2,962 research outputs found
Solvothermal synthesis of uniform bismuth nanospheres using poly(N-vinyl-2-pyrrolidone) as a reducing agent
Uniform bismuth nanospheres were successfully prepared from bismuth nitrate in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) by solvothermal process. The product was characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and energy-dispersive X-ray. PVP plays a critical role both as a reducing agent and a capping agent in the formation of bismuth nanospheres. Shape and size of bismuth nanospheres could be tuned by changing the employed PVP/bismuth salt ratio. It was also found the solvent had an effect on the morphologies of bismuth nanomaterials. The possible formation and growth mechanism of bismuth nanospheres were also discussed and proposed to explain the reduction step
Scaling Multi-Objective Security Games Provably via Space Discretization Based Evolutionary Search
In the field of security, multi-objective security games (MOSGs) allow
defenders to simultaneously protect targets from multiple heterogeneous
attackers. MOSGs aim to simultaneously maximize all the heterogeneous payoffs,
e.g., life, money, and crime rate, without merging heterogeneous attackers. In
real-world scenarios, the number of heterogeneous attackers and targets to be
protected may exceed the capability of most existing state-of-the-art methods,
i.e., MOSGs are limited by the issue of scalability. To this end, this paper
proposes a general framework called SDES based on many-objective evolutionary
search to scale up MOSGs to large-scale targets and heterogeneous attackers.
SDES consists of four consecutive key components, i.e., discretization,
optimization, restoration and evaluation, and refinement. Specifically, SDES
first discretizes the originally high-dimensional continuous solution space to
the low-dimensional discrete one by the maximal indifference property in game
theory. This property helps evolutionary algorithms (EAs) bypass the
high-dimensional step function and ensure a well-convergent Pareto front. Then,
a many-objective EA is used for optimization in the low-dimensional discrete
solution space to obtain a well-spaced Pareto front. To evaluate solutions,
SDES restores solutions back to the original space via bit-wisely optimizing a
novel solution divergence. Finally, the refinement in SDES boosts the
optimization performance with acceptable cost. Theoretically, we prove the
optimization consistency and convergence of SDES. Experiment results show that
SDES is the first linear-time MOSG algorithm for both large-scale attackers and
targets. SDES is able to solve up to 20 attackers and 100 targets MOSG
problems, while the state-of-the-art methods can only solve up to 8 attackers
and 25 targets ones. Ablation study verifies the necessity of all components in
SDES
FOXE1 polyalanine tract length screening by MLPA in idiopathic premature ovarian failure
<p>Abstract</p> <p>Background</p> <p>FOXE1 is one of the candidate genes for genetic predisposition to premature ovarian failure (POF) and it contains an alanine tract. Our purpose is to assess the influence of length of the alanine tract of FOXE1 on genetic susceptibility to POF.</p> <p>Methods</p> <p>The group studied consisted of 110 Chinese patients with idiopathic POF and 110 women from normal controls. The polyalanine tract and flanking sequence of FOXE1 was screened using the Multiple Ligation-dependent Probe Amplification (MLPA) technique and directly sequenced.</p> <p>Results</p> <p>Three variants of FOXE1-polyalanine length, containing 12, 14, or 16 alanine residues, and 5 different genotypes were identified. There were significantly lower frequencies of the 14/14 genotypes in cases with POF (X2 = 119.73, P = 0.001), as compared with the controls. The incidence of 16/16 genotypes of FOXE1-polyalanine was significantly higher in patients with POF (X2 = 3.403, P = 0.001) in comparison to the controls. The FOXE1 14 alanine allele was significantly less common in the POF patient group (186/220) than the controls (216/220) (X2 = 25.923, P = 0.0001). The FOXE1 16 alanine allele was significantly more common in the POF patient group (28/220) than the controls (4/220) (X2 = 19.412, P = 0.0001).</p> <p>Conclusion</p> <p>This finding provides evidence that polyalanine repeat expansions in FOXE1 may be responsible for the genetic aetiology of POF in Chinese women.</p
Upregulation of microRNA-25 associates with prognosis in hepatocellular carcinoma
BACKGROUND: Accumulating evidence has shown that up-regulation of microRNA-25(miR-25) is associated with the prognosis of several types of human malignant solid tumors. However, whether miR-25 expression has influence on the prognosis of hepatocellular carcinoma (HCC) is still unknown. METHODS: The differentially expressed amount of the miR-25 was validated in triplicate by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Survival rate was analyzed by log-rank test, and survival curves were plotted according to Kaplan–Meier. Multivariate analysis of the prognostic factors was performed with Cox regression model. RESULTS: The expression of miR-25 was significantly upregulated in HCC tissues when compared with adjacent normal tissues (p<0.0001). Patients who had high miR-25 expression had a shorter overall survival than patients who had low miR-25 expression (median overall survival, 31.0 months versus 42.9 months, p=0.0192). The multivariate Cox regression analysis indicated that miR-25 expression (HR=2.179; p=0.001), TNM stage (HR=1.782; p=0.014), and vein invasion (HR=1.624; p=0.020) were independent prognostic factors for overall survival. CONCLUSION: Our data suggests that the overexpression of miR-25 in HCC tissues is of predictive value on poor prognosis. VIRTUAL SLIDE: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/198961842111430
- …