Using geophysical logs in highwall blast design

Bulletin of Engineering Geology and the Environment - In surface coal mines, the characterisation of overburden strata by geophysical logging of open boreholes is an important tool for increasing...     

Antenatal steroids, condition at birth and respiratory morbidity and mortality in very preterm infants

The study purpose was to compare the effect of exercise training on serum lipid and apolipoprotein concentrations and the activities of intravascular enzymes related to lipid transport in previously untrained eumenorrheic, premenopausal (PRM) women (n = 21; mean age, 36 +/- 3 years) and estrogen-free postmenopausal (POM) women (n = 16; mean age, 68 +/- 8 years). Subjects trained at a progressive intensity and duration (50% to 75% maximal O2 consumption [VO2max], 200 to 300 kcal/session) 4 d/wk for 12 weeks. Before and after training, VO2max, body weight, relative body fat, and fasting blood samples were obtained following 2 weeks on a standardized diet designed to maintain body weight and during the early follicular stage for the PRM group. Blood samples were analyzed for serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), the cholesterol content of the HDL3 subfraction, apolipoprotein (apo)A-I and apoB, lipoprotein(a), and the activity of lecithin:cholesterol acyltransferase (LCAT). Total and hepatic triglyceride lipase activity (HTGLA) were determined from plasma samples obtained after heparin administration. The cholesterol content of the low-density lipoprotein (LDL) and HDL2 subfractions and endothelial-bound lipoprotein lipase activity (LPLA) were calculated. A two (group) x two (time) multivariate ANOVA (MANOVA), with repeated measures for time indicated that the exercise-induced changes in physiological measurements, serum lipid or apolipoprotein concentrations, or enzyme activities did not differ between groups. Serum concentrations of TC, LDL-C, and HDL3 cholesterol, TG, and apo A-I and apoB were higher in POM women compared with the PRM group (P < .05 for all). For the combined groups, body weight and relative body fat did not change with training, but VO2max increased an average of 18.5% (P < .05). LPLA, HTGLA, and LCAT activity were unaltered with exercise training. Except for a small but significant decrease in HDL-C (-5.5%) and an elevation in apoB (4.3%; P < .05 for both), the concentrations of serum lipids and apolipoproteins did not change over the training period. We conclude that in previously untrained women, menopausal status does not influence the exercise training response of serum lipids or apolipoproteins or activities of intravascular enzymes related to lipid transport.     

Prostate cancer screening--a physician survey in Missouri

This study investigated prostate cancer screening practices using prostate specific antigen testing (PSA), digital rectal examination (DRE), and transrectal ultrasonography (TRUS) by primary care physicians in Missouri. In 1993, a mail survey was sent to a stratified random sample of 750 physicians whose primary specialty was general practice, family practice, or internal medicine. Three separate mailings resulted in an overall adjusted response rate of 60 percent. Ninety-five percent of physicians were more inclined to use PSA compared with three years previously, with only 45 percent of physicians more inclined to use DRE. An increase in the use of PSA following a negative DRE was reported by 85 percent and a greater inclination to use TRUS following a positive PSA was reported by 90 percent Eighty-six percent agreed with the American Cancer Society (ACS) guidelines on prostate cancer screening. Using logistic regression adjusted across levels of demographic and practice factors, prevalence odds ratios were derived with results indicating that agreement with ACS guidelines and being in private practice are strong predictors of a physician's inclination to routinely screen asymptomatic patients for prostate cancer. Our findings have provided baseline information on prostate cancer screening in Missouri and suggest that primary care physicians view PSA testing as a useful procedure and appear to be using it in a manner similar to the general pattern seen across the country.     

Lidocaine and its analogues inhibit IL-5-mediated survival and activation of human eosinophils

Eosinophils and cytokines active on eosinophils, especially IL-5, are believed to be critically involved in chronic allergic diseases. IL-5 activates eosinophils and enhances their survival in vitro by delaying apoptosis. In this study, we found that lidocaine and six analogues blunt responses of eosinophils to IL-5. Lidocaine and its derivatives inhibit IL-5-mediated eosinophil survival in a concentration-dependent manner (IC50 = 110 microM for 30 pg/ml IL-5). At suboptimal lidocaine concentrations, the eosinophil survival response to IL-5 shifts and more IL-5 is required to maintain survival. The inhibitory effect requires at least 24-h exposure of eosinophils to lidocaine, and the protein kinase C activator, PMA, completely reverses the inhibition. A multiparameter flow-cytometric analysis shows that lidocaine hastens the apoptosis of eosinophils normally delayed by IL-5. Lidocaine does not affect IL-5R expression or IL-5-induced protein tyrosine phosphorylation. Lidocaine also inhibits eosinophil survival mediated by IL-3 or granulocyte-macrophage CSF, although less potently than that mediated by IL-5. Furthermore, lidocaine inhibits eosinophil superoxide production stimulated by IL-5, granulocyte-macrophage CSF, or IL-3, but not that stimulated by platelet-activating factor, immobilized IgG, or PMA. Lidocaine and its derivatives show novel immunomodulatory properties and are able to blunt eosinophil responses to cytokines in addition to their local anesthetic or antiarrhythmic properties. Thus, lidocaine and its derivatives may represent a new class of therapeutic agents to treat patients with allergic diseases.     

The selective 5-HT1B receptor inverse agonist 1'-methyl-5-[[2'-methyl-4'-(5-methyl-1,2, 4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydro- spiro[furo[2,3-f]indole-3,4'-piperidine] (SB-224289) potently blocks terminal 5-HT autoreceptor function both in vitro and in vivo

5-HT1 receptors are members of the G-protein-coupled receptor superfamily and are negatively linked to adenylyl cyclase activity. The human 5-HT1B and 5-HT1D receptors (previously known as 5-HT1Dbeta and 5-HT1Dalpha, respectively), although encoded by two distinct genes, are structurally very similar. Pharmacologically, these two receptors have been differentiated using nonselective chemical tools such as ketanserin and ritanserin, but the absence of truly selective agents has meant that the precise function of the 5-HT1B and 5-HT1D receptors has not been defined. In this paper we describe how, using computational chemistry models as a guide, the nonselective 5-HT1B/5-HT1D receptor antagonist 4 was structurally modified to produce the selective 5-HT1B receptor inverse agonist 5, 1'-methyl-5-[[2'-methyl-4'-(5-methyl-1,2, 4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6, 7-tetrahydrospiro[furo[2,3-f]indole-3,4'-piperidine] (SB-224289). This compound is a potent antagonist of terminal 5-HT autoreceptor function both in vitro and in vivo.     

Optimization of optical limiting devices based on excited-state absorption

Limiting devices protect sensitive optical elements from laser-induced damage (LID). Passive devices use focusing optics to concentrate the light through a nonlinear optical (NLO) element (or elements) to reduce the limiting threshold. Unfortunately, these NLO elements may themselves undergo LID for high inputs, restricting the useful dynamic range (DR). Recently, efforts at optimizing this DR have focused on distributing the NLO material along the propagation path z of a focused beam, resulting in different portions of the device (in z) exhibiting NLO response at different inputs. For example, nonlinear absorbers closer to the lens, i.e., upstream, protect device elements downstream near the focal plane. This results in an undesirable increase in the threshold, although the lowest threshold is always obtained with the final element at focus. Thus there is a compromise between DR and threshold. This compromise is determined by the material. We concentrate on reverse saturable absorber (RSA) materials (molecules exhibiting larger excited-state than ground-state absorption). We look at both tandem devices and devices in which the concentration of the NLO material is allowed to spatially vary in z. These latter devices require solid-state hosts. The damage threshold of currently available solid-state hosts is too low to allow known RSA materials to reach their maximum absorption, which occurs when all molecules are in their excited state. This is demonstrated by approximate analytical methods as well as by a full numerical solution of the nonlinear wave propagation equation over extremely large distances in z (up to 10(3)Z(0), where Z(0) is the Rayleigh range of the focused beam). The numerical calculations, based on a one-dimensional fast Fourier transform, indicate that proper inclusion of diffraction reduces the effectiveness of reverse saturable absorption for limiting, sometimes by more than a factor of 10. Liquid-based devices have higher damage thresholds (damage occurs to the cuvette wall) and, thus, larger nonlinear absorption. However, RSA material in liquid hosts may suffer from larger thermal lensing.     

Shear deformation under pyramidal indentations in soda-lime glass

The nature of the flow lines that occur in the deformed zone in soda-lime glass under pyramidal indentations has been investigated. A close examination of the deformed zone shows that the spiral flow lines meet at 110°, instead of the 90° required by the ideal rigid-plastic behaviour. The flow lines are indeed shear faults (of negligible thickness) produced by genuine shear displacements which are apparent at the intersection points of some of the flow lines. Evidence of void or crack formation at the intersection points or along the flow lines is also presented, along with a possible hardening effect from the suppression of slip at the intersection points of the flow lines.     

The influence of molecular weight distribution on melt viscosity,melt elasticity,processing behavior and properties of polystyrene

The influence of molecular weight and molecular weight distribution on the melt rheological behavior of two polystrenes of approximately the same weight average molecular weight, but of widely different molecular weight distribution, was determined. Then, using a series of capillaries with different length-to-diameter ratios in an Instron Capillary Rheometer, the entrance correction methods of E. B. Bagley and the relationships of W. Philippoff and F. H. Gaskins, the recoverable shear strain (S_R) in the melt at the capillary wall for these mono- and polydisperse polystyrenes was determined. Shear modulus (G) and normal stress (P_N) were calculated using the relationships: G = τ_RC/S_R and P_N = 2τ_RC S_R, where τ_RC is the corrected shear stress at the capillary wall. These are compared to values obtained using a Weissenberg Rheogonimeter. These two polystyrenes were also injection molded into an ASTM specimen mold over a wide range of stock temperature, using a 12 OZ . in-line reciprocating screw injection press, and evaluated for mechanical property values. The effects of the elasticity parameters (S_R G & P_N) and their magnitude on the rheology, processability and mechanical properties of these polystyrenes are discussed.     

The relative effects of selective intra-arterial and intravenous vasopressin infusion

The relative effects of selective intra-arterial and intravenous infusions of vasopressin were evaluated in 16 normotesive dogs. One group was infused via the left gastric artery, one was infused via a peripheral vein, and a control group was not infused. Flow to the stomach and bowel was reduced by an average of 73% and 45%, respectively. There was no significant difference between selective intra-arterial and intravenous infusions with regard to their effects on visceral flow or their systemic parameters. Control animals demonstrated only minor variations from base-line flow.     

Viscosity dependence of optical limiting in carbon black suspensions

We measure the optical limiting behavior of carbon black suspensions in various viscosity solvents by using a 10-Hz repetition rate, 532-nm, 5-ns pulsed laser. We found that, for common solvents used in the past such as water and ethanol, the limiting behavior ceases after a few laser firings and a turnover in the limiting curve appears. This can be explained by depletion of the carbon black within the focal volume. This turnover shifts to lower energies as the viscosity of the solvent becomes greater. However, for low viscosity liquids, such as carbon disulfide or pentane, the limiting is unaffected by the repetition rate, at least for frequencies up to 10 Hz, because of diffusion of the carbon black particles. This diffusion allows fresh material to replace the irradiated volume within the time between pulses.