Search results for "Granulation"
showing 10 items of 127 documents
Performances of a granular sequencing batch reactor (GSBR).
2007
Aerobic granulation in sequencing batch reactors is widely reported in literature and in particular in SBAR (Sequencing batch airlift reactor) configuration, due to the high localised hydrodynamic shear forces that occur in this type of configuration. The aim of this work was to observe the phenomenon of the aerobic granulation and to confirm the excellent removal efficiencies that can be achieved with this technology. In order to do that, a laboratory-scale plant, inoculated with activated sludge collected from a conventional WWTP, was operated for 64 days: 42 days as a SBAR and 22 days as a SBBC (sequencing batch bubble column). The performances of the pilot plant showed excellent organic…
Aerobic granular sludge treating anaerobically pretreated brewery wastewater at different loading rates.
2020
Abstract In this study, three different aerobic granular sludge (AGS) reactors fed with anaerobically pre-treated brewery wastewater were studied. The AGS reactors were operated under different conditions including organic loading rates (OLR) between 0.8 and 4.1 kg COD m−3 d−1, C:N:P ratios (100:10:1 and 100:6:1) and food to microorganism ratios (F/M) between 0.8 ± 0.6 and 1.2 ± 0.5 and 0.9 ± 0.3 kg-TCOD kg-VSS−1d−1. Stable granulation was achieved within two weeks and the size of the granules increased according to the OLR applied. The results indicated that low C:N:P and F/M ratios were favorable to achieve stable aerobic granules in the long term. The carbon removal rate was load-indepen…
Encapsulation Response ofCiona intestinalis(Ascidiacea) to Intratunical Erythrocyte Injection
1997
Abstract Electron microscopic studies on the encapsulation induced by erythrocyte injection into the tunic of the ascidian Ciona intestinalis were carried out. The observations reported in the present paper complete the description previously given of capsule architecture and contribute to the characterization of the cells involved in the inflammatory reaction. The inflamed area is surrounded by an ample and peculiar “three-layered coat” respectively composed of flattened and packed extratunical hemocytes, the monolayered epithelium, and a layer of intratunical electron-dense particles. The latter are also clustered, variously arranged, and distributed in the tunic ground substance. The epi…
Start-Up of Chitosan-Assisted Anaerobic Sludge Bed Reactors Treating Light Oxygenated Solvents under Intermittent Operation
2021
Quality of the granular sludge developed during the start-up of anaerobic up-flow sludge bed reactors is of crucial importance to ensure the process feasibility of treating industrial wastewater such as those containing solvents. In this study, the microbial granule formation from suspended-growth biomass was investigated in two chitosan-assisted reactors. These reactors operated mimicking industrial sites working with night closures treating a mixture of ethanol, ethyl acetate, and 1-ethoxy-2-propanol. Each reactor operated under different hydrodynamic regimes typical from UASB (R1: <
Specific and Redundant Roles for NFAT Transcription Factors in the Expression of Mast Cell-Derived Cytokines
2006
Abstract By virtue of their ability to express a plethora of biologically highly active mediators, mast cells (MC) are involved in both adaptive and innate immune responses. MC-derived Th2-type cytokines are thought to act as local amplifiers of Th2 reactions, including chronic inflammatory disorders such as allergic asthma, whereas MC-derived TNF-α is a critical initiator of antimicrobial defense. In this study, we demonstrate that the transcription factors NFATc1 and NFATc2 are part of a MC-specific signaling network that regulates the expression of TNF-α and IL-13, whereas NFATc3 is dispensable. Primary murine bone marrow-derived MC from NFATc2−/− mice, activated by either ionomycin or I…
Prevention of long-term IgE antibody production by gene gun-mediated DNA vaccination.
2004
Background Vaccination with allergen-encoding DNA represents a promising approach for the treatment of allergic diseases. Objective In a mouse model of type I allergy, we analyzed the ability of biolistic transfection to inhibit antigen-specific IgE production and to modulate T H 2 responses. Methods BALB/c mice were vaccinated by means of gene gun–mediated DNA immunization with plasmid vector pCMV-βGal, encoding β-galactosidase as a model allergen. Subsequently, mice were immunized by means of repeated intraperitoneal injection of β-galactosidase adsorbed to the adjuvant aluminum hydroxide. Development of IgE, IgG1, and IgG2a antibody titers during the course of immunization was followed, …
Mast cells are crucial for early inflammation, migration of Langerhans cells, and CTL responses following topical application of TLR7 ligand in mice.
2007
Abstract Until recently, IgE-activated mast cells have been regarded merely as effector cells of adaptive immune responses, involved in allergic reactions and mucosal immunity to parasites. Herein, we report that murine dermal mast cells, activated by local administration of a cream containing the synthetic TLR7 ligand imiquimod, are essential to initiate an early inflammatory reaction. The mast-cell–derived cytokines TNF-α and IL-1β play an important role in this process. Furthermore, TLR7-activated mast cells are also able to promote the emigration of Langerhans cells, which partly depends on the expression of mast-cell–derived IL-1β. We have previously shown that TLR7 ligation enhances t…
Classical and alternative pathways of mast cell activation.
2002
It has long since been recognized that mast cells are critical effectors of anaphylactic reactions, and the existence of these potentially hazardous cells has solely been justified due to their beneficial role in some infections with extracellular parasites. A novel understanding of mast cells as sentinels of the immune system has been made possible by taking advantage of mast cell-deficient mice in order to study the roles of mast cells in vivo and by detailed analyses of mast cell activation in vitro. Collectively, these experiments have revealed a variety of IgE-independent stimuli, which lead to the activation of mast cells as crucial initiators of an inflammatory response. Besides thei…
Interleukin-2 immediate type hypersensitivity?
2008
Two patients with metastatic malignant melanoma developed immediate type hypersensitivity-like symptoms while being treated with recombinant interleukin-(IL-)2 immunotherapy. Both patients showed positive skin prick tests to IL-2, enhanced basophil degranulation in vitro and responded to anti-histamines, but laboratory investigations suggested an IgE-independent, pseudoallergic mast cell degranulation against IL-2.
Kalanchoe pinnata inhibits mast cell activation and prevents allergic airway disease
2011
Aqueous extract of Kalanchoe pinnata (Kp) have been found effective in models to reduce acute anaphylactic reactions. In the present study, we investigate the effect of Kp and the flavonoid quercetin (QE) and quercitrin (QI) on mast cell activation in vitro and in a model of allergic airway disease in vivo. Treatment with Kp and QE in vitro inhibited degranulation and cytokine production of bone marrow-derived mast cells following IgE/FcɛRI crosslinking, whereas treatment with QI had no effect. Similarly, in vivo treatment with Kp and QE decreased development of airway hyperresponsiveness, airway inflammation, goblet cell metaplasia and production of IL-5, IL-13 and TNF. In contrast, treatm…