Full automatic synthesis of [<Superscript>18</Superscript>F]THK-5351 for tau protein PET imaging in Alzheimer’s disease patients: 1 year experience

[¹⁸F]THK-5351, a new candidate for tau protein imaging, is based on an aryl quinoline structure. We report the full automatic synthesis using disposable cassettes under pH controlled [¹⁸F]fluorination. After the trapping of 88.5 ± 21.9 GBq of [¹⁸F]fluoride, it was eluted with potassium methansulfonate (KOMs) (pH 7.8)/K₂₂₂. After drying, 3 mg of the precursor was added to 1 mL DMSO and subjected to [¹⁸F]fluorination at 110 °C for 10 min. After hydrolysis, the final product was purified by HPLC. The overall radiochemical yield was 31.9 ± 11.1% (n = 22), satisfying all quality control criteria. It was stable for up to 6 h with high radiochemical purity as 99.8 ± 0.5%.     

Stability of Periodic Solutions¶of Conservation Laws with Viscosity:¶Analysis of the Evans Function

Nonclassical conservation laws with viscosity arising in multiphase fluid and solid mechanics exhibit a rich variety of traveling-wave phenomena, including homoclinic (pulse-type) and periodic solutions along with the standard heteroclinic (shock, or front-type) solutions. Here, we investigate stability of periodic traveling waves within the abstract Evans-function framework established by R. A. Gardner. Our main result is to derive a useful stability index analogous to that developed by Gardner and Zumbrun in the traveling-front or -pulse context, giving necessary conditions for stability with respect to initial perturbations that are periodic on the same period T as the traveling wave; moreover, we show that the periodic-stability index has an interpretation analogous to that of the traveling-front or -pulse index in terms of well-posedness of an associated Riemann problem for an inviscid medium, now to be interpreted as allowing a wider class of measure-valued solutionsor, alternatively, in terms of existence and nonsingularity of a local “mass map” from perturbation mass to potential time-asymptotic T-periodic states. A closely related calculation yields also a complementary long-wave stability criterion necessary for stability with respect to periodic perturbations of arbitrarily large period NT, N → ∞. We augment these analytical results with numerical investigations analogous to those carried out by Brin in the traveling-front or -pulse case, approximating the spectrum of the linearized operator about the wave.The stability index and long-wave stability criterion are explicitly evaluable in the same planar, Hamiltonian cases as is the index of Gardner and Zumbrun, and together yield rigorous results of instability similar to those obtained previously for pulse-type solutions; this is established through a novel dichotomy asserting that the two criteria are in certain cases logically exclusive. In particular, we obtain results bearing on the nature and mechanism for formation of highly oscillatory Turing-like patterns observed numerically by Frid and Liu and ?ani? and Peters in models of multiphase flow. Specifically, for the van der Waals model considered by Frid and Liu, we show instability of all periodic waves such that the period increases with amplitude in the one-parameter family of nearby periodic orbits, and in particular of large- and small-amplitude waves; for the standard, double-well potential, this yields instability of all periodic waves.Likewise, for a quadratic-flux model like that considered by ?ani? and Peters, we show instability of large-amplitude waves of the type lying near observed patterns, and of all small-amplitude waves; our numerical results give evidence that intermediate-amplitude waves are unstable as well. These results give support for an alternative mechanism for pattern formation conjectured by Azevedo, Marchesin, Plohr, and Zumbrun, not involving periodic waves.     

Molecular thermodynamics approach for polymer-polymer miscibility

We extended the previous lattice model for polymer solution systems to binary polymer blend systems. Based on Müller’s Monte-Carlo simulation data for symmetric system (r₁ = 32 and r₂ = 32), the energy of mixing is correlated as a function of temperature and composition using an empirical expression. In addition, we introduce new universal functions which reflect the characteristics of polymer-polymer miscibility behaviors. In associated blend systems, specific interactions between polymer segments are considered by using a secondary lattice. Using only one or two adjustable parameters, the proposed model satisfactory correlates the experimental data of real polymer blend systems with greater accuracy than those of other models.     

Optimizing Dilute-Acid Pretreatment of Rapeseed Straw for Extraction of Hemicellulose

Biological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars prior to fermentation. Hydrolysis can be performed enzymatically or with mineral acids. In this study, dilute sulfuric acid was used as a catalyst for the pretreatment of rapeseed straw. The purpose of this study is to optimize the pretreatment process in a 15-mL bomb tube reactor and investigate the effects of the acid concentration, temperature, and reaction time. These parameters influence hemicellulose removal and production of sugars (xylose, glucose, and arabinose) in the hydrolyzate as well as the formation of by-products (furfural, 5-hydroxymethylfurfural, and acetic acid). Statistical analysis was based on a model composition corresponding to a 3³ orthogonal factorial design and employed the response surface methodology to optimize the pretreatment conditions, aiming to attain maximum xylan, mannan, and galactan (XMG) extraction from hemicellulose of rapeseed straw. The obtained optimum conditions were: H₂SO₄ concentration of 1.76% and temperature of 152.6 °C with a reaction time of 21 min. Under these optimal conditions, 85.5% of the total sugar was recovered after acid hydrolysis (78.9% XMG and 6.6% glucan). The hydrolyzate contained 1.60 g/L glucose, 0.61 g/L arabinose, 10.49 g/L xylose, mannose, and galactose, 0.39 g/L cellobiose, 0.94 g/L fructose, 0.02 g/L 1,6-anhydro-glucose, 1.17 g/L formic acid, 2.94 g/L acetic acid, 0.04 g/L levulinic acid, 0.04 g/L 5-hydroxymethylfurfural, and 0.98 g/L furfural.     

Platinum dendrites with controlled sizes for oxygen reduction reaction

Platinum dendrites were synthesized with the controlled sizes of 13–53 nm, and their electrocatalytic properties were evaluated for oxygen reduction reaction (ORR). Dendrites showed a superior activity for ORR and better selectivity for the production of H₂O, compared to commercial E-tek catalysts. Durability was also tested by estimating the change in electrochemically active surface area (ECSA) after extended periods of oxygen reduction. Dendrites with larger sizes showed improved durability.     

Microchip electrophoretic separation for the fast diagnosis of Anaplasma phagocytophilum infection in cattle

We report a diagnostic method for Anaplasma phagocytophilum (A. phagocytophilum) infection in cattle using a nested PCR and microchip electrophoresis (ME). A. phagocytophilum causes human granulocytic anaplasmosis and granulocytic ehrlichiosis, which are emerging tick‐borne zoonotic diseases. Nested PCR was used to amplify genomic DNA samples extracted from cattle blood. The amplified PCR products were analyzed under a sieving gel matrix of 0.7% poly(ethyleneoxide) (M_r=8 000 000) in a conventional glass microchip. In the ME assay, A. phagocytophilum was analyzed within 35 s with a relative standard deviation of 1.30% (n=5) using a programmed field strength gradient (PFSG) as follows: 615.3 V/cm for 0–24 s, 66.7 V/cm for 24–34 s, 615.3 V/cm for 34–100 s. The ME‐PFSG assay was clinically validated by comparing the 16S rRNA gene levels obtained by this method with those measured using conventional slab gel electrophoresis performed with ten cattle blood samples suspected of A. phagocytophilum infection. In contrast to slab gel electrophoresis, the proposed ME‐PFSG methodology had increased sensitivity (200–450 pg/μL), a faster analysis time (<35 s), and required a smaller sample volume (～162 fL).     

Sensitivity enhancement of CE and CE-MS for the analysis of peptides by a dynamic pH junction

An analytical method of CE-MS and CE with an online preconcentration technique induced by a dynamic pH junction, addition of organic solvent and large volume injection was developed for sensitive determination of peptides in biological samples. Leucine enkephalin, methionine enkephalin, dynorphin A, β-endorphin and angiotensin II were used as model peptides. The optimal online preconcentration conditions were obtained at a sample matrix consisting of 100?mM borate buffer (pH 10.0) with 50% v/v acetonitrile and a BGE containing 1?M formic acid at pH 2.0, along with a 25-cm injection length. Under the optimized conditions, a 4.0×10(3)-1.1×10(4)-fold increase in peak intensity was achieved without degrading the peak shape. This online preconcentration method was applied to analyze the intracellular angiotensin II within the peptides extracted from HL1 cells and approximately increase of 1×10(4)-fold sensitivity was achieved compared to normal condition. Thus, the developed method could be applied to the analysis of various peptides for peptidomics study in biological samples.     

Mass–yield distributions of fission products from photo-fission of natPb induced by 50–70 MeV bremsstrahlung

The mass–yield distributions of various fission products have been determined in the 50-, 60- and 70-MeV end point bremsstrahlung induced fission of ^natPb using off-line γ-ray spectrometric technique in the electron linac at Pohang Accelerator Laboratory, Korea. The mass–yield distributions are symmetric with average mass of 102.34, 102.25 and 102.03 and FWHM of 21, 22 and 23 mass unit, respectively. From the present data and literature data in the 50–85 MeV bremsstrahlung induced fission of ²⁰⁹Bi the following observations were obtained: (i) The average masses of the yield distributions in the 50–85 MeV bremsstrahlung induced fission of ^natPb and ²⁰⁹Bi are around 102.25 ± 0.25 and 103 ± 0.5, respectively. (ii) The FWHM of the mass–yield distributions increases from about 21 mass units at 50 MeV to 23 mass units at 70–85 MeV, which is explained from the point of increase in multi-chance fission probability with increasing excitation energy. (iii) Within the bremsstrahlung energy range of 50–85 MeV, the role of nuclear structure effect in the mass–yield distribution was observed in the photo-fission of ²⁰⁹Bi, whereas it was not seen in case of ^natPb. This may be due to the presence of so many isotopes in ^natPb unlike mono-isotopic ²⁰⁹Bi.     

Simultaneous qualitative and quantitative method using liquid chromatography selected reaction monitoring-triggered quantitation-enhanced data-dependent tandem mass spectrometry for the identification and classification of amphetamine-type stimulant abusers in human urine

Amphetamine (AP) and amphetamine‐type stimulants, methamphetamine (MA) and N,N‐dimethylamphetamine (DMA), are known as central nervous system stimulants, and their abuse throughout the world has recently increased. Since it is difficult to physically distinguish among AP, MA and DMA, analysts may not be aware of what abusers have administered. In this study, following the detection of specific metabolites of AP, MA and DMA as biomarkers in abuser urines, a rapid and sensitive method was developed for the identification and classification of AP‐type stimulants abusers. After the simple filtration of the urine samples, the samples were directly analyzed using a liquid chromatography/tandem mass spectrometry system with selected reaction monitoring (SRM)‐triggered quantitation‐enhanced data‐dependent MS/MS (QED‐MS/MS) for the simultaneous qualitative and quantitative analysis of p‐hydroxy AP, p‐hydroxy MA, p‐hydroxy DMA, AP, MA, DMA and DMA N‐oxide. The determination of p‐hydroxy AP, p‐hydroxy MA, AP, MA, DMA and DMA N‐oxide was accurate and reproducible, with the limits of quantitation of 5 ng/mL in urine. When applied to the urine samples of suspected AP‐type stimulants abusers, the abused drugs were precisely identified between MA and DMA abusers. Copyright © 2010 John Wiley & Sons, Ltd.     

Hawking temperature in Taub-NUT (A)dS spaces via the generalized uncertainty principle

Using the extended forms of the Heisenberg uncertainty principle (HUP) from string theory and the non-commutative geometries, we derive the Hawking temperature of the Taub-Nut-(A)dS black hole. We show that the generalized versions of the HUP increase the Hawking temperature as in the case of the Schwarzschild-(A)dS black hole.