Output Feedback Sliding Mode Control for Continuous Stirred Tank Reactors

The continuous stirred tank reactor (CSTR) is representative of a typical class of chemical equipment where the dynamics is nonlinear. The problematic issues in control of a CSTR are the model uncertainties and external disturbances. Driven by these challenging problems coupled with the need for demanding levels of performance, this paper establishes the dynamic model of CSTR and then proposes an output feedback sliding mode control in light of the established model. The validity of the control algorithm and of the presented model are further verified by MATLAB simulation and experimental trials

Coccomyxa Gloeobotrydiformis Polysaccharide Inhibits Lipopolysaccharide-Induced Inflammation in RAW 264.7 Macrophages

Background/Aims: Inflammation plays a vital role in the etiology and pathogenesis of chronic noncommunicable diseases (NCDs), which are the leading health issues throughout the world. Our previous studies verified the satisfactory therapeutic effects of Coccomyxa gloeobotrydiformis (CGD) polysaccharide on several NCDs. In this study, we aimed to investigate the anti-inflammatory effects of CGD polysaccharide, and the corresponding molecular mechanisms, on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells. Methods: A viability assay and a lactate dehydrogenase (LDH) assay were used to measure the cytotoxic effects of CGD polysaccharide on LPS-stimulated RAW264.7 cells. To investigate the potential anti-inflammatory mechanisms of CGD polysaccharide in LPS-stimulated RAW264.7 cells, nitric oxide (NO) production was determined using a NO assay and the expression of inflammatory mediators (PGE2, iNOS and COX-2), inflammatory cytokines (TNF-α, IL-6, IL-1β and IL-10) and inflammation-related signaling pathways (the MAPK/NF-κB, PI3K/AKT/JNK, JAK/STAT and Nrf2/HO-1pathways) were observed by western blotting. The translocation of NF-κB p65 was also observed using an immunofluorescent assay. Results: CGD polysaccharide significantly inhibited LPS-induced NO production and PGE2 expression by reducing the expression of iNOS and COX-2. It also suppressed the expression of the pro-inflammatory cytokines TNF-α, IL-6 and IL-1β, and up-regulated the expression of the anti-inflammatory cytokine IL-10. Further experiments demonstrated that CGD polysaccharide could inhibit inflammatory signaling pathways (the MAPK/NF-κB, PI3K/AKT/JNK and JAK/STAT pathways). At the same time, it enhanced the anti-inflammatory pathway Nrf2/HO-1. In addition, CGD polysaccharide did not display any cytotoxic effects, even at a high concentration. Conclusion: Taken together, the results suggest that CGD polysaccharide significantly inhibits LPS-induced inflammation in RAW264.7 cells. This effect lies in its regulatory effects on the signaling pathways MAPK/ NF-κB, PI3K/AKT/JNK, JAK/STAT and Nrf2/HO-1.Our findings reveal that CGD polysaccharide has the potential to be used as a relatively safe and effective drug as part of the treatment of NCDs

What are the risk factors of colonoscopic perforation?

<p>Abstract</p> <p>Background</p> <p>Knowledge of the factors influencing colonoscopic perforation (CP) is of decisive importance, especially with regard to the avoidance or minimization of the perforations. The aim of this study was to determine the incidence and risk factors of CP in one of the endoscopic training centers accredited by the World Gastroenterology Organization.</p> <p>Methods</p> <p>The prospectively collected data were reviewed of all patients undergoing either colonoscopy or flexible sigmoidoscopy at the Faculty of Medicine Siriraj Hospital, Bangkok, Thailand between January 2005 and July 2008. The incidence of CP was evaluated. Eight independent patient-, endoscopist- and endoscopy-related variables were analyzed by a multivariate model to determine their association with CP.</p> <p>Results</p> <p>Over a 3.5-year period, 10,124 endoscopic procedures of the colon (8,987 colonoscopies and 1,137 flexible sigmoidoscopies) were performed. There were 15 colonic perforations (0.15%). Colonoscopy had a slightly higher risk of CP than flexible sigmoidoscopy (OR 1.77, 95%CI 0.23-13.51; p = 1.0). Patient gender, emergency endoscopy, anesthetic method, and the specialty or experience of the endoscopist were not significantly predictive of CP rate. In multivariate analysis, patient age of over 75 years (OR = 6.24, 95%CI 2.26-17.26; p < 0.001) and therapeutic endoscopy (OR = 2.98, 95%CI 1.08-8.23; p = 0.036) were the only two independent risk factors for CP.</p> <p>Conclusion</p> <p>The incidence of CP in this study was 0.15%. Patient age of over 75 years and therapeutic colonoscopy were two important risk factors for CP.</p

