The swelling transition of lepidocrocite-type protonated layered titanates into anatase under hydrothermal treatment

The common facets of anatase crystals are the (001) and (101) planes. However, the phase transformation from lepidocrocite-type titanate into anatase by hydrothermal processing yields an anatase microstructure with high concentration of exposed (010) planes. The phase transformation of a lepidocrocite-type protonated layered titanate (HTO) into anatase was studied using XRD, TEM, FTIR, and measurement of pH and zeta potential. It was found that HTO is proton-deficient. The phase transformation process begins after uptake of a sufficient number of protons into the lepidocrocite-type structure. With the uptake of protons new hydroxyl groups form on the internal surfaces of the layered titanate and result in a bilayer state of HTO. The phase transformation reaction is a topotactic dehydration reaction in which anatase forms and water is expelled by syneresis

Classification, replication, and transcription of Nidovirales

Nidovirales is one order of RNA virus, with the largest single-stranded positive sense RNA genome enwrapped with membrane envelope. It comprises four families (Arterividae, Mesoniviridae, Roniviridae, and Coronaviridae) and has been circulating in humans and animals for almost one century, posing great threat to livestock and poultry，as well as to public health. Nidovirales shares similar life cycle: attachment to cell surface, entry, primary translation of replicases, viral RNA replication in cytoplasm, translation of viral proteins, virion assembly, budding, and release. The viral RNA synthesis is the critical step during infection, including genomic RNA (gRNA) replication and subgenomic mRNAs (sg mRNAs) transcription. gRNA replication requires the synthesis of a negative sense full-length RNA intermediate, while the sg mRNAs transcription involves the synthesis of a nested set of negative sense subgenomic intermediates by a discontinuous strategy. This RNA synthesis process is mediated by the viral replication/transcription complex (RTC), which consists of several enzymatic replicases derived from the polyprotein 1a and polyprotein 1ab and several cellular proteins. These replicases and host factors represent the optimal potential therapeutic targets. Hereby, we summarize the Nidovirales classification, associated diseases, “replication organelle,” replication and transcription mechanisms, as well as related regulatory factors

Growing a LaAlO3/SrTiO3 heterostructure on Ca2Nb3O10 nanosheets

The two-dimensional electron liquid which forms between the band insulators LaAlO3 (LAO) and SrTiO3 (STO) is a promising component for oxide electronics, but the requirement of using single crystal SrTiO3 substrates for the growth limits its applications in terms of device fabrication. It is therefore important to find ways to deposit these materials on other substrates, preferably Si, or Si-based, in order to facilitate integration with existing technology. Interesting candidates are micron-sized nanosheets of Ca2Nb3O10 which can be used as seed layers for perovskite materials on any substrate. We have used low-energy electron microscopy (LEEM) with in-situ pulsed laser deposition to study the subsequent growth of STO and LAO on such flakes which were deposited on Si. We can follow the morphology and crystallinity of the layers during growth, as well as fingerprint their electronic properties with angle resolved reflected electron spectroscopy. We find that STO layers, deposited on the nanosheets, can be made crystalline and flat; that LAO can be grown in a layer-by-layer fashion; and that the full heterostructure shows the signature of the formation of a conducting interface.Comment: 11 pages, 7 figure

Clinical features and prognosis of patients with primary biliary cholangitis complicated by hepatitis virus infection

