On formation of domain wall lattices

We study the formation of domain walls in a phase transition in which an S_5\times Z_2 symmetry is spontaneously broken to S_3\times S_2. In one compact spatial dimension we observe the formation of a stable domain wall lattice. In two spatial dimensions we find that the walls form a network with junctions, there being six walls to every junction. The network of domain walls evolves so that junctions annihilate anti-junctions. The final state of the evolution depends on the relative dimensions of the simulation domain. In particular we never observe the formation of a stable lattice of domain walls for the case of a square domain but we do observe a lattice if one dimension is somewhat smaller than the other. During the evolution, the total wall length in the network decays with time as t^{-0.71}, as opposed to the usual t^{-1} scaling typical of regular Z_2 networks.Comment: 7 pages, 4 figures. Minor changes, final version accepted for publication in Phys. Rev.

Scaling in Numerical Simulations of Domain Walls

We study the evolution of domain wall networks appearing after phase transitions in the early Universe. They exhibit interesting dynamical scaling behaviour which is not yet well understood, and are also simple models for the more phenomenologically acceptable string networks. We have run numerical simulations in two- and three-dimensional lattices of sizes up to 4096^3. The theoretically predicted scaling solution for the wall area density A ~ 1/t is supported by the simulation results, while no evidence of a logarithmic correction reported in previous studies could be found. The energy loss mechanism appears to be direct radiation, rather than the formation and collapse of closed loops or spheres. We discuss the implications for the evolution of string networks.Comment: 7pp RevTeX, 9 eps files (including six 220kB ones

Diagnostic relevance and clinical significance of the new enhanced performance M2 (MIT3) ELISA for the detection of IgA and IgG antimitochondrial antibodies in primary biliary cirrhosis

Background/aims: Antimitochondrial antibodies (AMAs) are the serological hallmark of primary biliary cirrhosis (PBC). We evaluated the sensitivity and specificity of a new M2 enhanced performance enzyme-linked immunosorbent assay (ELISA) (MIT3) for the detection of IgG- and IgA-specific isotypes of AMA in PBC patients including a number of PBC patients negative for AMA by indirect immunofluorescence (IIF) as well as in patients with diverse, non-PBC disorders. We also investigated the clinical significance of IgG and IgA AMA in PBC. Methods: One hundred and three Greek PBC patients including 27 with AMA IIF-negative at the time of the investigation, 29 with autoimmune hepatitis-1 (AIH-1), 12 with primary sclerosing cholangitis (PSC), 26 with hepatitis C virus (HCV), 15 with hepatitis B virus (HBV), and 29 healthy were investigated for AMA (IgG and IgA) using the MIT3-based ELISAs (INOVA Diagnostics, San Diego, CA). The samples were also tested by conventional anti-M2 ELISA (INOVA Diagnostics, Inc.). Results: The IgG MIT3-based ELISA significantly increased AMA detection in the cohort of PBC patients, over 26% of whom were AMA IIF-negative, from 63.1% by the conventional anti-M2, and 73.7% by IIF to 79.6% by MIT3-based ELISA (p < 0.001). IgA AMAs were detected in 47.6% patients. Overall, IgG/IgA AMAs were detected in 84/103 (81.6%). IgG MIT3-based ELISA detected 12/27 IIF AMA-negative samples (44.4%), while IgG/IgA MIT3-based ELISAs detected 13/27 IIF AMA-negative patients (48.1%). The specificities of MIT3-based ELISAs (IgG and IgA) were 82.8% and 89.7%, respectively, in AIH-1, 100% and 93.3%, respectively, in HBV, 100% in PSC, and 96% and 93.3%, respectively, in HCV. Patients positive for IgG AMA had significantly more severe disease as shown by worse histology and elevated biochemical markers; IgG and IgA AMA titers were associated positively with the Mayo risk score but none of the isotypes were able to predict disease outcome. Conclusions: The new IgG and IgA MIT3-based ELISAs seem to have higher specificity and sensitivity for AMA detection than IIF and the conventional anti-M2. Interestingly, these assays were able to unmask AMA presence in almost half of the AMA-negative samples by IIF. These findings may suggest the use of MIT3-based ELISAs as first-line investigation for AMA detection, particularly, when the laboratories are unfamiliar with the use and interpretation of the IIF patterns of AMA. The presence of IgG AMA seems to characterize PBC patients with more severe disease, but both IgG and IgA isotypes of AMAs were not predictive markers of disease outcome

