Quantum secret sharing between m-party and n-party with six states

We propose a quantum secret sharing scheme between $m$-party and $n$-party using three conjugate bases, i.e. six states. A sequence of single photons, each of which is prepared in one of the six states, is used directly to encode classical information in the quantum secret sharing process. In this scheme, each of all $m$ members in group 1 choose randomly their own secret key individually and independently, and then directly encode their respective secret information on the states of single photons via unitary operations, then the last one (the $m$th member of group 1) sends $1/n$ of the resulting qubits to each of group 2. By measuring their respective qubits, all members in group 2 share the secret information shared by all members in group 1. The secret message shared by group 1 and group 2 in such a way that neither subset of each group nor the union of a subset of group 1 and a subset of group 2 can extract the secret message, but each whole group (all the members of each group) can. The scheme is asymptotically 100% in efficiency. It makes the Trojan horse attack with a multi-photon signal, the fake-signal attack with EPR pairs, the attack with single photons, and the attack with invisible photons to be nullification. We show that it is secure and has an advantage over the one based on two conjugate bases. We also give the upper bounds of the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states. This protocol is feasible with present-day technique.Comment: 7 page

A large sample of low surface brightness disk galaxies from the SDSS. I: The sample and the stellar populations

We present the properties of a large sample (12,282) of nearly face-on low surface brightness (LSB) disk galaxies selected from the main galaxy sample of SDSS-DR4. These properties include B-band central surface brightness mu_0(B), scale lengths h, integrated magnitudes, colors, and distances D. This sample has mu_0(B) values from 22 to 24.5 mag arcsec^{-2} with a median value of 22.42 mag arcsec^{-2}, and disk scale lengths ranging from 2 to 19 kpc. They are quite bright with M_B taking values from -18 to -23 mag with a median value of -20.08 mag. There exist clear correlations between logh and M_B, logh and logD, logD and M_B. However, no obvious correlations are found between mu_0(B) and logh, colors etc. The correlation between colors and logh is weak even though it exists. Both the optical-optical and optical-NIR color-color diagrams indicate that most of them have a mixture of young and old stellar populations. They also satisfy color-magnitude relations, which indicate that brighter galaxies tend generally to be redder. The comparison between the LSBGs and a control sample of nearly face-on disk galaxies with higher surface brightness (HSB) with mu_0(B) from 18.5 to 22 mag arcsec^{-2} show that, at a given luminosity or distance, the observed LSB galaxies tend to have larger scale lengths. These trends could be seen gradually by dividing both the LSBGs and HSBGs into two sub-groups according to surface brightness. A volume-limited sub-sample was extracted to check the incompleteness of surface brightness. The only one of the property relations having an obvious change is the relation of logh versus mu_0(B), which shows a correlation in this sub-sample.Comment: 14 pages, 18 figures, accepted for publication in MNRA

Circular quantum secret sharing

A circular quantum secret sharing protocol is proposed, which is useful and efficient when one of the parties of secret sharing is remote to the others who are in adjacent, especially the parties are more than three. We describe the process of this protocol and discuss its security when the quantum information carrying is polarized single photons running circularly. It will be shown that entanglement is not necessary for quantum secret sharing. Moreover, the theoretic efficiency is improved to approach 100% as almost all the instances can be used for generating the private key, and each photon can carry one bit of information without quantum storage. It is straightforwardly to utilize this topological structure to complete quantum secret sharing with multi-level two-particle entanglement in high capacity securely.Comment: 7 pages, 2 figure

The Application of Predictor Feedback in Designing a Preview Controller for Discrete-Time Systems with Input Delay

© 2016 Fucheng Liao et al.This paper presents a method for designing a type one servomechanism for a discrete-time linear system with input delay subject to a previewable desired output and a nonmeasurable constant disturbance. The tracking problem of a delay system is transformed into a regulation problem of a delay-free system via constructing an augmented error system and a variable substitution. A controller is obtained with delay compensation and preview compensation based on preview control theory and the predictor method. When the state vector is not directly measurable, a full-dimensional observer is offered. The effectiveness of the design method is demonstrated by numerical simulations

A fluorescent immunosensor on optical fibre for the multiplex detection of proinflammatory cytokines

Cytokines are typical mediators of the immune response. Single cytokine measurement is unable to reflect the true complexity of these physiological processes and multiplex detection is required. In this work, we developed an optical fibre based biosensor for multiplex detection of cytokines. This multiplex biosensor has been successfully applied for the measurement of proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the linear range of 12.5–200 pg mL−1 with the limit of detection (LOD) of 12.5 pg mL−1. Additionally, it has compatible performance with ELISA kit for the monitoring of cytokines from rat PBMC cell culture mediums stimulated by LPS or UV radiation. Moreover, this universal platform could be applied for multiplex detection of other proteins by simply changing the capture/detection antibody pairs. This fibre based multiplex biosensor is designed for in-situ measurement of target cytokines, which is significant for the investigation of inflammatory processes or disease prognosis and treatment monitoring

A simple and versatile CRISPR/Cas12a-based immunosensing platform: Towards attomolar level sensitivity for small protein diagnostics

Recent advances in CRISPR/Cas biosensing have led to impressive performance in sensitivity, specificity, and speed for nucleic acid detection. However, the remarkable advantages (such as universality, ultralow, attomolar detection limits) of CRISPR/Cas biosensing systems are limited in testing non-nucleic acid targets. Herein, by synthesizing a functional hybrid conjugate of antibody and single strand DNA oligonucleotide, we had successfully demonstrated the capability to integrate CRISPR/Cas12a-based signal amplification into different types of immunoassay schemes without the need for any additional recognition molecule or molecular synthesis during the detection process, thus providing a simple but generally applicable approach to improve the conventional immunoassays with attomolar sensitivity for small protein detections, referred as the CRISPR-based Universal Immunoassay Signal Enhancer (CRUISE). CRUISE is capable of being integrated into various immunoassays either through the primary antibody or the secondary antibody, with sensitivity down to 1 fg mL−1 (∼50 aM) and 6 logs of linear range for detecting cytokines, such as IFN-γ and EGFR, under 3–4 h. It has a 103 times higher sensitivity compared to a commercial IFN-γ ELISA kit, but uses the same experimental scheme. The same 1 fg mL−1 sensitivity along with 6 logs of linear range was realized for IFN-γ detection in human plasma samples. We are expecting that our CRUISE provides an alternative but simple, user-friendly and effective strategy for those who rely on the use of immunoassays, while struggling with the limits of their sensitivity or detection ranges