Gamma irradiation induced surface modification of (PVC/HDPE)/ZnO nanocomposite for enhancing the oil removal and conductivity using COMSOL multiphysics

Blend nanocomposite film was prepared by loadings of irradiated ZnO in ratios of (5 wt%) inside the PVC/HDPE matrix using a hot-melt extruder technique. The physical and chemical properties of the irradiated and unirradiated ZnO samples are compared. The Vis-UV spectrum of ZnO shows an absorption peak at a wavelength of 373 nm that was slightly red-shifted to 375 nm for an irradiated sample of ZnO at a dose of 25 kGy due to the defect of crystal structure by the oxygen vacancy during gamma irradiations. This growth of the defect site leads to a decrease in energy gaps from 3.8 to 2.08 eV. AC conductivity of ZnO sample increased after the gamma irradiation process (25 kGy). The (PVC/HDPE)/ZnO nanocomposites were re-irradiated with γ rays at 25 kGy in the presence of four different media (silicon oil, sodium silicate, paraffin wax and water). FTIR and XRD were performed to monitor the changes in chemical composition. The new peak at 1723 cm^-1 attributed to C=O groups was observed in irradiated (PVC/HDPE)ZnO samples at only sodium silicate and water media. This process induced new function groups on the surface of the (PVC/HDPE)/ZnO blend sample. This work aims to develop (PVC/HDPE)ZnO for oil/water separation. The highest oil adsorption capability was observed in samples functionalized by C=O groups based on the different tested oils. The results suggest that the surface characterization of the (PVC/HDPE)/ZnO can be modified to enhance the oil adsorption potential. Further, the gamma irradiation dose significantly enhanced the AC conductivity compared to the unirradiated sample. According to COMSOL Multiphysics, the irradiated sample (PVC/HDPE)ZnO in water shows perfect uniform electric field distribution in medium voltage cables (22.000 V).

Antithrombotics prescription pattern and clinical outcomes in atrial fibrillation patients with type 2 diabetes mellitus

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) and Diabetes mellitus (DM) often coexist. As DM is considered while calculating the thromboembolic risk for AF patients, little is known about the prescription pattern of antithrombotic therapies in patients with AF and DM and their clinical outcomes.

Purpose

In this subsidiary study, we examined the prescription patterns of antithrombotic therapies and clinical outcomes of AF patients with type 2 DM.

Methods

We analyzed data from a single-center cohort of patients with a primary diagnosis of AF in a tertiary cardiac referral hospital in Malaysia from 1st January 2018 to 31st December 2020. Patients' clinical data and information related to antithrombotic therapy were traced through electronic Hospital Information system. A data collection form was used for data collection. The primary endpoint of the study was a composite cardiovascular (CV) event which consists of all-cause mortality, acute coronary syndrome (ACS), ischemic stroke and transient ischemic attack (TIA). The safety endpoint of the study was a bleeding event, defined as hemoglobin drop more than 2 g/dl, blood transfusion and bleeding at critical area.

Results

Of the 1006 AF patients (59.2% male; mean age 64.2 (12.1) years), 400 (39.8%) had a history of DM. Of these, 45.8% (n=183) were using warfarin; 46.5% (n=159) used direct oral anticoagulant (DOAC), 54.0% (n=216) used a single antiplatelet, 11.5% (n=46) used a double antiplatelet, 8.0% (n=32) used triple therapy which consists of two antiplatelet agents with one anticoagulant. The use of single antiplatelet agent (54.0% vs 46.4%, p=0.018) and double antiplatelet agents (11.5% vs 7.1%, p=0.016) was significantly associated with AF with DM patients, whereas there was no association between anticoagulant use and AF patients with or without DM (85.5% vs 82.5%, p=0.209). There was no association in composite CV events between AF patients with or without DM (12.0% vs 10.4%, p=0.427). The proportion of subjects who reported having bleeding events were also did not differ by the presence of AF patients with or without DM. (4.5% vs 2.8%, p=0.151).

Conclusion

Diabetes was associated with increased use of antiplatelet agents; however, DM was not associated with increased risk of composite CV events and bleeding events in patients with concurrent AF. The lack of an association between diabetes and CV risk contrasts with previous research, which could be due to improved diabetes treatment in this cohort of patients with relatively low fasting sugar readings. Further study on the degree of blood glucose as measured by glycosylated hemoglobin (HbA1c) is needed to confirm the finding.

Impact of γ-irradiation and SBR content in the compatibility of aminated (PVC/LLDPE)/ZnO for improving their AC conductivity and oil removal

In some cases, blends containing PVC and LLDPE show low compatibility. Adding styrene-butadiene rubber to the PVC/LLDPE mixtures leads to a noticeable increase in tensile strength and compatibility of the blends. Also, an improvement in tensile strength is observed after incorporating SBR compatibilizer resulting in entirely different gamma irradiation doses. Without a compatibilizer, the mixture exhibits a distributed PVC and LLDPE phase with variable sizes and shapes; even a sizable portion of the domains resemble droplets. Styrene butadiene rubber (SBR) and gamma radiation make mixtures of (PVC/LLDPE) more compatible. The SEM study of the blends demonstrated that adding the compatibilizer resulted in finer blend morphologies with less roughness. At the same time, gamma irradiation reduced this droplet and gave a more smooth surface. Poly(vinyl chloride) (PVC) was chemically modified with four different amino compounds, including ethylene diamine (EDA), aniline (An), p-anisidine (pA) and dimethyl aniline (DMA) for improving the electric conductivity and oil removal capability of the blend polymer. All ionomers were prepared by nucleophilic substitution in a solvent/non-solvent system under mild conditions. This work novelty shows a sustainable route for producing oil adsorption materials by recycling plastic waste. After the amination process of poly(vinyl chloride) the oil adsorption was significantly enhanced.

