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We describe an economical and environmentally advantageous, mechanical/chemical procedure for recycling spent lithium-ion batteries removed from a portable computer. The battery cathode comprises complex Li-based oxides: lithium-cobalt-oxide, lithium-nickel-cobalt-aluminum oxide and/or lithium-nickel-cobalt oxide, while the anode is constructed from a graphite-coated copper foil. Other carbon-containing materials should also be present. The electrolyte, the composition of which is not made available by the manufacturer, is probably a Li salt in organic solvent. Following hand removal of the non-metallic container, the battery elements undergo crushing/milling; no other component separation procedure is performed or required. Sixty minute dilute natural gas (4 vol.% in N2) sintering under reducing conditions (673–1123 K), followed by ice-water leaching, is used to efficiently separate Li from the heavy metals in the form of lithium carbonate at high yield and purity; 0.5 h smelting (1773 K) of the remaining metal clinker in air in a closed ceramic crucible, with sodium tetraborate as flux, allows recovery of the heavy, non-ferrous metals (Ni, Co, Cu and their alloys) as mm-size ingots (39% Co, 32.2% Ni, 26.3% Cu). Iron compounds, remanent Li, Al and unburnt graphite are removed as slag. Neither corrosive acids nor costly reagents are required, and hazardous liquid waste is not generated. [ABSTRACT FROM AUTHOR]

Specific conjugation of decyl β-D-maltoside (DM) or dodecyl β-D-maltoside (DDM) detergent micelles is accomplished between pH 7.0–8.5 in the presence of an amphiphilic analog of the amino acid histidine, bound to a 10-carbon hydrocarbon chain (His1-C10) and Ni2+ ions. Following addition of 10–15 wt% PEG-6000 as precipitant, phase separation in the form of oil-rich globules (30–600 µm) is observed by light microscopy. Other divalent cations: Zn2+, Fe2+, Cu2+ lead to dark precipitates rather than colorless globules; while Mg2+, Ca2+ do not promote any phase separation at all. Even in the absence of precipitant, dynamic light scattering (DLS) measurements demonstrate that DM micelles (hydrodynamic size ~ 6 nm) or DDM micelles (8 nm) self-associate into larger particles (9 nm and 411 nm for DM; 10 nm and 982 nm for DDM) in the presence of His1-C10 and nickel ions. Micellar conjugation is partially reversible in the presence of water soluble 50 mM EDTA, histidine or imidazole chelators. Cryo-transmission electron microscopy (cryo-TEM) imaging revealed the formation of non-uniformly dense detergent aggregates for both DM and DDM micelles in the presence of precipitant. The possible utility of such His1-tagged DM or DDM micelles for promoting crystallization of integral membrane proteins is discussed. [ABSTRACT FROM AUTHOR]

Electrostrictors, materials developing mechanical strain proportional to the square of the applied electric field, present many advantages for mechanical actuation as they convert electrical energy into mechanical, but not vice versa. Both high relative permittivity and reliance on Pb as the key component in commercial electrostrictors pose serious practical and health problems. Here we describe a low relative permittivity (<250) ceramic, ZrxCe1-xO2 (x < 0.2), that displays electromechanical properties rivaling those of the best performing electrostrictors: longitudinal electrostriction strain coefficient ~10−16 m2/V2; relaxation frequency ≈ a few kHz; and strain ≥0.02%. Combining X-ray absorption spectroscopy, atomic-level modeling and electromechanical measurements, here we show that electrostriction in ZrxCe1-xO2 is enabled by elastic dipoles produced by anharmonic motion of the smaller isovalent dopant (Zr). Unlike the elastic dipoles in aliovalent doped ceria, which are present even in the absence of an applied elastic or electric field, the elastic dipoles in ZrxCe1-xO2 are formed only under applied anisotropic field. The local descriptors of electrostrictive strain, namely, the cation size mismatch and dynamic anharmonicity, are sufficiently versatile to guide future searches in other polycrystalline solids. Electrostrictors are materials that develop mechanical strain proportional to the square of the applied electric field. Here authors report. Zr-doped-Ceria as a new lead-free electrostrictive material with a similar electrostriction coefficient to the best electrostrictor material currently in use. [ABSTRACT FROM AUTHOR]

