1,271 research outputs found

    Anion-Responsive Metallopolymer Hydrogels for Healthcare Applications

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    Metallopolymers combine a processable, versatile organic polymeric skeleton with functional metals, providing multiple functions and methodologies in materials science. Taking advantage of cationic cobaltocenium as the key building block, organogels could be simply switched to hydrogels via a highly efficient ion exchange. With the unique ionic complexion ability, cobaltocenium moieties provide a robust soft substrate for recycling antibiotics from water. The essential polyelectrolyte nature offers the metallopolymer hydrogels to kill multidrug resistant bacteria. The multifunctional characteristics of these hydrogels highlight the potential for metallopolymers in the field of healthcare and environmental treatment

    Anion-Responsive Metallopolymer Hydrogels for Healthcare Applications

    Get PDF
    Metallopolymers combine a processable, versatile organic polymeric skeleton with functional metals, providing multiple functions and methodologies in materials science. Taking advantage of cationic cobaltocenium as the key building block, organogels could be simply switched to hydrogels via a highly efficient ion exchange. With the unique ionic complexion ability, cobaltocenium moieties provide a robust soft substrate for recycling antibiotics from water. The essential polyelectrolyte nature offers the metallopolymer hydrogels to kill multidrug resistant bacteria. The multifunctional characteristics of these hydrogels highlight the potential for metallopolymers in the field of healthcare and environmental treatment

    On a universal photonic tunnelling time

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    We consider photonic tunnelling through evanescent regions and obtain general analytic expressions for the transit (phase) time τ\tau (in the opaque barrier limit) in order to study the recently proposed ``universality'' property according to which τ\tau is given by the reciprocal of the photon frequency. We consider different physical phenomena (corresponding to performed experiments) and show that such a property is only an approximation. In particular we find that the ``correction'' factor is a constant term for total internal reflection and quarter-wave photonic bandgap, while it is frequency-dependent in the case of undersized waveguide and distributed Bragg reflector. The comparison of our predictions with the experimental results shows quite a good agreement with observations and reveals the range of applicability of the approximated ``universality'' property.Comment: RevTeX, 8 pages, 4 figures, 1 table; subsection added with a new experiment analyzed, some other minor change

    Continuous variable polarization entanglement, experiment and analysis

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    We generate and characterise continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan {\it et al.}\cite{Duan00} and the Einstein-Podolsky-Rosen paradox criteria proposed by Reid and Drummond\cite{Reid88}, to Stokes operators; and use them to charactise the entanglement. Our results for the Einstein-Podolsky-Rosen paradox criteria are visualised in terms of uncertainty balls on the Poincar\'{e} sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound 3\sqrt{3} times more stringent than for the quadrature entanglement.Comment: 12 pages, 13 figure

    Barcoding utility in a mega-diverse, cross-continental genus: keeping pace with Cyrtodactylus geckos

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    Over the past decade, DNA barcoding has become a staple of low-cost molecular systematic investigations. The availability of universal primers and subsidized sequencing projects (PolarBOL, SharkBOL, SpongeBOL) have driven this popularity, often without appropriate investigation into the utility of barcoding data for the taxonomic group of interest. Here, our primary aim is to determine the phylogenetic value of DNA barcoding (mitochondrial locus COI) within the gecko genus Cyrtodactylus. With >40 new species described since last systematic investigation, Cyrtodactylus represents one of the most diverse extant squamate genera, and their contemporary distribution spans the Indian subcontinent, eastward through Indochina, and into AustraloPapua. The complex biogeographic history of this group, and morphology-only designation of many species have complicated our phylogenetic understanding of Cyrtodactylus. To highlight the need for continued inclusive molecular assessment, we use Vietnamese Cyrtodactylus as a case study showing the geopolitically paraphyletic nature of their history. We compare COI to the legacy marker ND2, and discuss the value of COI as an interspecific marker, as well as its shortcomings at deeper evolutionary scales. We draw attention back to the Cold Code as a subsidized method for incorporating molecular methods into species descriptions in the effort to maintain accurate phylogenies.This work was supported by the National Natural Science Foundation of China (NSFC grant no. 31090251 to Y.Z.), the Ministry of Science and Technology of China (MOST no. 2012FY110800 to W.W.), and the Joint Grant of CAS Kunming Branch and Guizhou Academy of Sciences (CASKMB no. 2014-001 to W.W.). This work was also supported by the Animal Branch of the Germplasm Bank of Wild Species, Chinese Academy of Sciences (the Large Research Infrastructure Funding, Funding code: GBOWS to W.W. and Y.Z.), an Australian American Association Fellowship to I.G.B, and National Science Foundation (USA) grants DEB 0844523 and EF 1241885 (sub-award 13-0632) to A.M.B

    Ginseng and Ganoderma lucidum Use after Breast Cancer Diagnosis and Quality of Life: A Report from the Shanghai Breast Cancer Survival Study

