119 research outputs found

    Understanding airline price dispersion in the presence of high-speed rail

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    This paper examines the price dispersion among China's ā€œBig Threeā€, namely, Air China, China Eastern and China Southern in the presence of high-speed rail (HSR). It has been found that HSR is positively and significantly associated with airline price dispersion on the long-haul routes, which may suggest that the presence of HSR can facilitate airline cooperation in setting prices and outputs, thereby leading to greater price dispersion. However, on the short-haul routes where HSR is highly substitutable, the HSR competition effect dominates, and smaller price dispersion is observed. All the market structure and competition variables included in this study support the conclusion that price dispersion is greater in more concentrated and more densely travelled markets. The contribution of airline cost to price dispersion is limited

    Evaluating the price effects of two airline mergers in China

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    This paper compares the price effects of two influential airline mergers taking place in China in 2010. We offer the first comparative analysis of two different types of airline mergers in the Chinese airline market: a parallel merger and a complementary merger. With a difference-in-differences approach, we found that the two types of mergers resulted in similar pricing patterns for the airlines involved in the mergers, suggesting that complementary mergers could also confer an increase in market power. It has been found that the negative impact of high-speed rail on fares gradually weakened after the mergers

    Fibroblasts and monocyte macrophages contract and degrade three-dimensional collagen gels in extended co-culture

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    BACKGROUND: Inflammatory cells are believed to play a prominent role during tissue repair and remodeling. Since repair processes develop and mature over extended time frames, the present study was designed to evaluate the effect of monocytes and fibroblasts in prolonged culture in three-dimensional collagen gels. METHODS: Blood monocytes from healthy donors and human fetal lung fibroblasts were cast into type I collagen gels and maintained in floating cultures for three weeks. RESULTS: Fibroblast-mediated gel contraction was initially inhibited by the presence of monocytes (P < 0.01). However, with extended co-culture, contraction of the collagen gels was greatly augmented (P < 0.01). In addition, with extended co-culture, degradation of collagen in the gels occurred. The addition of neutrophil elastase to the medium augmented both contraction and degradation (P < 0.01). Prostaglandin E(2) production was significantly increased by co-culture and its presence attenuated collagen degradation. CONCLUSION: The current study, therefore, demonstrates that interaction between monocytes and fibroblasts can contract and degrade extracellular matrix in extended culture

    Collaborative interactions between neutrophil elastase and metalloproteinases in extracellular matrix degradation in three-dimensional collagen gels

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    BACKGROUND: Extended culture of monocytes and fibroblasts in three-dimensional collagen gels leads to degradation of the gels (see linked study in this issue, "Fibroblasts and monocytes contract and degrade three-dimensional collagen gels in extended co-culture"). The current study, therefore, was designed to evaluate production of matrix-degrading metalloproteinases by these cells in co-culture and to determine if neutrophil elastase could collaborate in the activation of these enzymes. Since co-cultures produce prostaglandin E(2) (PGE(2)), the role of PGE(2) in this process was also evaluated. METHODS: Blood monocytes from healthy donors and human fetal lung fibroblasts were cast into type I collagen gels and maintained in floating cultures for three weeks. Matrix metalloproteinases (MMPs) were assessed by gelatin zymography (MMPs 2 and 9) and immunoblotting (MMPs 1 and 3). The role of PGE(2) was explored by direct quantification, and by the addition of exogenous indomethacin and/or PGE(2). RESULTS: Gelatin zymography and immunoblots revealed that MMPs 1, 2, 3 and 9 were induced by co-cultures of fibroblasts and monocytes. Neutrophil elastase added to the medium resulted in marked conversion of latent MMPs to lower molecular weight forms consistent with active MMPs, and was associated with augmentation of both contraction and degradation (P < 0.01). PGE(2) appeared to decrease both MMP production and activation. CONCLUSION: The current study demonstrates that interactions between monocytes and fibroblasts can mediate tissue remodeling

    BORIS/CTCFL promotes a switch from a proliferative towards an invasive phenotype in melanoma cells

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    Melanoma is among the most aggressive cancers due to its tendency to metastasize early. Phenotype switching between a proliferative and an invasive state has been suggested as a critical process for metastasis, though the mechanisms that regulate state transitions are complex and remain poorly understood. Brother of Regulator of Imprinted Sites (BORIS), also known as CCCTC binding factor-Like (CTCFL), is a transcriptional modulator that becomes aberrantly expressed in melanoma. Yet, the role of BORIS in melanoma remains elusive. Here, we show that BORIS is involved in melanoma phenotype switching. Genetic modification of BORIS expression in melanoma cells combined with whole-transcriptome analysis indicated that BORIS expression contributes to an invasion-associated transcriptome. In line with these findings, inducible BORIS overexpression in melanoma cells reduced proliferation and increased migration and invasion, demonstrating that the transcriptional switch is accompanied by a phenotypic switch. Mechanistically, we reveal that BORIS binds near the promoter of transforming growth factor-beta 1 (TFGB1), a well-recognized factor involved in the transition towards an invasive state, which coincided with increased expression of TGFB1. Overall, our study indicates a pro-invasive role for BORIS in melanoma via transcriptional reprogramming

