Phosphorus solubility in basaltic glass: Limitations for phosphorus immobilization in glass and glass-ceramics.

The composition of sewage sludge from urban wastewater treatment plants is simulated using P-doped basalts. Electron microscopy analyses show that the solubility of P in the basaltic melt is limited by the formation of a liquid-liquid immiscibility in the form of an aluminosilicate phase and a Ca-Mg-Fe-rich phosphate phase. The rheological behavior of these compositions is influenced by both phase separation and nanocrystallization. Upon a thermal treatment, the glasses will crystallize into a mixture of inosilicates and spinel-like phases at low P contents and into Ca-Mg-Fe phosphate at high P contents. Hardness measurements yield values between 5.41 and 7.66 GPa, inside the range of commercial glasses and glass-ceramics. Leaching affects mainly unstable Mg2+-PO43- complexes.

Análisis comparativo entre la técnica de Seldinger vs. disección abierta en la implantación de reservorios intravenosos / Comparative analysis between the seldinger technique vs. open dissection in the implantation of intravenous reservoirs

Objetivo. Analizar ventajas y desventajas de la técnica de Seldinger (TS) frente a la disección abierta (DA) en la implantación de reservorios intravenosos (RIVS), comparando tiempos quirúrgicos y complicaciones. Material y Método. Realizamos un estudio analítico retrospectivo tipo cohortes históricas, comparando nuestra experiencia en la implantación de RIVS por DA y por TS. Analizamos parámetros clínicos, quirúrgicos, destacando el tiempo operatorio y las complicaciones intra/postoperatorias. Resultados. Analizamos 193 RIVS (119 DA, 74 TS) implantados principalmente para quimioterapia (83,41%). El tiempo quirúrgico utilizado en procedimientos únicos fue de 72,85 ± 29,35 minutos para DA frente a 62,83 ± 20,08 minutos el Seldinger (p<0,05). No hubo diferencias operador-dependientes. No se encontraron diferencias estadísticamente significativas entre las poblaciones de las dos cohortes estudiadas ni en el porcentaje de complicaciones. Los RIVS de mayor tamaño presentaron una media mayor de necrosis de piel (p>0,05) en cambio, los de menor tamaño presentaron mayor tasa de infección (16%sobre 7,7% p>0,05). Tanto en la TS (51,67 vs 98,14 min) como en la DA (78,56 vs 123,61 min) el tiempo operatorio fue menor en los accesos venosos izquierdos. (d =171 vs i =19) Tras complicaciones se retiró el RIVS en 121 días de media. Conclusiones. La TS disminuyó la perdida definitiva de los accesos venosos intervenidos, pudiendo reutilizar la misma vena para la colocación de RIVS posteriores. La TS reduce el tiempo quirúrgico, sin incrementarse las complicaciones. El acceso venoso izquierdo no implica mayor tiempo quirúrgico. Las complicaciones podrían estar en relación al tamaño del RIVS (AU)

Objective. To analyze advantages and disadvantages between Seldinger’s technique (ST) and surgical dissection (SD) on intravenous sport-a-caths comparing surgical parameters as time and complications. Material and Method. An analytic retrospective study involving historic cohorts was realized, comparing our surgical experience on port-a-cath implantation with Seldinger technique or surgical dissection. Statistical analysis was made reflecting clinical and surgical parameters, such as surgical time length and intra/postoperative complications. Results. 193 Port-a-caths were analyzed (119 SD, 74 ST), mainly placed for chemotherapy treatment (83.41%). Surgical time length expended at single procedures was 72.85 ± 29.35 minutes for SD and62.83 ± 20.08 minutes for ST (p<0.05). There were none operator dependent differences. Statistically significant differences were not found between the two cohort’s populations, neither at complications percentages. Greater-sized port-a-caths presented a higher average of skin necrosis (p>0.05) however, lower-sized port-a-caths showed a high eraverage of infection (16% upon 7.7% p>0.05). Both ST (51.67 vs.98.14 min) and SD (78.56 vs. 123.61 min) showed lower surgical time length at left venous accesses (d =171 vs. i =19). Average in days for the extraction of port-a-caths with regard to complications was 121 days. Conclusion: Seldinger technique reduced the definitive lost of surgical dissected venous accesses, being possible further utilization of the same vein for subsequent port-a-caths. Seldinger technique reduces surgical time length without increasing complication’s rate. Left venous access does not imply higher surgical time length. Complications maybe related with port-a-cath’s size (AU)

