Dynamical effects induced by long range activation in a nonequilibrium reaction-diffusion system

We both show experimentally and numerically that the time scales separation introduced by long range activation can induce oscillations and excitability in nonequilibrium reaction-diffusion systems that would otherwise only exhibit bistability. Namely, we show that the Chlorite-Tetrathionate reaction, where autocatalytic species diffuses faster than the substrates, the spatial bistability domain in the nonequilibrium phase diagram is extended with oscillatory and excitability domains. A simple model and a more realistic model qualitatively account for the observed behavior. The latter model provides quantitative agreement with the experiments.Comment: 19 pages + 9 figure

High-field magnetization of the 3d heavy-fermion system LiV2_2O4−d_{4-d} (d = 0, 0.08)

Metamagnetic behavior has been observed in LiV2O4 powder sample around 38 T at 4.2 K. On the other hand, magnetization for oxygen deficient LiV2O3.92 shows no indication of metamagnetism up to 40 T, and shows substantially reduced magnetic moment compared to that of LiV2O4. These results suggest that ferromagnetic interaction is strongly enhanced by magnetic fields in LiV2O4, whereas antiferromagnetic interaction is dominant in LiV2O3.92.Comment: 9 pages, 3 figures, to be published in J. Phys.: Condens. Matte

Metal-insulator transition in the two-orbital Hubbard model at fractional band fillings: Self-energy functional approach

We investigate the infinite-dimensional two-orbital Hubbard model at arbitrary band fillings. By means of the self-energy functional approach, we discuss the stability of the metallic state in the systems with same and different bandwidths. It is found that the Mott insulating phases are realized at commensurate band fillings. Furthermore, it is clarified that the orbital selective Mott phase with one orbital localized and the other itinerant is stabilized even at fractional band fillings in the system with different bandwidths.Comment: 7 pages, 10 figure

Intensidades da poda seca e do desbaste de cacho na composição da uva Cabernet Sauvignon.

A pesquisa foi realizada durante quatro anos, num vinhedo de Cabernet Sauvignon (Vitis vinifera L.), em Bento Gonçalves-RS. O objetivo foi determinar o efeito das intensidades da poda seca e do desbaste de cacho em variáveis relacionadas aos componentes de produção da videira e à composição do mosto de uva. Os tratamentos consistiram em dois níveis de poda seca - curta e longa - e quatro de desbaste de cacho (%) - 0; 25; 50 e 75 -; com cinco repetições. O delineamento experimental foi o em blocos casualizados, com os tratamentos em parcelas subdivididas. Os resultados mostram que a poda seca e o desbaste de cacho tiveram efeito altamente significativo na produtividade do vinhedo que, na média dos quatro anos, variou de 10.971 kg/ha ? poda curta, 75% de desbaste ? a 32.819 kg/ha ? poda longa, 0% de desbaste. Houve, também, efeito significativo na produtividade por gema, peso de ramos podados por gema e por hectare, área foliar/peso fresco do fruto e produtividade/peso de ramos podados. Entretanto, o efeito nas variáveis relacionadas a açúcar e acidez do mosto da uva foi pouco expressivo. O componente 1 da análise de componentes principais discriminou o tratamento poda curta a 75% de desbaste de cacho dos tratamentos poda longa-0% de desbaste e poda longa-25% de desbaste

The Effect of Contrast Medium SonoVue® on the Electric Charge Density of Blood Cells

The effect of contrast medium SonoVue® on the electric charge density of blood cells (erythrocytes and thrombocytes) was measured using a microelectrophoretic method. We examined the effect of adsorbed H+ and OH− ions on the surface charge of erythrocytes or thrombocytes. Surface charge density values were determined from electrophoretic mobility measurements of blood cells performed at various pH levels. The interaction between solution ions and the erythrocyte’s or thrombocyte’s surface was described by a four-component equilibrium model. The agreement between the experimental and theoretical charge variation curves of the erythrocytes and thrombocytes was good at pH 2–9. The deviation observed at a higher pH may be caused by disregarding interactions between the functional groups of blood cells

Membrane-Bound TNF Induces Protective Immune Responses to M. bovis BCG Infection: Regulation of memTNF and TNF Receptors Comparing Two memTNF Molecules

Several activities of the transmembrane form of TNF (memTNF) in immune responses to intracellular bacterial infection have been shown to be different from those exerted by soluble TNF. Evidence is based largely on studies in transgenic mice expressing memTNF, but precise cellular mechanisms are not well defined and the importance of TNF receptor regulation is unknown. In addition, memTNF activities are defined for a particular modification of the extracellular domain of TNF but a direct comparison of different mutant memTNF molecules has not been done in vivo

Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale

<p>Abstract</p> <p>Background</p> <p>In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO.</p> <p>Methods</p> <p>The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up.</p> <p>Results</p> <p>There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time.</p> <p>Conclusions</p> <p>RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.</p

Metabolic Engineering of Cofactor F420 Production in Mycobacterium smegmatis

Cofactor F420 is a unique electron carrier in a number of microorganisms including Archaea and Mycobacteria. It has been shown that F420 has a direct and important role in archaeal energy metabolism whereas the role of F420 in mycobacterial metabolism has only begun to be uncovered in the last few years. It has been suggested that cofactor F420 has a role in the pathogenesis of M. tuberculosis, the causative agent of tuberculosis. In the absence of a commercial source for F420, M. smegmatis has previously been used to provide this cofactor for studies of the F420-dependent proteins from mycobacterial species. Three proteins have been shown to be involved in the F420 biosynthesis in Mycobacteria and three other proteins have been demonstrated to be involved in F420 metabolism. Here we report the over-expression of all of these proteins in M. smegmatis and testing of their importance for F420 production. The results indicate that co–expression of the F420 biosynthetic proteins can give rise to a much higher F420 production level. This was achieved by designing and preparing a new T7 promoter–based co-expression shuttle vector. A combination of co–expression of the F420 biosynthetic proteins and fine-tuning of the culture media has enabled us to achieve F420 production levels of up to 10 times higher compared with the wild type M. smegmatis strain. The high levels of the F420 produced in this study provide a suitable source of this cofactor for studies of F420-dependent proteins from other microorganisms and for possible biotechnological applications

Conversionless efficient and broadband laser light diffusers for high brightness illumination applications

Funder: Deutsche Forschungsgemeinschaft (German Research Foundation); doi: https://doi.org/10.13039/501100001659Abstract: Laser diodes are efficient light sources. However, state-of-the-art laser diode-based lighting systems rely on light-converting inorganic phosphor materials, which strongly limit the efficiency and lifetime, as well as achievable light output due to energy losses, saturation, thermal degradation, and low irradiance levels. Here, we demonstrate a macroscopically expanded, three-dimensional diffuser composed of interconnected hollow hexagonal boron nitride microtubes with nanoscopic wall-thickness, acting as an artificial solid fog, capable of withstanding ~10 times the irradiance level of remote phosphors. In contrast to phosphors, no light conversion is required as the diffuser relies solely on strong broadband (full visible range) lossless multiple light scattering events, enabled by a highly porous (>99.99%) non-absorbing nanoarchitecture, resulting in efficiencies of ~98%. This can unleash the potential of lasers for high-brightness lighting applications, such as automotive headlights, projection technology or lighting for large spaces