Accelerated ageing of an EAF black slag by carbonation and percolation for long-term behaviour assessment

The efficient reuse of industrial by-products, such as the electric arc furnace (EAF) black slag, is still hindered by concern over their long-term behaviour in outdoor environments. The aim of this study was to develop an accelerated ageing method to simulate the long-term natural carbonation of EAF slag exposed to the elements. The degree of carbonation achieved in a freshly produced slag after accelerated ageing and in a slag used on a fifteen-year-old unpaved road was very similar. The influence of particle size on accelerated carbonation was assessed, with it being concluded that the slag sample with a particle size bigger than 5-6 mm underwent slight carbonation over time when it was exposed to CO2. The accelerated ageing procedure based on percolating a previously carbonated water solution through the slag column allowed gradual leaching with simulated acid rain, as well as providing information about the gradual and total chemical release from the slag. Three classification groups were established according to the release rate of the determined elements. The joint use of the accelerated carbonation method and the percolation test is proposed as a useful tool for environmental risk assessment concerning the long-term air exposure of EAF black slag.

Spectroscopic analysis of the interaction of a peptide sequence of Hepatitis G virus with bilayers

Merocyanine 540 (MC540) has been used as external probe to determine the interaction of the peptide sequence 125-139 corresponding to the E2 protein of Hepatitis G virus, with lipid bilayers. The probe was incorporated into large unilamellar vesicles (LUVs) or small unilamellar vesicles (SUVs) of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). When incorporated into bilayers, MC540 shows two absorption maxima corresponding to the monomer (570 nm) and dimer (530 nm) form of the probe. Changes in the probe microenvironment are reflected by a modification in the position and/or intensity of these maxima. Addition of increasing amounts of peptide resulted in a slight decrease of the ratio A570/A530 thus indicating a change in MC540 partition into the membrane, going from a hydrophobic to a more hydrophilic environment. This effect was concomitant with an increase in dimer formation as stated from the values of the apparent dimerization constant (K(app)) obtained. Fluorescence spectra as well as steady state anisotropy measurements were in agreement with the above results indicating that the peptide was able to relocate the probe and displacing MC540 from its initial location into the bilayer. Results with SUVs or LUVs were similar for what curvature does not seem to play any role on peptide activity. These results reflect the ability of peptide to interact with biomimetic membranes in the lipid head group region.

Evaluating the impact of water supply strategies on p-xylene biodegradation performance in an organic media-based biofilter

The influence of water irrigation on both the long-term and short-term performance of p-xylene biodegradation under several organic loading scenarios was investigated using an organic packing material composed of pelletised sawdust and pig manure. Process operation in a modular biofilter, using no external water supply other than the moisture from the saturated inlet air stream, showed poor p-xylene abatement efficiencies (≈33 ± 7%), while sustained irrigation every 25 days rendered a high removal efficiency (RE) for a critical loading rate of 120 g m(-3)h(-1). Periodic profiles of removal efficiency, temperature and moisture content were recorded throughout the biofilter column subsequent to each biofilter irrigation. Hence, higher p-xylene biodegradation rates were always initially recorded in the upper module, which resulted in a subsequent increase in temperature and a decrease in moisture content. This decrease in the moisture content in the upper module resulted in a higher removal rate in the middle module, while the moisture level in the lower module steadily increased as a result of water condensation. Based on these results, mass balance calculations performed using measured bed temperatures and relatively humidity values were successfully used to account for water balances in the biofilter over time. Finally, the absence of bed compaction after 550 days of continuous operation confirmed the suitability of this organic material for biofiltration processes.

Lipophilic derivatization of synthetic peptides belonging to NS3 and E2 proteins of GB virus-C (hepatitis G virus) and its effect on the interaction with model lipid membranes

The synthesis by solid-phase methodologies of peptides belonging to structural and non-structural proteins of GB virus C as well as its N-alpha-acylation with myristate and palmitate fatty acids is described. To explore the peptide-lipid interactions we have used liposomes composed of dipalmitoylphosphatidylcholine as model membranes and complementary spectroscopic and calorimetric techniques. Our results show that structural and more clearly the structural lipophilic peptide sequences incorporated into lipid bilayers perturb the packing of lipids and affect their thermotropic properties, more than the non-structural selected sequence. However, the binding of the synthetic sequences to lipid membranes occurred without any restructuration of the peptides.

Openness to Experience and Depression* * The original data upon which this paper is based are available at www.hhpub.com/journals/ejpa

Summary: The present study examines, in the context of the Five Factor Model, the contradictory role played by the Openness to Fantasy and Openness to Actions facets (of the Openness to Experience factor) in the prediction of depression. The fact that our data are taken from a sample of the Spanish general population is also a cross-cultural contribution that must be emphasized. 112 participants - 50% females and 50% males - filled out the NEO-PI and the BDI depression questionnaires. A stepwise regression shows that the Fantasy facet of Openness to Experience makes a different - though still contradictory - contribution to the prediction of depression than the Actions facet. Both facets are statistically significant in the prediction of depression, but they apparently go in opposite directions. Whereas Openness to Actions predicts a lack of depression, Openness to Fantasy seems to be a predictor of depression. In order to clarify the possible role of gender in this “crossed prediction,” a univariate ANOVA was performed, taking depression from the BDI as a dependent variable and Gender, Fantasy and Actions as fixed factors. From this analysis we have seen that the contradictory role played by Fantasy in the prediction of depression is linked to gender: Women scored high in Fantasy and are thus statistically more susceptible to depression. These results are discussed from the point of view of the PB theory of depression.

Phenotypic changes in monocytes and alveolar macrophages in patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC)

The expression of Class II histocompatibility antigens (HLA-DR and HLA-DQ), leukocyte function associated antigen (LFA-1) and complement receptor type 3 (CR3) on peripheral blood monocytes and alveolar macrophages (M phi) from patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC) and age-matched controls was studied. The percentage of HLA-DR+ monocytes from 4 AIDS patients and 12 ARC patients was 52.4 +/- 16.4% (p less than 0.05) and 50.2+21.2% (p less than 0.01) respectively (Controls, 75.4 +/- 12.6%). HLA-DQ expression in monocytes from one AIDS and two ARC patients was 31%, 39% and 18% respectively (in normal individuals, DQ was expressed by approximately 40% monocytes). HLA-DR and HLA-DQ expression on alveolar M phi from one AIDS patient and 2 ARC patients were also depressed. CR3 was expressed by 65.9 +/- 11.1% monocytes from normal controls. Patients with AIDS had a slightly, but significantly lower, proportion of CR3+ monocytes (43.9 +/- 15.9%, p less than 0.05) (in normal controls, CR3 monocytes were 65.9 +/- 11.1%). However, monocytes from ARC patients and alveolar M phi from one AIDS and 2 ARC patients expressed CR3 in a normal range. LFA-1 was significantly depressed in monocytes from both AIDS (45.7 +/- 1%, p less than 0.005) and ARC (57.5 +/- 10.9%, p less than 0.005) patients in comparison with controls (87.4 +/- 8.7%). Only alveolar M phi from one AIDS patient could be studied for LFA-1 antigen and this was into the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Intravenous DSA of extracranial carotid lesions: comparison with other techniques and specimens

Intravenous digital subtraction arteriography (DSA) was performed in 306 patients with suspected ischemic cerebrovascular disease. Forty-eight carotid endarterectomies were performed in 43 of these patients. The percentage stenosis as determined on the intravenous DSA examination concurred (+/- 10%) with the surgical findings in 83.3%. There were 12.5% undercalls (false-negatives) and 4.3% overcalls (false-positives). Of the false-negative and false-positive examinations only three would have affected the clinical management of the patient, yielding an overall sensitivity of 93.7%. Nine surgical lesions had both intravenous DSA and conventional arteriography. Intravenous DSA was correct in six and arteriography in seven of these lesions. There were four surgically confirmed ulcerations. Two were evaluated by intravenous DSA alone. Two had intravenous DSA and arteriography. The latter showed both ulcers; the former, only one. Thirty-seven surgical lesions had both intravenous DSA and high-resolution real-time sonographic imaging. Sonography agreed in 67.5% and intravenous DSA in 83.7% of these lesions. When an abnormal supraorbital Doppler or an abnormal oculopneumoplethysmography/Gee examination is added to the sonographic examination, an overall sensitivity of 93% was obtained in detecting a surgical lesion (stenosis greater than 50%).