Diverse parameters, including chaotropicity, can limit the function of cellular systems and thereby determine the extent of Earth's biosphere. Whereas parameters such as temperature, hydrophobicity, pressure, pH, Hofmeister effects, and water activity can be quantified via standard scales of measurement, the chao-/kosmotropic activities of environmentally ubiquitous substances have no widely accepted, universal scale. We developed an assay to determine and quantify chao-/kosmotropicity for 97 chemically diverse substances that can be universally applied to all solutes. This scale is numerically continuous for the solutes assayed (from +361 kJ kg(-1)  mol(-1) for chaotropes to -659 kJ kg(-1)  mol(-1) for kosmotropes) but there are key points that delineate (i) chaotropic from kosmotropic substances (i.e. chaotropes ≥ +4; kosmotropes ≤ -4 kJ kg(-1)  mol(-1) ); and (ii) chaotropic solutes that are readily water-soluble (log P < 1.9) from hydrophobic substances that exert their chaotropic activity, by proxy, from within the hydrophobic domains of macromolecular systems (log P > 1.9). Examples of chao-/kosmotropicity values are, for chaotropes: phenol +143, CaCl(2) +92.2, MgCl(2) +54.0, butanol +37.4, guanidine hydrochloride +31.9, urea +16.6, glycerol [> 6.5 M] +6.34, ethanol +5.93, fructose +4.56; for kosmotropes: proline -5.76, sucrose -6.92, dimethylsulphoxide (DMSO) -9.72, mannitol -6.69, trehalose -10.6, NaCl -11.0, glycine -14.2, ammonium sulfate -66.9, polyethylene glycol- (PEG-)1000 -126; and for relatively neutral solutes: methanol, +3.12, ethylene glycol +1.66, glucose +1.19, glycerol [< 5 M] +1.06, maltose -1.43 (kJ kg(-1)  mol(-1)). The data obtained correlate with solute interactions with, and structure-function changes in, enzymes and membranes. We discuss the implications for diverse fields including microbial ecology, biotechnology and astrobiology.

Direct observations of structure-electrochemical activity relationships continue to be a key challenge in secondary battery research. (6)Li magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is the only structural probe currently available that can quantitatively characterize local lithium environments on the subnanometer scale that dominates the free energy for site occupation in lithium-ion (Li-ion) intercalation materials. In the present study, we use this local probe to gain new insights into the complex electrochemical behavior of activated 0.5(6)Li2MnO3·0.5(6)LiMn(0.5)Ni(0.5)O2, lithium- and manganese-rich transition-metal (TM) oxide intercalation electrodes. We show direct evidence of path-dependent lithium site occupation, correlated to structural reorganization of the metal oxide and the electrochemical hysteresis, during lithium insertion and extraction. We report new (6)Li resonances centered at ∼1600 ppm that are assigned to LiMn6-TM(tet) sites, specifically, a hyperfine shift related to a small fraction of re-entrant tetrahedral TMs (Mn(tet)), located above or below lithium layers, coordinated to LiMn6 units. The intensity of the TM layer lithium sites correlated with tetrahedral TMs loses intensity after cycling, indicating limited reversibility of TM migrations upon cycling. These findings reveal that defect sites, even in dilute concentrations, can have a profound effect on the overall electrochemical behavior.

In a 6-year prospective clinical study, 181 hydroxylapatite coated endosseous dental implants were placed into the anterior mandible of 48 patients. Twenty-one patients were treated with fixed prostheses and 27 patients with an overdenture. When the implants were exposed all 181 had integrated. To date, there is 100% survival of all implants and they all retain a functioning prostheses. The initial results were very promising, in both groups the interval success was over 95% in the first 4 years of the study. However, by year 6, the interval success rates had fallen to 83% for both the fixed and removable groups. This study also compares the construction and maintenance complications for the two types of restorations. The clinical time taken, after implant exposure, to construct the prostheses was similar whether the fixed (mean of 8 visits) or removable option (mean of 7 visits) was chosen. However, the removable restoration cost less than half the price of the fixed when both technical time and implant component costs were evaluated. Maintenance for both groups was higher than expected, but patients required more appointments in the removable group both in the first year and beyond. Regarding the prostheses itself, the incidence of remakes, relines and general adjustments was higher in the removable group. This study has shown that the overdenture offers an effective and initially a more economical alternative to the fixed prostheses, in the treatment of the edentulous mandible. However, long-term maintenance of such a prosthesis can be significant.

Spinel-structured LiMn 2 O 4 (LMO) is a desirable cathode material for Li-ion batteries due to its low cost, abundance, and high power capability. However, LMO suffers from limited cycle life that is triggered by manganese dissolution into the electrolyte during electrochemical cycling. Here, it is shown that single-layer graphene coatings suppress manganese dissolution, thus enhancing the performance and lifetime of LMO cathodes. Relative to lithium cells with uncoated LMO cathodes, cells with graphene-coated LMO cathodes provide improved capacity retention with enhanced cycling stability. X-ray photoelectron spectroscopy reveals that graphene coatings inhibit manganese depletion from the LMO surface. Additionally, transmission electron microscopy demonstrates that a stable solid electrolyte interphase is formed on graphene, which screens the LMO from direct contact with the electrolyte. Density functional theory calculations provide two mechanisms for the role of graphene in the suppression of manganese dissolution. First, common defects in single-layer graphene are found to allow the transport of lithium while concurrently acting as barriers for manganese diffusion. Second, graphene can chemically interact with Mn 3+ at the LMO electrode surface, promoting an oxidation state change to Mn 4+ , which suppresses dissolution. 1500646(2 of 10) wileyonlinelibrary.com power applications. Furthermore, LMO offers improved thermal stability relative to LiCoO 2 , especially in a highly delithiated state, resulting in safer batteries. [ 6 ] However, a major disadvantage of LMO spinel cathodes is that they lose capacity following long term cycling due to Mn 2+ dissolution from the surface of the cathode into the electrolyte during charge/discharge as a result of the disproportionation reaction: 2Mn 3+ → Mn 4+ + Mn 2+ . [ 7,8 ] Approaches that have shown promise in combating manganese dissolution include modifi cation of the composition of the parent LMO electrode by cation substitution (e.g., LiM x Mn 2x O 4 , M = Li, Co, Ni, Zn) [9][10][11][12][13][14] to reduce the amount of Mn 3+ in the structure, thereby increasing the average oxidation state on the manganese ions in the electrode above 3.5+. In addition, a variety of protective surface oxide coatings have been employed such as Al 2 O 3 , [ 15 ] ZrO 2 , [ 16 ] Y 2 O 3 , [ 17 ] and TiO 2 . [ 7 ] However, the realization of a thin and uniform surface fi lm that does not compromise surface conductivity remains an outstanding challenge.Here, we explore single-layer graphene coatings as an alternative strategy for suppressing manganese dissolution form spinel LMO cathodes. Graphene is a promising candidate for this application since it is an effective diffusion barrier for atomic-scale species [ 18,19 ] and can withstand numerous lithiation charge/discharge cycles. [ 20 ] In addition, graphene is an excellent conductor, which facilitates electron transfer and cycling rate. [ 21 ] Graphene is also known to yield a well-defi ned and stable solid electrolyte interphase (SEI) l...