[Comparative analysis between the Seldinger technique vs. open dissection in the implantation of intravenous reservoirs]. / Análisis comparativo entre la técnica de Seldinger vs. disección abierta en la implantación de reservorios intravenosos.

OBJECTIVE: To analyze advantages and disadvantages between Seldinger's technique (ST) and surgical dissection (SD) on intravenous port-a-caths comparing surgical parameters as time and complications. MATERIAL AND METHOD: An analytic retrospective study involving historic cohorts was realized, comparing our surgical experience on port-a-cath implantation with Seldinger technique or surgical dissection. Statistical analysis was made reflecting clinical and surgical parameters, such as surgical time length and intra/postoperative complications. RESULTS: 193 Port-a-caths were analyzed (119 SD, 74 ST), mainly placed for chemotherapy treatment (83.41%). Surgical time length expended at single procedures was 72.85 +/- 29.35 minutes for SD and 62.83 +/- 20.08 minutes for ST (p < 0.05). There were none operator-dependent differences. Statistically significant differences were not found between the two cohort's populations, neither at complications percentages. Greater-sized port-a-caths presented a higher average of skin necrosis (p > 0.05) however, lower-sized port-a-caths showed a higher average of infection (16% upon 7.7% p > 0.05). Both ST (51.67 vs. 98.14 min) and SD (78.56 vs. 123.61 min) showed lower surgical time length at left venous accesses (d = 171 vs. i = 19). Average in days for the extraction of port-a-caths with regard to complications was 121 days. CONCLUSION: Seldinger technique reduced the definitive lost of surgical dissected venous accesses, being possible further utilization of the same vein for subsequent port-a-caths. Seldinger technique reduces surgical time length without increasing complication's rate. Left venous access does not imply higher surgical time length. Complications may be related with port-a-cath's size.

Environmental geochemistry of ancient volcanic ashes.

Volcanic ashes from the Puna and surrounding Andean areas in northern Argentina show that sometimes volcanic ash deposits are very well preserved (up to several million years) and can remain a potential hazard for the environment in a similar way as current deposits. Eight ashes have been characterized by SEM-EDX and DRX, and their potential released geochemical fluxes were examined by using water and nitric acid batches, which are analyzed by ICP-OES, ICP-MS and ISE (F). Results demonstrate that water batch system is better medium than nitric acid for this study. The high and fast reactivity of these ancient ashes is mainly associated with their high content in glass. The order of magnitude of released contents of implied elements is consistent among the samples, i.e., Al>B>Fe>Zn>F>P>Mn>Ba>Sr>Li>Ti>Rb>Cu>Ni>Sb>Pb>As>Cr>V. Ash-water interaction, although infrequent in arid regions such as the Puna Region in northern Argentina, introduces rapid changes in the geochemical fluxes of elements and pH and may constitute a potential hazard for the environment. In fact, many of these elements are included in the drinking water guidelines due to their potential toxicity and may constitute potential hazards for the environment and human health.

Acoustic barriers obtained from industrial wastes.

Acoustic pollution is an environmental problem that is becoming increasingly more important in our society. Likewise, the accumulation of generated waste and the need for waste management are also becoming more and more pressing. In this study we describe a new material--called PROUSO--obtained from industrial wastes. PROUSO has a variety of commercial and engineering, as well as building, applications. The main raw materials used for this environmentally friendly material come from slag from the aluminium recycling process, dust from the marble industry, foundry sands, and recycled expanded polystyrene from recycled packaging. Some natural materials, such as plastic clays, are also used. To obtain PROUSO we used a conventional ceramic process, forming new mineral phases and incorporating polluted elements into the structure. Its physical properties make PROUSO an excellent acoustic and thermal insulation material. It absorbs 95% of the sound in the frequency band of the 500 Hz. Its compressive strength makes it ideal for use in ceramic wall building.

