Miscibility and Crystallization Behavior of Poly(ethylene terephthalate)/Poly(vinylidene fluoride) Blends

Poly(ethylene terephthalate) (PET) and poly(vinylidene fluoride) (PVF₂) are miscible in the melt‐state for the whole composition range. The glass transition temperature (T_g) of the solvent cast film decreases with the decrease in W_PET (weight fraction of PET) in the blend, however, the T_g for the repeated melt quenched blends remains invariant with W_PET. The melting point (T_m) and crystallization temperature (T_c) of PET decrease significantly with decrease in W_PET in the blend, but the T_m and T_c of PVF₂ decrease slightly with increase in W_PET. The crystallinity of both PET and PVF₂ decreases with increasing concentration of the other component in the blend, however, the decrease is larger for the former. The equilibrium melting points (T_m⁰'s) of PET in the blends are determined by the extrapolation procedures using (i) T_m–T_c method for 5% crystallinity and (ii) T_m–T_a method, where T_m, T_c and T_a are melting, crystallization and annealing temperatures, respectively. The data of both the methods indicate a large depression of T_m⁰ of PET with increase in PVF₂ concentration. The χ₁₂ values determined from both the data are essentially the same, –0.14. This negative value of χ₁₂ indicates that the two polymers are miscible in the melt‐state, however, they are not miscible in the crystalline state. The onset of degradation of PET increases with increase in PVF₂ concentration in the blend.     

CuO Bionanocomposite with Enhanced Stability and Antibacterial Activity against Extended-Spectrum Beta-Lactamase Strains

Worldwide, bacterial resistance to beta-lactam antibiotics is the greatest challenge in public health care. To overcome the issue, metal-based nanoparticles were extensively used as an alternative to traditional antibiotics. However, their unstable nature limits their use. In the present study a very simple, environmentally friendly, one-pot synthesis method that avoids the use of organic solvents has been proposed to design stable, novel nanocomposites. Formulation was done by mixing biogenic copper oxide (CuO) nanomaterial with glycerol and phospholipids isolated from egg yolk in an appropriate ratio at optimum conditions. Characterization was done using dynamic light scattering DLS, Zeta potential, high performance liquid chromatography (HPLC), and transmission electron microscopy (TEM). Further, its antibacterial activity was evaluated against the extended-spectrum beta-lactamase strains based on zone of inhibition and minimal inhibitory concentration (MIC) indices. Results from this study have demonstrated the formulation of stable nanocomposites with a zeta potential of 34.9 mV. TEM results indicated clear dispersed particles with an average of 59.3 ± 5 nm size. Furthermore, HPLC analysis of the egg yolk extract exhibits the presence of phospholipids in the sample and has significance in terms of stability. The newly formed nanocomposite has momentous antibacterial activity with MIC 62.5 μg/mL. The results suggest that it could be a good candidate for drug delivery in terms of bactericidal therapeutic applications.     

A Review of COVID-19 Modelling Strategies in Three Countries to Develop a Research Framework for Regional Areas

At the end of December 2019, an outbreak of COVID-19 occurred in Wuhan city, China. Modelling plays a crucial role in developing a strategy to prevent a disease outbreak from spreading around the globe. Models have contributed to the perspicacity of epidemiological variations between and within nations and the planning of desired control strategies. In this paper, a literature review was conducted to summarise knowledge about COVID-19 disease modelling in three countries—China, the UK and Australia—to develop a robust research framework for the regional areas that are urban and rural health districts of New South Wales, Australia. In different aspects of modelling, summarising disease and intervention strategies can help policymakers control the outbreak of COVID-19 and may motivate modelling disease-related research at a finer level of regional geospatial scales in the future.     

Genetic,structural and functional properties of an IgG DNA-binding monoclonal antibody from a lupus patient with nephritis

Antibodies binding to double-stranded (ds) DNA are strongly associated with renal involvement in patients with systemic lupus erythematosus (SLE). We have generated two new IgG DNA-binding monoclonal antibodies (mAb), RH-14 and DIL-6, from the peripheral blood lymphocytes of two SLE patients with glomerulonephritis using the heteromyeloma cell line CB-F7. RH-14 is an IgG1 λ antibody which also bound to single-stranded (ss)DNA, histones and nucleosomes. DIL-6 is an IgG3 λ antibody with restricted antigen binding specificity. cDNA encoding the variable regions of the heavy (V_H) and light (V_L) chains of RH-14 was sequenced and the antigen binding site of this mAb was computer modelled. Sequence analysis of V_H and V_L regions of RH-14 showed that V_H is derived from germ-line gene V3-7, a member of the V_H3 family, and V_L is derived from DPL 11, a member of the V_λ2 family. Somatic mutations and basic amino acid residues are identified in the complementarity- determining regions of both V_H and V_L regions. The nephritogenic properties of these mAb were analyzed by implanting and growing the hybridoma cells secreting the mAb in the peri toneum of SCID mice. The animals that received the RH-14 hybridoma produced higher levels of proteinuria (3 to ≥ 4) (p < 0.001) compared to the groups that received DIL-6 (trace to ≥ 1) or CB-F7 (trace). Electron microscopy of kidney sections from all the RH-14- implanted animals showed granular immunoglobulin deposition in the renal glomerular capil laries and mesangium. In this study we have shown for the first time using electron micros copy that a human IgG anti-dsDNA mAb, RH-14, is nephritogenic and that deposition of such an antibody alone is sufficient to induce renal damage.     

Prolonged ventricular pause associated with ticagrelor use: A case report

CaseWe report a case of a 76‐year‐old female who presented with non‐ST elevation myocardial infarction and developed a 22‐second ventricular pause with ticagrelor that did not recur after shifting to clopidogrel. Based on the Naranjo algorithm, the likelihood that our patient''s prolonged ventricular pause was due to ticagrelor exposure was probable.ConclusionTicagrelor use is associated with prolonged ventricular pauses, warranting close monitoring, particularly during the first week of therapy.     

Synthesis and Characterization of Manganese-Modified Black TiO2 Nanoparticles and Their Performance Evaluation for the Photodegradation of Phenolic Compounds from Wastewater

The release of phenolic-contaminated treated palm oil mill effluent (TPOME) poses a severe threat to human and environmental health. In this work, manganese-modified black TiO₂ (Mn-B-TiO₂) was produced for the photodegradation of high concentrations of total phenolic compounds from TPOME. A modified glycerol-assisted technique was used to synthesize visible-light-sensitive black TiO₂ nanoparticles (NPs), which were then calcined at 300 °C for 60 min for conversion to anatase crystalline phase. The black TiO₂ was further modified with manganese by utilizing a wet impregnation technique. Visible light absorption, charge carrier separation, and electron–hole pair recombination suppression were all improved when the band structure of TiO₂ was tuned by producing Ti³⁺ defect states. As a result of the enhanced optical and electrical characteristics of black TiO₂ NPs, phenolic compounds were removed from TPOME at a rate of 48.17%, which is 2.6 times higher than P25 (18%). When Mn was added to black TiO₂ NPs, the Ti ion in the TiO₂ lattice was replaced by Mn, causing a large redshift of the optical absorption edges and enhanced photodegradation of phenolic compounds from TPOME. The photodegradation efficiency of phenolic compounds by Mn-B-TiO₂ improved to 60.12% from 48.17% at 0.3 wt% Mn doping concentration. The removal efficiency of phenolic compounds from TPOME diminished when Mn doping exceeded the optimum threshold (0.3 wt%). According to the findings, Mn-modified black TiO₂ NPs are the most effective, as they combine the advantages of both black TiO₂ and Mn doping.     

Correlation between severity of coronary artery stenosis and perfusion defect assessed by SPECT myocardial perfusion imaging

Numerous non-invasive techniques are developed to assess the severity of coronary artery disease (CAD). Coronary angiography (CAG) is an established method for the diagnosis and to quantify the severity of coronary artery stenosis. Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) using Technetium-99m (Tc-99m) tetrofosmin is also a useful established technique for the assessment of severity of CAD. This prospective observational study was carried out in Bangabandhu Sheikh Mujib Medical University (BSMMU) to assess the severity of coronary artery stenosis using Tc-99m Single Photon Emission Computed Tomography myocardial perfusion imaging (SPECT-MPI) in comparison with CAG. Eighty two (82) consecutive patients with mean age 53.51(SD+/-7.08) years and Candian Cardiovascular Society (CCS) class I and II severity of chest pain, male: female ratio (4.8:1) was studied. Tc-99m SPECT-MPI was performed by one-day exercise stress and rest protocol. A total of two hundred and forty six coronary artery territories examined in this study. By CAG normal coronary arteries were found in seventy six, moderate stenosis in twenty four and severe stenosis in one hundred and forty-six coronary artery territories whereas SPECT-MPI found normal perfusion in twenty seven, mild perfusion abnormality in seventeen, moderate perfusion abnormality in thirty two and severe perfusion abnormality in one hundred and sixty five coronary artery territories. Sensitivity and specificity of SPECT-MPI using Tc-99m tetrofosmin in detecting coronary artery stenosis were 87.09% and 80.95% respectively. The positive predictive value, negative predictive value and accuracy of the test were 91.01%, 73.91% and 85.18% respectively. From this study it can be concluded that Tc-99m SPECT-MPI was a safe, effective and excellent non-invasive tool for the detection of severity of coronary artery lesion and can be used to predict severity of CAD.     

Health benefits of cyanidin-3-glucoside as a potent modulator of Nrf2-mediated oxidative stress

Inflammopharmacology - Berries are natural sources of anthocyanins, especially cyanidin-3-glucoside (C3G), and exhibit significant antioxidant, antidiabetic, anti-inflammatory, and cytoprotective...