1,055 research outputs found

    Even cycles and perfect matchings in claw-free plane graphs

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    Lov{\'a}sz showed that a matching covered graph GG has an ear decomposition starting with an arbitrary edge of GG. Let GG be a graph which has a perfect matching. We call GG cycle-nice if for each even cycle CC of GG, GV(C)G-V(C) has a perfect matching. If GG is a cycle-nice matching covered graph, then GG has ear decompositions starting with an arbitrary even cycle of GG. In this paper, we characterize cycle-nice claw-free plane graphs. We show that the only cycle-nice simple 3-connected claw-free plane graphs are K4K_4, W5W_5 and C6\overline C_6. Furthermore, every cycle-nice 2-connected claw-free plane graph can be obtained from a graph in the family F{\cal F} by a sequence of three types of operations, where F{\cal F} consists of even cycles, a diamond, K4K_4, and C6\overline C_6.Comment: 12 page

    Biosafey evaluation and anti-oxidative effects of ceria nanoparticles in vitro

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    Ceria nanoparticles are well known as high-performance catalysts due to the presence of mixed valence states of Ce3+ and Ce4+, and the presence of oxygen vacancies. Ceria nanoparticles are also potent free-radical scavengers due to its SOD mimics, catalase mimics and oxidase mimics. It is speculated that nanoceria would promote cell survival under conditions of oxidative stress due to its selective antioxidant properties. The antioxidant properties can be affected by the physicochemical properties of the materials and the target cells species. Therefore, in the present study, we evaluate the biosafety and protective effect of two different sizes of ceria nanoparticles in human umbilical vein endothelial cells (HUVECS) and human bronchial epithelial cells (HBE), as they are the primary routes of human exposure to nanoparticles through inhalation and injection. Based on the results of cell viability assay and cell membrane integrity assay, we found that ceria nanoparticles of both sizes are biocompatible to both HUVECS and HBE cells, though ceria nanoparticles have a slightly interference in the intracellular redox balance. In addition, ceria nanoparticles showed protective effect on the cell viability of both cells under oxidative stress. Detailed studies on the intracellular molecular mechanisms for the anti-oxidative effects will be studies to understand the nanoparticles-cell interactions. These results obtained in vitro may provide insights for real biomedical applications and risk assessment of ceria nanoparticle

    A Novelty Method for Identifying Risk Factors of Sudden Food Safety Event

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    Food is the basic material basis for human survival. Sudden food safety event risks mainly derive from accidental or natural food safety risks, poor food storage environments, and inefficient government regulation policies. The factor identification of sudden food safety risks is the key to controlling such risks. Therefore, the efficient and scientific identification of risk sources and types will be very important in managing sudden food safety risks. In this study, 16 sudden food safety event risk factors were identified through a literature review, and their interactive relationships were clarified using an interpretive structural model (ISM). Then, the weights of influencing factors were calculated through the analytic hierarchy process (AHP), and the combined weight of indices was determined. Results show that the 16 sudden food safety event risk factors can be divided into four levels. The quality standard for food safety (S5) and food storage (S14) is at the bottom layer of risks of sudden food safety events (the first-layer index weight is 36.899%). The judgment matrices at the four levels passed the consistency check. The influence weight of the factor "whether it contains transgenic raw materials" (S9) ranks second (the total weight is 18.151%). This index system for sudden food safety event risk factors is highly effective, with good operability for managing sudden food safety event risks. The obtained conclusions are important reference values for identifying the factors influencing food safety risk management, determining the emphasis of food safety supervision, realizing food risk prevention and control, and strengthening and guaranteeing the food safety level

    Bigeye tuna fishing ground in relation to thermocline in the Western and Central Pacific Ocean using Argo data

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    444-451The relationship beween thermocline and bigeye tuna (Thunnus obesus) fishing grounds in the Western and Central Pacific Ocean was evaluated by Argo data and monthly CPUE (catch per unit effort). The generalized additive model indicated evidence of nonlinear relationships between CPUE and six thermocline characteristics. The results suggested that the fishing grounds distributed where the upper boundary temperature was about 26 ºC and the upper boundary depth values between 70 and 100 m. The fishing grounds located between the two high value shapes of the lower boundary depth of thermocline, if the depth was >300 or <150 m, the CPUE tended to be low. The lower boundary temperature of the thermocline in the fishing grounds was lower than 13 ºC. Conversely, if the temperature was higher than 17 ºC, the hooking rates were very low. The strongest relationship between CPUE with thermocline thickness and thermocline strength was approximately at 60 m and 0.1 ºC/m. The optimum ranges for the upper boundary thermocline temperature and depth and the lower boundary thermocline temperature and depth, thermocline thickness and thermocline strength were between 26-29 ºC, 70-110 m, 11-13 ºC, 200-280 m, and 0.01-0.15 ºC/m, 60-80 m, respectively

    The Construction of a Clinical Decision Support System Based on Knowledge Base

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    Part 7: e-Health, the New Frontier of Service Science InnovationInternational audienceBased on a review of domestic and foreign research, application status, classification, composition, and the main problem of a clinical decision support system, this paper proposed a CDSS mode based on a knowledge base. On KB-CDSS mode, this paper discussed the architecture, principle, process, construction of the knowledge base, system design, and application value, then introduced the application WanFang Data Clinical Diagnosis and Treatment Knowledge Base

    Methyl 3,4-O-isopropyl­idene-2-O-[(methyl­sulfan­yl)thio­carbon­yl]-β-l-arabinoside

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    In the title compound, C11H18O5S2, the six- and five-membered rings adopt a chair and an approximately planar conformation, respectively

    Association between Functional Polymorphisms of Foxp3 Gene and the Occurrence of Unexplained Recurrent Spontaneous Abortion in a Chinese Han Population

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    Unexplained recurrent spontaneous abortion (URSA) is an alloimmune disease associated with the failure of fetal-maternal immunologic tolerance in which the regulatory T lymphocytes (Treg) play a pivotal role. It is well known that Forkhead box P3 (Foxp3) is a crucial regulatory factor for the development and function of Treg cells. It has also been established that deficiency of the Foxp3 gene suppresses the regulatory function of Treg cells. To determine if functional polymorphisms at the Foxp3 loci are associated with URSA in humans, we genotyped four common polymorphisms of Foxp3 gene in 146 unrelated URSA patients and 112 healthy women. The results showed that rs3761548A/C and rs2232365A/G polymorphisms were significantly associated with URSA. Additionally, we found that the allelic distribution of rs5902434 del/ATT in URSA group was slightly different from that in the control group. We conclude that functional polymorphisms of the Foxp3 gene may confer an important susceptibility to URSA in the Chinese Han population, probably by altering Foxp3 function and/or its expression

    Crystal Structure Manipulation of the Exchange Bias in an Antiferromagnetic Film

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    Exchange bias is one of the most extensively studied phenomena in magnetism, since it exerts a unidirectional anisotropy to a ferromagnet (FM) when coupled to an antiferromagnet (AFM) and the control of the exchange bias is therefore very important for technological applications, such as magnetic random access memory and giant magnetoresistance sensors. In this letter, we report the crystal structure manipulation of the exchange bias in epitaxial hcp Cr2O3 films. By epitaxially growing twined (10-10) oriented Cr2O3 thin films, of which the c axis and spins of the Cr atoms lie in the film plane, we demonstrate that the exchange bias between Cr2O3 and an adjacent permalloy layer is tuned to in-plane from out-of-plane that has been observed in (0001) oriented Cr2O3 films. This is owing to the collinear exchange coupling between the spins of the Cr atoms and the adjacent FM layer. Such a highly anisotropic exchange bias phenomenon is not possible in polycrystalline films.Comment: To be published in Scientific Reports, 12 pages, 6 figure

    Formation and dissolution of microbubbles on highly-ordered plasmonic nanopillar arrays

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    Bubble formation from plasmonic heating of nanostructures is of great interest in many applications. In this work, we study experimentally the intrinsic effects of the number of three-dimensional plasmonic nanostructures on the dynamics of microbubbles, largely decoupled from the effects of dissolved air. The formation and dissolution of microbubbles is observed on exciting groups of 1, 4, and 9 nanopillars. Our results show that the power threshold for the bubble formation depends on the number density of the nanopillars in highly-ordered arrays. In the degassed water, both the growth rate and the maximal radius of the plasmonic microbubbles increase with an increase of the illuminated pillar number, due to the heat balance between the heat loss across the bubble and the collective heating generated from the nanopillars. Interestingly, our results show that the bubble dissolution is affected by the spatial arrangement of the underlying nanopillars, due to the pinning effect on the bubble boundary. The bubbles on nanopillar arrays dissolve in a jumping mode with step-wise features on the dissolution curves, prior to a smooth dissolution phase for the bubble pinned by a single pillar. The insight from this work may facilitate the design of nanostructures for efficient energy conversion
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