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2016
Fernandes, CSM, Barbosa I, Castro R, Pina AS, Coroadinha AS, Barbas A, Roque ACA.  2016.  Retroviral particles are effectively purified on an affinity matrix containing peptides selected by phage-display. Biotechnology Journal. 11:1513–1524. Abstract

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Krings, B-J, Rodriguez H, Schleisiek A.  2016.  Scientific knowledge and the transgression of boundaries. , Wiesbaden: Springer VS Abstract

The aim of this book is to understand and critically appraise science-based transgression dynamics in their whole complexity. It includes contributions from experts with different disciplinary backgrounds, such as philosophy, history and sociology. Thus, it is in itself an example of boundary transgession. Scientific disciplines and their objects have tended to be seen as permanent and distinct. However, science is better conceived as an activity that constantly surpasses, erases and rebuilds all kinds of boundaries, either disciplinary, socio-ethical or ecological. This transgressive capacity, a characteristic trait of science and its applications, defines us as "knowledge societies." However, scientific and technological developments are also sources of serious environmental and social concerns.

Fernandes, CSM, Castro R, Coroadinha AS, Roque ACA.  2016.  Small synthetic ligands for the enrichment of viral particles pseudotyped with amphotropic murine leukemia virus envelope. Journal of Chromatography A. 1438:160–170.: Elsevier B.V. AbstractWebsite

Retroviral vectors gained popularity toward other viral vectors as they integrate their genome into hosts' genome, a characteristic required for the modification of stem cells. However, the production of viable particles for gene therapy is hampered by the low ratio of infectious to non-infectious viral particles after purification, low titers and limited number of competent viral receptors. We have developed de novo two fully synthetic triazine-based ligands that can selectively bind retroviral particles pseudotyped with amphotropic murine leukemia virus envelope (AMPHO4070A). A 78-membered library of triazine-based ligands was designed in silico and was virtually screened against the modeled structure of the AMPHO4070A protein. Ligands displaying the highest energy of binding were synthesized on cross-linked agarose and experimentally tested. Adsorbents containing ligands A5A10 and A10A11 showed selectivity toward viral particles containing the target protein (VLP-AMPHO), binding 19 ± 5 $μ$g/g support and 47 ± 13 $μ$g/g support, respectively. The elution conditions for both ligands were mild and with high recovery yields (80-100{%}), in comparison with common purification practices. These results were based on a lab-scale experimental setting with VLP integrity being confirmed through TEM. In particular, the elution buffer containing 12 mM imidazole allowed the recovery of intact amphotropic viral particles.

Muñoz-ruiz, M, Ribot JC, Grosso AR, Gonçalves-sousa N, Pamplona A, Pennington DJ, Regueiro JR, Fernández-malavé E, Silva-santos B.  2016.  TCR signal strength controls thymic differentiation of discrete proinflammatory γδT cell subsets. Nature immunology. , Number April AbstractWebsite

The mouse thymus produces discrete γδ T cell subsets that make either interferon-γ (IFN-γ) or interleukin 17 (IL-17), but the role of the T cell antigen receptor (TCR) in this developmental process remains controversial. Here we show that Cd3g(+/-) Cd3d(+/-) (CD3 double-haploinsufficient (CD3DH)) mice have reduced TCR expression and signaling strength on γδ T cells. CD3DH mice had normal numbers and phenotypes of αβ thymocyte subsets, but impaired differentiation of fetal Vγ6(+) (but not Vγ4(+)) IL-17-producing γδ T cells and a marked depletion of IFN-γ-producing CD122(+) NK1.1(+) γδ T cells throughout ontogeny. Adult CD3DH mice showed reduced peripheral IFN-γ(+) γδ T cells and were resistant to experimental cerebral malaria. Thus, TCR signal strength within specific thymic developmental windows is a major determinant of the generation of proinflammatory γδ T cell subsets and their impact on pathophysiology.

