5,404 research outputs found
Plasmonic Tamm states: second enhancement of light inside the plasmonic waveguide
A type of Tamm states inside metal-insulator-metal (MIM) waveguides is
proposed. An impedance based transfer matrix method is adopted to study and
optimize it. With the participation of the plasmonic Tamm states, fields could
be enhanced twice: the ffirst is due to the coupling between a normal waveguide
and a nanoscaled plasmonic waveguide and the second is due to the strong
localization and field enhancement of Tamm states. As shown in our 2D coupling
configuration, |E|^2 is enhanced up to 1050 times when 1550 nm light is coupled
from an 300 nm Si slab waveguide into an 40 nm MIM waveguide.Comment: 3 pages, 4 figure
Mapping the Milky Way with LAMOST II: the stellar halo
The radial number density and flattening of the Milky Way's stellar halo is
measured with metal-poor ([Fe/H]) K giants from LAMOST
DR3, using a nonparametric method which is model independent and largely avoids
the influence of halo substucture. The number density profile is well described
by a single power law with index , and flattening that
varies with radius. The stellar halo traced by LAMOST K giants is more
flattened at smaller radii, and becomes nearly spherical at larger radii. The
flattening, , is about 0.64, 0.8, 0.96 at , 20 and 30 kpc (where
), respectively. Moreover, the
leading arm of the Sagittarius dwarf galaxy tidal stream in the north, and the
trailing arm in the south, are significant in the residual map of density
distribution. In addition, an unknown overdensity is identified in the residual
map at (R,Z)=(30,15) kpc.Comment: 16 pages, 24 figures, accepted by MNRA
Differential requirement for Dab2 in the development of embryonic and extra-embryonic tissues
BACKGROUND: Disabled-2 (Dab2) is an endocytic adaptor protein involved in clathrin-mediated endocytosis and cargo trafficking. Since its expression is lost in several cancer types, Dab2 has been suggested to be a tumor suppressor. In vitro studies indicate that Dab2 establishes epithelial cell polarity and organization by directing endocytic trafficking of membrane glycoproteins. Dab2 also modulates cellular signaling pathways by mediating the endocytosis and recycling of surface receptors and associated signaling components. Previously, two independent gene knockout studies have been reported, with some discrepancies in the observed embryonic phenotypes. To further clarify the in vivo roles of Dab2 in development and physiology, we designed a new floxed allele to delete dab2 gene. RESULTS: The constitutive dab2 deleted embryos showed a spectrum in the degree of endoderm disorganization in E5.5 and no mutant embryos persisted at E9.5. However, the mice were grossly normal when dab2 deletion was restricted to the embryo proper and the gene was retained in extraembryonic tissues using Meox2-Cre and Sox2-Cre. Adult Dab2-deficient mice had a small but statistically significant increase in serum cholesterol levels. CONCLUSION: The study of the new dab2 mutant allele in embryos and embryoid bodies confirms a role for Dab2 in extraembryonic endoderm development and epithelial organization. Experimental results with embryoid bodies suggest that additional endocytic adaptors such as Arh and Numb could partially compensate for Dab2 loss. Conditional deletion indicates that Dab2 is dispensable for organ development, when the vast majority of the embryonic cells are dab2 null. However, Dab2 has a physiological role in the endocytosis of lipoproteins and cholesterol metabolism
PI-RCNN: An Efficient Multi-sensor 3D Object Detector with Point-based Attentive Cont-conv Fusion Module
LIDAR point clouds and RGB-images are both extremely essential for 3D object
detection. So many state-of-the-art 3D detection algorithms dedicate in fusing
these two types of data effectively. However, their fusion methods based on
Birds Eye View (BEV) or voxel format are not accurate. In this paper, we
propose a novel fusion approach named Point-based Attentive Cont-conv
Fusion(PACF) module, which fuses multi-sensor features directly on 3D points.
Except for continuous convolution, we additionally add a Point-Pooling and an
Attentive Aggregation to make the fused features more expressive. Moreover,
based on the PACF module, we propose a 3D multi-sensor multi-task network
called Pointcloud-Image RCNN(PI-RCNN as brief), which handles the image
segmentation and 3D object detection tasks. PI-RCNN employs a segmentation
sub-network to extract full-resolution semantic feature maps from images and
then fuses the multi-sensor features via powerful PACF module. Beneficial from
the effectiveness of the PACF module and the expressive semantic features from
the segmentation module, PI-RCNN can improve much in 3D object detection. We
demonstrate the effectiveness of the PACF module and PI-RCNN on the KITTI 3D
Detection benchmark, and our method can achieve state-of-the-art on the metric
of 3D AP.Comment: 8 pages, 5 figure
The K giant stars from the LAMOST survey data I: identification, metallicity, and distance
We present a support vector machine classifier to identify the K giant stars
from the LAMOST survey directly using their spectral line features. The
completeness of the identification is about 75% for tests based on LAMOST
stellar parameters. The contamination in the identified K giant sample is lower
than 2.5%. Applying the classification method to about 2 million LAMOST spectra
observed during the pilot survey and the first year survey, we select 298,036 K
giant candidates. The metallicities of the sample are also estimated with
uncertainty of \,dex based on the equivalent widths of Mg and iron lines. A Bayesian method is then developed to estimate the
posterior probability of the distance for the K giant stars, based on the
estimated metallicity and 2MASS photometry. The synthetic isochrone-based
distance estimates have been calibrated using 7 globular clusters with a wide
range of metallicities. The uncertainty of the estimated distance modulus at
\,mag, which is the median brightness of the K giant sample, is about
0.6\,mag, corresponding to % in distance. As a scientific verification
case, the trailing arm of the Sagittarius stream is clearly identified with the
selected K giant sample. Moreover, at about 80\,kpc from the Sun, we use our K
giant stars to confirm a detection of stream members near the apo-center of the
trailing tail. These rediscoveries of the features of the Sagittarius stream
illustrate the potential of the LAMOST survey for detecting substructures in
the halo of the Milky Way.Comment: 24 pages, 20 figures, submitted to Ap
Estrogen Inhibits Colon Polyp Formation by Reducing Angiogenesis in a Carcinogen-Induced Rat Model
Objective. To study the effects of estrogen on colon polyp formation, proliferation, and angiogenesis on a rat model of colon cancer induced by dimethylhydrazine (DMH). Methods. Thirty-six female ovariectomized (OVX) rats were randomly divided into 3 groups: (I) control group (administrated with vehicles weekly), (II) DMH group (administrated with DMH weekly), and (III) DMH + E2 group (administrated with DMH and 17β-estradiol weekly). The incidence, volumes, and multiplicity of colon polyps in each group were evaluated. The microvessel density (MVD), the expressions of Proliferating Cell Nuclear Antigen (PCNA), and the expressions of HIF-1α and VEGF in polyps were detected in each group. Results. Estrogen reduced the multiplicity, volumes, and the PCNA expressions of DMH-induced colon polyps. The MVD in DMH + E2 group was significantly lower than that in DMH group. Estrogen treatment decreased the HIF-1α and VEGF expressions at both mRNA and protein level. Conclusion. Estrogen replacement was protective for ovariectomized rats from DMH-induced carcinogenesis, and one of the mechanisms for this was due to estrogen’s inhibitive effects on blood vessel formation by downregulating VEGF and HIF-1α expressions
LIM-domain binding protein 2 was down-regulated by miRNA-96-5p inhibited the proliferation, invasion and metastasis of lung cancer H1299 cells
Objectives: Lung cancer was one of the most common malignancies around the world. It has great significance in to search for the mechanism of occurrence and development of lung cancer. LIM Domain Binding protein 2 (LDB2) belongs to the LIM-domain binding family, it can be used as a binding protein that combined with other transcription factors to form the transcription complex for regulating the expression of target genes. The expression of microRNA-96-5p (miR-96-5p) has been investigated in various tumors. The aim of this study is to investigate the potential role of LDB2 and miR-96-5p in lung cancer.
Methods: Real-time quantitative PCR was applied to detect the expression of LDB2 and miR-96-5p. The proliferation, invasion, and metastasis of H1299 cells were analyzed by CCK8, transwell, and wound healing assay after LDB2 or miR-96-5p transfection. Luciferase activities assay and western blot were used to reveal the targeted regulation between LDB2 and miR-96-5p.
Results: Here the authors found LDB2 was down-regulated in lung cancer tissues and negatively correlated with miR-96-5p expression, it could promote or inhibit the proliferation, invasion and metastasis of H1299 cells after LDB2 knockdown or overexpression and regulate the expression of cyclinD1, MMP9, Bcl-2, and Bax via ERK1/2 signaling pathway. Furthermore, miR-96-5p exerted its function by directly binding to 3′-UTR of LDB2 and regulating expression of LDB2. miR-96-5p could promote the proliferation, invasion, and metastasis of H1299 cells.
Conclusion: These findings demonstrate that LDB2 can act as a new regulator to inhibit cell proliferation, invasion, and metastasis via the ERK1/2 signaling pathway, and miR-96-5p may be a potential promising molecular by targeting LDB2 in lung cancer
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