Experimental investigation of the effect of topological insulator on the magnetization dynamics of ferromagnetic metal:BiSbTe1.5Se1.5andNi80Fe20heterostructure.

We have studied the spin-pumping phenomenon in ferromagnetic metal (FM) (Ni80Fe20)/topological insulator (TI) (BiSbTe1.5Se1.5) bilayer system to understand magnetization dynamics of FM in contact with a TI. TIs embody a spin-momentum-locked surface state that spans the bulk band gap. Due to this special spin texture of the topological surface state, the spin-charge interconversion efficiency of TI is even higher than that of heavy metals. We evaluated the parameters like effective damping coefficient (αeff), spin-mixing conductance (geff↑↓) and spin current density (jS0) to demonstrate an efficient spin transfer inNi80Fe20/BiSbTe1.5Se1.5heterostructure. To probe the effect of the topological surface state, a systematic low-temperature study is crucial as the surface state of TI dominates at lower temperatures. The exponential increase ofΔHfor all different thickness combinations of FM/TI bilayers and the enhancement of effective damping coefficient (αeff) with lowering temperature confirms that the spin chemical potential bias generated from spin-pumping induces spin current into the TI surface state. Furthermore, low-temperature measurements of effective magnetization (4πMeff) and magnetic anisotropy field (Hk) showed anomaly around the same temperature region where the resistivity of TI starts showing metallic behavior due to the dominance of conducting TI surface state. The anomaly inHkcan result from the emerging exchange coupling between the TI surface state and the local moments of the FM layer at the interface without any long-range ferromagnetic order in TI at the interface.

A rapidly spreading deleterious aphid endosymbiont that uses horizontal as well as vertical transmission.

Endosymbiotic bacteria that live inside the cells of insects are typically only transmitted maternally and can spread by increasing host fitness and/or modifying reproduction in sexual hosts. Transinfections of Wolbachia endosymbionts are now being used to introduce useful phenotypes into sexual host populations, but there has been limited progress on applications using other endosymbionts and in asexual populations. Here, we develop a unique pathway to application in aphids by transferring the endosymbiont Rickettsiella viridis to the major crop pest Myzus persicae. Rickettsiella infection greatly reduced aphid fecundity, decreased heat tolerance, and modified aphid body color, from light to dark green. Despite inducing host fitness costs, Rickettsiella spread rapidly through caged aphid populations via plant-mediated horizontal transmission. The phenotypic effects of Rickettsiella were sensitive to temperature, with spread only occurring at 19 °C and not 25 °C. Body color modification was also lost at high temperatures despite Rickettsiella maintaining a high density. Rickettsiella shows the potential to spread through natural M. persicae populations by horizontal transmission and subsequent vertical transmission. Establishment of Rickettsiella in natural populations could reduce crop damage by modifying population age structure, reducing population growth and providing context-dependent effects on host fitness. Our results highlight the importance of plant-mediated horizontal transmission and interactions with temperature as drivers of endosymbiont spread in asexual insect populations.

Renal disease and the surgical patient: Minimizing the impact.

Chronic kidney disease (CKD) is common in patients scheduled for surgery and increases the risk of postoperative acute kidney injury, major adverse cardiac events, and death. Acute kidney injury is a common complication of cardiac and noncardiac surgery and negatively affects both short- and long-term outcomes. If we can detect underlying CKD and other risk factors for acute kidney injury before surgery, we may in theory be able to give preventive therapies and improve perioperative outcomes.

Decreased trend in hospital mortality from pancreatic cancer despite increase in number of hospital admissions.

BACKGROUND AND AIM: Pancreatic cancer is one of the common cancers in US and is associated with high mortality and morbidity. The objectives of our study were to look at the recent trends in the number of hospitalizations with pancreatic cancer. METHODS: We identified patients with a discharge diagnosis of pancreatic cancer in the National Inpatient Sample from 2007 to 2011 using International Classification of Diseases-Clinical Modification, 9th revision (ICD-9-CM) codes. We looked at the yearly trend in the hospitalizations with pancreatic cancer and the outcomes which included length of stay (LOS), hospital charges and in-hospital mortality. We also performed multivariate analysis to look for the predictors of mortality. RESULTS: There were 450, 414 patients with discharge diagnosis of pancreatic cancer. There was 18% increase in hospitalizations with pancreatic cancer in 2011 compared to 2007. Most of the patients were Caucasian (63%) with the mean age of 68 ± 0.14 years, had Medicare (57%) as primary insurance, were from Southern region (35%) and had higher Charlson Comorbidity Index (CCI) (87% with CCI > = 5). 6% underwent Whipple's procedure in the index hospitalization. After the adjustment for inflation, the mean hospital charges increased from $ 47,331 in 20007 to $ 53, 854 in 2011 (p = 0.01). LOS decreased from 7.31 ± 0.11 days in 2007 to 6.70 ± 0.09 days in 2011 (<0.001). Despite the increase in the number of hospitalizations of patients with pancreatic cancer, mortality decreased from 9.8% in 2007 to 8.1% in 2011 (p<0.001). On multivariate analysis, the independent factors associated with higher mortality were older age, male sex African-American race, insurance status other than Medicare, higher CCI and enrollment in palliative care. There was regional variation in mortality. Whipple's procedure conferred lower mortality. CONCLUSIONS: Our study showed downward trends in LOS and in-hospital mortality despite increasing hospitalizations with pancreatic cancer.