Truthful Mechanisms for Secure Communication in Wireless Cooperative System

To ensure security in data transmission is one of the most important issues for wireless relay networks, and physical layer security is an attractive alternative solution to address this issue. In this paper, we consider a cooperative network, consisting of one source node, one destination node, one eavesdropper node, and a number of relay nodes. Specifically, the source may select several relays to help forward the signal to the corresponding destination to achieve the best security performance. However, the relays may have the incentive not to report their true private channel information in order to get more chances to be selected and gain more payoff from the source. We propose a Vickey-Clark-Grove (VCG) based mechanism and an Arrow-d'Aspremont-Gerard-Varet (AGV) based mechanism into the investigated relay network to solve this cheating problem. In these two different mechanisms, we design different "transfer payment" functions to the payoff of each selected relay and prove that each relay gets its maximum (expected) payoff when it truthfully reveals its private channel information to the source. And then, an optimal secrecy rate of the network can be achieved. After discussing and comparing the VCG and AGV mechanisms, we prove that the AGV mechanism can achieve all of the basic qualifications (incentive compatibility, individual rationality and budget balance) for our system. Moreover, we discuss the optimal quantity of relays that the source node should select. Simulation results verify efficiency and fairness of the VCG and AGV mechanisms, and consolidate these conclusions.Comment: To appear in IEEE Transactions on Wireless Communication

Metabonomics-based omics study and atherosclerosis

Atherosclerosis results from dyslipidemia and systemic inflammation, associated with the strong metabolism and interaction between diet and disease. Strategies based on the global profiling of metabolism would be important to define the mechanisms involved in pathological alterations. Metabonomics is the quantitative measurement of the dynamic multiparametric metabolic response of living systems to pathophysiological stimuli or genetic modification. Metabonomics has been used in combination with proteomics and transcriptomics as the part of a systems biology description to understand the genome interaction with the development of atherosclerosis. The present review describes the application of metabonomics to explore the potential role of metabolic disturbances and inflammation in the initiation and development of atherosclerosis. Metabonomics-based omics study offers a new potential for biomarker discovery by disentangling the impacts of diet, environment and lifestyle

Tetra­aqua­bis­(1,10-phenanthroline-κ2 N,N′)strontium 5,5′-diazene­diyl­ditetra­zolide

The title complex, [Sr(C12H8N2)2(H2O)4](C2N10), contains an [Sr(phen)2(H2O)4]2+ cation (phen is 1,10-phenanthroline) and a 5,5′-diazenediylditetra­zolide anion (site symmetry 2). The Sr2+ cation (site symmetry 2) is coordinated by four N atoms from two chelating phen and four water mol­ecules. In the crystal structure, the water mol­ecules and the N atoms in the tetra­zolide rings form an extensive range of O—H⋯N hydrogen bonds which link the complex into a two-dimensional structure. An adjacent layer further yields a three-dimensional supramolecular network by offset face-to-face π–π stacking inter­actions of the phen ligands [with centroid–centroid distances of 3.915 (2) and 4.012 (2) Å]. The two bridging N atoms of the anion are equally disordered about the twofold rotation axis

Experimental Test of Tracking the King Problem

In quantum theory, the retrodiction problem is not as clear as its classical counterpart because of the uncertainty principle of quantum mechanics. In classical physics, the measurement outcomes of the present state can be used directly for predicting the future events and inferring the past events which is known as retrodiction. However, as a probabilistic theory, quantum-mechanical retrodiction is a nontrivial problem that has been investigated for a long time, of which the Mean King Problem is one of the most extensively studied issues. Here, we present the first experimental test of a variant of the Mean King Problem, which has a more stringent regulation and is termed "Tracking the King". We demonstrate that Alice, by harnessing the shared entanglement and controlled-not gate, can successfully retrodict the choice of King's measurement without knowing any measurement outcome. Our results also provide a counterintuitive quantum communication to deliver information hidden in the choice of measurement.Comment: 16 pages, 5 figures, 2 table

Anticancer effect of a combination of cisplatin and matrine on cervical cancer U14 cells and U14 tumor-bearing mice, and possible mechanism of action involved

