1,201 research outputs found
Partially Penalized Immersed Finite Element Methods for Elliptic Interface Problems
This article presents new immersed finite element (IFE) methods for solving
the popular second order elliptic interface problems on structured Cartesian
meshes even if the involved interfaces have nontrivial geometries. These IFE
methods contain extra stabilization terms introduced only at interface edges
for penalizing the discontinuity in IFE functions. With the enhanced stability
due to the added penalty, not only these IFE methods can be proven to have the
optimal convergence rate in the H1-norm provided that the exact solution has
sufficient regularity, but also numerical results indicate that their
convergence rates in both the H1-norm and the L2-norm do not deteriorate when
the mesh becomes finer which is a shortcoming of the classic IFE methods in
some situations. Trace inequalities are established for both linear and
bilinear IFE functions that are not only critical for the error analysis of
these new IFE methods, but also are of a great potential to be useful in error
analysis for other IFE methods
Radiation and Environmental Biophysics: From Single Cells to Small Animals
In this chapter, two of very unique and novel radiation technologies for modern radiobiology studies are reviewed. First of all, it is concentrated on the developments of accelerator-based particle microbeam system, which has been effectively used for studying the puzzle of “radiation-induced bystander effect.” In addition, a recent published single-cell microbeam study, which is aiming to directly measure a cell’s radio-sensitivity combining microbeam system with self-referencing biosensor, is included. Then, toward the study of realistic irradiation scenarios in radiation biology in particular, such as a nuclear attack for homeland security concerns or a potential large-scale radiological event, there would be a major need to ascertain, within a few days, the radiation doses received by tens or hundreds of thousands of individuals. Specifically, biological tests would need to be established to estimate the likelihood of such radiation exposure to result in serious health consequences; tests that would then be applied to decide on the correct treatments that might mitigate the short- and long-term health effects of such radiation exposure. However, because of the complexity and difficulty of conducting tests in such circumstance, innovative irradiation systems and technology are required. So the new developments of small animal irradiation system for evaluating the radiation risk and carrying out animal model radiobiology experiments within the mimicked radiation scenarios are covered in the second half of this chapter
Pharmaceutical enterprises drug quality strategy Moran analysis considering government supervision and new media participation
The improvement of drug quality requires not only the supervision of government, but also the participation of new media. Therefore, this paper considers the impact of government regulation and new media reports on pharmaceutical enterprises, constructs a Moran Process evolutionary game model, and analyzes the evolution trajectory of pharmaceutical enterprises' choice of drug quality improvement strategy and drug cost reduction strategy. We obtain the conditions for the two strategies to achieve evolutionary stability under the dominance of external factors and the dominance of expected returns. To verify the theoretical results, we conduct a numerical simulation by the software MATLAB 2021b. The results show that, first of all, when the government penalty is high, the drug quality improvement strategy tends to become an evolutionary stable solution, increasing the penalty amount will help promote the improvement of drug quality. What's more, when the government penalty is low and the new media influence is low, the drug cost reduction strategy is easier to dominate. The higher the new media influence, the higher the probability that pharmaceutical enterprises choose the drug quality improvement strategy. Thirdly, when the number of pharmaceutical enterprises is lower than a threshold, the drug quality improvement strategy is easier to dominate. Finally, the drug quality improvement strategy is dominant when the quality cost factor is low and the government penalty is high, the drug cost reduction strategy is dominant when the quality cost factor is high and the government penalty is low. Above all, this paper provides countermeasures and suggestions for the drug quality improvement of pharmaceutical enterprises in practice
Superconvergent P1 honeycomb virtual elements and lifted P3 solutions
When solving the Poisson equation on honeycomb hexagonal grids, we show that
the virtual element is three-order superconvergent in -norm, and
two-order superconvergent in and norms. We define a local
post-process which lifts the superconvergent solution to a solution
of the optimal-order approximation. The theory is confirmed by a numerical
test
Isolation of AhDHNs from Arachis hypogaea L. and evaluation of AhDHNs expression under exogenous abscisic acid (ABA) and water stress
The peanut (Arachis hypogaea L.) is an important oil and cash crop all over the world. It is mostly planted in arid and semi-arid regions. To determine the mechanism by which dehydrins (DHNs) are regulated by abscisic acid (ABA) in peanuts, three Arachis hypogaea L. dehydrins (AhDHNs) were isolated from peanut plants and sequenced. By blasting the protein sequences of these AhDHNs, AhDHN1 was found belonging to the YnSKn subfamily. AhDHN2 and AhDHN3 were found belonging to the SKn and YnKn types, respectively. 100 μM ABA enhanced AhDHNs expression in peanut leaves. When peanut plants were treated with ABA and then with the ABA synthesis inhibitor sodium tungstate 12 h later, AhDHN expression was suppressed. However, AhDHN2 was inhibited by sodium tungstate at 2 h, though other AhDHNs were not. AhDHNs expressions increased greatly in peanut leaves treated with 30% polyethylene glycol (PEG). Sodium tungstate along with PEG inhibited the expression of AhDHNs. This study found that exogenous and endogenous ABA can both affect the expression of AhDHN independently. The differential expression of AhDHNs to exogenous ABA may be because of differences in the structure of different AhDHNs.Keywords: Arachis hypogaea L. dehydrins (AhDHNs), peanut, abscisic acid (ABA), expression, sodium tungstate, water stres
A new method of reconstructing Galactic three-dimensional structures using ultralong-wavelength radio observations
The free-free absorption of low frequency radio waves by thermal electrons in
the warm ionized medium of our Galaxy becomes very significant at
MHz (ultralong-wavelength), and the absorption strength depends on the radio
frequency. Upcoming space experiments such as the Discovering Sky at the
Longest wavelength (DSL) and Farside Array for Radio Science Investigations of
the Dark ages and Exoplanets (FARSIDE) will produce high-resolution
multi-frequency sky maps at the ultralong-wavelength, providing a new window to
observe the Universe. In this paper we propose that from these
ultralong-wavelength multi-frequency maps, the three-dimensional distribution
of the Galactic electrons can be reconstructed. This novel and robust
reconstruction of the Galactic electron distribution will be a key science case
of those space missions. Ultralong-wavelength observations will be a powerful
tool for studying the astrophysics relevant to the Galactic electron
distribution, for example, the impacts of supernova explosions on electron
distribution, and the interaction between interstellar atoms and ionizing
photons escaped from the HII regions around massive stars. An animation shows
the reconstructed results using {\tt NE2001} model as input test. On ArXiv, it
is given in the directory: Ancillary files. In the paper the animation is
linked to Fig. 5.Comment: 16 pages, 8 figures (including one animation, on ArXiv see the
ancillary files), Accepted for publication in Ap
Salvianolic acid B functioned as a competitive inhibitor of matrix metalloproteinase-9 and efficiently prevented cardiac remodeling
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