Nano-Fe3O4-synthetic talc gel was used as filler in the synthesis of waterborne polyurethane/Fe3O4-synthetic talc nanocomposites. This filler presents numerous edges (Si–O and Mg–O) and OH groups easily forming hydrogen bonds and polar interaction with water conferring hydrophilic character, consequently improving filler dispersion within a water-based matrix. Yet, the use of waterborne polyurethane (WPU) as matrix must be highlighted due to its environmentally friendly characteristics and low toxicity compared to solvent-based product. Fe3O4-synthetic talc-nanofillers were well dispersed into the polyurethane matrix even at high filler content as supported by XRD and TEM analyses. NMR indicates the interaction of filler OH groups with the matrix. For all nanocomposites, one can see a typical ferromagnetic behavior below Curie temperature (about 120 K) and a superparamagnetic behavior above this temperature. The use of Fe3O4-synthetic talc for obtaining magnetic nanocomposites resulted in improved materials with superior mechanical properties compared to solvent-based nanocomposites.

The present work aims to assess the efficiency of chars, obtained from the gasification and co-pyrolysis of rice wastes, as adsorbents of Cr3+ from aqueous solution. GC and PC chars, produced in the gasification and co-pyrolysis, respectively, of rice husk and polyethylene were studied. Cr3+ removal assays were optimised for the initial pH value, adsorbent mass, contact time and Cr3+ initial concentration. GC showed a better performance than PC with about 100% Cr3+ removal, due to the pH increase that caused Cr precipitation. Under pH conditions in which the adsorption prevailed (pH<5.5), GC presented the highest uptake capacity (21.1mg Cr3+ g−1 char) for the following initial conditions: 50mg Cr3+ L−1; pH 5; contact time: 24h;L/S ratio: 1000mLg−1. The pseudo-second order kinetic model showed the best adjustment to GC experimental data. Both the first and second order kinetic models fitted well to PC experimental data. The ion exchange was the dominant phenomenon on the Cr3+ adsorption by GC sample. Also, this char significantly reduced the ecotoxicity of Cr3+ solutions for the bacterium Vibrio fischeri. GC char proved to be an efficient material to remove Cr3+ from aqueous solution, without the need for further activation.

In the last two decades, it has been observed an increasing low enrolment of students in chemistry teaching courses in secondary schools. On the one hand, because of the negative connotation of chemistry, associated with the potentially toxic and pollutant chemical industry, and on the other hand, that the teaching of this subject is exclusively carried out only in a theoretical classroom environment with almost non-existent practical/experimental component, despite chemistry is an experimental science in its essence. This state of affairs has been reflected in chemistry degrees offered by Portuguese universities throughout the country, which in the application process for each academic year, ended up by never completely fulfilling the number of offered nunerus clausus. Considering that the pedagogical mission of the Faculty of Science and Technology of Universidade NOVA de Lisboa (FCT-NOVA), in particular its Department of Chemistry (DQ), aims to contribute to the human, scientific and technical development of students, a project has been settled in the last nine years in order to offer to high school students a unique opportunity to arouse in them the interest in Science in general and Chemistry in particular, to stimulate impart on them the joy of curiosity, while at the same time conferring the necessary skills for their future activity as students of higher education or in the labour market. It is also through the close contact with students that method, discipline, and intellectual honesty are transmitted and cultivated. The aim of this Project was thus to promote the study and taste interest for Chemistry, through experimental activities, fitting the Portuguese High School Education curricula, offered to students enrolled in Chemistry subjects attending the 10th, 11th and 12th grades (the latter, compulsory high school degree to apply to University Throughout 2016/17 academic year, DQ-FCT-NOVA will receive, from October to May, 1888 students visits from eleven High Schools distributed among Physical Chemistry for 10th/11th grade and of the 12th grade attending the Chemistry subject. The former are offer one single laboratory activity while the latter participate up to 10 different experimental activities. During 70 practical sessions of 2.5 hours each, with an average attendance of 27 students, the number of higher education school staff involved are 22. Each high school class is accompanied by 1 teacher, who's also proactively contributing to the design of the practical session. The session is carried out in groups of 2/3 students, and the laboratories have a capacity of 24/48 according onto classes sizes. A quality questionnaire is filled by the students in order to monitor the action. In 2015/16, 63 % of the students answered the questionnaire in which more than 90% students were very satisfied with the action. This project has already been implemented for 9 years reflecting a growing collaboration between FCT-NOVA and in High Schools in the vicinity (Setubal District). Above all, this Project allowed most of these schools to continue to motivate students to enrol in 12th grade Chemistry subject. Actually, in the first year of the initiative, many of these schools did not have enough students to open chemistry classes for the 12th grade. After the first initiative, almost all high schools have been able to maintain open 12th grade chemistry classes. On the other hand, FCT-NOVA, namely, the Applied Chemistry course, has been able to fill 100% of the numerus clausus available in the first phase of the application period, which is not the case for other higher education schools courses in Portugal for the same domain - Chemistry.

Arsenic is a widely distributed environmental toxin whose presence in drinking water poses a threat to >140 million people worldwide. The respiratory enzyme arsenite oxidase from various bacteria catalyses the oxidation of arsenite to arsenate and is being developed as a biosensor for arsenite. The arsenite oxidase from Rhizobium sp. str. NT-26 (a member of the Alphaproteobacteria) is a heterotetramer consisting of a large catalytic subunit (AioA), which contains a molybdenum centre and a 3Fe-4S cluster, and a small subunit (AioB) containing a Rieske 2Fe-2S cluster. Stopped-flow spectroscopy and isothermal titration calorimetry (ITC) have been used to better understand electron transfer through the redox-active centres of the enzyme, which is essential for biosensor development. Results show that oxidation of arsenite at the active site is extremely fast with a rate of >4000s−1 and reduction of the electron acceptor is rate-limiting. An AioB-F108A mutation results in increased activity with the artificial electron acceptor DCPIP and decreased activity with cytochrome c, which in the latter as demonstrated by ITC is not due to an effect on the protein-protein interaction but instead to an effect on electron transfer. These results provide further support that the AioB F108 is important in electron transfer between the Rieske subunit and cytochrome c and its absence in the arsenite oxidases from the Betaproteobacteria may explain the inability of these enzymes to use this electron acceptor.

Digestate from a biogas plant that uses solely biomass for biogas production was used as precursor material for the production of activated carbon as an alternative to increase its added value. The digestate was converted into hydrochar by hydrothermal carbonization varying the temperature (190–250°C), residence time (3 and 6h), and pH (5 and 7). Temperature followed by residence time had the strongest influence on the chemical composition and thermal stability of the hydrochars. A significant effect of the pH was not observed. The hydrochars were chemically activated to enhance the surface area and use them as activated carbon. As a consequence, the surface areas increased from 8 to 14m2/g (hydrochars) to 930–1351m2/g (activated carbons). Furthermore, large micropore volumes were measured (0.35–0.50cm3/g). The activated carbons were studied as adsorbents in gas phase applications, showing that the product of digestate is a very effective adsorbent for carbon dioxide (CO2). Especially the activated carbon obtained from the hydrochar produced at 250°C for 6h, which adsorbed 8.80mol CO2/kg at 30°C and 14.8bar. Additionally, the activated carbons showed a stronger affinity towards CO2 compared to methane (CH4), which makes this material suitable for the upgrading of raw biogas to biomethane.

