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The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30-150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.

The exploration of non-noble metal catalysts for the oxygen reduction reaction (ORR) is of great significance in energy conversion devices, such as fuel cells and metal-air batteries. In this work, a hybrid catalyst composed of MnO/Ni nanoparticles anchored on porous branched nitrogen-doped carbons (MnO/Ni@BNCs) were prepared by direct pyrolyzing melamine foams containing Mn(II) and Ni (II) ions at 800 °C under N2 atmosphere. On the basis of electrochemical tests, it was found that the MnO/Ni@BNCs hybrid catalyst showed a high efficient four-electron catalytic pathway towards ORR and gave a low yield of H2O2 (< 7.53 %). It also exhibited a good catalytic stability and methanol tolerance, exceeding the commercial Pt/C catalyst. The excellent catalytic performance was attributed to the synergetic effect between high catalytic activity of MnO and high electrical conductivity of Ni. Furthermore, the high surface area and porous structure characters of carbon support, which partially inherited the microstructure of melamine foam, also benefited the electron transfer and reactive species transformation during ORR process.

A method of performing city-scale ventilation assessments based on remote sensing (RS) and geographic information system (GIS) technology is proposed and applied effectively in an assessment of the local ventilation environment before and after the construction of the Yanqi Lake Eco-city in Huairou District, Beijing. The ventilation environment of a city is dependent on its background wind environment and ventilation potential. The background wind environment can be assessed through meteorological statistical analyses or numerical simulations, whereas the ventilation potential can be estimated using the underlying surface dynamic roughness length (RL) and the surrounding sky view factor (SVF). Based on the principle of morphology, the RL of a vegetation area is determined mainly by the vegetation types, vegetation canopy area index and vegetation height, whereas the RL of an urban area is defined mainly by the building area coverage and building height. The SVF can be estimated according to high-resolution digital raster elevation data. Based on the combination of the RL and SVF, the ventilation potential is graded, and the ventilation potential index (VPI) is defined and used to assess quantitatively the ventilation capacity of the city. The present study calculates the RL of the Yanqi Lake Eco-city using Landsat-TM5 satellite data from 26 July 2011, Geoscience Laser Altimeter System (GLAS) satellite data from 2005 and Beijing basic geographical data at 1:2000 from 2009. Subsequently, the RL and ventilation potential distribution of the Yanqi Lake Eco-city is mapped at a 100 m spatial resolution. The ventilation conditions before and after the construction of the Yanqi Lake Eco-city are evaluated using the VPI in combination with the background wind field. According to changes in the ventilation capacity, relevant policy suggestions for urban buildings and design factors for ventilated corridors are postulated.

Keloid is regarded as a fibroproliferative disorder with excessive accumulation of extracellular matrix. However, the molecular mechanism of keloid formation is not well understood and no treatment modality is consistently effective. Heat shock protein 47 (HSP47) is known as a collagen-specific molecular chaperone which plays a critical role in collagen biosynthesis. Results of our previous in vitro experiments demonstrated that HSP47 might be an important reason for excessive collagen accumulation in regard to keloid formation. Our objective is to investigate whether HSP47 has an influence on collagen metabolism in animal keloid models. The constructed plasmids, carrying HSP47-small hairpin RNA (shRNA), were transfected into animal keloid models, in comparison with the control groups. After transfection, the mRNA and protein expression of HSP47 and collage type I were detected by quantitative real-time PCR and Western blot. Both the mRNA and protein levels of HSP47 in animal keloid models were decreased dramatically after transfection of the HSP47- shRNA plasmid, in comparison with the control group. Following the down-regulation of HSP47, we found that the volume of animal keloid models and the major collagen expression were reduced correspondingly. Combining the results of our previous in vitro experiment results, we suggest that overexpression of HSP47 in keloid fibroblast cells could induce excessive collagen accumulation by enhancing collagen synthesis, which not only presents a possible mechanism of keloid formation, but also offers a therapeutic potential of RNA interference to HSP47 for the treatment of keloids and other fibroproliferative disorders.

Anodic electrochemiluminescence (ECL) of 3-mercaptopropionic acid (MPA)- capped CdTe/CdS core-shell quantum dots (QDs) with tripropylamine (TPrA) as the co-reactant were studied in aqueous (Tris buffer) solution for the first time. The results suggest that the oxidation of TPrA at a glassy carbon electrode (GCE) surface participated in the ECL of QDs, and the onset potential and the intensity of ECL of CdTe/CdS QDs were affected seriously by TPrA, as the co-reactant, in Tris buffer solution. The onset potential of ECL in this new system was about +0.5 V (vs. Ag/AgCl) and the ECL intensity greatly enhanced when TPrA was present. Various influencing factors, such as the electrolyte, pH, QDs concentration, potential range and scan rates on the ECL were studied. Based on the selective quenching by Cu2+ to the light emission from CdTe/CdS QDs/TPrA system, a highly sensitive and selective method for the determination of Cu2+ was developed. At the optimal conditions, the relative ECL intensity, I0/I, was proportional to the concentration of Cu2+ from 14 nM to 0.21 μM with the detection limit of 6.1 nM based on the signal-to-noise ratio of 3. The possible ECL mechanism of QDs and the quenching mechanism of ECL were proposed.

