Silver ionic conductivity enhancement by network former mixed in oxide-based glasses

Glasses in the binary system xAg₂P₂O₆ − (1 − x)Ag₂Te₂O₅ have been prepared for 0 x 1. For each composition only one glass transition temperature is observed in the temperature range of 180–220 °C. All glasses appear homogeneous considering their optical and electrical properties. Nevertheless, in SEM observations, some glass compositions appear to be heterogeneous after decoration following short nitric acid etching. For each composition, conductivity data obtained in the temperature range of 25–200 °C using impedance techniques obey an Arrhenius relationship with a composition independent pre-exponential term. Variation of the conductivity activation energy with x induces correlative variations of isothermal conductivity curves leading to an increase of the ionic conductivity of about one order of magnitude compared with linearity at 25 °C. This behaviour is discussed with respect to the thermodynamic properties of the glassy solutions.     

Long-Time Bath Correlations in the Pollak–Grabert–Hänggi Theory

We analyze some cases for which the Pollak–Grabert–Hänggi theory on the activated rate processes for generalized Langevin dynamics exhibits unexplained disagreements with numerical results. First we analyze carefully the PGH theory and we show that a kind of Markovian hypothesis implicitly made in the reasoning is sometimes violated. Then we propose modifications of the original theory in order to take into account the possible effects caused by this violation, and we compare the corrected results with simulations.     

基于耦合道Gamow壳模型计算17O和17F的能谱以及16O(p,p)反应的微分散射截面

利用耦合道Gamow壳模型计算了17O和17F的低激发能谱以及16O(p,p)反应的低能弹性散射截面。结果表明,17O和17F中非束缚共振态能级的核子发射宽度的计算需要合理地考虑连续态耦合效应。计算得到的17O和17F的低激发能谱以及16O(p,p)反应的低能弹性散射激发函数都与实验数据吻合较好。这说明基于现实核力的计算可更好地描述16O(p,p)反应的低能弹性散射截面。     

A tabu search procedure for multicommodity location/allocation with balancing requirements

We propose a tabu search heuristic for the location/allocation problem with balancing requirements. This problem typically arises in the context of the medium term management of a fleet of containers of multiple types, where container depots have to be selected, the assignment of customers to depots has to be established for each type of container, and the interdepot container traffic has to be planned to account for differences in supplies and demands in various zones of the geographical territory served by a container shipping company. It is modeled as a mixed integer program, which combines zero-one location variables and a multicommodity network flow structure. Extensive computational results on a set of benchmark problems and comparisons with an efficient dual ascent procedure are reported. These show that tabu search is a competitive approach for this class of problems.     

Demonstration of an optical self-clocked time-division switch

A novel architecture for an optical time-division switch is investigated and demonstrated at a bit rate of 625 Mbit/s. The self-clocked configuration eliminates some of the limitations found in previous optical implementations of time-division switches: the switch operation is asynchronous, no read gate is required, and an optimal number of delay lines is used. Furthermore, this paper reports the first experimental demonstration of optical space-sorting demultiplexing.     

A framework for the automated real-time detection of short tonal sounds from ocean observatories

Acquisition of acoustic data from ocean observatories is expected to play a key role for the long-term monitoring of marine mammals and anthropogenic noise. It typically requires processing of a large volume of acoustic data and it must rely on automated identification of signals. We present an algorithmic framework for the detection of short tonal sounds (e.g. cetacean calls, anthropogenic pings) intended to act as a first stage in a system for the automated real-time detection, classification, and localisation of acoustic sources. The algorithm was validated under a diversity of scenarios expected at ocean observatories. Using simulated signals that emulate a variety of cetacean call-types, perfect identification of signal position was obtained for signal to noise ratios of ?15 to ?5 dB, depending on the signal-type. Separation of real-world data segments with short tonal sounds (mainly cetacean calls) from segments with other sounds or noise resulted in Area Under the ROC Curve values between 0.96 and 0.98. The algorithm can be used to automatically identify cetacean calls and anthropogenic short tonal sounds much faster than in real-time, thereby reducing the burden put on data transmission, storage, or processing by classification and localisation algorithms.     

Implantation of undifferentiated and pre-differentiated human neural stem cells in the R6/2 transgenic mouse model of Huntington’s disease

Background

The expression pattern and function of miRNAs in the rat model of temporal lobe epilepsy have not been well defined. Profiling miRNA expression in the rat model of temporal lobe epilepsy and investigating the function of specific miRNAs in epilepsy offers the prospect of a deeper understanding of the mechanisms of epilepsy.

