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Wind turbines support grid frequency by rotor decelerating and then accelerating, but the instant power imbalance caused by rotor speed recovery may lead to a secondary frequency drop. Existing frequency regulation strategies find it challenging to balance secondary frequency drop depth with rotor speed recovery time. To address this issue, a frequency regulation scheme for wind turbines with adaptive coefficients and optimized power trajectory is proposed, considering both the kinetic energy release stage and rotor speed recovery stage. This scheme aims to minimize power imbalance and rotor speed deviation without compromising primary frequency regulation performance. Initially, a two-stage system frequency response model is established to analyze factors affecting secondary frequency drop and rotor speed recovery time. Then, the fuzzy logic-based droop gain and segmented inertia gain are introduced as control strategies for the first stage. Additionally, the criterion for exiting frequency regulation and optimized power trajectory with smooth time-varying changes are implemented as control strategies for the second stage. Simulation results show that the proposed scheme adaptively improves the frequency nadir and effectively balances secondary frequency drop with rotor speed recovery time under various scenarios.

Corrosion poses a significant threat to the structural integrity of steel rails, especially in an acidic environment. In this study, we evaluate the corrosion properties of U75V-welded joints using potentiodynamic polarization curves, electrochemical impedance measurements, and corrosion morphology studies under simulated acidic conditions. Compared to non-normalized joints, the normalized joints exhibit a higher self-corrosion current (4.65 × 10−5 A/cm2) and a more negative self-corrosion potential (−0.56919 mV). The smaller and more uniform grain size obtained after normalizing provides multiple active sites on the surface for polarization reactions. Furthermore, owing to significant erosion caused on the rail surface by the acidic solutions, normalizing treatment enhances the passivation effects on the surface, resulting in increased corrosion resistance (221.96 Ω cm2). Our findings provide insights into the impact of normalizing treatments on the corrosion mechanism of U75V rail joints under acidic conditions.

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is characterized by rapid progression and poor prognosis. Understanding the genetic mechanisms that affect cancer properties and reprogram tumor immune microenvironment will develop new strategies to maximize the benefits for cancer therapies. Methods Gene signatures and biological processes associated with advanced cancer and unfavorable outcome were profiled using bulk RNA sequencing and spatial transcriptome sequencing, Caprin-1 was identified as an oncogenesis to expedite pancreatic cancer growth by activating autophagy. The mechanism of Caprin-1 inducing autophagy activation was further explored in vitro and in vivo. In addition, higher level of Caprin-1 was found to manipulate immune responses and inflammatory-related pathways. The immune profiles associated with increased levels of Caprin-1 were identified in human PDAC samples. The roles of CD4+T cells, CD8+T cells and tumor associated macrophages (TAMs) on clinical outcomes prediction were investigated. Results Caprin-1 was significantly upregulated in advanced PDAC and correlated with poor prognosis. Caprin-1 interacted with both ULK1 and STK38, and manipulated ULK1 phosphorylation which activated autophagy and exerted pro-tumorigenic phenotypes. Additionally, the infiltrated CD4+T cells and tumor associated macrophages (TAMs) were increased in Caprin-1High tissues. The extensive CD4+T cells determined poor clinical outcome in Caprin-1high patients, arguing that highly expressed Caprin-1 may assist cancer cells to escape from immune surveillance. Conclusions Our findings establish causal links between the upregulated expression of Caprin-1 and autophagy activation, which may manipulate immune responses in PDAC development. Our study provides insights into considering Caprin-1 as potential therapeutic target for PDAC treatment.

