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ABSTRACT: This study investigated the differences between past and future temporal discounting in terms of neural activity in relation to temporal distance. Results show that brain regions are engaged differently in past and future temporal discounting. This is likely because past temporal discounting requires memory reconstruction, whereas future temporal discounting requires the processing of uncertainty about the future. In past temporal discounting, neural activity differed only when preferences were made between rewards received one hour prior and rewards received further in the past. The peak amplitudes of P2 and P3 varied as the temporal distance increased from 2weeks to 50years. In future temporal discounting, neural activity differed only when preferences were evaluated between two delayed rewards. The delay conditions (6months:5years) and (6months:50years) had a significant influence on P2 and N2. Findings indicate the existence of different decision-making systems operating in past and future temporal discounting.
Consciousness and Cognition 10/2012; 21(4):1662-1672. · 2.31 Impact Factor
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ABSTRACT: To evaluate the impact of single-nucleotide polymorphisms (SNPs) in CYP2C9, MDR1, SLCO1B1 and ABCG2 on the pharmacokinetics of fluvastatin in Chinese participants.A pharmacokinetic study of fluvastatin (single dose 40 mg) was conducted in 12 healthy Chinese volunteers. Plasma concentrations of fluvastatin were determined by a high-performance liquid chromatography with fluorescence detection. Pharmacokinetic parameters were calculated by non-compartmental method. The SNPs were determined by TaqMan®(MGB) genotyping assay.Effect of CYP2C9*3 (c.1075A>C) on area under the plasma concentration-time curve (AUC) of fluvastatin was statistically significant. Heterozygous variant (C/A) carriers had higher AUC values compared to homozygous wild type (A/A) carriers (922.03±148.17 µg · h · L - 1 vs. 496.00±168.93 µg · h · L - 1, P=0.003092). The elimination half-life (T 1/2) values of fluvastatin were longer in MDR1 2677non-G carriers than in MDR1 2677G carriers (2.21±0.47 h vs. 1.25±0.62 h, P=0.02319), and also they were longer in MDR1 1236T-2677non-G-3435T carriers than in MDR1 1236C-2677G-3435C carriers (2.31±0.51 h vs. 1.32±0.62 h, P=0.03320). MDR1 C3435T polymorphism had a significant effect on maximal plasma concentrations (C max) of fluvastatin. Mutation gene T (TT+CT) carriers had higher C max values compared to homozygous wild type (C/C) carriers (688.54±142.67 µg · L - 1 vs. . 413.78±177.83 µg · L - 1, P=0.01448). Some SNPs such as MDR1 C1236T, ABCG2 c.34G>A, ABCG2 c.421C>A, SLCO1B1 c.388 A>G, SLCO1B1 c.521 T>C, SLCO1B1 c.571 T>C and SLCO1B1 c.597 C>T have no significant effects on fluvastatin pharmacokinetics.CYP2C9*3(1075A>C), MDR1 C3435T and MDR1 G2677T/A were determinants of inter-subject variability in fluvastatin pharmacokinetics in healthy Chinese volunteers.
Arzneimittel-Forschung 08/2012; · 0.72 Impact Factor
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ABSTRACT: BCR-ABL transforms bone marrow progenitor cells and promotes genome instability, leading to development of chronic myelogenous leukemia (CML). The tyrosine kinase inhibitor imatinib effectively treats CML, but acquired resistance can develop because of BCR-ABL mutations. Mechanisms for acquisition of BCR-ABL mutations are not fully understood. Using a novel culture model of CML acquired resistance, we show that inhibition of SIRT1 deacetylase by small molecule inhibitors or gene knockdown blocks acquisition of BCR-ABL mutations and relapse of CML cells on tyrosine kinase inhibitors. SIRT1 knockdown also suppresses de novo genetic mutations of hypoxanthine phosphoribosyl transferase gene in CML and non-CML cells upon treatment with DNA damaging agent camptothecin. Although SIRT1 can enhance cellular DNA damage response, it alters functions of DNA repair machineries in CML cells and stimulates activity of error-prone DNA damage repair, in association with acquisition of genetic mutations. These results reveal a previously unrecognized role of SIRT1 for promoting mutation acquisition in cancer, and have implication for targeting SIRT1 to overcome CML drug resistance.Oncogene advance online publication, 12 March 2012; doi:10.1038/onc.2012.83.
