415 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

    Lower bounds of the Laplacian spectrum of graphs based on diameter

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    AbstractLet G be a connected graph of order n. The diameter of G is the maximum distance between any two vertices of G. In the paper, we will give some lower bounds for the algebraic connectivity and the Laplacian spectral radius of G in terms of the diameter of G

    Prognostic implications of plasma fibrinogen and serum Creactive protein levels in non-small cell lung cancer resection and survival

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    Purpose: To investigate the prognostic implications of plasma fibrinogen and serum C-reactive protein (CRP) levels in tumour resection and survival following successful tumour resection in patients with nonsmall cell lung cancer (NSCLC).Methods: One hundred and fifty-three NSCLC patients who underwent surgical resection at a tertiary care hospital from January 2006 through December 2010 were enrolled. Pre-operative serum CRP and plasma fibrinogen levels were  measured. The levels of these biomarkers correlated with tumour size and pathologic TNM stage. The possibility of complete resection and associated findings are reported.Results: Plasma fibrinogen (r = 0.381, p = 0.002) and serum CRP (r = 0.471, p < 0.001) levels were positively associated with tumour diameter. Increased levels of these biomarkers were significantly associated with sex, smoking status, histological type, tumour stage, and clinical stage. Partial tumour resection occurred in 28 % (27/95) of patients with an increased plasma fibrinogen level compared to 10 % (6/58) with a normal fibrinogen level (p = 0.008), and in 30 % (29/97) of patients with an increased serum CRP level compared to 11 % (6/56) with a normal CRP level (p = 0.006). Patients with elevated CRP and fibrinogen concentrations demonstrated higher susceptibility to disease advancement andsurvival compared to patients with normal fibrinogen and CRP levels.Conclusion: Pre-operative functional concentrations of serum CRP and plasma fibrinogen could serve as indicators of tumour resectability wherein a high tumour resection rate is possible in patients with favourable pre-operative levels of these biomarkers. Increased concentrations of serum CRP and plasma fibrinogen are associated with poor overall survival and progression-free survival.Key words: Plasma fibrinogen, serum C-reactive protein, biomarker, non-small cell lung cance

    Prediction of cervical lymph node metastasis in solitary papillary thyroid carcinoma based on ultrasound radiomics analysis

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    ObjectiveTo assess the utility of predictive models using ultrasound radiomic features to predict cervical lymph node metastasis (CLNM) in solitary papillary thyroid carcinoma (PTC) patients.MethodsA total of 570 PTC patients were included (456 patients in the training set and 114 in the testing set). Pyradiomics was employed to extract radiomic features from preoperative ultrasound images. After dimensionality reduction and meticulous selection, we developed radiomics models using various machine learning algorithms. Univariate and multivariate logistic regressions were conducted to identify independent risk factors for CLNM. We established clinical models using these risk factors. Finally, we integrated radiomic and clinical models to create a combined nomogram. We plotted ROC curves to assess diagnostic performance and used calibration curves to evaluate alignment between predicted and observed probabilities.ResultsA total of 1561 radiomics features were extracted from preoperative ultrasound images. After dimensionality reduction and feature selection, 16 radiomics features were identified. Among radiomics models, the logistic regression (LR) model exhibited higher predictive efficiency. Univariate and multivariate logistic regression results revealed that patient age, tumor size, gender, suspicious cervical lymph node metastasis, and capsule contact were independent predictors of CLNM (all P < 0.05). By constructing a clinical model, the LR model demonstrated favorable diagnostic performance. The combined model showed superior diagnostic efficacy, with an AUC of 0.758 (95% CI: 0.712-0.803) in the training set and 0.759 (95% CI: 0.669-0.849) in the testing set. In the training dataset, the AUC value of the nomogram was higher than that of the clinical and radiomics models (P = 0.027 and 0.002, respectively). In the testing dataset, the AUC value of the nomogram model was also greater than that of the radiomics models (P = 0.012). However, there was no significant statistical difference between the nomogram and the clinical model (P = 0.928). The calibration curve indicated a good fit of the combined model.ConclusionUltrasound radiomics technology offers a quantitative and objective method for predicting CLNM in PTC patients. Nonetheless, the clinical indicators persists as irreplaceable

    Levy Stability Index from Multifractal Spectrum

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    A method for extracting the Levy stability index μ\mu from the multi-fractal spectrum f(α)f(\alpha) in high energy multiparticle production is proposed. This index is an important parameter, characterizing the non-linear behaviour of dynamical fluctuations in high energy collisions. Using the random cascading α\alpha model as example, the validity of this method is tested. It is shown that this method, basing on a linear fit, is consistent with and more accurate than the usual method of fitting the ratio of qqth to 2nd order multi-fractal (R\'enyi) dimensions to the Peschanski formula.Comment: 7 pages 4 PS figures Record-No: HZPP-980

    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

    Human papillomavirus viral load as a useful triage tool for non-16/18 high-risk human papillomavirus positive women: A prospective screening cohort study

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    ASCCP cervical cancer screening guidelines recommend triaging high-risk human papillomavirus (hrHPV) positive women with cytology and genotyping, but cytology is often unavailable in resource-limited areas. We compared the long-term risk of cervical cancer and precancers among type-specific hrHPV-positive women triaged by viral load to cytology and visual inspection with acetic acid (VIA).A cohort of 1742 Chinese women was screened with cytology, VIA, and Hybrid Capture 2 (HC2) test and followed for ten years. All HC2-positive samples were genotyped. Viral load was measured by HC2 relative light units/cutoff (RLU/CO). Ten-year cumulative incidence rate (CIR) of cervical intraepithelial neoplasia grade 2 or worse (CIN2 +) for type-specific hrHPV viral load was estimated using Kaplan-Meier methods.Baseline hrHPV viral load stratified by specific genotypes was positively correlated with prevalent cytological lesions. Ten-year CIR of CIN2 + was associated with cytological lesions and viral load. Among HPV 16/18-positive women, ten-year CIR of CIN2 + was high, even with normal cytology (15.3%), normal VIA (32.4%), viral load with RLU/CO < 10 (23.6%) or RLU/CO < 100 (33.8%). Among non-16/18 hrHPV positive women, ten-year CIR of CIN2 + was significantly stratified by cytology grade of atypical squamous cell of undetermined significance or higher (2.0% VS. 34.6%), viral load cutoffs at 10 RLU/CO (5.1% VS. 27.2%), at 100 RLU/CO (11.0% VS. 35.5%), but not by VIA (19.1% VS. 19.0%).Our findings support the guidelines in referring all HPV16/18 positive women to colposcopy and suggest triaging non-16/18 hrHPV positive women using viral loads in resource-limited areas where cytology screening was inaccessible

    Effects of season and diel cycle on hydroacoustic estimates of density, Target Strength, and vertical distribution of fish in Yudong Reservoir, a plateau deep water reservoir in southwest China in a plateau deep

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    Hydroacoustics is a non-invasive fish stock assessment sampling technique that plays an important role in fishery science and management. However, non-standard hydroacoustic surveys could lead to biased results, and the factor of the sampling period (e.g., season and diel cycle) is extremely critical as it can greatly affect hydroacoustic results. Efforts to improve the accuracy and credibility of the hydroacoustic survey results are getting more and more attention. Thus, we conducted two diel hydroacoustic surveys in situ in summer and winter to detect whether there were diel and seasonal differences in density, Target Strength (TS) and vertical distribution of fish. The results indicated that nighttime had significantly higher fish mean density than daytime in summer and winter. No significant difference between summer and winter daytime, however, significant difference between summer and winter nighttime, but this bias could be accepted from the fisheries management perspective; The mean TS of the summer daytime was significantly higher than that of summer nighttime, winter daytime and winter nighttime, but there were no significant differences among summer nighttime, winter daytime, and winter nighttime, mainly due to mean TS may be overestimated from fish schooling behavior during summer daytime; The fish vertical distribution had significant seasonal correlations and was more dispersed in different water layers during the nighttime, proving that the assessment was better at nighttime than during the daytime. Consequently, the hydroacoustic surveys in Yudong Reservoir and other similar plateau deep water reservoirs should be performed at nighttime, which will yield relatively accurate density and TS, and dispersed vertical distribution of fish
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