Entanglement generation outside a Schwarzschild black hole and the Hawking effect

We examine the Hawking effect by studying the asymptotic entanglement of two mutually independent two-level atoms placed at a fixed radial distance outside a Schwarzschild black hole in the framework of open quantum systems. We treat the two-atom system as an open quantum system in a bath of fluctuating quantized massless scalar fields in vacuum and calculate the concurrence, a measurement of entanglement, of the equilibrium state of the system at large times, for the Unruh, Hartle-Hawking and Boulware vacua respectively. We find, for all three vacuum cases, that the atoms turn out to be entangled even if they are initially in a separable state as long as the system is not placed right at the even horizon. Remarkably, only in the Unruh vacuum, will the asymptotic entanglement be affected by the backscattering of the thermal radiation off the space-time curvature. The effect of the back scatterings on the asymptotic entanglement cancels in the Hartle-Hawking vacuum case.Comment: 15 pages, no figures, Revte

Case Report: The Clinical Toxicity of Dimethylamine Borane

Context: Dimethylamine borane (DMAB) is a reducing agent used in nonelectric plating of semiconductors. Exposures are usually through occupational contact. We report here four cases of people who suffered from work-related exposure to DMAB. Case presentation: Three patients exposed to DMAB decontaminated immediately by drinking a lot of water; they reported dizziness, nausea, diarrhea 6–8 hr later. The other patient did not decontaminate at once, and he suffered from more severe symptoms, including dizziness, nausea, limb numbness, slurred speech, irritable mood, and ataxia 13 hr later. Magnetic resonance imaging showed symmetric lesions with hyperintensity on T2WI and FLAIR in bilateral cerebellar dantate nuclei. This patient was readmitted to the hospital due to difficulty in walking and climbing 18 days after exposure. Lower leg weakness and drop foot were found bilaterally. A nerve conduction study revealed polyneuropathy with motor-predominant axonal degeneration. This patient receives regular outpatient followups and still walks with a clumsy gait and has difficulty with hand-grasping activity. Discussion: This case study demonstrates that DMAB is highly toxic to humans through any route of exposure, and dermal absorption is the major route of neurotoxicity. DMAB induces acute cortical and cerebellar injuries and delayed peripheral neuropathy. Relevance: Further investigation of the toxic mechanism of DMAB is warranted. Early decontamination with copious water is the best current treatment for exposure to DMAB

Quantification of Influenza Virus RNA in Aerosols in Patient Rooms

The potential for human influenza viruses to spread through fine particle aerosols remains controversial. The objective of our study was to determine whether influenza viruses could be detected in fine particles in hospital rooms. METHODS AND FINDINGS: We sampled the air in 2-bed patient isolation rooms for four hours, placing cyclone samplers at heights of 1.5m and 1.0m. We collected ten air samples each in the presence of at least one patient with confirmed influenza A virus infection, and tested the samples by reverse transcription polymerase chain reaction. We recovered influenza A virus RNA from 5/10 collections (50%); 4/5 were from particles>4 μm, 1/5 from 1-4 μm, and none in particles<1 μm. CONCLUSIONS: Detection of influenza virus RNA in aerosols at low concentrations in patient rooms suggests that healthcare workers and visitors might have frequent exposure to airborne influenza virus in proximity to infected patients. A limitation of our study was the small sample size. Further studies should be done to quantify the concentration of viable influenza virus in healthcare settings, and factors affecting the detection of influenza viruses in fine particles in the air.published_or_final_versio

Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes

The Kondo-effect is a many-body phenomenon arising due to conduction electrons scattering off a localized spin. Coherent spin-flip scattering off such a quantum impurity correlates the conduction electrons and at low temperature this leads to a zero-bias conductance anomaly. This has become a common signature in bias-spectroscopy of single-electron transistors, observed in GaAs quantum dots as well as in various single-molecule transistors. While the zero-bias Kondo effect is well established it remains uncertain to what extent Kondo correlations persist in non-equilibrium situations where inelastic processes induce decoherence. Here we report on a pronounced conductance peak observed at finite bias-voltage in a carbon nanotube quantum dot in the spin singlet ground state. We explain this finite-bias conductance anomaly by a nonequilibrium Kondo-effect involving excitations into a spin triplet state. Excellent agreement between calculated and measured nonlinear conductance is obtained, thus strongly supporting the correlated nature of this nonequilibrium resonance.Comment: 21 pages, 5 figure

Dose-dependent effects of Allopurinol on human foreskin fibroblast cell and human umbilical vein endothelial cell under hypoxia

Allopurinol, an inhibitor of xanthine oxidase, has been used in clinical trials of patients with cardiovascular and chronic kidney disease. These are two pathologies with extensive links to hypoxia and activation of the transcription factor hypoxia inducible factor (HIF) family. Here we analysed the effects of allopurinol treatment in two different cellular models, and their response to hypoxia. We explored the dose-dependent effect of allopurinol on Human Foreskin Fibroblasts (HFF) and Human Umbilical Vein Endothelial Cells (HUVEC) under hypoxia and normoxia. Under normoxia and hypoxia, high dose allopurinol reduced the accumulation of HIF-1α protein in HFF and HUVEC cells. Allopurinol had only marginal effects on HIF-1α mRNA level in both cellular systems. Interestingly, allopurinol effects over the HIF system were independent of prolyl-hydroxylase activity. Finally, allopurinol treatment reduced angiogenesis traits in HUVEC cells in an in vitro model. Taken together these results indicate that high doses of allopurinol inhibits the HIF system and pro-angiogenic traits in cells

