7 resultados para Generation of Laser induced Plasma

em University of Queensland eSpace - Australia


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This study compared the stress induced in captive estuarine crocodiles, Crocodylus porosus, by two different handling methods: manual restraint (noosing with ropes) and immobilization by electro-stunning. To stun, a short charge (approx. 6 s) at 110 V was delivered to the back of the necks of C. porosus using a custom-built device, which immobilized the animals for 5-10 min. Immobilized and restrained animals were measured and sexed, and the condition of the skin assessed. Blood samples were taken from some animals immediately after restraint or immobilization. Other animals were returned to their pens to recover for periods of 30 min, 1, 4, 12, 24 or 48 hours after which they were stunned and blood samples taken. Individual animals (mean body length 1.96 m, N=99) were bled only once. Haematocrit and haemoglobin concentrations were measured and plasma samples were analysed for corticosterone, glucose and lactate levels. Following restraint, there were significant increases in haematocrit, haemoglobin, glucose, lactate and corticosterone concentrations in C. porosus. For restrained animals, recovery to baseline levels occurred after approximately 8 hours. The stress response of stunned animals was significantly reduced compared to manually captured and restrained crocodiles. Both groups showed a significant increase in haematocrit, haemoglobin concentration and lactate levels, however the magnitude of change was significantly reduced, and recovery was faster in stunned animals. No increase in either glucose or corticosterone levels occurred with immobilisation. The results imply that immobilization by electro-stunning is much less stressful. (C) 2003 Wiley-Liss, Inc.

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We investigated whether the protection from graft-versus-host disease (GVHD) afforded by donor treatment with granulocyte colony-stimulating factor (G-CSF) could be enhanced by dose escalation. Donor treatment with human G-CSIF prevented GVHD in the B6 --> B6D2F1 murine model in a dose-dependent fashion, and murine G-CSF provided equivalent protection from GVHD at 10-fold lower doses. Donor pretreatment with a single dose of pegylated G-CSF (peg-G-CSF) prevented GVHD to a significantly greater extent than standard G-CSIF (survival, 75% versus 11%, P < .001). Donor T cells from peg-G-CSF-treated donors failed to proliferate to alloantigen and inhibited the responses of control T cells in an interleukin 10 (IL-10)-dependent-fashion in vitro. T cells from peg-GCSF-treated IL-10(-/-) donors induced lethal GVHD; T cells from peg-G-CSF-treated wild-type (wt) donors promoted long-term survival. Whereas T cells from peg-G-CSF wt donors were able to regulate GVHD induced by T cells from control-treated donors, T cells from G-CSF-treated wt donors and peg-G-CSF-treated IL-10(-/-) donors did not prevent mortality. Thus, peg-G-CSF is markedly superior to standard G-CSF for the prevention of GVHD following allogeneic stem cell transplantation (SCT), due to the generation of IL-10-producing regulatory T cells. These data support prospective clinical trials of peg-G-CSF-mobilized allogeneic blood SCT. (C) 2004 by The American Society of Hematology.

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We suggest a scheme to generate a macroscopic superposition state (Schrodinger cat state) of a free-propagating optical field using a beam splitter, homodyne measurement, and a very small Kerr nonlinear effect. Our scheme makes it possible to reduce considerably the required nonlinear effect to generate an optical cat state using simple and efficient optical elements.

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Purpose. The aims of this study are to evaluate whether cytochrome P450 (CYP)2D1/2D2-deficient dark agouti (DA) rats and/or CYP2D1/2D2-replete Sprague-Dawley (SD) rats are suitable preclinical models of the human, with respect to mirroring the very low plasma concentrations of metabolically derived oxymorphone seen in humans following oxycodone administration, and to examine the effects of streptozotocin-induced diabetes on the pharmacokinetics of oxycodone and its metabolites, noroxycodone and oxymorphone, in both rodent strains. Methods. High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was used to quantify the serum concentrations of oxycodone, noroxycodone, and oxymorphone following subcutaneous administration of bolus doses of oxycodone (2 mg/kg) to groups of nondiabetic and diabetic rats. Results. The mean (+/- SEM) areas under the serum concentration vs. time curves for oxycodone and noroxycodone were significantly higher in DA relative to SD rats (diabetic, p < 0.05; nondiabetic, p < 0.005). Serum concentrations of oxymorphone were very low (< 6.9 nM). Conclusions. Both DA and SD rats are suitable rodent models to study oxycodone's pharmacology, as their systemic exposure to metabolically derived oxymorphone (potent mu-opioid agonist) is very low, mirroring that seen in humans following oxycodone administration. Systemic exposure to oxycodone and noroxycodone was consistently higher for DA than for SD rats showing that strain differences predominated over diabetes status.

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Secretion of mucins and exudation of plasma are distinct processes of importance to innate immunity and inflammatory disease. Yet, little is known about their relation in human airways. The objective of the present study was to use the human nasal airway to determine mucinous secretion and plasma exudation in response to common challenge agents and mediators. Ten healthy volunteers were subjected to nasal challenge-lavage procedures. Thus, the nasal mucosa was exposed to increasing doses of histamine (40 and 400 mu g ml(-1)), methacholine (12.5 and 25 mg) and capsaicin (30 and 300 ng ml(-1)). Fucose was selected as a global marker of mucinous secretion and alpha(2)-macroglobulin as an index of exudation of bulk plasma. All challenge agents increased the mucosal output of fucose to about the same level (P < 0.01-0.05). Once significant secretion had been induced the subsequently increased dose of the challenge agent, in the case of histamine and methacholine, failed to further increase the response. Only histamine increased the mucosal output of alpha(2)-macroglobulin (P < 0.01). We conclude that prompt but potentially rapidly depleted mucinous secretion is common to different kinds of airway challenges, whereas inflammatory histamine-type mediators are required to produce plasma exudation. Along with the acknowledged secretion of mucins, a practically non-depletable, pluripotent mucosal output of plasma emerges as an important component of the innate immunity of human airways.

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The multimode operation of an optical parametric oscillator (OPO) operating below threshold is calculated. We predict that squeezing can be generated in a comb that is limited only by the phase matching bandwidth of the OPO. Effects of technical noise on the squeezing spectrum are investigated. It is shown that maximal squeezing can be obtained at high frequency even in the presence of seed laser noise and cavity length fluctuations. Furthermore the spectrum obtained by detuning the laser frequency off OPO cavity resonance is calculated.