319 research outputs found

    A Massive Protostar Embedded in the Scuba Core JCMT 18354-0649S

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    We report the discovery of an extremely red object embedded in the massive SCUBA core JCMT 18354-0649S. This object is not associated with any known radio or far-IR source, though it appears in Spitzer IRAC data obtained as part of the GLIMPSE survey. At shorter wavelengths, this embedded source exhibits an extreme color, K – L' = 6.7. At an assumed distance of 5.7 kpc, this source has a near-IR luminosity of ~1000 L_☉. Its spectral energy distribution (SED) rises sharply from 2.1 μm to 8 μm, similar to that of a Class 0 young stellar object. Theoretical modeling of the SED indicates that the central star has a mass of 6-12 M_☉, with an optical extinction of more than 30. As both inflow and outflow motions are present in JCMT 18354-0649S, we suggest that this deeply embedded source is (1) a massive protostar in the early stages of accretion, and (2) the driving source of a massive molecular outflow evident in HCN J = 3-2 profiles observed toward this region

    Generating CCG Categories

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    Previous CCG supertaggers usually predict categories using multi-class classification. Despite their simplicity, internal structures of categories are usually ignored. The rich semantics inside these structures may help us to better handle relations among categories and bring more robustness into existing supertaggers. In this work, we propose to generate categories rather than classify them: each category is decomposed into a sequence of smaller atomic tags, and the tagger aims to generate the correct sequence. We show that with this finer view on categories, annotations of different categories could be shared and interactions with sentence contexts could be enhanced. The proposed category generator is able to achieve state-of-the-art tagging (95.5% accuracy) and parsing (89.8% labeled F1) performances on the standard CCGBank. Furthermore, its performances on infrequent (even unseen) categories, out-of-domain texts and low resource language give promising results on introducing generation models to the general CCG analyses.Comment: Accepted by AAAI 202

    Properties of localization in silicon-based lattice periodicity breaking photonic crystal waveguides

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    The light localization effects in silicon photonic crystal cavities at different disorder degrees have been studied using the finite difference time domain (FDTD) method in this paper. Numerical results showed that localization occurs and enhancement can be gained in the region of the cavity under certain conditions. The stabilities of the localization effects due to the structural perturbations have been investigated too. Detailed studies showed that when the degree of structural disorder is small(about 10%), the localization effects are stable, the maximum enhancement factor can reach 16.5 for incident wavelength of 785 nm and 23 for 850 nm in the cavity, with the degree of disorder about 8%. The equivalent diameter of the localized spot is almost constant at different disorder degrees, approximating to {\lambda \mathord{/ {\vphantom {\lambda 7}} \kern-\nulldelimiterspace} 7}λ/7, which turned out to be independent on the structural perturbation

    Tumor-directed gene therapy in mice using a composite nonviral gene delivery system consisting of the piggyBac transposon and polyethylenimine

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    <p>Abstract</p> <p>Background</p> <p>Compared with viral vectors, nonviral vectors are less immunogenic, more stable, safer and easier to replication for application in cancer gene therapy. However, nonviral gene delivery system has not been extensively used because of the low transfection efficiency and the short transgene expression, especially <it>in vivo</it>. It is desirable to develop a nonviral gene delivery system that can support stable genomic integration and persistent gene expression <it>in vivo</it>. Here, we used a composite nonviral gene delivery system consisting of the <it>piggyBac </it>(PB) transposon and polyethylenimine (PEI) for long-term transgene expression in mouse ovarian tumors.</p> <p>Methods</p> <p>A recombinant plasmid PB [Act-RFP, HSV-tk] encoding both the herpes simplex thymidine kinase (HSV-tk) and the monomeric red fluorescent protein (mRFP1) under PB transposon elements was constructed. This plasmid and the PBase plasmid were injected into ovarian cancer tumor xenografts in mice by <it>in vivo </it>PEI system. The antitumor effects of HSV-tk/ganciclovir (GCV) system were observed after intraperitoneal injection of GCV. Histological analysis and TUNEL assay were performed on the cryostat sections of the tumor tissue.</p> <p>Results</p> <p>Plasmid construction was confirmed by PCR analysis combined with restrictive enzyme digestion. mRFP1 expression could be visualized three weeks after the last transfection of pPB/TK under fluorescence microscopy. After GCV admission, the tumor volume of PB/TK group was significantly reduced and the tumor inhibitory rate was 81.96% contrasted against the 43.07% in the TK group. Histological analysis showed that there were extensive necrosis and lymphocytes infiltration in the tumor tissue of the PB/TK group but limited in the tissue of control group. TUNEL assays suggested that the transfected cells were undergoing apoptosis after GCV admission <it>in vivo</it>.</p> <p>Conclusion</p> <p>Our results show that the nonviral gene delivery system coupling PB transposon with PEI can be used as an efficient tool for gene therapy in ovarian cancer.</p

    Effect of miR-181c-5p on vasculogenic mimicry in ovarian cancer stem-like cells and its mechanism

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    Objective To investigate the effect of miR-181c-5p on vasculogenic mimicry (VM) in ovarian cancer stem-like cells (OCS-LCs) and its mechanism. Methods OVCAR3 cells were induced into OCS-LCs by serum-free suspension culture. OVCAR3 cells were divided into groups A, B, and C and were transfected with NC-miR-181c-5p, siRNA-miR-181c-5p, and pRNA-miR-181c-5p, respectively. The sphere-forming experiment was used to assess the sphere formation ability of groups A, B, and C. RT-qPCR was used to measure the relative expression level of miR-181c-5p in cells of groups A, B, and C, and Western blot was used to measure the relative protein expression levels of Oct-4, Nanog, HIF-1α, and VEGF in cells of groups A, B, and C. CCK-8 assay was used to measure the viability of cells in groups A, B, and C, and the three-dimensional culture experiment was used to measure the angiogenesis rate of groups A, B, and C. Results OVCAR3 cells were successfully induced into OCS-LCs. RT-qPCR showed that group B had a significantly lower relative expression level of miR-181c-5p than group A, and group C had a significantly higher relative expression level than group A (t=2.25,8.68,P&lt;0.05). The sphere-forming experiment showed that compared with group A, group B had significant decreases in sphere-forming cycle, and increases in maximum sphere diameter, and sphere-forming rate, and compared group A with group C, these indicators had the same changes (t=5.56-33.66,P&lt;0.05). Western blot showed that compared with group A, group B had significant increases in the relative protein expression levels of Oct-4, Nanog, HIF-1α, and VEGF, and compared with group C, group A had significant increases in the relative expression levels of these proteins (t=4.51-56.15,P&lt;0.05). CCK-8 assay showed that group B had a significantly higher cell viability than group A, and group C had a significantly lower cell viability than group A (F=97.70-281.80,P&lt;0.05). The three-dimensional culture experiment showed that group B had a significant increase in angiogenesis rate compared with group A, and compared with group C, group A had a significant increase in angiogenesis rate (t=3.70,18.67,P&lt;0.05). Conclusion This study shows that miR-181c-5p may inhibit VM formation in OCS-LCs by reducing the protein expression levels of HIF-1α and VEGF in cells

    Long-Term Protection of CHBP Against Combinational Renal Injury Induced by Both Ischemia-Reperfusion and Cyclosporine A in Mice.

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    Renal ischemia-reperfusion (IR) injury and cyclosporine A (CsA) nephrotoxicity affect allograft function and survival. The prolonged effects and underlying mechanisms of erythropoietin derived cyclic helix B peptide (CHBP) and/or caspase-3 small interfering RNA (CASP-3siRNA) were investigated in mouse kidneys, as well as kidney epithelial cells (TCMK-1), subjected to transplant-related injuries. Bilateral renal pedicles were clamped for 30 min followed by reperfusion for 2 and 8 weeks, with/without 35 mg/kg CsA gavage daily and/or 24 nmol/kg CHBP intraperitoneal injection every 3 days. The ratio of urinary albumin to creatinine was raised by IR injury, further increased by CsA and lowered by CHBP at 2, 4, 6 and 8 weeks, whereas the level of SCr was not significantly affected. Similar change trends were revealed in tubulointerstitial damage and fibrosis, HMGB1 and active CASP-3 protein. Increased apoptotic cells in IR kidneys were decreased by CsA and CHBP at 2 and/or 8 weeks. p70 S6 kinase and mTOR were reduced by CsA with/without CHBP at 2 weeks, so were S6 ribosomal protein and GSK-3β at 8 weeks, with reduced CASP-3 at both time points. CASP-3 was further decreased by CHBP in IR or IR + CsA kidneys at 2 or 8 weeks. Furthermore, in TCMK-1 cells CsA induced apoptosis was decreased by CHBP and/or CASP-3siRNA treatment. Taken together, CHBP predominantly protects kidneys against IR injury at 2 weeks and/or CsA nephrotoxicity at 8 weeks, with different underlying mechanisms. Urinary albumin/creatinine is a good biomarker in monitoring the progression of transplant-related injuries. CsA divergently affects apoptosis in kidneys and cultured kidney epithelial cells, in which CHBP and/or CASP-3siRNA reduces inflammation and apoptosis

    Generation of True Quantum Random Numbers with On-Demand Probability Distributions via Single-Photon Quantum Walks

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    Random numbers are at the heart of diverse fields, ranging from simulations of stochastic processes to classical and quantum cryptography. The requirement for true randomness in these applications has motivated various proposals for generating random numbers based on the inherent randomness of quantum systems. The generation of true random numbers with arbitrarily defined probability distributions is highly desirable for applications, but it is very challenging. Here we show that single-photon quantum walks can generate multi-bit random numbers with on-demand probability distributions, when the required ``coin'' parameters are found with the gradient descent (GD) algorithm. Our theoretical and experimental results exhibit high fidelity for various selected distributions. This GD-enhanced single-photon system provides a convenient way for building flexible and reliable quantum random number generators. Multi-bit random numbers are a necessary resource for high-dimensional quantum key distribution

    Redactable Signatures for Signed CDA Documents

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    [[abstract]]The Clinical Document Architecture, introduced by Health Level Seven, is a XML-based standard intending to specify the encoding, structure, and semantics of clinical documents for exchange. Since the clinical document is in XML form, its authenticity and integrity could be guaranteed by the use of the XML signature published by W3C. While a clinical document wants to conceal some personal or private information, the document needs to be redacted. It makes the signed signature of the original clinical document not be verified. The redactable signature is thus proposed to enable verification for the redacted document. Only a little research does the implementation of the redactable signature, and there still not exists an appropriate scheme for the clinical document. This paper will investigate the existing web-technologies and find a compact and applicable model to implement a suitable redactable signature for the clinical document viewer.[[notice]]補正完畢[[incitationindex]]SC

    CRISPR/Cas12a-based approaches for efficient and accurate detection of Phytophthora ramorum

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    IntroductionPhytophthora ramorum is a quarantine pathogen that causes leaf blight and shoot dieback of the crown, bark cankers and death on a number of both ornamental and forest trees, especially in North America and northern Europe, where it has produced severe outbreaks. Symptoms caused by P. ramorum can be confused with those by other Phytophthora and fungal species. Early and accurate detection of the causal pathogen P. ramorum is crucial for effective prevention and control of Sudden Oak Death.MethodsIn this study, we developed a P. ramorum detection technique based on a combination of recombinase polymerase amplification (RPA) with CRISPR/Cas12a technology (termed RPACRISPR/ Cas12a).ResultsThis novel method can be utilized for the molecular identification of P. ramorum under UV light and readout coming from fluorophores, and can specifically detect P. ramorum at DNA concentrations as low as 100 pg within 25 min at 37°C.DiscussionWe have developed a simple, rapid, sensitive, unaided-eye visualization, RPA CRISPR/Cas12a-based detection system for the molecular identification of P. ramorum that does not require technical expertise or expensive ancillary equipment. And this system is sensitive for both standard laboratory samples and samples from the field
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