6,230 research outputs found

    Conflict-free connection numbers of line graphs

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    A path in an edge-colored graph is called \emph{conflict-free} if it contains at least one color used on exactly one of its edges. An edge-colored graph GG is \emph{conflict-free connected} if for any two distinct vertices of GG, there is a conflict-free path connecting them. For a connected graph GG, the \emph{conflict-free connection number} of GG, denoted by cfc(G)cfc(G), is defined as the minimum number of colors that are required to make GG conflict-free connected. In this paper, we investigate the conflict-free connection numbers of connected claw-free graphs, especially line graphs. We first show that for an arbitrary connected graph GG, there exists a positive integer kk such that cfc(Lk(G))≤2cfc(L^k(G))\leq 2. Secondly, we get the exact value of the conflict-free connection number of a connected claw-free graph, especially a connected line graph. Thirdly, we prove that for an arbitrary connected graph GG and an arbitrary positive integer kk, we always have cfc(Lk+1(G))≤cfc(Lk(G))cfc(L^{k+1}(G))\leq cfc(L^k(G)), with only the exception that GG is isomorphic to a star of order at least~55 and k=1k=1. Finally, we obtain the exact values of cfc(Lk(G))cfc(L^k(G)), and use them as an efficient tool to get the smallest nonnegative integer k0k_0 such that cfc(Lk0(G))=2cfc(L^{k_0}(G))=2.Comment: 11 page

    The impact of ischemic stroke on atrial fibrillation-related healthcare cost: a systematic review

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    OBJECTIVES: To summarize healthcare costs incurred from patients with atrial fibrillation (AF) who developed ischemic stroke and to explore the factors associated with increased cost, thereby highlighting the importance of anticoagulation therapy for stroke prophylaxis ...postprin

    A study on the association of the chromosome 12p13 locus with sporadic late-onset alzheimer's disease in Chinese

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    Recent linkage and association studies have implicated the chromosome 12p13 locus as possibly harboring genetic variants predisposed to Alzheimer's disease (AD). We attempted to replicate this association in a Chinese data set comprised of 256 AD cases and 264 age-matched normal controls. A total of 14 single nucleotide polymorphisms (SNPs) were examined. Single marker association revealed the two SNPs in NCAPD2 (rs7311174 and rs2072374) as showing nominal significant p values (p = 0.0491 and 0.0116, respectively). Haplotype analysis found LD block one to be significantly associated with AD (global p = 0.0250). Haplotypes CGGATG and CAGTCG were also significantly associated with AD (p = 0.0498 and p = 0.0482, respectively). These genetic analyses provide evidence that the chromosome 12p13 locus is associated with AD in Chinese. © 2009 S. Karger AG, Basel.postprin

    The cultivation, bioactive components and pharmacological effects of Armillaria mellea

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    Armillaria mellea, a symbiotic fungus in the underground tubers of Chinese medicinal orchid Gastrodia elata, is one of the main biological active components and pharmaceutical effects of its host gastrodia. The purpose of this review is to bring attention to the biological properties of this unique A. mellea mushroom and its constituents, as well as to suggest the potential for the development of new drugs related to this fungus. It contains various known and untapped bioactive metabolites such aspolysaccharides, sesquiterpene aryl esters, steroids and fibrinolytic enzymes. It could be exploited as an important source of new biological natural products with anticonvulsant, immunomodulatory andantimicrobial functions. The batch culture is preferred as an alternative means of getting bioactive components from Armellaria fermentation. Challenges in investigations on A. mellea include the optimization of culture parameters, the further elucidation of the molecular pharmacological mechanism and relationship between structure and function of their secondary metabolites

    Chaotic motions in the real fuzzy electronic circuits

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    Fuzzy electronic circuit (FEC) is firstly introduced, which is implementing Takagi-Sugeno (T-S) fuzzy chaotic systems on electronic circuit. In the research field of secure communications, the original source should be blended with other complex signals. Chaotic signals are one of the good sources to be applied to encrypt high confidential signals, because of its high complexity, sensitiveness of initial conditions, and unpredictability. Consequently, generating chaotic signals on electronic circuit to produce real electrical signals applied to secure communications is an exceedingly important issue. However, nonlinear systems are always composed of many complex equations and are hard to realize on electronic circuits. Takagi-Sugeno (T-S) fuzzy model is a powerful tool, which is described by fuzzy IF-THEN rules to express the local dynamics of each fuzzy rule by a linear system model. Accordingly, in this paper, we produce the chaotic signals via electronic circuits through T-S fuzzy model and the numerical simulation results provided by MATLAB are also proposed for comparison. T-S fuzzy chaotic Lorenz and Chen-Lee systems are used for examples and are given to demonstrate the effectiveness of the proposed electronic circuit. © 2013 Shih-Yu Li et al

    A randomised controlled trial to compare immunogenicity between intramuscular and intradermal trivalent influenza vaccination in nursing home older adults

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    BACKGROUND: Immunosenescence in older adults contributes to unsatisfactory immunogenicity towards influenza vaccine. Intradermal (ID) administration of influenza vaccine has been suggested to improve immunogenicity but there is no study regarding the immunogenicity of ID influenza vaccination in nursing home older adults ...postprin

    Effects of calcium phosphate nanocrystals on osseointegration of titainium implant in irradiated bone

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    Radiotherapy may compromise the integration of implant and cause implant loss. Implant surface modifications have the possibility of promoting cell attachment, cell growth, and bone formation which ultimately enhance the osseointegration process. The present study aimed to investigate the effects of calcium phosphate nanocrystals on implant osseointegration in irradiated bone. Sixteen rabbits were randomly assigned into control and nano-CaP groups, receiving implants with dual acid-etched surface or dual acid-etched surface discretely deposited of nanoscale calcium-phosphate crystals, respectively. The left leg of all the rabbits received 15 Gy radiation, followed by implants placement one week after. Four animals in each group were sacrificed after 4 and 12 weeks, respectively. Implant stability quotient (ISQ), ratio of bone volume to total volume (BV/TV), bone growth rate, and bone-to-implant contact (BIC) were evaluated. The nano-CaP group showed significantly higher ISQ (week 12, P = 0.031) and bone growth rate (week 6, P = 0.021; week 9, P = 0.001) than that in control group. No significant differences in BV/TV and BIC were found between two groups. Titanium implant surface modified with CaP nanocrystals provides a potential alternative to improve bone healing around implant in irradiated bone.published_or_final_versio

    The generalized 3-edge-connectivity of lexicographic product graphs

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    The generalized kk-edge-connectivity λk(G)\lambda_k(G) of a graph GG is a generalization of the concept of edge-connectivity. The lexicographic product of two graphs GG and HH, denoted by G∘HG\circ H, is an important graph product. In this paper, we mainly study the generalized 3-edge-connectivity of G∘HG \circ H, and get upper and lower bounds of λ3(G∘H)\lambda_3(G \circ H). Moreover, all bounds are sharp.Comment: 14 page
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