Experimental investigation of E-beam effect on the electric field distribution in cross-linked polyethylene/ZnO nanocomposites for medium-voltage cables simulated by COMSOL Multiphysics

This study investigated the electric field distribution of underground cable insulation in cross-linked polyethylene/zinc oxide (XLPE/ ZnO) nanoparticles (NPs) for medium-voltage (MV) cables. The ZnO NPs that were obtained by three methods of preparation were classified using transmission electron microscopy (TEM). The obtained ZnO NPs were semi-spheres with sizes of 35–55 nm on TEM images. XLPE/ ZnO films with various ZnO NP weight contents (i.e., 0, 1, 3, and 5%) were exposed to varied dosages of 3-MeV electron beam (EB); 0 kGy, 15 kGy, 20 kGy, and 25 kGy. The optimum film XLPE/ 5-ZnO, which has ZnO NP content (5 wt%), irradiated at 25 kGy, according to alternating current (AC)/ DC conductivity (AC: 1 × 10−4 S/m; DC: 12.44 × 10−2 S/m) in minimum relative permittivity (2.24), was obtained. COMSOL Multiphysics was used to simulate the electric field distribution within an MV cable of 25-kGy XLPE/ 5-ZnO insulation. The maximum uniform electric field was found in the middle of the 25-kGy XLPE/5-ZnO film sample, rather than at the top or bottom, which might be attributed to the significantly low relative permittivity of the new 25-kGy XLPE/5-ZnO film cable.

Prevalence of obesity and risk of chronic kidney disease among young adults in Egypt

Increasing body mass index (BMI) has reached epidemic proportions globally and recently emerged as strong, independent risk factors for chronic kidney disease (CKD). We conducted this study to verify the prevalence of obesity and the associated risk of developing CKD among 3000 Egyptian students. The World Health Organization classification of BMI categorized study population into 1-5 groups, 1146 subjects with normal BMI (20-25), 951 subjects with BMI 25-29.9, 540 subjects with BMI 30-34.9, 225 with BMI 35-39.9, and 138 with BMI above 40. The participants were subjected to clinical examination, anthropometric measurements, laboratory investigation, including urinary albumin/creatinine ratio (ACR) and estimation of glomerular filtration rate (eGFR). The prevalence of overweight, obesity, and metabolic syndrome (MS) was 31.7%, 30.1%, and 16%, respectively. The prevalence of CKD among subjects with BMI >25 was 6.5%, almost all of them had BMI >35. ACR and eGFR rose progressively with increasing BMI. Elevated mean arterial pressure (MAP), high sensitivity C-reactive protein, and MS increased the risk of development of CKD. Moreover, MAP, waist to height ratio, and triglycerides to high-density lipoprotein ratios at levels of >95 mm Hg, >0.6, and >3 had sensitivity 91.7%, 88.4%, and 86.7%; and specificity 92.3%, 96.4%, and 96.5%, respectively to predict CKD. The prevalence of obesity among Egyptian young adults was high (30.1%) and was associated with increased the risk of CKD (6.5%).

Metal chelates of phosphonate-containing ligands-V Stability of some 1-hydroxyethane-1,1-diphosphonic acid metal chelates

A detailed study of the complexes formed between 1-hydroxyethane-1,1-diphosphonic acid and twelve metal ions, including the alkaline earth and transition non-transition metal ions, is reported. The formation constants of the protonated and unprotonated complexes are measured from potentiometric data and possible structural formulae are given. The results reveal that only mononuclear (1:1) di-, mono- and unprotonated metal chelates are formed and that the general order of stability for the unprotonated complexes is Zn > Mn > Ca > Cu > Cd > Pd > Ni > Co reverse similar Sr > Mg > Ag > Ba.

Physical characteristics and polarographic reduction mechanism of some oxazolones

The redox potential (ΔE1/2), electron affinity (EA), ionization potential (IP), coulomb repulsion integral (J12), and electronic transition energy (ECT) of several oxazolone derivatives in DMF were computed. A linear correlation was shown to exist between ΔE1/2 and ECT• The polarographic reduction was investigated in ethanolic-Theil buffer solutions. At pH ≤ 7.2, two waves were obtained representing the uptake of 2- and 4-electron steps respectively. In alkaline media, a third wave appeared seemingly a result of the hydrolysis of oxazolones. The rate of hydrolysis was determined and the electrode mechanism was elucidated and confirmed via spectrophotometric and coulometric analysis. Key words: oxazolones, polarography, electrochemistry, electrode reaction, spectrophotometry, redox potential.