The excited-state dynamics of all-trans-retinoic acid (ATRA), both free in n-hexanol and bound to a TiO2 nanoparticle have been studied by use of femtosecond time-resolved visible absorption spectroscopy excited at 400 nm. Three excited singlet states, S3, S2, and S1, have been observed for the ATRA molecule, which can be assigned as 1Bu + (π, π*), (n, π*), and 2Ag - (π, π*) singlet excited manifolds, respectively. Photoinduced electron injection from the excited singlet state S3 to the conduction band of the TiO2 nanoparticle is observed in an ATRA-sensitized TiO2 colloidal solution in hexanol; the subsequent interfacial charge recombination between the injected electron and the ATRA cation is investigated. It is found that the charge recombination is mainly via the triplet state, and the branching ratio for the population on the excited triplet state and the ground state during the charge recombination is about 6.0. The observed rate constants for the charge recombination to the triplet state and the ground state are 1/19.0 (ps-1) and 1/140 (ps-1), respectively. Treating the charge recombination as a nonadiabatic process, we can obtain a reorganization energy having a value of 0.44 eV, which indicates that the charge recombination to the ground state is in the Marcus inverted region while the charge recombination to the triplet state lies within the normal region. An apparent electronic coupling matrix element at the closest contact of ATRA and the TiO2 nanoparticle, V 0 T = 5118 cm-1, has been evaluated for the charge recombination to the triplet state and V 0 G = 2670 cm-1 for that to the ground state. It is concluded that the interfacial charge recombination is strongly coupled. The electronic coupling matrix element is expected to decay exponentially on the charge separation distance, and in the microsecond domain, the observed V(r)G decays to 3.6 cm-1, corresponding to the trapped electron migrating away from the adsorbates at a distance of 2.0 nm on the TiO2 nanoparticles. The relevance of the triplet formation to the electroluminescence device is also discussed.

Summary Because of the strong demands of physical resources of big data, it is an effective and efficient way to store and process big data in clouds, as cloud computing allows on‐demand resource provisioning. With the increasing requirements for the resources provisioned by cloud platforms, the Quality of Service (QoS) of cloud services for big data management is becoming significantly important. Big data has the character of sparseness, which leads to frequent data accessing and processing, and thereby causes huge amount of energy consumption. Energy cost plays a key role in determining the price of a service and should be treated as a first‐class citizen as other QoS metrics, because energy saving services can achieve cheaper service prices and environmentally friendly solutions. However, it is still a challenge to efficiently schedule Virtual Machines (VMs) for service QoS enhancement in an energy‐aware manner. In this paper, we propose an energy‐aware dynamic VM scheduling method for QoS enhancement in clouds over big data to address the above challenge. Specifically, the method consists of two main VM migration phases where computation tasks are migrated to servers with lower energy consumption or higher performance to reduce service prices and execution time. Extensive experimental evaluation demonstrates the effectiveness and efficiency of our method. Copyright © 2016 John Wiley & Sons, Ltd.

Pyridoxine is always simultaneously administered orally with isoniazid for tuberculosis patients in the clinic to prevent or treat the nervous system side effects induced by isoniazid. So the aim of this research was to investigate the effects of pyridoxine on the intestinal absorption and pharmacokinetics of isoniazid. The intestinal absorption of isoniazid with or without pyridoxine was investigated by the rat single-pass intestinal perfusion model in situ, and a high-performance liquid chromatographic method was applied to study the pharmacokinetics of isoniazid with or without pyridoxine. The results suggested that the intestinal apparent permeability (P app) and intestinal absorption rate constant (K a) for isoniazid (30 μg/ml) were decreased by 43.7 and 36.4 %, respectively, by co-perfused pyridoxine (40 μg/ml). In vivo, the effect of pyridoxine on isoniazid pharmacokinetic correlated with the doses of pyridoxine. The blood concentrations of isoniazid at the absorption phase were affected by co-administered pyridoxine, but the AUC and C max of isoniazid were not greatly affected by pyridoxine as expected from the inhibition by pyridoxine of the intestinal absorption of isoniazid, which could be caused by its rapid absorption phase. Therefore, although the intestinal absorption of isoniazid could be significantly inhibited by pyridoxine, the pharmacokinetics of isoniazid oral administration was not greatly affected by the decreased intestinal absorption of isoniazid due to its rapid absorption.

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