1,032 research outputs found
Regeneration Of Diesel Particulate Filters With Hydrogen Rich Gas
The options for the regeneration of a Diesel Particulate Filter (DPF) using hydrogen rich gas are investigated. The advantages of using hydrogen rich gas for this purpose are described. The system requirements for such a system are also evaluated. The use of a plasmatron fuel converter for the onboard generation of hydrogen rich gas from diesel fuel is discussed. The advantages of homogeneous, non-catalytic reforming by the plasmatron fuel converter are described. Finally, the effect of homogeneous combustion of the hydrogen rich gas in the exhaust (upstream from the DPF) is investigated. I
Aspirin Resistance in Cardiovascular Disease: A Review
AbstractBackground. Aspirin is effective at reducing the cardiovascular event rate in defined patient groups. The introduction of antiplatelet therapies other than aspirin and the concept of aspirin resistance have led to critical reappraisal of current treatment. This review aims to clarify the evidence for aspirin resistance in patients with atherosclerosis.Methods. Medline search was performed to identify publications concerned with antiplatelet effects of aspirin and failure of aspirin therapy. Manual cross referencing was also performed.Results and conclusion. Wide variations in the rate of aspirin resistance (5.5–75%) have been reported. The lack of consensus on an appropriate definition and the number of different tests used to investigate aspirin resistance needs to be addressed. There are few studies where the primary aim was to document aspirin resistance or aspirin non-response. Further work should aim to investigate if aspirin resistance is clinically important and, if it is, what treatments may be beneficial to the at risk patient
From semiclassical transport to quantum Hall effect under low-field Landau quantization
The crossover from the semiclassical transport to quantum Hall effect is
studied by examining a two-dimensional electron system in an AlGaAs/GaAs
heterostructure. By probing the magneto-oscillations, it is shown that the
semiclassical Shubnikov-de Haas (SdH) formulation can be valid even when the
minima of the longitudinal resistivity approach zero. The extension of the
applicable range of the SdH theory could be due to the damping effects
resulting from disorder and temperature. Moreover, we observed plateau-plateau
transition like behavior with such an extension. From our study, it is
important to include the positive magnetoresistance to refine the SdH theory.Comment: 11 pages, 5 figure
Non-Linear Vibrations in Nuclei
We have perfomed Time Dependant Hartree-Fock (TDHF) calculations on the non
linear response of nuclei. We have shown that quadrupole (and dipole) motion
produces monopole (and quadrupole) oscillations in all atomic nuclei. We have
shown that these findings can be interpreted as a large coupling between one
and two phonon states leading to large anharmonicities.Comment: 4 pages, 3 figure
Quantitative trait loci for bone traits segregating independently of those for growth in an F-2 broiler X layer cross
An F broiler-layer cross was phenotyped for 18 skeletal traits at 6, 7 and 9 weeks of age and genotyped with 120 microsatellite markers. Interval mapping identified 61 suggestive and significant QTL on 16 of the 25 linkage groups for 16 traits. Thirty-six additional QTL were identified when the assumption that QTL were fixed in the grandparent lines was relaxed. QTL with large effects on the lengths of the tarsometatarsus, tibia and femur, and the weights of the tibia and femur were identified on GGA4 between 217 and 249 cM. Six QTL for skeletal traits were identified that did not co-locate with genome wide significant QTL for body weight and two body weight QTL did not coincide with skeletal trait QTL. Significant evidence of imprinting was found in ten of the QTL and QTL x sex interactions were identified for 22 traits. Six alleles from the broiler line for weight- and size-related skeletal QTL were positive. Negative alleles for bone quality traits such as tibial dyschondroplasia, leg bowing and tibia twisting generally originated from the layer line suggesting that the allele inherited from the broiler is more protective than the allele originating from the layer
New exact solution of Dirac-Coulomb equation with exact boundary condition
It usually writes the boundary condition of the wave equation in the Coulomb
field as a rough form without considering the size of the atomic nucleus. The
rough expression brings on that the solutions of the Klein-Gordon equation and
the Dirac equation with the Coulomb potential are divergent at the origin of
the coordinates, also the virtual energies, when the nuclear charges number Z >
137, meaning the original solutions do not satisfy the conditions for
