Pepsin was assembled on the surface of prepared poly(ethylene terephthalate)(PET-NH3^+) substrates.The composition and structure of the pepsin/PET-NH3^+ assembling films in different condition were characterized by X-...Pepsin was assembled on the surface of prepared poly(ethylene terephthalate)(PET-NH3^+) substrates.The composition and structure of the pepsin/PET-NH3^+ assembling films in different condition were characterized by X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM).展开更多
A novel method to fabricate composition- (IO) films using a positive sacrificial ZnO and topology-controlled ZnO/TiO2 inverse opals IO template has been developed. This method includes a two-step process, preparatio...A novel method to fabricate composition- (IO) films using a positive sacrificial ZnO and topology-controlled ZnO/TiO2 inverse opals IO template has been developed. This method includes a two-step process, preparation of ZnO IO by a simple electrochemical deposition using a self-assembly polystyrene colloidal crystal template and preparation of ZnO/TiO2 IO by a liquid phase deposition (LPD) process at room temperature. The composition and topology of ZnO/TiO2 IO can be easily controlled by changing the duration of the LPD. After 20 min LPD process, a ZnO/TiO2 composite IO with non-close-packed face-centered cubic air sphere array was obtained. Prolonging the duration to 60 min, a pure TiO2 IO (TIO-LPD60) with obviously thickened walls was formed. The formation mechanism for the compositional and topological variation was discussed. A preliminary study on UV photocatalytic property of the samples for degradation of methylene blue reveals that the composition and topology significantly influenced the photocatalytic activity of the IO film. The ZnO/TiO2 composite IO demonstrates a higher degree of activity than both pure ZnO and pure TiO2 IO, although they have a similar IO wall thickness. Moreover, with increasing IO wall thickness from -52 nm to -90 nm, TIO-LPD60 exhibits the highest level of photocatalytic performance.展开更多
Silk fibroin/cellulose blend films were prepared using N-methylmorpholine -N-oxide (NMMO) as solvent. The effects of different proportions and solid contents on properties of blend films were discussed. The mechanical...Silk fibroin/cellulose blend films were prepared using N-methylmorpholine -N-oxide (NMMO) as solvent. The effects of different proportions and solid contents on properties of blend films were discussed. The mechanical properties showed that the blend films had preferable moisture permeability and a high strength. The structures of the blend films were investigated by infrared spectrum and X-ray diffraction. The results indicated the occurrence of hydrogen bonds between hydroxyl groups of cellulose and amido groups of fibroin.展开更多
Soy protein isolate/carboxymethyl chitosan (SPI/CMCH) blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios (100:0, 88:12, 67:33, 50...Soy protein isolate/carboxymethyl chitosan (SPI/CMCH) blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios (100:0, 88:12, 67:33, 50:50, 33:67, 12:88, 0:100) on the water sorption isotherm. The moisture sorption isotherm of the SPI/CMCH blended films was determined using various relative humidity's (16%, 35%, 55% and 76% RH) at 25 ± 1℃. The isotherms showed that the equilibrium moisture content (EMC) of the films increased with increasing CMCH content and the EMC value sharply increased above aw = 0.55. Understanding of sorption isotherms is important for prediction of moisture sorption properties of films via moisture sorption empirical models. The Guggenheim-Oswin, Brunauer-Emmett-Teller (BET), and Anderson-de Boer (GAB) sorption model predictions were tested against the experimental data. The root mean square (RMS) values from the Oswin, BET, and GAB models respectively ranged from 698.54 to 1,557.54, 38.85 to 58.30, and 52.52 to 95.95. Therefore, the BET model was found to be the best-fit model for SPI/CMCH blended films at 25 ± 1 ℃.展开更多
The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen...The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation (QCM-D) in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.展开更多
Objective Hedyotis corymbosa(Shui Xian Cao,水线草,HC)is the main antitumor medicine in China and other southeast Asian countries.A comprehensive quality control system of HC was established in this study,as the curren...Objective Hedyotis corymbosa(Shui Xian Cao,水线草,HC)is the main antitumor medicine in China and other southeast Asian countries.A comprehensive quality control system of HC was established in this study,as the current system was ineffective.Methods Microscopy was used to observe the characteristics of the powder and cross-sectional tissue.Thin layer chromatography(TLC)was employed to separate HC from Hedyotis diffusa(Bai Hua She She Cao,白花蛇舌草,HD).Simultaneously,high-performance liquid chromatography(HPLC)was used to establish the characteristic spectrum of HC and determine the concentrations of hedyotiscone A.Regarding the issue of systematicness,concentrations of water,total ash,acid-insoluble ash,heavy metals(including lead,arsenic,mercury,cadmium and copper)and pesticide residue were measured by the methods described in the 2015 edition of Chinese Pharmacopoeia.Results Calcium oxalate needle crystal bundles and oil drops were observed in the cross-sectional tissue.Three characteristic blue fluorescent spots were observed in the HC samples by TLC.There were five distinct characteristic peaks in HC but not in HD,and hedyotiscone A was the sharpest characteristic peak.The generated linear equation of hedyotiscone A was Y=3.15×108X+312.04(r2=1.000)between 0.00005270 and 0.002108 mg/mL,and the average recovery was 100.42%.Precision[relative standard deviation(RSD)0.92%],repeatability(RSD 0.14%),and recovery(RSD 0.85%)met the requirements for quantitative analysis.Hedyotiscone A concentrations ranged from 0.00017%~0.00113%across different habitats.Concentrations of water,ash and acid-insoluble ash were 8.80%~11.2%,7.00%~15.3%and 0.440%~7.70%,respectively.Concentrations of Pb,As,Hg,Cd and Cu were 1.60~4.60,0.650~1.60,0.0300~0.100,0.240~0.690 and 10.1~16.6μg/g,respectively.Pesticide residues were less than 0.00100 ppm.Conclusion The quality control system can effectively distinguish HC from HD,so as to comprehensively control the quality of HC,to provide references for the clinical use of HC.展开更多
Food diversification is a way to strengthen national food security, for example by reducing the dependence on wheat flour as a main raw material of various food products through the use of cassava flour. Cassava flour...Food diversification is a way to strengthen national food security, for example by reducing the dependence on wheat flour as a main raw material of various food products through the use of cassava flour. Cassava flour, a rich source of carbohydrates, can be used in the making of flakes. In this study, the Virgin coconut oil (VCO) waste flour was added in cassava flour to produce gluten-free cassava flour flakes with high dietary fiber contents. The six different formulas of flakes were used in this study with addition of 0% (control), 10%, 20%, 30%, 40% and 50% coconut waste flour, respectively. Then, the chemical and microbiological characteristics of the flakes were measured. Based on the proximate data, both flours have a good quality. The microbiological analysis shows cassava flour and coconut waste flour have good sanitation and food safety. Results showed that flakes with 80% cassava flour and 20% coconut waste flour are gluten-free and contain 2.52% water, 2.27% ash, 14.40% fat, 4.50% protein, 76.31% carbohydrate, 8.56% dietary fiber. Therefore, it can be said that cassava flour flakes can serve as gluten-free and rich dietary fiber ready-to-eat food.展开更多
A total of 280-day-old broilers (Ross 308) were randomly assigned to seven groups each containing for replicates with 10 chicks. The control group received the corn soybean meal based diet. In the treatment groups t...A total of 280-day-old broilers (Ross 308) were randomly assigned to seven groups each containing for replicates with 10 chicks. The control group received the corn soybean meal based diet. In the treatment groups the basal diet was supplemented with one of following 0.2%, 0.4% and 0.6% Thyme and Mint extracts. Triglyceride was significantly decreased by addition of 0.2% and 0.4% of Thyme extract (TE). The TE supplemented diets contained significantly lower cholesterol concentration and low density lipoprotein compared to the control diet. High density lipoprotein content was not significantly affected by dietary treatments. Likewise, differences among groups were not significant for hematocrit and hemoglobin level. The addition of Mint extract (ME) to the broiler diet led to a significant reduction in the triglyceride, cholesterol concentration and LDL. Differences among groups were not significant for HDL, hematocrit, or hemoglobin level. The results showed that both of TE and ME supplementation significantly decreased plasma level of triglycerides and LDL-cholesterol were also numerically increased with the addition of both TE and ME.展开更多
