31 research outputs found

    Changes in Lp-PLA 2 are associated with elevated alanine aminotransferase levels: A nested case-control study in a three-year prospective cohort

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    Background/Aim: Elevation in liver enzymes and hepatic fat may indicate a higher susceptibility to cardiovascular disease (CVD). This research sought to find anthropometric/biochemical variables significantly related to the alanine aminotransferase (ALT) increase in healthy populations. Methods: Nine hundred healthy subjects were included in a 3-year prospective cohort study. The initial screening revealed that 538 were found to be nondiabetic (fasting glucose < 126 mg/dL) and had normal ALT levels. Among them, 79 individuals with slightly elevated ALT levels after three years were assigned to the elevated ALT group. Of the remaining 459 participants, 241 subjects matched to the increased ALT group were the control group. Results: After three years of follow-up, individuals with elevated ALT showed notably higher aspartate aminotransferase (AST), ALT, gamma-glutamyl-transferase (g-GT), high sensitivity C-reactive protein (hs-CRP), lipoprotein-associated phospholipase A2 (Lp-PLA2 ) activity, oxidised low-density lipoprotein (ox-LDL), urinary 8-epi-prostaglandin F2a (8-epi-PGF2a) levels and brachial-ankle pulse wave velocity (ba-PWV) in comparison to the control group. Changes (D) in ALT showed a positive correlation with D AST, D gammaGT, D hs-CRP, D Lp-PLA2 activity, D ox-LDL, D urinary 8-epi-PGF2a and D ba-PWV. Furthermore, a direct positive link was observed between the D Lp-PLA2 activity and D AST, D ox-LDL and D ba-PWV. Conclusion: Increased Lp-PLA2 activity and other CVD risk indicators were observed to have a pronounced association with elevated ALT levels. This mild ALT elevation could potentially contribute to chronic low-grade inflammation

    Prenatal allergen and diesel exhaust exposure and their effects on allergy in adult offspring mice

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    Multiple studies have suggested that prenatal exposure to either allergens or air pollution may increase the risk for the development of allergic immune responses in young offspring. However, the effects of prenatal environmental exposures on adult offspring have not been well-studied. We hypothesized that combined prenatal exposure to Aspergillus fumigatus (A. fumigatus) allergen and diesel exhaust particles will be associated with altered IgE production, airway inflammation, airway hyperreactivity (AHR), and airway remodeling of adult offspring. Following sensitization via the airway route to A. fumigatus and mating, pregnant BALB/c mice were exposed to additional A. fumigatus and/or diesel exhaust particles. At age 9-10 weeks, their offspring were sensitized and challenged with A. fumigatus. We found that adult offspring from mice that were exposed to A. fumigatus or diesel exhaust particles during pregnancy experienced decreases in IgE production. Adult offspring of mice that were exposed to both A. fumigatus and diesel exhaust particles during pregnancy experienced decreases in airway eosinophilia. These results suggest that, in this model, allergen and/or diesel administration during pregnancy may be associated with protection from developing systemic and airway allergic immune responses in the adult offspring

    Nonlinear Vibration Control Experimental System Design of a Flexible Arm Using Interactive Actuations from Shape Memory Alloy

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    The flexible arm easily vibrates due to its thin structural characteristics, which affect the operation accuracy, so reducing the vibration of the flexible arm is a significant issue. Smart materials are very widely used in the research topic of vibration suppression. Considering the hysteresis characteristic of the smart materials, based on previous simulation research, this paper proposes an experimental system design of nonlinear vibration control by using the interactive actuation from shape memory alloy (SMA) for a flexible arm. The experiment system was an interactive actuator&ndash;sensor&ndash;controller combination. The vibration suppression strategy was integrated with an operator-based vibration controller, a designed integral compensator and the designed n-times feedback loop. In detail, a nonlinear vibration controller based on operator theory was designed to guarantee the robust stability of the flexible arm. An integral compensator based on an estimation mechanism was designed to optimally reduce the displacement of the flexible arm. Obtaining the desired tracking performance of the flexible arm was a further step, by increasing the n-times feedback loop. From the three experimental cases, when the vibration controller was integrated with the designed integral compensator, the vibration displacement of the flexible arm was much reduced compared to that without the integral compensator. Increasing the number of n-times feedback loops improves the tracking performance. The desired vibration control performance can be satisfied when n tends to infinity. The conventional PD controller stabilizes the vibration displacement after the 7th vibration waveform, while the vibration displacement approaches zero after the 4th vibration waveform using the proposed vibration control method, which is proved to be faster and more effective in controlling the flexible arm&rsquo;s vibration. The experimental cases verify the effectiveness of the proposed interactive actuation vibration control approach. It is observed from the experimental results that the vibration displacement of the flexible arm becomes almost zero within less time and with lower input power, compared with a traditional controller

    Nonlinear Fault-Tolerant Vibration Control for Partial Actuator Fault of a Flexible Arm

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    This paper presents a nonlinear fault-tolerant vibration control system for a flexible arm, considering partial actuator fault. A lightweight flexible arm with lower stiffness will inevitably cause vibration which will impair the performance of the high-precision control system. Therefore, an operator-based robust nonlinear vibration control system is integrated by a double-sided interactive controller actuated by the Shape Memory Alloy (SMA) actuators for the flexible arm. Furthermore, to improve the safety and reliability of the safety-critical application, fault-tolerant dynamics for partial actuator fault are considered as an essential part of the proposed control system. The experimental cases are set to the partial actuator as faulty conditions, and the proposed vibration control scheme has fault-tolerant dynamics which can still effectively stabilize the vibration displacement. The reconfigurable controller improves the fault-tolerant performance by shortening the vibration time and reducing the vibration displacement of the flexible arm. In addition, compared with a PD controller, the proposed nonlinear vibration control has better performance than the traditional controller. The experimental results show that the effectiveness of the proposed method is confirmed. That is, the safety and reliability of the proposed fault-tolerant vibration control are verified even if in the presence of an actuator fault

    Nonlinear Vibration Control Experimental System Design of a Flexible Arm Using Interactive Actuations from Shape Memory Alloy

    No full text
    The flexible arm easily vibrates due to its thin structural characteristics, which affect the operation accuracy, so reducing the vibration of the flexible arm is a significant issue. Smart materials are very widely used in the research topic of vibration suppression. Considering the hysteresis characteristic of the smart materials, based on previous simulation research, this paper proposes an experimental system design of nonlinear vibration control by using the interactive actuation from shape memory alloy (SMA) for a flexible arm. The experiment system was an interactive actuator–sensor–controller combination. The vibration suppression strategy was integrated with an operator-based vibration controller, a designed integral compensator and the designed n-times feedback loop. In detail, a nonlinear vibration controller based on operator theory was designed to guarantee the robust stability of the flexible arm. An integral compensator based on an estimation mechanism was designed to optimally reduce the displacement of the flexible arm. Obtaining the desired tracking performance of the flexible arm was a further step, by increasing the n-times feedback loop. From the three experimental cases, when the vibration controller was integrated with the designed integral compensator, the vibration displacement of the flexible arm was much reduced compared to that without the integral compensator. Increasing the number of n-times feedback loops improves the tracking performance. The desired vibration control performance can be satisfied when n tends to infinity. The conventional PD controller stabilizes the vibration displacement after the 7th vibration waveform, while the vibration displacement approaches zero after the 4th vibration waveform using the proposed vibration control method, which is proved to be faster and more effective in controlling the flexible arm’s vibration. The experimental cases verify the effectiveness of the proposed interactive actuation vibration control approach. It is observed from the experimental results that the vibration displacement of the flexible arm becomes almost zero within less time and with lower input power, compared with a traditional controller

    Effect of arsenic on transcription factor AP-1 and NF-kB DNA binding activity and related gene expression

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    Both acute (24 h) and chronic (10&ndash;20 week) exposure of human fibroblast cells to low dose sodium arsenite (As(III)) significantly affects activating protein-1 (AP-1) and nuclear factor kappa B (NF-&kappa;B) DNA binding activity. Short-term treatment with 0.1&ndash;5 &mu;M As(III) up-regulates expression of c-Fos and c-Jun and the redox regulators, thioredoxin (Trx) and Redox factor-1 (Ref-1) and activates both AP-1 and NF-&kappa;B binding. Chronic exposure to 0.1 or 0.5 &mu;M As(III) decreased c-Jun, c-Fos and Ref-1 protein levels and AP-1 and NF-&kappa;B binding activity, but increased Trx expression. Short term exposure to phorbol 12-myristate 13-acetate (TPA), a phorbol ester tumour promoter, or hydrogen peroxide (H2O2) also activates AP-1 and NF-&kappa;B binding. However, pre-treatment with As(III) prevents this increase. These results suggest that As(III) may alter AP-1 and NF-&kappa;B activity, in part, by up-regulating Trx and Ref-1. The different effects of short- versus long-term As(III) treatment on acute-phase response to oxidative stress reflect changes in the expression of Ref-1, c-Fos and c-Jun, but not Trx.<br /

