Objective To report our experience of retrograde hepatectomy in 244 cases of difficultly resected liver cancer. Methods Large, poor-exposure and inferior vena cava (IVC)-involving liver cancers that were difficult t...Objective To report our experience of retrograde hepatectomy in 244 cases of difficultly resected liver cancer. Methods Large, poor-exposure and inferior vena cava (IVC)-involving liver cancers that were difficult to remove by classical hepatectomy, have been resected successfully by retrograde hepatectomy combined with vascular surgical techniques in 244 patients (group A). Thirty one patients with similar circumstances undergoing classical hepatectomy duing the same period served as controls (group B). Results There were no perioperative mortalities in both groups. The comparison between group A and group B, the estimated intraoperative blood loss was 1290±998 ml versus 2286±1363 ml, post-operative pleural effusions occurred in 26/244 versus 10/31, ascites in 72/244 versus 19/31, moderate to severe jaundice in 14/244 versus 5/31, effusion in the operative area in 17/244 versus 7/31, subphrenic infection in 3/244 versus 1/31, bile leakage in 2/244 versus 1/31, wound infection in 3/244 versus 1/31, respectively. The time until ALT normalizaton in the groups A and B was 13.8±5.1 days and 18.9±8.9 days respectively. The difference between the two groups were statistically significant (P<0.01). Conclusion Retrograde hepatectomy is a safe and effective method for difficultly resected liver cancer. Key words cancer - liver - liver surgery - retrograde展开更多
Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. Fi...Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. First of all, the thermal characteristic analysis was performed to verify the importance of laser module location. Laser module should be moved within 1 mm. Analysis conditions of three positions in driving range of the one-axis manipulator are selected. And a C coupling is used as a connection device for spindle and laser module. An initial model has one C coupling, and the number of C coupling has been increased from 1 to 2 in an improved model. And the analysis is carried out again for the one-axis manipulator. The results of the static analysis, the maximum displacement and the maximum stress are decreased by 22% and 11%, respectively, for the improved model when the laser module is located at farthest away from the spindle unit. As a result of the modal analysis, the first natural frequency mode is increased by 13%, 18% and 12% at these positions of the improved model, respectively. The harmonic analysis of the improved model was performed by analyzing the results of the modal analysis. The maximum deformation was 0.33 mm in driving unit at 222 Hz. And the maximum compliance of the ISO axis direction was 0.23 mm/N. Finally, the one-axis manipulator has been fabricated successfully using the analysis result.展开更多
The possibility of applying a high-pressure hydro-jet for renewal of the grinding wheel cutting ability was presented.This work was conducted in the internal cylindrical grinding process of the Titanium Grade 2 alloy,...The possibility of applying a high-pressure hydro-jet for renewal of the grinding wheel cutting ability was presented.This work was conducted in the internal cylindrical grinding process of the Titanium Grade 2 alloy,which belongs to the group of hard-to-cut materials.The analysis shows that the impact on the erosion effectiveness of the grinding wheel active surface(GWAS)depends upon the hydro-jet inclination angle and working pressure.Experimental results reveal that application of hydro-jet working pressure of 25 MPa allows for effective cleansing of the grinding wheel surface.Depending on the initial GWAS condition and the level of its smearing with chips of machined material,it is possible to increase the number of grinding wheel unevenness apexes by as much as 4.5 times.展开更多
Many difficult-to-cut materials such as Ni-base super alloy, titanium alloy, and austenite stainless steel which are used extensively in aerospace generally have high strength-to-weight ratios, high corrosion resistan...Many difficult-to-cut materials such as Ni-base super alloy, titanium alloy, and austenite stainless steel which are used extensively in aerospace generally have high strength-to-weight ratios, high corrosion resistance, high strength retention ability at elevated temperatures, and low thermal conductivity. These characteristics can result in uneven tool wear and chatter vibration. Therefore, determining the appropriate end-milling conditions is more difficult for difficult-to-cut materials than for other materials. There has been much research on the high-speed milling of difficult-to-cut materials, and effective end-milling conditions, end-mill tool shapes, and processing methods have been reported. In addition, irregular pitch and lead end-mills with different helix angles have been developed by tool maker＇s to reduce chatter vibration, making it easier to perform high-speed milling. However, there have been few reports of slotting information useful for determining appropriate end-milling conditions and processing methods for Ni-base super alloy. The aim of this study is to derive end-milling condition with high efficiency grooving process for Ni-base super alloy （Inconel 718） sheet. Effects of cutting parameters were examined from the view point of cutting resistance, ＂tool tip maximum temperature and tool flank wear width. As a result from experiments, if the grooving process condition of axial depth of cut is smaller than other conditions on the same material removable rate value, it has been found that it is possible to reduce the tool tip maximum temperature and prolong the tool life.展开更多
