BackgroundRecent studies implicate adipokines in the pathogenesis of inflammatory diseases, including psoriasis. In this study we evaluated the significance of serum resistin levels in psoriasis patients using a meta-analysis approach.223MethodsRelevant articles were retrieved by searching the following English and Chinese databases: Cochrane Library, PubMed, Springer Link, Chinese Biomedical Database (CBM) and Chinese National Knowledge Infrastructure (CNKI). The retrieved studies were subjected to a thorough screening procedure to identify case–control studies that contained the required data. Data was extracted from each study and Version 12.0 STATA statistical software was employed for statistical analyses.ResultsNine case–control studies, containing 421 psoriasis patients and 348 healthy controls, were included in this study. The major result of the meta-analysis revealed a statistically significant association between serum resistin levels and psoriasis (SMD = 2.22, 95%CI: 1.14-3.29, P < 0.001). Subgroup analysis based on ethnicity showed that, compared to the healthy controls, serum resistin levels were markedly higher in psoriasis patients in both Asian and Caucasian populations (Asians: SMD = 3.27, 95%CI = 1.62 ~ 4.91, P < 0.001; Caucasians: SMD = 0.91, 95%CI = 0.28 ~ 1.54, P < 0.001).ConclusionsBased on our results, we conclude that serum resistin level in psoriasis patients is higher than healthy controls, and raises the possibility that elevated serum resistin levels may be a novel diagnostic marker in psoriasis and may predict the occurrence of co-morbidities in psoriasis patients.

The cross-Kerr nonlinearity (XKNL) effect can induce efficient photon interactions in principle with which photonic multiqubit gates can be performed using far fewer physical resources than linear optical schemes. Unfortunately, it is extremely challenging to generate giant cross-Kerr nonlinearities. In recent years, much effort has been made to perform multiqubit gates via weak XKNLs. However, the required nonlinearity strengths are still difficult to achieve in the experiment. We here propose an XKNL-based scheme for realizing a twophoton polarization-parity gate, a universal two-qubit gate, in which the required strength of the nonlinearity could be orders of magnitude weaker than those required for previous schemes. The scheme utilizes a ring cavity fed by a coherent state as a quantum information bus which interacts with a path mode of the two polarized photons (qubits). The XKNL effect makes the bus pick up a phase shift dependent on the photon number of the path mode. Even when the potential phase shifts are very small they can be effectively measured using photon-number resolving detectors, which accounts for the fact that our scheme can work in the regime of tiny XKNL. The measurement outcome reveals the parity (even parity or odd parity) of the two polarization qubits.

We propose a mechanism of ground-state antiblockade of Rydberg atoms, which is then exploited to prepare two-atom entangled state via three different kinds of pulses. First we use the pulses in the form of sin2 and cos2 functions and obtain a maximally entangled state at an accurate interaction time. Then the method of stimulated Raman adiabatic passage (STIRAP) is adopted for the entanglement generation, which is immune to the fluctuations of revelent parameters but requires a long time. Finally we capitalize the advantages of the former two methods and employ shortcuts to adiabatic passage (STAP) to generate the maximal entanglement. The strictly numerical simulation reveals that the current scheme is robust against spontaneous emission of atoms due to the virtual excitation of Rydberg states, and all of the above methods favor a high fidelity with the present experimental technology.

We propose a scheme for multiparty hierarchical quantum-information splitting (QIS) with a multipartite entangled state, where a boss distributes a secret quantum state to two grades of agents asymmetrically. The agents who belong to different grades have different authorities for recovering boss's secret. Except for boss's Bell-state measurement, no nonlocal operation is involved. The presented scheme is also shown to be secure against eavesdropping. Such a hierarchical QIS is expected to find useful applications in the field of modern multipartite quantum cryptography. A fundamental ingredient for implementation of quantum technologies is the ability to faithfully transmit quantum states among quantum mechanical systems which are even far apart. Quantum-information splitting (QIS, also be referred to as quantum-secret sharing or quantum-state sharing in the literature), first introduced by Hillery, Bužek, and Berthiaume (HBB) [1], is a typical way for quantum state transfer, in which a secret quantum state is distributed by quantum teleportation [2] from a boss to more than one agents so that any one of them can recover the state with assistance of the others. QIS is a generalization of classical-secret sharing to quantum scenario. Classical-secret sharing is one of the most important information-theoretically secure cryptographic protocols and is germane to online auctions, electronic voting, shared electronic banking, cooperative activation of bombs, and so on. Also, QIS has extensive applications in quantum-information science, such as creating joint checking accounts containing quantum money [3], secure distributed quantum computation [4,5], and so on. KeywordsIn the original HBB QIS proposal with the quantum channel being a three-qubit Greenberger-Horne-Zeilinger (GHZ) state [6], the collaboration of two agents is implemented by means of classical communication about their single-particle measurement outcomes. This idea can be directly generalized to the case of N agents by using an (N + 1)-particle GHZ state, or by the way of Ref. [7]. These schemes are (N , N )-threshold schemes where all the N agents need collaborating in order to recover the secret state. Soon after, Cleve, Gottesman, and Lo (CGL) [8] proposed another type of QIS scheme with the idea of quantum error-correcting codes. The CGL scheme is a (K, N )-threshold scheme where K ([N/2] < K ≤ N ) of N agents can extract the quantum information of the original secret state by cooperation. The CGL QIS scheme, however, needs the cooperated agents to make nonlocal operations on their particles. That is, the K cooperated agents need to transmit their K particles to one laboratory and perform a collective operation (decoding operation) on them. In the last decade, both of the above two QIS ideas have triggered significant research activity (see, e.g., [9][10][11][12][13][14][15][16][17][18][19]), and some schemes have already been experimentally realized [20,21].A more general QIS scheme should involve the asymmetry between the powers of the differen...

We propose a scheme for hierarchical quantum information splitting with the recently realized six-photon cluster state (Lu et al. in Nat. Phys. 3:91, 2007), where a Boss distributes a quantum secret (quantum state) to five distant agents who are divided into two grades. Two agents are in the upper grade and three agents are in the lower grade. An agent of the upper grade only needs the collaboration of two of the other four agents for getting the secret, while an agent of the lower grade needs the collaboration of all the other four agents. In other words, the agents of two grades have different authorities to recover Boss's secret.Keywords Quantum secret · Hierarchical splitting · Photonic qubit · Cluster statesThe rapidly growing field of quantum information science is the fruit of the combination of information theory and quantum mechanics. Quantum information processing mainly involves the manipulation and transmission of information with the principle of quantum mechanics. The unique and useful properties of quantum mechanics is the inner reason for that why quantum information theory can implement many information processing tasks that classical information theory cannot achieve. In quantum information science, information is encoded in quantum states, and the information processing is in fact the manipulation and transfer of quantum states. Entanglement, the most intriguing property of quantum mechanics, is the center resource of quantum information science, and plays a powerful role in the transfer of quantum states. One well-known example is the quantum teleportation [1, 2] which utilizes the bipartite or multipartite entangled states to transport an unknown quantum state from one site to another one. However, not all entangled states can be used to implement perfect teleportation, and that whether or not an entangled state can implement teleportation is determined by its entanglement properties [3]. Thus teleportation can also reveal some properties of entangled states, especially multipartite entangled states [4,5]. On the

A simply protocol for quantum teleportation of an unknown two-atom entangled state using four-atom cluster state is investigated in cavity quantum electrodynamics (QED). In this protocol, by using a one-dimensional maximally four-atom cluster state as quantum channel, an unknown two-atom entangled state can be transmitted from the sender (Alice) to the receiver without apparent joint Bell-state measurement. According to the results measured by the sender, the receiver can obtain the original state with unit successful probability. The important features of our scheme can also be demonstrated in ion trap system.

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We investigate collective radiant properties of two separated atoms in X-type quantum states. We show that quantum correlations measured by quantum discord (QD) can trigger and enhance superradiance and subradiance in the two-atom system even though in the absence of interatomic quantum entanglement. We also explore quantum statistical properties of photons in the superradiance and subradiance by addressing the second-order correlation function. In particular, when the initial state of the two separated atoms is the Werner state with nonzero QD, we find that radiation photons in the superradiant region exhibit the nonclassical sub-Poissonian statistics and the degree of the sub-Poissonian statistics increases with increasing of the QD amount, while radiation photons in the subradiant region have either the subPoissonian or super-Poissonian statistics depending on the amount of QD and the directional angle. In the subradiant regime, we predict the QD-triggered photon statistics transition from the super-Poissonian to sub-Poissonian statistics. These results shed a new light on applications of QD as a quantum resource.