Mint is a medicinal and aromatic plant. It is very important for the pharmacopoeia, perfumes, confectionery and liquor industry. Some green mint leaves without rods are used as samples. Physical and mechanical propert...Mint is a medicinal and aromatic plant. It is very important for the pharmacopoeia, perfumes, confectionery and liquor industry. Some green mint leaves without rods are used as samples. Physical and mechanical properties of the sample such as the desorption isotherms, the density and volumetric withdrawal are determined. The kinetics of drying, where it follows the changes of the water content of the sample as a function of the drying time for the three temperatures 30, 40 and 50℃, is also presented and discussed.展开更多
Structural colors,derived from existing natural creatures,have aroused widespread attention in the materials regulation for different applications.Here,inspired by the color adjusting mechanism of hummingbird,we prese...Structural colors,derived from existing natural creatures,have aroused widespread attention in the materials regulation for different applications.Here,inspired by the color adjusting mechanism of hummingbird,we present a novel shape-memory structural color hydrogel film by introducing shape memory polymers(SMPs)into synthetic inverse opal scaffold structure.The excellent flexibility as well as the inverse opal structure of the hydrogel films imparts them with stable stretchability and brilliant structural colors.Benefiting from the transient structural anisotropy of copolymers,the hybrid films are possessed with shape-morphing behaviors capability.Based on the shape transformations and color responsiveness performance,we have demonstrated diverse structural color actuators with complex shapes for different tasks.Notably,as the photothermal responsive graphene quantum dots were integrated into the hydrogel,the hybrid films could also be endowed with the feature of light-controlled reversible deformation with synchronous structural color variation.These features demonstrate that the presented shape-memory structural color hydrogel film is valuable for soft robotics with multifunctions of sensing,communication and disguise.展开更多
The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the e...The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the exciting laser pulse and the receiving ultrasound transducers (PVDF films and PZT ceramics), as well as the reaction lifetimes in the photolysis processes of HbCO, the measured results are related to the geminate recombination and tertiary relaxation in photolyses of HbCO. Moreover, the quantum yields of the five mammals are also measured by laser pump-probe technique. The results show that the dynamic parameters, such as enthalpy and conformational volume changes, differ between the processes of the geminate recombination and tertiary relaxation. Also, the dynamic parameters differ among the five mammals although some of them may be consistent with each other.展开更多
In recent years, immense interest has been paid to the biomolecular architecture with the aim of protein assembly in two di- mensions on solid substrates, and the constructions of clay-protein ultrathin films (CPUFs...In recent years, immense interest has been paid to the biomolecular architecture with the aim of protein assembly in two di- mensions on solid substrates, and the constructions of clay-protein ultrathin films (CPUFs) are particularly concerned. This paper gives an overview of the recent research concerning the protein molecules (lysozyme, papain, protamine, bovine serum albumin) immobilized on clay mineral (Na-saponite) platelets and assembled in monolayered or multilayered hybrid ultrafilms or nanofilms. Two techniques including alternate layer-by-layer (LbL) assembly and the Langmuir-Blodgett (LB) are de- scribed in detail. A variety of means, including UV-vis absorption, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, XRD, AFM