Oncogene 03/2012; · 6.37 Impact Factor
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ABSTRACT: To enhance the synthesis process for biodiesel (fatty acid methyl ester, FAME), microwave absorption solid acid catalysts were used for transesterification under microwave radiation. The H2SO4/C catalyst was prepared by an impregnation method. The surface areas of active carbon and H2SO4/C were measured by the BET method. Synthesis reactions were carried out under different conditions using castor oil and methanol as the feedstock. The amounts of FAME in the product were analyzed by high-performance liquid chromatography. Experimental results showed that the microwave radiation exhibited a notable enhanced effect for transesterification by using the microwave absorption solid acid catalysts (H2SO4/C) compared with that of the conventional heating method. When the transesterification was carried out at 338 K, with 12:1 molar ratio of methanol to castor oil, 50 wt % loading amounts of H2SO4 and 5 wt % of catalyst to castor oil, after 60 min the yield of FAME 94 wt % was obtained. This method can also be used in the case of castor oil with high free fatty acid.
12/2008;
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The CMS Collaboration,
S Chatrchyan,
G Hmayakyan,
V Khachatryan,
A M Sirunyan,
W Adam,
T Bauer,
T Bergauer,
H Bergauer,
M Dragicevic, [......],
G Abdullaeva,
A Avezov,
M I Fazylov,
E M Gasanov,
A Khugaev,
Y N Koblik,
M Nishonov,
K Olimov,
A Umaraliev,
B S Yuldashev
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ABSTRACT: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 1034 cm−2 s−1 (1027 cm−2 s−1). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ≤ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.
Journal of Instrumentation 08/2008; 3(08):S08004. · 1.87 Impact Factor
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ABSTRACT: The relationship between grain yield and carbon isotope discrimination (Δ) was analysed in wheat grown under different water regimes in the Ningxia Province (north-west of China). When the association was significant, the relationships between grain yield, Δ and other drought tolerance related traits, such as leaf ash content (ma), chlorophyll concentration (Chl), relative water content (RWC), stomatal conductance (gS) and the ratio of internal CO2 leaf concentration to ambient CO2 concentration (Ci/Ca), were also examined. Using correlation analysis, the relationships were determined during two consecutive years in a set of 20 spring wheat cultivars (landraces, improved varieties and advanced lines) under rainfed and irrigated conditions, including saline conditions. The relationship between Δ and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, and the irrigation before anthesis. Δ predicted grain yield under limited irrigation (post-anthesis water stress) but not under pre-anthesis water stress (rainfed conditions), fully irrigated and saline conditions. Under limited irrigation, grain Δ correlated significantly to grain yield leaf ma at heading and maturity. It also significantly positively correlated to Chl, RWC, gS and Ci/Ca assessed at anthesis. A precise characterization of the timing and intensity of the abiotic constraints experienced by the crop is consequently needed before implementing the use of Δ in wheat breeding programmes.
Journal of Agronomy and Crop Science 09/2007; 193(6):422 - 434. · 2.43 Impact Factor
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ABSTRACT: The three-dimensional optical anisotropy of photo-buffed dye-doped polymer films and the resulting orientation imparted to a liquid crystal in contact are probed using total internal reflection. Although the linearly polarized writing light generates a uniaxial distribution of dye molecules, the polymer films are biaxial, a result of symmetry breaking by the film surface.
EPL (Europhysics Letters) 01/2007; 58(1):67. · 2.17 Impact Factor
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Phys. Rev. A. 01/2007; 75:032701.
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Chin. Phys. Lett. 01/2007; 16:2938.
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J. Tang,
G. Xing,
Y. Zhao,
L. Jing,
X. Gao,
Y. Cheng, H. Yuan,
F. Zhao,
Z. Chen,
H. Meng,
H. Zhang,
H. Qian,
R. Su,
K. Ibrahim
Advanced Materials 04/2006; 18(11):1458 - 1462. · 13.88 Impact Factor
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L. Song,
L. Ci,
L. Lv,
Z. Zhou,
X. Yan,
D. Liu, H. Yuan,
Y. Gao,
J. Wang,
L. Liu,
X. Zhao,
Z. Zhang,
X. Dou,
W. Zhou,
G. Wang,
C. Wang,
S. Xie
Advanced Materials 09/2004; 16(17):1529 - 1534. · 13.88 Impact Factor
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Chemical Vapor Deposition 06/2003; 9(3):119 - 121. · 1.80 Impact Factor
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ABSTRACT: This paper describes a novel pumping device without mechanical moving parts based on the periodic generation and collapse of a single vapour bubble in a channel. The channel shape is such that it creates an asymmetry in the surface tension forces, which results in a pumping effect. The principle can be implemented over a broad range of channel sizes and repetition frequencies. For illustration purposes, a particular implementation is described here where the working fluid is a salt solution in water, the channel diameters are of the order of 1 mm and the repetition frequency is between 1-10 Hz. In these conditions, the device develops a head of a few centimetres of water with typical flow rates in the range of 100 µl per minute. It appears possible to increase both head and flow rate by adjusting geometrical parameters and operating conditions. A simple modification of the design would render the same principle also applicable to the pumping of non-conducting liquids.