Primary pericardial sarcomas are extremely rare. We report a case of 19 year old male who presented with cough, dyspnoea, and orthopnea. Investigations and exploratory thoracotomy revealed a large pericardial mass. Su...Primary pericardial sarcomas are extremely rare. We report a case of 19 year old male who presented with cough, dyspnoea, and orthopnea. Investigations and exploratory thoracotomy revealed a large pericardial mass. Surgical debulking of the tumor was performed and the histopathological examination was compatible with synovial sarcoma. The tumor was unresectable due to its invasion and adhesion to mediastinal structures. Hence patient was started on palliative chemotherapy (adriamycin and ifosfamide based). Patient showed an initial symptomatic response but later on there was a clinical progres-sion and died within six months of his diagnosis.展开更多
The chemical mechanical polishing(CMP)technology has been widely used for surface modification of critical materials and components with high quality and efficiency.In a typical CMP process,the mechanical properties o...The chemical mechanical polishing(CMP)technology has been widely used for surface modification of critical materials and components with high quality and efficiency.In a typical CMP process,the mechanical properties of abrasives play a vital role in obtaining the ultra-precision and damage-free surface of wafers for improvement of their performances.In this work,a series of fine structured rod-shaped silica(RmSiO2)-based abrasives with controllable sizes and diverse ordered mesoporous structures were synthesized via a soft template approach,and successfully applied in the sustainable polishing slurry for improving the surface quality of cadmium zinc telluride(CZT)wafers.Compared with commercial silica gel,solid and mesoporous silica spheres,the RmSiO2 abrasives present superior elastic deformation capacity and surface precision machinability on account of their mesoporous structures and rod shapes.Especially,ultra-precision surface roughness and relatively effective material removal speed were achieved by the CMP process using the RmSiO2 abrasives with a length/diameter(L/d)ratio of 1.In addition,a potential CMP mechanism of the developed polishing slurry to CZT wafer was elucidated by analyzing X-ray photoelectron spectra and other characterizations.The proposed interfacial chemical and mechanical effects will provide a new strategy for improving abrasives’machinability and precision manufacture of hard-to-machine materials.展开更多
文摘Objective To report our experience of retrograde hepatectomy in 244 cases of difficultly resected liver cancer. Methods Large, poor-exposure and inferior vena cava (IVC)-involving liver cancers that were difficult to remove by classical hepatectomy, have been resected successfully by retrograde hepatectomy combined with vascular surgical techniques in 244 patients (group A). Thirty one patients with similar circumstances undergoing classical hepatectomy duing the same period served as controls (group B). Results There were no perioperative mortalities in both groups. The comparison between group A and group B, the estimated intraoperative blood loss was 1290±998 ml versus 2286±1363 ml, post-operative pleural effusions occurred in 26/244 versus 10/31, ascites in 72/244 versus 19/31, moderate to severe jaundice in 14/244 versus 5/31, effusion in the operative area in 17/244 versus 7/31, subphrenic infection in 3/244 versus 1/31, bile leakage in 2/244 versus 1/31, wound infection in 3/244 versus 1/31, respectively. The time until ALT normalizaton in the groups A and B was 13.8±5.1 days and 18.9±8.9 days respectively. The difference between the two groups were statistically significant (P<0.01). Conclusion Retrograde hepatectomy is a safe and effective method for difficultly resected liver cancer. Key words cancer - liver - liver surgery - retrograde
基金Project(2012-0005688) supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea Government (MEST)
文摘Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. First of all, the thermal characteristic analysis was performed to verify the importance of laser module location. Laser module should be moved within 1 mm. Analysis conditions of three positions in driving range of the one-axis manipulator are selected. And a C coupling is used as a connection device for spindle and laser module. An initial model has one C coupling, and the number of C coupling has been increased from 1 to 2 in an improved model. And the analysis is carried out again for the one-axis manipulator. The results of the static analysis, the maximum displacement and the maximum stress are decreased by 22% and 11%, respectively, for the improved model when the laser module is located at farthest away from the spindle unit. As a result of the modal analysis, the first natural frequency mode is increased by 13%, 18% and 12% at these positions of the improved model, respectively. The harmonic analysis of the improved model was performed by analyzing the results of the modal analysis. The maximum deformation was 0.33 mm in driving unit at 222 Hz. And the maximum compliance of the ISO axis direction was 0.23 mm/N. Finally, the one-axis manipulator has been fabricated successfully using the analysis result.
