Use of ash from sewage sludge in the preparation of desulfurant sorbents

This work aims to develop new uses for sewage sludge, which is a byproduct of municipal wastewater treatment plants, by examining the calcination of this waste, the characterization of ashes is obtained, and its use to prepare desulfurant sorbents. Samples of sewage sludge were obtained from a local municipal wastewater treatment plant. This plant applies a pre-treatment followed by a biological treatment, where anaerobic digestion and centrifugation reduces the sludge. Three samples were characterized (in humidity, volatile and fixed solids content), dried, and ignited at two temperatures, 550 and 750 C. The composition of the ash obtained at both ignition temperatures was studied by x-ray fluorescent spectroscopy and the BET specific surface area of the two ashes and of the prepared sorbents was measured. Ash composition was similar for the two temperatures tested, where the components were Si, Ca, Al, Fe, P, S, Mg, K, Cl, Zn and Ti. BET specific surface area values indicate that the lower temperature of calcination produces ash with the highest SSA values (18 m2/g against near 10 m2/g). Preparation of desulfurant sorbents was carried out by mixing the ash with CaO or Ca(OH)2 at room temperature and different experimental conditions. The BET SSA of the prepared desulfurant sorbents showed higher values for the sorbents prepared with the ashes obtained at the lowest temperature. The behaviour of the ash and the prepared sorbents was tested in a fixed bed reactor at 58 C with a flue gas containing 5000 ppm of SO2 with a relative humidity of 55%. Results in the desulfurization process show that the calcium from the sludge seems more efficient than the calcium added as CaO or Ca(OH)2 to prepare the sorbents

Elimination of scan impedance anomalies in ultra-wide band phased arrays of differentially fed tapered slot antenna elements

Scan impedance anomalies are associated to phased arrays. There are different phenomena in order to explain these scan blindnesses produced when the array scans at one frequency and one angle. The most popular technique for eliminating these scan blindnesses is based on the use of electric walls in the grid of the two dimensional array. In this paper we present a dual polarized ultra-wide band array based on “bunny ears” antennas from 0.3 GHz to 1 GHz which presents scan blindness. We analyze the cause of the anomaly and present a technique non based on electric walls in order to avoid the scan blindness with a small increase in the noise figure of the array

Expression of the skin-homing receptor in peripheral blood lymphocytes from subjects with nonimmediate cutaneous allergic drug reactions

Versión aceptadaBackground: In nonimmediate cutaneous reactions to drugs, the skin is the organ most frequently involved, and T lymphocytes may play a relevant role. T cells related to skin immune responses express the cutaneous lymphocyte-associated antigen (CLA), the skin homing receptor. Methods: We studied the expression of the CLA in peripheral blood T lymphocytes from nine subjects with exanthematous reactions induced by betalactams (4), phenytoin (2), propyphenazone (1), spiramycin plus metronidazol (1) and captopril plus tiazide (1). The cutaneous symptoms appeared at least six hours after drug intake. CLA expression was evaluated by flow cytometry at the time of the reaction (T1) and one month later (T2). HLA-DR activation marker expression was also evaluated at T1. In four patients, it was necessary to readminister the culprit drug to establish a causal relationship, and sequential estimation of the markers was performed. Two control groups were included: healthy controls and subjects exposed to the culprit drugs with good tolerance. Values were compared by nonparametric statistics. Results: The expression of circulating CLA+ T cells at T1 was increased compared to healthy controls (median=20.4 vs 9.4) (P<0.001), and the patients also expressed increased levels of HLA-DR (median=3.8) (P <0.005). Comparison between T1 and T2 (median=11.2) also showed differences in levels of CLA+ T cells (P <0.01). The patients re-exposed to the culprit drug showed an increase followed by a decrease of circulating CLA+ T cells (P <0.05) and CLA+ HLA-DR+ (P <0.05) paralleling the symptoms. Conclusions: These data support the immunological nature of delayed skin reactions to drugs and suggest that these CLA+ T cells parallel the disease evolution and may participate in the pathophysiological mechanisms

Subjects with allergic reactions to drugs show in vivo polarized patterns of cytokine expression depending on the chronology of the clinical reaction

Manuscrito aceptado el 28 junio de 2000Background: The mechanisms involved in adverse drug reactions with an immunologic basis (ADRIB) can be antibody dependent, mainly IgE or T cell dependent (sensitized T cells). These mechanisms are regulated by a number of cytokines, including IL-2, IL-4, IL-5, IFN-γ, and TNF-α, which follow the classical TH1/TH2 immunologic paradigm. Although evidence for this has been seen in ex vivo studies, the results are heterogeneous, and few in vivo studies have been carried out in subjects with ADRIB. Objective: We studied a group of patients who experienced either immediate reactions (n = 10) or nonimmediate reactions (n = 9) to drugs to determine the cytokine pattern profile during the acute stage of the response, as well as after recovery. Methods: PBMCs were taken at different time intervals of 24 hours or less and 7, 15, and 30 days after the onset of the reaction, and the specific cytokine transcription and production were determined by using quantitative competitive RT-PCR and ELISA, respectively. Results: There was a transient polarized pattern corresponding to a TH1 response with IL-2, IFN-γ, and TNF-α in nonimmediate reactions and to a TH2 response with IL-4 in immediate reactions. Conclusions: This is the first in vivo demonstration of these TH1/TH2 patterns in subjects with ADRIB and confirms that çan immunologic process is occurring related to the mechanisms involved in the pathologic manifestation. These findings are relevant to the understanding of the pathophysiologic mechanisms involved in ADRIB, suggesting that further studies in this direction are warranted.This work was supported in part by CICYT SAF 96/0240, Consejería de Salud de la Junta de Andalucía, FIS 98/0861, and the Spanish Society for Allergy and Clinical Immunology

Diseño de amplificadores diferenciales de bajo ruido para antenas uwb en la banda baja del proyecto Ska

Differential amplifiers can be an appropriate solution in the implementation of radio astronomy receivers, due to their efficient interference and harmonic isolation. In this paper, two different topologies are presented. The first one consists of two single ended amplifiers in a balanced topology. The second one is formed by cascading two simple differential stages. Both circuits operate in the 300MHz to 1GHz bandwidth. Firstly, gain and noise characterizations of each amplifier have been done. Lastly, noise analysis of the whole reception system, formed by the antenna and the differential amplifiers, is presented

Contribución al conocimiento de la pteridoflora de Andalucía: sobre el género Ophioglossum L. en Almería

Contribution to the knowledge about Andalusian pteridophyte flora: on the genus Ophiglossum L. inAlmeríaPalabras clave. Biodiversidad, Corología, Montañas Béticas, Sureste ibérico.Key words. Biodiversity, Chorology, Baetic Ranges, South-eastern Iberian Peninsula

Diseño y Caracterización de un Array Activo de Banda Ancha para Radioastronomía

The Square Kilometre Array (SKA) radio-telescope will become a reality in 2020. Nowadays, many research groups are validating the technologies that will be necessary to build this enormous instrument. In order to cover the bandwidth between 70 MHz and 10 GHz, different antenna array designs and configurations will be used. This paper presents the design and characterization of a planar aperture array based on bunny-ear antennas, whose design is proposed to cover the midfrequency range of the telescope (from 300 to 1000 MHz). One of the main advantages of the present solution is its fully differential nature, which avoids the use of passive baluns, although it requires some especial considerations during the design and measurement processes

Broadband active differential array for the mid-frequency SKA band

This paper presents the design and characterization process of an active array demonstrator for the mid-frequency range (i.e., 300 MHz-1000 MHz) of the future Square Kilometre Array (SKA) radio telescope. This demonstrator, called FIDA3 (FG-IGN: Fundación General Instituto Geográfico Nacional - Differential Active Antenna Array), is part of the Spanish contribution for the SKA project. The main advantages provided by this design include the use of a dielectric-free structure, and the use of a fully-differential receiver in which differential low-noise amplifiers (LNAs) are directly connected to the balanced tapered-slot antennas (TSAs). First, the radiating structure and the differential low-noise amplifiers were separately designed and measured, obtaining good results (antenna elements with low voltage standing-wave ratios, array scanning capabilities up to 45°, and noise temperatures better than 52 K with low-noise amplifiers at room temperature). The potential problems due to the differential nature of the proposed solution are discussed, so some effective methods to overcome such limitations are proposed. Second, the complete active antenna array receiving system was assembled, and a 1 m2 active antenna array tile was characterized

Anticonvulsant-induced Toxic Epidermal Necrolysis: Monitoring the Immunologic Response.

This work was supported in part by Grants CICYT SAF 96/0240 from the Consejería de Salud de la Junta de Andalucía and FIS 98/0861. Laura Leyva has a FIS fellowship 98/5061.Background Toxic epidermal necrolysis is a severe reaction with skin involvement induced by different drugs and other agents. The mechanisms implicated in the induction of the reaction are poorly understood. Objective To study the involvement of T lymphocytes and other immunocompetent cells in the peripheral blood, blister fluid, and affected skin of 3 patients who developed a severe reaction after receiving anticonvulsant medication. Methods Quantification of T lymphocytes expressing the skin homing receptor (cutaneous lymphocyte-associated antigen [CLA]) in peripheral blood, skin and skin blister fluid and assessment of other adhesion molecules, activation markers and inflammatory interleukins by flow cytometry, immunohistochemistry and RT-PCR. Results An increase in CD3+CLA+ cells paralleling the severity of the disease was observed in both peripheral blood and skin, tending to normalize as soon as patient’s condition improved. E-selectin was detected in endothelial vessels in parallel with CLA expression on lymphocytes. An overexpression of TNF-, IFN- and IL-2 was also observed in peripheral blood mononuclear cells. The expression of the different markers changed over the course of the disease. Conclusions. These data show an increase in activated T cells expressing the skin-homing receptor in both tissue and peripheral blood accompanying clinical symptoms, with a recruitment of macrophages and an overexpression of cytokines. All these results suggest an important role for T cells in the production of toxic epidermal necrolysis

Ameliorative Effect of the Oral Administration of Chuquiraga spinosa in a Murine Model of Breast Cancer Induced with 7,12-Dimethylbenz[a]anthracene (DMBA)

Objective: To determine the ameliorative effect of the ethanolic extract of Chuquiraga spinosa (ChS) on 7,12-Dimethylbenz[a]anthracene (DMBA)-induced breast cancer in rats. Methods: 36 female Holztman rats were divided into 6 groups. I) The negative control group received physiological saline (PS). II) ChS-200 group received 200 mg/kg of ChS. III) DMBA group was induced with DMBA (20 mg/Kg) dissolved in PS and administrated orally for 15 weeks. IV) DMBA + ChS-50 group, V) DMBA + ChS-250 group, and VI) DMBA + ChS-500 group, which received the extract orally for 15 weeks after DMBA induction. All data were expressed as mean and standard deviation. One-way analysis of variance (ANOVA) followed by Dunnet test was carried out to compare the mean value of different groups Histopathological analysis was evaluated by using Image J software. Results: Hematology showed that the triglyceride level was significantly lowered (P< 0.01) and high-density lipoprotein (HDL) level was significantly increased (P <0.01) in groups III, IV and V. Also, ChS extract significantly lowered the C reactive protein (CRP) level (P <0.01) and malondialdehyde level (P<0.05). There was a significant decrease in the frequency of DMBA-induced micronucleated polychromatic erythrocyte (P<0.01). Conclusions: Chuquiraga spinosa showed an ameliorative effect on DMBA-induced breast cancer in rats as well as antioxidant, antitumor and antigenotoxic properties.Revisión por pare