Conjugated compounds for molecular electronics: from synthesis to conductance studies.

This project concerns the synthesis and characterization of linear conjugated compounds, and assessment of their electrical performance. To that end, several oligo(phenylene-ethynylene)s (OPEs) were prepared and the available synthetic procedures reviewed and optimized. Monolayers of these compounds were transferred onto solid substrates by means of the Langmuir-Blodgett technique, and their physical and electrical properties evaluated by Atomic Force Microscopy (AFM) and Scanning Tunnelling Microscopy (STM). Two novel approaches to the formation of the top electrode on sandwich like metal|molecule|metal devices, based on the in-situ decomposition of gold complexes, are detailed. The synthetic methodologies appropriate for the preparation of gold ethynyl complexes Au(C≡CR)(L) (R = aryl, L= PPh3 and CNR) that are critical to the thermal and photochemical decomposition protocol are described. A convenient synthesis of bis(ethynyl) complexes trans-Ru(CCR)2(dppe)2 and unsymmetrically substituted derivatives trans-Ru(CCR1)(CCR2)(dppe)2 is described. A detailed structural and spectroelectrochemical study of the complexes, supported by TD-DFT calculations, demonstrated the relationships between the underlying electronic transitions that are responsible for the NIR absorption band shape and the relative orientations of the metal fragment and arylethynyl moieties in the oxidized species. Single molecule STM conductance studies were performed on a series of OPE and polyyne derivatives devoting special attention to the role of the molecular linker in the overall performance of the molecular junction. In that regard, a novel molecular linker CCSiMe3 was introduced and its electrical and mechanical properties benchmarked against literature known molecular anchoring groups i.e. NH2 and SH. Transistor-like behaviour was observed in preliminary electrochemical STM studies performed on complex Ru(CCC6H4CCSiMe3)2(dppe)2. Finally, the statistical treatment of the conductance (STM) and force (AFM) measurements and the Visual Basic (VBA) codes designed to analyse the large datasets collected are included

A shortest-path based clustering algorithm for joint human-machine analysis of complex datasets

Clustering is a technique for the analysis of datasets obtained by empirical studies in several disciplines with a major application for biomedical research. Essentially, clustering algorithms are executed by machines aiming at finding groups of related points in a dataset. However, the result of grouping depends on both metrics for point-to-point similarity and rules for point-to-group association. Indeed, non-appropriate metrics and rules can lead to undesirable clustering artifacts. This is especially relevant for datasets, where groups with heterogeneous structures co-exist. In this work, we propose an algorithm that achieves clustering by exploring the paths between points. This allows both, to evaluate the properties of the path (such as gaps, density variations, etc.), and expressing the preference for certain paths. Moreover, our algorithm supports the integration of existing knowledge about admissible and non-admissible clusters by training a path classifier. We demonstrate the accuracy of the proposed method on challenging datasets including points from synthetic shapes in publicly available benchmarks and microscopy data

Fears and catastrophic thoughts in medically complicated pregnancies

In our experience "High-risk" diagnosis stigmatizes the patient, compromises her self-esteem, fears come up, and often modifies her expectations of a successful pregnancy in a catastrophizing, unrealistic way. Thinking about the worst possible outcomes would facilitate adaptation to hostile environments, while optimistic thinking increases the risk of not reacting in time, but although this could explains why it could be possible to react with catastrophic thoughts to ambiguous situations, it still remains open the question about why some people have more frequent and harmful catastrophic thoughts leading to psychological distress and making it very difficult to cope with the unexpected pregnancy situationUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech