904 research outputs found

    Observation of eight-photon entanglement

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    Using ultra-bright sources of pure-state entangled photons from parametric down conversion, an eight-photon interferometer and post-selection detection, we demonstrate the ability to experimentally manipulate eight individual photons and report the creation of an eight-photon Schr\"odinger cat state with an observed fidelity of 0.708Β±0.0160.708 \pm 0.016.Comment: 6 pages, 4 figure

    Hidden attractors in fundamental problems and engineering models

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    Recently a concept of self-excited and hidden attractors was suggested: an attractor is called a self-excited attractor if its basin of attraction overlaps with neighborhood of an equilibrium, otherwise it is called a hidden attractor. For example, hidden attractors are attractors in systems with no equilibria or with only one stable equilibrium (a special case of multistability and coexistence of attractors). While coexisting self-excited attractors can be found using the standard computational procedure, there is no standard way of predicting the existence or coexistence of hidden attractors in a system. In this plenary survey lecture the concept of self-excited and hidden attractors is discussed, and various corresponding examples of self-excited and hidden attractors are considered

    A Novel Recombinant Peste des Petits Ruminants-Canine Adenovirus Vaccine Elicits Long-Lasting Neutralizing Antibody Response against PPR in Goats

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    BACKGROUND: Peste des petits ruminants (PPR) is a highly contagious infectious disease of goats, sheep and small wild ruminant species with high morbidity and mortality rates. The Peste des petits ruminants virus (PPRV) expresses a hemagglutinin (H) glycoprotein on its outer envelope that is crucial for viral attachment to host cells and represents a key antigen for inducing the host immune response. METHODOLOGY/PRINCIPAL FINDINGS: To determine whether H can be exploited to generate an effective PPRV vaccine, a replication-competent recombinant canine adenovirus type-2 (CAV-2) expressing the H gene of PPRV (China/Tibet strain) was constructed by the in vitro ligation method. The H expression cassette, including the human cytomegalovirus (hCMV) promoter/enhancer and the BGH early mRNA polyadenylation signal, was inserted into the SspI site of the E3 region, which is not essential for proliferation of CAV-2. Infectious recombinant rCAV-2-PPRV-H virus was generated in transfected MDCK cells and used to immunize goats. All vaccinated animals produced antibodies upon primary injection that were effective in neutralizing PPRV in vitro. Higher antibody titer was obtained following booster inoculation, and the antibody was detectable in goats for at least seven months. No serious recombinant virus-related adverse effect was observed in immunized animals and no adenovirus could be isolated from the urine or feces of vaccinated animals. Results showed that the recombinant virus was safe and could stimulate a long-lasting immune response in goats. CONCLUSIONS/SIGNIFICANCE: This strategy not only provides an effective PPR vaccine candidate for goats but may be a valuable mean by which to differentiate infected from vaccinated animals (the so-called DIVA approach)

    Isothiocyanate NB7M causes selective cytotoxicity, pro-apoptotic signalling and cell-cycle regression in ovarian cancer cells

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    The present report identifies indole-3-ethyl isothiocyanate NB7M as a potent cytotoxic agent with selective activity against cell lines derived from various tumour types. Ovarian cancer cell lines showed sensitivity to NB7M (60–70% cytotoxicity at 2.5 μM), in contrast to control cells (TCL-1 and HTR-8; IC50 ∼15 μM). In a screen performed by the National Cancer Institute (NCI) (NCI60 cancer cell-line assay) NB7M (NSC746077) reduced growth up to 100% with an IC50 between 0.1 and 10 μM depending on the cell line studied. Using SKOV-3 ovarian cancer cells as a model, mechanisms of cytotoxicity were analysed. NB7M caused hallmarks of apoptosis such as PARP-1 deactivation, chromatin condensation, DNA nicks, activation of caspases-9, -8, -3, loss of mitochondrial transmembrane depolarisation potential and upregulation of pro-apoptotic mitogen activated protein kinases (p38, SAP/JNK). NB7M downregulated phosphorylation of prosurvival kinases (PI-3K, AKT, IKKΞ±), transcription factor NF-ΞΊB, and expression of DNA-Pk and AXL receptor tyrosine kinase. Subcytotoxic doses of NB7M inhibited DNA synthesis, caused G1-phase cell-cycle arrest and upregulated p27 expression. The present report suggests that NB7M is a selective cytotoxic agent in vitro for cell lines derived from ovarian and certain other tumours. In addition, NB7M acts as a growth/cell-cycle-suppressing agent and may be developed as a potential therapeutic drug to treat ovarian cancer

    Experimental investigation of the entanglement-assisted entropic uncertainty principle

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    The uncertainty principle, which bounds the uncertainties involved in obtaining precise outcomes for two complementary variables defining a quantum particle, is a crucial aspect in quantum mechanics. Recently, the uncertainty principle in terms of entropy has been extended to the case involving quantum entanglement. With previously obtained quantum information for the particle of interest, the outcomes of both non-commuting observables can be predicted precisely, which greatly generalises the uncertainty relation. Here, we experimentally investigated the entanglement-assisted entropic uncertainty principle for an entirely optical setup. The uncertainty is shown to be near zero in the presence of quasi-maximal entanglement. The new uncertainty relation is further used to witness entanglement. The verified entropic uncertainty relation provides an intriguing perspective in that it implies the uncertainty principle is not only observable-dependent but is also observer-dependent.Comment: 14 pages, 5 figure

    Metabolic Profiles and cDNA-AFLP Analysis of Salvia miltiorrhiza and Salvia castanea Diel f. tomentosa Stib

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    Plants of the genus Salvia produce various types of phenolic compounds and tanshinones which are effective for treatment of coronary heart disease. Salvia miltiorrhiza and S. castanea Diels f. tomentosa Stib are two important members of the genus. In this study, metabolic profiles and cDNA-AFLP analysis of four samples were employed to identify novel genes potentially involved in phenolic compounds and tanshinones biosynthesis, including the red roots from the two species and two tanshinone-free roots from S. miltiorrhiza. The results showed that the red roots of S. castanea Diels f. tomentosa Stib produced high contents of rosmarinic acid (21.77 mg/g) and tanshinone IIA (12.60 mg/g), but low content of salvianolic acid B (1.45 mg/g). The red roots of S. miltiorrhiza produced high content of salvianolic acid B (18.69 mg/g), while tanshinones accumulation in this sample was much less than that in S. castanea Diels f. tomentosa Stib. Tanshinones were not detected in the two tanshinone-free samples, which produced high contents of phenolic compounds. A cDNA-AFLP analysis with 128 primer pairs revealed that 2300 transcript derived fragments (TDFs) were differentially expressed among the four samples. About 323 TDFs were sequenced, of which 78 TDFs were annotated with known functions through BLASTX searching the Genbank database and 14 annotated TDFs were assigned into secondary metabolic pathways through searching the KEGGPATHWAY database. The quantitative real-time PCR analysis indicated that the expression of 9 TDFs was positively correlated with accumulation of phenolic compounds and tanshinones. These TDFs additionally showed coordinated transcriptional response with 6 previously-identified genes involved in biosynthesis of tanshinones and phenolic compounds in S. miltiorrhiza hairy roots treated with yeast extract. The sequence data in the present work not only provided us candidate genes involved in phenolic compounds and tanshinones biosynthesis but also gave us further insight into secondary metabolism in Salvia

    Serum HER2 Level Measured by Dot Blot: A Valid and Inexpensive Assay for Monitoring Breast Cancer Progression

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    Human epidermal growth factor receptor 2 (HER2) is one of the most important prognostic and predictive factors for breast cancer patients. Recently, serum HER2 ECD level of patients detected by enzyme-linked immunoabsorbent assay (ELISA) has been shown to predict tumor HER2 status and reveal its association with tumor progression, recurrence and poor prognosis. In this study, we established a new method, dot blot assay, to measure the serum HER2 level in breast cancer patients and further to evaluate the clinical value for monitoring breast cancer progression. We found that the serum HER2 level measured by dot blot assay was significantly correlated with tissue HER2 status in breast cancer patients (Pβ€Š=β€Š0.001), and also significantly correlated with HER2 level measured by ELISA (Pβ€Š=β€Š1.06Γ—10βˆ’11). Compared with ELISA method, the specificity and sensitivity of dot blot assay were 95.3% and 65.0%, respectively. The serum HER2 levels of patients with grade III or ER-negative were higher than those with grade I–II (Pβ€Š=β€Š0.004) and ER-positive (Pβ€Š=β€Š0.033), respectively. Therefore, the novel dot blot method to detect serum HER2 level is a valid and inexpensive assay with potential application in monitoring breast cancer progression in clinical situations
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