Multifunctionalized gold nanobeacons (Au-nanobeacon) combine, in a single and unique platform, targeting, detection and silencing providing an effective impact in clinics boosting cancer theranostics. Here, we describe a nano-integrated platform based on Au-nanobeacons able to detect and inhibit gene expression specifically in cancer cells. The surfaces of gold nanoparticles (AuNPs) are functionalized with targeting peptides to enhance tumor cell recognition and uptake, and with fluorescently labeled antisense DNA hairpin oligonucleotides to detect AuNPs. These oligonucleotides, upon recognition and hybridization to the target, open their structure resulting in separating apart the dye and the quencher allowing the fluorophore to emit light and to monitor the intracellular interactions of AuNPs with the target and the specific silencing of gene expression. This strategy allows inhibiting KRAS gene expression in colorectal carcinoma cell lines with no relevant toxicity for healthy fibroblasts. Importantly, this nano-integrated platform can be easily adapted to hybridize with any specific target thus providing real benefits for the diagnosis and treatment of cancer.

The use of gold nanoparticles for effective gene silencing has demonstrated its potential as a tool for gene expression experiments and for the treatment of several diseases. Here, we used a gold nanobeacon designed to specifically silence the enhanced green fluorescence protein (EGFP) mRNA in embryos of a fli-EGFP transgenic zebrafish line, while simultaneously allowing the tracking and localization of the silencing events via the beacon’s emission. Fluorescence imaging measurements demonstrated a decrease of the EGFP emission with a concomitant increase in the fluorescence of the Au-nanobeacon. Furthermore, microinjection of the Au-nanobeacon led to a negligible difference in mortality and malformations in comparison to the free oligonucleotide, indicating that this system is a biocompatible platform for the administration of gene silencing moieties. Together, these data illustrate the potential of Au-nanobeacons as tools for in vivo zebrafish gene modulation with low toxicity which may be used towards any gene of interest.

Introduction of tyrosine kinase inhibitors for chronic myeloid leukemia treatment is associated with a 63% probability of maintaining a complete cytogenetic response, meaning that over 30% patients require an alternative methodology to overcome resistance, tolerance, or side effects. Considering the potential of nanotechnology in cancer treatment and the benefits of a combined therapy with imatinib, a nanoconjugate was designed to achieve BCR-ABL1 gene silencing. Gold nanoparticles were functionalized with a single-stranded DNA oligonucleotide that selectively targets the e14a2 BCR-ABL1 transcript expressed by K562 cells. This gold (Au)-nanoconjugate showed great efficacy in gene silencing that induced a significant increase in cell death. Variation of BCL-2 and BAX protein expression, an increase of caspase-3 activity, and apoptotic bodies in cells treated with the nanoconjugate demonstrate its aptitude for inducing apoptosis on K562 BCR-ABL1-expressing cells. Moreover, the combination of the silencing Au-nanoconjugate with imatinib prompted a decrease of imatinib IC50. This Au-nanoconjugate was also capable of inducing the loss of viability of imatinib-resistant K562 cells. This strategy shows that combination of Au-nanoconjugate and imatinib make K562 cells more vulnerable to chemotherapy and that the Au-nanoconjugate alone may overcome imatinib-resistance mechanisms, thus providing an effective treatment for chronic myeloid leukemia patients who exhibit drug tolerance.

Spacer-less RED stacks using membranes with integrated spacer profiles have been investigated during the last years to eliminate the spacer shadow effect. The presence of spacers partially blocks the membrane surface and creates a tortuous and thus longer path for ions in the channel, meaning higher ohmic resistance. Consequently, power outputs are reduced. Profiled membranes may solve this problem as they provide flow channels for the feed streams, while the relief formed on their surfaces keeps the membranes separated. Although the geometry and arrangement of so far used profiles led to lower ohmic resistance, it did not grant an efficient fluid mixing. Recently, so-called chevron profiles, with enhanced mixing, were proposed based on computational fluid dynamics (CFD) simulations. In the present study, the performance of such chevron-profiled membranes, prepared by thermal pressing, was experimentally validated in a reverse electrodialysis (RED) stack. According to the obtained experimental values of non-ohmic resistance and total pressure drop across the RED stack, the chevron-profiled membranes assure efficient fluid mixing at comparatively low hydraulic losses. The net power density obtained with chevron-profiled membranes was the highest obtained for the present stack design. It outperformed the alternative RED stack configurations investigated in this study, such as channels with optimized spacers and channels formed by pillar-profiled membranes. To allow for an even more straightforward and efficient RED stack assembling with chevron-profiled membranes, recommendations for a further simplified design, consisting of diagonal ridges that are assembled perpendicularly, are provided.

Abstract We show that a physical trigger, a non-ionizing infrared (IR) radiation at wavelengths strongly absorbed by liquid water, can be used to induce and kinetically control protein (periodic) self-assembly in solution. This phenomenon is explained by considering the effect of İR\} light on the structuring of protein interfacial water. Our results indicate that the İR\} radiation can promote enhanced mutual correlations of water molecules in the protein hydration shell. We report on the radiation-induced increase in both the strength and cooperativeness of H-bonds. The presence of a structured dipolar hydration layer can lead to attractive interactions between like-charged biomacromolecules in solution (and crystal nucleation events). Furthermore, our study suggests that enveloping the protein within a layer of structured solvent (an effect enhanced by İR\} light) can prevent the protein non-specific aggregation favoring periodic self-assembly. Recognizing the ability to affect protein-water interactions by means of İR\} radiation may have important implications for biological and bio-inspired systems.

Accepted Manuscript online January 16, 2017.Geobacter bacteria usually prevail among other microorganisms in soils and sediments where Fe(III) reduction has a central role. This reduction is achieved by extracellular electron transfer (EET), where the electrons are exported from the interior of the cell to the surrounding environment. Periplasmic cytochromes play an important role in establishing an interface between inner and outer membrane electron transfer components. In addition, periplasmic cytochromes, in particular nanowire cytochromes that contain at least 12 haem groups, have been proposed to play a role in electron storage in conditions of an environmental lack of electron acceptors. Up to date, no redox partners have been identified in Geobacter sulfurreducens, and concomitantly, the EET and electron storage mechanisms remain unclear. In this work, NMR chemical shift perturbation measurements were used to probe for an interaction between the most abundant periplasmic cytochrome PpcA and the dodecahaem cytochrome GSU1996, one of the proposed nanowire cytochromes in G. sulfurreducens. The perturbations on the haem methyl signals of GSU1996 and PpcA showed that the proteins form a transient redox complex in an interface that involves haem groups from two different domains located at the C-terminal of GSU1996. Overall, the present study provides for the first time a clear evidence for an interaction between periplasmic cytochromes that might be relevant for the EET and electron storage pathways in G. sulfurreducens.1D, one-dimensional; CbcL, c- and b-type cytochrome for low potential; EET, extracellular electron transfer; HP, His-patch; ImcH, inner membrane c-type cytochrome; MacA, metal-reduction-associated cytochrome; NaPi, sodium phosphate; NBAF, acetate-fumarate medium; NMR, nuclear magnetic resonance; PpcA, periplasmic c-type cytochrome; SDS–PAGE, sodium dodecyl sulphate–polyacrylamide gel electrophoresis; STC, small tetrahaem cytochrome.

Proteomic and genetic studies have identified a family of five triheme cytochromes (PpcA-E) that are essential in the iron respiratory pathways of Geobacter sulfurreducens. These include the reduction of Fe(iii) soluble chelated forms or Fe(iii) oxides{,} which can be used as terminal acceptors by G. sulfurreducens. The relevance of these cytochromes in the respiratory pathways of soluble or insoluble forms of iron is quite distinct. In fact{,} while PpcD had a higher abundance in the Fe(iii) oxides supplanted G. sulfurreducens cultures{,} PpcA{,} PpcB and PpcE were important in Fe(iii) citrate supplanted cultures. Based on these observations we probed the molecular interactions between these cytochromes and Fe(iii) citrate by NMR spectroscopy. NMR spectra were recorded for natural abundance and 15N-enriched PpcA{,} PpcB or PpcE samples at increasing amounts of Fe(iii) citrate. The addition of this molecule caused pronounced perturbations on the line width of the protein{'}s NMR signals{,} which were used to map the interaction region between each cytochrome and the Fe(iii) citrate molecule. The perturbations on the NMR signals corresponding to the backbone NH and heme methyl substituents showed that complex interfaces consist of a well-defined patch{,} which surrounds the more solvent-exposed heme IV methyl groups in each cytochrome. Overall{,} this study provides for the first time a clear illustration of the formation of an electron transfer complex between Fe(iii) citrate and G. sulfurreducens triheme cytochromes{,} shown to be crucial in this respiratory pathway.

