14,492 research outputs found
Polysaccharide Ecocomposite Materials: Materials: Synthesis, Characterization and Application for Removal of Pollutants and Bacteria
A novel, simple and totally recyclable method has been developed for the synthesis of nontoxic, biocompatible and biodegradable composite materials from cellulose and chitosan. In this method, [BMIm+Cl-], an ionic liquid (IL), was used as a solvent to dissolve and synthesize the [CEL+CS] composite materials. Since the IL can be removed from the materials by washing them with water, and recovered from the washed solution, the method is totally recyclable. XRD, FTIR, NIR and SEM were used to characterize the materials and to confirm that CEL and CS were successfully regenerated by the method without any chemical transformation. More importantly, we have successfully demonstrated that [CEL+CS] material can serve as an effective adsorbent for removal of various endocrine disruptors including polychlorophenols and bisphenol A. This is because the composites have combined advantages of their components, namely superior chemical stability and mechanical stability (from CEL) and excellent adsorption capability for pollutants (from CS)
TDP1/TOP1 ratio as a promising indicator for the response of small cell lung cancer to topotecan
BACKGROUND AND OBJECTIVE
Small cell lung cancer (SCLC) is one of the most challenging tumors to treat due to high proliferation rate, early metastatic dissemination and rapid development of chemotherapy resistance. The current treatment protocols involve the use of topoisomerase 1 (TOP1) poisons such as irinotecan and topotecan in combination with platinum-based compounds. TOP1 poisons kill cancer cells by trapping TOP1 on DNA, generating lethal DNA double-strand breaks. A potential mechanism employed by cancer cells to resist killing by TOP1 poisons is to overexpress enzymes involved in the repair of TOP1-DNA breaks. Tyrosyl DNA phosphodiesterase 1 (TDP1) is a key player in this process and despite its importance, no data is currently available to correlate TDP1 protein and mRNA levels with catalytic activity in SCLC. In addition, it is not known if TDP1 and TOP1 protein levels correlate with the cellular response of SCLC to TOP1 based therapies.
METHODS AND RESULTS
We report a remarkable variation in TDP1 and TOP1 protein levels in a panel of SCLC cell lines. TDP1 protein level correlates well with TDP1 mRNA and TDP1 catalytic activity, as measured by two newly developed independent activity assays, suggesting the potential utility of immunohistochemistry in assessing TDP1 levels in SCLC tissues. We further demonstrate that whilst TDP1 protein level alone does not correlate with topotecan sensitivity, TDP1/TOP1 ratio correlates well with sensitivity in 8 out of 10 cell lines examined.
CONCLUSION
This study provides the first cellular analyses of TDP1 and TOP1 in SCLC and suggests the potential utility of TDP1/TOP1 ratio to assess the response of SCLC to topotecan. The establishment and validation of an easy-to-use TDP1 enzymatic assay in cell extracts could be exploited as a diagnostic tool in the clinic. These findings may help in stratifying patients that are likely to benefit from TOP1 poisons and TDP1 inhibitors currently under development
Language and Proofs for Higher-Order SMT (Work in Progress)
Satisfiability modulo theories (SMT) solvers have throughout the years been
able to cope with increasingly expressive formulas, from ground logics to full
first-order logic modulo theories. Nevertheless, higher-order logic within SMT
is still little explored. One main goal of the Matryoshka project, which
started in March 2017, is to extend the reasoning capabilities of SMT solvers
and other automatic provers beyond first-order logic. In this preliminary
report, we report on an extension of the SMT-LIB language, the standard input
format of SMT solvers, to handle higher-order constructs. We also discuss how
to augment the proof format of the SMT solver veriT to accommodate these new
constructs and the solving techniques they require.Comment: In Proceedings PxTP 2017, arXiv:1712.0089
Preparation and characterization of electrolytic alumina deposit on austenitic stainless steel
Conversion coating modified by alumina has been studied as a way for improving the resistance to thermal oxidation of an austenitic stainless steel. Conversion coating, characterized by a particular morphology and strong interfacial adhesion with the substrate, facilitate the electrochemical deposition of ceramic layers and enhance their adhesion to the substrate. The influence of the current density and treatment time on alumina deposit was studied using statistical experimental designs like Doehlert uniform shell design. After heating, coatings present a continuous composition gradient with refractory compounds at the surface. The behavior at high temperature (1000 8C) of the alumina coating was investigated. The presence of alumina increases the oxidation resistance of an austenitic stainless steel at 1000 8C. The morphology and the chemical composition of the deposit are analyzed. Results on the thermal stability of coating on austenitic stainless steel are presented
On Dirac Zero Modes in Hyperdiamond Model
Using the SU(5) symmetry of the 4D hyperdiamond and results on the study of
4D graphene given in "Four Dimensional Graphene" (L.B Drissi, E.H Saidi, M.
