318 research outputs found
Role of exosomes in hepatocellular carcinoma and the regulation of traditional Chinese medicine
Hepatocellular carcinoma (HCC) usually occurs on the basis of chronic liver inflammatory diseases and cirrhosis. The liver microenvironment plays a vital role in the tumor initiation and progression. Exosomes, which are nanometer-sized membrane vesicles are secreted by a number of cell types. Exosomes carry multiple proteins, DNAs and various forms of RNA, and are mediators of cell-cell communication and regulate the tumor microenvironment. In the recent decade, many studies have demonstrated that exosomes are involved in the communication between HCC cells and the stromal cells, including endothelial cells, macrophages, hepatic stellate cells and the immune cells, and serve as a regulator in the tumor proliferation and metastasis, immune evasion and immunotherapy. In addition, exosomes can also be used for the diagnosis and treatment HCC. They can potentially serve as specific biomarkers for early diagnosis and drug delivery vehicles of HCC. Chinese herbal medicine, which is widely used in the prevention and treatment of HCC in China, may regulate the release of exosomes and exosomes-mediated intercellular communication. In this review, we summarized the latest progresses on the role of the exosomes in the initiation, progression and treatment of HCC and the potential value of Traditional Chinese medicine in exosomes-mediated biological behaviors of HCC
Stimulation of Escherichia coli DNA damage inducible DNA helicase DinG by the single-stranded DNA binding protein SSB
Escherichia coli DNA damage inducible protein DinG is a superfamily II DNA helicase and is closely related to human DNA helicase XPD. Here, we report that E. coli single-stranded DNA binding protein (SSB) is able to form a stable protein complex with DinG and to stimulate the DinG DNA helicase activity. An SSB mutant that retains the single-stranded DNA binding activity but fails to form a protein complex with DinG becomes a potent inhibitor for the DinG DNA helicase, suggesting that E. coli wild-type SSB stimulates the DinG DNA helicase via specific protein-protein interaction. Structured summary of protein interactions: SSB and SSB bind by molecular sieving (View interaction) DinG and SSB bind by molecular sieving (View interaction) DinG and SSB bind by cosedimentation in solution (View interaction) © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved
Optimization of A Recirculation Flow Type Casing Treatment with Guide Vanes for Centrifugal Compressors
A wider operating range as well as higher performance are necessary for turbocharger compressors so as to meet demands of modern engines. Recirculation flow type casing treatment is one of the most effective devices that have been widely investigated. Recirculating flow type casing can extend the operating range of the compressor to the low flow rate region by sucking the reverse flow at shroud wall side at small flow rate condition. The advantages of the recirculation flow type casing treatment are well known as (1) a low energy fluid is sucked out from the down-let slot located near a throat of a rotating impeller (2) flow incidence is reduced because that recirculation flow merges with incoming main flow upstream of the impeller inlet. However, increase in friction loss and mixing loss resulted from the casing treatment can be considered as the disadvantages of the casing treatment. In the present study, an application of three-dimensional guide vane with 14 blades inside the casing treatment is presented to overcome the disadvantages of the casing treatment. And it shows improvement compared with the guide vanes with 7 blades. The shape of the guide vanes were optimized by using a surrogate model assisted optimization code. Numerical results showed that the optimized guide vanes hold a possibility to improve off-design performance by reducing the excessive pre-whirl at the compressor inlet.Date of Conference: 19-22 April 2019Conference Location: Beijing, Chin
Positive and unlabeled learning for user behavior analysis based on mobile internet traffic data
With the rapid development of wireless communication and mobile Internet, mobile phone becomes ubiquitous and functions as a versatile and smart system, on which people frequently interact with various mobile applications (Apps). Understanding human behaviors using mobile phone is significant for mobile system developers, for human-centered system optimization and better service provisioning. In this paper, we focus on mobile user behavior analysis and prediction based on mobile Internet traffic data. Real traffic flow data is collected from the public network of Internet Service Providers (ISPs), by high-performance network traffic monitors.We construct User-App bipartite network to represent the traffic interaction pattern between users and App servers. After mining the explicit and implicit features from User-App bipartite network, we propose two positive and unlabeled learning (PU learning) methods, including Spy-based PU learning and K-means-based PU learning, for App usage prediction and mobile video traffic identification. We firstly use the traffic flow data of QQ, a very famous messaging and social media application possessing high market share in China, as the experimental dataset for App usage prediction task. Then we use the traffic flow data from six popular Apps, including video intensive Apps (Youku, Baofeng, LeTV, Tudou) and other Apps (Meituan, Apple), as the experimental dataset for mobile video traffic identification task. Experimental results show that our proposed PU learning methods perform well in both tasks
Evaluation of Control/User-Plane Denial-of-Service (DoS) Attack on O-RAN Fronthaul Interface
The open fronthaul interface defined by O-RAN ALLIANCE aims to support the
interoperability between multi-vendor open radio access network (O-RAN) radio
units (O-RU) and O-RAN distributed units (O-DU). This paper introduces a new
tool that could be used to evaluate Denial-of-Service (DoS) attacks against the
open fronthaul interface. We launched an array of control/user planes
(C/U-Planes) attacks with the tool under different traffic types and data
rates, and we evaluated their impacts on the throughput and block error rate
(BLER) of real-world O-RAN systems with commercial hardware.Comment: Accepted by IEEE INFOCOM Workshop: Next-generation Open and
Programmable Radio Access Networks (NG-OPERA
A monopolar symmetrical hybrid cascaded DC/DC converter for HVDC interconnections
With the rapid development of voltage source converter (VSC) based high voltage direct current (HVDC) transmission, it is an irresistible trend that HVDC grid will come into being. High-voltage and high-power DC/DC converters will serve as DC transformers in HVDC grid to interconnect DC lines with different voltage ratings. This paper proposes a monopolar symmetrical DC/DC converter which is composed of cascaded half-bridge sub-modules (SMs) and series-connected IGBTs. This hybrid topology features low capital costs, high efficiency, small footprint, and bidirectional power transfer capability. Operation principle, parameter design, and the control strategies of this topology are introduced. A 480MW, ±500kV/±160kV monopolar symmetrical DC/DC converter is simulated to verify its performance and evaluate the efficiency. In addition, a downscaled prototype rated at 2.4kW, ±300V/±100V has been built and tested. Experimental results further validate the effectiveness of the proposed DC/DC converter
Metabolic crosstalk: molecular links between glycogen and lipid metabolism in obesity.
