Chemical Barrier Research Articles

The preventive effect of Glycyrrhiza polysaccharide on lipopolysaccharide-induced acute colitis in mice by modulating gut microbial communities

Acute colitis is characterised by an unpredictable onset and causes intestinal flora imbalance together with microbial migration, which leads to complex parenteral diseases. Dexamethasone, a classic drug, has side effects, so it is necessary to use natural products without side effects to prevent enteritis. Glycyrrhiza polysaccharide (GPS) is an α-d-pyranoid polysaccharide with anti-inflammatory effects; however, its anti-inflammatory mechanism in the colon remains unknown. This study investigated whether GPS reduces the lipopolysaccharide (LPS)-induced inflammatory response in acute colitis. The results revealed that GPS attenuated the upregulation of tumour necrosis factor-α, interleukin (IL)-1β, and IL-6 in the serum and colon tissues and significantly reduced the malondialdehyde content in colon tissues. In addition, the 400 mg/kg GPS group showed higher relative expressions of occludin, claudin-1, and zona occludens-1 in colon tissues and lower concentrations of diamine oxidase, D-lactate, and endotoxin in the serum than the LPS group did, indicating that GPS improved the physical and chemical barrier functions of colon tissues. GPS increased the abundance of beneficial bacteria, such as Lactobacillus, Bacteroides, and Akkermansia, whereas pathogenic bacteria, such as Oscillospira and Ruminococcus were inhibited. Our findings indicate that GPS can effectively prevent LPS-induced acute colitis and exert beneficial effects on the intestinal health.

High sulfur loading and shuttle inhibition of advanced sulfur cathode enabled by graphene network skin and N, P, F-doped mesoporous carbon interfaces for ultra-stable lithium sulfur battery

Achieving high loading of active sulfur yet rational regulating the shuttle effect of lithium polysulfide (LiPS) is of great significance in pursuit of high-performance lithium-sulfur (Li-S) battery. Herein, we develop a free-standing graphene-nitrogen (N), phosphorus (P) and fluorine (F) co-doped mesoporous carbon-sulfur (G-NPFMC-S) film, which was used as a binder-free cathode in Li-S battery. The developed mesoporous carbon (MC) achieved a high specific surface area of 921 m²·g^–1 with a uniform pore size distribution of 15 nm. The inserted graphene network inside G-NPFMC-S cathode can effectively improve its electrical conductivity and simultaneously restrict the shuttle of LiPS. A high sulfur loading of 86% was achieved due to the excellent porous structures of graphene-NPFMC (G-NPFMC) composite. When implemented as a freestanding cathode in Li-S battery, this G-NPFMC-S achieved a high specific capacity (1,356 mAh·g^–1), favorable rate capability, and long-term cycling stability up to 500 cycles with a minimum capacity fading rate of 0.025% per cycle, outperforming the corresponding performances of NPFMC-sulfur (NPFMC-S) and MC-sulfur (MC-S). These promising results can be ascribed to the featured structures that formed inside G-NPFMC-S film, as that highly porous NPFMC can provide sufficient storage space for the loading of sulfur, while, the N, P, F-doped carbonic interface and the inserted graphene network help hinder the shuttle of LiPS via chemical adsorption and physical barrier effect. This proposed unique structure can provide a bright prospect in that high mass loading of active sulfur and restriction the shuttle of LiPS can be simultaneously achieved for Li-S battery.

Quantum chemical study of CO2 physisorption and chemisorption on EDA‐grafted graphene oxide

AbstractOrganic amine grafting on graphene oxide (GO) is a potentially good CO2 adsorbent. The mechanism of CO2 capture by ethylenediamine grafted GO (EDA‐GO) is studied in detail by quantum chemical method in this article. A reasonable adsorbent model is constructed, and through electrostatic potential analysis, it is found that the larger negative electrostatic potential (GOEP/GOCA: N(180)/N(30) site) is a better potential adsorption site. The physical adsorption energies are also larger (−44.37 kJ/mol, −49.90 kJ/mol) at the larger negative electrostatic potential sites. The quantum chemical calculation of CO2 adsorption is carried out at the optimal reaction site. Results show that EDA grafted on epoxy and carboxyl groups of GO have good adsorption performance for CO2. The catalytic effect of H2O in the atmosphere can significantly reduce the adsorption reaction energy, which only needs 20–45 kJ/mol. Compared with EDA‐GOEP, EDA‐GOCA has lower physical adsorption energy and chemical adsorption energy barrier. EDA‐GOCA has good adsorption performance. Moreover, the desorption energy barrier (29.0 kJ/mol) is slightly higher than the adsorption energy barrier (23.3 kJ/mol), which is conducive to adsorption and desorption repeatedly. It is helpful in the recycling and reuse of adsorbents. For the adsorption of CO2 by EDA‐GO, the conversion of hydroxyl and epoxy groups to carboxyl groups is very important. This study would contribute to the development and design of solid CO2 adsorbents based on GO. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

The role of dipotassium ethylenediaminetetraacetic acid and potassium oleate on chemical mechanical planarization relevant to heterogeneous materials of cobalt interconnects

Cobalt (Co) with its low resistivity, superior adhesion property, and void-free seamless fill ability, pledges to transform the landscape of integrated circuits in many areas, especially in interconnects and logic contacts. The present work describes the selection and optimization process of the complexing agent and inhibitor in chemical mechanical polishing barrier slurries relevant for heterogeneous materials of Co interconnects. An alkaline colloidal silica based slurry has been proposed, consisting of 0.5 wt% hydrogen peroxide, 5 mM dipotassium ethylenediaminetetraacetic acid (EDTA-2K), 13 mM potassium oleate (PO) and producing a Co removal rate of 45.6 Å/min, along with an appropriate removal rate selectivity between oxide dielectric, barrier layer and Co, which reaches above ∼ 2:1:1. Furthermore, synergetic effects of the oxidizer, complexing agent EDTA-2K and inhibitor PO on the Co CMP process have been investigated systematically by several analytical techniques, including electrochemical analysis, X-ray photoelectron spectroscopy survey, and adsorption isotherm characterization. The role of EDTA-2K affecting SERs and MRRs embodies in its strong complexing ability by dissociating to full deprotonated EDTA ion and then reacting with Co to produce very stable chelate Co(Ⅱ)EDTA. Moreover, the effect of inhibitor PO has a critical point. With the addition of PO at a low concentration, an effective passivation layer could be formed on Co surfaces spontaneously via chemisorption, protecting Co from severe pitting corrosion. While in case of PO at high concentration, Co(Ⅱ)PO ligand will be generated, reducing the stability of the original PO-Co passive layer and providing paths for complexing agent EDTA-2K to produce Co(Ⅱ)EDTA chelate.

Liquid-sodium compatibility of plasma-sprayed Titania-Stabilized Zirconia, Lanthanum Zirconate, and Yttrium Aluminum Monoclinic coatings

Air plasma-sprayed (APS) ceramic coatings are being explored as chemical, environmental, electrical, and thermal barrier systems for components employed in sodium-cooled fast-spectrum nuclear reactors. The design and constructional requirements of several components demand the APS coatings be in continuous contact with the aggressive and corrosive liquid-sodium (coolant) environments. Conventional APS coatings were found to be susceptible to liquid-metal corrosion in high-temperature liquid-sodium environments. Towards this, three of the emerging thermal barrier ceramics such as Titania-Stabilized Zirconia (TiSZ), Lanthanum Zirconate (LZ), and Yttrium Aluminum Monoclinic (YAM), are investigated in the current work by exposing APS deposited ceramic coatings in liquid-sodium at 400 °C for 500 h and 1000 h. TiSZ coatings exhibited severe erosion of the topcoat and a complete degradation at the end of 1000 h due to grain boundary dissolution and the weakening of intersplat boundaries. LZ coatings showed partial failure due to the combined effects of erosion of the topcoat and spallation due to the formation of delamination cracks in the bulk of the topcoat. Except for some mild surface attacks, YAM coatings revealed erosion resistance, phase stability, chemical inertness, and structural integrity in liquid-sodium.

How Do Self-Interaction Errors Associated with Stretched Bonds Affect Barrier Height Predictions?

Density functional theory (DFT) suffers from self-interaction errors (SIEs) that generally result in the underestimation of chemical reaction barrier heights. This is commonly attributed to the tendency of density functional approximations to overstabilize delocalized densities that typically occur in the stretched bonds of transition state structures. The Perdew-Zunger self-interaction correction (PZSIC) and locally scaled self-interaction correction (LSIC) improve the prediction of barrier heights of chemical reactions, with LSIC giving better accuracy than PZSIC on average. These methods employ an orbital-by-orbital correction scheme to remove the one-electron SIE. In the context of barrier heights, this allows an analysis of how the self-interaction correction (SIC) for each orbital contributes to the calculated barriers using Fermi-Löwdin orbitals (FLOs). We hypothesize that the SIC contribution to the reaction barrier comes mainly from a limited number of orbitals that are directly involved in bond-breaking and bond-making in the reaction transition state. We call these participant orbitals (POs), in contrast to spectator orbitals (SOs) which are not directly involved in changes to the bonding. Our hypothesis is that ΔETotalSIC ≈ ΔEPOSIC, where ΔETotalSIC is the difference in the SIC corrections for the reactants or products and the transition state. We test this hypothesis for the reaction barriers of the BH76 benchmark set of reactions. We find that the stretched-bond orbitals indeed make the largest individual SIC contributions to the barriers. These contributions increase the barrier heights relative to LSDA, which underpredicts the barrier. However, the full stretched-bond hypothesis does not hold in all cases for either PZSIC or LSIC. There are many cases where the total SIC contribution from the SOs is significant and cannot be ignored. The size of the SIC contribution to the barrier height is a key indicator. A large SIC correction is correlated to a large LSDA error in the barrier, showing that PZSIC properly gives larger corrections when corrections are needed most. A comparison of the performance of PZSIC and LSIC shows that the two methods have similar accuracy for reactions with large LSDA errors, but LSIC is clearly better for reactions with small errors. We trace this to an improved description of reaction energies in LSIC.

Thicket and mesh: Understanding turgor pressure resistance of outer membrane-cell wall system.

The cell envelope of Gram-negative bacteria is composed of three layers: the outer membrane (OM), the peptidoglycan cell wall (PG), and the inner membrane. Together, the cell envelope provides a physical and chemical barrier that protects against the turgor pressure generated by the solute concentration difference between the inside and outside of bacteria, which can range from 0.2 atm to 5 atm. Previously, we measured the contribution of each component to see how it responds to different strains and determined that most of the cell envelope's strength comes from the OM and PG. However, the combined contribution from the OM and the PG, especially considering the Braun's lipoprotein (Lpp) that connects the two, remains to be elucidated. To address this, we constructed and simulated a combined OM-PG system that contains both OM and PG connected by Lpp. We also imposed different initial PG strain levels by stretching it by 2.0X and 2.5X its original size. The results showed that OM can resist imposed tensions by PG up to 2.0x its resting size. Moreover, we explored how the OM/PG-spanning protein TolC can affect the overall resistance to tension, through both enhancement of the connections between the layers and weakening them individually.

Atomistic mechanisms for catalytic transformations of NO to NH3, N2O, and N2 by Pd

The industrial pollutant NO is a potential threat to the environment and to human health. Thus, selective catalytic reduction of NO into harmless N2, NH3, and/or N2O gas is of great interest. Among many catalysts, metal Pd has been demonstrated to be most efficient for selectivity of reducing NO to N2. However, the reduction mechanism of NO on Pd, especially the route of N−N bond formation, remains unclear, impeding the development of new, improved catalysts. We report here the elementary reaction steps in the reaction pathway of reducing NO to NH3, N2O, and N2, based on density functional theory (DFT)-based quantum mechanics calculations. We show that the formation of N2O proceeds through an Eley-Rideal (E−R) reaction pathway that couples one adsorbed NO* with one non−adsorbed NO from the solvent or gas phase. This reaction requires high NO* surface coverage, leading first to the formation of the trans-(NO)2* intermediate with a low N−N coupling barrier (0.58 eV). Notably, trans-(NO)2* will continue to react with NO in the solvent to form N2O, that has not been reported. With the consumption of NO and the formation of N2O* in the solvent, the Langmuir-Hinshelwood (L-H) mechanism will dominate at this time, and N2O* will be reduced by hydrogenation at a low chemical barrier (0.42 eV) to form N2. In contrast, NH3 is completely formed by the L-H reaction, which has a higher chemical barrier (0.87 eV). Our predicted E-R reaction has not previously been reported, but it explains some existing experimental observations. In addition, we examine how catalyst activity might be improved by doping a single metal atom (M) at the NO* adsorption site to form M/Pd and show its influence on the barrier for forming the N−N bond to provide control over the product distribution.

Construction of Human Three-Dimensional Lung Model Using Layer-by-Layer Method.

The respiratory tract is one of the frontline barriers for biological defense. Lung epithelial intercellular adhesions provide protection from bacterial and viral infections and prevent invasion into deep tissues by pathogens. Dysfunction of lung epithelial intercellular adhesion caused by pathogens is associated with development of several diseases, such as acute respiratory distress syndrome, pneumonia, and asthma. To elucidate the pathological mechanism of respiratory infections, two-dimensional cell cultures and animal models are commonly used, although are not useful for evaluating host specificity or human biological response. With the rapid progression and worldwide spread of severe acute respiratory syndrome coronavirus-2, there is increasing interest in the development of a three-dimensional (3D) in vitro lung model for analyzing interactions between pathogens and hosts. However, some models possess unclear epithelial polarity or insufficient barrier functions and need the use of complex technologies, have high cost, and long cultivation terms. We previously reported about the fabrication of 3D cellular multilayers using a layer-by-layer (LbL) cell coating technique with extracellular matrix protein, fibronectin (FN), and gelatin (G). In the present study, such a LbL cell coating technique was utilized to construct a human 3D lung model in which a monolayer of the human lower airway epithelial adenocarcinoma cell line Calu-3 cells was placed on 3D-cellular multilayers composed of FN-G-coated human primary pulmonary fibroblast cells. The 3D lung model thus constructed demonstrated an epithelial-fibroblast layer that maintained uniform thickness until 7 days of incubation. Moreover, expressions of E-cadherin, ZO-1, and mucin in the epithelial layer were observed by immunohistochemical staining. Epithelial barrier integrity was evaluated using transepithelial electrical resistance values. The results indicate that the present constructed human 3D lung model is similar to human lung tissues and also features epithelial polarity and a barrier function, thus is considered useful for evaluating infection and pathological mechanisms related to pneumonia and several pathogens. Impact statement A novel in vitro model of lung tissue was established. Using a layer-by-layer cell coating technique, a three-dimensional cultured lung model was constructed. The present novel model was shown to have epithelial polarity and chemical barrier functions. This model may be useful for investigating interaction pathogens and human biology.

Probing the human epidermis by combining ToF-SIMS and multivariate analysis.

The mammalian organism is continuously exposed to various biological and chemical threats from its surroundings. In order to provide protection against these threats, mammals have developed a specialized defense system at the interface with their environment. This system, known as the epidermis, is mainly composed of stratified keratinocytes organized in a complex self-renewing structure providing a mechanical and chemical barrier at the skin surface. However, numerous skin-related pathologies can interfere with the proper formation and function of the epidermal barrier. The pathogenesis of these alterations is often very complex. Understanding the changes induced in epidermal tissues by these pathologies at a molecular level is key for their treatment and prevention. In this context, this work aims at developing a thorough and reproducible characterization methodology of the human epidermis by applying ToF-SIMS to the study of an in vitro epidermal model known as reconstructed human epidermis (RHE). Indeed, although the potential of ToF-SIMS for the characterization of the mammalian skin has already been demonstrated, very few studies focus their efforts on the human epidermis itself. Here, we performed static ToF-SIMS characterizations of RHE cryosections, combining both high mass and high lateral resolution acquisitions. In addition, principal components analysis was used as a multivariate analysis tool. This contributed to the decorrelation of the complex datasets obtained from these biological systems and allowed capturing of their most statistically representative spectral features. Remarkably, this tool proved to be successful in extracting meaningful biological information from the datasets by yielding principal components distinguishing the cornified layers from the metabolically active epidermal cells. Finally, on the basis of multiple ToF-SIMS acquisitions, we showed that this methodology allows for the convenient production of experimental replicates, a key feature often difficult to achieve in ex vivo approaches.

