HERNANDEZ MONTELONGO, JESUS JACOBO
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Technological and geochemical analysis of lithic artifacts from the Parque Diana Cave, forest, and lakes of the Neuquén Province (Northwestern Patagonia, Argentina)
This study presents the results of the lithic artifact assemblage analysis from the Parque Diana Cave, located in the forested area of the Meliquina Lake region in the Andes Mountains, southwest Neuquén province. The analysis includes the classification and description of tools and debris, as well as the geochemical determination of an obsidian sample using ICP-MS and XRF to establish its provenance. The site reveals occupations from 2,370 ± 70 years BP to 580 ± 60 years BP. The earliest occupations are marked by the presence of a few tools, mainly made from non-local raw materials, indicating a period of exploration and sporadic use by steppe hunters. During the latest occupations (pottery period), activities primarily involved the final stages of bifacial tool production and reactivation, along with minimally shaped maintenance tools, typical of populations known in the western forest and lake areas of the mountain range. The supply of obsidian primarily came from forests and lakes within a 30 40 km radius, with a smaller contribution from a more distant source approximately 150 km north of the site. © 2025 Elsevier B.V., All rights reserved.
Nanoporous silicon microparticles embedded into oxidized hyaluronic acid/adipic acid dihydrazide hydrogel for enhanced controlled drug delivery
Oxidized hyaluronic acid cross-linked with adipic acid dihydrazide (oxi-HA/ADH) forms an injectable and biocompatible hydrogel suitable for treatment of musculoskeletal diseases and for drug delivery applications. In that sense, nanoporous silicon (nPSi) can be combined with biopolymers, such as oxi-HA/ADH hydrogel, to display new characteristics, which are not exhibited by the individual constituents alone. Under this context, in this work nPSi microparticles at concentrations from 0.1% to 1% m/v were embedded into oxi-HA/ADH hydrogel to improve its mechanical stability and enhance its control over drug release kinetics using Rose Bengal (RB) as a model drug because its cytotoxic effect in different cancer cell lines and tumors has been previously reported. Our results showed, for both compressive force and stress strength tests, that oxi-HA/ADH hydrogel with 1% nPSi microparticles doubled the values of control samples. Moreover, samples of oxi-HA/ADH with nPSi microparticles improved RB release kinetics control over pure oxi-HA/ADH hydrogel. Finally, the cell viability of nPSi microparticles embedded into oxi-HA/ADH hydrogel was confirmed using fibroblasts. © 2020 Elsevier B.V., All rights reserved.
A cluster of N-bubbles driven along a channel at high imposed driving pressure: Bubble areas, film lengths and vertex locations
A two-dimensional foam staircase structure is considered with N bubbles stacked in a zigzag fashion along a channel. A model is analysed for determining the configuration of a staircase set into motion under the action of a high imposed driving pressure. Minimum and also maximum permitted bubble sizes for which the staircase structure survives are identified. Both minimum and maximum sizes are found to be decreasing functions of N. Behaviours in the limit of large N are identified, albeit tentatively, as the methodology for computing the staircase structure is found to be highly stiff. Indeed, as N increases, tiny changes in the staircase configuration at the downstream end lead to large geometric changes at the upstream end, limiting the domain of N values for which structures can be readily computed. © 2025 Elsevier B.V., All rights reserved.
Revealing the ancient origins of blonde beers: Phylogeography and phylogenetics of cryotolerant fermentative yeast Saccharomyces eubayanus from pre-Hispanic pottery in Northwestern Patagonia, Argentina
This study presents an analysis of residuals and the identification of the oldest cryotolerant fermentative yeast Saccharomyces eubayanus, absorbed in the walls of ceramic vessels. The samples were dated between 920 and 750 years before present (BP) from the Meliquina Lake site in northwest Argentine Patagonia. This study provides more solid evidence supporting the hypothesis of a pre-Hispanic development area for fermented beverage production at the southernmost region between 38° and 40° south latitude on the continent. The isolation and subsequent phylogenetic and phylogeographic analysis of this yeast strain confirm its primitive nature, predating the previously known European hybrids. The associated context and chronology of its use, predating European-Indigenous contact, provide evidence of its management and utilization in native or autochthonous fermentative processes. Subsequently, for reasons still unclear, the strain migrated to Europe, where it hybridized with Old World strains, culminating in the emergence of blonde beers or lager in 16th century Bavaria. The deliberate or unintentional nature of this migration remains speculative, but it underscores the significant role this yeast strain played in the development of one of today s most popular fermented beverages, which necessitate fermentation at low temperatures. © 2025 Elsevier B.V., All rights reserved.