Positional distribution of fatty acids in cardiolipin of mitochondria from 21-day-old rats

Pure cardiolipins (1,3-diphosphatidylglycerol) were prepared from mitochondria of heart, liver and kidney from 21-day-old male Wistar rats and submitted toNaja naja venom phospholipase A₂ (EC 3.1.1.4) action. Incubation conditions were controlled carefully, and a complete hydrolysis of cardiolipin to lysocardiolipin {di [1 (1″) acylsn-glycero-3-phosphoryl] 1′, 3′-sn-glycerol} and fatty acids from positions 2 (2″) was obtained in less than two hr practically without side reactions. Cardiolipins from the three organs contained low levels of saturated fatty acids; stearic acid accounted for 0.4–0.7% and palmitic acid for 1.4–3.5% of total fatty acids. These percentages apparently depended on the organ. In all three cases, linoleic acid was the major component, but its percentage varied from 62–78% of total fatty acids. Acyl chains linked to positions 1 (1″) of all three cardiolipin preparations exhibited a similar pattern; they were composed of linoleic acid for 85–89%. This fatty acid also was the main component esterified at position 2 (2″), but its percentage was much more variable: from 39.8% in heart to 51.2% in kidney and 67.8% in liver mitochondria. The remaining acids comprised octadecenoic and polyunsaturated fatty acids with more than 18 carbon atoms in different proportions. As opposed to other phospholipids,cis-vaccenic acid, and not oleic acid, was the main octadecenoic acid present in cardiolipins. Octadecenoic acids were nine- to 10-fold more concentrated at positions 2 (2″) than at positions 1 (1″). The percentage ofcis-vaccenic acid was four- to five-fold higher than that of oleic acid at positions 2 (2″), whereas oleic acid dominated at positions 1 (1″). From results presented in this study and selected literature data, it may be concluded that fatty acids are asymmetrically distributed in cardiolipins of different origins, with linoleic acid showing a definite preference for position 1 (1″).     

Microbeam RBS on flat panel displays

We have demonstrated the utility of microbeam-Rutherford BackScattering (μ-RBS) in spatially resolved studies of operational plasma effects on the interior surfaces of plasma flat panel displays manufactured by Photonics Imaging. The experiments were performed at the Sandia Nuclear microprobe using a 2.8 MeV He beam with an average beam spot size of less than 8 μm. The interior surface of the top panes of the flat panels is composed of approximately 800 nm of MgO on top of a 2000 nm thick PbO layer. μ-RBS of sample panels operated under varying conditions measured changes in the surface MgO film thickness due to plasma erosion and redeposition as accurately as ± 1.5 nm. The high accuracy in the MgO thickness measurement was achieved by inferring the MgO thickness from the shift of the Pb front edge in the RBS spectrum. An estimate for the thickness accuracy as a function of the acquired statistics is presented. The surface of the flat panels' bottom panes is also comprised of MgO on top of PbO. However, troughs 100 μm wide by 10 μm deep were partially filled with phosphor and cover the entire width of the surface. This leaves only 100 μm long sections of MgO within the trough exposed. Using μ-RBS, we were able to analyze the surface composition of these regions.     

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Reliable Computing -     

A time-domain test for some types of nonlinearity

The bispectrum and third-order moment can be viewed as equivalent tools for testing for the presence of nonlinearity in stationary time series. This is because the bispectrum is the Fourier transform of the third-order moment. An advantage of the bispectrum is that its estimator comprises terms that are asymptotically independent at distinct bifrequencies under the hypothesis of linearity. An advantage of the third-order moment is that its values in any subset of joint lags can be used in the test, whereas when using the bispectrum the entire (or truncated) third-order moment is required to construct the Fourier transform. We propose a test for nonlinearity based upon the estimated third-order moment. We use the phase scrambling bootstrap method to give a nonparametric estimate of the variance of our test statistic under the hypothesis. Using a simulation study, we demonstrate that the test obtains its target significance level, with large power, when compared to an existing standard parametric test that uses the bispectrum. Further we show how the proposed test can be used to identify the source of nonlinearity due to interactions at specific frequencies. We also investigate implications for heuristic diagnosis of nonstationarity.     

Polymerase chain reaction versus culture for detection of Ureaplasma urealyticum and Mycoplasma hominis in the urogenital tract of adults and the respiratory tract of newborns

The efficiency of the polymerase chain reaction (PCR) was compared with that of culture for detection of Ureaplasma urealyticum and Mycoplasma hominis in 726 clinical specimens comprising 189 gynecological samples, 362 urological samples, and 175 samples from newborn infants. The sensitivity of PCR versus culture was 95% for both organisms, while the sensitivity of culture versus PCR was 91% for Ureaplasma urealyticum and 84% for Mycoplasma hominis. Furthermore, PCR tests were faster than culture tests, allowing the time to diagnosis to be reduced from two to five days to 24 h.     

