The production of hydrogen through water splitting using earth-abundant metal catalysts is a promising pathway for converting solar energy into chemical fuels. However, existing approaches for fine ...stoichiometric control, structural and catalytic modification of materials by appropriate choice of earth abundant elements are either limited or challenging. Here we explore the tuning of redox active immobilised molecular metal-chalcoxide electrocatalysts by controlling the chalcogen or metal stoichiometry and explore critical aspects of the hydrogen evolution reaction (HER). Linear sweep voltammetry (LSV) shows that stoichiometric and structural control leads to the evolution of hydrogen at low overpotential with no catalyst degradation over 1000 cycles. Density functional calculations reveal the effect of the electronic and structural features and confer plausibility to the existence of a unimolecular mechanism in the HER process based on the tested hypotheses. We anticipate these findings to be a starting point for further exploration of molecular catalytic systems.
Gene fusion is involved in the development of various types of malignancies. Recent advances in sequencing technology have facilitated identification of gene fusions and have stimulated the research ...of this field in cancer. In the present study, we performed next-generation transcriptome sequencing in order to discover novel gene fusions in gastric cancer. A total of 282 fusion transcript candidates were detected from 12 gastric cancer cell lines by bioinformatic filtering. Among the candidates, we have validated 19 fusion transcripts, which are 7 inter-chromosomal and 12 intra-chromosomal fusions. A novel DUS4L-BCAP29 fusion transcript was found in 2 out of 12 cell lines and 10 out of 13 gastric cancer tissues. Knockdown of DUS4L-BCAP29 transcript using siRNA inhibited cell proliferation. Soft agar assay further confirmed that this novel fusion transcript has tumorigenic potential. We also identified that microRNA-coding gene PVT1, which is amplified in double minute chromosomes in SNU-16 cells, is recurrently involved in gene fusion. PVT1 produced six different fusion transcripts involving four different genes as fusion partners. Our findings provide better insight into transcriptional and genetic alterations of gastric cancer: namely, the tumorigenic effects of transcriptional read-through and a candidate region for genetic instability.
Platinum nanoparticles in the size range of 1.7−7.1 nm were produced by alcohol reduction methods. A polymer (poly(vinylpyrrolidone), PVP) was used to stabilize the particles by capping them in ...aqueous solution. The particles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM investigations demonstrate that the particles have a narrow size distribution. Mesoporous SBA-15 silica with 9-nm pores was synthesized by a hydrothermal process and used as a catalyst support. After incorporation into mesoporous SBA-15 silica using low-power sonication, the catalysts were calcined to remove the stabilizing polymer from the nanoparticle surface and reduced by H2. Pt particle sizes determined from selective gas adsorption measurements are larger than those determined by bulk techniques such as XRD and TEM. Room-temperature ethylene hydrogenation was chosen as a model reaction to probe the activity of the Pt/SBA-15 materials. The reaction was shown to be structure insensitive over a series of Pt/SBA-15 materials with particle sizes between 1.7 and 3.6 nm. The hydrogenolysis of ethane on Pt particles from 1.7 to 7.1 nm was weakly structure sensitive with smaller particles demonstrating higher specific activity. Turnover rates for ethane hydrogenolysis increased monotonically with increasing metal dispersion, suggesting that coordinatively unsaturated metal atoms present in small particles are more active for C2H6 hydrogenolysis than the low index planes that dominate in large particles. An explanation for the structure sensitivity is suggested, and the potential applications of these novel supported nanocatalysts for further studies of structure−activity and structure−selectivity relationships are discussed.
The possibility of a light charged Higgs boson H± that decays predominantly to a charm quark and a bottom quark (cb) and with a mass in the range 80 GeV≤MH±≤90 GeV is studied in the context of a ...three-Higgs doublet model (3HDM). Searches for this decay at the Large Hadron Collider do not have sensitivity to this mass region at present. It is shown that the searches for H± at LEP2 could be supplemented by either one or two b-tags, which would enable such large branching ratios for H±→cb to be probed in the above mass region. We comment on the possibility of this 3HDM scenario to explain a slight excess in the searches for H± at LEP2, which is best fit by MH± of around 90 GeV, and discuss the prospects for detecting H±→cb decays at future e+e− colliders.
