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2015
Santos, TC, Silva MA, Morgado L, Dantas JM, Salgueiro CA.  2015.  Diving into the redox properties of Geobacter sulfurreducens cytochromes: a model for extracellular electron transfer. Dalton Trans. 44(20):9335-9344. AbstractWebsite

Geobacter bacteria have a remarkable respiratory versatility that includes the dissimilatory reduction of insoluble metal oxides in natural habitats and electron transfer to electrode surfaces from which electricity can be harvested. In both cases, electrons need to be exported from the cell interior to the exterior via a mechanism designated as extracellular electron transfer (EET). Several c-type cytochromes from G. sulfurreducens (Gs) were identified as key players in this process. Biochemical and biophysical data have been obtained for ten Gs cytochromes, including inner-membrane associated (MacA), periplasmic (PpcA, PpcB, PpcC, PpcD, PpcE and GSU1996) and outer membrane-associated (OmcF, OmcS and OmcZ). The redox properties of these cytochromes have been determined, except for PpcC and GSU1996. In this perspective, the reduction potentials of these two cytochromes were determined by potentiometric redox titrations followed by visible spectroscopy. The data obtained are taken together with those available for other key cytochromes to present a thorough overview of the current knowledge of Gs EET mechanisms and provide a possible rationalization for the existence of several multiheme cytochromes involved in the same respiratory pathways.

Baptista, AC, Botas A, Almeida A, Nicolau A, Falcão B, Soares M, Leitão JP, Martins R, Borges JP, Ferreira I.  2015.  Down conversion photoluminescence on PVP/Ag-nanoparticles electrospun composite fibers. Optical Materials. 39:278–281. AbstractWebsite

The influence of Ag nanoparticles (Ag NPs) on the luminescence of electrospun nonwoven mats made of polyvinylpyrrolidone (PVP) has been studied in this work. The PVP fibers incorporating 2.1–4.3 nm size Ag NPs show a significant photoluminescence (PL) band between 580 and 640 nm under 325 nm laser excitation. The down conversion luminescence emission is present even after several hours of laser excitation, which denotes the durability and stability of fibers to consecutive excitations. As so these one-dimensional photonic fibers made using cheap methods is of great importance for organic optoelectronic applications, fluorescent clothing or counterfeiting labels.

Baptista, AC, Botas AM, Almeida APC, Nicolau AT, Falcão BP, Soares MJ, Leitão JP, Martins R, Borges JP, Ferreira I.  2015.  Down conversion photoluminescence on PVP/Ag-nanoparticles electrospun composite fibers. Opt. Mater.. 39:278-281. AbstractWebsite

The influence of Ag nanoparticles (Ag NPs) on the luminescence of electrospun nonwoven mats made of polyvinylpyrrolidone (PVP) has been studied in this work. The PVP fibers incorporating 2.1–4.3 nm size Ag NPs show a significant photoluminescence (PL) band between 580 and 640 nm under 325 nm laser excitation. The down conversion luminescence emission is present even after several hours of laser excitation, which denotes the durability and stability of fibers to consecutive excitations. As so these one-dimensional photonic fibers made using cheap methods is of great importance for organic optoelectronic applications, fluorescent clothing or counterfeiting labels.

Pereira, CCL, Pereira LCJ, Leal JP, Laia CAT, Monteiro B.  2015.  Dy, Tb, Gd and Eu complexes with low melting point and magnetic behavior. Poyhedron. 91:42-46.
Palma, SI, Marciello M, Carvalho A, Veintemillas-Verdaguer S, Morales PM, Roque ACA.  2015.  Effects of phase transfer ligands on monodisperse iron oxide magnetic nanoparticles. Journal of Colloid & Interface Science. 437(1):147–155. AbstractWebsite

Oleic acid coated iron oxide nanoparticles synthesized by thermal decomposition in organic medium are highly monodisperse but at the same time are unsuitable for biological applications. Ligand-exchange reactions are useful to make their surface hydrophilic. However, these could alter some structural and magnetic properties of the modified particles. Here we present a comprehensive study and comparison of the effects of employing either citric acid (CA) or meso-2,3-dimercaptosuccinic acid (DMSA) ligand-exchange protocols for phase transfer of monodisperse hydrophobic iron oxide nanoparticles produced by thermal decomposition of Fe(acac)3 in benzyl ether. We show the excellent hydrodynamic size distribution and colloidal stability of the hydrophilic particles obtained by the two protocols and confirm that there is a certain degree of oxidation caused by the ligand-exchange. CA revealed to be more aggressive towards the iron oxide surface than DMSA and greatly reduced the saturation magnetization values and initial susceptibility of the resulting particles compared to the native ones. Besides being milder and more straightforward to perform, the DMSA ligand exchange protocol produces MNP chemically more versatile for further functionalization possibilities. This versatility is shown through the covalent linkage of gum Arabic onto MNP-DMSA using carboxyl and thiol based chemical routes and yielding particles with comparable properties.

Muelle, H, Barquinha P, Ferreira I, Fortunato E, Santos MC, Diniz MS.  2015.  Effects of ultra-sonication on the cyanobacteria Microcystis aeruginosa structure and growth. Microsc. Microanal.. 21:50-51. AbstractWebsite

The eutrophication of surface waters caused by cyanobacteria is a worldwide problem, leading to expensive
water treatment costs [1]. In addition, the production of microcystins by these microalgae may cause many
health problems to humans and animals (e.g. liver cancer) and even death [2]. Therefore, a variety of
methods have been developed to control cyanobacteria blooms, including physical and chemical treatments.
However, they have negative impacts on other species of (micro) algae and on other aquatic biota. As a
consequence, ultrasonic algae treatment has been proposed as a clean approach to controlling the blooms of
some algae species and microcystins degradation [3]. Still, the specific effects of ultra-sonication on
cyanobacteria are not well known. The present work aimed to study the effects of ultra-sonication on the
cyanobacteria structure under different ultrasound conditions (changing frequency and power) by using
conventional histology and electron microscopy methods.
Microcystis spp. were harvested in a lake from Azores (Portugal) and stored in the cool and dark until
transported to the laboratory. Cyanobacteria were cultured in liquid BG-11 axenic medium at 22ºC in an
incubator chamber, under continuous illumination (fluorescent cold white light).
Samples were collected and suspensions of cells (1ml each) were subjected to ultrasonic irradiation using
diverse ultrasonic equipment (UP100H; UP200S, sonoreactor UTR 200 and ultrasonic bath) and testing
different exposure times. All the experimental algal suspensions were exposed for 5 min to ultrasonication
(on ice for periods of 10s to avoid heating). After ultrasonication cyanobacteria growth was assessed for a
period of 14 days and structural changes in cells were evaluated by light (LM) and scanning electron
microscopy (SEM) examination. The results show growth inhibition of the cyanobacteria according to
intensity and power used in each ultrasonic device. The use of the most powerful devices (sonoreactor and
UP200S) resulted in a massive disrupting of cell walls with consequent cell death (Fig. 1e,f). Similar results
were obtained by Ahan et al. [1] and Nakano et al. [4] and showing cell wall disruption. However, even
after exposure to the most powerful instrumentation it was possible to detect some viable cells and after 14
days colonies were already visible. The results from light and electron microscopy showed noticeable
changes at the structural level such as disruption of cell gas vacuoles (arrowhead), colony disaggregation and
damage of cell walls of cells (Fig. 1c-f).
As a consequence, the use of ultrasounds to improve water quality from eutrophic waters must be considered
with careful in terms of efficiency and other complementary methods should be considered to assure good
water quality criteria. In addition, the effects of ultrasonication in other aquatic organisms require further
studies before using this technology to control algae blooms.

Poggi, F, Firmino A, Amado MP.  2015.  Energy supply-storage models for Rural Net-Zero Communities – An integrated approach. EMER 2015. :167-172., Madrid: ISBN-10: 1-62734-559-0; ISBN-13: 978-1-62734-559-0
Ito, Y, Tochio T, Fukushima S, Taborda A, Sampaio JM, Marques JP, Parente F, Indelicato P, Santos JP.  2015.  Experimental and theoretical determination of the Kα2/Kα1 intensity ratio for zinc. Journal of Quantitative Spectroscopy and Radiative Transfer. 151:295-299. AbstractWebsite

X-ray intensity ratios, such as the Kα2/Kα1 ratio, are parameters with a large application in atomic physics and related scientific and technological areas. D.

Vinhas, R, Cordeiro M, Carlos FF, Mendo S, Fernandes AR, Figueiredo S, Baptista PV.  2015.  Gold nanoparticle-based theranostics: disease diagnostic and treatment using a single nanomaterial. J. Nanobiosensors in Disease Diagnosis. 11-23(4) AbstractWebsite

Nanotheranostics takes advantage of nanotechnology-based systems in order to diagnose and treat a specific disease. This approach is particularly relevant for personalized medicine, allowing the detection of a disease at an early stage, to direct a suitable therapy toward the target tissue based on the molecular profile of the altered phenotype, subsequently facilitating disease monitoring and following treatment. A tailored strategy also enables to reduce the off-target effects associated with universal treatments and improve the safety profile of a given treatment. The unique optical properties of gold nanoparticles, their ease of surface modification, and high surface-to-volume ratio have made them central players in this area. By combining imaging, targeting, and therapeutic agents in a single vehicle, these nanoconjugates are (ought to be) an important tool in the clinics. In this review, the multifunctionality of gold nanoparticles as theranostics agents will be highlighted, as well as the requirements before the translation of these nanoplatforms into routine clinical practice.

Franco, R, Pedrosa P, Carlos FF, Veigas B, Baptista PV.  2015.  Gold Nanoparticles for DNA/RNA based diagnostics. Handbook of Nanoparticles. :1339-1364., Zurich: Springer International Publishing Switzerland
Martins, P, Jesus J, Santos S, Raposo LR, Roma-Rodrigues C, Baptista PV, Fernandes AR.  2015.  Heterocyclic Anticancer Compounds: Recent Advances and the Paradigm Shift towards the Use of Nanomedicine’s Tool Box. Molecules. 9(20):16852-16891. AbstractWebsite

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.

Loureiro, J, Mateus T, Filonovich S, Ferreira M, Figueira J, Rodrigues A, Donovan BF, Hopkins PE, Ferreira I.  2015.  Hydrogenated nanocrystalline silicon thin films with promising thermoelectric properties. Appl. Phys. A. 120(4):1497–1502. AbstractWebsite

The search for materials with suitable thermoelectric properties that are environmentally friendly and abundant led us to investigate p- and n-type hydrogenated nanocrystalline silicon (nc-Si:H) thin films, produced by plasma-enhanced chemical vapor deposition. The Seebeck coefficient and power factor were measured at room temperature showing optimized values of 512 µV K−1 and 3.6 × 10−5 W m−1 K−2, for p-type, and −188 µV K−1 and 2.2 × 10−4 W m−1 K−2, for n-type thin films. The thermoelectric output power of one nc-Si:H pair of both n- and p-type materials is ~91 µW per material cm3, for a thermal gradient of 8 K. The output voltage and current values show a linear dependence with the number of pairs interconnected in series and/or parallel and show good integration performance.

Maiti, BK, Maia LB, Silveira C, Todorovic S, Carreira C, Carepo M, Grazina R, Moura I, Moura JJG.  2015.  Incorporation of molybdenum in rubredoxin: Models for mononuclear molybdenum enzymes. J Biol Inorg Chem. 20:821-829.
Boavida, N, Böschen S.  2015.  Indicators in Technology Assessment – Passive Choices or Reflected Options? Parliaments and civil society in Technology Assessments. (Tomáš Michalek, and Constanze Scherz, Ed.)., Berlin
Roma-Rodrigues, C, Barroco C, Raposo LR, Costa MN, Fortunato E, Baptista PV, Fernandes AR, Santos-Sanches I.  2015.  Infection of human keratinocytes by Streptococcus dysgalactiae subspecies dysgalactiae isolated from milk of the bovine udder.. Microbes and Infection. 4(18):290-3. AbstractWebsite

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) are considered exclusive animal pathogens; however, a putative zoonotic upper limb cellulitis, a prosthetic joint infection and an infective endocarditis were described in humans. To unravel if bovine SDSD isolates are able to infect human cells, the adherence and internalization to human primary keratinocytes of two bovine SDSD strains isolated from milk collected from udder were analyzed. Bacterial adhesion assays and confocal microscopy indicate a high adherence and internalization of SDSD isolates to human cells, suggesting for the first time the ability of bovine isolates to infect human cells.

