Effect of water vapor on proton conduction of cesium dihydrogen phosphateand application to intermediate temperature fuel cells

The proton conduction and superionic phase transition of cesium dihydrogen phosphate, CsH₂PO₄ (CDP), were investigated under various humid conditions to evaluate the applicability of a CsH₂PO₄ solid electrolyte to an intermediate temperature fuel cell operating between 230 °C and 300 °C. The phase stability, superionic phase transition, and reversibility of dehydration of CsH₂PO₄ were evaluated under different ambient water vapor concentrations, from 0 to 90 mol%, through the measurements of conductivity. The dependence of conductivity on the water vapor concentration and the demonstrated reversibility of dehydration clearly showed the range in which CsH₂PO₄ is applicable to the intermediate temperature fuel cell. Additionally, we evaluated the protonic transport number of CsH₂PO₄, which was almost unity, and demonstrated fuel cell operation at 250 °C using a single cell fabricated with the CsH₂PO₄ electrolyte.     

GAS-LIQUID MASS TRANSFER CHARACTERISTICS OF LARGE-SCALE IMPELLERS: EMPIRICAL CORRELATIONS OF GAS HOLDUPS AND VOLUMETRIC MASS TRANSFER COEFFICIENTS IN STIRRED TANKS

Gas dispersion with large-scale impellers consisting of modified large paddle impellers in stirred tanks, with rather large ratios of both impeller diameter and impeller height to tank diameter, was experimentally examined in transition and turbulent mixing ranges. Gas holdups and volumetric gas-liquid mass transfer coefficients with large-scale impellers, i.e., Maxblend and Fullzone impellers, were measured in 0.31 and 0.6 m I.D. stirred tanks, and the gas dispersion performance of large-scale impellers was compared with that of double conventional small-scale high-speed impeller systems, i.e., double four-flat blade disk turbine impellers and double four-flat paddle impellers.

The gas holdups of the large-scale impellers were comparable with those of the small-scale impeller systems at a given rotational speed. The volumetric gas-liquid mass transfer coefficients for large-scale impellers were also similar to those of the small-scale impeller systems. It was found that the large-scale impellers are not more energy efficient than the small-scale impellers in obtaining good gas dispersion.

Empirical correlations for gas holdups and volumetric gas-liquid mass transfer coefficients were developed. They fit the experimental data in transition and turbulent mixing ranges reasonably well, with correlation factors greater than 0.84.     

Effect of pH on the properties of protonated polyaniline-based films for pH sensing applications

The chemical and physical properties of protonated polyaniline (PANI)-based films, including PANI-emeraldine salt (ES) and PANI/polyvinyl acetate (PVAc) films, before and after pH treatments are characterized and compared. Protonated PANI-based films are prepared by spin coating. The effects of pH value and immersion time on the film properties are investigated to gain a better understanding of their performance in pH sensing. The films are characterized based on color, morphology, chemical structure, phase state, and protonation state. Protonated PANI-based films exhibit a color change from green to dark blue as deprotonation occurs in solutions with higher pH. The highly porous structure of PANI/PVAc films is slightly affected by the pH of the solution. However, the globular structure of the PANI-ES films forms cracks with increasing immersion time. PANI/PVAc films exhibit better stability in acidic and neutral solutions than in alkaline solutions because of the hydrolysis of PVAc. Compared with the negligible differences in the PANI/PVAc film in buffers with different pH, PANI-ES exhibits noticeable changes. Therefore, PVAc improves the stability and performance of PANI for pH-sensing applications.     

Nonionic surfactant mixtures in an imidazolium-type room-temperature ionic liquid

The physicochemical properties of nonionic surfactant mixtures in an aprotic, imidazolium-type room-temperature ionic liquid (RT-IL) have been studied using a combination of static surface tensiometry, dynamic light scattering (DLS), and cryogenic transmission electron microscopy (cryo-TEM). The surfactants used in this study are phytosterol ethoxylates (BPS-n, where n is an oxyethylene chain length of either 5 or 30) and the selected RT-IL is 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF(6)). The shorter chain oxyethylene surfactant (BPS-5) exhibits greater surface activity in BmimPF(6) than BPS-30; hence, BPS-5 is a major component in driving the interfacial adsorption and molecular aggregation of the mixed system. The surface tension data demonstrate that an increased mole fraction of BPS-5 results in a decreased critical aggregation concentration (cac) and negatively increased Gibbs free energies estimated for molecular aggregation (ΔG(0)(agg)) and interfacial adsorption (ΔG(0)(ads)). Indeed, the compositions of the monolayer adsorbed at the air/solution interface and the molecular aggregate formed in the bulk solution are enriched with BPS-5. The combination of the DLS and cryo-TEM results demonstrates the spontaneous formation of multi-lamellar vesicles resulting from the BPS-5-rich composition of the molecular aggregates.     

Remodeling of Bone Marrow Niches and Roles of Exosomes in Leukemia

Leukemia is a hematological malignancy that originates from hematopoietic stem cells in the bone marrow. Significant progress has made in understanding its pathogensis and in establishing chemotherapy and hematopoietic stem cell transplantation therapy (HSCT). However, while the successive development of new therapies, such as molecular-targeted therapy and immunotherapy, have resulted in remarkable advances, the fact remains that some patients still cannot be saved, and resistance to treatment and relapse are still problems that need to be solved in leukemia patients. The bone marrow (BM) niche is a microenvironment that includes hematopoietic stem cells and their supporting cells. Leukemia cells interact with bone marrow niches and modulate them, not only inducing molecular and functional changes but also switching to niches favored by leukemia cells. The latter are closely associated with leukemia progression, suppression of normal hematopoiesis, and chemotherapy resistance, which is precisely the area of ongoing study. Exosomes play an important role in cell-to-cell communication, not only with cells in close proximity but also with those more distant due to the nature of exosomal circulation via body fluids. In leukemia, exosomes play important roles in leukemogenesis, disease progression, and organ invasion, and their usefulness in the diagnosis and treatment of leukemia has recently been reported. The interaction between leukemia cell-derived exosomes and the BM microenvironment has received particular attention. Their interaction is believed to play a very important role; in addition to their diagnostic value, exosomes could serve as a marker for monitoring treatment efficacy and as an aid in overcoming drug resistance, among the many problems in leukemia patients that have yet to be overcome. In this paper, we will review bone marrow niches in leukemia, findings on leukemia-derived exosomes, and exosome-induced changes in bone marrow niches.     

Effects of Thrombomodulin in Reducing Lethality and Suppressing Neutrophil Extracellular Trap Formation in the Lungs and Liver in a Lipopolysaccharide-Induced Murine Septic Shock Model

Neutrophil extracellular trap (NET) formation, an innate immune system response, is associated with thrombogenesis and vascular endothelial injury. Circulatory disorders due to microvascular thrombogenesis are one of the principal causes of organ damage. NET formation in organs contributes to the exacerbation of sepsis, which is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. We have previously reported that recombinant human soluble thrombomodulin (rTM) reduces lipopolysaccharide (LPS)-induced NET formation in vitro. Here, we aimed to show that thrombomodulin (TM)-mediated suppression of NET formation protects against organ damage in sepsis. Mice were injected intraperitoneally (i.p.) with 10 mg/kg LPS. rTM (6 mg/kg/day) or saline was administered i.p. 1 h after LPS injection. In the LPS-induced murine septic shock model, extracellular histones, which are components of NETs, were observed in the liver and lungs. In addition, the serum cytokine (interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), macrophage chemotactic protein-1 (MCP-1), and interleukin-10 (IL-10)) levels were increased. The administration of rTM in this model prevented NET formation in the organs and suppressed the increase in the levels of all cytokines except IL-1β. Furthermore, the survival rate improved. We provide a novel role of TM in treating inflammation and NETs in organs during sepsis.     