Oat β-glucan supplementation pre- and during pregnancy alleviates fetal intestinal immunity development damaged by gestational diabetes in rats.

Oat β-glucan (OG) has been shown to improve intestinal microecology in gestational diabetes mellitus (GDM), but the effect on fetal intestine health is unknown. Herein, we aimed to investigate the effects of OG supplementation during gestation in GDM dams on fetal intestinal immune development. OG was supplemented one week before mating until the end of the experiment. GDM rats were made with a high-fat diet (HFD) with a minimal streptozotocin (STZ) dose. The fetal intestines were sampled at gestation day (GD) 19.5, and the intestinal morphology, chemical barrier molecules, intraepithelial immune cell makers, and levels of inflammatory cytokines were investigated. The results showed that OG supplementation alleviated the decrease of the depth of fetal intestinal villi and crypts, the number of goblet cells (GCs), protein expression of mucin-1 (Muc1) and Muc2, the mRNA levels of Gpr41, Gpr43, and T cell markers, and increased the number of paneth cells (PCs), the mRNA levels of defensin-6 (defa6), and macrophage (Mø) marker and the expression of cytokines induced by GDM. In addition, OG supplementation alleviated the function of immune cell self-proliferation, chemotaxis and assembly capabilities, protein, fat, folic acid, and zinc absorption damaged by GDM. As indicated by these findings, OG supplementation before and during pregnancy improved the fetal intestinal chemical barriers, immune cells, cytokines, and the metabolism of nutrients to protect the fetal intestinal immunity.

The role of tumor microenvironment in cholangiocarcinoma

Cholangiocarcinoma (CCA) is an extremely aggressive neoplasia, mostly because of diagnostic delay and lack of effective therapies. CCA is typically surrounded by a peculiar microenvironment that includes abundant desmoplastic stroma and various cell types, which support and enhance CCA development. Among the tumor microenvironment (TME) cells, there are tumor infiltrating lymphocytes (TILs), such as CD8+ and CD4+ cells, Tregs, natural killers (NKs) and B lymphocytes. TILs contribute to an immunosuppressive microenvironment that leads to tumor immune escape. Dendritic cells (DCs) may lead to immunotolerance by maturation or antigen-presentation deficiency. Hepatic stellate cells (HSCs) are one of the major precursors of cancer-associated fibroblast (CAFs), which are distinguished in various subpopulations, each with different functions and interactions with other TME cells. CAFs can promote lymphangiogenesis, early lymph-node metastasis and proinflammatory environment, but they can also provide a physical and chemical barrier to protect CCA. Tumor-associated macrophages (TAMs) could be differentiated between two phenotypes, pro- and anti-inflammatory, and they may sustain invasiveness and immunosuppression. Myeloid-derived suppressor cells (MDSCs) impair cytotoxic T lymphocytes (CTLs) function, stimulating tumor proliferation and angiogenesis. Tumor-associated neutrophils (TANs) function is influenced by the TME, leading to tumor-suppressing or tumor-promoting functions. This paper aims to provide an overview of the CCA microenvironment cells, their role in tumor progression and possible correlated diagnostic, therapeutic and prognostic implications.

Covalent Grafting of 5-Aminolevulinic Acid onto Polylactic Acid Films and Their Photodynamic Potency in Preserving Salmon.

