AIM： To measure the time-dependent （viscoelastic） behavior in the change of the small intestinal opening angle and to test how well the behavior could be described by the Kelvin model for a standard linear solid. M...AIM： To measure the time-dependent （viscoelastic） behavior in the change of the small intestinal opening angle and to test how well the behavior could be described by the Kelvin model for a standard linear solid. METHODS： Segments from the duodenum, jejunum, and ileum were harvested from 10 female Wistar rats and the luminal diameter, wall thickness, and opening angle over time （θ（t）） were measured from rings cut from these segments. RESULTS： Morphometric variations were found along the small intestine with an increase in luminal area and a decrease in wall thickness from the duodenum to the ileum. The opening angle obtained after 60 rain was highest in the duodenum （220.8±12.9°）and decreased along the length of the intestine to 143.9±8.9° in the jejunum and 151.4±9.4° in the ileum. The change of opening angle as a function of time, fitted well to the Kelvin model using the equation θ（t）/θo = [1-ηexp （-λt）] after the ring was cut. The computed creep rate λ. did not differ between the segments. Compared to constant calculated from pig aorta and coronary artery, it showed that α agreed well （within 5%）, η was three times larger than that for vascular tissue, and λ ranged ±40% from the value of the pig coronary artery and was a third of the value of pig aorta. CONCLUSION： The change of opening angle over time for all the small intestine segments fits well to the standard linear spring-dashpot model. This viscoelastic constant of the rat small intestine is fairly homogenous along its length. The data obtained from this study add to a base set of biomechanical data on the small intestine and provide a reference state for comparison to other tissues,diseased intestinal tissue or intestinal tissue exposed to drugs or chemicals.展开更多
The classical definition of learning is： change and modification of behavior as a result of experience, training, and practice. In modem technological world; this definition has been changed and modified to include t...The classical definition of learning is： change and modification of behavior as a result of experience, training, and practice. In modem technological world; this definition has been changed and modified to include the changes and modification in behavior as a result of experience, training, and practice by using modem toolkits and metacognition for self-regulated, lifelong, open, flexible, and continuous learning in Virtual Learning Environment Framework （VLEF）. The classical factors of learning included： motivation, attitude, interest, attention, readiness, participation, and reinforcement. But, due to the modem toolkits, gadgets, and ICT technologies, there are new varieties in modes of presentations and instructions. The emerging learning factors to be integrated and blended include： multimedia, hypermedia, and multimodality. The researcher has intended to identify the gap in the existing literature for the inclusion of new emerging factors such as multimedia, hypermedia, and multimodal presentations. The purpose of the study was to identify the gap in the factors of learning for learning blend in this era of science and technology, especially, in the ICT-integrated form of blended learning. The methodology of the study was analysis and synthesis of literature in the form of reviewing literature for developing a model of blended leaning. The study is significant because it has filled the gap in factors of learning for making it blended in VLEF. The factors were analyzed and synthesized in the form of a model. The findings were summarized for drawing conclusion, and at the end there were made some suggestions and recommendations for blended learning environments.展开更多
基金Supported by the Karen Elise Jensens Foundation and the Danish Technical Research Council
文摘AIM： To measure the time-dependent （viscoelastic） behavior in the change of the small intestinal opening angle and to test how well the behavior could be described by the Kelvin model for a standard linear solid. METHODS： Segments from the duodenum, jejunum, and ileum were harvested from 10 female Wistar rats and the luminal diameter, wall thickness, and opening angle over time （θ（t）） were measured from rings cut from these segments. RESULTS： Morphometric variations were found along the small intestine with an increase in luminal area and a decrease in wall thickness from the duodenum to the ileum. The opening angle obtained after 60 rain was highest in the duodenum （220.8±12.9°）and decreased along the length of the intestine to 143.9±8.9° in the jejunum and 151.4±9.4° in the ileum. The change of opening angle as a function of time, fitted well to the Kelvin model using the equation θ（t）/θo = [1-ηexp （-λt）] after the ring was cut. The computed creep rate λ. did not differ between the segments. Compared to constant calculated from pig aorta and coronary artery, it showed that α agreed well （within 5%）, η was three times larger than that for vascular tissue, and λ ranged ±40% from the value of the pig coronary artery and was a third of the value of pig aorta. CONCLUSION： The change of opening angle over time for all the small intestine segments fits well to the standard linear spring-dashpot model. This viscoelastic constant of the rat small intestine is fairly homogenous along its length. The data obtained from this study add to a base set of biomechanical data on the small intestine and provide a reference state for comparison to other tissues,diseased intestinal tissue or intestinal tissue exposed to drugs or chemicals.
文摘The classical definition of learning is： change and modification of behavior as a result of experience, training, and practice. In modem technological world; this definition has been changed and modified to include the changes and modification in behavior as a result of experience, training, and practice by using modem toolkits and metacognition for self-regulated, lifelong, open, flexible, and continuous learning in Virtual Learning Environment Framework （VLEF）. The classical factors of learning included： motivation, attitude, interest, attention, readiness, participation, and reinforcement. But, due to the modem toolkits, gadgets, and ICT technologies, there are new varieties in modes of presentations and instructions. The emerging learning factors to be integrated and blended include： multimedia, hypermedia, and multimodality. The researcher has intended to identify the gap in the existing literature for the inclusion of new emerging factors such as multimedia, hypermedia, and multimodal presentations. The purpose of the study was to identify the gap in the factors of learning for learning blend in this era of science and technology, especially, in the ICT-integrated form of blended learning. The methodology of the study was analysis and synthesis of literature in the form of reviewing literature for developing a model of blended leaning. The study is significant because it has filled the gap in factors of learning for making it blended in VLEF. The factors were analyzed and synthesized in the form of a model. The findings were summarized for drawing conclusion, and at the end there were made some suggestions and recommendations for blended learning environments.
