15,451 research outputs found

    Capacity of a simultaneous quantum secure direct communication scheme between the central party and other M parties

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    We analyze the capacity of a simultaneous quantum secure direct communication scheme between the central party and other MM parties via M+1M+1-particle GHZ states and swapping quantum entanglement. It is shown that the encoding scheme should be secret if other MM parties wants to transmit M+1M+1 bit classical messages to the center party secretly. However when the encoding scheme is announced publicly, we prove that the capacity of the scheme in transmitting the secret messages is 2 bits, no matter how big MM is.Comment: 3 page

    A Simultaneous Quantum Secure Direct Communication Scheme between the Central Party and Other M Parties

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    We propose a simultaneous quantum secure direct communication scheme between one party and other three parties via four-particle GHZ states and swapping quantum entanglement. In the scheme, three spatially separated senders, Alice, Bob and Charlie, transmit their secret messages to a remote receiver Diana by performing a series local operations on their respective particles according to the quadripartite stipulation. From Alice, Bob, Charlie and Diana's Bell measurement results, Diana can infer the secret messages. If a perfect quantum channel is used, the secret messages are faithfully transmitted from Alice, Bob and Charlie to Diana via initially shared pairs of four-particle GHZ states without revealing any information to a potential eavesdropper. As there is no transmission of the qubits carrying the secret message in the public channel, it is completely secure for the direct secret communication. This scheme can be considered as a network of communication parties where each party wants to communicate secretly with a central party or server.Comment: 4 pages, no figur

    Probabilistic teleportation of unknown two-particle state via POVM

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    We propose a scheme for probabilistic teleportation of unknown two-particle state with partly entangled four-particle state via POVM. In this scheme the teleportation of unknown two-particle state can be realized with certain probability by performing two Bell state measurements, a proper POVM and a unitary transformation.Comment: 5 pages, no figur

    Paraoxonase 2 overexpression inhibits tumor development in a mouse model of ovarian cancer.

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    Ovarian cancer (OC) is most lethal malignancy among all gynecological cancer. Large bodies of evidences suggest that mitochondrial-derived ROS play a critical role in the development and progression of OC. Paraoxonase 2 (PON2) is a membrane-associated lactonase with anti-oxidant properties. PON2 deficiency aggravates mitochondrial ROS formation, systemic inflammation, and atherosclerosis. The role of PON2 in cancer development remains unknown. In this report, in human, we identified that PON2 expression is higher in early stages (but not in late stages) of OC when compared to normal tissue. Using a mouse xenograft model of OC, we demonstrate that overexpression of PON2 prevents tumor formation. Mechanistically, PON2 decreases OC cell proliferation by inhibiting insulin like growth factor-1 (IGF-1) expression and signaling. Intriguingly, PON2 reduces c-Jun-mediated transcriptional activation of IGF-1 gene by decreasing mitochondrial superoxide generation. In addition, PON2 impairs insulin like growth factor-1 receptor (IGF-1R) signaling in OC cells by altering cholesterol homeostasis, which resulted in reduced caveolin-1/IGF-1R interaction and IGF-1R phosphorylation. Taken together, we report for the first time that PON2 acts as a tumor suppressor in the early stage of OC by reducing IGF-1 production and its signaling, indicating PON2 activation might be a fruitful strategy to inhibit early stage ovarian tumor

    Impact of radiation therapy on survival in patients with triple‑negative breast cancer

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    Triple-negative breast cancer (TNBC) has a poorer prognosis compared with other sub-groups. In the current study, survival associated with locoregional treatment of females with TNBC was investigated. Specifically, 468 patients with stage I–III TNBC treated between 2002 and 2009 were identified. Data included patient and tumor characteristics, treatment received and survival. Data were compared using χ(2) and Fisher’s exact tests, as well as MANOVA. Kaplan-Meier curves were generated. The study cohort had a mean age of 54±13 years old with a mean follow-up period of 51±21 months. Of 468 patients, 249 (53%) underwent lumpectomy, 63 (14%) underwent simple mastectomy (SM) and 156 (33%) underwent modified radical mastectomy (MRM). Overall, 263 (56%) received adjuvant radiation, including 178/249 (71%) following lumpectomy, 13/63 (21%) following SM and 72/156 (46%) following MRM (P<0.0001). Following control for potential confounders in univariate tests, adjuvant radiation was associated with improved overall survival in the total cohort (HR, 0.46; 95% CI, 0.31–0.68; P=0.0001). When comparing survival by surgical type, receipt of adjuvant radiation significantly improved survival in the lumpectomy group (HR, 0.30; 95% CI, 0.16–0.58; P=0.0004), but was not associated with improved survival in the SM group (HR, 0.38; 95% CI, 0.05–3.04; P=0.36) or in the MRM group (HR, 0.79; 95% CI, 0.46–1.34; P=0.38). The survival benefit of adjuvant radiation in these TNBC patients is attributed to those undergoing breast-conserving therapy. There was no benefit in either mastectomy group. These data warrant validation from prospective trials, in order to develop tailored locoregional treatment for patients with TNBC
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