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Low Earth Orbit (LEO) satellites play a crucial role in enhancing global connectivity, serving a complementary solution to existing terrestrial systems. In wireless networks, scheduling is a vital process that allocates time-frequency resources to users for interference management. However, LEO satellite networks face significant challenges in scheduling their links towards ground users due to the satellites’ mobility and overlapping coverage. This paper addresses the dynamic link scheduling problem in LEO satellite networks by considering spatio-temporal correlations introduced by the satellites’ movements. The first step in the proposed solution involves modeling the network over Riemannian manifolds, thanks to their representation as symmetric positive definite matrices. We introduce two machine learning (ML)-based link scheduling techniques that model the dynamic evolution of satellite positions and link conditions over time and space. To accurately predict satellite link states, we present a recurrent neural network (RNN) over Riemannian manifolds, which captures spatio-temporal characteristics over time. Furthermore, we introduce a separate model, the convolutional neural network (CNN) over Riemannian manifolds, which captures geometric relationships between satellites and users by extracting spatial features from the network topology across all links. Simulation results demonstrate that both RNN and CNN over Riemannian manifolds deliver comparable performance to the fractional programming-based link scheduling (FPLinQ) benchmark. Remarkably, unlike other ML-based models that require extensive training data, both models only need 30 training samples to achieve over 99% of the sum rate while maintaining similar computational complexity relative to the benchmark.

Abstract Cell adhesion to the extracellular matrix and its natural outcome of cell spreading, along with the maintenance of barrier activity, are essential behaviors of epithelial cells, including retinal pigment epithelium (RPE). Disruptions in these characteristics can result in severe vision-threatening diseases such as diabetic macular edema and age-related macular degeneration. However, the precise mechanisms underlying how RPE cells regulate their barrier integrity and cell spreading are not fully understood. This study aims to elucidate the relative importance of upper glycolytic components in governing these cellular behaviors of RPE cells. Electric Cell-Substrate Impedance Sensing (ECIS) technology was utilized to assess in real-time the effects of targeting various upper glycolytic enzymes on RPE barrier function and cell spreading by measuring cell resistance and capacitance, respectively. Specific inhibitors used included WZB117 for Glut1 inhibition, Lonidamine for Hexokinase inhibition, PFK158 for PFKFB3/PFK axis inhibition, and TDZD-8 for Aldolase inhibition. Additionally, the viability of RPE cells was evaluated using a lactate dehydrogenase (LDH) cytotoxicity assay. The most significant decrease in electrical resistance and increase in capacitance of RPE cells were observed due to dose-dependent inhibition of Glut1 using WZB117, as well as Aldolase inhibition with TDZD-8. LDH level analysis at 24–72 h post-treatment with WZB117 (1 and 10 μM) or TDZD-8 (1 μM) showed no significant difference compared to the control, indicating that the disruption of RPE functionality was not attributed to cell death. Lastly, inhibition of other upper glycolytic components, including PFKFB3/PFK with PFK158 or Hexokinase with Lonidamine, did not significantly affect RPE cell behavior. This study provides insights into the varied roles of upper glycolytic components in regulating the functionality of RPE cells. Specifically, it highlights the critical roles of Glut1 and Aldolase in preserving barrier integrity and promoting RPE cell adhesion and spreading. Such understanding will guide the development of safe interventions to treat RPE cell dysfunction in various retinal disorders.

Abstract Background Cardiovascular magnetic resonance-feature tracking (CMR-FT) is a novel quantitative objective noninvasive technique in the assessment of myocardial deformation. The purpose of that study was to assess the capability of the CMR-FT in the detection of myocardial ischemia and viability. We investigated 30 patients (n = 480 myocardial segments), with known or suspected coronary artery disease (CAD). Dobutamine stress cardiovascular magnetic resonance (DS-CMR) and late gadolinium enhancement (LGE) were used to identify the viable non-ischemic, ischemic, and non-viable myocardial segments. Cine images at rest were used to calculate the segmental radial (Err), circumferential (Ecc), and longitudinal (Ell) strain parameters by manual contouring of endocardial and epicardial borders using Segment Software. Results Of the 480 myocardial segments and based on the DS-CMR and LGE results, 338 segments were defined as viable non-ischemic (remote), 101 segments were viable ischemic, and 41 segments were non-viable. Rest segmental Ecc, Err, and Ell values were significantly impaired in the non-viable (mean ± SD = − 3.94 ± 4.99%, 11.81 ± 12.55%, and − 7.50 ± 6.96%, respectively) compared to both viable groups, p

Abstract In the sugar industry, eliminating side impurities throughout the manufacturing process is the most significant obstacle to clarifying sugar solutions. Herein, magnetic chitosan (MCS) nanocomposite was Fabricated to be used as a biodegradable, environmentally friendly clarifying agent throughout the cane juice and sugar refining processes. Fe3O4 was synthesized using the coprecipitation procedure, and then MCS was combined using a cross-linking agent. Furthermore, 14.76 emu g−1 was the maximum saturation magnetization (Ms) value. Because MCS is magnetically saturated, it may be possible to employ an external magnetic field to separate the contaminant deposited on its surface. Additionally, zeta potential analysis showed outstanding findings for MCS with a maximum value of (+) 20.7 mV, with improvement in color removal % up to 44.8% using MCS with more than 24% in color removal % compared to the traditional clarification process. Moreover, utilizing MCS reduced turbidity from 167 to 1 IU. Overall, we determined that MCS nanocomposite exhibits considerable effectiveness in the clarifying process for different sugar solutions, performing as an eco-friendly bio-sorbent and flocculating material.

Vehicle-to-infrastructure (V2I) communication facilitates seamless interaction between vehicles and the surrounding infrastructure. Recently, there has been a notable surge in research interest in ambient backscatter communications (AmBC), primarily due to its ability to enable battery-free communication. Concurrently, reconfigurable intelligent surfaces (RISs) have garnered attention as a promising technology, particularly for the advancement of cellular systems beyond 5G. Additionally, non-orthogonal multiple access (NOMA) assumes a pivotal role in enhancing spectrum utilization. This paper proposes a new RIS-enhanced NOMA-AmBC system where all channels are characterized by Nakagami-m fading and with the main objective of assessing the performance of such system. To this end, new closed-form expressions for the outage probabilities (OPs) were derived under the practical assumption of imperfect successive interference cancellation (SIC). In addition, to gain a deep insight into the system’s performance, we derived asymptotic, upper-bound, and lower-bound expressions for the OPs. Furthermore, we proposed a power allocation optimization problem to achieve an outage-optimal performance. To validate the analytical results, we conducted extensive investigations using Monte Carlo simulations, which indicates a high degree of consistency. Moreover, our results underscore the remarkable performance improvements achieved by the RIS-assisted AmBC-NOMA system when compared to both the traditional benchmark AmBC-NOMA system and the RIS-assisted orthogonal multiple access (AmBCOMA) counterparts.