Methods

The lithium-pilocarpine-induced status epilepticus model and the temporal lobe epilepsy model were established in Sprague?CDawley rats. Samples were analysed to detect deregulated miRNAs in the hippocampal temporal lobe, and several of these deregulated miRNAs were confirmed by qPCR. The expression of the pro-apoptotic miR-34a was detected at 1?day, 7?days and 2?weeks post-status epilepticus and at 2?months after temporal lobe epilepsy. The antagomir of miR-34a was then utilised. The expression of miR-34a after targeting and the expression change of activated caspase-3 protein were examined. The effects of altering the expression of miR-34a and activated caspase-3 protein on neuronal survival and neuronal death or apoptosis post-status epilepticus were assessed.

Results

The miRNA microarray detected 9 up-regulated miRNAs (miR-146a, -211, -203, -210, -152, -31, -23a, -34a, -27a) and 15 down-regulated miRNAs (miR-138*, -301a, -136, -153, -19a, -135b, -325-5p, -380, -190, -542-3p, -33, -144, -542-5p, -543, -296*). Some of the deregulated miRNAs (miR-146a, miR-210, miR-27a, miR-135b and miR-33) were confirmed using qPCR. Furthermore, an increase in expression of the pro-apoptotic miR-34a was demonstrated in the post-status epilepticus rat hippocampus. miR-34a was significantly up-regulated at 1?day, 7?days and 2?weeks post-status epilepticus and at 2?months after temporal lobe epilepsy. Experiments with the miR-34a antagomir revealed that targeting miR-34a led to an inhibition of activated caspase-3 protein expression, which may contribute to increased neuronal survival and reduced neuronal death or apoptosis.

Conclusions

Our study showed the expression profile of miRNAs in the hippocampus in a rat model of temporal lobe epilepsy and an increase in the expression of the pro-apoptotic miR-34a in post-status epilepticus rats. The results show that miR-34a is up-regulated during seizure-induced neuronal death or apoptosis, and targeting miR-34a is neuroprotective and is associated with an inhibition of an increase in activated caspase-3 protein.     

Reverse engineering from spectrophotometric measurements: performances and efficiency of different optimization algorithms

A large number of parameters is often required to describe optical dispersion laws, and it is only through the use of an appropriate global optimization procedure that an accurate thin-film index determination can be achieved. In this paper, we propose to investigate the respective performances of three different optimization algorithms, namely Simulated Annealing, Genetic Algorithm and Clustering Global Optimization and compare results with a commercial software dedicated to thin-film index determination. This study is restricted to the single-layer thin-film index determination of transparent and absorbing materials. It includes the theoretical study of simulated reflection and transmission spectra, and the experimental characterization of Ta₂O₅ and Si layers.     

An Asymmetric Synthesis of L-694,458, a Human Leukocyte Elastase Inhibitor, via Novel Enzyme Resolution of beta-Lactam Esters

A convergent synthesis of [S-(R,S)]-2-[4-[(4-methylpiperazin-1-yl)carbonyl]phenoxy]-3,3-diethyl-N-[1-[3,4-(methylenedioxy)phenyl]butyl]-4-oxo-1-azetidinecarboxamide (L-694,458, 1), a potent human leukocyte elastase inhibitor, was achieved via chiral synthesis of key intermediates: (S)-3,3-diethyl-4-[4'-[(N-methylpiperazin-1-yl)carbonylphenoxy]-2-azetidinone (2) and (R)-alpha-propylpiperonyl isocyanate (3). Synthesis of beta-lactam 2 was achieved by a novel enantioselective lipase hydrolysis of ester 5 to produce (S)-3,3-diethyl-4-(4'-carboxyphenoxy)-2-azetidinone (6) (60% yield, three cycles, 93% ee) with isolation, epimerization, and recycling of the undesired (R)-ester 5. Isocyanate 3 was prepared by chiral addition of Zn(n-Pr)(2) to piperonal (98% yield, 99.2% ee), azide displacement and reduction to (R)-alpha-propylpiperonylamine (11) (58% yield, 85% ee), crystallization as the D-pyroglutamic acid salt (92% yield, 98.2% ee), and isocyanate formation (98% yield) with phosgene.