Characterization and Optimization of Fluorescent Organosilica Colloids for 3D Confocal Microscopy Prepared Under "Zero-Flow" Conditions.

We optimize and characterize the preparation of 3-trimethoxysilyl propyl methacrylate (TPM) colloidal suspensions for three-dimensional confocal microscopy. We revisit a simple synthesis of TPM microspheres by nucleation of droplets from prehydrolyzed TPM oil in a "zero-flow" regime and demonstrate how precise and reproducible control of particle size may be achieved via single-step nucleation with a focus on how the reagents are mixed. We also revamp the conventional dyeing method for TPM particles to achieve uniform transfer of a fluorophore to the organosilica droplets, improving particle identification. Finally, we illustrate how a ternary mixture of tetralin, trichloroethylene, and tetrachloroethylene may be used as a suspension medium which matches the refractive index of these particles while allowing independent control of the density mismatch between particle and solvent.

Single-orientation colloidal crystals from capillary-action-induced shear.

We study the crystallization of colloidal dispersions under capillary-action-induced shear as the dispersion is drawn into flat walled capillaries. Using confocal microscopy and small angle x-ray scattering, we find that the shear near the capillary walls influences the crystallization to result in large random hexagonal close-packed (RHCP) crystals with long-range orientational order over tens of thousands of colloidal particles. We investigate the crystallization mechanism and find partial crystallization under shear, initiating with hexagonal planes at the capillary walls, where shear is highest, followed by epitaxial crystal growth from these hexagonal layers after the shear is stopped. We then characterize the three-dimensional crystal structure finding that the shear-induced crystallization leads to larger particle separations parallel to the shear and vorticity directions as compared to the equilibrium RHCP structure. Confocal microscopy reveals that competing shear directions, where the capillary walls meet at a corner, create differently oriented hexagonal planes of particles. The single-orientation RHCP colloidal crystals remain stable after formation and are produced without the need of complex shear cell arrangements.

Sandfly fever in Afghanistan-a sometimes overlooked disease of military importance: a case series and review of the literature.

Sandfly fever, sometimes known as pappataci fever or Phlebotomus fever, is a vector transmitted viral illness with a history of affecting naïve military formations that travel through or fight in areas in which the infection is endemic. We present a series of 4 hospitalized cases of sandfly fever (2 presumptive, 2 laboratory confirmed) that were admitted to a Role 3 hospital in Afghanistan for evaluation and treatment following medical evacuation from a forward area for marked fevers and malaise. Laboratory evaluation of these cases was significant for leukopenia and thrombocytopenia, consistent with historical descriptions of sandfly fever. In the correct geographic and clinical setting, the finding of mild leukopenia among a cluster of febrile patients should prompt the clinician to at least consider a diagnosis of sandfly fever. A cluster investigation conducted by preventive medicine personnel identified numerous other presumed cases of sandfly fever in this forward special operations camp. Response efforts emphasized enforcement of standard vector-borne disease control measures by operational leadership in order to limit effect on tactical operations. We review historical instances of sandfly fever affecting military operations, and present a review of clinical presentation, transmission, management, and prevention.