Improving the Heat Resistance of Ribonuclease A by the Addition of Poly(N,N‐diethylaminoethyl methacrylate)‐graft‐poly(ethylene glycol) (PEAMA‐g‐PEG)

Poly(N,N‐diethylaminoethyl methacrylate)‐graft‐poly(ethylene glycol) (PEAMA‐g‐PEG) has previously been used as a novel additive to improve the heat resistance of lysozyme, which has a positive net charge and a negatively charged active site. In the present study, we show that PEAMA‐g‐PEG prevents heat inactivation of ribonuclease A (RNase A), which has a positive net charge and a positively charged active site. After treatment at 98 °C for 10 min, the enzymatic activity of RNase A complexed with PEAMA‐g‐PEG was maintained at up to 75% of the level of the native RNase A. The extents of inactivation of RNase A and the complex of RNase A with PEAMA‐g‐PEG were strongly dependent upon the heating temperature and incubation time. Circular dichroism (CD) spectral analysis revealed that heat‐induced irreversible inactivation was largely suppressed when RNase A was complexed with PEAMA‐g‐PEG. These findings suggest that the heat resistance of RNase A is improved by the external addition of PEAMA‐g‐PEG.

     

Characterization of epitaxial MgO growth on Si(001) surface

MgO epitaxial growth on a Si(001) surface by ultrahigh-vacuum molecular beam epitaxy was investigated. Epitaxial orientation and crystalline quality were characterized based on the three-dimensional reciprocal map obtained by Weissenberg RHEED. The epitaxial orientation and crystallinity were strongly dependent on the initial condition of the substrate. When MgO was deposited on a clean Si(001) surface at room temperature a MgO(001) film grew on the Si(001) substrate with two in-plane orientations:MgO[110]//Si[100] and MgO[100]//Si[100]. This is the first observation of MgO epitaxy with the former orientation, which has a smaller mismatch than the latter orientation. When the substrate was exposed to O₂ or thermally oxidized, the latterorientation predominantly grew on the substrate. Deposition of Mg on the substrate also produced the latter orientation. These results imply that nucleation sites on the initial substrate play an important role in determining the epitaxial orientation.     

Spectral analysis for intrinsic time processes

This paper discusses an estimation procedure for the spectral density of intrinsic time processes because there has been no argument of the spectral analysis for subordinated processes. Such processes have been proposed in a variety of contexts to describe asset price behavior. They are used when the movement of prices is tied to the number of market transactions, trading volume or the more illusive concept of information arrival. We develop the asymptotic theory for an estimated spectral density of intrinsic time processes and elucidate the asymptotics, which show some interesting structures. Also, numerical studies are given to confirm the results.     

Size series of small indium arsenide-zinc selenide core-shell nanocrystals and their application to in vivo imaging

We have developed a size series of unusually small, water-soluble (InAs)ZnSe (core)shell quantum dots (QDs) that emit in the near-infrared and exhibit new behavior in vivo, including multiple sequential lymph node mapping and extravasation from the vasculature. The biological utility of these fluorescent probes resulted from our intentional choice to match the semiconductor material and water-soluble ligand with a desired final hydrodynamic diameter and emission wavelength.     

Mono{hydrotris(mercaptoimidazolyl)borato} complexes of manganese(II), iron(II), cobalt(II), and nickel(II) halides

A series of [Tm(Me)M(mu-Cl)]2 and Tm(R)MCl (Tm(R) = tris(mercaptoimidazolyl)borate; R = Me, tBu, Ph, 2,6-iPr2C6H3 (Ar); M = Mn, Fe, Co, Ni) complexes have been prepared by treatment of NaTm(Me) or LiTm(R) with an excess amount of metal(II) chlorides, MCl2. Treatment of Tm(R)MCl (R = tBu, Ph, Ar) with NaI led to a halide exchange to afford Tm(R)MI. The molecular structures of [Tm(Me)M(mu-Cl)]2 (M = Mn, Ni), [Tm(Me)Ni(mu-Br)]2, Tm(tBu)MCl (M = Fe, Co), Tm(Ph)MCl (M = Mn, Fe, Co, Ni), Tm(Ar)MCl (M = Mn, Fe, Co, Ni), Tm(Ph)MI (M = Mn, Co), and Tm(Ar)MI (M = Fe, Co, Ni) have been determined by X-ray crystallography. The Tm(R) ligands occupy the tripodal coordination site of the metal ions, giving a square pyramidal or trigonal bipyramidal coordination geometry for Tm(Me)M(mu-Cl)]2 and a tetrahedral geometry for the Tm(R)MCl complexes, where the S-M-S bite angles are larger than the reported N-M-N angles of the corresponding hydrotris(pyrazolyl)borate (Tp(R)) complexes. Treatment of Tm(Ph)2Fe with excess FeCl2 affords Tm(Ph)FeCl, indicating that Tm(R)2M as well as Tm(R)MCl is formed at the initial stage of the reaction between MCl2 and the Tm(R) anion.     

On newforms for Kohnen plus spaces

In this article, we investigate the plus space of level N, where 4^?1 N is a square-free (not necessarily odd) integer. This is a generalization of Kohnen’s work. We define a Hecke isomorphism ${\wp_k}In this article, we investigate the plus space of level N, where 4⁻¹ N is a square-free (not necessarily odd) integer. This is a generalization of Kohnen’s work. We define a Hecke isomorphism ?_k{\wp_k} of M _k+1/2(4M) onto M_k+1/2⁺(8M){M_{k+1/2}^+(8M)} for any odd positive integer M. The methods of the proof of the newform theory are this isomorphism, Waldspurger’s theorem, and the dimension identity.     

Pd(II)-catalyzed synthesis of indoles from α-aryloxime O-pentafluorobenzoates via intramolecular aromatic C-H amination

α-Aryl-α-aminocarbonyloxime O-pentafluorobenzoates are found to be promising precursors for synthesis of 2,3-disubstituted indole derivatives catalyzed by PdCl₂(MeCN)₂ in the presence of MgO as a base. The reaction is supposed to proceed via intramolecular aromatic C-H amination of a vinyl nitrene-palladium intermediate.     

Dynamic out-of-plane deformation measurement using virtual speckle patterns

The novel measurement method based on the virtual speckle patterns has been reported. This method has the feature of analyzing the deformation map of an object in high resolution without any information except for speckle pattern images under a deformation process. In this paper, the method is applied to the measurement of dynamic events including a complex deformation distribution. The optical system of the method is improved in order to deal with the complex deformation distribution, which includes the increase and the decrease distributions. In experiments, the phenomenon of collision of the metal sphere on the thin polymer film is analyzed. The method can analyze the large deformation measurement of dynamic events, which cannot be measured by ordinary methods. It is confirmed that the measurement accuracy of this method even in measurements of dynamic events is high.     

Photoinduced heterolysis of the carbon-oxygen bond in bichromophoric 1-arylmethyloxy-2-pyridones

Irradiation of the title compound having a 9-anthryl (1a) or a 1-pyrenyl group (1b) in methanol was found to give the heterolytic C---O bond cleavage products: 1-hydroxy-2-pyridone and arylmethyl methyl ether, (which predominate for the reaction of 1a), along with 2-pyridone, aryl-substituted methanol and aryl aldehyde derived from the homolysis of the N---O bond (that mainly occurs in the photolysis of 1b). Spectroscopic analysis of the ground-state and excited singlet-state behavior of 1 revealed that a non-emissive intramolecular exciplex (whose formation rate is much faster in 1a than in 1b) plays a key role in inducing the C---O bond heterolysis.