Pina, AS, Carvalho S, Dias AMGC, Guilherme M, Pereira AS, Caraça LT, Coroadinha AS, Lowe CR, Roque ACA.  2016.  Tryptophan tags and de novo designed complementary affinity ligands for the expression and purification of recombinant proteins. Journal of Chromatography A. 1472:55–65. AbstractWebsite

A common strategy for the production and purification of recombinant proteins is to fuse a tag to the protein terminal residues and employ a “tag-specific” ligand for fusion protein capture and purification. In this work, we explored the effect of two tryptophan-based tags, NWNWNW and WFWFWF, on the expression and purification of Green Fluorescence Protein (GFP) used as a model fusion protein. The titers obtained with the expression of these fusion proteins in soluble form were 0.11 mg ml−1 and 0.48 mg ml−1 for WFWFWF and NWNWNW, respectively. A combinatorial library comprising 64 ligands based on the Ugi reaction was prepared and screened for binding GFP-tagged and non-tagged proteins. Complementary ligands A2C2 and A3C1 were selected for the effective capture of NWNWNW and WFWFWF tagged proteins, respectively, in soluble forms. These affinity pairs displayed 106 M−1 affinity constants and Qmax values of 19.11 ± 2.60 ug g−1 and 79.39 ug g−1 for the systems WFWFWF AND NWNWNW, respectively. GFP fused to the WFWFWF affinity tag was also produced as inclusion bodies, and a refolding-on column strategy was explored using the ligand A4C8, selected from the combinatorial library of ligands but in presence of denaturant agents.

Bianchi, C, Loureiro J, Duarte P, Marques J, Figueira J, Ropio I, Ferreira I.  2016.  V2O5 Thin Films for Flexible and High Sensitivity Transparent Temperature Sensor. Advanced Materials Technologies. 1(6):1600077. AbstractWebsite

This work reports the optimization of V2O5 Seebeck coefficient to obtain high sensitivity and transparent temperature sensors. It is observed that the film thickness plays a major role on the thermoelectric properties, together with the annealing step, obtaining a Seebeck coefficient of −690 μV K−1, for 75 nm thick V2O5 films deposited on glass, after an annealing step of 1 h at 773 K, in air. The V2O5 films are also deposited and optimized on polyimide substrates, but lower annealing temperature is required, 573 K for 3 h, to maintain the flexibility of the substrate and simultaneously high Seebeck coefficient, −591 μV K−1. These films are used in a simple design sensor and tested on the surface of a microfluidic channel (500 μm) made of polydimethylsiloxane, while having hot water flowing through it. The response time is below 1 s and the recovery time around 5 s.

Cruz, MV, Freitas F, Paiva A, Mano F, Dionísio M, Ramos AM, Reis MA.  2016.  Valorization of fatty acids-containing wastes and byproducts into short- and medium-chain length polyhydroxyalkanoates. New Biotechnology. 33(1):206-215.Website
Bianchi, C, Ferreira LM, Loureiro J, Rodrigues A, Duarte P, Baptista AC, Ferreira IM.  2016.  Vanadium Pentoxide Alloyed with Graphite for Thin-Film Thermal Sensors. J. Electron. Mater.. 45(3):1987–1991. AbstractWebsite

The thermoelectric (TE) properties of vanadium pentoxide (V2O5) alloyed with graphite (G) were studied as a function of its incorporation percentage. Variable weight percentages of graphite powder (0–50%) were added to V2O5 powder and their mixtures were evaporated by a thermal evaporation technique to form thin films with a thickness in the range of 30–80 nm. In the infrared wavelength region, the transmittance of the obtained films increased as the G percentage was increased, while in the visible range, it decreased with G up to 10%. The TE properties were improved when G was in the range of 10–30%, while it decreased for the other percentages: Seebeck coefficient (S) changed from 0.6 mV/K to 0.9 mV/K and was zero with a G of 50%; the electrical conductivity varied slightly from 5 (Ωm)−1 to 0.7 (Ωm)−1 while the mobility improved from 0.07 cm2/V s to 1.5 cm2/V s and the respective carrier concentration was reduced, from 1 × 1018 cm−3 to 4 × 1016 cm−3. These films were applied as temperature sensors evaluating the thermovoltage as a function of thermal gradient between two electrodes, in which one was maintained at room temperature.

Dias, AMGC, dos Santos R, Iranzo O, Roque ACA.  2016.  Affinity adsorbents for proline-rich peptide sequences: a new role for WW domains. RSC Adv.. 6:68979-68988.: The Royal Society of Chemistry AbstractWebsite

The WW domain derived from human Yes-associated protein (hYAP65_WW) recognizes proline-rich peptides. The structural and chemical robustness of WW domains makes them appealing candidates to target and capture these peptides in affinity purification processes. In this work{,} the chemical synthesis of the hYAP65_WW domain containing a terminal cysteine for oriented coupling onto the chromatographic matrix was successfully achieved by a fragment solution condensation reaction and by incorporation of pseudoproline dipeptide units. Both strategies yielded a hYAP65_WW protein with the characteristic WW domain folding. The purified hYAP65_WW domain was immobilized in a chromatographic matrix and tested for binding to a proline-rich peptide. The adsorbent bound 92 ng of peptide per mg of support and the elution was particularly efficient when employing a low pH or an increase in salt concentration. This work sets the ground for the application of WW domains as affinity reagents towards the capture and elution of peptides and proteins rich in proline sequences.

do Fraga, AC, Quitete CPB, Ximenes VL, Sousa-Aguiar EF, Fonseca IM, Rego AMB.  2016.  Biomass derived solid acids as effective hydrolysis catalysts. Journal of Molecular Catalysis A: Chemical. 422:248-257. AbstractWebsite

The conversion of cellulose into products with higher added value often includes a depolymerization step to obtain glucose, its fundamental unity. The depolymerization reaction is carried out via hydrolysis of the β-1,4-glycosidic bond. The search for a solid acid catalyst capable of breaking these bonds is gaining increasing prominence in the literature. In this regard, sulfonated carbons have shown promising results. This work evaluated the use of a residue from the extraction of palm oil as raw material for the production of sulfonated carbons. The raw material was carbonized and sulfonated. The obtained solid acids were tested in the hydrolysis of cellobiose, a dimer of glucose often used as a model compound for cellulose. The hydrolysis reaction is the first step in converting renewable carbon sources into chemical products and biofuels. Some aspects were investigated, as the effect of carbonization temperature on the concentration of sulfonic groups, the results showing that the content thereof reached a maximum value at 300°C. Regarding the hydrolysis of cellobiose, it has been identified that there is a relationship between the concentration of sulfonic acid groups and the activity of these catalysts. However, there is a drop in the turnover number as the amount of sulfonic acid sites increases. This was related to a preferred position sulfonation mechanism. Furthermore, sulfonated carbons showed higher activity than the commercial acid resins, indicating that this material may be a good option for the generation of solid acid catalysts.

Martins, M, Baptista PV, Mendo {AS}, Correia C, Videira P, Rodrigues AS, Muthukumaran J, Santos-Silva T, Silva A, {Guedes da Silva} F{MC }, Gigante J, Duarte A, Gajewska M, Fernandes AR.  2016.  In vitro and in vivo biological characterization of the anti-proliferative potential of a cyclic trinuclear organotin(IV) complex. Molecular Biosystems. 12:1015–1023., Number 3: ROYAL SOC CHEMISTRY Abstract

