194 research outputs found
Ternary Mixed Magnetic Co/Mn/Ni Dichloride Dihydrate
Ternary mixed magnetic Co1-xMnyNix-yCl2 center dot 2H(2)O has as its components three well studied antiferromagnets. Each is characterized by MCl2MCl2M...chemical and structural chains, with intrachain exchange interactions antiferromagnetic for the Mn component but ferromagnetic for the other two components. Competing ferromagnetic and antiferromagnetic intrachain exchange interactions occur in two different pairwise combinations. Reported here is the magnetic behavior of an equimolar mixture of the three components. One maximum appears in the magnetic susceptibility vs temperature, at 4.85 +/- 0.05 K, a quite interesting result since decidedly lower than the locations of susceptibility maxima in the pure components. A pronounced upturn in the susceptibility below 2.3 K also appears. Magnetization vs field isotherms display increasingly strong convex upward curvature and associated hysteresis with decreasing temperature. All of these characteristics differ markedly from those of the pure components
Community detection based on links and node features in social networks
© Springer International Publishing Switzerland 2015. Community detection is a significant but challenging task in the field of social network analysis. Many effective methods have been proposed to solve this problem. However, most of them are mainly based on the topological structure or node attributes. In this paper, based on SPAEM [1], we propose a joint probabilistic model to detect community which combines node attributes and topological structure. In our model, we create a novel feature-based weighted network, within which each edge weight is represented by the node feature similarity between two nodes at the end of the edge. Then we fuse the original network and the created network with a parameter and employ expectation-maximization algorithm (EM) to identify a community. Experiments on a diverse set of data, collected from Facebook and Twitter, demonstrate that our algorithm has achieved promising results compared with other algorithms
Macrostate Data Clustering
We develop an effective nonhierarchical data clustering method using an
analogy to the dynamic coarse graining of a stochastic system. Analyzing the
eigensystem of an interitem transition matrix identifies fuzzy clusters
corresponding to the metastable macroscopic states (macrostates) of a diffusive
system. A "minimum uncertainty criterion" determines the linear transformation
from eigenvectors to cluster-defining window functions. Eigenspectrum gap and
cluster certainty conditions identify the proper number of clusters. The
physically motivated fuzzy representation and associated uncertainty analysis
distinguishes macrostate clustering from spectral partitioning methods.
Macrostate data clustering solves a variety of test cases that challenge other
methods.Comment: keywords: cluster analysis, clustering, pattern recognition, spectral
graph theory, dynamic eigenvectors, machine learning, macrostates,
classificatio
Electrospun polylactic acid-chitosan composite: a bio-based alternative for inorganic composites for advanced application
Fabricating novel materials for biomedical applications mostly require the use of biodegradable materials. In this work biodegradable materials like polylactic acid (PLA) and chitosan (CHS) were used for designing electrospun mats. This work reports the physical and chemical characterization of the PLA-CHS composite, prepared by the electrospinning technique using a mixed solvent system. The addition of chitosan into PLA, offered decrease in fiber diameter in the composites with uniformity in the distribution of fibers with an optimum at 0.4wt% CHS. The fiber formation and the reduction in fiber diameter were confirmed by the SEM micrograph. The inverse gas chromatography and contact angle measurements supported the increase of hydrophobicity of the composite membrane with increase of filler concentration. The weak interaction between PLA and chitosan was confirmed by Fourier transform infrared spectroscopy and thermal analysis. The stability of the composite was established by zeta potential measurements. Cytotoxicity studies of the membranes were also carried out and found that up to 0.6% CHS the composite material was noncytotoxic. The current findings are very important for the design and development of new materials based on polylactic acid-chitosan composites for environmental and biomedical applications.info:eu-repo/semantics/publishedVersio
Advanced Multilevel Node Separator Algorithms
A node separator of a graph is a subset S of the nodes such that removing S
and its incident edges divides the graph into two disconnected components of
about equal size. In this work, we introduce novel algorithms to find small
node separators in large graphs. With focus on solution quality, we introduce
novel flow-based local search algorithms which are integrated in a multilevel
framework. In addition, we transfer techniques successfully used in the graph
partitioning field. This includes the usage of edge ratings tailored to our
problem to guide the graph coarsening algorithm as well as highly localized
local search and iterated multilevel cycles to improve solution quality even
further. Experiments indicate that flow-based local search algorithms on its
own in a multilevel framework are already highly competitive in terms of
separator quality. Adding additional local search algorithms further improves
solution quality. Our strongest configuration almost always outperforms
competing systems while on average computing 10% and 62% smaller separators
than Metis and Scotch, respectively
Tissue engineering scaffold material with enhanced cell adhesion and angiogenesis from soy protein isolate loaded with bio modulated micro-TiO2 prepared via prolonged sonication for wound healing applications
Tissue engineering is a technique that promotes healing by creating an ideal environment for endogenous cells to
migrate and grow into the site of injury via a scaffold, improving regeneration and reducing the time required for in vitro cell culture.
