Nanoarchitectonics of Ba0.97La0.02Ti1-xNb4x/5O3 (x = 0.00 and 0.10) polycrystalline compounds with electrical and optical properties

Journal of Materials Science: Materials in Electronics - A lead-free solid solution, of a composition Ba0.97La0.02Ti1-xNb4x/5O3 (for x?=?0.00 and 0.10) (noted BLT, BLT0.9Nb0.08), was...     

Lightweight Transfer Learning Models for Ultrasound-Guided Classification of COVID-19 Patients

Lightweight deep convolutional neural networks (CNNs) present a good solution to achieve fast and accurate image-guided diagnostic procedures of COVID-19 patients. Recently, advantages of portable Ultrasound (US) imaging such as simplicity and safe procedures have attracted many radiologists for scanning suspected COVID-19 cases. In this paper, a new framework of lightweight deep learning classifiers, namely COVID-LWNet is proposed to identify COVID-19 and pneumonia abnormalities in US images. Compared to traditional deep learning models, lightweight CNNs showed significant performance of real-time vision applications by using mobile devices with limited hardware resources. Four main lightweight deep learning models, namely MobileNets, ShuffleNets, MENet and MnasNet have been proposed to identify the health status of lungs using US images. Public image dataset (POCUS) was used to validate our proposed COVID-LWNet framework successfully. Three classes of infectious COVID-19, bacterial pneumonia, and the healthy lung were investigated in this study. The results showed that the performance of our proposed MnasNet classifier achieved the best accuracy score and shortest training time of 99.0% and 647.0 s, respectively. This paper demonstrates the feasibility of using our proposed COVID-LWNet framework as a new mobile-based radiological tool for clinical diagnosis of COVID-19 and other lung diseases.     

Composites based on (ethylene–propylene) copolymer and olive solid waste: Rheological,thermal, mechanical,and morphological behaviors

In the olive oil‐producing countries, large quantities of olive solid waste are dumped in nature causing several environmental problems. Therefore, the use of this by‐product as filler in (ethylene–propylene) matrix could be an effective way to reduce significantly the quantities of the disposed biomass and elaborate a cost‐effective material. However, the hydrophilic nature of this natural filler decreases the compatibility with the hydrophobic matrix. To improve the interfacial adhesion, maleated polypropylene was added as a compatibilizing agent. In a first step, the influence of the filler loading on the rheological, thermal, and mechanical properties was investigated. Composites with various filler contents were prepared by melt blending using a twin‐screw extruder and injection molding. The filler addition led to an increase of the viscoelastic properties and the crystallinity degree. Then, the coupling agent (MAPP) was reported to enhance the rheological, thermal, and mechanical properties of the composites up to a critical amount beyond which the plasticizing effect becomes more predominant than the reinforcing effect, a fact that could be responsible for the decrease of viscoelastic properties, crystallinity, and mechanical properties. POLYM. ENG. SCI., 56:27–35, 2016. © 2015 Society of Plastics Engineers     

Evaluation of activated carbons based on olive stones as catalysts during hydrogen production by thermocatalytic decomposition of methane

Catalytic decomposition of methane over carbon materials has been intensively studied as an environmental approach for CO₂-free hydrogen production without further by-products except hydrogen and valuable carbon. In this work, we will investigate the catalytic activity of activated carbons based on olive stones prepared by two different processes. Additionally, the effect of three major operational parameters: temperature, weight of catalyst and flow rate of methane, was determined. Therefore, a series of experiments were conducted in a horizontal-flow fixed bed reactor. The outflow gases were analysed using a mass spectrometer. The textural, structural and surface chemistry properties of both fresh and used activated carbons were determined respectively by N₂ gas adsorption, X-Ray Diffraction and Raman and Temperature Programmed Desorption. The results reveal that methane decomposition rate increases with temperature and methane flow however it decreases with catalyst weight. The two carbon samples exhibit a high initial activity followed by a rapid decay. Textural characterization of the deactivated carbon presents a dramatic drop of surface area, pore and micropore volumes against an increase of average pore diameter confirming that methane decomposition occurs mainly in micropores. XRD characterization shows a turbostratic structure of fresh samples with more graphitization in deposed carbon explaining the lowest activity at the end of reaction. Raman spectra reveal the domination of the two bands G and D which varying intensities affirm that the different carbons tend to organise in aromatic rings. Finally the surface chemistry qualitatively changes greatly after methane dissociation for CAGOC unlike CAGOP but quantitatively a small difference is observed which indicates that these functionalities may have a role in this heterogeneous reaction but cannot be totally responsible. Among the two catalysts tested, CAGOC has the highest initial methane decomposition rate but CAGOP is the most stable one.     