Relationship between NAFLD and Periodontal Disease from the View of Clinical and Basic Research,and Immunological Response

Periodontal disease is an inflammatory disease caused by pathogenic oral microorganisms that leads to the destruction of alveolar bone and connective tissues around the teeth. Although many studies have shown that periodontal disease is a risk factor for systemic diseases, such as type 2 diabetes and cardiovascular diseases, the relationship between nonalcoholic fatty liver disease (NAFLD) and periodontal disease has not yet been clarified. Thus, the purpose of this review was to reveal the relationship between NAFLD and periodontal disease based on epidemiological studies, basic research, and immunology. Many cross-sectional and prospective epidemiological studies have indicated that periodontal disease is a risk factor for NAFLD. An in vivo animal model revealed that infection with periodontopathic bacteria accelerates the progression of NAFLD accompanied by enhanced steatosis. Moreover, the detection of periodontopathic bacteria in the liver may demonstrate that the bacteria have a direct impact on NAFLD. Furthermore, Porphyromonas gingivalis lipopolysaccharide induces inflammation and accumulation of intracellular lipids in hepatocytes. Th17 may be a key molecule for explaining the relationship between periodontal disease and NAFLD. In this review, we attempted to establish that oral health is essential for systemic health, especially in patients with NAFLD.     

The molecular weight ratio of monomethoxypolyethylene glycol (mPEG) to protein determines the immunotolerogenicity of mPEG proteins

Immunotolerogenic activity of monomethoxypolyethylene glycol-(mPEG) conjugated proteins is a beneficial property in proteinpharmaceutics. However, procedures for the preparation of tolerogenicmPEG proteins have not yet been defined. We prepared mPEG proteinswith different mPEG contents using three proteins, hen egg lysozyme,ovalbumin and bovine gamma globulin, and their tolerogenicitiesto antigen-specific T and B cell responses were examined. Wefound the most appropriate ratio of tolerance induction to be1.5–2.0, which is the molecular weight ratio of conjugatedtotal mPEGs to protein. This value may assist in the preparationof tolerogenic mPEG proteins.     

Synthesis and Application of Stable Copper Oxide Nanoparticle Suspensions for Nanoparticulate Film Fabrication

Colloidal suspensions of copper oxide (CuO) nanoparticles were prepared by an alcothermal method, in which copper acetate was reacted with sodium hydroxide in the presence of acetic acid in ethanol at 78°C. The prepared suspension was stable for up to 1 month without stabilizers such as surfactants. Transmission electron microscopy analyses revealed that the suspension contained nanosized CuO particles of 5–10 nm size with a narrow size distribution. Nanoparticulate CuO films packed with grains smaller than 60 nm were fabricated on Si substrates by spin coating a suspension of CuO nanoparticles and subsequent heat treatment at 500°C.     

Phase diagram calculations of ZrO2-based ceramics with an emphasis on the reduction/oxidation equilibria of cerium ions in the ZrO2-YO1.5-CeO2-CeO1.5 system

Phase diagram calculations that were made previously for the ZrO₂-MO _m/2 (m = 2, 3, 4) systems and for the ZrO₂-YO_1.5-MO _m/2 (M = transition metals) systems have been extended to the ZrO₂-YO_1.5-CeO₂(-CeO_1.5) system to make an attempt to explain (1) thermogravimetric (TG) results as a function of oxygen potential, (2) electronic conductivity as a function of oxygen potential, and (3) a miscibility gap observed in air. The interaction parameters for the CeO₂-CeO_1.5-YO_1.5 system were obtained from the reported oxygen nonstoichiometry in CeO_2−x and rate earth doped ceria, (Ce,RE)O_2−δ . The interaction parameters for the ZrO₂-CeO₂ subsystem were obtained so as to reproduce the observed miscibility gap at 1273 K. Those thermodynamic properties can reproduce consistently the experimental behaviors of the electronic conductivity and the TG results in the (Zr_1−x Ce _x )_0.8Y_0.2O_1.9 solid solutions; these indicate the enhancement of reduction of CeO₂.