Heavy metal-rich wastes sequester in mineral phases through a glass-ceramic process.

Certain sludges generated by industry are rich in contaminating elements and are a major environmental problem. In this study, we determine the ability of these contaminating elements to be incorporated into a glass-matrix and in various mineral phases after a crystallization process. The contaminating elements studied were obtained from sewage sludges (SS) and galvanic sludges (GS), our raw materials. The sludge samples were taken from urban wastewater treatment plant in Catalonia (NE Spain) with high levels of phosphorus oxide (P(2)O(5)). In silica glasses, P(2)O(5) acts as a network former. We determined the chemical composition of both the SS and GS, as well as their thermal behaviour by differential thermal analysis and thermal gravimetric analysis (DTA-TG) to obtain their melting curves. The vitreous transition temperature of the obtained glass was established by dilatometer technique at 725 degrees C. The DTA-TG curve of the glass obtained has an exothermal wide peak at 860 degrees C corresponding to crystallization of the two phases: a spinel phase and a phosphate phase. A second exothermal wide peak at 960 degrees C was attributed to the crystallization of aluminium pyroxene, anorthite and fluor-apatite, with two exothermal phenomena attributed to the evolution of these phases. An exothermal peak at 1100 degrees C was attributed to gehlenite crystallization. Scanning electron microscope observations and energy-dispersed X-ray spectroscopy microanalyses of glass-ceramic showed that the contaminating elements were concentrated in the spinel phases, which are the first phases to crystallize during the cooling of glass. Finally, the spinel structure permits the incorporation of all the contaminating elements into it.

Maturation of Wilms' tumor pulmonary metastases to benign fibromas after therapy.

A 3-year-old girl with Wilms' tumor developed pulmonary metastases 5 months after diagnosis. All but one of the visible lesions disappeared after thoracic irradiation and multiple-agent chemotherapy. Subsequent thoracotomy revealed 17 small nodules in addition to the visible lesion, and all of them proved to be fibromas. It would appear that the Wilms' tumor metastases to the lung were made to mature to benign neoplastic processes after the treatments given.

[Treatment of rhabdomyosarcoma of the bladder without radical surgery]. / Tratamiento del rabdomiosarcoma de vejiga sin cirugía radical.

Authors present two cases of rhabdomyosarcoma of the bladder treated previously to surgery with chemotherapy (protocol T-2) and radiation therapy. In one of these patients surgery consisted only in a partial cystectomy, and in the other only a few biopsies were taken from the most suspicious zones, and these were all negative. Three years and four months after diagnosis and 15 months after completion of treatment, both children are alive and free of detectable disease.

[Pyloric atresia and epidermolysis bullosa. A coincidence? (author's transl)]. / Atresia del píloro y epidermólisis ampollosa ?Una coincidencia?

Three cases of the rare malformation pyloric atresia are presented, two of which are associated with epidermolysis bullosa, a rare malformation by itself. First two cases had a great pneumoperitoneum which suggested perforation of digestive tract. All three cases belonged to type I of pyloric atresia.

[Pyloric stenosis: An unfrequent complication (author's transl)]. / Una complicación poco frecuente de la estenosis hipertrófica de píloro.

We present one case of pyloric stenosis with hematemesis caused by a necrotizing gastritis that evolved to a gastric stenosis which had to be reoperated, having a favorable outcome.

[Foreign bodies in digestive tract (author's transl)]. / Cuerpos extranos digestivos

One hundred and seventy three cases of ingestion of foreign bodies by children are reported. Their nature and evolution inside the organism is discussed. Laparotomy was required in only one case.

[Congenital malformations associated with esophageal atresia (author's transl)]. / Malformaciones congénitas asociadas a las atresias esofágicas

In 67 patients with esophageal atresia we have found associated congenital anomalies in over 80% and 10 children could be considered as carriers of Vater association. The various malformations are reported and their etiopathogenic factors considered.