Влияние различных методов седации у больных с острой тяжелой черепно-мозговой травмой на перекисное окисление липидов

Objective: to study the impact of various sedation methods on lipid peroxidation in patients with acute severe brain injury. Subjects and methods. For this, 44 victims with this condition were examined. According the option of posttraumatic sedation therapy, the victims were divided into 3 groups: 1) 12 patients in whom sodium oxybutyrate was used for sedation; 2) 12 received thiopental sodium; 3) 20 patients were given propofol. The lipid peroxidation and antioxidant system were judged from the serum levels of fatty acid hydroperoxides and secondary lipid peroxidation products (malonic dialdehyde) and from the content of the endogenous antioxidant a-tocopherol. Results. The study performed indicated that the highest concentrations of fatty acid hydroperoxides were observed in Groups 1 and 2 within the first 24 posttraumatic hours. In Group 3 where propofol was used for sedation, the concentration of the hydroperoxides remained in the normal range although there was a tendency for their rise. Conclusion. Thus, propofol is the agent of choice for sedation that prevents the activation of lipid peroxidation and stabilizes some indices of the antioxidant system in patients with acute severe brain injury. Key words: brain injury, lipid peroxidation, sedation, sodium oxybutyrate, thiopental sodium, propofol.Цель исследования — изучить влияние различных методов седации у больных с острой тяжелой черепно-мозговой травмой на перекисное окисление липидов. Материал и методы. Для достижения указанной цели обследованы 44 пострадавших с острой тяжелой черепно-мозговой травмой. В зависимости от вида седационной терапии, проводившейся в посттравматическом периоде, больные были разделены на 3 группы. В I группу (12 чел.) вошли больные, которым с целью седации использовался оксибутират натрия, во II группе (12 чел.) больных применялся тиопентал натрия, и в III группе больных (20 чел.) вводился пропофол. О состоянии перекисного окисления липидов и антиоксидантной системы судили по уровню в сыворотке крови гидроперекисей жирных кислот и вторичных продуктов перекисного окисления липидов — малонового диальдегида, содержанию эндогенного антиоксиданта альфа-токоферола. Результаты. Проведенное исследование показало, что в 1-е сутки посттравматического периода наиболее высокие концентрации гидроперекисей жирных кислот отмечались в I и II группах больных. В III же группе больных, где для седации использовался пропофол, концентрация гидроперекисей оставались в пределах нормальных значений, хотя также оставалась тенденция к их росту. Заключение. Таким образом, наиболее благоприятным вариантом седации, предупреждающей активацию перекисного окисления липидов и стабилизирующей некоторые показатели антиоксидантной системы у больных с острой тяжелой черепно-мозговой травмой является пропофол. Ключевые слова: черепно-мозговая травма, перекисное окисление липидов, седация, оксибутират натрия, тиопентал натрия, пропофол

Antineutrino-Deuteron Experiment at Krasnoyrsk

This report is represented the results of some experiments, which carried out at the neutrino underground laboratory of Kranoyarsk nuclear plant.Comment: 8 pages, 3 figure

Initial Results from the CHOOZ Long Baseline Reactor Neutrino Oscillation Experiment

Initial results are presented from CHOOZ, a long-baseline reactor-neutrino vacuum-oscillation experiment. Electron antineutrinos were detected by a liquid scintillation calorimeter located at a distance of about 1 km. The detector was constructed in a tunnel protected from cosmic rays by a 300 MWE rock overburden. This massive shielding strongly reduced potentially troublesome backgrounds due to cosmic-ray muons, leading to a background rate of about one event per day, more than an order of magnitude smaller than the observed neutrino signal. From the statistical agreement between detected and expected neutrino event rates, we find (at 90% confidence level) no evidence for neutrino oscillations in the electron antineutrino disappearance mode for the parameter region given approximately by deltam**2 > 0.9 10**(-3) eV**2 for maximum mixing and (sin(2 theta)**2) > 0.18 for large deltam**2.Comment: 13 pages, Latex, submitted to Physics Letters

Limits on Neutrino Oscillations from the CHOOZ Experiment

We present new results based on the entire CHOOZ data sample. We find (at 90% confidence level) no evidence for neutrino oscillations in the anti_nue disappearance mode, for the parameter region given by approximately Delta m**2 > 7 x 10**-4 eV^2 for maximum mixing, and sin**2(2 theta) = 0.10 for large Delta m**2. Lower sensitivity results, based only on the comparison of the positron spectra from the two different-distance nuclear reactors, are also presented; these are independent of the absolute normalization of the anti_nue flux, the cross section, the number of target protons and the detector efficiencies.Comment: 19 pages, 11 figures, Latex fil

Search for neutrino oscillations on a long base-line at the CHOOZ nuclear power station

This final article about the CHOOZ experiment presents a complete description of the electron antineutrino source and detector, the calibration methods and stability checks, the event reconstruction procedures and the Monte Carlo simulation. The data analysis, systematic effects and the methods used to reach our conclusions are fully discussed. Some new remarks are presented on the deduction of the confidence limits and on the correct treatment of systematic errors.Comment: 41 pages, 59 figures, Latex file, accepted for publication by Eur.Phys.J.

Search for electron antineutrino interactions with the Borexino Counting Test Facility at Gran Sasso

Electron antineutrino interactions above the inverse beta decay energy of protons (E_\bar{\nu}_e>1.8) where looked for with the Borexino Counting Test Facility (CTF). One candidate event survived after rejection of background, which included muon-induced neutrons and random coincidences. An upper limit on the solar $\bar{\nu}_{e}$ flux, assumed having the $^8$B solar neutrino energy spectrum, of 1.1$\times10^{5}$ cm$^{-2}$~s$^{-1}$ (90% C.L.) was set with a 7.8 ton $\times$ year exposure. This upper limit corresponds to a solar neutrino transition probability, $\nu_{e} \to \bar{\nu}_{e}$, of 0.02 (90% C.L.). Predictions for antineutrino detection with Borexino, including geoneutrinos, are discussed on the basis of background measurements performed with the CTF.Comment: 10 pages, 9 figures, 5 table

Low-energy (anti)neutrino physics with Borexino: Neutrinos from the primary proton-proton fusion process in the Sun

The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations.Comment: Proceedings from NOW (Neutrino Oscillation Workshop) 201