and surface chemistry techniques, have been described for characterization of the films in terms of quantification of protein and clay. The result reveals that electrostatic interaction is a prominent but not the only driving force in CPUF construction. In the case of LB technique, we managed to manipulate the elementary clay mineral platelets (1.3 nm in thickness) and assemble proteins into CPUFs with the aid of surfactants, and the formation of CPUFs was monitored via surface pressure vs. time (a--t) kinetics curves and surface pressure vs. area (a--A) isotherms. The factors that in- fluence protein adsorption on the clay layer, such as surfactants, the concentration of clay, equilibrium time, categories of pro- tein, and injection methods, were investigated. The parameters such as protein amount (nS), packing density (O), and average surface area per molecule (.(2) of deposited CPUFs were measured via method of surface chemistry and spectroscopy. By comparing the results of surface chemistry with those of adsorption experiments, we demonstrate that the surface chemistry method is a useful tool in investigating CPUFs. We also found that the water soluble protein molecules could form protein-clay hybrid monolayer over the dilute clay dispersions without addition of surfactants, and CPUFs containing elementary clay sheets and protein with great homogeneity were easily prepared by controlling certain surface pressure. To investigate the bio-catalytic performance of the immobilized lysozyme in CPUFs, we deposited CPUFs onto a cover glass, and installed the cover glass in a flow cell-grown reactor for Comamonas testosteroni (WDL7-GFP) incubation. The results show that the pro- liferation of WDL7-GFP is greatly suppressed by lysozyme, which demonstrates that lysozyme still retains its bioactivity after it is immobilized in the CPUFs.展开更多
Bacteriorhodopsin (BR) is a photochromic membrane protein isolated from a strain of halobacteria.Embedment of BR into a polymeric matrix enables the application of the photoactive protein as an optical material.In thi...Bacteriorhodopsin (BR) is a photochromic membrane protein isolated from a strain of halobacteria.Embedment of BR into a polymeric matrix enables the application of the photoactive protein as an optical material.In this work,a chemically crosslinked BR/gelatin film was prepared.The cross-linked film was found to be highly stable even under extreme alkaline or detergent circumstance while BR maintained its bioactivity.The treatments of base and detergents also led to dramatic prolongation of the lifetime of M photoproduct,which might be beneficial for potential applications such as information storage.The BR/gelatin film was demonstrated to tentatively record a simple pattern.展开更多
文摘Pepsin was assembled on the surface of prepared poly(ethylene terephthalate)(PET-NH3^+) substrates.The composition and structure of the pepsin/PET-NH3^+ assembling films in different condition were characterized by X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM).
文摘A novel method to fabricate composition- (IO) films using a positive sacrificial ZnO and topology-controlled ZnO/TiO2 inverse opals IO template has been developed. This method includes a two-step process, preparation of ZnO IO by a simple electrochemical deposition using a self-assembly polystyrene colloidal crystal template and preparation of ZnO/TiO2 IO by a liquid phase deposition (LPD) process at room temperature. The composition and topology of ZnO/TiO2 IO can be easily controlled by changing the duration of the LPD. After 20 min LPD process, a ZnO/TiO2 composite IO with non-close-packed face-centered cubic air sphere array was obtained. Prolonging the duration to 60 min, a pure TiO2 IO (TIO-LPD60) with obviously thickened walls was formed. The formation mechanism for the compositional and topological variation was discussed. A preliminary study on UV photocatalytic property of the samples for degradation of methylene blue reveals that the composition and topology significantly influenced the photocatalytic activity of the IO film. The ZnO/TiO2 composite IO demonstrates a higher degree of activity than both pure ZnO and pure TiO2 IO, although they have a similar IO wall thickness. Moreover, with increasing IO wall thickness from -52 nm to -90 nm, TIO-LPD60 exhibits the highest level of photocatalytic performance.
文摘Silk fibroin/cellulose blend films were prepared using N-methylmorpholine -N-oxide (NMMO) as solvent. The effects of different proportions and solid contents on properties of blend films were discussed. The mechanical properties showed that the blend films had preferable moisture permeability and a high strength. The structures of the blend films were investigated by infrared spectrum and X-ray diffraction. The results indicated the occurrence of hydrogen bonds between hydroxyl groups of cellulose and amido groups of fibroin.
文摘Soy protein isolate/carboxymethyl chitosan (SPI/CMCH) blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios (100:0, 88:12, 67:33, 50:50, 33:67, 12:88, 0:100) on the water sorption isotherm. The moisture sorption isotherm of the SPI/CMCH blended films was determined using various relative humidity's (16%, 35%, 55% and 76% RH) at 25 ± 1℃. The isotherms showed that the equilibrium moisture content (EMC) of the films increased with increasing CMCH content and the EMC value sharply increased above aw = 0.55. Understanding of sorption isotherms is important for prediction of moisture sorption properties of films via moisture sorption empirical models. The Guggenheim-Oswin, Brunauer-Emmett-Teller (BET), and Anderson-de Boer (GAB) sorption model predictions were tested against the experimental data. The root mean square (RMS) values from the Oswin, BET, and GAB models respectively ranged from 698.54 to 1,557.54, 38.85 to 58.30, and 52.52 to 95.95. Therefore, the BET model was found to be the best-fit model for SPI/CMCH blended films at 25 ± 1 ℃.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.9732011CB606200 and No.81330031) and Fundamentat Research Funds for the Central Universities (No.SWJTU11CX054). The authors gratefully acknowledge assistance of Mr. Hai-bei Liu at Qsense company for consulting.
文摘The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation (QCM-D) in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.
基金support from the National Science foundation of China(No.81503041)the Science Research Projects of Chinese Pharmacopoeia(No.Z18)+2 种基金the Science Research Projects of the Hunan Provincial Department of Education(No.17C1213)the Science Research Projects of the Hunan Provincial Department of Education(No.14C0860)and the Key Projects of the Changsha Municipal Science and Technology Bureau(No.K1406030-31)
文摘Objective Hedyotis corymbosa(Shui Xian Cao,水线草,HC)is the main antitumor medicine in China and other southeast Asian countries.A comprehensive quality control system of HC was established in this study,as the current system was ineffective.Methods Microscopy was used to observe the characteristics of the powder and cross-sectional tissue.Thin layer chromatography(TLC)was employed to separate HC from Hedyotis diffusa(Bai Hua She She Cao,白花蛇舌草,HD).Simultaneously,high-performance liquid chromatography(HPLC)was used to establish the characteristic spectrum of HC and determine the concentrations of hedyotiscone A.Regarding the issue of systematicness,concentrations of water,total ash,acid-insoluble ash,heavy metals(including lead,arsenic,mercury,cadmium and copper)and pesticide residue were measured by the methods described in the 2015 edition of Chinese Pharmacopoeia.Results Calcium oxalate needle crystal bundles and oil drops were observed in the cross-sectional tissue.Three characteristic blue fluorescent spots were observed in the HC samples by TLC.There were five distinct characteristic peaks in HC but not in HD,and hedyotiscone A was the sharpest characteristic peak.The generated linear equation of hedyotiscone A was Y=3.15×108X+312.04(r2=1.000)between 0.00005270 and 0.002108 mg/mL,and the average recovery was 100.42%.Precision[relative standard deviation(RSD)0.92%],repeatability(RSD 0.14%),and recovery(RSD 0.85%)met the requirements for quantitative analysis.Hedyotiscone A concentrations ranged from 0.00017%~0.00113%across different habitats.Concentrations of water,ash and acid-insoluble ash were 8.80%~11.2%,7.00%~15.3%and 0.440%~7.70%,respectively.Concentrations of Pb,As,Hg,Cd and Cu were 1.60~4.60,0.650~1.60,0.0300~0.100,0.240~0.690 and 10.1~16.6μg/g,respectively.Pesticide residues were less than 0.00100 ppm.Conclusion The quality control system can effectively distinguish HC from HD,so as to comprehensively control the quality of HC,to provide references for the clinical use of HC.
文摘Food diversification is a way to strengthen national food security, for example by reducing the dependence on wheat flour as a main raw material of various food products through the use of cassava flour. Cassava flour, a rich source of carbohydrates, can be used in the making of flakes. In this study, the Virgin coconut oil (VCO) waste flour was added in cassava flour to produce gluten-free cassava flour flakes with high dietary fiber contents. The six different formulas of flakes were used in this study with addition of 0% (control), 10%, 20%, 30%, 40% and 50% coconut waste flour, respectively. Then, the chemical and microbiological characteristics of the flakes were measured. Based on the proximate data, both flours have a good quality. The microbiological analysis shows cassava flour and coconut waste flour have good sanitation and food safety. Results showed that flakes with 80% cassava flour and 20% coconut waste flour are gluten-free and contain 2.52% water, 2.27% ash, 14.40% fat, 4.50% protein, 76.31% carbohydrate, 8.56% dietary fiber. Therefore, it can be said that cassava flour flakes can serve as gluten-free and rich dietary fiber ready-to-eat food.
文摘A total of 280-day-old broilers (Ross 308) were randomly assigned to seven groups each containing for replicates with 10 chicks. The control group received the corn soybean meal based diet. In the treatment groups the basal diet was supplemented with one of following 0.2%, 0.4% and 0.6% Thyme and Mint extracts. Triglyceride was significantly decreased by addition of 0.2% and 0.4% of Thyme extract (TE). The TE supplemented diets contained significantly lower cholesterol concentration and low density lipoprotein compared to the control diet. High density lipoprotein content was not significantly affected by dietary treatments. Likewise, differences among groups were not significant for hematocrit and hemoglobin level. The addition of Mint extract (ME) to the broiler diet led to a significant reduction in the triglyceride, cholesterol concentration and LDL. Differences among groups were not significant for HDL, hematocrit, or hemoglobin level. The results showed that both of TE and ME supplementation significantly decreased plasma level of triglycerides and LDL-cholesterol were also numerically increased with the addition of both TE and ME.
文摘Mint is a medicinal and aromatic plant. It is very important for the pharmacopoeia, perfumes, confectionery and liquor industry. Some green mint leaves without rods are used as samples. Physical and mechanical properties of the sample such as the desorption isotherms, the density and volumetric withdrawal are determined. The kinetics of drying, where it follows the changes of the water content of the sample as a function of the drying time for the three temperatures 30, 40 and 50℃, is also presented and discussed.
基金supported by the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(52073060 and 61927805)+1 种基金the Shenzhen Fundamental Research Program(JCYJ20190813152616459)the Project funded by China Postdoctoral Science Foundation。
文摘Structural colors,derived from existing natural creatures,have aroused widespread attention in the materials regulation for different applications.Here,inspired by the color adjusting mechanism of hummingbird,we present a novel shape-memory structural color hydrogel film by introducing shape memory polymers(SMPs)into synthetic inverse opal scaffold structure.The excellent flexibility as well as the inverse opal structure of the hydrogel films imparts them with stable stretchability and brilliant structural colors.Benefiting from the transient structural anisotropy of copolymers,the hybrid films are possessed with shape-morphing behaviors capability.Based on the shape transformations and color responsiveness performance,we have demonstrated diverse structural color actuators with complex shapes for different tasks.Notably,as the photothermal responsive graphene quantum dots were integrated into the hydrogel,the hybrid films could also be endowed with the feature of light-controlled reversible deformation with synchronous structural color variation.These features demonstrate that the presented shape-memory structural color hydrogel film is valuable for soft robotics with multifunctions of sensing,communication and disguise.
基金supported by the National Natural Science Foundation of China(Grant No. 11074125)the National Basic Research Program of China(Grant No. 2012CB921504)+1 种基金the Foundamental Research Founds for Central Universities of China(Grant No. 1101020402)PAPD Project of Jiangsu Higher Education Institutions
文摘The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the exciting laser pulse and the receiving ultrasound transducers (PVDF films and PZT ceramics), as well as the reaction lifetimes in the photolysis processes of HbCO, the measured results are related to the geminate recombination and tertiary relaxation in photolyses of HbCO. Moreover, the quantum yields of the five mammals are also measured by laser pump-probe technique. The results show that the dynamic parameters, such as enthalpy and conformational volume changes, differ between the processes of the geminate recombination and tertiary relaxation. Also, the dynamic parameters differ among the five mammals although some of them may be consistent with each other.
基金supported by National Natural Science Foundation of China(21103039)Research Fund for the Doctoral Program of Higher Education of China (20110111120008)
文摘In recent years, immense interest has been paid to the biomolecular architecture with the aim of protein assembly in two di- mensions on solid substrates, and the constructions of clay-protein ultrathin films (CPUFs) are particularly concerned. This paper gives an overview of the recent research concerning the protein molecules (lysozyme, papain, protamine, bovine serum albumin) immobilized on clay mineral (Na-saponite) platelets and assembled in monolayered or multilayered hybrid ultrafilms or nanofilms. Two techniques including alternate layer-by-layer (LbL) assembly and the Langmuir-Blodgett (LB) are de- scribed in detail. A variety of means, including UV-vis absorption, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, XRD, AFM and surface chemistry techniques, have been described for characterization of the films in terms of quantification of protein and clay. The result reveals that electrostatic interaction is a prominent but not the only driving force in CPUF construction. In the case of LB technique, we managed to manipulate the elementary clay mineral platelets (1.3 nm in thickness) and assemble proteins into CPUFs with the aid of surfactants, and the formation of CPUFs was monitored via surface pressure vs. time (a--t) kinetics curves and surface pressure vs. area (a--A) isotherms. The factors that in- fluence protein adsorption on the clay layer, such as surfactants, the concentration of clay, equilibrium time, categories of pro- tein, and injection methods, were investigated. The parameters such as protein amount (nS), packing density (O), and average surface area per molecule (.(2) of deposited CPUFs were measured via method of surface chemistry and spectroscopy. By comparing the results of surface chemistry with those of adsorption experiments, we demonstrate that the surface chemistry method is a useful tool in investigating CPUFs. We also found that the water soluble protein molecules could form protein-clay hybrid monolayer over the dilute clay dispersions without addition of surfactants, and CPUFs containing elementary clay sheets and protein with great homogeneity were easily prepared by controlling certain surface pressure. To investigate the bio-catalytic performance of the immobilized lysozyme in CPUFs, we deposited CPUFs onto a cover glass, and installed the cover glass in a flow cell-grown reactor for Comamonas testosteroni (WDL7-GFP) incubation. The results show that the pro- liferation of WDL7-GFP is greatly suppressed by lysozyme, which demonstrates that lysozyme still retains its bioactivity after it is immobilized in the CPUFs.
基金supported by the National Basic Research Rrogram of China (973 Program,2009CB930000)National Natural Science Foundation of China (21034002)
文摘Bacteriorhodopsin (BR) is a photochromic membrane protein isolated from a strain of halobacteria.Embedment of BR into a polymeric matrix enables the application of the photoactive protein as an optical material.In this work,a chemically crosslinked BR/gelatin film was prepared.The cross-linked film was found to be highly stable even under extreme alkaline or detergent circumstance while BR maintained its bioactivity.The treatments of base and detergents also led to dramatic prolongation of the lifetime of M photoproduct,which might be beneficial for potential applications such as information storage.The BR/gelatin film was demonstrated to tentatively record a simple pattern.