Glycogen and lipids are major storage forms of energy that are tightly regulated by hormones and metabolic signals. We demonstrate that feeding mice a high-fat diet (HFD) increases hepatic glycogen due to increased expression of the glycogenic scaffolding protein PTG/R5. PTG promoter activity was increased and glycogen levels were augmented in mice and cells after activation of the mechanistic target of rapamycin complex 1 (mTORC1) and its downstream target SREBP1. Deletion of the PTG gene in mice prevented HFD-induced hepatic glycogen accumulation. Of note, PTG deletion also blocked hepatic steatosis in HFD-fed mice and reduced the expression of numerous lipogenic genes. Additionally, PTG deletion reduced fasting glucose and insulin levels in obese mice while improving insulin sensitivity, a result of reduced hepatic glucose output. This metabolic crosstalk was due to decreased mTORC1 and SREBP activity in PTG knockout mice or knockdown cells, suggesting a positive feedback loop in which once accumulated, glycogen stimulates the mTORC1/SREBP1 pathway to shift energy storage to lipogenesis. Together, these data reveal a previously unappreciated broad role for glycogen in the control of energy homeostasis
Classical model emerges in quantum entanglement: Quantum Monte Carlo study for an Ising-Heisenberg bilayer
By developing a cluster sampling of stochastic series expansion quantum Monte
Carlo method, we investigate a spin- model on a bilayer square lattice
with intra-layer ferromagnetic (FM) Ising coupling and inter-layer
antiferromagnetic Heisenberg interaction. The continuous quantum phase
transition which occurs at between the FM Ising phase and the
dimerized phase is studied via large scale simulations. From the analyzes of
critical exponents we show that this phase transition belongs to the
(2+1)-dimensional Ising universality class. Besides, the quantum entanglement
is strong between the two layers, especially in dimerized phase. The effective
Hamiltonian of single layer seems like a transverse field Ising model. However,
we found the quantum entanglement Hamiltonian is a pure classical Ising model
without any quantum fluctuations. Furthermore, we give a more general
explanation about how a classical entanglement Hamiltonian emerges
Ginsenoside Rh1 Improves the Effect of Dexamethasone on Autoantibodies Production and Lymphoproliferation in MRL/lpr Mice
Ginsenoside Rh1 is able to upregulate glucocorticoid receptor (GR) level, suggesting Rh1 may improve glucocorticoid efficacy in hormone-dependent diseases. Therefore, we investigated whether Rh1 could enhance the effect of dexamethasone (Dex) in the treatment of MRL/lpr mice. MRL/lpr mice were treated with vehicle, Dex, Rh1, or Dex + Rh1 for 4 weeks. Dex significantly reduced the proteinuria and anti-dsDNA and anti-ANA autoantibodies. The levels of proteinuria and anti-dsDNA and anti-ANA autoantibodies were further decreased in Dex + Rh1 group. Dex, Rh1, or Dex + Rh1 did not alter the proportion of CD4+ splenic lymphocytes, whereas the proportion of CD8+ splenic lymphocytes was significantly increased in Dex and Dex + Rh1 groups. Dex + Rh1 significantly decreased the ratio of CD4+/CD8+ splenic lymphocytes compared with control. Con A-induced CD4+ splenic lymphocytes proliferation was increased in Dex-treated mice and was inhibited in Dex + Rh1-treated mice. Th1 cytokine IFN-γ mRNA was suppressed and Th2 cytokine IL-4 mRNA was increased by Dex. The effect of Dex on IFN-γ and IL-4 mRNA was enhanced by Rh1. In conclusion, our data suggest that Rh1 may enhance the effect of Dex in the treatment of MRL/lpr mice through regulating CD4+ T cells activation and Th1/Th2 balance
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