94 research outputs found
The Design and Construction of Decision-Making Command System for Digital Oilfield Emergency Drill
AbstractWith the theme of global economic development. China's oil companies are moving forward in the digitization process, the ability to prevent and handle emergencies are in more urgent needs, when the Oilfields encounter risks of various major unexpected security incidents, an isolated burst event is likely to have spillover effects, then evolved into great social disasters, and posed a serious threat to production security, social stability and people's lives. This article contrary to the view of the above situation, combined with Virtual Reality technology and Workflow technology to build a Digital Oilfield Emergency decision-making command system, looking forward to play the aider and endorsement role with Oilfield Emergency command decision-making
Nonlinear stability for 3-D plane Poiseuille flow in a finite channel
In this paper, we study the nonlinear stability for the 3-D plane Poiseuille
flow at high Reynolds number in a finite channel
with non-slip boundary condition.
We prove that if the initial velocity satisfies
for some
independent of , then the solution of 3-D Naiver-Stokes equations
is global in time and does not transit away from the plane Poiseuille flow. To
our knowledge, this is the first nonlinear stability result for the 3-D plane
Poiseuille flow and the transition threshold is accordant with the numerical
result by Lundbladh et al. \cite{LHR}
Myricitrin Modulates NADPH Oxidase-Dependent ROS Production to Inhibit Endotoxin-Mediated Inflammation by Blocking the JAK/STAT1 and NOX2/p47 phox
Myricitrin, a naturally occurring polyphenol hydroxy flavonoid, has been reported to possess anti-inflammatory properties. However, the precise molecular mechanism of myricitrin’s effects on LPS-induced inflammation is unclear. In the present study, myricitrin significantly alleviated acute lung injury in mice. Myricitrin also markedly suppressed the production of NO, TNF-α, IL-6, and MCP-1 in RAW264.7 macrophage cells. The inhibition of NO was concomitant with a decrease in the protein and mRNA levels of iNOS. The phosphorylation of JAKs and STAT-1 was abrogated by myricitrin. Furthermore, myricitrin inhibited the nuclear transfer and DNA binding activity of STAT1. The JAK-specific inhibitor ruxolitinib simulated the anti-inflammatory effect of myricitrin. However, myricitrin had no impact on the MAPK signalling pathway. Myricitrin attenuated the generation of intracellular ROS by inhibiting the assembly of components of the gp91phox and p47phox. Suppression of ROS generation using NAC or apocynin or by silencing gp91phox and p47phox all demonstrated that decreasing the level of ROS inhibited the LPS-induced inflammatory response. Collectively, these results confirmed that myricitrin exhibited anti-inflammatory activity by blocking the activation of JAKs and the downstream transcription factor STAT1, which may result from the downregulation of NOX2-dependent ROS production mediated by myricitrin
Salidroside Inhibits HMGB1 Acetylation and Release through Upregulation of SirT1 during Inflammation
HMGB1, a highly conserved nonhistone DNA-binding protein, plays an important role in inflammatory diseases. Once released to the extracellular space, HMGB1 acts as a proinflammatory cytokine that triggers inflammatory reaction. Our previous study showed that salidroside exerts anti-inflammatory effect via inhibiting the JAK2-STAT3 signalling pathway. However, whether salidroside inhibits the release of HMGB1 is still unclear. In this study, we aim to study the effects of salidroside on HMGB1 release and then investigate the potential molecular mechanisms. In an experimental rat model of sepsis caused by CLP, salidroside administration significantly attenuated lung injury and reduced the serum HMGB1 level. In RAW264.7 cells, we investigated the effects of salidroside on LPS-induced HMGB1 release and then explored the underlying molecular mechanisms. We found that salidroside significantly inhibited LPS-induced HMGB1 release, and the inhibitory effect was correlated with the HMGB1 acetylation levels. Mechanismly, salidroside inhibits HMGB1 acetylation through the AMPK-SirT1 pathway. In addition, SirT1 overexpression attenuated LPS-induced HMGB1 acetylation and nucleocytoplasmic translocation. Furthermore, in SirT1 shRNA plasmid-transfected cells, salidroside treatment enhanced SirT1 expression and reduced LPS-activated HMGB1 acetylation and nucleocytoplasmic translocation. Collectively, these results demonstrated that salidroside might reduce HMGB1 release through the AMPK-SirT1 signalling pathway and suppress HMGB1 acetylation and nucleocytoplasmic translocation
Characterisation of cognitive load using machine learning classifiers of electroencephalogram data
A high cognitive load can overload a person, potentially resulting in catastrophic accidents. It is therefore important to ensure the level of cognitive load associated with safety-critical tasks (such as driving a vehicle) remains manageable for drivers, enabling them to respond appropriately to changes in the driving environment. Although electroencephalography (EEG) has attracted significant interest in cognitive load research, few studies have used EEG to investigate cognitive load in the context of driving. This paper presents a feasibility study on the simulation of various levels of cognitive load through designing and implementing four driving tasks. We employ machine learning-based classification techniques using EEG recordings to differentiate driving conditions. An EEG dataset containing these four driving tasks from a group of 20 participants was collected to investigate whether EEG can be used as an indicator of changes in cognitive load. The collected dataset was used to train four Deep Neural Networks and four Support Vector Machine classification models. The results showed that the best model achieved a classification accuracy of 90.37%, utilising statistical features from multiple frequency bands in 24 EEG channels. Furthermore, the Gamma and Beta bands achieved higher classification accuracy than the Alpha and Theta bands during the analysis. The outcomes of this study have the potential to enhance the Human–Machine Interface of vehicles, contributing to improved safety
