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We consider the Br vacancy in CsPbBr3 as a prototype for the impact of structural dynamics on defect energetics in halide perovskites (HaPs). Using first-principles molecular dynamics based on density functional theory, we find that the static picture of defect energetics breaks down; the energy level associated with a Br vacancy is found to be intrinsically dynamic, oscillating by as much as 1 eV on the picosecond time scale at room temperature. These significant energy fluctuations are correlated with the distance between the neighboring Pb atoms across the vacancy and with the electrostatic potential at these Pb atomic sites. We expect this unusually strong coupling of structural dynamics and defect energetics to bear important implications for both experimental and theoretical analyses of defect characteristics in HaPs. It may also hold significant ramifications for carrier transport and defect tolerance in this class of photovoltaic materials.

In recent years, inorganic cesium amp; 8722;lead amp; 8722;halide perovskites, CsPbX3 X I, Br, Cl , have attracted interest for optoelectronic applications such as highly efficient thin film light emitting diodes or wide gap absorber materials for photovoltaics. However, phase segregation and secondary phases in as deposited thin films are still considered to be limiting factors for devices based on CsPbX3. Here, we report a correlative electron microscopy and spectroscopy approach for the identification of secondary phases and their distributions in Cs amp; 8722;Pb amp; 8722;Br thin films, deposited by solutionbased and coevaporation methods on various substrates. We identified phases by their compositional, structural, and optoelectronic properties, using X ray diffraction, spectroscopy, and a variety of microscopy techniques. We found that the Cs amp; 8722;Pb amp; 8722;Br films contain ternary Cs4PbBr6 and CsPb2Br5 phases in addition to CsPbBr3, a finding consistent with calculations of formation enthalpies by means of the density functional theory showing that these values are very similar for the three ternary phases. We find that these phases can exhibit different spatial distributions inside the film and discuss the influence of the deposition method and synthesis parameters on the resulting phase composition of the Cs amp; 8722;Pb amp; 8722;Br layers

We consider the Br vacancy in CsPbBr

We consider the Br vacancy in CsPbBr3 as a prototype for the impact of structural dynamics on defect energetics in halide perovskites (HaPs). Using first-principles molecular dynamics based on density functional theory, we find that the static picture of defect energetics breaks down; the energy of the Br vacancy level is found to be intrinsically dynamic, oscillating by as much as 1 eV on the ps time scale at room temperature. These significant energy fluctuations are correlated with the distance between the neighboring Pb atoms across the vacancy and with the electrostatic potential at these Pb atomic sites. We expect this unusually strong coupling of structural dynamics and defect energetics to bear important implications for both experimental and theoretical analysis of defect characteristics in HaPs. It may also hold significant ramifications for carrier transport and defect tolerance in this class of photovoltaic materials., 5 figures, 1 table

While drilling the gas cap zone of the offshore Cantarell 69-I well, a gas kick was taken, becoming a blowout. The gas ignited, causing a large fire situation, and as a consequence the drilling rig was severely damaged. Due to the flowing conditions of the well, it was not possible to achieve well control through the tubing string. Therefore, two different alternatives were analyzed to solve the problem: momentum and dynamic kill. This paper presents the results obtained applying both techniques, as well as the well control analysis and procedure. First, the pressure profile in the well was calculated, as well as the gas flow rate (230 MMscfd) in blowout conditions. Then the kill flow rate (considering seawater) was calculated for both methods. The dynamic method yielded a kill flow rate of 19 bbl/min. Once the flow rate required to control the well was defined, the casing head was inspected to assure the success of the attempt, and it was in good condition to perform the operations. The operative sequence to control the contingency in a minimum time consisted of connecting the 20 x 13 3/8-inch casing head to a cementing ship through 2-inch lines in order to pump seawater. The total time required to control the gas blowout was 11 hours after the kick was taken. The success consisted of reaching a flowing pressure at the tie-back depth (680 m) greater than the reservoir pressure, which was generated by the frictional pressure losses and the hydrostatic head of the multiphase flow (gas and seawater) inside the injection string.

We present 13 patients with 15 episodes of colonic volvulus, who underwent colonoscopy to decompress and/or devolvulate. Colonoscopic exploration demonstrated a non obstructive dilatation in three cases. In the remaining 10 patients, with 12 episodes of volvulus, decompression was obtained in 83.3% and devoluvulation in 41.6%. There were two failures, due to peritoneal metastases and adhesions which fixed the volvulus. In 40% of the cases there were mild ischemic signs. Forty per cent of the patients were submitted to elective surgery and the two failures (20%) were operated in emergency. The remaining 4 patients declined surgical treatment. At is allows differential diagnosis, we think that, for these patients, colonoscopy should be the first therapeutic approach; it also allows decompression and/or devolvulation and an early diagnosis of the associated ischemia.

This paper describes the histological features of the vagus nerve after its stimulation with an electrostimulation system that is being developed for morbid obesity treatment. An electrostimulation system was implanted laparoscopically around the ventral vagal trunk of five Large White female pigs (49.63±1.94kg.). Vagal nerve stimulation was performed by continuous constant voltage current pulses. Thoracic samples of both ventral and dorsal vagal trunks were obtained thoracoscopically one month after implantation. Animals were sacrificed one month after thoracoscopic vaguectomy. Tissue samples were then harvested from the vagal nerve at the implantation site, 1cm cranial to it, thoracic portion of ventral and dorsal vagal trunks, sub-diaphragmatic dorsal vagal trunk, left and right vagus nerves. Specimens were analysed with light microscope. The severity of the lesions was graded from 0 to 4 (0: no lesion, 1: mild, 2: moderate, 3: severe and 4: extremely severe), taking into account fibrosis, vascularization, necrosis, fiber degeneration and inflammation. Electrode implantation resulted in thickened epineurium and endoneural connective tissue. The greatest lesion score was evidenced at the leads implantation site in the ventral vagal trunk, followed by, in order of decreasing lesion severity, left vagus nerve, thoracic portion of ventral vagal trunk, subdiaphragmatic dorsal vagal trunk, thoracic portion of dorsal vagal trunk and right vagus nerve. The stimulation device used in this study caused connective tissue growth, greatest in the samples located closer to the implantation site. However, there was no sign of altered vascularization in any studied specimen.

Aging and age-related diseases are one of the most important health issues that the world will confront during the 21st century. Only by understanding the proximal causes will we be able to find treatments to reduce or delay the onset of degenerative diseases associated with aging. Currently, the prevalent paradigm in the field is the accumulation of damage. However, a new theory that proposes an alternative explanation is gaining momentum. The hyperfunction theory proposes that aging is not a consequence of a wear and tear process, but a result of the continuation of developmental programs during adulthood. Here we use Drosophila melanogaster, where evidence supporting both paradigms has been reported, to identify which parameters that have been previously related with lifespan best predict the rate of aging in wild type flies cultured at different temperatures. We find that mitochondrial function and mitochondrial reactive oxygen species (mtROS) generation correlates with metabolic rate, but not with the rate of aging. Importantly, we find that activation of nutrient sensing pathways (i.e. insulin-PI3K/Target of rapamycin (Tor) pathway) correlates with lifespan, but not with metabolic rate. Our results, dissociate metabolic rate and lifespan in wild type flies and instead link nutrient sensing signaling with longevity as predicted by the hyperfunction theory. This study was supported by the European Research Council (ERC Starting Grant to A.S.), the Academy of Finland (Research Academy Fellowship to A.S), the Spanish Ministry of Economy and Competitiveness (BFU2009-11879/BFI; RD12/0043/0018 and PI1400328 to R.P.), and the Autonomous Government of Catalonia (2014SGR168 to R.P).