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    Objective: To evaluate associations between quality of life (QOL) and use of ginseng and Ganoderma lucidum (G. lucidum) among breast cancer survivors. Methods: Included in this study were 4,149 women with breast cancer who participated in the Shanghai Breast Cancer Survival Study. Ginseng use was assessed at 6-, 18-, and 36-month post-diagnosis surveys; G. lucidum use was assessed at the 6- and 36-month surveys. QOL was evaluated at the 6- and 36-month surveys. Multiple linear regression models were used to examine associations between ginseng and G.lucidum use and QOL assessed at the 36-month survey, with adjustment for potential confounders and baseline QOL. Results: At 6 months post-diagnosis, 14.2 % of participants reported regular use of ginseng and 58.8 % reported use of G. lucidum. We found no significant associations between ginseng use at 6, 18, and 36 months post-diagnosis and participants’ total QOL score or individual scores for psychological, physical, or social well-being. Post-diagnosis G. lucidum use was positively associated with social well-being (adjusted mean difference: 1.26; 95 % CI: 0.66, 1.86), but was inversely associated with physical well-being (adjusted mean difference: 21.16; 95 % CI: 21.86, 20.47) with a dose-response pattern observed for cumulative number of times of use (P for trend,0.001 for both). Conclusion: We found no evidence that post-diagnosis ginseng use improved the QOL of breast cancer survivors. Post

    An Unusual Topological Structure of the HIV-1 Rev Response Element

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    SummaryNuclear export of unspliced and singly spliced viral mRNA is a critical step in the HIV life cycle. The structural basis by which the virus selects its own mRNA among more abundant host cellular RNAs for export has been a mystery for more than 25 years. Here, we describe an unusual topological structure that the virus uses to recognize its own mRNA. The viral Rev response element (RRE) adopts an “A”-like structure in which the two legs constitute two tracks of binding sites for the viral Rev protein and position the two primary known Rev-binding sites ∼55 Å apart, matching the distance between the two RNA-binding motifs in the Rev dimer. Both the legs of the “A” and the separation between them are required for optimal RRE function. This structure accounts for the specificity of Rev for the RRE and thus the specific recognition of the viral RNA

    Early Planet Formation in Embedded Disks (eDisk) X: Compact Disks, Extended Infall, and a Fossil Outburst in the Class I Oph IRS43 Binary

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    We present the first results from the Early Planet Formation in Embedded Disks (eDisk) ALMA Large Program toward Oph IRS43, a binary system of solar mass protostars. The 1.3 mm dust continuum observations resolve a compact disk, ~6au radius, around the northern component and show that the disk around the southern component is even smaller, <~3 au. CO, 13CO, and C18O maps reveal a large cavity in a low mass envelope that shows kinematic signatures of rotation and infall extending out to ~ 2000au. An expanding CO bubble centered on the extrapolated location of the source ~130 years ago suggests a recent outburst. Despite the small size of the disks, the overall picture is of a remarkably large and dynamically active region.Comment: Paper 10 of the ALMA eDisk Large Program. Accepted for publication in Ap

    Early Planet Formation in Embedded Disks (eDisk). VIII. A Small Protostellar Disk around the Extremely Low-Mass and Young Class 0 Protostar, IRAS 15398-3359

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    Protostellar disks are a ubiquitous part of the star formation process and the future sites of planet formation. As part of the Early Planet Formation in Embedded Disks (eDisk) large program, we present high-angular resolution dust continuum (40\sim40\,mas) and molecular line (150\sim150\,mas) observations of the Class 0 protostar, IRAS 15398-3359. The dust continuum is small, compact, and centrally peaked, while more extended dust structures are found in the outflow directions. We perform a 2D Gaussian fitting to find the deconvolved size and 2σ2\sigma radius of the dust disk to be 4.5×2.8au4.5\times2.8\,\mathrm{au} and 3.8au3.8\,\mathrm{au}, respectively. We estimate the gas+dust disk mass assuming optically thin continuum emission to be 0.61.8Mjup0.6-1.8\,M_\mathrm{jup}, indicating a very low-mass disk. The CO isotopologues trace components of the outflows and inner envelope, while SO traces a compact, rotating disk-like component. Using several rotation curve fittings on the PV diagram of the SO emission, the lower limits of the protostellar mass and gas disk radius are 0.022M0.022\,M_\odot and 31.2au31.2\,\mathrm{au} from our Modified 2 single power-law fitting. A conservative upper limit of the protostellar mass is inferred to be 0.1M0.1\,M_\odot. The protostellar mass-accretion rate and the specific angular momentum at the protostellar disk edge are found to be between 1.36.1×106Myr11.3-6.1\times10^{-6}\,M_\odot\,\mathrm{yr^{-1}} and 1.23.8×104kms1pc1.2-3.8\times10^{-4}\,\mathrm{km\,s^{-1}\,pc}, respectively, with an age estimated between 0.47.5×1040.4-7.5\times10^{4}\,yr. At this young age with no clear substructures in the disk, planet formation would likely not yet have started. This study highlights the importance of high-resolution observations and systematic fitting procedures when deriving dynamical properties of deeply embedded Class 0 protostars.Comment: 28 pages, 16 figures. Accepted for publication in ApJ as one of the first-look papers of the eDisk ALMA Large Progra
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