The research described in this report seeks to present proof-of-concept for a novel and robust platform for purification of antibody fragments and to define and optimize the controlling parameters. Purification of antigen-binding F(ab′)2 fragments is achieved in the absence of chromatographic media or specific ligands, rather by using clusters of non-ionic detergent (e.g. Tween-60, Brij-O20) micelles chelated via Fe2+ ions and the hydrophobic chelator, bathophenanthroline (batho). These aggregates, quantitatively capture the F(ab′)2 fragment in the absence or presence of E. coli lysate and allow extraction of only the F(ab′)2 domain at pH 3.8 without concomitant aggregate dissolution or coextraction of bacterial impurities. Process yields range from 70 to 87% by densitometry. Recovered F(ab′)2 fragments are monomeric (by dynamic light scattering), preserve their secondary structure (by circular dichroism) and are as pure as those obtained via Protein A chromatography (from a mixture of F(ab′)2 and Fc fragments). The effect of process parameters on Ab binding and Ab extraction (e.g. temperature, pH, ionic strength, incubation time, composition of extraction buffer) are reported, using a monoclonal antibody (mAb) and polyclonal human IgG's as test samples. [ABSTRACT FROM AUTHOR]

We describe a laboratory-scale process for recycling rare earth metals from end-of-life rare-earth/iron/boron alloy permanent magnets using a 2-h chlorine gas treatment at 673 K. This treatment does not require any special preparation of the magnets; they can be used without demagnetization, crushing or milling. Following treatment at 673 K, a clinker powder consisting of rare earth metal chlorides with minimal amounts of other metals is obtained, while hematite and iron oxychloride sublimate. Following literature sources, we suggest that the rare earth metal chlorides in the clinker may be readily reduced to metal, either by electrolysis in relatively low temperature eutectic melts or by metallothermic reduction in mixtures with alkali or alkaline earth metals. [ABSTRACT FROM AUTHOR]

A new technique for promoting nucleation and growth of membrane protein (MP) crystals from micellar environments is reported. It relies on the conjugation of micelles that sequester MPs in protein detergent complexes (PDCs). Conjugation via amphiphilic [metal:chelator] complexes presumably takes place at the micelle/water interface, thereby bringing the PDCs into proximity, promoting crystal nucleation and growth. We have successfully applied this approach to two light-driven proton pumps: bacteriorhodopsin (bR) and the recently discovered King Sejong 1–2 (KS1–2), using the amphiphilic 4,4′-dinonyl-2,2′-dipyridyl (Dinonyl) (0.7 mM) chelator in combination with Zn2+, Fe2+, or Ni2+ (0.1 mM). Crystal growth in the presence of the [metal–chelator] complexes leads to purple, hexagonal crystals (50–75 µm in size) of bR or pink, rectangular/square crystals (5–15 µm) of KS1–2. The effects of divalent cation identity and concentration, chelator structure and concentration, ionic strength and pH on crystal size, morphology and process kinetics, are described. [ABSTRACT FROM AUTHOR]

We have adapted the X-ray diffraction technique of measuring crystal lattice parameters as a function of sample orientation in order to investigate the Poisson ratio ( ν) of thin films of Ce Gd O with different degrees of in-plane compressive strain. Since Gd-doped ceria is mechanically inelastic, the unstrained lattice constant is not well-defined. Therefore in order to determine the Poisson ratio, more than one strain state of the same sample must be characterized. We have accomplished this with a home-built, diffractometer-compatible sample-bender. Using this device, we find that the Poisson ratio of as-deposited thin films of Gd-doped ceria is a decreasing function of the in-plane compressive strain. At total strain ≈ −0.9 %, ν is > 0.45, indicating that the material tends to preserve volume. Increase of the in-plane strain to ≈ −2 % produces a monotonic decrease in the Poisson ratio to ~0.2. Such low values are indicative of reduced volume. We explain this behavior by noting earlier results from our group suggesting that, at temperatures below 200 °C and at low strain values, Ce Gd O responds to non-isotropic mechanical stress by reorienting the locally distorted Ce-V -O units. At higher strain values this mechanism is apparently no longer effective. Measurement of the Poisson ratio of inelastic thin films by this technique is straightforward and not diffractometer-dependent. It therefore represents a practical method for ceramic thin film characterization. [ABSTRACT FROM AUTHOR]

Purpose: One possible source of chronic low back pain is a degenerated intervertebral disc. In this review, various diagnostic methods for the assessment of the presence of degenerative changes are described. These include clinical MRI, a number of novel MRI techniques and nuclear magnetic resonance spectroscopy. Methods: Non-systematic literature review. Results: Clinical MRI is the most commonly employed technique to determine the general 'health status' of the intervertebral disc. Novel MRI techniques, such as quantitative MRI, T1ρ MRI, sodium MRI and nuclear magnetic resonance spectroscopy, are more sensitive in quantifying the biochemical changes of disc degeneration, as measured by alteration in collagen structure, as well as water and proteoglycan loss. As potential future diagnostic alternatives, miniature sensors are currently being developed to measure parameters associated with the disc degeneration cascade, such as intradiscal pressure and PG concentration. However, none of the methods listed above show sufficient specificity to identify a degenerated disc as the actual source of the pain. Provocative discography is the only test aimed at a direct diagnosis of discogenic pain, but it has a high false positive rate and there is some evidence of long-term adverse effects. Imaging techniques have also been tested for this purpose, but their validity has not been confirmed and they do appear to be problematic. Conclusions: A reliable diagnostic tool that could help a clinician to determine if a disc is the source of the pain in patients with chronic LBP is still not available. New MRI techniques are under investigation that could result in a significant improvement over current methods, particularly as they can allow monitoring, not only of morphological but also of biochemical changes. [ABSTRACT FROM AUTHOR]