Halting Tumor Progression via Novel Non-Hydroxamate Triazole-Based Mannich Bases MMP-2/9 Inhibitors; Design,Microwave-Assisted Synthesis,and Biological Evaluation

Matrix metalloproteinases (MMPs) are key signaling modulators in the tumor microenvironment. Among MMPs, MMP-2 and MMP-9 are receiving renewed interest as validated druggable targets for halting different tumor progression events. Over the last decades, a diverse range of MMP-2/9 inhibitors has been identified starting from the early hydroxamic acid-based peptidomimetics to the next generation non-hydroxamates. Herein, focused 1,2,4-triazole-1,2,3-triazole molecular hybrids with varying lengths and decorations, mimicking the thematic features of non-hydroxamate inhibitors, were designed and synthesized using efficient protocols and were alkylated with pharmacophoric amines to develop new Mannich bases. After full spectroscopic characterization the newly synthesized triazoles tethering Mannich bases were subjected to safety assessment via MTT assay against normal human fibroblasts, then evaluated for their potential anticancer activities against colon (Caco-2) and breast (MDA-MB 231) cancers. The relatively lengthy bis-Mannich bases 15 and 16 were safer and more potent than 5-fluorouracil with sub-micromolar IC₅₀ and promising selectivity to the screened cancer cell lines rather than normal cells. Both compounds upregulated p53 (2–5.6-fold) and suppressed cyclin D expression (0.8–0.2-fold) in the studied cancers, and thus, induced apoptosis. 15 was superior to 16 in terms of cytotoxic activities, p53 induction, and cyclin D suppression. Mechanistically, both were efficient MMP-2/9 inhibitors with comparable potencies to the reference prototype hydroxamate-based MMP inhibitor NNGH at their anticancer IC₅₀ concentrations. 15 (IC₅₀ = 0.143 µM) was 4-fold more potent than NNGH against MMP-9 with promising selectivity (3.27-fold) over MMP-2, whereas 16 was comparable to NNGH. Concerning MMP-2, 16 (IC₅₀ = 0.376 µM) was 1.2-fold more active than 15. Docking simulations predicted their possible binding modes and highlighted the possible structural determinants of MMP-2/9 inhibitory activities. Computational prediction of their physicochemical properties, ADMET, and drug-likeness metrics revealed acceptable drug-like criteria.     

Assessment of the potential of Arabic gum as an antimicrobial and antioxidant agent in developing vegan “egg-free” mayonnaise

The main factors affecting the spoilage of mayonnaise are lipid oxidation and microbial contamination. Therefore, the investigation was carried out to estimate the antimicrobial and antioxidant properties of the aqueous extract of the Arabic gum (AG). The effect of the addition of AG powder on physical–chemical and sensory properties has been evaluated in different percentages of 25, 50, 75, and 100 into mayonnaise. At the highest concentration of AG 20 mg/ml, the DPPH result represented high antioxidant activity at 92.13%. AG had inhibitory effects on gram-negative and gram-positive bacteria, with Staphylococcus aureus and Bacillus subtilis being the most susceptible bacteria. The use of AG as an egg substitute in mayonnaise has been shown to have a great effect on physical–chemical properties. All mayonnaise samples were sensory acceptable, particularly vegan mayonnaise (100% AG) and still acceptable for consumption at 5°C for 5 months of storage. AG could be considered an additive with significant emulsifier properties, antioxidant, and antimicrobial activities. Therefore, AG is a good choice to produce new vegetarian products for consumers who are unable to eat egg-based foods.     

A Novel Approach for Improving Dynamic Biometric Authentication and Verification of Human Using Eye Blinking Movement

Wireless Personal Communications - Biometric authentication is used in Smart devices to lock and unlock devices instead of a PIN. However, using devices in uncontrolled environments is highly...     

Synthesis and Evaluation of New Anionic Gemini Dispersants as Oil Dispersants to Treat Crude Oil Spill Pollution

Floating petroleum oil spills on the marine ecosystem are generally associated with an escalation of serious environmental problems. This research aimed to synthesis five water-soluble anionic Gemini dispersants to minimize the effect of floating petroleum oil spills on the marine ecosystem. Referring to the spacer type, these dispersant are classified into two categories: the first category is the three acyl amine Gemini dispersants of N,N′- diacyl, (distearoyl-, dipalmitoy-, and dimyristoyl-) N,N-′ sodium 2-hydroxy 3-propane sulfonate propane 1,3 diamine, denoted S, P, and M, and the second category is two alkyl amine Gemini dispersants of N,N′dialkyl -(dicetyl-, and dilauryl-) N,N′-sodium 2-hydroxy 3-propane sulfonate propane 1,3 diamine, denoted C and L. Fourier transform infrared and ¹H NMR spectroscopy, gel permeation chromatography, and elemental analysis were used to verify the chemical formula of the synthesized dispersants. The effectiveness of the synthesized dispersants was investigated as regards their dynamic interfacial tension, carbon–chain length, and hydrophilic–lipophilic balance. The dispersion efficiency of the synthesized dispersant was detected qualitatively and quantitatively using the screen test and Warren Spring Laboratory methods, respectively. Experimental outcomes showed that the maximum dispersion efficiency of 94.7 wt% was achieved by dispersant C at a dispersant\oil ratio of 1:20 at 25°C.     

Optimizing the Performance of the Meso-Scale Continuous-Flow Photoreactor for Efficient Photocatalytic CO2 Reduction with Water Over Pt/TiO2/RGO Composites

Catalysis Letters - Tuning the reaction parameters to maximize products yield is one of the major needs for any process. The goal of this research is to increase the reduction of CO2 with water by...     

Evaluation of synthesized polyaniline nanofibres as corrosion protection film coating on copper substrate by electrophoretic deposition

Journal of Materials Science - In this current paper, we report the use of inexpensive, simple electrophoretic deposition (EPD) technique in developing polyaniline (PANI) aqueous colloidal...