Postoperative Infectious Complications Worsen Long-Term Survival After Curative-Intent Resection for Hepatocellular Carcinoma

Background: Postoperative infectious complications may be associated with a worse long-term prognosis for patients undergoing surgery for a malignant indication. The current study aimed to characterize the impact of postoperative infectious complications on long-term oncologic outcomes among patients undergoing resection for hepatocellular carcinoma (HCC). Methods: Patients who underwent curative-intent resection for HCC between 2000 and 2017 were identified from an international multi-institutional database. The relationship between postoperative infectious complications, overall survival (OS), and recurrence-free survival (RFS) was analyzed. Results: Among 734 patients who underwent HCC resection, 269 (36.6%) experienced a postoperative complication (Clavien-Dindo grade 1 or 2 [n = 197, 73.2%] vs grade 3 and 4 [n = 69, 25.7%]). An infectious complication was noted in 81 patients (11.0%) and 188 patients (25.6%) had non-infectious complications. The patients with infectious complications had worse OS (median: infectious complications [46.5 months] vs no complications [106.4 months] [p < 0.001] and non-infectious complications [85.7 months] [p < 0.05]) and RFS (median: infectious complications [22.1 months] vs no complications [45.5 months] [p < 0.05] and non-infectious complications [38.3 months] [p = 0.139]) than the patients who had no complication or non-infectious complications. In the multivariable analysis, infectious complications remained an independent risk factor for OS (hazard ratio [HR], 1.7; p = 0.016) and RFS (HR, 1.6; p = 0.013). Among the patients with infectious complications, patients with non-surgical-site infection (SSI) had even worse OS and RFS than patients with SSI (median OS: 19.5 vs 70.9 months [p = 0.010]; median RFS: 12.8 vs 33.9 months [p = 0.033]). Conclusion: Infectious complications were independently associated with an increased long-term risk of tumor recurrence and death. Patients with non-SSI versus SSI had a particularly worse oncologic outcome.info:eu-repo/semantics/publishedVersio

Tumor Necrosis Impacts Prognosis of Patients Undergoing Curative-Intent Hepatocellular Carcinoma

info:eu-repo/semantics/publishedVersio

Multi-Institutional Development and External Validation of a Nomogram for Prediction of Extrahepatic Recurrence After Curative-Intent Resection for Hepatocellular Carcinoma

Backgrounds: Extrahepatic recurrence of hepatocellular carcinoma (HCC) after surgical resection is associated with unfavorable prognosis. The objectives of the current study were to identify the risk factors and develop a nomogram for the prediction of extrahepatic recurrence after initial curative surgery. Methods: A total of 635 patients who underwent curative-intent resection for HCC between 2000 and 2017 were identified from an international multi-institutional database. The clinicopathological characteristics, risk factors, and long-term survival of patients with extrahepatic recurrence were analyzed. A nomogram for the prediction of extrahepatic recurrence was established and validated in 144 patients from an external cohort. Results: Among the 635 patients in the derivative cohort, 283 (44.6%) experienced recurrence. Among patients who recurred, 80 (28.3%) patients had extrahepatic ± intrahepatic recurrence, whereas 203 (71.7%) had intrahepatic recurrence only. Extrahepatic recurrence was associated with more advanced initial tumor characteristics, early recurrence, and worse prognosis versus non-extrahepatic recurrence. A nomogram for the prediction of extrahepatic recurrence was developed using the β-coefficients from the identified risk factors, including neutrophil-to-lymphocyte ratio, multiple lesions, tumor size, and microvascular invasion. The nomogram demonstrated good ability to predict extrahepatic recurrence (c-index: training cohort 0.786; validation cohort: 0.845). The calibration plots demonstrated good agreement between estimated and observed extrahepatic recurrence (p = 0.658). Conclusions: An externally validated nomogram was developed with good accuracy to predict extrahepatic recurrence following curative-intent resection of HCC. This nomogram may help identify patients at high risk of extrahepatic recurrence and guide surveillance protocols as well as adjuvant treatments.info:eu-repo/semantics/publishedVersio

A hybrid fuzzy logic proportional-integral-derivative and conventional on-off controller for morphing wing actuation using shape memory alloy: part 1, morphing system mechanisms and controller architecture design

The present paper describes the design of a hybrid actuation control concept, a fuzzy logic proportional-integral-derivative plus a conventional on-off controller, for a new morphing mechanism using smart materials as actuators, which were made from shape memory alloys (SMA). The research work described here was developed for the open loop phase of a morphing wing system, whose primary goal was to reduce the wing drag by delaying the transition (from laminar to fully turbulent flows) position toward the wing trailing edge. The designed controller drives the actuation system equipped with SMA actuators to modify the flexible upper wing skin surface. The designed controller was also included, as an internal loop, in the closed loop architecture of the morphing wing system, based on the pressure information received from the flexible skin mounted pressure sensors and on the estimation of the transition location. The controller's purposes were established following a comprehensive presentation of the morphing wing system architecture and requirements. The strong nonlinearities of the SMA actuators' characteristics and the system requirements led to the choice of a hybrid controller architecture as a combination of a bi-positional on-off controller and a fuzzy logic controller (FLC). In the chosen architecture, the controller would behave as a switch between the SMA cooling and heating phases, situations where the output current is 0A or is controlled by the FLC. In the design phase, a proportional-integral-derivative scheme was chosen for the FLC. The input-output mapping of the fuzzy model was designed, taking account of the system's error and its change in error, and a final architecture for the hybrid controller was obtained. The shapes chosen for the inputs' membership functions were s-function, \u3c0-function, and z-function, and product fuzzy inference and the center average defuzzifier were applied (Sugeno).Peer reviewed: YesNRC publication: Ye

On-off and proportional-integral controller for a morphing wing. Part 1: actuation mechanism and control design

The main objective of this research work is the development of an actuation control concept for a new morphing actuation mechanism made of smart materials, which is built from a shape memory alloy (SMA). Two lines of smart actuators were incorporated to a rectangular wing to modify the upper wing surface, made of a flexible skin, with the intention to move the laminarto- turbulent transition point closer to the wing trailing edge. After a brief introduction of the morphing wing system architecture and requirements, the actuation lines' design and instrumentation are presented. The integrated controller controls the SMA actuators via an electrical current supply, so that the transducer position can be used to eliminate the deviation between the required values for vertical displacements (corresponding to the optimized airfoils) and their physical values. The final configuration of the integrated controller is a combination of a bi-positional (on-off) controller and a PI (proportional-integral) controller, due to the two heating and cooling phases of the SMA wires' interconnection. This controller must behave like a switch between the cooling and the heating phases, situations where the output current is 0 A, or is controlled by a PI type law. The PI controller for the heating phase is optimally tuned using integral and surface minimum error criteria (Ziegler-Nichols). The controller is numerically tested on the linear identified system in terms of time response, Bode diagram, amplitude and phase stability margins, and root-locus.Peer reviewed: YesNRC publication: Ye

On-off and proportional-integral controller for a morphing wing. Part 2: control validation - numerical simulations and experimental tests

The second part of this article describes the numerical simulation and experimental validations of actuators control system for a morphing wing application, which was developed and designed in the first part of this article. After the description of the finally adopted control architecture, the validation for the non-linear system model is presented. First, the integrated controller is validated numerically with MATLAB/Simulink software, followed by a physical implementation of the control and experimental validation in the wind tunnel. To implement the controller on the physical model, two programmable switching power supplies, AMREL SPS100-33, and Quanser Q8 data acquisition card were used. The inputs of the data acquisition card were the two signals issued by the linear variable differential transformer potentiometers, indicating the positions of the actuators, and the six signals recorded by thermocouples installed on the SMA wires. The acquisition board output channels were used to control the required power supply to obtain the desired skin deflections. The control experimental validation was performed first on a bench test and then in the wind tunnel test. A number of optimized airfoil shapes, used in the design phase, were translated into actuators vertical displacements which were used as input signals for the controller. In the wind tunnel tests, a comparative study was realized around the transition point position for the reference airfoil and for each optimized airfoil.Peer reviewed: YesNRC publication: Ye

A genetic algorithm optimization method for a morphing wing tip demonstrator validated using infra red experimental data

In the present paper an \u2018in-house\u2019 genetic algorithm is described and applied to an optimization problem of improving the aerodynamic performances of an airfoil through upper surface morphing. The results of the optimization of the flow behavior for the airfoil morphing upper-surface problem are validated with experimental transition results obtained with Infra-red Thermography for the CRIAQ MDO 505 wing tip demonstrator, proving that the 2D numerical optimization using the \u2018in-house\u2019 genetic algorithm is an important tool in improving various aspects of a wing\u2019s performancesPeer reviewed: YesNRC publication: Ye