New hexatic liquid phase observed in lyotropic thin films

The study of isotopic enrichment of water in human plasma and erythrocyte

Life does not sustain without water. For water, there is a natural abundance of stable isotope hydrogen and oxygen. Water molecules get across cell membranes through a plasma membrane protein, named aquaporin. Moreover, the kidney is the main organ to maintain water homeostasis. Here, we study the stable isotopic ratios of hydrogen and oxygen in human blood plasma and erythrocyte corresponding to kidney functions. We extract waters from human plasma and erythrocyte, collected from 110 participants, including 51 clinically stable outpatients with end-stage renal disease (ESRD) and 59 subjects with normal renal function (NRF). We observed that (i) both extracellular (blood plasma) and intracellular (erythrocyte) biology waters are isotopic differences between the ESRD and NRF participants, (ii) the natural abundance of isotopic waters of ESRD is hypo-isotopic, and (iii) the isotopic enrichment of water between erythrocyte and blood plasma are distinct. In addition, we introduce an empirical formula using entropy transformation to describe isotopic water enrichment for biology. Accordingly, the natural abundance of stable isotope water of blood plasma and erythrocyte may be possibly put in practice a new sign for assessments of kidney dysfunctions.

Defect-mediated emulsification in two dimensions

We consider two-dimensional dispersions of droplets of isotropic phase in a liquid with an XY -like order parameter, tilt, nematic, and hexatic symmetries being included. Strong anchoring boundary conditions are assumed. Textures for a single droplet and a pair of droplets are calculated and a universal droplet-droplet pair potential is obtained. The interaction of dispersed droplets via the ordered phase is attractive at large distances and repulsive at short distances, which results in a well defined preferred separation for two droplets and topological stabilization of the emulsion. This interaction also drives self-assembly into chains. Preferred separations and energy barriers to coalescence are calculated, and the effects of thermal fluctuations and film thickness are discussed.

Hexagonal order in crystalline and columnar phases of hard rods

We report a study of colloidal suspensions of highly monodisperse semiflexible chiral rodlike viruses, denoted fd, in the range of high concentrations. Small angle x-ray scattering experiments reveal the existence of two hexagonal phases: the first one is crystalline and the second one is hexatic columnar, as shown by its short-range positional order. The suspension of rodlike viruses is the first experimental system showing the whole phase sequence with increasing particle concentration theoretically predicted for systems of hard rods, ranging from the chiral nematic via the smectic to columnar and crystalline phases.

Depletion potential between large spheres immersed in a multicomponent mixture of small spheres

We analyze the depletion potential between large spheres in a multicomponent mixture of dense small spheres (up to seven components) using the integral equation theory (IET), in which semiempirical bridge functions are incorporated, and the insertion approach within the framework of density functional theory (DFT). The diameters of the small spheres considered are in the range of d(S)-5d(S). The results from the IET and DFT are in close agreement with each other. The depletion potential in the mixture is substantially different from that in a one-component system of dense small spheres with diameter d(S). In comparison with the latter, the former possesses in general a less pronounced oscillatory structure, and the free-energy barrier for large spheres to overcome before reaching the contact is significantly reduced. This tendency can be enhanced as the number of components increases. In a several-component mixture of small spheres whose diameters are suitably chosen and in which the packing fractions of the components share the same value, the depletion potential is essentially short ranged and attractive and possesses a sufficiently large, negative value at the contact.

Observation of a liquid phase with an orthorhombic orientational order

Using surface x-ray diffraction, we have determined the structure of liquid Bi monolayers on Cu(111) for a range of coverages. By combining diffuse scattering data from the liquid with information from the substrate scattering, the ordering properties of Bi have been fully determined. Even though the substrate is hexagonal, we find that the liquid does not show hexatic order but has an orthorhombic orientational order that occurs in three domains. Simultaneously, Bi has partial solidlike properties, even well above its melting point.