Hidden Tree Structure is a Key to the Emergence of Scaling in the World Wide Web

Preferential attachment is the most popular explanation for the emergence of scaling behavior in the World Wide Web, but this explanation has been challenged by the global information hypothesis, the existence of linear preference and the emergence of new big internet companies in the real world. We notice that most websites have an obvious feature that their pages are organized as a tree (namely hidden tree) and hence propose a new model that introduces a hidden tree structure into the Erd\H{o}s-R\'e}yi model by adding a new rule: when one node connects to another, it should also connect to all nodes in the path between these two nodes in the hidden tree. The experimental results show that the degree distribution of the generated graphs would obey power law distributions and have variable high clustering coefficients and variable small average lengths of shortest paths. The proposed model provides an alternative explanation to the emergence of scaling in the World Wide Web without the above-mentioned difficulties, and also explains the "preferential attachment" phenomenon.Comment: 4 Pages, 7 Figure

Inhibitory effects of total saponins from Ilex pubescens Hook against hydrogen peroxide-induced cardiomyocyte apoptosis

Purpose: To study the protective effects of total saponins from Ilex pubescens Hook (IPTS) against cardiomyocyte apoptosis.Methods: Response surface methodology (RSM) based on Box-Benhnken Design (BBD) was carried out to optimize the extraction of IPTS. Thereafter, H9c2 cell model prepared by hydrogen peroxide (H2O2) treatment was used to investigate the effects of IPTS on cardiomyocyte apoptosis. Cell viability was determined using MTT assay, while the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), creatine kinase (CK) and catalase (CAT) were measured as indices of oxidative stress. Expressions of proteins related to apoptosis (caspase-3, Bax and Bcl-2) were measured using Western blot assay.Results: Optimal IPTS extraction was achieved with extraction temperature of 86.6 °C, extraction time of 2.23 h and water: raw material ratio of 10.8 mL/g. IPTS extract, at doses of 200, 400, 600 and 800 μg/mL, significantly increased the viability of H2O2-treated H9c2 cells (p < 0.05), but significantly decreased LDH and CK activities (p < 0.01). It also led to significant increases in SOD and CAT activities, and significant decreases in the levels of MDA in these cells (p < 0.01). There were significant down-regulation of the protein expressions of caspase-3 and Bax (p < 0.01) in IPTS-treated H9c2 cells, as well as significant up-regulation of Bcl-2 protein expression (p < 0.01).Conclusion: These results suggest that IPTS can protect cardiomyocytes against apoptosis via the inhibition of oxidative stress and mitochondria-induced intrinsic apoptosis.Keywords: Ilex pubescens, Total saponins, Cardiomyocytes, Apoptosis, H9c2 cell

Quantum Liouville Theory On The Riemann Sphere With n>3n>3 Punctures

We have studied the quantum Liouville theory on the Riemann sphere with n>3 punctures. While considering the theory on the Riemann surfaces with n=4 punctures, the quantum theory near an arbitrary but fixed puncture can be obtained via canonical quantization and an extra symmetry is explored. While considering more than four distinguished punctures, we have found the exchange relations of the monodromy parameters from which we can get a reasonable quantum theory.Comment: 13 page

Evaluation for Core Competence of Private Enterprises in Xuchang City Based on an Improved Dynamic Multiple-Attribute Decision-Making Model

Because Deng’s grey relational degree is inconspicuous, Deng’s relational degree with an exponential function is first presented. Then, we demonstrate that improved Deng’s relational degree is more conspicuous than the original model. Then, we construct a multiple-attribute decision-making model, based on improved Deng’s relational degree with multiple stages, and a method for determining the weight of the index is also developed. Finally, the core competence of private enterprises in Henan province is analyzed, illustrating the validity and feasibility of the improved model

Angiotensin-converting enzyme gene 2350 G/A polymorphism and susceptibility to atrial fibrillation in Han Chinese patients with essential hypertension

OBJECTIVE: The angiotensin-converting enzyme gene is one of the most studied candidate genes related to atrial fibrillation. Among the polymorphisms of the angiotensin-converting enzyme gene, the 2350 G/A polymorphism (rs4343) is known to have the most significant effects on the plasma angiotensin-converting enzyme concentration. The aim of the present study was to investigate the association of the angiotensin-converting enzyme 2350 G/A polymorphism with atrial fibrillation in Han Chinese patients with essential hypertension. METHODS: A total of 169 hypertensive patients were eligible for this study. Patients with atrial fibrillation (n = 75) were allocated to the atrial fibrillation group, and 94 subjects without atrial fibrillation were allocated to the control group. The PCR-based restriction fragment length polymorphism technique was used to assess the genotype frequencies. RESULTS: The distributions of the angiotensin-converting enzyme 2350 G/A genotypes (GG, GA, and AA, respectively) were 40.43%, 41.49%, and 18.08% in the controls and 18.67%, 46.67%, and 34.66% in the atrial fibrillation subjects (p = 0.037). The frequency of the A allele in the atrial fibrillation group was significantly greater than in the control group (58.00% vs. 38.83%, p = 0.0007). Compared with the wild-type GG genotype, the GA and AA genotypes had an increased risk for atrial fibrillation. Additionally, atrial fibrillation patients with the AA genotype had greater left atrial dimensions than the patients with the GG or GA genotypes (

Phenylpropanoid, neolignan and iridoid glycosides from Pedicularis semitorta

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