4,408 research outputs found

    Genetic diversity analysis and conservation of the Chinese herb Salvia miltiorrhiza collected from different geographic origins in China

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    Salvia miltiorrhiza is an economically important floral herb. However, little work has been conducted to further our understanding of the genetics of this herb. In this study, a representative set of germplasm ofS. miltiorrhiza populations was used to analyze genetic diversity using amplified fragment length polymorphism (AFLP) methodology. Twenty seven S. miltiorrhiza geographical populations from ten provinces in China were selected based on morphological diversity and geographic origin. A total of 528 unambiguous bands were identified by ten primer combinations of EcoRI +3 and MseI +3. Of those, 476 showed a clear polymorphism, representing 90% of the total bands. The samples showed different levels of similarity ranging between 0.504 and 0.789. The unweighted pair-group method with arithmetic averaging (UPGMA) cluster analysis conducted on polymorphic AFLP markers revealed that all these S. miltiorrhiza populations could be clearly distinguished into eight distinct groups as well as an intermediate. The population genetic diversity of S. miltiorrhiza revealed here had clear implications for conservation, management and use of the S. miltiorrhiza germplasm

    GaN nanorod light emitting diodes with suspended graphene transparent electrodes grown by rapid chemical vapor deposition

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    Ordered and dense GaN light emitting nanorods are studied with polycrystalline graphene grown by rapid chemical vapor deposition as suspended transparent electrodes. As the substitute of indium tin oxide, the graphene avoids complex processing to fill up the gaps between nanorods and subsequent surface flattening and offers high conductivity to improve the carrier injection. The as-fabricated devices have 32% improvement in light output power compared to conventional planar GaN-graphene diodes. The suspended graphene remains electrically stable up to 300 degrees C in air. The graphene can be obtained at low cost and high efficiency, indicating its high potential in future applications

    Heterogeneity of Paucigranulocytic Asthma: A Prospective Cohort Study with Hierarchical Cluster Analysis.

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    BACKGROUND: Asthma, a heterogeneous disease, can be divided into 4 inflammatory phenotypes using induced sputum cell counts-eosinophilic asthma (EA), neutrophilic asthma (NA), mixed granulocytic asthma, and paucigranulocytic asthma (PGA). Although research has focused on EA and NA, there is little known about PGA. OBJECTIVE: To study the heterogeneity of PGA and identify possible PGA clusters to guide clinical treatment. METHODS: Patients with PGA were grouped by hierarchical cluster analysis and enrolled into a prospective cohort study to validate the clusters, relative to future risk of asthma exacerbations in a real-world setting. Clusters were validated by tree analysis in a separate population. Finally, we explored PGA stability. RESULTS: Cluster analysis of 145 patients with PGA identified 3 clusters: cluster 1 (nĀ = 110, 75.9%) was "mild PGA," cluster 2 (nĀ = 20, 13.8%) was "PGA with psychological dysfunction and rhinoconjunctivitis and other allergic diseases," and cluster 3 (nĀ = 15, 10.3%) was "smoking-associated PGA." Cluster 3 had significantly increased risk of severe exacerbation (relative risk [RR]Ā = 6.43, PĀ = .01), emergency visit (RRĀ =Ā 8.61, PĀ = .03), and hospitalization (RRĀ = 12.94, PĀ <Ā .01). Results of the cluster analysis were successfully validated in an independent PGA population classified using decision tree analysis. Although PGA can transform into or develop from other phenotypes, 70% were stable over time. CONCLUSIONS: Among 3 identified PGA clusters, cluster 3 had a higher risk of severe exacerbation. PGA heterogeneity indicates the requirement of novel targeted interventions

    On the Complexity of Query Result Diversification

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    Query result diversification is a bi-criteria optimization problem for ranking query results. Given a database D, a query Q and a positive integer k, it is to find a set of k tuples from Q(D) such that the tuples are as relevant as possible to the query, and at the same time, as diverse as possible to each other. Subsets of Q(D) are ranked by an objective function defined in terms of relevance and diversity. Query result diversification has found a variety of applications in databases, information retrieval and operations research. This paper studies the complexity of result diversification for relational queries. We identify three problems in connection with query result diversification, to determine whether there exists a set of k tuples that is ranked above a bound with respect to relevance and diversity, to assess the rank of a given k-element set, and to count how many k-element sets are ranked above a given bound. We study these problems for a variety of query languages and for three objective functions. We establish the upper and lower bounds of these problems, all matching, for both combined complexity and data complexity. We also investigate several special settings of these problems, identifying tractable cases. 1