Advances in nanocatalysts design for biofuels production

The exploitation of nanocatalysts, at the boundary between homogeneous and heterogeneous catalysis, is tracking new efficient ways to produce renewable biofuels in environmentally friendly conditions. Their solid state makes them recyclable, and their nanomateric particle size enables high activities approaching those offered by homogeneous catalysts, as well as novel and unique catalytic behaviors not accessible to solids above the nanometer range. Furthermore, the use of magnetically active materials has led to the development of nanocatalysts easily recoverable through the application of magnetic fields. In this mini-review, latest achievements in the production of advanced biofuels using stable, highly active, cheap and reusable nanocatalysts are described. Specifically, biodiesel and high density fuels have been chosen as major topics of research for the design of catalytic nanomaterials

Antibody Repertoires in Humanized NOD-scid-IL2Rγnull Mice and Human B Cells Reveals Human-Like Diversification and Tolerance Checkpoints in the Mouse

Immunodeficient mice reconstituted with human hematopoietic stem cells enable the in vivo study of human hematopoiesis. In particular, NOD-scid-IL2Rγnull engrafted mice have been shown to have reasonable levels of T and B cell repopulation and can mount T-cell dependent responses; however, antigen-specific B-cell responses in this model are generally poor. We explored whether developmental defects in the immunoglobulin gene repertoire might be partly responsible for the low level of antibody responses in this model. Roche 454 sequencing was used to obtain over 685,000 reads from cDNA encoding immunoglobulin heavy (IGH) and light (IGK and IGL) genes isolated from immature, naïve, or total splenic B cells in engrafted NOD-scid-IL2Rγnull mice, and compared with over 940,000 reads from peripheral B cells of two healthy volunteers. We find that while naïve B-cell repertoires in humanized mice are chiefly indistinguishable from those in human blood B cells, and display highly correlated patterns of immunoglobulin gene segment use, the complementarity-determining region H3 (CDR-H3) repertoires are nevertheless extremely diverse and are specific for each individual. Despite this diversity, preferential DH-JH pairings repeatedly occur within the CDR-H3 interval that are strikingly similar across all repertoires examined, implying a genetic constraint imposed on repertoire generation. Moreover, CDR-H3 length, charged amino-acid content, and hydropathy are indistinguishable between humans and humanized mice, with no evidence of global autoimmune signatures. Importantly, however, a statistically greater usage of the inherently autoreactive IGHV4-34 and IGKV4-1 genes was observed in the newly formed immature B cells relative to naïve B or total splenic B cells in the humanized mice, a finding consistent with the deletion of autoreactive B cells in humans. Overall, our results provide evidence that key features of the primary repertoire are shaped by genetic factors intrinsic to human B cells and are principally unaltered by differences between mouse and human stromal microenvironments

Can information affect sensory perceptions? Evidence from a survey on Italian organic food consumers

This paper aims to investigate the influence of information on consumers’ preferences and sensory perceptions of organic food using a sample of 301 Italian organic food consumers. Consumers stated their preferences for “core organic” attributes, labels and information on food products and performed blind and informed tests on strawberry yoghurts and cookies. Data were analysed using descriptive analysis, Mann-Whitney U tests and Wilcoxon signed-rank test. Results revealed that consumers appreciate “core organic” attributes, like artisanal production and variability of sensory attributes. Comparing blind and informed tests, results showed that information affects the overall liking of products and consumers’ perception of product-specific sensory attributes. However, the influence of information on sensory perceptions depends on the product category, sensory attributes and the type of information provided

Caracterization of molecules reorganisation for diblock copolymer and development of resonant soft X-ray reflectivity

Un copolymère dibloc se compose de deux blocs liés par des liaisons covalentes. Ces blocs peuvent être choisis avec des propriétés spécifiques : par exemple, les diblocs copolymères amphiphiles sont composés d un bloc hydrophile et l autre hydrophobe. On peut les utiliser pour obtenir une couche mince de polymère dont la composition de surface peut être modifiée entre hydrophile et hydrophobe. Lorsque l environnement est modifié, une réorganisation moléculaire de la surface se produit et réduit l énergie de surface. Cependant, on en sait peu sur la structure du volume de la couche mince pendant cette réorganisation. L investigation de la réorganisation de surface, dans le volume et leur corrélation sont donc les principaux objectifs de cette thèse. La réflectivité de rayons X ou de neutrons est une technique puissante pour étudier la structure interne des couches minces normalement à leur surface. L XPS quantifie la composition chimique de la surface ; la mesure de l angle de contact la caractérise qualitativement. Enfin, le MEB et l AFM sondent la topographie de surface de la couche à des échelles micro- et nanométrique. Nous détaillons la morphologie de surface des couches minces de copolymères diblocs en fonction de l épaisseur initiale. Ensuite, la dynamique de formation de l ordre lamellaire du volume est présentée. Enfin, on compare des couches minces de polymère sur un substrat hydrophile ou hydrophobe. Nous développons aussi une nouvelle technique de réflectivité des rayons X mous résonante pour obtenir un contraste supérieur entre les deux blocs. Nous avons appliqué cette technique à la structure lamellaire formée par notre copolymère dibloc symétriquePARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF