Liver transplantation(LT)is the most effective treatment for patients with end-stage liver disease,and maintaining vascular patency of the transplanted liver is one of the crucial prerequisites for surgical success.De...Liver transplantation(LT)is the most effective treatment for patients with end-stage liver disease,and maintaining vascular patency of the transplanted liver is one of the crucial prerequisites for surgical success.Despite hepatic vein complic-ations following LT occurring at a relatively low frequency,ranging between 2%to 11%,delayed diagnosis and treatment may lead to graft dysfunction and even patient mortality.Clinical manifestations of hepatic vein complications are often subtle and nonspecific,posing challenges for early diagnosis.Signs may initially present as mild abnormalities in liver function,delayed recovery of liver function,unexplained ascites,lower limb edema,and perineal edema.Prolonged duration of these complications can lead to hepatic sinusoidal dilatation and eventual liver failure due to prolonged hepatic congestion.Ultrasonography has become the preferred imaging modality for post-liver transplant evaluation due to its convenience and non-invasiveness.Although hepatic vein complications may manifest as disappearance or flattening of the hepatic vein spectrum on routine ultrasound imaging,these findings lack specificity.Contrast-enhanced ultrasound that visualizes the filling of contrast agent in the hepatic veins and dynamically displays blood flow perfusion information in the drainage area can,however,significantly improve diagnostic confidence and provide additional information beyond routine ultrasound examination.展开更多
Liver transplantation is the primary therapeutic choice for end-stage liver disease.Currently,biliary complications are among the main factors affecting the survival rate and quality of life of liver transplant recipi...Liver transplantation is the primary therapeutic choice for end-stage liver disease.Currently,biliary complications are among the main factors affecting the survival rate and quality of life of liver transplant recipients.Nevertheless,the clinical manifestations of biliary complications following liver transplantation are often non-specific,making early diagnosis and timely treatment crucial for improving patient outcomes.Ultrasound is the preferred imaging method following liver transplantation.Importantly,contrast-enhanced ultrasound,with the adminis-tration of contrast agents,can improve the resolution of biliary images and enable real-time,dynamic visualization of microcirculation perfusion in the biliary system and surrounding tissues.The present article describes the normal ultra-sonic features of the biliary system following liver transplantation and briefly reviews the progress in the ultrasonic diagnosis of common biliary complications,including anastomotic biliary strictures,non-anastomotic biliary strictures,biliary leakage,biloma,and bile sludge/bile stone.展开更多
Friction stir welding was used to join two AA2060-T8 plates,and then the effect of precipitate evolution on microstructure and corrosion behavior of the joint was investigated.The evolution of precipitates on the top ...Friction stir welding was used to join two AA2060-T8 plates,and then the effect of precipitate evolution on microstructure and corrosion behavior of the joint was investigated.The evolution of precipitates on the top surface of the joint was characterized by scanning electron microscopy and transmission electron microscopy.The corrosion behaviors of different regions in the joint were investigated by an electrochemistry method and an alternating salt spray exposure.The corrosion was mainly dependent on the nature of precipitates in each region of the joint.The shoulder affected zone had the worst corrosion resistance as a result of the re-dissolved ofθ′(Al2Cu),T1(Al2CuLi)andδ′(Al3Li)phases,the formation of intergranular precipitates and precipitate-free zones.However,the thermomechanically affected zone had a slightly improved corrosion resistance because it had no intergranular precipitates.The heat affected zone and base metal had the best corrosion resistance.展开更多
This study investigates the cryogenic tensile properties and fracture behavior of fiction stir welded and post-weld heat-treated joints of 32Mn-7Cr-1Mo-0.3N steel. Cryogenic brittle fracture, which occurred in the as-...This study investigates the cryogenic tensile properties and fracture behavior of fiction stir welded and post-weld heat-treated joints of 32Mn-7Cr-1Mo-0.3N steel. Cryogenic brittle fracture, which occurred in the as-welded joint, is related to the residual particles that contain tungsten in the joint band structure. Post-weld water toughening resulted in the cryogenic intergranular brittleness of the joint, which is related to the non-equilibrium segregation of solute atoms during the post-weld water toughening. Annealing at 55OC for 30rain can effectively inhibit the cryogenic intergranular brittleness of the post- weld water-toughened joint. The yield strength, ultimate tensile strength, and uniform elongation of the annealed joint are approximately 95%, 87%, and 94% of the corresponding data of the base metal.展开更多