    AIM2 in regulatory T cells restrains autoimmune diseases

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    The inflammasome initiates innate defence and inflammatory responses by activating caspase-1 and pyroptotic cell death in myeloid cells1,2. It consists of an innate immune receptor/sensor, pro-caspase-1, and a common adaptor molecule, ASC. Consistent with their pro-inflammatory function, caspase-1, ASC and the inflammasome component NLRP3 exacerbate autoimmunity during experimental autoimmune encephalomyelitis by enhancing the secretion of IL-1Ī² and IL-18 in myeloid cells3ā€“6. Here we show that the DNA-binding inflammasome receptor AIM27ā€“10 has a T cell-intrinsic and inflammasome-independent role in the function of T regulatory (Treg) cells. AIM2 is highly expressed by both human and mouse Treg cells, is induced by TGFĪ², and its promoter is occupied by transcription factors that are associated with Treg cells such as RUNX1, ETS1, BCL11B and CREB. RNA sequencing, biochemical and metabolic analyses demonstrated that AIM2 attenuates AKT phosphorylation, mTOR and MYC signalling, and glycolysis, but promotes oxidative phosphorylation of lipids in Treg cells. Mechanistically, AIM2 interacts with the RACK1ā€“PP2A phosphatase complex to restrain AKT phosphorylation. Lineage-tracing analysis demonstrates that AIM2 promotes the stability of Treg cells during inflammation. Although AIM2 is generally accepted as an inflammasome effector in myeloid cells, our results demonstrate a T cell-intrinsic role of AIM2 in restraining autoimmunity by reducing AKTā€“mTOR signalling and altering immune metabolism to enhance the stability of Treg cells

    Measurement of \psip Radiative Decays

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    Using 14 million psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^- pi^+pi^-, gamma K^{*0} K^- pi^+ +c.c., gamma K^{*0}\bar K^{*0}, gamma pi^+pi^- p pbar, gamma 2(K^+K^-), gamma 3(pi^+pi^-), and gamma 2(pi^+pi^-)K^+K^- with the invariant mass of hadrons below 2.9GeV/c^2. We also report branching fractions of psi(2S) decays into 2(pi^+pi^-) pi^0, omega pi^+pi^-, omega f_2(1270), b_1^\pm pi^\mp, and pi^0 2(pi^+pi^-) K^+K^-.Comment: 5 pages, 4 figure

    Measurements of J/ĻˆJ/\psi and Ļˆ(2S)\psi(2S) decays into Ī›Ī›Ė‰Ļ€0\Lambda \bar{\Lambda}\pi^0 and Ī›Ī›Ė‰Ī·\Lambda \bar{\Lambda}\eta

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    Using 58 million J/ĻˆJ/\psi and 14 million Ļˆ(2S)\psi(2S) events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays J/ĻˆJ/\psi and Ļˆ(2S)ā†’Ī›Ī›Ė‰Ļ€0\psi(2S) \to \Lambda \bar{\Lambda}\pi^0 and Ī›Ī›Ė‰Ī·\Lambda \bar{\Lambda}\eta are measured. For the isospin violating decays, the upper limits are determined to be B(J/Ļˆā†’Ī›Ī›Ė‰Ļ€0)<6.4Ɨ10āˆ’5{\cal B}(J/\psi \to \Lambda \bar{\Lambda}\pi^0)<6.4\times 10^{-5} and B(Ļˆ(2S)ā†’Ī›Ī›Ė‰Ļ€0)<4.9Ɨ10āˆ’5{\cal B}(\psi(2S) \to \Lambda \bar{\Lambda}\pi^0)<4.9\times 10^{-5} at the 90% confidence level. The isospin conserving process J/Ļˆā†’Ī›Ī›Ė‰Ī·J/\psi \to \Lambda \bar{\Lambda}\eta is observed for the first time, and its branching fraction is measured to be B(J/Ļˆā†’Ī›Ī›Ė‰Ī·)=(2.62Ā±0.60Ā±0.44)Ɨ10āˆ’4{\cal B}(J/\psi \to \Lambda \bar{\Lambda}\eta)=(2.62\pm 0.60\pm 0.44)\times 10^{-4}, where the first error is statistical and the second one is systematic. No Ī›Ī›Ė‰Ī·\Lambda \bar{\Lambda}\eta signal is observed in Ļˆ(2S)\psi(2S) decays, and B(Ļˆ(2S)ā†’Ī›Ī›Ė‰Ī·)<1.2Ɨ10āˆ’4{\cal B}(\psi(2S) \to \Lambda \bar{\Lambda}\eta)<1.2\times 10^{-4} is set at the 90% confidence level. Branching fractions of J/ĻˆJ/\psi decays into Ī£+Ļ€āˆ’barĪ›\Sigma^+ \pi^- bar{\Lambda} and Ī£Ė‰āˆ’Ļ€+Ī›\bar{\Sigma}^- \pi^+ \Lambda are also reported, and the sum of these branching fractions is determined to be B(J/Ļˆā†’Ī£+Ļ€āˆ’Ī›Ė‰+c.c.)=(1.52Ā±0.08Ā±0.16)Ɨ10āˆ’3{\cal B}(J/\psi \to \Sigma^+\pi^- \bar{\Lambda} + c.c.)=(1.52\pm 0.08\pm 0.16)\times 10^{-3}.Comment: 7 pages, 10 figures. Phys.Rev.D comments considere
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