A novel photodynamic inactivation (PDI)-mediated antimicrobial film of polylactic acid/5-aminolevulinic acid (PLA/ALA) was successfully fabricated by a covalent grafting method using low-temperature plasma. The chemical structure, surface morphology, hydrophilic ability, and mechanical and barrier properties of the films were characterized, and their antibacterial, anti-biofilm potency and preservation effects on ready-to-eat salmon were investigated during storage. Results showed that the amino group of ALA was covalently grafted with the carboxyl group on the surface of PLA after the plasma treatment, with the highest grafting rate reaching ∼50%. The fabricated PLA/ALA films displayed an enhanced barrier ability against water vapor and oxygen. Under blue light-emitting diode illumination, the PLA/ALA films generated massive reactive oxygen species from the endogenous porphyrins in cells induced by ALA and then fatally destroyed the cell wall of planktonic cells and the architectural structures of sessile biofilms of the pathogens (Listeria monocytogenes and Vibrio parahaemolyticus) and spoilage bacterium (Shewanella putrefaciens). More importantly, the PDI-mediated PLA/ALA films potently inhibited 99.9% native bacteria on ready-to-eat salmon and significantly suppressed the changes of its drip loss, pH, and lipid oxidation (MDA) during storage, and on this basis, the shelf life of salmon was extended by 4 days compared with that of the commercial polyethylene film. Therefore, the PDI-mediated PLA/ALA films are valid in inactivating harmful bacterial and preserving the quality of seafood.

Battle for control of anthocyanin biosynthesis in two Brassicaceae species infected with turnip mosaic virus.

It has previously been found that turnip mosaic virus (TuMV) greatly suppresses anthocyanin accumulation (AA) in Brassica rapa leaves, and that such leaves become infected whilst anthocyanin-enriched leaves on the same plants are rarely infected. To clarify whether AA is a defense against TuMV, in this study we examined tissue-level patterns of spontaneous AA in relation to the cellular localization of a TuMV strain that expresses a yellow fluorescent protein. We found that TuMV infection was significantly blocked by AA, suggesting that it functions as a chemical barrier against TuMV. We next analysed changes in expression of genes related to anthocyanin biosynthesis in TuMV-infected leaves of Arabidopsis. TuMV also suppressed AA that is induced by high light in Arabidopsis, and this this suppression was mainly due to inhibited expression of anthocyanin late-biosynthesis genes (LBGs). Most positive transcription factors of LBGs were also down-regulated, while the negative regulator SPL15 was highly up-regulated. Cucumber mosaic virus (CMV) also moderately suppressed AA in Arabidopsis, but in a different manner. Since it appeared that anthocyanin-enriched leaves of Arabidopsis were resistant to TuMV but not CMV, our results suggested that the anthocyanin-associated resistance that we observed was specific to TuMV.

Role of Phenylpropanoids and Flavonoids in Plant Resistance to Pests and Diseases

Phenylpropanoids and flavonoids are specialized metabolites frequently reported as involved in plant defense to biotic or abiotic stresses. Their biosynthetic accumulation may be constitutive and/or induced in response to external stimuli. They may participate in plant signaling driving plant defense responses, act as a physical or chemical barrier to prevent invasion, or as a direct toxic weapon against microbial or insect targets. Their protective action is described as the combinatory effect of their localization during the host's interaction with aggressors, their sustained availability, and the predominance of specific compounds or synergy with others. Their biosynthesis and regulation are partly deciphered; however, a lot of gaps in knowledge remain to be filled. Their mode of action on microorganisms and insects probably arises from an interference with important cellular machineries and structures, yet this is not fully understood for all type of pests and pathogens. We present here an overview of advances in the state of the art for both phenylpropanoids and flavonoids with the objective of paving the way for plant breeders looking for natural sources of resistance to improve plant varieties. Examples are provided for all types of microorganisms and insects that are targeted in crop protection. For this purpose, fields of phytopathology, phytochemistry, and human health were explored.

Next-Generation Heterocyclic Electrophiles as Small-Molecule Covalent MurA Inhibitors.

