BACKGROUND Venous thromboembolism(VTE)is a potentially fatal complication of hepatectomy.The use of postoperative prophylactic anticoagulation in patients who have undergone hepatectomy is controversial because of the...BACKGROUND Venous thromboembolism(VTE)is a potentially fatal complication of hepatectomy.The use of postoperative prophylactic anticoagulation in patients who have undergone hepatectomy is controversial because of the risk of postoperative bleeding.Therefore,we hypothesized that monitoring plasma D-dimer could be useful in the early diagnosis of VTE after hepatectomy.AIM To evaluate the utility of monitoring plasma D-dimer levels in the early diagnosis of VTE after hepatectomy.METHODS The medical records of patients who underwent hepatectomy at our institution between January 2017 and December 2020 were retrospectively analyzed.Patients were divided into two groups according to whether or not they developed VTE after hepatectomy,as diagnosed by contrast-enhanced computed tomography and/or ultrasonography of the lower extremities.Clinicopathological factors,including demographic data and perioperative D-dimer values,were compared between the two groups.Receiver operating characteristic curve analysis was performed to determine the D-dimer cutoff value.Univariate and multivariate analyses were performed using logistic regression analysis to identify significant predictors.RESULTS In total,234 patients who underwent hepatectomy were,of whom(5.6%)were diagnosed with VTE following hepatectomy.A comparison between the two groups showed significant differences in operative time(529 vs 403 min,P=0.0274)and blood loss(530 vs 138 mL,P=0.0067).The D-dimer levels on postoperative days(POD)1,3,5,7 were significantly higher in the VTE group than in the non-VTE group.In the multivariate analysis,intraoperative blood loss of>275 mL[odds ratio(OR)=5.32,95%confidence interval(CI):1.05-27.0,P=0.044]and plasma D-dimer levels on POD 5≥21μg/mL(OR=10.1,95%CI:2.04-50.1,P=0.0046)were independent risk factors for VTE after hepatectomy.CONCLUSION Monitoring of plasma D-dimer levels after hepatectomy is useful for early diagnosis of VTE and may avoid routine prophylactic anticoagulation in the postoperative period.展开更多
In this paper, a wireless power transmission system using magnetic resonance coupling was proposed and demonstrated for supplying power at high efficiency to electrical devices in a space enclosed by metal walls. This...In this paper, a wireless power transmission system using magnetic resonance coupling was proposed and demonstrated for supplying power at high efficiency to electrical devices in a space enclosed by metal walls. This is applicable to power supply to electrical sensors or devices working in the area surrounded by metal walls. Proposed magnetic resonance coupling system is driven at a resonance frequency of 50 Hz, which is selected to avoid eddy current loss on the surrounding metals. Firstly, resonator designs and its performance limitation were described. Secondly, the equivalent circuits and theoretical transmission efficiency were presented. Finally, power transmission was experimentally demonstrated and transmission efficiency was measured in some conceivable situations. As a result, electric power of 3 W was supplied to LEDs over a stainless steel wall. When the stainless steel wall thickness was 10 mm, transmission efficiency of approximately 40% was achieved over the transmission distance of 12 cm. Moreover, in the demonstration of transmission through a metal pipe, 1.2 W of power was transmitted to LEDs in a 10 mm thick metal pipe.展开更多
基金This study was reviewed and approved by the Ethics Committee of the Kobe University Graduate School of Medicine(Provided ID Number:B210306).
文摘BACKGROUND Venous thromboembolism(VTE)is a potentially fatal complication of hepatectomy.The use of postoperative prophylactic anticoagulation in patients who have undergone hepatectomy is controversial because of the risk of postoperative bleeding.Therefore,we hypothesized that monitoring plasma D-dimer could be useful in the early diagnosis of VTE after hepatectomy.AIM To evaluate the utility of monitoring plasma D-dimer levels in the early diagnosis of VTE after hepatectomy.METHODS The medical records of patients who underwent hepatectomy at our institution between January 2017 and December 2020 were retrospectively analyzed.Patients were divided into two groups according to whether or not they developed VTE after hepatectomy,as diagnosed by contrast-enhanced computed tomography and/or ultrasonography of the lower extremities.Clinicopathological factors,including demographic data and perioperative D-dimer values,were compared between the two groups.Receiver operating characteristic curve analysis was performed to determine the D-dimer cutoff value.Univariate and multivariate analyses were performed using logistic regression analysis to identify significant predictors.RESULTS In total,234 patients who underwent hepatectomy were,of whom(5.6%)were diagnosed with VTE following hepatectomy.A comparison between the two groups showed significant differences in operative time(529 vs 403 min,P=0.0274)and blood loss(530 vs 138 mL,P=0.0067).The D-dimer levels on postoperative days(POD)1,3,5,7 were significantly higher in the VTE group than in the non-VTE group.In the multivariate analysis,intraoperative blood loss of>275 mL[odds ratio(OR)=5.32,95%confidence interval(CI):1.05-27.0,P=0.044]and plasma D-dimer levels on POD 5≥21μg/mL(OR=10.1,95%CI:2.04-50.1,P=0.0046)were independent risk factors for VTE after hepatectomy.CONCLUSION Monitoring of plasma D-dimer levels after hepatectomy is useful for early diagnosis of VTE and may avoid routine prophylactic anticoagulation in the postoperative period.
文摘In this paper, a wireless power transmission system using magnetic resonance coupling was proposed and demonstrated for supplying power at high efficiency to electrical devices in a space enclosed by metal walls. This is applicable to power supply to electrical sensors or devices working in the area surrounded by metal walls. Proposed magnetic resonance coupling system is driven at a resonance frequency of 50 Hz, which is selected to avoid eddy current loss on the surrounding metals. Firstly, resonator designs and its performance limitation were described. Secondly, the equivalent circuits and theoretical transmission efficiency were presented. Finally, power transmission was experimentally demonstrated and transmission efficiency was measured in some conceivable situations. As a result, electric power of 3 W was supplied to LEDs over a stainless steel wall. When the stainless steel wall thickness was 10 mm, transmission efficiency of approximately 40% was achieved over the transmission distance of 12 cm. Moreover, in the demonstration of transmission through a metal pipe, 1.2 W of power was transmitted to LEDs in a 10 mm thick metal pipe.
