Conductivity and dielectric properties of aqueous cadmium sulfate solutions

The results of measurements of concn.- and temp.-dependences of electrolyte conductance and of high frequency permittivity of aq. solns. of CdSO4 are compared on the basis of the chem. model of electrolyte solns. Both methods yield results which are compatible with regard to ion assocn. and hydration and with thermodn. data. The coulombic and noncoulombic parts of the enthalpy and entropy of ion-pair formation are of the same order of magnitude

Investigation of the Li-Co antisite exchange in Fe-substitued LiCoPO4 cathode for high-voltage lithium ion batteries

Carbon coated olivine Pnma LiCoPO4 (LCP/C) and Fe-substituted LiCo0.8Fe0.2PO4 (LCFP/C) were synthesized by a solvothermal method and their structural features and electrochemical properties were investigated. The electrochemical performance of LCFP/C is better than that of LCP/C, owing to the partial substitution of Co by Fe which effectively suppresses the increasement of antisite exchange between Li+ and Co2+ ions within the structure during cycling, despite a similar amount of Li–Co antisite exchange in pristine LCP/C and LCFP/C samples. Furthermore, direct visualization of Co in Li sites in the pristine samples and after 50 cycles was achieved through high-resolution scanning transmission electron microscopy for both LCP/C and LCFP/C. It was found that LCP/C locally formed a new cation-ordered structure after cycling due to the Li–Co antisite exchange, while the structure of LCFP/C remains almost the same. This study provides direct evidence that Fe substitution reduced the Li–Co exchange and improved the electrochemical cycling life of the LiCoPO4 cathode for high-voltage lithium ion batteries

Noninvasive management of the diabetic foot with critical limb ischemia: current options and future perspectives

Foot ulcers are a major complication in patients with diabetes mellitus and involve dramatic restrictions to quality of life and also lead to enormous socio-economical loss due to the high amputation rate. The poor and slow wound healing is often aggravated by the frequent comorbidity of foot ulcers with peripheral arterial disease, making the treatment of this condition even more complicated. While the local treatment of foot ulcers is mainly based on mechanical relief and prevention or treatment of infection, improving perfusion of the impaired tissue remains the major challenge in peripheral arterial disease. While focal arterial stenosis is the domain of interventional angioplasty or vascular surgery, patients with critical limb ischemia and lacking options for revascularization have a much worse prognosis, because current treatment options avoiding amputation are scarce. However, based on recent research efforts, there is rising hope for promising and more-effective therapeutic approaches for these patients. Here, we discuss the current improvements of established therapies aimed at an improvement of limb perfusion, as well as the development of novel cutting-edge therapies based on stem-cell technology. The experiences of a ‘high-volume center’ for treatment of diabetic foot syndrome with a current major amputation rate of 4% are discussed