The quantum solvation, adiabatic versus nonadiabatic, and Markovian versus non-Markovian nature of electron transfer rate processes

In this work, we revisit the electron transfer rate theory, with particular interests in the distinct quantum solvation effect, and the characterizations of adiabatic/nonadiabatic and Markovian/non-Markovian rate processes. We first present a full account for the quantum solvation effect on the electron transfer in Debye solvents, addressed previously in J. Theore. & Comput. Chem. {\bf 5}, 685 (2006). Distinct reaction mechanisms, including the quantum solvation-induced transitions from barrier-crossing to tunneling, and from barrierless to quantum barrier-crossing rate processes, are shown in the fast modulation or low viscosity regime. This regime is also found in favor of nonadiabatic rate processes. We further propose to use Kubo's motional narrowing line shape function to describe the Markovian character of the reaction. It is found that a non-Markovian rate process is most likely to occur in a symmetric system in the fast modulation regime, where the electron transfer is dominant by tunneling due to the Fermi resonance.Comment: 13 pages, 10 figures, submitted to J. Phys. Chem.

Detrended fluctuation analysis on the correlations of complex networks under attack and repair strategy

We analyze the correlation properties of the Erdos-Renyi random graph (RG) and the Barabasi-Albert scale-free network (SF) under the attack and repair strategy with detrended fluctuation analysis (DFA). The maximum degree k_max, representing the local property of the system, shows similar scaling behaviors for random graphs and scale-free networks. The fluctuations are quite random at short time scales but display strong anticorrelation at longer time scales under the same system size N and different repair probability p_re. The average degree , revealing the statistical property of the system, exhibits completely different scaling behaviors for random graphs and scale-free networks. Random graphs display long-range power-law correlations. Scale-free networks are uncorrelated at short time scales; while anticorrelated at longer time scales and the anticorrelation becoming stronger with the increase of p_re.Comment: 5 pages, 4 figure

Epileptiform discharge upregulates p-ERK1/2, growth-associated protein 43 and synaptophysin in cultured rat hippocampal neurons

AbstractExtracellular signal-regulated protein kinase, ERK1/2 is activated by phosphorylation (p-ERK1/2) during environmental stress such as epileptiform discharge. We investigated the role of ERK1/2 in abnormal axon growth and synapse reorganization in cultured neurons displaying epileptiform activity.The cultured neurons displaying epileptiform activity were treated with magnesium-free extracellular fluid for 3h and monitored epileptiform discharges using whole-cell patch clamp. Two study groups, neurons displaying epileptiform activity and the same neurons treated with ERK1/2 inhibitor U0126, were studied at six time points, 0min, 30min, 2h, 6h, 12h, and 24h following discharge. The expressions of p-ERK1/2, C-fos, growth-associated protein 43 (GAP-43) and synaptophysin (SYP), as markers of axon growth and synapse reorganization, were investigated by double-label immunofluorescence and western blotting.In the neurons displaying epileptiform activity, p-ERK1/2 was detected immediately following discharge, and expression peaked at 30min. The expression of C-fos, GAP-43 and SYP followed the same pattern as p-ERK1/2. In the treated group, p-ERK1/2 was inhibited completely, and C-fos, GAP-43 and SYP were reduced.These findings indicate that epileptiform discharge activates ERK1/2 which regulates C-fos in cultured neurons displaying epileptiform activity, and this cascade may upregulate GAP-43 and SYP to contribute to axon growth and synapse reorganization to potentiate epileptic activities

1-(2-Nitro­benz­yl)-1H-pyrrole-2-carbaldehyde

In the title compound, C12H10N2O3, the five- and six-membered rings form a dihedral angle of 83.96 (6)°. The nitro group is twisted by 5.92 (8)° from the plane of the attached benzene ring. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into columns in the [100] direction, with a short distance of 3.725 (3) Å between the centroids of benzene rings inside these columns

Optimizing and controlling functions of complex networks by manipulating rich-club connections

Traditionally, there is no evidence suggesting that there are strong ties between the rich-club property and the function of complex networks. In this study, we find that whether a very small portion of rich nodes connected to each other or not can strongly affect the frequency of occurrence of basic building blocks (motif) within networks, and therefore the function, of a heterogeneous network. Conversely whether a homogeneous network has a rich-club property or not generally has no significant effect on its structure and function. These findings open the possibility to optimize and control the function of complex networks by manipulating rich-club connections. Furthermore, based on the subgraph ratio profile, we develop a more rigorous approach to judge whether a network has a rich-club or not. The new method does not calculate how many links there are among rich nodes but depends on how the links among rich nodes can affect the overall structure as well as function of a given network. These results can also help us to understand the evolution of dynamical networks and design new models for characterizing real-world networks.Comment: 6 pages, 3 figure

Suppression of Superconductivity by Twin Boundaries in FeSe

Low-temperature scanning tunneling microscopy and spectroscopy are employed to investigate twin boundaries in stoichiometric FeSe films grown by molecular beam epitaxy. Twin boundaries can be unambiguously identified by imaging the 90{\deg} change in the orientation of local electronic dimers from Fe site impurities on either side. Twin boundaries run at approximately 45{\deg} to the Fe-Fe bond directions, and noticeably suppress the superconducting gap, in contrast with the recent experimental and theoretical findings in other iron pnictides. Furthermore, vortices appear to accumulate on twin boundaries, consistent with the degraded superconductivity there. The variation in superconductivity is likely caused by the increased Se height in the vicinity of twin boundaries, providing the first local evidence for the importance of this height to the mechanism of superconductivity.Comment: 6 pages, 7 figure

Monitoring, cataloguing, and weather scenarios of thunderstorm outflows in the northern Mediterranean

High sampling rate (10Hz) anemometric measurements of the "Wind, Ports, and Sea" monitoring network in the northern Tyrrhenian Sea have been analysed to extract the thunderstorm-related signals and catalogue them into three families according to the different time-scale of each event, subdivided among 10min, 1, and 10h events. Their characteristics in terms of direction of motion and seasonality/daily occurrence have been analysed: The results showed that most of the selected events come from the sea and occur from 12:00 to 00:00UTC during the winter season. In terms of peak wind speed, the strongest events all belonged to the 10min family, but no systematic correlation was found between event duration and peaks. Three events, each one representative of the corresponding class of duration, have been analysed from the meteorological point of view, in order to investigate their physical nature. According to this analysis, which was mainly based on satellite images, meteorological fields obtained from GFS analyses related to convection in the atmosphere, and lightning activity, the thunderstorm-related nature of the 10min and 1h events was confirmed. The 10h event turned out to be a synoptic event, related to extra-tropical cyclone activity