The development of planar high-K/III-V p-channel MOSFETs for post-silicon CMOS

Conventional Si complementary-metal-oxide-semiconductor (CMOS) scaling is fast approaching its limits. The extension of the logic device roadmap for future enhancements in transistor performance requires non-Si materials and new device architectures. III-V materials, due to their superior electron transport properties, are well poised to replace Si as the channel material beyond the 10nm technology node to mitigate the performance loss of Si transistors from further reductions in supply voltage to minimise power dissipation in logic circuits. However several key challenges, including a high quality dielectric/III-V gate stack, a low-resistance source/drain (S/D) technology, heterointegration onto a Si platform and a viable III-V p-metal-oxide-semiconductor field-effect-transistor (MOSFET), need to be addressed before III-Vs can be employed in CMOS. This Thesis specifically addressed the development and demonstration of planar III-V p-MOSFETs, to complement the n-MOSFET, thereby enabling an all III-V CMOS technology to be realised. This work explored the application of InGaAs and InGaSb material systems as the channel, in conjunction with Al2O3/metal gate stacks, for p-MOSFET development based on the buried-channel flatband device architecture. The body of work undertaken comprised material development, process module development and integration into a robust fabrication flow for the demonstration of p-channel devices. The parameter space in the design of the device layer structure, based around the III-V channel/barrier material options of In_x≥0.53Ga_1-xAs/In_0.52Al_0.48As and In_x≥0.1Ga_1-xSb/AlSb, was systematically examined to improve hole channel transport. A mobility of 433 cm²/Vs, the highest room temperature hole mobility of any InGaAs quantum-well channel reported to date, was obtained for the In_0.85Ga_0.15As (2.1% strain) structure. S/D ohmic contacts were developed based on thermally annealed Au/Zn/Au metallisation and validated using transmission line model test structures. The effects of metallisation thickness, diffusion barriers and de-oxidation conditions were examined. Contacts to InGaSb-channel structures were found to be sensitive to de-oxidation conditions. A fabrication process, based on a lithographically-aligned double ohmic patterning approach, was realised for deep submicron gate-to-source/drain gap (L_side) scaling to minimise the access resistance, thereby mitigating the effects of parasitic S/D series resistance on transistor performance. The developed process yielded gaps as small as 20nm. For high-k integration on GaSb, ex-situ ammonium sulphide ((NH₄)₂S) treatments, in the range 1%-22%, for 10min at 295K were systematically explored for improving the electrical properties of the Al₂O₃/GaSb interface. Electrical and physical characterisation indicated the 1% treatment to be most effective with interface trap densities in the range of 4 - 10×10¹²cm^-2eV^-1 in the lower half of the bandgap. An extended study, comprising additional immersion times at each sulphide concentration, was further undertaken to determine the surface roughness and the etching nature of the treatments on GaSb. A number of p-MOSFETs based on III-V-channels with the most promising hole transport and integration of the developed process modules were successfully demonstrated in this work. Although the non-inverted InGaAs-channel devices showed good current modulation and switch-off characteristics, several aspects of performance were non-ideal; depletion-mode operation, modest drive current (I_d,sat=1.14mA/mm), double peaked transconductance (g_m=1.06mS/mm), high subthreshold swing (SS=301mV/dec) and high on-resistance (R_on=845kΩ.μm). Despite demonstrating substantial improvement in the on-state metrics of I_d,sat (11×), g_m (5.5×) and R_on (5.6×), inverted devices did not switch-off. Scaling gate-to-source/drain gap (L_side) from 1μm down to 70nm improved I_d,sat (72.4mA/mm) by a factor of 3.6 and gm (25.8mS/mm) by a factor of 4.1 in inverted InGaAs-channel devices. Well-controlled current modulation and good saturation behaviour was observed for InGaSb-channel devices. In the on-state In_0.3Ga_0.7Sb-channel (I_d,sat=49.4mA/mm, g_m=12.3mS/mm, R_on=31.7kΩ.μm) and In_0.4Ga_0.6Sb-channel (I_d,sat=38mA/mm, g_m=11.9mS/mm, R_on=73.5kΩ.μm) devices outperformed the InGaAs-channel devices. However the devices could not be switched off. These findings indicate that III-V p-MOSFETs based on InGaSb as opposed to InGaAs channels are more suited as the p-channel option for post-Si CMOS.

