622 research outputs found
Influence of unsymmetrical periodicity on extraordinary transmission through periodic arrays of subwavelength holes
Quadrate hole array is explored to study the influence of unsymmetrical
periodicity on extraordinary optical transmission through periodic arrays of
subwavelength holes. It is found that the transmission efficiency of light and
the ratio between transmission efficiencies of horizontal and vertical
polarized light can be continuously tuned by rotating the quadrate hole array.
We can calculate out the transmission spectra (including the heights and
locations of peaks) for any rotation angle with a simple theoretical
model.Comment: 6 pages, 5 figure
Interference of surface plasmon polaritions controlled by the phase of incident light
Interference patterns of surface plasmon polaritons(SPPs) are observed in the
extraordinary optical transmission through subwavelength holes in optically
thick metal plate. It is found that the phase of incident light can be
transferred to SPPs. We can control the destructive and constructive
interference of SPPs by modulating the relative phase between two incident
beams. Using a slightly displaced Mach-Zehnder interferometer, we also observe
a SPPs interference pattern composed of bright and dark stripes.Comment: 3pages,5figure
Newly identified NO-sensor guanylyl cyclase/connexin 43 association is involved in cardiac electrical function
Background: Guanylyl cyclase, a heme-containing alpha 1 beta 1 heterodimer (GC1), produces cGMP in response to Nitric oxide (NO) stimulation. The NO-GC1-cGMP pathway negatively regulates cardiomyocyte contractility and protects against cardiac hypertrophy-related remodeling. We recently reported that the beta 1 subunit of GC1 is detected at the intercalated disc with connexin 43 (Cx43). Cx43 forms gap junctions (GJs) at the intercalated disc that are responsible for electrical propagation. We sought to determine whether there is a functional association between GC1 and Cx43 and its role in cardiac homeostasis.
Methods and Results: GC1 and Cx43 immunostaining at the intercalated disc and coimmunoprecipitation from membrane fraction indicate that GC1 and Cx43 are associated. Mice lacking the alpha subunit of GC1 (GC alpha 1 knockout mice) displayed a significant decrease in GJ function (dye-spread assay) and Cx43 membrane lateralization. In a cardiac-hypertrophic model, angiotensin II treatment disrupted the GC1-Cx43 association and induced significant Cx43 membrane lateralization, which was exacerbated in GC alpha 1 knockout mice. Cx43 lateralization correlated with decreased Cx43-containing GJs at the intercalated disc, predictors of electrical dysfunction. Accordingly, an ECG revealed that angiotensin II-treated GCa1 knockout mice had impaired ventricular electrical propagation. The phosphorylation level of Cx43 at serine 365, a protein-kinase A upregulated site involved in trafficking/assembly of GJs, was decreased in these models.
Conclusions: GC1 modulates ventricular Cx43 location, hence GJ function, and partially protects from electrical dysfunction in an angiotensin II hypertrophy model. Disruption of the NO-cGMP pathway is associated with cardiac electrical disturbance and abnormal Cx43 phosphorylation. This previously unknown NO/Cx43 signaling could be a protective mechanism against stress-induced arrhythmia
Spatial mode properties of plasmon assisted transmission
Orbital angular momentum of photons is explored to study the spatial mode
properties of plasmon assisted transmission process. We found that photons
carrying different orbital angular momentums have different transmission
efficiencies, while the coherence between these spatial modes can be preserved
Identification and Nearly Full-Length Genome Characterization of Novel Porcine Bocaviruses
The genus bocavirus includes bovine parvovirus (BPV), minute virus of canines (MVC), and a group of human bocaviruses (HBoV1-4). Using sequence-independent single primer amplification (SISPA), a novel bocavirus group was discovered with high prevalence (12.59%) in piglet stool samples. Two nearly full-length genome sequences were obtained, which were approximately 5,100 nucleotides in length. Multiple alignments revealed that they share 28.7–56.8% DNA sequence identity with other members of Parvovirinae. Phylogenetic analyses indicated their closest neighbors were members of the genus bocavirus. The new viruses had a putative non-structural NP1 protein, which was unique to bocaviruses. They were provisionally named porcine bocavirus 1 and 2 (PBoV1, PBoV2). PBoV1 and PBoV2 shared 94.2% nucleotide identity in NS1 gene sequence, suggesting that they represented two different bocavirus species. Two additional samples (6V, 7V) were amplified for 2,407 bp and 2,434 bp products, respectively, including a partial NP1 gene and the complete VP1 gene; Phylogenetic analysis indicated that 6Vand 7V grouped with PBoV1 and PBoV2 in the genus of bocavirus, but were in the separate clusters. Like other parvoviruses, PBoV1, PBoV2, 6Vand 7V also contained a putative secretory phospholipase A2 (sPLA2) motif in the VP1 unique region, with a conserved HDXXY motif in the catalytic center. The conserved motif YXGXF of the Ca2+-binding loop of sPLA2 identified in human bocavirus was also found in porcine bocavirus, which differs from the YXGXG motif carried by most other parvoviruses. The observation of PBoV and potentially other new bocavirus genus members may aid in molecular and functional characterization of the genus bocavirus
Human Bocavirus Infection, People’s Republic of China
A newly identified parvovirus, human bocavirus (HBoV), was found in 21 (8.3%) of 252 nasopharyngeal aspirates from hospitalized children with lower respiratory tract infection in Hunan Province, People’s Republic of China. Viral loads were 104 to 1010 copies/mL. Phylogenetic analysis of the VP1 gene showed a single genetic lineage of HBoV worldwide
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