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Objective: To evaluate the efficacy of drug-eluting beads transarterial chemoembolization (DEB-TACE) in the treatment of hepatocellular carcinoma (HCC) by propensity score matching (PSM) technique. Methods: The clinical data of HCC patients treated with DEB-TACE in the First Affiliated Hospital of Zhengzhou University from June 2017 to June 2020 as well as their 36-month-follow-up data were retrospectively analyzed. The subjects were matched in pairs based on baseline data and laboratory indicators using the PSM method and divided into a pirarubicin group (n = 34), raltitrexed group (n = 34), and arsenic trioxide group (n = 34). Clinical efficacy was evaluated according to mRECIST criteria. The levels of alpha fetal protein (AFP), carcinoma embryonic antigen (CEA) and carbohydrate antigen-125 (CA125) in serum were detected by enzyme-linked immunosorbent assay (ELISA). The progression-free survival (PFS) and overall survival (OS) were recorded by outpatient, inpatient, and telephone follow-up. Adverse reactions were counted. Results: After PSM, no significant differences were seen in gender, age, tumor burden, Child-Pugh grade, portal vein tumor thrombus or TACE frequency among the three groups (all P>0.05). The ORR rate of the pirarubicin group and arsenic trioxide group at both 3(rd) and 6(th) month post-operation was significantly higher than that of the raltitrexed group (all P0.05). Before treatment, no significant differences were observed in AFP, CEA, or CA125 levels among the three groups (all P>0.05). After treatment, the levels of AFP in the pirarubicin group and arsenic trioxide group were lower than those in the raltitrexed group (both P0.05). There were no significant differences in PFS and OS among the three groups (all P>0.05), and the incidence of fever, abdominal pain, and myelosuppression showed no significant differences among the three groups (all P>0.05). Conclusion: The efficacies of DEB-TACE loaded with pirarubicin, raltitrexed, or arsenic trioxide in treating HCC were generally comparable, and the survival benefit of patients was similar. The short-term efficacy of the pirarubicin group and arsenic trioxide group was slightly better than that of the raltitrexed group.

In the contemporary distribution network, unbalanced and harmonic distortions have been considered some major power quality problems, which have escalated especially due to the high penetration of unbalanced and nonlinear loads. This study first analyzes the dispute around the distortion restraint and grid-connected unbalanced/harmonic current suppression quantitatively and proposes a distributed control strategy that facilitates an effective suppression of output voltage and grid-connected current, with accurate unbalanced/harmonic power sharing. Compared with the majority of existing studies only addressing the voltage-controlled mode (VCM) inverters, our scheme can also be applied to current-controlled mode (CCM) inverters without adding additional current regulation loops. The proposed control strategy is independent of line parameters and robust to load changes. The corresponding small-signal dynamic model is constructed to analyze the system stability and the controller hardware-in-the-loop simulations aid in determining the outcome of the proposed strategy.

The power quality of virtual synchronous generator (VSG) inevitably deteriorates in the presence of local nonlinear loads and distorted grid. In this paper, the conflict involved in the simultaneous elimination of distortion for both the inverter local load voltage and the grid exchanged current is first described. A unified control structure is presented that enables a tunable tradeoff between the two constrained harmonic sources. Then, a hybrid harmonic suppression scheme is proposed to enable the further improvement of the adaptability of VSG, which mainly consists of a local voltage harmonic control loop and an adaptive grid current-controlled loop. The local voltage harmonic control loop aims to scale down the inverter output impedance via a negative feedback loop, while the grid current-controlled compensator is intended to counteract the adverse effects from a weak grid via an additional voltage, which leads to substantially lower total harmonic distortion for both the local load voltage and the grid current at the same time. Small-signal modelling is performed to investigate the system stability and its robustness to parameter perturbations. The effectiveness of the proposed methodology is verified using hardware-in-the-loop simulations.

This paper studies the distributed secondary control of DC microgrids (MGs) in the case of asynchronous sampling, including both the stability condition and accurate consensus algorithm. The asynchrony means that the update actions of each distributed generation (DG) based on the local information and information received from neighbors are independent of the actions of others at sampled discrete times, which would cause deviation from the accurate convergence and even lead to instability in the worst case. First, a small-signal model of MG installed with secondary voltage control is established to include the individual sampling periods. A stability criterion based on the periodic continuity of sampling instant offset is thus formulated to reveal a stability mapping of multiple sampling. By quantifying the accuracy deviations caused by the asynchrony, an improved ratio consensus strategy is proposed that allows the deviation to be estimated accurately via an auxiliary signal and compensated with respect to the eventual equilibrium to produce an exact solution. Our approach customizes the stability and accuracy for distributed secondary control considering asynchronous sampling in MG, which has been ignored in most existing literature. The effectiveness of the proposed methodology is verified by simulations.

ObjectiveTo investigate the clinical effect of laparoscopic versus open hepatectomy in the treatment of patients with regional hepatolithiasis. MethodsA total of 87 patients with regional hepatolithiasis who were admitted to The First People′s Hospital of Xianyang from January 2010 to June 2017 were enrolled. Among these patients, 38 underwent laparoscopic hepatectomy (laparoscopic group) and 49 underwent open hepatectomy (open group). Propensity score matching was conducted to balance confounding factors between the two groups and then the perioperative indices were compared between the two groups. The t-test was used for comparison of continuous data between groups, and the chi-square test or Fisher′s exact test was used for comparison of categorical data between groups. ResultsA total of 27 pairs of patients were matched successfully. There were no significant differences between the two groups in the type of hepatectomy, a combination with common bile duct exploration, rate of intraoperative hepatic portal occlusion, time of operation, rate of intraoperative blood transfusion, intraoperative stone clearance rate, total postoperative complications, and incidence of serious complication (all P＞0.05). Compared with the open group, the laparoscopic group had significantly lower intraoperative blood loss (126.4±18.7 ml vs 143.2±241 ml, t=2.862, P=0.006) and shorter length of hospital stay (11.7±2.3 d vs 13.4±1.9 d, t=2.961, P=0.004). ConclusionLaparoscopic hepatectomy has a comparable clinical effect to open hepatectomy in the treatment of regional hepatolithiasis and has the advantages of low intraoperative blood loss and rapid postoperative recovery.