Simultaneous quantitative analysis of anionic, cationic, and nonionic surfactants in water by electrospray ionization mass spectrometry with flow injection analysis

A rapid method is described for the quantitative analysis of anionic, cationic, and nonionic surfactants in water samples by flow injection analysis coupled to electrospray ionization mass spectrometry (FIA/ESI-MS). All surfactants were isolated by liquid-liquid extraction and quantified using labeled triethoxylated nonylphenol ([13C6]-NP3EO) and sodium dibutylnaphthalenesulfonate as internal standards. FIA/ESI-MS was performed by alternating both positive and negative ionization modes, which allows simultaneous analysis of most common surfactants in a short time. Quality parameters of the method, such as linear range, repeatability, reproducibility, and limits of detection were studied. This method was applied to the analysis of wastewater treatment plant effluents from Catalonia (NE Spain).     

Pulmonary embolism in patients using estrogen-progestagen contraceptives

OBJECTIVES: The risk of thromboembolism in patients taking estrogen-progestagen oral contraceptive drugs has apparently increased since the introduction of third-generation progestagens (desogestrel, gestodene). We examined the clinical features, risk factors and outcome of pulmonary embolism in this context. PATIENTS AND METHODS: We reviewed 11 cases of thromboembolism in patients on oral contraception and hospitalized in emergency situations in 1995 and 1996 for pulmonary embolism in order to determine the gravity of the thromboembolic event, risk factors and type of drug used. RESULTS: Early clinical signs had preceded the onset of embolism by 2 to 164 days. PaO2 was below 70 mmHg in 4 patients. Diagnosis was achieved with pulmonary scintigraphy (11 cases), spiral CT (3 cases) and angiopneumography (2 cases). Duplex Doppler visualized the phlebitis in 7 patients. Given heparin (with fibrinolysis in 3 cases) then anti-vitamin K, and after withdrawal of the oral contraceptive, outcome was favorable in all cases. There were no recurrences. The nature of the oral contraceptive varied. Five patients were taking third-generation progestagens. In two cases, embolism had occurred following a change from a second-generation to a third-generation progestagen. Family history of phlebitis and/or abnormal laboratory findings were observed in 6 patients: resistance to activated protein C (2 patients), protein C deficiency (2 patients), anticardiolipin (2 patients) and low-titre antinuclear antibodies (2 patients). CONCLUSION: Pulmonary embolism in patients on oral contraceptives persists despite changes in the hormone content of the drugs. Diagnosis is often delayed. Family history of thrombosis or biological risk factors are often found.     

A Negotiation Meta Strategy Combining Trade-off and Concession Moves

In this paper we present a meta strategy that combines two negotiation tactics. The first one based on concessions, and the second one, a trade-off tactic. The goal of this work is to demonstrate by experimental analysis that the combination of different negotiation tactics allows agents to improve the negotiation process and as a result, to obtain more satisfactory agreements. The scenario proposed is based on two agents, a buyer and a seller, which negotiate over four issues. The paper presents the results and analysis of the meta strategy’s behaviour.     

Potential Environmental Applications of Pure Zeolitic Material Synthesized from Fly Ash

A pure 4A∕X (60∕40) zeolite product was synthesized from silica extracts of the Meirama fly ash in northwestern Spain. A high cation-exchange capacity (4.7 meq∕g) was obtained for the zeolitic material. The potential application of this coal fly ash conversion product for decontamination of high heavy metal waters was evaluated using three high heavy metal waters from acid mine drainage around the pyrite Huelva belt. The results were compared with those obtained with an equivalent pure commercial synthetic zeolite. A considerable reduction in the heavy metal content was attained (Zn from 174 to <0.1 mg∕L, Cu from 36 to 0.1 mg∕L, Fe from 444 to 0.8 mg∕L, Mn from 74 to <0.1 mg∕L, Pb from 1.5 to <0.1 mg∕L, and Cd from 0.4 to <0.1 mg∕L), even in high Ca and Fe waters using zeolite doses from 5 to 30 mg∕L. Both precipitation and cation-exchange processes accounted for the reduction in the pollutant concentration in the treated waters. Leachable hazardous elements from coal fly ash, such as Mo, B, As, V, and Cr, were not fixed in the synthesis of pure zeolites from the silica extracts. Consequently, they did not restrict the potential applications of this material as an ion exchanger, unlike the zeolitic material obtained from fly ash by direct alkaline conversion.     

Compatibility between 3T 1H SV-MRS data and automatic brain tumour diagnosis support systems based on databases of 1.5T 1H SV-MRS spectra

Object

This study demonstrates that 3T SV-MRS data can be used with the currently available automatic brain tumour diagnostic classifiers which were trained on databases of 1.5T spectra. This will allow the existing large databases of 1.5T MRS data to be used for diagnostic classification of 3T spectra, and perhaps also the combination of 1.5T and 3T databases.

Materials and methods

Brain tumour classifiers trained with 154 1.5T spectra to discriminate among high grade malignant tumours and common grade II glial tumours were evaluated with a subsequently-acquired set of 155 1.5T and 37 3T spectra. A similarity study between spectra and main brain tumour metabolite ratios for both field strengths (1.5T and 3T) was also performed.

Results

Our results showed that classifiers trained with 1.5T samples had similar accuracy for both test datasets (0.87 ± 0.03 for 1.5T and 0.88 ± 0.03 for 3.0T). Moreover, non-significant differences were observed with most metabolite ratios and spectral patterns.

Conclusion

These results encourage the use of existing classifiers based on 1.5T datasets for diagnosis with 3T ¹H SV-MRS. The large 1.5T databases compiled throughout many years and the prediction models based on 1.5T acquisitions can therefore continue to be used with data from the new 3T instruments.     

Audio‐visual interactions and soundscape preferences

The analysis of preferences for combinations of four sounds and eight visual landscapes revealed that the sound and not the visual component dominated the patterns of preference. This is attributed to the more varied nature of the sounds in comparison with the relatively homogenous quality of the visual scenes shown. The affective role of sound in combination with the visual setting deserves more attention and this traditional ingredient of landscaping deserves to be revived.     

Patterns of metal bioaccumulation in two filter-feeding macroinvertebrates: Exposure distribution, inter-species differences and variability across developmental stages

This study focused on the metal bioaccumulation of two aquatic insects (Ephoron virgo and Hydropsyche spp.) in order to evaluate the spatial distribution of metals, the interspecific differences between both filter-feeders and the bioaccumulation dynamics during E. virgo development stages. Hg, Cd, Ni, Cr, As, Pb, Cu, Ti, Zn and Mn were quantified in insects and in suspended particulate matter (SPM) sampled downstream and upstream of a chemical plant, where more than 300,000 t of polluted sediments are deposited. Hg concentrations were one order of magnitude higher downstream of the sediment dump, which showed that the Hg pollution originated in the chemical plant. Cd, Ni, Cr, Pb, Ti, Zn and Mn in invertebrates revealed that metal pollution was present upstream in other parts of the river. Interspecific differences were observed for all metals but Mn; significantly higher concentrations were observed in E. virgo over Hydropsyche exocellata, except for Cd, which showed 10-fold higher values. Hg and Cd increased until E. virgo nymphs reached 11 mm and decreased afterwards in late instars when nymphs were about to emerge. Cr, Pb, Ti and Mn decreased along early instars followed by a steady state in late instars. Similar values were obtained for Cu, As and Zn along all instars. Sexual differences between males and females of E. virgo were observed for Cd, Cu and Mn. Hg and Cd persistence was strong across developmental stages since high concentrations were found in eggs and emerging adults. Because the behavior of different metals varied for the two species and during the developmental stages of E. virgo, care should be taken in the interpretation of insect metal concentrations when analyzing the food chain transfer of metals in river ecosystems.     

Optimal metric for condition rating of existing buildings: is five the right number?

In the context of the built environment in the recent years, the concept of maintenance has changed from corrective to preventive maintenance. There is evidence that preventive maintenance is much more efficient than corrective maintenance, since severe deteriorations that may represent danger to people are avoided, and also money is saved. To make periodic inspections of the buildings is useful to quantify, the extent to which deteriorations are severe or not, in order to facilitate decision making and prioritise interventions. To this purpose, many scales have been used and are used to assess the severity of damage and degradation of the building components. But it appears evident that there is not consensus among users and these scales are different between them, with different number of degrees and metrics for the measurement of the condition state. The main goal of this paper is to calculate which is the optimal metric (which is the optimal number of degrees) of a severity scale of damages in buildings, so the corresponding scale could be of widespread and of common use among professionals, avoiding the problems of comparison between different evaluators. The proposed methodology to calculate the optimal metric of a scale can be also extended to other scopes.