Xanthophylls, Phytosterols and Pre-β1-HDL are Differentially Affected by Fenofibrate and Niacin HDL-Raising in a Cross-Over Study

Fenofibrate and extended‐release (ER) niacin similarly raise high‐density lipoprotein cholesterol (HDL‐C) concentration but their effects on levels of potent plasma antioxidant xanthophylls (lutein and zeaxanthin) and phytosterols obtained from dietary sources, and any relationship with plasma lipoproteins and pre‐β1‐HDL levels, have not been investigated. We studied these parameters in 66 dyslipidemic patients treated for 6 week with fenofibrate (160 mg/day) or ER‐niacin (0.5 g/day for 3 week, then 1 g/day) in a cross‐over study. Both treatments increased HDL‐C (16 %) and apolipoprotein (apo) A‐I (7 %) but only fenofibrate increased apoA‐II (28 %). Lutein and zeaxanthin levels were unaffected by fenofibrate but inversely correlated with percentage change in apoB and low‐density lipoprotein cholesterol and positively correlated with end of treatment apoA‐II. ApoA‐II in isolated HDL in vitro bound more lutein than apoA‐I. Xanthophylls were increased by ER‐niacin (each ~30 %) without any correlation to lipoprotein or apo levels. Only fenofibrate markedly decreased plasma markers of cholesterol absorption; pre‐β1‐HDL was significantly decreased by fenofibrate (?19 %, p < 0.0001), with little change (3.4 %) for ER‐niacin. Although fenofibrate and ER‐niacin similarly increased plasma HDL‐C and apoA‐I, effects on plasma xanthophylls, phytosterols and pre‐β1‐HDL differed markedly, suggesting differences in intestinal lipidation of HDL. In addition, the in vitro investigations suggest an important role of plasma apoA‐II in xanthophyll metabolism.     

Ozone Generation by Indoor,Electrostatic Air Cleaners

ABSTRACT

This experimental study extends prior studies to consider the influences of discharge polarity, current, relative humidity, air temperature, and wire diameter and material on ozone generation rate in two-stage, wire-plate indoor air cleaners. Promising methods of decreasing the quantity of ozone released into living and work spaces are identified. Use of positive corona discharge is imperative since ozone generation rates are nearly an order of magnitude higher with negative discharge. For a specific precipitator design, the most important parameter in predicting ozone generation rate is current level. Changes in temperature and relative humidity of the inlet air stream over the range of ambient conditions expected in typical homes have less impact. In the commercial air cleaner studied, a 40% reduction in current from 1.08 to 0.60 mA, reduces ozone generation rate by nearly 50% from 0.005 to 0.0025 mg s^?1. This reduction in current reduces particle collection efficiency by 20%. An increase in relative humidity from 17 to 55% decreases ozone generation rate 17%. An increase in air temperature from 293 to 301K decreases ozone generation rate by 6%. Ozone production can be controlled by the selection of wire diameter and material. At a fixed voltage, use of 0.10 mm rather than 0.20 mm tungsten discharge wires reduces ozone generation rate by 40%. The accompanying reduction in current does not cause a reduction in collection efficiency as long as the voltage in the collection stage is held constant. The benefit of controlling ozone generation rate by selection of wire material is that the electrical characteristics of the air cleaner are not affected. With a positive corona discharge, ozone generation rate is decreased by 30% with copper wires and by 50% with silver wires as compared to the rate with standard tungsten wires.     

A Stochastic Model for Particle Deposition and Bounceoff

A new model for particle deposition and bounceoff that combines current knowledge of turbulent bursts with the stochastic properties of turbulent fluctuations is presented. The model predictions for deposition velocities agree with experimental results in the literature for dimensionless particle relaxation time τ_p ⁺ > 2. For τ_p ⁺ > 10, most of the particles delivered to the edge of the viscous sublayer are able to deposit onto the surface due to their inertia; the deposition velocity approaches an asymptotic value because the process becomes limited by the rate of turbulent delivery to the viscous sublayer. Because of the penetration of turbulent fluctuations into the viscous sublayer, the minimum values of vertical velocities needed for particles to deposit onto the surface are smaller than those predicted by the free flight model. Most of the deposition occurs from those turbulent fluctuations at the upper tail of the distribution of the vertical component of air velocity.

In addition to the deposition velocity, the model is able to provide the distribution of particle velocities on reaching the surface which is used to compute the fraction of particle bounceoff. The model predictions for the fractions of rebound agree reasonably with the measured results from a wind tunnel experiment for τ_p ⁺ > 2. However, both the deposition velocity and the fraction of rebound are underestimated by the model for τ_p ⁺ < 2. Other mechanisms such as Brownian diffusion must be included in further revisions to this model in order to obtain satisfactory predictions for smaller values of τ_p ⁺.     

Shear buckling in foam-filled web core sandwich panels using a Pasternak foundation model

Web core panels, foam-filled sandwich panels with interior webs, are a structurally efficient option for transverse load bearing applications. In web core panels, the interaction between the webs and core material can have a substantial impact on web shear buckling strength and is a key element of lightweight structural design. The present work is an investigation of web buckling behavior in web core panels under a distributed load. To solve this problem, web shear buckling was analyzed for the case of pure shear loading with foam support, and this analytic model was extended to the case of panels with a transverse distributed load. The webs are modeled as simply supported plates resting on a Pasternak elastic foundation. To that end, a buckling model for plates on a Pasternak foundation is presented, along with closed-form approximations of the solution for square and infinitely long plates. An accurate model for the foundation constants is developed using energy methods. Applicability of the plate buckling model to web core panels with transverse loads is presented via a finite element study. In panels, the slenderness and spacing of the webs have a slight effect on the boundary conditions between the webs and face sheets. The effect is relatively small, however, and the model presented in this work underpredicts buckling strength by less than 25%. The model in this work is thus a reasonable approach to the practical design of web core panels.     

Development and use of specific polymerase reaction for the detection of an organism resembling Ehrlichia sp. in white-tailed deer

OBJECTIVE: To establish the pharmacodynamic and safety equivalence between 2 sustained-release forms of leuprorelin 11.25 mg and 3.75 mg, in the treatment of metastatic prostatic carcinoma. METHODS: 44 patients received subcutaneous injections of leuprorelin for 9 months (randomization: 2/l): either 11.25 mg every three months (n = 29) or 3.75 mg monthly (n = 15). Main criterion: centralized monthly assay of plasma testosterone (T). RESULTS: The equivalence of the 2 forms in terms of mean plasma testosterone was demonstrated (p = 0.002): 1 month: T = 0.19 +/- 0.03 ng/ml; 3 months: T = 0.27 +/- 0.04 ng/ml. Exploratory analysis did not reveal any significant difference between the groups for the number of patients castrated at each visit or for the number of patients with all T values < or = 0.5 ng/ml, or for clinical responses or safety. CONCLUSION: The 2 forms have a comparable efficacy and safety.     

Interaction of the adaptor protein Shc and the adhesion molecule cadherin

In mitogenic signaling pathways, Shc participates in the growth factor activation of Ras by interacting with activated receptors and/or the Grb-2.Sos complex. Using several experimental approaches we demonstrate that Shc, through its SH2 domain, forms a complex with the cytoplasmic domain of cadherin, a transmembrane protein involved in the Ca2+-dependent regulation of cell-cell adhesion. This interaction is demonstrated in a yeast two-hybrid assay, by co-precipitation from mammalian cells, and by direct biochemical analysis in vitro. The Shc-cadherin association is phosphotyrosine-dependent and is abrogated by addition of epidermal growth factor to A-431 cells maintained in Ca2+-free medium, a condition that promotes changes in cell shape. Shc may therefore participate in the control of cell-cell adhesion as well as mitogenic signaling through Ras.     

Analysis of Load Average and its Relationship to Program Run Time on Networks of Workstations

Parallel processing systems using networks of workstations are being used to provide an alternative to expensive parallel processors. Scheduling of tasks on these networks is an important and practical problem that must be addressed. Although CPU load is an important parameter to many of the proposed scheduling schemes, no quantitative analysis of CPU load and its precise relation to the run time of application programs has to date been presented. The work in this paper describes the experimental analysis of one common load measure, the UNIX load average, and its relationship to the run time of computation-bound parallel programs. Data was gathered using a test application program designed to mimic common applications, performing long bursts of computation with occasional interprocess data exchange over the network. The resulting execution times and measured load averages were then analyzed using regression analysis to detect load-run time trends. This paper describes the test program and the experiments, then details the results of the data analysis. A technique is then presented for the evaluation of the load-run time relationship for a computation-bound program on a network of workstations.     

Addition of the MSA1 signal and anchor sequences to the malaria merozoite surface antigen 1 C-terminal region enhances immunogenicity when expressed by recombinant vaccinia virus

Genes encoding four different C-terminal fragments of a Plasmodium falciparum merozoite surface antigen were generated: MSA1C-(Si,A), containing signal and anchor regions of MSA1; MSA1C-(Si,nA), containing the signal but not the anchor; MSA1C-(nSi,A), containing the anchor but not the signal, and MSA1C-(nSi,nA) containing neither the signal nor the anchor region. Each gene was inserted into the thymidine kinase region of vaccinia virus, under the control of a synthetic strong early/ late promoter. When the plasmodial genes were expressed in cells infected by the recombinant vaccinia virus, the two proteins containing the signal region were transported to the surface of infected cells. Infection of mice and rabbits with the latter recombinant viruses stimulated C-terminal-specific antibody levels that were 10-80-fold higher than those induced by the two recombinant viruses without the signal region. The combination of the signal and anchor regions with the C-terminal MSA1 protein also generated the most effective neutralization in a P. falciparum invasion assay.