A simple steady state iterative solution of Münch pressure-flow in unbranched sieve tubes containing only water and sucrose is derived. The iterative equations can be solved on a programmable desk calculator. Solutions are presented for steady state transport with specific mass transfer rates up to 1.5 x 10(-5) mole second(-1) centimeters(-2) (= 18.5 grams hour(-1) centimeters(-2)) over distanc...

Currently, health care workers (HCWs) in the United States are being vaccinated against smallpox, and there is a possibility that this will be expanded to a more widespread vaccination program. Inadvertent transmission of vaccinia virus to patients with illnesses that are contraindications to vaccination is theoretically possible. Vaccinia virus is shed from the vaccination lesion of healthy pr...

We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping efficiency of these flows is limited by the presence of "unstirred" concentration boundary layers nea...

1. The factor responsible for the spreading property of testicle extracts was found to be soluble in water, in salt solution, and in acid media. It is relatively stable at high hydrogen ion concentrations, and it is not precipitated or inactivated by hydrochloric acid up to pH 2.0. The spreading substance is not soluble in acetone, ether, alcohol, chloroform, or pyridine. It is inactivated by c...

The level of hydration in the human body is carefully adjusted to control the electrolyte balance that governs the biochemical processes that sustain life. An electrolyte deficiency caused by deor overhydration will not only limit human performance, but can also lead to serious health problems and death if left untreated. Because humans can withstand a change in hydration of only ±20%, frequent...

C31G is a specific formulation which contains equal molar concentrations of alkyi N-betaine and alkyl N.N-dimethylamine oxide. Vaginal suppositories containing 500 mg of C31G, this potent antimicrobial substance, were prepared by the fusion method in a variety of Suppocire and Witepsol bases with different melting points and hydroxyl values. In vitro release and diffusion characteristics of C31...

Problems associated with islet transplantation for Type 1 Diabetes (T1D) such as shortage of donor cells, use of immunosuppressive drugs remain as major challenges. Immune isolation using encapsulation may circumvent the use of immunosuppressants and prolong the longevity of transplanted islets. The encapsulating membrane must block the passage of host's immune components while providing suffic...

The endothelium serves as a protective semipermeable barrier in blood vessels and lymphatic vessels. Leukocytes and pathogens can pass directly through the endothelium by opening holes in endothelial cells, known as transcellular tunnels, which are formed by contact and self-fusion of the apical and basal plasma membranes. Here we test the hypothesis that the actin cytoskeleton is the primary b...

Introduction Dialysis is frequently used in continuous flow analysis to separate low molecular weight analytes from protein containing samples. The dialyser assembly consists of two clear plastic blocks with matching donor and recipient grooves, between which is sandwiched a semipermeable membrane. The airsegmented donor (diluted sample) stream and recipient streams flow at constant rates along...

Solutions of a wide variety of electrolytes, isotonic with liver or with kidney tissue, have approximately the same osmotic pressure as solutions of sodium chloride isotonic with tissues of the two organs respectively; that is, with solutions approximately twice as concentrated as the sodium chloride of mammalian blood plasma. The molar concentration of various electrolytes isotonic with liver ...