Biomedical subjects

Yong Liang Zhang

Publications and source records attributed to Yong Liang Zhang.

4 recordsLinked to original sources

PubMed2005

MAP kinases in immune responses.

MAP kinases are evolutionarily conserved signaling regulators from budding yeast to mammals and play essential roles in both innate and adaptive immune responses. There are three main families of MAPKs in mammals. Each of them has its own activators, inactivators, substrates and scaffolds, which altogether form a fine signaling network in response to different extracellular or intracellular stimulation. In this review, we summarize recent advances in understanding of the regulation of MAP kinases and the roles of MAP kinases in innate and adaptive immune responses.

Animals↗

PubMed2003

Surfactant driven flows overlying a hydrophobic epithelium: film rupture in the presence of slip.

Both for tear films and along the airways within the lung, one has an extremely thin fluid layer overlying a biological substrate; in both cases surfactants either of natural origin, or artificially introduced, are important in driving fluid flows. There is evidence that slip can occur when hydrophilic liquids, similar to mucus or aqueous tear films, overlie hydrophobic epithelium. Utilizing results from recent experimental findings we examine the possible influence of slip upon tear film rupture, important in so-called dry eye, and upon surfactant-induced flows within the lung, used in surfactant replacement therapy.

Epithelium↗

PubMed2003

Analysis of tear film rupture: effect of non-Newtonian rheology.

We investigate the rupture mechanism of a precorneal thin mucus coating sandwiched between the aqueous tear film and the corneal epithelial surface with a monolayer of surfactant overlying the aqueous layer. The Ostwald constitutive relation is employed to model mucus and a linear equation of state describing the relationship between surface tension and surfactant concentration is adopted. Three nonlinear coupled evolution equations governing the transport of surfactant, mucus, and total liquid layer thicknesses, based on lubrication theory and a perturbation expansion technique, have been derived. The resulting equations are solved numerically in order to explore the influence of the rheological properties of mucus, aqueous-mucus thickness ratio, aqueous-mucus interfacial tension, Marangoni number, and surfactant concentration on both the onset of instability and tear film evolution in the presence of van der Waals interactions, which could rupture the tear film. Our results reveal that the influence of rheological properties, aqueous-mucus thickness ratio, and interfacial tension on the time required for film rupture can be significant and varies considerably, depending on the magnitude of the Hamaker constants governing the strength of the van der Waals forces.

Data Interpretation, Statistical↗

PubMed2003

A theoretical study of chemical delivery within the lung using exogenous surfactant.

A mathematical model is developed for lung injury treatments involving the delivery of therapeutic chemicals, such as drugs and gene vectors, into the lung using simultaneous tracheal instillation of exogenous pulmonary surfactant. The influence of exogenous surfactant dose, flow rate, bulk liquid viscosity, pulmonary absorption rate and chemical molecular diffusivity on the chemical delivery to the lung is investigated. Our results reveal that different pulmonary absorption rates lead to significantly different distribution patterns and change the time taken for the total amount of chemical to be absorbed along the airways. The various factors can also influence where the majority of the chemical is placed within the lung and this is relevant to the targeting of drugs to particular lung generations.

Absorption↗