Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are bein...Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are being sought because of environmental concerns and rising landfill costs.We have developed a process in which this waste can be treated with a variety of enzymes to extract gelatin and a hydrolysate.These recovered protein fractions,practically devoid of chromium,could be used in a wide range of products,including adhesives,cosmetics,films,encapsulating agents,animal feed and fertilizer.A chromium product is also isolated that can be chemically treated and recycled back into the tanning process.Finally,we have shown,by using a computer-assisted process simulation and cost estimation,that a profit could be realized by the tanneries,not only by reducing the need to landfill but also from the return from the sale of the protein products.展开更多
Fish oils are important substances in the field of food and drug delivery.Due to their unstable double bonds,fishy taste,and poor water solubility,it is pivotal to investigate novel dosage forms for fish oils,such as ...Fish oils are important substances in the field of food and drug delivery.Due to their unstable double bonds,fishy taste,and poor water solubility,it is pivotal to investigate novel dosage forms for fish oils,such as encapsulated droplets.In this work,we primarily prepared gelatin-stabilized fish oil-loaded traditional emulsions and investigated their emulsion forms,droplets,and storage stability under different preparation and storage conditions.Our results showed that higher gelatin solution pH,higher storage temperature in the range of 4–37℃,and increased storage time induced the emulsion form switch from a liquid form to a redispersible gel form of the fish oil emulsion.The droplets had core-shell microstructures and a trimodal size distribution,which decreases linearly with increasing gelatin solution pH and homogenizing time,but decreases exponentially with increasing homogenizing speed.In addition,storage temperature showed a notably different effect on traditional emulsion storage.This work provides a fundamental knowledge for the formation,microstructure,and properties of gelatin-based traditional emulsions.It also provides a promising new application for fish oil-loaded emulsions in food beverages,soft candy,and other food products.展开更多
As a non-thermal processing technology,high hydrostatic pressure(HHP)can be used for starch modification without affecting the quality and flavour constituents.The effect of HHP on starch is closely related to the tre...As a non-thermal processing technology,high hydrostatic pressure(HHP)can be used for starch modification without affecting the quality and flavour constituents.The effect of HHP on starch is closely related to the treatment time of HHP.In this paper,we investigated the impacts of HHP treatment time(0,5,10,15,20,25,30 min)on the microstructure,gelatinization and thermal properties as well as in vitro digestibility of oat starch by scanning electron microscopy,X-ray diffraction,Fourier transform infrared spectroscopy,13C NMR and differential scanning calorimeter.Results showed that 5-min HHP treatment led to deformation and decreases in short-range ordered and doublehelix structures of oat starch granules,and further extending the treatment time to 15 min or above caused the formation of a gelatinous connection zone,increase of particle size,disintegration of short-range ordered and double-helix structures,and crystal structure change from A type to V type,indicating gelatinization occurred.Longer treatment time also resulted in the reduction in both the viscosity and the stability of oat starch.These indicated that HHP treatment time greatly influenced the microstructure of oat starch,and the oat starch experienced crystalline destruction(5 min),crystalline disintegration(15 min)and gelatinization(>15 min)during HHP treatment.Results of in vitro digestibility showed that the rapidly digestible starch(RDS)content declined first after treatment for 5 to 10 min then rose with the time extending from 15 to 30 min,indicating that longer pressure treatment time was unfavourable to the health benefits of oat starch for humans with diabetes and cardiovascular disease.Therefore,the 500-MPa treatment time for oat starch is recommended not more than 15 min.This study provides theoretical guidance for the application of HHP technology in starch modification and development of health foods.展开更多
