The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Chwen-jen Shieh - One of the best experts on this subject based on the ideXlab platform.
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studies of optimum conditions for covalent Immobilization of candida rugosa lipase on poly γ glutamic acid by rsm
Bioresource Technology, 2008Co-Authors: Shu-wei Chang, Jeifu Shaw, K H Yang, S F Chang, Chwen-jen ShiehAbstract:Poly(γ-glutamic acid) (γ-PGA) is a material of polymer. Immobilization of Candida rugosa lipase (Lipase AY-30) by covalent binding on γ-PGA led to a markedly improved performance of the enzyme. Response surface methodology (RSM) and 3-level-3-factor fractional factorial design were employed to evaluate the effects of Immobilization parameters, such as Immobilization time (2–6 h), Immobilization temperature (0–26 °C), and enzyme/support ratio (0.1–0.5, w/w). Based on the analysis of ridge max, the optimum Immobilization conditions were as follows: Immobilization time 2.3 h, Immobilization temperature 13.3 °C, and enzyme/support ratio 0.41 (w/w); the highest lipase activity obtained was 1196 U/mg-protein.
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optimum Immobilization of candida rugosa lipase on celite by rsm
Applied Clay Science, 2007Co-Authors: Shuofen Chang, Shu-wei Chang, Yuehorng Yen, Chwen-jen ShiehAbstract:Abstract Immobilization of Candida rugosa lipase (lipase AY-30) by adsorption on Celite led to a markedly improved performance of the enzyme. Immobilization conditions and characterization of the immobilized enzyme were investigated. Lipase activity was measured with glycerol tributyrate as substrate. Response surface methodology (RSM) and 3-level–3-factor fractional factorial design were employed to evaluate the effects of Immobilization parameters, such as Immobilization time (30–90 min), Immobilization temperature (0–20 °C), and enzyme/support ratio (0.3–0.5, w/w), on the specific activity of immobilized lipase. Based on the analysis of ridge max, the optimum Immobilization conditions were as follows: Immobilization time 59.1 min, Immobilization temperature 10.7 °C, and enzyme/support ratio 0.5 (w/w); the highest specific activity obtained was 18.16 U/mg-protein with activity yield of 34.1%.
Shu-wei Chang - One of the best experts on this subject based on the ideXlab platform.
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studies of optimum conditions for covalent Immobilization of candida rugosa lipase on poly γ glutamic acid by rsm
Bioresource Technology, 2008Co-Authors: Shu-wei Chang, Jeifu Shaw, K H Yang, S F Chang, Chwen-jen ShiehAbstract:Poly(γ-glutamic acid) (γ-PGA) is a material of polymer. Immobilization of Candida rugosa lipase (Lipase AY-30) by covalent binding on γ-PGA led to a markedly improved performance of the enzyme. Response surface methodology (RSM) and 3-level-3-factor fractional factorial design were employed to evaluate the effects of Immobilization parameters, such as Immobilization time (2–6 h), Immobilization temperature (0–26 °C), and enzyme/support ratio (0.1–0.5, w/w). Based on the analysis of ridge max, the optimum Immobilization conditions were as follows: Immobilization time 2.3 h, Immobilization temperature 13.3 °C, and enzyme/support ratio 0.41 (w/w); the highest lipase activity obtained was 1196 U/mg-protein.
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optimum Immobilization of candida rugosa lipase on celite by rsm
Applied Clay Science, 2007Co-Authors: Shuofen Chang, Shu-wei Chang, Yuehorng Yen, Chwen-jen ShiehAbstract:Abstract Immobilization of Candida rugosa lipase (lipase AY-30) by adsorption on Celite led to a markedly improved performance of the enzyme. Immobilization conditions and characterization of the immobilized enzyme were investigated. Lipase activity was measured with glycerol tributyrate as substrate. Response surface methodology (RSM) and 3-level–3-factor fractional factorial design were employed to evaluate the effects of Immobilization parameters, such as Immobilization time (30–90 min), Immobilization temperature (0–20 °C), and enzyme/support ratio (0.3–0.5, w/w), on the specific activity of immobilized lipase. Based on the analysis of ridge max, the optimum Immobilization conditions were as follows: Immobilization time 59.1 min, Immobilization temperature 10.7 °C, and enzyme/support ratio 0.5 (w/w); the highest specific activity obtained was 18.16 U/mg-protein with activity yield of 34.1%.
Mustapha Zidi - One of the best experts on this subject based on the ideXlab platform.
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Mechanical and microstructural changes of skeletal muscle following Immobilization and/or stroke
Biomechanics and Modeling in Mechanobiology, 2019Co-Authors: Naïm Jalal, Jean-michel Gracies, Mustapha ZidiAbstract:Patient management following a stroke currently represents a medical challenge. The presented study investigates the effect of Immobilization on skeletal muscles in short positions after a stroke. A rat model was implemented in order to compare four situations within 14 days including control group, Immobilization of one forelimb without stroke, stroke without Immobilization and stroke with Immobilization of the paretic forelimb. To analyze the changes of the mechanical properties of the passive skeletal muscle, the biological tissue is assumed to behave as a visco-hyperelastic and incompressible material characterized by the first-order Ogden’s strain energy function coupled with second-order Maxwell’s model. The material parameters were identified from inverse finite element method by using uniaxial relaxation tests data of skeletal muscle samples. Based on measurements of histological parameters, we observe that muscle Immobilization led to microconstituents changes of skeletal muscles that were correlated with degradations of its mechanical properties. In the case of Immobilization without stroke, the neurological behavior was also altered in the same manner as in the case of a stroke. We showed that Immobilization of skeletal muscles in short positions produced contractile tissue atrophy, connective tissue thickening and alteration of passive mechanical behavior that were more damaging than the effects produced by a stroke. These results showed then that Immobilization of skeletal muscles in short positions is highly deleterious with or without a stroke.
Lucette Toussaint - One of the best experts on this subject based on the ideXlab platform.
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Functional plasticity of sensorimotor representations following short-term Immobilization of the dominant versus non-dominant hands
Acta Psychologica, 2015Co-Authors: Aurore Meugnot, Lucette ToussaintAbstract:The main purpose of the present study was to investigate the functional plasticity of sensorimotor representations for dominant versus non-dominant hands following short-term upper-limb sensorimotor deprivation. All participants were right-handed. A splint was placed either on the right hand or on the left hand of the participants during a brief period of 48 h and was used for the input/output signal restrictions. The participants were divided into 3 groups: right hand Immobilization, left hand Immobilization and control (without Immobilization). The immobilized participants performed the hand laterality task before (pre-test) and immediately after (post-test) splint removal. The pre-/post-test procedure was similar for the control group. The main results showed a significant response time improvement when judging the laterality of hand stimuli in the control group. In contrast, the results showed a weaker response time improvement for the left-hand Immobilization group and no significant improvement for the right-hand Immobilization group. Overall, these results revealed that Immobilization-induced effects were lower for the non-dominant hand and also suggested that 48 h of upper-limb Immobilization led to an inter-limb transfer phenomenon regardless of the immobilized hand. The Immobilization-induced effects were highlighted by the slowdown of the sensorimotor processes related to manual actions, probably due to an alteration in a general cognitive representation of hand movements.
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Short-term limb Immobilization affects cognitive motor processes.
