18 research outputs found

    Optimized operational approach for multi-type reactive power compensation to enhance the grid integration strength of new energy clusters

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    The insufficient system strength in the high-proportion new energy access area has gradually emerged as a crucial factor contributing to the transient overvoltage issue. Therefore, it is imperative to propose a reactive power optimization operation mode that takes into consideration both the power grid strength and system operating voltage of the new energy cluster system. Firstly, the relationship between the evaluation index of power grid strength and the performance of system voltage response is elucidated, while analyzing the influence mechanism of various reactive power compensation devices on the power grid strength of new energy cluster systems. Then, a reactive power operation optimization model is proposed to maximize the strength of the system grid and minimize the voltage deviation. To solve this problem, a hybrid approach combining genetic algorithm and CPLEX solver is employed. Finally, the effectiveness of the proposed method is validated through a typical simulation example

    Natrium Benzoate Alleviates Neuronal Apoptosis via the DJ-1-Related Anti-oxidative Stress Pathway Involving Akt Phosphorylation in a Rat Model of Traumatic Spinal Cord Injury

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    This study aimed to explore the neuroprotective effects and mechanisms of natrium benzoate (NaB) and DJ-1 in attenuating reactive oxygen species (ROS)-induced neuronal apoptosis in traumatic spinal cord injury (t-SCI) in rats. T-SCI was induced by clip compression. The protein expression and neuronal apoptosis was evaluated by Western blotting, double immunofluorescence staining and transmission electron microscope (TEM). ROS level, spinal cord water content (SCWC) and Evans blue (EB) extravasation was also examined. Locomotor function was evaluated by Basso, Beattie, and Bresnahan (BBB) and inclined plane test (IPT) scores. We found that DJ-1 is expressed in spinal cord neurons and increased after t-SCI. At 24 h post-injury, the levels of DJ-1, p-Akt, SOD2, ROS, p-p38 MAPK/p38 MAPK ratio, and CC-3 increased, while the Bcl-2/Bax ratio decreased. NaB upregulated DJ-1, p-Akt, and SOD2, decreased ROS, p-p38 MAPK/p38 MAPK ratio, and CC-3, and increased the Bcl-2/Bax ratio, which were reversed by DJ-1 siRNA. The proportion of CC-3- and TUNEL-positive neurons also increased after t-SCI and was reduced by NaB. These effects were reversed by MK2206. Moreover, the level of oxDJ-1 increased after t-SCI, which was decreased by DJ-1 siRNA, NaB or the combination of them. NaB also reduced mitochondrial vacuolization, SCWC and EB extravasation, and improved locomotor function assessed by the BBB and IPT scores. In conclusion, NaB increased DJ-1, and thus reduced ROS and ROS-induced neuronal apoptosis by promoting Akt phosphorylation in t-SCI rats. NaB shows potential as a therapeutic agent for t-SCI, with DJ-1 as its main target

    Neutralizing antibodies against porcine epidemic diarrhea virus block virus attachment and internalization

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    Abstract Background Porcine epidemic diarrhea virus (PEDV) is emerging as a pathogenic coronavirus that causes a huge economic burden to the swine industry. Interaction of the viral spike (S) surface glycoprotein with the host cell receptor is recognized as the first step of infection and is the main determinant of virus tropism. The mechanisms by which neutralizing antibodies inhibit PEDV have not been defined. Isolating PEDV neutralizing antibodies are crucial to identifying the receptor-binding domains of the viral spike and elucidating the mechanism of protection against PEDV infection. Methods B cell hybridoma technique was used to generate hybridoma cells that secrete specific antibodies. E.coli prokaryotic expression system and Bac-to-Bac expression system were used to identify the target protein of each monoclonal antibody. qPCR was performed to analyze PEDV binding to Vero E6 cells with neutralizing antibody. Results We identified 10 monoclonal antibodies using hybridoma technology. Remarkably, 4 mAbs (designed 2G8, 2B11, 3D9, 1E3) neutralized virus infection potently, of which 2B11 and 1E3 targeted the conformational epitope of the PEDV S protein. qPCR results showed that both 2B11 and 2G8 blocked virus entry into Vero cells. Conclusion The data suggested that PEDV neutralizing antibody inhibited virus infection by binding to infectious virions, which could work as a tool to find the receptor-binding domains

    Mitochondrial Dysfunction and Chronic Liver Disease

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    Mitochondria are generally considered the powerhouse of the cell, a small subcellular organelle that produces most of the cellular energy in the form of adenosine triphosphate (ATP). In addition, mitochondria are involved in various biological functions, such as biosynthesis, lipid metabolism, oxidative phosphorylation, cell signal transduction, and apoptosis. Mitochondrial dysfunction is manifested in different aspects, like increased mitochondrial reactive oxygen species (ROS), mitochondrial DNA (mtDNA) damage, adenosine triphosphate (ATP) synthesis disorder, abnormal mitophagy, as well as changes in mitochondrial morphology and structure. Mitochondrial dysfunction is related to the occurrence and development of various chronic liver diseases, including hepatocellular carcinoma (HCC), viral hepatitis, drug-induced liver injury (DILI), alcoholic fatty liver (AFL), and non-alcoholic fatty liver (NAFL). In this review, we summarize and discuss the role and mechanisms of mitochondrial dysfunction in chronic liver disease, focusing on and discussing some of the latest studies on mitochondria and chronic liver disease

    Overexpression of miR-125a-5p Inhibits Hepatocyte Proliferation through the STAT3 Regulation In Vivo and In Vitro

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    microRNAs (miRNAs) are critically involved in liver regeneration (LR). miR-125a-5p (miR-125a) is a tumor-suppressing miRNA, but its role in LR has not been studied. Our previous studies have proved that miR-125a was related to LR at the initiation phase, while the mechanism hepatocyte proliferation triggered by miR-125a in LR has been rarely evaluated. Herein, we mainly studied the molecular mechanism of miR-125a in triggering hepatocyte proliferation and the proliferation stage of LR. Firstly, a striking reduction of miR-125a was found at 24 h as well as 30 h following partial hepatectomy (PH) in rat liver tissue by miRNAs expression profiles as well as qRT-PCR analysis. Furthermore, in vitro, upregulation of miR-125a decreased proliferation as well as G1/S conversion, which promoted hepatocytes apoptosis. STAT3 was the target of miR-125a. In vivo, upregulation of miR-125a by tail vein injection of agomir inhibited LR index. Upregulation of miR-125a inhibited LR index and hepatocytes proliferation by STAT3/p-STAT3/JUN/BCL2 axis. In summary, these current discoveries indicated that miR-125a inhibited hepatocytes proliferation as well as LR by targeting STAT3 and via acting on the STAT3/p-STAT3/JUN/BCL2 axis

    S100A4 enhances protumor macrophage polarization by control of PPAR-γ-dependent induction of fatty acid oxidation

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    Background The peroxisome proliferator-activated receptor γ (PPAR-γ)-dependent upregulation of fatty acid oxidation (FAO) mediates protumor (also known as M2-like) polarization of tumor-associated macrophages (TAMs). However, upstream factors determining PPAR-γ upregulation in TAM protumor polarization are not fully identified. S100A4 plays crucial roles in promotion of cancer malignancy and mitochondrial metabolism. The fact that macrophage-derived S100A4 is major source of extracellular S100A4 suggests that macrophages contain a high abundance of intracellular S100A4. However, whether intracellular S100A4 in macrophages also contributes to cancer malignancy by enabling TAMs to acquire M2-like protumor activity remains unknown.Methods Growth of tumor cells was evaluated in murine tumor models. TAMs were isolated from the tumor grafts in whole-body S100A4-knockout (KO), macrophage-specific S100A4-KO and transgenic S100A4WT−EGFP mice (expressing enhanced green fluorescent protein (EGFP) under the control of the S100A4 promoter). In vitro induction of macrophage M2 polarization was conducted by interleukin 4 (IL-4) stimulation. RNA-sequencing, real-time quantitative PCR, flow cytometry, western blotting, immunofluorescence staining and mass spectrometry were used to determine macrophage phenotype. Exogenous and endogenous FAO, FA uptake and measurement of lipid content were used to analyze macrophage metabolism.Results TAMs contain two subsets based on whether they express S100A4 or not and that S100A4+ subsets display protumor phenotypes. S100A4 can be induced by IL-4, an M2 activator of macrophage polarization. Mechanistically, S100A4 controls the upregulation of PPAR-γ, a transcription factor required for FAO induction during TAM protumor polarization. In S100A4+ TAMs, PPAR-γ mainly upregulates CD36, a FA transporter, to enhance FA absorption as well as FAO. In contrast, S100A4-deficient TAMs exhibited decreased protumor activity because of failure in PPAR-γ upregulation-dependent FAO induction.Conclusions We find that macrophagic S100A4 enhances protumor macrophage polarization as a determinant of PPAR-γ-dependent FAO induction. Accordingly, our findings provide an insight into the general mechanisms of TAM polarization toward protumor phenotypes. Therefore, our results strongly suggest that targeting macrophagic S100A4 may be a potential strategy to prevent TAMs from re-differentiation toward a protumor phenotype

