The Experts below are selected from a list of 53610 Experts worldwide ranked by ideXlab platform
Violette Mulot - One of the best experts on this subject based on the ideXlab platform.
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investigating the effect of Freezing operating conditions on microstructure of frozen minced beef using an innovative x ray micro computed tomography method
Journal of Food Engineering, 2019Co-Authors: Violette Mulot, Ndoye Fatoutoutie, Hayat Benkhelifa, Didier Pathier, Denis FlickAbstract:Abstract The Freezing rate determines the ice crystal size distribution and morphology. Ice crystal characteristics may have a direct impact on the microstructure of food products, providing irreversible cell and tissue damages resulting in quality losses. In this paper, an innovative method was used for imaging and quantifying ice crystals directly in frozen samples of minced beef by X-ray micro-computed tomography. The results were compared to those obtained by X-ray micro-computed tomography on freeze-dried samples. The effects of the integral cooling rate on ice crystal characteristics were studied for various mechanical and cryogenic Freezing operating conditions. It was pointed out that crystals become 2.5 times smaller when the Freezing Temperature goes down from −30 °C to −100 °C. These crystals are also more numerous with a narrower distribution. Fluorescence optical microscopy and electron scanning microscopy were also used to do qualitative analysis. These results confirmed the effect of the Freezing Temperature on ice crystal sizes.
Yaopeng Zhang - One of the best experts on this subject based on the ideXlab platform.
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fabrication and characterization of regenerated antheraea pernyi silk fibroin scaffolds for schwann cell culturing
European Polymer Journal, 2019Co-Authors: Shengzhi Zou, Huili Shao, Xinru Wang, Suna Fan, Jiaming Zhang, Yaopeng ZhangAbstract:Abstract Antheraea pernyi silk, which is from a kind of non-mulberry silkworm produced in China, has better mechanical properties and cytocompatibility than the extensively studied silk from mulberry silkworm (Bombyx mori). In this work, the regenerated Antheraea pernyi silk fibroin (RASF) scaffolds were prepared from RASF aqueous solutions with different concentrations by a freeze-drying method. The morphologies, structures and properties of the obtained RASF scaffolds were investigated. It was found that with the decrease of RASF solution concentration and the increase of Freezing Temperature, the porosity of the scaffold increased while its apparent density decreased. The micro-morphology of the scaffold from the 1 wt% RASF solution was irregular. When the solution concentration was increased to the range of 4–13 wt%, the micro-morphologies of the obtained scaffolds mainly showed lamellar-like structure. And with the increase of solution concentration, the lamellar gap of the scaffold decreased while the lamellar thickness of the scaffold increased. However, with the further increase of solution concentration, the morphology of scaffold could gradually transfer into porous structure. In addition, the scaffold micro-morphology could be also affected by Freezing Temperature. Moreover, with the increase of RASF solution concentration or (and) the decrease of Freezing Temperature, the obtained scaffold had higher content of β-sheet conformation and higher crystallinity, which could improve its mechanical properties. It was further found that the swelling ratio and degradation rate of RASF scaffold prepared for tissue engineering increased with the decrease of solution concentration. The results of MTT indicated that the obtained RASF scaffold had no cytotoxicity. Moreover, the results of field emission scanning electron microscopy and laser confocal scanning microscopy revealed that the viability, cytocompatibility and migration ability of Schwann cells cultured on RASF scaffold were much better than those cultured on regenerated Bombyx mori silk fibroin (RBSF) scaffold. The RASF scaffold prepared in this work may have great potential applications in the area of nerve tissue engineering.
Denis Flick - One of the best experts on this subject based on the ideXlab platform.