This paper addresses the unexplored challenge of achieving secure communication in a full-duplex (FD) cognitive radio (CR) system employing a reconfigurable intelligent surface (RIS) where a passive eavesdropper (Eve) is equipped with multiple antennas. The secondary base station (SBS), operating in full-duplex mode, serves as an uplink (UL) communication provider for secondary users (SUs) while actively launching a jamming signal against Eve to degrade its downlink (DL) interception capability, thus aiding the primary network. This study faces several technical challenges. First, complex interference management arises as the FD-SBS must manage interference between UL communications and active jamming signals to ensure both secure communication and minimal interference to legitimate users. Additionally, optimizing multi-dimensional beamforming across the primary base station (PBS) DL, the FD-SBS jamming, the passive RIS, and the UL communication power imposes substantial complexities due to conflicting objectives and constraints. To this end, we propose a coordinated beamforming approach, which maximizes the minimum secrecy rate with a minimum target rate for the UL SUs, a maximum DL PBS transmission power, jamming power limits and RIS unit modulus constraints. To address the problem non-convexity, it is decomposed into four sub-problems, which are solved via employing semidefinite programming (SDP) and successive convex approximation (SCA) based alternating optimization. Simulation results show the effectiveness of RIS phase shift optimization to enhance secrecy performance, how much jamming power is needed to keep balance between the secrecy performance and the UL communication service, as well as the effectiveness of the proposed solution against various benchmarks.

Diabetic retinopathy (DR) is a salient cause of blindness worldwide. There is still an immense need to understand the pathophysiology of DR to discover better diagnostic and therapeutic modalities. Human retinal endothelial cells (HRECs) were treated with 15-HETE or D-glucose, then miRNAs were isolated, and a microarray was performed. MirWALK 2 and Ingenuity Pathway Analysis (IPA) were used to analyze the microarray results. Exosomal miRNAs from 15-HETE-treated HRECs were isolated, microarrayed, and then imported into IPA for further analysis. The microarray results showed that 15-HETE downregulated 343 miRNAs and upregulated 297 miRNAs in HRECs. High glucose treatment induced a differential expression of HREC-miRNAs where 185 miRNAs were downregulated and 244 were upregulated. Comparing the impact of 15-HETE versus DG or diabetic mouse retina elaborated commonly changing miRNAs. Pathway and target analysis for miRNAs changed in 15-HETE-treated HRECs revealed multiple targets and pathways that may be involved in 15-HETE-induced retinal endothelial dysfunction. The HREC-exosomal miRNAs were differentially expressed after 15-HETE treatment, with 34 miRNAs downregulated and 45 miRNAs upregulated, impacting different cellular pathways. Here, we show that 15-HETE induces various changes in the cellular and exosomal miRNA profile of HRECs, highlighting the importance of targeting the 12/15 lipoxygenase pathway in DR.

Abstract Proliferative diabetic retinopathy (PDR) remains a leading cause of blindness despite progress in screening and treatment. Recently, the Warburg effect, a metabolic alteration affecting amino acid (AA) metabolism in proliferating cells, has drawn attention regarding its role in PDR. This study aimed to investigate the impact of the Warburg effect on AA metabolism in human retinal endothelial cells (HRECs) subjected to PDR-associated risk factors and validate the findings in patients with PDR. In vitro experiments exposed HRECs to high glucose (HG) and/or hypoxia (Hyp), known inducers of the Warburg effect. The HG + Hyp group of HRECs exhibited significant differences in non-essential AAs with aliphatic non-polar side chains, mainly driven by elevated glycine concentrations. Pathway enrichment analysis revealed several glycine metabolism-related pathways significantly altered due to the Warburg effect induced by HG + Hyp. Crucially, vitreous humor samples from PDR patients displayed higher glycine levels compared to non-diabetic and diabetic patients without PDR. The odds ratio for PDR patients with glycine levels above the cut-off of 0.0836 µM was 28 (p = 0.03) compared to non-PDR controls. In conclusion, this study provides mechanistic insights into how a specific Warburg effect subtype contributes to glycine accumulation in PDR and supports glycine's potential as a biomarker for PDR pathogenesis.

Intelligent reflecting surfaces (IRS) are considered one of the prominent technologies to be adopted in 6G and beyond networks. However, one of the main IRS limitations is restricting the communication to the reflective dimension, which means that users located behind the IRS surface cannot benefit from it. In this paper, we make use of intelligent omni-surfaces (IOS), as an alternative to IRS, in addition to unmanned aerial vehicles (UAV) to achieve secure communication in an Internet-of-Things (IoT) communication system. Specifically, we propose IOS-UAV assisted communication wherein an access point (AP) tries to send confidential information to a legitimate IoT device in presence of an eavesdropper. The UAV serves two fold; it acts as a friendly jammer that is trying to degrade the signal quality at the eavesdropper and as a source of energy to power up the IoT device via simultaneous wireless information and power transfer (SWIPT) to address the limited power available to it. We formulate an average secrecy rate maximization problem, which jointly optimizes the AP and UAV transmission powers, the UAV trajectory, IOS phase shifts and power splitting factor. The formulated problem is non-convex, therefore we exploit successive convex approximation (SCA) to tackle this issue. Simulation results show that the iterative SCA solution converges rapidly. Besides, the proposed scheme outperforms the traditional system without IOS by a gap of 140% in terms of the secrecy capacity.

Acquiring accurate instantaneous channel state information (CSI) is a challenging aspect of massive multi-input multi-output (MIMO) communication. Utilizing statistical information, such as channel covariance matrix, to design statistical beamforming vectors is robust when compared to instantaneous CSI. In this paper, we propose a novel MIMO covariance shaping scheme over Riemannian manifolds. It serves as an effective statistical beamforming solution to a number of close proximity user equipment (UE) that are undergoing substantial channel correlation. Proposed algorithm exploits the Hermitian positive definite nature of covariance matrices lying over Riemannian manifold. We introduce Wasserstein distance function as a Riemannian metric to measure distances between channel covariance matrices. Furthermore, K-means clustering technique is utilized to effectively identify the optimal shape of effective optimal covariance matrices. Our findings suggest that maximizing the geodesic distance between covariance matrices ultimately leads to a corresponding increase in the network throughput, as determined by the beamforming vector used to shape the covariance matrices. Simulation results validate that the proposed solution converges faster than Euclidean-based state-of-the-art, while maintaining the same computational complexity. Finally, the sum rate performance asymptotically achieves full capacity for two-UE case and more than 96% of the upper bound exhaustive search benchmark for multi-UE scenario.

Abstract An intact epithelium is key to maintaining corneal integrity and barrier function which can lead to impaired ocular defense and sight-threatening opacity when compromised. Electrical cell-substrate impedance sensing or ECIS is a non-invasive method to measure real-time cellular behaviors including barrier function and cell migration. The current study uses ECIS technology to assess and optimize human telomerase-immortalized corneal epithelial cells to generate quantifiable measurements that accurately reflect changes in cell behavior in vitro. Five cell densities were assessed in two different media to determine the optimal conditions for monitoring of cellular behavior over time. Parameters of evaluation included: overall impedance (Z), barrier resistance (R), cell capacitance (C), and mathematical modeling of the R data to further generate Rb (the electrical resistance between HUCLs), α (the resistance between the HUCLs and the substrate), and Cm (the capacitance of the cell membrane) measurements. All parameters of assessment strongly indicated DMEM/F12 at 60,000 cells as the optimal condition for ECIS assessment of HUCLs. Furthermore, this work highlights the ability of the sensitive ECIS biosensor technology to comprehensively and quantitatively assess corneal epithelial cell structure and function and the importance of optimizing not only cell density, but choice of media used for in vitro culturing.

In this paper, we propose two novel geometric machine learning (G-ML) methods for the wireless link scheduling problem in device-to-device (D2D) networks. In dynamic D2D networks (e.g., vehicular networks), obtaining a large number of training samples is time-consuming for real-time response, and acquiring accurate instantaneous channel state information (CSI) is challenging due to high mobility. Our goal is to efficiently represent D2D networks on Riemannian manifold and use G-ML with few training wireless network layouts and no CSI to approach the sum rate maximization performance as state-of-the-arts which is much needed in dynamic networks. To this aim, we first model the local graph around each D2D pair as a point through a set of regularized Laplacian matrices on the Riemannian manifold. We compute the Riemannian metric, e.g., Log-Euclidean metric (LEM), among D2D pairs, which are suitable measures of interference among these pairs. We use LEM in the geometric support vector machine (G-SVM) method to classify the link scheduling decisions in a supervised learning manner. Then we propose geometric $k$ -means clustering for unsupervised scheduling method for the case when no labeled training is available in some dynamic networks. Simulation results demonstrate that the proposed methods achieve promising performance for sum rate maximization against the existing state-of-the-arts approaches with only around a hundred training wireless network layouts for training and without using CSI.

Drones are imperative for the 5G architecture as a mobile source to expand network coverage and support seamless services, particularly through enabling device-to-device (D2D) communication. Such deployment of drones in D2D settings raises various security threats in drone communication. While the existing D2D communication security standard within the 4G cellular architecture may address some of these issues, the standard includes heavy traffic toward the network core servers. If this security standard is to be adopted in the 5G D2D security services with the same traffic load, it may negatively impact the 5G network performance. Therefore, this paper proposes a lightweight proxy signature-based authentication mechanism for a swarm of drones compatible with the 5G D2D standard mechanisms. This paper proposes a distributed delegation-based authentication mechanism to reduce the traffic overhead toward the 5G core network. In this scheme, the legitimate drones are authorized as proxy delegated signers to perform authentication on behalf of the core network. Furthermore, we propose a mechanism to elect and relocate a new leader relay drone from the existing drone swarm. We implemented the proposed authentication algorithm in the 5G D2D-based communication package over NS-3 while performing the computational calculations on a RaspberryPi3 device to mimic the drone calculation process and delays. The performance of the proposed authentication shows a promising reduction in the authentication time and shows lightweight and reliable compatibility.

Covariance matrices of spatially-correlated wireless channels in millimeter wave (mmWave) vehicular networks can be employed to design environment-aware beamforming codebooks. Such covariance matrices can be represented over non-Euclidean (i.e., curved surfaces) manifolds, thanks to their symmetric positive definite (SPD) structures. In this paper, we propose three learning models for channel covariance estimation over Riemannian manifolds. First, we propose an unsupervised Riemannian K-means clustering approach, where Log-Euclidean metric (LEM) is utilized as a distance metric among channel covariance matrices over the Riemannian manifold. Second, we propose a Riemannian Competitive Learning (RCL) model, which is an online clustering solution that is intended to reduce the learning time of the offline K-means models. Third, we apply a Riemannian Dictionary Learning (RDL) model that leverages the sparsity properties of mmWave channels, while estimating their channel covariance matrices. Simulation results show that the proposed Riemannian K-means, online RCL and RDL models can achieve 41%, 30% and 44% higher data rate, respectively, than their Euclidean-based counterparts. Furthermore, they require few training samples and hence fast construction of codebook design in dynamic environments, which leads to low latency communication.

Despite the prevalence of diabetic retinopathy, the majority of adult diabetic patients develop visually debilitating corneal complications, including impaired wound healing. Unfortunately, there is limited treatment for diabetes-induced corneal damage. The current project investigates a novel, peptide-based combination therapy, thymosin beta-4 and vasoactive intestinal peptide (Tβ4/VIP), against high-glucose-induced damage to the corneal epithelium. Electric cell–substrate impedance sensing (ECIS) was used for real-time monitoring of barrier function and wound healing of human corneal epithelial cells maintained in either normal glucose (5 mM) or high glucose (25 mM) ± Tβ4 (0.1%) and VIP (5 nM). Barrier integrity was assessed by resistance, impedance, and capacitance measurements. For the wound healing assay, cell migration was also monitored. Corneal epithelial tight junction proteins (ZO-1, ZO-2, occludin, and claudin-1) were assessed to confirm our findings. Barrier integrity and wound healing were significantly impaired under high-glucose conditions. However, barrier function and cell migration significantly improved with Tβ4/VIP treatment. These findings were supported by high-glucose-induced downregulation of tight junction proteins that were effectively maintained similar to normal levels when treated with Tβ4/VIP. These results strongly support the premise that Tβ4 and VIP work synergistically to protect corneal epithelial cells against hyperglycemia-induced damage. In addition, this work highlights the potential for significant translational impact regarding the treatment of diabetic patients and associated complications of the cornea.

Abstract Background Thalassemia is the most prevalent single-gene disorder. Myocardial and hepatic iron depositions lead to complications and eventually death. We aimed to assess the diagnostic efficacy of magnetic resonance imaging T2* (MRI T2*) in quantifying iron overload in liver and heart in transfusion-dependent B-thalassemia major (TDT) children. Methods Prospective clinical study was carried on sixty children diagnosed with TDT. All of them underwent laboratory investigations, including CBC, serum iron, and ferritin levels. MRI T2* of the heart and liver was carried out to measure the iron overload and estimate the left ventricular ejection fraction (LVEF). Results Thirty-eight males and 22 females with TDT with a mean age of 13.23 years were included. Twenty cases (33.3%) had severe liver iron overload, while 36 (60%) had normal cardiac iron. There was a moderate significant negative association between hepatic and cardiac iron deposition (P = 0.03). All cases with severe cardiac iron overload had impaired LVEF below 56%. A non-significant positive association was noticed between cardiac iron deposition and LVEF in T2* (P = 0.08). A moderate negative significant association was detected between hepatic iron deposition and serum ferritin, while a fair negative significant association was found between serum ferritin and cardiac iron deposition with P values of 0.04 and 0.02, respectively. Conclusion MRI T2* is the gold standard for monitoring and follow-up of iron overload in the heart and liver. It should be routinely performed in all TDT children as liver iron, and serum ferritin do not reflect cardiac iron overload.

Objective: The mitochondrial nicotinamide adenine dinucleotide (NAD) kinase (MNADK) mediates de novo mitochondrial NADP biosynthesis by catalyzing the phosphorylation of NAD to yield NADP. In this study, we investigated the function and mechanistic basis by which MNADK regulates metabolic homeostasis. Methods: Generalized gene set analysis by aggregating human patient genomic databases, metabolic studies with genetically engineered animal models, mitochondrial bioenergetic analysis, as well as gain- and loss- of-function studies were performed to address the functions and mechanistic basis by which MNADK regulates energy metabolism and redox state associated with metabolic disease. Results: Human MNADK common gene variants or decreased expression of the gene are significantly associated with the occurrence of type-2 diabetes, non-alcoholic fatty liver disease (NAFLD), or hepatocellular carcinoma (HCC). Ablation of the MNADK gene in mice led to decreased fat oxidation, coincident with increased respiratory exchange ratio (RER) and decreased energy expenditure upon energy demand triggered by endurance exercise or fasting. On an atherogenic high-fat diet (HFD), MNADK-null mice exhibited hepatic insulin resistance and glucose intolerance, indicating a type-2 diabetes-like phenotype in the absence of MNADK. MNADK deficiency led to a decrease in mitochondrial NADP(H) but an increase in cellular reactive oxygen species (ROS) in mouse livers. Consistently, protein levels of the major metabolic regulators or enzymes were decreased, while their acetylation modifications were increased in the livers of MNADK-null mice. Feeding mice with a HFD caused S-nitrosylation (SNO) modification, a posttranslational modification that represses protein activities, on MNADK protein in the liver. Reconstitution of an SNO-resistant MNADK variant, MNADK-S193, into MNADK-null mice mitigated hepatic steatosis induced by HFD. Conclusion: MNADK, the only known mammalian mitochondrial NAD kinase, plays important roles in preserving energy homeostasis to mitigate the risk of metabolic disorders.

Spectrum sharing between different technologies has become a necessity as the RF spectrum has become more congested than ever due to the increasing number of connected devices and applications all wishing to access the spectrum simultaneously. Vehicular networks are one of many scenarios of spectrum sharing as vehicles are expected to share the same spectrum for radar sensing and communication purposes. Channel assignment among radar sensors and communication transceivers in automotive systems is crucial for the success of future vehicular networks. This paper proposes an optimization framework for the channel assignment to multiple automotive radars and communication transceivers aiming at maximizing the number of served vehicles under hard quality of service requirements. The channel assignment problem is formulated as an integer linear optimization with binary variables. A heuristic solution that is based on ordered sequential channel assignment (OSCA) is proposed and is shown to achieve at least 92% of the solution obtained from branch-and-cut based techniques with much less computational complexity and run-time; at most 2% of the run-time of branch-and-cut.

Abstract Background The use of natural products is an essential way to new pharmaceutical leads for the discovery and development of new drugs to treat diseases. Propolis (Pro) is a natural resinous product produced by honey bees. It has a strong cytoprotective effect against various exogenous toxic agents. The current study was designed to evaluate the possible protective effect of propolis against the toxicity of aluminum chloride (AlCl3) on hepatorenal structure and function in male white albino rats. Methods Thirty mature males of albino rat, Rattus rattus, weighing about 80-90g were divided into five groups contained 6 rats each. The first group acts as a control (received only saline solution); the second group (Al) had given orally 40 mg/kg b.w. of AlC13, the third group (Pro) had administrated orally 150 mg/kg b.w. of propolis and the fourth group (Al+Pro) had given 40 mg/kg b.w. of AlCl3 in the morning and 150 mg/kg b.w. of propolis in the evening. These four groups had given the treatments for two months. The fifth group (Al-Pro) had given 40 mg/kg b.w. of AlC13 chloride for one month then had given 40 mg/kg b.w. of AlCl3 combined with 150 mg/kg b.w. of propolis for another month. Results The AlCl3-treated group showed a significant increase in the activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), acid phosphatase (AP), and lactate dehydrogenase (LDH) in the plasma. Also, glucose, total protein, albumin, creatinine, uric acid, urea, cholesterol, and triglycerides in the plasma were significantly increased. The histological examination for the liver and kidney sections revealed marked histopathological alternations. The treatment with propolis combined with AlCl3 improved the previous mentioned biochemical and histological alterations induced by AlCl3. Conclusion It can be concluded that the combination of propolis with AlCl3 alleviated the toxic effects of AlCl3. The propolis has protective influences on the hepatorenal structure and function and could be able to resist AlCl3 intoxication.

Bone Morphogenetic Protein 4 (BMP4) is a secreted growth factor of the Transforming Growth Factor beta (TGFβ) superfamily. The goal of this study was to test whether BMP4 contributes to the pathogenesis of diabetic retinopathy (DR). Immunofluorescence of BMP4 and the vascular marker isolectin-B4 was conducted on retinal sections of diabetic and non-diabetic human and experimental mice. We used Akita mice as a model for type-1 diabetes. Proteins were extracted from the retina of postmortem human eyes and 6-month diabetic Akita mice and age-matched control. BMP4 levels were measured by Western blot (WB). Human retinal endothelial cells (HRECs) were used as an in vitro model. HRECs were treated with BMP4 (50 ng/mL) for 48 h. The levels of phospho-smad 1/5/9 and phospho-p38 were measured by WB. BMP4-treated and control HRECs were also immunostained with anti-Zo-1. We also used electric cell-substrate impedance sensing (ECIS) to calculate the transcellular electrical resistance (TER) under BMP4 treatment in the presence and absence of noggin (200 ng/mL), LDN193189 (200 nM), LDN212854 (200 nM) or inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2; SU5416, 10 μM), p38 (SB202190, 10 μM), ERK (U0126, 10 μM) and ER stress (Phenylbutyric acid or PBA, 30 μmol/L). The impact of BMP4 on matrix metalloproteinases (MMP2 and MMP9) was also evaluated using specific ELISA kits. Immunofluorescence of human and mouse eyes showed increased BMP4 immunoreactivity, mainly localized in the retinal vessels of diabetic humans and mice compared to the control. Western blots of retinal proteins showed a significant increase in BMP4 expression in diabetic humans and mice compared to the control groups (p < 0.05). HRECs treated with BMP4 showed a marked increase in phospho-smad 1/5/9 (p = 0.039) and phospho-p38 (p = 0.013). Immunofluorescence of Zo-1 showed that BMP4-treated cells exhibited significant barrier disruption. ECIS also showed a marked decrease in TER of HRECs by BMP4 treatment compared to vehicle-treated HRECs (p < 0.001). Noggin, LDN193189, LDN212854, and inhibitors of p38 and VEGFR2 significantly mitigated the effects of BMP4 on the TER of HRECs. Our finding provides important insights regarding the role of BMP4 as a potential player in retinal endothelial cell dysfunction in diabetic retinopathy and could be a novel target to preserve the blood–retinal barrier during diabetes.

The maritime land–sea communication channel experiences multipath shadowing and fading due to ships, onshore and offshore structures, and reflections from the sea surface. When using low altitude antennas, the sea surface itself can block the propagation of radio waves when the first Fresnel zone is obstructed. The latter can occur within a few kilometres of the transmitter at microwave frequencies. Sea reflections are stronger than ground reflections due to the higher conductivity of the sea, leading to more interference problems. In this paper, a microwave frequency patch antenna array is analysed, designed, and simulated for a novel system to improve marine communications to be applied by unmanned aerial vehicles (UAVs). The patch antenna array with flexible substrate will be studied with different frequencies. In this way, the test will check and obtain the best characteristics for an antenna that is built into the UAV with CTS studio.

Angiogenesis, neovascularization, and vascular remodeling are highly dynamic processes, where endothelial cell–cell adhesion within the vessel wall controls a range of physiological processes, such as growth, integrity, and barrier function. The cadherin–catenin adhesion complex is a key contributor to inner blood–retinal barrier (iBRB) integrity and dynamic cell movements. However, the pre-eminent role of cadherins and their associated catenins in iBRB structure and function is not fully understood. Using a murine model of oxygen-induced retinopathy (OIR) and human retinal microvascular endothelial cells (HRMVECs), we try to understand the significance of IL-33 on retinal endothelial barrier disruption, leading to abnormal angiogenesis and enhanced vascular permeability. Using electric cell-substrate impedance sensing (ECIS) analysis and FITC-dextran permeability assay, we observed that IL-33 at a 20 ng/mL concentration induced endothelial-barrier disruption in HRMVECs. The adherens junction (AJs) proteins play a prominent role in the selective diffusion of molecules from the blood to the retina and in maintaining retinal homeostasis. Therefore, we looked for the involvement of adherens junction proteins in IL-33-mediated endothelial dysfunction. We observed that IL-33 induces α-catenin phosphorylation at serine/threonine (Ser/Thr) residues in HRMVECs. Furthermore, mass-spectroscopy (MS) analysis revealed that IL-33 induces the phosphorylation of α-catenin at Thr654 residue in HRMVECs. We also observed that PKCμ/PRKD1-p38 MAPK signaling regulates IL-33-induced α-catenin phosphorylation and retinal endothelial cell-barrier integrity. Our OIR studies revealed that genetic deletion of IL-33 resulted in reduced vascular leakage in the hypoxic retina. We also observed that the genetic deletion of IL-33 reduced OIR-induced PKCμ/PRKD1-p38 MAPK-α-catenin signaling in the hypoxic retina. Therefore, we conclude that IL-33-induced PKCμ/PRKD1-p38 MAPK-α-catenin signaling plays a significant role in endothelial permeability and iBRB integrity.

In this article, we propose a resource allocation (RA) scheme for vehicular communication networks (VCNs). The proposed scheme exploits the spectral efficiency of full-duplex (FD) communications to fulfill the reliability constraints of vehicle-to-vehicle (V2V) links and the high capacity requirements of vehicle-to-infrastructure (V2I) links. Also, it is capable of coping with the fast variations of the channels due to the high mobility. Based on the links requirements, the RA problem is formulated as a non-convex problem, which is solved in two steps. First, the optimal power allocation (PA) is obtained by solving a system of linear equations. Second, the channel assignment (CA), which turns out to be a maximum weight bipartite matching problem, is solved using the Hungarian method. Also, a heuristic hybrid scheme, which combines the proposed FD scheme and the half-duplex (HD) scheme that optimally finds the RA, is proposed. Compared to the optimal HD-based scheme, simulation results show that the proposed FD scheme always offers higher sum of the V2I links' capacities except for the case in which V2V links require low transmission rates, while the hybrid scheme ensures higher performance for all potential cases.

We consider intermittently connected vehicular networks (ICVNs) in which base stations (BSs) are installed along a highway to connect moving vehicles with internet. Due to the deployment cost, it is hard to cover the entire highway with BSs. To minimize the outage time in the uncovered area (UA), several store-carry-forward (SCF) schemes have been proposed in which a vehicle is selected to act as a relay by buffering data to be relayed to a target vehicle in the UA. In this paper, we propose a full-duplex (FD) SCF scheme that exploits the relay's ability to simultaneously receive and transmit in order to improve the effective communication time (ECT) with the target vehicle and accordingly deliver more data to it in the UA. The optimal power allocation (PA) that maximizes the ergodic capacities of the links is determined and the amount of data that can be buffered inside the BS coverage and can be delivered by each relay candidate to the target vehicle in the UA is found. Since the relay cannot deliver more data in the UA than what can be buffered inside the coverage, the performance of each relay candidate is limited by the minimum of the two amounts and hence is used as a relay selection (RS) criteria. To reduce the computational complexity, an alternative RS scheme that selects the relay candidate that offers the highest ECT is proposed. As compared to half-duplex SCF schemes, simulation results show that the proposed FD schemes are capable of delivering significantly higher amount of data to the target vehicle in the UA.

There is an urgent need to support high data rate among connected vehicles for both safety and infotainment purposes. However, high rate for vehicular communications is impacted by several challenges such as optimal beam tracking for multiple simultaneous-transmitting vehicles in highly-dynamic environments. In this paper, we aim to maximize the overall network throughput for multi-vehicular communications. We propose a reinforcement learning (RL) approach called combinatorial multi-armed bandit (CMAB) framework, where multiple arms (i.e., actions) form a super arm and can be played together, to handle the beam selection problem in a vehicular network. More specifically, we propose an adaptive combinatorial Thompson sampling algorithm, namely adaptive CTS, that CMAB embodies for appropriate selection of simultaneous beams in a high-mobility vehicular environment. The proposed approach applies the smart exploration-exploitation trade-off for the fast selection of beams. As the proposed adaptive CTS scheme produces a higher complexity over the search space which increases exponentially with the number of user, we also propose a sequential Thompson sampling (TS) algorithm where beam selection is performed in a one-by-one manner. We analyze the regret bounds for the proposed beam tracking algorithms. The performance of the proposed strategies are evaluated for multi-vehicle millimeter-wave (mmWave) simulation environments. Our results suggest that the proposed sequential approach performs almost similar to the simultaneous adaptive CTS scheme for tracking optimal beams in a multi-vehicular network with much reduced complexity. Simulation results also show that both of our proposed strategies approach the optimal achievable rate achieved by the genie-aided solution.

Abstract Background To establish a more accurate technique for the assessment of the left ventricular function correlated with patients’ clinical condition avoiding the miscalculation of the ejection fraction in valvular regurgitation. A prospective study carried out between July 2018 and June 2019. The studied group included 35 subjects, 25 patients with valvular regurgitation, and 10 healthy control subjects. All subjects underwent cardiovascular magnetic resonance examination to evaluate the ejection fraction by two methods: the volumetric method which assesses stroke volume via subtraction of the end-systolic volume from the end-diastolic volume, and phase-contrast method which assesses the aortic stroke volume via a through-plane phase contrast across the aortic valve. The sensitivity, specificity, P value and the area under the curve of both methods were calculated. Results In the healthy group, using the volumetric method, the calculated mean ejection fraction was 62.44 ± 6.61, while that calculated by the phase-contrast method was 64.34 ± 5.33, with a non-significant difference (P = 0.62) showing the validity of the phase-contrast method. In the patients’ group, by using the volumetric method, the calculated mean ejection fraction was 47.17 ± 14.31%, which was significantly higher than that calculated by the phase-contrast method (29.39 ± 7.98%) (P = 0.02). According to the results of the calculation of the ejection fraction by the volumetric method, there were 18 patients (72%) having impaired cardiac function and 7 (28%) patients of normal function; while according to the phase-contrast method, all the 25 patients had impaired cardiac function. The current study shows that the phase-contrast cardiac magnetic resonance had 89.29% sensitivity and 85.7% specificity in diagnosing impaired cardiac function with the area under the curve of 0.87 (P = 0.00). Conclusion The phase-contrast cardiac magnetic resonance can provide a better assessment of the ejection fraction in valvular regurgitation.

Abstract Background Cardiac magnetic resonance (CMR) is an extremely accurate and useful modality that can give much data about myocardial damage after acute myocardial infarction and consequently can give a good idea about long-term prognosis. Unfortunately, this modality is still underused in Egypt. We tried to assess the prognostic significance of different parameters derived from CMR in Egyptian patients presenting with ST-elevation myocardial infarction (STEMI) treated by primary percutaneous intervention (PPCI). Twenty-five patients who presented with acute STEMI and were successfully reperfused by PPCI within 12 h from symptoms onset were included. CMR was performed 2–4 days after PPCI. Six months of long-term follow-up for major adverse cardiovascular events (re-infarction, new-onset heart failure and cardiac death) was done. CMR-derived parameters (edema volume, area at risk, infarction volume, infarction percentage, microvascular obstruction volume, microvascular obstruction percentage, myocardial salvage and myocardial salvage index) were analyzed in relation to incidence of major adverse cardiovascular events (MACE). Results Seven patients suffered from MACE. Univariate logistic regression analysis showed a significant correlation between edema volume (P = 0.04), area at risk (P = 0.05), infarction percentage (P = 0.05) and the occurrence of MACE. Multivariate logistic regression analysis showed that infarction percentage (P = 0.05) is the best parameter that can predict MACE. Conclusion Infarction percentage is potentially the most important prognosticator derived from CMR in Egyptian patients with acute STEMI successfully reperfused by PPCI.

Purpose: Mitochondrial dysfunction is central to breaking the barrier integrity of retinal endothelial cells (RECs) in various blinding eye diseases such as diabetic retinopathy and retinopathy of prematurity. Therefore, we aimed to investigate the role of different mitochondrial constituents, specifically those of oxidative phosphorylation (OxPhos), in maintaining the barrier function of RECs. Methods: Electric cell-substrate impedance sensing (ECIS) technology was used to assess in real time the role of different mitochondrial components in the total impedance (Z) of human RECs (HRECs) and its components: capacitance (C) and the total resistance (R). HRECs were treated with specific mitochondrial inhibitors that target different steps in OxPhos: rotenone for complex I, oligomycin for complex V (ATP synthase), and FCCP for uncoupling OxPhos. Furthermore, data were modeled to investigate the effects of these inhibitors on the three parameters that govern the total resistance of cells: Cell–cell interactions (Rb), cell–matrix interactions (α), and cell membrane permeability (Cm). Results: Rotenone (1 µM) produced the greatest reduction in Z, followed by FCCP (1 µM), whereas no reduction in Z was observed after oligomycin (1 µM) treatment. We then further deconvoluted the effects of these inhibitors on the Rb, α, and Cm parameters. Rotenone (1 µM) completely abolished the resistance contribution of Rb, as the Rb became zero immediately after the treatment. Secondly, FCCP (1 µM) eliminated the resistance contribution of Rb only after 2.5 h and increased Cm without a significant effect on α. Lastly, of all the inhibitors used, oligomycin had the lowest impact on Rb, as evidenced by the fact that this value became similar to that of the control group at the end of the experiment without noticeable effects on Cm or α. Conclusion: Our study demonstrates the differential roles of complex I, complex V, and OxPhos coupling in maintaining the barrier functionality of HRECs. We specifically showed that complex I is the most important component in regulating HREC barrier integrity. These observed differences are significant since they could serve as the basis for future pharmacological and gene expression studies aiming to improve the activity of complex I and thereby provide avenues for therapeutic modalities in endothelial-associated retinal diseases.

Water shortages greatly threaten global food security and limit crop production. Hence, increasing crop water stress tolerance is a critical way to secure agricultural production. 24-Epibrassinolide (EBL) and spermine (Spm) are closely involved in plant growth and development, as well as stress tolerance. In this study, the potential role of 0.1 mg L−1 EBL and/or 25 mg L−1 Spm foliage applications in improving the tolerance of maize to water-deficit conditions (50% and 75% field capacity) was investigated. We found that EBL, either alone or in combination with Spm, plays a major role in maize drought tolerance through upregulating the expression of both regulatory genes (ZmBZR1 and ZmBES1) of the brassinosteroid signal transduction pathway and gene-encoding antioxidant defense enzymes ZmSOD, ZmCAT, ZmAPX, ZmMDHAR, ZmDHAR, and ZmGR. Moreover, exogenous treatments alleviated the inhibition of maize plant growth and productivity and mitigated drought-induced oxidative stress by improving antioxidant enzyme (superoxide dismutase, catalase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase) activity, enhancing antioxidant molecule (ascorbate, glutathione) content, preventing reactive oxygen species accumulation, and maintaining cell membrane integrity. These findings reveal that the application of EBL, either individually or in combination with Spm, can be a good strategy for ameliorating water stress in sustainable agricultural systems.

The mechanisms of diabetic retinopathy (DR), are not yet fully understood. We previously demonstrated an upregulation of retinal bone morphogenetic protein-2 (BMP2) in experimental diabetes and in retinas of diabetic human subjects. The purpose of current study was to investigate the role of non-canonical inflammatory pathway in BMP2-induced retinal endothelial cell (REC) barrier dysfunction. For this purpose, we used RT-PCR and western blotting to evaluate the levels of BMP2 signaling components (BMP2, BMP4, BMP receptors), VEGF, phosphorylated p38 MAPK and NFκB, and oxidative stress markers in cultured human retinal endothelial cells (HRECs) subjected to BMP2 (50ng/ml) for up to 24 h. Also, effect of high glucose (HG, 30mM D-glucose) on the expression of BMP2 and its downstream genes was examined in HRECs. H2-DCF is a fluorogenic dye that measures the levels of cellular reactive oxygen species (ROS) was used to measure the pro-oxidative effect of BMP2. Moreover, we evaluated the effect of inhibiting p38 and VEGF signaling on BMP2-induced HRECs barrier dysfunction by measuring the trans-endothelial cell electrical resistance (TER) using electric cell-substrate impedance sensing (ECIS). We also tested the effect of HG on the integrity of HRECs barrier in the presence or absence of inhibitors of BMP2 signaling. Our data reveals that BMP2 and high glucose upregulates BMP components of the BMP signaling pathway (SMAD effectors, BMP receptors, and TGFβ ligand itself) and induces phosphorylation of p38 MAPK and NFκB with nuclear translocation of NFκB. Inhibition of p38 or NFκB attenuated BMP2-induced VEGF expression and barrier dysfunction in HRECs. Also, inhibition of VEGFR2 attenuated BMP2-induced barrier dysfunction. Moreover, BMP2 induces generation of ROS and endothelial nitric oxide synthase (eNOS) expression and activity in HRECs. Finally, HG upregulated BMP2 and its downstream genes (SMAD, BMP4, ALKs, and TGF-β) in HRECs and BMP2 inhibitors attenuated HG-induced HRECs barrier dysfunction. Our results suggest that in addition to the regular canonical SMAD signaling BMP2 induces non-canonical inflammatory pathway in HRECs via activation of p38/NFκB pathway that causes the upregulation of VEGF and the disruption of HRECs. Inhibition of BMP2 signaling is a potential therapeutic intervention to preserve endothelial cell barrier function in DR.

An integrated access and backhaul (IAB) network architecture can enable flexible and fast deployment of the next-generation cellular networks. However, mutual interference between access and backhaul links, small inter-site distance, and spatial dynamics of user distribution pose major challenges in the practical deployment of the IAB networks. To tackle these problems, we leverage the flying capabilities of unmanned aerial vehicles (UAVs) as hovering IAB-nodes and propose an interference management algorithm to maximize the overall sum rate of the IAB network. In particular, we jointly optimize the user and base station associations, the downlink power allocations for access and backhaul transmissions, and the spatial configurations of the UAVs. We consider two spatial configuration modes of the UAVs, distributed UAVs and drone antenna array (DAA), and show how they are intertwined with the spatial distribution of ground users. Our numerical results show that the proposed algorithm achieves an average of 2.9× and 6.7× gains in the received downlink signal-to-interference-plus-noise ratio (SINR) and overall network sum rate, respectively. Finally, the numerical results reveal that UAVs can not only be used for coverage improvement but also for capacity boosting in the IAB cellular networks.

Fusarium graminearum is a major global pathogen of cereals and is considered the main causal agent of Fusarium head blight disease in wheat. Infection with Fusarium graminearum causes a significant reduction in crop yield and quality; therefore, it is very important to improve wheat pathogen resistance. In the present study, the plasmid pAHCht-2 harboring the rice chitinase (Cht-2) gene for pathogen resistance and the plasmid pAB6 containing the gus reporter and bar selectable marker genes were used for genetic transformation of immature embryo-derived calli of the Egyptian wheat cultivar Giza 164 using particle bombardment. Associated changes in defense mechanisms in the transgenic plants were investigated. The transgenic plants had significantly decreased total protein content, phenolic compounds and antioxidant enzyme activities (peroxidase and catalase), and significantly increased phenylalanine ammonia lyase and chitinase activities compared with non-transgenic plants under biotic stress conditions caused by F. graminearum infection. Our results show that activating a specific program of gene expression related to environmental stress conditions can reduce the cost of the stress on plant metabolism.

