Epithelial Heat Shock Proteins Mediate the Protective Effects of Limosilactobacillus reuteri in Dextran Sulfate Sodium-Induced Colitis

Defects in gut barrier function are implicated in gastrointestinal (GI) disorders like inflammatory bowel disease (IBD), as well as in systemic inflammation. With the increasing incidence of IBD worldwide, more attention should be paid to dietary interventions and therapeutics with the potential to boost the natural defense mechanisms of gut epithelial cells. The current study aimed to investigate the protective effects of Limosilactobacillus reuteri ATCC PTA 4659 in a colitis mouse model and delineate the mechanisms behind it. Wild-type mice were allocated to the control group; or given 3% dextran sulfate sodium (DSS) in drinking water for 7 days to induce colitis; or administered L. reuteri for 7 days as pretreatment; or for 14 days starting 7 days before subjecting to the DSS. Peroral treatment with L. reuteri improved colitis severity clinically and morphologically and reduced the colonic levels of Tumor necrosis factor-alpha (TNF-alpha) (Tnf), Interleukin 1-beta (Il1 beta), and nterferon-gamma (Ifng), the crucial pro-inflammatory cytokines in colitis onset. It also prevented the CD11b(+)Ly6G(+) neutrophil recruitment and the skewed immune responses in mesenteric lymph nodes (MLNs) of CD11b(+)CD11c(+) dendritic cell (DC) expansion and Foxp3(+)CD4(+) T-cell reduction. Using 16S rRNA gene amplicon sequencing and RT-qPCR, we demonstrated a colitis-driven bacterial translocation to MLNs and gut microbiota dysbiosis that were in part counterbalanced by L. reuteri treatment. Moreover, the expression of barrier-preserving tight junction (TJ) proteins and cytoprotective heat shock protein (HSP) 70 and HSP25 was reduced by colitis but boosted by L. reuteri treatment. A shift in expression pattern was also observed with HSP70 in response to the pretreatment and with HSP25 in response to L. reuteri-DSS. In addition, the changes of HSPs were found to be correlated to bacterial load and epithelial cell proliferation. In conclusion, our results demonstrate that the human-derived L. reuteri strain 4659 confers protection in experimental colitis in young mice, while intestinal HSPs may mediate the probiotic effects by providing a supportive protein-protein network for the epithelium in health and colitis

A Two-Step Hydrothermal Synthesis Approach to Monodispersed Colloidal Carbon Spheres

This work reports a newly developed two-step hydrothermal method for the synthesis of monodispersed colloidal carbon spheres (CCS) under mild conditions. Using this approach, monodispersed CCS with diameters ranging from 160 to 400 nm were synthesized with a standard deviation around 8%. The monomer concentration ranging from 0.1 to 0.4 M is in favor of generation of narrower size distribution of CCS. The particle characteristics (e.g., shape, size, and distribution) and chemical stability were then characterized by using various techniques, including scanning electron microscopy (SEM), FT-IR spectrum analysis, and thermalgravity analysis (TGA). The possible nucleation and growth mechanism of colloidal carbon spheres were also discussed. The findings would be useful for the synthesis of more monodispersed nanoparticles and for the functional assembly

Self-assembly of particles : some thoughts and comments

Self-assembly can happen to particles at all length scales, including atomic, nano-, meso- and macro-particles. Although widely used in nanoresearch, many nano-structures reported in the literature are not self-assembled, posing some fundamental questions. This paper will briefly review this topic, answering the following questions: what is the current status in self-assembling nanoparticles? Why is it so difficult to produce self-assembled structures of nanoparticles? How can we effectively overcome the difficulty? The important role of controlling forces of various types in relation to different self-assembly techniques is discussed. Self-assembly is demonstrated as a complex problem that still needs intensive multi-scaled studies

Improvement in EMI Shielding Properties of Silicone Rubber/POE Blends Containing ILs Modified with Carbon Black and MWCNTs