In this work, the effect of the addition of sonicated TiO2 in the soy protein isolate (SPI) matrix for tissue engineering applications
was studied. In comparison to adding expensive nano TiO2, this method of incorporating sonicated TiO2 into the SPI matrix will aid
in achieving improved properties at a lower cost. The effect of the addition of sonicated TiO2 on the morphological, UV
transmittance, mechanical, thermal, surface energy, and hydrophilicity of SPI films was investigated. The result shows that the
uniformly distributed TiO2 particles successfully blocked 95% of UV light. Scanning electron microscopy revealed a significant
reduction in the TiO2 agglomerate size and homogeneous distribution of the same when sonication was applied instead of
mechanical dispersion. A simultaneous increase of tensile strength (from 3.16 to 4.58 MPa) and elongation at break values (from
24.25% to 95.31%) with 0.5% TiO2 was observed. The addition of 0.25% TiO2 was found to significantly enhance the elongation at
break value to 120.83%. Incorporation of micro-TiO2 particles could improve the surface roughness, surface energy, and wettability
of SPI films. In vitro cell adhesion studies and in vivo subcutaneous implantation studies were performed to assess the cell growth
and angiogenesis of the developed film membranes. An MTT assay showed that SPI-1%TiO2 film favored cell viability up to 118%,
and in vivo subcutaneous implantation studies showed enhanced cell growth and angiogenesis for SPI-1% TiO2 films. This SPI-TiO2
film with enhanced surface properties can be used as an ideal candidate for tissue engineering applications.info:eu-repo/semantics/publishedVersio
Polylactic acid/nano chitosan composite fibers and their morphological, physical characterization for the removal of cadmium(II) from water
This work discusses the fabrication of polylactic acid (PLA)/nano chitosan
(nCHS) composite fibers by electrospinning method for Cd2+ metal ion adsorption
from water. Here nCHS was synthesized by ionic gelation method and
which is used as a reinforcement for PLA. The scanning electron microscopic
analysis revealed that the addition 0.1 wt% nCHS has decreased the fiber diameter
as well as the secondary pore size and hence imparted unique properties
to electrospun composite fibers. The positive zeta potential values for the composites
indicated their higher stability, though; the inclusion of nCHS reduced
the crystallinity of the neat membranes. The contact angle measurements
showed that the hydrophilicity of the composite was increased up to 0.1 wt%
nCHS, and hence the surface energy was increased. Inverse gas chromatography
results suggested that the basic character of the composites has intensified
with the increase in nCHS addition. The adsorption capacity of the neat
electrospun PLA and PLA–nCHS composites for Cd2+ ions were investigated
and studies revealed that adsorption capacity of the composite was two times
faster (approximately 70%) in comparison with neat PLA fibers. The increase
in surface area as well as presence nCHS improved the adsorption capacity of
the electrospun membrane.info:eu-repo/semantics/publishedVersio
Review Article p16 INK4A and p14 ARF Gene Promoter Hypermethylation as Prognostic Biomarker in Oral and Oropharyngeal Squamous Cell Carcinoma: A Review
Head and neck squamous cell carcinoma is a heterogeneous group of tumors with each subtype having a distinct histopathological and molecular profile. Most tumors share, to some extent, the same multistep carcinogenic pathways, which include a wide variety of genetic and epigenetic changes. Epigenetic alterations represent all changes in gene expression patterns that do not alter the actual DNA sequence. Recently, it has become clear that silencing of cancer related genes is not exclusively a result of genetic changes such as mutations or deletions, but it can also be regulated on epigenetic level, mostly by means of gene promoter hypermethylation. Results from recent studies have demonstrated that DNA methylation patterns contain tumor-type-specific signatures, which could serve as biomarkers for clinical outcome in the near future. The topic of this review discusses gene promoter hypermethylation in oral and oropharyngeal squamous cell carcinoma (OSCC). The main objective is to analyse the available data on gene promoter hypermethylation of the cell cycle regulatory proteins p16 INK4A and p14 ARF and to investigate their clinical significance as novel biomarkers in OSCC. Hypermethylation of both genes seems to possess predictive properties for several clinicopathological outcomes. We conclude that the methylation status of p16 INK4A is definitely a promising candidate biomarker for predicting clinical outcome of OSCC, especially for recurrence-free survival
- …