Trace volatile constituents of human urine, serum, and cerebrospinal fluid were concentrated on a porous polymer precolumn, and resolved with high-efficiency glass capillary columns. Thin-film glass columns facilitate effective resolution of underivatized compounds within the volatility range up to docosane in relatively short analysis times. Glass capillary columns coated with stationary phase...

Glass capillaries with diameters of 1.5 mm were used. The tips of the capillaries were sharpened by a flaming-brown micropipette puller (Model P-1000, Sutter Instrument, USA) to obtain needle-shape capillaries. Anhydrous alcohol (99.5%) and anhydrous toluene (99.9%) were purchased from Shimakyus Pure Chemical (Osaka, Japan) and J. T. Baker (Phillipsburg, NJ, USA). MTS (Methyltrichlorosilane, CH...

The reflectance factors of transparent fibers, free delustering agent, are predicted by geometric as well as Kubelka-Munk models. Transparent fibers are simulated by a net of glass capillary tubes containing different solutions of dyestuffs. Based on the results, prediction of the reflectance factor of capillary net by geometric model is relatively better than those obtained from Kubelka-Munk...

Investigation of the identity and modes of action of neurotransmitters in the mammalian central nervous system can be facilitated by simultaneous intracellular recording of membrane potential and extracellular iontophoresis of agonists and antagonists. We describe here techniques for conveniently constructing a compound microelectrode, originally described by Sonnhof (Pflugers Arch 341, 351-358...

In this report we demonstrate electrical communication in the microcirculation between arterioles and capillary networks in situ. Microvessel networks in the hamster cheek pouch, which included capillaries and their feeding arterioles, were labeled with the voltage-sensitive dye di-8-ANEPPS by intraluminal perfusion through a micropipette. Pulses of 140 mM potassium solution were applied by pre...

Capillary circulation is delicately regulated by microvascular constriction mechanisms, thereby controlling capillary perfusion and transmural pressure. The influence of posture on capillary flow has been investigated in both diseased and healthy people. However, its influence on capillary pressure has rarely been investigated. We measured capillary pressures in the supine and sitting positions...

Various liquid phases for glass capillary columns have been evaluated for gas-liquid chromatographic analysis of methyl ester trimethylsilylether derivatives of bile acids from serum and bile. Bile acid analysis is rapid and exhibits high separation efficiency with a 20 X 0.3 mm glass capillary column whose internal surface is covered with a crystal layer of barium carbonate and coated with pol...