Due to their small size and unique properties, multifunctional nanoparticles arise as versatile delivery systems easily grafted with a vast array of functional moieties, such as anticancer cytotoxic chemotherapeutics and targeting agents. Here, we formulated a multifunctional gold-nanoparticle (AuNP) system composed of a monoclonal antibody against epidermal growth factor receptor (EGFR) (anti-EGFR D-11) for active targeting and a Co(II) coordination compound [CoCl(H2O)(phendione)2][BF4] (phendione =1.10-phenanthroline-5.6-dione) (TS265) with proven antiproliferative activity towards cancer cells (designated as TargetNanoTS265). The efficacy of this nanoformulation, and the non-targeted counterpart (NanoTS265), were evaluated in vitro using cancer cell models and in vivo using mice xenografts. Compared to the free compound, both nanoformulations (TargetNanoTS265 and NanoTS265) efficiently delivered the cytotoxic cargo in a controlled selective manner due to the active targeting, boosting tumor cytotoxicity. Treatment of HCT116-derived xenographs tumors with TargetNanoTS265 led to 93% tumor reduction. This simple conceptual nanoformulation demonstrates the potential of nanovectorization of chemotherapeutics via simple assembly onto AuNPs of BSA/HAS-drug conjugates that may easily be expanded to suit other cargo of novel compounds that require optimized controlled delivery to cancer target.

Recent studies show the incorporation of graphene oxide (GO) in cement composites. But these composites are frequently incompatible with original materials for building rehabilitation. To overcome this limitation, natural hydraulic lime mortars were used as matrix, and the influence of GO percentage and type of mixing was investigated. The influence on the microstructure, mechanical and physical properties was assessed. The best results were obtained with dispersed GO at concentrations of 0.05% and 0.1%. A slight improvement of mechanical and physical characteristics was achieved. This could lead to new mortars with improved properties that can be used for building rehabilitation.

The electronic and optical properties of p-type copper oxides (CO) strongly depend on the production technique as it influences the obtained phases: cuprous oxide (Cu2O) or cupric oxide (CuO), the most common ones. Cu films deposited by thermal evaporation have been annealed in air atmosphere, with temperature between 225 and 375 °C and time between 1 and 4 h. The resultant CO films have been studied to understand the influence of processing parameters in the thermoelectric, electrical, optical, morphological, and structural properties. Films with a Cu2O single phase are formed when annealing at 225 °C, while CuO single phase films can be obtained at 375 °C. In between, both phases are obtained in proportions that depend on the film thickness and annealing time. The positive sign of the Seebeck coefficient (S), measured at room temperature (RT), confirms the p-type behavior of both oxides, showing values up to 1.2 mV·°C–1 and conductivity up to 2.9 (Ω·m)−1. A simple detector using Cu2O have been fabricated and tested with fast finger touch events.

Mesoporous silica, SBA-15, decorated with different amounts of TiO2 (anatase) were prepared by a sol-gel method followed by hydrothermal treatment and calcination, in the presence of a soft template, copolymer Pluronic 123. Tetraethyl orthosilicate (TEOS) was used as the SiO2 precursor and commercially available TiO2 anatase nanoparticles as the supported photocatalyst. The materials were characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS), N2 adsorption-desorption isotherms, raman spectroscopy, ground state diffuse reflectance (GSDR), laser induced luminescence (LIL) and X-ray photoelectron spectroscopy (XPS). The zeta potentials of the pure SBA-15, TiO2/SBA-15 substrate and the commercial anatase sample were monitored through a complete range of pH values. All the nanomaterials developed in this work were studied in terms of their photoactivity in the UV range and in the visible range, separately. In the first case, hydroxyl radicals (OH) were confirmed to be the key active oxidizers in the photodegradation of the pesticide amicarbazone in aqueous medium. On the other hand, in the visible range, and following a dye sensitization process via a fluorescent rhodamine-like dye, two different mechanisms could be identified for the formation of the superoxide radical anion, O2−.

Heterogeneous catalysis is an exciting field in constant development. New and improved catalysts that can both be effective and economical are always on demand. Activated carbons may well play an important role in this field, as they are a cheaper alternative while more environmentally benign. In this paper, a brief overview of the effort developed in the application of activated carbon as heterogeneous catalysts in various reactions is presented. Functionalised activated carbon has been used as catalyst for fine chemical reactions. Gas-phase reactions for NO, N2O and CO2 conversions were thoroughly studied using activated carbon as catalyst support. In situ characterization techniques proved to be valuable tools to understand carbon gasification mechanism.

Rice straw (RS), rice husk (RH) and polyethylene (PE) were blended and submitted to gasification and pyrolysis processes. The chars obtained were submitted to textural, chemical, and ecotoxic characterisations, towards their possible valorisation. Gasification chars were mainly composed of ashes (73.4–89.8wt%), while pyrolysis chars were mainly composed of carbon (53.0–57.6wt%). Silicon (Si) was the major mineral element in all chars followed by alkaline and alkaline-earth metal species (AAEMs). In the pyrolysis chars, titanium (Ti) was also a major element, as the feedstock blends contained high fractions of PE which was the main source of Ti. Gasification chars showed higher surface areas (26.9–62.9m2g−1) and some microporosity, attributed to porous silica. On the contrary, pyrolysis chars did not present a porous matrix, mainly due to their high volatile matter content. The gasification bed char produced with 100% RH, at 850°C, with O2 as gasification agent, was selected for further characterization. This char presented the higher potential to be valorised as adsorbent material (higher surface area, higher content of metal cations with exchangeable capacity, and lowest concentrations of toxic heavy metals). The char was submitted to an aqueous leaching test to assess the mobility of chemical species and the ecotoxic level for V. fischeri. It was observed that metallic elements were significantly retained in the char, which was attributed mainly to its alkaline character. This alkaline condition promoted some ecotoxicity level on the char eluate that was eliminated after the pH correction.

Accepted Manuscript online November 14, 2016.The periplasmic triheme cytochrome PpcA from Geobacter sulfurreducens is highly abundant; it is the likely reservoir of electrons to the outer surface to assist the reduction of extracellular terminal acceptors; these include insoluble metal oxides in natural habitats and electrode surfaces from which electricity can be harvested. A detailed thermodynamic characterization of PpcA showed that it has an important redox-Bohr effect that might implicate the protein in e-/H+ coupling mechanisms to sustain cellular growth. This functional mechanism requires control of both the redox state and the protonation state. In the present study, isotope-labeled PpcA was produced and the three-dimensional structure of PpcA in the oxidized form was determined by NMR. This is the first solution structure of a G. sulfurreducens cytochrome in the oxidized state. The comparison of oxidized and reduced structures revealed that the heme I axial ligand geometry changed and there were other significant changes in the segments near heme I. The pH-linked conformational rearrangements observed in the vicinity of the redox-Bohr center, both in the oxidized and reduced structures, constitute the structural basis for the differences observed in the pKa values of the redox-Bohr center, providing insights into the e-/H+ coupling molecular mechanisms driven by PpcA in G. sulfurreducens.EET, extracellular electron transfer; IM, inner membrane; IPTG, isopropyl β-d-thiogalactoside; MFCs, microbial fuel cells; NOE, Nuclear Overhauser effect; OM, outer membrane; rmsd, root mean square deviation.