1,407 research outputs found

    The multiple originator broadcasting problem in graphs

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    AbstractGiven a graph G and a vertex subset S of V(G), the broadcasting time with respect to S, denoted by b(G,S), is the minimum broadcasting time when using S as the broadcasting set. And the k-broadcasting number, denoted by bk(G), is defined by bk(G)=min{b(G,S)|S⊆V(G),|S|=k}.Given a graph G and two vertex subsets S, S′ of V(G), define d(v,S)=minu∈Sd(v,u), d(S,S′)=min{d(u,v)|u∈S, v∈S′}, and d(G,S)=maxv∈V(G)d(v,S) for all v∈V(G). For all k, 1⩽k⩽|V(G)|, the k-radius of G, denoted by rk(G), is defined as rk(G)=min{d(G,S)|S⊆V(G), |S|=k}.In this paper, we study the relation between the k-radius and the k-broadcasting numbers of graphs. We also give the 2-radius and the 2-broadcasting numbers of the grid graphs, and the k-broadcasting numbers of the complete n-partite graphs and the hypercubes

    C1q/TNF-related protein 3 (CTRP3) and 9 (CTRP9) concentrations are decreased in patients with heart failure and are associated with increased morbidity and mortality.

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    BACKGROUND: Biochemical marker has revolutionized the approach to the diagnosis of heart failure. However, it remains difficult to assess stability of the patient. As such, novel means of stratifying disease severity are needed. C1q/TNF-Related Protein 3 (CTRP3) and C1q/TNF-Related Protein 9 (CTRP9) are novel adipokines that contribute to energy homeostasis with additional anti-inflammatory and anti-ischemic properties. The aim of our study is to evaluate concentrations of CTRP3 and CTRP9 in patients with HFrEF (heart failure with reduced ejection fraction) and whether associated with mortality. METHODS: Clinical data and plasma were obtained from 176 healthy controls and 168 patients with HFrEF. CTRP3 and CTRP9 levels were evaluated by enzyme-linked immunosorbent assay. RESULTS: Both CTRP3 and CTRP9 concentrations were significantly decreased in the HFrEF group compared to the control group (p \u3c 0.001). Moreover, patients with higher New York Heart Association class had significantly lower CTRP3 or CTRP9 concentrations. Correlation analysis revealed that CTRP3 and CTRP9 levels were positively related with LVEF% (CTRP3, r = 0.556, p \u3c 0.001; CTRP9, r = 0.526, p \u3c 0.001) and negatively related with NT-proBNP levels (CTRP3, r = - 0.454, p \u3c 0.001; CTRP9, r = - 0.483, p \u3c 0.001). After a follow up for 36 months, after adjusted for age, LVEF and NT-proBNP, we observed that CTRP3 or CTRP9 levels below the 25th percentile was a predictor of total mortality (CTRP3,HR:1.93,95%CI1.03~3.62,P = 0.042;CTRP9,HR:1.98,95%CI:1.02~3.85,P = 0.044) and hospitalizations (CTRP3,HR:2.34,95% CI:1.43~3.82,P = 0.001;CTRP9,HR:2.67,95%CI:1.58~4.50,P \u3c 0.001). CONCLUSIONS: CTRP3 and CTRP9 are decreased in patients with HFrEF, proportionate to disease severity, and each is associated with increased morbidity and mortality. TRIAL REGISTRATION: NCT01372800 . Registered May 2011

    Variability of particulate organic carbon in inland waters observed from MODIS Aqua imagery

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    LETTER • THE FOLLOWING ARTICLE IS OPEN ACCESS Variability of particulate organic carbon in inland waters observed from MODIS Aqua imagery Hongtao Duan1, Lian Feng2, Ronghua Ma1, Yuchao Zhang1 and Steven Arthur Loiselle3 Published 19 August 2014 • © 2014 IOP Publishing Ltd Environmental Research Letters, Volume 9, Number 8 Article PDF Figures References Citations PDF 2919 Total downloads Cited by 6 articles Article has an altmetric score of 1 Turn on MathJax Share this article Article information Abstract Surface concentrations of particulate organic carbon (POC) in shallow inland lakes were estimated using MODIS Aqua data. A power regression model of the direct empirical relationship between POC and the atmospherically Rayleigh-corrected MODIS product (Rrc,645-Rrc,1240)/(Rrc,859-Rrc,1240) was developed (R2 = 0.72, RMSE = 35.86 μgL−1, p < 0.0001, N = 47) and validated (RMSE = 44.46 μgL−1, N = 16) with field data from 56 lakes in the Middle and Lower reaches of the Yangtze River, China. This algorithm was applied to an 11 year series of MODIS data to determine the spatial and temporal distribution of POC in a wide range of lakes with different trophic and optical properties. The results indicate that there is a general increase in minimum POC concentrations in lakes from middle to lower reaches of the Yangtze River. The temporal dynamics of springtime POC in smaller lakes were found to be influenced by local meteorological conditions, in particular precipitation and wind speed, while larger lakes were found to be more sensitive to air temperature

    The analysis on the single particle model of CDW

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    Gruner put forward a single particle model of charge-density wave, which is a typical nonlinear differential equation, and also a mathematical model of pendulum. This Letter analyzes the solution of equation by the rotated vector fields theory, providing the relation between the applied field E and the periodic solution, and the conclusion that the critical value of E for the periodic solution is fixed in the over-damped situation. With these conclusions, it derives the formulae of nonlinear conductivity, narrow-band noise, which are consistent with the empirical ones given by Fleming.Comment: This is a version with a physics focus, the part with a mathematical focus is submitted at arXiv:0807.328

    Neuroblastomas in Eastern China: a retrospective series study of 275 cases in a regional center

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    Purpose Most studies on neuroblastoma (NB) have been conducted in Western countries or Japan. The objective of our study was to analyze clinical and pathological features, MYCN status, surgical methods, and prognosis in Chinese NB patients. Methods A retrospective, single-center case series study of 275 NBs was implemented. Clinical manifestations, pathological features, MYCN status, and surgical treatment were analyzed. Log-rank test and Cox hazards models were used to assess overall survivals (OSs). Results The cohort consisted of 105 females and 170 males, with an age range of five days to 15 years. MYCN amplification was detected in 21.5% of all cases. The median OS was 15.0 months for MYCN amplified group. The five-year OS rates were 70.8% and 18.3% for MYCN unamplified and amplified groups, respectively, and the comparison of Kaplan–Meier curves for these two groups showed statistical significance (P < .001 by log-rank test). Gross total resection (GTR, n = 111) and subtotal resection (STR, n = 58) were administered in 169 patients at stages 3 and 4 who received chemotherapy and the comparison of Kaplan–Meier curves for different groups in these patients had statistical significance (STR vs. GTR, P = .009; MYCN unamplified vs. amplified, P < .001 by log-rank test, respectively).The multivariate survival analyses showed statistical significance (STR vs. GTR, P = .047; MYCN unamplified vs. amplified, P = .001 by Cox regression model). Conclusions MYCN amplification is an independently adverse prognostic factor in Chinese NB patients at stages 3 and 4 and GTR is associated with improved OS compared with STR in these patients

    The cross-reactivity of the enterovirus 71 to human brain tissue and identification of the cross-reactivity related fragments

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    <p>Abstract</p> <p>Background</p> <p>EV71 occasionally cause a series of severe neurological symptoms, including aseptic meningitis, encephalitis, and poliomyelitis-like paralysis. However, the neurological destruction mechanism was remained to be clarified. This study described the cross reaction between EV71 induced IgG and human brain tissue.</p> <p>Results</p> <p>Cross reaction of the IgG from 30 EV71 infected patients' sera to human tissues of cerebra was observed, which suggested that some EV71 antigens could induce IgG cross-reactivity to human cerebra. To identify the regions of EV71 virus that containing above antigens, the polypeptide of virus was divided into 19 peptides by expression in prokaryotes cell. Mouse anti-sera of these peptides was prepared and applied in immunohistochemical staining with human adult and fetus brain tissue, respectively. The result indicated the 19 peptides can be classified into three groups: strong cross-reactivity, weak cross-reactivity and no cross-reactivity with human brain tissue according the cross reaction activity. Then, the increased Blood Brain Barrier (BBB) permeability and permits IgG entry in neonatal mice after EV71 infection was determined.</p> <p>Conclusion</p> <p>EV71 induced IgG could enter BBB and cross-reacted with brain tissue in EV71 infected neonatal mice, and then the peptides of EV71 that could induce cross-reactivity with brain tissue were identified, which should be avoided in future vaccine designing.</p

    Prevalence of A2143G mutation of H. pylori-23S rRNA in Chinese subjects with and without clarithromycin use history

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    <p>Abstract</p> <p>Background</p> <p>A2143G mutation of <it>23S rRNA </it>gene of <it>H. pylori </it>results in clarithromycin (CLR) resistance. To investigate the prevalence of the CLR resistance-related A2143G mutation of the <it>H. pylori</it>-specific <it>23S rRNA </it>gene in Chinese subjects with and without CLR use history, 307 subjects received the treatment with amoxicillin and omeprazole (OA) and 310 subjects received a placebo in 1995, and 153 subjects received a triple therapy with OA and CLR (OAC) in 2000. DNA was extracted from fasting gastric juice at the end of the intervention trial in 2003. <it>H. pylori </it>infection was determined by <it>H. pylori</it>-specific <it>23S rRNA </it>PCR, ELISA, and<sup>13</sup>C-urea breath test assays. Mutations of the <it>23S rRNA </it>gene were detected by RFLP assays.</p> <p>Results</p> <p>The presence of <it>23S rRNA </it>due to <it>H. pylori </it>infection in the OA group remained lower than that in the placebo group 7.3 yrs after OA-therapy [51.1% (157/307) vs. 83.9% (260/310), p = 0.0000]. In the OAC group, the <it>23S rRNA </it>detection rate was 26.8% (41/153) three yrs after OAC-treatment. The A2143G mutation rate among the <it>23S rRNA</it>-positive subjects in the OAC group [31.7% (13/41)] was significantly higher than that in the OA group [10.2% (16/157)] and the placebo group [13.8% (36/260)]. The frequency of the AAGGG → CTTCA (2222–2226) and AACC → GAAG (2081–2084) sequence alterations in the OAC group was also significantly higher than those in the OA group and the placebo group.</p> <p>Conclusion</p> <p>Primary prevalence of the A2143G mutation was 10~14% among Chinese population without history of CLR therapy. Administration of CLR to eliminate <it>H. pylori </it>infection increased the prevalence of the A2143G mutation in Chinese subjects (32%) significantly.</p
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