696 research outputs found
Эффекты ниацин-оксиэтилидендифософнат германата и альфа-липоевой кислоты на диабет-индуцированный оксидантный стресс в ткани сетчатки
Odessa National Medical University, Odessa, Ukraine, Conferinţa știinţifică cu participare internaţională ”Actualităţi în farmacologie și în farmacologia clinică” întru comemorarea celor 100 de ani de la nașterea ilustrului savant, profesor universitar, laureat al Premiului de Stat al Republicii Moldova Efim Muhin 29 noiembrie – 1 decembrie 2018 Chișinău, Republica MoldovaEffects of two weeks treatment with niacin-oxyethylidendiphosphonatogermanate (MIGU-4, 2,5; 25,0 mg/kg, i.p.) and alpha-lipoic acid (LA, 5,0 and 50,0 mg/kg, i.p.) as well as their combined usage (MIGU-4 – 2,5, and LA – 5,0 mg/kg) upon antioxidative enzymes and level of malon dialdehyde (MDA) in retina tissue of rats with streptozotocin (STZ)induced diabetes was determined. It was established that in six weeks after STZ administration superoxiddismutase (SOD) activity decreased by 33,4% (P<0,05), catalase (CAT) – by 28,2% (P<0,05), glutathione peroxidase (GPx) – by 39,8%, glutathione reductase (GR) – by 48,3%, and MDA level raised by 2,65 times when compared with intact rats (P<0,05). MIGU-4 treatment (25,0 mg/kg, i.p.) increased SOD activity by 38,1% (P<0,05), GPx and GR – by 62,9% (P<0,05) and by 35,2% (P<0,05), when compared with diabetes rats. MDA level was reduced by 30,2% (P<0,05) correspondently. The SOD activity under condition of combined MIGU-4 (2,5 mg/ kg) and LA (5,0 mg/kg) administration exceeded its level in rats with diabetes by 41,3% (P<0,05), while activity of GPx and GR also was higher by 52,4% and by 47,8% (P<0,05) correspondently. MDA level reduction was higher than in groups which were given MIGU-4 or LA alone (P<0,05). Thus, niacin-oxyethylidendiphosphonato-germanate caused prevention on diabetes-induced deterioration of antioxidant enzymes activity and level of MDA in retina tissue. Combined usage of MIGU-4 and LA was resulted in heightened preventive effects upon manifestations of oxidative stress.Au fost investigate efectele administrării de două săptămani a hidroxietilidendifosfonat germanatului (MIGU-4, 2,5; 25,0 mg/kg, i.p.) şi a acidului alfa-lipoic (LC, 5,0 şi 50,0 mg/kg, i.p.) şi efectul utilizării lor combinate (MIGU-4 – 2,5 şi LC – 5,0 mg/kg) asupra activităţii enzimelor antioxidante şi nivelului de malondialdehidă (MDA) in ţesutul retinei şobolanilor cu diabet indus de streptozotocină (STZ). S-a constatat că după 6 săptămani de la momentul aplicării STZ, activitatea superoxid dismutazei (SOD) a scăzut cu 33,4% (P <0,05), a catalazei (CAT) – cu 28,2% (P <0,05), a glutationperoxidazei – cu 39,8%, a glutationreductazei (GR) – cu 48,3%, cu o creştere a conţinutului de MDA de 2,65 ori, comparativ cu şobolanii intacţi (P <0,05). Odată cu introducerea MIGU-4 (25,0 mg/kg, i.p.), activitatea SOD a fost mai mare cu 38,1% (P <0,05), a HP şi GR – cu 62,9% (P <0,05 ) şi, respectiv, 35,2% (P <0,05), in comparaţie cu animalele cu diabet zaharat. Nivelul MDA a scăzut cu 30,2% (P <0,05). Eficacitatea MIGU-4 (25,0 mg/ kg) a fost comparabilă cu cea a LK utilizată in doză de 50,0 mg/kg. In cazul folosirii combinate a MIGU-4 (2,5 mg/kg) şi a LC (5,0 mg/kg), activitatea SOD a depăşit-o pe cea a şobolanilor cu diabet zaharat cu 41,3% (P <0,05), GP şi GR fiind mai mari cu 52,4% şi, respectiv, cu 47,8% (P <0,05). Scăderea nivelului MDA a fost mai mare decat in cazul grupurilor care utilizează MIGU-4 sau LC (P <0,05). Astfel, administrarea hidroxietildidenfosfonat germanatului previne dereglările activităţii enzimelor antioxidante şi nivelului MDA induse de diabet in ţesutul retinian. Administrarea asociată a MIGU-4 şi a LC este insoţită de o acţiune preventivă sporită impotriva manifestărilor stresului oxidativ.