Identification of novel molecules that can selectively inhibit the growth of tumor cells, avoid causing side effects to patients and/or intrinsic or acquired resistance, usually associated with common chemotherapeutic agents, is of utmost importance. Organometallic compounds have gained importance in oncologic chemotherapy, such as organotin(IV) complexes. In this study, we assessed the anti-tumor activity of the cyclic trinuclear organotin(IV) complex with an aromatic oximehydroxamic acid group [nBu(2)Sn(L)](3)(H2L = N,2-dihydroxy-5-[N-hydroxyethanimidoyl]benzamide) - MG85 - and provided further characterization of its biological targets. We have previously shown the high anti-proliferative activity of this complex against human colorectal and hepatocellular carcinoma cell lines and lower cytotoxicity in neonatal non-tumor fibroblasts. MG85 induces tumor cell apoptosis and down-regulation of proteins related to tubulin dynamics (TCTP and COF1). Further characterization included the: (i) evaluation of interference in the cell cycle progression, including the expression of critical genes; (ii) affinity to DNA and the corresponding mode of binding; (iii) genotoxic potential in cells with deficient DNA repair pathways; and (iv) in vivo tumor reduction efficiency using mouse colorectal carcinoma xenografts.

Lyubchik, S, Lygina E, Lyubchyk A, Lyubchik S, Loureiro JM, Fonseca IM, Ribeiro AB, Pinto MM, Figueiredo AMSá.  2016.  The Kinetic Parameters Evaluation for the Adsorption Processes at ``Liquid–Solid'' Interface. Electrokinetics Across Disciplines and Continents: New Strategies for Sustainable Development. (Ribeiro, Alexandra B., Mateus, Eduardo P., Couto, Nazaré, Eds.).:81–109., Cham: Springer International Publishing Abstract

The kinetic parameters of the adsorption process at ``liquid–solid'' interface have been evaluated through the sets of time-based experiments of the Cr(III) adsorption under varying temperature, initial metal concentration, and carbon loading for two sets of the commercially available activated carbons and their post-oxidized forms with different texture and surface functionality.

Foti, A, Hartmann T, Coelho C, Santos-Silva T, Romão MJ, Leimkühler S.  2016.  Optimization of the Expression of Human Aldehyde Oxidase for Investigations of Single-Nucleotide Polymorphisms. Drug Metabolism and Disposition. 44:1277–1285., Number 8: American Society for Pharmacology and Experimental Therapeutics AbstractWebsite

Aldehyde oxidase (AOX1) is an enzyme with broad substrate specificity, catalyzing the oxidation of a wide range of endogenous and exogenous aldehydes as well as N-heterocyclic aromatic compounds. In humans, the enzyme’s role in phase I drug metabolism has been established and its importance is now emerging. However, the true physiologic function of AOX1 in mammals is still unknown. Further, numerous single-nucleotide polymorphisms (SNPs) have been identified in human AOX1. SNPs are a major source of interindividual variability in the human population, and SNP-based amino acid exchanges in AOX1 reportedly modulate the catalytic function of the enzyme in either a positive or negative fashion. For the reliable analysis of the effect of amino acid exchanges in human proteins, the existence of reproducible expression systems for the production of active protein in ample amounts for kinetic, spectroscopic, and crystallographic studies is required. In our study we report an optimized expression system for hAOX1 in Escherichia coli using a codon-optimized construct. The codon-optimization resulted in an up to 15-fold increase of protein production and a simplified purification procedure. The optimized expression system was used to study three SNPs that result in amino acid changes C44W, G1269R, and S1271L. In addition, the crystal structure of the S1271L SNP was solved. We demonstrate that the recombinant enzyme can be used for future studies to exploit the role of AOX in drug metabolism, and for the identification and synthesis of new drugs targeting AOX when combined with crystallographic and modeling studies.