    Characterization of protective immune responses against Neisseria gonorrhoeae induced by intranasal immunization with adhesion and penetration protein

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    Drug-resistant N. gonorrhoeae is an urgent threat to global public health, and vaccine development is the best long-term strategy for controlling gonorrhea. We have previously shown that adhesion and penetration protein (App) play a role in the adhesion, invasion, and reproductive tract colonization of N. gonorrhoeae. Here, we describe the immune response induced by intranasal immunization with passenger and translocator fragments of App. The recombinant App passenger and translocator fragments induced high titers of IgG and IgA antibodies in serum and vaginal washes. Antibodies produced by App passenger and the combination of passenger and translocator mediated the killing of N. gonorrhoeae via serum bactericidal activity and opsonophagocytic activity, whereas antisera from translocator-immunized groups had lower bactericidal activity and opsonophagocytic activity. The antisera of the App passenger and translocator, alone and in combination, inhibited the adhesion of N. gonorrhoeae to cervical epithelial cells in a concentration-dependent manner. Nasal immunization with App passenger and translocator fragments alone or in combination induced high levels of IgG1, IgG2a, and IgG2b antibodies and stimulated mouse splenocytes to secrete cytokines IFN-γ and IL-17A, suggesting that Th1 and Th17 cellular immune responses were activated. In vivo experiments have shown that immune App passenger and transporter fragments can accelerate the clearance of N. gonorrhoeae in the vagina of mice. These data suggest that the App protein is a promising N. gonorrhoeae vaccine antigen

    miR-541-3p Promoted Porcine Reproductive and Respiratory Syndrome Virus 2 (PRRSV-2) Replication by Targeting Interferon Regulatory Factor 7

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    Porcine reproductive and respiratory syndrome (PRRS) is a disease caused by PRRS virus (PRRSV), which seriously harms the pig industry. Revealing the mechanism by which PRRSV inhibits immune response will help prevent and control PRRS. Here, we found that PRRSV-2 may hijack host miR-541-3p to inhibit host innate immune response. Firstly, this work showed that miR-541-3p mimics could facilitate the replication of PRRSV-2 and the results of the quantitative real time polymerase chain reaction (qRT-PCR) showed that PRRSV-2 could up-regulate the expression of miR-541-3p in MARC-145 cells. Since previous studies have shown that type I interferon could effectively inhibit the replication of PRRSV-2, the present work explored whether miR-541-3p regulated the expression of type I interferon and found that miR-541-3p could negatively regulate the transcription of type I interferon by targeting interferon regulatory factor 7 (IRF7). More importantly, PRRSV-2 infection could down-regulate the expression of IRF7 and over-expression of IRF7 could down-regulate the replication of PRRSV-2 in MARC-145 cells. In conclusion, PRRSV-2 infection up-regulated the expression of miR-541-3p to promote its replication in MARC-145 cells, since miR-541-3p can negatively regulate the transcription of type I interferon by targeting IRF7
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