Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this...Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.展开更多
The authors presented indoor practice experiments of parameters affect on foaming and foam stability. Experiments were carried out and special equipments were used to determine foaming and foam stability; tests were t...The authors presented indoor practice experiments of parameters affect on foaming and foam stability. Experiments were carried out and special equipments were used to determine foaming and foam stability; tests were tabulated and charted. The effects of chemical and physical parameters on foaming and foam stability have been conducted.展开更多
Scaffolds with multimodal pore structure are essential to cells differentiation and proliferation in bone tissue engineering. Bi-/multi-modal porous PLGA/hydroxyapatite composite scaffolds were prepared by supercritic...Scaffolds with multimodal pore structure are essential to cells differentiation and proliferation in bone tissue engineering. Bi-/multi-modal porous PLGA/hydroxyapatite composite scaffolds were prepared by supercritical C02 foaming in which hydroxyapatite acted as heterogeneous nucleation agent. Bimodal porous scaffolds were prepared under certain conditions, i.e. hydroxyapatite addition of 5%, depressurization rate of 0.3 MPa. min-1, soaking temperature of 55 ℃, and pressure of 9 MPa. And scaffolds presented specific structure of small pores （122 μM ± 66 μm） in the cellular walls of large pores （552 μm ±127 μm）. Furthermore, multimodal porous PLGA scaffolds with micro-pores （37 μM ± 11μM） were obtained at low soaking pressure of 7.5 MPa. The interconnected porosity of scaffolds ranged from （52.53 ± 2.69）% to （83.08±2.42）% by adjusting depressurization rate, while compression modulus satisfied the requirement of bone tissue engineering. Solvent-free CO2 foaming method is promising to fabricate bi-/multi-modal porous scaffolds in one step, and bioactive particles for osteogenesis could serve as nucleation agents.展开更多
In recent years,air-foam combining the advantages of both liquid and air drilling has been utilized as a drilling medium. Air-foam drilling has proved its efficiency in numerous situations where serious problems were ...In recent years,air-foam combining the advantages of both liquid and air drilling has been utilized as a drilling medium. Air-foam drilling has proved its efficiency in numerous situations where serious problems were encountered,such as in fractured formations and depleted or high permeable zones. However,the major disadvantage of air-foam drilling system is that the foam can only be used once,so that an extremely large pit is required to contain the foam to allow sufficient room for cuttings and for the foam to dissipate. Moreover,it needs enormous volume prepared,consuming abundance of water and ingredient additives,which results in the high cost of foam drilling. The recycling foam fluid by using foam breaking technology is the only effective method to solve these problems associated with the known foam drilling. Various types of equipment and technique have been employed to suppress foam formation in biological and process equipment in foam drilling. The study described various methods of foam breaking technology,and the trend of the foam breaking technology for foam drilling is discussed.展开更多
A series of Al‐containing mesostructured cellular silica foams(Al‐MCFs)with different Si/Al molar ratios(x;x=10,20,30,40,or50)were prepared by a post synthetic method using aluminum isopropoxide as an alumina source...A series of Al‐containing mesostructured cellular silica foams(Al‐MCFs)with different Si/Al molar ratios(x;x=10,20,30,40,or50)were prepared by a post synthetic method using aluminum isopropoxide as an alumina source.The corresponding NiMo catalysts supported on Al‐MCFs were prepared and evaluated using dibenzothiophene(DBT)as the probe reactant.All the synthesized samples were characterized by small‐angle X‐ray scattering,scanning electron microscopy,nitrogen adsorption‐desorption,UV‐Vis diffuse reflectance spectroscopy,H2temperature‐programmed reduction,27Al MAS NMR,temperature‐programmed desorption of ammonia,pyridine‐FTIR,Raman spectroscopy,HRTEM,and X‐ray photoelectron spectroscopy to analyze their physicochemical properties and to gain a deeper insight of the interrelationship between the structures and the catalytic performance.The synthesis mechanism was proposed to involve the formation of Br?nsted acid and Lewis acid sites through the replacement of Si4+with Al3+.Aluminum introduced into MCFs by the post synthetic method has a negligible influence on the mesostructure of the parent MCFs but can form silicoaluminate materials with moderate Br?nsted acidity.For Al‐MCFs(x)materials,the detection of tetrahedrally coordinated Al3+cations demonstrated that the Al species had been successfully incorporated into the silicon frameworks.Furthermore,the DBT hydrodesulfurization(HDS)catalytic activity of the NiMo/Al‐MCFs(x)catalysts increased with increasing Si/Al molar ratio,and reached a maximum at a Si/Al molar ratio of20.The interaction of Ni and Mo species with the support became stronger when Al was incorporated into the MCFs supports.The high activities of the NiMo/Al‐MCFs catalysts for the DBT HDS were attributed to the suitable acidity properties and good dispersions of the Ni and Mo active phases.展开更多
基金supported by the National Key Technology Research and Development Program of China (Grant No.2006BAD30B01)the Research Award Fund for Excellent Young Scientist of Shandong Province,China (Grant No.BS2009HZ005)
文摘Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.