The possibility of a light charged Higgs boson H± that decays predominantly to quarks (cs and/or cb) and with a mass in the range 80 GeV ≤ mH± ≤ 90 GeV is studied in the context of ...three-Higgs-doublet models (3HDMs). At present, the Large Hadron Collider (LHC) has little sensitivity to this scenario, and currently the best constraints are from LEP2 and Tevatron searches. The branching ratio of H± → cb can be dominant in two of the five types of 3HDM, and we determine the parameter space where this occurs. The decay H± → cb has recently been searched for at the LHC for the first time, and with increased integrated luminosity, one would expect sensitivity to the region 80 GeV ≤ m H ± ≤ 90 GeV due to the smaller backgrounds with respect to H± → cs decays.
Pesticide exposure has been implicated in the etiopathogenesis of Parkinson's disease (PD); in particular, the organochlorine insecticide dieldrin is believed to be associated with PD. Emerging ...evidence indicates that histone modifications play a critical role in cell death. In this study, we examined the effects of dieldrin treatment on histone acetylation and its role in dieldrin-induced apoptotic cell death in dopaminergic neuronal cells. In mesencephalic dopaminergic neuronal cells, dieldrin induced a time-dependent increase in the acetylation of core histones H3 and H4. Histone acetylation occurred within 10 min of dieldrin exposure indicating that acetylation is an early event in dieldrin neurotoxicity. The hyperacetylation was attributed to dieldrin-induced proteasomal dysfunction, resulting in accumulation of a key histone acetyltransferase (HAT), cAMP response element-binding protein. The novel HAT inhibitor anacardic acid significantly attenuated dieldrin-induced histone acetylation, Protein kinase C delta proteolytic activation and DNA fragmentation in dopaminergic cells protected against dopaminergic neuronal degeneration in primary mesencephalic neuronal cultures. Furthermore, 30-day exposure of dieldrin in mouse models induced histone hyperacetylation in the striatum and substantia nigra. For the first time, our results collectively demonstrate that exposure to the neurotoxic pesticide dieldrin induces acetylation of core histones because of proteasomal dysfunction and that hyperacetylation plays a key role in dopaminergic neuronal degeneration after exposure of dieldrin.
Bin picking is still a challenge in robotics, as patent in recent robot competitions. These competitions are an excellent platform for technology comparisons since some participants may use ...state-of-the-art technologies, while others may use conventional ones. Nevertheless, even though points are awarded or subtracted based on the performance in the frame of the competition rules, the final score does not directly reflect the suitability of the technology. Therefore, it is difficult to understand which technologies and their combination are optimal for various real-world problems. In this paper, we propose a set of performance metrics selected in terms of actual field use as a solution to clarify the important technologies in bin picking. Moreover, we use the selected metrics to compare our four original robot systems, which achieved the best performance in the Stow task of the Amazon Robotics Challenge 2017. Based on this comparison, we discuss which technologies are ideal for practical use in bin picking robots in the fields of factory and warehouse automation.
Multi-walled nitrogen-doped carbon (CN
x
) nanotubes, synthesized by an aerosol-assistant catalytic chemical vapor deposition technique, were investigated for electrochemical intercalation with ...lithium. Nanotube morphologies and nitrogen contents in the samples produced from toluene and acetonitrile taken in various proportions were determined by transmission electron microscopy and X-ray photoelectron spectroscopy. It was found that the first discharge capacity of CN
x
electrodes increases with nitrogen content. The irreversible capacity was partially attributed to pyridinic-like nitrogen atoms, which can strongly bind with Li ions confirmed by result of quantum-chemical calculation. The CN
x
electrode with the lowest nitrogen content (∼1 at.%) in the considered set of the samples showed the highest reversible capacity 270
mAh
g
−
1 at the current density of 0.2
mA
cm
−
2 and the highest value of exchange current density, suggesting that the electrochemical activity of carbon nanotubes is enhanced by light incorporation of nitrogen atoms.
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