1,416 research outputs found

    Functionalization of Surfaces Using Photolithography and Other Techniques

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    Coated materials are encountered on a daily basis, and are a part of almost everything manufactured today. Despite their ubiquity, investigations on their chemical functionality and structure still provide interesting research potential. This dissertation investigates two kinds of coatings, polymeric and self-assembled monolayers (SAMs). The polymeric coatings investigated are in the form of photoresists that are used to create substrates for laser ablation. Adjusting the composition of the photoresists leads to the formation of unique structures during this laser ablation. Another application of photoresists that was studied is the creation of transferable microstructures on a flexible substrate. These microstructures, in the form of arches, are created using multiphoton absorption polymerization. The creation of a patterned SAMs substrate with the potential application as a microarray was explored. Photolithography and soft lithography approaches were tested to create these amine-functionalized surfaces. In addition, silicon nitride surfaces were investigated as a suitable substrate for alkylphosphonate SAMs. A variety of surface techniques including sum frequency generation and X-ray photoelectron spectroscopy were employed to study these surfaces and ultimately the presence of a multilayer, more than one monolayer, was found

    Embodied semantics in a second language: critical review and clinical implications

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    The role of the sensorimotor system in second language (L2) semantic processing as well as its clinical implications for bilingual patients has hitherto been neglected. We offer an overview of the issues at stake in this under-investigated field, presenting the theoretical and clinical relevance of studying L2 embodiment and reviewing the few studies on this topic. We highlight that (a) the sensorimotor network is involved in L2 processing, and that (b) in most studies, L2 is differently embodied than L1, reflected in a lower degree or in a different pattern of L2 embodiment. Importantly, we outline critical issues to be addressed in order to guide future research. We also delineate the subsequent steps needed to confirm or dismiss the value of language therapeutic approaches based on embodiment theories as a complement of speech and language therapies in adult bilinguals

    Inside the "African Cattle Complex": Animal Burials in the Holocene Central Sahara

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    Cattle pastoralism is an important trait of African cultures. Ethnographic studies describe the central role played by domestic cattle within many societies, highlighting its social and ideological values well beyond its mere function as 'walking larder'. Historical depth of this African legacy has been repeatedly assessed in an archaeological perspective, mostly emphasizing a continental vision. Nevertheless, in- depth site-specific studies, with a few exceptions, are lacking. Despite the long tradition of a multi-disciplinary approach to the analysis of pastoral systems in Africa, rarely do early and middle Holocene archaeological contexts feature in the same area the combination of settlement, ceremonial and rock art features so as to be multi- dimensionally explored: the Messak plateau in the Libyan central Sahara represents an outstanding exception. Known for its rich Pleistocene occupation and abundant Holocene rock art, the region, through our research, has also shown to preserve the material evidence of a complex ritual dated to the Middle Pastoral (6080-5120 BP or 5200-3800 BC). This was centred on the frequent deposition in stone monuments of disarticulated animal remains, mostly cattle. Animal burials are known also from other African contexts, but regional extent of the phenomenon, state of preservation of monuments, and associated rock art makes the Messak case unique. GIS analysis, excavation data, radiocarbon dating, zooarchaeological and isotopic (Sr, C, O) analyses of animal remains and botanical data are used to explore this highly formalized ritual and lifestyles of a pastoral community in the Holocene Sahara

    The first record of the marbled spinefoot, Siganus rivulatus Forsskål & Niebuhr, 1775 and further records of the dusky spinefoot, Siganus luridus (Rüppell, 1829) from Malta

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    Here we report the first record of the Marbeled spinefoot, Siganus rivulatus Forsskål and Niebuhr, 1775 (Acanthuriformes: Siganidae), collected in July 2022 from Maltese coastal waters. The specimen was identified through morphological characters and confirmed genetically through DNA barcoding, given that the family Siganidae is composed of several species belonging to only one genus with similar and overlapping morphological characters. Previous to this report, the closest record of S. rivulatus was off the island of Sicily. Thus, the presence of S. rivulatus in Maltese waters suggests that this species is expanding its distribution within the Mediterranean Sea. Additionally, this study compares this central Mediterranean record of S. rivulatus with genetic data of the Dusky spinefoot, Siganus luridus (Rüppell, 1829), a previously established species. Individual records of Siganus (rabbitfishes) are important to note, as they represent the first warning signs of a possible invasion. Previous work has shown that these species drastically alter the ecosystems of the Mediterranean region through their herbivorous diet and grazing behaviour. Therefore, we need to closely monitor for more individuals and establish mitigation measures against established and expanding populations of these two species.peer-reviewe

    Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate

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    BACKGROUND: Human variant Creutzfeldt-Jakob Disease (vCJD) results from foodborne transmission of prions from slaughtered cattle with classical Bovine Spongiform Encephalopathy (cBSE). Atypical forms of BSE, which remain mostly asymptomatic in aging cattle, were recently identified at slaughterhouses throughout Europe and North America, raising a question about human susceptibility to these new prion strains. METHODOLOGY/PRINCIPAL FINDINGS: Brain homogenates from cattle with classical BSE and atypical (BASE) infections were inoculated intracerebrally into cynomolgus monkeys (Macacca fascicularis), a non-human primate model previously demonstrated to be susceptible to the original strain of cBSE. The resulting diseases were compared in terms of clinical signs, histology and biochemistry of the abnormal prion protein (PrPres). The single monkey infected with BASE had a shorter survival, and a different clinical evolution, histopathology, and prion protein (PrPres) pattern than was observed for either classical BSE or vCJD-inoculated animals. Also, the biochemical signature of PrPres in the BASE-inoculated animal was found to have a higher proteinase K sensitivity of the octa-repeat region. We found the same biochemical signature in three of four human patients with sporadic CJD and an MM type 2 PrP genotype who lived in the same country as the infected bovine. CONCLUSION/SIGNIFICANCE: Our results point to a possibly higher degree of pathogenicity of BASE than classical BSE in primates and also raise a question about a possible link to one uncommon subset of cases of apparently sporadic CJD. Thus, despite the waning epidemic of classical BSE, the occurrence of atypical strains should temper the urge to relax measures currently in place to protect public health from accidental contamination by BSE-contaminated products

    Biomechanical factors in atherosclerosis: mechanisms and clinical implications†

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    Blood vessels are exposed to multiple mechanical forces that are exerted on the vessel wall (radial, circumferential and longitudinal forces) or on the endothelial surface (shear stress). The stresses and strains experienced by arteries influence the initiation of atherosclerotic lesions, which develop at regions of arteries that are exposed to complex blood flow. In addition, plaque progression and eventually plaque rupture is influenced by a complex interaction between biological and mechanical factors—mechanical forces regulate the cellular and molecular composition of plaques and, conversely, the composition of plaques determines their ability to withstand mechanical load. A deeper understanding of these interactions is essential for designing new therapeutic strategies to prevent lesion development and promote plaque stabilization. Moreover, integrating clinical imaging techniques with finite element modelling techniques allows for detailed examination of local morphological and biomechanical characteristics of atherosclerotic lesions that may be of help in prediction of future events. In this ESC Position Paper on biomechanical factors in atherosclerosis, we summarize the current ‘state of the art' on the interface between mechanical forces and atherosclerotic plaque biology and identify potential clinical applications and key questions for future researc

    Translational opportunities of single-cell biology in atherosclerosis

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    The advent of single-cell biology opens a new chapter for understanding human biological processes and for diagnosing, monitoring, and treating disease. This revolution now reaches the field of cardiovascular disease (CVD). New technologies to interrogate CVD samples at single-cell resolution are allowing the identification of novel cell communities that are important in shaping disease development and direct towards new therapeutic strategies. These approaches have begun to revolutionize atherosclerosis pathology and redraw our understanding of disease development. This review discusses the state-of-the-art of single-cell analysis of atherosclerotic plaques, with a particular focus on human lesions, and presents the current resolution of cellular subpopulations and their heterogeneity and plasticity in relation to clinically relevant features. Opportunities and pitfalls of current technologies as well as the clinical impact of single-cell technologies in CVD patient care are highlighted, advocating for multidisciplinary and international collaborative efforts to join the cellular dots of CVD

    Novel methodologies for biomarker discovery in atherosclerosis

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    Identification of subjects at increased risk for cardiovascular events plays a central role in the worldwide efforts to improve prevention, prediction, diagnosis, and prognosis of cardiovascular disease and to decrease the related costs. Despite their high predictive value on population level, traditional risk factors fail to fully predict individual risk. This position paper provides a summary of current vascular biomarkers other than the traditional risk factors with a special focus on the emerging −omics technologies. The definition of biomarkers and the identification and use of classical biomarkers are introduced, and we discuss the limitations of current biomarkers such as high sensitivity C-reactive protein (hsCRP) or N-terminal pro-brain natriuretic peptide (NT-proBNP). This is complemented by circulating plasma biomarkers, including high-density lipoprotein (HDL), and the conceptual shift from HDL cholesterol levels to HDL composition/function for cardiovascular risk assessment. Novel sources for plasma-derived markers include microparticles, microvesicles, and exosomes and their use for current omics-based analytics. Measurement of circulating micro-RNAs, short RNA sequences regulating gene expression, has attracted major interest in the search for novel biomarkers. Also, mass spectrometry and nuclear magnetic resonance spectroscopy have become key complementary technologies in the search for new biomarkers, such as proteomic searches or identification and quantification of small metabolites including lipids (metabolomics and lipidomics). In particular, pro-inflammatory lipid metabolites have gained much interest in the cardiovascular field. Our consensus statement concludes on leads and needs in biomarker research for the near future to improve individual cardiovascular risk predictio
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