Исследовали влияние двухнедельного введения ниациноксиэтилидендифосфонат германата (МИГУ-4, 2,5; 25,0 мг/кг, в/бр) и альфа-липоевой кислоты (ЛК, 5,0 и 50,0 мг/кг, в/бр), а также влияние их совместного применения (МИГУ-4 – 2,5, и ЛК – 5,0 мг/кг) на активность антиоксидантних ферментов и уровень малонового диальдегида (МДА) в ткани сетчатки крыс со стрептозотоцин (СТЗ)-индуцированным диабетом. Установлено, что через 6 недель с момента применения СТЗ активность супероксидисмутазы (СОД) уменьшилась на 33,4% (P<0,05), каталазы (КАТ) – на 28,2% (P<0,05), глутатионпероксидазы (ГП) – на 39,8%, глутатионредуктазы (ГР) – на 48,3% при увеличении содержания МДА в 2,65 раза в сравнении с интактными крысами (P<0,05). На фоне введения МИГУ-4 (25,0 мг/кг, в/бр) активность СОД была выше на 38,1% (P<0,05), ГП и ГР – на 62,9% (P<0,05) и соответственно 35,2% (P<0,05) при сравнении с животными с диабетом. При этом уровень МДА уменьшался на 30,2% (P<0,05). При комбинированном применении МИГУ-4 (2,5 мг/кг) и ЛК (5,0 мг/кг) активность СОД превышала таковую у крыс с диабетом на 41,3% (P<0,05), в то время как активность ГП и ГР была выше на 52,4% и соответственно 47,8% (P<0,05) соответственно. Величина снижения уровня МДА была выше, чем в группах с применением одного МИГУ-4 или ЛК (P<0,05). Таким образом, применение ниацин-оксиэтилидендифосфонат германата предотвращает диабет-вызванные нарушения активности антиоксидантных ферментов и уровня МДА в ткани сетчатки. Совместное введение МИГУ-4 и ЛК сопровождается потенцированным превентивным действием в отношении проявлений оксидативного стресса
Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA
Inclusive photoproduction of D*+- mesons has been measured for photon-proton
centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality
Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of
37 pb^-1. Total and differential cross sections as functions of the D*
transverse momentum and pseudorapidity are presented in restricted kinematical
regions and the data are compared with next-to-leading order (NLO) perturbative
QCD calculations using the "massive charm" and "massless charm" schemes. The
measured cross sections are generally above the NLO calculations, in particular
in the forward (proton) direction. The large data sample also allows the study
of dijet production associated with charm. A significant resolved as well as a
direct photon component contribute to the cross section. Leading order QCD
Monte Carlo calculations indicate that the resolved contribution arises from a
significant charm component in the photon. A massive charm NLO parton level
calculation yields lower cross sections compared to the measured results in a
kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure
Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA
Correlations between charged particles in deep inelastic ep scattering have
been studied in the Breit frame with the ZEUS detector at HERA using an
integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in
terms of the angular separation between current-region particles within a cone
centred around the virtual photon axis. Long-range correlations between the
current and target regions have also been measured. The data support
predictions for the scaling behaviour of the angular correlations at high Q2
and for anti-correlations between the current and target regions over a large
range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations
and Monte Carlo models correctly describe the trends of the data at high Q2,
but show quantitative discrepancies. The data show differences between the
correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
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