Roma-Rodrigues, C, Heuer-Jungemann A, de Fernandes {MANCR}, Kanaras {AG }, Baptista {PMRV}.  2016.  Peptide-coated gold nanoparticles for modulation of angiogenesis in vivo. International journal of nanomedicine. 11:2633–2639.: Dove Medical Press Abstract

In this work, peptides designed to selectively interact with cellular receptors involved in the regulation of angiogenesis were anchored to oligo-ethylene glycol-capped gold nanoparticles (AuNPs) and used to evaluate the modulation of vascular development using an ex ovo chick chorioallantoic membrane assay. These nanoparticles alter the balance between naturally secreted pro- and antiangiogenic factors, under various biological conditions, without causing toxicity. Exposure of chorioallantoic membranes to AuNP-peptide activators of angiogenesis accelerated the formation of new arterioles when compared to scrambled peptide-coated nanoparticles. On the other hand, antiangiogenic AuNP-peptide conjugates were able to selectively inhibit angiogenesis in vivo. We demonstrated that AuNP vectorization is crucial for enhancing the effect of active peptides. Our data showed for the first time the effective control of activation or inhibition of blood vessel formation in chick embryo via AuNP-based formulations suitable for the selective modulation of angiogenesis, which is of paramount importance in applications where promotion of vascular growth is desirable (eg, wound healing) or ought to be contravened, as in cancer development.

Terao, M, Romão MJ, Leimkühler S, Bolis M, Fratelli M, Coelho C, Santos-Silva T, Garattini E.  2016.  Structure and function of mammalian aldehyde oxidases. Archives of Toxicology. 90:753–780., Number 4 AbstractWebsite

Mammalian aldehyde oxidases (AOXs; EC1.2.3.1) are a group of conserved proteins belonging to the family of molybdo-flavoenzymes along with the structurally related xanthine dehydrogenase enzyme. AOXs are characterized by broad substrate specificity, oxidizing not only aromatic and aliphatic aldehydes into the corresponding carboxylic acids, but also hydroxylating a series of heteroaromatic rings. The number of AOX isoenzymes expressed in different vertebrate species is variable. The two extremes are represented by humans, which express a single enzyme (AOX1) in many organs and mice or rats which are characterized by tissue-specific expression of four isoforms (AOX1, AOX2, AOX3, and AOX4). In vertebrates each AOX isoenzyme is the product of a distinct gene consisting of 35 highly conserved exons. The extant species-specific complement of AOX isoenzymes is the result of a complex evolutionary process consisting of a first phase characterized by a series of asynchronous gene duplications and a second phase where the pseudogenization and gene deletion events prevail. In the last few years remarkable advances in the elucidation of the structural characteristics and the catalytic mechanisms of mammalian AOXs have been made thanks to the successful crystallization of human AOX1 and mouse AOX3. Much less is known about the physiological function and physiological substrates of human AOX1 and other mammalian AOX isoenzymes, although the importance of these proteins in xenobiotic metabolism is fairly well established and their relevance in drug development is increasing. This review article provides an overview and a discussion of the current knowledge on mammalian AOX.

Kiazadeh, A, Gomes HL, Barquinha P, Martins J, Rovisco A, Pinto JV, Martins R, Fortunato E.  2016.  {Improving positive and negative bias illumination stress stability in parylene passivated IGZO transistors}. APPLIED PHYSICS LETTERS. 109, Number 5 Abstract
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2015
Moretto, SM, Moniz AB, Robinson D.  2015.  Visions on high-speed trains: a methodological analysis, WPS05/2015. :27., Monte de Caparica: IET Working Papers Series Abstract

Future Oriented Technology Analysis (FTA) has been visible in railway planning since 2001. Over a dozen reports have been produced in the past thirteen years, the majority being descriptive endogenous technocentric visions. They have played a role in the revitalization of the sector, predominantly relating to collective alignments and interdependencies in choice and form of the technological path the various stakeholders’ follow to achieve policy goals. A striking example is the case of ERRAC visions, where strategic agendas and roadmaps greatly impacted the high-speed train technology transition from the second to the third generation of vehicles. However, today’s socio-economic events have revealed the limitations of previously applied FTA fall short for railways. In particular, there is an inability to bridge technocentric visions with the societal challenges that are becoming increasingly prominent on the policy agenda. To fill this FTA-need in railways it is here proposed a role for constructive technology assessment as bridging function towards achieving success in the transition to a next generation of high-speed trains. The findings here presented result from the analysis of reports and interviews with their commissioning institutions and drafters.

Mendo, {AS}, Figueiredo S, Roma-Rodrigues C, Videira {PA }, Ma Z, Diniz M, Larguinho M, Costa PM, Lima {JC }, Pombeiro {AJL }, Baptista {PV}, Fernandes {AR}.  2015.  Characterization of antiproliferative potential and biological targets of a copper compound containing 4'-phenyl terpyridine, sep. JBIC Journal of Biological Inorganic Chemistry. 20:935–948., Number 6: Springer Abstract

Several copper complexes have been assessed as anti-tumor agents against cancer cells. In this work, a copper compound [Cu(H2O){OS(CH3)(2)}L](NO3)(2) incorporating the ligand 4'-phenyl-terpyridine antiproliferative activity against human colorectal, hepatocellular carcinomas and breast adenocarcinoma cell lines was determined, demonstrating high cytotoxicity. The compound is able to induce apoptosis and a slight delay in cancer cell cycle progression, probably by its interaction with DNA and induction of double-strand pDNA cleavage, which is enhanced by oxidative mechanisms. Moreover, proteomic studies indicate that the compound induces alterations in proteins involved in cytoskeleton maintenance, cell cycle progression and apoptosis, corroborating its antiproliferative potential.

Martins, P, Jesus J, Santos S, Raposo {LR }, Roma-Rodrigues C, Baptista {PMRV}, de Fernandes {MANCR}.  2015.  Heterocyclic anticancer compounds: Recent advances and the paradigm shift towards the use of nanomedicine's tool Box, sep. Molecules. 20:16852–16891., Number 9: MDPI - Multidisciplinary Digital Publishing Institute Abstract

The majority of heterocycle compounds and typically common heterocycle fragments present in most pharmaceuticals currently marketed, alongside with their intrinsic versatility and unique physicochemical properties, have poised them as true cornerstones of medicinal chemistry. Apart from the already marketed drugs, there are many other being investigated for their promising activity against several malignancies. In particular, anticancer research has been capitalizing on the intrinsic versatility and dynamic core scaffold of these compounds. Nevertheless, as for any other promising anticancer drugs, heterocyclic compounds do not come without shortcomings. In this review, we provide for a concise overview of heterocyclic active compounds and families and their main applications in medicine. We shall focus on those suitable for cancer therapy while simultaneously addressing main biochemical modes of action, biological targets, structure-activity relationships as well as intrinsic limitation issues in the use of these compounds. Finally, considering the advent of nanotechnology for effective selective targeting of drugs, we shall discuss fundamental aspects and considerations on nanovectorization of such compounds that may improve pharmacokinetic/pharmacodynamic properties of heterocycles.

De Schutter, A, Correia HD, Freire DM, Rivas MG, Rizzi A, Santos-Silva T, González PJ, Van Doorslaer S.  2015.  Ligand Binding to Chlorite Dismutase from Magnetospirillum sp, October. The journal of physical chemistry. B. 119:13859—13869., Number 43 AbstractWebsite
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Andrade, MS, Silva VS, Lourenco AM, Lobo AM, Rzepa HS.  2015.  Chiroptical Properties of Streptorubin B: The Synergy Between Theory and Experiment, OCT. CHIRALITY. 27:745-751., Number 10 Abstract
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Rodrigues, J, Mata D, Pimentel A, Nunes D, Martins R, Fortunato E, Neves AJ, Monteiro T, Costa FM.  2015.  {One-step synthesis of ZnO decorated CNT buckypaper composites and their optical and electrical properties}, may. Materials Science and Engineering: B. 195:38–44. AbstractWebsite
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Veigas, B, Fortunato E, Baptista {PV }.  2015.  Mobile based gold nanoprobe TB diagnostics for point-of-need, jan. Mobile Health Technologies: Methods and Protocols. Part 1(Rasooly, {Avraham }, Herold, {Keith E. }, Eds.).:41–56., United States: Humana Press Abstract

