The effects of plasma etching induced gate oxide degradation onMOSFET's 1/f noise

The effects of the plasma etching process induced gate oxide damages on device's low frequency noise behavior are investigated on MOSFET's fabricated with different field plate perimeter to gate area ratio antennas. Abnormal 1/f noise spectrum with a shoulder centered in the frequency range of 100 and to 1 kHz was frequently observed in small geometry devices, and it is attributable to a nonuniform distribution of oxide traps induced by plasma etching process     

A set of electrophoretic molecular markers for strain typing and population genetic studies of Histoplasma capsulatum

A set of eleven biallelic and three multiallelic molecular markers have been developed to analyze populations of Histoplasma capsulatum. All markers are amplified by polymerase chain reaction (PCR) and can be readily scored using minimal amounts of template DNA. The 11 biallelic loci have polymorphic restriction endonuclease sites or small insertions or deletions which may be assessed by agarose gel electrophoresis. These markers are inherited in an unambiguous manner and are ideal for assessing structure and gene flow within US populations of H. capsulatum, but are monomorphic in non-US populations. Both length and sequence variation are present in the multiallelic loci, which can be scored by direct sequencing, polyacrylamide gel electrophoresis, or single-strand conformation polymorphism (SSCP): As they are hypervariable, the multiallelic loci can be used to type isolates and to assess the level of genetic variation within populations. Preliminary results indicate that the three multiallelic markers presented are sufficient to distinguish isolates at the individual level and are polymorphic in both US and non-US populations. This collection of molecular markers will be a useful tool in population and epidemiology studies of H. capsulatum.     

Efficient generation of a reshaped human mAb specific for the {alpha} toxin of Clostridium perfringens

We have used the technique of antibody reshaping to producea humanized antibody specific for the a toxin of Clostridiumperfringens. The starting antibody was from a mouse hybridomafrom which variable (V) region nucleo-tide sequences were determined.The complementarity-determining regions (CDRs) from these Vregions were then inserted into human heavy and light chainV region genes with human constant region gene fragments subsequentlyadded. The insertion of CDRs alone into human frameworks didnot produce a functional reshaped antibody and modificationsto the V region framework were required. With minor frameworkmodifications, the affinity of the original murine mAb was restoredand even exceeded. Where affinity was increased, an alteredbinding profile to overlapping peptides was observed. Computermodelling of the reshaped heavy chain V regions suggested thatamino acids adjacent to CDRs can either contribute to, or distort,CDR loop conformation and must be adjusted to achieve high bindingaffinity.     

Indoor temperature changes in retrofit homes

The behavioral response (e.g. changes in indoor temperatures, attention to window and door openings) to residential technical efficiency improvements (e.g. attic insulation, storm windows) is an important and largely unresolved issue. Although there is considerable discussion concerning the extent to which households take back some of the energy savings due to technical efficiency improvements in increased comfort, there is almost no empirical evidence on the subject.Detailed electricity billing data (from mid-1981 to mid-1983) were analyzed for 79 households that received financial assistance from the Bonneville Power Administration to retrofit their homes in mid-1982. The mean retrofit expenditure in these homes was $1900; the mean reduction in annual electricity use was 4700 kWh, of which 83% was due to reductions in space heating electricity use. Analysis of the electricity billing data suggests that these households increased their indoor temperature settings after retrofit by almost 1 °F on average. This temperature increase led to an estimated average loss of almost 600 kWh of electricity saving. In other words, roughly 10% of the energy saving due to retrofit was taken back in terms of increased comfort. These results concerning changes in indoor temperatures should be viewed cautiously because of limitations in the analytical method and the large variation across households.     

A new technique for on-line and off-line high speed computation

A novel technique for both online and offline computation is presented. With this technique, a reconstruction analysis in elementary particle physics, otherwise prohibitively long, has been accomplished. It will be used online in an upcoming Fermilab experiment to reconstruct more than 100000 events per second and to trigger on the basis of that information. The technique delivers 40 gigaoperations per second, has a bandwidth on the order of gigabytes per second, and has a modest cost. An overview of the program, details of the system, and performance measurements are presented     

Metabolism of lysophosphatidylcholine by swine platelets

Incubation of intact platelets from Sinclair(S-1) miniature swine with³²P-labeled lysophosphatidylcholine (lyso PC) indicated the presence of an active lysophospholipase with a pH optimum of 8.0 for hydrolysis of the substrate. However, lyso PC was incorporated into the membrane phosphatidylcholines by the acyltransferase pathway upon addition of ATP, Mg⁺⁺ and CoA to the platelet suspension. These results suggest that intact platelets are able to resist the cytotoxic effects of lyso PC in plasma, and the phospholipids in platelet membranes are not readily affected by the lipid environment of the plasma. The acyltransfer reaction apparently is saturated with endogenous free fatty acids since arachidonic acid added exogenously did not further enhance the incorporation activity. Neither the acyltransferase nor the lysophospholipase activity was affected by Ca⁺⁺, but divalent metal ions such as Zn⁺⁺ inhibited the lysophospholipase activity. Cholesterol but not cholesteryl esters elicited a biphasic effect on both enzymes, stimulating at low concentration but inhibiting at a cholesterol to lyso PC ratio greater than 1. Serum albumin inhibited the lysophospholipase but gave a small biphasic effect to the acyltransferase.     

Inhibition of sickle beta-chain (betaS)-dependent polymerization by nonhuman alpha-chains. A superinhibitory mouse-horse chimeric alpha-chain

Horse alpha-chain inhibits sickle beta-chain-dependent polymerization; however, its inhibitory potential is not as high as that of mouse alpha-chain. Horse alpha-(1-30) and alpha-(31-141) segments make, respectively, minor and major contributions to the inhibitory potential of horse alpha-chain. The sum of the inhibitory potential of the two segments does not account for the inhibitory potential of the full-length horse alpha-chain. Although the polymerization inhibitory potential of horse alpha-chain is lower than mouse alpha-chain, the inhibitory potential of horse alpha-(31-141) is comparable to that of mouse alpha-(31-141). When mouse alpha-(1-30) is stitched to horse alpha-(31-141), the product is a chimeric alpha-chain with an inhibitory potential greater than mouse alpha-chain. In contrast, the stitching of horse alpha-(1-30) with mouse alpha-(31-141) had no additional inhibitory potential. Molecular modeling studies of HbS containing the mouse-horse chimeric alpha-chain indicate altered side-chain interactions at the alpha1beta1 interface when compared with HbS. In addition, the AB/GH corner perturbations facilitate a different stereochemistry for the interaction of the epsilon-amino group of Lys-16(alpha) with the beta-carboxyl group of Asp-116(alpha), resulting in a decrease in the accessibility of the side chain of Lys-16(alpha) to the solvent. Based on molecular modeling, we speculate that these perturbations by themselves, or in synergy with the altered conformational aspects of the alpha1beta1 interactions, represent the molecular basis of the superinhibitory potential of the mouse-horse chimeric alpha-chains.     

Effects of temperature and duration of storage on the degradation of malathion residues in dry rapeseed

Rapeseed containing up to 1 ppm malathion and ≤ 10% moisture was stored for up to 32 weeks at 10, 20 and 30°C to determine the time required to reach residue levels of 0.1 ppm. Malathion levels < 0.1 ppm were found only in seed at 20°C, 7.7% moisture content by 32 weeks and at 30°C, 7.1% moisture content by 16 weeks. The malathion degradation rates were related to calculated safe storage times to determine acceptable storage conditions. An improved analytical method of malathion extraction from rapeseed was developed. Manipulation of temperature ≤ 60°C for short periods was ineffective in lowering malathion residues to 0.1 ppm.