Pulsed laser-deposited n-Si/NiO_x photoanodes for stable and efficient photoelectrochemical water splitting

An electrocatalytic and stable nickel oxide (NiO_x) thin layer was successfully deposited on an n-Si (100) substrate by pulsed laser deposition (PLD), acting as a photoanode for efficient photo-oxidation of water under solar illumination. It was revealed that the formed n-Si/NiO_x heterojunction with good Schottky contact could improve photogenerated charge separation, and thus n-Si photoanodes deposited with a 105 nm-thick NiO_x electrocatalytic layer exhibited a photovoltage of ∼350 mV, leading to greatly improved photoelectrochemical performances for water oxidation. The stability of the photoanode was significantly enhanced with the increasing thickness of NiO_x protective layers. This study demonstrates a simple and effective method to enable the use of planar n-Si (100) substrates as efficient and durable photoanodes for practical solar water oxidation

Mimotopes selected with neutralizing antibodies against multiple subtypes of influenza A

<p>Abstract</p> <p>Background</p> <p>The mimotopes of viruses are considered as the good targets for vaccine design. We prepared mimotopes against multiple subtypes of influenza A and evaluate their immune responses in flu virus challenged Balb/c mice.</p> <p>Methods</p> <p>The mimotopes of influenza A including pandemic H1N1, H3N2, H2N2 and H1N1 swine-origin influenza virus were screened by peptide phage display libraries, respectively. These mimotopes were engineered in one protein as multi- epitopes in Escherichia coli (E. coli) and purified. Balb/c mice were immunized using the multi-mimotopes protein and specific antibody responses were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). The lung inflammation level was evaluated by hematoxylin and eosin (HE).</p> <p>Results</p> <p>Linear heptopeptide and dodecapeptide mimotopes were obtained for these influenza virus. The recombinant multi-mimotopes protein was a 73 kDa fusion protein. Comparing immunized infected groups with unimmunized infected subsets, significant differences were observed in the body weight loss and survival rate. The antiserum contained higher HI Ab titer against H1N1 virus and the lung inflammation level were significantly decreased in immunized infected groups.</p> <p>Conclusions</p> <p>Phage-displayed mimotopes against multiple subtypes of influenza A were accessible to the mouse immune system and triggered a humoral response to above virus.</p

Glial Progenitor-Like Phenotype in Low-Grade Glioma and Enhanced CD133-Expression and Neuronal Lineage Differentiation Potential in High-Grade Glioma

Background: While neurosphere-as well as xenograft tumor-initiating cells have been identified in gliomas, the resemblance between glioma cells and neural stem/progenitor cells as well as the prognostic value of stem/progenitor cell marker expression in glioma are poorly clarified. Methodology/Principal Findings: Viable glioma cells were characterized for surface marker expression along the glial genesis hierarchy. Six low-grade and 17 high-grade glioma specimens were flow-cytometrically analyzed for markers characteristics of stem cells (CD133); glial progenitors (PDGFR alpha, A2B5, O4, and CD44); and late oligodendrocyte progenitors (O1). In parallel, the expression of glial fibrillary acidic protein (GFAP), synaptophysin and neuron-specific enolase (NSE) was immunohistochemically analyzed in fixed tissue specimens. Irrespective of the grade and morphological diagnosis of gliomas, glioma cells concomitantly expressed PDGFRa, A2B5, O4, CD44 and GFAP. In contrast, O1 was weakly expressed in all low-grade and the majority of high-grade glioma specimens analyzed. Co-expression of neuronal markers was observed in all high-grade, but not low-grade, glioma specimens analyzed. The rare CD133 expressing cells in low-grade glioma specimens typically co-expressed vessel endothelial marker CD31. In contrast, distinct CD133 expression profiles in up to 90% of CD45-negative glioma cells were observed in 12 of the 17 high-grade glioma specimens and the majority of these CD133 expressing cells were CD31 negative. The CD133 expression correlates inversely with length of patient survival. Surprisingly, cytogenetic analysis showed that gliomas contained normal and abnormal cell karyotypes with hitherto indistinguishable phenotype. Conclusions/Significance: This study constitutes an important step towards clarification of lineage commitment and differentiation blockage of glioma cells. Our data suggest that glioma cells may resemble expansion of glial lineage progenitor cells with compromised differentiation capacity downstream of A2B5 and O4 expression. The concurrent expression of neuronal markers demonstrates that high-grade glioma cells are endowed with multi-lineage differentiation potential in vivo. Importantly, enhanced CD133 expression marks a poor prognosis in gliomas