Background: Ballistics gelatin is a common tissue surrogate used in bacterial contamination models for projectile wounds. Although these studies have demonstrated that bacteria are transferred from the surface of the ...Background: Ballistics gelatin is a common tissue surrogate used in bacterial contamination models for projectile wounds. Although these studies have demonstrated that bacteria are transferred from the surface of the gelatin to the wound track by a projectile, quantifiable results have been inconsistent and not repeatable in successive tests.Methods: In this study, five areas of a typical contamination model in which bacterial recovery or survival are affected were identified for optimization. The first was a contaminated "skin" surrogate, where the novel use of vacuum filtration of a bacterial culture and buffer onto filter paper was employed. The other possibly problematic areas of the bacterial distribution model included the determination of bacterial survival when the contamination model is dried, survival in solid and molten gelatin, and the effect of high-intensity lights used for recording high-speed video.Results: Vacuum filtration of bacteria and buffer resulted in a consistent bacterial distribution and recovery. The use of phosphate buffer M9(pH 7) aided in neutralizing the ballistics gelatin and improving bacterial survival in solid gelatin. Additionally, the use of high-intensity lights to record high-speed video and the use of a 42℃ water bath to melt the gelatin were found to be bactericidal for gram-positive and gram-negative bacteria.Conclusion: Multiple areas of a typical contamination model in which bacterial survival may be impeded were identified, and methods were proposed to improve survival in each area. These methods may be used to optimize the results of bacterial contamination models for medical applications, such as understanding the progression of infection in penetrating wounds and to identify possible sources of contamination for forensic purposes.展开更多
Development of functional bioinspired hydrogels that have good releases control character is necessary for the application of these materials in biomedical engineering.Herein,we report a composite hydrogel prepared fr...Development of functional bioinspired hydrogels that have good releases control character is necessary for the application of these materials in biomedical engineering.Herein,we report a composite hydrogel prepared from several biocompatible carboxymethyl konjac glucomannan(CKGM)/gelatin(G)/tannic acid(TA)functional nano-hydroxyapatite(TA@n-HA),which has good biodegradability and pH sensitivity.The mechanism of interaction between hydrogels was confirmed by Fourier transform infrared spectroscopy,X-ray diffraction,Scanning electron microscopy and Thermogravimetric analysis.The physico-chemical properties of CKGM/G hydrogels have been significantly improved through the incorporation of TA@n-HA within the matrix.Studies in the sustained release of epigallocatechin gallate(EGCG)demonstrated that the TA@n-HA/CKGM/G hydrogels exhibit not only better pH sensitive properties,but also enhanced biocompatibility and encapsulation in comparison to the matrix devoid of TA@n-HA.Consequently,TA@n-HA/CKGM/G hydrogels using EGCG as a drug release model show the potential for drug delivery.展开更多
The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions.In this work,we mainly explore the effect of pH change on the droplet and creaming s...The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions.In this work,we mainly explore the effect of pH change on the droplet and creaming stability of fish oil-loaded emulsions synergistically(Span 80 and SL)or competitively(Tween 80 and SDS)stabilized by gelatin/surfactant.The results demonstrated that initial droplet stability and droplet storage stability,and creaming stability of the pH-adjusted emulsions are dependent on both the adsorption ways of emulsifiers and the adjusted pH:(1)Competitively stabilized emulsions have more stable droplets than synergistically stabilized emulsions;(2)SDS-dominant competitively stabilized emulsions have more stable droplets than gelatin-dominant emulsions;(3)Basic pH-adjusted emulsions have more stable droplets than acidic pH-adjusted emulsions;(4)The synergistically stabilized emulsions at acidic pH have significantly higher creaming indexes than that at basic pH;and(5)The competitively stabilized emulsions have high or similar creaming indexes to that at acidic pH.Further,the mechanisms are proposed according to Stokes’Law.This work will provide useful information to understand the interfacial properties of mixed emulsifiers in the food emulsions and promising application perspective for the development of food beverages including acidic and alkali beverages.展开更多
