Emerging effects of non-coding RNA in vascular endothelial cells during strokes.

Vascular and neurological damage are the typical outcomes of ischemic strokes. Vascular endothelial cells (VECs), a substantial component of the blood-brain barrier (BBB), are necessary for normal cerebrovascular physiology. During an ischemic stroke (IS), changes in the brain endothelium can lead to a BBB rupture, inflammation, and vasogenic brain edema, and VECs are essential for neurotrophic effects and angiogenesis. Non-coding RNAs (nc-RNAs) are endogenous molecules, and brain ischemia quickly changes the expression patterns of several non-coding RNA types, such as microRNA (miRNA/miR), long non-coding RNA (lncRNA), and circular RNA (circRNA). Furthermore, vascular endothelium-associated nc-RNAs are important mediators in the maintenance of healthy cerebrovascular function. In order to better understand how VECs are regulated epigenetically during an IS, in this review, we attempted to assemble the molecular functions of nc-RNAs that are linked with VECs during an IS.

Loss of imprinting and abnormal expression of the insulin-like growth factor 2 gene in gastric cancer.

This study examined the frequency of loss of imprinting (LOI) and expression of the insulin-like growth factor 2 (IGF2) gene, and their relationship to selected clinical and pathological factors, in a well defined series of 90 Chinese patients with gastric cancer (GC) and 90 matched patients (controls) diagnosed with nonmalignant conditions. Using peripheral blood and gastric tissue samples, polymerase chain reaction-based assays and restriction endonuclease (Apa I) digestion revealed 33 GC patients and 21 controls to be Apa I informative. LOI of IGF2 was positive in 48.5% (16/33) of primary GC tumor tissues, in 21.2% (7/33) of histologically normal adjacent gastric mucosa (AM) and in 12.1% (4/33) of distant gastric mucosa (DM), and in 15.2% (5/33) of peripheral blood lymphocytes (PBLs). The prevalence of IGF2 LOI in PBL was not statistically different between GC patients (5/33, 15.2%) and control subjects (2/21, 9.5%), P = 0.69. Although patients who were found to have LOI of IGF2 were more likely to have advanced stage gastric tumors (P = 0.04), no statistically significant differences in survival were found based on imprinting status. IGF2 LOI was associated with an increased expression of IGF2 level in both tumors (P < 0.01) and blood (P < 0.01). The results of this study implicate IGF2 LOI in the molecular pathogenesis of GC, most likely through increased IGF2 expression. Although the precise molecular mechanisms by which LOI of IGF2 increases GC risk require further study, LOI of IGF2 may be a potentially important clinical epigenetic marker to identify individuals at increased risk for gastric malignancy.

A comparative study of the structural, electronic, and vibrational properties of NH3BH3 and LiNH2BH3: theory and experiment.

Herein, we systematically investigate the structural, electronic, and vibrational properties of ammonia borane (NH(3)BH(3), AB) and lithium amidoborane (LiNH(2)BH(3,) LAB) through both density functional calculations and experiments. AB and LAB samples are generated and their vibrational spectra are obtained by using Fourier transformed infrared spectroscopy (FTIR). The measured vibrational spectra are in good agreement with the calculated ones. Our calculations show that the Li-related vibration modes are primarily found in the low-frequency region (<1000 cm(-1)), and that the intermolecular interactions significantly influence the vibrational spectra. Electronic structure calculations provide insights into the differences between the binding natures of AB and LAB and their influence on the vibrational properties of these compounds.

Hydrogen-rich boron-containing materials for hydrogen storage.

Hydrogen-rich boron-containing compounds have received extensive attention as potential hydrogen storage media for vehicular applications. The past years have seen significant progresses in material discovery, material composition/structure tailoring, catalyst identification and regeneration chemistry, which give rise to state-of-the-art hydrogen storage materials/technologies. Lithium tetrahydroborate-related materials exhibit the hitherto highest reversible hydrogen capacity via solid-gas reactions. Catalytic hydrolysis of sodium tetrahydroborate offers an on-demand hydrogen generation system for vehicular applications. Ammonia borane-related materials exhibit a satisfactory combination of material properties that are suited for on-board hydrogen sources, coupled with significant advances in spent fuels regeneration. This Perspective discusses the current progresses of these representative reversible or irreversible material systems, aiming at providing an outline of the forefront of hydrogen storage materials/technologies for transportation applications.

Functional anion concept: effect of fluorine anion on hydrogen storage of sodium alanate.

Doping NaAlH(4) with Ti-catalyst has produced a promising hydrogen storage system that can be reversibly operated at moderate temperature conditions. Of the various dopant precursors, TiCl(3) was well recognized due to its pronounced catalytic effect on the reversible dehydrogenation processes of sodium aluminium hydrides. Quite recently we experimentally found that TiF(3) was even better than TiCl(3) in terms of the critical hydrogen storage properties of the doped hydrides, in particular the dehydriding performance at Na(3)AlH(6)/NaH + Al step at moderate temperature. We present here the DFT calculation results of the TiF(3) or TiCl(3) doped Na(3)AlH(6). Our computational studies have demonstrated that F(-) and Cl(-) anions differ substantially from each other with regard to the state and function in the doped sodium aluminium hydride. In great contrast to the case of chloride doping where Cl(-) anion constitutes the "dead weight" NaCl, the fluoride doping results in a substitution of H(-) by F(-) anion in the hydride lattice and accordingly, a favorable thermodynamics adjustment. These results well explain the observed dehydriding performance associated with TiF(3)/TiCl(3)-doping. More significantly, the coupled computational and experimental efforts allow us to put forward a "functional anion" concept. This renews the current mechanism understanding in the catalytically enhanced sodium alanate.

Exploration of the nature of active Ti species in metallic Ti-doped NaAlH4.

Clarification of the nature of active Ti species has been a key challenge in developing Ti-doped NaAlH(4) as a potential hydrogen storage medium. Previously, it has been greatly hindered by the invisibility of Ti-containing species in conventional analysis techniques. In the present study, for the first time, the catalytically active Ti-containing species have been definitely identified by X-ray diffraction in the hydrides doped with metallic Ti. It was found that mechanical milling of a NaH/Al mixture or NaAlH(4) with metallic Ti powder resulted in the formation of nanocrystalline Ti hydrides. The variation of the preparation conditions during the doping process leads to a slight composition variation of the Ti hydrides. The catalytic enhancement arising upon doping the hydride with commercial TiH(2) was quite similar to that achieved in the hydrides doped with metallic Ti. Moreover, the cycling stability that was previously established in metallic Ti-doped hydrides was also observed in the hydrides doped with TiH(2). These results clearly demonstrate that the in situ formed Ti hydrides act as active species to catalyze the reversible dehydrogenation of NaAlH(4). The mechanism by which Ti hydrides catalyze the reversible de-/hydrogenation reactions of NaAlH(4) was discussed.