Imaging findings of solitary fibrous tumor of the prostate: a case report

The imaging findings of a solitary fibrous tumor of the prostate are presented. A 35-year-old male presented with urinary retention and was found on transrectal ultrasonography to have a hypoechoic tumor of the prostate, measuring 5.5 cm in size. Magnetic resonance imaging on, the tumor showed low signal intensity on T1-weighted images and heterogeneous mixed signal intensity on T2-weighted images. Gadolinium-enhanced dynamic study showed gradual enhancement from the periphery to the center, and the enhancement is sustained. On immunohistochemistry, the spindle cells of the tumor showed positive staining for CD34 and bcl-2. Although the tumor was labeled as a low-grade malignancy on account of a low mitotic index (MIB-1 index) of about 5%, the patient developed local recurrence of the tumor with bladder wall invasion 12 months later.     

High-dimensional Edgeworth expansion of a test statistic on independence and its error bound

In this paper, we calculate Edgeworth expansion of a test statistic on independence when some of the parameters are large, and simulate the goodness of fit of its approximation. We also calculate an error bound for Edgeworth expansion. Some tables of the error bound are given, which show that the derived bound is sufficiently small for practical use.     

Synthesis and spectroscopic study of phenylene-(poly)ethynylenes substituted by amino or amino/cyano groups at terminal(s): electronic effect of cyano group on charge-transfer excitation of acetylenic π-systems

To gain insight into substituent electronic effect on charge-transfer excitation of acetylenic π-systems, phenylene-(poly)ethynylenes substituted by Ph₂N or Ph₂N/cyano groups were synthesized by combination of Sonogashira coupling and double elimination protocol of β-substituted sulfones. These substituted phenyleneethynylenes showed large molar absorption coefficients ?, and emitted strong fluorescence upon UV light irradiation. Phenylene-(poly)ethynylenes, which involve butadiyne or hexatriyne motifs, emitted fluorescence in remarkably lower fluorescence quantum yields Φ_F as their polyethynylene motifs -(CC)_n- expanded. The drastic decrease of fluorescence quantum yields Φ_F were explained in terms of increasing nonradiative reaction rate constants k_nr, which had been determined by the corresponding fluorescence quantum yields Φ_F and lifetime values τ. The emission underwent a large bathochromic shift in polar solvents because the charge-separated excited state is more stabilized than the ground state. Comparison of slope values ρ in Lippert/Mataga plot for the Ph₂N and Ph₂N/cyano-substituted phenylene-(poly)ethynylenes revealed that the latter underwent large change of dipole moments upon photo-excitation although highly expanded acetylenic π-systems with cyano group did little.     

Platinum dissolution and deposition in the polymer electrolyte membrane of a PEM fuel cell as studied by potential cycling

The behavior of platinum dissolution and deposition in the polymer electrolyte membrane of a membrane-electrode-assembly (MEA) for a proton-exchange membrane fuel cell (PEMFC) was studied using potential cycling experiment and high-resolution transmission electron microscopy (HRTEM). The electrochemically active surface area decreased depending on the cycle number and the upper potential limit. Platinum deposition was observed in the polymer electrolyte membrane near a cathode catalyst layer. Platinum deposition was accelerated by the presence of hydrogen transported through the membrane from an anode compartment. Platinum was transported across the membrane and deposited on the anode layer in the absence of hydrogen in the anode compartment. This deposition was also affected by the presence of oxygen in the cathode compartment.     

Recognition of Multiple Methyl Groups on Aromatic Rings by a Polyaromatic Cavity

The methyl group is a small substituent, usually showing relatively weak or no interactions with other functional groups and metal ions. Herein, we present the recognition of the number of methyl groups on synthetic and natural aromatic compounds (i.e., benzene and xanthine derivatives, respectively) by the 1 nm‐sized polyaromatic cavity of a coordination capsule in water. Detailed competitive encapsulation experiments as well as X‐ray crystallographic analysis revealed that multiple guest–host CH₃–polyaromatic interactions in the confined nanospace are key driving forces for the high selectivity.     

Anisotropic Expansion of an M2L4 Coordination Capsule: Host Capability and Frame Rearrangement

Anisotropic expansion of a spherical M₂L₄ coordination capsule through the elongation of the ligand led to a new M₂L′₄ capsule. The expanded capsule provides an elliptical cavity encircled by polyaromatic frameworks with large openings and thereby can encapsulate elliptical fullerene C₇₀ and monofunctionalized fullerene C₆₀ in high yields. In addition, selective formation of a new M₂L₂L′₂ capsule occurs by mixing the original M₂L₄ and expanded M₂L′₄ capsules in a 1:1 ratio upon addition of C₆₀ or monofunctionalized C₆₀ as a template molecule.     

Bimetallic Au–Ni Nanoparticles Embedded in SiO2 Nanospheres: Synergetic Catalysis in Hydrolytic Dehydrogenation of Ammonia Borane

Gold–nickel nanoparticles (NPs) of 3–4 nm diameter embedded in silica nanospheres of around 15 nm have been prepared by using [Au(en)₂Cl₃] and [Ni(NH₃)₆Cl₂] as precursors in a NP‐5/cyclohexane reversed‐micelle system, and by in situ reduction in an aqueous solution of NaBH₄/NH₃BH₃. Compared with monometallic Au@SiO₂ and Ni@SiO₂, the as‐synthesized Au–Ni@SiO₂ catalyst shows higher catalytic activity and better durability in the hydrolysis of ammonia borane, generating a nearly stoichiometric amount of hydrogen. During the generation of H₂, the synergy effect between gold and nickel is apparent: The nickel species stabilizes the gold NPs and the existence of gold helps to improve the catalytic activity and durability of the nickel NPs.     

Determination of the liver cytosolic proteins that bind to p-hydroxyacetophenone

The purpose of the present study was to determine the proteins that bind to acetophenones in the liver. Immobilized p-hydroxyacetophenone (p-HAP) was used as a ligand of affinity chromatography. Analysis using sodium dodesyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that five polypeptides in the liver cytosolic fraction specifically bound to the p-HAP matrix. These polypeptides were digested with Lys-specific protease and used to generate peptide maps by reversed-phase high-performance liquid chromatography. Consequently, identification from a data base of protein sequences revealed that the five polypeptides were glycogen phosphorylase, cytosolic aldehyde dehydrogenase, adenosine kinase, class I alcohol dehydrogenase and glutathione S-transferase A2. In addition to p-HAP, acetylsalicylic acid also displayed a prominent ability to elute these five enzymes from the p-HAP affinity column loaded with the cytosolic fraction of the liver. Thus, p-HAP has affinities to the above liver enzymes and is a useful ligand for analysis of them.     

Preparation, properties, and reduction of heteroaromatic quinoids with 1,4-diazacyclopentadien-2-ylidene terminals

New n-type heteroaromatic quinoids with 1,4-diazacyclopentadien-2-ylidene terminals were prepared. These quinoids possess strong electron-accepting properties, comparable to dicyanomethylene analogues. Both the radical anions and dianions were generated by metal reduction using 3% Na-Hg in THF and were spectroscopically characterized.     

Syntheses of some 2-hydroxypyrazine 1-oxides

A series of 2-hydroxypyrazine 1-oxides were prepared from the corresponding chloropyrazines by two methods, including oxidation processes in satisfactory yields. The treatment of 2,3-diphenylpyrazine 1,4-dioxide ( 6 ) led to 2,3-dichloro-5,6-diphenylpyrazine ( 7 ) and 2-chloro-5,6-diphenylpyrazine 1-oxide ( 8 ), and the latter was converted to 5,6-diphenyl-2-hydroxypyrazine 1-oxide ( 9 ) by an alkaline hydrolysis.