Resource allocation in OFDMA networks with half-duplex and imperfect full-duplex users

Recent studies indicate the feasibility of in-band fullduplex (FD) wireless communications, where a wireless radio transmits and receives simultaneously in the same band. Due to its potential to increase the capacity, analyzing the performance of a cellular network that contains full-duplex devices is crucial. In this paper, we consider maximizing the weighted sum-rate of downlink and uplink of a single cell OFDMA network which consists of an imperfect FD base-station (BS) and a mixture of half-duplex and imperfect full-duplex mobile users. To this end, the joint problem of sub-channel assignment and power allocation is investigated and a two-step solution is proposed. A heuristic algorithm to allocate each sub-channel to a pair of downlink and uplink users with polynomial complexity is presented. The power allocation problem is convexified based on the difference of two concave functions approach, for which an iterative solution is obtained. Simulation results demonstrate that when all the users and the BS are perfect FD nodes the network throughput could be doubled, Otherwise, the performance improvement is limited by the inter-node interference and the self-interference. We also investigate the effect of the self-interference cancellation capability and the percentage of FD users on the network performance in both indoor and outdoor scenarios.Comment: 6 pages, 8 figures, Accepted in IEEE International Conference on Communication (ICC), Malaysia, 201

Resource Allocation in Heterogenous Full-duplex OFDMA Networks: Design and Analysis

Recent studies indicate the feasibility of full-duplex (FD) bidirectional wireless communications. Due to its potential to increase the capacity, analyzing the performance of a cellular network that contains full-duplex devices is crucial. In this paper, we consider maximizing the weighted sum-rate of downlink and uplink of an FD heterogeneous OFDMA network where each cell consists of an imperfect FD base-station (BS) and a mixture of half-duplex and imperfect full-duplex mobile users. To this end, first, the joint problem of sub-channel assignment and power allocation for a single cell network is investigated. Then, the proposed algorithms are extended for solving the optimization problem for an FD heterogeneous network in which intra-cell and inter-cell interferences are taken into account. Simulation results demonstrate that in a single cell network, when all the users and the BSs are perfect FD nodes, the network throughput could be doubled. Otherwise, the performance improvement is limited by the inter-cell interference, inter-node interference, and self-interference. We also investigate the effect of the percentage of FD users on the network performance in both indoor and outdoor scenarios, and analyze the effect of the self-interference cancellation capability of the FD nodes on the network performance.Comment: arXiv admin note: text overlap with arXiv:1605.0194

Resource Allocation in Heterogenous Full-duplex OFDMA Networks: Design and Analysis

Recent studies indicate the feasibility of full-duplex (FD) bidirectional wireless communications. Due to its potential to increase the capacity, analyzing the performance of a cellular network that contains full-duplex devices is crucial. In this paper, we consider maximizing the weighted sum-rate of downlink and uplink of an FD heterogeneous OFDMA network where each cell consists of an imperfect FD base-station (BS) and a mixture of half-duplex and imperfect full-duplex mobile users. To this end, first, the joint problem of sub-channel assignment and power allocation for a single cell network is investigated. Then, the proposed algorithms are extended for solving the optimization problem for an FD heterogeneous network in which intra-cell and inter-cell interferences are taken into account. Simulation results demonstrate that in a single cell network, when all the users and the BSs are perfect FD nodes, the network throughput could be doubled. Otherwise, the performance improvement is limited by the inter-cell interference, inter-node interference, and self-interference. We also investigate the effect of the percentage of FD users on the network performance in both indoor and outdoor scenarios, and analyze the effect of the self-interference cancellation capability of the FD nodes on the network performance

DRUJ instability after distal radius fracture: A comparison between cases with and without ulnar styloid fracture

AbstractBackgroundBecause of the importance of the DRUJ in upper extremity function and the prevalence of distal radius fractures, either with or without ulnar styloid fracture, this study was designed to assess the relationship between ulnar styloid fracture and the incidence of DRUJ instability after treatment of distal radius fractures treated with ORIF (volar plate).Methods112 patients suffering from type two and three distal radius fractures (Fernandez classification), were evaluated. Depending on the presence of ulnar styloid avulsion fracture, patients were divided into two groups: 86 cases with isolated radial fracture and 26 cases with a distal radius fracture accompanied by ulnar styloid fracture. All patients underwent distal radius fracture ORIF. CT scanning was done both immediately after surgery and 3 months post-op. DRUJ stability was examined using the modified radioulnar line method and the incidence of DRUJ instability was compared between the two groups.ResultsImmediate instability was seen in 11 patients. Three of these patients had concomitant ulnar styloid fracture and were excluded for further fixation. Three months later, another 9 cases were diagnosed with DRUJ instability, 2 of whom had concomitant ulnar styloid fracture and the other 7 suffered from isolated distal radius fracture. Chi-square test revealed no significant difference (p < 0.05). There were no cases of delayed union or non-union distal radius fracture.ConclusionOur study demonstrated that untreated stable or minimally displaced ulnar styloid fracture accompanied by distal radius fracture, has no adverse effect on DRUJ stability following ORIF of the radius

Correction to: 1,25-Dihydroxyvitamin D3 modulates adipogenesis of human adipose-derived mesenchymal stem cells dose-dependently (Nutrition & Metabolism, (2021), 18, 1, (29), 10.1186/s12986-021-00561-4)

Following publication of the original article 1, the authors identified an error in the affiliation of Dr. Mehdi Hedayati. © 2021, The Author(s)

Molecular mechanisms of vitamin D plus Bisphenol A effects on adipogenesis in human adipose-derived mesenchymal stem cells