文摘The authors presented indoor practice experiments of parameters affect on foaming and foam stability. Experiments were carried out and special equipments were used to determine foaming and foam stability; tests were tabulated and charted. The effects of chemical and physical parameters on foaming and foam stability have been conducted.
基金Support by the National Natural Science Foundation of China(21276225,21476196)
文摘Scaffolds with multimodal pore structure are essential to cells differentiation and proliferation in bone tissue engineering. Bi-/multi-modal porous PLGA/hydroxyapatite composite scaffolds were prepared by supercritical C02 foaming in which hydroxyapatite acted as heterogeneous nucleation agent. Bimodal porous scaffolds were prepared under certain conditions, i.e. hydroxyapatite addition of 5%, depressurization rate of 0.3 MPa. min-1, soaking temperature of 55 ℃, and pressure of 9 MPa. And scaffolds presented specific structure of small pores （122 μM ± 66 μm） in the cellular walls of large pores （552 μm ±127 μm）. Furthermore, multimodal porous PLGA scaffolds with micro-pores （37 μM ± 11μM） were obtained at low soaking pressure of 7.5 MPa. The interconnected porosity of scaffolds ranged from （52.53 ± 2.69）% to （83.08±2.42）% by adjusting depressurization rate, while compression modulus satisfied the requirement of bone tissue engineering. Solvent-free CO2 foaming method is promising to fabricate bi-/multi-modal porous scaffolds in one step, and bioactive particles for osteogenesis could serve as nucleation agents.
基金Project supported by the Key Science &Technology Research Program of Zhongyuan Petroleum Exploration Bureau (No.20083022)
文摘In recent years,air-foam combining the advantages of both liquid and air drilling has been utilized as a drilling medium. Air-foam drilling has proved its efficiency in numerous situations where serious problems were encountered,such as in fractured formations and depleted or high permeable zones. However,the major disadvantage of air-foam drilling system is that the foam can only be used once,so that an extremely large pit is required to contain the foam to allow sufficient room for cuttings and for the foam to dissipate. Moreover,it needs enormous volume prepared,consuming abundance of water and ingredient additives,which results in the high cost of foam drilling. The recycling foam fluid by using foam breaking technology is the only effective method to solve these problems associated with the known foam drilling. Various types of equipment and technique have been employed to suppress foam formation in biological and process equipment in foam drilling. The study described various methods of foam breaking technology,and the trend of the foam breaking technology for foam drilling is discussed.
基金supported by National Natural Science Foundation of China (21276277,U1463207)CNOOC Project+1 种基金CNPC major projectthe Opening Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology (2015K003)~~
文摘A series of Al‐containing mesostructured cellular silica foams(Al‐MCFs)with different Si/Al molar ratios(x;x=10,20,30,40,or50)were prepared by a post synthetic method using aluminum isopropoxide as an alumina source.The corresponding NiMo catalysts supported on Al‐MCFs were prepared and evaluated using dibenzothiophene(DBT)as the probe reactant.All the synthesized samples were characterized by small‐angle X‐ray scattering,scanning electron microscopy,nitrogen adsorption‐desorption,UV‐Vis diffuse reflectance spectroscopy,H2temperature‐programmed reduction,27Al MAS NMR,temperature‐programmed desorption of ammonia,pyridine‐FTIR,Raman spectroscopy,HRTEM,and X‐ray photoelectron spectroscopy to analyze their physicochemical properties and to gain a deeper insight of the interrelationship between the structures and the catalytic performance.The synthesis mechanism was proposed to involve the formation of Br?nsted acid and Lewis acid sites through the replacement of Si4+with Al3+.Aluminum introduced into MCFs by the post synthetic method has a negligible influence on the mesostructure of the parent MCFs but can form silicoaluminate materials with moderate Br?nsted acidity.For Al‐MCFs(x)materials,the detection of tetrahedrally coordinated Al3+cations demonstrated that the Al species had been successfully incorporated into the silicon frameworks.Furthermore,the DBT hydrodesulfurization(HDS)catalytic activity of the NiMo/Al‐MCFs(x)catalysts increased with increasing Si/Al molar ratio,and reached a maximum at a Si/Al molar ratio of20.The interaction of Ni and Mo species with the support became stronger when Al was incorporated into the MCFs supports.The high activities of the NiMo/Al‐MCFs catalysts for the DBT HDS were attributed to the suitable acidity properties and good dispersions of the Ni and Mo active phases.