Trapping phosphorus (III) into polyoxometalates: synthesis, characterisation and electronic behaviour study

The introduction of electronically-active heteroanions into polyoxometalates (POMs) is one of the emerging topics in this field. The novel clusters have shown unprecedented intramolecular electron-transfer features that can be directly mediated by the incorporated heteroanions. In this thesis, we will focus on the study of phosphite (HPO32-) as new non-traditional heteroanions, discover HPO32- templated nanostructures, investigate their electronic behaviours as well as understand the self-assembly process of HPO32--templated species. The thesis starts with incorporating HPO32- into POM cages. The feasibility of this work was illustrated by the successful trapping of HPO32- into a “Trojan Horse” type {W18O56} nanocage. The reactivity of embedded {HPO3} was fully studied, showing the cluster undergoes a structural rearrangement in solution whereby the {HPO3} moieties dimerise to form a weakly interacting (O3PH···HPO3) moiety. In the crystalline state a temperature-dependent intramolecular redox reaction and structural rearrangement occurs. This rearrangement appears to proceed via an intermediate containing two different templates, a pyramidal {HPO3} and a tetrahedral {PO4} moiety. {HPO3} templated POM cages were then vigorously expanded and led to the isolation of five either fully oxidised or mixed-valence clusters trapped with mono-, di-, or tri- {HPO3}. Interestingly, an intriguing 3D honeycomb-like host-guest structure was also synthesised. The porous framework was self-aggregated by a tri-phopshite anion templated {W21} cluster with a {VO4} templated Wells-Dawson type {W18} acting as a guest species within the hexagonal channels. Based on this work, we further extended the templating anions to two different redox-active heteroanions, and discovered a unique mixed-heteroatom templated system built by pairing redox-active {HPIIIO3} with {TeO3}, {SeO3} or {AsO3}. Two molecular systems were developed, ie. “Trojan Horse” type [W18O56(HPO3)0.8(SeO3)1.2(H2O)2]8- and cross-shaped [H4P4X4W64O224]32-/36-, where X=TeIV, SeIV, AsIII. In the case of {W18(HPO3)0.8(SeO3)1.2}, the compound is found to be a mixture of heteroleptic {W18(HPO3)(SeO3)} and homoleptic {W18(SeO3)2} and {W18(HPO3)2}, identified by single crystal x-ray diffraction, NMR as well as high resolution mass spectrometry. The cluster exhibited similar temperature-dependent electronic features to “Trojan Horse” type {W18(HPO3)2O56}. However, due to the intrinsic reactivity difference between {HPO3} and {SeO3}, the thermal treatment leads to the formation of an unusual species [W18O55(PO4)(SeO3)]5-, in which {HPO3} was fully oxidised to {PO4} within the cage, whereas and lone-pair-containing {SeO3} heteroanions were kept intact inside the shell. This finding is extremely interesting, as it demonstrated that multiple and independent intramolecular electronic performance can be achieved by the coexistence of distinct heteroatoms within a single molecule. On the other hand, the cross-shaped [H4P4X4W64O224]32-/36- were constructed by four {W15(HPO3)(XO3)} building units linked by four {WO6} octahedra. Each building unit traps two different heteroatoms. It is interesting to note that the mixed heteroatom species show self-sorting, with a highly selective positional preference. Smaller ionic sized {HPO3} are self-organised into the uncapped side of {W15} cavity, whereas closed side are occupied by larger heteroatoms, which is surprisingly opposed to steric hindrance. Density functional theory (DFT) calculations are currently underway to have a full understanding of the preference of heteroatom substitutions. This series of clusters is of great interest in terms of achieving single molecule-based heteroatom-dependent multiple levels of electron transfer. It has opened a new way to design and synthesise POMs with higher diversity of electrical states, which may lead to a new type of Q-bits for quantum computing. The third chapter is focused on developing polyoxotungstate building blocks templated by {HPO3}. A series of building blocks, {W15O48(HPO3)2}, {W9O30(HPO3)} {W12O40(HPO3)2} and hexagonal {W6O18(HPO3)} have been obtained. The first four building blocks have been reported with {SeO3} and/or {TeO3} heteroanions. This result demonstrates {HPO3} has a similar reactivity as {SeO3} and {TeO3}, therefore studying the self-assembly of {HPO3}-based building blocks would be helpful to have a general understanding of pyramidal heteroatom-based molecular systems. The hexagonal {W6O18(HPO3)} is observed for the first time in polyoxotungstates, showing some of reactivity difference between {HPO3} and {SeO3} and {TeO3}. Furthermore, inorganic salts and pH values have some directing influence on the formation and transformation of various building blocks, resulting in the discovery of a family of {HPO3}-based clusters with nuclearity ranging from {W29} to {W106}. High resolution mass spectrometry was also carried out to investigate the cluster solution behaviour and also gain information of building block speciation. It is found that some clusters experienced decomposition, which gives rise to potential building blocks accountable for the self-assembly.

