1,200 research outputs found

    Does Hawking effect always degrade fidelity of quantum teleportation in Schwarzschild spacetime?

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    Previous studies have shown that the Hawking effect always destroys quantum correlations and the fidelity of quantum teleportation in the Schwarzschild black hole. Here, we investigate the fidelity of quantum teleportation of Dirac fields between users in Schwarzschild spacetime. We find that, with the increase of the Hawking temperature, the fidelity of quantum teleportation can monotonically increase, monotonically decrease, or non-monotonically increase, depending on the choice of the initial state, which means that the Hawking effect can create net fidelity of quantum teleportation. This striking result banishes the extended belief that the Hawking effect of the black hole can only destroy the fidelity of quantum teleportation. We also find that quantum steering cannot fully guarantee the fidelity of quantum teleportation in Schwarzschild spacetime. This new unexpected source may provide a new idea for the experimental evidence of the Hawking effect.Comment: 21 pages, 3 figures, accepted for publication in JHE

    Gaussian quantum steering in multi-event horizon spacetime

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    We study Gaussian quantum steering in the Schwarzschild-de Sitter (SdS) spacetime which is endowed with both a black hole event horizon (BEH) and a cosmological event horizon (CEH), giving rise to two different Hawking temperatures. It is shown that the Hawking effect of the black hole always reduces the quantum steering, but the Hawking effect of the expanding universe not always plays the same role. For the first time, we find that the Hawking effect can improve quantum steering. We also find that the observer who locates in the BEH has stronger steerability than the observer who locates in CEH. Further, we study the steering asymmetry, and the conditions for two-way, one-way and no-way steering in the SdS spacetime. Finally, we study the Gaussian quantum steering in the scenario of effective equilibrium temperature. We show that quantum steering reduces monotonically with the effective temperature but now increases monotonically with the Hawking temperature of the black hole, which banishes the belief that the Hawking effect can only destroy quantum steering.Comment: 18 pages, 5 figure

    catena-Poly[silver(I)-μ-acridine-9-carboxyl­ato-κ3 N:O,O′]

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    In the title coordination polymer, [Ag(C14H8NO2)]n, the AgI cation is coordinated by two O atoms and one N atom from two symmetry-related acridine-9-carboxyl­ate ligands in a distorted trigonal-planar geometry. The metal atoms are connected by the ligands to form chains running parallel to the b axis. π–π stacking inter­actions [centroid-to-centroid distances 3.757 (2)–3.820 (2) Å] and weak Ag⋯O inter­actions further link the chains to form a layer network parallel to the ab plane. The AgI cation is disordered over two positions, with refined site-occupancy factors of 0.73 (3):0.27 (3)

    Suppression of Long Non-Coding RNA LINC00652 Restores Sevoflurane-Induced Cardioprotection Against Myocardial Ischemia-Reperfusion Injury by Targeting GLP-1R Through the cAMP/PKA Pathway in Mice

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    Background/Aims: Long non-coding RNA (lncRNA) and glucagon-like peptide 1 receptor (GLP-1R) are crucial for heart development and for adult heart structural maintenance and function. Herein, we performed a study to explore the effect of lncRNA LINC00652 (LINC00652) on myocardial ischemia-reperfusion (I/R) injury by targeting GLP-1R through the cyclic adenosine monophosphate-protein kinase A (cAMP/PKA) pathway. Methods: Bioinformatics software was used to screen the long-chain non-coding RNAs associated with myocardial ischemia-reperfusion and to predict target genes. The mRNA and protein levels of LINC00652, GLP-1R and CREB were detected by RT-qPCR and western blotting. In order to identify the interaction between LINC00652 and myocardial I/R injury, the cardiac function, the hemodynamic changes, the pathological changes of the myocardial tissues, the myocardial infarct size, and the apoptosis of myocardial cells of mice were measured. Meanwhile, the levels of serum IL-1β and TNF-α were detected. Results: LINC00652 was overexpressed in the myocardial cells of mice with myocardial I/R injury. GLP-1R is the target gene of LINC00652. We also determined higher levels of LINC00652 and GLP-1R in the I/R modeled mice. Additionally, si-LINC00652 decreased cardiac pathology, infarct size, apoptosis rates of myocardial cells, and levels of IL-1β and TNF-α, and increased GLP-1R expression cardiac function, normal hemodynamic index, and the expression and phosphorylation of GLP-1R and CREB proteins. Conclusion: Taken together, our key findings of the present highlight LINC00652 inhibits the activation of the cAMP/PKA pathway by targeting GLP-1R to reduce the protective effect of sevoflurane on myocardial I/R injury in mice

