Porous silica-based materials are attractive for biomedical applications due to their biocompatibility and biodegradable character. In addition, inorganic supports such as porous silicon are being developed due to integrated circuit chip compatibility and tunable properties leading to a wide range of multidisciplinary applications. In this contribution, biosilica extracted from a rarely studied plant material (Equisetum Myriochaetum), its conversion to silicon and the potential for both materials to be used as supports for enzyme immobilization are investigated. E. myriochaetum was subject to conventional acid digestion to extract biogenic silica with a% yield remarkably higher (up to 3 times) than for other Equisetum sp. (i.e. E. Arvense). The surface area of the isolated silica was ∼400 m/g, suitable for biotechnological applications. Biogenic silicon was obtained by magnesiothermic reduction. The materials were characterized by SEM-EDX, XRD, FT-IR, ICP-OES, TGA and BET analysis and did not contain significant levels of class 1 heavy elements (such as Pb, Cd, Hg and As). Two commercial peroxidases, horseradish peroxidase (HRP) and Coprinus cinereus peroxidase (CiP) were immobilized onto the biogenic materials using three different functionalization routes: (A) carbodiimide, (B) amine + glutaraldehyde and (C) amine + carbodiimide. Although both biogenic silica and porous silicon could be used as supports differences in behaviour were observed for the two enzymes. For HRP, loading onto biogenic silica via the glutaraldehyde immobilization technique (route B) was most effective. The loading of CiP showed a much higher peroxidase activity onto porous silicon than silica functionalized by the carbodiimide method (route A). From the properties of the extracted materials obtained from Equisetum Myriochaetum and the immobilization results observed, these materials appear to be promising for industrial and biomedical applications.

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A small base of research suggests that adolescent substance use is a growing public health concern in Mexico. Employing confidential methods, the International Longitudinal Survey of Adolescent Health was administered to assess substance use among 1,238 students in northern Mexico. A large proportion of students indicated lifetime use of tobacco and alcohol. Gender differences in tobacco, alcohol, and marijuana were also evident. The current findings are congruent with the sparse extant data on youths' substance use in Mexico and highlight the need for early prevention interventions.

Since ancient times Andean societies have formed an intimate relationship with volcanoes, the beginnings of which can be traced right back to the initial peopling of the region. By studying rocks used for stone tools and other everyday artifacts, we explore the volcanic landscapes of early hunter-gatherer groups (11,500–9,500 cal BP) of the highlands of the Atacama Desert (22–24°S/67–68°W). Petrological classification of the lithic assemblages of three Early Holocene archaeological sites showed the procurement of a great diversity of volcanic and subvolcanic rocks, including pumice, granitic rocks, micro-diorites, a large variety of tuffs and andesites, dacites, cherts, basalts, obsidians, among others. Field surveys enabled us to detect many of their sources related to volcanic features such as craters, maars, caldera-domes, lava flows, probable hydrothermal deposits, and ignimbrites. In these places, we also document large quarry-workshops and campsites from different periods, indicating intense and repeated human occupation over time. By comparing the artifacts with geological samples collected in the field, it was possible to assign the source of origin of a large part of the archaeological assemblages. Our data suggest that the volcanic features of the Atacama highlands were integrated into the mobility and interaction networks of ancient hunter-gatherer groups at an early date.

Resumen:El patrón de producción de la cadena autopartes del departamento de Santander está enfocado en la fabricación de partes de ejes con diferencial, platos, prensas, discos y transmisiones cardánicas. En el año 2015, la cadena del sector autopartes del departamento de Santander aportó con un 2% a la producción total del país, generó el 4,23% de los empleos de este sector en el ámbito nacional. En cuanto al comercio internacional del sector autopartes, las importaciones del sector del departamento de Santander tuvieron su origen en Estados Unidos con un 28% de las importaciones, seguido de China con un 20% de las importaciones y Brasil con un 12% de las importaciones del sector autopartes del departamento de Santander en el año 2015. Es de destacar que las exportaciones de autopartes del departamento de Santander han tenido una caída a partir del año 2012, teniendo una variación negativa en el período 2011-2015 de -68% debido principalmente al traslado de la producción de la empresa DANA-Transejes fuera del departamento de Santander. Las exportaciones realizadas durante el 2015 están dirigidas hacia el mercado Ecuatoriano con un 50% de las exportaciones del sector autopartes de Santander y hacia los países miembros de la Alianza del Pacifico con el 28.7% de las exportaciones. La empresa Transejes Transmisiones Homocinéticas de Colombia S.A es la empresa exportadora más representativa del sector autopartes del departamento con ventas por US$ 3.362.255.