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Luminescent polybenzoxazine: Synthesis, characterization, and photophysical properties

Research Abstract

Polybenzoxazines are a class of luminescent polymers that exhibit light emission properties, making them suitable for various applications. This manuscript presents the synthesis, characterization, and thermal behavior of a novel luminescent polybenzoxazine, named P‐BZ‐CP. The synthesis of P‐BZ‐CP involved a three‐stage process, starting with the formation of Bis‐OHOMe through the reaction of cyclopentanone and vanillin, followed by a Mannich condensation reaction with p‐toluidine to obtain the monomer M‐BZ‐CP. Thermal ring‐opening polymerization of M‐BZ‐CP at 250°C resulted in the synthesis of P‐BZ‐CP. Comprehensive characterization techniques, including NMR, FTIR, XRD, SEM, TGA, and DSC, were employed to analyze the structure and properties of both M‐BZ‐CP and P‐BZ‐CP. The thermal behavior of M‐BZ‐CP curing was investigated using DSC, highlighting the temperature‐dependent …

Research Authors
Osama Younis, Aya Khamies, Xinchun Yang, Kamal I Aly
Research Date
Research Department
Research Journal
Polymers for Advanced Technologies
Research Member
Research Year
2024

Fabrication and impact on photocatalytic activity of Cu-doped ZnO/SnO2 nanostructures with for enhancing the electrochemical performance

Research Abstract

This study employed the ball milling process to successfully craft nanostructures of Cu-doped ZnO/SnO2 (ZOSn/Cu), which were thoroughly characterized through various methods. The X-ray diffraction (XRD) analysis revealed the presence of the Zn2SnO4 cubic spinel phase in the nanostructure samples, along with diffraction peaks corresponding to ZnO or SnO2 phases. Notably, the photocatalytic degradation performance of the structured catalysts was greatly improved compared to undoped ZOSn/Cu nanostructures, achieving MB elimination rates of 60% and 80% after 120 min of irradiation, with an overall degradation of approximately 90%. The ZOSn/Cu electrode, designed for energy storage, demonstrated superior performance, boasting a specific capacitance of 380.0 Fg−1, outperforming the pure ZOSn/Cu electrode. Its trimetallic composition of zinc, copper, and tin contributed to enhanced electrochemical properties. This electrode demonstrated excellent cyclic stability, maintaining around 90% of its capacity, along with key characteristics like corrosion resistance, high conductivity, and a wealth of active sites. These properties make it highly promising for advanced energy storage applications.

Research Authors
Hasna Abdullah Alali, K. Omri, Sajid Ali Ansari, K. Alamer, O. Saber, H. Mahfoz Kotb, Z. Alhashem, Shrouq H. Aleithan
Research Date
Research Department
Research Journal
Transition Metal Chemistry
Research Pages
11
Research Publisher
Springer
Research Rank
Q3
Research Vol
https://doi.org/10.1007/s11243-024-00626-2
Research Website
https://doi.org/10.1007/s11243-024-00626-2
Research Year
2024

Enhanced Control of Nonlinear Systems Under Control Input Constraints and Faults: A Neural Network-Based Integral Fuzzy Sliding Mode Approach

Research Abstract

Many existing control techniques proposed in the literature tend to overlook faults and physical limitations in the systems, which significantly restricts their applicability to practical, real-world systems. Consequently, there is an urgent necessity to advance the control and synchronization of such systems in real-world scenarios, specifically when faced with the challenges posed by faults and physical limitations in their control actuators. Motivated by this, our study unveils an innovative control approach that combines a neural network-based sliding mode algorithm with fuzzy logic systems to handle nonlinear systems. This proposed controller is further enhanced with an intelligent observer that takes into account potential faults and limitations in the control actuator, and it integrates a fuzzy logic engine to regulate its operations, thus reducing system chatter and increasing its adaptability. This strategy enables the system to maintain regulation in the face of control input constraints and faults and ensures that the closed-loop system will achieve convergence within a finite-time frame. The detailed explanation of the control design confirms its finite-time stability. The robust performance of the proposed controller applied to autonomous and non-autonomous systems grappling with control input limitations and faults demonstrates its effectiveness.

 
Research Authors
Guangyi Yang, Stelios Bekiros, Qijia Yao, Jun Mou, Ayman A Aly, Osama R Sayed
Research Date
Research Department
Research Journal
Entropy
Research Member
Research Pages
1078
Research Vol
26
Research Year
2024

Occurrence, distribution, and composition of black sand along the Red Sea, Egypt

Research Abstract

Black sand along the Red Sea is often composed of volcanic minerals and heavy minerals. The Red Sea region is known for its unique geological features, and black sand beaches can be found in various areas along its shores. The study presents a comprehensive semi-quantitative chemical analysis of black sand samples collected from various locations along the red sea, revealing significant variations in their elemental compositions. The main oxides were identified in each sample, determined through X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses, indicate diverse mineralogical compositions. The spatial distribution of minerals at each site is depicted through mapping. Additionally, Fourier-transform infrared (FTIR) spectra offer information on the functional groups present in the samples, revealing the existence of hydroxyl groups, aliphatic compounds, and adsorbed water molecules. For Qusier …

Research Authors
Mohamed Hamed, Mohamed Abd El-Aal, Mostafa A Khaled, Sobhi M Ghoneim, Eman Saad, Jae-Seong Lee, Alaa El-Din H Sayed
Research Date
Research Publisher
Science of The Total Environment
Research Year
2024

Black sand nanoparticles and heat stress impacts the neurological and oxidative stress indices and splenic-renal histology of Clarias gariepinus

Research Abstract

In Egypt, while many studies have focused on the radiometry and mineralogy of black sands, research on their effects on nearby aquatic organisms is rare. This study aimed to assess the combined effects of heat stress (HS) and black sand nanoparticles (BS-NPs) on renal function, antioxidant responses (TAC, SOD, CAT), neuro-stress indicators (AchE, cortisol), and to conduct histopathological investigations in the kidney and spleen tissues of African catfish Clarias gariepinus over a 15-day period to exposure to control, HS (32 °C), BS (6.4 g/kg diet) and HS + BS groups. The outcomes revealed that thermal stress alone showed no significant difference from the control. However, creatinine and uric acid levels were significantly higher in the BS-NPs and HS + BS-NPs groups (p < 0.001). Antioxidant markers (TAC, SOD, and CAT) were substantially reduced across all treated groups (0.05 ≥ p < 0.0001 …

Research Authors
Alaa El-Din Hamid Sayed, Rashad EM Said, Mohamed Abd El-Aal, Eman Saad, Walied A Kamel, Mohamed Hamed
Research Date
Research Department
Research Journal
Scientific Reports
Research Publisher
Nature Publishing Group UK
Research Year
2024

Differential susceptibility to hypoxia in hypoxia-inducible factor 1-alpha (HIF-1α)-targeted freshwater water flea Daphnia magna mutants

Research Abstract

The water flea, Daphnia magna, serves as a key model organism for investigating the response of aquatic organisms to environmental stressors, including hypoxia. Hypoxia-inducible factor 1-alpha (HIF-1α) is a central regulatory protein involved in the cellular response to hypoxic conditions. In this study, we used CRISPR/Cas9 gene editing to create D. magna mutant lines with targeted alterations in the HIF-1α gene. Mutants demonstrated decreased survival and reproductive output and down-regulated genes for the HIF-1α–mediated pathway in low-oxygen conditions. These findings suggest that the HIF-1α pathway is a critical component of resistance to hypoxia in D. magna. This study provides novel insights into the molecular basis of hypoxia tolerance of HIF-1α in D. magna and expands our understanding of how aquatic organisms can adapt to or be challenged by changing oxygen levels in the face of global …

Research Authors
Yoseop Lee, Eunjin Byeon, Jin-Sol Lee, Piotr Maszczyk, Hyung Sik Kim, Alaa El-Din H Sayed, Zhou Yang, Jae-Seong Lee, Duck-Hyun Kim
Research Date
Research Department
Research Journal
Marine Pollution Bulletin
Research Member
Research Year
2024

Climate Change Induce the Toxicity of Black Sand Nanoparticles on Catfish (Clarias gariepinus) Using Hemato-Hepatological Biomarkers

Research Abstract

This study aimed to explore the effects of heat stress and black sand acute exposure on the erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices. Catfish were subjected to black sand nanoparticles (6.4 g of nanoparticles black sand per kg of diet), thermal stress (32 °C), and a combined treatment involving both stressors over a period of 15 days. Catfish exposed to black sand nanoparticles and heat stress singly and/or in combination showed significantly lower red blood cells (RBCs) count, hemoglobin (Hb), platelets, white blood cells (WBCs) count, large lymphocytes, small lymphocytes, and monocytes. Antioxidant indices decreased in black sand NPs and heat stress combination compared to other groups. Notably, the combination of black sand nanoparticles and heat stress led to a substantial increase in the percentages of both RBCs alterations and nuclear abnormalities. Histological examinations of the liver revealed various features, including intracellular bleeding, cytoplasmic vacuolation, tissue deterioration, hepatocyte pyknotic nuclei, nuclear displacement, shrinkage, and accumulation of melanomacrophage cells. In conclusion, the study underscores that the effects of black sand nanoparticles on erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices, become more pronounced under elevated temperatures indicating the potential for synergistic effects between pollution and climate change. This holistic approach is crucial for developing more accurate forecasts of the complex interactions between environmental stressors and their implications for aquatic ecosystems.

Research Authors
Alaa El-Din H Sayed, Mohamed Hamed, Mohamed Abd El-Aal, Mervat Naguib, Eman Saad, Hamdy AM Soliman
Research Date
Research Department
Research Journal
BioNanoScience
Research Year
2024

Toxicity and speciation of inorganic arsenics and their adverse effects on in vivo endpoints and oxidative stress in the marine medaka Oryzias melastigma

Research Abstract

Here, we investigate the effects of acute and chronic exposure to arsenate (AsV) and arsenite (AsIII) in the marine medaka Oryzias melastigmaIn vivo effects, biotransformation, and oxidative stress were studied in marine medaka exposed to the two inorganic arsenics for 4 or 28 days. An investigation of embryonic development revealed no effect on in vivo parameters, but the hatching rate increased in the group exposed to AsIII. Exposure to AsIII also caused the greatest accumulation of arsenic in medaka. For acute exposure, the ratio of AsV to AsIII was higher than that of chronic exposure, indicating that bioaccumulation of inorganic arsenic can induce oxidative stress. The largest increase in oxidative stress was observed following acute exposure to AsIII, but no significant degree of oxidative stress was induced by chronic exposure. During acute exposure to AsV, the increase in the enzymatic activity of …

Research Authors
Eunjin Byeon, Haksoo Jeong, Min-Sub Kim, Seong Chan Yun, Jin-Sol Lee, Min-Chul Lee, Jin-Hyoung Kim, Alaa El-Din Hamid Sayed, Jun Bo, Hyung Sik Kim, Chulho Yoon, Atsushi Hagiwara, Yoshitaka Sakakura, Jae-Seong Lee
Research Date
Research Department
Research Journal
Journal of Hazardous Materials
Research Member
Research Year
2024

Melatonin counteracts polyethylene microplastics induced adreno-cortical damage in male albino rats

Research Abstract

There are various substances that can disrupt the homeostatic mechanisms of the body, defined as endocrine-disrupting chemicals (EDCs). The persistent nature of microplastics (MPs) is a cause for concern due to their ability to accumulate in food chains and widespread use, making their toxic effects particularly alarming. The potential of MPs for disrupting the endocrine system was observed in multiple tissues. Moreover, the adrenal gland is known to be extremely sensitive to EDCs, while with the effect of MPs on the adrenal gland has not previously been studied. This study aimed to highlight the potential polyethylene microplastics (PE-MPs) induced adreno-toxic effects rather than exploring the implicated mechanisms and concluding if melatonin (Mel) can afford protection against PE-MPs induced adreno-toxicity. To fulfill the goal, six groups of rats were used; control, Mel, PE-MPs (3.75 mg/kg), PE-MPs (15 …

Research Authors
Amina A Farag, Heba Bayoumi, Shaimaa E Radwaan, Walaa Bayoumie El Gazzar, Heba S Youssef, Hend Elsayed Nasr, Amira M Badr, Heba M Mansour, Amira Elalfy, Alaa El-Din Hamid Sayed, Tayseir G Kharboush, Elshaimaa Ahmed Fahmy Aboelkomsan, Rania E Sliem
Research Department
Research Journal
Ecotoxicology and Environmental Safety
Research Member
Research Year
2024

Reproductive and endocrine-disrupting toxicity of pyrogallol in catfish (Clarias gariepinus)

Research Abstract

Endocrine disruptors are synthetic or natural chemicals that can agonize/antagonize hormone receptors or can interfere with the production and secretion of hormones, leading to altered tissue histology and physiology. Pyrogallol is a contaminant widely distributed in aquatic environments that presents health risks to both humans and animals. However, the potential for endocrine disruption by pyrogallol, particularly in fish, are lacking. The purpose of this study was to shed light on how pyrogallol may affect hormone signalling, histopathology, and reproductive outcomes in African catfish Clarias gariepinus. To investigate this, African catfish were exposed to one sublethal concentration of pyrogallol at either 0, 1, 5 or 10 mg/L for 15 days. We then assessed the effects of pyrogallol on the thyroid gland as well as the reproductive system by measuring sex hormone, seminal quality, gonadal histopathology, and …

Research Authors
Mohamed Hamed, Rashad EM Said, Christopher J Martyniuk, Hamdy AM Soliman, Alaa El-Din H Sayed, Alaa GM Osman
Research Date
Research Department
Research Journal
Environmental Pollution
Research Member
Research Year
2024
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