Membrane
hideA membrane is a layer of material which serves as a selective barrier between two phases and remains impermeable to specific particles, molecules, or substances when exposed to the action of a driving force. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream.
Membranes can be of various thickness, with homogeneous or heterogeneous structure. Membrane can also be classified according to their pore diameter. According to IUPAC, there are three different types of pore size classifications: microporous (dp < 2nm), mesoporous (2nm < dp < 50nm) and macroporous (dp > 50nm). Membranes can be neutral or charged, and particles transport can be active or passive. The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. Membranes can be generally classified into three groups: inorganic, polymeric or biological membranes. These three types of membranes differ significantly in their structure and functionality.
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News tagged with membrane
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Millions of people around the world use medicines based on statins to lower their blood cholesterol, but new research from the University of Gothenburg, published in the prestigious journal PNAS, shows that s ...
The Physics Of A Bump In A Rug
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Scientists often have to make sacrifices for their work. Physicist Dominic Vella chopped his bathroom rug into strips, and L. Mahadevan's coauthor ran off with his bookshelf. With these sacrifices, these two ...
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Chemistry Team Seeks to Use Artificial Photosynthesis and Nanotubes to Generate Hydrogen Fuel with Sunlight
Oct 14, 2009 |
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(PhysOrg.com) -- A team of four chemists at the University of Rochester have begun work on a new kind of system to derive usable hydrogen fuel from water using only sunlight.
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Infectious diseases currently cause about one-third of all human deaths worldwide, more than all forms of cancer combined. Advances in cell biology and microbial genetics have greatly enhanced understanding of the cause and ...
Come on in: Nuclear barrier less restrictive than expected in new cells
Oct 06, 2009 |
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When it comes to the two basic types of cells, prokaryotes and eukaryotes, compartmentalization is everything. Prokaryotes are evolutionarily ancient cells that only have a membrane surrounding their outer boundary, while ...
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Researchers at Fox Chase Cancer Center have demonstrated that a protein called NEDD9 may be required for some of the most aggressive forms of breast cancer to grow. Their findings, based on the study of a mouse model of breast ...
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(PhysOrg.com) -- Just as people plug in to computers, smart phones and electric outlets to communicate, electric fish communicate by quickly plugging special channels into their cells to generate electrical ...
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Sep 28, 2009 |
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(PhysOrg.com) -- Using an RNA-powered nanomotor, University of Cincinnati (UC) biomedical engineering researchers have successfully developed an artificial pore able to transmit nanoscale material through ...
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New data on signaling proteins, called G proteins, may prove important in fighting diseases such as cardiovascular, neurodegenerative disorders, and cancer. For many decades scientists have puzzled on "How ...
Study finds new way deadly food-borne bacteria spread
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University of Central Florida Microbiology Professor Keith Ireton has uncovered a previously unknown mechanism that plays an important role in the spread of a deadly food-borne bacterium.
