3,100 research outputs found
Broadband enhancement of light harvesting in luminescent solar concentrator
Luminescent solar concentrator (LSC) can absorb large-area incident sunlight,
then emit luminescence with high quantum efficiency, which finally be collected
by a small photovoltaic (PV) system. The light-harvesting area of the PV system
is much smaller than that of the LSC system, potentially improving the
efficiency and reducing the cost of solar cells. Here, based on Fermi-golden
rule, we present a theoretical description of the luminescent process in
nanoscale LSCs where the conventional ray-optics model is no longer applicable.
As an example calculated with this new model, we demonstrate that a slot
waveguide consisting of a nanometer-sized low-index slot region sandwiched by
two high-index regions provides a broadband enhancement of light harvesting by
the luminescent centers in the slot region. This is because the slot waveguide
can (1) greatly enhance the spontaneous emission due to the Purcell effect, (2)
dramatically increase the effective absorption cross-section of luminescent
centers, and (3) strongly improve the quantum efficiency of luminescent
centers. It is found that about 80% solar photons can be ultimately converted
to waveguide-coupled luminescent photons even for a low luminescent quantum
efficiency of 0.5. This LSC is potential to construct a tandem structure which
can absorb nearly full-spectrum solar photons, and also may be of special
interest for building integrated nano-PV applications
2,2′-[1,1′-(Octane-1,8-diyldioxydinitrilo)diethylidyne]diphenol
The title compound, C24H32N2O4, has a crystallographic inversion centre at the mid-point of the central C—C bond. At each end of the molecule, intramolecular O—H⋯N hydrogen bonds generate six-membered S(6) ring motifs. The crystal structure is stabilized by pairs of weak intermolecular C—H⋯O hydrogen bonds that link neighbouring molecules into R
2
2(40) ring motifs, which in turn form infinite one-dimensional supramolecular ribbon structures
Bis[(E)-4-bromo-2-(ethoxyiminomethyl)phenolato-κ2 N,O 1]copper(II)
The title compound, [Cu(C9H9BrNO2)2], is a centrosymmetric mononuclear copper(II) complex. The Cu atom is four-coordinated in a trans-CuN2O2 square-planar geometry by two phenolate O and two oxime N atoms from two symmetry-related N,O-bidentate (E)-4-bromo-2-(ethoxyiminomethyl)phenolate oxime-type ligands. An interesting feature of the crystal structure is the centrosymmetric intermolecular Cu⋯O interaction [3.382 (1) Å], which establishes an infinite chain structure along the b axis
Pressure-induced dimerization and molecular orbitals formation in Na2RuO3 with strong correlation-enhanced spin-orbit coupling effect
First-principles calculations and simulations are conducted to clarify the
nonmagnetic insulating ground state of the honeycomb lattice compound Na2RuO3
with 4d^4 electronic configuration and explore the evolutions of crystal
structure and electronic property under pressure. We reveal that individual
Coulomb correlation or spin-orbit coupling (SOC) effect cannot reproduce the
experimentally observed nonmagnetic insulating behavior of Na2RuO3, whereas the
Coulomb correlation enhanced SOC interactions give rise to an unusual
spin-orbital-entangled J = 0 nonmagnetic insulating state, which contrasts with
the SOC assisted Mott insulating state in d^5 ruthenates and iridates.
Furthermore, a pressure-induced structural dimerization transition has been
predicted around 15-17.5 GPa. The honeycomb lattice of the high-pressure
dimerized phase features with parallel pattern of the short Ru-Ru dimers
aligning along the crystallographic b direction. Accompanied with the
structural dimerization, the electronic structure shows striking reconstruction
by formation of molecular orbitals. Interestingly, the cooperation of Coulomb
correlation together with SOC can realize a nonmagnetic insulating state in the
high-pressure dimerized phase. The d^4 ruthenate Na2RuO3 with honeycomb lattice
will provide a new platform to explore unusual physics and rich phase diagram
due to the delicate interplay of lattice degree of freedom, electron
correlations, and SOC interactions.Comment: 24 pages, 9 figures
4-({4-[1-(Methoxyimino)ethyl]anilino}(phenyl)methylene)-3-methyl-2-phenyl-1H-pyrazol-5(4H)-one
In the title compound, C26H24N4O2, the dihedral angles between the central pyrazole ring and the other three benzene rings are 40.02 (3), 77.51 (5) and 55.72 (3)°. A strong intramolecular N—H⋯O hydrogen bond forms a six-membered ring with an S(6) motif. In the crystal structure, a weak intermolecular C—H⋯N interaction with graph-set motif R
2
2(8) and C—H⋯O hydrogen bonds link each molecule to three others, forming an infinite two-dimensional supramolecular structure
Original Article Correlations of IFN-γ-inducible protein-10 with the risk of chronic hepatitis B and the efficacy of interferon therapy in Asians
Abstract: Purpose: The aim of this study was to identify the correlations of IFN-γ-inducible protein-10 (IP-10) with the risk of chronic hepatitis B (CHB) and the efficacy of interferon therapy in Asians. Method: Serum IP-10 levels were assayed using enzyme linked immunosorbent assay (ELISA) in both CHB and control group. CHB group received interferon-α2b treatment to compare the pre-treatment and post-treatment serum IP-10 levels. Relevant studies met predefined inclusion and exclusion criteria were enrolled into further meta-analysis. Stata 12.0 software was applied for data analysis. Result: Our case-control study demonstrated that CHB group had evaluated serum IP-10 levels compared with control group (285.7 ± 41.6 pg/mL vs. 79.1 ± 33.8 pg/mL, t = 21.85, P < 0.001. After treatment for 12 weeks, CHB group had remarkably decreased post-treatment serum IP-10 levels than pre-treatment (78.5 ± 20.4 pg/mL vs. 285.7 ± 41.6 pg/mL, t = 33.76, P < 0.001). No significance was observed on post-treatment serum IP-10 levels between CHB and control group (78.5 ± 20.4 pg/mL vs. 78.1 ± 33.8 pg/mL, t = 0.07, P = 0.947). Meta-analysis results demonstrated that serum IP-10 levels in CHB group were obviously higher than healthy controls (SMD = 2.21, 95% CI = 1.55~2.87, P < 0.001). A subgroup based on the HBeAg states revealed that serum IP-10 levels in both HBeAg-positive and HBeAg-negative CHB patients were notably higher than healthy controls (HBeAg-positive: SMD = 2.00, 95% CI = 1.13-2.87, P < 0.001; HBeAg-negative: SMD = 1.34, 95% CI = 0.97-1.72, P < 0.001). Conclusion: Serum IP-10 may be correlated with the risk of CHB and the efficiency of interferon therapy, thus IP-10 may be a good biomarker for the diagnosis and treatment of CHB
Human Circulating MicroRNA-1 and MicroRNA-126 as Potential Novel Indicators for Acute Myocardial Infarction
Circulating miRNAs have been shown as promising biomarkers for various pathologic conditions. The aim of this study was to clarify that circulating miR-1 and miR-126 in human plasma might be useful as biomarkers in acute myocardial infarction (AMI). In our study, after pre-test, two candidate miRNAs were detected by using real-time RT-PCR. Cardiac troponin I (cTnI) concentrations were measured by ELISA assay in plasma from patients with AMI (n=17) and healthy subjects (n=25), simultaneously. Increased miR-1 and decreased miR-126 in plasma from patients with AMI after the onset of symptoms compared with healthy subjects were found. A remarkable finding in this study is that miR-1, miR-126 and cTnI expression levels exhibited the same trend. Our results suggest that the plasma concentrations of miR-1 and miR-126 may be useful indicators for AMI
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