Divergence of a genomic island leads to the evolution of melanization in a halophyte root fungus
AbstractUnderstanding how organisms adapt to extreme living conditions is central to evolutionary biology. Dark septate endophytes (DSEs) constitute an important component of the root mycobiome and they are often able to alleviate host abiotic stresses. Here, we investigated the molecular mechanisms underlying the beneficial association between the DSE Laburnicola rhizohalophila and its host, the native halophyte Suaeda salsa, using population genomics. Based on genome-wide Fst (pairwise fixation index) and Vst analyses, which compared the variance in allele frequencies of single-nucleotide polymorphisms (SNPs) and copy number variants (CNVs), respectively, we found a high level of genetic differentiation between two populations. CNV patterns revealed population-specific expansions and contractions. Interestingly, we identified a ~20 kbp genomic island of high divergence with a strong sign of positive selection. This region contains a melanin-biosynthetic polyketide synthase gene cluster linked to six additional genes likely involved in biosynthesis, membrane trafficking, regulation, and localization of melanin. Differences in growth yield and melanin biosynthesis between the two populations grown under 2% NaCl stress suggested that this genomic island contributes to the observed differences in melanin accumulation. Our findings provide a better understanding of the genetic and evolutionary mechanisms underlying the adaptation to saline conditions of the L. rhizohalophila–S. salsa symbiosis.</jats:p
A Phenotypic characterization of two isolates of a multidrug resistant outbreak strain of mycobacterium tuberculosis with opposite epidemiological fitness
Tuberculosis (TB) is an infectious disease, caused by Mycobacterium tuberculosis, primarily affecting the lungs. The M. tuberculosis strain of the Haarlem family named M was responsible for a large multidrug-resistant TB (MDR-TB) outbreak in Buenos Aires. This outbreak started in the early 1990s and in the mid 2000s still accounted for 29% of all MDR-TB cases in Argentina. By contrast, a clonal variant of strain M, named 410, has caused a single tuberculosis case since the onset of the outbreak. The molecular bases of the high epidemiological fitness of the M strain remain unclear. To assess its unique molecular properties, herein, we performed a comparative protein and lipid analysis of a representative clone of the M strain (Mp) and the nonprosperous M variant 410. We also evaluated their growth in low pH. The variant 410 had higher levels of latency proteins under standard conditions and delayed growth at low pH, suggesting that it is more sensitive to stress stimuli than Mp. Moreover, Mp showed higher levels of mycolic acids covalently attached to the cell wall and lower accumulation of free mycolic acids in the outer layer than the 410 strain. The low expression of latency proteins together with the reduced content of surface mycolic acids may facilitate Mp to evade the host immune responses.Fil: Bei, Jinlong. Guangdong Academy of Agricultural Sciences; ChinaFil: Bigi, MarÃa Mercedes. Universidad de Buenos Aires. Facultad de AgronomÃa; ArgentinaFil: Lima, AnalÃa. Instituto Pasteur de Montevideo; UruguayFil: Zhang, Qi. Guangdong Academy of Agricultural Sciences; ChinaFil: Blanco, Federico Carlos. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de BiotecnologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Lopez, Beatriz. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Yu, Ting. Guangdong Academy of Agricultural Sciences; ChinaFil: Wang, Zhilin. Guangdong Academy of Agricultural Sciences; ChinaFil: Dai, Zhangyan. Guangdong Academy of Agricultural Sciences; ChinaFil: Chen, Zhuang. Guangdong Academy of Agricultural Sciences; ChinaFil: Cataldi, Angel Adrian. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de BiotecnologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Sasiain, MarÃa del Carmen. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Ritacco, Gloria Viviana. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: de la Barrera, Silvia Susana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Soria, Marcelo Abel. Universidad de Buenos Aires. Facultad de AgronomÃa. Departamento de BiologÃa Aplicada y Alimentos. Cátedra de MicrobiologÃa AgrÃcola; ArgentinaFil: Durán, Rosario. Instituto Pasteur de Montevideo; UruguayFil: Bigi, Fabiana. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de BiotecnologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Experimental observation of topological Fermi arcs in type-II Weyl semimetal MoTe2
Weyl semimetal is a new quantum state of matter [1-12] hosting the condensed
matter physics counterpart of relativisticWeyl fermion [13] originally
introduced in high energy physics. The Weyl semimetal realized in the TaAs
class features multiple Fermi arcs arising from topological surface states [10,
11, 14-16] and exhibits novel quantum phenomena, e.g., chiral anomaly induced
negative mag-netoresistance [17-19] and possibly emergent supersymmetry [20].
Recently it was proposed theoretically that a new type (type-II) of Weyl
fermion [21], which does not have counterpart in high energy physics due to the
breaking of Lorentz invariance, can emerge as topologically-protected touching
between electron and hole pockets. Here, we report direct spectroscopic
evidence of topological Fermi arcs in the predicted type-II Weyl semimetal
MoTe2 [22-24]. The topological surface states are confirmed by directly
observing the surface states using bulk-and surface-sensitive angle-resolved
photoemission spectroscopy (ARPES), and the quasi-particle interference (QPI)
pattern between the two putative Fermi arcs in scanning tunneling microscopy
(STM). Our work establishes MoTe2 as the first experimental realization of
type-II Weyl semimetal, and opens up new opportunities for probing novel
phenomena such as exotic magneto-transport [21] in type-II Weyl semimetals.Comment: submitted on 01/29/2016. Nature Physics, in press. Spectroscopic
evidence of the Fermi arcs from two complementary surface sensitive probes -
ARPES and STS. A comparison of the calculated band structure for T_d and 1T'
phase to identify the topological Fermi arcs in the T_d phase is also
included in the supplementary informatio
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