Realizing Physical Approximation of the Partial Transpose

The partial transpose by which a subsystem's quantum state is solely transposed is of unique importance in quantum information processing from both fundamental and practical point of view. In this work, we present a practical scheme to realize a physical approximation to the partial transpose using local measurements on individual quantum systems and classical communication. We then report its linear optical realization and show that the scheme works with no dependence on local basis of given quantum states. A proof-of-principle demonstration of entanglement detection using the physical approximation of the partial transpose is also reported.Comment: 5 pages with appendix, 3 figure

Experimental Implementation of the Universal Transpose Operation

The universal transpose of quantum states is an anti-unitary transformation that is not allowed in quantum theory. In this work, we investigate approximating the universal transpose of quantum states of two-level systems (qubits) using the method known as the structural physical approximation to positive maps. We also report its experimental implementation in linear optics. The scheme is optimal in that the maximal fidelity is attained and also practical as measurement and preparation of quantum states that are experimentally feasible within current technologies are solely applied.Comment: 4 pages, 4 figure

Pseudogap Behavior Revealed in Interlayer Tunneling in Overdoped Bi2_2Sr2_2CaCu2_2O8+x_{8+x}

We report heating-compensated interlayer tunneling spectroscopy (ITS) performed on stacks of overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ intrinsic junctions, where most of bias-induced heating in the ITS was eliminated. The onset temperature of the pseudogap (PG), revealed in the hump structure of the electronic excitation spectra, reached nearly room temperature for our overdoped intrinsic junctions, which represented the genuine PG onset. At a temperature below but close to $T_c$, both the superconducting coherence peak and the pseudogap hump coexisted, implying that the two gaps are of separate origins. The hump voltage increased below $T_c$, following the superconducting gap voltage, which led to a conclusion that the hump structure below $T_c$ in our ITS arose from the combined contribution of the quasiparticle spectral weights of two different characters; one of the superconducting state and another of the PG state near the antinodal region.Comment: accepted in Phys. Rev.

Exposures to Particulate Matter and Polycyclic Aromatic Hydrocarbons and Oxidative Stress in Schoolchildren

BACKGROUND: Air pollution is known to contribute to respiratory and cardiovascular mortality, and morbidity. Oxidative stress has been suggested as one of the main mechanisms for these effects on health. OBJECTIVE: The aim of this study was to analyze the effects of exposure to particulate matter (PM) with aerodynamic diameters <= 10 mu m (PM(10)) and <= 2.5 mu M (PM(2.5)) and polycyclic aromatic hydrocarbons (PAHs) on urinary malondialdehyde (MDA) levels in schoolchildren. METHODS: The study population consisted of 120 schoolchildren. The survey and measurements were conducted in four cities two in China (Ala Shan and Beijing) and two in Korea (Jeju and Seoul) between 4 and 9 June 2007. We measured daily ambient levels of PM and their metal components at the selected schools during the study period. We also measured urinary 1-hydroxypyrene (1-OHP) and 2-naphthol, to assess PAH exposure, and MDA, to assess oxidative stress. Measurements were conducted once a day for 5 consecutive days. We constructed a linear mixed model after adjusting for individual variables to estimate the effects of PM and PAH on oxidative stress. RESULTS: We found statistically significant increases in urinary MDA levels with ambient PM concentrations from the current day to the 2 previous days (p < 0.0001). Urinary 1-OHP level also showed a positive association with urinary MDA level, which was statistically significant with or without PM in the model (p < 0.05). Outdoor PM and urinary 1-OHP were synergistically associated with urinary MDA levels. Some metals bound to PM(10) (aluminum, iron, strontium, magnesium, silicon, arsenic, barium, zinc, copper, and cadmium) and PM(2.5) (magnesium, iron, strontium, arsenic, cadmium, zinc, aluminum, mercury, barium, and copper) also had significant associations with urinary MDA level. CONCLUSION: Exposure to PM air pollution and PAHs was associated with oxidative stress in schoolchildren.Environmental SciencesPublic, Environmental & Occupational HealthToxicologySCI(E)40ARTICLE4579-58311

Identification of novel peptides that stimulate human neutrophils

Neutrophils play a key role in innate immunity, and the identification of new stimuli that stimulate neutrophil activity is a very important issue. In this study, we identified three novel peptides by screening a synthetic hexapeptide combinatorial library. The identified peptides GMMWAI, MMHWAM, and MMHWFM caused an increase in intracellular Ca2+ in a concentration-dependent manner via phospholipase C activity in human neutrophils. The three peptides acted specifically on neutrophils and monocytes and not on other non-leukocytic cells. As a physiological characteristic of the peptides, we observed that the three peptides induced chemotactic migration of neutrophils as well as stimulated superoxide anion production. Studying receptor specificity, we observed that two of the peptides (GMMWAI and MMHWFM) acted on formyl peptide receptor (FPR)1 while the other peptide (MMHWAM) acted on FPR2. Since the three novel peptides were specific agonists for FPR1 or FPR2, they might be useful tools to study FPR1- or FPR2-mediated immune response and signaling

Real-time heart rate variability according to ambulatory glucose profile in patients with diabetes mellitus

BackgroundAutonomic neuropathy commonly occurs as a long-term complication of diabetes mellitus (DM) and can be diagnosed based on heart rate variability (HRV), calculated from electrocardiogram (ECG) recordings. There are limited data on HRV using real-time ECG and ambulatory glucose monitoring in patients with DM. The aim of this study was to investigate real-time HRV according to ambulatory glucose levels in patients with DM.MethodsA total of 43 patients (66.3 ± 7.5 years) with DM underwent continuous real-time ECG monitoring (225.7 ± 107.3 h) for HRV and ambulatory glucose monitoring using a remote monitoring system. We compared the HRV according to the ambulatory glucose profile. Data were analyzed according to the target in glucose range (TIR).ResultsThere were no significant differences in the baseline characteristics of the patients according to the TIR. During monitoring, we checked ECG and ambulatory glucose levels (a total of 15,090 times) simultaneously for all patients. Both time- and frequency-domain HRVs were lower when the patients had poorly controlled glucose levels (TIR < 70%) compared with well controlled glucose levels (TIR > 70%). In addition, heart and respiratory rates increased with real-time glucose levels (P < 0.001).ConclusionsPoorly controlled glucose levels were independently associated with lower HRV in patients with DM. This was further substantiated by the independent continuous association between real-time measurements of hyperglycemia and lower HRV. These data strongly suggest that cardiac autonomic dysfunction is caused by elevated blood sugar levels

Homeobox gene Dlx-2 is implicated in metabolic stress-induced necrosis

<p>Abstract</p> <p>Background</p> <p>In contrast to tumor-suppressive apoptosis and autophagic cell death, necrosis promotes tumor progression by releasing the pro-inflammatory and tumor-promoting cytokine high mobility group box 1 (HMGB1), and its presence in tumor patients is associated with poor prognosis. Thus, necrosis has important clinical implications in tumor development; however, its molecular mechanism remains poorly understood.</p> <p>Results</p> <p>In the present study, we show that Distal-less 2 (Dlx-2), a homeobox gene of the Dlx family that is involved in embryonic development, is induced in cancer cell lines dependently of reactive oxygen species (ROS) in response to glucose deprivation (GD), one of the metabolic stresses occurring in solid tumors. Increased Dlx-2 expression was also detected in the inner regions, which experience metabolic stress, of human tumors and of a multicellular tumor spheroid, an <it>in vitro </it>model of solid tumors. Dlx-2 short hairpin RNA (shRNA) inhibited metabolic stress-induced increase in propidium iodide-positive cell population and HMGB1 and lactate dehydrogenase (LDH) release, indicating the important role(s) of Dlx-2 in metabolic stress-induced necrosis. Dlx-2 shRNA appeared to exert its anti-necrotic effects by preventing metabolic stress-induced increases in mitochondrial ROS, which are responsible for triggering necrosis.</p> <p>Conclusions</p> <p>These results suggest that Dlx-2 may be involved in tumor progression via the regulation of metabolic stress-induced necrosis.</p