Determination of origin of ephedrine used as precursor for illicit methamphetamine by carbon and nitrogen stable isotope ratio analysis

The sale of ephedrine, one of the precursors of methamphetamine, is strictly controlled and monitored in various countries to prevent the production of illicit methamphetamine. There are three kinds of production scheme for ephedrine manufacture, and it is very useful for precursor control to investigate the origin of ephedrine used for the synthesis of illicit methamphetamine. By means of stable isotope ratio mass spectrometry (IR-MS), we investigated the origin of ephedrine based on the delta(13)C and delta(15)N values. The various origins of ephedrine (biosynthetic, semisynthetic, or synthetic) could be discriminated clearly by using these values. The delta(15)N values of synthetic ephedrine were more negative than those of ephedrine from other sources. By the repeated distillation of methylamine in our laboratory, we confirmed that this could be due to isotope separation during distillation for the purification of methylamine used for ephedrine synthesis. The values for ephedrine used as the precursor were well-correlated with those for methamphetamine synthesized from it. This drug characterization analysis should be useful to illuminate the origin of the precursors used for clandestine methamphetamine and to trace the diversion of medicinal ephedrine for illicit manufacture of methamphetamine.     

Structural change of cellulose contained in immature cotton boll during its growth

An attempt was made to clarify the change in the structure of immature cotton (Gossypium spp.) boll during its growth. For this purpose, five immature cotton bolls with length less than 4.64 cm were adopted as samples and cellulose fibres taken from these bolls were subjected to SEM observation, ¹³C NMR, X-ray diffraction and IR analysis. Intramolecular hydrogen bonds were progressively formed during the growth of first cell wall but crystallization did not occur at this stage. Crystallization, as detected by X-ray diffraction, takes place after the formation of O₃…O'₅ and O₂…O'₆ intramolecular hydrogen bonds. The crystallization is well correlated with the formation of intermolecular hydrogen bonds, as detected by IR analysis. The conformational regularity of molecular chains (formation of intramolecular hydrogen bonds) is concluded to be prerequisite for the crystallization of cotton fibre.     

In vitro heat generation by ferrimagnetic maghemite microspheres for hyperthermic treatment of cancer under an alternating magnetic field

Ferrimagnetic materials can be expected to be useful as thermo seeds for hyperthermic treatment of cancer, especially where the cancer is located in deep parts of body, as they can generate heat by magnetic hysteretic loss when they are placed in an alternating magnetic field. Recently, it was reported that ferrimagnetic maghemite (γ-Fe₂O₃) microspheres 20–30 μm in diameter prepared in aqueous solution can show excellent heat generating ability. However, these microspheres have many cracks on their surfaces. In this study, the preparation conditions for the microspheres was further optimized in order to obtain crack-free ferrimagnetic microspheres, and the in vitro heat generation of the obtained microspheres was measured in an agar phantom under an alternating magnetic field. Crack-free γ-Fe₂O₃ microspheres 20–30 μm in diameter were obtained successfully. Their saturation magnetization and coercive force were 68 emu g⁻¹ and 198 Oe, respectively. Their heat generation under an alternating magnetic field of 300 Oe at 100 kHz was estimated to be 42 W g⁻¹. The microspheres showed in vitro heat generation when they were dispersed in an agar phantom and placed under an alternating magnetic field. It is believed that these microspheres may be useful for the in situ hyperthermic treatment of cancer.     

Schizosaccharomyces pombe reporter strains for relative quantitative assessment of heterochromatin silencing

The fission yeast Schizosaccharomyces pombe has been emerging as an important model organism for studying the formation and repression of heterochromatin. To enable simple and relative quantitative assessment of heterochromatin silencing, we have created bioluminescence‐based reporter strains. A green‐emitting click beetle luciferase (CBG68) gene was inserted within pericentromeric heterochromatin or at the silent mating‐type locus via homologous recombination. In the same strains, a red‐emitting click beetle luciferase (CBR) gene is expressed from the euchromatic leu1⁺ locus and can be used as a reference in dual‐colour assays. Our reporter strains are suitable for performing Chroma‐Glo? assays, which can be carried out directly in the culture medium without prior cell lysis and in a multiwell format. Our reporter system reliably reflects the state of chromatin and can be easily adapted for use in high‐throughput screening approaches. Copyright © 2012 John Wiley & Sons, Ltd.     

Preparation and some properties of stereocomplex‐type poly(lactic acid)/layered silicate nanocomposites

Stereocomplex‐type poly(lactic acid)‐ [PLA]‐ based blends were prepared by solution casting of equimolar PLLA/PDLA with different amounts of organo‐modified montmorillonite. The homocrystallization and stereocomplexation of PLAs were enhanced by annealing of the blends. The stereocomplexation of PLAs, intercalation of the polymer chains between the silicates layers, and morphological structure of the filled PLAs were analyzed by wide‐angle X‐ray diffraction and transmission electron microscope. Thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), and tensile test were performed to study the thermal and mechanical properties of the blends. The homo‐ and stereocomplex crystallization of neat PLLA/PDLA were enhanced by annealing. The effect of annealing on the crystallization was emphasized by the addition of clay. With this structural change, thermal stabilities properties were also improved by the addition of clay. The silicate layers of the clay were slightly stacked but intercalated and distributed in the PLA‐matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Analysis of the Enhanced Stability of R(+)-Alpha Lipoic Acid by the Complex Formation with Cyclodextrins

R(+)-alpha lipoic acid (RALA) is one of the cofactors for mitochondrial enzymes and, therefore, plays a central role in energy metabolism. RALA is unstable when exposed to low pH or heat, and therefore, it is difficult to use enantiopure RALA as a pharma- and nutra-ceutical. In this study, we have aimed to stabilize RALA through complex formation with cyclodextrins (CDs). α-CD, β-CD and γ-CD were used for the formation of these RALA-CD complexes. We confirmed the complex formation using differential scanning calorimetry and showed by using HPLC analysis that complexed RALA is more stable than free RALA when subjected to humidity and high temperature or acidic pH conditions. Scanning electron microscopy studies showed that the particle size and shape differed depending on the cyclodextrin used for complexation. Further, the complexes of CD and RALA showed a different particle size distribution pattern compared with that of CD itself or that of the physical mixture of RALA and CD.     

Isotope dilution inductively coupled plasma mass spectrometry for determination of 126Sn content in spent nuclear fuel sample

The ¹²⁶Sn content in a spent nuclear fuel solution was determined by isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) for its inventory estimation in high-level radioactive waste. A well-characterized irradiated UO₂ fuel sample dissolved in a hot cell was used as a sample to evaluate the reliability of the methodology. Prior to the ICP-MS measurement, Sn was separated from Te (¹²⁶Te), which causes major isobaric interference in the determination of ¹²⁶Sn content, along with highly radioactive coexisting elements, such as Sr (⁹⁰Sr), Y (⁹⁰Y), Cs (¹³⁷Cs) and Ba (^137m Ba), using an anion-exchange column. The absence of counts attributed to Te at m/z = 125, 128, and 130 in the Sn-containing effluent (Sn fraction) indicates that Te was completely removed from the anion-exchange column. After washing, Sn retained on the column was readily eluted with 1 M HNO₃ accompanied with approximately 80% of the Cd and 0.03% of the U in the initial sample. Owing to the presences of Cd and U in Sn fraction, the measurements of ¹¹⁶Sn and ¹¹⁹Sn were affected by the isobaric ¹¹⁶Cd and the doubly charged ²³⁸U²⁺ion, resulting in the positive bias of the determined values. With the exception of the isotopic ratios including ¹¹⁶Sn and ¹¹⁹Sn, ¹¹⁷Sn/¹²⁶Sn, ¹¹⁸Sn/¹²⁶Sn, ¹²⁰Sn/¹²⁶Sn, ¹²²Sn/¹²⁶Sn and ¹²⁴Sn/¹²⁶Sn were successfully determined and showed good agreement with those obtained through ORIGEN2 calculations. The measured concentration of ¹²⁶Sn in the spent nuclear fuel sample solution was 0.74 ± 0.14 ng/g, which corresponds to 23.0 ± 4.5 ng per gram of the irradiated UO₂ fuel (excluding the presence of ¹²⁶Sn in the insoluble residue). The results reported in this paper are the first experimental values of ¹²⁶Sn content and isotope ratios in the spent nuclear fuel solution originating in spent nuclear fuel irradiated at a nuclear power plant in Japan.     