Purpose: To investigate the anticancer effects of cisplatin (DDP) in combination with matrine on cervical cancer U14 cell tumor-bearing mice. Methods: The cell proliferation of cervical cancer U14 cells treated with DDP (25, 20, 15, 10 and 5 μg/mL); matrine (2.5, 2.0, 1.5, 1.0 and 0.5 mg/mL); or DDP (15 μg/mL) + matrine (2.5, 2.0, 1.5, 1.0 and 0.5 mg/mL) was determined with MTT assay. The anticancer effect of DDP + matrine in U14 tumor-bearing mice was also investigated, based on expression of tumor suppressor lung cancer 1 (TSLC1) using quantitative real time-polymerase chain reaction (qRT-PCR) and immunohistochemistry. Results: The inhibition of proliferation of U14 cells ranged from 26.68–70.25, 10.20–61.73, and 51.89–89.75 % for DDP, matrine and DDP + matrine, respectively. In mice with U14 solid tumors, the DDP group had 12.3 % weight loss (p < 0.05). Treatment with DDP, matrine, and DDP + matrine reduced tumor growth by 64.56, 42.22–56.67, and 67.78–81.11 %, respectively (p < 0.01). Results from RT-qPCR and immunohistochemistry showed corresponding increases in expression levels of TSLC1. Conclusion: These results indicate that the anticancer activity of DDP + matrine is higher than that of a single treatment with either DPP or matrine. The likely mechanism of action might be related to promotion of TSLC1 expression. This finding provides a potential strategy for the management of cervical cancer

Multilayer Photonic Crystal for Spectral Narrowing of Emission

Multilayer colloidal crystal has been prepared by the layer-by-layer deposition of silica microspheres on a glass slide. Each layer is a slab consisting of a fcc close-packed colloidal arrays. By properly choosing the sizes of spheres, the whole spectral feature of multilayer colloidal crystal can be tuned. Here, we engineered a multilayer superlattice structure with an effective passband (380 nm) between two stop bands (366 nm and 400 nm). This gives a strong narrowing effect on emission spectrum (378 nm). With the stop bands at the shortwave and longwave edges of emission spectrum, the passband in the central wavelength region can be regarded as a strong decrease of suppression effect and enhancement of a narrow wavelength region of emission. The FWHM values of stop band modified emission spectrum were narrowed from 59 nm to 22 nm. The spectral narrowing modification effect of suitably engineered colloidal crystals shows up their importance in potential application as optical filters and lasing devices

1-Chloro­methyl-1H-1,2,3-benzotriazole

In the title compound, C7H6ClN3, the benzotriazole ring is essentially planar with a maximum deviation of 0.0110 (15)Å, and makes a dihedral angle of 0.46 (8)° with the benzene ring. In the crystal, mol­ecules are linked through inter­molecular C—H⋯N hydrogen bonds, forming chains along the c axis

Impermeable inorganic “walls” sandwiching perovskite layer toward inverted and indoor photovoltaic devices

Interfaces between the perovskite active layer and the charge-transport layers (CTLs) play a critical role in both efficiency and stability of halide-perovskite photovoltaics. One of the major concerns is that surface defects of perovskite could cause detrimental nonradiative recombination and material degradation. In this work, we addressed this challenging problem by inserting ultrathin alkali-fluoride (AF) films between the tri-cation lead-iodide perovskite layer and both CTLs. This bilateral inorganic “walls” strategy makes use of both physical-blocking and chemical-anchoring functionalities of the continuous, uniform and compact AF framework: on the one hand, the uniformly distributed alkali-iodine coordination at the perovskite-AF interfaces effectively suppresses the formation of iodine-vacancy defects at the surfaces, thus reducing the trap-assisted recombination at the perovskite-CTL interfaces and therewith the open-voltage loss; on the other hand, the impermeable AF buffer layers effectively prevent the bidirectional ion migration at the perovskite-CTLs interfaces even under harsh working conditions. As a result, a power-conversion efficiency (PCE) of 22.02% (certified efficiency 20.4%) with low open-voltage deficit (<0.4 V) was achieved for the low-temperature processed inverted planar perovskite solar cells. Exceptional operational stability (500 h, ISOS-L-2) and thermal stability (1000 h, ISOS-D-2) were obtained. Meanwhile, a 35.7% PCE was obtained under dim-light source (1000 lux white LED light) with the optimized device, which is among the best records in perovskite indoor photovoltaics