Stochastic dynamics beyond the weak coupling limit: thermalization

We discuss the structure and asymptotic long-time properties of coupled equations for the moments of a Brownian particle's momentum derived microscopically beyond the lowest approximation in the weak coupling parameter. Generalized fluctuation-dissipation relations are derived and shown to ensure convergence to thermal equilibrium at any order of perturbation theory.Comment: 6+ page

Assessment of the diagnostic significance of the quantitative determination of the final products of lipid peroxidation for the prognosis of complications of dental implantation

Diagnostic significance and key characteristics of laboratory tests (quantitative determination of Schiff bases in blood, saliva and bone tissue) for the prognosis of complications of dental implan-tation were determined. The study included 73 patients with diagnosed complications of implanto-logical treatment, in the form of peri-implantitis (main group) and 51 patients with a successful out-come of dental implantation (comparison group). The groups were formed by monitoring patients for 12 months after dental implantation. In the blood plasma, saliva, and also bone homogenates ob-tained at the stage of preparation for dental implantation, the content of the end products of lipid peroxidation (Schiff bases) was determined. For each of the studied parameters, ROC-curves were constructed, the areas under them (AUC) were determined, the optimal cut-off values were estab-lished, as well as the corresponding sensitivity and specificity values. The optimal characteristics are diagnostic models involving the study of saliva and bone crumb obtained during the preparation of the implant bed. The combination of these diagnostic methods allows predicting the development of complications of dental implantation at an early stage with a high degree of certainty.Определена диагностическая значимость и ключевые характеристики лабораторных тестов (количественное определение шиффовых оснований в крови, слюне и костной ткани) для прогноза осложнений дентальной имплантации. В исследование включены 73 пациента с диагностированными осложнениями имплантологического лечения в виде периимплантита (основная группа) и 51 пациент с благополучным исходом дентальной имплантации (группа сравнения). Группы сформированы по результатам наблюдения за пациентами в течение 12 месяцев после дентальной имплантации. В плазме крови, слюне, а также гомогенатах костной крошки, полученных на этапе подготовки к дентальной имплантации, определяли содержание конечных продуктов перекисного окисления липидов (шиффовы основания). Для каждого из изучаемых параметров построены ROC-кривые, определены площади под ними (AUC), установлены оптимальные точки отсечения (cut-off value), а также соответствующие им значения чувствительности и специфичности. Оптимальные характеристики имеют диагностические модели, предусматривающие исследование слюны и костной крошки, получаемой при подготовке ложа для имплантата. Сочетание этих методов диагностики позволяет с высокой степенью достоверности прогнозировать развитие осложнений дентальной имплантации на ранних этапах

Transient mobility mechanisms of deposited metal atoms on insulating surfaces: Pd on MgO (100)

The importance and mechanisms of transient mobility of atoms and molecules adsorbing at surfaces have been a subject of controversy for many years. We used classical molecular dynamics simulations to examine transient mobility of Pd atoms adsorbing on the MgO (100) surface with incident kinetic energies not exceeding 0.4 eV. The calculations show that deposited Pd atoms exhibit high mobility at temperatures below 80 K where the contribution from thermal diffusion processes should be negligible. For our selected deposition conditions, aimed at simulation of Pd cluster growth experiments, an estimated 76 of the impinging Pd atoms are expected to travel up to 20 à away from the collision site before capture on a 5 K surface. We find that mobility of metal atoms on oxide surfaces is expected to decrease with decreasing incident energy and increase with decreasing incident angle. Comparison with prior studies highlights similarities and differences with other surface diffusion processes, such as long jumps. At higher surface temperatures, the observed mobility will mainly be due to thermally activated processes rather than transient mobility mechanisms. Atoms that exhibit transient mobility upon deposition may quickly migrate to surface features and defects affecting kinetics of growth and structures of nanoclusters and surface layers. © 2012 American Chemical Society