Pt‐Rh/TiO2/activated carbon as highly active and stable HI decomposition catalyst for hydrogen production in sulfur‐iodine (SI) process

Pt‐TiO₂ loaded on activated carbon was studied as an active and stable catalyst to HI decomposition for H₂ formation in the sulfur‐iodine process. Although the activity of TiO₂‐loaded catalyst was slightly lower HI conversion than that of CeO₂ loaded one, the higher stability against HI decomposition reaction was achieved and almost equilibrium conversion was sustained over ~65 h examined. Moreover, effects of Rh or Ir addition on HI conversion were studied and it was found that Pt‐Rh bimetallic system was highly active and stable to HI decomposition. Scanning transmission electron micrograph observation suggested that the increased HI decomposition activity was assigned to the increased dispersion of Pt particles. High dispersion state of Pt was sustained after HI decomposition at 773 K by addition of Rh. Since the formation of PtI₄ was suggested by X‐ray photoelectron spectroscopy measurement during HI decomposition, increased stability by addition of Rh seems to be assigned to the high chemical stability of Rh against iodine. Almost the equilibrium HI conversion on Pt‐Rh‐TiO₂/M563 was sustained over 300 hours at 673 K.     

Energy and environment policy integration: The case of energy conservation policies and technologies in Japan

Among the OECD countries, Japan has achieved one of the lowest energy intensities and has been successful in reducing emissions of key air pollutants and CO₂ associated with energy use while maintaining a relatively high rate of economic growth, indicating that in Japan energy and environment policies have been able to address each other effectively. This study shows that in both policy domains, considerable importance was attached to the enhancement of energy conservation. The industrial sector has been the most responsive in reducing energy intensity as well as in controlling pollution. Aided by government fiscal measures, the iron and steel, chemicals and automobile industries have pursued both energy conservation and pollution control through suitable process or product innovation. The recent response to global environment issues shows that both the government and the industrial sector are determined to enhance energy conservation and environmental amelioration through technological innovation, indicating that Japanese technologies will continue to be ‘environmentally competitive’.     

Characterization of a Maltogenic Amylase of Thermononospora viridis and Application in Branched Cyclodextrin Production

Some kinetic characteristics and actions on various cyclodextrins (CDs) of a maltogenic α-amylase of T. viridis (TVA) were examined to apply in the branched CD production. Michaelis constants (Km) for hydrolysis of α-, β- and γ-CDs by the enzyme were 6.5, 7.6 and 10.8 mM, and apparent molecular activities (k_θ) for these saccharides were 11.0, 67.2 and 432.8 s⁻¹, respectively. The (k_θ) values for various branched CDs were remarkably smaller than those for unbranched CDs. The TVA cleaved first the ring of maltosyl-β-CD, and the branched nonasaccharide formed was immediately degraded to give branched hexa- and penta-saccharides with simultaneous formation of smaller unbranched saccharides. As a minor action, the enzyme released a glucose molecule from the side chain of maltosyl-β-CD to give glucosyl-β-CD which was readily degraded to smaller saccarides. The enzyme had an ability to hydrolyze unbranched CDs preferentially in the presence of significant amounts of branched CDs. These characteristics of the enzyme are consistent with its potential industrial use in the branched CD production.