    DNA barcoding of Scomberomorus (Scombridae, Actinopterygii) reveals cryptic diversity and misidentifications

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    The genus Scomberomorus is economically important; however, the taxonomic status and phylogenetic relationships in this genus are not clearly resolved, making it difficult to effectively protect and exploit fish resources. To clarify the taxonomic status of Scomberomorus species, mitochondrial cytochrome c oxidase I (COI) gene sequences of 150 samples were analyzed. The average genetic distance among 14 species was approximately 11 times greater than the distances within species, in accordance with the ‘10× rule’ of species identification. Five of the 14 species did not form monophyletic clades based on a Bayesian inference gene tree. The application of four DNA-based species delimitation methods (automatic barcode gap discovery, barcode index numbers, Poisson tree process, and the K/θ method) yielded several key results. (1) Cryptic species were detected within Scomberomorus commerson. (2) A Scomberomorus queenslandicus sample from Australia was misidentified as S. commerson in the Barcode of Life Data System (BOLD). (3) Specimens originally identified as Scomberomorus guttatus was differentiated into four OTUs or species, two in the Yellow, South China, and Java seas, and two in geographically distant areas, one each in the Arabian Sea and the Bay of Bengal. (4) Six specimens from South Africa originally identified as S. plurilineatus most likely do not belong to the species. (5) Specimens identified as S. maculatus and S. regalis were conspecific; however, introgression cannot be ruled out. Our findings revealed cryptic diversity and difficulties in morphological identification of species in the genus Scomberomorus. This study provides scientifically based support for the conservation of germplasm resources of the genus Scomberomorus

    A novel procedure for precise quantification of Schistosoma japonicum eggs in bovine feces

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    Schistosomiasis japonica is a zoonosis with a number of mammalian species acting as reservoir hosts, including water buffaloes which can contribute up to 75% to human transmission in the People's Republic of China. Determining prevalence and intensity of Schistosoma japonicum in mammalian hosts is important for calculating transmission rates and determining environmental contamination. A new procedure, the formalin-ethyl acetate sedimentation-digestion (FEA-SD) technique, for increased visualization of S. japonicum eggs in bovine feces, is described that is an effective technique for identifying and quantifying S. japonicum eggs in fecal samples from naturally infected Chinese water buffaloes and from carabao (water buffalo) in the Philippines. The procedure involves filtration, sedimentation, potassium hydroxide digestion and centrifugation steps prior to microscopy. Bulk debris, including the dense cellulosic material present in bovine feces, often obscures schistosome eggs with the result that prevalence and infection intensity based on direct visualization cannot be made accurately. This technique removes nearly 70% of debris from the fecal samples and renders the remaining debris translucent. It allows improved microscopic visualization of S. japonicum eggs and provides an accurate quantitative method for the estimation of infection in bovines and other ruminant reservoir hosts. We show that the FEA-SD technique could be of considerable value if applied as a surveillance tool for animal reservoirs of S. japonicum, particularly in areas with low to high infection intensity, or where, following control efforts, there is suspected elimination of schistosomiasis japonica.This work was partially supported by the following grants: The National High Technology Research and Development Program of China (grant No. 2007AA02Z153), and National Science and Technology Major Program (grant Nos. 2009ZX10004-302, 2008ZX10004-011)

    Cell surface sialylation and fucosylation are regulated by the cell recognition molecule L1 via PLCγ and cooperate to modulate embryonic stem cell survival and proliferation

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    AbstractCell surface glycosylation patterns are markers of cell type and status. However, the mechanisms regulating surface glycosylation patterns remain unknown. Using a panel of carbohydrate markers, we have shown that cell surface sialylation and fucosylation are upregulated in L1-transfected embryonic stem cells (L1-ESCs). Consistently, the mRNA levels of sialyltransferase ST6Gal1 and ST3Gal4, and fucosyltransferase FUT9 were significantly increased in L1-transfected ESCs. Activation of L1 signaling promoted cell survival and inhibited cell proliferation. ShRNAs knocking down FUT9, ST6Gal1 and ST3Gal4 blocked these effects. A phospholipase Cγ (PLCγ) inhibitor and shRNA reduced ST6Gal1, ST3Gal4 and FUT9 mRNA levels in the L1-ESCs. Thus, embryonic stem cell surface sialylation and fucosylation are regulated via PLCγ by L1, with which they cooperate to modulate cell survival and proliferation

    Curcumin Protects Intestinal Mucosal Barrier Function of Rat Enteritis via Activation of MKP-1 and Attenuation of p38 and NF-κB Activation

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    BACKGROUND: Intestinal mucosa barrier (IMB) dysfunction results in many notorious diseases for which there are currently few effective treatments. We studied curcumin's protective effect on IMB and examined its mechanism by using methotrexate (MTX) induced rat enteritis model and lipopolysaccharide (LPS) treated cell death model. METHODOLOGY/PRINCIPAL FINDINGS: Curcumin was intragastrically administrated from the first day, models were made for 7 days. Cells were treated with curcumin for 30 min before exposure to LPS. Rat intestinal mucosa was collected for evaluation of pathological changes. We detected the activities of D-lactate and diamine oxidase (DAO) according to previous research and measured the levels of myeloperoxidase (MPO) and superoxide dismutase (SOD) by colorimetric method. Intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were determined by RT-PCR and IL-10 production was determined by ELISA. We found Curcumin decreased the levels of D-lactate, DAO, MPO, ICAM-1, IL-1β and TNF-α, but increased the levels of IL-10 and SOD in rat models. We further confirmed mitogen-activated protein kinase phosphatase-1 (MKP-1) was activated but phospho-p38 was inhibited by curcumin by western blot assay. Finally, NF-κB translocation was monitored by immunofluorescent staining. We showed that curcumin repressed I-κB and interfered with the translocation of NF-κB into nucleus. CONCLUSIONS/SIGNIFICANCE: The effect of curcumin is mediated by the MKP-1-dependent inactivation of p38 and inhibition of NF-κB-mediated transcription. Curcumin, with anti-inflammatory and anti-oxidant activities may be used as an effective reagent for protecting intestinal mucosa barrier and other related intestinal diseases

    ANTIOXIDANT AND SGC-7901 CELL INHIBITION ACTIVITIES OF RHIZOMA DIOSCOREAE BULBIFERAE. ETHANOL EXTRACTS

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    The objective of this research was to study the pharmacology of Dioscorea bulbifera L. on antioxidant and anticancer activity. Alcohol extracts of Dioscorea bulbifera L. were made out by different concentration alcohol; they were tested by Hydroxyl radical scavenging test, reducing capacity test and total antioxidant capacity test. In the anticancer test, MTT test was used to study the inhibition rate. The results told that 70% ethanol extracts could scavenge most DPPH• at 2mg/ml. The rate was 55.2%; 80% ethanol extract could clear the most •OH. The clearance rate was 51.2%. 80% ethanol crude extracts possessed the strongest reducing ability per gram of the extract equal to 49.3μmol Fe2 +. Different concentrations of the extracts could inhibit the proliferation of line SGC-7901, and with the concentration increased, the inhibition rate was gradually increased
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