Insights about the Absence of Rb Cation from the 3D Perovskite Lattice: Effect on the Structural,Morphological, and Photophysical Properties and Photovoltaic Performance

Efficiencies >20% are obtained from the perovskite solar cells (PSCs) employing Cs⁺ and Rb⁺ based perovskite compositions; therefore, it is important to understand the effect of these inorganic cations specifically Rb⁺ on the properties of perovskite structures. Here the influence of Cs⁺ and Rb⁺ is elucidated on the structural, morphological, and photophysical properties of perovskite structures and the photovoltaic performances of resulting PSCs. Structural, photoluminescence (PL), and external quantum efficiency studies establish the incorporation of Cs⁺ (x < 10%) but amply rule out the possibility of Rb‐incorporation into the MAPbI₃ (MA = CH₃NH₃ ⁺) lattice. Moreover, morphological studies and time‐resolved PL show that both Cs⁺ and Rb⁺ detrimentally affect the surface coverage of MAPbI₃ layers and charge‐carrier dynamics, respectively, by influencing nucleation density and by inducing nonradiative recombination. In addition, differential scanning calorimetry shows that the transition from orthorhombic to tetragonal phase occurring around 160 K requires more thermal energy for the Cs‐containing MAPbI₃ systems compared to the pristine MAPbI₃. Investigation including mixed halide (I/Br) and mixed cation A‐cation based compositions further confirms the absence of Rb⁺ from the 3D‐perovskite lattice. The fundamental insights gained through this work will be of great significance to further understand highly promising perovskite compositions.     

Development of environmentally friendly,antifouling coatings based on tethered quaternary ammonium salts in a crosslinked polydimethylsiloxane matrix

The concept of tethering quaternary ammonium salts (QASs) to a crosslinked polysiloxane matrix to produce a hybrid antifouling/fouling-release coating was investigated. A statistical experimental design was used to determine the effect of QAS concentration on biocidal activity toward a marine bacterium, Cellulophaga lytica (C. lytica). In addition to measuring biocidal activity, coating film quality as well as stability upon water immersion were evaluated. The results of the study showed that biocidal activity was strongly dependent on QAS concentration. For addition-curable coatings, the presence of 4 wt% QAS moieties resulted in approximately 50% reduction in C. lytica biofilm retention without any leachate toxicity. Attempts to increase the level of QAS moieties to increase biocidal activity resulted in coating delamination from the substrate and unacceptable film quality upon artificial seawater immersion due to excessive swelling. As a result, a moisture-curable system based on tethered QASs was investigated since moisture curing allows for higher crosslink densities to be achieved which would be expected to minimize swelling upon artificial seawater immersion. The moisture-curable coating developed showed enhanced stability upon artificial seawater immersion, greater than 80% reduction in C. lytica biofilm retention, and greater than 90% reduction in biofilm growth for the marine algae, Navicula incerta. Presented at 2007 FutureCoat! Conference, sponsored by Federation of Societies for Coatings Technology, October 3–5, 2007, in Toronto, Ont., Canada.     

Ultra-wideband bandpass filter with multiple notch-bands on multilayer liquid crystal polymer substrate

Novel compact ultra-wideband (UWB) bandpass filters (BPFs) with single or multiple notch-bands to avoid interference from existing radio systems are presented. A compact UWB BPF is proposed and designed based on broadside-coupled stepped impedance resonators (SIRs) at first, and then notch-bands are generated by embedding open-circuit stubs into broadside-coupled SIRs. Because of the harmonic suppression behaviour of SIRs, the proposed UWB BPFs have a wide stopband and high rejection level. The characteristic of the proposed notch-structure was investigated by full-wave simulations. Multilayer liquid crystal polymer (LCP) technology was used to implement the designed UWB BPFs. In the experiments, a UWB BPF with excellent stopband performance was designed to meet the Federal communications commission-defined indoor limits at first, and then UWB BPFs with single, double and triple notch-bands were designed to demonstrate the flexible notch-band, high-selectivity and wideband harmonic suppression performances of the proposed filter. The designed BPFs were fabricated by a multilayer LCP lamination process and measured using a vector network analyser. Good agreement between the predicted and measured results was obtained as presented here.     

Design and implementation of a high level programming environmentfor FPGA-based image processing

Reconfigurable hardware in the form of field programmable gate arrays (FPGAs) has been proposed as a way of obtaining high performance for computationally intensive DSP applications such as image processing (IP), even under real time requirements. The inherent reprogrammability of FPGAs gives them some of the flexibility of software while keeping the performance advantages of an application specific solution. However, a major disadvantage of FPGAs is their low level programming model. To bridge the gap between these two levels, the authors present a high level software environment for FPGA-based image processing, which aims to hide hardware details as much as possible from the user. Their approach is to provide a very high level image processing coprocessor (IPC) with a core instruction set based on the operations of image algebra. The environment includes a generator which generates optimised architectures for specific user-defined operations     

AXL Knock-Out in SNU475 Hepatocellular Carcinoma Cells Provides Evidence for Lethal Effect Associated with G2 Arrest and Polyploidization

AXL, a member of the TAM family, is a promising therapeutic target due to its elevated expression in advanced hepatocellular carcinoma (HCC), particularly in association with acquired drug resistance. Previously, RNA interference was used to study its role in cancer, and several phenotypic changes, including attenuated cell proliferation and decreased migration and invasion, have been reported. The mechanism of action of AXL in HCC is elusive. We first studied the AXL expression in HCC cell lines by real-time PCR and western blot and showed its stringent association with a mesenchymal phenotype. We then explored the role of AXL in mesenchymal SNU475 cells by CRISPR-Cas9 mediated gene knock-out. AXL-depleted HCC cells displayed drastic phenotypic changes, including increased DNA damage response, prolongation of doubling time, G2 arrest, and polyploidization in vitro and loss of tumorigenicity in vivo. Pharmacological inhibition of AXL by R428 recapitulated G2 arrest and polyploidy phenotype. These observations strongly suggest that acute loss of AXL in some mesenchymal HCC cells is lethal and points out that its inhibition may represent a druggable vulnerability in AXL-high HCC patients.     

The Influence of Gravitational Field on Generalized Thermoelasticity with Two-Temperature under Three-Phase-Lag Model

The problem of the generalized thermoelastic medium for three different theories under the effect of a gravitational field is investigated. The Lord- Shulman, Green-Naghdi III, three-phase-lag theories are discussed with twotemperature. The normal mode analysis is used to obtain the analytical expressions of the displacement components, force stress, thermodynamic temperature and conductive temperature. The numerical results are given and presented graphically, when the thermal force is applied. Comparisons are made with the results predicted by three-phase-lag model, Green-Naghdi III and Lord-Shulman theories in the presence and absence of gravity as well as two temperature.     

Optimal Bottleneck-Driven Deep Belief Network Enabled Malware Classification on IoT-Cloud Environment

Cloud Computing (CC) is the most promising and advanced technology to store data and offer online services in an effective manner. When such fast evolving technologies are used in the protection of computer-based systems from cyberattacks, it brings several advantages compared to conventional data protection methods. Some of the computer-based systems that effectively protect the data include Cyber-Physical Systems (CPS), Internet of Things (IoT), mobile devices, desktop and laptop computer, and critical systems. Malicious software (malware) is nothing but a type of software that targets the computer-based systems so as to launch cyber-attacks and threaten the integrity, secrecy, and accessibility of the information. The current study focuses on design of Optimal Bottleneck driven Deep Belief Network-enabled Cybersecurity Malware Classification (OBDDBN-CMC) model. The presented OBDDBN-CMC model intends to recognize and classify the malware that exists in IoT-based cloud platform. To attain this, Z-score data normalization is utilized to scale the data into a uniform format. In addition, BDDBN model is also exploited for recognition and categorization of malware. To effectually fine-tune the hyperparameters related to BDDBN model, Grasshopper Optimization Algorithm (GOA) is applied. This scenario enhances the classification results and also shows the novelty of current study. The experimental analysis was conducted upon OBDDBN-CMC model for validation and the results confirmed the enhanced performance of OBDDBN-CMC model over recent approaches.     

Effect of Fe2O3 as an Aggregate Replacement on Mechanical,and Gamma/ Neutron Radiation Shielding Properties of Phosphoaluminate Glasses

Journal of Inorganic and Organometallic Polymers and Materials - In the present work, we examined the impact of Fe2O3 on the mechanical and photon shielding characteristics of lead-phosphoaluminate...     

Atovaquone Suppresses Triple-Negative Breast Tumor Growth by Reducing Immune-Suppressive Cells

A major contributing factor in triple-negative breast cancer progression is its ability to evade immune surveillance. One mechanism for this immunosuppression is through ribosomal protein S19 (RPS19), which facilitates myeloid-derived suppressor cells (MDSCs) recruitment in tumors, which generate cytokines TGF-β and IL-10 and induce regulatory T cells (Tregs), all of which are immunosuppressive and enhance tumor progression. Hence, enhancing the immune system in breast tumors could be a strategy for anticancer therapeutics. The present study evaluated the immune response of atovaquone, an antiprotozoal drug, in three independent breast-tumor models. Our results demonstrated that oral administration of atovaquone reduced HCC1806, CI66 and 4T1 paclitaxel-resistant (4T1-PR) breast-tumor growth by 45%, 70% and 42%, respectively. MDSCs, TGF-β, IL-10 and Tregs of blood and tumors were analyzed from all of these in vivo models. Our results demonstrated that atovaquone treatment in mice bearing HCC1806 tumors reduced MDSCs from tumor and blood by 70% and 30%, respectively. We also observed a 25% reduction in tumor MDSCs in atovaquone-treated mice bearing CI66 and 4T1-PR tumors. In addition, a decrease in TGF-β and IL-10 in tumor lysates was observed in atovaquone-treated mice with a reduction in tumor Tregs. Moreover, a significant reduction in the expression of RPS19 was found in tumors treated with atovaquone.     

Performance Enhancement of Dynamic Spectrum Access via Channel Reservation for Cognitive Radio Networks

Wireless Personal Communications - In cognitive radio networks models, quality of service (QoS) of primary users (PUs) must be assured. Dynamic spectrum access is a paradigm by which a radio system...