin,Chinese fir was impregnated with a shellac solution.Since the shellac solution was difficult to penetrate into fast-growing Chinese fir,so microwave pretreatment was used to irradiate the wood to improve the permeability.This study investigated the effects of four factors,including the content of moisture in the wood before it was microwaved,the chamber pressure of microwave,the time of microwaving and the vacuum impregnation on the mechanical properties of Chinese fir wood.When the moisture content of wood before microwave was approximately 50%–60%,after microwaving and impregnation,the ultimate strength in static bending(modulus of rupture[MOR])and strength in compression perpendicular to the grain(SCPG)of the wood increased significantly.A microwave time of 100 seconds was more effective at improving the MOR and SCPG of the wood.If the wood was microwaved for too short or long period of time,the microwave pretreatment was not effective.When the samples were immersed in shellac for a longer period,the MOR and SCPG of Chinese fir gradually increased,but when the wood was impregnated for more than 12 hours,the increases were not significant.After the shellac penetrated the Chinese fir wood,it spread on the inner wall surface of tracheid to form a shellac film and easily formed plug-like deposits in microcapillaries.The use of Fourier-transform infrared spectroscopy,scanning electron microscopy and scanning electron microscopy-energy dispersion x-ray indicated that the microwave pretreatment can destroy the pit membranes on tracheids and facilitate the ability of shellac to penetrate the channel.展开更多
Based on the observation and record of trapping effect of Cinara pinea in urban green space for three consecutive years,the occurrence regularity and causes of C.pinea in urban green space were summarized.The results ...Based on the observation and record of trapping effect of Cinara pinea in urban green space for three consecutive years,the occurrence regularity and causes of C.pinea in urban green space were summarized.The results showed that the quantity of C.pinea was different in different months from August to December,and the damage degree of C.pinea was reduced in the next spring.During rainy and snowy weather from August to December,the number of C.pinea was relatively large,and the egg quantity of C.pinea in February and the number of C.pinea in April were relatively low.Some suggestions on the prevention and control of C.pinea in urban parks were put forward.展开更多
基金the financial support received from Silpakorn University Research and Development Institutesupported by the Higher Education Re-search Promotion and National Research University Project of Thailand,Office of the Higher Education Commission(2559A11462006)Faculty of Pharmacy,Silpakorn Univer-sity
文摘The aim of this study was to elucidate the optimized fabrication factors influencing the formation and properties of shellac(SHL) nanofibers loaded with an antimicrobial monolaurin(ML). The main and interaction effects of formulation and process parameters including SHL content(35%–40% w/w), ML content(1%–3% w/w), applied voltage(9–27 kV) and flow rate(0.4–1.2 ml/h) on the characteristic of nanofibers were investigated through a total of 19 experiments based on a full factorial design with three replicated center points. As a result, the SHL content was the major parameter affecting fiber diameter. Another response result revealed that the SHL content would be also the most significant negative impact on amount of beads. An increase in the concentration of SHL leaded to a reduction in the amount of beads. From the results of characterization study, it was proved that ML might be entrapped between the chains of SHL during the electrospinning process exhibiting an excellent encapsulation. According to the response surface area, small(?488 nm) and beadless(?0.48) fibers were obtained with the SHL and ML contents of 37.5% and 1.1% w/w respectively, at the applied voltage of 18 k V and the flow rate of 0.8 ml/h. In addition, the results of the kill-kinetic studies showed that SHL nanofibers loaded with ML exhibited an excellent antibacterial activity against Staphylococcus aureus, while Escherichia coli was less affected due to the hydrophilic structure of the its outer membrane. ML also exerted an antifun-gal activity by reducing the number of Candida albicans colonies. Based on their structural and antimicrobial properties, SHL nanofibers containing ML could be potentially used as a medicated dressing for wound treatment.
基金the 2018 Forestry Science and Technology Research Project by Forestry Department of Fujian Province(No.2018-26)Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University(CXZX2019111S)+1 种基金National Natural Science Foundation of China(31971593,32071688)the Natural Science Foundation of Fujian Province Department of Science and Technology(2019J01386).
文摘To improve the mechanical properties of fast-growing Chinese fir(Cunnighamia lanceolate),expand its range of application,increase its value,and avoid the environmental pollution caused by impregnation with synthetic resin,Chinese fir was impregnated with a shellac solution.Since the shellac solution was difficult to penetrate into fast-growing Chinese fir,so microwave pretreatment was used to irradiate the wood to improve the permeability.This study investigated the effects of four factors,including the content of moisture in the wood before it was microwaved,the chamber pressure of microwave,the time of microwaving and the vacuum impregnation on the mechanical properties of Chinese fir wood.When the moisture content of wood before microwave was approximately 50%–60%,after microwaving and impregnation,the ultimate strength in static bending(modulus of rupture[MOR])and strength in compression perpendicular to the grain(SCPG)of the wood increased significantly.A microwave time of 100 seconds was more effective at improving the MOR and SCPG of the wood.If the wood was microwaved for too short or long period of time,the microwave pretreatment was not effective.When the samples were immersed in shellac for a longer period,the MOR and SCPG of Chinese fir gradually increased,but when the wood was impregnated for more than 12 hours,the increases were not significant.After the shellac penetrated the Chinese fir wood,it spread on the inner wall surface of tracheid to form a shellac film and easily formed plug-like deposits in microcapillaries.The use of Fourier-transform infrared spectroscopy,scanning electron microscopy and scanning electron microscopy-energy dispersion x-ray indicated that the microwave pretreatment can destroy the pit membranes on tracheids and facilitate the ability of shellac to penetrate the channel.
基金Hebei Provincial Construction Science and Technology Research Project (2019-2072)。
文摘Based on the observation and record of trapping effect of Cinara pinea in urban green space for three consecutive years,the occurrence regularity and causes of C.pinea in urban green space were summarized.The results showed that the quantity of C.pinea was different in different months from August to December,and the damage degree of C.pinea was reduced in the next spring.During rainy and snowy weather from August to December,the number of C.pinea was relatively large,and the egg quantity of C.pinea in February and the number of C.pinea in April were relatively low.Some suggestions on the prevention and control of C.pinea in urban parks were put forward.