    On Enterprisesā€™ Total Budget Management Based on Big Data Analysis

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    At present, there is a delay in the transmission and acceptance of information in the total budget management of enterprises, which can only provide a basis for short-term decision-making, but has limitations on long-term decision-making. However, big data analysis can increase the efficiency of capital operations, carry out budget supervision and help companies make long-term decisions. This dissertation attempts to solve the problems above by using the Lasso method and the GM-Model. Based on big data, a series of experiments are carried out on the comprehensive budget management of enterprises to study the methods and application effects of big data analysis and prediction of enterprise income. Finally, through experiments, it is found that the predicted value of the first three years is larger than the actual value, and the deviation is gradually reduced in the following years. However, the actual income in 2001 is almost the same as the predicted value. These results indicate that using this method more accurately requires a large data from different years to support and operate

    Cytochrome P450 enzymes in the black-spotted frog (Pelophylax nigromaculatus): molecular characterization and upregulation of expression by sulfamethoxazole

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    Cytochrome P450 (CYP) enzymes are crucial for the detoxification of xenobiotics, cellular metabolism, and homeostasis. This study investigated the molecular characterization of CYP enzymes in the black-spotted frog, Pelophylax nigromaculatus, and examined the regulation of CYP expression in response to chronic exposure to the antibiotic sulfamethoxazole (SMX) at various environmental concentrations (0, 1, 10, and 100Ā Ī¼g/L). The full-length cDNA of Pn-CYP26B1 was identified. The sequence included open reading frames of 1,536 bp, encoding proteins comprising 511 amino acids. The signature motif, FxxGxxxCxG, was highly conserved when compared with a number of selected animal species. SMX significantly upregulated the expression of the protein CYP26B1 in frog livers at concentrations of 1 and 10Ā Ī¼g/L. SMX showed an affinity for CYP26B1 of āˆ’7.6Ā kcal/mol, indicating a potential mechanism for SMX detoxification or adaptation of the frog. These findings contributed to our understanding of the environmental impact of antibiotics on amphibian species and underscored the importance of CYP enzymes in maintaining biochemical homeostasis under exposure to xenobiotic stress

    Effects on Physicochemical and Dissolution Characteristics of Lentinus edodes Stem Powder by Jet Milling

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    In order to increase the utilization rate of shiitake mushroom by-products, the shiitake mushroom stem was crushed after superfine grinding with a jet mill, with coarse powder and 40 mesh powder as the control. The effect of jet milling on the physicochemical properties of shiitake mushroom stem powder and the dissolution amount of functional components represented by ergosterol and polysaccharides were studied. The cumulative dissolution rate of ergosterol and polysaccharides was fitted by the Weibull model. The results showed that after superfine grinding by jet milling, the average particle size (D50) of powder decreased to 3.21 Ī¼m, bulk density, tap density and L* value increased from 0.15 g/mL to 0.25 g/mL, 0.23 g/mL to 0.42 g/mL, 65.31 to 73.49, respectively. The superfine powder fluidity, water holding capacity and swelling capacity were significantly enhanced (P<0.05). The cumulative dissolution 50% of the time (T50) of ergosterol and polysaccharide in superfine powder was reduced by 2.56 min and 8.14 min, respectively, compared with coarse powder. And cumulative dissolution rate at 45 min (Q45) increased by 10.88% and 19.15%, respectively. The powder properties and the dissolution rate of the functional ingredients were improved, after the jet milling to treat the shiitake mushroom stem, which was conducive to the comprehensive utilization of shiitake mushroom by-products

    Integrating NGS-derived mutational profiling in the diagnosis of multiple lung adenocarcinomas

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    MICROABSTRACT: Integration of Next Generation Sequencing (NGS) information for use in distinguishing between Multiple Primary Lung Cancer and intrapulmonary metastasis was evaluated. We used a probabilistic model, comprehensive histologic assessment and NGS to classify patients. Integrating NGS data confirmed initial diagnosis (n = 41), revised the diagnosis (n = 12), while resulted in non-informative data (n = 8). Accuracy of diagnosis can be significantly improved with integration of NGS data. BACKGROUND: Distinguishing between multiple primary lung cancers (MPLC) and intrapulmonary metastases (IPM) is challenging. The goal of this study was to evaluate how Next Generation Sequencing (NGS) information may be integrated in the diagnostic strategy. PATIENTS AND METHODS: Patients with multiple lung adenocarcinomas were classified using both the comprehensive histologic assessment and NGS. We computed the joint probability of each pair having independent mutations by chance (thus being classified as MPLC). These probabilities were computed using the marginal mutation rates of each mutation, and the known negative dependencies between driver genes and different gene loci. With these NGS-driven data, cases were re-classified as MPLC or IPM. RESULTS: We analyzed 61 patients with a total of 131 tumors. The most frequent mutation was KRAS (57.3%) which occured at a rate higher than expected (p < 0.001) in lung cancer. No mutation was detected in 25/131 tumors (19.1%). Discordant molecular findings between tumor sites were found in 46 patients (75.4%); 11 patients (18.0%) had concordant molecular findings, and 4 patients (6.6%) had concordant molecular findings at 2 of the 3 sites. After integration of the NGS data, the initial diagnosis was confirmed for 41 patients (67.2%), the diagnosis was revised for 12 patients (19.7%) or was considered as non-informative for 8 patients (13.1%). CONCLUSION: Integrating the information of NGS data may significantly improve accuracy of diagnosis and staging
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