121 research outputs found

    On the thermal and thermodynamic (In)stability of methylammonium lead halide perovskites

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    The interest of the scientific community on methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) for hybrid organic-inorganic solar cells has grown exponentially since the first report in 2009. This fact is clearly justified by the very high efficiencies attainable (reaching 20% in lab scale devices) at a fraction of the cost of conventional photovoltaics. However, many problems must be solved before a market introduction of these devices can be envisaged. Perhaps the most important to be addressed is the lack of information regarding the thermal and thermodynamic stability of the materials towards decomposition, which are intrinsic properties of them and which can seriously limit or even exclude their use in real devices. In this work we present and discuss the results we obtained using non-ambient X-ray diffraction, Knudsen effusion-mass spectrometry (KEMS) and Knudsen effusion mass loss (KEML) techniques on MAPbCl3, MAPbBr3 and MAPbI3. The measurements demonstrate that all the materials decompose to the corresponding solid lead (II) halide and gaseous methylamine and hydrogen halide, and the decomposition is well detectable even at moderate temperatures (~60 °C). Our results suggest that these materials may be problematic for long term operation of solar devices

    Lignin-based nano-enabled agriculture: A mini-review

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    Nowadays sustainable nanotechnological strategies to improve the efficiency of conventional agricultural practices are of utmost importance. As a matter of fact, the increasing use of productive factors in response to the growing food demand plays an important role in determining the environmental impact of agriculture. In this respect, low-efficiency conventional practices are becoming obsolete. On the other hand, the exploitation of nanoscaled systems for the controlled delivery of fertilizers, pesticides and herbicides shows great potential towards the development of sustainable, efficient and resilient agricultural processes, while promoting food security. In this context, lignin - especially in the form of its nanostructures - can play an important role as sustainable biomaterial for nano-enabled agricultural applications. In this review, we present and discuss the current advancements in the preparation of lignin nanoparticles for the controlled release of pesticides, herbicides, and fertilizers, as well as the latest findings in terms of plant response to their application. Special attention has been paid to the state-of-the-art literature concerning the release performance of these lignin-based nanomaterials, whose efficiency is compared with the conventional approaches. Finally, the major challenges and the future scenarios of lignin-based nano-enabled agriculture are considered

    Dynamics of a vortex lattice in a non-equilibrium polariton superfluid

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    If a quantum fluid is put in motion with enough angular momentum, at equilibrium the ground state of the system is given by an array of quantised vortices. In a driven-dissipative polariton fluid, we demonstrate that the reverse process is also possible. Upon initially imprinting a static and regular vortex array, the quantum fluid starts rotating. By tracking on picosecond time scales many quantized vortices, we present the first measure of rigid-body rotation in a polariton condensate. Such many-body motion agrees with the Feynman quantization of superfluid velocity, which we show to be valid even if our system is expanding and equilibrium is never attained

    Clinical and organizational evidence of the efficacy and effectiveness from cardiac rehabilitation: an update

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    The increasing evidence on the favourable cost/effectiveness impact of the comprehensive cardiac rehabilitation program for the treatment of a wide spectrum of cardiovascular conditions have imposed to healthcare services a major attention on a critical analysis of the results in different clinical indications and delivery organisations. The Regional Health Agency of Liguria, in the occasion of drawing up regional guidelines directed to define the clinical indications and the effectiveness of the cardiac rehabilitation delivery model (in-patients, out-patients and home-based) and its requisites, indications and procedures, has updated the reference guidelines (PLNG and SIGN) with the evidence provided by the more recent literature, focusing its attention on the clinical and, in particular, organizational effectiveness. The document, on the base of these evidences, provides some effective proposals and some organizational advices

    Characteristics of people living in Italy after a cancer diagnosis in 2010 and projections to 2020

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    BACKGROUND: Estimates of cancer prevalence are widely based on limited duration, often including patients living after a cancer diagnosis made in the previous 5 years and less frequently on complete prevalence (i.e., including all patients regardless of the time elapsed since diagnosis). This study aims to provide estimates of complete cancer prevalence in Italy by sex, age, and time since diagnosis for all cancers combined, and for selected cancer types. Projections were made up to 2020, overall and by time since diagnosis. METHODS: Data were from 27 Italian population-based cancer registries, covering 32% of the Italian population, able to provide at least 7 years of registration as of December 2009 and follow-up of vital status as of December 2013. The data were used to compute the limited-duration prevalence, in order to estimate the complete prevalence by means of the COMPREV software. RESULTS: In 2010, 2,637,975 persons were estimated to live in Italy after a cancer diagnosis, 1.2 million men and 1.4 million women, or 4.6% of the Italian population. A quarter of male prevalent cases had prostate cancer (n\u2009=\u2009305,044), while 42% of prevalent women had breast cancer (n\u2009=\u2009604,841). More than 1.5 million people (2.7% of Italians) were alive since 5 or more years after diagnosis and 20% since 6515 years. It is projected that, in 2020 in Italy, there will be 3.6 million prevalent cancer cases (+\u200937% vs 2010). The largest 10-year increases are foreseen for prostate (+\u200985%) and for thyroid cancers (+\u200979%), and for long-term survivors diagnosed since 20 or more years (+\u200945%). Among the population aged 6575 years, 22% will have had a previous cancer diagnosis. CONCLUSIONS: The number of persons living after a cancer diagnosis is estimated to rise of approximately 3% per year in Italy. The availability of detailed estimates and projections of the complete prevalence are intended to help the implementation of guidelines aimed to enhance the long-term follow-up of cancer survivors and to contribute their rehabilitation need

    Genetic analysis of the skeletal remains attributed to Francesco Petrarca

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    Abstract We report on the mitochondrial DNA (mtDNA) analysis of the supposed remains of Francesco Petrarca exhumed in November 2003, from the S. Maria Assunta church, in Arquà Padua (Italy) where he died in 1374. The optimal preservation of the remains allowed the retrieval of sufficient mtDNA for genetic analysis. DNA was extracted from a rib and a tooth and mtDNA sequences were determined in multiple clones using the strictest criteria currently available for validation of ancient DNA sequences, including independent replication. MtDNA sequences from the tooth and rib were not identical, suggesting that they belonged to different individuals. Indeed, molecular gender determination showed that the postcranial remains belonged to a male while the skull belonged to a female. Historical records indicated that the remains were violated in 1630, possibly by thieves. These results are consistent with morphological investigations and confirm the importance of integrating molecular and morphological approaches in investigating historical remains.
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