Objective: A comparative study of manual and automated post processing software tools to measure CT parameters before Transcatheter Aortic Valve Implantation (TAVI). Patients and methods: 51 patients were included; all admitted to the Cardiology Department with clinically established severe aortic stenosis, in whom TAVI was the treatment of choice. All patients underwent CT angiography (CTA) pre-TAVI. The CT images were post processed and the needed CT parameters were calculated using both manual and automated methods. The results were compared for statistical analysis. Results: Only 43 patients completed the study, with mean age 65 years old. The automated software provided accurate almost similar results as the manual method, especially for aortic annulus area and aortic circumference measurements (p-value = 1 and 0.548) and was accepted for left and right coronary artery ostium height (p-value = 0.191 and 0.635). However, there was a statistically significant difference for the minor diameter axis and mean annular diameter (p-value = 0.001 and 0.021). Conclusion: The automated software introduced rapid, accurate and reliable measurements for the aortic annulus in cases prepared for TAVI and can be used as a standard method. Also, it can be performed by junior staff with avoidable human errors.

We propose a new sparsity-aware framework to model and mitigate the joint effects of narrow-band interference (NBI) and impulsive noise (IN) in hybrid powerline and unlicensed wireless communication systems. The proposed mitigation techniques, based on the principles of compressive sensing, exploit the inherent (non-contiguous or contiguous) sparse structures of NBI and IN in the frequency and time domains, respectively. For the non-contiguous NBI and IN, we develop a multi-level orthogonal matching pursuit recovery algorithm that exploits prior knowledge about the sparsity level at each receive antenna and powerline to further reduce computational complexity without performance loss. In addition, for the non-contiguous asynchronous NBI scenario, we investigate the application of time-domain windowing to enhance the NBI's sparsity and, hence, improve the NBI mitigation performance. For the contiguous NBI and IN scenario, we estimate the NBI and IN signals by modeling their burstiness as block-sparse vectors with and without prior knowledge of the bursts' boundaries. Moreover, we show how to exploit the spatial correlations of the NBI and IN across the receive antennas and powerlines to convert a non-contiguous NBI and IN problem to a block-sparse estimation problem with much lower complexity. Furthermore, we investigate a Bayesian linear minimum mean square error-based approach for estimating both non-contiguous and contiguous NBI and IN based on their second-order statistics to further improve the estimation performance. Finally, our numerical results illustrate the superiority of the joint processing of our proposed NBI and IN sparsity-based mitigation techniques compared to separate processing of the wireless and powerline received signals.

Diabetic retinopathy is a major cause of ocular complications in patients with type 1 and type 2 diabetes in developed countries. Due to the continued increase in the number of people with obesity and diabetes in the United States of America and globally, the incidence of diabetic retinopathy is expected to increase significantly in the coming years. Diabetic retinopathy is widely accepted as a combination of neurodegenerative and microvascular changes; however, which change occurs first is not yet understood. Although the pathogenesis of diabetic retinopathy is very complex, regulated by numerous signaling pathways and cellular processes, maintaining glucose homeostasis is still an essential component for normal physiological functioning of retinal cells. The maintenance of glucose homeostasis is finely regulated by coordinated interplay between glycolysis, Krebs cycle, and oxidative phosphorylation. Glycolysis is the most conserved metabolic pathway in biology and is tightly regulated to maintain a steady-state concentration of glycolytic intermediates; this regulation is called scheduled or regulated glycolysis. However, an abnormal increase in glycolytic flux generates large amounts of intermediate metabolites that can be shunted into different damaging pathways including the polyol pathway, hexosamine pathway, diacylglycerol-dependent activation of the protein kinase C pathway, and Amadori/advanced glycation end products (AGEs) pathway. In addition, disrupting the balance between glycolysis and oxidative phosphorylation leads to other biochemical and molecular changes observed in diabetic retinopathy including endoplasmic reticulum-mitochondria miscommunication and mitophagy dysregulation. This review will focus on how dysregulation of glycolysis contributes to diabetic retinopathy.

Purpose: The purpose of this study was to emphasize the value of calcium scoring (Ca score) using a large field of view (“large FOV”) as a screening method for detection of extracardiac incidental findings. Materials and methods: 64-Multislice CT angiography using a “large FOV” in the preliminary calcium score followed by the post-contrast routine “small FOV” examination was performed for 382 consecutive patients between January 2011 and December 2012. Results: 375 Patients (203 men and 172 women) with age range between 40 and 80 years (mean, 60 years), were studied, using a “large FOV” technique. Among whole incidental extracardiac findings, “significant” extracardiac abnormalities (emergent and intermediate findings) were detected in 24.8% of cases, among which 13.6% would have been missed if only using a “small FOV” technique. Conclusion: Results showed that using Ca score with a “large FOV” is favorable for better, accurate and more frequent detection of extracardiac incidental findings. With usage of low dose technique, the difference in dose between “small FOV” and “large FOV” techniques is justified for detection of supplementary “significant” extra-cardiac findings including serious findings such as lung cancer or metastatic deposits.

Purpose: To elucidate the diagnostic role of multidetector DSCT for the assessment of myocardial perfusion in correlation with coronary luminal integrity in a single CT scan while both tubes were operated in single energy mode. Methods and material: Thirty-five patients were subjected to single acquisition contrast-enhanced, ECG-gated DSCT of the heart at rest. Postprocessing was performed generating two image sets: coronary CT angiographic images (cCTA) and myocardial perfusion images (CTP) for respective correlative assessment of coronary luminal integrity and myocardial perfusion. Perfusion defect was detected subjectively using gray scale images and the color coded first pass and color overlaid late enhancement (color attenuation) images were used for semi-objective evaluation and final objective and quantitative confirmation by density measurement. Results: Significant correlation and good agreement between the findings of DSCT myocardial perfusion and the findings of stenosis and its degree on cCTA on a segmental basis is noted with Cohen’s Kappa = 0.67 and prevalence and bias adjusted Kappa = 0.71 emphasizing the high diagnostic value of DSCT myocardial perfusion as compared to cCTA as the gold reference standard. Conclusion: We propose that comprehensive evaluation of coronary artery morphology and myocardial perfusion in patients with CAD could be achieved by single reproducible non-invasive contrast enhanced CT acquisition using DSCT scanners while operated in single energy mode with high sensitivity, specificity and diagnostic accuracy, it also has the potential to be the first, independent and stand out imaging choice in such field.

Purpose: To emphasis the role of MSCT utilizing the remodeling index in assessment of positive coronary remodeling which was associated with plaque rupture and vulnerability. Methods and material: Studied group included 35 patients with positive coronary remodeling. One lesion per patient was assessed, either a solitary lesion or the most significant one. All patients were subjected to history taking and radiological evaluation using a contrast-enhanced 64 MSCT then post processed. Assessment of the plaque causing positive remodeling regarding the site, number (single, kissing, or multiple), relative composition and predominant type in H.U. was performed. Specific measurements at the reference and remodeling segment were taken. Calculation of remodeling index was done. Two comparative groups were made between subjects with remodeling index (RI)

Purpose: In pediatric population with SNHL, a radiological presurgical mapping exam is usually performed, purpose of this study is to improve the inter-rater agreement giving different imaging modalities using MDCT and MRI to facilitate identifying patients in need for surgical modification before cochlear implant. Methods and material: 120 pediatric patients ranging between 1 and 12 years with an average age of 5 years diagnosed with congenital or acquired SNHL and requiring cochlear implant (CI) after proper surgical selection were included in the study. All patients underwent combined 64 detector MDCT using pediatric low dose protocol with sagittal, Stenvers views in addition to standard axial and coronal plane reconstruction from single acquisition volume. In the same session, 3D DRIVE MRI axial plane reformatted into sagittal plane for the IAC and inner ear as well as axial T2WI/FLAIR for the whole brain. Two different head and neck radiologists blindedly reported the inner ear, cochlear nerve development, temporal bone anatomy, operative window, as well as normal variants that could hinder implantation as well as causes of central hearing loss. Findings were compared with operative findings. Results: Patients were categorized into four groups; according to the capability of electrode implant, modification of surgical techniques and expected response with high intra-observer was noted with a PABAK value of 0.96 for observer A and of 0.93 for observer B. Lower inter observer agreement was observed on an individual usage of radiological techniques for reaching diagnosis (conventional CT, MRI, or Stenvers/sagittal oblique techniques alone) with a PABAK value of 0.93, 0.78 and 0.73, respectively. A higher inter observer agreement was met on combining all these radiological modalities together (PABAK value of 0.96). Conclusion: Stenvers view efficiently makes pre-surgical mapping for the intra-cochlear electrode pathway by identifying the cochlear turns, round and oval window, vestibule and SCC as well as facial nerve canal in one view helping the surgeon in optimizing the technique. MRI identifies the fibrous labyrinthitis ossificans not detected by CT and evaluates the cochlear nerve development and integrity of central auditory pathway. Combined MDCT/MRI imaging protocol helps the clinician in proper patient categorization, optimize their surgical approach and the type of electrode. Clinical relevance/application: SNHL is a malfunction of the inner ear, vestibulocochlear nerve or central auditory pathway. Imaging helps to establish treatment regimens that improve auditory function.

Retinal hyperpermeability and subsequent macular edema is a cardinal feature of early diabetic retinopathy (DR). Here, we investigated the role of bioactive lipid metabolites, in particular 12/15-lipoxygenase (LOX)-derived metabolites, in this process. LC/MS lipidomic screen of human retinal endothelial cells (HRECs) demonstrated that 15-HETE was the only significantly increased metabolite (2.4 ± 0.4-fold, P = 0.0004) by high glucose (30 mM) treatment. In the presence of arachidonic acid, additional eicosanoids generated by 12/15-LOX, including 12- and 11-HETEs, were significantly increased. Fluorescein angiography and retinal albumin leakage showed a significant decrease in retinal hyperpermeability in streptozotocin-induced diabetic mice lacking 12/15-LOX compared with diabetic WT mice. Our previous studies demonstrated the potential role of NADPH oxidase in mediating the permeability effect of 12- and 15-HETEs, therefore we tested the impact of intraocular injection of 12-HETE in mice lacking the catalytic subunit of NADPH oxidase (NOX2). The permeability effect of 12-HETE was significantly reduced in NOX2−/− mice compared with the WT mice. In vitro experiments also showed that 15-HETE induced HREC migration and tube formation in a NOX-dependent manner. Taken together our data suggest that 12/15-LOX is implicated in DR via a NOX-dependent mechanism.

Purpose: To assess the role of 64-row multidetector computed tomography virtual hysterosalpingography (MDCT VHSG) in the evaluation of the female reproductive tract in infertile patients and compare it with conventional X-ray hysterosalpingography (HSG). Methods and material: The studied group included 25 patients with infertility. All patients were evaluated with 64-row MDCT VHSG and X-ray HSG. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of both examinations for uterine pathology, fallopian tube pathology and per lesion pathology were calculated. The duration for both examinations, patient discomfort and patient effective dose were documented. Results: The mean duration for MDCT VHSG and X-ray HSG was 6.5 ± 1.9 and 26.9 ± 2.9 min respectively, MDCT VHSG has a significantly less median patient discomfort and mean patient effective dose. Sensitivity, specificity, PPV and NPV for uterine pathology were 100%, 100%, 100% and 100% respectively for MDCT VHSG and 90%, 93.3%, 90% and 93.3% respectively for X-ray HSG, the inter-method agreement for uterine pathology was k = 0.83. Sensitivity, specificity, PPV and NPV for the detection of fallopian tube pathology were 100%, 93%, 91 and 100% respectively for MDCT VHSG and 100%, 86%, 85% and 100% respectively for X-ray HSG and k = 0.76. Sensitivity, specificity, PPV and NPV for per patient pathology were 100%, 91%, 93% and 100% respectively for MDCT VHSG and 87%, 80%, 87% and 80% respectively for X-ray HSG and k = 0.75. Conclusion: MDCT VHSG could be an excellent new alternative diagnostic procedure in the infertility assessment workup.

Background/Aim: Hepatic injury is a hallmark adverse reaction to Valproate (VPA), a common used drug in the management of numerous CNS disorders, including epilepsy. DHA has a myriad of health benefits, including renal- and hepato-protective effects. Unfortunately, however, the underpinnings of such liver-pertinent VPA- and DHA-actions remain largely undefined. Accordingly, this study attempted to unveil the cellular and molecular triggers whereby VPA evokes, while DHA abates, hepatotoxicity. Methods: We evaluated activity and/or expression of cellular markers of oxidative stress, inflammation, and apoptosis in rat liver, following treatment with VPA (500 mg/kg/day) with and without concurrent treatment with DHA (250 mg/kg/day) for two weeks. Results and conclusion: VPA promoted hepatic oxidative stress as evidenced by enhancing activity/expression of NADPH-oxidase and its subunits, a ROS-generator, and by accumulation of lipid-peroxides. Moreover, VPA enhanced hepatic phosphorylation/activation of mitogen-activated protein kinase (MAPK), and expression of cyclooxygenase-2(COX-2), as proinflammatory signals. Besides, VPA promoted hepatocellular apoptosis, as attested by enhanced expression of cleaved caspase-9 and increased number of TUNEL-positive hepatocytes. Lastly, VPA upregulated levels of hypoxia-inducible factor-1-alpha (HIF-1α), a multifaceted modulator of hepatocytic biology, and activity of its downstream antioxidant enzyme heme-oxygenase-1(HO-1). These changes were significantly blunted by co-administration of DHA. Our findings demonstrate that VPA activated NADPH-oxidase and HIF-1α to induce oxidative-stress and hypoxia as initiators of hepatic injury. These changes were further aggravated by up-regulation of inflammatory (MAPK and COX-2) and apoptotic cascades, but could be partly lessened by HO-1 activation. Concurrent administration of DHA mitigated all VPA-induced anomalies.

Background Pulmonary tuberculosis (PTB) is an increasing global health problem that continues to cause significant morbidity and mortality. The impact of PTB has been measured in terms morbidity and mortality and little attention has been paid to continuing respiratory disability in those who were cured. Pulmonary hypertension (PHT) is a serious respiratory disability that results from structural lung damage and chronic hypoxia. This study was conducted to investigate the presence of PHT in a cohort of treated PTB patients who presented with shortness of breath. Methods This is a cross-sectional study that included 14 consecutive patients who were cured of PTB and presented with shortness of breath. Demographic and clinical data were recorded for all patients. PHT was diagnosed using Doppler echocardiography. Results Fourteen patients who were treated for PTB and were found to have PHT were studied. All patients were sputum smear negative at the time of the study. The mean age (SD) was 43.1 (13.6) and half of the patients were males. The mean number of years since PTB was diagnosed (SD) was 9.4 (10.9). All patients had abnormal chest x-rays. The commonest radiological abnormality was fibrocavitation which occurred in 50% of patients. Estimated pulmonary artery systolic pressure (PASP) of 51 to 80 mm/Hg was found in 9 patients (64.3%) whereas PASP of 40 to 50 mm/Hg was found in 4 patients (28.6%) and one patient had PASP more than 80 mm/Hg. Conclusions Different grades of PHT occurred in this cohort of treated PTB patients on average about 9 years after cure. The findings of this study support implementation of strategies for early detection and prevention of PTB. For those who were cured from PTB, longer periods of disability should be implemented in assessment of disease burden.