The study of DNA damage induced by Fenton reaction (Fe2+/H2O2) in vitro was performed based on the direct electrochemical oxidation of 8-hydroxydeoxyguanosine (8-OH-dG), the biomarker of DNA oxidative damage, at an electrochemically modified glassy carbon electrode (GCE). The effects of antioxidants, such as ascorbic acid, and hydroxyl-radical scavenger (mannitol) on the DNA damage were also investigated. 8-OH-dG, the oxidation product of guanine residues in DNA, has shown significantly oxidative peak on the electrochemically modified GCE. The oxidative peak current of 8-OH-dG was linear with the damaged DNA concentration in the range of 10–200 mg/L. The experimental results demonstrate that ascorbic acid has ambivalent effect on DNA oxidative stress. It can promote DNA oxidative damage when ascorbic acid concentration is below 1.5 mM and protect DNA from damage in the range of 1.5–2.5 mM. As a hydroxyl-radical scavenger, mannitol inhibits significantly DNA oxidative damage. The influence of Fe2+, as reactant, and EDTA as iron chelator in the system were also studied. The proposed electrochemical method can be used for the estimation of DNA oxidative damage from new point of view.

Two exo-cyclic 11-vertex isocloso ruthenaborane clusters [(PPh3)(p-ClPhCO2)2RuB10H8] (1) and [(PPh3)2Ru(PPh3)(p-ClPhCO2)RuB10H9]·0.5C5H12·H2O (2·0.5C5H12·H2O) have been synthesized and characterized by elemental analysis, FT-IR, NMR spectra and single-crystal X-ray diffraction analysis. The structure analysis shows that both of the clusters are based on an 11-vertex closo-type {RuB10} cluster-geometry with the nine-coordinate metal atom occupying the six-connected apical position. In cluster 1, the metal center has three exo-polyhedral ligands, one triphenylphosphine and two dative oxygen atoms of para-chlorobenzoates which form two exo-cyclic five-membered Ru-O-C-O-B rings with the other oxygen atoms bonding to B(2) and B(3) atoms. The cluster 2 also has one exo-polyhedral para-chlorobenzoate to form one exo-cyclic five-membered Ru-O-C-O-B ring in one side. There is another exo-polyhedral ruthenium atom bonded to the cluster center {RuB10} via one Ru-Ru linkage and two RuHμB bridges forming a closed exo-polyhedral tetrahedron configuration in the other side.

The reaction of [RuCl 2 (PPh 3 ) 3 ] with closo-[B 10 H 10 ] 2- and C 5 H 5 FeC 5 H 4 COOH (FcCO 2 H) in refluxing CH 2 Cl 2 solution affords three ruthenaborane clusters: [PPh3(H20)(FcCO2)RuBioH8Cl] (1), [(PPh3) 2 ClRu(PPh3)(FcCO 2 )RuBioH9].0.5CH2Cl2 (2x0.5CH 2 Cl 2 ) and [PPh3(FcCO 2 ) 2 RuB 10 H 8 ] (3). All of these compounds are characterized by FT-IR, NMR spectroscopic techniques, elemental analysis and single-crystal X-ray analysis. They are all based on a closo-type 1:2:4:2:2 [RuB 10 ] stack with the metal occupying the unique six-connected apical position and can be considered as having isocloso structures derived from the complete capping of the open face of an arachano geometry to give a completely closed deltahedral cluster. Compounds 1 and 2 both have an exo-polyhedral ferrocenecarboxylate that is attached with one {Ru-O} and one {B-O} bond each, resulting in one exo-cyclic five-membered Ru-O-C-O-B ring. There is in addition one exo-polyhedral ruthenium atom bonded to the center {RuB 10 } cluster via one {Ru-Ru) linkage and two (RUH μ B) bridges, which forms a closed exo-polyhedral tetrahedron configuration in compound 2. Compound 3 has two exo-polyhedral ferrocenecarboxylates to form two five-membered Ru-O-C-O-B rings engendering a symmetrical conformation. All of these new 11-vertex ruthenaboranes can be considered as having isocloso structures derived from the complete capping of the open face of an arachano geometry to give a completely closed deltahedral cluster.

The transient interaction between a refraction index grating and light beams during simultaneous writing and thermal fixing of a photorefractive hologram is investigated. With a diffusion- and photovoltaic-dominated carrier transport mechanism and carrier thermal activation (temperature dependent) considered in Fe:LiNbO3 crystal, from the standpoint of field–material coupling, the theoretical thermal fixing time and the space-charge field buildup, spatial distribution, and temperature dependence are given numerically by combining the band transport model with mobile ions with the coupled-wave equation. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 372–376, 1999.