Journal of Experimental Psychology: Learning Memory and Cognition, 2013Co-Authors: Lucette Toussaint, Aurore MeugnotAbstract:We examined the effects of a brief period of limb Immobilization on the cognitive level of action control. A splint placed on the participants' left hand was used as a means of Immobilization. We used a hand mental rotation task to investigate the Immobilization-induced effects on motor imagery performance (Experiments 1 and 2) and a number mental rotation task to investigate whether Immobilization-induced effects are also found when visual imagery is involved (Experiment 2). We also examined whether the effects of Immobilization vary as a function of individuals' vividness of motor imagery (Experiment 2). The immobilized participants performed the mental rotation tasks before and immediately after the splint removal. The control group did not undergo the Immobilization procedure. For hand stimuli, response time analysis showed a lack of task-repetition benefit following Immobilization (Experiments 1 and 2) except when the visual imagery task was performed first (Experiment 2). Following Immobilization, a flattening in the response time profile for left hand stimuli was observed as a function of stimuli rotation (Experiments 1 and 2), especially for participants with less vivid motor imagery (Experiment 2). We did not find an Immobilization-induced effect on number stimuli. These findings revealed that the cognitive representation of hand movements is modified by Immobilization and that sensorimotor deprivation specifically affects motor simulation of the immobilized hand. We discuss the possibility that Immobilization affects the sensorimotor system due to the reduced processing of proprioceptive feedback, which lead some participants to switch from a motor to a visual imagery strategy. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
Aurore Meugnot - One of the best experts on this subject based on the ideXlab platform.
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Functional plasticity of sensorimotor representations following short-term Immobilization of the dominant versus non-dominant hands
Acta Psychologica, 2015Co-Authors: Aurore Meugnot, Lucette ToussaintAbstract:The main purpose of the present study was to investigate the functional plasticity of sensorimotor representations for dominant versus non-dominant hands following short-term upper-limb sensorimotor deprivation. All participants were right-handed. A splint was placed either on the right hand or on the left hand of the participants during a brief period of 48 h and was used for the input/output signal restrictions. The participants were divided into 3 groups: right hand Immobilization, left hand Immobilization and control (without Immobilization). The immobilized participants performed the hand laterality task before (pre-test) and immediately after (post-test) splint removal. The pre-/post-test procedure was similar for the control group. The main results showed a significant response time improvement when judging the laterality of hand stimuli in the control group. In contrast, the results showed a weaker response time improvement for the left-hand Immobilization group and no significant improvement for the right-hand Immobilization group. Overall, these results revealed that Immobilization-induced effects were lower for the non-dominant hand and also suggested that 48 h of upper-limb Immobilization led to an inter-limb transfer phenomenon regardless of the immobilized hand. The Immobilization-induced effects were highlighted by the slowdown of the sensorimotor processes related to manual actions, probably due to an alteration in a general cognitive representation of hand movements.
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Short-term limb Immobilization affects cognitive motor processes.
Journal of Experimental Psychology: Learning Memory and Cognition, 2013Co-Authors: Lucette Toussaint, Aurore MeugnotAbstract:We examined the effects of a brief period of limb Immobilization on the cognitive level of action control. A splint placed on the participants' left hand was used as a means of Immobilization. We used a hand mental rotation task to investigate the Immobilization-induced effects on motor imagery performance (Experiments 1 and 2) and a number mental rotation task to investigate whether Immobilization-induced effects are also found when visual imagery is involved (Experiment 2). We also examined whether the effects of Immobilization vary as a function of individuals' vividness of motor imagery (Experiment 2). The immobilized participants performed the mental rotation tasks before and immediately after the splint removal. The control group did not undergo the Immobilization procedure. For hand stimuli, response time analysis showed a lack of task-repetition benefit following Immobilization (Experiments 1 and 2) except when the visual imagery task was performed first (Experiment 2). Following Immobilization, a flattening in the response time profile for left hand stimuli was observed as a function of stimuli rotation (Experiments 1 and 2), especially for participants with less vivid motor imagery (Experiment 2). We did not find an Immobilization-induced effect on number stimuli. These findings revealed that the cognitive representation of hand movements is modified by Immobilization and that sensorimotor deprivation specifically affects motor simulation of the immobilized hand. We discuss the possibility that Immobilization affects the sensorimotor system due to the reduced processing of proprioceptive feedback, which lead some participants to switch from a motor to a visual imagery strategy. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