To understand the effects of the rifle bullet parameters on the bullet-gelatin interaction quantitatively, a finite element model of bullet penetrating gelatin was set up and computational re- suits are compared with ...To understand the effects of the rifle bullet parameters on the bullet-gelatin interaction quantitatively, a finite element model of bullet penetrating gelatin was set up and computational re- suits are compared with experimental ones. The penetration of the rifle bullet into the gelatin was simulated by the nonlinear finite element method. The quantitative analysis of the changes in the ge- latin interaction with the rifle bullet were conducted by changing the bullet parameters, such as at- tack angle on gelatin, initial velocity, warhead＇ s tip and location of mass center of bullet. Results demonstrate that with the increase of the attack angle, instable moment of the bullet moves forward, the length of narrow wound channel shortens, and when penetration is completed diameters of tem- porary cavities increase, the gelatin energy and energy transmission ratio increases; With the in- crease of the impact velocity, instable moment of the bullet moves forward, the maximum forces acting on the gelatin and the gelatin energy increase remarkably ; the length of narrow wound channel shortens, diameters of temporary cavities increase when penetration is completed, the gelatin energy and energy transmission ratio increase; The warhead＇ s tip and location of mass center have a influ- ence on the instable moment of the bullet and length of the narrow wound channel. The instable mo- ment delays and narrow wound channel increases when the warhead＇s tip flattens. The instable mo- ment moves forward a little and the narrow wound channel shortens a little when location of mass center moves back.展开更多
A glucose oxidation catalyst comprising carbon nanotube,tetrathiafulvalene(TTF),gelatin,glutaraldehyde(GA)and glucose oxidase(GOx)(CNT/[TTF-GOx]/Gelatin+GA)is suggested to enhance the reactivity of glucose oxidation r...A glucose oxidation catalyst comprising carbon nanotube,tetrathiafulvalene(TTF),gelatin,glutaraldehyde(GA)and glucose oxidase(GOx)(CNT/[TTF-GOx]/Gelatin+GA)is suggested to enhance the reactivity of glucose oxidation reaction(GOR),and the performance and stability of enzymatic biofuel cells(EBCs)using this catalyst.In this catalyst,TTF is used as mediator to transfer electron effectively,while GA is crosslinked to gelatin to form non-soluble network.The structure prevents the dissolution of gelatin from aqueous electrolyte and reduces the leaching-out of GOx and TTF molecules.To confirm the crosslinking effect of GA and gelatin,Fourier-transform infrared spectroscopy(FT-IR)and electrochemical evaluations are utilized.According to FT-IR analysis,it was observed that the amide I peak shifted after crosslinking.This is evidence showing the appropriate network formation and the reactivity of CNT/[TTFGOx]/Gelatin+GA is well preserved even after multiple potential cycling.In addition,its GOx activity is regularly monitored for one month and the measurements prove that the structure prevents the leaching out of GOx molecules.Based on that,EBC using the anodic catalyst shows excellent performances,such as open circuit voltage of 0.75 V and maximum power density of 184μW/cm^(2).展开更多
Tilapia skin gelatin hydrolysates(TSGH)were obtained by complex protease hydrolysis.The amino acid sequences of 50 peptides in TSGH were identified,and most of these peptides were found to contain the-Gly-Pro-sequence...Tilapia skin gelatin hydrolysates(TSGH)were obtained by complex protease hydrolysis.The amino acid sequences of 50 peptides in TSGH were identified,and most of these peptides were found to contain the-Gly-Pro-sequence.The osteoporosis(OP)rat model induced by retinoic acid was prepared,and the effects of different doses of TSGH on OP in vivo were evaluated.Serum calcium(Ca)and phosphate(P),alkaline phosphatase activity,and osteocalcin levels in OP rats were regulated by TSGH.The bone length,dry weight index,maximum load,and Ca content of OP rats significantly increased by treatment TSGH in a dosedependent manner.Micro-CT images of the femurs and tibias of the rats indicated that the bone mineral density,cortical bone thickness,and cortical/trabecular bone area ratios were recovered and that OP symptoms were improved.Tartrate-resistant acid phosphate and hematoxylin-eosin staining showed that osteoclast numbers and histomorphological changes in the femurs in OP rats could be recovered by TSGH.展开更多