Abstract Hypertriglyceridemic pancreatitis (HTGP) is featured by higher incidence of complications and poor clinical outcomes. Gut microbiota dysbiosis is associated with pancreatic injury in HTGP and the mechanism remains unclear. Here, we observe lower diversity of gut microbiota and absence of beneficial bacteria in HTGP patients. In a fecal microbiota transplantation mouse model, the colonization of gut microbiota from HTGP patients recruits neutrophils and increases neutrophil extracellular traps (NETs) formation that exacerbates pancreatic injury and systemic inflammation. We find that decreased abundance of Bacteroides uniformis in gut microbiota impairs taurine production and increases IL-17 release in colon that triggers NETs formation. Moreover, Bacteroides uniformis or taurine inhibits the activation of NF-κB and IL-17 signaling pathways in neutrophils which harness NETs and alleviate pancreatic injury. Our findings establish roles of endogenous Bacteroides uniformis-derived metabolic and inflammatory products on suppressing NETs release, which provides potential insights of ameliorating HTGP through gut microbiota modulation.

Abstract Press‐pack insulated gate bipolar transistor modules (PP‐IGBTs) have been widely used in high‐voltage and high‐power‐density applications, such as high‐voltage direct‐current (HVDC) converters, because of their advantages of low thermal resistance, double side cooling, and short‐circuit failure mode. Package failure is one of the main reasons for IGBT module failure. Package condition monitoring is the key to realizing modules fault diagnosis, condition prediction, and intelligent operation and maintenance. At present, a variety of characteristic parameters, such as on voltage and junction temperature, are used in package condition monitoring. However, the characteristic parameters show different variation laws under different package degradation modes. Therefore, the relationship between package degradation modes and characteristic parameters is the key to realizing the condition monitoring, so as to improve the reliability of the power electronic system. In this paper, first, the package structure of a PP‐IGBT is analyzed. Second, the mechanisms of fretting wear degradation, gate‐oxide degradation, spring degradation, lid warping degradation, micro arcing degradation, short‐circuit failure, and open‐circuit failure are reviewed. The variation laws of characteristic parameters under each degradation and failure mode are then investigated. Finally, three difficult problems including characteristic parameter measurement, especially pressure monitoring, high‐sensitivity detection, and characterization and evaluation, are discussed and analyzed.

Abstract Background Glabridin (Glab) is a bioactive component of licorice that can ameliorate diabetes, but its role in diabetic nephropathy (DN) has seldom been reported. Herein, we explored the effect and underlying mechanism of Glab on DN. Methods The bioactive component-target network of licorice against DN was by a network pharmacology approach. The protective effect of Glab on the kidney was investigated by a high-fat diet with streptozotocin induced-diabetic rat model. High glucose-induced NRK-52E cells were used for in vitro studies. The effects of Glab on ferroptosis and VEGF/Akt/ERK pathways in DN were investigated in vivo and in vitro using qRT-PCR, WB, and IHC experiments. Results Bioinformatics analysis constructed a network comprising of 10 bioactive components of licorice and 40 targets for DN. 13 matching targets of Glab were mainly involved in the VEGF signaling pathway. Glab treatment ameliorated general states and reduced FBG, HOMA-β, and HOMA-insulin index of diabetic rats. The renal pathological changes and the impaired renal function (the increased levels of Scr, BUN, UREA, KIM-1, NGAL, and TIMP-1) were also improved by Glab. Moreover, Glab repressed ferroptosis by increasing SOD and GSH activity, and GPX4, SLC7A11, and SLC3A2 expression, and decreasing MDA and iron concentrations, and TFR1 expression, in vivo and in vitro. Mechanically, Glab significantly suppressed VEGF, p-AKT, p-ERK1/2 expression in both diabetic rats and HG-induced NRK-52E cells. Conclusions This study revealed protective effects of Glab on the kidney of diabetic rats, which might exert by suppressing ferroptosis and the VEGF/Akt/ERK pathway.

