In the paper, resonances of different waveguide structures with various vertical indirect coupled cavities were investigated by FDTD (finite difference-time domain). In the silicon cavity, Fano resonance could be observed at about 1430 nm. The coupling distance for the gold cavity/air cavity had less effect on the transmittance of the main waveguide but had a great influence on the transmission for water cavity in the visible region, which showed that water cavity could adjust resonance of waveguide structures. In addition, with the increment of refractive index n, the resonance peak at about 850 nm moved to the long wavelength (redshift). Dispersion rate about 2 × 10–3/nm indicated that the transparent dielectric selectively absorbed the surface plasmon polariton wave and the sensitivity of the waveguide structure designed in this paper has high stability for the refractive index of the main waveguide cavity. Obvious Fano resonance could be observed with the increase of refractive index for silicon cavity. Among the four dielectrics, silicon and water are suitable for studying Fano resonance and filter dielectrics.
With the help of quantum mechanical calculations, we have examined the series of central system X(ML)3+(X = O, S, Se; M = Au, Ag, Cu). Using a scalar–relativistic density functional approach, we studied the geometry structures, Mulliken populations and charges of the systems. Structure parameters of the experimental systems are reproduced well with Xα method. The metallophilic interaction energy is analyzed and decomposed. For the systems with different central atoms and different metal atoms, the nature of the metallophilic attraction interaction is analyzed. 相似文献
Copper (Cu(II)) and nickel (Ni(II)) are often encountered in wastewaters. This study investigated the individual toxic effects
of long-term addition of Cu(II) and Ni(II) on the biochemical properties of aerobic granules in sequencing batch reactors
(SBRs). The biochemical properties of aerobic granules were characterized by extracellular polymeric substances (EPS) content,
dehydrogenase activity, microbial community biodiversity, and SBR performance. One SBR was used as a control system, while
another two received respective concentration of Cu(II) and Ni(II) equal to 5 mg/L initially and increased to 15 mg/L on day 27.
Results showed that the addition of Cu(II) drastically reduced the biomass concentration, bioactivity, and biodiversity of
aerobic granules, and certainly deteriorated the treatment performance. The toxic effect of Ni(II) on the biodiversity of
aerobic granules was milder and the aerobic granular system elevated the level of Ni(II) toxicity tolerance. Even at a concentration
of 15 mg/L, Ni(II) still stimulated the biomass yield and bioactivity of aerobic granules to some extent. The elevated tolerance
seemed to be owed to the concentration gradient developed within granules, increased biomass concentration, and promoted EPS
production in aerobic granular systems. 相似文献
Fermentative hydrogen production, as a process for clean energy recovery from organic wastewater, is limited by its low hydrogen
yield due to incomplete conversion of substrates, with most of the fermentation products being volatile fatty acids (VFAs).
Thus, further recovery of the energy from VFAs is expected. In this work, microbial fuel cell (MFC) was applied to recover
energy in the form of electricity from mixed VFAs of acetate, propionate, and butyrate. Response surface methodology was adopted
to investigate the relative contribution and possible interactions of the three components of VFAs. A stable electricity generation
was demonstrated in MFCs after the enrichment of electrochemically active bacteria. Analysis showed that power density was
more sensitive to the composition of mixed VFAs than coulombic efficiency. The electricity generation could mainly be attributed
to the portion of acetate and propionate. However, the two components showed an antagonistic effect when propionate exceeded
19%, causing a decrease in coulombic efficiency. Butyrate was found to exert a negative impact on both power density and coulombic
efficiency. Denaturing gradient gel electrophoresis profiles revealed the enrichment of electrochemically active bacteria
from the inoculum sludge. Proteobacteria (Beta-, Delta-) and Bacteroidetes were predominant in all VFA-fed MFCs. Shifts in
bacterial community structures were observed when different compositions of VFA mixtures were used as the electron donor.
The overall electron recovery efficiency may be increased from 15.7% to 27.4% if fermentative hydrogen production and MFC
processes are integrated. 相似文献
Ischaemic post-conditioning (PostC) is a clinically relevant cardioprotective modality that has been confirmed in many species including human. It remains unknown if PostC can still protect heart in Type 2 diabetes, a rapidly growing disease in the world. This study investigated the efficacy of PostC in the leptin receptor-deficient db/db mice, which possess Type 2 diabetic characteristics including obesity, hyperglycaemia and hyperleptinaemia. Adult male C57BL/6J wild-type (WT) and db/db mice were anaesthetized, mechanically ventilated and subjected to left coronary artery occlusion for 30 min. followed by 24 hrs of reperfusion. For the PostC groups, the hearts underwent six cycles of 10 sec. of reperfusion and 10 sec. of re-occlusion at the onset of reperfusion. The mice were sacrificed at the end of 24 hrs reperfusion for infarct size measurement. PostC significantly reduced infarct size in WT mice (n = 6/group; P < 0.05), but not in the db/db mice. To identify alterations in protein expression by PostC, proteomic analyses were performed in the heart samples using two-dimensional differential in-gel electrophoresis with three CyDye labelling, followed by mass spectrometry. The results show that mitochondrial proteins (F(1)-ATPase γ and Echs1) were down-regulated by PostC in WT heart. Such change was absent in the db/db heart. On the other hand, PostC reduced Hsp20 in the diabetic heart. In summary, PostC fails to protect Type 2 diabetic mice against ischaemia-reperfusion injury. The potential protein targets for the loss of PostC may include F(1)-ATPase γ, Echs1 and Hsp20 that could regulate cellular ATP consumption/production and defense response to ischaemic stress. 相似文献
Glucose toxicity is an important initiator of cardiovascular disease, contributing to the development of cardiomyocyte death and diabetic complications. The present study investigated whether high glucose state could induce apoptosis of rat cardiomyocyte cell line H9C2 through microRNA regulated insulin-like growth factor (IGF-1) signaling pathway. Our data showed that H9C2 cells exposed to high glucose have increased miR-1 expression level, decreased mitochondrial membrane potential, increased cytochrome-c release, and increased apoptosis. Glucose induced mitochondrial dysfunction, cytochrome-c release and apoptosis was blocked by IGF-1. Using prediction algorithms, we identified 3′-untranslated regions of IGF-1 gene are the target of miR-1. miR-1 mimics, but not mutant miR-1, blocked the capacity of IGF-1 to prevent glucose-induced mitochondrial dysfunction, cytochrome-c release and apoptosis. In conclusion, our data demonstrate that IGF-1 inhibits glucose-induced mitochondrial dysfunction, cytochrome-c release and apoptosis and IGF-1’s effect is regulated by miR-1. 相似文献