Biosorption of Hg2+, Cd2+, and Zn2+ by Ca-alginate and immobilized wood-rotting fungus Funalia trogii

Funalia trogii biomass was immobilized in Ca-alginate gel beads. The live and heat inactivated immobilized forms were used for the biosorption of Hg2+, Cd2+ and Zn2+ ions by using plain Ca-alginate gel beads as a control system. The effect of pH was investigated and the maximum adsorption of metal ions on the Ca-alginate and both live and inactivated immobilized fungal preparations were observed at pH 6.0. The temperature change between 15 and 45 degrees C did not affect the biosorption capacity. The biosorption of Hg2+, Cd2+ and Zn2+ ions on the Ca-alginate beads and on both immobilized forms was studied in aqueous solutions in the concentration range of 30-600 mg/L. The metal biosorption capacities of the heat inactivated immobilized F. trogii for Hg2+, Cd2+ and Zn2+ were 403.2, 191.6, and 54.0 mg/g, respectively, while Hg2+, Cd2+ and Zn2+ biosorption capacities of the immobilized live form were 333.0, 164.8 and 42.1 mg/g, respectively. The same affinity order on a molar basis was observed for single or multi-metal ions (Hg2+ > Cd2+ > Zn2+). The Langmuir and the Freundlich type models were found to exhibit good fit to the experimental data. The experimental data were analyzed using the first-order (Langergren equations) and the second order (Ritchie equations). The experimental biosorption capacity with time is found to be best fit the second-order equations. The alginate-fungus system could be regenerated by washing with a solution of hydrochloride acid (10 mM). The percent desorption achieved was as high as 97. The biosorbents were reused in five biosorption-desorption cycles without significant loss of their initial biosorption capacity.     

Metabolic profile and biological activity of Sideritis brevibracteata P. H. Davis endemic to Turkey

Essential oil and phenolic compositions of Sideritis brevibracteata P.H. Davis, which is an endemic species in Turkey and commonly used as a herbal tea for some diseases, were determined by GC-MS and Liquid chromatography–mass spectrometry (LC-MS/MS) techniques. While the main components of the essential oil were determined as caryophyllene, germacrene-D, and α-cadinene, the phenolic compounds quercetagetin-3,6-dimethylether and chlorogenic acid were found to be the main compounds in the extracts of the species. The characteristic diterpenoids of Sideritis species such as siderol, linearol, eubotriol, sideridiol, and athonolone were isolated and their structures were elucidated by 1D and 2D NMR (Nuclear Magnetic Resonance) techniques. Weak inhibitory activity of species against butyryl-cholinesterase was determined. Antioxidant capacity of the acetone and methanol extracts was determined by DPPH free radical scavenging activity, β-carotene linoleic acid assays, and CUPRAC assays.     

Photocatalytic degradation of Congo Red by hydrothermally synthesized nanocrystalline TiO2 and identification of degradation products by LC-MS

Degradation of Congo Red (CR) dye in aqueous solutions was investigated by means of photocatalysis of TiO2 which was hydrothermally synthesized at 200 degrees C in 2 h, in anatase phase with 8 nm crystallite size. Efficiency of TiO2 in photocatalytic degradation under visible irradiation was studied by investigating the effects of amount of TiO2, irradiation time, initial CR concentration and pH. It was found that complete decolorization is achieved within 30 min of irradiation. Effects of nitrate and sulphate ions and humic acid on the degradation were also tested. The results were compared with Degussa P-25 TiO2 at the same degradation conditions. Degradation products were detected using LC-MS technique. The probable pathways for the formation of degradation products were proposed.     

Formulation and In Vitro Evaluation of Bisphosphonate Loaded Microspheres for Implantation in Osteolysis

ABSTRACT

Chitosan and poly(lactide-co-glycolide) acid (PLGA) microspheres loaded with alendronate sodium (AS) were prepared for orthopedic as well as dental applications. In orthopedics the aim was to make the total joint prostheses stay in the body for a long time without causing bone tissue loss, while in dentistry it was aimed to treat the alveolar bone resorption caused by periodontitis and also to make the dental treatment using implants easier by reducing the bone loss in patients with osteoporosis. Solvent evaporation method was used to prepare AS loaded PLGA microspheres and emulsion polimerization method was used to prepare AS loaded chitosan microspheres. Particle size, loading efficacy, surface characteristics, and in vitro release characteristics were examined on prepared formulations. After the examination of the scanning electron microscopy photographs of microspheres, chitosan microspheres were observed to have spherical structure and smooth surface characteristics while PLGA microspheres were observed to have spherical porous surface structure. Loading efficacy was found to be 3.30% for chitosan microspheres and 7.70% for PLGA microspheres. It was observed that 85% of AS had been released at the end of the third day from chitosan microspheres whereas 58% was released at the end of the fifth day from PLGA microspheres. It was found that chitosan microspheres gave first order release while PLGA microspheres gave zero order release.     

Effects of different filler types on decay resistance and thermal,physical, and mechanical properties of recycled high-density polyethylene composites

In this study, flexural properties, impact strength, thermal performance, water absorption, biological durability, and morphology of wood-plastic composites (WPCs) filled with different filler types were investigated. Six different formulations of WPCs were fabricated from mixtures of carpenter waste and recycled high-density polyethylene (R-HDPE). The carpenter waste was derived from wood and particle board wastes, and R-HDPE was used as the polymer matrix, with and without addition of maleic anhydrite grafted polyethylene (MAPE). All formulations were compression moulded in a hot press for 3 min at 170 °C. Investigations on the compression moulded specimens revealed that water absorption values in the particleboard waste flour specimens were lower than in the wood-waste flour WPCs. However, the wood-waste flour-filled composites exhibited higher mechanical property values than the particleboard waste flour WPCs. Statistically, only the wood-waste flour-filled composites with MAPE were significantly different. The use of MAPE (3 wt%) had a positive effect on the water absorption, crystallinity degree, and flexural properties of the WPCs. In addition, the peak temperatures of the composites did not show any variation, while thermal decomposition of the composites showed minor variations under the thermogravimetric analysis. Furthermore, the decay resistance of the composites improved with the use of particleboard waste flour. The obtained results demonstrate that particleboard waste flour, such as wood-waste flour, is potentially suitable as a raw material in WPCs.     

Comparison of fabric properties knitted by pin spacer compact and conventional compact yarns

This study examined the influence of pin spacer apparatus attachment on compact yarn quality parameters and physical properties of knitted fabrics manufactured using those 100% cotton compact yarns. Two groups of compact yarns were spun on regular compact yarn spinning frame with and without addition of pin spacer apparatus which is placed at the end of the drawing unit of regular compact yarn spinning frame. Totally eight yarns were spun at four different yarn number levels (Ne 24/1, Ne 30/1, Ne 36/1 and Ne 40/1) and two different spinning conditions (with and without pin spacer apparatus). Spun yarn types were then knitted on the industrial sized plain knitting machine. Knitted fabrics were used in the greige and dyed form to evaluate their bursting strength (kPa), dimensional change, abrasion related mass loss (%), pilling resistance, air permeability (mm/s) and colour difference. Test results were then statistically evaluated and influence of pin spacer attachment on yarn quality parameters and fabric properties was determined. In the frame of this experimental work, attachment of pin spacer apparatus improved compact yarn characteristics especially at yarn evenness, imperfection and hairiness values. In case of knitted fabric properties, it was found that pin spacer apparatus attached compact yarn utilization significantly improved air permeability properties of knitted fabrics.     

Hydrogen: A brief overview on its sources,production and environmental impact

A brief overview is presented involving the terms of availability of hydrogen, its properties and possible sources and its production methods, and finally, its relationship with renewable energy utilisation, environment and climate.Solar hydrogen, preferably obtained from water, is confirmed once more to be the most environment and climate compatible (causing the least damage), energy source; though not necessarily the most economic one. Production cost of hydrogen obtained from terrestrial biomass, is not the lowest either, however carbon-neutral feature of terrestrial biomass renders it highly desirable in view of steep rise in global temperature.     

Development of polyampholyte hydrogels based on laponite for electrically stimulated drug release

Polyampholyte hydrogels (PAHs) composed of laponite, polyacrylamide and poly(3‐acrylamidopropyl)trimethylammonium chloride crosslinked with ethylene glycol dimethacrylate were synthesized and characterized for their sensitivity to external conditions and their ability to control the release of the active drug agent paracetamol. Three PAHs were synthesized by taking the weight ratio of laponite to total monomer as 7, 15 and 29%. PAHs were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and swelling measurements carried out in various media. Equilibrium and pulsatile swelling studies were performed on all hydrogels to determine to what extent the hydrogels would respond to changes in environmental pH, ionic strength and electric field, and how fast that response would be. Paracetamol was loaded into the hydrogels, and was released into buffered solutions as a function of pulsatile changes in pH and electric field. © 2014 Society of Chemical Industry     

One-Pot Synthesis of Poly(linoleic acid)-g-Poly(styrene)-g-Poly(ε-caprolactone) Graft Copolymers

One-pot synthesis of graft copolymers by ring-opening polymerization and free radical polymerization using polymeric linoleic acid peroxide (PLina) is reported. Graft copolymers having structures of poly(linoleic acid)-g-polystyrene-g-poly(ε-caprolactone) were synthesized from PLina, possessing peroxide groups on the main chain by the combination of free radical polymerization of styrene and ring-opening polymerization of ε-caprolactone in one-step. Principal parameters, such as monomer concentration, initiator concentration, and polymerization time, which effect the one-pot polymerization reactions were evaluated. The obtained graft copolymers were characterized by ¹H-NMR and DOSY-NMR spectroscopy, gel permeation chromatography, thermal gravimetric analysis and differential scanning calorimetry techniques.