A new method for producing optically active polybutadiene

The anionic polymerization of butadiene monomer in cyclohexane at 20°C gave polybutadiene (PB50) with a narrow molecular weight distribution. This polymer was allowed to react with 4-phenyl-1,2,4-triazoline-3,5-dione via the ‘ene’ reaction to the extent of 5, 10 and 15%. These functionalized polymers were reacted with N-phthaloyl-L -leucine acid chloride in the presence of pyridine at room temperature. These reactions lead to the replacement of N-H by an optically active group, and the resulting polymers became optically active. Some structural characterization and physical properties of these optically active polybutadienes are reported. © 1998 Society of Chemical Industry     

Immunogenicity of MultiTEP-Platform-Based Recombinant Protein Vaccine,PV-1950R,Targeting Three B-Cell Antigenic Determinants of Pathological α-Synuclein

Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) are characterized by the aberrant accumulation of intracytoplasmic misfolded and aggregated α-synuclein (α-Syn), resulting in neurodegeneration associated with inflammation. The propagation of α-Syn aggregates from cell to cell is implicated in the spreading of pathological α-Syn in the brain and disease progression. We and others demonstrated that antibodies generated after active and passive vaccinations could inhibit the propagation of pathological α-Syn in the extracellular space and prevent/inhibit disease/s in the relevant animal models. We recently tested the immunogenicity and efficacy of four DNA vaccines on the basis of the universal MultiTEP platform technology in the DLB/PD mouse model. The antibodies generated by these vaccines efficiently reduced/inhibited the accumulation of pathological α-Syn in the different brain regions and improved the motor deficit of immunized female mice. The most immunogenic and preclinically effective vaccine, PV-1950D, targeting three B-cell epitopes of pathological α-Syn simultaneously, has been selected for future IND-enabling studies. However, to ensure therapeutically potent concentrations of α-Syn antibodies in the periphery of the vaccinated elderly, we developed a recombinant protein-based MultiTEP vaccine, PV-1950R/A, and tested its immunogenicity in young and aged D-line mice. Antibody responses induced by immunizations with the PV-1950R/A vaccine and its homologous DNA counterpart, PV-1950D, in a mouse model of PD/DLB have been compared.     

Investigation of the performance of several chemical additives on inhibition of asphaltene precipitation

The inhibition effects of several chemical additives on asphaltene precipitation were investigated by the microscopic method. The additives consist of a synthesized deep eutectic solvent (SDES), a commercial inhibitor, and three surfactants, namely lauric acid, octyl phenol, and dodecyl amine. The results showed the octyl phenol with 500 mg/L concentration is similar to commercial inhibitor and later SDES had the maximum effects on delaying the asphaltene precipitation onset point. The mean particle size of asphaltene using octyl phenol, SDES, lauric acid, and dodecyl amine decreased about 55%, 41%, 24%, and 18%, respectively, compared to the oil sample without any chemical additives.     

One-pot synthesis of amphiphilic nanogels from vinylated SPIONs/HEMA/PEG via a combination of click chemistry and surfactant-free emulsion photopolymerization: Unveiling of the protein-nanoparticle interactions

In this study, freshly prepared Fe₃O₄ nanoparticles (MNP1) were coated with 3-aminopropyltriethoxysilane (APTES) to produce core–shell Fe₃O₄@SiO₂ nanoparticles (MNP2), amine terminated nanoparticles was converted into the triazide in the presence of as-prepared triflic azide (MNP3). Propargyl acrylate (PgA) was synthesized from propargyl alcohol and acryloyl chloride and their structures were characterized by FT-IR and ¹H NMR spectroscopy. MNP3 were modified by PgA via click reaction to produce fully decorated triazole product (MNP4). Photopolymerization of MNP4 in the presence of hydroxyethyl methacrylate (HEMA) and acrylated methyl ether poly (ethylene glycol) (ACMPEG) were carried out by emulsion method without any surfactant (MNP5). The in-vitro release behavior of quercetin from MNP5s was investigated at two pHs (7.4 and 5.8). The effect of fetal bovine serum (FBS) on MNPs and its ability to cover magnetite nanoparticles was investigated.     

Experimental evaluation of a vibration-based leak detection technique for water pipelines

Conventional water pipeline leak detection surveys employ labour-intensive acoustic techniques, which are usually expensive and not amenable for continuous monitoring of distribution systems. Many previous studies attempted to address these limitations by proposing and evaluating a myriad of continuous, long-term monitoring techniques. However, these techniques have difficulty to identify leaks in the presence of pipeline system complexities (e.g. T-joints), offered limited compatibility with popular pipe materials (e.g. PVC), and were in some cases intrusive in nature. Recently, a non-intrusive pipeline surface vibration-based leak detection technique has been proposed to address some of the limitations of the previous studies. This new technique involves continuous monitoring of the change in the cross-spectral density of surface vibration measured at discrete locations along the pipeline. Previously, the capabilities of this technique have been demonstrated through an experimental campaign carried out on a simple pipeline set-up. This paper presents a follow-up evaluation of the new technique in a real-size experimental looped pipeline system located in a laboratory with complexities, such as junctions, bends and varying pipeline sizes. The results revealed the potential feasibility of the proposed technique to detect and assess the onset of single or multiple leaks in a complex system.     

Preparation and characterization of photocatalytic titania–alumina composite membranes by sol–gel methods

Titania–alumina composite membranes containing 10 and 20 mol% alumina were prepared by two different sol–gel methods; co-hydrolysis and separately peptized. The samples were characterized by different techniques. XRD results showed that for the composite membranes the anatase to rutile transformation temperature was increased by 200 and 300 °C. According to specific surface area results, alumina effectively increased the specific surface area of composite membranes compared to pure titania membranes. Microstructure of composite supported membranes was considered by scanning electron microscopy and showed a crack-free layer with 1 μm thickness. The photocatalytic activity of composite samples showed that alumina addition up to an optimum amount can slightly affect the photocatalytic activity of titania.     

Preparation of Janus-type superparamagnetic iron oxide nanoparticles modified with functionalized PCL/PHEMA via photopolymerization for dual drug delivery

In this study, superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by the coprecipitation of FeCl₂˙4H₂O and FeCl₃˙6H₂O and applied as a core for preparation of Janus nanoparticles. Accordingly, freshly modified methacrylated iron oxide nanoparticles were reacted with two functionalized polymers. Acrylated poly(ε-caprolactone) (PCL) and acrylated poly(2-hydroxyethyl methacrylate) (PHEMA) were synthesized via ring-opening and free-radical polymerization, respectively, and subsequent modification with acryloyl chloride. Acrylated PCL as the hydrophobic part and acrylated PHEMA as the hydrophilic domain were grafted on the surface of methacrylated iron oxide nanoparticles with two morphologies. Pickering emulsion and solution photopolymerization reactions were used to prepare nanoparticles with “Janus” and “mixed” morphologies, respectively. The products were characterized in each step using Fourier-transform infrared spectroscopy (FT-IR), Proton nuclear magnetic resonance (¹H-NMR), thermogravimetric analysis (TGA), dynamic light scaterring (DLS), transmission electron microscope (TEM), vibrating-sample magnetometer (VSM), energy dispersive X-ray (EDX), and ultraviolet–visible spectroscopy (UV-Vis). Quercetin and 5-FU (as two anticancer drugs) were loaded in the mentioned nanoparticles, and the drug loading capacity and encapsulation efficiency (EE) of these nanoparticles were calculated. in vitro release behavior at two pH values (5.8 and 7.4) and at 37°C demonstrated that morphology can affect the release profile. Finally, rat C6 cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay for drug-free and drug-loaded nanoparticles.     

Effect of egg consumption on inflammatory markers: a systematic review and meta-analysis of randomized controlled clinical trials

There is little evidence about whether eggs affect inflammation. The aim of this meta-analysis was to explore the effects of egg consumption on inflammation. A systematic search of online databases (Institute for Scientific Information (ISI), Scopus, Ovid, PubMed, Cochrane) was used to gather clinical trials that assessed the effect of egg consumption on circulating inflammatory biomarkers. Using a random-effects model, pooled weighted mean differences (WMD) and corresponding standard deviations (SD) were calculated. Of the 21 eligible studies found, nine trials were eligible for analysis. Eight trials assessed high-sensitivity C-reactive protein (hs-CRP), four trials assessed interleukin-6 (IL-6), and five trials assessed tumor necrosis factor-alpha (TNF-α). Egg consumption did not affect hs-CRP (WMD 0.24 mg/L; 95% CI: -0.43, 0.90; I² = 53.8; P = 0.48), IL-6 (WMD 0.20 pg/mL; 95% CI: -0.71, 1.11; I² = 69.3; P = 0.50), and TNF-α (WMD: -0.38 pg/mL; 95% CI: -0.87, 0.10; I² = 0.00; P = 0.12) relative to controls. Overall, this meta-analysis revealed that egg consumption had no significant effect on serum biomarkers of inflammation in adults. © 2019 Society of Chemical Industry