We examine the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62 mm APM2 and 25 mm projectiles. A threshold impact angle(critical angle) exists beyond which ricochet cannot occur. The...We examine the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62 mm APM2 and 25 mm projectiles. A threshold impact angle(critical angle) exists beyond which ricochet cannot occur. The Autodyn simulation code with the smooth particle hydrodynamic(SPH) method and Impetus Afea Solver with the corpuscular model are used and the results are compared with experimental and analytical results. The resistance force in sand for spheres was proportional to a term quadratic in velocity plus a term linear in velocity. The drag coefficient for the quadratic term was 0.65. The Autodyn and Impetus Afea codes simulate too large penetration due to the lack of a linear velocity resistance force. Critical ricochet angles were consistent with analytical results in the literature. In ballistic gelatin at velocities of 50–850 m/s a drag coefficient of 0.30 fits the high speed camera recordings if a linear velocity resistance term is included. However, only a quadratic velocity resistance force with drag coefficient that varies with the Reynolds number also fits the measurements. The simulation of a sphere in water with Autodyn showed too large drag coefficient. The 7.62 mm APM2 core simulations in sand fit reasonable well for both codes. The 25 mm projectile ricochet simulations in sand show consistency with the high speed camera recordings. Computer time was reduced by one to two orders of magnitudes when applying the Impetus Afea Solver compared to Autodyn code due to the use of the graphics processing units(GPU).展开更多
为了改善燕麦粉加工的适应性,选用植物乳杆菌(Lactobacillus plantarum HH-LP56)分别对燕麦生粉和不同糊化度(13%、17%、24%、30%、34%)燕麦熟粉进行发酵改性,探究乳酸菌发酵对燕麦粉的游离氨基酸、淀粉酶活性、还原糖含量和热特性,以...为了改善燕麦粉加工的适应性,选用植物乳杆菌(Lactobacillus plantarum HH-LP56)分别对燕麦生粉和不同糊化度(13%、17%、24%、30%、34%)燕麦熟粉进行发酵改性,探究乳酸菌发酵对燕麦粉的游离氨基酸、淀粉酶活性、还原糖含量和热特性,以及燕麦-小麦复配面团的流变发酵特性和馒头质构特性的影响。结果表明:乳酸菌发酵促进了燕麦生粉中游离氨基酸的释放,增加了燕麦生粉和熟粉中淀粉酶活性和还原糖含量。将发酵改性燕麦生/熟粉与小麦粉进行复配,改善了面团的发酵特性,制得的馒头比体积上升,硬度下降,馒头的品质特性得到有效改善。展开更多
文摘Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are being sought because of environmental concerns and rising landfill costs.We have developed a process in which this waste can be treated with a variety of enzymes to extract gelatin and a hydrolysate.These recovered protein fractions,practically devoid of chromium,could be used in a wide range of products,including adhesives,cosmetics,films,encapsulating agents,animal feed and fertilizer.A chromium product is also isolated that can be chemically treated and recycled back into the tanning process.Finally,we have shown,by using a computer-assisted process simulation and cost estimation,that a profit could be realized by the tanneries,not only by reducing the need to landfill but also from the return from the sale of the protein products.
基金This research has been supported by research grants from the National Key R&D Program of China(No.2019YFD0902003-2)and Shanghai Municipal Education Commission-Gaoyuan Discipline of Food Science&Technology Grant Support(Shanghai Ocean University).
文摘Fish oils are important substances in the field of food and drug delivery.Due to their unstable double bonds,fishy taste,and poor water solubility,it is pivotal to investigate novel dosage forms for fish oils,such as encapsulated droplets.In this work,we primarily prepared gelatin-stabilized fish oil-loaded traditional emulsions and investigated their emulsion forms,droplets,and storage stability under different preparation and storage conditions.Our results showed that higher gelatin solution pH,higher storage temperature in the range of 4–37℃,and increased storage time induced the emulsion form switch from a liquid form to a redispersible gel form of the fish oil emulsion.The droplets had core-shell microstructures and a trimodal size distribution,which decreases linearly with increasing gelatin solution pH and homogenizing time,but decreases exponentially with increasing homogenizing speed.In addition,storage temperature showed a notably different effect on traditional emulsion storage.This work provides a fundamental knowledge for the formation,microstructure,and properties of gelatin-based traditional emulsions.It also provides a promising new application for fish oil-loaded emulsions in food beverages,soft candy,and other food products.
基金supported financially by the National Natural Science Foundation of China (Grant No.31760468 and32060515)Inner Mongolia Autonomous Region Science and Technology Plan Project (No.2020GG0064)
文摘As a non-thermal processing technology,high hydrostatic pressure(HHP)can be used for starch modification without affecting the quality and flavour constituents.The effect of HHP on starch is closely related to the treatment time of HHP.In this paper,we investigated the impacts of HHP treatment time(0,5,10,15,20,25,30 min)on the microstructure,gelatinization and thermal properties as well as in vitro digestibility of oat starch by scanning electron microscopy,X-ray diffraction,Fourier transform infrared spectroscopy,13C NMR and differential scanning calorimeter.Results showed that 5-min HHP treatment led to deformation and decreases in short-range ordered and doublehelix structures of oat starch granules,and further extending the treatment time to 15 min or above caused the formation of a gelatinous connection zone,increase of particle size,disintegration of short-range ordered and double-helix structures,and crystal structure change from A type to V type,indicating gelatinization occurred.Longer treatment time also resulted in the reduction in both the viscosity and the stability of oat starch.These indicated that HHP treatment time greatly influenced the microstructure of oat starch,and the oat starch experienced crystalline destruction(5 min),crystalline disintegration(15 min)and gelatinization(>15 min)during HHP treatment.Results of in vitro digestibility showed that the rapidly digestible starch(RDS)content declined first after treatment for 5 to 10 min then rose with the time extending from 15 to 30 min,indicating that longer pressure treatment time was unfavourable to the health benefits of oat starch for humans with diabetes and cardiovascular disease.Therefore,the 500-MPa treatment time for oat starch is recommended not more than 15 min.This study provides theoretical guidance for the application of HHP technology in starch modification and development of health foods.
基金sponsored by the Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-14-2-0095
文摘Background: Ballistics gelatin is a common tissue surrogate used in bacterial contamination models for projectile wounds. Although these studies have demonstrated that bacteria are transferred from the surface of the gelatin to the wound track by a projectile, quantifiable results have been inconsistent and not repeatable in successive tests.Methods: In this study, five areas of a typical contamination model in which bacterial recovery or survival are affected were identified for optimization. The first was a contaminated "skin" surrogate, where the novel use of vacuum filtration of a bacterial culture and buffer onto filter paper was employed. The other possibly problematic areas of the bacterial distribution model included the determination of bacterial survival when the contamination model is dried, survival in solid and molten gelatin, and the effect of high-intensity lights used for recording high-speed video.Results: Vacuum filtration of bacteria and buffer resulted in a consistent bacterial distribution and recovery. The use of phosphate buffer M9(pH 7) aided in neutralizing the ballistics gelatin and improving bacterial survival in solid gelatin. Additionally, the use of high-intensity lights to record high-speed video and the use of a 42℃ water bath to melt the gelatin were found to be bactericidal for gram-positive and gram-negative bacteria.Conclusion: Multiple areas of a typical contamination model in which bacterial survival may be impeded were identified, and methods were proposed to improve survival in each area. These methods may be used to optimize the results of bacterial contamination models for medical applications, such as understanding the progression of infection in penetrating wounds and to identify possible sources of contamination for forensic purposes.
