In this study,the effects of geometrical and physical factors on light particles dispersion in stirred tank were investigated by agitation characteristic curve.The experiments and CFD simulations with discrete phase m...In this study,the effects of geometrical and physical factors on light particles dispersion in stirred tank were investigated by agitation characteristic curve.The experiments and CFD simulations with discrete phase model(DPM)and volume of fluid model(VOF)were conducted in this paper.Five factors,which include four geometrical factors(submergence,impeller-to-tank ratio,number of impeller blades and baffling mode)and a physical factor(liquid viscosity)were considered.For each factor,the power consumption curve and agitation characteristic curve were drawn to compare the power consumption and mixing results in the stirred tank.Characteristics of the agitation characteristic curves were compared with the previous published literatures and theories.It is found that the agitation characteristic curves reflect the tendency of power consumption and particles distribution well in stirred tank.The good agreement indicates the applicability of the agitation characteristic curves for the study of light particles distribution in stirred tank.展开更多
BACKGROUND Laparoscopic pancreaticoduodenectomy(LPD)is a surgical procedure for treating pancreatic cancer;however,the risk of complications remains high owing to the wide range of organs involved during the surgery a...BACKGROUND Laparoscopic pancreaticoduodenectomy(LPD)is a surgical procedure for treating pancreatic cancer;however,the risk of complications remains high owing to the wide range of organs involved during the surgery and the difficulty of anastomosis.Pancreatic fistula(PF)is a major complication that not only increases the risk of postoperative infection and abdominal hemorrhage but may also cause multi-organ failure,which is a serious threat to the patient’s life.This study hypothesized the risk factors for PF after LPD.AIM To identify the risk factors for PF after laparoscopic pancreatoduodenectomy in patients with pancreatic cancer.METHODS We retrospectively analyzed the data of 201 patients admitted to the Fudan University Shanghai Cancer Center between August 2022 and August 2023 who underwent LPD for pancreatic cancer.On the basis of the PF’s incidence(grades B and C),patients were categorized into the PF(n=15)and non-PF groups(n=186).Differences in general data,preoperative laboratory indicators,and surgery-related factors between the two groups were compared and analyzed using multifactorial logistic regression and receiver-operating characteristic(ROC)curve analyses.RESULTS The proportions of males,combined hypertension,soft pancreatic texture,and pancreatic duct diameter≤3 mm;surgery time;body mass index(BMI);and amylase(Am)level in the drainage fluid on the first postoperative day(Am>1069 U/L)were greater in the PF group than in the non-PF group(P<0.05),whereas the preoperative monocyte count in the PF group was lower than that in the non-PF group(all P<0.05).The logistic regression analysis revealed that BMI>24.91 kg/m²[odds ratio(OR)=13.978,95%confidence interval(CI):1.886-103.581],hypertension(OR=8.484,95%CI:1.22-58.994),soft pancreatic texture(OR=42.015,95%CI:5.698-309.782),and operation time>414 min(OR=15.41,95%CI:1.63-145.674)were risk factors for the development of PF after LPD for pancreatic cancer(all P<0.05).The areas under the ROC curve for BMI,hypertension,soft pancreatic texture,and time prediction of PF surgery were 0.655,0.661,0.873,and 0.758,respectively.CONCLUSION BMI(>24.91 kg/m²),hypertension,soft pancreatic texture,and operation time(>414 min)are considered to be the risk factors for postoperative PF.展开更多
目的通过对多模态MRI指标与临床指标结合分析,建立复杂性肛瘘术后肛门排粪失禁预测模型,并对模型进行验证。方法回顾性分析2020年1月至2023年5月我院肛肠科收治的71例复杂性肛瘘患者资料。统计术后三个月是否有肛门失禁症状,根据肛门失...目的通过对多模态MRI指标与临床指标结合分析,建立复杂性肛瘘术后肛门排粪失禁预测模型,并对模型进行验证。方法回顾性分析2020年1月至2023年5月我院肛肠科收治的71例复杂性肛瘘患者资料。统计术后三个月是否有肛门失禁症状,根据肛门失禁进行分组,结合患者多模态MRI数据指标及临床指标等变量进行Logistic回归分析,建立术后肛门失禁预测模型。结果71例患者中,最终共纳入71人,其中男性65人,年龄21至63岁,平均年龄39.23±10.71岁,经括约肌型46例,括约肌上型25例。Logistic回归分析结果显示,MRI肛瘘分型、MRI病变直径、肛门外括约肌(exteral anal sphincter,EAS)萎缩分级、EAS厚度、年龄是复杂性肛瘘术后并发肛门失禁的独立危险因素(P<0.05)。依此进行因素筛选从而构建预测模型,绘制受试者工作特征(receiver operating characteristic,ROC)曲线,曲线下面积(area under the curve,AUC)为0.940(P<0.001),模型预测质量评分0.87分,有较高的预测效能。结论MRI多模态成像指标结合临床风险因素建立的预测模型准确度良好,可以在治疗前方案的制订提供良好的影像学证据与参考,可以更好对肛门失禁情况进行提前预判。展开更多
基金Supported by the National Natural Science Foundation of China(51474109,51609090,51679097).
