Dose-response function for the soiling of silica-soda-lime glass due to dry deposition

Several exposure campaigns of silica-soda-lime window glass have been performed in 30 European sites and 1 in Canada in order to understand, quantify and model the phenomenon of soiling. In this purpose samples were exposed sheltered from the rain. Parallel to exposure, several meteorological parameters and pollution concentrations have been monitored. This paper shows first results on the establishment of a dose-response function for glass soiling. Statistical analyses show that PM(10) is not the only parameter, but also SO(2) and NO(2) atmospheric concentrations seem to be responsible for the optical impairment of glass surfaces, expressed as haze.

Antibacterial activity of some Artemisia species extract

The antimicrobial activities of ethanol, methanol and hexane extracts from Artemisia absinthium, Artemisia annua and Artemisia vulgaris were studied. Plant extracts were tested against five Gram-positive bacteria, two Gram-negative bacteria and one fungal strain. The results indicated that Artemisia annua alcoholic extracts are more effective against tested microorganisms. However, all plants extracts have moderate or no activity against Gram-negative bacteria. The obtained results confirm the justification of extracts of Artemisia species use in traditional medicine as treatment for microbial infections.

Manipulation and tracking of superparamagnetic nanoparticles using MRI

The use of magnetic fields in magnetic resonance imaging (MRI) for the tracking and delivery of chemotherapeutics bound to superparamagnetic nanoparticles offers a promising method for the non-invasive treatment of inoperable tumours. Here we demonstrate that superparamagnetic magnetite nanoparticles fabricated by an easily scalable method can be driven and tracked in real time at high velocities in vitro using MRI hardware. Force balance calculations are consistent with the magnetic properties of individual 10 nm diameter particles that move collectively as micron sized agglomerates with hydrodynamic diameter similar to that inferred from zero-magnetic-field dynamic light scattering measurements.

The pocket echocardiograph: a useful new tool?

AIMS

Hand-carried ultrasound scanners are getting smaller. The Acuson P10 is the latest and smallest portable echocardiograph available on the market.

METHODS AND RESULTS

We tested the ability of this scanner to allow qualitative assessment of LV size and function in an unselected group of 30 patients [19 male, 11 female; mean age (SD) 64.7 (10.3) years] seen by a consultant cardiologist (accredited for advanced echocardiography) during a week on call in a regional cardiac tertiary facility. Patients had focused scans (parasternal long-axis and apical four chamber views) for a maximum of 4 min, and an assessment of LVEF (normal/abnormal) and LV dimension (LVD) (dilated/non-dilated) was recorded. Where available, this was compared with results of alternative imaging modalities. In 23 (77%) patients, it was possible to assess LVEF and LVD; of these, 19 (83%) had alternative imaging techniques, which confirmed the findings. It was possible to obtain a parasternal long-axis image in 28 (93%) patients and apical four-chamber views in 23 (77%). Clinical management was altered by the findings of the portable scan in two patients.

CONCLUSION

The 'pocket scanner' allows accurate qualitative assessment of left ventricular dimensions and function in a substantial proportion of patients seen in tertiary cardiology practice.

Subaortic dynamic obstruction: a contributing factor to haemodynamic instability in tako-tsubo syndrome?

We present a case of transient apical ballooning with haemodynamic instability in a female patient with normal coronaries and a history of poorly controlled systemic arterial hypertension. There was dynamic obstruction of the outflow tract and moderate secondary mitral regurgitation at presentation. These were due to systolic anterior motion of the mitral valve, which normalised gradually with the recovery of left ventricular function, and to a 'sigmoid' septum. Mid-cavity obstruction is potentially an important contributory factor to the haemodynamic instability sometimes encountered in this syndrome.

Modelling of the calcareous stone sulphation in polluted atmosphere after exposure in the field

Parisian Lutetian and Val-de-Loire Turonian Richemont limestone tablets were exposed, sheltered and unsheltered from rain, for up to 3 years in Paris and Tours, respectively. Sulphur concentrations below the stone surfaces were measured from powders obtained by milling the stone in successive steps of 0.1 mm. In tablets exposed to rain, measured sulphur concentration remains equal to the stone background concentration, implying that the sulphur deposited between rain events is leached by the next event. In contrast, in tablets sheltered from rain, the sulphur concentration in the first layer below the stone surface increases non-linearly with time. Sulphation does not, however, penetrate more than 0.2 mm. A sigmoidal Hill curve provides a good fit with changes in measured sulphur concentration over time within the first layer of each sheltered stone. This model reveals a cumulative phenomenon of sulphation, characterized by a saturation level that obstructs deeper penetration of sulphur within the stone. The model shows the same type of time evolution of sulphation for both stones, but with different coefficients; these coefficients are related to the atmospheric environment of exposure and to the different intrinsic properties of each stone.

Modeling of soiling based on silica-soda-lime glass exposure at six European sites

Samples of silica-soda-lime float glass, a material selected as a pertinent soiling sensor, were exposed for up to 28 months at four urban sites (Athens, Krakow, London and Prague) and at a semi-urban one (Monte Libretti, near Rome), sheltered from rain. This exhaustive experience permitted to complete and to test the generalisation ability of the results previously obtained on the same material, exposed according to the same protocol, during 24 months, at a single site (Paris). The model previously fitted for the Paris experiment, the Hill equation, could be successfully generalised for four other sites of exposure (Athens, Krakow, Prague and Rome). The analytical form of this model was interpreted in terms of a physical description of the soiling phenomenon. Some of the model coefficients were different from one site to another, depending on the specific environment of exposure (air pollution levels, meteorological factors), while the other ones were rather equivalent. The analysis of the model coefficients, on the one hand, led to an estimation of the period after which soiling is close to its saturation level, and on the other hand, it will permit to correlate these coefficients to the environmental factors, in order to select the most appropriate ones for building dose-response functions for soiling, with broad geographical application.

Spontaneous right atrial thrombus in a patient with Crohn's disease: an unusual right atrial mass

Crohn's disease is associated with systemic manifestations including increased risk of thromboembolism. We report a young female patient with active Crohn's disease who presented with spontaneous right atrial thrombus.