50 research outputs found
Age- and sex-related changes in fasting plasma glucose and lipoprotein in cynomolgus monkeys
BACKGROUND: The age-related dysfunction of glucose and lipid metabolism has a long-standing relationship with cardiovascular and neurodegenerative disease. However, the effects of metabolic dysfunction on men and women are different. Reasons for these sex differences remains unclear. Cynomolgus monkeys have been used, in the past, for the study of human metabolic diseases due to their biologically proximity to humans. Nevertheless, few studies to date have focused on both age- and sex-related differences in glucose and lipid metabolism. The present study was designed to specifically address these questions by using a large cohort of cynomolgus monkeys (N = 1,399) including 433 males and 966 females with ages ranging 4 to 24 years old. METHODS: Fasting plasma glucose (FPG) and lipid parameters including total cholesterol (T-Cho), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured. All these parameters were compared between ages and sexes. RESULTS: Among the entire cohort, age was strongly correlated with levels of FPG, TG and HDL. Consequently, sex-related analysis revealed that females had significantly higher average levels of FPG, T-Cho, TG, HDL-C and LDL-C than their male counterparts. In addition, more female (28.5 %) than male (16 %) monkeys qualified for impaired fasting plasma glucose (IFPG). In those IFPG animals, sex-related differences were also detected i.e. females had significantly increased levels of T-Cho, TG and LDL-C. CONCLUSIONS: The result, for the first time, demonstrated the similarities and differences in detail between male and female cynomolgus monkeys in relationship to age-related glucose and lipoprotein metabolisms, and differences under various physiological conditions. The detailed glucose and lipoprotein profiling should provide additional and important insights for prediabetic conditions. Cynomolgus monkeys appear to be an excellent model for translational research of diabetes and for novel therapeutic strategies testing to overt diabetes
A preliminary study of a CH<sub>4</sub> / O<sub>2</sub> solid oxide fuel cell
687-689Lanthanum calcium chromite (LCC) supported on yttria stabilized zirconia (YSZ) prepared in this laboratory exhibits very good performances both as anode and cathode in a fuel cell when operated in the range of 1023 to 1173 K. In the anodic mode it shows reactivities towards H2, CO and CH4 oxidation with the products being CO2 and H2O. Current density of -100 mA cm-2 at the cell potential of 900 mV is achieved while the maximum output power is obtained at ~ 200 mA cm-2, and 400 mV cell voltage and corresponds to 140 mW cm-2. In the experiments the theoretical cell voltage at the open circuit condition is not achieved. Very interestingly, under moderate loads the anodic selectivity is switched to CO and H2 rather than CO2 and H2O and under high drain currents the cell behaves as an oxygen pump
An exploratory study of the catalytic activities of ruthenium supported on rare earth oxides
873-874Rare earth oxides supported ruthenium, prepared by the impregnation method, shows total surface areas of 40 to 145 m2g-1 and Ru-loadings of 5.0 to 1.0 wt%. The dispersion of Ru as signified by H/Ruatomic ratio in conventional adsorption studies are in the range of 0.2 to 0.8 after calcination and reduction of the catalyst samples at 673 K. The conversion of CO/H2 as followed by a pulse method results in largely Cl to C6 hydrocarbons with traces of higher hydrocarbons and probably, oxygenates. The olefin contents are in the range of 10 to 80% depending on the nature of the support and ruthenium loading
On the dehydrogenation of 1- and 2-propanols on Cu(111) surface: A UBI-QEP based approach
2049-2054The method of unity bond index-quadratic
exponential potential (UBI-QEP) has been employed to investigate the energetics
of routes to adsorption and decomposition of 1- and 2-propanols on Cu(111) plane.
Both the clean and pre-adsorbed oxygen containing surfaces have been considered.
A mechanism based on the formation or surface alkoxide groups which become more
favored in the presence of adsorbed oxygen and further elimination of β-hydrogen to yield exclusively the corresponding aldehyde/ketone is
confirmed on the basis of the energy criteria. The latter process is somewhat hindered
in the presence or surface oxygen. The early adsorption of water and the lack of
H/D scrambling as reported previously have been rationalized
Artificial neural network aided design of a multi-component catalyst for the steam reforming of methanol
64-66A neural network
based on the feed forward back propagation
error has been
developed for the design and simulation of the
catalytic
properties of a multi-component system based on Cu-M-Al2O3
(M=Zn,Cr,Zr) for the steam reforming of methanol. Due to the limited size of the
data set, cross validation method has to be used to enhance and also evaluate the
prediction ability of the network. The best structural organization has been found
to include 4,3 ,6,3 nodes in the input, two hidden layers and the
output layer
respectively
A UBI-QEP based study of the energetics of formic acid decomposition on Cu<sub>85</sub>Pd<sub>15</sub>(110) surface
1258-1261The method of
unity bond index-quadratic exponential potential has been employed to calculate
the heats of adsorption of formic acid and its fragments and the activation
energy of the catalytic dehydrogenation of formic acid on Cu85Pd15(110)
surface. The active site being a 3-fold
site composed of one Pd and two Cu atoms. The calculations based on assuming hydrogen
bonding interactions between the adsorbed formic acid and formate species best
account for the experimental findings. It is concluded that the rate
determining step is the decomposition of formate occurring with an ac tivar.ion
energy of 125 kJmol-1, while desorption of the products, CO2
and H2 require activation energies of 20 and 83 kJmol-1