An Experimental and Numerical Program to Study the Properties of Thin Biological Membranes and Water Filling Process

Boundary conditions are usually the key problem in the establishment of a numerical model for simulation. An algorithmic method is needed to obtain a concrete numerical solution when the combined controlling equation sets are difficult to solve analytically. In this research, a type of algorithm known as the double forward method (DFM) is proposed to solve complex boundary conditions. The accuracy of the DFM is controllable, and it was found to be reliable when applying it to the water filling process in a water supply pipeline system. The DFM can also be used to solve multidimensional problems. In addition, the established water filling model in this study combined an open channel flow and a pressured flow, and a surge tank boundary condition was developed to fit the entire water filling process.

Download Full-text

Electron Diffraction of Wet Biological Membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050809 ◽

1974 ◽

Vol 32 ◽

pp. 158-159

Author(s):

S.W. Hui ◽

D.F. Parsons

Keyword(s):

Electron Diffraction ◽

Data Collection ◽

Biological Membranes ◽

Small Areas ◽

Electron Diffraction Technique ◽

Electron Microscopes ◽

Collection Time ◽

Camera Length

The development of the hydration stages for electron microscopes has opened up the application of electron diffraction in the study of biological membranes. Membrane specimen can now be observed without the artifacts introduced during drying, fixation and staining. The advantages of the electron diffraction technique, such as the abilities to observe small areas and thin specimens, to image and to screen impurities, to vary the camera length, and to reduce data collection time are fully utilized. Here we report our pioneering work in this area.

Download Full-text

Observation of Concanavalin-A receptors on hydrated planar erythrocyte membrane film by in situ electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076640 ◽

1983 ◽

Vol 41 ◽

pp. 608-609

Author(s):

Neng-Bo He ◽

S.W. Hui

Keyword(s):

Lipid Bilayers ◽

Erythrocyte Membrane ◽

Lipid Membranes ◽

Surface Film ◽

Biological Membranes ◽

Electron Microscopic Observation ◽

Electron Microscopic ◽

Black Lipid Membranes ◽

Fine Mesh ◽

Planar Films

Monolayers and planar "black" lipid membranes have been widely used as models for studying the structure and properties of biological membranes. Because of the lack of a suitable method to prepare these membranes for electron microscopic observation, their ultrastructure is so far not well understood. A method of forming molecular bilayers over the holes of fine mesh grids was developed by Hui et al. to study hydrated and unsupported lipid bilayers by electron diffraction, and to image phase separated domains by diffraction contrast. We now adapted the method of Pattus et al. of spreading biological membranes vesicles on the air-water interfaces to reconstitute biological membranes into unsupported planar films for electron microscopic study. hemoglobin-free human erythrocyte membrane stroma was prepared by hemolysis. The membranes were spreaded at 20°C on balanced salt solution in a Langmuir trough until a surface pressure of 20 dyne/cm was reached. The surface film was repeatedly washed by passing to adjacent troughs over shallow partitions (fig. 1).

Download Full-text