Unravelling the Potential of Silicon Carbide for Water Treatment: Insights on the Interactions of Fluoroquinolone Antibiotics

Silicon - Antibiotics and their residues, particularly those belonging to the fluoroquinolone class, are harmful to aquatic and human life, making their removal essential. Although 2D materials are...     

Fast l₁-SPIRiT compressed sensing parallel imaging MRI: scalable parallel implementation and clinically feasible runtime

We present l?-SPIRiT, a simple algorithm for auto calibrating parallel imaging (acPI) and compressed sensing (CS) that permits an efficient implementation with clinically-feasible runtimes. We propose a CS objective function that minimizes cross-channel joint sparsity in the wavelet domain. Our reconstruction minimizes this objective via iterative soft-thresholding, and integrates naturally with iterative self-consistent parallel imaging (SPIRiT). Like many iterative magnetic resonance imaging reconstructions, l?-SPIRiT's image quality comes at a high computational cost. Excessively long runtimes are a barrier to the clinical use of any reconstruction approach, and thus we discuss our approach to efficiently parallelizing l?-SPIRiT and to achieving clinically-feasible runtimes. We present parallelizations of l?-SPIRiT for both multi-GPU systems and multi-core CPUs, and discuss the software optimization and parallelization decisions made in our implementation. The performance of these alternatives depends on the processor architecture, the size of the image matrix, and the number of parallel imaging channels. Fundamentally, achieving fast runtime requires the correct trade-off between cache usage and parallelization overheads. We demonstrate image quality via a case from our clinical experimentation, using a custom 3DFT spoiled gradient echo (SPGR) sequence with up to 8× acceleration via Poisson-disc undersampling in the two phase-encoded directions.     

Heat Transfer Measurements inside Narrow Channels with Ribs and Trenches

Detailed heat transfer coefficient distributions are obtained for high aspect ratio (width/height = 12.5) duct with rib and trench enhancement features oriented normal to the coolant flow direction. A transient thermochromic liquid crystal technique has been used to experimentally measure heat transfer coefficients from which Nusselt numbers are calculated on the duct surface featuring heat transfer enhancement features. Reynolds number (calculated based on duct hydraulic diameter) ranging from 7100 to 22400 were experimentally investigated. Detailed measurements of heat transfer provided insight into the role of protruding ribs and trenches on the fluid dynamics in the duct. Experimentally obtained Nusselt numbers are normalized by Dittus-Boelter correlation for developed turbulent flow in circular duct. The triangular trenches provide heat transfer enhancement ratios up to 1.9 for low Reynolds numbers. The in-line rib configuration shows similar levels to the trench whereas staggered rib configuration provides heat transfer enhancement ratios up to 2.2 for a low Reynolds number of 7100.     

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.     

HIoTPOT: Surveillance on IoT Devices against Recent Threats

Honeypot Internet of Things (IoT) (HIoTPOT) keep a secret eye on IoT devices and analyzes the various recent threats which are dangerous to IoT devices. In this paper, implementation of a research honeypot is presented which is used to learn the recent tactics and ethics used by black hat community to attack on IoT devices. As IoT is open and easy for accessing, all the intruders are highly attracted towards IoT. Recently Telnet based attacks are very famous on IoT devices to get easy access and attack on other devices. To reduce these kinds of threats, it is necessary to know in details about intruder, therefore the aim of this research work is to implement novel based secret eye server known as HIoTPOT which will make the IoT environment more safe and secure.     

In Vivo Imaging of Composite Hydrogel Scaffold Degradation Using CEST MRI and Two‐Color NIR Imaging

Hydrogel scaffolding of stem cells is a promising strategy to overcome initial cell loss and manipulate cell function post‐transplantation. Matrix degradation is a requirement for downstream cell differentiation and functional tissue integration, which determines therapeutic outcome. Therefore, monitoring of hydrogel degradation is essential for scaffolded cell replacement therapies. It is shown here that chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) can be used as a label‐free imaging platform for monitoring the degradation of crosslinked hydrogels containing gelatin (Gel) and hyaluronic acid (HA), of which the stiffness can be fine‐tuned by varying the ratio of the Gel:HA. By labeling Gel and HA with two different near‐infrared (NIR) dyes having distinct emission frequencies, it is shown here that the HA signal remains stable for 42 days, while the Gel signal gradually decreases to <25% of its initial value at this time point. Both imaging modalities are in excellent agreement for both the time course and relative value of CEST MRI and NIR signals (R² = 0.94). These findings support the further use of CEST MRI for monitoring biodegradation and optimizing of gelatin‐containing hydrogels in a label‐free manner.     

Luminescent properties and X-ray photoelectron spectroscopy study of ZnAl2O4:Ce,Tb phosphor

Cerium (Ce³⁺)- and terbium (Tb³⁺) co-doped zinc aluminate (ZnAl₂O₄) nanocrystals were successfully prepared by a combustion method using urea as fuel. The as-prepared samples were annealed in hydrogen atmosphere to improve their optical properties and crystallinity. The structure and morphology of the samples analyzed using X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) showed that ZnAl₂O₄ crystallized in a well known cubic spinel structure. As deduced from X-ray photoelectron spectroscopy (XPS) data, there was partial inversion of cations in as-prepared (unannealed) samples implying that the ZnAl₂O₄ did not crystallize in a cubic normal spinel. Instead, the XPS data demonstrated possible structural readjustment from inverse to normal spinel after annealing. The excitation and emission data collected when ZnAl₂O₄:Ce³⁺,Tb³⁺ samples, with different concentrations of Ce³⁺ and Tb³⁺ ions, were excited at different wavelengths showed that green emission of Tb³⁺ was sensitized by Ce³⁺, i.e. there was energy transfer from Ce³⁺ to Tb³⁺ resulting in improvement of green emission from Tb³⁺. This study therefore, sets out to discuss the sensitizing effect of Ce³⁺ and the effect of annealing on the structure of ZnAl₂O₄:Ce³⁺,Tb³⁺.     

Investigations on the low voltage cathodoluminescence stability and surface chemical behaviour using Auger and X-ray photoelectron spectroscopy on LiSrBO3:Sm phosphor

Orange-red emissive LiSrBO₃:Sm³⁺ phosphors were synthesized through the solid-state reaction method. Under UV radiation (221 nm) and low-voltage electron beam (2 keV, 12 mA/cm²) excitation, the Sm³⁺ doped LiSrBO₃ phosphor shows emission corresponding to the characteristic ⁴G_5/2-⁶H_7/2 transitions of Sm³⁺ with the strongest emission at 601 nm. A high stability of cathodoluminescence (CL) emission during prolong electron bombardment with low-energy electrons was observed. Surface sensitive diagnostic tools such as Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to study the surface chemistry. AES results revealed modifications in the surface concentrations of Li, Sr, B, O and C on the surface of the LiSrBO₃:Sm³⁺ phosphor as indicated by the changes in their Auger peak to peak heights (APPH) as a function of electron dose. Observed changes in the high resolution XPS spectra of the LiSrBO₃:Sm³⁺ surface irradiated with the low energy electron beam provide evidence of compositional and structural changes as a result of the electron beam stimulated surface chemical reactions (ESSCRs). Additional SrO₂ was identified by XPS on the phosphor surface after it received an electron dose of 300 C/cm² together with the increase in the concentrations of chemical species containing the B-C-O bonding. The new surface chemical species formed during electron beam bombardment are possibly responsible for the stability of the CL in the LiSrBO₃:Sm³⁺ phosphor.     

Error detection and correction in switched linear controllers via periodic and non-concurrent checks

Control systems that utilize switched linear controllers have proven to be useful (and, in some cases, essential) for accomplishing certain control objectives in particular classes of plants. These controllers are often digital in nature and, as such, are subject to internal hardware malfunctions (faults). In this paper, we present a systematic methodology for constructing embeddings to protect switched linear controllers against hardware faults that corrupt their internal state. Our methodology is based on replacing the original controller with a redundant (higher dimensional) controller that preserves the functionality of the original controller while enabling error detection and correction. More importantly, this methodology allows an external mechanism to detect and identify transient state-transition faults through non-concurrent (e.g. periodic) parity checks. The resulting error detection and correction procedures can then be performed periodically, thereby relaxing the reliability requirements and overhead associated with the checking mechanism.