Characterization of optically active and photocurable ORMOSIL thin films deposited using the Aerosol process

Aerosol-gel process is a deposition method based on the sol-gel polymerization of a liquid film produced from an ultrasonically sprayed aerosol. This process offers an attractive alternative for the deposition of photocurable SiO₂—TiO₂ ORMOSIL films. 3-(trimethoxysilyl) propylmethacrylate and tetraisopropyl-orthotitanate complexed with methacrylic acid were used as sol-gel precursors. Doping with a terbium:sulphosalicylic acid complex was also studied to test the deposition of spectroscopically active photocurable films. FTIR spectroscopy has been used to study the precursor solutions and ORMOSIL films. It is shown that titanium precursor incorporation enhances the solution reactivity, which yields optical quality thin films. Photopolymerization and photoluminescence properties of the films are reported and discussed with respect to the experimental parameters. The results allow envisaging the UV-imprinting fabrication of Aerosol-gel-derived active waveguides.     

On the adjoint-consistent formulation of interface conditions in goal-oriented error estimation and adaptivity for fluid–structure interaction

The numerical solution of fluid–structure-interaction problems poses a paradox in that most of the computational resources are consumed by the subsystem of least practical interest, viz., the fluid. Goal-oriented adaptive discretization methods provide a paradigm to bypass this paradox. Based on the solution of a dual problem, the contribution of local residuals to the error in a specific goal functional is estimated, and only the regions that yield a dominant contribution are refined. In the present work, we address a fundamental complication in the application of goal-oriented adaptivity to fluid–structure-interaction problems, namely, that the treatment of the interface conditions has nontrivial consequences for the properties of the dual problem. In the context of a linearized model problem, we consider two equivalent discretizations differing only on the formulation of the interface coupling terms. By means of an adjoint consistency analysis, we show that only one of these discretizations is adjoint consistent. Numerical experiments convey that the two discretizations behave very differently for the dual problem, and that the adjoint-consistent discretization yields more reliable error estimates. Based on the adjoint-consistent discretization, we finally present some h- and hp-adaptive results, confirming that tremendous savings in computational cost can be realized through the use of goal-oriented refinement strategies. The numerical experiments illustrate that the goal-oriented approach effectively equilibrates the error contributions of the fluid and structure subsystems, which is imperative for efficiently resolving the coupled fluid–structure-interaction problem, and which cannot be accomplished by uniform or residual-based refinement strategies.     

Plasma L-arginine concentration, oxygenation index, and systemic blood pressure in premature infants

OBJECTIVE: To determine the relationships between plasma L-arginine concentrations and the severity of respiratory distress syndrome (RDS) or systemic blood pressure in premature infants. DESIGN: Prospective, observational study. SETTING: Neonatal intensive care, tertiary referral hospital. SUBJECTS: Fifty-three premature infants. INTERVENTIONS: We measured arginine and nutritional intake, plasma arginine concentration, total amino acid concentrations, and blood pressure on days 3, 7, 14, and 21 of life. In 33 infants who received assisted ventilation, oxygenation index could be calculated to reflect the severity of RDS. The relationships between plasma arginine and oxygenation index or blood pressure were analyzed using multiple linear regression. MEASUREMENTS AND MAIN RESULTS: On day 3, plasma arginine concentrations were decreased compared with normal published values. Arginine concentrations increased with the day of life of measurement (p < .001) and with arginine intake (p < .001). After adjusting for arginine intake and day of life, an inverse relationship was found between oxygenation index and plasma arginine concentrations: (p = .025). No similar relationship was found between oxygenation index and the concentration of total amino acids. A weak positive relationship was found between plasma arginine concentration and systemic blood pressure. CONCLUSIONS: Increments in the oxygenation index, reflective of an increased severity of RDS, are associated with a decrease in plasma arginine concentration. This finding may reflect arginine consumption by the nitric oxide synthase pathway in the lungs of premature infants with RDS, or may be explained by increased arginine catabolism. The lack of a similar relationship between total plasma amino acids and oxygenation index supports the first interpretation.     

Does waterborne citalopram affect the aggressive and sexual behaviour of rainbow trout and guppy?

Citalopram is one of several selective serotonin reuptake inhibitors (SSRIs) commonly found in treated sewage effluents. Accordingly, there are concerns about possible adverse effects of SSRIs on aquatic organisms, particularly behavioural effects similar to those associated with SSRI use in humans. Rainbow trout fry and adult male guppies were therefore exposed to waterborne citalopram, ranging from environmentally relevant to high concentrations (1, 10, 100 μg/L) for 3-7 days. Under these experimental conditions citalopram does not appear to cause significant effects on aggression in rainbow trout fry or on sexual behaviour in male guppies. This may be explained by a relatively low uptake of citalopram from water to fish.     

First year serologic response to treatment for syphilis: a model for prediction of seroreversion

There is no straightforward test available, within weeks of treatment for syphilis, to assess adequacy of serologic response. We propose a method to predict non-treponemal seroreversion based on short term response. To develop and illustrate this method, we used data from 370 individuals with infectious syphilis. Individual serologic response appears to be a linear function of (log) time, suggesting the possibility of using rapid plasma reagin titres recorded in the first few months after treatment to determine the slope of the linear treatment response line. The slope of the response line, during the first year after treatment, is an important predictor of seroreversion but must be considered in conjunction with pre-treatment titre. We recommend development of an action line be developed based on these variables. Such a line would indicate the necessity for retreatment if the line plotted from the patient's first year response failed to fall below the action line.     

Diagnosing left lower lobe pneumonia: usefulness of the ''spine sign'' on lateral chest radiographs

Percutaneous cardiopulmonary assist devices (PCPS) have become available in interventional cardiology within recent years. These tools offer the opportunity of performing percutaneous transluminal coronary angioplasty (PTCA) in high-risk patients characterized by significant stenoses of several coronary arteries and a poor left ventricular function. It is unclear for which patients PCPS are necessary and which patients will profit by PTCA as compared to coronary artery bypass grafting (CABG). Therefore, the anticipated risk of CABG and of PTCA without assist devices was calculated according to risk scores and compared with our results of assisted PTCA. In addition the long-term survival rate was investigated. In 35 patients (mean 65.5 years of age, 12 females, 23 males), we performed PTCA concomitant with the use of cardiac assist devices. The indications for the use of a cardiac assist device were severely impaired LV function (EF 30% +/- 8.9%) in combination with significant coronary artery disease (2.7 +/- 0.3 vessels) and a significant supply area of the vessel to be dilated. In 6 patients, PCPS was started before coronary angioplasty because of hemodynamic instability. In 21 cases, PCPS was on a standby basis without being connected to the patient's circulation. In 8 patients, a left heart assist device, the 14F-Hemopump, was inserted percutaneously. The patients were analyzed using risk scores of angioplasty and of coronary bypass graft surgery. The calculated risk of hemodynamic compromise during PTCA according to the risk scores was more than 50%. The anticipated risk of a fatal outcome following CABG would have been 19.8%. PTCA was performed on an average of 2.0 coronary arteries per patient and was successful in 85%. We observed a decline in angina pectoris classification (CCS) from 3.5 to 1.6. An average reduction of 1.1 NYHA class was achieved. The in-hospital mortality was 8.6% (3 patients: 1 x sepsis, 1 x early reocclusion, 1 x cerebral embolism). At 24 months follow-up, a re-PTCA was necessary in four cases because of restenosis. In the remainder, NYHA and CCS class were stable during the follow-up period. An additional five patients died during the first year and two patients in the second year. We conclude that PTCA with the use of a cardiac assist device shows favorable short-term results in a subset of patients with extended coronary artery disease and severely impaired LV function who are not suitable for nonsupported PTCA or CABG due to their risk profile. However, the long term results are not satisfying and stress the need for complete revascularisation with CABG once the patient's condition is stabilized by means of supported PTCA.