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291.
292.
Jacqueline Dupont 《Journal of the American Oil Chemists' Society》1965,42(11):903-907
Young adult female rats were fed diets containing 2% of calories from corn oil plus 20, 40, 60 or 80% of calories as beef
tallow or diets containing 2% corn oil and the calorie allowance restricted to 80, 60, 40 or 20% of ad libitum consumption.
Incorporation of C14-acetate into cholesterol and total fat was determined as an indication of rate of synthesis.
As dietary fat was increased there was a linear increase in cholesterol radioactivity, as measured in serum, liver and carcass.
As calories were decreased there were small but significant increases in cholesterol radioactivity. There was a highly significant
decrease in incorporation of acetate into total fat as dietary fat increased, and a decrease in total fat radioactivity when
calorie intake was restricted. The differences in rate of cholesterol biosynthesis were not accompanied by differences in
total quantity of cholesterol. The conclusion reached was that utilization of fat for energy results in accelerated cholesterol
biosynthesis.
Presented in part at the annual meeting of the Federation of American Societies for Experimental Biology, Chicago, 1964. 相似文献
293.
A number of studies have been conducted on serum cholesterol disappearance following a single injection of tracer. They have shown 2 or 3 component curves depending on the length of time of observation. They have been interpreted to indicate pools of cholesterol in fast or slow equilibrium with serum and generally depicted as representing groups of tissues. A cholesterol kinetic study was conducted using rats so that each tissue could be analyzed for appearance-disappearance of cholesterol from 30 minutes to 75 days. Serum and liver appeared to die-away for 30 days in a 2 component configuration, then exhibited a repetition of the same curve in the next 30 days. Skeletal muscle and kidney had a slow buildup for 2 weeks, then a plateau for 2 weeks then a 2 component die-away. Adipose showed a high plateau from 30 minutes to 30 days then a 2 component die-away, with specific activity higher than serum at all times. The data are interpreted to indicate that adipose tissue sequestered part of the tracer dose and all tissues reached equilibrium at about 30 days. After that time all tissues had a statistically significant 2 component die-away curve. The mathematical models tested suggest that in the steady state, cholesterol enters and exits the slow pool of serum, kidney, muscle and adipose and in liver enters both pools. Interpretation of the complete die-away is that the tracer dose first equilibrates with membrane free cholesterol, then with the intracellular cholesterol, and finally dies-away at the rate of release by the slow intercellular pool. 相似文献
294.
Morcrette M Rozier P Dupont L Mugnier E Sannier L Galy J Tarascon JM 《Nature materials》2003,2(11):755-761
Although widely used, the most promising Li-based technologies still suffer from a lack of suitable electrodes. There is therefore a need to seek new materials concepts to satisfy the increasing demands for energy storage worldwide. Here we report on a new layered electrode material, Cu(2.33)V(4)O(11), which shows a sustainable reversible capacity of 270 mA h g(-1) at a voltage of about 2.7 V, and electrochemically reacts with Li in an unusual and spectacular way. The reaction entails a reversible Li-driven displacement process leading to the growth and disappearance of Cu dendrites with a concomitant reversible decomposition and recrystallization of the initial electrode material. We show from structural considerations that the uniqueness of Cu(2.33)V(4)O(11) is rooted in the peculiar flexibility of the stacked [V(4)O(11)](n) layers, which is due to the presence of pivot oxygen atoms. Fully reversible displacement reactions could provide a new direction for developing an alternative class of higher energy density Li storage electrodes. 相似文献
295.
296.
Preliminary information is given indicating that all tissues of the miniature swine examined thus far contain cholanoic (bile)
acids. Thin layer and gas chromatographic analyses suggest that the cholanoic acids are conjugated with glycine and taurine.
The amounts appear to be substantial and should be assessed in regard to studies of cholesterol turnover. 相似文献
297.
Nickel aluminide intermetallics (e.g., Ni3Al and NiAl) are considered to be attractive materials for high-temperature structural applications. Laser-engineered net
shaping (LENS) is a rapid prototyping process, which involves laser processing fine metal powders into three-dimensional shapes
directly from a computer-aided design (CAD) model. In this work, an attempt has been made to fabricate aluminide intermetallic
compounds via reactive in-situ alloying from elemental powders using the LENS process. In-situ reactive alloying was achieved by delivering elemental Ni and Al powders from two different powder feeders, eliminating segregation
observed in the samples deposited by using the premixed elemental powders. Nickel aluminides of various compositions were
obtained easily by regulating the ratio of their feed rates. The aluminide deposits exhibited a high solidification and subsolidus
cracking susceptibility and porosity formation. The observed porosity resulted from a water-atomized Ni powder and can be
minimized or eliminated by the use of a N2-gas-atomized Ni powder of improved quality. Cracking was due to the combined effect of the high thermal stresses generated
from the LENS processing and the brittleness of the intermetallics. Crack-free deposits were fabricated by preheating the
substrate to a temperature of 450 °C to 500 °C during LENS processing. Compositionally graded Ni-Al deposits with a gradient
microstructure were also produced by the in-situ reactive processing. 相似文献
298.
299.
Sansonetti P. Alard F. Vassallo C. Kammerer P. Francois P.L. Monerie M. Gabriagues J.M. Dupont P. 《Electronics letters》1982,18(23):989-990
We report experimental evidence of fundamental mode cutoff in depressed inner cladding single-mode fibres. It is characterised by a sharp decrease in the transmission curve and by a local increase of the fundamental mode spot size. Both phenomena are theoretically explained. 相似文献
300.
Indium Phosphide‐Based Quantum Dots with Shell‐Enhanced Absorption for Luminescent Down‐Conversion
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Dorian Dupont Mickael D. Tessier Philippe F. Smet Zeger Hens 《Advanced materials (Deerfield Beach, Fla.)》2017,29(29)
It is shown that admixing small amounts of cadmium into the shell of InP/ZnSe core/shell quantum dots results in an increased absorption of blue light and a limited redshift of the band‐edge emission. These effects reflect the reduced bandgap of (Zn,Cd)Se alloys and their smaller conduction‐band offset with InP. Nevertheless, adjusting the InP core size enables InP/ZnSe and InP/(Zn,Cd)Se quantum dots with identical emission characteristics to be made. Processing both materials into remote phosphor disks, it is demonstrated that the shell‐enhanced absorbance of InP/(Zn,Cd)Se has the double benefit of suppressing self‐absorption and reducing the amount of quantum dots by weight needed to attain a given blue‐to‐red color conversion. 相似文献