Poly ionic liquid Nanovesicle Templated Carbon Nanocapsules Functionalized with Uniform Iron Nitride Nanoparticles as Catalytic Sulfur Host for Li S Batteries

Poly ionic liquid s PIL are common precursors for heteroatom doped carbon materials. Despite a relatively higher carbonization yield, the PIL to carbon conversion process faces challenges in preserving morphological and structural motifs on the nanoscale. Assisted by a thin polydopamine coating route and ion exchange, imidazolium based PIL nanovesicles were successfully applied in morphology maintaining carbonization to prepare carbon composite nanocapsules. Extending this strategy further to their composites, we demonstrate the synthesis of carbon composite nanocapsules functionalized with iron nitride nanoparticles of an ultrafine, uniform size of 3 5 nm termed FexN C . Due to its unique nanostructure, the sulfur loaded FexN C electrode was tested to efficiently mitigate the notorious shuttle effect of lithium polysulfides LiPSs in Li S batteries. The cavity of the carbon nanocapsules was spotted to better the loading content of sulfur. The well dispersed iron nitride nanoparticles effectively catalyze the conversion of LiPSs to Li2S, owing to their high electronic conductivity and strong binding power to LiPSs. Benefiting from this well crafted composite nanostructure, the constructed FexN C S cathode demonstrated a fairly high discharge capacity of 1085 mAh g 1 at 0.5 C initially, and a remaining value of 930 mAh g 1 after 200 cycles. In addition, it exhibits an excellent rate capability with a high initial discharge capacity of 889.8 mAh g 1 at 2 C. This facile PIL to nanocarbon synthetic approach is applicable for the exquisite design of complex hybrid carbon nanostructures with potential use in electrochemical energy storage and conversio

Differential cell susceptibilities to kras(G12D) in the setting of obstructive chronic pancreatitis

BACKGROUND & AIMS: Activating mutation of the KRAS gene is common in some cancers, such as pancreatic cancer, but rare in other cancers. Chronic pancreatitis is a predisposing condition for pancreatic ductal adenocarcinoma (PDAC), but how it synergizes with KRAS mutation is not known. METHODS: We used a mouse model to express an activating mutation of Kras in conjunction with obstruction of the main pancreatic duct to recapitulate a common etiology of human chronic pancreatitis. Because the cell of origin of PDAC is not clear, Kras mutation was introduced into either duct cells or acinar cells. RESULTS: Although Kras(G12D) expression in both cell types was protective against damage-associated cell death, chronic pancreatitis induced p53, p21, and growth arrest only in acinar-derived cells. Mutant duct cells did not elevate p53 or p21 expression and exhibited increased proliferation driving the appearance of PDAC over time. CONCLUSIONS: One mechanism by which tissues may be susceptible or resistant to KRAS(G12D)-initiated tumorigenesis is whether they undergo a p53-mediated damage response. In summary, we have uncovered a mechanism by which inflammation and intrinsic cellular programming synergize for the development of PDAC

System identification of an enclosure with leakages using a probabilistic approach

This paper presents a model-based method for the system identification of a rectangular enclosure with an unknown number of air leakages subjected to uniform external noise, according to the probabilistic approach. The method aims to identify the number and corresponding locations and sizes of air leakages utilizing a set of measured, interior, sound pressure data in the frequency domain. System identification of an enclosure with an unknown number of air leakages is not trivial. Different classes of acoustic models are required to simulate an enclosure with different numbers of leakages. By following the traditional system of identification techniques, the "optimal" class of models is selected by minimizing the discrepancy between the measured and modeled interior sound pressure. By doing this, the most complicated model class (that is, the one with the highest number of uncertain parameters) will always be selected. Therefore, the traditional system identification techniques found in the literature to date cannot be employed to solve this problem. Our proposed system identification methodology relies on the Bayesian information criterion (BIC) to identify accurately the number of leakages in an enclosure. Unlike all deterministic system identification approaches, the proposed methodology aims to calculate the posterior (updated) probability density function (PDF) of leakage locations and sizes. Therefore, the uncertainties introduced by measurement noise and modeling error can be explicitly addressed. The coefficient of variable (COV) of uncertain parameters, which can be easily calculated from the PDF, provides valuable information about the reliability of the identification results. © 2008 Elsevier Ltd. All rights reserved.H. F. Lam, C. T. Ng, Y. Y. Lee and H. Y. Sunhttp://www.elsevier.com/wps/find/journaldescription.cws_home/622899/description#descriptio

Memory effect in the deposition of C20 fullerenes on a diamond surface

In this paper, the deposition of C-20 fullerenes on a diamond (001)-(2x1) surface and the fabrication of C-20 thin film at 100 K were investigated by a molecular dynamics (MD) simulation using the many-body Brenner bond order potential. First, we found that the collision dynamic of a single C-20 fullerene on a diamond surface was strongly dependent on its impact energy. Within the energy range 10-45 eV, the C-20 fullerene chemisorbed on the surface retained its free cage structure. This is consistent with the experimental observation, where it was called the memory effect in "C-20-type" films [P. Melion , Int. J. Mod. B 9, 339 (1995); P. Milani , Cluster Beam Synthesis of Nanostructured Materials (Springer, Berlin, 1999)]. Next, more than one hundred C-20 (10-25 eV) were deposited one after the other onto the surface. The initial growth stage of C-20 thin film was observed to be in the three-dimensional island mode. The randomly deposited C-20 fullerenes stacked on diamond surface and acted as building blocks forming a polymerlike structure. The assembled film was also highly porous due to cluster-cluster interaction. The bond angle distribution and the neighbor-atom-number distribution of the film presented a well-defined local order, which is of sp(3) hybridization character, the same as that of a free C-20 cage. These simulation results are again in good agreement with the experimental observation. Finally, the deposited C-20 film showed high stability even when the temperature was raised up to 1500 K

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter