Filiera della canapa industriale (Cannabis sativa L.): sfide e nuove opportunità

La Cannabis Sativa è una pianta utilizzata in maniera sempre maggiore in diverse filiere del mercato: agro- alimentare, tessile, edile, cosmetico e della chimica verde, sostituendo prodotti "classici" con nuovi prodotti più performanti dal punto di vista ambientale e tecnologico. La "canapa industriale" ha un contenuto in tetraidriocannabinolo (THC) inferiore allo 0,2%, che ne permette la coltivazione e la commercializzazione in Europa (Reg. CE n.1673/2000 e Reg. CE n.73/2009). Ampiamente coltivata in Italia e nel mondo fino alla metà del secolo scorso, principalmente per ottenerne prodotti da impiegare nell'industria tessile, motivazioni economiche e politiche (Legge 22/12/1975 n.685) ne hanno segnato il declino. Oggi comunque questa coltura sta conoscendo un nuovo periodo di espansione per le caratteristiche e i molteplici usi che la rendono particolarmente vicina ai principi della green economy. In Europa la superficie coltivata ha raggiunto il valore di circa 25.000 ha nel 2016, in crescita del 37% rispetto al 2014. Il ritorno della canapicoltura sta avvenendo su basi completamente diverse rispetto al passato, quando l'unico prodotto vendibile era la fibra lunga, per la creazione di tessuti e cordami, ottenuta attraverso procedimenti che richiedevano enormi impieghi di manodopera. Oggi, dal punto di vista delle possibilità d'impiego, la canapa presenta caratteristiche di versatilità che rendono questa materia prima utilizzabile in molti settori per le sue proprietà: produzione di carta (la canapa ha una resa in polpa per ettaro 4 volte superiore rispetto al legno, oltre a richiedere 1/7 del quantitativo di solventi chimici), industria chimica, industria alimentare (attraverso l'impiego di olio e farine ricavate dai semi della canapa) e produzione di energia pulita. Inoltre è importante ricordare la capacità fitodepuratrice della canapa (già sfruttata nel nostro Paese per il recupero dell'area industriale di Porto Marghera nel Veneziano). Le radici fittonanti riescono a raggiungere profondità maggiori rispetto ad altre piante a rapido accrescimento, inoltre gli inquinanti vengono accumulati in foglie e semi, permettendo un utilizzo sicuro della fibra. Dunque la canapa, pur essendo una coltura tradizionale, ben si presta a molteplici utilizzazioni innovative, che la identificano come una delle colture erbacee più promettenti nello scenario agricolo internazionale. Il presente lavoro ha l'obiettivo di analizzare il mercato e le potenzialità di crescita della canapa nei differenti settori, tenendo in considerazione anche le iniziative finalizzate a promuovere e sostenere, sul territorio, un modello di sviluppo diffuso fondato sulla valorizzazione delle risorse presenti a livello locale e, quindi, sull'integrazione delle diverse attività economiche potenzialmente interessate all'impiego della canapa

Everolimus and enteric-coated mycophenolate sodium Ab initio after liver transplantation: Midterm results

Background and aim. Everolimus (EVR) use in liver transplantation (OLT) has been prescribed with calcineurin inhibitors (CNIs), steroids, and monoclonal antibodies. The aim of our study was to evaluate the safety, feasibility, and impact on renal function of EVR ab initio, in combination with enteric-coated mycophenolate sodium (EC-MPS) without the use of induction treatment, steroids, or CNIs.Patients and methods. We retrospective analyzed nine consecutive patients who underwent OLT at our institution. The initial dose of EVR (1.5 mg/d) was adjusted to achieve trough levels of 8 to 12 ng/mL. EC-MPS introduced at 1080 mg/d was maintained at the same dose over time.Results. At a mean follow-up of 21.48 (standard deviation [SD] 1.4) months from OLT, 7/9 recipients were alive with stable graft function. The 2-year patient and graft survivals were 77%. One recipient died due to cerebral hemorrhage and one, lung failure. No clinical evidence of an acute rejection episode was observed. Mean estimated glomerular filtration rate value, according to the Modification of Diet in Renal Disease formula increased from 59.5 (SD 9.89) mL/min/1.73 m(2) at OLT to 100.2 (SD 47.5) mL/min/1.73 m(2) (P = .03) after 12 months and 98.71 (SD 33.74) mL/min/1.73 m(2) (P = .03) after 24 months' follow-up.Conclusion. A double immunosuppression therapy with EVR and EC-MPS ab initio seemed to be efficacions and safe, representing a valid alternative to CNIs to prevent renal failure after OLT

Development and tests of a new prototype detector for the XAFS beamline at Elettra Synchrotron in Trieste

