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The effects of extraction methods (including maceration, microwave, ultrasound and magnetic field assisted extraction) and solvent evaporation methods (including water bath evaporation, vacuum freezing, vacuum and oven drying) on antioxidant activity of astaxanthin from H. pluvialis were studied. The potential antioxidant activities of extracts and dry astaxanthin samples were measured by 2, 2-Diphenyl-1-picrylhydrazyl (DPPH·), Hydroxyl (OH·) radical scavenging activity and linoleic acid emulsion. Being compared with the antioxidant activities of astaxanthin at concentration of 25 μg/ml, the magnetic field extracts and sample by treated water bath evaporation showed the highest DPPH radical scavenging activity of 60.76 and 57.6%, respectively. While magnetic field extract and vacuum freeze-drying sample of astaxanthin showed the highest hydroxyl radical scavenging activity of 18.8 and 16.78%, respectively. The results were found to be significantly higher than the other methods processed samples of the respective varieties (p <0.05). All extracts and drying samples exhibited good antioxidant activity against the linoleic acid emulsion system (p < 0.05). [ABSTRACT FROM AUTHOR]

A number of regulations have been implemented that aim to control the release of potentially adverse endocrine disrupters into the aquatic environment based on evidence from laboratory studies. Currently, such studies rely on testing approaches with adult fish because reliable alternatives have not been validated so far. Fish embryo tests have been proposed as such an alternative, and here we compared two species (medaka and zebrafish) to determine their suitability for the assessment of substances with estrogenic and anti-androgenic activity. Changes in gene expression (in here the phrase gene expression is used synonymously to gene transcription, although it is acknowledged that gene expression is additionally regulated, e.g., by translation and protein stability) patterns between the two species were compared in short term embryo exposure tests (medaka: 7-day post fertilization [dpf]; zebrafish: 48 and 96 h post fertilization [hpf]) by using relative quantitative real-time RT-PCR. The tested genes were related to the hypothalamic-gonadal-axis and early steroidogenesis. Test chemicals included 17α-ethinylestradiol and flutamide as estrogenic and anti-androgenic reference compounds, respectively, as well as five additional substances with endocrine activities, namely bisphenol A, genistein, prochloraz, linuron and propanil. Estrogenic responses were comparable in 7-dpf medaka and 48/96-hpf zebrafish embryos and included transcriptional upregulation of aromatase b, vitellogenin 1 as well as steroidogenic genes, suggesting that both species reliably detected exposure to estrogenic compounds. However, anti-androgenic responses differed between the two species, with each species providing specific information concerning the mechanism of anti-androgenic disruption in fish embryos. Although small but significant changes in the expression of selected genes was observed in 48-hpf zebrafish embryos, exposure prolonged to 96 hpf was necessary to obtain a response indicative of anti-androgenic activity. In contrast, for medaka clear anti-androgenic response, e.g. transcriptional downregulation of 11β-hydroxylase, 3β-hydroxysteroid-dehydrogenase, gonadotropin-releasing hormone receptor 2, was already observed at the pre-hatch stage. Together, this data suggests that medaka and zebrafish embryos would provide a beneficial alternative testing platform for endocrine disruption that involves additive information on interspecies and exposure time variability when using both species. [ABSTRACT FROM AUTHOR]

Even though GPCR signaling in human platelets is directly involved in hemostasis and thrombus formation, the sequence of events by which G protein activation leads to αIIbβ3 integrin activation (inside-out signaling) is not clearly defined. We previously demonstrated that a conformationally sensitive domain of one G protein, i.e. Gα13 switch region 1 (Gα13SR1), can directly participate in the platelet inside-out signaling process. Interestingly however, the dependence on Gα13SR1 signaling was limited to PAR1 receptors, and did not involve signaling through other important platelet GPCRs. Based on the limited scope of this involvement, and the known importance of G13 in hemostasis and thrombosis, the present study examined whether signaling through another switch region of G13, i.e. Gα13 switch region 2 (Gα13SR2) may represent a more global mechanism of platelet activation. Using multiple experimental approaches, our results demonstrate that Gα13SR2 forms a bimolecular complex with the head domain of talin and thereby promotes β3 integrin activation. Moreover, additional studies provided evidence that Gα13SR2 is not constitutively associated with talin in unactivated platelets, but becomes bound to talin in response to elevated intraplatelet calcium levels. Collectively, these findings provide evidence for a novel paradigm of insideout signaling in platelets, whereby β3 integrin activation involves the direct binding of the talin head domain to the switch region 2 sequence of the Gα13 subunit. [ABSTRACT FROM AUTHOR]

