1,721,068 research outputs found
The European Young Chemists Award 2016
No full textThe future is in good hands! The European Young Chemist Award for 2016 was awarded at the 6th EuCheMS Chemistry Congress in Seville. Reflections on the participants and their chemistry from the Convener of the event, Professor Bruno Pignataro, are given in the Guest Editorial
New Strategies in Chemical Synthesis and Catalysis
No full textProviding a comprehensive overview of the essential topics, this book covers the core areas of organic, inorganic, organometallic, biochemical synthesis and catalysis. The authors are among the rising stars in European chemistry, a selection of participants in the 2010 European Young Chemists Award competition, and their contributions deal with most of the frontier issues in chemical synthesis. They give an account of the latest research results in chemistry in Europe, as well as the state of the art in their field of research and the outlook for the future. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA
Printing Biology for Advanced Synthetic Biosystem
No full textPrinting technologies represent a powerful tool for the direct micro- and nano- fabrication of biomolecular structures at the interface between life and materials sciences (Arrabito et al., 2012). Their continuous development over the last years has permitted the onset of man-made biosystems with customizable dimensions (from the micron-scale down to the nanometer scale), composition (organic molecules, DNA, proteins, phospholipids), and relevant functions (molecular interactions, drug screening, cellular biointerfaces, cell-like compartments). In this work, we show the possibility to leverage the fabrication of a wide class of solid-supported or liquid-liquid based synthetic compartments by printing tools at different scales. Scanning probe lithography methodologies will be shown for sub- cellular scale manipulation of living cells or for studies of molecular interactions onto porous surfaces. In particular, DNA-based protein immobilization coupled with dip-pen or polymer pens lithography permits the scalable fabrication of single-cell biochips (Arrabito et al., 2013; Arrabito et al., 2014). Inkjet printing will be shown for the fabrication of size scalable aqueous or oil-based synthetic compartments leading to molecular interaction studies at solid-liquid or liquid-liquid interfaces. The effect of droplet downsizing down to the femtoliter scale will be shown to affect the molecular interactions within aqueous compartments, mimicking the behaviour observed in cellular organells, in terms of molecular confinement and molecular crowding effects (Arrabito et al., 2019). In the case of oil-based compartments, fragmentation phenomena at surfactant-laden water-based interfaces bring to the formation of femtoliter- scale oil compartments detected by a microfluidic platform (Arrabito et al., 2019)
Printing Biology: engineering analytical platforms by molecular inks
No full textThe assembly of life-like artificial biosystems allows understanding the molecular origins of life,
whilst guiding the nature-inspired development of analytical platforms for biotechnologies (e.g.
molecular sensing, lab-on-chip, Point-of-care) [1]. These systems mimic and even improve the
functional features of biological systems, reproducing their collective behaviors, fine organization,
adaptivity to environmental stimuli [2]. This work shows the possibility to readily produce these
systems by an integrative approach we herein define as Printing Biology [3], a new research field
which stems from the emerging world of additive manufacturing and the bottom up Synthetic
Biology fabrication. This work shows the adaptability of Printing Biology to fabricate artificial
biosystems at different scales (from nanometers up to millimeters) and variable chemical
composition (DNA, proteins, phospholipids), showing functionalities allowing the determination of
molecular interactions and features in conditions mimicking living systems. This work shows two
different analytical platforms by inkjet printing (IJP) and microcantilever spotting (ȝCS). The
molecular inks are dispensed in the form of aqueous or non-aqueous compartments, whose volume
typically spans from femtoliter (10-15 L) up to picoliter (10-12 L) scales. The coefficient of variation
of the dispensed droplets is typically below the 3%, allowing for excellent reproducibility in the
deposition process. The dispensed droplet spacing can be tuned in order to obtain a final sessile
droplet with a volume at higher scales (up to nanoliter or event microliter scale). The formulation of
molecular inks will be in particular analyzed, taking into consideration all the most relevant
parameters (e.g. viscosity, ionic force, surface tension, solute-solvent interactions) which guide the
deposition process and the activity retaining of the dispensed biomolecules [4]. The analytical
determination of the dispensed molecules will be carried out by employing optical detection, in
particular fluorescence intensity and fluorescence lifetime. Three different ink printable
formulations will be employed, including DNA, proteins and phospholipids. The dispensed systems
