Membrane current responses to intracellular injections of inositol 1,3,4,5-tetrakisphosphate and inositol 1,3,4-trisphosphate in NG108-15 hybrid cells

AbstractIontophoretic injections of inositol 1,4,5-trisphosphate inside neuroblastoma × glioma NG108-15 hybrid cells evoked an outward K+ current across the outer cell membrane, probably activated by the release of intracellular Ca2+. No such current was produced by equivalent intracellular injections of inositol 1,3,4-trisphosphate or inositol 1,3,4,5-tetrakisphosphate. Instead, these compounds evoked an inward current with a reversal potential of about −20 mV, and which may therefore be due to a non-specific cation conductance. This suggests that these derivatives are unable to release sufficient Ca2+ to activate the Ca2+-dependent K+ current in these cells

Bradykinin inhibits potassium (M) currents in N1E- 115 neuroblastoma cells Responses resemble those in NG108-15 neuroblastoma x glioma hybrid cells

AbstractApplication of bradykinin to voltage-clamped N1E-115 mouse neuroblastoma cells evoked sequential outward and inward membrane currents, accompanied by an increase and decrease of membrane conductance, respectively. Methacholine produced an inward current with a decreased conductance. The outward current response to bradykinin was imitated by intracellular inositol 1,4,5-trisphosphate (IP3). Bath application of phorbol dibutyrate induced an inward current and potentiated the response to IP3. We conclude that the response of these cells to bradykinin is identical to that of NG108-15 hybrid cells, and therefore may be attributed to the dual effects of inositol trisphosphate and diacylglycerol formed by hydrolysis of phosphatidylinositide

Cavity QED and Quantum Computation in the Weak Coupling Regime

In this paper we consider a model of quantum computation based on n atoms of laser-cooled and trapped linearly in a cavity and realize it as the n atoms Tavis-Cummings Hamiltonian interacting with n external (laser) fields. We solve the Schr{\" o}dinger equation of the model in the case of n=2 and construct the controlled NOT gate by making use of a resonance condition and rotating wave approximation associated to it. Our method is not heuristic but completely mathematical, and the significant feature is a consistent use of Rabi oscillations. We also present an idea of the construction of three controlled NOT gates in the case of n=3 which gives the controlled-controlled NOT gate.Comment: Latex file, 22 pages, revised version. To appear in Journal of Optics B : Quantum and Semiclassical Optic

Site‐Selective trans‐Hydrostannation of 1,3‐ and 1,n‐Diynes: Application to the Total Synthesis of Typhonosides E and F, and a Fluorinated Cerebroside Analogue

Propargyl alcohols are privileged substrates for stereochemically unorthodox trans‐hydrostannation reactions catalyzed by [Cp*RuCl]4 (Cp*=pentamethylcyclopentadienyl), because an incipient hydrogen bond between the ‐OH group and the polarized [Ru‐Cl] unit assists substrate binding. For this very reason, it is also possible to subject diyne derivatives carrying one ‐OH group to site‐selective stannylation, even if the acetylene units are conjugated and hence, electronically coupled. An unusual temperature dependence was observed in that heating tends to improve site‐selectivity, whereas per‐stannylation is favored when the reaction is carried out in the cold. This counterintuitive trend can be rationalized based on spectroscopic data; additional support comes from the isolation of the unusual bimetallic complex 11. The bridging fulvene and enynyl ligands in 11 are thought to reflect an interligand redox isomerization process likely triggered by synchronous activation of the 1,3‐diyne substrate by two metal centers. The preparative relevance of site‐selective trans‐hydrostannation is illustrated by the total synthesis of two members of the typhonoside series of glycolipids, which are endowed with neuroprotective properties. Moreover, the preparation of a fluoroalkene sphingosine analogue shows that the tin residue also serves as a versatile handle for late‐stage modification of a bioactive target compound

Explicit Form of the Evolution Operator of Tavis-Cummings Model : Three and Four Atoms Cases

In this letter the explicit form of evolution operator of the Tavis-Cummings model with three and four atoms is given. This is an important progress in quantum optics or mathematical physics.Comment: Latex file, 10 pages. We combined quant-ph/0404034(the three atoms case) and quant-ph/0406184(the four atoms case) into an article. to appear in International Journal of Geometric Methods in Modern Physic

Overcoming data scarcity of Twitter: using tweets as bootstrap with application to autism-related topic content analysis

Notwithstanding recent work which has demonstrated the potential of using Twitter messages for content-specific data mining and analysis, the depth of such analysis is inherently limited by the scarcity of data imposed by the 140 character tweet limit. In this paper we describe a novel approach for targeted knowledge exploration which uses tweet content analysis as a preliminary step. This step is used to bootstrap more sophisticated data collection from directly related but much richer content sources. In particular we demonstrate that valuable information can be collected by following URLs included in tweets. We automatically extract content from the corresponding web pages and treating each web page as a document linked to the original tweet show how a temporal topic model based on a hierarchical Dirichlet process can be used to track the evolution of a complex topic structure of a Twitter community. Using autism-related tweets we demonstrate that our method is capable of capturing a much more meaningful picture of information exchange than user-chosen hashtags.Comment: IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining, 201

Early Experience in the Treatment of Intra-Cranial Aneurysms by Endovascular Flow Diversion: A Multicentre Prospective Study

INTRODUCTION: Flow diversion is a new approach to the endovascular treatment of intracranial aneurysms which uses a high density mesh stent to induce sac thrombosis. These devices have been designed for the treatment of complex shaped and large size aneurysms. So far published safety and efficacy data on this approach is sparse. MATERIAL AND METHODS: Over 8 months, standardized clinical and angiographic data were collected on 70 patients treated with a flow diverter device (SILK flow diverter (SFD)) in 18 centres worldwide. Treatment and early follow up details were audited centrally. SFDs were deployed alone in 57 (81%) or with endosaccular coils in 10 (14%) aneurysms, which included: 44 (63%) saccular, 26 (37%) fusiform shapes and 18 (26%) small, 37 (53%) large, 15 (21%) giant sizes. Treatment outcome data up to 30 days were reported for all patients, with clinical (50 patients) and imaging (49 patients) follow up (median 119 days) data available. RESULTS: Difficulties in SFD deployment were reported in 15 (21%) and parent artery thrombosis in 8 (11%) procedures. Procedural complications caused stroke in 1 and serious extracranial bleeding in 3 patients; 2 of whom developed fatal pneumonias. Delayed worsening of symptoms occurred in 5 patients (3 transient, 1 permanent neurological deficit, and 1 death) and fatal aneurysm bleeding in 1 patient. Overall permanent morbidity rates were 2 (4%) and mortality 4 (8%). Statistical analysis revealed no significant association between complications and variables related to treated aneurysm morphology or rupture status. CONCLUSION: This series is the largest reporting outcome of the new treatment approach and provides data for future study design. Procedural difficulties in SFD deployment were frequent and anti-thrombosis prophylaxis appears to reduce the resulting clinical sequelae, but at the cost of morbidity due to extracranial bleeding. Delayed morbidity appears to be a consequence of the new approach and warrants care in selecting patients for treatment and future larger studies

Actin turnover-dependent fast dissociation of capping protein in the dendritic nucleation actin network: evidence of frequent filament severing

Actin forms the dendritic nucleation network and undergoes rapid polymerization-depolymerization cycles in lamellipodia. To elucidate the mechanism of actin disassembly, we characterized molecular kinetics of the major filament end-binding proteins Arp2/3 complex and capping protein (CP) using single-molecule speckle microscopy. We have determined the dissociation rates of Arp2/3 and CP as 0.048 and 0.58 s(-1), respectively, in lamellipodia of live XTC fibroblasts. This CP dissociation rate is three orders of magnitude faster than in vitro. CP dissociates slower from actin stress fibers than from the lamellipodial actin network, suggesting that CP dissociation correlates with actin filament dynamics. We found that jasplakinolide, an actin depolymerization inhibitor, rapidly blocked the fast CP dissociation in cells. Consistently, the coexpression of LIM kinase prolonged CP speckle lifetime in lamellipodia. These results suggest that cofilin-mediated actin disassembly triggers CP dissociation from actin filaments. We predict that filament severing and end-to-end annealing might take place fairly frequently in the dendritic nucleation actin arrays

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV