Facial defect coverage is a common subject in the field of reconstructive surgery.There are many methods for facial defect reconstruction,and reconstructive surgeons should choose the most appropriate method on a case...Facial defect coverage is a common subject in the field of reconstructive surgery.There are many methods for facial defect reconstruction,and reconstructive surgeons should choose the most appropriate method on a case-by-case basis to achieve both functional and aesthetic improvement.Among various options for facial reconstruction,the local flap technique is considered the best reconstructive modality to provide good tissue matches of color and texture,which is consistent with the ideal goal of reconstruction(replacement of like-with-like).Keystone design perforator island flap(KDPIF),devised by Behan in 2003,has been applied to various fields of reconstructive surgery in the past decade due to its design simplicity,robust vascular supply,and reproducibility.Several studies have reported KDPIF reconstruction of facial defects,such as large parotid defects,small-to-moderate nasal defects,and eyelid defects.However,KDPIF has been used relatively less in facial defects than in other body regions,such as the trunk and extremities.The purpose of this review is to provide an organized overview of facial KDPIF reconstruction including the classification of KDPIF,modifications,physiology,mechanism of flap movement,consideration of facial relaxed skin tension lines and aesthetics,surgical techniques,clinical applications,and precautions for successful execution of KDPIF reconstruction.展开更多
Perforation is a pivotal technique employed to establish main flow channels within the reservoir formation at the outset of hydraulic fracturing operations.Optimizing perforation designs is critical for augmenting the...Perforation is a pivotal technique employed to establish main flow channels within the reservoir formation at the outset of hydraulic fracturing operations.Optimizing perforation designs is critical for augmenting the efficacy of hydraulic fracturing and boosting oil or gas production.In this study,we employ a hybrid finite-discrete element method,known as the continuous–discontinuous element method(CDEM),to simulate the initiation of post-perforation hydraulic fractures and to derive enhanced design parameters.The model incorporates the four most prevalent perforation geometries,as delineated in an engineering technical report.Real-world perforations deviate from the ideal cylindrical shape,exhibiting variable cross-sectional profiles that typically manifest as an initial constriction followed by an expansion,a feature consistent across all four perforation types.Our simulations take into account variations in perforation hole geometries,cross-sectional diameters,and perforation lengths.The findings show that perforations generated by the 39g DP3 HMX perforating bullet yield the lowest breakdown pressure,which inversely correlates with increases in sectional diameter and perforation length.Moreover,this study reveals the relationship between breakdown pressure and fracture degree,providing valuable insights for engineers and designers to refine perforation strategies.展开更多
文摘Facial defect coverage is a common subject in the field of reconstructive surgery.There are many methods for facial defect reconstruction,and reconstructive surgeons should choose the most appropriate method on a case-by-case basis to achieve both functional and aesthetic improvement.Among various options for facial reconstruction,the local flap technique is considered the best reconstructive modality to provide good tissue matches of color and texture,which is consistent with the ideal goal of reconstruction(replacement of like-with-like).Keystone design perforator island flap(KDPIF),devised by Behan in 2003,has been applied to various fields of reconstructive surgery in the past decade due to its design simplicity,robust vascular supply,and reproducibility.Several studies have reported KDPIF reconstruction of facial defects,such as large parotid defects,small-to-moderate nasal defects,and eyelid defects.However,KDPIF has been used relatively less in facial defects than in other body regions,such as the trunk and extremities.The purpose of this review is to provide an organized overview of facial KDPIF reconstruction including the classification of KDPIF,modifications,physiology,mechanism of flap movement,consideration of facial relaxed skin tension lines and aesthetics,surgical techniques,clinical applications,and precautions for successful execution of KDPIF reconstruction.
基金support from the National Natural Science Foundation of China(Grant Nos.52178324,12102059)the China Postdoctoral Science Foundation(Grant No.2023M743604)+1 种基金the Beijing Natural Science Foundation(Grant No.3212027),the National Key R&D Program of China(Grant No.2023YFC3007203)the 2019 Foreign Experts Plan of Hebei Province.
文摘Perforation is a pivotal technique employed to establish main flow channels within the reservoir formation at the outset of hydraulic fracturing operations.Optimizing perforation designs is critical for augmenting the efficacy of hydraulic fracturing and boosting oil or gas production.In this study,we employ a hybrid finite-discrete element method,known as the continuous–discontinuous element method(CDEM),to simulate the initiation of post-perforation hydraulic fractures and to derive enhanced design parameters.The model incorporates the four most prevalent perforation geometries,as delineated in an engineering technical report.Real-world perforations deviate from the ideal cylindrical shape,exhibiting variable cross-sectional profiles that typically manifest as an initial constriction followed by an expansion,a feature consistent across all four perforation types.Our simulations take into account variations in perforation hole geometries,cross-sectional diameters,and perforation lengths.The findings show that perforations generated by the 39g DP3 HMX perforating bullet yield the lowest breakdown pressure,which inversely correlates with increases in sectional diameter and perforation length.Moreover,this study reveals the relationship between breakdown pressure and fracture degree,providing valuable insights for engineers and designers to refine perforation strategies.