Silicone rubber (SR)/polyolefin elastomer (POE) blends containing ionic liquids modified with carbon blacks (CB-IL) and multi-walled carbon nanotubes (CNT-IL) were prepared by melt-blending and hot pressing. SR/POE/CB-IL and SR/POE/CB-CNT-IL composites showed co-continuous structural morphologies. The cation−π interactions between ILs and CNTs were stronger than those between ILs and CBs due to the large length and high surface area of CNTs, which promoted better dispersion of carbon fillers. SR/POE/CB-CNT-IL composites showed higher EMI SE than SR/POE/CB-IL composites containing identical filler contents because the CNTs with larger aspect ratios helped form more electrically-conductive networks

In-plane shear experimental method and mechanical behavior of ceramic matrix mini-composites

In-plane shear mechanical experiments of ceramic matrix mini-composites (CMMC) were realized in this paper by overcoming the difficulties of material preparation, specimen design, gripping and loading, deformation measurement, etc. The in-plane shear stress-strain responses of different matrix volume fractions were obtained based on the method. The stress-strain response of CMMC was strongly non-linear, and its elastic modulus and strength were positively correlated to the matrix volume fraction. The main factors affecting the digital image correlation (DIC) based micro-region shear deformation measurement are analyzed quantitatively, and the corresponding solutions are discussed. The DIC calculation time model is established, and the accurate estimation of DIC processing time is realized. The shear strain field evolution clearly captured the matrix crack initiation and propagation

Solvothermal synthesis of ZnO-decorated α-Fe2O3 nanorods with highly enhanced gas-sensing performance toward n-butanol

This paper reports a newly developed solvothermal strategy for the synthesis of ZnO-decorated α-Fe2O3 nanorods based on the reaction of α-Fe2O3 nanorods with zinc sulfate and urea in autoclaves at 180 °C. The resulting nanocomposites consist of porous α-Fe2O3 nanorods with diameters of 100–200 nm and a surface decorated with small ZnO nanoparticles (10–20 nm). The ZnO NPs are found to grow epitaxially on {110} planes of α-Fe2O3, forming an interfacial orientation relationship of (100)ZnO/(110)α-Fe2O3. The addition of ZnO is found to shift the Fe 2p peak position in the α-Fe2O3/ZnO nanocomposites to higher binding energies due to the formation of the α-Fe2O3/ZnO heterojunction interface. The gas-sensing results show that the ZnO-decorated α-Fe2O3 nanorods exhibit excellent sensitivity, selectivity, and stability toward n-butanol gas at a low optimum temperature of 225 °C. In particular, they show higher sensitivity compared to pure α-Fe2O3 (4 times higher) and ZnO nanorods (2.5 times higher), respectively, along with faster response times. The significant enhancement in sensitivity may be attributed to the chemical and electronic sensitization induced by the ZnO nanoparticles deposited on the surfaces of the α-Fe2O3 nanorods. The findings reported in this study will be useful for the design and construction of surface modified-metal oxide nanostructures with enhanced gas-sensing performance

Crystal plane-dependent gas-sensing properties of zinc oxide nanostructures: experimental and theoretical studies

The sensitivity of a metal oxide gas sensor is strongly dependent on the nature of the crystal surface exposed to the gas species. In this study, two types of zinc oxide (ZnO) nanostructures: nanoplates and nanorods with exposed (0001) and (10[1 with combining macron]0) crystal surfaces, respectively, were synthesized through facile solvothermal methods. The gas-sensing results show that sensitivity of the ZnO nanoplates toward ethanol is two times higher than that of the ZnO nanorods, at an optimum operating temperature of 300 °C. This could be attributed to the higher surface area and the exposed (0001) crystal surfaces. DFT (Density Functional Theory) simulations were carried out to study the adsorption of ethanol on the ZnO crystal planes such as (0001), (10[1 with combining macron]0), and (11[2 with combining macron]0) with adsorbed O− ions. The results reveal that the exposed (0001) planes of the ZnO nanoplates promote better ethanol adsorption by interacting with the surface oxygen p (O2p) orbitals and stretching the O–H bond to lower the adsorption energy, leading to the sensitivity enhancement of the nanoplates. These findings will be useful for the fabrication of metal oxide nanostructures with specifically exposed crystal surfaces for improved gas-sensing and/or catalytic performance