The molecular conformation and mobility of the intercalated surfactant molecules, cetyltrimethylammonium bromide (CTMAB), have been studied using Fourier transform IR spectroscopy (FTIR) and high-resolution single-pulse

Using energy-filtered transmission electron microscopy we measured surface-plasmon resonances of gold nanoplatelets with different shapes and edge lengths at high spatial resolution. We find equidistant maxima of the energy-loss probability along the platelet edges. The plasmon dispersion of the different geometries is very similar, i.e., hardly dependent on specimen shape. The experimental results are verified by means of finite-difference time-domain calculations which reveal the presence of wedge-plasmon polaritons propagating along the platelet edges. At platelet corners, apart from radiative losses, wedge-plasmon polaritons are partially reflected or transmitted to neighboring edges. The interference of all these contributions leads to the observed plasmon resonance modes. This is an essential step towards a thorough understanding of plasmon eigenmodes in prismatic nanoplatelets.

The ordering conformation of surfactant molecules in intercalated montmorillonite prepared at various concentrations was investigated by 13C MAS NMR. The 13C MAS NMR study demonstrates the coexistence of ordered and disordered chain conformations. Two main resonance peaks are associated with the backbone alkyl chains: the resonance at 33 ppm corresponds to the ordered conformation (all-trans), and the resonance at 30 ppm corresponds to the disordered conformation (mixture of trans and gauche). Deconvolution of 13C MAS NMR spectra indicates that the ordering conformation of surfactant molecules within the gallery of montmorillonite depends very much on their orientation and packing density. When amine chains are oriented parallel to the silicate layers, the amount of all-trans conformer decreases with the increase of amine concentration. However, the amount of all-trans conformer increases with the increase of amine concentration when amine chains radiate from the silicate layers. Furthermore, 13C MAS NMR spectra show that the intercalated surfactant molecules in the clay minerals never attained the complete liquidlike or solidlike behavior.

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The Sae2/CtIP protein is required for efficient processing of DNA double-strand breaks that initiate homologous recombination in eukaryotic cells. Sae2/CtIP is also important for survival of single-stranded Top1-induced lesions and CtIP is known to associate directly with transcription-associated complexes in mammalian cells. Here we investigate the role of Sae2/CtIP at single-strand lesions in budding yeast and in human cells and find that depletion of Sae2/CtIP promotes the accumulation of stalled RNA polymerase and RNA-DNA hybrids at sites of highly expressed genes. Overexpression of the RNA-DNA helicase Senataxin suppresses DNA damage sensitivity and R-loop accumulation in Sae2/CtIP-deficient cells, and a catalytic mutant of CtIP fails to complement this sensitivity, indicating a role for CtIP nuclease activity in the repair process. Based on this evidence, we propose that R-loop processing by 5’ flap endonucleases is a necessary step in the stabilization and removal of nascent R-loop initiating structures in eukaryotic cells.

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Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp aging-related diseases. Particularly, clinical epidemiological studies and studies of telomerase-deficient mice have shown a direct link between telomere shortening and hypertension. 6 In addition, experimental evidence reveals that both elevated Hcy level and hypertension are related to DNA methylation of leukocytes and are associated with the burden of oxidative stress, inflammation, altered elasticity of the vascular wall, and renal function; all key contributors to age-dependent shortening of leukocyte telomere length (LTL). 7 Our previous in vivo and in vitro studies demonstrated that Hcy could promote the recruitment of methylation-sensitive transcription factors to demethylated promoters of atherosclerosis-related genes by reducing DNA methyltransferase 1 activity. 8, 9 The human telomerase reverse transcriptase (hTERT) gene might regulate telomerase activity and maintain telomere length by encoding the catalytic subunit of the telomerase holoenzyme. 5 The hTERT level is tightly regulated by DNA methssential hypertension (EH) is a complex disorder involving approximately one-third of the adult population worldwide. 1,2 Epidemiological studies have documented that aging as well as genetic and environmental factors such as physical inactivity, obesity, high sodium and low potassium diet, and alcohol consumption are associated with the development of hypertension. 3,4 In addition, dysregulated methionine metabolism leading to high plasma homocysteine (Hcy) levels (≥10 mmol/L), known as hyperhomocysteinemia-type EH (HHcy-EH), might play a role. 5 However, the mechanisms underlying HHcy-EH and its adverse complications remain unknown. Editorial p 1828Telomere dynamics (telomere length and its age-dependent shortening) provide valuable insights into the pathogenesis of Background: Elevated homocysteine (Hcy) levels might play a role in the development of essential hypertension (EH). Telomere dynamics provide valuable insight into the pathogenesis of age-related diseases. The contribution of Hcy to leukocyte telomere length (LTL) shortening in EH and the underlying mechanism was examined.