The effects of phenobarbital on biliary lipid metabolism in cholesterol gallstone subjects

The effect of 1.7–2.2 mg/day oral phenobarbital over short (1 MO) and long term (6–24 MO) treatment on primary bile acid (BA) secretion, composition, synthesis, pool size, and enterohepatic cycling rates as well as phospholipid (PL) and cholesterol (C) secretion rates and biliary composition was determined in 12 asymptomatic cholesterol gallstone subjects while 5 normals had only short term studies. Phenobarbital enhanced BA and C secretion (BA-636±166 to 2110±382 mg/hr, p<0.001 and C-42±5 to 224±48 mg/hr, p<0.001) and BA cycling rate in all subjects studied during stimulated enterohepatic circulation but, during fasting, it only enhanced BA secretion (451±129 vs. 759±159 mg/hr, p<0.05) in gallstone subjects. Cholic acid (CA) production rate (171±28 to 395±9 mg/hr, p<0.05) and pool size (727±80 to 1209±132 mg/hr, p<0.05) were increased during long term treatment of gallstone subjects, while the proportion of CA in bile and deoxycholic acid (DCA) in feces increased. Treatment decreased biliary cholesterol from supersaturated to saturated levels (9.5±0.6 vs. 6.1±0.9 moles%, p<0.02) in all fasting gallstone subjects and decreased cholesterol crystal loads during long term treatment; but, while prohibiting gallstone growth, it did not affect stone dissolution over 24 month's treatment. Phenobarbital also failed to affect biliary lipid composition or bile acid pool size in short term treatment of normals. Thus, phenobarbital affected hepatic metabolism of CA by enhancing production rate, secretion, and pool size; and in testinal metabolism of both CA and chenodeoxycholic (CDC) acids by increasing their cycling rates. Phenobarbital may have failed to produce stone dissolution by enhancing CA production and pool size more than that of CDC. Portions of this work were presented at the National Meeting of the American Federation of Clinical Research, Atlantic City, April 29, 1973 and at the Annual Meeting of the Canadian Society of Clinical Investigation, Winnepeg, Manitoba, January 21, 1975 as well as that of the Royal College of Physicians and Surgeons of Canada, January 27, 1977 at Toronto, Canada.     

Chemisorption of hydrogen on the missing-row Pt(110)-(1 × 2) surface

Chemisorption of hydrogen on the missing-row reconstructed Pt(110)-(1 × 2) surface has been studied by TPD, quantitative LEED, and DFT calculations. An (atypical) chemisorption site on the outermost close-packed rows with an ideal coverage of 0.5 ML (β₂-state) is found. Adsorption sites on the (111) microfacets are occupied only at higher coverage (β₁-state). After exposures of more than 400 L, the TPD spectra clearly reveal the controversly discussed α-state. In the same coverage range, an intense 1 × 4 superstructure becomes visible at LEED energies around 50 eV. The saturation coverage for chemisorption at T = 120 K is 33% higher than assumed previously.     

New method for thermo-optical modeling in liquid crystals

To investigate the thermo-optical effect in liquid crystal(s) (LC)s the statistical methods of experiment planning are applied. The experiment was conducted in accordance with the technique of orthogonal central compositional planning. In the course of the experiment, physical parameters (scanning velocity, laser beam intensity, LC temperature) have been varied on five levels. The obtained mathematical model describes the dependence of light-scattering texture dimensions in the LC layer onphysical parameters of information by thermo-optical registration. Such a model allows us to determine the suitable function model to obtain the preset dimensions of the light-scattering texture in a LC layer.     

Progress Toward Development of All-Printed RFID Tags: Materials, Processes, and Devices

Printed electronics provides a promising potential pathway toward the realization of ultralow-cost RFID tags for item-level tracking of consumer goods. Here, we report on our progress in developing materials, processes, and devices for the realization of ultralow-cost printed RFID tags. Using printed nanoparticle patterns that are subsequently sintered at plastic-compatible temperatures, low-resistance interconnects and passive components have been realized. Simultaneously, printed transistors with mobilities >10/sup -1/ cm/sup 2//V-s have been realized using novel pentacene and oligothiophene precursors for pMOS and ZnO nanoparticles for nMOS. AC performance of these devices is adequate for 135-kHz RFID, though significant work remains to be done to achieve 13.56-MHz operation.