Photon correlations in the collective emission of hybrid gold-(CdSe/CdS/CdZnS) nanocrystal supraparticles.

We investigate the photon statistics of the light emitted by single self-assembled hybrid gold-CdSe/CdS/CdZnS colloidal nanocrystal supraparticles through the detailed analysis of the intensity autocorrelation functiong(2)(τ). We first reveal that, despite the large number of nanocrystals involved in the supraparticle emission, antibunching can be observed. We then present a model based on non-coherent Förster energy transfer and Auger recombination that well captures photon antibunching. Finally, we demonstrate that some supraparticles exhibit a bunching effect at short time scales corresponding to coherent collective emission.

Fluorescence decay enhancement and FRET inhibition in self-assembled hybrid gold CdSe/CdS/CdZnS colloidal nanocrystal supraparticles.

We report on the synthesis of hybrid light emitting particles with a diameter ranging between 100 and 500 nm, consisting in a compact semiconductor CdSe/CdS/CdZnS nanocrystal aggregate encapsulated by a controlled nanometric size silica and gold layers. We first characterize the Purcell decay rate enhancement corresponding to the addition of the gold nanoshell as a function of the particle size and find a good agreement with the predictions of numerical simulations. Then, we show that the contribution corresponding to Förster resonance energy transfer is inhibited.

Age dependent influence of external temperature on the pathogenesis of idiopathic lower extremity deep vein thrombosis.

AIM: The aim of the present study was to investigate the relationship between the incidence of idiopathic lower extremity deep vein thrombosis (DVT), age, location of the thrombus, and changes of temperature. MATERIAL AND METHOD: During the two year period between May 2009 and April 2011, inclusive, 124 consecutive patients were diagnosed as having idiopathic lower extremity DVT at the Vascular Surgery Clinic, Clinical Center of Nis, Serbia. RESULTS: In patients younger than 45 years, the increase in average daily temperature with 1 degree C 7 days before the event took place was associated (p 0.05) with a decrease of the risk of occurrence of idiopathic DVT of the lower limbs of 3.6% (0.4 6.7%) as well as DVT above the knees (p 0.01) of 4.7 % (1.3 8.0%). In patients of the age of 45 years and over the age of 45 years the increase of average daily temperature with 1 degree C 7 days before the event took place was associated (p 0.01) with the increase of the risk of occurrence of DVT below the knees of 9.4% (3.3 15.9%). CONCLUSION: According to the results of this study, one can conclude that the influence of external temperature change on DVT incidence and location is based on age.

Nature, strength, and consequences of indirect adsorbate interactions on metals

Atoms and molecules adsorbed on metals affect each other indirectly even over considerable distances. Via systematic density-functional calculations, we establish the nature and strength of such interactions, and explain for what adsorbate systems they critically affect important materials properties. This is verified in kinetic Monte Carlo simulations of epitaxial growth, which help rationalize a number of recent experimental reports on anomalously low diffusion prefactors.