Espumas rígidas de tipo composite basadas en biopolímeros combinados con arcillas fibrosas y su método de preparación

Espumas rígidas de tipo composite basadas en biopolímeros combinados con arcillas fibrosas y su método de preparación. La presente invención se refiere a espumas rígidas de tipo composite que comprenden una matriz biopolimérica y partículas de silicatos pertenecientes a la familia de las arcillas fibrosas (sepiolita y palygorskita). La invención también se refiere al procedimiento de preparación de estos materiales, en el que la etapa de secado mediante liofilización o secado supercrítico es fundamental para obtener materiales de alta porosidad, así como a su uso en aplicaciones diversas tales como aislamiento acústico y térmico, material de embalaje, soporte de sólidos con propiedades eléctricas, magnéticas y ópticas, así como de fármacos y especies biológicas.Peer reviewedConsejo Superior de Investigaciones Científicas (España

Chitosan-smectite biointerfaces vs. Alkylammonium-clay interfaces in adsorption process

Two series of chitosan-clay nanocomposites were synthesized using commercial (CLOISITE® Na+ ) and Na+ -enriched Serbian clay from seldom investigated locality Mečji Do. The samples were characterized by X-ray diffraction and intercalation of chitosan into bilayer structures was confirmed for particular chitosan/clay ratio in both series of chitosan-clay naonocomposites. Reactivity of chitosan-smectite biointerfaces vs. alkylammonium-clay interfaces in adsorption process was compared using textile dye Reactive Black 5 (RB5) as adsorbate. Chitosan-clay naonocomposites had similar adsorption uptake, being more than three times higher than adsorption uptake of commercial alkylammonium-clay CLOISITE® 30B.The Langmuir adsorption model was found to be appropriate for all investigated adsorbents

Brown tumor of the jaw after pregnancy and lactation in a MEN1 patient

Skeletal manifestations of primary hyperparathyroidism (pHPT) include brown tumors (BT), which are osteoclastic focal lesions often localized in the jaws. Brown tumors are a rare manifestation of pHTP in Europe and USA; however, they are frequent in developing countries, probably related to vitamin D deficiency and longer duration and severity of disease. In the majority of cases, the removal of the parathyroid adenoma is enough for the bone to remineralize, but other cases require surgery. Hyperparathyroidism in MEN1 develops early, and is multiglandular and the timing of surgery remains questionable. To our knowledge, there are no reports of BT in MEN 1 patients. We present a 29-year-old woman with MEN 1 who developed a brown tumor of the jaw 24 months after getting pregnant, while breastfeeding. Serum corrected calcium remained under 2.7 during gestation, and at that point reached a maximum of 2.82 mmol/L. Concomitant PTH was 196 pg/mL, vitamin D 13.7 ng/mL and alkaline phosphatase 150 IU/L. Bone mineral density showed osteopenia on spine and femoral neck (both T-scores = −1.6). Total parathyroidectomy was performed within two weeks, with a failed glandular graft autotransplantation, leading to permanent hypoparathyroidism. Two months after removal of parathyroid glands, the jaw tumor did not shrink; thus, finally it was successfully excised. We hypothesize that higher vitamin D and mineral requirements during maternity may have triggered an accelerated bone resorption followed by appearance of the jaw BT. We suggest to treat pHPT before planning a pregnancy in MEN1 women or otherwise supplement with vitamin D, although this approach may precipitate severe hypercalcemia

Estrategias de inmovilización de enzimas redox en el desarrollo de biosensores amperométricos

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Analítica y Análisis Instrumental. Fecha de lectura: 20-12-200

Hybrid and biohybrid silicate based materials: molecular vs. block-assembling bottom–up processes

Este artículo ha sido publicado como parte del número especial dedicado a Hybrid materials.This critical review introduces a discussion on the influence of preparative procedures (nanofabrication) of nanostructured hybrids and biohybrids, comparing their structural and textural characteristics that determine the properties of the resulting materials. Selected examples of silicate-based hybrids of analogous compositions prepared by both molecular and blocks-assembly bottom-up strategies are discussed to show advantages and inconveniences of each methodology (341 references).CICYT, Spain MAT2009-09960; CSIC Spain PIF08-018; Spanish Ministry of Science and Innovation (MICINN)Peer reviewe

