Accumulation of Four Electrons on a Terphenyl (Bis)disulfide

The activation of N2, CO2 or H2O to energy-rich products relies on multi-electron transfer reactions, and consequently it seems desirable to understand the basics of light-driven accumulation of multiple redox equivalents. Most of the previously reported molecular acceptors merely allow the storage of up to two electrons. We report on a terphenyl compound including two disulfide bridges, which undergoes four-electron reduction in two separate electrochemical steps, aided by a combination of potential compression and inversion. Under visible-light irradiation using the organic super-electron donor tetrakis(dimethylamino)ethylene, a cascade of light-induced reaction steps is observed, leading to the cleavage of both disulfide bonds. Whereas one of them undergoes extrusion of sulfur to result in a thiophene, the other disulfide is converted to a dithiolate. These insights seem relevant to enhance the current fundamental understanding of photochemical energy storage

Диагностика фемороацетабулярного импинджмент-синдрома: роль магнитно-резонансной томографии

The aim of the study was to determine the role of MRI in diagnostics of femoroacetabular impingement syndrome of the hip. Materials and Methods. MRI-scanning results were analyzed for 142 persons (63 (44.4%) males, 79 (55,6%) females; mean age 34 ± 3.2 y.o.), 122 (85.9%) of them had complaints of pain sensation located in the hip joint. All the patients were divided into two groups: an experimental group (n = 122 (85.9%; 62 (50.8%) males, 60 (49.8%) females; mean age 33 ± 5.7 y.o) and a control group (n = 20 (14.1%); 15 (75.0%) males, 5 (25.0%) females; mean age 30 ± 3.8 y.o.). The enrollment criteria for the control group were: absence of complaints of pain sensation located in the hip joint, under sixty years of age. The age limit was provided the high risk of involutional changes in the hip within the patients of this age. In all patients MRI examination were done by high-field MR-scanners associated to designed protocol. While interpreting the results values of neck-shaft angle, lateral center edge angle, Tonnis angle and alpha angle were determined. Results. Different types of femoroacetabular impingement syndrome were determined in 35 (28.7%) patients. In all patients pathologic parameters were observed: abnormal (39 degrees) lateral center edge angle (n = 17; 48.6%), abnormal (55 degrees) alpha angle (n = 17; 48.6%) were determined. Conclusion. MRI allowed to determine abnormality of configuration of the femoral bone and acetabulum, to characterize the pathological conditions of the labrum and subchondral bone. The main symptoms of femoroacetabular impingement syndrome are pathologic configuration of the femoral head and acetabulum. The degeneration and tear of the labrum could be observed in the early stage of disease.Цель: оценить роль высокопольной МРТ в диагностике импинджмент-синдрома тазобедренного сустава. Материал и методы. Проанализированы результаты клинического и лучевого обследования 142 пациентов (63 (44,4%) мужчины и 79 (55,6%) женщин; средний возраст 34 ± 3,2 года), 122 (85,9%) из них предъявляли жалобы на боли и нарушение функции тазобедренного сустава (62 (50,8%) мужчины и 60 (49,8%) женщин; средний возраст 33 ± 5,7 года) и составили основную группу наблюдения (1-я). Остальные 20 (14,1%) обследованных (15 (75,0%) мужчин и 5 (25,0%) женщин; средний возраст 30 ± 3,8 года) составили контрольную группу (2-я). Критерии отбора пациентов в контрольную группу: отсутствие жалоб на боль и ограничение движений в тазобедренном суставе, возраст моложе 60 лет. Возрастные ограничения были обусловлены высокой долей инволютивных изменений структур тазобедренного сустава у таких пациентов. Всем больным выполняли рентгенографию и МРТ тазобедренных суставов по разработанной методике на аппаратах с индукцией магнитного поля 1,5 Тл. По результатам МРТ производили вычисление шеечно-диафизарного угла (ШДУ), угла Виберга, ацетабулярного индекса, угла альфа. Результаты. Фемороацетабулярный импинджмент-синдром был выявлен у 35 (28,7%) обследованных. У всех пациентов отмечали отклонения морфометрических параметров сустава: уменьшение ШДУ (n = 11; 31,5%), увеличение угла альфа (n = 17; 48,6%) и угла Виберга (n = 14; 40,0%), уменьшение ацетабулярного индекса (n = 12; 34,3%). Дегенеративные изменения суставной губы различной степени были обнаружены у всех пациентов. Выводы. Выполнение МРТ обеспечивает получение комплексной характеристики всех патологических признаков импинджмент-синдрома тазобедренного сустава. Основными МР-признаками фемороацетабулярного импинджмент-синдрома являются нарушения конфигурации головки проксимального отдела бедренной кости и формы вертлужной впадины. Дегенеративные изменения и повреждения суставной губы возникают уже на ранних сроках от момента появления болевого синдрома

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe