Patients with Inflammatory Bowel Disease Show IgG Immune Responses Towards Specific Intestinal Bacterial Genera

Introduction: Inflammatory bowel disease (IBD) is characterized by a disturbed gut microbiota composition. Patients with IBD have both elevated mucosal and serum levels of IgG-antibodies directed against bacterial antigens, including flagellins. In this study, we aimed to determine to which intestinal bacteria the humoral immune response is directed to in patients with IBD. Methods: Fecal and serum samples were collected from patients with IBD (n=55) and age- and sex-matched healthy controls (n=55). Fecal samples were incubated with autologous serum and IgG-coated fractions were isolated by magnetic-activated cell sorting (MACS) and its efficiency was assessed by flow cytometry. The bacterial composition of both untreated and IgG-coated fecal samples was determined by 16S rRNA-gene Illumina sequencing. Results: IgG-coated fecal samples were characterized by significantly lower microbial diversity compared to the fecal microbiome. Both in patients with IBD and controls, serum IgG responses were primarily directed to Streptococcus, Lactobacillus, Lactococcus, Enterococcus, Veillonella and Enterobacteriaceae, as well as against specific Lachnospiraceae bacteria, including Coprococcus and Dorea (all P<0.001), and to Ruminococcus gnavus-like bacteria (P<0.05). In contrast, serological IgG responses against typical commensal, anaerobic and colonic microbial species were rather low, e.g. to the Lachnospiraceae members Roseburia and Blautia, to Faecalibacterium, as well as to Bacteroides. Patients with IBD showed more IgG-coating of Streptococcus, Lactobacillus, and Lactococcus bacteria compared to healthy controls (all P<0.05). No differences in IgG-coated bacterial fractions were observed between Crohn’s disease and ulcerative colitis, between active or non-active disease, nor between different disease locations. Conclusion: The IgG immune response is specifically targeted at distinct intestinal bacterial genera that are typically associated with the small intestinal microbiota, whereas responses against more colonic-type commensals are lower, which was particularly the case for patients with IBD. These findings may be indicative of a strong immunological exposure to potentially pathogenic intestinal bacteria in concordance with relative immune tolerance against commensal bacteria

Yttria-stabilized zirconia thin films grown by reactive rf magnetron sputtering

Zirconia thin films were deposited on different substrates by reactive r.f, magnetron sputtering. It was found that zirconia layers grew preferentially in the (200) direction with a columnar microstructure that is independent of the oxygen flow, argon to oxygen flow ratios and sputtering pressure. On the other hand the substrate roughness clearly affects the orientation of zirconia. Distinct changes were observed in the case of heated substrates. The heating of the substrates does not change the form of the zirconia, but strongly influences its orientation. When the substrate temperature increases, the crystallographic orientation gets more and more random, typically for the polycrystalline state. A decrease in the optical transmittance and an increase in the colour intensity of the layers with an increase in the substrate temperature was also found. As is shown, the oxygen non-stoichiometry of the zirconia is responsible for these changes

Yttria-stabilized zirconia thin films grown by r.f. magnetron sputtering from an oxide target

Yttria-stabilized zirconia thin films with cubic crystallographic structure were deposited onto glass substrates by r.f. magnetron sputtering from an oxide target. It was found that zirconia growth is strongly dependent on the sputtering power and pressure. At low power and high pressure, zirconia grows preferentially in the (200) direction with columnar microstructure. In contrast, high power and low sputtering pressures promote the growth of randomly oriented polycrystalline zirconia. Increasing the argon flow at constant power and sputtering pressure again favours preferential growth of zirconia layers, however, not in the (200) direction as before, but in the (111) direction

Superconducting thick-films based on Bi-Pb-Sr-Ca-Cu nitrate pastes, screen-printed on alumina and ZrO2 buffered alumina

This study demonstrates the preparation of screen printed Bi-(Pb)-Sr-Ca-Cu-oxide superconducting films starting from a paste, based on spray dried nitrate solutions. The spray dried precursor powder was studied using TGA-DTA and XRD. It is shown that decomposition to oxides occurs at temperatures more than 200 degrees C lower than those in the respective oxide/carbonate mixture. The thick film properties were studied using XRD, SEM-EDAX and electrical resisitivity measurements. The films, coated on alumina substrates, showed clear superconducting transition below 60K, but did not reach zero resistivity. Films coated on alumina with a ZrO2 buffer layer and sintered at 835 degrees C showed T-c, 0 up to 77 K

The continuous spatio-temporal model (CSTM) as an exhaustive framework for multi-scale spatio-temporal analysis

When studying geographical phenomena, different levels of spatial and temporal granularity often have to be considered. While various approaches have been proposed to analyse geographical data in a multi-scale perspective, they have all focused on either spatial or temporal attributes rather than on the integration of space and time over multiple scales. This study introduces the continuous spatio-temporal model (CSTM), a conceptual model that seeks to address this shortcoming. The presented model is based on (1) the continuous temporal model (CTM), a multi-scale model for temporal information, and (2) the continuous spatial model (CSM), an extension of CTM for multi-scale spatial raster data. At the core of the presented conceptual model is a spatio-temporal evolution element or, in short, stevel, which is described by four variables: (1) pixel location, (2) spatial resolution, (3) temporal interval, and (4) temporal resolution. By varying one or more of these variables, a CSTM-tree consisting of (sets of) stevel arrays is created, forming the basis of an exhaustive CSTM-typology. These arrays can then be used to systematically cluster spatio-temporal information. The value of our approach is illustrated by means of a simplified example of mean temperature evolution. Various suggestions are made for modifications to be developed in future research

Improving the properties of polymer-steel composites by using silane coupling agents

status: publishe

Characterization of bulk microdefects in Ge single crystals

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