Measurement of the intersystem crossing rate in aluminum tris(8-hydroxyquinoline) and its modulation by an applied magnetic field

Copyright 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics 106, 043511 (2009) and may be found at

Reduced hole mobility due to the presence of excited states in poly-(3-hexylthiophene)

Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Applied Physics Letters 93, 233306 (2008) and may be found at

Salinity effect and seed priming treatments on the germination of Suaeda salsa in the tidal marsh of the Yellow River estuary

The effects of salinity and seed priming treatments (hydropriming, water, KNO3 and KH2PO3) on the germination of the euhalophyte Suaeda salsa in intertidal zone of the Yellow River estuary were investigated. Results show that the seed germination percentage decreased with increasing NaCl concentration, and at the high NaCl level (800 mM), the lowest germination percentage was recorded. At the low NaCl levels, the highest germination rate was observed on day two and the seedling length was promoted slightly. In contrast, the germination delayed and the seedling length decreased at the high salinity. According to the survival functions, we also found that, at the low salinity, the seeds germinated quickly at the initial days and then the germination rate decreased, while few seeds germinated at the initial days at the high salinity. From the results of germination percentage and seedling length, we found that the effect of Yellow river water on germination was similar to the 400 mM NaCl. For priming treatments, the hydropriming has no promotion to the seeds germination, but it promoted the seedling growth at the river water and 400 mM NaCl. Seeds primed with KNO3 could improve the germination at the low salinity, while priming with KH2PO4 could improve the seedling growth at the high salinity, indicating that seed priming with proper nutrient (N, P) solutions could improve the germination or seedling growth as the nutrient (N, P) availability in the soil of S. salsa marsh was very limited.Keywords: Suaeda salsa, germination, salinity, priming, Yellow River estuar

Adventitious shoot regeneration from leaf explants of miniature paprika (Capsicum annuum) ‘Hivita Red’ and ‘Hivita Yellow’

A simple and efficient protocol was developed for in vitro propagation of two miniature paprika cultivars. Seeds of miniature paprika (Capsicum annuum) ‘Hivita Red’ and ‘Hivita Yellow’ were decontaminated and placed in a petri dish containing a half-strength MS medium and then wereincubated in the dark for 7 10 days for germination. Leaf explants excised from one month-old aseptic seedlings were cultured on a MS medium supplemented with TDZ (0.1, 0.5, 1.0, 2.0, or 3.0 mgL-1) alone or in a combination with NAA (0.1 or 0.01 mgL-1) for four weeks. The highest number of regenerated shoot buds was obtained when leaf explants were cultured on a MS medium supplemented with 2.0 mgL-1 TDZ and 0.1 mgL-1 NAA with an average shoots per explant of 8.0 in ‘Hivita Red’ and 5.6 in ‘Hivita Yellow’. Regenerated shoot buds were separated and transferred onto a MS medium without growth regulators for shoot growth and rooting. Plantlets were successfully acclimatized in a greenhouse andcultivated for three months. After about two months, they started to produce flowers and continuously produced fruits. Morphology and fruit shape of regenerated plants were normal and plants set seeds asthe same as to the seed-raised plants

Large enhancement of the photovoltaic effect in ferroelectric complex oxides through bandgap reduction

Tuning the bandgap in ferroelectric complex oxides is a possible route for improving the photovoltaic activity of materials. Here, we report the realization of this effect in epitaxial thin films of the ferroelectric complex oxide Bi3.25La0.75Ti3O12 (BLT) suitably doped by Fe and Co. Our study shows that Co (BLCT) doping and combined Fe, Co (BLFCT) doping lead to a reduction of the bandgap by more than 1 eV compared to undoped BLT, accompanied by a surprisingly more efficient visible light absorption. Both BLCT and BLFCT films can absorb visible light with a wavelength of up to 500 nm while still exhibiting ferroelectricity, whereas undoped BLT only absorbs UV light with a wavelength of less than 350 nm. Correlated with its bandgap reduction, the BLFCT film shows a photocurrent density enhanced by 25 times compared to that of BLT films. Density functional theory calculations indicate that the bandgap contraction is caused by the formation of new energy states below the conduction bands due to intermixed transition metal dopants (Fe, Co) in BLT. This mechanism of tuning the bandgap by simple doping can be applied to other wide-bandgap complex oxides, thereby enabling their use in solar energy conversion or optoelectronic applications

Protective Effect of Ginseng Polysaccharides on Influenza Viral Infection

Ginseng polysaccharide has been known to have multiple immunomodulatory effects. In this study, we investigated whether Panax ginseng polysaccharide (GP) would have a preventive effect on influenza infection. Administration of mice with GP prior to infection was found to confer a survival benefit against infection with H1N1 (A/PR/8/34) and H3N2 (A/Philippines/82) influenza viruses. Mice infected with the 2009 H1N1 virus suspended in GP solution showed moderately enhanced survival rates and lower levels of lung viral titers and the inflammatory cytokine (IL-6). Daily treatment of vaccinated mice with GP improved their survival against heterosubtypic lethal challenge. This study demonstrates the first evidence that GP can be used as a remedy against influenza viral infection

Ferroelectric polarization switching with a remarkably high activation energy in orthorhombic GaFeO3 thin films

Orthorhombic GaFeO3 (o-GFO) with the polar Pna2(1) space group is a prominent ferrite owing to its piezoelectricity and ferrimagnetism, coupled with magnetoelectric effects. Herein, we demonstrate large ferroelectric remanent polarization in undoped o-GFO thin films by adopting either a hexagonal strontium titanate (STO) or a cubic yttrium-stabilized zirconia (YSZ) substrate. The polarization-electric-field hysteresis curves of the polar c-axis-grown o-GFO film on a SrRuO3/STO substrate show the net switching polarization of similar to 35 mu C cm(-2) with an unusually high coercive field (E-c) of +/- 1400 kV cm(-1) at room temperature. The positive-up and negative-down measurement also demonstrates the switching polarization of similar to 26 mu C cm(-2). The activation energy for the polarization switching, as obtained by density-functional theory calculations, is remarkably high, 1.05 eV per formula unit. We have theoretically shown that this high value accounts for the extraordinary high E-c and the stability of the polar Pna2(1) phase over a wide range of temperatures up to 1368 K.111714Ysciescopu

A conserved arginine residue is critical for stabilizing the N2 FeS cluster in mitochondrial complex I.

Respiratory complex I (NADH:ubiquinone oxidoreductase), the first enzyme of the electron-transport chain, captures the free energy released by NADH oxidation and ubiquinone reduction to translocate protons across an energy-transducing membrane and drive ATP synthesis during oxidative phosphorylation. The cofactor that transfers the electrons directly to ubiquinone is an iron-sulfur cluster (N2) located in the NDUFS2/NUCM subunit. A nearby arginine residue (R121), which forms part of the second coordination sphere of the N2 cluster, is known to be posttranslationally dimethylated but its functional and structural significance are not known. Here, we show that mutations of this arginine residue (R121M/K) abolish the quinone-reductase activity, concomitant with disappearance of the N2 signature from the electron paramagnetic resonance (EPR) spectrum. Analysis of the cryo-EM structure of NDUFS2-R121M complex I at 3.7 Å resolution identified the absence of the cubane N2 cluster as the cause of the dysfunction, within an otherwise intact enzyme. The mutation further induced localized disorder in nearby elements of the quinone-binding site, consistent with the close connections between the cluster and substrate-binding regions. Our results demonstrate that R121 is required for the formation and/or stability of the N2 cluster and highlight the importance of structural analyses for mechanistic interpretation of biochemical and spectroscopic data on complex I variants