29 research outputs found
Using the new INTRABEAM mobile intraoperative radiotherapy system during surgery for pancreatic cancer: a case report
Abstract Background Pancreatic cancer is one of the most common fatal malignancies and has a poor prognosis. Surgical treatment is the most important treatment method, but there is a low rate of radical excision; moreover, the postoperative recurrence rate is high, with a local recurrence rate greater than 50%. The usefulness of intraoperative radiotherapy for pancreatic cancer has previously been examined. However, prior research was based on the traditional high-energy electron beam, which causes serious radiation toxicity. Therefore, the tumor radiation dose was limited, subsequently limiting the effect. In contrast, there is also a low-energy X-ray radiation system called INTRABEAM®. Use of INTRABEAM has been applied clinically, but the treatment effect of INTRABEAM in pancreatic cancer has not been reported. Case presentation We present a case of a 56-year-old Chinese man with local advanced pancreatic cancer with invasion of the coeliac trunk artery and origin of the portal vein. He underwent distal pancreatectomy and splenectomy along with intraoperative radiotherapy using a portable INTRABEAM radiation system. The radiotherapy dose was 10 Gy and irradiation time was 27.4 minutes. There were no obvious postoperative complications. His abdominal pain was alleviated after surgery, and no obvious tumor recurrence has been observed in short-term follow-up. Conclusions We believe that it is safe to apply intraoperative radiotherapy using the INTRABEAM radiation system in pancreatic cancer. This approach appears promising for further future development
Second-Order EKF White Noise Estimator Design for Hybrid Systems
The extended Kalman filter (EKF) has a wide range of applications (especially in power battery management systems) with a rapidly increasing market share. It aims to minimize the symmetric loss function (mean square error) and it has high accuracy and efficiency in battery state estimation. This study deals with the second-order extended Kalman filter-based process and the measurement white noise estimation problem for nonlinear continuous-discrete systems. The design of the white noise filter and smoother were, firstly, converted into a linear estimation problem by the second-order Taylor series expansion approximation and the function that makes the second-order term approximately equivalent to the estimation error variance. Secondly, based on the projection formula of the Kalman filtering (KF) theory and the Lemma of expectation for quadratic and quartic product traces of random vectors, the second-order EKF was derived. Then, to generate white noise estimators in the forms of filtering and smoothing, we derived a recursive solution, using an innovation method. Finally, a numerical example is given to show the effectiveness of the proposed method
Second-Order EKF White Noise Estimator Design for Hybrid Systems
The extended Kalman filter (EKF) has a wide range of applications (especially in power battery management systems) with a rapidly increasing market share. It aims to minimize the symmetric loss function (mean square error) and it has high accuracy and efficiency in battery state estimation. This study deals with the second-order extended Kalman filter-based process and the measurement white noise estimation problem for nonlinear continuous-discrete systems. The design of the white noise filter and smoother were, firstly, converted into a linear estimation problem by the second-order Taylor series expansion approximation and the function that makes the second-order term approximately equivalent to the estimation error variance. Secondly, based on the projection formula of the Kalman filtering (KF) theory and the Lemma of expectation for quadratic and quartic product traces of random vectors, the second-order EKF was derived. Then, to generate white noise estimators in the forms of filtering and smoothing, we derived a recursive solution, using an innovation method. Finally, a numerical example is given to show the effectiveness of the proposed method
Percutaneous Microwave Coagula-tion for the Treatment of Small Solitary Focal Nodular Hyperplasia of Liver
Abstract Background: Whether percutaneous microwave coagulation (PMC) is safe and effective for the treatment of symptomatic focal nodular hyperplasia (FNH) of the liver remains unknown. Methods: Between January 2006 and September 2015, sixteen patients with solitary symptomatic FNHs in the liver (the largest diameter less than 5 cm) were treated by PMC. The safty and effectiveness were analyzed. Results: There were 4 males and 12 females. All these patients suffered from upper abdominal pain. The FNHs ranged in size from 3.2 cm to 5.0 cm (3.9 cm ± 0.12 cm). All the PMC procedures were performed successfully. All 16 patients had symptomatic improvement after the treatment with no procedure-related morbidity or mortality. Among 16 patients, 15 (93.8%) patients with FNHs were assessed to be ablated completely by CT examination performed within four weeks after PMC treatment. One patient failed to follow up regularly, but showed up 2 years and 7 months later for suffering upper abdominal pain again with original FNH enlargement, and the patient received surgical resection of the FNH and achieved asymptomatic aftermath. Conclusion: PMC is safe and effectiveness for symptomatic liver FNHs. PMC should be considered to be an alternative modality for those solitary FNHs with less than 5 cm in diameter
Flexibility Demand Analysis and Regulation Capacity Sharing Decisions Between Interconnected Power Systems Considering Differences in Regulation Performance
To cope with the demand for large amount of flexibility regulation caused by high penetration of intermittent renewable energy, it is necessary to classify and measure the demand capacity for different regulation performance, and to reasonably allocate flexibility resources for different regions and different regulation capacities. This study proposes a flexibility demand analysis and regulation capacity sharing decisions between interconnected power systems considering differences in regulation performance. Firstly, the empirical mode decomposition (EMD) method is used to decompose the historical operating load curves of each sub-region, and the demand capacities of different regulation performances are calculated based on the obtained decomposition results of trend components and fluctuation components. Then, the probability density and the regulation demand capacity interval at different confidence levels are calculated based on the regulation capacity statistics of the sample of historical operation days. Finally, the regulation capacity sharing decisions between the interconnected regions are made based on the cost of various regulation resources in different sub-regions and the confidence level requirements of internal resources in sub-regions to meet regulation demand. A scenario based on the interconnection operation of two regional grids and the self-sufficiency rate of regulation capacity in each sub-region is no less than 0.95 confidence level is used to verify the effectiveness and feasibility of the proposed method. The simulation results demonstrate that the regulation capacity demand considering the difference in regulation quality can provide a detailed basis for the cross-region deployment of different quality flexibility resources, and the total cost of regulation capacity of the regional grid after adopting the cross-region sharing decision model is reduced by about 4.51% compared with the system independent optimization model
MiR-324-5p Suppresses Hepatocellular Carcinoma Cell Invasion by Counteracting ECM Degradation through Post-Transcriptionally Downregulating ETS1 and SP1.
Hepatocellular carcinoma (HCC) is one of the common malignancies, which is highly metastatic and the third common cause of cancer deaths in the world. The invasion and metastasis of cancer cells is a multistep and complex process which is mainly initiated by extracellular matrix (ECM) degradation. Aberrant expression of microRNA has been investigated in HCC and shown to play essential roles during HCC progression. In the present study, we found that microRNA-324-5p (miR-324-5p) was downregulated in both HCC cell lines and tissues. Ectopic miR-324-5p led to the reduction of HCC cells invasive and metastatic capacity, whereas inhibition of miR-324-5p promoted the invasion of HCC cells. Matrix metalloproteinase 2 (MMP2) and MMP9, the major regulators of ECM degradation, were found to be downregulated by ectopic miR-324-5p, while upregulated by miR-324-5p inhibitor. E26 transformation-specific 1 (ETS1) and Specificity protein 1 (SP1), both of which could modulate MMP2 and MMP9 expression and activity, were presented as the direct targets of and downregulated by miR-324-5p. Downregulation of ETS1 and SP1 mediated the inhibitory function of miR-324-5p on HCC migration and invasion. Our study demonstrates that miR-324-5p suppresses hepatocellular carcinoma cell invasion and might provide new clues to invasive HCC therapy