Procedimiento de preparación de materiales con propiedades superparamagnéticas para la extracción de iones cesio en medio acuoso, material obtenido y utilización

La presente invención se refiere a un procedimiento de obtención de materiales superparamagnéticos con propiedades de adsorción de iones cesio basado en el ensamblado a un sólido inorgánico poroso de nanopartículas de óxidos de hierro que le confiere el comportamiento superparamagnético a temperatura ambiente y de agentes adsorbentes selectivos de cesio, como son los hexacianoferratos. La invención también se refiere al material obtenido mediante este procedimiento, así como a su uso en aplicaciones de eliminación de iones cesio en medio acuoso, de especial importancia para la descontaminación de aguas, suelos, alimentos, etc. que contengan cesio radioactivoPeer reviewedConsejo Superior de Investigaciones CientíficasA1 Solicitud de patente con informe sobre el estado de la técnic

Procedimiento de preparación de materiales con propiedades superparamagnéticas para la extracción de iones cesio en medio acuoso, material obtenido y utilización

La presente invención se refiere a un procedimiento de obtención de materiales superparamagnéticos con propiedades de adsorción de iones cesio basado en el ensamblado a un sólido inorgánico poroso de nanopartículas de óxidos de hierro que le confiere el comportamiento superparamagnético a temperatura ambiente y de agentes adsorbentes selectivos de cesio, como son los hexacianoferratos. La invención también se refiere al material obtenido mediante este procedimiento, así como a su uso en aplicaciones de eliminación de iones cesio en medio acuoso, de especial importancia para la descontaminación de aguas, suelos, alimentos, etc. que contengan cesio radioactivoPeer reviewedConsejo Superior de Investigaciones CientíficasB1 Patente sin examen previ

Integration of a Copper-Containing Biohybrid (CuHARS) with Cellulose for Subsequent Degradation and Biomedical Control

We previously described the novel synthesis of a copper high-aspect ratio structure (CuHARS) biohybrid material using cystine. While extremely stable in water, CuHARS is completely (but slowly) degradable in cellular media. Here, integration of the CuHARS into cellulose matrices was carried out to provide added control for CuHARS degradation. Synthesized CuHARS was concentrated by centrifugation and then dried. The weighed mass was re-suspended in water. CuHARS was stable in water for months without degradation. In contrast, 25 μg/mL of the CuHARS in complete cell culture media was completely degraded (slowly) in 18 days under physiological conditions. Stable integration of CuHARS into cellulose matrices was achieved through assembly by mixing cellulose micro- and nano-fibers and CuHARS in an aqueous (pulp mixture) phase, followed by drying. Additional materials were integrated to make the hybrids magnetically susceptible. The cellulose-CuHARS composite films could be transferred, weighed, and cut into usable pieces; they maintained their form after rehydration in water for at least 7 days and were compatible with cell culture studies using brain tumor (glioma) cells. These studies demonstrate utility of a CuHARS-cellulose biohybrid for applied applications including: (1) a platform for biomedical tracking and (2) integration into a 2D/3D matrix using natural products (cellulose).This work was funded with the support of grant awards from the National Science Foundation (NSF #1547693 and NSF#1632891), and the MINECO (Spain) project MAT2015-71117-R. M. Darder acknowledges the joint sponsorship by the Fulbright Scholar Program and the Spanish Ministry of Education

Efficient and ecological removal of anionic pollutants by cationic starch-clay bionanocomposites

The present work introduces the role of bio-hybrid materials based on the combination of cationic starch and clays belonging to the smectites family, in the removal of pollutants such as organic dyes and pesticides of anionic character. Two types of smectite clay minerals have been used as inorganic counterpart of the bionanocomposites: a purified bentonite from deposits in Maghnia, in the West of Algeria, and the commercial Cloisite® (Na-montmorillonite). In the first stage, potato starch was modified with glycidyltrimethylammonium chloride, and then incorporated to the clay by ion-exchange reaction at diverse biopolymer/clay ratio. These bionanocomposites were characterized by using various techniques: IR spectroscopy, XRD, TG-DTA and FE-SEM. The excess of cationic charge in these bionanocomposites results of great interest for their application in the removal of anionic pollutants, such as the anionic dye Congo Red and the 2,4-dichlorophenoxy acetic herbicide, from water solution. © 2013 by American Scientific Publishers.Peer Reviewe