ObjectiveTo investigate the clinical features and prognosis of patients with primary biliary cholangitis(PBC) complicated by hepatitis virus infection. MethodsA total of 16 patients who were admitted to Beijing YouAn Hospital from October 2004 to October 2012 and diagnosed with PBC complicated by hepatitis virus infection were enrolled, among whom 7 had chronic hepatitis B virus infection, 3 had hepatitis C, 4 had hepatitis E, 1 had hepatitis B and hepatitis C, and 1 had hepatitis A. A total of 76 hospitalized patients with PBC alone were enrolled as controls. The two groups were compared in terms of clinical features, laboratory markers, and autoantibodies, and follow-up visits were performed to investigate prognostic features. The independent samples t-test was used for comparison of normally distributed continuous data, and the Mann-Whitney U rank sum test was used for comparison of non-normally distributed continuous data; the chi-square test or Fisher′s exact test was used for comparison of categorical data. The Kaplan-Meier method was used to calculate survival rates and the log-rank test was used to compare survival rates between groups. ResultsCompared with the control group, the PBC-hepatitis virus infection group had significantly lower proportion of female patients (χ2=12.22, P=0.002), alkaline phosphatase (U=225.00, P＜0.001), CHO (U=363.50, P=0.036), and IgG level (t=2.79, P=0.007), and no patients in the PBC-hepatitis virus infection group experienced abdominal wall varices, upper gastrointestinal bleeding, or hepatic encephalopathy. The PBC-hepatitis virus infection group had various autoantibodies including anti-nuclear antibody, smooth muscle antibody, anti-parietal cell antibody (APCA), anti-liver specific protein antibody, and anti-myocardial antibody, as well as a significantly higher APCA positive rate than the control group (25% vs 3.9%, χ2=5.608, P=0.016). The median follow-up time was 49.5 months (2-312 months). The PBC-hepatitis virus infection group had a significantly lower incidence rate of adverse events than the control group (25.0% vs 64.5%, χ2=8.43, P=0.005), and there were no significant differences between the two groups in cumulative survival rate and proportion of patients who did not experience any adverse event (both P＞0.05). ConclusionMost patients with PBC complicated by hepatitis virus infection are in the early stage of PBC and have various nonspecific autoantibodies. Current study does not indicate that hepatitis virus infection has influence on the survival of PBC patients

High-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles for phenol hydrogenation

A high-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles (MSN), PdRu/MSN, was prepared by a facile impregnation-hydrogen reduction method. It was found that PdRu/MSN showed 5 times higher activity than that of Pd/MSN towards the liquid-phase hydrogenation of phenol. The catalysts were characterized comprehensively by multiple techniques, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature program reduction (TPR). It was revealed that adding Ru could effectively improve the Pd dispersion and promote the electronic interaction between the Pd and Ru, both of which contribute to enhancing the catalytic activity. (C) 2014 Elsevier B.V. All rights reserved

A Platinum Monolayer Core-Shell Catalyst with a Ternary Alloy Nanoparticle Core and Enhanced Stability for the Oxygen Reduction Reaction

We synthesize a platinum monolayer core-shell catalyst with a ternary alloy nanoparticle core of Pd, Ir, and Ni. A Pt monolayer is deposited on carbon-supported PdIrNi nanoparticles using an underpotential deposition method, in which a copper monolayer is applied to the ternary nanoparticles; this is followed by the galvanic displacement of Cu with Pt to generate a Pt monolayer on the surface of the core. The core-shell Pd1Ir1Ni2@Pt/C catalyst exhibits excellent oxygen reduction reaction activity, yielding a mass activity significantly higher than that of Pt monolayer catalysts containing PdIr or PdNi nanoparticles as cores and four times higher than that of a commercial Pt/C electrocatalyst. In 0.1 M HClO4, the half-wave potential reaches 0.91 V, about 30 mV higher than that of Pt/C. We verify the structure and composition of the carbon-supported PdIrNi nanoparticles using X-ray powder diffraction, X-ray photoelectron spectroscopy, thermogravimetry, transmission electron microscopy, and energy dispersive X-ray spectrometry, and we perform a stability test that confirms the excellent stability of our core-shell catalyst. We suggest that the porous structure resulting from the dissolution of Ni in the alloy nanoparticles may be the main reason for the catalyst’s enhanced performance

A Review of Optimization for System Reliability of Microgrid

Clean and renewable energy is the only way to achieve sustainable energy development, with considerable social and economic benefits. As a key technology for clean and renewable energy, it is very important to research the reliability optimization of microgrids. This paper reviews the research progress in microgrid reliability optimization. This paper first classifies and summarizes the existing research on microgrid control strategies and reliability assessment. Then, the system reliability optimization framework is summarized in terms of both microgrid systems and optimization objectives. Next, we summarize the most commonly used optimization algorithms for microgrid reliability for different microgrid systems. Finally, we provide a bibliometric analysis of the literature on the reliability research of microgrids. In addition, we propose some research challenges in the future for the reliability of microgrids