The microstructures and hot tensile behaviors of ZK30 alloys subjected to single-and multi-pass friction stir processing(FSP)were systematically investigated.Following single-pass FSP(S-FSP),coarse grains underwent re...The microstructures and hot tensile behaviors of ZK30 alloys subjected to single-and multi-pass friction stir processing(FSP)were systematically investigated.Following single-pass FSP(S-FSP),coarse grains underwent refinement to 1−2μm,with a distinct basal texture emerging in the stir zone(SZ).Additionally,second-phase particles were fragmented,dispersed,and partially dissolved.Multi-pass FSP(M-FSP)further enhanced the homogeneity of the microstructure,reduced texture intensity differences,and decreased the fraction of second-phase particles by 50%.Both S-FSP and M-FSP SZs demonstrated superplasticity at strain rates below 1×10^(−3)s^(−1)and at temperatures of 250−350℃.The S-FSP SZ exhibited an elongation of 390%at 250℃and 1×10^(−4)s^(−1),while the M-FSP SZ achieved an elongation of 406%at 350℃and 1×10^(−3)s^(−1).The superplastic deformation of SZ was co-dominated by grain boundary sliding(GBS)and the solute-drag mechanism in S-FSP and mainly by GBS in M-FSP.展开更多
Virtual reality(VR)offers an artificial,computer generated simulation of a real life environment.It originated in the 1960 s and has evolved to provide increasing immersion,interactivity,imagination,and intelligence.B...Virtual reality(VR)offers an artificial,computer generated simulation of a real life environment.It originated in the 1960 s and has evolved to provide increasing immersion,interactivity,imagination,and intelligence.Because deep learning systems are able to represent and compose information at various levels in a deep hierarchical fashion,they can build very powerful models which leverage large quantities of visual media data.Intelligence of VR methods and applications has been significantly boosted by the recent developments in deep learning techniques.VR content creation and exploration relates to image and video analysis,synthesis and editing,so deep learning methods such as fully convolutional networks and general adversarial networks are widely employed,designed specifically to handle panoramic images and video and virtual 3 D scenes.This article surveys recent research that uses such deep learning methods for VR content creation and exploration.It considers the problems involved,and discusses possible future directions in this active and emerging research area.展开更多
Virtual reality(VR)allows users to explore and experience a computer-simulated virtual environment so that VR users can be immersed in a totally artificial virtual world and interact with arbitrary virtual objects.How...Virtual reality(VR)allows users to explore and experience a computer-simulated virtual environment so that VR users can be immersed in a totally artificial virtual world and interact with arbitrary virtual objects.However,the limited physical tracking space usually restricts the exploration of large virtual spaces,and VR users have to use special locomotion techniques to move from one location to another.Among these techniques,redirected walking(RDW)is one of the most natural locomotion techniques to solve the problem based on near-natural walking experiences.The core idea of the RDW technique is to imperceptibly guide users on virtual paths,which might vary from the paths they physically walk in the real world.In a similar way,some RDW algorithms imperceptibly change the structure and layout of the virtual environment such that the virtual environment fits into the tracking space.In this survey,we first present a taxonomy of existing RDW work.Based on this taxonomy,we compare and analyze both contributions and shortcomings of the existing methods in detail,and find view manipulation methods offer satisfactory visual effect but the experience can be interrupted when users reach the physical boundaries,while virtual environment manipulation methods can provide users with consistent movement but have limited application scenarios.Finally,we discuss possible future research directions,indicating combining artificial intelligence with this area will be effective and intriguing.展开更多
基金Supported by The Shenzhen Science and Technology Research and Development Fund,No.JCYJ20220530163011026 and No.JCYJ20210324131809027Shenzhen Medical Key Discipline Project,No.G2021008 and No.G2022008.
