1,693 research outputs found
Characterization of the Soluble Nanoparticles Formed through Coulombic Interaction of Bovine Serum Albumin with Anionic Graft Copolymers at Low pH
A static light scattering (SLS) study of bovine serum albumin (BSA) mixtures
with two anionic graft copolymers of poly (sodium acrylate-co-sodium
2-acrylamido-2-methyl-1-propanesulphonate)-graft-poly (N,
N-dimethylacrylamide), with a high composition in poly (N,
N-dimethylacrylamide) (PDMAM) side chains, revealed the formation of oppositely
charged complexes, at pH lower than 4.9, the isoelectric point of BSA. The
core-corona nanoparticles formed at pH = 3.00, were characterized. Their
molecular weight and radius of gyration were determined by SLS, while their
hydrodynamic radius was determined by dynamic light scattering. Small angle
neutron scattering measurements were used to determine the radius of the
insoluble complexes, comprising the core of the particles. The values obtained
indicated that their size and aggregation number of the nanoparticles, were
smaller when the content of the graft copolymers in neutral PDMAM side chains
was higher. Such particles should be interesting drug delivery candidates, if
the gastrointestinal tract was to be used
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Structure in mind, structure in vocal tract
We update our understanding of the view that grammar regulates intersegmental temporal coordination and present an extension of that view to a new domain: we argue that inter-segmental coordination is basic to prosody. It is the glue joining segments together differently in different languages (here, illustrated with examples from Arabic and Spanish) and orchestrates their unfolding in ways corresponding to constructs posited in theoretical analysis. The correspondence is one between organization in mind-brain and organization in vocal tract. Moreover, for both mind-brain and vocal tract, the organization is phonological and abstract. It is so because it holds over segments of various identities: in Arabic, the first segment in /bka/ is not prosodified as part of the same unit as /ka/ and this holds true also for /blat/, /klat/ and so on, regardless of sonority. In contrast, in English or Spanish, a different organization holds. Crucially, uniformity in organization (same organization presiding over sequences with varying segmental makeup) does not imply uniqueness of phonetic exponents: prosodic organization is pleiotropic, simultaneously expressed by more than one phonetic exponent. Finally, two properties of coordination relations are underscored: lawful flexibility and abstractness. The first is revealed in the degrees of freedom with which movements corresponding to any given effector begin; the second in invariances of task-relevant kinematic signatures regardless of the effectors implicated in any given segmental sequence. Once again, abstract phonological structure is mirrored in vocal tracts via coordination relations holding across physiology and the particular modes of its operation
Evaluation of the effect of six different paint cross section preparation methods on the performances of Fourier Transformed Infrared microscopy in attenuated total reflection mode
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The usefulness of diffuse pattern of distribution in 99mTc-(V) DMSA scintimammography in the evaluation of in situ breast carcinomas
Scintimammographic findings with 99mTc-(V)DMSA and 99mTc-MIBI in usual-type ductal epithelial hyperplasia (HUT) and apocrine metaplasia (AM) of the breast, in relation with the cell proliferation index (Ki-67) and the presence of estrogen receptors (ERs)
Image processing applications: From particle physics to society
We present an embedded system for extremely efficient real-time pattern recognition execution, enabling technological advancements with both scientific and social impact. It is a compact, fast, low consumption processing unit (PU) based on a combination of Field Programmable Gate Arrays (FPGAs) and the full custom associative memory chip. The PU has been developed for real time tracking in particle physics experiments, but delivers flexible features for potential application in a wide range of fields. It has been proposed to be used in accelerated pattern matching execution for Magnetic Resonance Fingerprinting (biomedical applications), in real time detection of space debris trails in astronomical images (space applications) and in brain emulation for image processing (cognitive image processing). We illustrate the potentiality of the PU for the new applications
Ancient encaustic: An experimental exploration of technology, ageing behaviour and approaches to analytical investigation
The composition of the ancient wax-based painting technique known as encaustic has long been the subject of debate. Ancient sources provide few details of the technology, and modern understanding of the medium is restricted to theoretical interpretation and experimental observation. In this multi-analytical collaborative study, a number of analytical approaches were used to investigate the physical and molecular properties of a range of experimentally prepared encaustic paints before and after ageing. Analysis using gas chromatography mass spectrometry, Fourier transform infrared spectroscopy (invasive and non-invasive), X-ray diffraction and thermogravimetric analysis demonstrated how differences in the technology of production alter the properties and composition of the medium and showed how these are modified by the addition of pigment and the effects of ageing. Comparison of results from the different analytical techniques highlights the benefit of an integrated analytical approach to the analysis of ancient encaustic paints and the fundamental importance of insights from invasive study to evaluating the results of non-invasive analysis
Performing Values Practices and Grassroots Organizing: The Case of Solidarity Economy Initiatives in Greece
This article discusses solidarity economy initiatives as instances of grassroots organizing, and explores how ‘values practices’ are performed collectively during times of crisis. In focusing on how power, discourse and subjectivities are negotiated in the everyday practices of grassroots exchange networks (GENs) in crisis-stricken Greece, the study unveils and discusses three performances of values practices, namely mobilization of values, re-articulation of social relations, and sustainable living. Based on these findings, and informed by theoretical analyses of performativity, we propose a framework for studying the production and reproduction of values in the context of GENs, and the role of values in organizing alternatives
Enzyme-Nanoporous Gold Biocomposite: Excellent Biocatalyst with Improved Biocatalytic Performance and Stability
Background: Applications involving biomolecules, such as enzymes, antibodies, and other proteins as well as whole cells, are often hampered by their unstable nature at extremely high temperature and in organic solvents. Methodology/Principal Findings: We constructed enzyme-NPG biocomposites by assembling various enzymes onto the surface of nanoporous gold (NPG), which showed much enhanced biocatalytic performance and stability. Various enzymes with different molecular sizes were successfully tethered onto NPG, and the loadings were 3.6, 3.1 and 0.8 mg g 21 for lipase, catalase and horseradish peroxidase, respectively. The enzyme-NPG biocomposites exhibited remarkable catalytic activities which were fully comparable to those of free enzymes. They also presented enhanced stability, with 74, 78 and 53 % of enzymatic activity retained after 20 successive batch reactions. Moreover, these novel biocomposites possessed significantly enhanced reaction durability under various thermal and in organic solvent systems. In a sample transesterification reaction, a high conversion rate was readily achieved by using the lipase-NPG biocomposite. Conclusion/Significance: These nano-biocomposite materials hold great potential in applications such as biosensing, molecular electronics, catalysis, and controlled delivery
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