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171.
Nathan A. Lockwood Maria-Victoria Meli Aditya Surjosantoso Evelina B. Kim Juan J. de Pablo Nicholas L. Abbott 《Liquid crystals》2007,34(12):1387-1396
Differential scanning calorimetry (DSC) was used to characterize interactions of synthetic LCs, 4-pentyl-4'-cyanobiphenyl (5CB) and TL205 (a mixture of cyclohexane-fluorinated biphenyls and fluorinated terphenyls) with simple mimics of cell membranes. The investigation was motivated by reports that living cells can be placed into contact with TL205 without apparent toxicity, whereas contact of cells with 5CB leads to cell death. The tendency was examined for 5CB and TL205 to spontaneously partition into and influence the organization for model cell membranes composed of phospholipids. Upon contact of an aqueous dispersion of DPPC liposomes with neat LC for 4 h, 5CB partitioned into the liposomes at a weight ratio of 5:1 DPPC:5CB, whereas TL205 partitioned at a ratio of 310:1 DPPC:TL205. DSC endotherms indicated that the 5CB spontaneously partitioned into the liposomes was far more perturbing than TL205. DSC endotherms of DPPC bilayers containing the same concentration of either 5CB or TL205 also revealed 5CB to be more perturbing than TL205. The effect of up to 7.8 wt % of TL205 was small, resulting in a shift in the melting transition from 41.4°C to 40.1°C and a minor change in peak width, indicating only minor effects on the organization of the bilayer. These effects are similar to those caused by cholesterol in DPPC bilayers. In contrast, 5CB shifted the DPPC melting transition from 41.4°C to ∼36°C and increased the width of the transition peak by a factor of ten, indicating a destabilization of the ordered phase in the bilayer and a disruption of the cooperative nature of the gel-to-LC transition of the phospholipid bilayer. Taken together, the results demonstrate that 5CB and TL205 differ significantly in their interactions with model cell membranes, which suggests one possible origin of their different toxicities toward cells. 相似文献
172.
Single crystals of N‐carbamothioylacetamide (NCTA) were grown by slow evaporation technique at constant temperature. The structure is elucidated by single crystal XRD analysis. The studies reveal that the molecule is associated with accommodating weak C–O···H, N–H···O, N–H···S, C–H···N, C···C and H···H stacking interactions which are responsible for the formation and strengthening of supramolecular assembly. Inter‐ and intramolecular hydrogen bonding interactions exhibit supramolecular architecture in the crystal packing. Two different types of architecture, i.e., a column like packing, and cluster network type of infrastructure are observed. Hirshfeld surfaces and Fingerprint plots were used to locate and analyze the percentage of hydrogen bonding interactions. The various functional groups present in the molecule are confirmed by FT‐IR analysis. Density functional theory computations of the vibrational spectrum, molecular geometry, HOMO‐LUMO energy gaps, NBO and hyperpolarizability (β) were successfully evaluated. Facts concerning with the size, shape, charge density distribution and site of chemical reactivity of the molecule have been obtained by mapping electron density with electrostatic potential (ESP). 相似文献
173.
J. Liu X. Gao L.Q. Hu M. Asif Z.Y. Chen B.J. Ding Q. Zhou H.Q. Liu Y.X. Jie W. Kong S.Y. Lin Y.H. Ding L. Gao Q. Xu the HT- Team 《Physics letters. A》2006,350(5-6):386-391
Recent progress of lower hybrid (LH) experiments with new graphite limiters configuration in the HT-7 tokamak is presented. The lower hybrid current drive (LHCD) efficiency can be determined by fitting based on experimental data. Improved particle confinement was observed via LHCD (PLHW>300 kW) characterized by the particle confinement time τp increased about 1.56 times. It is found that runaways are suppressed during loop voltage is decreasing at the flat-top phase of LH discharges. The main limitations of pulse length are presented in long-pulse experiments with new limiter configuration. 相似文献
174.
Eich T Sieglin B Scarabosio A Fundamenski W Goldston RJ Herrmann A;ASDEX Upgrade Team 《Physical review letters》2011,107(21):215001
Experimental measurements of the SOL power decay length (λ(q)) estimated from analysis of fully attached divertor heat load profiles from two tokamaks, JET and ASDEX Upgrade, are presented. Data was measured by means of infrared thermography. An empirical scaling reveals parametric dependency λ(q) in mm = 0.73B(T)(-0.78)q(cyl)(1.2)P(SOL)(0.1)R(geo)(0), where B(T)(T) describes the toroidal magnetic field, q(cyl) the cylindrical safety factor, P(SOL)(MW) the power crossing the separatrix and R(geo)(m) the major radius of the device. A comparison of these measurements to a heuristic particle drift-based model shows satisfactory agreement in both absolute magnitude and scaling. Extrapolation to ITER gives λ(q) ? 1 mm. 相似文献
175.
Yun GS Lee W Choi MJ Lee J Park HK Tobias B Domier CW Luhmann NC Donné AJ Lee JH;KSTAR Team 《Physical review letters》2011,107(4):045004
The filamentary nature and dynamics of edge-localized modes (ELMs) in the KSTAR high-confinement mode plasmas have been visualized in 2D via electron cyclotron emission imaging. The ELM filaments rotating with a net poloidal velocity are observed to evolve in three distinctive stages: initial linear growth, interim quasisteady state, and final crash. The crash is initiated by a narrow fingerlike perturbation growing radially from a poloidally elongated filament. The filament bursts through this finger, leading to fast and collective heat convection from the edge region into the scrape-off layer, i.e., ELM crash. 相似文献
176.
Korsholm SB Stejner M Bindslev H Furtula V Leipold F Meo F Michelsen PK Moseev D Nielsen SK Salewski M de Baar M Delabie E Kantor M Bürger A;TEXTOR Team 《Physical review letters》2011,106(16):165004
In this Letter we report measurements of collective Thomson scattering (CTS) spectra with clear signatures of ion Bernstein waves and ion cyclotron motion in tokamak plasmas. The measured spectra are in accordance with theoretical predictions and show clear sensitivity to variation in the density ratio of the main ion species in the plasma. Measurements with this novel diagnostic demonstrate that CTS can be used as a fuel ion ratio diagnostic in burning fusion plasma devices. 相似文献
177.
Conway GD Angioni C Ryter F Sauter P Vicente J;ASDEX Upgrade Team 《Physical review letters》2011,106(6):065001
A complex interaction between turbulence driven E × B zonal flow oscillations, i.e., geodesic acoustic modes (GAMs), the turbulence, and mean equilibrium flows is observed during the low to high (L-H) plasma confinement mode transition in the ASDEX Upgrade tokamak. Below the L-H threshold at low densities a limit-cycle oscillation forms with competition between the turbulence level and the GAM flow shearing. At higher densities the cycle is diminished, while in the H mode the cycle duration becomes too short to sustain the GAM, which is replaced by large amplitude broadband flow perturbations. Initially GAM amplitude increases as the H-mode transition is approached, but is then suppressed in the H mode by enhanced mean flow shear. 相似文献
178.
Aditya Sharma K. D. Verma Mayora Varshney Devendra Singh Moti Singh K. Asokan 《辐射效应与固体损伤》2013,168(12):930-937
In this paper, we present the impact of swift heavy ion beam irradiation on the structural, optical and electronic properties of SnO2 thin films. Thin films were deposited using the pulsed laser deposition technique on Al2O3 substrates. Atomic force microscopy, X-ray diffraction, UV–visible absorption and temperature-dependent resistivity measurements were performed to explore the morphological, structural, optical and electronic properties of the as-deposited and irradiated samples. The peak intensity of the (200) peak was found to decrease monotonously with increasing irradiation fluence. The band gap energy of the 1×1011 ion/cm2 irradiated sample was found to increase. The electrical resistivity of the samples showed a continuous increase with the irradiation fluence. 相似文献
179.
180.
Aditya Sharma Mayora Varshney Hyun-Joon Shin K.D. Verma 《Journal of Physics and Chemistry of Solids》2014
CeO2 thin films were deposited on quartz substrates by using the rf-sputtering technique. The 80-keV Ni- ion-implanted and, subsequently, post-annealed films have shown the formation of Ni oxide and Ni metallic phases at 7 at% of Ni concentration. Such secondary phases were dissolved by swift heavy ion irradiation with 200-MeV Ag+15 ion beams. Structural properties, surface roughness, and magnetic behavior of the samples were investigated by X-ray diffraction, atomic force microscopy, and hysteresis loop measurements, respectively. Dissolution of secondary phases has been discussed in the light of irradiation-induced local temperature rise and energy loss processes. 相似文献