Heterocyclic electrophiles as small covalent fragments showed promising inhibitory activity on the antibacterial target MurA (UDP-N-acetylglucosamine 1-carboxyvinyltransferase, EC:2.5.1.7). Here, we report the second generation of heterocyclic electrophiles: the quaternized analogue of the heterocyclic covalent fragment library with improved reactivity and MurA inhibitory potency. Quantum chemical reaction barrier calculations, GSH (L-glutathione) reactivity assay, and thrombin counter screen were also used to demonstrate and explain the improved reactivity and selectivity of the N-methylated heterocycles and to compare the two generations of heterocyclic electrophiles.

Unfolding the role of placental-derived Extracellular Vesicles in Pregnancy: From homeostasis to pathophysiology.

The human placenta is a critical structure with multiple roles in pregnancy, including fetal nutrition and support, immunological, mechanical and chemical barrier as well as an endocrine activity. Besides, a growing body of evidence highlight the relevance of this organ on the maternofetal wellbeing not only during gestation, but also from birth onwards. Extracellular vesicles (EVs) are complex macromolecular structures of different size and content, acting as carriers of a diverse set of molecules and information from donor to recipient cells. Since its early development, the production and function of placental-derived EVs are essential to ensure an adequate progress of pregnancy. In turn, the fetus receives and produce their own EVs, highlighting the importance of these components in the maternofetal communication. Moreover, several studies have shown the clinical relevance of EVs in different obstetric pathologies such as preeclampsia, infectious diseases or gestational diabetes, among others, suggesting that they could be used as pathophysiological biomarkers of these diseases. Overall, the aim of this article is to present an updated review of the published basic and translational knowledge focusing on the role of placental-derived EVs in normal and pathological pregnancies. We suggest as well future lines of research to take in this novel and promising field.

Dysregulated hepatic lipid metabolism and gut microbiota associated with early-stage NAFLD in ASPP2-deficiency mice

Growing evidence indicates that lipid metabolism disorders and gut microbiota dysbiosis were related to the progression of non-alcoholic fatty liver disease (NAFLD). Apoptosis-stimulating p53 protein 2 (ASPP2) has been reported to protect against hepatocyte injury by regulating the lipid metabolism, but the mechanisms remain largely unknown. In this study, we investigate the effect of ASPP2 deficiency on NAFLD, lipid metabolism and gut microbiota using ASPP2 globally heterozygous knockout (ASPP2+/-) mice. ASPP2+/- Balb/c mice were fed with methionine and choline deficient diet for 3, 10 and 40 day to induce an early and later-stage of NAFLD, respectively. Fresh fecal samples were collected and followed by 16S rRNA sequencing. HPLC-MRM relative quantification analysis was used to identify changes in hepatic lipid profiles. The expression level of innate immunity-, lipid metabolism- and intestinal permeability-related genes were determined. A spearman's rank correlation analysis was performed to identify possible correlation between hepatic medium and long-chain fatty acid and gut microbiota in ASPP2-deficiency mice. Compared with the WT control, ASPP2-deficiency mice developed moderate steatosis at day 10 and severe steatosis at day 40. The levels of hepatic long chain omega-3 fatty acid, eicosapentaenoic (EPA, 20:5 n-3) and docosahexaenoic (DHA, 22:6 n-3), were decreased at day 10 and increased at day 40 in ASPP+/- mice. Fecal microbiota analysis showed significantly increased alpha and beta diversity, as well as the composition of gut microbiota at the phylum, class, order, family, genus, species levels in ASPP2+/- mice. Moreover, ASPP-deficiency mice exhibited impaired intestinal barrier function, reduced expression of genes associated with chemical barrier (REG3B, REG3G, Lysozyme and IAP), and increased expression of innate immune components (TLR4 and TLR2). Furthermore, correlation analysis between gut microbiota and fatty acids revealed that EPA was significantly negatively correlated with Bifidobacterium family. Our findings suggested that ASPP2-deficiency promotes the progression of NAFLD, alterations in fatty acid metabolism and gut microbiota dysbiosis. The long chain fatty acid EPA was significantly negatively correlated with Bifidobacterial abundance, which is a specific feature of NAFLD in ASPP2-deficiency mice. Totally, the results provide evidence for a mechanism of ASPP2 on dysregulation of fatty acid metabolism and gut microbiota dysbiosis.

Probiotics (Lactobacillus plantarum HNU082) Supplementation Relieves Ulcerative Colitis by Affecting Intestinal Barrier Functions, Immunity-Related Gene Expression, Gut Microbiota, and Metabolic Pathways in Mice.

Probiotics can effectively improve ulcerative colitis (UC), but the mechanism is still unclear. Here, shotgun metagenome and transcriptome analyses were performed to explore the therapeutic effect and the mechanism of the probiotic Lactobacillus plantarum HNU082 (Lp082) on UC. The results showed that Lp082 treatment significantly ameliorated dextran sulfate sodium (DSS)-induced UC in mice, which was manifested as increases in body weight, water intake, food intake, and colon length and decreases in disease activity index (DAI), immune organ index, inflammatory factors, and histopathological scores after Lp082 intake. An in-depth study discovered that Lp082 could improve the intestinal mucosal barrier and relieve inflammation by cooptimizing the biological barrier, chemical barrier, mechanical barrier, and immune barrier. Specifically, Lp082 rebuilt the biological barrier by regulating the intestinal microbiome and increasing the production of short-chain fatty acids (SCFAs). Lp082 improved the chemical barrier by reducing intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM) and increasing goblet cells and mucin2. Lp082 ameliorated the mechanical barrier by increasing zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), and occludin while decreasing claudin-1 and claudin-2. Lp082 optimized the immune barrier by reducing the content of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), myeloperoxidase (MPO), and interferon-γ (IFN-γ) and increasing IL-10, transforming growth factor-β1 (TGF-β1), and TGF-β2, inhibiting the NF-κB signaling pathway. Taken together, probiotic Lp082 can play a protective role in a DSS-induced colitis mouse model by protecting the intestinal mucosal barrier, attenuating the inflammatory response, and regulating microbial imbalance. This study provides support for the development of probiotic-based microbial products as an alternative treatment strategy for UC. IMPORTANCE Many studies have focused on the therapeutic effect of probiotics on ulcerative colitis (UC), but few studies have paid attention to the mechanism of probiotics, especially the therapeutic effect. This study suggests that Lp082 has a therapeutic effect on colitis in mice. Its mechanisms of action include protecting the mucosal barrier and actively modulating the gut microbiome, modulating inflammatory pathways, and reducing neutrophil infiltration. Our study enriches the mechanism and provides a new prospect for probiotics in the treatment of colitis, helps to deepen the understanding of the intestinal mucosal barrier, and provides guidance for the future probiotic treatment of human colitis.

Chemical Stability of Atomic Layer Deposited (ALD) Alumina Thin Films in Aqueous Solutions

Aluminum oxide (alumina) thin films deposited through atomic layer deposition (ALD) are of great interest in chemical barrier and corrosion protection applications. However, the stability of ALD alumina in aqueous solutions is still not fully understood. Due to its metastable amorphous phase, the hydration and degradation behavior of ALD alumina films behaves differently from its crystalline Al2O3 counterpart. A full understanding of why these films hydrate and/or dissolve requires the exploration of different deposition conditions and ion content in solutions used. This talk will discuss efforts to further elucidate the hydration and dissolution behavior of ALD alumina films. For this study, alumina thin films were ALD deposited onto silicon substrate at 150 °C using trimethylaluminum (TMA) and H2O. These films were then studied in Type 1 DI water, 2M NaCl, .5M NaCl, and .1M NaCl solutions at room temperature. Films were gently dried using a nitrogen gun and thickness was measured using a Cauchy ellipsometry model. After 15 days of immersion in Type 1 DI water, significant thickness growth is observed at twice (27 days) and 2.5 times (33 days) the normalized thickness. Similar hydration is not observed in salt-containing aqueous solutions nor upon exposure to air. We will discuss the possible effects of CO2 dissolution and carbonate formation as well as ionic species on the hydration and dissolution processes of these alumina films. Finally, we will show how a post-ALD plasma treatment to the film’s surface alters the hydration and dissolution behavior, improving stability in several aqueous conditions.