Hydrochemical characterization of a mine water geothermal energy resource in NW Spain.

Abandoned and flooded mine networks provide underground reservoirs of mine water that can be used as a renewable geothermal energy source. A complete hydrochemical characterization of mine water is required to optimally design the geothermal installation, understand the hydraulic behavior of the water in the reservoir and prevent undesired effects such as pipe clogging via mineral precipitation. Water pumped from the Barredo-Figaredo mining reservoir (Asturias, NW Spain), which is currently exploited for geothermal use, has been studied and compared to water from a separate, nearby mountain mine and a river that receives mine water discharge and partially infiltrates into the mine workings. Although the hydrochemistry was altered during the flooding process, the deep mine waters are currently near neutral, net alkaline, high metal waters of Na-HCO3 type. Isotopic values suggest that mine waters are closely related to modern meteoric water, and likely correspond to rapid infiltration. Suspended and dissolved solids, and particularly iron content, of mine water results in some scaling and partial clogging of heat exchangers, but water temperature is stable (22°C) and increases with depth, so, considering the available flow (>100Ls-1), the Barredo-Figaredo mining reservoir represents a sustainable, long-term resource for geothermal use.

Prediction of the flooding of a mining reservoir in NW Spain.

Abandoned and flooded mines constitute underground reservoirs which must be managed. When pumping is stopped in a closed mine, the process of flooding should be anticipated in order to avoid environmentally undesirable or unexpected mine water discharges at the surface, particularly in populated areas. The Candín-Fondón mining reservoir in Asturias (NW Spain) has an estimated void volume of 8 million m3 and some urban areas are susceptible to be flooded if the water is freely released from the lowest mine adit/pithead. A conceptual model of this reservoir was undertaken and the flooding process was numerically modelled in order to estimate the time that the flooding would take. Additionally, the maximum safe height for the filling of the reservoir is discussed.

Thalidomide--effect on T cell subsets as a possible mechanism of action.

Thalidomide is the drug of choice in the erythema nodosum leprosum (ENL) type of lepra reaction. Lately it has been used successfully in other diseases, such as discoid lupus erythematosus, actinic prurigo, Behcet's disease, etc. However, its mechanism of action remains unknown. In patients for whom thalidomide provided relief in their disorder, the proportions of T lymphocytes and their subsets in peripheral blood were assessed by means of monoclonal antibodies. Three lepromatous leprosy patients with ENL had their T helper populations significantly increased after thalidomide therapy. A 14-year-old girl with Behcet's syndrome showed a consistent decrease in Ia+ cells throughout her three-month course of thalidomide therapy. The same findings were observed in two patients with the actinic prurigo type of polymorphous light eruption. From these results, we conclude that thalidomide may act as an immunomodulating agent on T cell subsets.

Immunopathology of polymorphous light eruption. T lymphocytes in blood and skin.

Polymorphous light eruption (PLE; actinic prurigo) is a relatively common dermatologic disease. People suffering from it have a pruritic skin eruption on exposed areas. PLE may be an immunologically mediated disease. Sixteen patients with PLE were studied. T lymphocytes and the helper and suppressor-cytotoxic subsets were assessed in peripheral blood by an indirect immunofluorescent method with the use of monoclonal antibodies. Total T lymphocytes were significantly increased as compared to controls. By an indirect immunoperoxidase technic with the use of monoclonal antibodies, characterization of the dermal cell infiltrate was done. Predominance of T total, T helper, and cells marked with Ia antigen were found. These findings suggest that an abnormal immune response is responsible for the tissue damage in PLE.

Treatment of onychomycosis with ketoconazole and nonsurgical avulsion of the affected nail.

Thirteen of sixteen patients with onychomycosis who were treated with a 40 percent urea cream in order to remove the diseased nail and then treated with ketoconazole, 200 mg a day orally, for three months, were cured of the disease. This seems to be a good alternative treatment for onychomycosis.