Nanotechnology based diagnostics has provided improved tools for pathogen detection and sensitive and specific characterization of antibiotic resistance signatures. Tuberculosis (TB) is caused by members of the Mycobacterium tuberculosis Complex (MTBC) and, according to the World Health Organization, is one of the most serious infectious diseases in the world. Recent advances in molecular diagnostics of TB have improved both the detection time and sensitivity but they still require specialized technical personnel and cumbersome laboratory equipment. Diagnostics at point-of-need is crucial to TB control as it may provide rapid identification of pathogen together with the resistance profile of TB strains, originated from single nucleotide polymorphisms (SNPs) in different loci , allowing for a more accurate indication of the adequate therapy.Gold nanoparticles have been widely used in molecular diagnostics platforms. Here, we describe the use of gold nanoprobes (oligonucleotide functionalized gold nanoparticles) to be used in a non-crosslinking colorimetric method for the direct detection of specific DNA targets. Due to the remarkable optical properties of gold nanoparticles, this detection system provides colorimetric detection of the pathogen together with the potential of identification of several single nucleotide polymorphisms (SNPs) involved in TB resistance to antibiotics. For point-of-need use, we adapted this strategy to a low-cost mobile scheme using a paper based revelation platform and where the spectral signature is transposed to RGB data via a smartphone device. This way, identification of pathogen and characterization of resistance signatures is achieved at point-of-need.

Pavan, M, Rühle S, Ginsburg A, Keller DA, Barad H-N, Sberna PM, Nunes D, Martins R, Anderson AY, Zaban A, Fortunato E.  2015.  {TiO2/Cu2O all-oxide heterojunction solar cells produced by spray pyrolysis}, jan. Solar Energy Materials and Solar Cells. 132:549–556. AbstractWebsite

Here we present for the first time a TiO2/Cu2O all-oxide heterojunction solar cell entirely produced by spray pyrolysis onto fluorine doped tin oxide (FTO) covered glass substrates, using silver as a back contact. A combinatorial approach was chosen to investigate the impact of the TiO2 window layer and the Cu2O light absorber thicknesses. We observe an open circuit voltage up to 350mV and a short circuit current density which is strongly dependent of the Cu2O thickness, reaching a maximum of {\~{}}0.4mA/cm2. Optical investigation reveals that a thickness of 300nm spray pyrolysis deposited Cu2O is sufficient to absorb most photons with an energy above the symmetry allowed optical transition of 2.5eV, indicating that the low current densities are caused by strong recombination in the absorber that consists of small Cu2O grains.

Restani, {RB }, Conde J, Pires {RF }, Martins P, Fernandes {AR}, Baptista {PV}, Bonifacio {VDB }, Aguiar-Ricardo A.  2015.  POxylated Polyurea Dendrimers: Smart Core-Shell Vectors with IC50 Lowering Capacity, aug. Macromolecular Bioscience. 15:1045–1051., Number 8: WILEY-V C H VERLAG GMBH Abstract

The design and preparation of highly efficient drug delivery platforms using green methodologies is at the forefront of nanotherapeutics research. POxylated polyurea dendrimers are efficiently synthesized using a supercritical-assisted polymerization in carbon dioxide. These fluorescent, pH-responsive and water-soluble core-shell smart nanocarriers show low toxicity in terms of cell viability and absence of glutathione depletion, two of the major side effect limitations of current vectors. The materials are also found to act as good transfection agents, through a mechanism involving an endosomal pathway, being able to reduce 100-fold the IC50 of paclitaxel.

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