Thermo-economic analysis of an efficient lignite-fired power system integrated with flue gas fan mill pre-drying

[EN] Lignite is a domestic strategic reserve of low rank coals in many countries for its abundant resource and competitive price. Combustion for power generation is still an important approach to its utilization. However, the high moisture content always results in low efficiencies of lignite-direct-fired power plants. Lignite pre-drying is thus proposed as an effective method to improve the energy efficiency. The present work focuses on the flue gas pre-dried lignite-fired power system (FPLPS), which is integrated with fan mill pulverizing system and waste heat recovery. The thermo-economic analysis model was developed to predict its energy saving potential at design conditions. The pre-drying upgrade factor was defined to express the coupling of pre-drying system with boiler system and the efficiency improvement effect. The energy saving potential of the FPLPS, when applied in a 600 MW supercritical power unit, was determined to be 1.48 %-pts. It was concluded that the improvement of boiler efficiency mainly resulted from the lowered boiler exhaust temperature after firing pre-dried low moisture content lignite and the lowered dryer exhaust gas temperature after pre-heating the boiler air supply.This work was supported by National Natural Science Foundation of China (NO. 51436006), the National Basic Research Program of China (973 Program, NO.2015CB251504), and the Fundamental Research Funds for the Central Universities.Han, X.; Wang, J.; Liu, M.; Karellas, S.; Yan, J. (2018). Thermo-economic analysis of an efficient lignite-fired power system integrated with flue gas fan mill pre-drying. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 261-268. https://doi.org/10.4995/IDS2018.2018.739326126

The consumption of exergy for lignite drying with different technologies: a comparative theoretical study

[EN] Pre-drying is an effective method to upgrade lignite and broaden its utilization areas. Various drying technologies could be applied to pre-dry lignite. The drying temperature in these drying technologies are different, which means that energy at different grades is used in these dryers. To analyze the irreversibilities of drying process, the exergetic analysis models are developed in this study. The exergy feeding and consumption rates are defined as the indicators. Various lignite drying technologies are calculated and quantitatively compared. Results show that exergy consumption rate for steam fluid-bed dryer is the smallest, which is 432.6 kJ (kg H2O)-1.Liu, M.; Wang, S.; Liu, R.; Han, X.; Yan, J. (2018). The consumption of exergy for lignite drying with different technologies: a comparative theoretical study. Editorial Universitat Politècnica de València. 1261-1268. https://doi.org/10.4995/IDS2018.2018.73721261126

CXCL9 expression in breast cancer and its correlation with the characteristics of tumor immunoinfiltration

Objective·To explore the effect of C-X-C motif chemokine ligand 9 (CXCL9) expression on the prognosis of breast cancer patients and its correlation with tumor-infiltrating immune cells (TIICs).Methods·Transcriptome data of 1 100 breast tumor tissues and 112 adjacent tissues were obtained from The Cancer Genome Atlas (TCGA) database. CIBERSORT deconvolution algorithm was used to analyze the proportion of TIIC subgroups in breast cancer immune microenvironment and its effect on the prognosis of patients. Differentially expressed genes, immune-related genes and breast cancer prognostic-related genes were downloaded from TCGA database, ImmPort database and GEPIA2 data platform, respectively. The intersection relationships of the three gene sets were analyzed by using R language, and the target genes were screened. Based on the downloaded transcriptome data, CXCL9 positive-related genes, the difference of CXCL9 mRNA expression in breast cancer tissues and adjacent tissues and its effect on the prognosis of patients were analyzed. STRING data platform was used to analyze the protein-protein interaction (PPI) network of CXCL9. Gene Ontology (GO) function analysis and Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis were performed on CXCL9 positive correlation genes and the genes corresponding to the interacting proteins obtained from the PPI network by using R language. Spearman correlation coefficient was used to analyze the correlation between CXCL9 mRNA expression and TIIC subgroups and immune checkpoint-related genes. Paraffin tissue samples of 60 clinical breast cancer patients were collected and made into tissue chips. The correlation between CXCL9 expression and CD8+ T cells infiltration in the tissue chips was detected by immunohistochemical staining (IHC). The types of CXCL9+ cells in breast cancer interstitium were analyzed by multiplex immunohistochemistry staining (mIHC). Kaplan-Meier (KM) survival curve was used to analyze the effect of CXCL9 mRNA expression and CD8+ T cell infiltration on the prognosis of breast cancer patients.Results·CIBERSORT algorithm analysis showed that the distribution proportion of TIIC subgroups in breast cancer immune microenvironment varied greatly, and their effect on patients′ prognosis was also different. The Venn diagram of three types of gene sets was drawn, and CXCL9 was screened out. The top 150 positive correlation genes with CXCL9 were obtained. CXCL9 mRNA expression levels in four molecular types of breast cancer were higher than those in adjacent tissues (all P=0.000), and their high expressions were significantly associated with good prognosis of patients (P=0.013). A total of 41 interacting proteins were obtained through PPI network analysis. GO and KEGG analysis showed that CXCL9 and its related genes were mainly enriched in biological functions and pathways related to immune regulation. Spearman correlation coefficient analysis showed that the expression level of CXCL9 mRNA was positively correlated with CD8+ T cells infiltration ratio, negatively correlated with M2-type macrophages infiltration ratio, and positively correlated with most immune checkpoint genes expression (all P<0.05). IHC experiments showed that CXCL9 was highly expressed in breast cancer tissues compared with adjacent tissues, accompanied by an increased percentage of CD8+ T cells infiltration (P=0.000). mIHC results showed that CXCL9 was expressed in some CD68+ tumor-associated macrophages (TAMs) and CD11c+ dendritic cells (DCs) in the stroma of breast cancer. KM survival curve showed that when CXCL9 was highly expressed, CD8+ T cells high infiltration could prolong the survival of breast cancer patients.Conclusion·CXCL9 can be used as a biomarker for good prognosis of breast cancer patients. The high expression of CXCL9 in the microenvironment of breast cancer is positively correlated with the infiltration ratio of CD8+ T cells and may activate its anti-tumor effect. The expression of CXCL9 may be closely related to the recruitment of lymphocytes into the tumor microenvironment for anti-tumor immune response

Study on the coupling mechanism and suppression characteristics of swirl premixing combustion self-excited oscillation

The numerical simulation method was used to study the mutual influence of flow field disturbance, vortex change, flame structure change, heat release pulsation, and pressure pulsation on the coupling mechanism and suppression characteristics of self-excited oscillations. The results indicate that perturbations from the jet have a direct impact on the structure of the flame and the alteration of the vortex. Vortex changes have a direct impact on heat release and flame structure. Changes in flame structure can cause pulsations in heat release. Oscillatory combustion is caused by the coupling of multiple factors, including heat release pulsations, flow field perturbations, acoustic vibrations, vortex variations, and flame variations. Pressure pulsations can be suppressed by a circumferentially arranged jet. The optimal solution for suppressing pressure pulsations can be achieved by adjusting the optimal jet angle (φ) and jet rotation direction. Adjusting the value of |φ| can solve the problems of poor local ΔPmax suppression caused by upstream swirled interference and the narrow range of downstream influence of the jet, at |φ| = 10°, the suppression effect is more pronounced in the counter-rotating direction than in the forward-rotating direction

A Bioinspired Cell Membrane Disruptor Opens Pyroptosis-deficient Cells Membrane and Ignites Powerful Antitumour Immune Function

Gasdermin protein, a membrane disruptor, can mediate immunogenic pyroptosis and elicit anti-tumour immune function. However, cancer cells downregulate gasdermin and develop membrane repair mechanisms to resist pyroptosis. Therefore, an artificial membrane disruptor (AMD) that can directly mediate membrane rupture in pyroptosis-deficient cells and induce antitumour immune responses in a controllable manner is valuable in preclinical and clinical research. Here, we have established a micron-scale Ce6-based artificial membrane disruptor (AMD) to directly induce plasma membrane rupture (PMR) in gasdermin-deficient tumour cells. Compared to free Ce6 molecules, micron-scale AMDs specifically localised Ce6 to the plasma membrane without labelling other organelles. Due to the plasma membrane specificity, AMDs mediated irreversible and fast PMR under 660 nm red light. In addition, our AMDs were able to mediate PMR and lytic cell death in a catalytic manner, such that the Ce6 used by AMDs is one-fifth that of Ce6 alone when mediating 80% of cancer cell death. In vivo, our AMDs exhibited tumour targeting and penetration, indicating that light-driven PMR was tumour specific. We applied AMDs to antitumour therapy in gasdermin-deficient tumours, the results showed that all tumours could be efficiently eliminated with negligible damage to major organs by synergising with anti-PD-1 therapy. Tumour regression was correlated with PMR-mediated inflammation and T-cell-based immune responses. Our study provides new insights for designing the bioinspired membrane disruptor for PMR and mediating anti-tumour immunotherapy. In addition, AMD is a reliable tool for investigating the immunogenicity of PMR in vitro and in vivo

A Bioinspired Immunostimulatory System for Inducing Powerful Antitumor Immune Function by Directly Causing Plasma Membrane Rupture

Abstract The Gasdermin protein is a membrane disruptor that can mediate immunogenic pyroptosis and elicit anti‐tumor immune function. However, cancer cells downregulate Gasdermin and develop membrane repair mechanisms to resist pyroptosis. Therefore, an artificial membrane disruptor (AMD) that can directly mediate membrane rupture in pyroptosis‐deficient cells and induce antitumor immune responses in a controllable manner will be valuable in preclinical and clinical research. A micron‐scale Ce6‐based AMD that can directly induce plasma membrane rupture (PMR) in gasdermin‐deficient tumor cells is established. Micron‐scale AMDs localize Ce6 specifically to the plasma membrane without labeling other organelles. Compared to free Ce6 molecules, the use of AMDs results in a higher degree of specificity for the plasma membrane. Due to this specificity, AMDs mediate fast and irreversible PMR under 660 nm red light. Furthermore, the AMDs are capable of inducing programmed cell death and lytic cell death in a catalytic manner, demonstrating that the amount of Ce6 used by AMDs is only one‐fifth of that used by Ce6 alone when inducing 80% of cancer cell death. In vivo, the AMDs show specificity for tumor targeting and penetration, suggesting that light‐driven programmed cell death is specific to tumors. AMDs are applied to antitumor therapy in gasdermin‐deficient tumors, resulting in efficient tumor elimination with minimal damage to major organs when combined with anti‐PD‐1 therapy. Tumor regression is correlated with PMR‐mediated inflammation and T‐cell‐based immune responses. This study provides new insights for designing bioinspired membrane disruptors for PMR and mediating anti‐tumor immunotherapy. Additionally, AMD is a dependable tool for examining the immunogenicity of PMR both in vitro and in vivo

Bidirectional controlling synthesis of branched PdCu nanoalloys for efficient and robust formic acid oxidation electrocatalysis

Through a two-way control of hexadecyl trimethyl ammonium bromide (CTAB) and hydrochloric acid (HCl), the PdCu nanoalloys with branched structures are synthesized in one step by hydrothermal reduction and used as electrocatalysts for formic acid oxidation reaction (FAOR). In this two-way control strategy, the CTAB is used as a structure-oriented surfactant, while a certain amount of HCl is used to control the reaction kinetics for achieving gradual growth of multi-dendritic structures. The characterizations including scanning transmission electron microscope (STEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) suggest that PdCu nanoalloys with unique multi-dendritic branches have favorable electronic structure and lattice strain for electrocatalyzing the oxidation of formic acid. In specific, among the electrocatalysts with different Pd/Cu ratios, the Pd1Cu1 branched nanoalloys have the largest electrochemically active surface area (ECSA) and the best performance for the FAOR. The catalytic activity of the Pd1Cu1 branched nanoalloys is 2.4 times that of commercial Pd black. After the chronoamperometry test, the Pd1Cu1 branched nanoalloys still maintain their original morphologies and higher current density than that of the commercial Pd black. In addition, in the CO-stripping tests, the initial oxidation potential and the oxidation peak potential of the PdCu branched nanoalloys for CO adsorption are lower than those of commercial Pd balck, evincing their better anti-poisoning performance. (C) 2021 Elsevier Inc. All rights reserved

Core-shell Au@PtIr nanowires with dendritic alloy shells as efficient bifunctional catalysts toward methanol oxidation and hydrogen evolution reactions

Nanocatalysts with combination of unique morphologies and synergistic interactions have a potential to enhance electrocatalytic ability related to the reactions in fuel cells. Here, we show a wet-chemistry-based synthesis of dendritic Au@PtIr nanowires (NWs) with core-shell constructions regarding Te NWs as sacrificial templates for methanol oxidation reaction (MOR) and hydrogen evolution reaction (HER). Regarding the synthesis of Au@PtIr NWs, Au NWs are firstly obtained through galvanic replacement with Te templates, followed by growth of alloy PtIr shells in subsequent seed-mediated growth. The as synthesized core-shell Au@PtIr nanowires combine the advantage of one-dimensional (1D) dendritic feature that facilitate fast electron transport and provide more interfaces and interstices between catalytic active sites and electrolyte, with the synergistic interactions in alloy shells. Consequently, the as-prepared Au@PtIr NWs show good catalytic properties in MOR and HER in terms of higher activity, larger electrochemically active surface areas (ECSAs) and better anti-toxicity than commercial Pt/C. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved