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To solve the problem of oscillation instability in permanent magnetic synchronous generator (PMSG)-based wind power connected systems during low-voltage ride through (LVRT) process, a parameter adjustment strategy based on interaction energy path optimization is proposed in this paper. Firstly, a modular state-space model of PMSG under fault transient conditions is constructed, and the system is divided into five subsystems. Then, the dynamic energy function of subsystems reflecting the oscillation stability of the system is derived. Based on that, the dynamic energy flow path is described considering the introduction of LVRT control. On this basis, the interaction energy between LVRT control links and subsystems is analyzed, and the coupling mechanism of voltage support and damping characteristics in the LVRT process is explained. Further, aiming at the optimal change rate of the total interaction energy in the LVRT process, the adjustment strategy of LVRT control parameters is constructed to meet voltage and damping requirements. Finally, a PMSG-connected system model is built on the MATLAB/Simulink platform to verify the effectiveness of the adjustment strategy. The results show that the proposed method can effectively improve the damping level under the fault transient condition, as well as supporting system voltage.
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Background: Myeloid-derived suppressor cells (MDSCs) have crucial immunosuppressive role in T cell dysfunction in various disease processes. However, the role of MDSCs and their impact on Tregs in COPD have not been fully understood. The aim of the present study is to investigate the immunomodulatory role of MDSCs and their potential impact on the expansion and function of Tregs in COPD patients. Methods: Peripheral blood samples were collected to analyze circulating MDSCs, Tregs, PD-1/PD-L1 expression to assess the immunomodulatory role of MDSC and their potential impact on the expansion and function of Treg in COPD. A total of 54 COPD patients and 24 healthy individuals were enrolled in our study. Flow cytometric analyses were performed to identify granulocytic MDSCs (G-MDSCs), monocytic MDSCs (M-MDSCs), Tregs, and the expression of PD-1/PD-L1(L2) on MDSCs and Tregs in peripheral blood. Results: Our results revealed a significantly higher percentage of G-MDSCs and M-MDSCs (p < 0.001) in COPD patients compared to the healthy controls. Additionally, a significantly higher proportion of peripheral blood Tregs was observed in COPD patients. Furthermore, an increased expression of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on Tregs (p < 0.01) was detected in COPD patients. The expression of PD-1 on CD4+ Tcells and Tregs, but not CD8+Tcells, was found to be increased in patients with COPD compared to controls. Furthermore, an elevated expression of PD-L1 on M-MDSCs (p < 0.01) was also observed in COPD patients. A positive correlation was observed between the accumulation of M-MDSCs and Tregs in COPD patients. Additionally, the percentage of circulating M-MDSCs is positively associated with the level of PD-1 (r = 0.51, p < 0.0001) and CTLA-4 (r = 0.42, p = 0.0014) on Tregs in COPD. Conclusion: The recruitment of MDSCs, accumulation of Tregs, and up-regulation of CTLA-4 on Treg in COPD, accompanied by an increased level of PD-1/PD-L1, suggest PD-1/PD-L1 axis may be potentially involved in MDSCs-induced the expansion and activation of Treg at least partially in COPD.
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Células Supresoras de Origen Mieloide , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Antígeno B7-H1/metabolismo , Antígeno CTLA-4 , Células Supresoras de Origen Mieloide/metabolismo , Receptor de Muerte Celular Programada 1 , Linfocitos T Reguladores/metabolismoRESUMEN
Myeloid-derived suppressor cells (MDSCs) are a heterogeneous family of myeloid cells that suppress T cell immunity in tumor-bearing hosts. The present study aimed to examine roles of T and MDSC subsets in lung malignancy. The study analyzed 102 cases with lung malignancy and 34 healthy individuals. Flow cytometry was performed for identification of T cell and MDSC subsets and their phenotypic characteristics in peripheral blood. The lung malignancy cases exhibited lower frequencies of granulocyte-like MDSCs (G-MDSCs) expressing PD-L2 and PD-L1 than healthy controls (P=0.013 and P<0.001, respectively). Additionally, there was a higher frequency of monocyte-like MDSCs (M-MDSCs) expressing PD-L1 in the peripheral blood of patients with lung malignancy than healthy controls (P<0.001). The frequencies of G-MDSCs and M-MDSCs were positively correlated with proportions of PD-1+ and CTLA-4+ regulatory T cells (Tregs). In vitro co-culture assay demonstrated M-MDSCs of lung malignancy enhanced naive T cell apoptosis and promoted Treg subset differentiation compared with M-MDSCs of healthy controls. The findings suggested accumulation of MDSC subsets in lung malignancy and MDSCs expressing PD-L2 and PD-L1 induced Treg expansion by binding to PD-1 on the surface of Tregs.
