Proteins rather than mRNAs regulate nucleation and persistence of Oskar germ granules in Drosophila.

RNA granules are membraneless condensates that provide functional compartmentalization within cells. The mechanisms by which RNA granules form are under intense investigation. Here, we characterize the role of mRNAs and proteins in the formation of germ granules in Drosophila. Super-resolution microscopy reveals that the number, size, and distribution of germ granules is precisely controlled. Surprisingly, germ granule mRNAs are not required for the nucleation or the persistence of germ granules but instead control their size and composition. Using an RNAi screen, we determine that RNA regulators, helicases, and mitochondrial proteins regulate germ granule number and size, while the proteins of the endoplasmic reticulum, nuclear pore complex, and cytoskeleton control their distribution. Therefore, the protein-driven formation of Drosophila germ granules is mechanistically distinct from the RNA-dependent condensation observed for other RNA granules such as stress granules and P-bodies.

Urinary iodine and sodium status of urban Korean subjects: a pilot study.

OBJECTIVES: We estimated iodine status of Korean population by determining the concentration of spot urinary iodine (UI) with a reliable method based on the Sandell-Kolthoff reaction. MATERIALS AND METHODS: A total of 540 urine samples from apparently healthy subjects were collected, and UI, urinary sodium (UNa), and urinary creatinine (UCr) were determined from those samples and analyzed with age. RESULTS: There were significant decreases in either UI (P<0.0001), UI/UCr ratio (P=0.0001), UNa (P<0.0001), or UNa/Cr ratio (P=0.0001) in younger subjects than older ones. The median value of UI was 267.6 µg/L, but the median UI of the younger group (191.8 µg/L) was significantly decreased compared to that of the older group (383.9 µg/L). CONCLUSIONS: This study showed that the median of UI in Korean urban population was in a more than adequate iodine nutritional state, but UI was significantly different between the younger age group and the older age group.

Phase behavior of hexa-peri-hexabenzocoronene derivative in organic solvent.

The phase behavior of HBC-C12 in p-xylene at various concentrations has been investigated by differential scanning calorimetry, polarized optical microscopy, small angle neutron scattering and wide-angle X-ray scattering techniques, and a phase diagram depending on concentration and temperature has been determined with detailed structural information. At room temperature, HBC-C12 in p-xylene forms needle-like crystalline aggregates with a rectangular columnar packing which is essentially the same as the crystalline phase of HBC-C12 in bulk. Upon heating, it undergoes two transitions, a transition from the rectangular columnar packing to another rectangular columnar packing with a small step change in the lattice parameter c, and then a transition to isotropic phase. In the isotropic phase, HBC-C12 molecules form stacked cylindrical particles which consist of ∼11-13 molecules depending on temperature. Upon cooling, HBC-C12 in p-xylene makes an abrupt transition from the isotropic to the rectangular columnar packing, which is in contrast with the gradual columnar to isotropic transition upon heating. These results provide important information for optimizing the conditions of discotic liquid crystal solution for the fabrication of DLC thin films using solution-processing techniques.

Effect of film thickness on the columnar packing structures of discotic supramolecules in thin films.

The effects of film thickness on the columnar packing structure of discotic supramolecules in a thin supported film have been investigated by grazing-incidence small-angle X-ray scattering technique using magnetically aligned cobalt octa(n-decylthio)porphyrazine (CoS10) films on octadecyltrichlorosilane (OTS)-functionalized substrates as model systems. Magnetically aligned CoS10 films with a range of film thicknesses (49-845 nm) form uniaxially oriented 'edge-on' columnar superstructures with their columnar directors perpendicular to the applied magnetic field. However, the orientational ordering of the columnar packing in the plane perpendicular to the applied magnetic field is strongly dependent on the film thickness. While being damped by the elasticity of the side chains of CoS10, the strong interfacial interaction at the film-substrate interface propagates up to 50-100 nm from the substrate, maintaining the orientation of columnar packing in the plane perpendicular to the applied magnetic field. When the distance from the film-substrate interface becomes larger than about 100 nm, symmetric tilting of columnar layer orientation, which saturates at 11.5 degrees , occurs due to longitudinal edge dislocations induced by accumulated elastic deformation.

Folded catadioptric panoramic lens with an equidistance projection scheme.

A new formula for a catadioptric panoramic lens with an equidistance projection scheme has been derived. The fabricated lens has a field of view that is wider than that of any previously reported panoramic lens, and the nonimaged region near the back of the camera has a constant volume with zero angular extension.