Cocrystal Growth in Organic Semiconductor Thin Films: Simulation of Pentacene, Perfluoropentacene, and Their 1:1 Blend Deposited On Graphite

The understanding of crystal formation in thin films and the precise knowledge of the relation between structure and surface diffusion are two important requirements for the efficient (nano)fabrication of organic electronic devices. Here a computational approach for simulating vapor-phase deposition is employed to obtain and investigate three types of crystalline thin films on graphite. All systems, namely pentacene, perfluoropentacene, and their 1:1 blend, which forms an alternate cocrystal, are constituted by recumbent molecules in accordance with experimental findings. The contributions of intermolecular interactions and of molecular rearrangements occurring during the deposition are analyzed to rationalize the final morphologies. Then, the generated structures are employed to evaluate the energy barriers that prevent molecular diffusion at terraces and step-edges, and to study the reorganization of the films upon high-temperature annealing. The broad agreement with experimental observations and the possibility of evaluating the potential energy surface at the molecular detail render the proposed approach a promising tool to make predictions for other systems

Anchoring Institutions in Agents\u27 Attitudes: Towards a Logical Framework for Autonomous Multi-Agent Systems

The aim of this paper is to provide a logical framework for the specification of autonomous Multi-Agent Systems (MAS). A MAS is autonomous in so far as it is capable of binding (?nomos?) itself (?auto?) independently of any external normative constraint specified by a designer. In particular, a MAS is autonomous if it is able to maintain its social institutions (i.e. rule-governed social practices) only by way of the agents? attitudes. In order to specify an autonomous MAS, we propose the logic AL (Acceptance Logic) in which the acceptance of a proposition by the agents qua group members (i.e. group acceptance) is introduced. Such propositions are true w.r.t. an institutional context and correspond to facts that are instituted in an attitude-dependent way (i.e. normative and institutional facts). Finally, we contend that the present approach paves the way for a foundation of legal institutions, for studying the interaction between social and legal institutions and, eventually, for understanding and modeling institutional change

Observation and cancellation of the dc Stark shift in strontium optical lattice clocks

We report on the observation of a dc Stark frequency shift at the $10^{-13}$ level by comparing two strontium optical lattice clocks. This frequency shift arises from the presence of electric charges trapped on dielectric surfaces placed under vacuum close to the atomic sample. We show that these charges can be eliminated by shining UV light on the dielectric surfaces, and characterize the residual dc Stark frequency shift on the clock transition at the $10^{-18}$ level by applying an external electric field. This study shows that the dc Stark shift can play an important role in the accuracy budget of lattice clocks, and should be duly taken into account

Measurement of the Blackbody Radiation Shift of the 133Cs Hyperfine Transition in an Atomic Fountain

We used a Cs atomic fountain frequency standard to measure the Stark shift on the ground state hyperfine transiton frequency in cesium (9.2 GHz) due to the electric field generated by the blackbody radiation. The measures relative shift at 300 K is -1.43(11)e-14 and agrees with our theoretical evaluation -1.49(07)e-14. This value differs from the currently accepted one -1.69(04)e-14. The difference has a significant implication on the accuracy of frequency standards, in clocks comparison, and in a variety of high precision physics tests such as the time stability of fundamental constants.Comment: 4 pages, 2 figures, 2 table

Clinical frailty scale as a predictor of outcome in elderly patients affected by moderate or severe traumatic brain injury

BackgroundOlder age is a well-known risk factor for unfavorable outcome in traumatic brain injury (TBI). However, many older people with TBI respond well to aggressive treatments, suggesting that chronological age and TBI severity alone may be inadequate prognostic markers. Frailty is an age-related homeostatic imbalance of loss of physiologic and cognitive reserve resulting in both limitation in autonomy of activities of daily living and vulnerability to adverse events. We hypothesized that frailty would be associated with 6-month adverse functional outcome in older people affected by moderate or severe TBI.MethodsThis was a single-center prospective observational study. We enrolled consecutive patients aged ≥65 years after TBI with Glasgow Coma Scale ≤13 and admitted to our Neurosurgical Intensive Care Unit. Frailty was evaluated by Clinical Frailty Scale (CFS). Relationships between TBI severity, frailty and extended Glasgow Outcome Scale (GOSE) at 6-month were evaluated.ResultsSixty patients were studied, 65% were males, their age was 76 years (IQR 70–80) and their admission GCS was 8 (IQR 6–11) with a GCS motor score of 5 (IQR 4–5). Twenty eight were vulnerable-frail (defined as CFS ≥ 4). Vulnerable-frail patients showed greater 6-month mortality and unfavorable outcome compared to non-frail [87% vs. 30% OR and 95% CI: 15.7 (3.9–55.2), p < 0.0001 and 92% vs. 51% OR and 95% CI: 9.9 (2.1–46.3), p = 0.002]. In univariate analysis patients with unfavorable outcome were more frequently male and vulnerable-frail, had a higher prevalence of pre-existing neurodegenerative disease, abnormal pupil, lower GCS and had worst CT scan characteristics. At multivariate analysis, only CFS ≥ 4 and traumatic subarachnoid hemorrhage remained associated to 6-month outcome.ConclusionFrailty was associated with 6 month-outcome, suggesting that the pre-injury functional status could represent an additional indicator to stratify patient’s severity and to predict outcome

How to Modulate Peripheral and Central Nervous System to Treat Acute Postoperative Pain and Prevent Pain Persistence

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Opioid-Free Anesthesia and Postoperative Outcomes in Cancer Surgery : A Systematic Review

This research received no external funding.Peer reviewedPublisher PD

Lattice Induced Frequency Shifts in Sr Optical Lattice Clocks at the 10−1710^{-17} Level

We present a comprehensive study of the frequency shifts associated with the lattice potential for a Sr lattice clock. By comparing two such clocks with a frequency stability reaching $5\times 10^{-17}$ after a one hour integration time, and varying the lattice depth up to $U_0=900 \, E_r$ with $E_r$ being the recoil energy, we evaluate lattice related shifts with an unprecedented accuracy. We put the first experimental upper bound on the recently predicted frequency shift due to the magnetic dipole (M1) and electric quadrupole (E2) interactions. This upper bound is significantly smaller than the theoretical upper limit. We also give a new upper limit on the effect of hyperpolarizability with an improvement by more than one order of magnitude. Finally, we report the first observation of the vector and tensor shifts in a lattice clock. Combining these measurements, we show that all known lattice related perturbation will not affect the clock accuracy down to the $10^{-17}$ level, even for very deep lattices, up to $U_0=150\,E_r$

h and r adaptation on simplicial meshes using MMG tools

We review some recent work on the enhancement and application of both − and ℎ− adaptation techniques, benefitting of the functionalities of the remeshing platform Mmg: www.mmgtools.org. Several contributions revolve around the level-set adaptation capabilities of the platform. These have been used to identify complex surfaces and then to either produce conformal 3D meshes, or to define a metric allowing to perform ℎ-adaptation and control geometrical errors in the context of immersed boundary flow simulations. The performance of the recent distributed memory parallel implementation ParMmg is also discussed. In a similar spirit, we propose some improvements of −adaptation methods to handle embedded fronts