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In this work, a novel composite material based on ZnO nanoparticles incorporated into cellulose polymers has been designed and prepared. For this purpose, the ex-situ prepared ZnO nanoparticles were dispersed into cellulose using mechanical milling. The effect of the percentage of ZnO nanoparticles doping into the prepared composite was studied. Dielectric properties of composite, as influenced by the compaction density, the level of ZnO nanoparticles doping into cellulose, and the temperature, were characterized using a liquid test fixture, a precision inductance capacitance and resistance meter at a radio frequency ranging from 5 to 30 MHz. It has been shown that ε' and ε" respectively correspondent to the dielectric constant and the loss factor of composite were affected by level of ZnO nanoparticles, compaction density and temperature of the samples. Both ε' and ε" increased with increasing the temperature and the level of ZnO nanoparticles, but decreased with increasing the frequency. [ABSTRACT FROM AUTHOR]

Objective: Non-respiratory long-coronavirus disease 2019 (COVID-19) symptoms are mainly related to a long-lasting endothelial dysfunction and microcirculation impairment. We hypothesized that Sulodexide, a purified glycosaminoglycan mixture with a beneficial endothelial effect in arterial and venous peripheral diseases, may be effective in a subset of patients with long COVID-19., Approach and Results: We conducted a multicenter prospective quasi-experimental study. A total of 290 patients from the TUN-EndCOV study with long-COVID-19 symptoms and endothelial dysfunction were included. The endothelial function was clinically assessed using a post-occlusive reactive hyperemia protocol with finger thermal monitoring device. Endothelial quality index (EQI) was assessed at inclusion and at 21 days later. The study population was assigned to a sulodexide group (144 patients) or a no-medical treatment group (146 patients). Clinical characteristics were similar at inclusion in the two groups. Fatigue, shortness of breath, and chest pain were the most common symptoms, respectively, 54.5, 53.8, and 28.3%. At 21 days, the sulodexide group improved significantly better than the no-medical treatment group in chest pain (83.7 vs. 43.6%, p < 10 -3 ), palpitations (85.2 vs. 52.9%, p = 0.009), and endothelial function [median delta-EQI 0.66 (0.6) vs. 0.18 (0.3); p < 10 -3 ]. Endothelial function improvement was significantly correlated with chest pain and palpitations recovery (AUC, i.e., area under the curve = 0.66, CI [0.57- 0.75], p = 0.001 and AUC = 0.60, CI [0.51- 0.69], p = 0.03, respectively)., Conclusion: Sulodexide significantly improves long-lasting post-COVID-19 endothelial dysfunction and alleviates chest pain and palpitations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Charfeddine, Ibnhadjamor, Jdidi, Torjmen, Kraiem, Bahloul, Makni, Kallel, Moussa, Boudaya, Touil, Ghrab, Elghoul, Meddeb, Thabet, Ben Salem, Addad, Bouslama, Milouchi, Hammami, Abdessalem and Abid.)

This work is devoted to the synthesis and study of the different properties of ZnO nanoparticles (NPs) doped with the Ni element. We have used a simple co-precipitation technique for the synthesis of our samples and various structural, morphological and optical techniques for their analysis. Energy-Dispersive X-ray spectroscopy (EDX) confirms the stoichiometry of the samples. The X-Ray Diffraction (XRD) patterns reveal the hexagonal wurtzite phase of polycrystalline ZnO with a P 63 mc space group. Debye Scherrer and Williamson-Hall methods show that the average size of crystallites is around 40 nm. Transmission electron microscopy (TEM) images confirm the XRD results. The optical spectrum of Zn 0.95 Ni 0.5 O shows the presence of near-band-edge (NBE) ultraviolet emission. The absorption defect bands appearing near the blue-green region and near infrared emission are attributed to the Ni 2+ intra-3d luminescence. The electronic structure of the Ni 2+ doped ZnO NPs confirms the T d site symmetry of Ni 2+ in the ZnO host crystal and leads to a perfect correlation between calculated and experimental energy levels., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