Bousmina, CPM-11-01, Phys. Rev. D (2011)), we engineer a class of 4D lattice
QCD fermions whose Dirac operators have two zero modes. We show that generally
the zero modes of the Dirac operator in hyperdiamond fermions are captured by a
tensor {\Omega}_{{\mu}}^{l} with 4\times5 complex components linking the
Euclidean SO(4) vector {\mu}; and the 5-dimensional representation of SU(5).
The Bori\c{c}i-Creutz (BC) and the Karsten-Wilzeck (KW) models as well as their
Dirac zero modes are rederived as particular realizations of
{\Omega}_{{\mu}}^{l}. Other features are also given. Keywords: Lattice QCD,
Bori\c{c}i-Creutz and Karsten-Wilzeck models, 4D hyperdiamond, 4D graphene,
SU(5) Symmetry.Comment: LaTex, 28 pages, To appear in Phys Rev
EXPERIMENTAL STUDY OF RC EXTERIOR BEAM-COLUMN JOINT SUBJECTED TO TORSIONAL MOMENT
This paper presents the results of an experimental program conducted in order to investigate the behavior of Type-I beam-column Joints, where the beam was subjected to shear stresses due to combined effect of shear force and torsional moment (beam eccentric loading). Four beam-column joint specimens were constructed and tested up to failure in order to better understand the complicated behaviour due to combined loading transmitted from the beam to the column. The studied parameters were the configuration of beam side and secondary reinforcement and the existence of the joint reinforcing stirrups. Generally, the shear failure at the beam zone or at the joint panel was noticed to be the governing mode of failure for all tested specimens. The test results shed the light on the importance of longitudinal side reinforcing steel configuration, the inadequate embedded length of the beam side and secondary steel into the joint panel including stirrups led to decrease the beam capacity but it kept the failure away from the joint panel
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Draft genome sequence of an enterococcus faecalis strain (24FS) that was isolated from healthy infant feces and exhibits high antibacterial activity, multiple-antibiotic resistance, and multiple virulence factors
Enterococcus faecalis 24FS is a bacteriocin-producing, multiply antibiotic-resistant, and potentially virulent bacterium isolated from healthy infant feces. The draft 2.9-Mb genome sequence revealed 2,968 protein-encoding genes; 11 antibiotic resistance, 8 virulence, and 3 bacteriocin genes; and 2 plasmids, 4 prophages, 30 insertion sequence (IS) elements, 1 transposon, and 1 integron
Requirements Modeling Methodology Based on Knowledge Engineering: A Case Study of Railway Control System
The complexity of the verification and the validation of embedded systems is increasing. This paper explores the first requirements engineering processes in the solution domain, which are analysis and specification. In this work we present an architecture of a requirement specification system. We show how the requirements are analysed and structured to generate a dependency graph. This latter will serve to analyse requirements and to model specifications on goal model. In this paper we will focus on the analysis, and structuring processes. We will explain the requirement classification criteria. Keywords: Requirements Modeling, Qualification Strategy, Knowledge Engineering, Ontology, Dependency Graph, Embedded System, ERTMS/ETC
Supersymmetric mode converters
Originally developed in the context of quantum field theory, the concept of
supersymmetry (SUSY) can be used to systematically design a new class of
optical structures. In this work, we demonstrate how key features arising from
optical supersymmetry can be exploited to control the flow of light for mode
division multiplexing applications. Superpartner configurations are
experimentally realized in coupled optical networks, and the corresponding
light dynamics in such systems are directly observed. We show that SUSY can be
judiciously utilized to remove the fundamental mode of a multimode optical
structure, while establishing global phase matching conditions for the
remaining set of modes. Along these lines, supersymmetry may serve as a
promising platform for a new generation of versatile optical components with
novel properties and functionalities.Comment: 14 pages, 4 figure
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