Fabrication of solid thin film electrolyte and LiCoO2 by aerosol flame pyrolysis deposition

Aerosol flame pyrolysis deposition method was applied to deposit the oxide glass electrolyte film and LiCoO₂ cathode for thin film type Li-ion secondary battery. The thicknesses of as-deposited porous LiCoO₂ and Li₂O–B₂O₃–P₂O₅ electrolyte film were about 6 μm and 15 μm, respectively. The deposited LiCoO₂ was sintered for 2 min at 700 °C to make partially densified cathode layer, and the deposited Li₂O–P₂O₅–B₂O₃ glass film completely densified by the sintering at 700 °C for 1 h. After solid state sintering process the thicknesses were reduced to approximately 4 μm and 6 μm, respectively. The cathode and electrolyte layers were deposited by continuous deposition process and integrated into a layer by co-sintering. It was demonstrated that Aerosol flame deposition is one of the good candidates for the fabrication of thin film battery.     

Degradation of polystyrene using montmorillonite clay catalysts

Summary The performance of acid-treated montmorillonite catalysts in the degradation of polystyrene (PS) was investigated in this study. The degradation was carried out in a semi-batch reactor with a mixture of PS and catalyst at 400-450^oC. The commercial Süd Chemie acid-treated montmorillonite clays (K-series) showed good catalytic activity for the degradation of PS. The styrene monomer and ethylbenzene were major liquid products. The increase of surface acidity enhanced further cracking of styrene dimer and trimer to produce styrene monomer. Higher production of ethylbenzene for K30 may be related to its bigger pore volume and surface area compared to those of K5. High degradation temperature favored styrene monomer production.     

Asymmetric silyl nitronate cycloadditions with bornane-10,2-sultam derivatives

Asymmetric silyl nitronate cycloadditions with N-acryloyl (2R)-bornane-10,2-sultam, N-acryloyl (2S)-bornane-10,2-sultam, and N-methacryloyl (2R)-bornane-10,2-sultam have been studied. The asymmetric silyl nitronate cycloaddidon/elimination methodology provides a general route for the asymmetric synthesis of 2-isoxazolines.     

The C-H activation of methane by laser-ablated zirconium atoms: CH2=ZrH2, the simplest carbene hydride complex, agostic bonding, and (CH3)2ZrH2

Reaction of laser-ablated Zr with CH(4) ((13)CH(4), CD(4), and CH(2)D(2)) in excess neon during condensation at 5 K forms CH(2)=ZrH(2), the simplest alkylidene hydride complex, which is identified by infrared absorptions at 1581.0, 1546.2, 757.0, and 634.5 cm(-)(1). Density functional theory electronic structure calculations using a large basis set with polarization functions predict a C(1) symmetry structure with agostic C-H- - -Zr bonding and distance of 2.300 A. Identification of the agostic CH(2)=ZrH(2) methylidene complex is confirmed by an excellent match of calculated and observed isotopic frequencies particularly for the four unique CHD=ZrHD isotopic modifications. The analogous reactions in excess argon give two persistent photoreversible matrix configurations for CH(2)=ZrH(2). Finally, methane activation by CH(2)=ZrH(2) gives the new (CH(3))(2)ZrH(2) molecule.     

Studies on the Complexes of N,N′-Bis[o-(diphenylphosphino)benzylidene]ethylenediamine with Transition Metal Ions

The thermodynamic parameters for the interaction of Cu²⁺, Ni²⁺, Co²⁺, Cd²⁺, andAg⁺ with the new title ligand have been determined by titration calorimetry in 50% THF–methanol (V/V) at 25 °C.Ag⁺ exhibited remarkably higher complexation selectivity.Ag⁺ and several transition metal ions have been transportedusing this ligand as carrier in a bulk liquid membrane. CompetitiveAg⁺–M²⁺ transport studies have also beencarried out for the same system. In this membrane transport study, high transport of Ag⁺ was observed in both single and competitiveAg⁺–M²⁺ transport studies. The complexformation of N,N-bis[o-(diphenylphosphino)benzylidene]ethylenediamine (P₂N₂) with silver,[Ag(P₂N₂)] (NO₃), (1) is reported. Complex 1 has been characterized by X-ray crystallography. 1 ismonoclinic, space group P2_1/n (No. 14), with cell dimensionsa = 13.398(4) , b=12.577(5) , c = 21.521(4) , =100.14(2) , V = 3570(2) ³ and Z = 4.     

X-ray magnetic circular dichroism of Pseudomonas aeruginosa nickel(II) azurin

We show that X-ray magnetic circular dichroism (XMCD) can be employed to probe the oxidation states and other electronic structural features of nickel active sites in proteins. As a calibration standard, we have measured XMCD and X-ray absorption (XAS) spectra for the nickel(II) derivative of Pseudomonas aeruginosa azurin (NiAz). Our analysis of these spectra confirms that the electronic ground state of NiAz is high-spin (S = 1); we also find that the L(3)-centroid energy is 853.1(1) eV, the branching ratio is 0.722(4), and the magnetic moment is 1.9(4) mu(B). Density functional theory (DFT) calculations on model NiAz structures establish that orbitals 3d(x2-y2) and 3d(z2) are the two valence holes in the high-spin Ni(II) ground state, and in accord with the experimentally determined orbital magnetic moment, the DFT results also demonstrate that both holes are highly delocalized, with 3d(x2-y2) having much greater ligand character.     

Experimental and theoretical study on the olefin metathesis of alkenyl Baylis-Hillman adducts using second-generation Grubbs catalyst

[reaction: see text] We have investigated the olefin metathesis from alkenyl Baylis-Hillman adducts using second-generation Grubbs catalyst. In the experiment, the ring-closing metathesis (RCM) product could not be found, while the cross-metathesis (CM) products were found. The computational studies provided consistent explanations for the experimental result. The most limiting factor for the RCM process using second-generation Grubbs catalyst is caused by the high strain and steric effect in the metallacyclobutane intermediates.     

Decreased in vitro interaction between p53 and nuclear stress proteins in the p53-deficient mouse

In a previous study, the strength of the interaction between the nuclear stress proteins (sps) 25a, 70i, 72c, and 90 and the tumor suppressor protein p53 was determined by an in vitro fluorescence binding assay. The relative binding of the individual sps with p53, derived from the bone marrow of transgenic mice heterozygous at the p53 locus (p53+/-), was reduced compared to the interaction of sps and p53 derived from wild-type (p53+/+) mice. In order to determine if the genotype of the p53 donor or the genotype of the sp donor determined the binding efficiency, p53 expression was induced by retinoic acid and sp synthesis by bleomycin. P53 derived from either wild-type or heterozygous animals was cross-reacted with nuclear sps obtained from either wild-type or heterozygous animals. Each of the sps, 25a, 70i, 72c, and 90, bound to wild-type p53 with a similar efficiency, irrespective of the genotype of the sp donor mouse (p53+/+ or p53+/-). In contrast, when the sp interaction with p53 obtained from the heterozygous mouse was measured, the relative value of the fluorescence complex was significantly reduced. The data suggest that the strength of the interaction between p53 and nuclear sps is related to the genotype of the p53 donor, and not to the genotype of the animals from which the sps are derived.     

Cancer cells undergoing epigenetic transition show short-term resistance and are transformed into cells with medium-term resistance by drug treatment

To elucidate the epigenetic mechanisms of drug resistance, epigenetically reprogrammed H460 cancer cells (R-H460) were established by the transient introduction of reprogramming factors. Then, the R-H460 cells were induced to differentiate by the withdrawal of stem cell media for various durations, which resulted in differentiated R-H460 cells (dR-H460). Notably, dR-H460 cells differentiated for 13 days (13dR-H460 cells) formed a significantly greater number of colonies showing drug resistance to both cisplatin and paclitaxel, whereas the dR-H460 cells differentiated for 40 days (40dR-H460 cells) lost drug resistance; this suggests that 13dR-cancer cells present short-term resistance (less than a month). Similarly, increased drug resistance to both cisplatin and paclitaxel was observed in another R-cancer cell model prepared from N87 cells. The resistant phenotype of the cisplatin-resistant (CR) colonies obtained through cisplatin treatment was maintained for 2–3 months after drug treatment, suggesting that drug treatment transforms cells with short-term resistance into cells with medium-term resistance. In single-cell analyses, heterogeneity was not found to increase in 13dR-H460 cells, suggesting that cancer cells with short-term resistance, rather than heterogeneous cells, may confer epigenetically driven drug resistance in our reprogrammed cancer model. The epigenetically driven short-term and medium-term drug resistance mechanisms could provide new cancer-fighting strategies involving the control of cancer cells during epigenetic transition.Subject terms: Tumour heterogeneity, Epigenetics     

Photocatalytic synthesis of copper colloids from CuII by the ferrihydrite core of ferritin

The iron-storage protein ferritin encapsulates a nanoparticle of iron oxide. The size and properties of these nanoparticles can be adjusted by controlled oxidative hydrolysis reactions of Fe(II). This mineralized ferritin protein cage has previously been shown to act as an effective photocatalyst for reduction of Cr(VI). In the present work, we demonstrate that Fe(O)OH-mineralized ferritin catalyzes the photoreduction of Cu(II) to form a stable, air-sensitive, colloidal dispersion of Cu(0). In addition, the particle sizes of the Cu colloids can be controlled by varying the ratio of Cu(II) to ferritin. This illustrates an important principle, namely that the properties of one preformed material can be utilized for the specific synthesis of a second material, thus tailoring the desired physical properties of the final products. This procedure represents a multistep materials synthesis: the formation of a new nanomaterial from a catalytic precursor.