Modification of alkenyl chain profile in plasmalogens of rat heart mitochondria by dietary trielaidin

Effects of dietary trielaidin upon the alkenyl chain profile of plasmalogens were studied using heart mitochondria of rats fed a semi-purified diet containing 10% of fat supplement in which elaidic acid accounted for 69% of total fatty acids. Alkyl substituted dioxane (ASD) derivatives of the alkenyl groups of plasmalogens were prepared and analyzed by silver nitrate TLC and by GLC on different phases (BDS and OV-275). After two months of feeding the experimental diet, 40% of the ASD contained atrans-octadecenyl chain, suggesting that dietary elaidic acid was reduced in vivo to the corresponding alcohol and incorporated into plasmalogens. There was a simultaneous decrease in the percentage of ASD containing saturated chains, but the percentage of ASD substituted withcis-octadecenyl chains was not significantly affected. These observations suggested that elaidic acid may compete with saturated fatty acids, but not withcis-octadecenoic acids during the plasmalogen biosynthesis. Feeding trielaidin did not seem to have any significant influence on the relative proportions of plasmalogens, which accounted for 11–12%, on a phosphorus basis, of total heart mitochondria phospholipids.     

Scalarization of dyadic spectral Green's functions and networkformalism for three-dimensional full-wave analysis of planar lines andantennas

A novel and systematic method is presented for the complete determination of dyadic spectral Green's functions directly from Maxwell's equations. With the use of generalized scalarizations developed in this paper, four general and concise expressions for the spectral Green's functions for one-dimensionally inhomogeneous multilayer structures, excited by three-dimensional electric and magnetic current sources, are given in terms of modal amplitudes together with appropriate explicit singular terms at the source region. It is shown that Maxwell's equations in spectral-domain can be reduced, by using dyadic spectral eigenfunctions, to two sets of z-dependent inhomogeneous transmission-line equations for the modal amplitudes. One set of the transmission-line equations are due to the transverse current sources and the other set due to the vertical current sources. Utilizing these equations, network schematizations of the excitation, transmission and reflection processes of three-dimensional electromagnetic waves in one-dimensionally inhomogeneous multilayer structures are achieved in a full-wave manner. The determination of the spectral Green's functions becomes so simple that it is accomplished by the investigation of voltages and currents on the derived equivalent circuits. Examples of singleand multilayer structures are used to validate the general expressions and the equivalent circuits     

Contribution oftrans-18∶1 acids from dairy fat to european diets

Twelve commercial samples of French butter, purchased in October–November, and 12 other samples, purchased in May–June, were analyzed with particular attention to theirtrans-octadecenoic acid contents. The isomeric fatty acids were quantitated by a combination of gas-liquid chromatography (GLC) of total fatty acids as isopropyl esters on a polar capillary column (CPSil 88) and of silver nitrate-impregnated thin-layer chromatography followed by GLC of the pooled saturated (used as internal standards) andtrans-octadecenoic acid fractions. Autumn butters contained 3.22±0.44%trans-octadecenoic acids (relative to total fatty acids), whereas those collected during the spring contained 4.28±0.47% (P<0.01). Minimum and maximum values for the two sets of butters were 2.46 (autumn) and 5.10% (spring), respectively. The annual mean value for thetrans-octadecenoic acid content in all butter samples was 3.8% of total fatty acids (ca. 2% for thetrans-11 18∶1 acid). This value allows calculation of the daily individual intake oftrans-octadecenoic acids from dairy products by populations of member states of the European Economic Community (EEC). It varies from 0.57 g (Portugal) to 1.66 g (Denmark). The mean value for the twelve countries of the EEC is 1.16 g/person/d, which is close to data published for the United States. In France, the consumption oftrans octadecenoic acids from dairy fat is higher than that from margarines (ca. 1.5 vs. 1.1 g/person/d).     

Tissue fixation security in transosseous rotator cuff repairs: a mechanical comparison of simple versus mattress sutures

The primary purpose of this investigation was to compare tissue fixation security by simple sutures versus mattress sutures in transosseous rotator cuff repair. These two repair techniques were each performed in 17 human cadaver shoulders, with two bone tunnels being used for the repair by two simple sutures and two other bone tunnels being used for the repair by one mattress suture. The repairs were loaded to failure in a servohydraulic materials test system. Rotator cuff repair by simple sutures was found to be significantly stronger than repair by mattress sutures (P = .0007). The average ultimate load to failure for the simple suture construct (189.62 N) was 39.72% greater than that for the mattress suture construct (135.71 N). Most of the failures occurred by suture breakage at the knot. Load-sharing by multiple suture tails and multiple knots in the simple suture configuration likely contributed to its superior strength characteristics compared with the mattress suture configuration.