Preparation and properties of Sr(CrMnFeCoNi)(3)O-4 and Sr (MgAlTiCrFe)(12)O-19 high entropy strontium ferrite systems and valance state analysis

Two high-entropy ferrite ceramic systems, Sr(CrMnFeCoNi)(12)O-19 and Sr(MgAlTiCrFe)(12)O-19, were designed according to AB(12)O(19) composition and synthesised using elevated-temperature solid phase reaction. The B-site was loaded with five atoms in equal proportions. We focused on preparing high-entropy hexagonal magnetoplumbite strontium ferrites. However, spinel structure significantly formed in the Sr(CrMnFeCoNi)(12)O-19 system. The extruded strontium outside the lattice pulled out a part of chromium, causing phase separation and element segregation. The strontium extrusion outside the lattice and non-formation of hexagonal ferrite, which was reported for the first time, could be attributed to the electrovalence change in the elements. First-principles calculation of the (CrMnFeCoNi)(3)O-4 spinel system was used to analyse the band structure and density state. After entropy engineering design, it was mutated into a wide direct band gap (2.3 eV at 0 K). Although the nonmagnetic elements reduced the magnetic performance, they significantly improved the mechanical performance with a flexural strength of 208.7 +/- 0.9 MPa. These results may contribute to the element selection and preparation of high-entropy strontium ferrites

Preparation and properties of Sr(CrMnFeCoNi)(3)O-4 and Sr (MgAlTiCrFe)(12)O-19 high entropy strontium ferrite systems and valance state analysis

Two high-entropy ferrite ceramic systems, Sr(CrMnFeCoNi)(12)O-19 and Sr(MgAlTiCrFe)(12)O-19, were designed according to AB(12)O(19) composition and synthesised using elevated-temperature solid phase reaction. The B-site was loaded with five atoms in equal proportions. We focused on preparing high-entropy hexagonal magnetoplumbite strontium ferrites. However, spinel structure significantly formed in the Sr(CrMnFeCoNi)(12)O-19 system. The extruded strontium outside the lattice pulled out a part of chromium, causing phase separation and element segregation. The strontium extrusion outside the lattice and non-formation of hexagonal ferrite, which was reported for the first time, could be attributed to the electrovalence change in the elements. First-principles calculation of the (CrMnFeCoNi)(3)O-4 spinel system was used to analyse the band structure and density state. After entropy engineering design, it was mutated into a wide direct band gap (2.3 eV at 0 K). Although the nonmagnetic elements reduced the magnetic performance, they significantly improved the mechanical performance with a flexural strength of 208.7 +/- 0.9 MPa. These results may contribute to the element selection and preparation of high-entropy strontium ferrites

Perovskite Micro-Nano Cage SrTiO3: Formation Mechanism, Vacancy Analysis, and Exciton Dynamics

In the former research, we produced the regular polyhedron single-crystalline SrTiO3 particles with multiple crystal facets exposed by a one-step hydrothermal method. In this work, the dissolution process mechanism of SrTiO3 has been analyzed based on the evidence of the crystal structure and particle morphology with a completely new point of view. The anisotropic formation process of perovskite micro-nano cage SrTiO3 was primarily summarized, and the defective vacancy composition was analyzed. Simultaneously, based on femtosecond transient absorption spectroscopy, the exciton dynamic of SrTiO3 was deduced, and it will play a key role in improving the photoelectric properties of SrTiO3. Furthermore, the abundant defective vacancies promote the ability of SrTiO3 to oxidize Co species, which has a great advantage in the wastewater treatment processes

Perovskite Micro-Nano Cage SrTiO3: Formation Mechanism, Vacancy Analysis, and Exciton Dynamics

In the former research, we produced the regular polyhedron single-crystalline SrTiO3 particles with multiple crystal facets exposed by a one-step hydrothermal method. In this work, the dissolution process mechanism of SrTiO3 has been analyzed based on the evidence of the crystal structure and particle morphology with a completely new point of view. The anisotropic formation process of perovskite micro-nano cage SrTiO3 was primarily summarized, and the defective vacancy composition was analyzed. Simultaneously, based on femtosecond transient absorption spectroscopy, the exciton dynamic of SrTiO3 was deduced, and it will play a key role in improving the photoelectric properties of SrTiO3. Furthermore, the abundant defective vacancies promote the ability of SrTiO3 to oxidize Co species, which has a great advantage in the wastewater treatment processes