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investigating the effect of Freezing operating conditions on microstructure of frozen minced beef using an innovative x ray micro computed tomography method
Journal of Food Engineering, 2019Co-Authors: Violette Mulot, Ndoye Fatoutoutie, Hayat Benkhelifa, Didier Pathier, Denis FlickAbstract:Abstract The Freezing rate determines the ice crystal size distribution and morphology. Ice crystal characteristics may have a direct impact on the microstructure of food products, providing irreversible cell and tissue damages resulting in quality losses. In this paper, an innovative method was used for imaging and quantifying ice crystals directly in frozen samples of minced beef by X-ray micro-computed tomography. The results were compared to those obtained by X-ray micro-computed tomography on freeze-dried samples. The effects of the integral cooling rate on ice crystal characteristics were studied for various mechanical and cryogenic Freezing operating conditions. It was pointed out that crystals become 2.5 times smaller when the Freezing Temperature goes down from −30 °C to −100 °C. These crystals are also more numerous with a narrower distribution. Fluorescence optical microscopy and electron scanning microscopy were also used to do qualitative analysis. These results confirmed the effect of the Freezing Temperature on ice crystal sizes.
Rui L Reis - One of the best experts on this subject based on the ideXlab platform.
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influence of Freezing Temperature and deacetylation degree on the performance of freeze dried chitosan scaffolds towards cartilage tissue engineering
European Polymer Journal, 2017Co-Authors: L L Reys, Simone S Silva, Rogerio P Pirraco, Alexandra P Marques, Joao F Mano, Tiago H Silva, Rui L ReisAbstract:Abstract Chitosan-based porous structures have been significantly studied across the world as potential tissue engineering scaffolds. Despite the differences in chitosan produced from squid pens or crustacean shells, with the former being more reactive and easily available with a higher degree of deacetylation (DD), most of the studies report the use of crab or shrimp chitosan as they are readily available commercial sources. The aim of this work was to highlight the great potential of chitosan produced from squid pens for biomedical application. From freeze-dried scaffolds for soft tissue engineering, we investigated the influence of the DD of chitosan and the Freezing Temperature during processing on their performance. Chitosan was obtained by deacetylation of β-chitin previously isolated from endoskeleton of giant squid Dosidicus gigas (DD 91.2%) and compared with a commercially available batch obtained from crab shells (DD 76.6%). Chitosan solutions were frozen at −80° C or −196° C and further freeze-dried to obtain 3D porous structures (scaffolds). Scaffolds prepared at −196° C have a compact structure with smaller pores, while those prepared at −80° C showed a lamellar structure with larger pores. The compressive modulus varied from 0.7 up to 8.8 MPa. Both types of scaffolds were stable on PBS, including in the presence of lysozyme, up to 4 weeks. Furthermore, the squid chitosan scaffolds processed at −80° C promoted ATDC5 chondrocyte-like cells adhesion and proliferation. The results suggest that the developed squid chitosan scaffolds might be further exploited for applications in cartilage tissue engineering.
Naoki Izumi - One of the best experts on this subject based on the ideXlab platform.
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vacuum Freezing type ice slurry production using ethanol solution 1st report measurement of vapor liquid equilibrium data of ethanol solution at 20 c and at the Freezing Temperature
International Journal of Refrigeration-revue Internationale Du Froid, 2009Co-Authors: Tatsunori Asaoka, Akio Saito, Seiji Okawa, Tetsuya Ito, Naoki IzumiAbstract:Abstract In this study, an original method for the production of ice slurry from ethanol solution without using a refrigerator is proposed. This system has advantages compared with similar existing systems using materials other than ethanol solution. In this paper, the vapor–liquid equilibrium data of ethanol solution at 20 °C and at the Freezing Temperature are measured, which is necessary to calculate the COP of this ice slurry producing system. In the experiments, two experimental methods are proposed to measure the saturated pressure and the vapor composition of ethanol solution. Each method has an advantage in their operating Temperature range. As a result, the vapor–liquid equilibrium diagrams of ethanol solution at 20 °C and at the Freezing Temperature, and approximations of saturated pressure of various concentrations of ethanol solution for varying liquid Temperature, are obtained.