Conceptualisation, design and development of a primary school based child healthy weight intervention

INTRODUCTION: In common with much of the developed world, Scotland has a severe and well established problem with overweight and obesity in childhood with recent figures demonstrating that 31% of Scottish children aged 2-15 years old were overweight including obese in 2014. This problem is more pronounced in socioeconomically disadvantaged groups and in older children across all economic groups (Scottish Health Survey, 2014). Children who are overweight or obese are at increased risk of a number of adverse health outcomes in the short term and throughout their life course (Lobstein and Jackson-Leach, 2006). The Scottish Government tasked all Scottish Health Boards with developing and delivering child healthy weight interventions to clinically overweight or obese children in an attempt to address this health problem. It is therefore imperative to deliver high quality, affordable, appropriately targeted interventions which can make a sustained impact on children’s lifestyles, setting them up for life as healthy weight adults. This research aimed to inform the design, readiness for application and Health Board suitability of an effective primary school-based curricular child healthy weight intervention. METHODS: the process involved in conceptualising a child healthy weight intervention, developing the intervention, planning for implementation and subsequent evaluation was guided by the PRECEDE-PROCEED Model (Green and Kreuter, 2005) and the Intervention Mapping protocol (Lloyd et al. 2011). RESULTS: The outputs from each stage of the development process were used to formulate a child healthy weight intervention conceptual model then develop plans for delivery and evaluation. DISCUSSION: The Fit for School conceptual model developed through this process has the potential to theoretically modify energy balance related behaviours associated with unhealthy weight gain in childhood. It also has the potential to be delivered at a Health Board scale within current organisational restrictions.

Feasibility study to inform the design of a UK multi-centre randomised controlled trial of prophylactic antibiotics for the prevention of recurrent cellulitis of the leg

Background: This paper describes the results of a feasibility study for a randomised controlled trial (RCT). Methods: Twenty-nine members of the UK Dermatology Clinical Trials Network (UK DCTN) expressed an interest in recruiting for this study. Of these, 17 obtained full ethics and Research & Development (R&D) approval, and 15 successfully recruited patients into the study. A total of 70 participants with a diagnosis of cellulitis of the leg were enrolled over a 5-month period. These participants were largely recruited from medical admissions wards, although some were identified from dermatology, orthopaedic, geriatric and general surgery wards. Data were collected on patient demographics, clinical features and willingness to take part in a future RCT. Results: Despite being a relatively common condition, cellulitis patients were difficult to locate through our network of UK DCTN clinicians. This was largely because patients were rarely seen by dermatologists, and admissions were not co-ordinated centrally. In addition, the impact of the proposed exclusion criteria was high; only 26 (37%) of those enrolled in the study fulfilled all of the inclusion criteria for the subsequent RCT, and were willing to be randomised to treatment. Of the 70 participants identified during the study as having cellulitis of the leg (as confirmed by a dermatologist), only 59 (84%) had all 3 of the defining features of: i) erythema, ii) oedema, and iii) warmth with acute pain/tenderness upon examination. Twenty-two (32%) patients experienced a previous episode of cellulitis within the last 3 years. The median time to recurrence (estimated as the time since the most recent previous attack) was 205 days (95% CI 102 to 308). Service users were generally supportive of the trial, although several expressed concerns about taking antibiotics for lengthy periods, and felt that multiple morbidity/old age would limit entry into a 3-year study. Conclusion: This pilot study has been crucial in highlighting some key issues for the conduct of a future RCT. As a result of these findings, changes have been made to i) the planned recruitment strategy, ii) the proposed inclusion criteria and ii) the definition of cellulitis for use in the future trial.

Le diagnostic anténatal modifie-t-il la prise en charge néonatale et le devenir à 1 an des enfants suivis pour atrésie de l’œsophage de type III ?

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Mesoscale Optoelectronic Design of Wire-Based Photovoltaic and Photoelectrochemical Devices

The overarching theme of this thesis is mesoscale optical and optoelectronic design of photovoltaic and photoelectrochemical devices. In a photovoltaic device, light absorption and charge carrier transport are coupled together on the mesoscale, and in a photoelectrochemical device, light absorption, charge carrier transport, catalysis, and solution species transport are all coupled together on the mesoscale. The work discussed herein demonstrates that simulation-based mesoscale optical and optoelectronic modeling can lead to detailed understanding of the operation and performance of these complex mesostructured devices, serve as a powerful tool for device optimization, and efficiently guide device design and experimental fabrication efforts. In-depth studies of two mesoscale wire-based device designs illustrate these principles—(i) an optoelectronic study of a tandem Si|WO3 microwire photoelectrochemical device, and (ii) an optical study of III-V nanowire arrays.

The study of the monolithic, tandem, Si|WO3 microwire photoelectrochemical device begins with development and validation of an optoelectronic model with experiment. This study capitalizes on synergy between experiment and simulation to demonstrate the model’s predictive power for extractable device voltage and light-limited current density. The developed model is then used to understand the limiting factors of the device and optimize its optoelectronic performance. The results of this work reveal that high fidelity modeling can facilitate unequivocal identification of limiting phenomena, such as parasitic absorption via excitation of a surface plasmon-polariton mode, and quick design optimization, achieving over a 300% enhancement in optoelectronic performance over a nominal design for this device architecture, which would be time-consuming and challenging to do via experiment.

The work on III-V nanowire arrays also starts as a collaboration of experiment and simulation aimed at gaining understanding of unprecedented, experimentally observed absorption enhancements in sparse arrays of vertically-oriented GaAs nanowires. To explain this resonant absorption in periodic arrays of high index semiconductor nanowires, a unified framework that combines a leaky waveguide theory perspective and that of photonic crystals supporting Bloch modes is developed in the context of silicon, using both analytic theory and electromagnetic simulations. This detailed theoretical understanding is then applied to a simulation-based optimization of light absorption in sparse arrays of GaAs nanowires. Near-unity absorption in sparse, 5% fill fraction arrays is demonstrated via tapering of nanowires and multiple wire radii in a single array. Finally, experimental efforts are presented towards fabrication of the optimized array geometries. A hybrid self-catalyzed and selective area MOCVD growth method is used to establish morphology control of GaP nanowire arrays. Similarly, morphology and pattern control of nanowires is demonstrated with ICP-RIE of InP. Optical characterization of the InP nanowire arrays gives proof of principle that tapering and multiple wire radii can lead to near-unity absorption in sparse arrays of InP nanowires.

A Comparison Study of the English III/American Literature Success of African American High School Students and That of Students Whose Home Language is Haitian Creole

The purpose of the study was to compare the English III success of students whose home language is Haitian Creole (SWHLIHC) with that of the more visible African American high school students in the Miami Dade County Public Schools System, in an effort to offer insight that might assist educators in facilitating the educational success of SWHLIHC in American Literature class. The study was guided by two important theories on how students interact with and learn from literature. They are Reader Response Theory which advocates giving students the opportunity to become involved in the literature experience (Rosenblatt, 1995), and Critical Literacy, a theory developed by Paolo Freire and Henry Giroux, which espouses a critical approach to analysis of society that enables people to analyze social problems through lenses that would reveal social inequities and assist in transforming society into a more equitable entity. Data for the study: 10th grade reading FCAT scores, English III/American Literature grades, and Promotion to English IV records for the school year 2010-2011 were retrieved from the records division of the Miami Dade County Public Schools System. The study used a quantitative methods approach, the central feature of which was an ex post facto design with hypotheses (Newman, Newman, Brown, & McNeely, 2006). The ex post facto design with hypotheses was chosen because the researcher postulated hypotheses about the relationships that might exist between the performances of SWHLIHC and those of African American students on the three above mentioned variables. This type of design supported the researcher’s purpose of comparing these performances. One way analysis of variance (ANOVA), two way ANOVAs, and chi square tests were used to examine the two groups’ performances on the 10th grade reading FCAT, their English III grades, and their promotion to English IV. The study findings show that there was a significant difference in the performance of SWHLIHC and African American high school students on all three independent variables. SWHLIHC performed significantly higher on English III success and promotion to English IV. African American high school students performed significantly higher on the reading FCAT.

Towards in silico IBV vaccine design: defining the role of polymorphism in viral attenuation

The gammacoronavirus, Infectious Bronchitis Virus (IBV), is a respiratory pathogen of chickens. IBV is a constant threat to poultry production as established vaccines are often ineffective against emerging strains. This requires constant and rapid vaccine production by a process of viral attenuation by egg passage, but the essential forces leading to attenuation in the virus have not yet been characterised. Knowledge of these factors will lead to the development of more effective, rationally attenuated, live vaccines and reduction of the mortality and morbidity caused by this pathogen. M41 CK strain was egg passaged four times many years ago at Houghton Poultry Research Station and stored as M41-CK EP4 (stock virus at The Pirbright Institute since 1992). It was the first egg passage to have its genome pyrosequenced and was therefore used as the baseline reference. The overall aim of this project was to analyse deep sequence data obtained from four IBV isolates (called A, A1, C and D) each originating from the common M41-CK EP4 (ep4) and independently passaged multiple times in embryonated chicken eggs (figure 1.1). Highly polymorphic encoding regions of the IBV genome were then identified which are likely involved in the attenuation process through the formation of independent SNPs and/or SNP clusters. This was then used to direct targeted investigation of SNPs during the attenuation process of the four IBV passages. A previously generated deep sequence dataset was used as a preliminary map of attenuation for one virulent strain of IBV. This investigation showed the nucleocapsid and spike as two highly polymorphic encoding regions within the IBV genome with the highest proportion of SNPs compared to encoding region size. This analysis then led to more focussed studies of the nucleocapsid and spike encoding region with the ultimate aim of mapping key attenuating regions and nucleotide positions. The 454 pyrosequencing data and further investigation of nucleocapsid and spike encoding regions have identified the SNPs present at the same nucleotide positions within analysed A, A1, C and D isolates. These SNPs probably play a crucial role in viral attenuation and universal vaccine production but it is not clear if independent SNPs are also involved in loss of virulence. The majority of SNPs accumulated at different nucleotide positions without further continuation in Sanger sequenced egg passages presenting S2 subunit (spike) and nucleocapsid as polymorphic encoding regions which in nature remain highly conserved.

Design and characterization of Electrochemical Sensors for Organic Bioelectronics

This Ph.D. Thesis concerns the design and characterisation of functional electrochemical interfaces in organic electronic devices for bioelectronic applications. The Thesis is structured as follows: Chapter I – Technological context that has inspired the research, introduction to Organic Bioelectronics and literature review concerning Organic Electrochemical Transistors (OECTs) for sensing applications. Chapter II – Working principle of an all-polymeric OECT and operando microscopic characterization using scanning electrochemical techniques. Chapter III – Dopamine detection with all-polymeric OECT sensors. Development of a potentiodynamic approach to address selectivity issues in the presence of interfering species and design of a needle-type, sub-micrometric OECT sensor for spatially resolved detection of biological Dopamine concentrations. Chapter IV – Development of an OECT pH sensor. Characterization of the electrochemical transducer and functionalization of the OECT gate electrode with the sensing material. Potentiodynamic and potentiostatic operation modalities are explored and the sensing performances are assessed in both cases. The final device is realized on a flexible substrate and tested in Artificial Sweat. Chapter V – Study of two-terminal, electrochemically gated sensors inspired by the OECT configuration. Design and characterization of novel functional materials showing a potentiometric transduction of the chemical signal that can be exploited in the realization of electrochemical sensors with simplified geometry for wearable applications. Chapter VI – Conclusion.

New Metal Tetrazolate Complexes: Design, Synthesis, Characterization and Applications

This final thesis is aimed at summarizing the research program I have carried out during my PhD studies, that has been dealing with the design, the preparation, characterization and applications of new Re(I), Ru(II), and Ir(III) metal complexes containing anionic ligands such as 5-aryl tetrazolates [R-CN4]- or their neutral analogues, N-alkyltetrazoles [R-CN4-R1]. Chapter 1 consists of a brief introduction on tetrazoles and metal-tetrazolato complexes, and on the photophysical properties of d6 transition metal complexes. In chapter 2, the synthesis, characterization and study of the photophysical properties of new luminescent Ir(III)-tetrazolate complexes are discussed. Moreover, the application of one of the new Ir(III)-CN complexes as emissive core in the fabrication of an OLED device is reported. In chapter 3, the study of the antimicrobial activity of new Ru(II)-alkyltetrazole complexes is reported. When the pentatomic ring was substituted with a long alkyl residue, antimicrobial activity toward Deinococcus radiodurans was observed. In chapter 4, a new family of luminescent Re(I)-tetrazolate complexes is reported. In this study, different N-alkyl tetrazoles play the role of diimine (diim) ligands in the preparation of new Re(I) tricarbonyl complexes. In addition, absorption and emission titration experiments were performed to study their interaction with Bovine Serum Albumin (BSA). In chapter 5, the synthesis and characterization of new luminescent Re(I)-tetrazolate complexes are discussed. The use of sulfonated diimine ligands in the preparation of new Re(I) tricarbonyl complexes led to the first example Re(I) complexes for the luminescent staining of proteins. In chapter 6, the synthesis, a new family of Ir(III)-NO2 tetrazole complexes displaying unexpected photophysical properties are discussed. Moreover, the possibility to tune the luminescent output of such systems upon chemical modification of the pending nitro group was verified by performing reduction tests with sodium dithionite; this represents encouraging evidence for their possible application as hypoxia-responsive luminescent probes in bioimaging.

Design of luminescent metal complexes for polymer science

The program of my PhD studies has been dealing with the investigation of the research outcomes that may result from the use of luminescent Iridium(III) cyclometalated complexes in the field of polymer science. In particular, my activity has been focused on exploring two main applicative contexts, i.e. Ir(III) complexes for preparing polymers and in combination with polymers. In the first part, a new set of luminescent Ir(III) complexes was exploited as photocatalysts for light-assisted atom transfer radical polymerization of methyl methacrylate. The decoration of both cyclometalated and ancillary ligands with sp3 hybridized nitrogen substituents together with the use of specific counterions, imparted suitable photophysical and redox properties for an efficient photocatalyzed process. The second part has been focused on the employment of Ir(III) tetrazole complexes as phosphorescent dyes in polymeric materials. Colourless luminescent solar concentrators were prepared blending two Ir(III) cyclometalates with acrylate polymers. Their performances were investigated, leading to promising outcomes comparable, or superior, to those obtained from colourless LSCs based on organic fluorophores. As a complementary approach, Ir(III) complexes were covalently linked to polymers in the side chain, to obtain a new class of metallopolymers. To this extent, a bifunctional tetrazolate molecule, equipped with a coordination site and a polymerizable unit, was designed. The photophysical properties of the resultant luminescent polymeric films were discussed. In the end, an additional project involving both polymers and metal compounds was carried out during my experience as a visiting PhD student at Humboldt – University of Berlin. Polystyrene and polyethylene glycol -based ion-exchange resins were functionalized with peptides through a ligation pathway, for the selective chelation of Copper(II) in aqueous solutions. The coordinating capability of the materials towards Cu2+ ions was tested by ICP-MS analysis. The resins strategically modified with ion-selective peptides, may be exploited in the preparation of water-processing devices.

Design, synthesis and photovoltaic properties of some thiophene-based conjugated polymers for organic solar cells

The current issue of the resource of energy combined with the tendency to give a green footprint to our lifestyle have prompted the research to focus the attention on alternative sources with great strides in the optimization of polymeric photovoltaic devices. The research work described in this dissertation consists in the study of different semiconducting π-conjugated materials based on polythiophenes (Chapter I). In detail, the GRIM polymerization was deepened defining the synthetic conditions to obtain regioregular poly(3-alkylthiophene) (Chapter II). Since the use of symmetrical monomers functionalized with oxygen atom(s) allows to adopt easy synthesis leading to performing materials, disubstituted poly(3,4-dialkoxythiophene)s were successfully prepared, characterized and tested as photoactive materials in solar cells (Chapter III). A “green” resource of energy should be employed through sustainable devices and, for this purpose, the research work was continued on the synthesis of thiophene derivatives soluble in eco-friendly solvents. To make this possible, the photoactive layer was completely tailored starting from the electron-acceptor material. A fullerene derivative soluble in alcohols was successfully synthetized and adopted for the realization of the new devices (Chapter IV). New water/alcohol soluble electron-donor materials with different functional groups were prepared and their properties were compared (Chapter V). Once found the best ionic functional group, a new double-cable material was synthetized optimizing the surface area between the different materials (Chapter VI). Finally, other water/alcohol soluble materials were synthetized, characterized and used as cathode interlayers in eco-friendly devices (Chapter VII). In this work, all prepared materials were characterized by spectroscopy analyses, gel permeation chromatography and thermal analyses. Cyclic voltammetry, X-ray diffraction, atomic force microscopy and external quantum efficiency were used to investigate some peculiar aspects.

Design, Synthesis And Biological Evaluation Of Hybrid Bioisoster Derivatives Of N-acylhydrazone And Furoxan Groups With Potential And Selective Anti-trypanosoma Cruzi Activity.

Hybrid bioisoster derivatives from N-acylhydrazones and furoxan groups were designed with the objective of obtaining at least a dual mechanism of action: cruzain inhibition and nitric oxide (NO) releasing activity. Fifteen designed compounds were synthesized varying the substitution in N-acylhydrazone and in furoxan group as well. They had its anti-Trypanosoma cruzi activity in amastigotes forms, NO releasing potential and inhibitory cruzain activity evaluated. The two most active compounds (6, 14) both in the parasite amastigotes and in the enzyme contain the nitro group in para position of the aromatic ring. The permeability screening in Caco-2 cell and cytotoxicity assay in human cells were performed for those most active compounds and both showed to be less cytotoxic than the reference drug, benznidazole. Compound 6 was the most promising, since besides activity it showed good permeability and selectivity index, higher than the reference drug. Thereby the compound 6 was considered as a possible candidate for additional studies.

Iis--integrated Interactome System: A Web-based Platform For The Annotation, Analysis And Visualization Of Protein-metabolite-gene-drug Interactions By Integrating A Variety Of Data Sources And Tools.

High-throughput screening of physical, genetic and chemical-genetic interactions brings important perspectives in the Systems Biology field, as the analysis of these interactions provides new insights into protein/gene function, cellular metabolic variations and the validation of therapeutic targets and drug design. However, such analysis depends on a pipeline connecting different tools that can automatically integrate data from diverse sources and result in a more comprehensive dataset that can be properly interpreted. We describe here the Integrated Interactome System (IIS), an integrative platform with a web-based interface for the annotation, analysis and visualization of the interaction profiles of proteins/genes, metabolites and drugs of interest. IIS works in four connected modules: (i) Submission module, which receives raw data derived from Sanger sequencing (e.g. two-hybrid system); (ii) Search module, which enables the user to search for the processed reads to be assembled into contigs/singlets, or for lists of proteins/genes, metabolites and drugs of interest, and add them to the project; (iii) Annotation module, which assigns annotations from several databases for the contigs/singlets or lists of proteins/genes, generating tables with automatic annotation that can be manually curated; and (iv) Interactome module, which maps the contigs/singlets or the uploaded lists to entries in our integrated database, building networks that gather novel identified interactions, protein and metabolite expression/concentration levels, subcellular localization and computed topological metrics, GO biological processes and KEGG pathways enrichment. This module generates a XGMML file that can be imported into Cytoscape or be visualized directly on the web. We have developed IIS by the integration of diverse databases following the need of appropriate tools for a systematic analysis of physical, genetic and chemical-genetic interactions. IIS was validated with yeast two-hybrid, proteomics and metabolomics datasets, but it is also extendable to other datasets. IIS is freely available online at: http://www.lge.ibi.unicamp.br/lnbio/IIS/.

Study Of The Homogeneity Of Drug Loaded In Polymeric Films Using Near-infrared Chemical Imaging And Split-plot Design.

Split-plot design (SPD) and near-infrared chemical imaging were used to study the homogeneity of the drug paracetamol loaded in films and prepared from mixtures of the biocompatible polymers hydroxypropyl methylcellulose, polyvinylpyrrolidone, and polyethyleneglycol. The study was split into two parts: a partial least-squares (PLS) model was developed for a pixel-to-pixel quantification of the drug loaded into films. Afterwards, a SPD was developed to study the influence of the polymeric composition of films and the two process conditions related to their preparation (percentage of the drug in the formulations and curing temperature) on the homogeneity of the drug dispersed in the polymeric matrix. Chemical images of each formulation of the SPD were obtained by pixel-to-pixel predictions of the drug using the PLS model of the first part, and macropixel analyses were performed for each image to obtain the y-responses (homogeneity parameter). The design was modeled using PLS regression, allowing only the most relevant factors to remain in the final model. The interpretation of the SPD was enhanced by utilizing the orthogonal PLS algorithm, where the y-orthogonal variations in the design were separated from the y-correlated variation.