Search results for " Matrix"
showing 10 items of 2053 documents
Effect of sodium bicarbonate treatment on mechanical properties of flax-reinforced epoxy composite materials
2017
This paper deals with the evaluation of the effect of an eco-friendly and cost-effective surface treatment based on the use of sodium bicarbonate on the mechanical properties of flax-reinforced epoxy composites. To this aim, unidirectional fabrics were soaked for five days in 5 and 10% in weight of sodium bicarbonate solution at 25℃. Quasi-static and dynamic mechanical tests were performed and the fracture surfaces of the composites were analyzed through scanning electron microscopy. Results evidenced that this treatment improves the fiber–matrix adhesion thus increasing the performances of the composites. Treating the fabrics with 10% w/w of bicarbonate solution leads to improvements of ∼…
Synthesis and degradation of type IV collagen in rat skeletal muscle during immobilization in shortened and lengthened positions
2003
Aim: Type IV collagen is a major protein in basement membranes surrounding and supporting skeletal muscle cells. In the present study, we tested the hypotheses that immobilization down-regulates synthesis and up-regulates degradation of type IV collagen in skeletal muscle. Methods: mRNA level and concentration of type IV collagen as well as mRNA levels and activities of proteins involved in its degradation were analysed from soleus (SOL), gastrocnemius (GAS) and extensor digitorum longus muscles after immobilization in shortened and lengthened positions for 1, 3 and 7 days. Results: Following immobilization, type IV collagen mRNA level was decreased in SOL and GAS suggesting down-regulat…
A Method to Extract the Complete Fiber Network Topology of Planar Fibrous Tissues and Scaffolds
2010
Improving fabrication protocols and design strategies, investigating on how fibrous ECM and synthetic architectures affect cell morphology, metabolism and phenotypic expression, predicting mechanical behaviors, have increasingly become crucial goals in the understanding of native tissues and in the development of engineered tissue. In the present study, an image-based analysis approach that provides an automatic tool to fully characterize engineered tissue fiber network topology was developed. The following micro architectural features were detected: fiber angle distribution, fiber connectivity, fiber overlap spatial density, and fiber diameter. In order to demonstrate the potential of this…
Spectral moments of the edge adjacency matrix in molecular graphs. 3. Molecules containing cycles
1998
A substructural approach to quantitative structure−property relationships based on the spectral moments of the edge adjacency matrix is extended to molecules containing cycles. Spectral moments are expressed as linear combinations of structural fragments of any kind of nonweighted graphs. The boiling points of a series of 80 cycloalkanes was well-described by the present approach. The predictive power of the model was proved by using a test set of another 26 compounds. An equation that expresses the contribution of the different fragments of the molecules to the boiling point was obtained.
Elastic neutron scattering of dry and rehydrated trehalose coated carboxy-myoglobin
2008
We report here a comparison between the hydrogen atoms mean square displacements measured by elastic neutron scattering on trehalose coated carboxy-myoglobin, at ILL on the backscattering spectrometers IN13 and IN16. An inconsistency is observed when comparing the mean square displacements measured on the two spectrometer, on samples of identical composition, since they resulted of larger amplitude on IN13 (either in condition of drought or after overnight rehydration under 75% D2O atmosphere), notwithstanding the lower time window accessible on this instrument with respect to IN16. Such inconsistency disappears when the data obtained on this last spectrometer are analyzed in two separate r…
Characterization of heat-labile toxin-subunit B from Escherichia coli by liquid chromatography-electrospray ionization-mass spectrometry and matrix-a…
2012
The possibilities of characterizing the heat-labile enterotoxin (LT) of enterotoxigenic Escherichia coli (ETEC) by liquid chromatography electrospray mass spectrometry (LC/ESI-MS) and matrix-assisted laser desorption with time-of-flight mass spectrometry (MALDI-TOF-MS) were investigated. The B subunit from recombinant E. coli (expression in Pichia pastoris) can be detected by LC/ESI-MS expressed in P. pastoris and the charge envelope signals can be observed; LC/ESI-MS and MALDI-TOF-MS analysis allowed the acquisition of labile toxin subunit B (LTB) molecular weight and preliminary structural characterization of LTB toxin. MALDI-TOF analysis after reduction and alkylation of the protein evid…
Mass spectrometric studies of benzoxazine resorcarenes
2002
Eleven differently substituted 3,4-dihydro-2H-1,3-benzoxazine resorcarenes were studied by electrospray ionisation (ESI) and matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry, using Fourier transform ion cyclotron resonance (FT-ICR) and time-of-flight (TOF) mass spectrometers, respectively. Under ESI conditions it was possible to transfer the intact resorcarenes from solution to the gas phase, yielding [M + H]+ and [M + 2H]+ ions as the main ions observed. Energy increase of the ions induced ready decomposition through successive eliminations of four CH2NR groups. Ion-molecule reactions showed that the ionising proton was situated somewhere inside the molecule and could …
Structural analysis of the O-specific polysaccharide isolated from Plesiomonas shigelloides O51 lipopolysaccharide.
2009
Plesiomonasshigelloides strain CNCTC 110/92 (O51) was identified as a new example of plesiomonads synthesising lipopolysaccharides (LPSs) that show preference for a non-aqueous surrounding during phenol/water extraction. Chemical analyses combined with (1)H and (13)C NMR spectroscopy, MALDI-TOF and ESI mass spectrometry showed that the repeating units of the O-specific polysaccharides isolated from phenol and water phase LPSs of P. shigelloides O51 have the same structure: -->4)-beta-D-GlcpNAc3NRA-(1-->4)-alpha-L-FucpAm3OAc-(1-->3)-alpha-D-QuipNAc-(1-->, containing the rare sugar constituent 2,3-diamino-2,3-dideoxyglucuronic acid (GlcpNAc3NRA), and substituents such as D-3-hydroxybutyric ac…
Structural analysis of the lipid A isolated from Hafnia alvei 32 and PCM 1192 lipopolysaccharides[S]
2010
Hafnia alvei, a Gram-negative bacterium, is an opportunistic pathogen associated with mixed hospital infections, bacteremia, septicemia, and respiratory diseases. The majority of clinical symptoms of diseases caused by this bacterium have a lipopolysaccharide (LPS, endotoxin)-related origin. The lipid A structure affects the biological activity of endotoxins predominantly. Thus, the structure of H. alvei lipid A was analyzed for the first time. The major form, asymmetrically hexa-acylated lipid A built of beta-D-GlcpN4P-(1-->6)-alpha-D-GlcpN1P substituted with (R)-14:0(3-OH) at N-2 and O-3, 14:0(3-(R)-O-12:0) at N-2', and 14:0(3-(R)-O-14:0) at O-3', was identified by ESI-MS(n) and MALDI-tim…
CUDA-enabled Sparse Matrix–Vector Multiplication on GPUs using atomic operations
2013
We propose the Sliced Coordinate Format (SCOO) for Sparse Matrix-Vector Multiplication on GPUs.An associated CUDA implementation which takes advantage of atomic operations is presented.We propose partitioning methods to transform a given sparse matrix into SCOO format.An efficient Dual-GPU implementation which overlaps computation and communication is described.Extensive performance comparisons of SCOO compared to other formats on GPUs and CPUs are provided. Existing formats for Sparse Matrix-Vector Multiplication (SpMV) on the GPU are outperforming their corresponding implementations on multi-core CPUs. In this paper, we present a new format called Sliced COO (SCOO) and an efficient CUDA i…