Synthesis and Characterization of Poly(2‐hydroxyethylmethacrylate‐hydroxyapatite) a Novel Composite for the Removal of Lead(II) from Aqueous Solutions

In the present study, a novel adsorbent, poly (2‐hydroxyethylmethacrylate‐hydroxyapatite) [P(HEMA‐Hap)], was prepared and characterized. The synthesis was achieved by means of free‐radical polymerization and a number of structural characterization methods, including FT‐IR, XRD, TGA, SEM, BET‐porosity, and swelling tests. Pb²⁺ adsorption was performed using a series of pH, time, and temperature ranges. The reusability of the composite was also tested. The results obtained indicated that the novel adsorbent is able to bind Pb²⁺ ions with strong chemical affinity. The adsorption results were fitted to the classic Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) sorption models. Thermodynamic parameters obtained demonstrated that the sorption process was spontaneous (ΔG < 0), endothermic (ΔH > 0), as expected. The process was also consistent with the pseudo‐second‐order model, and chemical adsorption was determined to be the rate‐controlling step. It was also shown that the composite could be used for five consecutive adsorption processes.     

马粪海胆卵母细胞线粒体DNA和RNAs的分离

于１９８２年１２月－１９８４年５月，以青岛汇泉湾习见的马粪海胆为材料，运用０．５ｍｏｌ／Ｌ ＫＣｌ或０．５ｍｏｌ／Ｌ ＬｉＣｌ诱导法得到其卵母细胞；差速离心技术提取其线粒体；ＳＤＳ萃取到线体核酸；再以羟基磷灰石柱层析分离邮线粒体核酸各组分。结果表明，从所得各种分离产物测不出任何蛋白质，所以，应用上述各种方法和技术，能够有效地分离出海胆卵母细胞线粒体中的ＤＮＡ，ｒＲＮＡ，ｔＲＮＡ和多核苷酸。     

The structure and material composition of ossified aortic valves identified using a set of scientific methods

Degenerative aortic stenosis has become a common and dangerous disease in recent decades. This disease leads to the mineralization of aortic valves, their gradual thickening and loss of functionality. We studied the detailed assessment of the proportion and composition of inorganic and organic components in the ossified aortic valve, using a set of analytical methods applied in science: polarized light microscopy, scanning electron microscopy, X-ray fluorescence, X-ray diffraction, gas chromatography/mass spectrometry and liquid chromatography–tandem mass spectrometry. The sample valves showed the occurrence of phosphorus and calcium in the form of phosphate and calcium carbonate, hydroxyapatite, fluorapatite and hydroxy-fluorapatite, with varying content of inorganic components from 65 to 90 wt%, and with phased development of degenerative disability. The outer layers of the plaque contained an organic component with peptide bonds, fatty acids, proteins and cholesterol. The results show a correlation between the formation of fluorapatite in aortic valves and in other parts of the human bodies, associated with the formation of bones.     

Preparation of Magnetic Hydroxyapatite and Their Use as Recyclable Adsorbent for Phenol in Wastewater

Magnetic hydroxyapatite (HAP), which combined superparamagnetic Fe₃O₄ nanoparticles and HAP, composite materials were prepared by ultrasound method in this paper. It has also been found that these materials have the ability to adsorb phenol in wastewater. The magnetic materials were investigated by scanning electron microscope, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, thermal gravimetric analysis, vibrating sample magnetometer, and N₂ adsorption in order to elucidate the morphology, structure, and other properties. When the prepared magnetic materials were calcined at 200°C, the prepared Fe₃O₄ was oxidized to Fe₂O₃, possessing loose‐shaped holes with a high specific area of 325.2 m²/g, a magnetization intensity of 12.5 emu/g, and the N₂ adsorption isotherm belongs to porous adsorption type I. Moreover, the magnetic HAP can adsorb 90% phenol in wastewater. This means that it is an excellent recyclable phenol sorbent for sewage treatment. Experiments confirmed that the Freundlich adsorption isotherms model applies to lower phenol concentrations (0–50 mg/L), while for high phenol concentrations (50–500 mg/L) the Langmuir adsorption isotherms model fits. The magnetic sorbents have the capacity to regenerate after reaching adsorption saturation using ethanol as eluant and external magnetic field as separation unit. The efficiency of adsorption was reduced only by 10% over a six time use period.     

Potential routes to carbon inclusion in apatite minerals: a DFT study

We have conducted a computational study to investigate a number of possible routes for the incorporation of carbon into apatites. Using density functional theory (DFT) we have calculated geometry optimised structures for fluor- and hydroxy-apatites with and without various substitutions. We have studied several different carbonate substitutions, pure carbonate and pure formate apatites, neutral carbon atoms occupying interstices, and carbon dioxide and acetylene absorbed in oxyapatite.