Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and education.Recently,MIP-VPP employing liquid cryst...Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and education.Recently,MIP-VPP employing liquid crystal displays(LCDs)has gained traction,increasingly replacing digital micromirror devices,particularly among hobbyists and in educational settings,and is now beginning to be used in industrial environments.However,LCD-based MIP-VPPsuffers from pronounced pixelated aliasing arising from LCD’s discrete image pixels and itsdirect-contact configuration in MIP-VPP machines,leading to rough surfaces on the 3D-printed parts.Here,we propose a vibration-assisted MIP-VPP method that utilizes a microscalevibration to uniformize the light intensity distribution of the LCD-based mask image on VPP’s building platform.By maintaining the same fabrication speed,our technique generates asmoother,non-pixelated mask image,reducing the roughness on flat surfaces and boundary segments of 3D-printed parts.Through light intensity modeling and simulation,we derived an optimal vibration pattern for LCD mask images,subsequently validated by experiments.We assessed the surface texture,boundary integrity,and dimensional accuracy of componentsproduced using the vibration-assisted approach.The notably smoother surfaces and improved boundary roughness enhance the printing quality of MIP-VPP,enabling its promisingapplications in sectors like the production of 3D-printed optical devices and others.展开更多
BACKGROUND Because of the mild inflammatory status in acute uncomplicated appendicitis,our team developed a novel technical protocol for single-port laparoscopic appendec-tomy using needle-type grasping forceps(SLAN)a...BACKGROUND Because of the mild inflammatory status in acute uncomplicated appendicitis,our team developed a novel technical protocol for single-port laparoscopic appendec-tomy using needle-type grasping forceps(SLAN)and achieved positive clinical outcomes.However,the intraoperative procedure lacked stability and fluency due to a series of problems highlighted by the small incision design of the proto-col(only 1 cm long).Therefore,there is a growing clinical demand to further opti-mize the SLAN protocol.CASE SUMMARY An adult male patient was admitted for persistent right lower abdominal pain with preoperative computed tomography findings suggestive of appendicitis accompanied by localized peritonitis.A modified technical protocol for SLAN based on minimally invasive surgical principles was used,and the patient was confirmed to have acute simple appendicitis by postoperative pathological ana-lysis.Postoperative recovery was uneventful,and no postoperative complications,such as incision infection or severe incision pain,were observed.The patient was discharged successfully on postoperative day 2.CONCLUSION The modified technical protocol of SLAN may be a new minimally invasive surgical alternative for patients with acute simple appendicitis.展开更多
The“Announcement on Deepening the Value-Added Tax Reform”clearly outlines the preferential policy regarding incremental retention tax rebates.With the advancement of value-added tax(VAT)reform and the improvement of...The“Announcement on Deepening the Value-Added Tax Reform”clearly outlines the preferential policy regarding incremental retention tax rebates.With the advancement of value-added tax(VAT)reform and the improvement of VAT legislation in China,VAT tax planning for construction enterprises,particularly related to retained tax credits,has become routine.This paper,focusing on the characteristics of construction enterprises,analyzes VAT retained tax credits at the end of the period,the status of tax refunds,practical issues,and related processes,and offers suggestions for policy application and risk prevention.展开更多
文摘Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and education.Recently,MIP-VPP employing liquid crystal displays(LCDs)has gained traction,increasingly replacing digital micromirror devices,particularly among hobbyists and in educational settings,and is now beginning to be used in industrial environments.However,LCD-based MIP-VPPsuffers from pronounced pixelated aliasing arising from LCD’s discrete image pixels and itsdirect-contact configuration in MIP-VPP machines,leading to rough surfaces on the 3D-printed parts.Here,we propose a vibration-assisted MIP-VPP method that utilizes a microscalevibration to uniformize the light intensity distribution of the LCD-based mask image on VPP’s building platform.By maintaining the same fabrication speed,our technique generates asmoother,non-pixelated mask image,reducing the roughness on flat surfaces and boundary segments of 3D-printed parts.Through light intensity modeling and simulation,we derived an optimal vibration pattern for LCD mask images,subsequently validated by experiments.We assessed the surface texture,boundary integrity,and dimensional accuracy of componentsproduced using the vibration-assisted approach.The notably smoother surfaces and improved boundary roughness enhance the printing quality of MIP-VPP,enabling its promisingapplications in sectors like the production of 3D-printed optical devices and others.
基金Supported by Natural Science Foundation of Liaoning Province,No.2023-MS-354Science and Technology Project for Youth of Chaoyang Central Hospital,China Medical University.
文摘BACKGROUND Because of the mild inflammatory status in acute uncomplicated appendicitis,our team developed a novel technical protocol for single-port laparoscopic appendec-tomy using needle-type grasping forceps(SLAN)and achieved positive clinical outcomes.However,the intraoperative procedure lacked stability and fluency due to a series of problems highlighted by the small incision design of the proto-col(only 1 cm long).Therefore,there is a growing clinical demand to further opti-mize the SLAN protocol.CASE SUMMARY An adult male patient was admitted for persistent right lower abdominal pain with preoperative computed tomography findings suggestive of appendicitis accompanied by localized peritonitis.A modified technical protocol for SLAN based on minimally invasive surgical principles was used,and the patient was confirmed to have acute simple appendicitis by postoperative pathological ana-lysis.Postoperative recovery was uneventful,and no postoperative complications,such as incision infection or severe incision pain,were observed.The patient was discharged successfully on postoperative day 2.CONCLUSION The modified technical protocol of SLAN may be a new minimally invasive surgical alternative for patients with acute simple appendicitis.
文摘The“Announcement on Deepening the Value-Added Tax Reform”clearly outlines the preferential policy regarding incremental retention tax rebates.With the advancement of value-added tax(VAT)reform and the improvement of VAT legislation in China,VAT tax planning for construction enterprises,particularly related to retained tax credits,has become routine.This paper,focusing on the characteristics of construction enterprises,analyzes VAT retained tax credits at the end of the period,the status of tax refunds,practical issues,and related processes,and offers suggestions for policy application and risk prevention.
