Display omitted
•111-oriented Pt nanorods were grown on polyhedral ceria by a colloidal strategy.•The Pt nanorods show strong atomic and electronic coupling with ceria support.•The coupling effects ...improve O2 adsorption and activation on Pt sites.•The Pt nanorods/doped ceria catalyst exhibits excellent ORR activity and stability.
Promoting the oxygen reduction reaction (ORR) performance is an urgent need to reduce the amount of Pt catalysts in fuel cells. One of the most promising strategies is interface engineering which takes advantage of the synergistic catalytic proficiencies of double or even multiple components. Herein, we synthesized the electrocatalyst that comprises Pt nanorods atomically oriented along the (111) nanofacets of Gd-doped cerium oxide polyhedra, which was much superior to commercial Pt/C catalyst for the four-electron ORR, with a 4-fold improvement of ORR intrinsic activity than Pt/C, as well as producing much less of the undesirable two-electron ORR product H2O2. It also features a remarkable stability, with negligible activity degradation in 5000-cycle test. The exposure of Pt(111) facets and the oxygen vacancy-mediated interfacial PtCe alloying facilitate O2 adsorption and dissociation together with desorption of OHad, which can account for the exceptional ORR electrocatalytic performance.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The mechanical and chemical durability is one of the most crucial properties for proton exchange membranes in practical fuel cell applications. In the present paper, we report the physical ...reinforcement of chemically stable, highly proton conductive tandemly sulfonated, partially fluorinated polyphenylenes using porous polyethylene (PE). With the PE pores completely and homogeneously filled by ionomers through a push coating approach, the resulting reinforced membranes were more proton conductive (183.1-389.2 mS cm
−1
) than the commercial perfluorinated ionomer (Nafion: 120.6-187.2 mS cm
−1
) membrane at high humidity (80-95% RH). Benefiting from the tough PE supporting layer, the reinforced membranes outperformed the parent ionomer membranes in stretchability with maximum strain up to 453%. The combination of intrinsic chemical stability of partially fluorinated polyphenylene ionomers and physical reinforcement with PE substrates contributed for the reinforced membranes to achieving superior durability to survive more than 20 000 cycles in severe accelerated durability test combining OCV hold and wet/dry frequent cycling.
The chemically stable, partially fluorinated polyphenylene ionomer membranes reinforced with porous polyethylene substrates achieved superior durability to survive more than 20 000 cycles in severe accelerated durability test.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
The technical possibility and possible issues of an intermediate–temperature–operated polymer electrolyte fuel cell (@120 °C) is investigated with an eye toward the launching of new fuel cell ...heavy–duty vehicles on the world market. Commercial perfluorosulfonic acid membrane and a commercial Pt catalyst supported on carbon are selected to clarify the possible issues in the fuel cells. The cell resistivity at high humidity is less than 0.1 Ω cm
–2
. The mass activity (@ 0.85 V, Pt loading amount: 0.33 mg
Pt
cm
−2
) approaches 850 A g
Pt
–1
. The high gas crossover rate through the membrane leads to decreased open circuit voltage, which necessitates the use of higher Pt loadings (>0.30 mg
Pt
cm
–2
) at the cathode to mitigate the effect of the mixed potential. Pt degradation during 120 °C operation at low humidity is found to be much lower than that during 80 °C operation at high humidity based on the results of load–cycle durability testing.
Microglial removal of dying cells plays a beneficial role in maintaining homeostasis in the CNS, whereas under some pathological conditions, inflammatory microglia can cause excessive clearance, ...leading to neuronal death. However, the mechanisms underlying dying cell removal by inflammatory microglia remain poorly understood. In this study, we performed live imaging to examine the purinergic regulation of dying cell removal by inflammatory activated microglia. Lipopolysaccharide (LPS) stimulation induces rapid death of primary rat microglia, and the surviving microglia actively remove dying cells. The nonselective P2 receptor antagonist, suramin, inhibited dying cell removal to the same degree as that of the selective P2Y2 antagonist, AR-C118925. This inhibition was more potent in LPS-stimulated microglia than in non-stimulated ones. LPS stimulation elicited distribution of the P2Y2 receptor on the leading edge of the plasma membrane and then induced drastic upregulation of P2Y2 receptor mRNA expression in microglia. LPS stimulation caused upregulation of the dying cell-sensing inflammatory Axl phagocytic receptor, which was suppressed by blocking the P2Y2 receptor and its downstream signaling effector, proline-rich tyrosine kinase (Pyk2). Together, these results indicate that inflammatory stimuli may activate the P2Y2 receptor, thereby mediating dying cell removal, at least partially, through upregulating phagocytic Axl in microglia.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The mechanical durability of our hydrocarbon polymer electrolyte membrane, poly(sulfophenylene quinquephenylene) (SPP-QP) or polyphenylene ionomer, was evaluated in wet/dry cycle tests in fuel cells ...according to the US-DOE protocol, where the effect of gas diffusion layers (hard or soft GDL) was investigated. The membrane exhibited mechanical failure with the hard GDL and H2 crossover (permeation through the membrane) jumping from 0.01% to ca. 2% after 4,000 cycles. Post-test analyses indicated that the edge of the membrane under the gasket was the most damaged, where the dimensional change upon humidification/dehumidification was restricted. Use of the soft GDL significantly improved the wet/dry cycle durability of the membrane with no practical changes in the H2 crossover, even after 30,000 cycles, due to the strong adhesion of the GDL to the catalyst layers. The mechanical durability of the SPP-QP membrane was better than that of our previous aromatic-based ionomer membrane containing ether and ketone groups in the main chain. The loss of molecular weight and the sulfonic acid groups was rather minor for the SPP-QP membrane, indicating chemical robustness of the membrane under the severe wet/dry cycle conditions.
•Sulfonated polyphenylene ionomer membranes are durable in wet/dry cycling in fuel cells.•Soft gas diffusion layer improves significantly mechanical durability of the ionomer membranes.•Strong adhesion of the gas diffusion layer to the catalyst layer prevents mechanical failure of the membrane.•Structural changes (loss of molecular weight and sulfonic acid groups) of the membrane are minor after 30,000 wet/dry cycles.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The preferentially expressed antigen of melanoma (PRAME), a tumor-associated antigen, is considered a prognostic marker for various human malignancies. The prognostic significance of PRAME expression ...for diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab-containing chemotherapy has not been evaluated to date, and the ability of immunohistochemistry (IHC) to detect PRAME expression in these patients has not yet been studied, although IHC is simple to perform in clinical practice. We evaluated the prognostic significance of PRAME expression based on IHC analysis in 160 DLBCL patients treated with R-CHOP therapy. There was a significant association between higher PRAME expression and shorter progression-free survival (PFS), and a trend toward shorter overall survival (OS) in patients with higher PRAME expression than that in patients with lower PRAME expression (5-year PFS, 48.1 vs. 61.1 %; 5-year OS, 65.6 vs. 79.1 %). Patients with high PRAME expression tended to have lower chemotherapeutic responses. Thus, IHC is useful for detecting and assessing PRAME expression in DLBCL. Further, we found a positive correlation between IHC and quantitative real-time RT-PCR measurements of PRAME expression. Our findings indicate that IHC results of PRAME expression can be a novel prognostic maker in DLBCL patients treated with R-CHOP therapy.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Chromosome translocations involving the immunoglobulin heavy chain (
IGH
) gene locus at chromosome region 14q32 are often observed in B-cell lymphoid neoplasms. Of these, t(14;18)(q32;q21) results ...in juxtaposition of the
IGH
gene on chromosome 14 and the
BCL2
gene on chromosome 18, leading to the overexpression of BCL2 anti-apoptotic protein, which plays a critical role in the development of follicular lymphoma (FL). However, BCL2 overexpression is not observed in approximately 10 % of FL, and the molecular pathogenesis of BCL2-negative FL has not been elucidated. Here, we identify the SRY-related high-morbidity-group (HMG) box 5 (
SOX5
) gene on chromosome 12p12 as a novel
IGH
-involved translocation partner in the case of BCL2-negative follicular lymphoma (FL) with a complex karyotype including t(12;14)(p12.2;q32) by long-distance inverse PCR. As a result of this translocation, the
SOX5
gene is juxtaposed to the enhancer of the IGH gene; SOX5 overexpression in neoplastic cells was demonstrated by immunohistochemistry. The results of the present study suggest a role for SOX5 in the molecular pathogenesis of FL.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Careful design of the structures of interfaces between nanofillers and polymer matrices can significantly improve the mechanical and thermal properties of the overall nanocomposites. Here, we ...investigate how the grafting density on the surface of nanocelluloses influences the properties of nanocellulose/cellulose triacetate (CTA) composites. The surface of nanocellulose, which was prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl oxidation, was modified with long poly(ethylene glycol) (PEG) chains at different grafting densities. The PEG-grafted nanocelluloses were homogeneously embedded in CTA matrices. The mechanical and thermal properties of the nanocomposites were characterized. Increasing the grafting density caused the soft PEG chains to form denser and thicker layers around the rigid nanocelluloses. The PEG layers were not completely miscible with the CTA matrix. This structure considerably enhanced the energy dissipation by allowing sliding at the interface, which increased the toughness of the nanocomposites. The thermal and mechanical properties of the composites could be tailored by controlling the grafting density. These findings provide a deeper understanding about interfacial design for nanocellulose-based composite materials.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM, UPUK
Isolated primary granulocytic sarcoma is a rare disease that presents as an extramedullary tumor of myeloid lineage cells. Most patients subsequently develop acute myelogenous leukemia (AML) within a ...short period, and their prognosis is poor. Herein, we report the case of a 33-year-old woman with a primary isolated granulocytic sarcoma which originated in the small intestine. After she recovered from surgery, she received intensive chemotherapy equivalent to that for AML, followed by allogeneic bone marrow transplantation from an HLA-matched, unrelated donor. Four years after the transplantation, she remains in complete remission without graft-versus-host disease or any other symptoms. This case illustrates the effectiveness of our therapeutic strategy for isolated granulocytic sarcoma, not only with surgical resection of the tumor and intensive chemotherapy equivalent to that for AML, but also with allogeneic bone marrow transplantation, performed while no sign of AML is observed.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Fast scanning calorimetry (FSC) enables rapid sample cooling from the melt at rates of several thousand Kelvin per second. A perfect amorphous state for polypropylene (PP) can be achieved by ...fast cooling at rates of 5000 K s
−1
. In comparison, polyethylene (PE) crystallizes during cooling, even at cooling rates accessible with FSC. Thus, in this study, a novel method was proposed for determining the PP/PE mixing ratio with a standard deviation of 1.4 mass% that combines FSC and differential scanning calorimetry. The proposed method considers the above thermal behavior of the components of polyolefin blends. In addition, the proposed method is expected to provide a convenient way to analyze the composition of recycled polyolefins from the market or industrial processes without the need for high‐temperature solvents that are typically used in nuclear magnetic resonance or for calibration curves in Fourier transform infrared spectrophotometry.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
