83 research outputs found

    Single-step deposition of hexamethyldisiloxane surface gradient coatings with a high amplitude of water contact angles over a polyethylene foil

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    One interesting category of nano- and micro-engineered surfaces is surface gradients, which allow the controlled optimization of biointerfaces at a small scale in an extended area length. Plasma coatings offer a large diversity of functionalities at the nanoscale, accompanied by high chemical stability and adhesion on a variety of substrates at ambient temperature. Atmospheric-pressure plasma-assisted deposition could be employed for the generation of surface gradients on thermosensitive materials. In this study, a corona plasma jet is used to deposit polydimethylsiloxane/SiO2-like surface gradients on polyethylene foil by varying the O2 concentration in the discharge during the movement of the plasma source. We obtained, in a single-step approach, gradient coatings along a length of ∼10 cm, with a gradual variation of both chemistry and surface energy

    Small unilamellar liposomes as a membrane model for cell inactivation by cold atmospheric plasma treatment

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    International audienceCold atmospheric plasma is thought to be a promising tool for numerous biomedical applications due to its ability to generate a large diversity of reactive species in a controlled way. In some cases, it can also generate pulsed electric fields at the zone of treatment, which can induce processes such as electroporation in cell membranes. However, the interaction of these reactive species and the pulse electric field with cells in a physiological medium is very complex and still need a better understanding in order to be useful for future applications. A way to reach this goal is to work with model cell membranes such as liposomes, with the simplest physiological liquid and in a controlled atmosphere in order to limit the number of parallel reactions and processes. In this work, where this approach has been chosen, 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC) small unilamellar vesicles (SUV) has been synthesized in phosphate buffered aqueous solution and this solution has been treated by a nanosecond pulsed plasma jet under a pure nitrogen atmosphere. Only the composition of the plasma gas has been changed in order to generate different cocktails of reactive species. After the quantification of the main plasma reactive species in the PBS solution, structural, surface charge state, and chemical modifications generated on the plasma treated liposomes, due to the interaction with the plasma reactive species, has been carefully characterized. These results allow going further in the understanding of the effect of plasma reactive species on model cell membranes in physiological liquids. Permeation through the liposomal membrane and reaction of plasma reactive species with molecules encapsulated inside the liposomes has also been evaluated. New processes of degradation are finally presented and discussed, which come from the specific conditions of plasma treatment under pure nitrogen atmosphere

    Neolithic genomic data from southern France showcase intensified interactions with hunter-gatherer communities

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    SummaryArchaeological research shows that the dispersal of the Neolithic took a more complex turn when reaching western Europe, painting a contrasted picture of interactions between autochthonous hunter-gatherers (HGs) and incoming farmers. In order to clarify the mode, the intensity, and the regional variability of biological exchanges implied in these processes, we report new palaeogenomic data from Occitanie, a key region in Southern France. Genomic data from 28 individuals originating from six sites spanning from c. 5,500 to c. 2,500 BCE allow us to characterize regional patterns of ancestries throughout the Neolithic period. Results highlight major differences between the Mediterranean and Continental Neolithic expansion routes regarding both migration and interaction processes. High proportions of HG ancestry in both Early and Late Neolithic groups in Southern France support multiple pulses of inter-group gene flow throughout time and space and confirm the need for regional studies to address the complexity of the processes involved

    A case of projectile trauma from the medieval Poulton Chapel, Cheshire, the United Kingdom

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    Excavations at the medieval cemetery of Poulton Chapel, Cheshire, have uncovered over 900 articulated human skeletal remains, with numbers predicted to reach as high as 1500 as excavations continue. The demographics of this archaeological site is typical of a medieval rural assemblage. However, SK535 provides a glimpse into some of the traumatic aspects of medieval life. The excavation of SK535 revealed a middle‐aged adult male around 168 cm in stature. His position of burial was typical of Christian burials with an east‐west orientation, but the positioning of his arms identified that this was not a typical burial. His right arm was flexed at the elbow crossing the thorax, whereas the left arm was in the extended position. This is different from the other arm positions observed at Poulton Chapel. A metal object, identified here as a Type M7 bodkin arrowhead, was recovered from underneath the right arm, from within the thorax. This arrowhead was potentially armour piercing, and the type was commonly used during the 12th–13th century. Radiocarbon dates obtained for SK535 coincide with the time of the use of this arrowhead. Following the initial assessment, the only other instance of trauma identified in SK535 was a healed transverse fracture to the right distal ulna. Due to the location of Poulton Chapel in Cheshire, SK535 could have been wounded by an arrow carrying the M7 bodkin during English‐Welsh border skirmishes, which occurred frequently during this time period. The demographic profile of this individual indicates a possible professional fighter of the medieval period; however, no firm skeletal evidence of occupation could be provided. Nonetheless, this case study not only highlights the violence experienced during the medieval period but also indicates the ability for the survival of some traumas

