Engineered core - shell nanoparticles: synthesis, characterisation, and biocompatibility studies

Superparamagnetic iron oxide nanoparticles (SPIONs) have emerged as promising contrast agents for Magnetic Resonance Imaging (MRI). Some SPIONs are already approved for clinical use. Coating of these nanoparticles with an additional biocompatible layer serves to improve the colloidal stability and biocompatibility. The present thesis is focused on the synthesis, characterization, and in vitro biocompatibility assessment of SPIONs as well as the assessment of the potential impact of the so-called bio-corona on the surface of these nanoparticles on their behavior. In addition, synthesis and magnetic evaluation of novel nanocomposites was also performed. In Paper I, the production of mono-dispersed, necking-free, single-core iron oxide-silica shell nanoparticles with tunable shell thickness was achieved by a carefully optimized inverse microemulsion method. The development of novel nanomaterials for biomedical applications need to be accompanied by careful scrutiny of their biocompatibility with a particular focus on the possible interactions with the primary defense system against foreign invasion, the immune system. Consequently, in Paper II, our efforts in synthesizing high quality core–shell nanoparticles with superparamagnetic character and sufficiently high magnetization were coupled with in vitro biocompatibility assessment and studies of cellular internalization using primary human macrophages and dendritic cells. The silica-coated nanoparticles were nontoxic to primary human monocyte-derived macrophages at all doses tested whereas dose- and size-dependent toxicity was observed for primary monocyte-derived dendritic cells exposed to smaller silica-coated nanoparticles, but not for the same-sized, commercially available dextran-coated iron oxide nanoparticles. Furthermore, the silica-coated iron oxide nanoparticles were taken up in both cell types through an active, actin cytoskeleton-dependent process to a significantly higher degree when compared to the dextran-coated nanoparticles, irrespective of size. This has potentially useful implications for labeling of immune cells for visualization, diagnosis or treatment of inflammatory processes. When nanomaterials confront physiological media, the formation of a “corona” of proteins by adsorption to the surface of nanomaterials occurs which will influence how the particles will interact with a biological system and consequently will affect the fate of the particles. The potential effect of the protein corona on the magnetic and biological behavior of silica- versus dextran-coated SPIONs was addressed in Paper III. A thorough physical characterization of SPIONs without and with a protein corona as well as in vitro biocompatibility and cellular internalization using human primary macrophages was performed. Modulation of the magnetization and relaxivity signals of the SPIONs was noted following interaction with human plasma proteins. Macrophage viability was influenced by the presence or absence of a protein corona on silica-coated SPIONs but in the case of the dextran-coated SPIONs. Macrophage production of pro-inflammatory TNF-α was not triggered by SPIONs with or without a corona. Moreover, comprehensive assessment of the protein corona using mass spectrometry and bioinformatics tools revealed distinctive compositions on the two types of nanoparticles. Further studies need to be performed to understand the interrelationship between the acquired protein corona on the SPIONs and their function as MRI contrast agents. In Paper IV, incorporation of iron oxide nanoparticles homogeneously dispersed in a polymeric matrix and assessment of the magnetic and optical properties of the resulting structured nanomaterials are presented. Magnetic evaluation of the nanocomposite revealed its ferromagnetic properties while the low loading of nanoparticles with very good distribution in the nanostructure yielded materials with good magneto-optical properties. These materials have potential applications as micro actuators, sensors, relays and magneto optical devices based on the Faraday effect. Overall, this thesis attempts an interdisciplinary approach to the synthesis and characterization of nanomaterials and their biocompatibility assessment, with the aim to enable future applications in nanomedicine

Effects of a culturally responsive speech and language intervention for students of Indigenous and non-Indigenous ancestry

This study explored the effectiveness of a speech and language intervention that was designed to be culturally responsive and adapted to provide explicit language instruction. Participants included all 774 kindergarten students from a mid-sized rural school district in British Columbia. Seventy-seven students screened as at risk received the intervention, and the remaining students participated in the regular kindergarten curriculum. Results indicated statistically significant effects of the intervention on language and vocabulary skills. No differential effects were observed between students of Indigenous and non-Indigenous heritage. Results are discussed in terms of culturally responsive and explicit instruction for early language development.Key words: early intervention, language intervention, cultural responsiveness, Aboriginal educationCette étude a examiné l'efficacité d'une intervention orthophonique et linguistique conçue pour être culturellement adaptée et permettre un enseignement explicite des langues. 774 élèves de maternelle d'un district scolaire rural de taille moyenne en Colombie-Britannique ont participé à cette étude. Parmi eux, 77 étudiants, sélectionnés comme étant à risque, ont participé à l'intervention, tandis que les autres étudiants ont participé au programme de maternelle habituel. Les résultats ont montré des effets statistiquement significatifs de l'intervention sur le langage et le vocabulaire. Aucune différence n'a été observée entre les étudiants ayant un patrimoine culturel autochtone ou non autochtone. Ces résultats sont débatus en termes d'enseignement explicite et culturellement adapté pour le développement précoce du langage.Mots clés: intervention précoce, intervention linguistique, sensibilisation à la culturel, éducation des Autochtone

Bericht über die Tätigkeit der Kommission für Archäologie Außereuropäischer Kulturen des Deutschen Archäologischen Instituts in den Jahren 2005–2006

Die Berichte über die Tätigkeit der Kommission für Archäologie Außereuropäischer Kulturen des Deutschen Archäologischen Instituts in den Jahren 2005–2006 umfassen die Proyecto Arqueológico Bajo Río Grande, Peru (Andentransekt 2), 5000 Jahre Siedlungsgeschichte in Palpa, die Ausgrabungen in der Loma Salvatierra (Bolivien), die Ausgrabungen und Surveys in Marokko, die Ausgrabungen in Sri Lanka und die Ausgrabungen des DAI und der Mongolischen Akademie der Wissenschaften in Karakorum

Moral Reasoning in Psychopaths

Patienten mit der psychischen Störung „Psychopathie“ zeigen ein Muster von emotionaler Abgestumpftheit, Impulsivität und unmoralischem Verhalten. Zur Untersuchung moralischen Urteilens wurden in der vorliegenden Studie alltagsrelevante Konflikte mit moralischem bzw. neutralem Inhalt entwickelt und 12 „psychopathischen“ forensischen Patienten sowie 12 nicht-psychopathischen forensischen Patienten präsentiert. „Psychopathische“ im Vergleich zu nicht-psychopathischen Patienten berichteten signifikant positivere Gefühle bei unmoralischen Entscheidungen als Nicht-Psychopathen. Außerdem wurden in der Gruppe der „Psychopathen“ im Vergleich zu den Nicht-Psychopathen signifikant häufiger unmoralische Entscheidungen auf moralische Konflikte getroffen. Diese Befunde deuten darauf hin, dass eine Störung der Emotionsverarbeitung ursächlich für dissoziales Verhalten bei „Psychopathen“ sein könnte.Psychopathic patients show a behavioral pattern that is characterized by indifference, impulsivity and antisocial behavior. To investigate moral reasoning we developed conflicts of everyday life with either moral or neutral content. These conflicts were then presented to a group of 12 psychopathic forensic patients as well as to a group of 12 non-psychopathic forensic patients.Psychopathic compared to non-psychopathic patients reported significantly higher positive feelings when choosing an immoral response alternative than non-psychopaths. Furthermore, psychopaths picked significantly more often an immoral response alternative in the conflicts with moral content than did the non-psychopaths. These results indicate that impairment in emotional processing abilities may be at the core of antisocial behavior in psychopathy

Bericht über die Tätigkeit der Kommission für Archäologie Außereuropäischer Kulturen des Deutschen Archäologischen Instituts im Jahr 2004

Die Berichte über die Tätigkeit der Kommission für Archäologie Außereuropäischer Kulturen des Deutschen Archäologischen Instituts im Jahr 2004 umfassen die vorspanische Bewässerungslandwirtschaft in der Küstenwüste Südperus, Ausgrabungen in Pernil Alto, Grabungen in der Loma Salvatierra, Bolivien, Archäologische Forschungen im marokkanischen Rif, die Zitadelle von Tissamaharama, Sri Lanka, die deutsch-vietnamesische Ausgrabung auf dem Gräberfeld der Sa-Huynh-Kultur von Lai Nghiin der Provinz Quang Nam in Mittelvietnam und Ausgrabungen im Palastbezirk von Karakorum, Mongolei.

Shrinking and boundedly complete Schauder frames in Fréchet spaces

We study Schauder frames in Fréchet spaces and their duals, as well as perturbation results. We define shrinking and boundedly complete Schauder frames on a locally convex space, study the duality of these two concepts and their relation with the reflexivity of the space. We characterize when an unconditional Schauder frame is shrinking or boundedly complete in terms of properties of the space. Several examples of concrete Schauder frames in function spaces are also presented.This research was partially supported by MEC and FEDER Project MTM2010-15200 and GVA Prometeo II/2013/013. The authors are thankful to D. Freeman for pointing out several relevant references to them. They also want to thank the referees for their careful reading of the manuscript and for their helpful suggestions.Bonet Solves, JA.; Fernandez, C.; Galbis, A.; Ribera Puchades, JM. (2014). Shrinking and boundedly complete Schauder frames in Fréchet spaces. Journal of Mathematical Analysis and Applications. 410(2):953-966. https://doi.org/10.1016/j.jmaa.2013.09.010S953966410

Invertebrate neurophylogeny: suggested terms and definitions for a neuroanatomical glossary

<p>Abstract</p> <p>Background</p> <p>Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa.</p> <p>Results</p> <p>We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section.</p> <p>Conclusions</p> <p>The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses.</p

Occupation and skin cancer: the results of the HELIOS-I multicenter case-control study

<p>Abstract</p> <p>Background</p> <p>Non-melanoma skin cancer (NMSC) is the most frequent tumour among Caucasian populations worldwide. Among the risk factors associated with this tumour, there are host-related factors and several environmental agents. A greater likelihood of high exposure to physical agents (with the exception of solar radiation) and chemical agents depends on the work setting. Our objective is to evaluate the role of occupational exposures in NMSC, with special emphasis on risk factors other than solar radiation and skin type.</p> <p>Methods</p> <p>We analysed 1585 cases (1333 basal cell carcinoma (BCC) and 183 squamous cell carcinoma (SCC)) and 1507 controls drawn from the Helios-I multicenter study. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression mixed models.</p> <p>Results</p> <p>For NMSC as a whole (both <it>histological types</it>), miners and quarrymen, secondary education teachers, and masons registered excess risk, regardless of exposure to solar radiation and skin type (OR 7.04, 95% CI 2.44–20.31; OR 1.75, 95% CI 1.05–2.89 and OR 1.54, 95% CI 1.04–2.27, respectively). Frequency of BCC proved higher among railway engine drivers and firemen (OR 4.55; 95% CI 0.96–21.57), specialised farmers (OR 1.65; 95% CI 1.05–2.59) and salesmen (OR 3.02; 95% CI 1.05–2.86), in addition to miners and quarrymen and secondary education teachers (OR 7.96; 95% CI 2.72–23.23 and OR 1.76; 95% CI 1.05–2.94 respectively). The occupations that registered a higher risk of <it>SCC (though not of BCC</it>) were those involving direct contact with livestock, construction workers not elsewhere classified (OR 2.95, 95% CI 1.12–7.74), stationary engine and related equipment operators not elsewhere classified (OR 5.31, 95% CI 1.13–21.04) and masons (OR 2.55, 95% CI 1.36–4.78).</p> <p>Conclusion</p> <p>Exposure to hazardous air pollutants, arsenic, ionizing radiations and burns may explain a good part of the associations observed in this study. The Helios study affords an excellent opportunity for further in-depth study of physical and chemical agents and NMSC based on matrices of occupational exposure.</p

Global short-term mortality risk and burden associated with tropical cyclones from 1980 to 2019: a multi-country time-series study

Summary Background The global spatiotemporal pattern of mortality risk and burden attributable to tropical cyclones is unclear. We aimed to evaluate the global short-term mortality risk and burden associated with tropical cyclones from 1980 to 2019. Methods The wind speed associated with cyclones from 1980 to 2019 was estimated globally through a parametric wind field model at a grid resolution of 0·5° × 0·5°. A total of 341 locations with daily mortality and temperature data from 14 countries that experienced at least one tropical cyclone day (a day with maximum sustained wind speed associated with cyclones ≥17·5 m/s) during the study period were included. A conditional quasi-Poisson regression with distributed lag non-linear model was applied to assess the tropical cyclone-mortality association. A meta-regression model was fitted to evaluate potential contributing factors and estimate grid cell-specific tropical cyclone effects. Findings Tropical cyclone exposure was associated with an overall 6% (95% CI 4-8) increase in mortality in the first 2 weeks following exposure. Globally, an estimate of 97 430 excess deaths (95% empirical CI [eCI] 71 651-126 438) per decade were observed over the 2 weeks following exposure to tropical cyclones, accounting for 20·7 (95% eCI 15·2-26·9) excess deaths per 100 000 residents (excess death rate) and 3·3 (95% eCI 2·4-4·3) excess deaths per 1000 deaths (excess death ratio) over 1980-2019. The mortality burden exhibited substantial temporal and spatial variation. East Asia and south Asia had the highest number of excess deaths during 1980-2019: 28 744 (95% eCI 16 863-42 188) and 27 267 (21 157-34 058) excess deaths per decade, respectively. In contrast, the regions with the highest excess death ratios and rates were southeast Asia and Latin America and the Caribbean. From 1980-99 to 2000-19, marked increases in tropical cyclone-related excess death numbers were observed globally, especially for Latin America and the Caribbean and south Asia. Grid cell-level and country-level results revealed further heterogeneous spatiotemporal patterns such as the high and increasing tropical cyclone-related mortality burden in Caribbean countries or regions. Interpretation Globally, short-term exposure to tropical cyclones was associated with a significant mortality burden, with highly heterogeneous spatiotemporal patterns. In-depth exploration of tropical cyclone epidemiology for those countries and regions estimated to have the highest and increasing tropical cyclone-related mortality burdens is urgently needed to help inform the development of targeted actions against the increasing adverse health impacts of tropical cyclones under a changing climate