Electronic structure and ferroelectricity in SrBi2Ta2O9

The electronic structure of SrBi2Ta2O9 is investigated from first-principles, within the local density approximation, using the full-potential linearized augmented plane wave (LAPW) method. The results show that, besides the large Ta(5d)-O(2p) hybridization which is a common feature of the ferroelectric perovskites, there is an important hybridization between bismuth and oxygen states. The underlying static potential for the ferroelectric distortion and the primary source for ferroelectricity is investigated by a lattice-dynamics study using the Frozen Phonon approach.Comment: 17 pages, 7 figures. Phys. Rev. B, in pres

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Update on sepsis-associated acute kidney injury: Emerging targeted therapies

Sepsis-associated acute kidney injury (SA-AKI) is an independent predictor of increased mortality and morbidity. It is essential that further advances in the treatment of sepsis should prioritize targeted therapies in SA-AKI in order to improve these bleak outcomes. As yet, a unique therapy that effectively reduces the impact of acute kidney injury has not been demonstrated. However, the emergence of novel targeted therapies, perhaps in combination, has the possibility of significantly reducing the long-term sequelae of an episode of SA-AKI. In this review, we will focus on the shared etiology of these conditions and how this is managed with targeted therapy and finally the emerging novel therapies that may play an additional role to current treatment strategies

Update on sepsis-associated acute kidney injury: Emerging targeted therapies

Sepsis-associated acute kidney injury (SA-AKI) is an independent predictor of increased mortality and morbidity. It is essential that further advances in the treatment of sepsis should prioritize targeted therapies in SA-AKI in order to improve these bleak outcomes. As yet, a unique therapy that effectively reduces the impact of acute kidney injury has not been demonstrated. However, the emergence of novel targeted therapies, perhaps in combination, has the possibility of significantly reducing the long-term sequelae of an episode of SA-AKI. In this review, we will focus on the shared etiology of these conditions and how this is managed with targeted therapy and finally the emerging novel therapies that may play an additional role to current treatment strategies