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Abstract The topology of flame-flame interaction is analysed for single turbulent premixed flames with increasing turbulence intensity. Morse theory for critical points is used for identifying the flame-flame interaction and characterising the local topology. The interactions have been categorised into four different groups, namely reactant pocket, tunnel formation, tunnel closure and product pocket. A histogram showing the frequency of occurrence of each of these groups is presented for single flames representative of hydrocarbon-air combustion and is compared with the results of colliding hydrogen-air flames. It is observed that most interactions for a single flame occur toward the leading edge. Also, more interactions are observed for higher intensity turbulence. The cylindrical topology types are found to dominate over spherical topology types. The relative frequency of occurrence of each type of topology is observed to change with changes in turbulence intensity. With increasing turbulence intensity, the fraction of product pockets and tunnel formation events increases whereas the fraction of reactant pockets and tunnel closure events decreases. The rise in product pockets is mirrored by the drop in reactant pockets, and likewise, the rise in tunnel formation events is mirrored by the drop in tunnel closure events. [ABSTRACT FROM AUTHOR]

Abstract In turbulent premixed flame propagation, the formation of isolated pockets of reactants or products is associated with flame pinch–off events which cause rapid changes in the flame surface area. Previous topological analysis of these phenomena has been carried out based on Morse theory and Direct Numerical Simulation (DNS) in two spatial dimensions. The present work extends the topological analysis to three dimensions with emphasis on the formation and subsequent burnout of reactant pockets. Singular behaviour observed previously for terms of the Surface Density Function (SDF) transport equation in the two–dimensional case is shown to occur also in three dimensions. Further singular behaviour is observed in the displacement speed close to reactant pocket burnout. The theory is compared against DNS data from hydrogen–air flames and good agreement is obtained. [ABSTRACT FROM AUTHOR]

The present paper described an exotic route of reactive calcination (RC) of a precursor (basic cobalt–manganese carbonate) for the synthesis of highly active Mn promoted Co 3 O 4 spinel catalyst (Cat-R) for simultaneous oxidation of CO–CH 4 emissions from CNG fuelled vehicles. The RC route involved feed of a low concentration of chemically reactive, 4.5% CO–air mixture over the precursor at low temperature in the beginning and finally increased to 400 °C. The precursor was also calcined around 400 °C following two other methods: (1) conventionally in stagnant air (Cat-S) and, (2) in flowing air (Cat-F). The catalysts were characterized by XRD, SEM, SEM-EDX, N 2 -sorption, XPS, TPR, Particle size, and FTIR techniques. The RC produced Mn promoted Co 3 O 4 spinel (Cat-R) with the highest surface area, smallest nano-size crystallites and highly dispersed oxygen deficient structural defect morphology as compared to Cat-F and Cat-S. The Cat-R showed total oxidation of lean CO–CH 4 mixture at the lowest temperature (340 °C) in comparison to Cat-F (380 °C) and Cat-S (420 °C). A synergetic effect was observed that the temperature for total oxidation of CH 4 in CO–CH 4 mixture was 80 °C less than when CH 4 was oxidized separately over Cat-R. The remarkable activity of Cat-R over other catalysts in simultaneous oxidation of CO–CH 4 was associated with the presence of its unusual textural and morphological characteristics. The activity order of the catalysts produced by various calcination strategies for CO–CH 4 oxidation was as follows: Cat-R > Cat-F > Cat-S. Thus, RC route can be recommended for synthesis of highly active catalysts over conventional methods for control of CO–CH 4 emissions from CNG vehicles. [ABSTRACT FROM AUTHOR]

A review of the immunogenic mechanisms that underlie the antitumor effect of two anti-epidermal growth factor receptor monoclonal antibodies, cetuximab and panitumumab in head and neck cancer.The tumor antigen (TA)-targeted monoclonal antibodies (mAb) cetuximab and panitumumab target the human epidermal growth factor receptor and have been integrated into treatment regimens for advanced squamous cell carcinoma of the head and neck (SCCHN). The therapeutic efficacy of these mAbs has been found to be enhanced when combined with radiotherapy and chemotherapy. However, clinical trials indicate that these findings are limited to fewer than 20% of treated patients. Therefore, identifying patients who are likely to benefit from these agents is crucial to improving therapeutic strategies. Interestingly, it has been noted that TA-targeted mAbs mediate their effects by contributing to cell-mediated cytotoxicity in addition to inhibition of downstream signaling pathways. Here, we describe the potential immunogenic mechanisms underlying these clinical findings, their role in the varied clinical response and identify the putative biomarkers of antitumor activity. We review potential immunological biomarkers that affect mAb therapy in SCCHN patients, the implications of these findings and how they translate to the clinical scenario, which are critical to improving patient selection and ultimately outcomes for patients undergoing therapy. [ABSTRACT FROM PUBLISHER]

• Bacteroidetes and Firmicutes were most prevalent bacteria in the sheep rumen. • Bacteroidetes were negatively correlated with the Euryarchaeota. • Archaea constituted ∼2.5% of the ruminal microbiota. • Methanobrevibacter gottschalkii constituted > 50% of the ruminal archaea. • Hydrogenotrophic methanogens distribution leads to the variability in methane yield. An in vivo study aiming to investigate the rumen methanogens community structure was conducted in Mandya sheep fed on straw and concentrate diet. The ruminal fluid samples were collected and processed for unravelling the rumen microbiota and methanogens diversity. Further, the daily enteric methane emission and methane yield was also quantified using the SF 6 tracer technique. Results indicated that the Bacteroidetes (∼57%) and Firmicutes (25%) were two prominent affiliates of the bacterial community. Archaea represented about 2.5% of the ruminal microbiota. Methanobacteriales affiliated methanogens were the most prevalent in sheep rumen. The study inveterate that the ruminal archaea community in sheep is composed of 9 genera and 18 species. Methanobrevibacter represented the largest genus of the archaeome, while methylotrophs genera constituted only 13% of the community. Methanobrevibacter gottschalkii was the prominent methanogen, and Methaobrevibacter ruminantium distributed at a lower frequency (∼2.5%). Among Methanomassiliicoccales , Group 12 sp. ISO4-H5 constituted the most considerable fraction (∼11%). KEGG reference pathway for methane metabolism indicated the formation of methane through hydrogenotrophic and methylotrophic pathways, whereas the acetoclastic pathway was not functional in sheep. The enteric methane emission and methane yield was 19.7 g/d and 20.8 g/kg DMI, respectively. Various species of Methanobrevibacter were differently correlated, and the distribution of hydrogenotrophic methanogens mainly explained the variability in methane yield between the individual sheep. It can be inferred from the study that the hydrogenotrophic methanogens dominate the rumen archaeal community in sheep and methylotrophic/aceticlastic methanogens represent a minor fraction of the community. Further studies are warranted for establishing the metabolic association between the prevalent hydrogenotrophs and methylotrophs to identify the key reaction for reducing methane emission. [ABSTRACT FROM AUTHOR]

We have established that mucosal immunization can generate high-avidity human immunodeficiency virus (HIV)-specific CD8+ T cells compared with systemic immunization, and interleukin (IL)-13 is detrimental to the functional avidity of these T cells. We have now constructed two unique recombinant HIV-1 vaccines that co-express soluble or membrane-bound forms of the IL-13 receptor α2 (IL-13Rα2), which can 'transiently' block IL-13 activity at the vaccination site causing wild-type animals to behave similar to an IL-13 KO animal. Following intranasal/intramuscular prime-boost immunization, these IL-13Rα2-adjuvanted vaccines have shown to induce (i) enhanced HIV-specific CD8+ T cells with higher functional avidity, with broader cytokine/chemokine profiles and greater protective immunity using a surrogate mucosal HIV-1 challenge, and also (ii) excellent multifunctional mucosal CD8+ T-cell responses, in the lung, genito-rectal nodes (GN), and Peyer's patch (PP). Data revealed that intranasal delivery of these IL-13Rα2-adjuvanted HIV vaccines recruited large numbers of unique antigen-presenting cell subsets to the lung mucosae, ultimately promoting the induction of high-avidity CD8+ T cells. We believe our novel IL-13R cytokine trap vaccine strategy offers great promise for not only HIV-1, but also as a platform technology against range of chronic infections that require strong sustained high-avidity mucosal/systemic immunity for protection. [ABSTRACT FROM AUTHOR]

From decades, the solar-driven conversion of carbon dioxide (CO 2) into other valuable chemical products has captured enormous interest of scientists as a promising route to tackle the global warming and energy crisis. Recently, all-inorganic lead halide perovskite quantum dots (ILHP QDs) have witnessed as a new class of materials for CO 2 photoreduction owing to their outstanding optoelectronic properties and low-cost solution processing. This review summarizes the physicochemical properties and synthesis approaches of the ILHP QDs together with their advantages as photocatalysts for CO 2 reduction. Particularly, strategies for improving the photocatalytic activity of these semiconductors are thoroughly summarized and discussed. Finally, we focus on limitations and favourable perspectives for the rational design of perovskite-based photocatalysts. • An overview of recent trends in photocatalytic CO 2 reduction over inorganic lead halide perovskitesn overview of recent trends in photocatalytic CO 2 reduction over inorganic lead halide perovskites. • Physicochemical properties and synthesis approaches of the inorganic lead halides perovskite QDs. • Challenges and opportunities of inorganic lead halide perovskites for photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

Purpose Head and neck cancer (HNC) cells express low HLA class I antigen processing machinery (APM) components, providing a major immune escape strategy from cytotoxic T lymphocyte (CTL)-mediated lysis. Epidermal growth factor receptor (EGFR)-specific CTL are induced by the therapeutic mAb cetuximab in treated patients. Therefore, the effect and molecular mechanism of EGFR inhibition on HLA class I APM expression has important implications for adaptive immunity generated in cetuximab-treated HNC patients. Experimental design Using a prospective clinical trial of neoadjuvant, single-agent cetuximab, we correlated immunohistochemistry (IHC) results with clinical response. Flow cytometry and signaling studies were performed using HNC lines treated with cetuximab alone or with Fc γ receptor (Fc γ R) bearing lymphocytes to establish the mechanism of EGFR-dependent regulation of HLA APM expression. Results Cetuximab-mediated EGFR blockade triggered STAT1 activation and upregulation of HLA-B/C alleles more prominently than HLA-A alleles. Cetuximab-induced HLA class I upregulation was most prominent in cetuximab-treated HNC patients with beneficial clinical response to cetuximab. EGFR signaling blockade enhanced IFN γ receptor 1 (IFNAR) on HNC, and augmented induction of HLA class I and TAP1/2 expression by IFN γ which was abrogated in STAT1−/− cells. In addition, cetuximab treatment enhanced the HNC cell recognition by EGFR853-861 specific CTL and also enhanced surface presentation of non-EGFR TA such as MAGE-3271-279. Conclusions HLA class I induction is a favorable biomarker for cetuximab therapy. EGFR signaling mediates a novel immune escape mechanism through STAT1 suppression. Reversal of HLA downregulation using cetuximab should be combined with strategies to enhance adaptive cellular immunity. [ABSTRACT FROM AUTHOR]