Background: The intervertebral disc (IVD) is a complex cartilaginous structure which functions to resist biomechanical loads during spinal movement. It consists of the highly viscous cartilaginous nucleus pulposus, which is surrounded laterally by a thick outer ring of fibrous cartilage-the annulus fibrosus-and sandwiched inferiorly and superiorly by the cartilage end-plates. The main extracellular matrix molecules of the disc are collagens, proteoglycans, glycoproteins and elastin. The disc also contains appreciable amounts of water, matrix-degrading protease enzymes and their inhibitors, soluble signalling molecules and various metabolic breakdown products. Methods: This review provides a comprehensive description of the biochemical composition of the extracellular matrix of the IVD and, specifically, the proteases involved in its molecular turnover. Quantitation of the turnover rates using racemization of aspartic acid as a molecular clock is also discussed. Conclusions: Molecular turnover rates of the major constituent matrix macromolecules of the IVD are found to be particularly slow, especially in the case of collagen. Over a normal human life span, this slow turnover may compromise the structural integrity of the IVD extracellular matrix essential for normal physiological functioning. [ABSTRACT FROM AUTHOR]

XRD measurement of the room temperature in-plane and out-of-plane d-spacings of the (422) diffraction peak of 11 thin film samples of fluorite CeGdO demonstrates that the zz and xx (=yy) components of the strain tensor for this material are not related via a constant, i.e. the Poisson ratio, as is the case for elastic materials. Rather, these strains are independent. We attribute this behavior to the inelastic character of CeGdO deriving from the chemical strain effect, i.e. the lability of point defect-containing complexes under stress. Chemical strain is dependent on the thermal and mechanical history of the film, and above 200 °C, is no longer observed, being transformed into elastic strain and stress. This transformation may compromise the mechanical stability of CeGdO containing devices, which must operate over a broad temperature range. Measurements analogous to those described here can assist in predicting the magnitude of such an effect. [ABSTRACT FROM AUTHOR]

Purpose: Aggrecan is one of the major macromolecular components of the intervertebral disc (IVD) and its loss is an early sign of degeneration. Restoration of aggrecan, and hence of biomechanical properties, is a major objective of biological therapies. At present, assessment of aggrecan concentration via its glycosaminoglycan (GAG) content is accomplished using biochemical and histological methods which require sacrifice of tissue. A minimally invasive method for assessing GAG, and hence aggrecan, which can avoid destruction of tissue, would be of benefit. Methods: We have developed a needle micro-osmometer that is capable of measuring flux of saline into excised human nucleus pulposus (NP) tissue. Using the isotropic osmotic stress technique to assess the swelling pressure of the excised NP tissue and assuming negligible collagen tensile stress, we were able to relate the flux to the tissue fixed charge density (FCD). GAG concentration is evaluated from its FCD via the radioactive tracer technique. Samples representing different ages (28-59 years) and degeneration grades (1-4) were analyzed. Results: The flux is controlled by both the osmotic pressure difference across the probe's semi-permeable membrane and by the tissue permeability. A linear correlation was found between flux and the tissue FCD. The equation describing the linear fit is FCD/(total tissue hydration) = 1.97 × 10 + 8283 × flux ( R = 0.836, p < 10). Thus, by measuring saline flux, the concentration of GAG can be determined. Conclusions: Micro-osmometry provides a reliable and minimally invasive tool for assessing GAG content in excised NP tissue. This method may be usefully applied in tissue engineering applications. It may also be useful for in vivo measurements if the question of the degenerative effect of needle puncture can be overcome. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid compounds were prepared by the reaction of a tin chloride-substituted polyoxometalate, [PSn(Cl)W11O39]4− with tris(2-aminoethyl)amine, and poly(propylene)imine (DAB-Am) tetraamine and octaamine dendrimers. Translational diffusion coefficients of the hybrid compounds were measured in DMSO- d 6 by the stimulated echo diffusion (STE) NMR technique. Molecular radii were derived from the diffusion coefficients by the Stokes–Einstein equation and appeared to be incorrect because of fast exchange on the NMR time scale of the counter cation in the solution, which led to an averaging of the NMR signal and high diffusion coefficients. An effective hydrodynamic diameter of the [PSn(Cl)W11O39]4−–polypropylenimine octaamine hybrid adduct was measured in a light scattering experiment. [ABSTRACT FROM AUTHOR]