A new megastigmane glycoside, phoenixoside A, from Phoenix dactylifera

A new megastigmane glycoside, phoenixoside A (1), has been isolated from the n-butanol--soluble fraction of seeds of Phoenix dactylifera. The structure was characterized as (6S,7Z,9R)-hydroxy-3-oxo-ionol-9-O-beta-D-glucopyranosyl-(1" --> 6')-beta-D-glucopyranoside on the basis of 1D and 2D NMR spectroscopy, high-resolution mass spectrometry, and CD spectroscopy.     

Characterization of catechol 1,2-dioxygenase from cell extracts of Sphingomonas xenophaga QYY

Sphingomonas xenophaga QYY, capable of growing significantly on more than ten kinds of aromatic compounds as sole carbon source, was used to study characterization of catechol 1,2-dioxygenase (C12O) in cell extracts. Characterization of the crude C12O showed that the maximum activity was obtained at 40-70℃ and pH 7.8-8.8. Metal ions had different influences on the activity of crude C12O. It was suggested that strain QYY possessed an inducible and ferric-dependent C12O. Kinetic studies showed that the value ...     

Real‐Time Interrogation of Aspirin Reactivity,Biochemistry, and Biodistribution by Hyperpolarized Magnetic Resonance Spectroscopy

Hyperpolarized magnetic resonance spectroscopy enables quantitative, non‐radioactive, real‐time measurement of imaging probe biodistribution and metabolism in vivo. Here, we investigate and report on the development and characterization of hyperpolarized acetylsalicylic acid (aspirin) and its use as a nuclear magnetic resonance (NMR) probe. Aspirin derivatives were synthesized with single‐ and double‐¹³C labels and hyperpolarized by dynamic nuclear polarization with 4.7 % and 3 % polarization, respectively. The longitudinal relaxation constants (T₁) for the labeled acetyl and carboxyl carbonyls were approximately 30 seconds, supporting in vivo imaging and spectroscopy applications. In vitro hydrolysis, transacetylation, and albumin binding of hyperpolarized aspirin were readily monitored in real time by ¹³C‐NMR spectroscopy. Hyperpolarized, double‐labeled aspirin was well tolerated in mice and could be observed by both ¹³C‐MR imaging and ¹³C‐NMR spectroscopy in vivo.     

Optical modelling of P3HT:PC<Subscript>71</Subscript>BM semi-transparent organic solar cell

The optical properties of a novel semi-transparent organic solar cell were investigated both experimentally and by transfer matrix modelling to maximize photocurrent generation. The effect of multilayer anode thickness and illumination direction was studied. Bottom illumination was shown to provide enhanced exciton generation and increased photocurrent. Changing the multilayer anode thickness also influenced the device reflectance and photocurrent generation.     

Thermal effect analysis on crosstalk and performance of optoelectronic transmitter modules for optical interconnects

This paper presents thermal analysis on crosstalk and performance of optoelectronic transmitter modules and also demonstrates the thermal analysis for efficient heat dissipation for the transmitter modules. The thermal crosstalk model for analysis is based on interconnects parameters for vertically stacked and horizontally packaged optoelectronic transmitter modules. While the analytical expression is used to estimate the thermal critical frequency, f _{crit_th} , above which signals become severely deteriorated, a Teflon-based thermal printed circuit board (PCB) has been designed for packaging the optoelectronic transmitter modules to ensure efficient heat dissipation. The thermal and performance analysis of the packaged modules show that the chips operate at temperatures below the f _{crit_th} , which is apt for reliable data and signal transmission.     

Fabrication and characterization of jute fabrics reinforced polypropylene-based composites: effects of ionizing radiation and disaccharide (sucrose)

Composites were prepared successfully by compression molding technique using jute fabrics (reinforcing agent) and polypropylene (matrix). Jute fabrics were treated with disaccharide (sucrose) solution and composites were fabricated with the treated fabric and polypropylene. The fiber content of the prepared composites was 40% by weight. It was found that the sucrose (2% solution) decreased the tensile strength (TS) and elongation at break about 6% and 37%, respectively, but tensile modulus and impact strength improved about 27% and 32%, respectively. When gamma radiation was applied through the untreated and treated composites the mechanical properties were improved much higher in non-treated Jute/PP-based composites than that of sucrose treated composites. For 5.0?kGy gamma dose the highest mechanical properties were observed for non-treated composites. At 5.0?kGy gamma dose the improvement of TS was 14% and 2% for non-treated and sucrose treated composites, respectively. The water uptake property of the sucrose treated composites was performed up to 10 days and composites absorbed 18% water. The functional groups of the both composites were analyzed by Fourier transform infrared spectroscopy machine. The scanning electron microscopic images of the both composites were taken for the surface and fiber adhesion analysis.     

Deuteron-induced activation cross-sections on natural copper up to 24 MeV

Activation cross-sections of ^natCu(d,x)^62,65Zn,⁶⁴Cu,^60g+mCo,⁵⁹Fe reactions were measured using a stacked foil activation technique combined with HPGe gamma-ray spectrometry up to the deuteron energy of 24 MeV. Measured data were critically compared with the available literature data and theoretical data extracted from the TENDL-2012 library, and found only partial agreements among them. Cross-sections of ^natCu(d,x)⁵⁹Fe reactions are reported here for the first time in the energy region of 19–23 MeV. Measured cross-sections of the long-lived ⁶⁵Zn, ^60gCo and ⁵⁹Fe radionuclides are significant for understanding the activation behaviour of copper, an essential structural material used in accelerator and nuclear industry.     

A host-guest optical sensor for aliphatic amines based on lipophilic cyclodextrin

A host-guest optical sensor for the determination of aliphatic amines as exemplified by octylamine is proposed. It is based on the reversible fluorescence enhancement of heptakis(2,6-di-O-isobutyl)-β-cyclodextrin(DOB-β-CD) hosting tetraphenylporphyrin (TPP) immobilized in poly(vinyl chloride) (PVC) membrane by aliphatic amine extracted from aqueous phase into membrane phase. The optimum membrane contained 1.15 wt % TPP, 6.15 wt % DOB-β-CD as sensing reagent and other membrane materials. The fluorescence enhancement of the membrane resulted from the formation of a stable three-component complex among DOB-β-CD, TPP, and aliphatic amines. With the optimum conditions described, the fluorescence response of the sensor to octylamine shows a good correlation with the theoretically derived equation in the range 1.0 × 10^–6 to 8.0 × 10^–4 mol/L. The response characteristics including reversibility, response time, reproducibility and lifetime and selectivity of this optical device are also discussed in detail. This sensor has also been applied for the determination of octylamine in water samples containing interferents with satisfactory recovery.     

Real‐Time Interrogation of Aspirin Reactivity,Biochemistry, and Biodistribution by Hyperpolarized Magnetic Resonance Spectroscopy

Hyperpolarized magnetic resonance spectroscopy enables quantitative, non‐radioactive, real‐time measurement of imaging probe biodistribution and metabolism in vivo. Here, we investigate and report on the development and characterization of hyperpolarized acetylsalicylic acid (aspirin) and its use as a nuclear magnetic resonance (NMR) probe. Aspirin derivatives were synthesized with single‐ and double‐¹³C labels and hyperpolarized by dynamic nuclear polarization with 4.7 % and 3 % polarization, respectively. The longitudinal relaxation constants (T₁) for the labeled acetyl and carboxyl carbonyls were approximately 30 seconds, supporting in vivo imaging and spectroscopy applications. In vitro hydrolysis, transacetylation, and albumin binding of hyperpolarized aspirin were readily monitored in real time by ¹³C‐NMR spectroscopy. Hyperpolarized, double‐labeled aspirin was well tolerated in mice and could be observed by both ¹³C‐MR imaging and ¹³C‐NMR spectroscopy in vivo.     

Novel Visible-Light-Driven Photocatalyst Co<Subscript>3</Subscript>O<Subscript>4</Subscript>/FeWO<Subscript>4</Subscript> for Efficient Decomposition of Organic Pollutants

A highly efficient and visible light (λ ≥ 420 nm) responsive composite photocatalyst, Co₃O₄/FeWO₄ was prepared by simple impregnation method. The heterojunction semiconductors Co₃O₄/FeWO₄ demonstrated notably high photocatalytic activity over a wide range of composition than the individual component Co₃O₄ or FeWO₄ for the complete degradation of 1,4-dichlorobenzene (DCB) in aqueous phase under visible light irradiation. The photocatalytic activity of composite was optimized at 1/99 Co₃O₄/FeWO₄ composition. After 2 h of visible light irradiation 51% decomposition of 1,4-dichlorobenzene (DCB) was observed utilizing 1/99 Co₃O₄/FeWO₄ photocatalyst while the end members demonstrated a negligible degradation under the same experimental condition. The valence band (VB) and conduction band (CB) of Co₃O₄ is located above the VB and CB of FeWO₄, respectively. Both the semiconductors Co₃O₄ and FeWO₄ exhibit strong absorption over the wide range of visible light. The obviously enhanced photocatalytic performance of Co₃O₄/FeWO₄ composite has been discussed on the hole (h⁺) as well as electron (e^?) transfer mechanism between the VB and CB of individual semiconductors.