determining solution. Any divergences of the wave functions also imply that the
probability density of the meson or the electron would rapidly increase when
they are closing to the atomic nucleus. What it predicts is not a truth that
the atom in ground state would rapidly collapse to the neutron-like. We
consider that the atomic nucleus has definite radius and write the exact
boundary condition for the hydrogen and hydrogen-like atom, then newly solve
the radial Dirac-Coulomb equation and obtain a new exact solution without any
mathematical and physical difficulties. Unexpectedly, the K value constructed
by Dirac is naturally written in the barrier width or the equivalent radius of
the atomic nucleus in solving the Dirac equation with the exact boundary
condition, and it is independent of the quantum energy. Without any divergent
wave function and the virtual energies, we obtain a new formula of the energy
levels that is different from the Dirac formula of the energy levels in the
Coulomb field.Comment: 12 pages,no figure
Adhesion of Listeria monocytogenes to materials commonly found in domestic kitchens
The aim of this work was to investigate the adhesion of Listeria monocytogenes ATCC 15313 to glass,
granite, marble, polypropylene from a bowl (PPb), polypropylene from a cutting board (PPcb) and stainless
steel (SS), which are materials commonly used in kitchens. Marble and granite were chosen because they are
applied as kitchen bench covers and pavements in many countries and there are no literature reports on their
behaviour in terms of microbial adhesion. The effect of surface hydrophobicity and roughness on the
adhesion process was also analysed. The results showed that the highest extent of adhesion of
L. monocytogenes occurred to stainless steel, followed by glass and in less extent to the other materials
studied. However, it was not possible to establish a correlation between surface hydrophobicity or roughness
and the extent of adhesion of L. monocytogenes. The adherence of L. monocytogenes should be dependent on
other factors, like the presence of exopolymers and surface charge.Fundação para a Ciência e a Tecnologia (FCT
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Microtearing Instabilities and Electron Transport in the NSTX Spherical Tokamak
We report a successful quantitative account of the experimentally determined electron thermal conductivity χe in a beam-heated H mode plasma by the magnetic fluctuations from microtearing instabilities. The calculated χe based on existing nonlinear theory agrees with the result from transport analysis of the experimental data. Without using any adjustable parameter, the good agreement spans the entire region where there is a steep electron temperature gradient to drive the instability
6-methylmercaptopurine-induced leukocytopenia during thiopurine therapy in inflammatory bowel disease patients
Background and Aim: Thiopurines have a favorable benefit–risk ratio in the treatment of inflammatory bowel disease. A feared adverse event of thiopurine therapy is myelotoxicity, mostly occurring due to toxic concentrations of the pharmacologically active metabolites 6-thioguaninenucleotides. In oncology, myelosuppression has also been associated with elevated 6-methylmercaptopurine (6-MMP). In this case series, we provide a detailed overview of 6-MMP-induced myelotoxicity in inflammatory bowel disease patients. Methods: We retrospectively scrutinized pharmacological laboratory databases of five participating centers over a 5-year period. Patients with leukocytopenia at time of elevated 6-MMP levels (>5700 pmol/8 × 108 red blood cells) were included for detailed chart review. Results: In this case series, we describe demographic, clinical, and pharmacological aspects of 24 cases of 6-MMP-induced myelotoxicity on weight-based thiopurine therapy with a median steady-state 6-MMP level of 14 500 pmol/8 × 108 red blood cells (range 6600–48 000). All patients developed leukocytopenia (white blood cell count 2.7 ± 0.9 × 109/L) after a median period of 11 weeks after initiation of thiopurine therapy (interquartile range 6–46 weeks). Eighteen patients (75%) developed concurrent anemia (median hemoglobin concentration 6.9 × 109/L), and four patients developed concurrent thrombocytopenia (median platelet count 104 × 109/L). Leukocytopenia resolved in 20 patients (83%) within 4 weeks upon altered thiopurine treatment regimen, and white blood cell count was increasing, but not yet normalized, in the remaining four patients. Conclusion: We observed that thiopurine-induced myelotoxicity also occurs because of (extremely) high 6-MMP concentrations in patients with a skewed thiopurine metabolism. Continued treatment with adapted thiopurine therapy was successful in almost all patients
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