    The preburning condition of Chalcolithic cremated human remains from the Perdigoes enclosures (Portugal)

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    The Iberian Chalcolithic displayed a remarkable variety of funerary practices, which has been related to interpopulation differences, intrapopulation social-cultural differences, and complex multistage funerary rituals. Perdigoes, a Chalcolithic set of ditched enclosures, reflects such diversity including a wide array of funerary practices. Among those practices is cremation, which, despite relatively rare, is represented in different structures in Perdigoes. One of these structures (Pit 40) presents an unparalleled high minimum number of individuals (n = 240), contrasting with nearby and coeval structures. In this study, we analyse heat-induced bone changes and other archaeothanatological variables to tentatively assess the preburning condition of the human remains. The results of Pit 40 are also compared with other comparable contexts to assess if this unique context presents further funerary differences relative to those other contexts in, for example, body processing. Our results suggest preferential cremation of fleshed human remains, but burning of at least a minority of skeletonised remains and deposition of possibly unburned remains also likely occurred. Body processing appears to be comparable with that of the cremation contexts of Perdigoes but contrasts with that of another nearby context (Dolmen of Olival da Pega 2b) in which burned bones were also found.Portuguese Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [PEst-OE/SADG/UI0283/2013, POCI-01-0145-FEDER-016766, PTDC/EPH-ARQ/0798/2014, PTDC/IVC-ANT/1201/2014, SFRH/BPD/84268/2012]info:eu-repo/semantics/publishedVersio

    Population genomics of post-glacial western Eurasia.

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    Western Eurasia witnessed several large-scale human migrations during the Holocene <sup>1-5</sup> . Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations

    Publisher Correction: Population genomics of post-glacial western Eurasia.

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    Annexe 2. Description de sépultures représentatives

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    Exemple de sépulture multiple La sépulture 85 (fig. 44) Cette tombe a livré les squelettes complets en connexion de trois adultes, qui ont été enregistrés à la fouille du sud au nord sous les US 308, 307 et 306. Les sujets 307 et 308 ont la tête à l’est, le sujet 306 la tête à l’ouest. La tête de 307 prend appui sur celle de 308 dont le membre supérieur droit est recouvert par le membre supérieur gauche et l’hémi-thorax gauche de 307 ; le coude gauche de ce dernier repose sur l’hémi-thorax dr..

    Catalytic production of hydroxyl radicals under physiological conditions

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    Burial practices at the dawn of the neolithic (6th millennium and first half of the 5th millennium cal-BC) in southern France and Italy: from “simple” pit graves to an architectural typology [La sépulture au début du Néolithique (VIe millénaire et première moitié du Ve millénaire cal BC) en France méridionale et en Italie : de l’idée d’une « simple » fosse à une typologie architecturale]

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    For a long time, the matter of burial practices at the dawn of the neolithic in the north-western Mediterranean region had been considered as settled. These practices were thought to be highly uniform, consisting of primary burials that obeyed a particular norm in which the deceased were always placed individually in a “simple” pit, lying in a contracted position on one side and with few grave goods, if any. However, an archaeo-thanatological approach, applied to virtually the entire corpus of available documentation and osteological collections in Italy and southern France, has invalidated the hypothesis of uniform burial patterns and revealed a multiplicity of funeral practices. We chose to focus on graves used for primary individual burials because these were considered to be the norm. Our paper presents the results of a series of taphonomic analyses (many applied for the first time to these graves), which have produced a very different picture, which indicate much more complex practices than simple pit burials. The reconstruction of 48 individual graves has demonstrated the existence of five different types. This new architectural typology definitively shows that the funerary system of early farmers in Italy and southern France was much more diverse and complex than previously thought, and thus offers new pointers to unravel the polymorphism of the impresso-cardial complex
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