Combinación de sistemas de flujo de baja y alta presion para la determinacion de Mg, Ca y Sr en salmueras por espectrofotometria de absorcion atomica con llama

This article describes the combination of low- and high-pressure flow systems for the determination of Magnesium, Calcium and Strontium by flame atomic absorption spectrometry (FAAS). In the low-pressure system a short C-18 RP column (length 0,5 cm) was utilized for the preconcentration/matrix separation step, xylenol orange was used as chelating agent and tetrabutylamonium acetate for ion pair formation. The hydraulic high pressure nebulization (HHPN) was used for sample transport and sample introduction in the high pressure system. The repeatabilities and detection limits for Mg, Ca and Sr were determined and compared with those obtained by pneumatic nebulization (PN). The results show that the detection limits obtained using the HHPN for Mg, Ca and Sr are between 1.5 to 2 times better than those obtained by PN when the signal transient was measured in area. The system presented a sampling frequency of 130 h-1 for direct determination of Mg, Ca or Sr in samples of saturated sodium chloride used in the production of chlorine and sodium hydroxide.

Espectrofotometría de absorción atómica con tubo en la llama: aplicación en la determinación total de cadmio, plomo y zinc en aguas frescas, agua de mar y sedimentos marinos

Thermospray flame furnace Atomic Absorption Spectrometry (TS-FF-AAS) was used for the total determination of Cd, Pb and Zn in fresh water and seawater samples at µg L-1 levels, and in marine sediment samples at µg g-1 levels. Using a sample loop of 50 µL and a peristaltic pump the samples were transported into the metallic tube placed over an air/acetylene flame, through a ceramic capillary (o.d. = 3.2 mm) containing two parallel internal orifices (i.d = 0.5 mm). The detection limits determined for Cd, Pb and Zn using a synthetic water matrix (2.5% m/v NaCl, 0.5% m/v MgCl2 and 0.8% m/v CaCl2) were 0.32 µg L-1; 2.6 µg L-1 and 0.21 µg L-1 respectively. The methodology by TS-FF-AAS was validated by determination of Cd, Pb and Zn in certified reference materials of water and marine sediment, and the t-test for differences between means was applied. No statistically significant differences were established in fresh water and seawater (p>0.05), whereas differences became apparent in marine sediment (p<0.03).

Preconcentración y atomización con tubo en la llama para la determinación de Cadmio en agua de mar

A flow injection on-line pre-concentration system coupled to thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) for cadmium determination at sub μg L-1 levels in seawater samples was developed. The on-line system was evaluated by analysing cadmium containing in a synthetic seawater matrix (2.5% m/v NaCl, 0.5% m/v MgCl2 and 0.8% m/v CaCl2). A sample volume of 2 mL allows determining Cd with a detection limits of 30 ng L-1 (3* σblank/slope), pre-concentration factor of 34 and repeatability of 1,8% (calculated as RSD, N=8 and containing 200 ng L-1 of Cd ).

The materno-fetal interface in llama (Lama guanicoe glama)

Samples from 9 llamas (28 through 36 weeks of gestation) were collected and fixed in 4% buffered paraformaldehyde (light microscopy) and in 2.5% buffered glutaraldehyde (transmission and scanning electron microscopy). The material was processed in paraplast and slides (5mm) were stained with HE, PAS, Masson-Trichrome, acid phosphatase and Perl's. The uteroferrin was immunolocalized. The results show that llama placenta is chorioallantoic, diffuse, folded and epitheliochorial, and the fetus is covered with an epidermal membrane. The trophoblast cells have variable morphology: cubic, rounded and triangular cells, with cytoplasm containing PAS-positive granules. Binucleated cells with large cytoplasm and rounded nuclei, as well as giant trophoblastic cells with multiple nuclei were also observed. Numerous blood vessels were observed beneath the cells of the uterine epithelium and around the chorionic subdivided branches. Glandular activity was shown by PAS, Perl's, and acid phosphatase positive reactions in the cytoplasm and glandular lumen, and by immunolocalization of the uteroferrin in the glandular epithelium. The uterine glands open in spaces formed by the areoles, which are filled by PAS-positive material. The llama fetus was covered by the epidermal membrane, composed of stratified epithelium, with up to seven layers of mono-, bi- or trinucleated cells. The high level of maternal and fetal vascularization surfaces indicates an intense exchange of substances across both surfaces. The metabolic activity shown in the uterine glands suggests an adaptation of the gestation to the high altitudes of the natural habitat of this species.

El llac i la flama. Apunts sobre la poesia contemporània a Mallorca. 'El lago y la llama. Apuntes sobre la poesía contemporánea en Mallorca'.

Introducción y edición a cargo de Maria Antònia Perelló Femenia. Resumen tomado de la publicación

La flama del vent. 'La llama del viento'.

Debido al formato del libro, que contiene ilustraciones y es de fácil lectura, está recomendado para lectura infantil y juvenil

L'Escala acull la flama olímpica.'La Escala acoge la llama olímpica'.

Imágenes de la llegada a L'Escala de la llama olímpica proveniente de Olímpia el 13 de junio de 1992. Se recogen también los actos posteriores a esta celebración y previos a los juegos olímpicos de Barcelona.

El alcoholismo llama a tu puerta.

Se exponen los resultados de una encuesta sobre el consumo de alcohol en los jóvenes. Entre otras conclusiones destacan la edad de inicio en el consumo de alcohol, entre los 14 y 16 años, pero algunos comienzan a los ocho; el consumo se realiza en fines de semana y fiestas especiales; se bebe sobre todo cerveza, con una media semanal equivalente a 12 botellines de 250 cc; se emborracha el 65 por ciento de los jóvenes; o el alcohol es la tercera causa de muerte entre los jóvenes. Se explican los efectos del consumo de alcohol; los comportamientos sospechosos de los jóvenes ante los padres o las razones por las que beben los adolescentes y el papel de la familia para tratar de solucionar el problema.

La Enseñanza, un problema a resolver entre todos : el Sumo Pontífice llama la atención sobre la disminución en el aflujo de nuevos profesionales a la docencia.

Transcripción del discurso que Su Santidad el Papa Pablo VI, dirigió a los congresistas de la Oficina Catequística Italiana el 28 de agosto de 1964. Destacó la importancia de la educación y la enseñanza en las escuelas cristianas. Exaltó la labor de los docentes religiosos tanto en los colegios, difundiendo la religión como asignatura, como en las parroquias dónde se enseña el catecismo y animó a la colaboración entre religiosos y familias para la formación de los jóvenes.

La calidad de la escuela pública : recuperar la llama.

Monográfico con el título: 'El cambio en educación'. Resumen basado en el de la publicación

The materno-fetal interface in llama (Lama guanicoe glama)

Samples from 9 llamas (28 through 36 weeks of gestation) were collected and fixed in 4% buffered paraformaldehyde (light microscopy) and in 2.5% buffered glutaraldehyde (transmission and scanning electron microscopy). The material was processed in paraplast and slides (5μm) were stained with HE, PAS, Masson-Trichrome, acid phosphatase and Perl's. The uteroferrin was immunolocalized. The results show that llama placenta is chorioallantoic, diffuse, folded and epitheliochorial, and the fetus is covered with an epidermal membrane. The trophoblast cells have variable morphology: cubic, rounded and triangular cells, with cytoplasm containing PAS-positive granules. Binucleated cells with large cytoplasm and rounded nuclei, as well as giant trophoblastic cells with multiple nuclei were also observed. Numerous blood vessels were observed beneath the cells of the uterine epithelium and around the chorionic subdivided branches. Glandular activity was shown by PAS, Perl's, and acid phosphatase positive reactions in the cytoplasm and glandular lumen, and by immunolocalization of the uteroferrin in the glandular epithelium. The uterine glands open in spaces formed by the areoles, which are filled by PAS-positive material. The llama fetus was covered by the epidermal membrane, composed of stratified epithelium, with up to seven layers of mono-, bi- or trinucleated cells. The high level of maternal and fetal vascularization surfaces indicates an intense exchange of substances across both surfaces. The metabolic activity shown in the uterine glands suggests an adaptation of the gestation to the high altitudes of the natural habitat of this species.

Dotrina de religiosos / co[m]puesta por el maestro fray Hu[m]berto de romanis ... de la orde[n] d[e] los predicadores ... Este es el libro q[ue] en latin se llama, Humbertus de eruditione religiosorum.

Il. xil.

Fogosa activa llama del amor ... que en el Teatro de Valencia representò el Colegio de Pescadores à la proclamacion de nuestro ... Monarca

Tít. tomado de principio de texto