基金financially supported by the National Natural Science Foundation of China(Grant No.31772045)the program on Fujian Agriculture and Forestry University of doctoral students going abroad(Grant No.324-112110089)scientific research foundation graduate school of Fujian Agriculture and Forestry University(Grant No.324-1122yb064)。
文摘Development of functional bioinspired hydrogels that have good releases control character is necessary for the application of these materials in biomedical engineering.Herein,we report a composite hydrogel prepared from several biocompatible carboxymethyl konjac glucomannan(CKGM)/gelatin(G)/tannic acid(TA)functional nano-hydroxyapatite(TA@n-HA),which has good biodegradability and pH sensitivity.The mechanism of interaction between hydrogels was confirmed by Fourier transform infrared spectroscopy,X-ray diffraction,Scanning electron microscopy and Thermogravimetric analysis.The physico-chemical properties of CKGM/G hydrogels have been significantly improved through the incorporation of TA@n-HA within the matrix.Studies in the sustained release of epigallocatechin gallate(EGCG)demonstrated that the TA@n-HA/CKGM/G hydrogels exhibit not only better pH sensitive properties,but also enhanced biocompatibility and encapsulation in comparison to the matrix devoid of TA@n-HA.Consequently,TA@n-HA/CKGM/G hydrogels using EGCG as a drug release model show the potential for drug delivery.
基金supported by research grants from the National Key R&D Program of China(No.2019YFD0902003)Shanghai Municipal Education Commission-Gaoyuan Discipline of Food Science&Technology Grant Support(Shanghai Ocean University).
文摘The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions.In this work,we mainly explore the effect of pH change on the droplet and creaming stability of fish oil-loaded emulsions synergistically(Span 80 and SL)or competitively(Tween 80 and SDS)stabilized by gelatin/surfactant.The results demonstrated that initial droplet stability and droplet storage stability,and creaming stability of the pH-adjusted emulsions are dependent on both the adsorption ways of emulsifiers and the adjusted pH:(1)Competitively stabilized emulsions have more stable droplets than synergistically stabilized emulsions;(2)SDS-dominant competitively stabilized emulsions have more stable droplets than gelatin-dominant emulsions;(3)Basic pH-adjusted emulsions have more stable droplets than acidic pH-adjusted emulsions;(4)The synergistically stabilized emulsions at acidic pH have significantly higher creaming indexes than that at basic pH;and(5)The competitively stabilized emulsions have high or similar creaming indexes to that at acidic pH.Further,the mechanisms are proposed according to Stokes’Law.This work will provide useful information to understand the interfacial properties of mixed emulsifiers in the food emulsions and promising application perspective for the development of food beverages including acidic and alkali beverages.
文摘To understand the effects of the rifle bullet parameters on the bullet-gelatin interaction quantitatively, a finite element model of bullet penetrating gelatin was set up and computational re- suits are compared with experimental ones. The penetration of the rifle bullet into the gelatin was simulated by the nonlinear finite element method. The quantitative analysis of the changes in the ge- latin interaction with the rifle bullet were conducted by changing the bullet parameters, such as at- tack angle on gelatin, initial velocity, warhead＇ s tip and location of mass center of bullet. Results demonstrate that with the increase of the attack angle, instable moment of the bullet moves forward, the length of narrow wound channel shortens, and when penetration is completed diameters of tem- porary cavities increase, the gelatin energy and energy transmission ratio increases; With the in- crease of the impact velocity, instable moment of the bullet moves forward, the maximum forces acting on the gelatin and the gelatin energy increase remarkably ; the length of narrow wound channel shortens, diameters of temporary cavities increase when penetration is completed, the gelatin energy and energy transmission ratio increase; The warhead＇ s tip and location of mass center have a influ- ence on the instable moment of the bullet and length of the narrow wound channel. The instable mo- ment delays and narrow wound channel increases when the warhead＇s tip flattens. The instable mo- ment moves forward a little and the narrow wound channel shortens a little when location of mass center moves back.