Journal of Micromechanics and Microengineering 04/2001; 11(3):270. · 2.11 Impact Factor
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Molecular Crystals and Liquid Crystals. 04/2001; 358(1):311-319.
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ABSTRACT: The flow induced by the suitably timed growth and collapse of one or several bubbles in a finite tube joining two liquid reservoirs is simulated by a simple quasi-one-dimensional model. Viscous and surface tension effects are accounted for in an approximate manner. It is shown that, in certain parameter ranges, the system is capable of a net pumping action that moves the liquid from one reservoir to the other even in the presence of an adverse pressure difference. The fact that this net pumping effect is also encountered in the case of a single bubble, provided it is not located at the midpoint of the tube, is particularly remarkable. The mechanism responsible for this result is discussed. In practice the effect can be exploited to build a micropump by embedding electrical heaters in the wall of a small channel.
Journal of Micromechanics and Microengineering 11/1999; 9(4):402. · 2.11 Impact Factor
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ABSTRACT: The motion of two equal spherical bubbles moving along their line of centres in a viscous liquid is studied numerically in bispherical coordinates. The unsteady Navier-Stokes equations are solved using a mixed spectral/finite-difference scheme for Reynolds numbers up to 200. Free-slip conditions at the bubble surfaces are imposed, while the normal stress condition is replaced by the sphericity constraint under the assumption of small Weber number. The vorticity shed by the upstream bubble affects the drag on the trailing bubble in a very complex fashion that appears to be quite beyond the power of existing asymptotic analyses. The separation between two equal bubbles rising in line under the action of buoyancy is predicted to reach an equilibrium value dependent on the Reynolds number. This result is at variance with experiment. The explanation offered of this difference casts further doubt on the feasibility of a simplified simulation of bubbly liquid dynamics.
Journal of Fluid Mechanics 11/1994; 278:325 - 349. · 2.46 Impact Factor
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ABSTRACT: In order to understand the phosphorescence dynamics, a photo-pulse stimulation technique was used to release the stored photo-energy from trapped Eu2+ ions in SrAl2O4 : Eu,Dy single crystal fibers at 80 K. It was found that the lifetime of the photo-stimulated luminescence from trapped Eu2+ ions is 108 ns, 3 times faster than that of the normal luminescence. The fast decay can be caused by retrapping or lattice relaxation. Thermoluminescence results indicate that the retrapping process is negligible. Lattice relaxation might be the physical reason to accelerate the decay process through multiple phonon processes.
Journal of Luminescence.
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S. Chatrchyan,
G Hmayakyan,
V Khachatryan,
AM Sirunyan,
W Adam,
T Bauer,
T Bergauer,
H Bergauer,
M Dragicevic,
J. Ero, [......],
M. Baarmand,
L Baksay,
S Guragain,
M. Hohlmann,
H Mermerkaya,
R Ralich,
I Vodopiyanov,
MR Adams,
IM Anghel,
L Apanasevich
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ABSTRACT: HIV-1 integrase(IN) is one of three viral enzymes required for replication. IN mediates integration of viral DNA into the host genome in two steps: 3′-processing and strand transfer. It is currently recognized as an important target for therapeutic development against AIDS. QSAR (Quantitative Structure-Activity Relationship) modeling was utilized to study HIV-1 integrase inhibition. QSAR models were constructed to predict the IC50 values for the two structural classes (salicyhydrazines and tyrphostins) independently and in combination. The results showed that the models for different structural classes have different dependence on the same descriptors. It suggests that salicylhydrazines and tyrphostins might have different binding sites in HIV-1 integrase.
Journal of Molecular Structure THEOCHEM 529:273-282. · 1.44 Impact Factor
