Endoscopic submucosal dissection(ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions,and has the advantage of en bloc resection which yields a higher complete resection ...Endoscopic submucosal dissection(ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions,and has the advantage of en bloc resection which yields a higher complete resection and remission rate compared to endoscopic mucosal resection(EMR).However,the learning process of this advanced endoscopic procedure requires a lengthy training period and considerable experience to be proficient.A well framed training protocol which is safe,effective,easily reproducible and cost-effective is desirable to teach ESD.In addition,the training course may need to be tailored around settings such as ethnicity,culture,workload,and disease incidence.In Asian countries with a large volume of early gastric lesions which need endoscopic treatment,endoscopists would be able to learn ESD expanding their skills from EMR to ESD under the supervision of experts.Whereas,in Western countries due to the low incidence of superficial gastric tumors,trials have utilized simulator models to improve learning.In Korea,the Korean Society of Gastrointestinal Endoscopy(KSGE) is playing an important role in training many gastroenterologists who have shown an interest in performing ESD by providing an annual live demonstration and a nationwide tutoring program.The purpose of this article is to introduce our ESD tutoring experience,review the published papers related to this topic,and propose several suggestions for future directions in teaching and learning ESD.展开更多
Many kinds of feed additives （e.g., probiotics, prebiotics, antibiotics, etc.） can be used in chicken diets to stimulate intestinal morphological maturation and, consequently, intestinal function. The aim of this tr...Many kinds of feed additives （e.g., probiotics, prebiotics, antibiotics, etc.） can be used in chicken diets to stimulate intestinal morphological maturation and, consequently, intestinal function. The aim of this trial was to investigate the possibility that natural zeolite including plant extract （ZEM） could encourage the hypertrophy of intestinal villi and the absorptive function of epithelial cells in broiler chickens. At 7 days old, 64 male Marshall Chunky broilers were divided into four groups, each with four replicates of four chickens. The birds were fed a basal mash diet supplemented with ZEM at 0% （control）, 0.05%, 0.1%, and 0.2% for 42 days. At 49 days old, four chickens from each treatment were killed to obtain intestinal samples. Morphological intestinal assessment was conducted using both a light and a scanning electron microscope. A tendency to increased villus height and cell area could be observed throughout the intestinal segments of the broilers fed ZEM. Particularly, the villus height in the duodenum was significantly increased （P 〈 0.05） in the 0.05% ZEM group when compared with the control group. The area of the villus cells tended to be higher in the ZEM groups in all intestinal regions and showed a significant increase （P 〈 0.05） in the ileal part of the 0.2% ZEM group. Also, the assessment of cells mitosis in the intestinal crypts showed significantly higher numbers （P 〈 0.05） in all levels of ZEM groups in the duodenum and a tendency to increase in value in the jejunum and ileum, as compared with the control group. More protuberated cells and multi-cell clusters were found in the ZEM groups than in the control group, resulting in a rough cellular surface. In conclusion, the present study might suggest that the intestinal villi and epithelial cells on the villus apical surface are hypertrophied in the ZEM groups, and that intestinal villi adapt to enhance their absorption capacity by increasing the absorptive surface area. These results are indicated that ZEM can provide effective nutritive value when used as a feed additive.展开更多
Eggshells are one of the most common and well-studied biomaterials in nature and exhibit unique properties of gas conduction. However, the morphologies of eggshells at the submicro-/nano-scale and their impact on eggs...Eggshells are one of the most common and well-studied biomaterials in nature and exhibit unique properties of gas conduction. However, the morphologies of eggshells at the submicro-/nano-scale and their impact on eggshell functions remain unclear. In this work, the architecture of hen＇s eggshell at different length scales has been systematically investigated by scanning electron microscopy （SEM） and environmental SEM （ESEM）. It is found that the skeleton of calcium carbonate （CaCO3） has hierarchical structures at nano- to micro-scales： primary nano-particles of -10 Fain loosely congregate giving a porous and rough texture, and compose the upper-level morphologies including submicro spheres, nano-rods, rhombohedral-cleavage pattern and slices, which are elaborately arranged in a surface layer, palisade layer and mammillary layer along the radial direction. Accordingly, the pore system exhibits a three-level hierarchy, namely nano-scale pores （between nano-rods and primary nano-particles）, submicro-scale pores （＂bubble pores＂） and micro-scale pores （opening of ＂gas pores＂）. Further investigation shows that hen＇s eggshell regulates gas conduction through adjusting the sizes and numbers of submicro-scale ＂bubble pores＂. Based on our observations, a new description of hen＇s eggshell is presented, which amends the conventional view of micro-scale, straight and permeating ＂gas pores＂, and reveals the role of hierarchical pores in gas conduction and contamination resistance.展开更多
文摘Endoscopic submucosal dissection(ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions,and has the advantage of en bloc resection which yields a higher complete resection and remission rate compared to endoscopic mucosal resection(EMR).However,the learning process of this advanced endoscopic procedure requires a lengthy training period and considerable experience to be proficient.A well framed training protocol which is safe,effective,easily reproducible and cost-effective is desirable to teach ESD.In addition,the training course may need to be tailored around settings such as ethnicity,culture,workload,and disease incidence.In Asian countries with a large volume of early gastric lesions which need endoscopic treatment,endoscopists would be able to learn ESD expanding their skills from EMR to ESD under the supervision of experts.Whereas,in Western countries due to the low incidence of superficial gastric tumors,trials have utilized simulator models to improve learning.In Korea,the Korean Society of Gastrointestinal Endoscopy(KSGE) is playing an important role in training many gastroenterologists who have shown an interest in performing ESD by providing an annual live demonstration and a nationwide tutoring program.The purpose of this article is to introduce our ESD tutoring experience,review the published papers related to this topic,and propose several suggestions for future directions in teaching and learning ESD.
文摘Many kinds of feed additives （e.g., probiotics, prebiotics, antibiotics, etc.） can be used in chicken diets to stimulate intestinal morphological maturation and, consequently, intestinal function. The aim of this trial was to investigate the possibility that natural zeolite including plant extract （ZEM） could encourage the hypertrophy of intestinal villi and the absorptive function of epithelial cells in broiler chickens. At 7 days old, 64 male Marshall Chunky broilers were divided into four groups, each with four replicates of four chickens. The birds were fed a basal mash diet supplemented with ZEM at 0% （control）, 0.05%, 0.1%, and 0.2% for 42 days. At 49 days old, four chickens from each treatment were killed to obtain intestinal samples. Morphological intestinal assessment was conducted using both a light and a scanning electron microscope. A tendency to increased villus height and cell area could be observed throughout the intestinal segments of the broilers fed ZEM. Particularly, the villus height in the duodenum was significantly increased （P 〈 0.05） in the 0.05% ZEM group when compared with the control group. The area of the villus cells tended to be higher in the ZEM groups in all intestinal regions and showed a significant increase （P 〈 0.05） in the ileal part of the 0.2% ZEM group. Also, the assessment of cells mitosis in the intestinal crypts showed significantly higher numbers （P 〈 0.05） in all levels of ZEM groups in the duodenum and a tendency to increase in value in the jejunum and ileum, as compared with the control group. More protuberated cells and multi-cell clusters were found in the ZEM groups than in the control group, resulting in a rough cellular surface. In conclusion, the present study might suggest that the intestinal villi and epithelial cells on the villus apical surface are hypertrophied in the ZEM groups, and that intestinal villi adapt to enhance their absorption capacity by increasing the absorptive surface area. These results are indicated that ZEM can provide effective nutritive value when used as a feed additive.
文摘Eggshells are one of the most common and well-studied biomaterials in nature and exhibit unique properties of gas conduction. However, the morphologies of eggshells at the submicro-/nano-scale and their impact on eggshell functions remain unclear. In this work, the architecture of hen＇s eggshell at different length scales has been systematically investigated by scanning electron microscopy （SEM） and environmental SEM （ESEM）. It is found that the skeleton of calcium carbonate （CaCO3） has hierarchical structures at nano- to micro-scales： primary nano-particles of -10 Fain loosely congregate giving a porous and rough texture, and compose the upper-level morphologies including submicro spheres, nano-rods, rhombohedral-cleavage pattern and slices, which are elaborately arranged in a surface layer, palisade layer and mammillary layer along the radial direction. Accordingly, the pore system exhibits a three-level hierarchy, namely nano-scale pores （between nano-rods and primary nano-particles）, submicro-scale pores （＂bubble pores＂） and micro-scale pores （opening of ＂gas pores＂）. Further investigation shows that hen＇s eggshell regulates gas conduction through adjusting the sizes and numbers of submicro-scale ＂bubble pores＂. Based on our observations, a new description of hen＇s eggshell is presented, which amends the conventional view of micro-scale, straight and permeating ＂gas pores＂, and reveals the role of hierarchical pores in gas conduction and contamination resistance.
