Marangoni force-driven manipulation of photothermally-induced microbubbles.

The generation and manipulation of microbubbles by means of temperature gradients induced by low power laser radiation is presented. A laser beam (λ = 1064 nm) is divided into two equal parts and coupled to two multimode optical fibers. The opposite ends of each fiber are aligned and separated a distance D within an ethanol solution. Previously, silver nanoparticles were photo deposited on the optical fibers ends. Light absorption at the nanoparticles produces a thermal gradient capable of generating a microbubble at the optical fibers end in non-absorbent liquids. The theoretical and experimental studies carried out showed that by switching the thermal gradients, it is possible to generate forces in opposite directions, causing the migration of microbubbles from one fiber optic tip to another. Marangoni force induced by surface tension gradients in the bubble wall is the driving force behind the manipulation of microbubbles. We estimated a maximum Marangoni force of 400nN for a microbubble with a radius of 110 µm.

National climate policies across Europe and their impacts on cities strategies.

Globally, efforts are underway to reduce anthropogenic greenhouse gas emissions and to adapt to climate change impacts at the local level. However, there is a poor understanding of the relationship between city strategies on climate change mitigation and adaptation and the relevant policies at national and European level. This paper describes a comparative study and evaluation of cross-national policy. It reports the findings of studying the climate change strategies or plans from 200 European cities from Austria, Belgium, Estonia, Finland, France, Germany, Ireland, Italy, Netherlands, Spain and the United Kingdom. The study highlights the shared responsibility of global, European, national, regional and city policies. An interpretation and illustration of the influences from international and national networks and policy makers in stimulating the development of local strategies and actions is proposed. It was found that there is no archetypical way of planning for climate change, and multiple interests and motivations are inevitable. Our research warrants the need for a multi-scale approach to climate policy in the future, mainly ensuring sufficient capacity and resource to enable local authorities to plan and respond to their specific climate change agenda for maximising the management potentials for translating environmental challenges into opportunities.

Tolerability during double-blind randomized phase I trials with the house dust mite allergy immunotherapy tablet in adults and children.

BACKGROUND AND OBJECTIVE: The orodispersible house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet (ALK, Denmark) is being developed for the treatment of HDM respiratory allergic disease. The objective of the 2 phase I trials was to investigate tolerability and the acceptable dose range of HDM SLIT-tablet treatment in adults and children with HDM respiratory allergic disease. PATIENTS AND METHODS: The trials were randomized, multiple-dose, dose-escalation, double-blind, placebo-controlled phase I trials including patients with HDM-induced asthma, with or without rhinoconjunctivitis. Both trials were registered in EudraCT (Trial 1: 2005-002151-41; Trial 2: 2007-000402-67). Trial 1 included 71 adults (18-63 years) and trial 2 included 72 children (5-14 years). Both trials included 6 dose groups that were randomized 3:1 to active treatment or placebo once daily for 28 days. Adverse events (AEs) were coded in MedDRA (version 8.1 or later). Immunological variables included specific IgE and IgE-blocking factor. RESULTS: No serious AEs were reported. In trial 1 (maximum dose, 32 development units [DU]), 1 patient in the 16 DU group discontinued due to AEs. The entire 32 DU group was discontinued as 1 patient had a severe adverse reaction. In trial 2 (maximum dose, 12 DU), no patients discontinued prematurely. The most frequently reported AEs were mild application-site related events. The total number of events was dose-related within each trial. HDM SLIT-tablet treatment induced changes in immunological parameters in a dose-dependent manner. CONCLUSIONS: These trials demonstrate that doses up to 12 DU of HDM SLIT-tablet were tolerated in the selected populations, and thus are suitable for further clinical investigations in adults and children with HDM respiratory allergic disease.

A benchmark for Monte Carlo simulations in gamma-ray spectrometry Part II: True coincidence summing correction factors.

The goal of this study is to provide a benchmark for the use of Monte Carlo simulation when applied to coincidence summing corrections. The examples are based on simple geometries: two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The coincidence corrective factors are computed for four radionuclides. The exercise input files and calculation results with practical recommendations are made available for new users on a dedicated webpage.

Radionuclide activities and metal concentrations in sediments of the Sebou Estuary, NW Morocco, following a flooding event.

This study presents metal concentrations (Fe, Mg, Mn, Co, Cu, Zn, Pb, As, Sr and V) and radionuclide activities ((40)K, (137)Cs, (210)Pb, (226)Ra, (228)Ac, (234)Th and (212)Pb) in surface deposits and a sediment core from the Sebou Estuary, Northwest Morocco. Samples were collected in April 2009, about 2 months after a flooding event, and analysed using a well-type coaxial gamma-ray detector and inductively coupled plasma-quadrupole mass spectrometry. Activities of radionuclides and concentrations of almost all elements in surface samples displayed only moderate spatial variation, suggesting homogenous deposition of eroded local soil in response to intense precipitation. Excess (210)Pb displayed relatively constant activity throughout the sediment core, preventing dating and precluding determination of the historical accumulation rates of pollutants at the core site. Some elements showed non-systematic trends with depth and displayed local maxima and minima. Other elements presented relatively systematic concentration trends or relatively constant levels with discrete maxima and/or minima. Except for Mn, Sr and Cr, all metal concentrations in sediment were below levels typical of polluted systems, suggesting little human impact or losses of metals from sediment particles.

Successful micronucleus testing with the EPI/001 3D reconstructed epidermis model: preliminary findings.

Currently, the cosmetics industry relies on the results of in vitro genotoxicity tests to assess the safety of chemicals. Although the cytokinesis-block micronucleus (CBMN) test for the detection of cells that have divided once is routinely used and currently accepted by regulatory agencies, it has some limitations. Reconstituted human epidermis (RHE) is widely used in safety assessments because its physiological properties resemble those of the skin, and because it allows testing of substances such as hydrophobic compounds. Thus, the micronucleus test is being adapted for application in RHE-reconstructed tissues. Here we investigated whether two different reconstructed epidermis models (EPI/001 from Straticell, and RHE/S/17 from Skinethic) are suitable for application of the micronucleus test. We found that acetone does not modify micronucleus frequency, cell viability, and model structure, compared with non-treated RHE. Treatment of the EPI/001 model with mitomycin C and vinblastine resulted in a dose-dependent increase of micronucleus frequency as well as a decrease of tissue viability and of binucleated cell rate, while no changes of the epidermal structure were observed. The number of binucleated cells obtained with the RHE/S/17 model was too small to permit micronucleus testing. These results indicate that the proliferative rate of the tissue used is a critical parameter in performing the micronucleus test on a 3D model.

Consistency test of coincidence-summing calculation methods for extended sources.

An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.

A benchmark for Monte Carlo simulation in gamma-ray spectrometry.

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The action outputs (input files and efficiency calculation results, including practical recommendations for new users) are made available on a dedicated webpage.

Efficient in vitro photodynamic inactivation using repetitive light energy density on Candida albicans and Trichophyton mentagrophytes.

BACKGROUND: We compared the effectiveness of a single irradiation vs repetitive irradiation of light, for in vitro photodynamic inactivation (PDI) of Candida albicans and Trichophyton mentagrophytes, by using methylene blue (MB) and rose bengal (RB) as photosensitizers (PS). METHODS: MB from 5 to 60 µM and RB from 0.5 to 10 µM, with energy densities from 10 to 60 J/cm2, were tested in C. albicans. We further optimize the PDI by reducing the light energy density and PS concentration for the single irradiation experiments by using repetitive doses (two and three times). MB was tested in C. albicans and T. mentagrophytes, and RB was tested in C. albicans. RESULTS: MB-PDI and RB-PDI in C. albicans significantly reduced the number of colony-forming units per milliliter (CFU/mL) when compared to the control groups. Using a single irradiation, over 99% growth inhibition of C. albicans was obtained with MB at 20 µM-60 J/cm2, and with RB at 1 µM-30 J/cm2 and 5 µM-10 J/cm2. With repetitive doses, similar results were obtained by reducing several times the light energy density and the PS concentration for C. albicans and T. mentagrophytes. CONCLUSIONS: The results showed that RB was more effective than MB for C. albicans inactivation. In addition, it is possible to significantly reduce the amount of PS and light energy density requirements by using repetitive irradiations in both genera tested. It makes the technique less invasive and could reduce the side effects in people extremely sensitive to the PS or the light.

Numerical analysis of alpha spectra using two different codes.

This work presents an intercomparison between commercial software for alpha-particle spectrometry, Genie 2000, and the new free available software, Winalpha, developed by International Atomic Energy Agency (IAEA). In order to compare both codes, different environmental spectra containing plutonium, uranium, thorium and polonium have been analyzed, together with IAEA test alpha spectra. A statistical study was performed in order to evaluate the precision and accuracy in the analyses, and to enhance the confidence in using the software on alpha spectrometric studies.

An intercomparison of Monte Carlo codes used in gamma-ray spectrometry.

In an intercomparison exercise, the Monte Carlo codes most commonly used in gamma-ray spectrometry today were compared with each other in order to gauge the differences between them in terms of typical applications. No reference was made to experimental data; instead, the aim was to confront the codes with each other, as they were applied to the calculation of full-energy-peak and total efficiencies. Surprising differences between the results of different codes were revealed.

Optimized background reduction in low-level gamma-ray spectrometry at a surface laboratory.

The background of a coaxial Ge detector placed at a surface laboratory has been reduced by means of a background reduction setup consisting of a passive shield of low-activity lead, a simple radon suppression system and an active shield with a plastic scintillation plate. In particular, we have devoted our efforts to in-depth optimization of each parameter associated with different anticoincidence setups and to their subsequent intercomparison. The overall performance of the active shield was improved by using the optimum time parameters for each setup. The final objective is to decrease the cosmic-ray background and, by this way, to reduce the detection limits of gamma-ray spectrometers at conventional laboratories, and consequently make them competitive for different measurements like (210)Pb dating.

Equivalence of computer codes for calculation of coincidence summing correction factors - Part II.

The aim of this study was to check for equivalence of computer codes that are capable of performing calculations of true coincidence summing (TCS) correction factors. All calculations were performed for a set of well-defined detector parameters, sample parameters and decay scheme data. The studied geometry was a point source of (133)Ba positioned directly on the detector window of a low-energy (n-type) detector. Good agreement was established between the TCS correction factors computed by the different codes.

Trapping and manipulation of microparticles using laser-induced convection currents and photophoresis.

In this work we demonstrate optical trapping and manipulation of microparticles suspended in water due to laser-induced convection currents. Convection currents are generated due to laser light absorption in an hydrogenated amorphous silicon (a:Si-H) thin film. The particles are dragged towards the beam's center by the convection currents (Stokes drag force) allowing trapping with powers as low as 0.8 mW. However, for powers >3 mW trapped particles form a ring around the beam due to two competing forces: Stokes drag and thermo-photophoretic forces. Additionally, we show that dynamic beam shaping can be used to trap and manipulate multiple particles by photophotophoresis without the need of lithographically created resistive heaters.

Effect of NMDA antagonists on the activity of glutaminase and aspartate aminotransferase in the developing rat cerebellum.

Chronic treatment of rats from postnatal day 6 to 25 with drugs that interact with the N-methyl-D-aspartate (NMDA) receptor induced a differential effect on the activity of some enzymes involved in neurotransmitter synthesis. Two of these drugs ((5R,10S)-(+)-5-methyl-10,11 -dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine hydrogen maleate (MK-801) and 3-(2-carboxypiperazin-4-yl)propyl-1phosphonic acid (CPP)) caused a marked reduction (20-40%) of glutaminase and aspartate aminotransferase activity in the cerebellum. These changes were observed only at a very precise time of development (i.e. 10 to 19 postnatal day). The competitive antagonist, amino phosphonovaleric acid (APV), did not affect any of the enzymes studied at all tested ages. When animals were treated with NMDA only a slight, but significant, increase in the activity of glutaminase was observed at 9-11 postnatal day only. Any of the agonists or antagonists tested significantly affected the activity of lactate dehydrogenase as compared to control animals. Histologic observations of cerebella treated with the indicated drugs showed that only MK-801, and CPP to a lesser extent, induced a small reduction in the width of the internal granule layer. The body weight of animals treated with MK-801 was clearly reduced, but only in more mature rats (> 16 postnatal day), when animals did not show any alteration in the enzymes tested. These results support the suggestion that presynaptic influences, particularly from glutamatergic neurons, are critical to promote cerebellar granule neurons differentiation during critical periods of the cerebellar development.

Determination of vitamins A and E in infant milk formulae by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method was developed for the determination, in one run, of retinol and alpha-tocopherol in infant milk formulae. The method involved saponification at room temperature and a later extraction of vitamins with n-hexane. The vitamins were resolved with a C18 reversed-phase column and they were detected by UV spectrophotometry. Linearity, precision, recovery and sensitivity were satisfactory. The main advantage of the method proposed is the simultaneous determination of both vitamins using a common extraction procedure and UV detection with a variable-wavelength spectrophotometer.

Determination of water-soluble vitamins in infant milk by high-performance liquid chromatography.

A rapid, simple and reliable liquid chromatographic method has been developed for the simultaneous determination of nicotinamide, thiamin, riboflavin, pyridoxine, pyridoxal, pyridoxamine, cyanocobalamine and folic acid in liquid and powdered infant milk. Ion-pair chromatography with a reversed-phase C18 column is used. Six vitamins were resolved in a single analysis; total analysis time never exceeded 55 min. A mobile phase of methanol-water (15:85), 5 mM octanesulfonic acid, with 0.5% triethylamine at pH 3.6 and a flow-rate of 1.0 ml/min gave the most satisfactory separation of these vitamins using a UV detector set at different wavelengths. Sample preparation involves acidification to precipitate proteins, and centrifugation followed by gravity filtration. Linearity, precision, recovery and sensitivity were always satisfactory. Detection limits ranged from 0.02 to 0.10 microgram/ml and determination limits ranged from 0.03 to 0.25 microgram/ml.

Determination of available lysine in infant milk formulae by high-performance liquid chromatography.

A high-performance liquid chromatography (HPLC) method to determine available lysine is proposed. Available lysine was measured by an optimised fluorodinitrobenzene method on the basis of the reactivity of the free epsilon-amino group of the lysine. The classical acid hydrolysis has been improved and shortened from the usual time of 12 h to 2 h 30 min using an oil bath. Optimal resolution and quantitation of Nn-dinitrophenyllysine was obtained with a Nova-Pak C18 column using an isocratic elution with 35% methanol and 65% 0.01 M sodium acetate buffer (pH 4.5) and a flow-rate of 1 ml/min. Satisfactory results were obtained for the reliability of the method in terms of linearity from 0.1 to 5.0 mg/l of lysine-free base, precision (R.S.D. values between 4.3% and 7.8%), recovery (91.5%) and sensitivity (detection limit of 0.02 mg/l). The proposed method has also been checked for lack of interferences from other dinitrophenyl-amino acids.

Progress of browning reactions during storage of liquid infant milks.

Changes in furfural compounds and reactive lysine were monitorized in three commercial liquid infant milks during 9 months of storage at 20, 30, and 37 degrees C. Samples consisted of two ultrahigh temperature (UHT)-treated milks and one conventionally sterilized milk. Reactive lysine remained constant throughout storage at the three temperatures, whereas, in general an increase in furfural compounds was observed. The heat treatment used in the manufacture of milk is an important factor that influences the levels of furfural compounds although the composition of the milk is also a critical factor. Finally, a study was conducted to find the kinetic equations describing furfural compounds changes and allowing for the prediction of the influence of time and temperature of storage on those changes.

Patient satisfaction and allergen immunotherapy.

Although health-related quality of life and patient satisfaction are shifting doctors' attention to the patient, the scant number of publications on quality of life questionnaires and allergen immunotherapy contrasts with the quickly growing number of those dealing with this topic and pharmacotherapy. We delivered an original, self-administered patient satisfaction questionnaire to 95 patients (age = 17.7 +/- 7.9 years) suffering from allergic rhinoconjunctivitis (45%) and/or asthma (55%), who had been receiving allergen immunotherapy for more than 1 year (22.2 +/- 10.5 months). The anonymous, voluntary questionnaire was filled in at home; although only 32% were returned, we found no significant differences relating to age, sex, asthma, allergen sensitization or allergen immunotherapy regimen between the source sample and those who replied. Patient expectations, which were scored on a scale of 1 to 10 points, were rather poor, in sharp contrast with patient perception score after treatment (5.4 +/- 1.8 vs. 8.0 +/- 2.0, p < 0.0001). Perception scores did not differ between patients receiving seasonal or perennial allergen immunotherapy, nor did they depend on the duration of treatment. In addition, patient age, sex, diagnosis or sensitization did not appear to influence perceptions. In conclusion, our data suggest that when a voluntary, anonymous questionnaire is used, patients express a poor opinion of allergen immunotherapy, in contrast with high satisfaction after treatment, provided that allergen immunotherapy lasts long enough.