基金supported by the Advanced Research Project funded by the SeoulTech(Seoul National University of Science and Technology)。
文摘A glucose oxidation catalyst comprising carbon nanotube,tetrathiafulvalene(TTF),gelatin,glutaraldehyde(GA)and glucose oxidase(GOx)(CNT/[TTF-GOx]/Gelatin+GA)is suggested to enhance the reactivity of glucose oxidation reaction(GOR),and the performance and stability of enzymatic biofuel cells(EBCs)using this catalyst.In this catalyst,TTF is used as mediator to transfer electron effectively,while GA is crosslinked to gelatin to form non-soluble network.The structure prevents the dissolution of gelatin from aqueous electrolyte and reduces the leaching-out of GOx and TTF molecules.To confirm the crosslinking effect of GA and gelatin,Fourier-transform infrared spectroscopy(FT-IR)and electrochemical evaluations are utilized.According to FT-IR analysis,it was observed that the amide I peak shifted after crosslinking.This is evidence showing the appropriate network formation and the reactivity of CNT/[TTFGOx]/Gelatin+GA is well preserved even after multiple potential cycling.In addition,its GOx activity is regularly monitored for one month and the measurements prove that the structure prevents the leaching out of GOx molecules.Based on that,EBC using the anodic catalyst shows excellent performances,such as open circuit voltage of 0.75 V and maximum power density of 184μW/cm^(2).
基金National Natural Science Foundation of China(Grant No.31360381)for the financial support on this research。
文摘Tilapia skin gelatin hydrolysates(TSGH)were obtained by complex protease hydrolysis.The amino acid sequences of 50 peptides in TSGH were identified,and most of these peptides were found to contain the-Gly-Pro-sequence.The osteoporosis(OP)rat model induced by retinoic acid was prepared,and the effects of different doses of TSGH on OP in vivo were evaluated.Serum calcium(Ca)and phosphate(P),alkaline phosphatase activity,and osteocalcin levels in OP rats were regulated by TSGH.The bone length,dry weight index,maximum load,and Ca content of OP rats significantly increased by treatment TSGH in a dosedependent manner.Micro-CT images of the femurs and tibias of the rats indicated that the bone mineral density,cortical bone thickness,and cortical/trabecular bone area ratios were recovered and that OP symptoms were improved.Tartrate-resistant acid phosphate and hematoxylin-eosin staining showed that osteoclast numbers and histomorphological changes in the femurs in OP rats could be recovered by TSGH.
文摘We examine the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62 mm APM2 and 25 mm projectiles. A threshold impact angle(critical angle) exists beyond which ricochet cannot occur. The Autodyn simulation code with the smooth particle hydrodynamic(SPH) method and Impetus Afea Solver with the corpuscular model are used and the results are compared with experimental and analytical results. The resistance force in sand for spheres was proportional to a term quadratic in velocity plus a term linear in velocity. The drag coefficient for the quadratic term was 0.65. The Autodyn and Impetus Afea codes simulate too large penetration due to the lack of a linear velocity resistance force. Critical ricochet angles were consistent with analytical results in the literature. In ballistic gelatin at velocities of 50–850 m/s a drag coefficient of 0.30 fits the high speed camera recordings if a linear velocity resistance term is included. However, only a quadratic velocity resistance force with drag coefficient that varies with the Reynolds number also fits the measurements. The simulation of a sphere in water with Autodyn showed too large drag coefficient. The 7.62 mm APM2 core simulations in sand fit reasonable well for both codes. The 25 mm projectile ricochet simulations in sand show consistency with the high speed camera recordings. Computer time was reduced by one to two orders of magnitudes when applying the Impetus Afea Solver compared to Autodyn code due to the use of the graphics processing units(GPU).
文摘为了改善燕麦粉加工的适应性,选用植物乳杆菌(Lactobacillus plantarum HH-LP56)分别对燕麦生粉和不同糊化度(13%、17%、24%、30%、34%)燕麦熟粉进行发酵改性,探究乳酸菌发酵对燕麦粉的游离氨基酸、淀粉酶活性、还原糖含量和热特性,以及燕麦-小麦复配面团的流变发酵特性和馒头质构特性的影响。结果表明:乳酸菌发酵促进了燕麦生粉中游离氨基酸的释放,增加了燕麦生粉和熟粉中淀粉酶活性和还原糖含量。将发酵改性燕麦生/熟粉与小麦粉进行复配,改善了面团的发酵特性,制得的馒头比体积上升,硬度下降,馒头的品质特性得到有效改善。