    Seven new species and a checklist of the genus Thecobathra Meyrick from China (Lepidoptera: Yponomeutidae)

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    Fan, Ximei, Jin, Qing, Li, Houhun (2008): Seven new species and a checklist of the genus Thecobathra Meyrick from China (Lepidoptera: Yponomeutidae). Zootaxa 1821: 13-24, DOI: 10.5281/zenodo.18302

    Alteration of GSH level, gene expression and cell transformation in NIH3T3 cells by chronic exposure to low dose of arsenic

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    It is well established that arsenic toxicity is postulated to be primarily due to the binding of As(III) to sulfhydryl-containing enzymes. However, the mechanism of carcinogenesis induced by arsenic is still unclear. The interaction of arsenic with GSH and related enzymes seems a very important issue regarding mechanism of arsenical induced toxicity or carcinogenesis. The purpose of this work is to investigate the effect of chronic exposure to low dose of As(III) on GSH level, gene expression and cell transformation in NIH3T3 cells. The results showed that long-term, low dose arsenic treatment makes 3T3 cell more resistant to acute arsenic treatment. There were morphology changes after long-term arsenic treatment. First, partially immortalized 3T3 cell became immortalized. In addition, the cells were doubling more quickly than the control cells and attained higher density than the control cells at confluence. Second, cells treated with 0.1 &micro;.M As(III) exhibited anchorage-independent growth. Arsenic could enhance GSH level at 0.5 -10 &micro;M dose of arsenic in 24 h treatment and decrease it at 25 &micro;M and above. In long-term treatment with low dose of arsenic, GSH levels were decreased. As(I1I) can increase both glutathione S-transferase (GST) and glutathione reductase (GR) activities at low dose (0.5-10 M), but decreased GST and GR activities at 25 M and higher dose of arsenic, while in long-term As(III) treatment, GST and GR activities are increased. Both long-term and short-term treatments with As(III) can induce GR gene expression. GPx mRNA levels were decreased both in acute and chronic arsenic treated cells. Chronic treatment with As(III) also decreased the p53 mRNA level. Taken together, our results suggest that As(III) can alter GST, GR enzyme activities as well as GSH level and related gene expression both in long-term and short-term treatment but in a different manner in different doses. Alteration of cellular GSH level by As(III) might play all important role in gene expression and arsenic induced cell transformation.<br /

    Genetic Mapping and Comparative Expression Analysis of Transcription Factors in Cotton

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    <div><p>Transcription factors (TFs) play an important role in the regulation of plant growth and development. The study of the structure and function of TFs represents a research frontier in plant molecular biology. The findings of these studies will provide significant information regarding genetic improvement traits in crops. Currently, a large number of TFs have been cloned, and their function has been verified. However, relatively few studies that genetically map TFs in cotton are available. To genetically map TFs in cotton in this study, specific primers were designed for TF genes that were published in the Plant Transcription Factor Database. A total of 977 TF primers were obtained, and 31 TF polymorphic loci were mapped on 15 cotton chromosomes. These polymorphic loci were clearly preferentially distributed on chromosomes 5, 11, 19 and 20; and TFs from the same family mapped to homologous cotton chromosomes. <i>In-silico</i> mapping verified that many mapped TFs were mapped on their corresponding chromosomes or their homologous chromosomes’ corresponding chromosomes in the diploid genomes. QTL mapping for fiber quality revealed that TF-Ghi005602-2 mapped on Chr19 was associated with fiber length. Eighty-five TF genes were selected for RT-PCR analysis, and 4 TFs were selected for qRT-PCR analysis, revealing unique expression patterns across different stages of fiber development between the mapping parents. Our data offer an overview of the chromosomal distribution of TFs in cotton, and the comparative expression analysis between <i>Gossypium hirsutum</i> and <i>G</i>. <i>barbadense</i> provides a rough understanding of the regulation of TFs during cotton fiber development.</p></div
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