文摘In this study,the effects of geometrical and physical factors on light particles dispersion in stirred tank were investigated by agitation characteristic curve.The experiments and CFD simulations with discrete phase model(DPM)and volume of fluid model(VOF)were conducted in this paper.Five factors,which include four geometrical factors(submergence,impeller-to-tank ratio,number of impeller blades and baffling mode)and a physical factor(liquid viscosity)were considered.For each factor,the power consumption curve and agitation characteristic curve were drawn to compare the power consumption and mixing results in the stirred tank.Characteristics of the agitation characteristic curves were compared with the previous published literatures and theories.It is found that the agitation characteristic curves reflect the tendency of power consumption and particles distribution well in stirred tank.The good agreement indicates the applicability of the agitation characteristic curves for the study of light particles distribution in stirred tank.
文摘BACKGROUND Laparoscopic pancreaticoduodenectomy(LPD)is a surgical procedure for treating pancreatic cancer;however,the risk of complications remains high owing to the wide range of organs involved during the surgery and the difficulty of anastomosis.Pancreatic fistula(PF)is a major complication that not only increases the risk of postoperative infection and abdominal hemorrhage but may also cause multi-organ failure,which is a serious threat to the patient’s life.This study hypothesized the risk factors for PF after LPD.AIM To identify the risk factors for PF after laparoscopic pancreatoduodenectomy in patients with pancreatic cancer.METHODS We retrospectively analyzed the data of 201 patients admitted to the Fudan University Shanghai Cancer Center between August 2022 and August 2023 who underwent LPD for pancreatic cancer.On the basis of the PF’s incidence(grades B and C),patients were categorized into the PF(n=15)and non-PF groups(n=186).Differences in general data,preoperative laboratory indicators,and surgery-related factors between the two groups were compared and analyzed using multifactorial logistic regression and receiver-operating characteristic(ROC)curve analyses.RESULTS The proportions of males,combined hypertension,soft pancreatic texture,and pancreatic duct diameter≤3 mm;surgery time;body mass index(BMI);and amylase(Am)level in the drainage fluid on the first postoperative day(Am>1069 U/L)were greater in the PF group than in the non-PF group(P<0.05),whereas the preoperative monocyte count in the PF group was lower than that in the non-PF group(all P<0.05).The logistic regression analysis revealed that BMI>24.91 kg/m²[odds ratio(OR)=13.978,95%confidence interval(CI):1.886-103.581],hypertension(OR=8.484,95%CI:1.22-58.994),soft pancreatic texture(OR=42.015,95%CI:5.698-309.782),and operation time>414 min(OR=15.41,95%CI:1.63-145.674)were risk factors for the development of PF after LPD for pancreatic cancer(all P<0.05).The areas under the ROC curve for BMI,hypertension,soft pancreatic texture,and time prediction of PF surgery were 0.655,0.661,0.873,and 0.758,respectively.CONCLUSION BMI(>24.91 kg/m²),hypertension,soft pancreatic texture,and operation time(>414 min)are considered to be the risk factors for postoperative PF.
文摘目的通过对多模态MRI指标与临床指标结合分析,建立复杂性肛瘘术后肛门排粪失禁预测模型,并对模型进行验证。方法回顾性分析2020年1月至2023年5月我院肛肠科收治的71例复杂性肛瘘患者资料。统计术后三个月是否有肛门失禁症状,根据肛门失禁进行分组,结合患者多模态MRI数据指标及临床指标等变量进行Logistic回归分析,建立术后肛门失禁预测模型。结果71例患者中,最终共纳入71人,其中男性65人,年龄21至63岁,平均年龄39.23±10.71岁,经括约肌型46例,括约肌上型25例。Logistic回归分析结果显示,MRI肛瘘分型、MRI病变直径、肛门外括约肌(exteral anal sphincter,EAS)萎缩分级、EAS厚度、年龄是复杂性肛瘘术后并发肛门失禁的独立危险因素(P<0.05)。依此进行因素筛选从而构建预测模型,绘制受试者工作特征(receiver operating characteristic,ROC)曲线,曲线下面积(area under the curve,AUC)为0.940(P<0.001),模型预测质量评分0.87分,有较高的预测效能。结论MRI多模态成像指标结合临床风险因素建立的预测模型准确度良好,可以在治疗前方案的制订提供良好的影像学证据与参考,可以更好对肛门失禁情况进行提前预判。
