Facile synthesis of three dimensional porous hydroxyapatite using carboxymethylcellulose as a template

A novel simple and convenient process for the synthesis of three dimensional porous hydroxyapatite (HAP) using natural apatite and carboxymethylcellulose (CMC) was introduced. In the synthesis processing, natural apatite was used as a source for calcium and phosphorus precursors and chemical precipitation method assisted by CMC was developed. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that CMC can control the HAP formation, modulate the particle morphology and structure, and effectively reduce the aggregation of HAP powders. This synthesis route makes it easy to obtain some submicron particles for special requirements. Keywords: Porous hydroxyapatite, Crystal growth, Carboxymethylcellulose, Wet chemical metho

Effect of Hydroxyapatite on the Migration of Fe(III) Ions: Kinetic, Equilibrium and Thermodynamic Study

The recycling and regeneration of Fe(III) is the key point for promoting the oxidation reaction of ore to produce acidic mine drainage (AMD). Hydroxyapatite (HAP) has excellent adsorption ability of Fe(III), which has good biocompatibility and is widely distributed in nature. In order to achieve the source treatment of AMD, the migration and transformation of Fe(III) in the presence of HAP were systematically investigated. In this study, the influence of HAP on the migration of Fe(III) was evaluated though the transformation capacity of Fe(III) by HAP. The adsorption transformation kinetic, equilibrium and thermodynamics of Fe(III) using HAP were also systematic investigated. The transformation efficiency of Fe(III) increased with the increasing initial pH value and reached 99.8% at a pH of 5 due to the hydrolysis reaction. The transformation efficiency was also up to 99% at an initial pH of 2 when the reaction temperature increased to 313 K. However, the transformation capability of Fe(III) decreases with reaction temperature. The kinetics of the adsorption of Fe(III) fitted the pseudo second order kinetic model. Experimental results were also analyzed by the Langmuir isotherm equations at room temperatures. RL separation factor for Langmuir isotherm showed that the migration of Fe(III) is successfully hindered by HAP. Various thermodynamic parameters such as enthalpy (ΔH), Gibbs free energy (ΔG) and entropy (ΔS) changes were computed, which showed that the transport lag of Fe(III) caused by HAP is spontaneous and endothermic

Single and Combined Effects of Chlorpyrifos and Glyphosate on the Brain of Common Carp: Based on Biochemical and Molecular Perspective

Chlorpyrifos (CPF) and glyphosate (GLY) are the most widely used organophosphate insecticide and herbicide worldwide, respectively; co-occurrence of CPF and GLY in aquatic environments occurs where they inevitably have potential hazards to fish. However, the potential mechanisms of CPF and GLY to induce toxicity have not been fully explored. To identify the adverse impacts of CPF and GLY on fish, either alone or in combination (MIX), CPF (25 μg/L) and GLY (3.5 mg/L) were set up according to an environmentally relevant concentration to expose to common carp for 21 days. After exposure, CPF and GLY decreased the activities of acetylcholinesterase and Na+/K+-ATPase, altered monoamine oxidase levels, decreased antioxidant enzyme activities (superoxide dismutase, catalase, glutathione S-transferase and glutamic reductase), and induced the accumulation of malondialdehyde in the carp brain. The parameters in the MIX groups had a greater impact compared to that in the CPF or GLY group, suggesting that both single and combined exposure could affect neurological signaling systems and cause oxidative stress and lipid peroxidation damage in carp brains, and that MIX exposure increases the impact of each pollutant. RNA-seq results showed that single or combined exposure to CPF and GLY induced global transcriptomic changes in fish brains, and the number of differentially expressed genes in MIX-treated carp brains were globally increased compared to either the CPF or GLY groups, suggesting that the effects of co-exposure were greater than single exposure. Further analysis results revealed that the global transcriptomic changes participated in oxidative stress, immune dysfunction, and apoptosis of fish brains, and identified that the P13k-Akt signaling pathway participates in both single and combined exposure of CPF- and GLY-induced toxicity. Taken together, our results demonstrated that the interaction of CPF and GLY might be synergic and provided novel insights into the molecular mechanisms of fish brains coping with CPF and GLY

The growth mechanism of titania/hydroxyapatite and its application in the photodegradation of methyl orange dye under UV irradiation

In this work, titania/hydroxyapatite (TiO2/HAP) composite materials were synthesized via a wet chemistry method. Morphological field emission scanning electron microscopy and electronic differential system field analysis revealed the growth mechanism that TiO2 began to divorce from surface on HAP with the Ti content of 2.60% while separated from the surface of HAP with the Ti content of 4.83%. Furthermore, Fourier transform infrared spectroscopy verified that the crystal structure of TiO2/HAP remained stable in the degradation process of MO. Especially, the TiO2/HAP has a good photocatalytic activity and photostability with the Ti content of 2.55%. Keywords: Titania/hydroxyapatite, Growth mechanism, Structural, Photocatalytic activit

Isolation of Extracellular Outer Membrane Vesicles (OMVs) from <i>Escherichia coli</i> Using EVscore47 Beads

Outer membrane vesicles (OMVs) are attractive for biomedical applications based on their intrinsic properties in relation to bacteria and vesicles. However, their widespread use is hampered by low yields and purities. In this study, EVscore47 multifunctional chromatography microspheres were synthesized and used to efficiently isolate functional OMVs from Escherichia coli. Through this technology, OMV loss can be kept to a minimum, and OMVs can be harvested using EVscore47 at 11-fold higher yields and ~13-fold higher purity than those achieved by means of ultracentrifugation. Based on the results presented here, we propose a novel EVscore47-based isolation of OMVs that is fast and scalable