AIM: To investigate the feasibility and accuracy of cone beam computed tomography(CBCT) in assessing the ablation zone after liver tumor ablation.METHODS: Twenty-three patients(17 men and 6 women, range: 45-85 years o...AIM: To investigate the feasibility and accuracy of cone beam computed tomography(CBCT) in assessing the ablation zone after liver tumor ablation.METHODS: Twenty-three patients(17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasoundguided percutaneous tumor ablation [radiofrequency(n = 14), microwave(n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography(MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the nonparametric paired Wilcoxon t-test.RESULTS: Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient(4%). The ablation zone was identified in 21/23(91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage(at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2(9%), 8(35%), and 13(56%), patients respectively. Registration quality between periprocedural CBCT and post-procedural MDCT images was good to excellent in 17/23(74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm3(range: 4-95 cm3) and 30 cm3(range: 4-124 cm3), respectively(P-value > 0.2). There was a good correlation(r = 0.79) between the volumes of the two techniques. CONCLUSION: Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.展开更多
The effect of grain boundaries on cyclic deformation and fatigue crack growth in aluminum bicrystals has been studied.The effect of a grain boundary is restricted in a narrow area, termed as grain boundary affecting z...The effect of grain boundaries on cyclic deformation and fatigue crack growth in aluminum bicrystals has been studied.The effect of a grain boundary is restricted in a narrow area, termed as grain boundary affecting zone(GBAZ),where the incompatible plastic strain treats internal stress which conversely promotes inhomogeneous slip in the area and grain boundary cracking.As an extended stage I crack initiated from a notch approaches the grain boundary under a constant cyclic stress,the crack front branches splits into several pieces, meanwhile,the growth rate of the crack reduces to a minimum value at the center of the GBAZ.Such microstructure-sensitive growth of extended stage I cracks is mainly attributed to the grain boundary-induced crack tip sheilding.展开更多
One of the most intriguing questions in eusocial insects is to understand how the overt reproductive conflict in the colony appears limited when queens or kings are senescent or lost because the morphologically simila...One of the most intriguing questions in eusocial insects is to understand how the overt reproductive conflict in the colony appears limited when queens or kings are senescent or lost because the morphologically similar individuals in the colony are reproductively totipotent.Whether there are some individuals who preferentially differentiate into replacement reproductives or not has received little attention.The consistent individual behavioral differences(also termed“animal personality”)of individuals from the colony can shape cunningly their task and consequently affect the colony fitness but have been rarely investigated in eusocial insects.Here,we used the termite Reticulitermes labralis to investigate if variations in individual personalities(elusiveness and aggressiveness)may predict which individuals will perform reproductive differentiation within colonies.We observed that when we separately reared elusive and aggressive workers,elusive workers differentiate into reproductives significantly earlier than aggressive workers.When we reared them together in the proportions 12:3,10:5,and 8:7(aggressive workers:elusive workers),the first reproductives mostly differentiated from the elusive workers,and the reproductives differentiated from the elusive workers significantly earlier than from aggressive workers.Furthermore,we found that the number of workers participating in reproductive differentiation was significantly lower in the groups of both types of workers than in groups containing only elusive workers.Our results demonstrate that the elusiveness trait was a strong predictor of workers’differentiation into replacement reproductives in R.labralis.Moreover,our results suggest that individual personalities within the insect society could play a key role in resolving the overt reproductive conflict.展开更多
文摘AIM: To investigate the feasibility and accuracy of cone beam computed tomography(CBCT) in assessing the ablation zone after liver tumor ablation.METHODS: Twenty-three patients(17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasoundguided percutaneous tumor ablation [radiofrequency(n = 14), microwave(n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography(MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the nonparametric paired Wilcoxon t-test.RESULTS: Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient(4%). The ablation zone was identified in 21/23(91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage(at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2(9%), 8(35%), and 13(56%), patients respectively. Registration quality between periprocedural CBCT and post-procedural MDCT images was good to excellent in 17/23(74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm3(range: 4-95 cm3) and 30 cm3(range: 4-124 cm3), respectively(P-value > 0.2). There was a good correlation(r = 0.79) between the volumes of the two techniques. CONCLUSION: Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.
文摘The effect of grain boundaries on cyclic deformation and fatigue crack growth in aluminum bicrystals has been studied.The effect of a grain boundary is restricted in a narrow area, termed as grain boundary affecting zone(GBAZ),where the incompatible plastic strain treats internal stress which conversely promotes inhomogeneous slip in the area and grain boundary cracking.As an extended stage I crack initiated from a notch approaches the grain boundary under a constant cyclic stress,the crack front branches splits into several pieces, meanwhile,the growth rate of the crack reduces to a minimum value at the center of the GBAZ.Such microstructure-sensitive growth of extended stage I cracks is mainly attributed to the grain boundary-induced crack tip sheilding.
基金This work was supported by the NSFC-Yunnan United fund(U2102221)National Natural Science Foundation of China(31360104)by the Project for Graduate Innovation Team of Northwestern Polytechnical University(02020-19GH010208),Xi'an,China。
文摘One of the most intriguing questions in eusocial insects is to understand how the overt reproductive conflict in the colony appears limited when queens or kings are senescent or lost because the morphologically similar individuals in the colony are reproductively totipotent.Whether there are some individuals who preferentially differentiate into replacement reproductives or not has received little attention.The consistent individual behavioral differences(also termed“animal personality”)of individuals from the colony can shape cunningly their task and consequently affect the colony fitness but have been rarely investigated in eusocial insects.Here,we used the termite Reticulitermes labralis to investigate if variations in individual personalities(elusiveness and aggressiveness)may predict which individuals will perform reproductive differentiation within colonies.We observed that when we separately reared elusive and aggressive workers,elusive workers differentiate into reproductives significantly earlier than aggressive workers.When we reared them together in the proportions 12:3,10:5,and 8:7(aggressive workers:elusive workers),the first reproductives mostly differentiated from the elusive workers,and the reproductives differentiated from the elusive workers significantly earlier than from aggressive workers.Furthermore,we found that the number of workers participating in reproductive differentiation was significantly lower in the groups of both types of workers than in groups containing only elusive workers.Our results demonstrate that the elusiveness trait was a strong predictor of workers’differentiation into replacement reproductives in R.labralis.Moreover,our results suggest that individual personalities within the insect society could play a key role in resolving the overt reproductive conflict.