文摘Liver transplantation(LT)is the most effective treatment for patients with end-stage liver disease,and maintaining vascular patency of the transplanted liver is one of the crucial prerequisites for surgical success.Despite hepatic vein complic-ations following LT occurring at a relatively low frequency,ranging between 2%to 11%,delayed diagnosis and treatment may lead to graft dysfunction and even patient mortality.Clinical manifestations of hepatic vein complications are often subtle and nonspecific,posing challenges for early diagnosis.Signs may initially present as mild abnormalities in liver function,delayed recovery of liver function,unexplained ascites,lower limb edema,and perineal edema.Prolonged duration of these complications can lead to hepatic sinusoidal dilatation and eventual liver failure due to prolonged hepatic congestion.Ultrasonography has become the preferred imaging modality for post-liver transplant evaluation due to its convenience and non-invasiveness.Although hepatic vein complications may manifest as disappearance or flattening of the hepatic vein spectrum on routine ultrasound imaging,these findings lack specificity.Contrast-enhanced ultrasound that visualizes the filling of contrast agent in the hepatic veins and dynamically displays blood flow perfusion information in the drainage area can,however,significantly improve diagnostic confidence and provide additional information beyond routine ultrasound examination.
基金Supported by the Shenzhen Third People’s Hospital Research Fund,No.25270G1043The Basic and Applied Basic Research Foundation of Guangdong Province,No.2025A1515011934.
文摘Liver transplantation is the primary therapeutic choice for end-stage liver disease.Currently,biliary complications are among the main factors affecting the survival rate and quality of life of liver transplant recipients.Nevertheless,the clinical manifestations of biliary complications following liver transplantation are often non-specific,making early diagnosis and timely treatment crucial for improving patient outcomes.Ultrasound is the preferred imaging method following liver transplantation.Importantly,contrast-enhanced ultrasound,with the adminis-tration of contrast agents,can improve the resolution of biliary images and enable real-time,dynamic visualization of microcirculation perfusion in the biliary system and surrounding tissues.The present article describes the normal ultra-sonic features of the biliary system following liver transplantation and briefly reviews the progress in the ultrasonic diagnosis of common biliary complications,including anastomotic biliary strictures,non-anastomotic biliary strictures,biliary leakage,biloma,and bile sludge/bile stone.
基金Beijing Natural Science Foundation (Grant No. 3194048)China Friction Stir Welding Center and to Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development (Grant No. BIPT2018006) for the financial support
文摘Friction stir welding was used to join two AA2060-T8 plates,and then the effect of precipitate evolution on microstructure and corrosion behavior of the joint was investigated.The evolution of precipitates on the top surface of the joint was characterized by scanning electron microscopy and transmission electron microscopy.The corrosion behaviors of different regions in the joint were investigated by an electrochemistry method and an alternating salt spray exposure.The corrosion was mainly dependent on the nature of precipitates in each region of the joint.The shoulder affected zone had the worst corrosion resistance as a result of the re-dissolved ofθ′(Al2Cu),T1(Al2CuLi)andδ′(Al3Li)phases,the formation of intergranular precipitates and precipitate-free zones.However,the thermomechanically affected zone had a slightly improved corrosion resistance because it had no intergranular precipitates.The heat affected zone and base metal had the best corrosion resistance.
基金Financial support by State Key Lab of Advanced Welding and Joining,Harbin Institute of Technology
文摘This study investigates the cryogenic tensile properties and fracture behavior of fiction stir welded and post-weld heat-treated joints of 32Mn-7Cr-1Mo-0.3N steel. Cryogenic brittle fracture, which occurred in the as-welded joint, is related to the residual particles that contain tungsten in the joint band structure. Post-weld water toughening resulted in the cryogenic intergranular brittleness of the joint, which is related to the non-equilibrium segregation of solute atoms during the post-weld water toughening. Annealing at 55OC for 30rain can effectively inhibit the cryogenic intergranular brittleness of the post- weld water-toughened joint. The yield strength, ultimate tensile strength, and uniform elongation of the annealed joint are approximately 95%, 87%, and 94% of the corresponding data of the base metal.
基金supported by Hebei Natural Science Foundation,China (No.E2020203158)Hebei Provincial Department of Human Resources and Social Security,China (No.E2020100006)。
文摘The microstructures and hot tensile behaviors of ZK30 alloys subjected to single-and multi-pass friction stir processing(FSP)were systematically investigated.Following single-pass FSP(S-FSP),coarse grains underwent refinement to 1−2μm,with a distinct basal texture emerging in the stir zone(SZ).Additionally,second-phase particles were fragmented,dispersed,and partially dissolved.Multi-pass FSP(M-FSP)further enhanced the homogeneity of the microstructure,reduced texture intensity differences,and decreased the fraction of second-phase particles by 50%.Both S-FSP and M-FSP SZs demonstrated superplasticity at strain rates below 1×10^(−3)s^(−1)and at temperatures of 250−350℃.The S-FSP SZ exhibited an elongation of 390%at 250℃and 1×10^(−4)s^(−1),while the M-FSP SZ achieved an elongation of 406%at 350℃and 1×10^(−3)s^(−1).The superplastic deformation of SZ was co-dominated by grain boundary sliding(GBS)and the solute-drag mechanism in S-FSP and mainly by GBS in M-FSP.
基金supported by the National Natural Science Foundation of China(Grant Nos.61902012,61932003)supported by a Victoria Early-Career Research Excellence Award.
文摘Virtual reality(VR)offers an artificial,computer generated simulation of a real life environment.It originated in the 1960 s and has evolved to provide increasing immersion,interactivity,imagination,and intelligence.Because deep learning systems are able to represent and compose information at various levels in a deep hierarchical fashion,they can build very powerful models which leverage large quantities of visual media data.Intelligence of VR methods and applications has been significantly boosted by the recent developments in deep learning techniques.VR content creation and exploration relates to image and video analysis,synthesis and editing,so deep learning methods such as fully convolutional networks and general adversarial networks are widely employed,designed specifically to handle panoramic images and video and virtual 3 D scenes.This article surveys recent research that uses such deep learning methods for VR content creation and exploration.It considers the problems involved,and discusses possible future directions in this active and emerging research area.
基金the National Natural Science Foundation of China under Grant Nos.61902012 and 61932003Frank Steinicke was supported by funds from the BMBF,BMWi,DFG,and EU.
文摘Virtual reality(VR)allows users to explore and experience a computer-simulated virtual environment so that VR users can be immersed in a totally artificial virtual world and interact with arbitrary virtual objects.However,the limited physical tracking space usually restricts the exploration of large virtual spaces,and VR users have to use special locomotion techniques to move from one location to another.Among these techniques,redirected walking(RDW)is one of the most natural locomotion techniques to solve the problem based on near-natural walking experiences.The core idea of the RDW technique is to imperceptibly guide users on virtual paths,which might vary from the paths they physically walk in the real world.In a similar way,some RDW algorithms imperceptibly change the structure and layout of the virtual environment such that the virtual environment fits into the tracking space.In this survey,we first present a taxonomy of existing RDW work.Based on this taxonomy,we compare and analyze both contributions and shortcomings of the existing methods in detail,and find view manipulation methods offer satisfactory visual effect but the experience can be interrupted when users reach the physical boundaries,while virtual environment manipulation methods can provide users with consistent movement but have limited application scenarios.Finally,we discuss possible future research directions,indicating combining artificial intelligence with this area will be effective and intriguing.