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OBJECTIVE: Membranous nephropathy is a leading cause of adult-onset nephrotic syndrome. Peripheral T cells and myeloid-derived suppressor cells (MDSCs) are closely associated with autoimmune diseases, while their exact roles and interaction in these processes are unclear. Here, we studied the roles of T cells, MDSCs, and their subsets in patients with idiopathic membranous nephropathy (IMN). MATERIALS AND METHODS: 35 IMN patients and 30 healthy controls were included in this retrospective study. Flow cytometry was performed to determine the phenotype of human T cells and MDSCs in peripheral blood mononuclear cells (PBMCs). Anti-PLA2R was measured by ELISA. Values ≥ 20 RU/mL were defined as positive and < 14 RU/mL as negative. RESULTS: A higher ratio of CD4/CD8 T cells with a lower proportion of Tregs, a remarkably lower proportion of G-MDSCs (but not M-MDSCs), lower frequency of PD-L2+G-MDSCs, and higher frequency of PD-L1+M-MDSCs were found in IMN patients compared to healthy controls. The ratio of CD4/CD8 T cells was higher, and the frequencies of PD-1+CD4+ T cells, CTLA-4+CD4+ T cells, PD-1+Tregs, and CTLA-4+Tregs were lower in PBMCs of PLA2R-positive IMN patients compared to PLA2R-negative IMN patients. CONCLUSION: Tregs and G-MDSCs were reduced in the circulation of the IMN patients, which may promote understanding of the crucial functions that are mediated by these cells in the pathogenesis of IMN.
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Glomerulonefritis Membranosa , Células Supresoras de Origen Mieloide , Humanos , Glomerulonefritis Membranosa/inmunología , Glomerulonefritis Membranosa/sangre , Masculino , Femenino , Células Supresoras de Origen Mieloide/inmunología , Persona de Mediana Edad , Estudios Retrospectivos , Adulto , Receptores de Fosfolipasa A2/inmunología , Citometría de Flujo , Linfocitos T CD8-positivos/inmunología , Linfocitos T Reguladores/inmunología , Estudios de Casos y Controles , Relación CD4-CD8 , Anciano , Receptor de Muerte Celular Programada 1/sangre , Receptor de Muerte Celular Programada 1/metabolismoAsunto(s)
Aneurisma Falso , Enfermedades Pulmonares Fúngicas , Mucormicosis , Humanos , Arteria Pulmonar/diagnóstico por imagen , Mucormicosis/diagnóstico , Mucormicosis/diagnóstico por imagen , Aneurisma Falso/complicaciones , Aneurisma Falso/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Enfermedades Pulmonares Fúngicas/complicaciones , Enfermedades Pulmonares Fúngicas/diagnóstico por imagenRESUMEN
The prevalence of Anaplastic Lymphoma Kinase gene (ALK) fusion is about 5% among patients with lung adenocarcinoma, underscoring the importance of pinpointing distinct fusion variants for optimizing treatment approaches. This is the first reported case of a 74-year-old female with stage IV lung adenocarcinoma, featuring a novel Kinesin Family Member 13A (KIF13A)-ALK fusion, identified via next-generation sequencing (NGS) and confirmed with fluorescence in situ hybridization (FISH). Initially undergoing chemotherapy and then crizotinib, she achieved a partial response (PR) before progressing with multiple bone metastases. However, subsequent treatment with alectinib as a third-line option yielded positive results. A stable disease state persisted for an impressive 31 months of progression-free survival (PFS), accompanied by minimal toxicity symptoms. Up until now, a remarkable near 4-year span of overall survival (OS) has been consistently observed and monitored. This report of a KIF13A-ALK fusion case benefit significantly from alectinib with extensive follow-up. The case diversifies the array of ALK fusion partners and holds clinical relevance in refining therapeutic choices for KIF13A-ALK fusion-associated lung cancer.