The Kondo effect in ferromagnetic atomic contacts

Iron, cobalt and nickel are archetypal ferromagnetic metals. In bulk, electronic conduction in these materials takes place mainly through the $s$ and $p$ electrons, whereas the magnetic moments are mostly in the narrow $d$-electron bands, where they tend to align. This general picture may change at the nanoscale because electrons at the surfaces of materials experience interactions that differ from those in the bulk. Here we show direct evidence for such changes: electronic transport in atomic-scale contacts of pure ferromagnets (iron, cobalt and nickel), despite their strong bulk ferromagnetism, unexpectedly reveal Kondo physics, that is, the screening of local magnetic moments by the conduction electrons below a characteristic temperature. The Kondo effect creates a sharp resonance at the Fermi energy, affecting the electrical properties of the system;this appears as a Fano-Kondo resonance in the conductance characteristics as observed in other artificial nanostructures. The study of hundreds of contacts shows material-dependent lognormal distributions of the resonance width that arise naturally from Kondo theory. These resonances broaden and disappear with increasing temperature, also as in standard Kondo systems. Our observations, supported by calculations, imply that coordination changes can significantly modify magnetism at the nanoscale. Therefore, in addition to standard micromagnetic physics, strong electronic correlations along with atomic-scale geometry need to be considered when investigating the magnetic properties of magnetic nanostructures.Comment: 7 pages, 5 figure

Oxaliplatin-dacarbazine combination chemotherapy for the treatment of advanced soft tissue sarcoma of the limbs

<p>Abstract</p> <p>Background</p> <p>This study was designed to explore the feasibility, safety, and outcomes of pre-operative oxaliplatin-dacarbazine combination therapy for the treatment of advanced soft tissue sarcoma (STS) of the limb.</p> <p>Patients and Methods</p> <p>Between November 2005 and November 2008, 31 patients with advanced limb STS classified with stage IV STS were randomly assigned into experimental or control groups, and both were given 2 cycles of chemotherapy before undergoing surgery. The regimen for the experimental group was oxaliplatin (120 mg/m², d₁) in combination with dacarbazine (175 mg/m², d₁₃), while that for the control group was a standard vincristine, epirubicin, cyclophosphamide therapy. Operations were carried out four weeks after the second chemotherapy cycle, followed by another 24 more chemotherapy cycles of the previous regimen.</p> <p>Results</p> <p>Following preoperative chemotherapy, the experimental group exhibited a significant improvement in tumor regression compared to controls. Both regimens were well-tolerated, and no significant differences in adverse reactions were noted. At a median follow-up of 24 months, 28 patients were still alive and had normal limb function. The progression free survival rate of the experimental group was significantly higher than that of the control group (10/15 vs. 4/16, <it>p </it>< 0.05).</p> <p>Conclusion</p> <p>Oxaliplatin- dacarbazine neoadjuvant/adjuvant chemotherapy improved the prognosis of patients with advanced limb STS in comparison with vincristine, epirubicin, cyclophosphamide combination therapy.</p

Biodistribution of gold nanoparticles in mouse lung following intratracheal instillation

<p>Abstract</p> <p>Background</p> <p>The fate of gold nanoparticles, 2, 40 and 100 nm, administered intratracheally to adult female mice was examined. The nanoparticles were traced by autometallography (AMG) at both ultrastructural and light microscopic levels. Also, the gold content was quantified by inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA). The liver is the major site of deposition of circulating gold nanoparticles. Therefore the degree of translocation was determined by the hepatic deposition of gold. Mice were instilled with 5 intratracheal doses of gold nanoparticles distributed over a period of 3 weeks and were killed 24 h after the last dose. One group of mice were given a single intratracheal dose and were killed after 1 h.</p> <p>Results</p> <p>The instilled nanoparticles were found in lung macrophages already 1 h after a single instillation. In mice instilled treated repeatedly during 3 weeks, the load was substantial. Ultrastructurally, AMG silver enhanced gold nanoparticles were found in lysosome-/endosome-like organelles of the macrophages and analysis with AMG, ICP-MS and NAA of the liver revealed an almost total lack of translocation of nanoparticles. In mice given repeated instillations of 2 nm gold nanoparticles, 1.4‰ (by ICP-MS) to 1.9‰ (by NAA) of the instilled gold was detected in the liver. With the 40 nm gold, no gold was detected in the liver (detection level 2 ng, 0.1‰) except for one mouse in which 3‰ of the instilled gold was found in the liver. No gold was detected in any liver of mice instilled with 100 nm gold (detection level 2 ng, 0.1‰) except in a single animal with 0.39‰ of the dose in the liver.</p> <p>Conclusion</p> <p>We found that that: (1) inert gold nanoparticles, administered intratracheally are phagocytosed by lung macrophages; (2) only a tiny fraction of the gold particles is translocated into systemic circulation. (3) The translocation rate was greatest with the 2 nm gold particles.</p