120 research outputs found

    A-Optimal designs for mixture polynomial models with heteroscedastic errors

    Get PDF
    This paper searches A A -optimal designs for mixture polynomial models when the errors are heteroscedastic. Sufficient conditions are given so that A A -optimal designs for the complex mixture polynomial models can be constructed from the direct sum of A A -optimal designs for their sub-mixture models with different structures of heteroscedasticity. Several examples are presented to further illustrate and check optimal designs based on A A -optimality criterion

    Role of glucose in the repair of cell membrane damage during squeeze distortion of erythrocytes in microfluidic capillaries

    Get PDF
    The rapid development of portable precision detection methods and the crisis of insufficient blood supply worldwide has led scientists to study mechanical visualization features beyond the biochemical properties of erythrocytes. Combined evaluation of currently known biochemical biomarkers and mechanical morphological biomarkers will become the mainstream of single-cell detection in the future. To explore the mechanical morphology of erythrocytes, a microfluidic capillary system was constructedin vitro, with flow velocity and glucose concentration as the main variables, and the morphology and ability of erythrocytes to recover from deformation as the main objects of analysis. We showed the mechanical distortion of erythrocytes under various experimental conditions. Our results showed that glucose plays important roles in improving the ability of erythrocytes to recover from deformation and in repairing the damage caused to the cell membrane during the repeated squeeze process. These protective effects were also confirmed inin vivoexperiments. Our results provide visual detection markers for single-cell chips and may be useful for future studies in cell aging

    PGK1 is a Potential Survival Biomarker and Invasion Promoter by Regulating the HIF-1α–Mediated Epithelial-Mesenchymal Transition Process in Breast Cancer

    Get PDF
    Background/Aims: Glycolysis, a multi-step enzymatic reaction, is considered to be the root of cancer development and progression. The aim of this study is to figure out which glycolysis enzyme participates in the progression of breast cancer and its possible mechanisms. Materials: We firstly screened out PGK1 by performing an RT-PCR array of glycolysis-related genes in three paired breast cancer samples, and further investigated PGK1 using TCGA and our own database. The effect and mechanism of PGK1 on cell invasion was further explored both in vitro and using patient samples. Results: PGK1 was most upregulated in T3N0 with distant metastases compared to those with no metastases. In the TCGA database, high PGK1 expression predicted poor overall survival (OS) in breast cancer and some other cancers (P< 0.001). In the validation cohort, high PGK1 expression was significantly correlated with larger tumor size (P=0.011) and advanced TNM stage (P=0.033), and PGK1 expression was an independent prognostic factor for OS and disease free survival (DFS) in both univariate and multivariate regression analyses (P< 0.05). Functional studies indicated that knockdown of PGK1 expression significantly inhibited invasion and reversed the epithelial-mesenchymal transition process in breast cancer cells (P< 0.05). Mechanistically, PGK1 increased HRE luciferase activity in a dose-dependent manner, while silencing PGK1 expression decreased HRE activity. Conclusion: High PGK1 expression was associated with poor prognosis in breast cancer, because PGK1 and HIF-1α formed a positive feed-forward loop and thus stimulated breast cancer progression and metastases. Based on these results, PGK1 may serve as a promising biomarker and target therapy for breast cancer

    Locus-specific epigenetic remodeling controls addiction- and depression-related behaviors

    Get PDF
    Chronic exposure to drugs of abuse or stress regulates transcription factors, chromatin-modifying enzymes and histone post-translational modifications in discrete brain regions. Given the promiscuity of the enzymes involved, it has not yet been possible to obtain direct causal evidence to implicate the regulation of transcription and consequent behavioral plasticity by chromatin remodeling that occurs at a single gene. We investigated the mechanism linking chromatin dynamics to neurobiological phenomena by applying engineered transcription factors to selectively modify chromatin at a specific mouse gene in vivo. We found that histone methylation or acetylation at the Fosb locus in nucleus accumbens, a brain reward region, was sufficient to control drug- and stress-evoked transcriptional and behavioral responses via interactions with the endogenous transcriptional machinery. This approach allowed us to relate the epigenetic landscape at a given gene directly to regulation of its expression and to its subsequent effects on reward behavior

    Noise Analysis of Computer Chassis and Secondary Sound Source Noise Reduction

    No full text
    This article focuses on computer noise analysis and noise reduction processing. With the popularity of computers, people are increasingly demanding the comfort of using computers. Solving the noise problem of the computer case can make the working environment more comfortable. People working in a noisy environment for a long time can cause anxiety and the quality of work is not high. The main purpose of this paper is to analyse the characteristics of computer noise and to reduce the noise of the chassis through the secondary sound source. Through the comparison of the experimental and simulation results, the noise reduction effect of the secondary sound source on the computer case is obtained. This paper can provide a scientific reference for the manufacture of computer chassis and improvement of noise

    New types of general single/multiple integral inequalities

    No full text
    Abstract By introducing some concepts such as multiple integral inner product (MIIP) and multiple integral inner product space (MIIPS), new series of single/multiple integral inequalities are developed in a systematic way, which produce more accurate bounds on the cross terms from the direct Lyapunov method than those in the literature. Some previous integral inequalities including both single and multiple integral inequalities can be regarded as special cases of the proposed inequalities. Accordingly, such integral inequalities are less conservative in comparison with the existing integral inequalities
    • …
    corecore