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Polyetheretherketone (PEEK) can be used as a framework material for removable and fixed dental prostheses. However, information about the use of PEEK as a post-and-core restoration is scarce. The purpose of this in vitro study was to evaluate the effect of different surface treatments on the push-out bond strength of milled polyetheretherketone posts to resin cement. Sixty intact human maxillary central incisors were selected and endodontically treated, and standardized post spaces were prepared. Sixty PEEK posts were milled from a prefabricated PEEK blank by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system and divided into 3 groups (n=15) according to the surface treatment: acid etching by using 98% sulfuric acid (AE); airborne-particle abrasion by using 50-μm Al 2 O 3 (AA); nonthermal plasma treatment (NTP); in addition, PEEK posts (n=15) received no treatment (NT) and served as a control. All posts were bonded by using a self-adhesive resin cement. Three sections (coronal, middle, and apical) were obtained for each specimen. Push-out bond strength measurements (MPa) for each section were recorded by using a universal testing machine at a crosshead speed of 0.5 mm/min until failure occurred. The post-cement interfaces and failure modes were evaluated by using scanning electron microscopy. The data obtained were statistically analyzed by using 1-way ANOVA and the pair-wise Tukey (HSD) test to study the difference between group mean values (α=.05). The overall mean ±standard deviation of the push-out bond strength was 11 ±2 MPa for AE group, 6 ±1 MPa for AA group, 5 ±1 MPa for NTP group, and 3 ±1 MPa for NT group. A statistically significant difference was found among all groups subjected to different surface treatments as indicated by the ANOVA test (P <.001). The pair-wise Tukey honestly significant difference (HSD) test showed a significant difference among the AE group and all groups (P <.001); however, no significant difference was observed between the AA and NTP groups (P >.05). Moreover, a significant difference was observed among all root sections (P <.001). Surface treatment of PEEK posts with 98% sulfuric acid for 60 seconds showed significantly higher bond strength values than those in other groups. The bond strength of PEEK posts to resin cement was significantly higher in the coronal section than that in other sections. [ABSTRACT FROM AUTHOR]

Chlorine-mediated electrochemical urea oxidation was investigated using a new electrochemical cell design with horizontally oriented electrodes. By virtue of the novel electrode configuration, the new electrochemical cell is self-stirred by the H2 bubbles evolving at the cathode surface and contains a built-in cooler to remove excess heat generated during electrolysis. The effect of current density, pH. NaCl concentration and initial urea concentration on the urea removal and specific electrical energy consumption were investigated. The % urea removal ranged from 55% to 90% depending on the operating conditions. The rate of urea removal increased with increasing current density and NaCl concentration, while increasing the solution pH and initial urea concentration were found to decrease the rate of removal. Energy consumption decreased with increasing NaCl concentration and increasing initial urea concentration. A kinetic approach and response surface methodology were used to model the temporal profile of urea oxidation and to optimize the process variables. After 33.4 min of electrolysis of a solution containing 348.6 ppm urea, 3% NaCl concentration and an initial pH of 5.6 using an applied current density of 4.6 mA/cm² (2.6 A), 73.8% urea removal could be achieved with an extremely low energy consumption of 9.58 kW h/kg urea. The influential priorities of the five operating parameters on % urea removal and specific energy consumption were different. The obtained results revealed that the use of kinetic and statistical modeling is an adequate approach to optimize the process variables of electrochemical urea degradation. [ABSTRACT FROM AUTHOR]

The applications of edible coatings stemmed exclusively from alginate in food packaging are restricted due to their inherent deficient antimicrobial, barrier, and UV-barrier properties. In this work, we aimed to design smart alginate-based coatings for active food packaging through the addition of both aloe vera (AV) and garlic oil (GO). The interactions between the film components were verified by FTIR and XRD. Thermal and mechanical properties were improved by the presence of AV and GO. The presence of AV and GO did not significantly influence the transparency of alginate films. The films exhibited a significant UV-shielding to all UV regions. Water vapor permeability was significantly (p < 0.05) reduced either through the incorporation of AV or GO. The antimicrobial properties of the prepared films were considerably improved by the presence of AV and GO. The shelf-life of tomatoes (Solanum lycopersicum L.) was extended when coated with the alginate film incorporated with AV and GO. Owing to the outstanding UV-shielding, mechanical, thermal, and antimicrobial properties, the alginate/AV/GO active coatings could potentially be implemented in the food packaging industry. • Aloe vera (AV) and garlic oil (GO) were incorporated into alginate. • UV-shielding properties were significantly improved compared with neat alginate. • GO and AV significantly improved thermal, mechanical and antimicrobial properties. • The prepared active edible films extended the shelf-life of tomatoes. • The prepared active edible films could be used potentially in food packaging. [ABSTRACT FROM AUTHOR]

This work aims to prepare multifunctional edible coating based on alginate and Aloe vera (AV) optimized to minimum water vapor permeability (WVP) using Box-Behnken design. Titanium oxide nanoparticles (n TiO 2) were incorporated into the optimized film at different contents. FTIR confirmed the structures, while XRD confirmed n TiO 2 incorporation with a size ranging from 20.38 to 28.81 nm. The UV-shielding was enhanced either in the presence of AV or n TiO 2. Thermal stability by TGA was improved upon increasing the n TiO 2 content. WVP was significantly decreased from 21.53 g mm/m2 day kPa for calcium alginate to 7.18 g mm/m2 day kPa in the presence of AV and n TiO 2 (5 wt%). Color measurements showed non-significant changes in the film's transparency after AV and n TiO 2 incorporation. Mechanical and antimicrobial properties were improved in the presence of n TiO 2. Shelf-life studies on tomatoes showed significant resistance to mass loss and spoilage when coated with (alginate/AV) film containing 5 wt% of n TiO 2. • Alginate and Aloe vera were optimized using Box-Behnken design to a minimum WVP. • n TiO 2 was added to the optimized system at 1, 3 and 5% contents. • n TiO 2 improved WVP, thermal, mechanical, UV-shielding and antimicrobial properties. • n TiO 2 did not affect the film's transparency. • n TiO 2 nanocomposite extended the shelf-life of tomatoes. [ABSTRACT FROM AUTHOR]

Edible films based on chitosan biguanidine hydrochloride and CMC were optimized for the minimum water vapor permeability (WVP) using the 3-level factorial design. Titanium oxide nanoparticles (n TiO 2) were incorporated in different contents into the optimized film (O wvp). FTIR and 1H NMR confirmed the successful preparation of films. FE-SEM showed that n TiO 2 was homogeneously distributed, with a size of about 25.78 nm for the film containing 5 wt% of n TiO 2. XRD was used to study the film's crystallinity, and calculate the crystallite size of n TiO 2 using Debye–Scherrer Equation. Thermal stability, by TGA, was improved while the water vapor permeability was reduced upon increasing the n TiO 2 content. Color measurements showed that the n TiO 2 incorporation didn't significantly affect the transparency. Elongation at break was decreased upon n TiO 2 incorporation while tensile strength and Young's modulus were increased with increasing n TiO 2 up to 3 wt% then begin to decrease. The nanocomposites exhibited significant UV-barrier properties and enhanced antimicrobial activity especially at high contents of n TiO 2. Shelf-life studies on green bell pepper coated with the nanocomposite films showed excellent resistance to mass loss and spoilage during storage. The obtained data confirm the efficiency of the prepared n TiO 2 nanocomposite films to extend the shelf-life of food. • Carboxymethyl cellulose and chitosan biguanidine was optimized to a minimum WVP. • n TiO 2 was added to the optimized system in different contents. • n TiO 2 improved WVP, thermal, mechanical, UV-shielding and antimicrobial properties. • n TiO 2 didn't affect the film's transparency. • n TiO 2 nanocomposite extended the shelf-life of pepper. [ABSTRACT FROM AUTHOR]

Zinc crosslinked supramolecular hydrogels from O -carboxymethyl chitosan biguanidine were successfully prepared. The structures of the prepared hydrogels were verified by 1H NMR, FTIR and XRD. FE-SEM verified the porous structure of hydrogels especially at high contents of Zn2+ ions. The integral procedure decomposition temperatures calculated from TGA curves showed that the thermal stability was increased upon increasing the content of Zn2+ ions. Cytotoxicity assays confirmed that the amounts of Zn2+ ions released from hydrogels were below the toxic level towards a breast cancer cell line (MCF-7). The prepared hydrogels exhibited a significant microbial inhibition towards different species of bacteria and fungi, particularly at high Zn contents. Based on the obtained interesting data, the prepared zinc/ O -carboxymethyl chitosan biguanidine could be used in drug delivery and biomedical applications. [ABSTRACT FROM AUTHOR]

Chitosan biguanidine hydrochloride (CBg) was prepared as a novel multifunctional biodegradable polymer with antimicrobial and excellent water-solubility properties, and used as a crosslinker to prepare carboxymethyl cellulose (CMC)/alginate (A)/CBg edible coating. FTIR confirmed the successful preparation of CBg and CMC/A/CBg films. Wide-angle X-ray diffraction showed that the amorphous structure of CMC/A had some degree of order after CBg addition. The film thickness and solubility were decreased after CBg addition due to the formation of a dense crosslinked structure. CBg addition significantly improved the thermal properties of the films as detected from the calculated IPDT values from TGA curves. Water vapor permeability was reduced to 54% of the value of CMC/A when CBg was added by15 wt%. The addition of CBg didn't change the transparency of CMC/A films. The mechanical properties and antibacterial properties were significantly enhanced after the addition of CBg. CMC/A/CBg were coated on tomato fruits, and the shelf-life studies showed that the storage weight loss was significantly reduced, and the spoilage was inhibited after coating. These results suggest that CMC/A/CBg edible coating might be a promising candidate in food preservation industries. • Chitosan biguanidine hydrochloride (CBg) was used as a crosslinker for carboxymethyl cellulose (CMC)/alginate (A) system. • Films exhibited a reduced water vapor permeability and good color properties with CBg addition. • Films mechanical, thermal and antibacterial properties were improved with increasing the CBg percent. • Tomato spoilage was inhibited during the storage period when coated with CMC/A/CBg films. • The mass loss of tomatoes was significantly reduced for coated tomatoes. [ABSTRACT FROM AUTHOR]

This study aims to prepare binary edible films made from carboxymethyl cellulose (CMC) and chitosan biguanidine hydrochloride (CBg) activated with frankincense oil (FO). The interactions between CMC, CBg and FO were confirmed by FTIR. XRD showed that the addition of FO led to decreasing the crystallinity of CMC/CBg films. The water vapour permeability was reduced upon increasing the FO content. The presence of FO made the films brighter and didn't change their transparency as detected from the color measurements. The films exhibited better mechanical properties in the presence of FO as detected from the improved values of both tensile strength and elongation at break. The prepared films exhibited excellent antibacterial activity especially at high content of FO (5%). CMC/CBg/FO films might be used potentially in the production of edible films due to their excellent physical and antibacterial properties. • Novel edible films from carboxymethyl cellulose (CMC), chitosan biguanidine (CBg) and frankincense oil (FO) were prepared. • Films exhibited a reduced water vapor permeability. • FO did not affect the color or the transparency of the films. • Films mechanical and antibacterial properties were improved with increasing the FO percent. • CMC/CBg/FO can be used as antibacterial edible films with excellent physical properties. [ABSTRACT FROM AUTHOR]

Novel antimicrobial copolymers resulted from free radical copolymerization of gelatinized corn starch in aqueous solution with different amounts of 4-acrylamidobenzoic acid monomer using ammonium persulfate (APS)/sodium bisulfite (NaHSO 3) as a redox initiator. The grafting copolymerization was evidenced by FTIR, 1HNMR, scanning electron microscopy (SEM) and X-ray diffraction. The thermal stability was improved after the grafting reaction as detected from IPDT values calculated from the thermogravimetric analysis. The effect of changing grafting parameters (initiator concentration, monomer concentration, reaction time and temperature) on graft copolymerization were studied by measuring the grafting percentage (%G), grafting efficiency (%GE) and homopolymer percentage (%H). The optimum grafting conditions were determined as follows: Initiator concentration [I] = 3 × 10-2 mol/L, monomer concentration [M] = 0.25 mol/L, reaction temperature = 65 °C and reaction time = 2 h. The prepared copolymers exhibited swelling ability in both water and 0.9% saline solution. The antimicrobial study revealed a high degree of inhibition against different strains of Gram-positive bacteria, Gram-negative bacteria and fungi when compared with neat starch. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Novel thienoquinoline-2-carboxamide-chalcone derivatives. • Structural elucidation. • Good Antiproliferaive Activity. • EGFR-kinase inhibition. • Molecular docking to ATP-binding and allosteric binding site. Abstract Novel thienoquinoline carboxamide-chalcone derivatives were prepared via the cyclization of acylated chalcones and 2-mercaptoquinoline-3-carbaldehyde in DMF with K 2 CO 3. Thienoquinolines 9a–f , h exhibited promising antiproliferative effect against all the tested cell lines and gave a significant activity as EGFR inhibitors, with IC 50 values ranging from 0.5 and 3.2 µM, and compounds 9e and 9f being the most active of the series. They also showed better activity than Erlotinib against melanoma cancer cell line A375. Moreover, compound 9f influenced pre G1 apoptosis and cell cycle arrest at G2/M phase. The binding mode of the best EGFR inhibitor 9e in the EGFR active site revealed that the thienoquinoline ring occupied the ATP-binding site while the chalcone moiety is located in the allosteric site and is responsible for the enhanced activity of these compounds. [ABSTRACT FROM AUTHOR]

This work aims to study the effect of a vinyl-modified montmorillonite (VMT) on the physical and antimicrobial properties of chitosan- graft -polyacrylic acid superabsorbent (Ch- g -PA). Ch- g -PA was first optimized using Box-Behnken design to obtain the maximum equilibrium swelling, and the model was efficient to express the experimental swelling data ( R 2  = 0.999). VMT was further added to the optimized Ch- g -PA in different contents 0, 4, 7 and 10 wt%. FTIR confirmed the successful synthesis of the copolymers and their nanocomposites. Morphology and the average pores size were studied using SEM. Wide angle X-ray diffraction showed the formation of exfoliated nanocomposites after VMT addition. Thermal stability studied by TGA was greatly enhanced in the presence of VMT. The swelling kinetics by Voigt-based viscoelastic model showed that the equilibrium swelling was increased by increasing the VMT up to 7 wt% then decreased after further incorporation. The superabsorbents exhibited salt and pH-responsive properties and showed a pH-reversibility at two buffer solutions (pH = 2 and pH = 9). Moreover, the prepared superabsorbents exhibited a strong bacterial and fungal killing ability which becomes more pronounced upon increasing the VMT content. The obtained results encourage the usage of the prepared copolymer nanocomposites in many fields as antimicrobial superabsorbents of improved physical properties. [ABSTRACT FROM AUTHOR]

Novel bioactive edible films based on sodium alginate (A) and chitosan biguanidine hydrochloride (CG) with different weight percents were successfully prepared. 13 C NMR and 1 H NMR confirmed the successful guanidylation of chitosan. Fourier transform infrared confirmed the successful reaction between CG and A. The interaction between CG and A was confirmed through the reduction of the crystalline peaks of both CG and A as detected from their wide-angle X-ray diffraction. Thermogravimetric analysis confirmed that CG enhanced the thermal stability of films as detected from the calculated integral procedure decomposition temperature (IPDT) values. CG incorporation improved the mechanical properties of dry and wet samples. A/CG films exhibited a reduced water vapor permeability and good color properties. The antibacterial study proved that the prepared films showed a remarkable antibacterial killing ability. These results revealed that A/CG films could be an alternative candidate to be used as antibacterial edible films in food industries. [ABSTRACT FROM AUTHOR]

Background The hepatitis C virus (HCV) epidemic is particularly devastating in Egypt where its prevalence is about 12%. Chronic HCV infection can result in the accumulation of immune complexes and stimulate antibodies, which can result in extrahepatic manifestations (EHM). Aim of the work To assess the efficacy and safety of combined pegylated interferon and ribavirin therapy in the management of rheumatological EHM in HCV patients. Patients and methods Twenty-seven out of 50 consecutive HCV patients with rheumatologic EHM were eligible and included in this study. All patients included in this study were subjected to full history taking, clinical examination and laboratory investigations. Results The mean age of the patients was 43.8 ± 7.6 years. The clinical response of the patients was: 2 patients (7.4%) were complete clinical responders, 5 (18.5%) were partial responders, 3 (11.1%) showed relapse and 17 (63%) were non-responders. There was a significant improvement in the number of patients with fatigue, polymerase chain reaction positivity and elevated liver enzymes ( p < 0.0001, p < 0.0001, p = 0.03, p = 0.01 respectively). There was no significant correlation between virological and clinical responses. There was a significant correlation between virological and biochemical responses ( p = 0.02). Minor side effects of the AVT developed in 13 (48.1%) patients: anemia ( n = 5), mild thrombocytopenia ( n = 8), flu-like symptoms ( n = 7) and mild depression ( n = 1). Conclusion Peg IFN and ribavirin did not improve HCV rheumatological extrahepatic manifestations. Antiviral treatment may also induce or worsen autoimmune disorders and is sometimes associated with major immune-mediated adverse events. [ABSTRACT FROM AUTHOR]

New acyloxy nitroso compounds, 4-nitrosotetrahydro-2 H -pyran-4-yl 2,2,2-trichloroacetate and 4-nitrosotetrahydro-2 H -pyran-4-yl 2,2-dichloropropanoate were prepared. These compounds release HNO under neutral conditions with half-lives between 50 and 120 min, identifying these HNO donors as kinetically intermediate to the much slower acetate derivative and the faster trifluoroacetic acid derivative. These compounds or HNO-derived from these compounds react with thiols, including glutathione, thiol-containing enzymes and heme-containing proteins in a similar fashion to other acyloxy nitroso compounds. HNO released from these acyloxy nitroso compounds inhibits activated platelet aggregation. These acyloxy nitroso compounds augment the range of release for this group of HNO donors and should be valuable tools in the further study of HNO biology. [ABSTRACT FROM AUTHOR]