Browsing by Subject "Scanning electron microscopy"
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- PublicationOpen AccessA new morpho-functional classification of the Fallopian tube based on its three-dimensional myoarchitecture(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Muglia, U.; Motta, P. M.The recent direct observations, under scanning electron microscopy (SEM), of the threedimensional architecture of myosalpinx in different mammals allows us classify salpinxes according to the myoarchitecture of their tubo-uterine junction (TUJ) and isthmus segments. Based upon the myoarchitecture of the outer wall of the TUJ we could find barrier-like species (rat and sow), sphincter-like species type a (rabbit and ewe) and sphincter-like species type b (cow and woman). The different architecture of TUJ can be explained by the different nature of the mating process. Based upon the myoarchitecture of the isthmus we could distinguish type 1 (rat) and type 2 (rabbit, ewe, sow, cow and woman) salpinxes. In the latter the close fusion of musculature deriving from the meso (extrinsic musculature) with the musculature of salpinx (intrinsic musculature) suggests the existence of a unique mesosalpinx contractile system. The myosalpinx is mostly made up of a single network of muscular fibers. Such a plexiform structure, owing to the uneven distribution of fibers, rather than producing a series of regular contraction waves, is more likely to generate random contraction waves. The random propagation of muscular network contraction may deform the plexiform wall of the myosalpinx causing the stirring of tubal contents. By such a stirring movement the contact between hormones and nutrients and the eggs or embryos is intensified, thus favoring a correct fertilization and early embryo development. Taken all together, these systematic results probably suggest an additional and rather new function for the musculature of the tube, namely to increase fertility in a large number of species.
- PublicationOpen AccessAnalysis of the porosity and microhardness of glass ionomer cements(Kaunas University of Technology (Lithuania), 2022-02-18) Cabello Malagón, Inmaculada; Cánovas Hernández, Basilio; Martínez Hernández, Elisa; Serna Muñoz, Clara; Pérez Silva, Amparo; Ortiz Ruiz, Antonio José; Dermatología, Estomatología, Radiología y Medicina FísicaGlass ionomer cements (GICs) are currently the first-choice materials in minimally invasive dentistry and are widely used in paediatric dentistry. The objective of this study was to evaluate the influence of viscosity and mixing on porosity and the relationship between the porosity and microhardness of GICs. Nine GICs were used: EQUIA® Forte Fil, Ionostar®Plus, 3MTMKetacTM Universal AplicapTM, Riva Light Cure HV®, Riva Silver®, Riva Protect®, VitremerTM, VitrebondTM Plus and Activa BioActive RestorativeTM. Samples were prepared from each material and images were obtained by scanning electron microscopy (SEM). Using software, the number and diameter of pores, area, and percentage of area they occupied were measured. After SEM analysis, the samples were used to make surface microhardness (SMH) measurements. Ionostar® Plus, EQUIA® Forte Fil and Riva Light Cure HV® had the highest number of pores. Riva Protect® had the largest pores and the highest percentage of pore-occupied area, while Activa BioActive RestorativeTM and VitrebondTM Plus had a smaller pore size and a smaller percentage by area. Riva Silver® and EQUIA® Forte Fil showed the highest microhardness values and VitrebondTM Plus and VitremerTM the lowest. In conclusion, when the cement viscosity is low, the type of mixture determines the degree of porosity, but has less influence when viscosity is high. There was no correlation between microhardness and the porosity of GICs.
- PublicationRestrictedFire in the Early Palaeolithic: evidence from burnt small mammal bones at Cueva negra del Estrecho del Río Quípar, Murcia, Spain(Elsevier, 2016-10) Rhodes, S.E.; Walker, M.J.; López Jiménez, A.; López Martínez, M.; Haber Uriarte, María; Fernández Jalvo, Y.; Chazan, M.; Prehistoria, Arqueología, Historia Antigua, Historia Medieval y Ciencias y Técnicas HistoriográficasThe development of pyrotechnology is a hallmark of human history, providing our ancestors with warmth, security and cooked food. Evidence for fire use before 400 thousand years ago (kya) remains contentious due largely to the taphonomically fragile nature of charcoal and ash. As such, it is imperative to the study of prehistoric fire that we develop techniques and methodologies for identifying anthropogenic fire use via more robust materials. A new methodology described by Fernández-Jalvo and Avery (2015) based on small mammal taphonomy to identify high intensity fire events from the distant past is replicated herein. When we applied this method to assemblages from Cueva Negra del Estrecho del Río Quípar, an upland rock-shelter in southeastern Spain, dated to between 780 kya and 980 kya, we recognized a spatial relationship between highly heat modified micromammal specimens and a previously reported delineated feature of thermally altered and carbonate rich sediment which also includes heat-fractured chert and calcined bone (the fire feature). The proportion of heavily heat-modified specimens (charred and/or calcined specimens) identified within the stratigraphic context associated with the fire feature proved statistically significant (x2 = 169.18, p < 0.001) when compared with the proportion of similarly modified specimens from overlying deposits (within other stratigraphic layers). The degree of discolouration seen on the micromammal remains within the fire feature has been linked to temperatures exceeding 600 °C (Shipman et al., 1984), and as such supports claims that the fire feature may have an anthropogenic origin. Environmental scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) of bone specimens confirms that this discolouration is due to burning rather than post-depositional mineral staining. This confirms that methodology, which represents a novel line of evidence for identifying pyrotechnical events at early Palaeolithic sites, can be used to identify potentially anthropogenic fire events from the distant past when alternative scenarios are excluded. Furthermore, studies of this type showcase the value of including detailed taphonomic studies of microfauna assemblages within multidisciplinary research projects.
- PublicationOpen AccessThe prestige-goods model applied to the Iberian Southeast during the Early Iron Age: the Phoenician scarab from Castellar de Librilla(Universidad de Sevilla, 2022-03-11) Cutillas Victoria, Benjamín; Boschloos, Vanessa; Baños Serrano, José; Prehistoria, Arqueología, Historia Antigua, Historia Medieval y Ciencias y Técnicas HistoriográficasThe establishment of Phoenician colonies in the Iberian Southeast from the 8th century BC led to a significant increase in productive and commercial activities with the autochthonous communities. However, prestige goods of high value destined for reduced consumption groups also circulated within these networks. The presence of a scarab found during an archaeological survey in the settlement of Castellar de Librilla (Librilla, Región de Murcia) reveals the inclusion of certain autochthonous elites in these circuits. This paper discusses the context, typological classification and comparative analysis of the scarab to better determine its origin and chronological framework. The incorporation of new archaeometric data through scanning electron microscopy (SEM), focused on the gold bezel setting in which the scarab is set, has been essential to improving our understanding of this piece of personal adornment. The results of the iconographic and microanalytic study point to the exceptional value of this artefact, which make it possible to recognise the participation and agency of the autochthonous elites of Castellar de Librilla in the commercial systems of Mediterranean prestige goods. -----------------