Gastric carcinoids(GCs),which originate from gastric enterochromaffin-like(ECL) mucosal cells and account for 2.4% of all carcinoids,are found increasingly in the course of upper gastrointestinal tract endoscopy.Curre...Gastric carcinoids(GCs),which originate from gastric enterochromaffin-like(ECL) mucosal cells and account for 2.4% of all carcinoids,are found increasingly in the course of upper gastrointestinal tract endoscopy.Current nosography includes those occurring in chronic conditions with hypergastrinemia,as the type 1 associated with chronic atrophic gastritis,and the type 2 associated with Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1,and type 3,which is unrelated to hypergastrinemia and is frequently malignant,with distant metastases.The optimal clinical approach to GCs remains to be elucidated,depending upon type,size and number of carcinoids.While there is agreement concerning the treatment of type 3 carcinoids,for types 1 and 2,current possibilities include simple surveillance,endoscopic polypectomy,surgical excision,associated or not with surgical antrectomy,or total gastrectomy.Moreover,the recent introduction of somatostatin analogues represents a therapeutic option of possibly outstanding relevance.展开更多
The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated.Several differently shaped pin fins(i.e.,circular,elliptical,and drop-sha...The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated.Several differently shaped pin fins(i.e.,circular,elliptical,and drop-shaped)with the same cross-sectional areas were compared in a staggered arrangement.The Reynolds number based on the obstructed section hydraulic diameter(defined as the ratio of the total wetted surface area to the open duct volume available for flow)was varied from 4800 to 8200.The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them,which decreased the aerodynamic penalty compared to circular pin fins.The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins.In terms of specific performance parameters,drop-shaped pin fins are a promising alternative configuration to circular pin fins.展开更多
文摘Gastric carcinoids(GCs),which originate from gastric enterochromaffin-like(ECL) mucosal cells and account for 2.4% of all carcinoids,are found increasingly in the course of upper gastrointestinal tract endoscopy.Current nosography includes those occurring in chronic conditions with hypergastrinemia,as the type 1 associated with chronic atrophic gastritis,and the type 2 associated with Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1,and type 3,which is unrelated to hypergastrinemia and is frequently malignant,with distant metastases.The optimal clinical approach to GCs remains to be elucidated,depending upon type,size and number of carcinoids.While there is agreement concerning the treatment of type 3 carcinoids,for types 1 and 2,current possibilities include simple surveillance,endoscopic polypectomy,surgical excision,associated or not with surgical antrectomy,or total gastrectomy.Moreover,the recent introduction of somatostatin analogues represents a therapeutic option of possibly outstanding relevance.
基金the National Natural Science Foundation of China(Grant no.51276090)for this project.
文摘The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated.Several differently shaped pin fins(i.e.,circular,elliptical,and drop-shaped)with the same cross-sectional areas were compared in a staggered arrangement.The Reynolds number based on the obstructed section hydraulic diameter(defined as the ratio of the total wetted surface area to the open duct volume available for flow)was varied from 4800 to 8200.The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them,which decreased the aerodynamic penalty compared to circular pin fins.The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins.In terms of specific performance parameters,drop-shaped pin fins are a promising alternative configuration to circular pin fins.