The flowback rate of a shale gas well is controlled by many factors, such as geological and engineering factors, which have a certain complexity. For the aforementioned reason, the knowledge-driven method often has difficulty effectively capturing the correlation rules among multiple datasets. As a data-driven algorithm, deep learning has strong advantages in data correlation analysis, nonlinear fitting and other applications. In this paper, an algorithm is set up to forecast the shale gas well flowback rate by using a deep learning algorithm based on the flowback characteristic factors and data from 286 shale gas wells in the Weiyuan field. An algorithm and prediction model of the flowback parameters of the Weiyuan shale gas wells is established to effectively capture their flowback characteristics. First, the general situation of the study area is briefly introduced, and the data used to predict the flowback rate in this area are analyzed. Second, based on the deep learning algorithm, two kinds of deep feedforward neural network structures and a neural network-based prediction method of shale gas well flowback rate are designed. Finally, according to the regional data, the prediction and analysis of the flowback rate of Weiyuan shale gas wells are carried out. The results show that the correlations between 17 factors, such as fracturing section length and shale gas well flowback rate, are not obvious, but that the deep learning method proposed in this paper can effectively and accurately capture the correlations between the data and predict the flowback rate. The results show high accuracy. • An approach of Shale gas well flowback rate prediction based on a deep learning algorithm is designed. • Two kinds of deep feedforward neural network structures for shale gas well flowback rate prediction are designed. • The flowback rate of Weiyuan shale gas wells are carried out using proposed algorithm. [ABSTRACT FROM AUTHOR]

At present, there are many problems in coal mine operation, such as formation of large amounts of dust, complex dust migration behavior, severe respiratory harm, poor on-site performance of spray dust removal technology under windy conditions, and low collection efficiency of respirable dust. To solve the above problems, the finite element method of computational fluid dynamics (CFD) was used. The Spalart-Allmaras turbulence model of COMSOL software and the tracking module for atomized particles broken by droplets were used. They were combined with the Fraunhofer diffraction principle to study the distributions of the velocity of the airflow field, droplet size, droplet velocity and wind resistance for a supersonic water siphonic atomization device. The influence of the above factors on dust removal at different aerodynamic pressures was studied experimentally. The relationships between spray characteristics, flow field velocity distribution, dust removal effect and spray characteristics were revealed. The research showed that with increasing pressure, the supersonic component accounted for an increased proportion of the flow field inside the nozzle, average velocity of the flow field increased, atomization efficiency increased, droplet particle size decreased, and droplet velocity increased. The particle size of the droplets first increased, then decreased and then increased with increasing spraying distance. Additionally, the range of high-speed fine droplet size fog increased with increasing pressure. At the same transverse wind speed, with increasing pressure, the deflection point of the fog field moved backward, and the wind resistance of the spray was enhanced. With the increase in aerodynamic pressure, the dust isolation and negative pressure effect of spray and the dust collection efficiency increased, and there was an optimal value for dust removal in a limited space. The reason was that when the pressure increased to a certain extent, the air flow reversed in the coil at the bottom of the limited space, which blew the dust that was not aggregated at the bottom away from the area where dust was falling. Thus, the dust was entrained in fog droplets but could not be removed from the air flow. The dust dispersion in the air flow after purification differed greatly at different pressures because the removal efficiency of dust in the 2.5–10 μm particle size range was mainly affected by the pressure. In a field study of a fully mechanized mining face, the fog curtain formed by the device covered the whole section under the condition of airflow disturbance with large transverse velocity, and the comprehensive respirable dust removal efficiency of the working area reached 92.3%. Thus, this method showed good wind resistance and dust removal performance. The study of this technology can provide a clean working environment and theoretical guidance for the safe production of coal in the future, especially for fully mechanized mining faces. [Display omitted] • The transonic flow field distribution has significant influence on the supersonic atomization effect. • The droplet size of supersonic atomization does not always increase with the increase of jet distance. • The increase of aerodynamic pressure is conducive to the resistance of droplets to ambient airflow disturbance. • The trapping characteristics of dust do not depend on the droplet size. • The dust of 2.5–10 μm in the fully mechanized mining face of coal mine is efficiently removed. [ABSTRACT FROM AUTHOR]