Plant terpenoid metabolism co-opts a component of the cell wall biosynthesis machinery

Glycosylation is one of the most prevalent molecular modifications in nature. Single or multiple sugars can decorate a wide range of acceptors from proteins to lipids, cell wall glycans and small molecules, dramatically affecting their activity. Here, we discovered that by ‘hijacking’ an enzyme of the cellulose synthesis machinery involved in cell wall assembly, plants evolved cellulose synthase-like enzymes (Csls) and acquired the capacity to glucuronidate specialized metabolites, that is, triterpenoid saponins. Apparently, endoplasmic reticulum-membrane localization of Csls and of other pathway proteins was part of evolving a new glycosyltransferase function, as plant metabolite glycosyltransferases typically act in the cytosol. Discovery of glucuronic acid transferases across several plant orders uncovered the long-pursued enzymatic reaction in the production of a low-calorie sweetener from licorice roots. Our work opens the way for engineering potent saponins through microbial fermentation and plant-based systems. [Figure not available: see fulltext.]. © 2020, The Author(s), under exclusive licence to Springer Nature America, Inc

Electrochemical Ceramic Membrane Reactors in Future Energy and Chemical Process Engineering

Electrochemical ceramic membrane reactors (ECMRs) with their unique ability to efficiently couple electrical, chemical, and thermal energy sectors can be a large part of the transition toward renewable energies and defossilized economies. ECMRs utilize ceramic conductors to extract or distribute oxide ions or protons – directly controlled by an external electric current. This article gives an overview of ECMR properties along with the functionalities and advantages. For many reactions, e.g., the direct synthesis of ammonia, ECMRs are not available at the preferred temperature range of 300 – 550 °C. To evidence the possibility of such reactors, functional materials are reviewed. A simple thermodynamic methodology is proposed to determine the suitability of reactions for particular combinations of coupled energy sectors

IgA anti-b2GPI antibodies in patients with autoimmune liver diseases

Introduction Recently, we reported a high prevalence of immunoglobulin G and/or immunoglobulin M anticardiolipin antibodies (aCL) in patients with autoimmune liver diseases, namely, autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC), which were independent of the respective isotypes of antibodies against beta 2-glycoprotein I (anti-b2GPI). Immunoglobulin A (IgA) aCL and IgA anti-b2GPI are the least studied of the three specific isotypes either in antiphospholipid syndrome (APS) or in other conditions. Methods Therefore, we investigated the prevalence and clinical significance of IgA anti-b2GPI and IgA aCL by enzyme-linked immunosorbent assays in another set of Caucasian patients with autoimmune liver diseases (59 AIH, 96 PBC, and 37 PSC). The disease controls group consisted of 50 hepatitis C virus (HCV) patients, 50 hepatitis B virus (HBV), 30 alcoholic liver disease (ALD), 30 non-alcoholic steatohepatitis (NASH), and 110 healthy controls. Results and Discussion IgA anti-b2GPI prevalence was higher in AIH (50.8%) compared to PBC (p=0.005), PSC (p=0.008), NASH (p=0.004), ALD (p=0.01), and HCV (p=0.002). The titers were also significantly higher in AIH compared to any other group of the study. IgA aCL prevalence was higher in AIH (33.9%) compared to PBC (p=0.005), PSC (p=0.014), NASH (p=0.001), ALD (p=0.004), and HCV (p < 0.001). IgA anti-b2GPI or IgA aCL were not associated with APS features in patients with liver autoimmunity. Of note, IgA anti-b2GPI and IgA aCL were associated with clinical and biochemical markers of disease severity in AIH and PBC. We demonstrated a high prevalence and high titers of IgA anti-b2GPI in patients with AIH compared to any other liver disease of the study. Conclusion IgA anti-b2GPI and IgA aCL were associated with the severity and biochemical activity of AIH and PBC, but long-term prospective studies are needed to address whether this new finding is of clinical importance in AIH and PBC patients