Identification of meibomian gland testosterone metabolites produced by tissue-intrinsic intracrine deactivation activity.

Intracrinology-wherein hormones are synthesized in the organ where they exert their effect without release into circulation-has been described. However, molecular mechanisms of hormone deactivation within intracrine tissue are still largely unknown. The meibomian glands in the eyelids produce oil (meibum) to the ocular surface to prevent dehydration (dry eye).

A Unified Model for Non-Fickian Diffusion and Anomalous Swelling of Glassy Polymer Gels.

A sheet of glassy polymers placed in a solvent shows swelling behaviors quite different from that of soft polymers (rubbers and gels). (1) Non-Fickian diffusion (called case II diffusion): As solvent permeates into the sample, a sharp front is created between the swollen part and the glassy part, and it moves toward the center at constant speed. (2) Nonmonotonous swelling: The thickness of the sample first increases and then decreases toward the equilibrium value.

d -Alanine Affects the Circadian Clock to Regulate Glucose Metabolism in the Kidney.

Key Points: d-Alanine affects the circadian clock to regulate gluconeogenesis in the kidney. d-Alanine itself has a clear intrinsic circadian rhythm, which is regulated by urinary excretion, and acts on the circadian rhythm. d-Alanine is a signal activator for circadian rhythm and gluconeogenesis through circadian transcriptional network.

Effect of fluid viscoelasticity, shear stress, and interface tension on the lift force in lubricated contacts.

We consider a cylinder immersed in viscous fluid moving near a flat substrate covered by an incompressible viscoelastic fluid layer, and study the effect of the fluid viscoelasticity on the lift force exerted on the cylinder. The lift force is zero when the viscoelastic layer is not deformed, but becomes non-zero when it is deformed. We calculate the lift force by considering both the tangential stress and the normal stress applied at the surface of the viscoelastic layer.

Minimal upstream open reading frame of Per2 mediates phase fitness of the circadian clock to day/night physiological body temperature rhythm.

Body temperature in homeothermic animals does not remain constant but displays a regular circadian fluctuation within a physiological range (e.g., 35°C-38.

Universality in the Dynamics of Vesicle Translocation through a Hole.

We analyze the translocation process of a spherical vesicle, made of a membrane and incompressible fluid, through a hole smaller than the vesicle size, driven by pressure difference Δ. We show that such a vesicle shows certain universal characteristics, which are independent of the details of the membrane elasticity: (i) there is a critical pressure Δ below which no translocation occurs; (ii) Δ decreases to zero as the vesicle radius approaches the hole radius , satisfying the scaling relation Δ ∼ ( - ); and (iii) the translocation time τ diverges as Δ decreases to Δ, satisfying the scaling relation τ ∼ (Δ - Δ).

Interplay of Consolidation Fronts and Cracks in Drying Colloidal Coatings and Its Application in Controlling Crack Pattern Formation.

Cracks are frequently observed in drying colloidal coatings. Although a rich collection of crack patterns has been reported, the systematic study on how cracks grow into the final morphology during the drying process remains elusive. In this work, we use directional drying channels with wedge-shaped edges of different angles to study the interplay of advancing consolidation fronts and propagating cracks.

The identification of novel small extracellular vesicle (sEV) production modulators using luciferase-based sEV quantification method.

Small extracellular vesicles (sEVs) are nano-sized vesicles secreted from various cells that contain bioactive metabolites and function as key regulators for intercellular communication. sEVs modulate diverse biological and pathological processes in the body, and the amount of circulating sEVs has been reported to correlate with certain disease progression. Therefore, the identification of small molecular compounds that can control sEV production may become a novel therapeutic strategy.

Diffusion Limited Escape Rate of a Complex Molecule in Multi-dimensional Confinement.

The rate at which a Brownian particle confined in a closed space escapes from the space by passing through a narrow passage is called the escape rate. The escape rate is relevant to many diffusion limited processes in polymer and colloidal systems, such as colloidal aggregation, polymerization reaction, polymer translocation through a membrane, etc. Here, we propose a variational principle to calculate the escape rate of complex molecules doing Brownian motion in a multi-dimensional phase space.

Nmu/Nms/Gpr176 Triple-Deficient Mice Show Enhanced Light-Resetting of Circadian Locomotor Activity.