Oxidative stress can induce cell dysfunction and lead to a broad range of degenerative alterations, including carcinogenesis, aging, and other oxidative stress-related conditions. To avoid undergoing carcinogenesis in response to oxidative stress, cells trigger a succession of checkpoint responses, including premature senescence and apoptosis. Increasing evidence indicates that H2O2, an important cause of oxidative stress, functions as an important physiological regulator of intracellular signaling pathways that participate in regulation of cell premature senescence and apoptosis. However, the precise mechanisms underlying this process remain to be studied extensively. In this study, we describe the importance of Pim-1 kinase in this checkpointresponsetooxidativestress.Pim-1bindstoandphosphorylates the transcription factor high mobility group box transcription factor 1 (HBP1), activating it. H2O2 enhances the interaction between Pim-1 and HBP1 and promotes HBP1 accumulation. In turn, HBP1 rapidly and selectively up-regulates Pim-1 expression in H2O2-stimulated cells, thereby creating a Pim-1-HBP1 positive feedback loop that regulates H2O2-induced premature senescence and apoptosis. Furthermore, the Pim-1-HBP1 positive feedback loop exerts its effect by regulating the senescence markers DNMT1 and p16 and the apoptosis marker Bax. The Pim-1-HBP1 axis thus constitutes a novel checkpoint pathway critical for the inhibition of tumorigenesis. [ABSTRACT FROM AUTHOR]

The activity of the CDK inhibitor p21 is associated with diverse biological activities, including cell proliferation, senescence, and tumorigenesis. However, the mechanisms governing transcription of p21 need to be extensively studied. In this study, we demonstrate that the high-mobility group box-containing protein 1 (HBP1) transcription factor is a novel activator of p21 that works as part of a complex mechanism during senescence and tumorigenesis. We found that HBP1 activates the p21 gene through enhancing p53 stability by inhibiting Mdm2-mediated ubiquitination of p53, a well known positive regulator of p21. HBP1 was also found to enhance p21 transcription by inhibiting Wnt/β-catenin signaling. We identified histone methyltransferase EZH2, the catalytic subunit of polycomb repressive complex 2, as a target of Wnt/β-catenin signaling. HBP1-mediated repression of EZH2 through Wnt/β-catenin signaling decreased the level of trimethylation of histone H3 at lysine 27 of overall and specific histone on the p21 promoter, resulting in p21 transactivation. Although intricate, the reciprocal partnership of HBP1 and p21 has exceptional importance. HBP1-mediated elevation of p21 through the Mdm2/p53 and TCF4/EZH2 pathways contributes to both cellular senescence and tumor inhibition. Together, our results suggest that the HBP1 transcription factor orchestrates a complex regulation of key genes during cellular senescence and tumorigenesis with an impact on protein ubiquitination and overall histone methylation state. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the role of phosvitin in bone formation in chicken embryos. The yolk P content, P/N ratio and secondary structure of phosvitin, alkaline phosphatase (ALP) activity of the tibia, and body length were determined during incubation. A high correlation was found between the phosphate group content of phosvitin and both secondary structure and bone metabolism (ALP activity in the tibia, body length). The ALP activity and body length growth slightly lagged behind changes in the P/N ratio and the secondary structure of phosvitin. The phosphate content of phosvitin decreased, the γ-random coil and (3-turn gradually transformed into a-helixes, and the secondary structure of protein tended to become more orderly; these changes mainly occurred on d 13 to 16. Bone formation of the chicken embryos occurred primarily on d 14 to 18, whereas ALP activity and body length growth increased substantially. The results indicate that phosvitin P is involved in chicken embryo bone formation through dephosphorylation. [ABSTRACT FROM AUTHOR]