The study aimed to examine the applicability of carbon nanoparticles as a tracer for lymph node mapping and the related factors of lymph node and No.8p subgroup metastasis in patients with gastric cancer.Clinical data...The study aimed to examine the applicability of carbon nanoparticles as a tracer for lymph node mapping and the related factors of lymph node and No.8p subgroup metastasis in patients with gastric cancer.Clinical data of 50 patients with gastric cancer,who had not received treatment preoperatively and underwent gastrectomy in Department of Gastrointestinal Surgery,Wuhan Union Hospital,between October 2014 and August 2015,were retrospectively analyzed.These patients were found to have no distant metastasis preoperatively.Thirty-five out of 50 patients were subjected to lymphatic mapping technique using carbon nanoparticles as the tracer,and the rest 15 cases did not experience the lymphatic mapping and served as controls.The sensitivity,specificity,false positive rate and false negative rate were calculated according to the number of lymph nodes,and the staining and metastasis condition of lymph nodes.The diagnostic value of carbon nanoparticles on metastatic lymph nodes was evaluated.The relationship between the metastasis of lymph nodes or subgroup No.8p lymph nodes and clinicopathologic features was analyzed by χ^2-test or Fisher＇s exact test.All patients underwent D2 surgery（lymph node dissection including all the group 1 and group 2 nodes） plus the dissection of the subgroup No.8p lymph nodes.It was found that the average number of harvested lymph nodes in lymphatic mapping technique group（45.7±14.5） was greater than that in control group（39.2±11.7）,but the difference was not significantly different（P=0.138〉0.05）.The success rate,the accuracy,sensitivity,specificity and false negative rate was 97%,57%,28%,62% and 72% respectively.The metastasis of lymph nodes was correlated to the depth of cancer invasion（T stage）（P=0.004〈0.05）,and the metastasis of No.8p lymph nodes was correlated to the extent of lymph node involvement（N stage）（P=0.007〈0.05）.Six cases had lymph node metastasis in subgroup No.8p,and their TNM stages and clinical stages were as follows：T1N2M0 ⅡA,T3N3M0 ⅢB,T4 a N3M0 ⅢC,T4 a N3M0 ⅢC,T4 a N3M0 ⅢC,and T4 b N3M0 ⅢC.In conclusion,our study indicated that carbon nanoparticles failed to show good selectivity for metastatic lymph nodes;the result of lymphatic mapping does not achieve a satisfactory performance;the incidence of lymph node metastasis may increase,accompanying with the increase of the depth of cancer invasion;No.8p lymph node metastasis tends to occur for gastric carcinoma patients with the extent of lymph node metastasis over N2 stage.展开更多
Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little i...Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D printers.In this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were tested.The experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed HIPS.The prediction models of the process parameters were regressed to produce the optimal combination of process parameters.The experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile strength.With an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer thickness.In addition,they all increased with an increase of infill density.It was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were optimal.Our results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.展开更多
文摘The study aimed to examine the applicability of carbon nanoparticles as a tracer for lymph node mapping and the related factors of lymph node and No.8p subgroup metastasis in patients with gastric cancer.Clinical data of 50 patients with gastric cancer,who had not received treatment preoperatively and underwent gastrectomy in Department of Gastrointestinal Surgery,Wuhan Union Hospital,between October 2014 and August 2015,were retrospectively analyzed.These patients were found to have no distant metastasis preoperatively.Thirty-five out of 50 patients were subjected to lymphatic mapping technique using carbon nanoparticles as the tracer,and the rest 15 cases did not experience the lymphatic mapping and served as controls.The sensitivity,specificity,false positive rate and false negative rate were calculated according to the number of lymph nodes,and the staining and metastasis condition of lymph nodes.The diagnostic value of carbon nanoparticles on metastatic lymph nodes was evaluated.The relationship between the metastasis of lymph nodes or subgroup No.8p lymph nodes and clinicopathologic features was analyzed by χ^2-test or Fisher＇s exact test.All patients underwent D2 surgery（lymph node dissection including all the group 1 and group 2 nodes） plus the dissection of the subgroup No.8p lymph nodes.It was found that the average number of harvested lymph nodes in lymphatic mapping technique group（45.7±14.5） was greater than that in control group（39.2±11.7）,but the difference was not significantly different（P=0.138〉0.05）.The success rate,the accuracy,sensitivity,specificity and false negative rate was 97%,57%,28%,62% and 72% respectively.The metastasis of lymph nodes was correlated to the depth of cancer invasion（T stage）（P=0.004〈0.05）,and the metastasis of No.8p lymph nodes was correlated to the extent of lymph node involvement（N stage）（P=0.007〈0.05）.Six cases had lymph node metastasis in subgroup No.8p,and their TNM stages and clinical stages were as follows：T1N2M0 ⅡA,T3N3M0 ⅢB,T4 a N3M0 ⅢC,T4 a N3M0 ⅢC,T4 a N3M0 ⅢC,and T4 b N3M0 ⅢC.In conclusion,our study indicated that carbon nanoparticles failed to show good selectivity for metastatic lymph nodes;the result of lymphatic mapping does not achieve a satisfactory performance;the incidence of lymph node metastasis may increase,accompanying with the increase of the depth of cancer invasion;No.8p lymph node metastasis tends to occur for gastric carcinoma patients with the extent of lymph node metastasis over N2 stage.
基金supported by the National Natural Science Foundation of China(Grant No.51975097)the National Key Research and Development Project(Grant No.2020YFA0713702).
文摘Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D printers.In this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were tested.The experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed HIPS.The prediction models of the process parameters were regressed to produce the optimal combination of process parameters.The experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile strength.With an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer thickness.In addition,they all increased with an increase of infill density.It was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were optimal.Our results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.