will be determined by analyzing their molecular content (down to few zeptomoles) and molecular
conformation within the dispensed droplet. Three representative examples will be shown. The first
is the formulation of DNA oligonucleotides fL-scale ink imbibition by ȝCS into nylon to realize a
flexible sensor for DNA detection [5]. The second is the realization of stable pL- or fL-scale
aqueous compartments stabilized in mineral oil to study molecular interactions in restricted
volumes, permitting to highlight the effect of molecular crowding in compartments mimicking subcellular scale systems [6]. Finally, the fabrication of phospholipids by ȝCS onto glass surface are reported, allowing for membrane-protein interaction studies at solid-liquid interfaces
Semitransparent Design of Planar n-i-p Perovskite Solar Cells using a Cost-Effective, Perovskite-Compatible DMD Structure as the Top Electrode
No full textIn recent years, a significant emphasis has been placed on developing multi-functional solar cells that integrate new features such as color and transparency, thereby opening up the possibility of unconventional photovoltaic (PV) applications, including building-integrated PV (BIPV) systems, tandem solar cells, and wearable electronics. In particular, the integration of semitransparent (ST) solar cells into buildings as power-generating windows, facades or other aesthetic architectural elements constitutes one of the most intriguing perspectives [1]. Since silicon-based panels are generally opaque and unaesthetic, there has been a growing research interest in emerging thin-film solar cells that can be made truly semitransparent, display different colors, and be easily adapted to any type and surface of buildings. Among third-generation PVs, perovskite solar cells (PSCs) are particularly attractive for these applications owing to their superior performances. Over the past few years, tremendous efforts have been applied to develop esthetic semitransparent perovskite solar cells (ST-PSCs) by exploring various kinds of transparent electrodes, controlling the morphology, and engineering the bandgap of the perovskite absorber [2].
Here, a novel multilayer dielectric/metal/dielectric (DMD) transparent electrode based on non-precious copper (Cu) and molybdenum suboxide (MoOx) is manufactured via thermal evaporation and successfully incorporated as top anode in semitransparent planar n-i-p PSCs. Continuous and percolative Cu films as thin as 9.5 nm are grown onto the oxide surface by means of a pre-deposited ultra-thin Au seed layer, which also acts as an effective Cu diffusion barrier. The final MoOx/Au-seed/Cu/MoOx DMD structure shows a very good trade-off between optical transparency and electrical conductivity as well as a great thermal and mechanical stability. Whilst silver and gold are typically used in such DMD structures [3], their replacement with copper allows for a substantial cost reduction without sacrificing the device performance and stability. Through this strategy, PCEs as high as 12.5%, along with acceptable transparency levels, are successfully achieved. It is also demonstrated that the performance of the fabricated devices can be further improved by introducing specific interfacial layers as well as by incorporating appropriate solvent additives into the perovskite precursor solution.
References
[1] C. J. Traverse, R. Pandey, M. C. Barr, R. R. Lunt, Nat. Energy 2017, 2, 849.
[2] Q. Xue, R. Xia, C. J. Brabec, H.-L. Yip, Energy Environ. Sci. 2018, 11 (7), 1688.
[3] E. Della Gaspera, Y. Peng, Q. Hou, L. Spiccia, U. Bach, J. J. Jasieniak, Y.-B. Cheng, Nano Energy 2015, 13, 249.
[4] G. Giuliano, S. Cataldo, M. Scopelliti, F. Principato, D. Chillura Martino, T. Fiore, B. Pignataro, Adv. Mater. Technol. 2019, 4 (5), 1800688
Oxidation effects in antiaggregogenic properties of Epigallocatechingallate
Full text linkEpigallocatechin-gallate (EGCG), the most abundant flavonoid in green tea, has been extensively studied for its potential in the treatment of amyloid related disorders. This molecule was found to modulate abnormal protein self-assembly, reducing resulting cellular toxicity. EGCG is known to suppress or to slow down the aggregation processes of several proteins, thus supporting the idea that general mechanisms regulate its anti-aggregogenic effects and, interestingly, in the oxidised form it demonstrated an higher efficiency in reducing protein aggregation with respect to intact molecule.
We here investigate the effects of intact and oxidized EGCG the thermal aggregation pathway of Bovine Serum Albumin (BSA), a well-known model protein whose aggregation processes are known in details.
By means of different spectroscopic methods, we evaluate similarities and differences of the two molecules during protein aggregation. Different solution conditions are investigated, close and away from the isoelectric point of the protein, with the aim of eliciting the role of electrostatics in the observed EGCG-Protein interaction and in the supramolecular assembly which are dramatically dependent on solution conditions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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