88 research outputs found
Biodistribution analysis of cisplatin in liposomal form in animals with cisplatinresistant and cisplatin-sensitive carcinoma
Aim: To analyze the relation between pharmacokinetics of cisplatin in liposomal form and antitumor efficacy toward cisplatinresistant and cisplatin-sensitive variants of Guerin carcinoma. Concentration of platinum was measured by atomic absorption spectrophotometry (С115М1 “Selmi”, Ukraine). Elimination constant was calculated based on the dynamics of cisplatin concentration in time period between 1 h to 24 h using nonlinear regression analysis. Area under curve (AUC24) was calculated by the trapezium method. Results: It was shown that for liposomal form of cisplatin (LCp) AUC24 in tumor practically didn’t depend on the level of the tumor sensitivity, while in animals with the resistant variant (CpRGC), AUC24 for free cisplatin (FCp) decreased by 70% less (p < 0.001) as compared to the sensitive tumor strain (CpSGC). Significant decrease of elimination constant of LCp compared to FCp in blood serum of rats bearing either CpRGC or CpSGC tumors favors cisplatin accumulation in tumor tissues with low vascularization level. The dynamics of cisplatin concentration in CpRGC variant was characterized by 90% higher level in 24 h after administration of LCp as compared to FCp (p < 0.05). This fact may explain increased antitumor efficacy of LCp compared to FCp toward CpRGC variant. In the study of kidney function, AUC24 index for LCp was by 68.6% (p < 0.01) and 50.7% (p < 0.05) lower than AUC24 index for FCp in rats with CpRGC and CpSGC variants, respectively. No significant differences have been found in biodistribution of cisplatin in both pharmaceutical forms in liver and lung in CpRGC-r CpSGC-bearing rats. Conclusion: The results suggest that cisplatin in liposomal form possesses higher specificity of antitumor action than free cisplatin
Magnetic anisotropy of epitaxial Co2Fe-Ge Heusler alloy films on MgO (100) substrates
Films of Co2Fe-Ge Heusler alloy with variable Ge concentration deposited on monocrystalline MgO (100) substrates by magnetron co-sputtering are investigated using microstructural, morphological, magnetometric, and magnetic resonance methods. The films were found to grow epitaxially, with island-like or continuous-layer morphology depending the Ge-content. The ferromagnetic resonance data versus out-of-plane and in-plane angle indicate the presence of easy plane and 4-fold in-plane anisotropy. The magnetometry data indicate additional weak 2-fold in-plane anisotropy and pronounced at low fields rotatable anisotropy. The observed magnetic anisotropy properties discussed in correlation with the microstructure and morphology of the films
Effective action approach and Carlson-Goldman mode in d-wave superconductors
We theoretically investigate the Carlson-Goldman (CG) mode in two-dimensional
clean d-wave superconductors using the effective ``phase only'' action
formalism. In conventional s-wave superconductors, it is known that the CG mode
is observed as a peak in the structure factor of the pair susceptibility
only just below the transition temperature T_c and only
in dirty systems. On the other hand, our analytical results support the
statement by Y.Ohashi and S.Takada, Phys.Rev.B {\bf 62}, 5971 (2000) that in
d-wave superconductors the CG mode can exist in clean systems down to the much
lower temperatures, . We also consider the manifestations of
the CG mode in the density-density and current-current correlators and discuss
the gauge independence of the obtained results.Comment: 23 pages, RevTeX4, 12 EPS figures; final version to appear in PR
Energy characteristics of plasma streams, generated by MPC
In present paper, results of experimental investigations of energy characteristics of plasma stream, generated by magnetoplasma compressor (MPC) are presented. It is shown that total energy contained in the plasma stream strongly depends on the discharge current, mass flow rate and sort of working gas. Radial distributions of energy density in plasma streams for different MPC modes of operations and energy transfer efficiency from the acceleration channel to the plasma stream are investigated.Представлены результаты экспериментальных исследований энергетических характеристик плазменных потоков, генерируемых магнитоплазменным компрессором (МПК). Показано, что полная энергия в плазменном потоке существенно зависит от разрядного тока, массового расхода и сорта рабочего газа. Также исследовано радиальное распределение плотности энергии в плазменном потоке и коэффициент передачи энергии от ускорительного канала в плазменный поток в разных режимах работы МПК.Представлено результати експериментальних досліджень енергетичних характеристик плазмових потоків, що генерує магнітоплазмовий компресор (МПК). Показано, що повна енергія в плазмовому потоці значним чином залежить від розрядного струму, масової витрати та сорту робочого газу. Також було досліджено радіальний розподіл густини енергії в плазмовому потоці і коефіцієнт передачі енергії від розрядного каналу в плазмовий потік в різних режимах роботи МПК
Diagnostics of plasma streams and plasma-surface interaction of essentially different duration of plasma pulses
Studies of main characteristics of the plasma streams generated by magneto-plasma compressor (MPC) and quasi-stationary plasma accelerator QSPA Kh-50 have been performed. Main features of Plasma Surface Interaction (PSI) have been researched in dependence on plasma heat loads, plasma density and pulses duration. QSPA Kh-50 creates long pulse plasma streams (pulse length of 0.25 ms) with heat load on exposed surfaces of (0.45…0.75) MJ/m² . The MPC generates short (duration of 10…20 μs) compressed plasma streams with plasma density up to 10¹⁸ cm⁻³ , and plasma energy density of (0.05…0.5) MJ/m² . Performed studies of plasma-surface interaction include measurements of plasma energy deposited to the material surface as a function of the impacting energy and kind of targets. Temporal and spatial dependencies of electron density and temperature have been found. Special attention was paid to the dynamics of the spectral lines near surfaces of exposed targets.Изучены основные характеристики плазменных потоков, генерируемых магнитоплазменным компрессором (МПК) и квазистационарным плазменным ускорителем КСПУ Х-50. Исследованы основные особенности плазмоповерхностного взаимодействия в зависимости от тепловой плазменной нагрузки, плотности и длительности импульса. КСПУ Х-50 генерирует длинноимпульсные плазменные потоки (длительность импульса 0,25 мс) с тепловой нагрузкой на облучаемую мишень (0,45…0,75) MДж/м² . МПК генерирует короткие (длительность 10...20 мкс) компрессионные плазменные потоки плотностью плазмы до 10¹⁸ см⁻³ и плотностью энергии в диапазоне (0,05…0,5) MДж/м² . Представленные исследования плазмо- поверхностного взаимодействия включали измерения энергии, достигающей поверхность материала, как функцию энергии плазмы и сорта материала. Получены временные и пространственные распределения электронной плотности плазмы. Особое внимание уделялось динамике спектральных линий около поверхности облучённых мишеней.Вивчені основні характеристики плазмових потоків, що генеруються магнітоплазмовим компресором (МПК) та квазістаціонарним плазмовим прискорювачем КСПП Х-50. Досліджено основні особливості плазмовоповерхневої взаємодії в залежності від теплового навантаження, густини та тривалості імпульсу. КСПП Х-50 генерує довгоімпульсні плазмові потоки (довжина імпульсу 0,25 мс) з тепловим навантаженням на опромінену мішень (0,45…0,75) MДж/м² . МПК генерує короткі (тривалість 10...20 мкс) компресійні плазмові потоки з густиною плазми, що сягає 10¹⁸ см⁻³, та густиною енергії в діапазоні (0,05…0,5) MДж/м² . Представлені дослідження плазмовоповерхневої взаємодії включали вимірювання енергії плазми, що досягає поверхні матеріалу, як функція енергії плазмі та сорту матеріалу. Отримано часові та просторові розподіли електронної густини плазми. Особлива увага приділялась динаміці спектральних ліній біля поверхні опромінених мішеней
Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits
The WWgamma triple gauge boson coupling parameters are studied using p-pbar
-> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were
collected with the DO detector from an integrated luminosity of 162 pb^{-1}
delivered by the Fermilab Tevatron Collider. The cross section times branching
fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV
and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum)
pb. The one-dimensional 95% confidence level limits on anomalous couplings are
-0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events
We present a measurement of the top quark pair ttbar production cross section
in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1}
of data collected by the DO detector at the Fermilab Tevatron Collider. We
select events with one charged lepton (electron or muon), large missing
transverse energy, and at least four jets, and extract the ttbar content of the
sample based on the kinematic characteristics of the events. For a top quark
mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1}
(syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging
We present a measurement of the top quark pair () production cross
section () in collisions at TeV
using 230 pb of data collected by the D0 experiment at the Fermilab
Tevatron Collider. We select events with one charged lepton (electron or muon),
missing transverse energy, and jets in the final state. We employ
lifetime-based b-jet identification techniques to further enhance the
purity of the selected sample. For a top quark mass of 175 GeV, we
measure pb, in
agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let
Search for single top quark production in ppbar collisions at sqrt(s)=1.96 TeV
We present a search for electroweak production of single top quarks in the
s-channel and t-channel using neural networks for signal-background separation.
We have analyzed 230 pb of data collected with the D0 detector at the
Fermilab Tevatron Collider at a center-of-mass energy of 1.96 TeV and find no
evidence for a single top quark signal. The resulting 95% confidence level
upper limits on the single top quark production cross sections are 6.4 pb in
the s-channel and 5.0 pb in the t-channel.Comment: 9 pages, 4 figure
Measurement of the WW production cross section in p anti-p collisions at s**(1/2) = 1.96 TeV
We present a measurement of the W boson pair-production cross section in p
anti-p collisions at a center-of-mass energy of sqrt{s}=1.96 TeV. The data,
collected with the Run II DO detector, correspond to an integrated luminosity
of 224-252 pb^-1 depending on the final state (ee, emu or mumu). We observe 25
candidates with a background expectation of
8.1+/-0.6(stat)+/-0.6(syst)+/-0.5(lum) events. The probability for an upward
fluctuation of the background to produce the observed signal is 2.3x10^-7,
equivalent to 5.2 standard deviations.The measurement yields a cross section of
13.8+4.3/-3.8(stat)+1.2/-0.9(syst)+/-0.9(lum) pb, in agreement with predictions
from the standard model.Comment: submitted to PR
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