Voltage stability region assessment is the key to ensuring the reliable operation of offshore wind farms However, the traditional analysis method, which treats the WFs as a PQ node and directly connected to the infinite power grid, fails to take the cable capacitance and the dynamics of the converter into account, resulting an inaccurate evaluation of voltage stability. The contribution of this paper is to propose a more accurate method for assessing the voltage stability of OWFs. Firstly, based on the equivalent circuit method, the point of common coupling (PCC) and internal voltage characterization models of OWF considering the cable capacitance parameters are derived. Then, the coupling interface between the dynamic of the converter and the voltage characteristics of the system is designed, and the transfer function of the power injection from the DC side of the converter to the voltage of the collector system is established, which fully reflects the OWF Pin→Udc→Id→Upcc→Pout transitive relationship. Finally, a voltage stability criterion based on dPw, out/dId&dUdc/dt direction discrimination is proposed, and the influence of cable parameters, output power, and grid impedance on the voltage stability margin is analyzed. The accuracy of the proposed method is verified based on the RT-LAB platform.

Owing to the advantages of short-circuit failure mode, double-sided heat dissipation, and low thermal resistance, press-pack insulated gate bipolar transistors (PP-IGBTs) are widely used in high-power-density applications, such as high-voltage direct-current converters. As the core device of large-capacity power equipment, the reliability of a PP-IGBT is directly related to the security of the power system. In recent years, a silver-sintered package has been proposed to improve the electro-thermal performance of PP-IGBTs. However, the long-term reliability of this package has not been proven. In response to this problem, 3300-V/50-A silver-sintered PP-IGBT (SPP-IGBT) modules are used in long-reliability research. First, electro-thermal-stress finite-element models of PP-IGBTs and SPP-IGBTs were proposed and the accuracy of models verified by experiments. Through a simulation comparison, the results show that under the rated operating conditions, the on-voltage and maximum temperature of SPP-IGBTs dropped by 9.3% and 3.7%, respectively. In addition, the temperature and stress of each component were reduced, among which the surface stress of the IGBT chip emitter dropped by as much as 24.7%. Subsequently, a power-cycle test platform was established, and three PP-IGBTs and three SPP-IGBTs were tested. Finally, the experimental results were compared and analyzed, and the reasons for the sharp increase of on-voltage and metal melt were explored. The results show that the silver-sintered package improves the electrical-thermal performance and long-term reliability of the module.

Abstract Given the urgent need for photovoltaic (PV) energy to participate in grid frequency regulation, a control strategy of the DC/DC converter of a two‐stage PV system based on the virtual governor (PV‐VG) is proposed in this paper. First, a one‐step PV maximum power point estimation (MPPE) method is proposed, which can obtain the reference voltage corresponding to the maximum power point and the power deload point, and some complex iterative calculations and sampling processes are circumvented. Then, based on the constant DC bus voltage of the two‐stage PV system, the coupling mathematical model of boost circuit duty cycle (D) and PV output power is established. According to the power setting and frequency deviation, the D is taken as the direct control target to reflect the direct coupling characteristics of D and grid frequency (f‐D) so that the PV system can adjust the output power reference independently according to the grid frequency deviation. Finally, a simulation model is built in Matlab/Simulink and RT‐LAB, and the results show that the accuracy of the proposed one‐step MPPE method is over 99.8%, and the correctness and efficiency of the PV‐VG control strategy are verified in some case study.

Abstract To achieve better antitumour efficacy, it is urgent to improve anticancer drug delivery efficiency in targeting cancer cells. In this work, chitosan-functionalized graphene oxide (ChrGO) nanosheets were fabricated via microwave-assisted reduction, which were employed to the intracellular delivery nanosystem for anticancer drug agent in breast cancer cells. Drug loading and release research indicated that adriamycin can be efficiently loaded on and released from the ChrGO nanosheets. Less drug release during delivery and better biocompatibility of ChrGO/adriamycin significantly improve its safety and therapeutic efficacy in HER2-overexpressing BT-474 cells. Furthermore, ChrGO/adriamycin in combination with trastuzumab exhibited synergistic antitumour activity in BT-474 cells, which demonstrated superior therapeutic efficacy compared with each drug alone. Cells treated with trastuzumab (5 μg/mL) or equivalent ChrGO/adriamycin (5 μg/mL) each elicited 54.5% and 59.5% cell death, respectively, while the combination treatment with trastuzumab and ChrGO/adriamycin resulted in a dramatic 88.5% cell death. The dual-targeted therapy displayed higher apoptosis, indicating superior therapeutic efficacy due to the presence of different mechanisms of action. The combined treatment of ChrGO/adriamycin and trastuzumab in BT-474 cells induced cell cycle arrest and apoptosis, which ultimately led to the death of augmented cancer cells. This work has provided a facile microwave-assisted fabrication of ChrGO as a controlled and targeted intracellular drug delivery nanosystem, which is expected to be a novel promising therapy for treating HER2-overexpressing breast cancer cells.

Acute pancreatitis (AP) is a leading cause of death and is commonly accompanied by systemic manifestations that are generally associated with a poor prognosis. Many cytokines contribute to pancreatic tissue damage and cause systemic injury. Interleukin-17 (IL-17) is a cytokine that may play a vital role in AP. Specifically, IL-17 has important effects on the immune response and causes interactions between different inflammatory mediators in the AP-related microenvironment. In this literature review, we will discuss the existing academic understanding of IL-17 and the impacts of IL-17 in different cells (especially in acinar cells and immune system cells) in AP pathogenesis. The clinical significance and potential mechanisms of IL-17 on AP deterioration are emphasized. The evidence suggests that inhibiting the IL-17 cytokine family could alleviate the pathogenic process of AP, and we highlight therapeutic strategies that directly or indirectly target IL-17 cytokines in acute pancreatitis.

Background and Objectives: Acute pancreatitis (AP) is defined as an acute inflammatory disorder of the pancreas and is a common gastrointestinal disease. Since currently used indicators lack specifics and cannot accurately reflect the phase of disease, better diagnostic approaches need to be explored. Fibrinogen-like protein 1 (FGL-1) is a reactant in acute inflammatory diseases and is increased in the plasma of AP patients. In the current study, we aim to investigate the clinical benefits of FGL-1 in predicting the severity of AP and infected pancreatic necrosis (IPN), which can improve the diagnostic efficiency of AP. Materials and Methods: In this study, 63 patients diagnosed with AP from December 2018 to September 2019 were enrolled. Regarding the severity of AP, patients were separated into severe acute pancreatitis (SAP, n = 12) and No-SAP groups (n = 51). On the basis of infective conditions, patients were divided into IPN (n = 9) and No-IPN (n = 54) groups. The demographic data (sex and age) and blood parameters (WBC, HCT, glucose, calcium, FIB, APTT, PCT, CRP, and FGL-1) were retrospectively analyzed. Results: The plasma FGL-1 levels were increased in both SAP (p < 0.01) and IPN (p < 0.05) subgroups compared to the healthy control group. Multivariate analysis showed that elevated plasma FGL-1 (p < 0.01) and PCT levels (p < 0.05) within 72 h after the onset of AP were positively correlated with the severity of AP, while increased plasma FGL-1 (p < 0.01) and CRP (p < 0.05) levels were positively correlated with the occurrence of IPN. The combination of FGL-1 and PCT showed superiority to both individual markers in SAP prediction. However, the combination of FGL-1 and CRP showed no diagnostic advantage over CRP in IPN prediction. Conclusions: Plasma FGL-1 within 72 h after the onset could be used for the stratification of AP and its infectious complications. The combination of PCT and FGL-1 presents an enormous advantage for the early identification of SAP.

Photovoltaic virtual synchronous generator (PV-VSG) technology, by way of simulating the external characteristics of a synchronous generator (SG), gives the PV energy integrated into the power grid through the power electronic equipment the characteristics of inertial response and active frequency response (FR)—this attracts much attention. Due to the high volatility and low adjustability of PV energy output, it does not have the characteristics of a prime mover (PM), so it must be equipped with energy storage systems (ESSs) in the DC or AC side to realize the PV-VSG technology. However, excessive reliance on ESSs will inevitably affect the application of VSG technology in practical PV power plants (PV-PPs). In view of this, this paper proposes the PV power reserve control type VSG (PV-PRC-VSG) control strategy. By reducing the active power output of part of the PV-PPs, the internal PV-PPs can maintain a part of the active power up/down-regulation ability in real time, instead of relying on external ESSs. By adjusting the active reserve power of this part, the output of the PV-PPs can be controlled within a certain range, and the PV-PPs can better simulate the PM characteristics and realize the FR of the grid by combining the VSG technology. At the same time, the factors affecting the reserve ratio are analyzed, and the position of the voltage operating point in PRC mode is deduced. Finally, the simulation results show that the proposed control strategy is effective and correct.

The casting production process typically involves single jobs and small batches, with multiple constraints in the molding and smelting operations. To address the discrete optimization challenge of casting production scheduling, this paper presents a multi-objective batch scheduling model for molding and smelting operations on unrelated batch processing machines with incompatible job families and non-identical job sizes. The model aims to minimise the makespan, number of batches, and average vacancy rate of sandboxes. Based on the genetic algorithm, virus optimization algorithm, and two local search strategies, a hybrid algorithm (GA-VOA-BMS) has been designed to solve the model. The GA-VOA-BMS applies a novel Batch First Fit (BFF) heuristic for incompatible job families to improve the quality of the initial population, adopting the batch moving strategy and batch merging strategy to further enhance the quality of the solution and accelerate the convergence of the algorithm. The proposed algorithm was then compared with multi-objective swarm optimization algorithms, namely NSGA-II, SPEA-II, and PESA-II, to evaluate its effectiveness. The results of the performance comparison indicate that the proposed algorithm outperforms the others in terms of both quality and stability.

Abstract A flexible casting job shop scheduling problem (FCJSP) with batch processing machines is proposed based on the analysis of the flexible job shop scheduling problem (FJSP) and the study of the expendable casting process. Considering the makespan under the influence of the energy consumption, the authors apply the time execution window to the FCJSP model in conjunction with the characteristics of casting production. A hybrid particle swarm optimisation algorithm (HPSO) is developed to solve the FCJSP. The HPSO employs a block integration decoding rule to address scheduling integration. Particle swarm optimisation is used for global search, employing both discrete and continuous search strategies. Furthermore, the local search employs tabu search with neighbourhood operations based on knowledge‐driven techniques. Simulation experiments demonstrate the feasibility of the proposed optimisation model. In the end, the HPSO algorithm has been successfully applied to the real expendable casting scheduling. The results demonstrate that it is more efficient and robust than previously reported algorithms.

Purpose: To explore the mechanism with which Yiqi Huoxue Huatan formula regulates inflammation in chronic obstructive pulmonary disease (COPD). Methods: COPD rat models (n=60) were procured and administered with prednisone and Yiqi Huoxue Huatan formula. Histological examination of lung tissues was carried out and bronchoalveolar fluid was collected for further analysis. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to evaluate the expression of different genes and proteins. The study also assessed pulmonary functions in each rat. Results: The results showed that Yiqi Huoxue Huatan formula relieved the lung inflammation and helped to preserve alveolar structure, and its anti-inflammatory efficacy was superior to prednisone. Moreover, it significantly improved pulmonary function in COPD rats. This formula was shown to repress the activity of both PI3K/AKT and NF-κB signaling pathways. Conclusion: Yiqi Huoxue Huatan formula may be effective in treating COPD by attenuating local inflammation and improving pulmonary function. [ABSTRACT FROM AUTHOR]

Abstract Background Chronic lung allograft dysfunction (CLAD) directly causes an abysmal long-term prognosis after lung transplantation (LTx), but effective and safe drugs are not available. Metformin exhibits high therapeutic potential due to its antifibrotic and immunomodulatory effects; however, it is unclear whether metformin exerts a therapeutic effect in CLAD. We sought to investigate the effect of metformin on CLAD based on rat models. Methods Allogeneic LTx rats were treated with Cyclosporin A (CsA) in the first week, followed by metformin, CsA, or vehicle treatment. Syngeneic LTx rats received only vehicles. All rats were sacrificed on post-transplant week 4. Pathology of lung graft, spleen, and thymus, extent of lung fibrosis, activity of profibrotic cytokines and signaling pathway, adaptive immunity, and AMPK activity were then studied. Results Allogeneic recipients without maintenance CsA treatment manifested CLAD pathological characteristics, but these changes were not observed in rats treated with metformin. For the antifibrotic effect, metformin suppressed the fibrosis extent and profibrotic cytokine expression in lung grafts. Regarding immunomodulatory effect, metformin reduced T- and B-cell infiltration in lung grafts, spleen and thymus weights, the T- and B-cell zone areas in the spleen, and the thymic medullary area. In addition, metformin activated AMPK in lung allografts and in α-SMA+ cells and T cells in the lung grafts. Conclusions Metformin attenuates CLAD in rat models, which could be attributed to the antifibrotic and immunomodulatory effects. AMPK activation suggests the potential molecular mechanism. Our study provides an experimental rationale for further clinical trials.

Abstract Background The survival benefit of adjuvant transarterial chemoembolization (TACE) in patients with hepatectomy for hepatocellular carcinoma (HCC) after hepatectomy remains controversial. We aimed to investigate the survival efficacy of adjuvant TACE after hepatectomy for HCC. Methods 1491 patients with HCC who underwent hepatectomy between January 2018 and September 2021 at four medical centers in China were retrospectively analyzed, including 782 patients who received adjuvant TACE and 709 patients who did not receive adjuvant TACE. Propensity score matching (PSM) (1:1) was performed to minimize selection bias, which balanced the clinical characteristics of the two groups. Results A total of 1254 patients were enrolled after PSM, including 627 patients who received adjuvant TACE and 627 patients who did not receive adjuvant TACE. Patients who received adjuvant TACE had higher disease-free survival (DFS, 1- ,2-, and 3-year: 78%-68%-62% vs. 69%-57%-50%, p

In this paper, the problem of integration and scheduling of automated guided vehicles (AGVs) and inspection machines in medical sample-testing laboratories is addressed with the objective of minimizing the maximum turnaround time (TAT). A genetic algorithm (GA) with a sliding time window (STW) heuristic algorithm (GA-STW) is proposed for the studied problem while incorporating the vehicle assignment algorithm (VAA) for decoding operations. A mathematical model for AGV and inspection machine integration scheduling is established, and a dual-coding method for the inspection process and machine is used to solve the model. VAA was used to assign suitable AGVs to each transportation task during the decoding stage. The STW heuristic algorithm was used to further optimize the initial solution and allocate samples to appropriate inspection machines while scheduling the shortest transportation time for AGVs. The crossover operators, mutation operators, and elite numbers were experimentally optimized. A numerical simulation of standard examples demonstrated the superiority of the proposed algorithm.

The unequal area facility layout problem (UA-FLP) refers to the reasonable arrangement of a certain number of facilities in a given layout area. The facility layout should satisfy given layout constraints and optimize given optimization objectives as far as possible. In this paper, a method combining improved lowest horizontal line method and particle swarm optimization algorithm is proposed to solve UA-FLP, which achieves multi-objective optimization of material handling cost, the adjacent value and the utilization rate of floor shop. On the one hand, the algorithm formulates facility packing rules through the improved lowest horizontal line method, which simplifies the legalization of facility layout. On the other hand, a modified particle swarm optimization (PSO) algorithm combining objective space division method (OSD) and niche technology is used for multi-objective optimization. The proposed algorithm overcomes the shortcomings of previous facility layout methods such as complex overlapping interference process, large amount of calculation and long time for multi-objective optimization. Compared with the comparison methods, the results show that material handling cost is reduced by 1%–6% and the utilization ratio of floor shop is increased by 2%–7%.