90 research outputs found

    Decoupled UL/DL User Association in Wireless-Powered HetNets with Full-Duplex Small Cells

    Get PDF
    In this paper, we propose two downlink (DL)-uplink (UL) decoupled (DUDe) user association schemes in wireless-powered full-duplex (FD) heterogeneous networks (HetNets). We consider a two-tier HetNet comprising of half-duplex (HD) massive multi-antenna macrocell base stations (MBSs) and dual-antenna FD small cell base stations (SBSs) to support UL and DL transmissions of FD user equipments (UEs). Each FD UE is first associated to one MBS/SBS, based on the mean maximum received power (MMP) scheme or maximum received power (MRP) to harvest energy. During the consecutive data transmission phase, UEs choose to receive DL traffic from the same MBSs/SBSs as that associated with during energy harvesting phase, and send UL traffic through the same/another SBS. Leveraging tools from the stochastic geometry, we develop an analytical framework to analyze the average harvested energy and derive expressions for the UL and DL coverage probabilities of the proposed DUDe user association schemes. Our results show that there is an optimal value for the SBS density in the wireless-powered FD HetNets, at which both DL and UL coverage probabilities are maximized. Moreover, by applying MMPA and MRPA scheme, wireless-powered FD HetNets with DUDe achieves up to 138.78%138.78\% and 83.37%83.37\% energy efficiency gain over the FD HetNets with DL/UL coupled user association scheme and without wireless power transfer, respectively

    Designing multi-period supply contracts in a two-echelon supply chain with asymmetric information

    Get PDF
    We study a two-echelon supply chain consisting of a supplier and a retailer, where the supplier uses a simple and easily implementable incentive scheme - making a side payment - to influence the retailer’s ordering plan. The supplier makes a take-it-or-leave-it offer to the retailer in the form of a menu of contracts, each consisting of a procurement plan plus a side payment. The retailer, who possesses private information about customer demand and his cost parameters, either accepts one of the contracts or imposes his own optimal plan. We formulate the supplier’s problem of designing optimal contracts with the realistic assumption that the retailer’s outside option depends on his private information. Taking into account the retailer’s reaction to the proposed offer, the supplier faces a nested (bi-level) optimization problem, which we transform into a single-level mixed integer programming formulation. In our analysis, we use a network interpretation for the set of incentive constraints and show some properties of optimal contracts. This enables us to considerably reduce the number of incentive constraints and to find optimal values of the side payment quantities. Our findings regarding the possible behavior of the opportunistic retailer deviate from those of previous studies as a result of considering more realistic assumptions

    Targeting of oncogenic signaling pathways by berberine for treatment of colorectal cancer

    Get PDF
    Studies indicate that inhibiting a single signaling pathway or one single product of a gene is insufficient for the prevention and treatment of cancer. This is due to the fact that dysregulation must occur in more than 500 genes in order to produce a cancerous phenotype. Despite this evidence, available drugs used for cancer treatment focus on a single target. Meanwhile, berberine as a nutraceutical is capable of targeting various processes involved in tumor development including proliferation, invasion, angiogenesis, and metastasis. In comparison with synthetic agents, berberine is cheaper, safer, and more available. Berberine has shown anti-inflammatory properties which make it an ideal option in order to prevent inflammation-associated cancers. Colorectal cancer is one of the most common cancers all over the world and its incidence is increasing each day. Therefore, further investigations about berberine could be helpful in the discovery of novel agents for preventing and/or treating colorectal cancer. This review emphasizes the studies investigating the roles of berberine in colorectal cancer such as controlling cell signaling pathways, inducing apoptosis, regulating microRNAs, attenuating oxidative stress, and affecting inflammation. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

    The effects of expression of different microRNAs on insulin secretion and diabetic nephropathy progression

    Get PDF
    MicroRNAs (miRNAs) have recently become well-known efficacious biomarkers for the diagnosis of diabetic nephropathy (DN). MiRNAs, short noncoding RNAs, are posttranscriptional regulators of gene expression, which regulate several biological cell functions, including insulin production and secretion, as well as insulin resistance in tissues. Today, the focus of the medical world is centered on the role of miRNAs as mediators for different diseases, such as DN and end-stage renal diseases (ESRD). MiRNAs are stable and detectable in human biological fluids, so their detection for early diagnosis of different diseases is highly sensitive and specific. Previous reports have shown that the alteration of miRNA profiles significantly correlates with specific stages of DN, kidney fibrosis, and renal dysfunction. This review was aimed at assessing the pathway of different miRNA expressions responsible for insulin secretion disorder and DN progression. © 2018 Wiley Periodicals, Inc

    Staphylococcus aureus enterotoxin b down-regulates the expression of transforming growth factor-beta (TGF-β) signaling transducers in human glioblastoma

    Get PDF
    Background: It has been revealed that Staphylococcus aureus enterotoxin B (SEB) may feature anti-cancer and anti-metastatic advantages due to its ability to modify cell immunity processes and signaling pathways. Glioblastoma is one of the most aggressive human cancers; it has a high mortality nature, which makes it an attractive area for the development of novel therapies. Objectives: We examined whether the SEB could exert its growth inhibitory effects on glioblastoma cells partially through the manipulation of a key tumor growth factor termed transforming growth factor-beta (TGF-β). Materials and Methods: A human primary glioblastoma cell line, U87, was treated with different concentrations of SEB. The cell quantity was measured by the MTT assay at different exposure times. For molecular assessments, total ribonucleic acid (RNA) was extracted from either non-treated or SEB-treated cells. Subsequently, the gene expression of TGF-β transducers, smad2/3, at the messenger RNA (mRNA) level, was analyzed via a quantitative real-time polymerase chain reaction (qPCR) using the SYBR Green method. Significant differences between cell viability and gene expression levels were determined (Prism 5.0 software) using a one-way analysis of variance (ANOVA) test. Results: We reported that SEB could effectively down-regulate smad2/3 expression in glioblastoma cells at concentrations as quantity as 1 µg/mL and 2 µg/mL (P < 0.05 and P < 0.01, respectively). The SEB concentrations effective at regulating smad2/3 expression were correlated with those used to inhibit the proliferation of glioblastoma cells. Our results also showed that SEB was able to decrease smad2/3 expression at the mRNA level in a concentration- and time-dependent manner. Conclusions: We suggested that SEB could represent an agent that can significantly decrease smad2/3 expression in glioblastoma cells, leading to moderate TGF-β growth signaling and the reduction of tumor cell proliferation. © 2016, Ahvaz Jundishapur University of Medical Sciences

    Electric-field-induced alignment of electrically neutral disk-like particles: modelling and calculation

    Get PDF
    This work reveals a torque from electric field to electrically neutral flakes that are suspended in a higher electrical conductive matrix. The torque tends to rotate the particles toward an orientation with its long axis parallel to the electric current flow. The alignment enables the anisotropic properties of tiny particles to integrate together and generate desirable macroscale anisotropic properties. The torque was obtained from thermodynamic calculation of electric current free energy at various microstructure configurations. It is significant even when the electrical potential gradient becomes as low as 100 v/m. The changes of electrical, electroplastic and thermal properties during particles alignment were discussed

    The effects of alpha-lipoic acid supplementation on inflammatory markers among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials

    Get PDF
    Objective: This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to determine the effect of alpha-lipoic acid (ALA) supplementation on the inflammatory markers among patients with metabolic syndrome (MetS) and related disorders. Methods: We searched the following databases until November 2017: PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. Three reviewers independently assessed study eligibility, extracted data, and evaluated risk of bias of included primary studies. Statistical heterogeneity was assessed using Cochran's Q test and I-square (I2) statistic. Data were pooled by using the random-effect model and standardized mean difference (SMD) was considered as the summary effect size. Results: Eighteen trials out of 912 potential citations were found to be eligible for our meta-analysis. The findings indicated that ALA supplementation significantly decreased C-reactive protein (CRP) (SMD = - 1.52; 95 CI, - 2.25, - 0.80; P &lt; 0.001), interlokin-6 (IL-6) (SMD = - 1.96; 95 CI, - 2.60, - 1.32; P &lt; 0.001), and tumor necrosis factor alpha levels (TNF-α) (SMD = - 2.62; 95 CI, - 3.70, - 1.55; P &lt; 0.001) in patients diagnosed with metabolic diseases. Conclusion: In summary, the current meta-analysis demonstrated the promising impact of ALA administration on decreasing inflammatory markers such as CRP, IL-6 and TNF-α among patients with MetS and related disorders. © 2018 The Author(s)

    Reduced Incidence of Slowly Progressive Heymann Nephritis in Rats Immunized With a Modified Vaccination Technique

    Get PDF
    A slowly progressive Heymann nephritis (SPHN) was induced in three groups of rats by weekly injections of a chemically modified renal tubular antigen in an aqueous medium. A control group of rats received the chemically unmodified version of the antigen in an aqueous solution. One group of SPHN rats were pre- and post-treated with weekly injections of IC made up of rKF3 and rarKF3 IgM antibody at antigen excess (MIC) (immune complexes [ICs] containing sonicated ultracentrifuged [u/c] rat kidney fraction 3 [rKF3] antigen and IgM antibodies specific against the antigen, at slight antigen excess). One group of SPHN rats were post-treated with MIC 3 weeks after the induction of the disease and one group of SPHN animals received no treatment. The control group of rats received pre- and post-treatment with sonicated u/c rKF3
    corecore