Improvement in flow-sheet of extraction chromatography for trivalent minor actinides recovery

Journal of Radioanalytical and Nuclear Chemistry - Extraction chromatography flow-sheet employing octyl(phenyl)-N,N-diisobutylcarbonoylmethylphosphine oxide and bis(2-ethylhexyl) hydrogen phosphate...     

HPLC with fluorescence detection assay of perampanel,a novel AMPA receptor antagonist,in human plasma for clinical pharmacokinetic studies

Perampanel (Fycompa®), a novel α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptor antagonist, is registered for the adjunctive treatment of patients (aged ≥12 years) with refractory partial‐onset seizures. To support therapeutic drug monitoring, a simple high‐performance liquid chromatography (HPLC) assay with fluorescence detection was developed to determine perampanel concentrations in human plasma and validated to support clinical trials. Human plasma samples (1.0 mL) were processed by liquid extraction using diethyl ether, followed by chromatographic separation on a YMC Pack Pro C₁₈ column (150 × 4.6 mm i.d., 5 µm) with isocratic elution of acetonitrile–water–acetic acid–sodium acetate (840:560:3:1.8, v/v/v/w) at a flow rate of 1.0 mL/min. Column eluent was monitored at excitation and emission wavelengths of 290 and 430 nm, respectively. The assay was linear (range 1.0–500 ng/mL) and this could be extended to 25 µg/mL by 50‐fold dilution integrity. No endogenous peaks were detected in the elution of analytes in drug‐free blank human plasma from six individuals and no interference was observed with co‐medications tested. Intra‐ and inter‐batch reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. Validation data demonstrated that our assay is simple, selective, reproducible and suitable for therapeutic drug monitoring of perampanel. Copyright © 2015 John Wiley & Sons, Ltd.     

Preparation and properties of the biodegradable graded blend of poly(L‐lactic acid) and poly(ethylene oxide)

We prepared biodegradable poly(ethylene oxide) (PEO)/poly(L ‐lactic acid) (PLLA) graded blends by the dissolution–diffusion process, and discussed the biodegradability and tensile strength of the graded blends by comparing isotropic blend and PLLA only. All the graded blends were degraded more largely than the PLLA only and isotropic blend (PEO: 37.5 wt %), which had the same content as the total content of those graded blends. The graded blend having most excellent wide compositional gradient was degraded most largely with the enzyme. Thus, graded structure of the blends promoted their biodegradabilities large. It was considered that the dissolution of PEO with water increased the surface area attacked by the enzyme, while PEO caught PLLA oligomers to promote the biodegradation of PLLA. Then, the biodegradabilities of the graded blends were suppressed by the increasing crystallinity of PLLA. Furthermore, the strengths of all the graded blends were larger than those of the isotropic blend. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2972–2981, 2007     

Constructing finitely presented monoids which have no finite complete presentation

Squier (1987) showed that if a monoid is defined by a finite complete rewriting system, then it satisfies the homological finiteness condition FP₃, and using this fact he gave monoids (groups) which have solvable word problems but cannot be presented by finite complete systems. In the present paper we show that a monoid cannot have a finite complete presentation if it contains certain special elements. This observation enables us to construct monoids without finite complete presentation in a direct and elementary way. We give a finitely presented monoid which has (1) a word problem solvable in linear time and (2) linear growth but (3) no finite complete presentation. We also give a finitely presented monoid which has (1) a word problem solvable in linear time, (2) finite derivation type in the sense of Squier and (3) the property FP_∞, but (4) no finite complete presentation.     

Synthesis and structure-activity relationships of N-substituted 2-[(2-imidazolylsulfinyl)methyl]anilines as a new class of gastric H+/K(+)-ATPase inhibitors.

A series of N-substituted 2-[(2-imidazolylsulfinyl)methyl]anilines (3) was synthesized and evaluated for its biological activity against gastric H+/K(+)-ATPase prepared from rabbit stomach and gastric acid secretions in Heidenhain pouch dogs. Monoalkyl substituents on the nitrogen atom of the aniline moiety markedly inhibited the enzyme activity to the same degree as omeprazole, a representative H+/K(+)-ATPase inhibitor. Most of these compounds, administered at 3 mg/kg i.v. inhibited histamine-stimulated gastric acid secretion. The inhibitory activity of these derivatives on the enzymes at pH 6.0 was more potent than that at pH 7.4, and was distinctly correlated to stability in aqueous solution at pH 5.0.     

High-throughput characterization of local conductivity of Nd0.9Ca0.1Ba2Cu3O7−δ thin film by the low-temperature scanning microwave microscope

We developed a scanning microwave microscope (SμM) designed for high-throughput electric-property screening as well as for rapid construction of electronic phase diagrams at low temperatures. As a sensor probe, we used a high-Qλ/4 coaxial cavity resonator to which a thin needle with ball-tip end was attached. The sensor module was mounted on the low-temperature XYZ stage, which allowed us to map out the change of resonance frequency and quality factor due to the local tip-sample interaction at low temperatures. From the measurements of combinatorial thin films, such as Ti_1−xCo_xO_2−δ and Nd_0.9Ca_0.1Ba₂Cu₃O_7−δ (NCBCO), it was demonstrated that this SμM system has enough performance for the high-throughput characterization of sample conductance under variable temperature conditions.     

Rugged distal tips for CO2 laser medicine

Low-loss and rugged distal tips for CO₂ laser have been proposed and fabricated based on a commercially available stainless steel (St) pipe. A method of smoothening the inner surface of the St pipe with a rough inner surface is put forward. Fabrication parameters, transmission properties, and mechanical strength of the cyclic olefin polymer-coated silver hollow St distal tip are experimentally discussed.     

Photocarrier injection and the I-V characteristics of La0.8Sr0.2MnO3/SrTiO3:Nb heterojunctions

Oxide heterojunctions made of p-type La_0.8Sr_0.2MnO₃ (LSMO) and niobium-doped n-type SrTiO₃ (STO:Nb) have been fabricated by the pulsed laser deposition (PLD) technique and characterized under UV light irradiation by measuring the current-voltage, photovoltaic properties and the junction capacitance. It is shown that the heterojunctions work as an efficient UV photodiode, in which photogenerated holes in the STO:Nb substrate are injected to the LSMO film. The maximum surface hole density Q/e and external quantum efficiency γ are estimated to be 8.3×10¹² cm⁻² and 11% at room temperature, respectively. They are improved significantly in a p-i-n junction of LSMO/STO/STO:Nb, where Q/e and γ are 3.0×10¹³ cm⁻² and 27%, respectively.     

Preparation and condensation reactions of a new light-fluorous Mukaiyama reagent: reliable purification with fluorous solid phase extraction for esters and amides

A modified light-fluorous Mukaiyama reagent bearing a C₈F₁₇ tag was prepared and examined in ester and amide forming condensation reactions. Following the reactions, the desired product was effectively separated from the fluorous pyridone by-product using a simple fluorous solid phase extraction.