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We report an experimental study of recently formulated entropic Leggett-Garg inequality (ELGI) by Usha Devi et al. (arXiv: 1208.4491v2 (2012). This inequality places a bound on the statistical measurement outcomes of dynamical observables describing a macrorealistic system. Such a bound is not necessarily obeyed by quantum systems, and therefore provides an important way to distinguish quantumness from classical behavior. Here we study ELGI using a two-qubit nuclear magnetic resonance system. To perform the noninvasive measurements required for the ELGI study, we prepare the system qubit in a maximally mixed state as well as use the 'ideal negative result measurement' procedure with the help of an ancilla qubit. The experimental results show a clear violation of ELGI by over four standard deviations. These results agree with the predictions of quantum theory. The violation of ELGI is attributed to the fact that certain joint probabilities are not legitimate in the quantum scenario, in the sense they do not reproduce all the marginal probabilities. Using a three-qubit system, we experimentally demonstrate that three-time joint probabilities do not reproduce certain two-time marginal probabilities.

One of the most remarkable properties of the nitrogen-vacancy (NV) center in diamond is that optical illumination initializes its electronic spin almost completely, a feature that can be exploited to polarize other spin species in their proximity. Here we use field-cycled nuclear magnetic resonance (NMR) to investigate the mechanisms of spin polarization transfer from NVs to 13 C spins in diamond at room temperature. We focus on the dynamics near 51 mT, where a fortuitous combination of energy matching conditions between electron and nuclear spin levels gives rise to alternative polarization transfer channels. By monitoring the 13 C spin polarization as a function of the applied magnetic field, we show 13 C spin pumping takes place via a multi-spin cross relaxation process involving the NVspin and the electronic and nuclear spins of neighboring P1 centers. Further, we find that this mechanism is insensitive to the crystal orientation relative to the magnetic field, although the absolute level of 13 C polarization ⎯ reaching up to ~3% under optimal conditions ⎯ can vary substantially depending on the interplay between optical pumping efficiency, photo-generated carriers, and laser-induced heating.

In a further study on the chemical constituents of Garcinia assigu, two new benzophenones corresponding to the 13-O-methyl ethers (1 and 2) of the known isogarcinol and garcinol, respectively, were isolated and characterized, along with known benzophenones (3-6). Inhibitory effects of the benzophenones isolated from this plant on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells and their radical-scavenging ability against 1,1-diphenyl-2-picrylhydrazyl (DPPH) were demonstrated. The cyclized polyprenylbenzophenones (1-5) showed comparable or stronger potential cancer chemopreventive activity when compared to glycyrrhetic acid, a known anti-tumor promoter.

Reduction and alkylation of purified hepatitis-associated Australia antigen (hepatitis B antigen) resulted in a total loss of serologic activity. The reduced and alkylated protein formed a single band with a sedimentation coefficient of 31S on analytical ultracentrifugation, and no subunits were detected by Sephadex gel filtration. Although this preparation induced a delayed hypersensitivity response when injected into guinea pigs, it failed to stimulate humoral antibody formation. The data suggest that hepatitis B antigen is a conformational antigen critically dependent upon the disulfide bonds of the protein moiety.

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Two novel metabolites of mixed biogenesis, polycerasoidin [1] and polycerasoidol [2], have been isolated from the stem bark of Polyalthia cerasoides. Their structures were established on the basis of nmr spectroscopic techniques, including 2D correlated nmr spectroscopy (COSY 45, HMQC, and HMBC).The genus Polyalthia includes more than 150 species of trees belonging to the family Annonaceae. It is considered one