文摘The possibility of applying a high-pressure hydro-jet for renewal of the grinding wheel cutting ability was presented.This work was conducted in the internal cylindrical grinding process of the Titanium Grade 2 alloy,which belongs to the group of hard-to-cut materials.The analysis shows that the impact on the erosion effectiveness of the grinding wheel active surface(GWAS)depends upon the hydro-jet inclination angle and working pressure.Experimental results reveal that application of hydro-jet working pressure of 25 MPa allows for effective cleansing of the grinding wheel surface.Depending on the initial GWAS condition and the level of its smearing with chips of machined material,it is possible to increase the number of grinding wheel unevenness apexes by as much as 4.5 times.
文摘Many difficult-to-cut materials such as Ni-base super alloy, titanium alloy, and austenite stainless steel which are used extensively in aerospace generally have high strength-to-weight ratios, high corrosion resistance, high strength retention ability at elevated temperatures, and low thermal conductivity. These characteristics can result in uneven tool wear and chatter vibration. Therefore, determining the appropriate end-milling conditions is more difficult for difficult-to-cut materials than for other materials. There has been much research on the high-speed milling of difficult-to-cut materials, and effective end-milling conditions, end-mill tool shapes, and processing methods have been reported. In addition, irregular pitch and lead end-mills with different helix angles have been developed by tool maker＇s to reduce chatter vibration, making it easier to perform high-speed milling. However, there have been few reports of slotting information useful for determining appropriate end-milling conditions and processing methods for Ni-base super alloy. The aim of this study is to derive end-milling condition with high efficiency grooving process for Ni-base super alloy （Inconel 718） sheet. Effects of cutting parameters were examined from the view point of cutting resistance, ＂tool tip maximum temperature and tool flank wear width. As a result from experiments, if the grooving process condition of axial depth of cut is smaller than other conditions on the same material removable rate value, it has been found that it is possible to reduce the tool tip maximum temperature and prolong the tool life.
文摘Primary pericardial sarcomas are extremely rare. We report a case of 19 year old male who presented with cough, dyspnoea, and orthopnea. Investigations and exploratory thoracotomy revealed a large pericardial mass. Surgical debulking of the tumor was performed and the histopathological examination was compatible with synovial sarcoma. The tumor was unresectable due to its invasion and adhesion to mediastinal structures. Hence patient was started on palliative chemotherapy (adriamycin and ifosfamide based). Patient showed an initial symptomatic response but later on there was a clinical progres-sion and died within six months of his diagnosis.
基金the National Key R&D Program of China(2018YFA0703400)the Xinghai Science Funds for Distinguished Young Scholars+1 种基金Thousand Youth Talents at Dalian University of Technology,the Collaborative Innovation Center of Major Machine Manufacturing in Liaoning,Liaoning BaiQianWan Talents ProgramDalian National Laboratory for Clean Energy(DNL),DNL Cooperation Fund,Chinese Academy of Sciences(DNL180402)。
文摘The chemical mechanical polishing(CMP)technology has been widely used for surface modification of critical materials and components with high quality and efficiency.In a typical CMP process,the mechanical properties of abrasives play a vital role in obtaining the ultra-precision and damage-free surface of wafers for improvement of their performances.In this work,a series of fine structured rod-shaped silica(RmSiO2)-based abrasives with controllable sizes and diverse ordered mesoporous structures were synthesized via a soft template approach,and successfully applied in the sustainable polishing slurry for improving the surface quality of cadmium zinc telluride(CZT)wafers.Compared with commercial silica gel,solid and mesoporous silica spheres,the RmSiO2 abrasives present superior elastic deformation capacity and surface precision machinability on account of their mesoporous structures and rod shapes.Especially,ultra-precision surface roughness and relatively effective material removal speed were achieved by the CMP process using the RmSiO2 abrasives with a length/diameter(L/d)ratio of 1.In addition,a potential CMP mechanism of the developed polishing slurry to CZT wafer was elucidated by analyzing X-ray photoelectron spectra and other characterizations.The proposed interfacial chemical and mechanical effects will provide a new strategy for improving abrasives’machinability and precision manufacture of hard-to-machine materials.
