Differential leukocyte recruitment from whole blood via endothelial adhesion molecules under shear conditions

The objective of this study was to determine if vascular cell adhesion molecule (VCAM-1), E-selectin, and P-selectin could selectively recruit leukocyte subpopulations, and whether this was affected by shear force or adhesion molecule concentration. Cover slips coated with purified adhesion molecules were incorporated into laminar flow chambers. Whole human blood was perfused for 5 minutes over these cover slips at relative shear forces of 2 to 40 dynes/cm2. Chasing the whole blood with buffer permitted visualization of leukocyte-substratum interactions. Leukocytes were observed to roll on and adhere to VCAM-1 at shears between 2 and 15 dynes/cm2. As assessed by cover slip staining, the majority of these cells were lymphocytes, but eosinophils, monocytes, and, surprisingly, neutrophils were also recruited, events inhibitable by anti-4-integrin antibody (HP1/2). Neutrophils were effectively recruited onto the selectins, with interactions occurring at shears as high as 30 and 40 dynes/cm2 for E- and P-selectin respectively. Eosinophils had high affinity for P- but not E-selectin. Mononuclear cells did not have high affinity for either selectin, but interacted avidly with VCAM-1. Antibodies against P-selectin (G1) and E-selectin (ES-1) completely blocked interactions on these substrates. Reducing the concentration of adhesion molecules did not appreciably change recruitment patterns except for VCAM-1, where neutrophils were no longer recruited. The novel use of whole blood in flow chambers shows a partial selectivity of selectins and VCAM-1 for certain subpopulations of leukocytes under varying physiologic shear conditions.     

Endogenous interleukin-10 regulates hemodynamic parameters, leukocyte-endothelial cell interactions, and microvascular permeability during endotoxemia

The objective of this study was to determine whether endogenous IL-10 is capable of regulating hemodynamic parameters, leukocyte recruitment, and microvascular permeability in response to endotoxin. Intravital microscopy was used to examine hemodynamic parameters, leukocyte rolling and adhesion, and microvascular permeability in cremasteric postcapillary venules in wild-type mice and in IL-10-deficient (IL-10(-/-)) mice exposed to lipopolysaccharide (LPS). Doses of LPS (3 or 30 microg/kg, IV), which did not reduce blood pressure and minimally altered microvascular hemodynamic factors in wild-type mice, caused significant reductions in these parameters in IL-10(-/-) mice, demonstrating at least a 10-fold increased sensitivity in IL-10(-/-) mice to LPS-induced hemodynamic alterations. Furthermore, in response to LPS (30 microg/kg, IV), leukocyte rolling, adhesion, and fluorescein isothiocyanate-albumin extravasation were increased in the IL-10(-/-) mice. Antibody blockade experiments showed that in both types of mice, leukocyte rolling was mediated by E-selectin and P-selectin. Leukocyte accumulation into other tissues, such as lung, also was enhanced greatly in IL-10(-/-) mice. This was specific to endotoxin, because acute chemotactic stimuli including N-formyl-methionyl-leucyl-phenylalanine elicited similar responses in IL-10(-/-) and wild-type mice. These results suggest that endogenous IL-10 may be a homeostatic regulator of hemodynamic parameters, leukocyte-endothelial cell interactions, and microvascular dysfunction in response to endotoxin and provide potential mechanisms to explain the protective effect of IL-10 against LPS-induced mortality.     

Wrinkle-resistant cotton by photoinitiated reaction with glycidyl methacrylate followed by crosslinking reactions

A wrinkle-resistant cotton fabric was produced by photoinitiated free-radical reaction of a glycidyl methacrylate monomer from a methanol-water solution to form a poly(glycidyl methacrylate) copolymer, followed by crosslinking reactions of oxirane groups of the copolymer with cellulose. The product had increased conditioned and wet recovery angles and retained breaking and tearing strengths and stiffness values in the ranges normally obtained for wrinkle-resistant cottons. The effects of these reactions on the fiber structure were determined by transmission electron microscopy. The modified fibers were resistant to dissolution in cupriethylenediamine dihydroxide.     

Monolithic crystalline multijunction solar cell development and analysis at the US Air Force research laboratory

As satellite payload electrical power system requirements continue to grow, satellite systems employing flat panel arrays have reached limits set by either on-orbit dynamics that limit the size and shape of the deployed array, mass constraints set by the launch vehicle, or by the limits set by the volume constraints of the launch shroud. This has caused several satellite programs to approach power margin limits early in the design cycle, and to either compromise on satellite capabilities or perform costly redesigns. A very leveraging parameter for raising satellite power levels and reducing costs is the efficiency of the solar cells employed by satellite systems. State of the art efficiencies have reached 26.5% efficiency at load, and 30.1% for prototype cells, and solar arrays using GaAs based multijunction solar cells have achieved deployed solar array power densities of 70 W/kg and stowed volume power densities of 8 kW/m³. A simplified approach to the unwieldy dark current electrical analysis of multijunction solar cells has been developed, correlated with the performance of dual and triple junction solar cells, and explains ideality factors and reverse saturation currents that appear large. It was found that introducing a fourth junction with modest performance could raise the efficiency of multijunction solar cells to 31.5% efficiency at load, raise total power levels to 22 kW, raise the power densities to 100 W/kg and 9 kW/m³ with no impact to the configuration or operation of satellite solar arrays.     

Rißlage in Polyamid-6- und -66-Filamentgarnen nach Schädigung durch Spannungsrißkorrosion

Stress induced cracks have been definitely produced in PA-6- and PA-66-filament yarns. As a function of treatment conditions the position of the cracks with respect to the fibre axis varies. This phenomenon is explained on the basis of a skin-core structure of the fibre and a ballance of the internal (due to swelling) and external stresses. The resulting correlations allow a calculation of the internal stresses due to swelling during treatment of the fibres with swelling agents.     

Estimation of quantitative trait loci parameters for milk production traits in German Holstein dairy cattle population

The main objective of this study was to estimate the proportion of total genetic variance attributed to a quantitative trait locus (QTL) on Bos taurus autosome 6 (BTA6) for milk production traits in the German Holstein dairy cattle population. The analyzed chromosomal region on BTA6 spanned approximately 70 cM, and contained 6 microsatellite markers. Milk production data were obtained from routine genetic evaluation for 4500 genotyped German Holstein bulls. Technical aspects related to the estimation of model parameters for a large data set from routine genotype recording were outlined. A fixed QTL model and a random QTL model were introduced to incorporate marker information into parameter estimation and genetic evaluation. Estimated QTL variances, expressed as the ratio of QTL to polygenic variances, were 0.04, 0.03, and 0.07 for milk yield; 0.06, 0.08, and 0.14 for fat yield; and 0.04, 0.04, and 0.11 for protein yield, in the first 3 parities, respectively. The estimated QTL positions, expressed as distances from the leftmost marker DIK82, were 18, 31, and 17 cM for milk yield; 25, 17, and 9 cM for fat yield; and 16, 30, and 17 cM for protein yield in the 3 respective parities. Because the data for the parameter estimation well represented the current population of active German Holstein bulls, the QTL parameter estimates have been used in routine marker-assisted genetic evaluation for German Holsteins.     

Carboxyethylation of cotton by treatment with acrylamide

New methods for the treatment of cotton with acrylamide have been studied which permit the preparation of modified fabrics with relatively high degrees of carboxyethyl substitution. Wet treatment with acrylamide and sodium hydroxide can be used to produce cottons bearing both carboxyethyl and carbamoylethyl ether substituents. Adjustment of reaction conditions controls the amount and ratio of these substituents. The effects of varying the concentrations of the reactants, the time and the temperature of reaction, and the solvent media employed have been determined. Some elucidation of the chemical mechanisms is provided. Previous work has shown that dry heat treatments of cotton impregnated with acrylamide and alkali can be used to produce high carbamoylethyl substitutions with little or no carboxyethyl substitution. The present work provides an extension of the cotton-acrylamide treatment whereby fabrics can be produced with only carboxyethyl or carbamoylethyl groups, or with mixtures of the two.     

Fiber Bragg Gratings in Small-Core Ge-Doped Photonic Crystal Fibers

This paper reports fiber Bragg gratings （FBGs） inscribed in a small-core Ge-doped photonic crystal fibers with a UV laser and a Talbot interferometer. The responses of such FBGs to temper- ature, strain, bending, and transverse-loading were systematically investigated. The Bragg wavelength of the FBGs shifts toward longer wavelengths with increasing temperature, tensile strain, and transverse-loading. The bending and transverse- loading properties of the FBGs are sensitive to the fiber orientations.