11,932 research outputs found

    Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition

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    We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the EPR-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction and the addition particularly in the small squeezing regime, whereas the optimal operation becomes the photon subtraction in the large-squeezing regime.Comment: 6 pages, 6 figures, published versio

    Quantum linear amplifier enhanced by photon subtraction and addition

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    A deterministic quantum amplifier inevitably adds noise to an amplified signal due to the uncertainty principle in quantum physics. We here investigate how a quantum-noise-limited amplifier can be improved by additionally employing the photon subtraction, the photon addition, and a coherent superposition of the two, thereby making a probabilistic, heralded, quantum amplifier. We show that these operations can enhance the performance in amplifying a coherent state in terms of intensity gain, fidelity, and phase uncertainty. In particular, the photon subtraction turns out to be optimal for the fidelity and the phase concentration among these elementary operations, while the photon addition also provides a significant reduction in the phase uncertainty with the largest gain effect.Comment: published version, 7 pages, 9 figure

    Insight into highly conserved H1 subtype-specific epitopes in influenza virus hemagglutinin

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    Influenza viruses continuously undergo antigenic changes with gradual accumulation of mutations in hemagglutinin (HA) that is a major determinant in subtype specificity. The identification of conserved epitopes within specific HA subtypes gives an important clue for developing new vaccines and diagnostics. We produced and characterized nine monoclonal antibodies that showed significant neutralizing activities against H1 subtype influenza viruses, and determined the complex structure of HA derived from a 2009 pandemic virus A/Korea/01/2009 (KR01) and the Fab fragment from H1-specific monoclonal antibody GC0587. The overall structure of the complex was essentially identical to the previously determined KR01 HA-Fab0757 complex structure. Both Fab0587 and Fab0757 recognize readily accessible head regions of HA, revealing broadly shared and conserved antigenic determinants among H1 subtypes. The beta-strands constituted by Ser110-Glu115 and Lys169-Lys170 form H1 epitopes with distinct conformations from those of H1 and H3 HA sites. In particular, Glu112, Glu115, Lys169, and Lys171 that are highly conserved among H1 subtype HAs have close contacts with HCDR3 and LCDR3. The differences between Fab0587 and Fab0757 complexes reside mainly in HCDR3 and LCDR3, providing distinct antigenic determinants specific for 1918 pdm influenza strain. Our results demonstrate a potential key neutralizing epitope important for H1 subtype specificity in influenza virus

    Hypochoeris radicata attenuates LPS-induced inflammation by suppressing P38, ERK, and JNK phosphorylation in Raw 264.7 macrophages

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    Hypochoeris radicata, an invasive plant species, is a large and growing threat to ecosystem integrity on Jeju Island, a UNESCO World Heritage site. Therefore, research into the utilization of H. radicata is important and urgently required in order to solve this invasive plant problem in Jeju Island. The broader aim of our research is to elucidate the biological activities of H. radicata, which would facilitate the conversion of this invasive species into high value added products. The present study was undertaken to identify the pharmacological effects of H. radicata flower on the production of inflammatory mediators in macrophages. The results indicate that the ethyl acetate fraction of H. radicata extract (HRF-EA) inhibited the production of pro-inflammatory molecules such as NO, iNOS, PGE2, and COX-2, and cytokines such as TNF-α, IL-1β, and IL-6 in LPS-stimulated RAW 264.7 cells. Furthermore, the phosphorylation of MAPKs such as p38, ERK, and JNK was suppressed by HRF-EA in a concentration-dependent manner. In addition, through HPLC and UPLC fingerprinting, luteolins were also identified and quantified as extract constituents. On the basis of these results, we suggest that H. radicata may be considered possible anti-inflammatory candidates for pharmaceutical and/or cosmetic applications

    A Korean multi-center, real-world, retrospective study of first-line pazopanib in unselected patients with metastatic renal clear-cell carcinoma

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    BACKGROUND: The efficacy and/or tolerability of pazopanib in patients with metastatic renal cell carcinoma (mRCC) have been found to differ in Western and Asian populations. This retrospective multicenter study analyzed the results of first-line pazopanib treatment in 93 consecutive patients with mRCC who were treated at the medical oncology departments of three tertiary cancer centers in Seoul, Korea. METHODS: The decision to administer pazopanib as first-line therapy was at the discretion of the treating physician in all patients with mRCC. Patients enrolled in clinical trials were excluded to ensure that the results would reflect real-world outcomes representative of daily clinical settings. All patients received 800 mg/day pazopanib. Outcomes included response rate, progression-free survival (PFS), overall survival (OS), and safety. RESULTS: The 93 patients included72 (77 %) male and 21 (23 %) female individuals, of median age 65 years (range, 19–84 years). The median number of metastatic sites per patient was two (range, 1–5), with the lungs being the most frequently involved site. Most patients had favorable (n = 46) or intermediate (n = 36) risk as determined by Memorial Sloan Kettering Cancer Center criteria. Pazopanib was generally welltolerated: the major hematologic adverse effect was grade 1/2 anemia (14 %); and the most frequently observed non-hematologic toxicity was grade 1/2 mucositis (22 %), followed by hair discoloration and hypertension. Of the 93 patients, three (3 %) showed complete response, 52 (56 %) showed partial response, and 21 (23 %) showed stable disease, making the objective response rate 59 % and the disease control rate 82 %. At a median follow-up of 21 months, the estimated median PFS and OS were 12.2 months (95 % confidence interval, 7.1–17.4 months) and 21.9 months (95 % confidence interval, 12.9–30.9 months), respectively. CONCLUSIONS: In this retrospective study, first-line therapy with pazopanib demonstrated clinically relevant efficacy and tolerability in unselected real-world Korean patients with mRCC. OS and PFS of these Korean patients were similar to those reported in phase III trials
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