124 research outputs found

    Composite bond strength improvement with thermal vibration: an experimental non-randomised study

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    Background. Secondary caries formation is a relevant issue due to poor long-term quality of composite fillings, with inherent subsequent chipping and cracking of the material. We developed a method to improve physical, mechanical and chemical properties of available composites based on thermal vibration imposed on unpolymerised composite in the formed tooth cavity directly prior to polymerisation.Objectives. Effect assessment of thermal vibration exposure on bond strength in composite restorative polymer matrix in various composite brands.Methods. The study used synchronous thermal analysis, including differential scanning calorimetry and thermogravimetry, to estimate and register thermal effects of physical and chemical processes within a temperature programme, as well as determine gaseous release, air contact and decomposition-related sample mass variation, thermal stability, reaction kinetics, polymer and inorganic filler component chemical composition, humidity and softening degree. The study covered 90 specimens 30 mg each prepared of three different composites.Results. Synchronous thermal analysis revealed a statistically significant increase in polymer matrix bond strength in the composites Estelite Sigma Quick (Tokuyama Dental), Filtek Bulk Fill Posterior Restorative (3M Espe) and DentLight (VladMiVa) after thermal vibration exposure vs. classical polymerisation of same composites (p < 0.0001). The bond strength increased by 17.00, 22.51 and 11.31%, respectively.Conclusion. The developed exposure method for altering the composite filling physical and chemical properties has been shown advantageous in a laboratory setting. Thermal vibration-pretreated composite fillings had a higher polymer matrix bond strength vs. same composites polymerised under standard conditions.The pretreatment improves composite filling quality via directly affecting the material physical and mechanical properties of hardness and bending strength

    Anti-inflammatory and immunomodulating effects of the bacterial lysate in the <em>in vivo</em> models of aseptic lymphadenitis and pneumococcal pneumonia

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    Bacterial lysates may produce immunoregulatory effects in the inflammatory diseases that are not directly caused by infectious agents; they may also stimulate the immune response against pathogens which are not a part of the lysate composition. Imudon® is a polyvalent bacterial lysate that is available in orodispersible tablets. However, the influence of this drug product on aseptic inflammation and immune defense against the infectious agents, the antigens of which are not contained in this preparation have not been studied so far. The aim of this study, therefore, was to determine the anti-inflammatory and immunomodulating effects of Imudon® using the models of aseptic lymphadenitis (in Wistar rats) and pneumococcal pneumonia (in Balb/c mice), i.e., the conditions not related to the specific components of the bacterial lysate. Lymphadenitis was induced in rats by administration of λ-carrageenan into a cervical lymph node via an open operative approach. Whereas pneumonia was induced in mice by administering Streptococcus pneumoniae suspension intranasally. The choice of pneumococcus was determined by the absence of pneumococcal antigens in Imudon®, i.e., it cannot be a direct inducer of adaptive immune response against pneumococcal infection. Imudon® was administered intragastrically as a crushed tablet suspension following a therapeutic-preventive regimen (for 14 days daily until the induction of inflammation and for 3 [in the lymphadenitis model] or 5 days [in the model of pneumonia] in three doses thereafter). In the lymphadenitis model, Imudon® demonstrated both local and systemic anti-inflammatory responses manifested in the reduced number of circulating leucocytes and lower TNFα levels and by ameliorated histological features of inflammation in the operated lymph node. In rats, the anti-inflammatory effect was most pronounced when the product was administered at a dose of 2.2 mg/kg (equivalent to a human therapeutic dose) and 6.6 mg/kg. In the model of pneumonia, administration of Imudon® at 4.44 mg/kg (equivalent to a human therapeutic dose) and 13.32 mg/kg demonstrated a trend towards increased survival rate as compared to the control group. On Day 5 after infection Imudon® (4.44 and 13.32 mg/kg) decreased significantly the severity of inflammation and bacterial titer in the lungs. The titer of anti-pneumococcal immunoglobulins A in the bronchoalveolar lavage fluid were found to be higher in the Imudon® treated group (13.32 mg/kg) compared to control group. The results of this study showed high antiinflammatory and immunomodulatory activities of Imudon® and provided an insight into the mechanisms that underlie the clinical effects of this drug in various inflammatory diseases

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Выращивание Ipomoea batatas (L.) Lam. в условиях светокультуры in vitro и ex vitro

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    Relevance. Currently, food products that include prebiotics, in particular, inulin, are particularly popular. Interest in this substance is justified by its valuable properties – it is a good immunomodulator, cleanses the body of toxins, radionuclides, "bad" cholesterol, promotes the assimilation of useful trace elements necessary for human life. Inulin is contained in plants such as jerusalem artichoke, chicory, as well as in sweet potatoes, the popularity of which is increasing every year. However, sweet potato plants are afraid of cold and frost-resistant. Therefore, the creation of new varieties and hybrids that are resistant to low temperatures is an urgent problem. Cellular biotechnology is aimed at solving this problem using methods of clonal microreproduction, cell selection, somatic hybridization, etc. For rapid reproduction and obtaining high-quality planting material, biotechnology methods are used, in particular, clonal micro-propagation. However, in this technology there are difficulties associated with poor adaptation of microclones to ex vitro conditions. This fact introduces an additional requirement for the selection of optimal rooting modes in vitro and ex vitro adaptation of microclones.Material and methodology. The aim of the work was to study the influence of cultivation conditions on in vitro rooting and ex vitro adaptation of I. batatas (L.) microclones. The object of the study was sweet potato microgears propagated in vitro. I. batatas micro-gears were cultured in vitro on a Murashige-Skug medium, differing by the type of auxins. The influence of red (R) and far red (FR) light on the shoots rooting in vitro and the adaptation of microclones ex vitro was studied.Results. It has been experimentally established that the cultivation of micro-gears on a medium containing indolyl butyric acid at a concentration of 0.5-1 mg/l and under conditions of illumination by LED lamps of red and far red light in equal amounts leads to the production of microclones with a well-developed root system and vegetative biomass. The use of an aeroponic installation at the last stage of clonal micro-propagation makes it possible to obtain high-quality planting material that can adapt well to open ground conditions.Актуальность. В настоящее время особой популярностью пользуются продукты питания, в состав которых входят пребиотики, в частности, инулин. Интерес к данному веществу оправдан его ценными свойствами – он является хорошим иммуномодулятором, очищает организм от токсинов, радионуклидов, «плохого» холестерина, способствует усвоению полезных микроэлементов, необходимых для жизнедеятельности человека. Инулин содержится в таких растениях, как топинамбур, цикорий, а также в батате, популярность которого с каждым годом возрастает. Однако растения батата боятся холода и неморозоустойчивы. Поэтому создание новых сортов и гибридов, обладающих устойчивостью к пониженным температурам является актуальной проблемой. Клеточная биотехнология направлена на решение данной проблемы с применением методов клонального микроразмножения, клеточной селекции, соматической гибридизации и др. Для быстрого размножения и получения высококачественного посадочного материала применяют методы биотехнологии, в частности, клональное микроразмножение. Однако в этой технологии существуют трудности, связанные с плохой адаптацией микроклонов к условиям ex vitro. Этот факт вносит дополнительное требование к подбору оптимальных режимов укоренения in vitro и адаптации ex vitro микроклонов.Материал и методика. Целью работы было изучение влияния условий культивирования на укоренение in vitro и адаптации ex vitro микроклонов I. batatas (L.). Объектом исследования были микрочеренки батата, размноженные in vitro. Микрочеренки I. batatas культивировали in vitro на питательной среде, содержащей минеральные соли по прописи Мурасига и Скуга, а также различные ауксины. Изучали влияние красного (R) и дальнего красного (FR) света на укоренение микропобегов in vitro и адаптацию микроклонов ex vitro.Результаты. Экспериментально установлено, что выращивание микрочеренков на питательной среде, содержащей ИМК в концентрации 0,5-1 мг/л и в условиях освещения светодиодными лампами красного и дальнего красного света в равном соотношении, приводит к получению микроклонов с хорошо развитой корневой системой и надземной биомассой. Применение аэропонной установки на последнем этапе клонального микроразмножения позволяет получать высококачественный посадочный материал, способный хорошо переносить адаптацию к условиям открытого грунта

    Measurement of the cross-section for b-jets produced in association with a Z boson at root s=7 TeV with the ATLAS detector ATLAS Collaboration

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    A measurement is presented of the inclusive cross-section for b-jet production in association with a Z boson in pp collisions at a centre-of-mass energy of root s = 7 TeV. The analysis uses the data sample collected by the ATLAS experiment in 2010, corresponding to an integrated luminosity of approximately 36 pb(-1). The event selection requires a Z boson decaying into high P-T electrons or muons, and at least one b-jet, identified by its displaced vertex, with transverse momentum p(T) > 25 GeV and rapidity vertical bar y vertical bar < 2.1. After subtraction of background processes, the yield is extracted from the vertex mass distribution of the candidate b-jets. The ratio of this cross-section to the inclusive Z cross-section (the average number of b-jets per Z event) is also measured. Both results are found to be in good agreement with perturbative QCD predictions at next-to-leading order

    Measurement of charged-particle event shape variables in inclusive root(s)=7 TeV proton-proton interactions with the ATLAS detector

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    The measurement of charged-particle event shape variables is presented in inclusive inelastic pp collisions at a center-of-mass energy of 7 TeV using the ATLAS detector at the LHC. The observables studied are the transverse thrust, thrust minor, and transverse sphericity, each defined using the final-state charged particles' momentum components perpendicular to the beam direction. Events with at least six charged particles are selected by a minimum-bias trigger. In addition to the differential distributions, the evolution of each event shape variable as a function of the leading charged-particle transverse momentum, charged-particle multiplicity, and summed transverse momentum is presented. Predictions from several Monte Carlo models show significant deviations from data

    Search for the standard model Higgs boson in the diphoton decay channel with 4.9fb -1 of pp collision data at √s=7TeV with atlas

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    A search for the standard model Higgs boson is performed in the diphoton decay channel. The data used correspond to an integrated luminosity of 4.9  fb-1 collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of √s=7  TeV. In the diphoton mass range 110–150 GeV, the largest excess with respect to the background-only hypothesis is observed at 126.5 GeV, with a local significance of 2.8 standard deviations. Taking the look-elsewhere effect into account in the range 110–150 GeV, this significance becomes 1.5 standard deviations. The standard model Higgs boson is excluded at 95% confidence level in the mass ranges of 113–115 GeV and 134.5–136 GeV

    Measurement of the production cross section for W-bosons in association with jets in pp collisions at √s=7 TeV with the ATLAS detector

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    This Letter reports on a first measurement of the inclusive W + jets cross section in proton–proton collisions at a centre-of-mass energy of 7 TeV at the LHC, with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the W -boson, are presented as a function of jet multiplicity and of the transverse momentum of the leading and next-to-leading jets in the event. Measurements are also presented of the ratio of cross sections σ(W + n)/σ(W + n − 1) for inclusive jet multiplicities n = 1–4. The results, based on an integrated luminosity of 1.3 pb−1, have been corrected for all known detector effects and are quoted in a limited and well-defined range of jet and lepton kinematics. The measured cross sections are compared to particle-level predictions based on perturbative QCD. Next-toleading order calculations, studied here for n 2, are found in good agreement with the data. Leadingorder multiparton event generators, normalized to the NNLO total cross section, describe the data well for all measured jet multiplicities.
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