Distribution characteristics of methamphetamine and amphetamine in urine and hair specimens collected from alleged methamphetamine users in northern Taiwan

This study was conducted to better understand the distribution characteristics of methamphetamine and amphetamine in urine and hair specimens collected from alleged methamphetamine users in the local population. It is anticipated that the data hereby obtained will be helpful to the interpretation of the time and pattern of drug use. Eight alleged methamphetamine-using arrestees from Keelung Police Department (north of Taipei, Taiwan) consented to contribute both urine and hair specimens. Each arrestee contributed seven urine specimens collected at 0, 12, 24, 48, 72, 96, and 120 h, respectively, after the arrest. Hair specimens were cut into 2-cm sections. The limits of detection and quantitation of the urine protocol were 40 and 50 ng/mL, respectively, for both amphetamine and methamphetamine, while the corresponding limits of detection and quantitation for the hair protocol were 0.8 and 1.0 ng/mg, respectively. The concentration variations of methamphetamine and amphetamine in the urine specimens exhibited three distinct patterns: (a) continuous decrease in the analytes’ concentrations for specimens collected at hours 0-120; (b) increase in the analytes’ concentrations in specimens collected at hours 0-12, followed by decrease; (c) increase in analytes’ concentrations in specimens collected at later times. Together with the amphetamine/methamphetamine concentration ratios found in these urine specimens, the observed trends in the changes of the analytes’ concentrations are helpful for the interpretation on the time of drug use. Unlike urine specimens, amphetamine/methamphetamine concentration ratios in various hair specimens and hair sections remain relatively constant.     

Synthesis of sterically hindered 3,5,5-trimethyl 2,6-dioxo tetrahydro pyrimidine as HCV protease inhibitors

An efficient route for the synthesis of sterically hindered substituted and unsubstituted 2,6-dioxo tetrahydropyrimidines from amine 1 is described. These analogs are active against HCV NS3 serine protease. The biological data for some of the representative examples are also reported.     

Differential Sensing of Serine and Tyrosine with Aligned CdS Nanowire Arrays Based on pH‐Dependent Photoluminescence Behavior

Up and down: Differential sensing of serine and tyrosine is achieved with aligned CdS nanowire arrays by exploring the pH‐dependent PL behavior of the nanowire arrays toward exposure to the two amino acid solutions (see picture).

     

Genomic splice site prediction algorithm based on nucleotide sequence pattern for RNA viruses

Splice site prediction on an RNA virus has two potential difficulties seriously degrading the performance of most conventional splice site predictors. One is a limited number of strains available for a virus species and the other is the diversified sequence patterns around the splice sites caused by the high mutation frequency. To overcome these two difficulties, a new algorithm called Genomic Splice Site Prediction (GSSP) algorithm, was proposed for splice site prediction of RNA viruses. The key idea of the GSSP algorithm was to characterize the interdependency among the nucleotides and base positions based on the eigen-patterns. Identified by a sequence pattern mining technique, each eigen-pattern specified a unique composition of the base positions and the nucleotides occurring at the positions. To remedy the problem of insufficient training data due to the limited number of strains for an RNA virus, a cross-species strategy was employed in this study. The GSSP algorithm was shown to be effective and superior to two conventional methods in predicting the splice sites of five RNA species in the Orthomyxoviruses family. The sensitivity and specificity achieved by the GSSP algorithm was higher than 99 and 94%, respectively, for the donor sites, and was higher than 96 and 92%, respectively, for the acceptor sites. Supplementary data associated with this work are freely available for academic use at http://homepage.ntu.edu.tw/ approximately d91548013/.     

Prime Number Decomposition, the Hyperbolic Function and Multi-Path Michelson Interferometers

The phase φ of any wave is determined by the ratio x/λ consisting of the distance x propagated by the wave and its wavelength λ. Hence, the dependence of φ on λ constitutes an analogue system for the mathematical operation of division, that is to obtain the hyperbolic function f(ξ)≡1/ξ. We take advantage of this observation to decompose integers into primes and implement this approach towards factorization of numbers in a multi-path Michelson interferometer. This work is part of a larger program geared towards unraveling the connections between quantum mechanics and number theory. We briefly summarize this aspect.     

Atomic scale control of catalytic process in oxidation of Pb thin films

Using scanning tunneling microscopy (STM), we demonstrate that oxidation on Pb films is greatly enhanced by atomic Cs catalysts. With only a minute concentration of isolated Cs substitutional atoms in the surface layer (0.004 ML coverage), surface oxidation rates are greatly enhanced. First-principles density functional theory (DFT) calculations reveal that a substitutional Cs atom strongly increases O₂ binding on the surface. Then, with additional oxygen exposure this substitutional Cs-initiated oxidation process results in growth of PbO layers in an auto-catalytic manner. Furthermore, we investigate the role of temperature in the oxidation of the Pb films with and without Cs, and we explore the overall morphology of the resultant oxide layers.     

Parallel Raman microspectroscopy using programmable multipoint illumination

We present a novel parallel Raman microspectroscopy scheme for simultaneously collecting Raman spectra from multiple points. This scheme is realized by projectinga multiple-point laser illumination pattern using a spatial light modulator (SLM) and wide-field Raman imaging collection. We demonstrate the performance of this scheme using uniform samples, trapped polymer microparticles and fixed polymer microparticles with mixed molecular composition within a 50×50 μm(2) field of view. This scheme enables the acquisition of Raman spectra from as many as 40 points simultaneously using a single illumination pattern and detector recording frame without scanning.     

Flexible optitrode for localized light delivery and electrical recording

We present optitrode, a miniaturized flexible probe for integrated, localized light delivery and electrical recording. This device features an annular light guide with transparent polymer and fused silica layers surrounding a twisted-wire tetrode. We have developed a novel fabrication process, V-groove guided capillary assembly, to achieve high-precision, coaxial alignment of the various layers of the device. Optitrode with a length-to-diameter ratio ～500 (5 cm long, 100 μm diameter) has been fabricated, and both the electrical and optical functions have been characterized. The prototype can deliver 11% (110 mW) of the total laser power under abrupt bending angle ～25°.     

Morphology and formation mechanism of ceria nanoparticles by spray pyrolysis

Ceria-based materials are used in industrial applications such as catalyst supports, carbon monoxide reduction catalysts, and solid oxide fuel cell electrolytes. Various applications require different morphological particles. The ceria particles with various morphologies from the precursors of cerium(III) acetate hydrate, cerium(IV) nitrate hydrate, and cerium(IV) ammonium nitrate were prepared by spray pyrolysis (SP) because SP has the potential for simple and continuous process. The precursor behaviors and the particle morphologies were characterized by thermogravimetric analysis and by transmission electron microscopy. Four main morphologies of solid spherical, hollow spherical with a single pore, hollow concave, and hollow spherical with multiple pores were observed. The experimental results suggest that the morphological formation mechanism is highly correlated with the factors of precursor solubilities, solvent evaporation rates (droplet diameters), and precursor melting temperatures. In addition, total concentrations of cerium(III) in the ceria particles from various precursors were examined using X-ray photoelectron spectroscopy.     

Adlay Seed (Coix lacryma-jobi L. var. Ma-yuen Stapf.) Ethanolic Extract Fractions and Subfractions Induce Cell Cycle Arrest and Apoptosis in Human Breast and Cervical Cancer Cell Lines

The antitumor effects of Coix lacryma-jobi L. var. ma-yuen Stapf. (adlay seed) ethanolic extract have been increasingly shown. This study aimed to investigate the beneficial effects of both the fractions and subfractions of adlay seed ethanolic extract on the human breast (MCF-7) and cervical (HeLa) cancer cell lines, as well as exploring their possible mechanisms of action. The ethanolic extracts were obtained from different parts of adlay seed, including AHE (adlay hull extract), ATE (adlay testa extract), ABE (adlay bran extract) and PAE (polished adlay extract). The results of a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl- tetrazolium bromide (MTT) assay showed that AHE-Ea and ATE-Ea showed significant growth inhibitory effects in a dose-dependent manner. The results also showed that the AHE-Ea-K, AHE-Ea-L, ATE-Ea-E and ATE-Ea-F subfractions inhibited cell proliferation, induced cell cycle arrest in the G0/G1 phase and decreased CDK4/Cyclin D1 protein expression. Finally, the extract activated caspase-3 activity and PARP protein expression, which induced MCF-7 and HeLa cell apoptosis. We then used liquid chromatography–mass spectrometry (LC/MS) to identify the potential active components., Quercetin showed an anticancer capacity. In conclusion, the AHE-Ea-K, AHE-Ea-L, ATE-Ea-E and ATE-Ea-F subfractions showed antitumor effects through the inhibition of MCF-7 and HeLa cell line viability, as well as inducing apoptosis and cell cycle arrest.