The COVID-19 disease is a multisystem disease due in part to the vascular endothelium injury. Lasting effects and long-term sequelae could persist after the infection and may be due to persistent endothelial dysfunction. Our study focused on the evaluation of endothelial quality index (EQI) by finger thermal monitoring with E4 diagnosis Polymath in a large cohort of long COVID-19 patients to determine whether long-covid 19 symptoms are associated with endothelial dysfunction. This is a cross-sectional multicenter observational study with prospective recruitment of patients. A total of 798 patients were included in this study. A total of 618 patients (77.4%) had long COVID-19 symptoms. The mean EQI was 2.02 ± 0.99 IC 95% [1.95 - 2.08]. A total of 397 (49.7%) patients had impaired EQI. Fatigue, chest pain, and neuro-cognitive difficulties were significantly associated with endothelium dysfunction with an EQI <2 after adjustment for age, sex, diabetes, hypertension, dyslipidemia, coronary heart disease, and the severity of acute COVID-19 infection. In multivariate analysis, endothelial dysfunction (EQI <2), female gender, and severe clinical status at acute COVID-19 infection with a need for oxygen supplementation were independent risk factors of long COVID-19 syndrome. Long COVID-19 symptoms, specifically non-respiratory symptoms, are due to persistent endothelial dysfunction. These findings allow for better care of patients with long COVID-19 symptoms., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Charfeddine, Ibn Hadj Amor, Jdidi, Torjmen, Kraiem, Hammami, Bahloul, Kallel, Moussa, Touil, Ghrab, Elghoul, Meddeb, Thabet, Kammoun, Bouslama, Milouchi, Abdessalem and Abid.)

Titanium dioxide nanoparticles were widely used in food as dietary supplements, in drugs, in toothpaste, ect. Few numbers of studies were interested to the neurotoxicity of TiO 2 NPs through oral pathway. The present study aims firstly to understand the connection between the physicochemical properties of TiO 2 NPs and their associated toxicological oral pathway by evaluation the colloidal stability of TiO 2 NPs over time in different media simulating physiological gastric, intestinal and serum conditions at 37 °C to be close to the oral administraton. Secondly, this study aims to evaluate the neurotoxicity of a subchronic intragastric administration of TiO 2 NPs to rats. Different doses of anatase TiO 2 NPs were administrated to Wistar rats every day for consecutives eight weeks. Titanium (Ti) content in brain, oxidative antioxidant biomarkers, lipid peroxidation, nitric oxide (NO) levels, tumor necrosis factor-alpha (TNF-α) levels, histophatological changes, degenerated and apoptosis neurons were investigated. Results suggested that TiO 2 NPs can reach the brain and cross the brain blood barrier (BBB) to been accumulated in the brain of rats causing cerebral oxidative stress damage, increasing NO levels and histopathological injury. At higher dose, we observed the most cerebral injury by the highest accumulation of Ti and by the remarkable increase of TNF-α besides to the most increase of degenerated and apoptosis neurons in the brain of exposed rats. TiO 2 NPs led to a neurotoxic damage accompanied by the increase of degenerated and apoptotic neurons in cerebral cortex., (Copyright © 2019. Published by Elsevier Inc.)

Titanium dioxide nanoparticles (TiO 2 NPs) are widely used for their whiteness and opacity in several applications such as food colorants, drug additives, biomedical ceramic, and implanted biomaterials. Research on the neurobiological response to orally administered TiO 2 NPs is still limited. In our study, we investigate the effects of anatase TiO 2 NPs on the brain of Wistar rats after oral intake. After daily intragastric administration of anatase TiO 2 NPs (5-10 nm) at 0, 50, 100, and 200 mg/kg body weight (BW) for 60 days, the coefficient of the brain, acethylcholinesterase (AChE) activities, the level of interleukin 6 (IL-6), and the expression of glial fibrillary acidic protein (GFAP) were assessed to quantify the brain damage. The results showed that high-dose anatase TiO 2 NPs could induce a downregulated level of AChE activities and showed an increase in plasmatic IL-6 level as compared to the control group accompanied by a dose-dependent decrease inter-doses, associated to an increase in the cerebral IL-6 level as a response to a local inflammation in brain. Furthermore, we observed elevated levels of immunoreactivity to GFAP in rat cerebral cortex. We concluded that oral intake of anatase TiO 2 NPs can induce neuroinflammation and could be neurotoxic and hazardous to health.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used for their whiteness and opacity. We investigated the hematological effects and genotoxicity of anatase TiO2 NPs following sub-chronic oral gavage treatment. TiO2-NPs were characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Wistar rats were treated with anatase TiO2 NPs by intragastric administration for 60 days. Hematological analysis showed a significant decrease in RBC and HCT and a significant increase in MCV, PLT, MPV and WBC at higher doses. Furthermore, abnormally shaped red cells, sometimes containing micronuclei, and hyper-segmented neutrophil nuclei were observed with TiO2 NPs treatment. The micronucleus test revealed damage to chromosomes in rat bone marrow at 100 and 200mg/kg bw; the comet assay showed significant DNA damage at the same doses., (Copyright © 2015 Elsevier B.V. All rights reserved.)