Parametric study of nonlinear electrostatic waves in two-dimensional quantum dusty plasmas

The nonlinear properties of two-dimensional cylindrical quantum dust-ion-acoustic (QDIA) and quantum dust-acoustic (QDA) waves are studied in a collisionless, unmagnetized and dense (quantum) dusty plasma. For this purpose, the reductive perturbation technique is employed to the quantum hydrodynamical equations and the Poisson equation, obtaining the cylindrical Kadomtsev–Petviashvili (CKP) equations. The effects of quantum diffraction, as well as quantum statistical and geometric effects on the profiles of QDIA and QDA solitary waves are examined. It is found that the amplitudes and widths of the nonplanar QDIA and QDA waves are significantly affected by the quantum electron tunneling effect. The addition of a dust component to a quantum plasma is seen to affect the propagation characteristics of localized QDIA excitations. In the case of low-frequency QDA waves, this effect is even stronger, since the actual form of the potential solitary waves, in fact, depends on the dust charge polarity (positive/negative) itself (allowing for positive/negative potential forms, respectively). The relevance of the present investigation to metallic nanostructures is highlighted.

Vasoactivity of AG014699, a clinically active small molecule inhibitor of poly(ADP-ribose) polymerase: a contributory factor to chemopotentiation in vivo?

Purpose: Poly(ADP-ribose) polymerase (PARP) plays an important role in DNA repair, and PARP inhibitors can enhance the activity of DNA-damaging agents in vitro and in vivo. AG014699 is a potent PARP inhibitor in phase II clinical development. However, the range of therapeutics with which AG014699 could interact via a DNA-repair based mechanism is limited. We aimed to investigate a novel, vascular-based activity of AG014699, underlying in vivo chemosensitization, which could widen its clinical application.

Experimental Design: Temozolomide response was analyzed in vitro and in vivo. Vessel dynamics were monitored using “mismatch” following the administration of perfusion markers and real-time analysis of fluorescently labeled albumin uptake in to tumors established in dorsal window chambers. Further mechanistic investigations used ex vivo assays of vascular smooth muscle relaxation, gut motility, and myosin light chain kinase (MLCK) inhibition.

Results: AG014699 failed to sensitize SW620 cells to temozolomide in vitro but induced pronounced enhancement in vivo. AG014699 (1 mg/kg) improved tumor perfusion comparably with the control agents nicotinamide (1 g/kg) and AG14361 (forerunner to AG014699; 10 mg/kg). AG014699 and AG14361 relaxed preconstricted vascular smooth muscle more potently than the standard agent, hydralazine, with no impact on gut motility. AG014699 inhibited MLCK at concentrations that relaxed isolated arteries, whereas AG14361 had no effect.

Conclusion: Increased vessel perfusion elicited by AG014699 could increase tumor drug accumulation and therapeutic response. Vasoactive concentrations of AG014699 do not cause detrimental side effects to gut motility and may increase the range of therapeutics with which AG014699 could be combined with for clinical benefit.

Measurement of the duration of X-ray lasing pumped by an optical laser pulse of picosecond duration

Measurements of the duration of X-ray lasing pumped with picosecond pulses from the VULCAN optical laser are obtained using a streak camera with 700 fs temporal resolution. Combined with a temporal smearing due to the spectrometer employed, we have measured X-ray laser pulse durations for Ni-like silver at 13.9 nm with a total time resolution of 1.1 ps. For Ni-like silver, the X-ray laser output has a steep rise followed by an approximately exponential temporal decay with measured full-width at half-maximum (FWHM) of 3.7 (+/-0.5) ps. For Ne-like nickel lasing at 23.1 nm, the measured duration of lasing is approximate to10.7 (+/-1) ps (FWHM). An estimate of the duration of the X-ray laser gain has been obtained by temporally resolving spectrally integrated continuum and resonance line emission. For Ni-like silver, this time of emission is approximate to22 (+/-2) ps (FWHM), while for Ne-like nickel we measure approximate to35 (+/-2) ps (FWHM). Assuming that these times of emission correspond to the gain duration, we show that a simple model consistently relates the gain durations to the measured durations of X-ray lasing. (C) 2002 Elsevier Science B.V. All rights reserved.

A review of X-ray laser development at Rutherford Appleton Laboratory

Recent experiments undertaken at the Rutherford Appleton Laboratory to produce X-ray lasing over the 5-30 nm wavelength range are reviewed. The efficiency of lasing is optimized when the main pumping pulse interacts with a preformed plasma. Experiments using double 75-ps pulses and picosecond pulses superimposed on 300-ps background pulses are described. The use of travelling wave pumping with the approximately picosecond pulse experiments is necessary as the gain duration becomes comparable to the time for the X-ray laser pulse to propagate along the target length. Results from a model taking account of laser saturation and deviations from the speed of light c of the travelling wave and X-ray laser group velocity are presented. We show that X-ray laser pulses as short as 2-3 ps can be produced with optical pumping pulses of approximate to1-ps.

Simvastatin Decreases Lipopolysaccharide-induced Pulmonary Inflammation in Healthy Volunteers

RATIONALE:
Simvastatin inhibits inflammatory responses in vitro and in murine models of lung inflammation in vivo. As simvastatin modulates a number of the underlying processes described in acute lung injury (ALI), it may be a potential therapeutic option.
OBJECTIVES:
To investigate in vivo if simvastatin modulates mechanisms important in the development of ALI in a model of acute lung inflammation induced by inhalation of lipopolysaccharide (LPS) in healthy human volunteers.
METHODS:
Thirty healthy subjects were enrolled in a double-blind, placebo-controlled study. Subjects were randomized to receive 40 mg or 80 mg of simvastatin or placebo (n = 10/group) for 4 days before inhalation of 50 microg LPS. Measurements were performed in bronchoalveolar lavage fluid (BALF) obtained at 6 hours and plasma obtained at 24 hours after LPS challenge. Nuclear translocation of nuclear factor-kappaB (NF-kappaB) was measured in monocyte-derived macrophages.
MEASUREMENTS AND MAIN RESULTS:
Pretreatment with simvastatin reduced LPS-induced BALF neutrophilia, myeloperoxidase, tumor necrosis factor-alpha, matrix metalloproteinases 7, 8, and 9, and C-reactive protein (CRP) as well as plasma CRP (all P < 0.05 vs. placebo). There was no significant difference between simvastatin 40 mg and 80 mg. BALF from subjects post-LPS inhalation induced a threefold up-regulation in nuclear NF-kappaB in monocyte-derived macrophages (P < 0.001); pretreatment with simvastatin reduced this by 35% (P < 0.001).
CONCLUSIONS:
Simvastatin has antiinflammatory effects in the pulmonary and systemic compartment in humans exposed to inhaled LPS.

Predictors of mortality in acute lung injury during the era of lung protective ventilation

Background: Lung protective ventilation has been widely adopted for the management of acute lung injury (ALI) and acute respiratory distress syndrome ( ARDS). Consequently, ventilator associated lung injury and mortality have decreased. It is not known if this ventilation strategy changes the prognostic value of previously identified demographic and pulmonary predictors of mortality, such as respiratory compliance and the arterial oxygen tension to inspired oxygen fraction ratio (Pao(2)/Fio(2)).

Proteomic profiling of the retinal dysplasia and degeneration chick retina

Purpose: In our previous paper we undertook proteomic analysis of the normal developing chick retina to identify proteins that were differentially expressed during retinal development. In the present paper we use the same proteomic approach to analyze the development and onset of degeneration in the retinal dysplasia and degeneration (rdd) chick. The pathology displayed by the rdd chick resembles that observed in some of the more severe forms of human retinitis pigmentosa.

A randomized clinical trial of hydroxymethylglutaryl-Coenzyme A reductase inhibition for Acute Lung Injury (The HARP study)

Rationale: There is no effective pharmacological treatment for acute lung injury (ALI). Statins are a potential new therapy because they modify many of the underlying processes important in ALI.

Objectives: To test whether simvastatin improves physiological and biological outcomes in ALI.

Methods: We conducted a randomized, double-blinded, placebo-controlled trial in patients with ALI. Patients received 80 mg simvastatin or placebo until cessation of mechanical ventilation or up to 14 days. Extravascular lung water was measured using thermodilution. Measures of pulmonary and nonpulmonary organ function were assessed daily. Pulmonary and systemic inflammation was assessed by bronchoalveolar lavage fluid and plasma cytokines. Systemic inflammation was also measured by plasma C-reactive protein.

Measurements and Main Results: Sixty patients were recruited. Baseline characteristics, including demographics and severity of illness scores, were similar in both groups. At Day 7, there was no difference in extravascular lung water. By Day 14, the simvastatin-treated group had improvements in nonpulmonary organ dysfunction. Oxygenation and respiratory mechanics improved, although these parameters failed to reach statistical significance. Intensive care unit mortality was 30% in both groups. Simvastatin was well tolerated, with no increase in adverse events. Simvastatin decreased bronchoalveolar lavage IL-8 by 2.5-fold (P = 0.04). Plasma C-reactive protein decreased in both groups but failed to achieve significance in the placebo-treated group.

Conclusions: Treatment with simvastatin appears to be safe and may be associated with an improvement in organ dysfunction in ALI. These clinical effects may be mediated by a reduction in pulmonary and systemic inflammation.

Teaching and learning technologies in Higher Education: Applied behaviour analysis and autism.

Professionals on both international and national levels who work with children with autism are expressing the need for graduate-level training in applied behaviour analysis. The implementation of effective instruction in higher education for professionals working with children with autism and their families is a complex undertaking: the learner needs to acquire an understanding of the principles and procedures of applied behaviour analysis and also adapt this knowledge to the learning prerequisites of individuals with autism. In this paper we outline some current thinking about adult education and blended learning technologies and then describe and illustrate with examples emerging possibilities of multimedia technology in the development of teaching materials. We conclude that synergies between graduate-level curriculum requirements, knowledge of adult learning, and communication technology are necessary to establish comprehensive learning environments for professionals who specialize in autism intervention.

Nasal potential difference to detect Na+ channel dysfunction in acute lung injury

Pulmonary fluid clearance is regulated by the active transport of Na+ and Cl- through respiratory epithelial ion channels. Ion channel dysfunction contributes to the pathogenesis of various pulmonary fluid disorders including high-altitude pulmonary edema (HAPE) and neonatal respiratory distress syndrome (RDS). Nasal potential difference (NPD) measurement allows an in vivo investigation of the functionality of these channels. This technique has been used for the diagnosis of cystic fibrosis, the archetypal respiratory ion channel disorder, for over a quarter of a century. NPD measurements in HAPE and RDS suggest constitutive and acquired dysfunction of respiratory epithelial Na+ channels. Acute lung injury (ALI) is characterized by pulmonary edema due to alveolar epithelial-interstitial-endothelial injury. NPD measurement may enable identification of critically ill ALI patients with a susceptible phenotype of dysfunctional respiratory Na+ channels and allow targeted therapy toward Na+ channel function. text of link

Remediation of phenol-contaminated water by adsorption using poly(methyl methacrylate) (PMMA)

Recently polymeric adsorbents have been emerging as highly effective alternatives to activated carbons for pollutant removal from industrial effluents. Poly(methyl methacrylate) (PMMA), polymerized using the atom transfer radical polymerization (ATRP) technique has been investigated for its feasibility to remove phenol from aqueous solution. Adsorption equilibrium and kinetic investigations were undertaken to evaluate the effect of contact time, initial concentration (10-90 mg/L), and temperature (25-55 degrees C). Phenol uptake was found to increase with increase in initial concentration and agitation time. The adsorption kinetics were found to follow the pseudo-second-order kinetic model. The intra-particle diffusion analysis indicated that film diffusion may be the rate controlling step in the removal process. Experimental equilibrium data were fitted to five different isotherm models namely Langmuir, Freundlich, Dubinin-Radushkevich, Temkin and Redlich-Peterson by non-linear least square regression and their goodness-of-fit evaluated in terms of mean relative error (MRE) and standard error of estimate (SEE). The adsorption equilibrium data were best represented by Freundlich and Redlich-Peterson isotherms. Thermodynamic parameters such as Delta G degrees and Delta H degrees indicated that the sorption process is exothermic and spontaneous in nature and that higher ambient temperature results in more favourable adsorption. (C) 2011 Elsevier B.V. All rights reserved.

Contractile and vasorelaxant effects of hydrogen sulfide and its biosynthesis in the human internal mammary artery

This study aimed to test these hypotheses: cystathionine gamma-lyase (CSE) is expressed in a human artery, it generates hydrogen sulfide (H2S), and H2S relaxes a human artery. H2S is produced endogenously in rat arteries from cysteine by CSE. Endogenously produced H2S dilates rat resistance arteries. Although CSE is expressed in rat arteries, its presence in human blood vessels has not been described. In this study, we showed that both CSE mRNA, determined by reverse transcription-polymerase chain reaction, and CSE protein, determined by Western blotting, apparently occur in the human internal mammary artery (internal thoracic artery). Artery homogenates converted cysteine to H2S, and the H2S production was inhibited by DL-propargylglycine, an inhibitor of CSE. We also showed that H2S relaxes phenylephrine-precontracted human internal mammary artery at higher concentrations but produces contraction at low concentrations. The latter contractions are stronger in acetylcholine-prerelaxed arteries, suggesting inhibition of nitric oxide action. The relaxation is partially blocked by glibenclamide, an inhibitor of K-ATP channels. The present results indicate that CSE protein is expressed in human arteries, that human arteries synthesize H2S, and that higher concentrations of H2S relax human arteries, in part by opening K-ATP channels. Low concentrations of H2S contract the human internal mammary artery, possibly by reacting with nitric oxide to form an inactive nitrosothiol. The possibility that CSE, and the H2S it generates, together play a physiological role in regulating the diameter of arteries in humans, as has been demonstrated in rats, should be considered.