82 research outputs found

    Overvoltage and Insulation Coordination of Overhead Lines in Multiple-Terminal MMC-HVDC Link for Wind Power Delivery

    Get PDF
    The voltage-sourced converter-based HVDC link, including the modular multilevel converter (MMC) configuration, is suitable for wind power, photovoltaic energy, and other kinds of new energy delivery and grid-connection. Current studies are focused on the MMC principles and controls and few studies have been done on the overvoltage of transmission line for the MMC-HVDC link. The main reason is that environmental factors have little effect on DC cables and the single-phase/pole fault rate is low. But if the cables were replaced by the overhead lines, although the construction cost of the project would be greatly reduced, the single-pole ground fault rate would be much higher. This paper analyzed the main overvoltage types in multiple-terminal MMC-HVDC network which transmit electric power by overhead lines. Based on ±500 kV multiple-terminal MMC-HVDC for wind power delivery project, the transient simulation model was built and the overvoltage types mentioned above were studied. The results showed that the most serious overvoltage was on the healthy adjacent line of the faulty line caused by the fault clearing of DC breaker. Then the insulation coordination for overhead lines was conducted according to the overvoltage level. The recommended clearance values were given

    Salt stress perception and metabolic regulation network analysis of a marine probiotic Meyerozyma guilliermondii GXDK6

    Get PDF
    IntroductionExtremely salt-tolerant microorganisms play an important role in the development of functional metabolites or drug molecules.MethodsIn this work, the salt stress perception and metabolic regulation network of a marine probiotic Meyerozyma guilliermondii GXDK6 were investigated using integrative omics technology.ResultsResults indicated that GXDK6 could accept the salt stress signals from signal transduction proteins (e.g., phosphorelay intermediate protein YPD1), thereby contributing to regulating the differential expression of its relevant genes (e.g., CTT1, SOD) and proteins (e.g., catalase, superoxide dismutase) in response to salt stress, and increasing the salt-tolerant viability of GXDK6. Omics data also suggested that the transcription (e.g., SMD2), translation (e.g., MRPL1), and protein synthesis and processing (e.g., inner membrane protein OXA1) of upregulated RNAs may contribute to increasing the salt-tolerant survivability of GXDK6 by improving protein transport activity (e.g., Small nuclear ribonucleoprotein Sm D2), anti-apoptotic ability (e.g., 54S ribosomal protein L1), and antioxidant activity (e.g., superoxide dismutase). Moreover, up to 65.9% of the differentially expressed genes/proteins could stimulate GXDK6 to biosynthesize many salt tolerant-related metabolites (e.g., β-alanine, D-mannose) and drug molecules (e.g., deoxyspergualin, calcitriol), and were involved in the metabolic regulation of GXDK6 under high NaCl stress.DiscussionThis study provided new insights into the exploration of novel functional products and/or drugs from extremely salt-tolerant microorganisms.Graphical Abstrac

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

    Get PDF
    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    Nurse managers' experience during the COVID‐19 pandemic in China: A qualitative study

    No full text
    Abstract Aims The aim of the study was to explore the experiences of female new nurse managers during the COVID‐19 pandemic. Design This was a phenomenological study, and qualitative descriptive analysis was used. Methods New nurse managers were defined as new nurse managers with less than 3 years of management experience in this study. During November and December of 2021, 18 female new nurse managers were interviewed face‐to‐face with a semi‐structured interview guide in three municipal hospitals. The study followed the Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines for evaluating qualitative research reports. Data analysis was performed using Colaizzi's seven‐step method. Results Four main themes and 10 sub‐themes were extracted from the collected data. The four major themes were as follows: (1) a shift in stress; (2) work‐related physical and psychological discomfort; (3) reflection on the cause; (4) coping and struggles. Conclusions New nurse managers were experiencing great stress and exhaustion in their roles. It is important that they are helped to handle situations. Providing them with readily accessible support, addressing their psychosocial needs and addressing exhaustion is necessary. Considering their short management time, the hospital should provide adequate support in human, financial and material areas and provide training to help new nurse managers better adapt to their new roles. In addition, nurse directors should create a culture of mutual respect, identify workplace bullying and create a harmonious and cooperation‐oriented work environment for new nurse managers. Patient or Public Contribution No patient or public contribution
    corecore