Coimbra, J, Mota C, Santos S, Baptista PV, Fernandes AR.  2015.  Inorganic Compounds Going NANO. Annals of Medicinal Chemistry and Research. 2(1)medicinalchemistry-1-1010.pdf
Moniz, AB.  2015.  Intuitive Interaction Between Humans and Robots in Work Functions at Industrial Environments: The Role of Social Robotics. Social Robots from a Human Perspective. (Vincent, Jane, Taipale, Sakari, Sapio, Bartolomeo, Lugano, Giuseppe, Fortunati, Leopoldina, Eds.).:67-76., Heidelberg: Springer
Carvalho, F, Atilano ML, Pombinho R, Covas G, Gallo RL, Filipe SR, Sousa S, Cabanes D.  2015.  L-Rhamnosylation of Listeria monocytogenes wall teichoic acids promotes resistance to antimicrobial peptides by delaying interaction with the membrane. PLoS Pathogens. 11:e1004919.
Albuquerque, I, Almeida T.  2015.  A light in the dark: a conceptual approach to the creative use of light in contemporary art. 14° Encontro Internacional de Arte e Tecnologia. , Aveiro, Portugal: Universidade de Aveiro
Fortes, P, Alvarenga A, Seixas J, Rodrigues S.  2015.  Long term energy scenarios: Bridging the gap between socio-economic storylines and energy Modeling. Technological Forecasting & Social Change. 91:161-178.Website
Nojima, T, Gomes T, Grosso AR, Kimura H, Dye M J, Dhir S, Carmo-fonseca M, Proudfoot N J.  2015.  Mammalian NET-Seq Reveals Genome-wide Nascent Transcription Coupled to RNA Processing. Cell. 161:526–540., Number 3 AbstractWebsite

Transcription is a highly dynamic process. Consequently, we have developed native elongating transcript sequencing technology for mammalian chromatin (mNET-seq), which generates single-nucleotide resolution, nascent transcription profiles. Nascent RNA was detected in the active site of RNA polymerase II (Pol II) along with associated RNA processing intermediates. In particular, we detected 5'splice site cleavage by the spliceosome, showing that cleaved upstream exon transcripts are associated with Pol II CTD phosphorylated on the serine 5 position (S5P), which is accumulated over downstream exons. Also, depletion of termination factors substantially reduces Pol II pausing at gene ends, leading to termination defects. Notably, termination factors play an additional promoter role by restricting non-productive RNA synthesis in a Pol II CTD S2P-specific manner. Our results suggest that CTD phosphorylation patterns established for yeast transcription are significantly different in mammals. Taken together, mNET-seq provides dynamic and detailed snapshots of the complex events underlying transcription in mammals.

Roma-Rodrigues, C, Raposo LR, Fernandes AR.  2015.  microRNAs based therapy of Hypertrophic cardiomyopathy: the road traveled so far. BioMed Research International. :983290. AbstractWebsite

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease characterized by variable expressivity, age penetrance, and a high heterogeneity. The transcriptional profile (miRNAs, mRNAs), epigenetic modifications, and posttranslational modifications seem to be highly relevant for the onset of the disease. miRNAs, small noncoding RNAs with 22 nucleotides, have been implicated in the regulation of cardiomyocyte function, being differentially expressed in several heart diseases, including HCM. Moreover, a different miRNA expression profile in the various stages of HCM development is also observed. This review summarizes the current knowledge of the profile of miRNAs characteristic of asymptomatic to overt HCM patients, discussing alongside their potential use for diagnosis and therapy. Indeed, the stability and specificity of miRNAs make them suitable targets for use as biomarkers for diagnosis and prognosis and as therapeutical targets.

Pina, AS, Dias AMGC, Ustok FI, Khoury GE, Fernandes CSM, Branco RJF, Lowe CR, Roque ACA.  2015.  Mild and cost-effective green fluorescent protein purification employing small synthetic ligands. Journal of Chromatography A. 1418:83-93. AbstractWebsite

Abstract The green fluorescent protein (GFP) is a useful indicator in a broad range of applications including cell biology, gene expression and biosensing. However, its full potential is hampered by the lack of a selective, mild and low-cost purification scheme. In order to address this demand, a novel adsorbent was developed as a generic platform for the purification of \{GFP\} or \{GFP\} fusion proteins, giving \{GFP\} a dual function as reporter and purification tag. After screening a solid-phase combinatorial library of small synthetic ligands based on the Ugi-reaction, the lead ligand (A4C7) selectively recovered \{GFP\} with 94% yield and 94% purity under mild conditions and directly from Escherichia coli extracts. Adsorbents containing the ligand \{A4C7\} maintained the selectivity to recover other proteins fused to GFP. The performance of \{A4C7\} adsorbents was compared with two commercially available methods (immunoprecipitation and hydrophobic interaction chromatography), confirming the new adsorbent as a low-cost viable alternative for \{GFP\} purification.