1,721,353 research outputs found
Il ruolo dello scienziato nel mondo di oggi
No full textScientific research underpins socioeconomic progress and will enable mankind to address the major challenges of our time through currently unknown solutions. In particular, curiosity-driven fundamental research is essential to achieve groundbreaking innovation. To reach this goal, scientists must focus on the quality of their work and uphold the core values of research: integrity, ethics, transparency, reproducibility, collaboration across geographic boundaries, and interdisciplinary dialogue. Passion, creativity, humility and perseverance are essential qualities of the scientist, along with the ability to communicate effectively with the public and policymakers, to generate trust for research and support informed decisions at all levels
Nanomachines. Fundamentals and Applications. By Joseph Wang
No full textThe field of nanomachines has come a long way
since its inception. The term “molecular machine”
appeared for the first time in the title of a scientific
paper about two decades ago. The first monograph
in the field was published ten years later, and
substantially revised and expanded in 2008. The
publication of hundreds of papers and of several
book series, themed journal issues, and reviews is
evidence of the impact of this area in the scientific
community. The multitude of research articles that
are still appearing in top journals shows that
nanoscale machines and motors continue to attract
interest. They are important topics in the courses of
nanoscience and nanotechnology that are nowadays
offered by most universities worldwide.
Indeed, the appeal and challenges associated with
these research topics constitute a strong element of
attraction and motivation for students at both
graduate and undergraduate levels
Photochemistry of supramolecular systems and nanostructured assemblies. in memory of Professor Nick Turro (1938-2012)
No full textPhotochemistry is an important branch
of modern science at the crossroads of
chemistry, physics, and biology, with
implications in the fields of engineering
andmedicine. It encompasses phenomena
which are of the utmost relevance both
for living organisms and for technology.
Research on biological systems in the
past four decades has shownmagnificently
that the value of the function that can be
obtained from the interaction between
light and matter is highly dependent on
the degree of organization and complexity
of the matter that has to receive and
process the photons. In the same period
‘the chemistry beyond the molecule’ – that
is, supramolecular chemistry – moved its
first steps and rapidly established itself as
one of the most flourishing areas of
chemical sciences. The idea began to arise
that molecules might be used as building
blocks for the assembly of multicomponent
materials and nanoscale devices exhibiting
novel and valuable functionalities.
In more recent times, the set of components
that may be used to assemble new
systems and materials by a bottom-up
approach has been further extended,
owing to the progress in the synthesis
and characterization of nanoscale crystals
of various sizes and shapes, tubes, wires,
ribbons, capsules, graphene derivatives,
monolayers, and so on
Luminescent sensors based on quantum dot-molecule conjugates
Full text linkSemiconductor quantum dots (QDs) are inorganic nanoparticles that exhibit unique size-dependent
optical and electronic properties; in particular, they are strongly luminescent. Their surface can be
chemically modified, by either covalent or non-covalent approaches, in order to interface them with
molecular units endowed with specific physical and chemical properties. Photoinduced electron- and
energy-transfer processes between quantum dots and attached molecular species offer versatile
strategies to modulate the photophysical properties of these nanoassemblies in response to a chemical
stimulation. Hence, QD–molecule conjugates are appealing platforms for developing luminescent
sensors according to a modular design. In this review we discuss the principles underlying the rational
construction of this kind of multicomponent species, and we illustrate selected examples of luminescent
QD-based sensors taken from the recent literature
A Molecular Cable Car for Transmembrane Ion Transport
Full text linkThe controlled transport of molecular and ionic substrates across bilayer membranes is a fundamental task for the operation of living organisms. It is also a highly fascinating and demanding challenge for artificial molecular machines. The recent report of a synthetic transmembrane molecular shuttle that can transport potassium ions selectively down a gradient in a liposomal system makes a small but significant step towards this goal
Light on Molecular Devices
No full textAlberto Credi is a Professor of Chemistry at the Universit di Bologna (Italy) and an Associate Research Director at the Consiglio Nazionale delle Ricerche. He is a current member of the ChemPhotoChem Editorial Board
Le macchine molecolari
Full text linkLa costruzione di macchine nanometriche è uno straordinario risultato scientifico che può innescare una nuova rivoluzione industriale, capace di cambiare le nostre vite con applicazioni innovative nella tecnologia dei materiali, nell’informatica, nella robotica e nella medicina
Inner filter effects and other traps in quantitative spectrofluorimetric measurements: Origins and methods of correction
No full textSpectrofluorimetry is an analytical technique endowed with excellent versatility and high sensitivity. The low cost, handiness of use, and compact size of modern spectrofluorimeters has fostered their widespread availability in chemical laboratories. However, the utilization of spectrofluorimetry to determine concentrations - an essential task to investigate intermolecular association phenomena - is complicated by the non-linear instrument-dependent relationship between the concentration of the luminescent analyte and the detected emission signal, as well as by the spectrophotometric characteristics of the sample. Here we discuss the instrumental factors affecting the luminescence intensity observed in solution experiments with fixed excitation and emission wavelengths, and we propose a simple data correction method that converts the measured intensity value into a quantity which is linearly proportional to the concentration of the luminophore of interest. Two examples illustrating the method and its application for the study of self-assembly processes, taken from our research, will also be presented
Electroactive [2]catenanes
No full text[2]Catenanes are intriguing species composed of two interlocked macrocycles, whose unique structural
and topological features can translate into new physico-chemical properties, including the ability to
behave as molecular switches and mechanical machines. Electrochemical methods are an excellent choice
for the characterization of catenanes incorporating redox-active units in their molecular components, and
can also be employed to control the state of the system by electrochemically induced switching. Here
we present a few examples of [2]catenanes which contain two identical or different electroactive units
in each molecular ring and are characterized by intercomponent electron donor-acceptor interactions.
These case studies show the potential of electrochemistry for providing fundamental information on
the organization of the redox sites within the catenane structure, their electronic interactions, and the
behaviour of the reduced/oxidized forms, particularly with regard to co-conformational changes induced
by the electron-transfer processes
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