The suprachiasmatic nucleus (SCN) is the master circadian clock in mammals and is properly entrained by environmental light cycle. However, the molecular mechanism(s) determining the magnitude of phase shift by light is still not fully understood. The orphan G-protein-coupled receptor Gpr176 is enriched in the SCN, controls the pace (period) of the circadian rhythm in behavior but is not apparently involved in the light entrainment; Gpr176 animals display a shortened circadian period in constant darkness but their phase-resetting responses to light are normal.

Wetting dynamics of viscoelastic solid films.

We study the wetting phenomena of a soft viscoelastic solid film on a smooth and flat substrate. A poly-dimethylsiloxane (PDMS) rubber film is suspended from a stage at both ends, and the wetting behavior of the film against a glass substrate is observed while lowering the stage at a constant velocity. We find that the dynamics of the rubber-glass-air contact lines vary with the lowering velocity of the stage.

Circadian protection against bacterial skin infection by epidermal CXCL14-mediated innate immunity.

The epidermis is the outermost layer of the skin and the body's primary barrier to external pathogens; however, the early epidermal immune response remains to be mechanistically understood. We show that the chemokine CXCL14, produced by epidermal keratinocytes, exhibits robust circadian fluctuations and initiates innate immunity. Clearance of the skin pathogen in nocturnal mice was associated with CXCL14 expression, which was high during subjective daytime and low at night.

Derivation of Two-Fluid Model Based on Onsager Principle.

Using the Onsager variational principle, we study the dynamic coupling between the stress and the composition in a polymer solution. In the original derivation of the two-fluid model of Doi and Onuki the polymer stress was introduced ; therefore, a constitutive equation is required to close the equations. Based on our previous study of viscoelastic fluids with homogeneous composition, we start with a dumbbell model for the polymer, and derive all dynamic equations using the Onsager variational principle.

A light-induced small G-protein gem limits the circadian clock phase-shift magnitude by inhibiting voltage-dependent calcium channels.

Calcium signaling is pivotal to the circadian clockwork in the suprachiasmatic nucleus (SCN), particularly in rhythm entrainment to environmental light-dark cycles. Here, we show that a small G-protein Gem, an endogenous inhibitor of high-voltage-activated voltage-dependent calcium channels (VDCCs), is rapidly induced by light in SCN neurons via the calcium (Ca)-mediated CREB/CRE transcriptional pathway. Gem attenuates light-induced calcium signaling through its interaction with VDCCs.

Enhanced Electro-actuation in Dielectric Elastomers: The Nonlinear Effect of Free Ions.

Plasticized poly(vinyl chloride) (PVC) is a jelly-like soft dielectric material that attracted substantial interest recently as a new type of electro-active polymers. Under electric fields of several hundred volt/mm, PVC gels undergo large deformations. These gels can be used as artificial muscles and other soft robotic devices, with striking deformation behavior that is quite different from conventional dielectric elastomers.

Capillary Rising in a Tube with Corners.

We studied the dynamics of a fluid rising in a capillary tube with corners. In the cornered tube, unlike the circular tube, fluid rises with two parts, the bulk part where the entire cross-section is occupied by the fluid and the finger part where the cross-section is only partially filled. Using the Onsager principle, we derive coupled time-evolution equations for the two parts.

Evaporation Dynamics of Sessile Droplets: The Intricate Coupling of Capillary, Evaporation, and Marangoni Flow.

A single-component droplet placed on a completely wetting substrate shows a pseudostable apparent contact angle (θ) during evaporation. We propose a simple theory to explain the phenomenon accounting for the liquid evaporation and the internal flow induced by the capillary and Marangoni effects. The theory predicts that when evaporation starts, the contact angle approaches to θ in a short time τ, remains constant for most of the time of evaporation, and finally increases rapidly when the droplet size becomes very small.

Gas-liquid transition of van der Waals fluid confined in fluctuating nano-space.

Gas-liquid transition is generally a complex process, which involves nucleation of droplets and their growth by evaporation-condensation or collision-coalescence processes. Here, we focus on a microscopic system in which there is only one liquid droplet at most. In this case, we can develop an equilibrium theory for the formation of the droplet in the gas phase using the classical nucleation theory.