Background: Obesity is considered a major health concern and mounting evidence suggests that the exposure to environmental endocrine disruptors, including Bisphenol-A (BPA), may enhance the risk to develop the disease. Moreover, growing documents propose that the vitamin D may contribute to adipogenic signaling and lipid accumulation during adipocyte differentiation. We focused on the molecular mechanism of vitamin D and BPA in human adipose-derived mesenchymal stem cells (hADMSCs) which vitamin D and BPA may influence adipose tissue development and function. Methods: Human adipose-derived mesenchymal stem cells were cultured for 14 days in lipogenic differentiation media containing continuous concentrations of vitamin D plus BPA (0.1 nM or 10 nM). The expression of adipogenic markers including the peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding protein α (C/EBP α) CCAAT-enhancer-binding protein β (C/EBP β), fatty acid synthase (FASN), lipoprotein lipase (LPL), sterol regulatory element-binding protein-1c (SREBP1c), insulin-induced gene-2 (INSIG2), vitamin D receptor (VDR), estrogen receptor-beta (ER-β), fatty acid-binding protein-4 (FABP4), and glucose transporter-4 (GLUT4) was measured using Quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Lipid accumulation was visualized with staining with Oil Red O. Results: In the morphological assessment of mesenchymal stem cells treated with a concentration of 10 nM vitamin D plus BPA, more lipid accumulations were observed in comparison with the group with 0.1 nM concentration. Treatment of hADMSCs with vitamin D plus BPA (0.1 nM) significantly inhibited the induction of PPARγ, C/EBP β, C/EBP α, and FASN related to adipocyte differentiation and development. However, the exposure of cells to the concentration of 10 nM vitamin D plus BPA induced the expression of these genes associated to the adipogenesis. The remarkable increase in the level of SREBP1c was associated to the suppression of INSIG2 in treated preadipocytes with 10 nM vitamin D plus BPA. Our findings showed that the expression of VDR, ERβ, GLUT4, and FABP4 were upregulated through differentiation with the highest concentrations in 0.1 nM vitamin D plus BPA group for VDR, ERβ, and GLUT4. Conclusions: Vitamin D plus BPA at concentration of 10 nM boosted the adipogenesis during the critical stages of adipocytes development, whereas it seems to inhibit this process at concentration of 0.1 nM. © 2021, The Author(s)

Bisphenol A enhances adipogenic signaling pathways in human mesenchymal stem cells

Background: The endocrine disruptor Bisphenol-A (BPA), has been involved in dysregulating adipose tissue development and increasing the risk of obesity. The objective of this experiment was to investigate whether treatment of human mesenchymal stem cells with BPA could modulate adipogenesis and adipocyte differentiation. Methods: In this experimental study, the human adipose-derived mesenchymal stem cells (hASCs) were cultured for 2 weeks with continuous exposure to 10- 10 M or 10- 8 M concentrations of BPA. The extent of triglyceride accumulation was visualized by Oil Red O staining. To evaluate BPA effect on the expression levels of key adipogenic trascripotion factors and proteins, we used Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and ELISA. Results: The results presented a dose-dependent triglyceride accumulation in treated cells with BPA. Additionally, we observed that BPA induced transcription of the Peroxisome proliferator-activated receptor-gamma (PPARγ), CCAAT-enhancer-binding protein-alpha (C/EBPα), CCAAT-enhancer-binding protein-beta (C/EBPβ), sterol regulatory element-binding protein-1c (SREBP1c), Fatty acid synthase (FASN), and lipoprotein lipase (LPL); BPA suppressed the expression of Fatty acid binding protein-4 (FABP4) and Estrogen receptor-beta (ERβ). Conclusions: Our findings supported the hypothesis that BPA enhances adipogenic differentiation thereby may play a role in development of obesity and dysregulation of metabolic homoeostasis. © 2020 The Author(s)

1,25-Dihydroxyvitamin D3 modulates adipogenesis of human adipose-derived mesenchymal stem cells dose-dependently

Purpose: 1,25-dihydroxyvitamin D3 may regulate adipogenesis in adipocytes in-vitro, but little is known about possible molecular mechanisms related to the inhibitory effect of 1,25-dihydroxyvitamin D3 on adipogenesis in humans� adipose tissue. Methodology: In this study, human adipose-derived mesenchymal stem cells (hASCs) were cultured for 14 days in adipogenic differentiation media containing concentrations of 1,25-dihydroxyvitamin D3 (10�10�10�8 M). The extent of adipogenic differentiation in ASCs was assessed by Oil Red O staining and quantitative polymerase chain reaction (PCR) to determine expression levels of key adipogenic markers. Results: Our results showed that vitamin D receptor (VDR), as a mediator of most actions of 1,25-dihydroxyvitamin D3, glucose trasporter-4 (GLUT4),and fatty acid binding protein-4 (FABP4) was expressed in vitamin D-treated hASCs. However, the protein level of these markers was lower than the control group. Treatment of human preadipocytes with 1,25-dihydroxyvitamin D3 significantly altered expression of adipogenic markers and triglyceride accumulation in a dose-dependent manner. 1,25-dihydroxyvitamin D3 at concentration of 10�8 M enhanced expression of sterol regulatory element-binding protein-1c (SREBP1c), CCAAT-enhancer-binding protein-β (C/EBPβ), a mitotic clonal expansion, peroxisome proliferator-activated receptor-gamma (PPARγ), fatty acid synthase (FASN), a marker of de novo lipogenesis,and lipoprotein lipase (LPL). Conclusion: Our findings revealed that 1,25-dihydroxyvitamin D3 may provoke adipocyte development in critical periods of adipogenesis at concentration of 10�8 M, thereby leading to a greater risk of obesity in adulthood and an augmented risk of obesity-related diseases including diabetes, cardiovascular diseases, and some cancers. © 2021, The Author(s)

One-step versus two-step screening for diagnosis of gestational diabetes mellitus in Iranian population : A randomized community trial

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