The XAFS beamline at Elettra Synchrotron in Trieste combines X-ray absorption spectroscopy and X-ray diffraction to provide chemically specific structural information of materials. It operates in the energy range 2.4-27 keV by using a silicon double reflection Bragg monochromator. The fluorescence measurement is performed in place of the absorption spectroscopy when the sample transparency is too low for transmission measurements or the element to study is too diluted in the sample. We report on the development and on the preliminary tests of a new prototype detector based on Silicon Drift Detectors technology and the SIRIO ultra low noise front-end ASIC. The new system will be able to reduce drastically the time needed to perform fluorescence measurements, while keeping a short dead time and maintaining an adequate energy resolution to perform spectroscopy. The custom-made silicon sensor and the electronics are designed specifically for the beamline requirements.Comment: Proceeding of the 6YRM 12th-14th Oct 2015 - L'Aquila (Italy). Accepted for publication on Journal of Physics: Conference Serie

Blood Transfusions and Adverse Events after Colorectal Surgery: A Propensity-Score-Matched Analysis of a Hen-Egg Issue

Blood transfusions are considered a risk factor for adverse outcomes after colorectal surgery. However, it is still unclear if they are the cause (the hen) or the consequence (the egg) of adverse events. A prospective database of 4529 colorectal resections gathered over a 12-month period in 76 Italian surgical units (the iCral3 study), reporting patient-, disease-, and procedure-related variables, together with 60-day adverse events, was retrospectively analyzed identifying a subgroup of 304 cases (6.7%) that received intra- and/or postoperative blood transfusions (IPBTs). The endpoints considered were overall and major morbidity (OM and MM, respectively), anastomotic leakage (AL), and mortality (M) rates. After the exclusion of 336 patients who underwent neo-adjuvant treatments, 4193 (92.6%) cases were analyzed through a 1:1 propensity score matching model including 22 covariates. Two well-balanced groups of 275 patients each were obtained: group A, presence of IPBT, and group B, absence of IPBT. Group A vs. group B showed a significantly higher risk of overall morbidity (154 (56%) vs. 84 (31%) events; OR 3.07; 95%CI 2.13-4.43; p = 0.001), major morbidity (59 (21%) vs. 13 (4.7%) events; OR 6.06; 95%CI 3.17-11.6; p = 0.001), and anastomotic leakage (31 (11.3%) vs. 8 (2.9%) events; OR 4.72; 95%CI 2.09-10.66; p = 0.0002). No significant difference was recorded between the two groups concerning the risk of mortality. The original subpopulation of 304 patients that received IPBT was further analyzed considering three variables: appropriateness of BT according to liberal transfusion thresholds, BT following any hemorrhagic and/or major adverse event, and major adverse event following BT without any previous hemorrhagic adverse event. Inappropriate BT was administered in more than a quarter of cases, without any significant influence on any endpoint. The majority of BT was administered after a hemorrhagic or a major adverse event, with significantly higher rates of MM and AL. Finally, a major adverse event followed BT in a minority (4.3%) of cases, with significantly higher MM, AL, and M rates. In conclusion, although the majority of IPBT was administered with the consequence of hemorrhage and/or major adverse events (the egg), after adjustment accounting for 22 covariates, IPBT still resulted in a definite source of a higher risk of major morbidity and anastomotic leakage rates after colorectal surgery (the hen), calling urgent attention to the implementation of patient blood management programs

Design and simulation of losses in Ge/SiGe terahertz quantum cascade laser waveguides

The waveguide losses from a range of surface plasmon and double metal waveguides for Ge/Si1-xGex THz quantum cascade laser gain media are investigated at 4.79 THz (62.6 µm wavelength). Double metal waveguides demonstrate lower losses than surface plasmonic guiding with minimum losses for a 10 µm thick active gain region with silver metal of 21 cm-1 at 300 K reducing to 14.5 cm-1 at 10 K. Losses for silicon foundry compatible metals including Al and Cu are also provided for comparison and to provide a guide for gain requirements to enable lasers to be fabricated in commercial silicon foundries. To allow these losses to be calculated for a range of designs, the complex refractive index of a range of nominally undoped Si1-xGex with x = 0.7, 0.8 and 0.9 and doped Ge heterolayers were extracted from Fourier transform infrared spectroscopy measurements between 0.1 and 10 THz and from 300 K down to 10 K. The results demonstrate losses comparable to similar designs of GaAs/AlGaAs quantum cascade laser plasmon waveguides indicating that a gain threshold of 15.1 cm-1 and 23.8 cm-1 are required to produce a 4.79 THz Ge/SiGe THz laser at 10 K and 300 K, respectively, for 2 mm long double metal waveguide quantum cascade lasers with facet coatings. © 2020 OSA - The Optical Society. All rights reserved

IRST SiPM characterizations and application studies

This paper reports on work undertaken, in collaboration with ITC-IRST at Trento, to characterize and test the silicon photomultiplers produced by them, with a view to their future application in high energy and astrophysics experiments. Results of static and dynamic measurents with various IRST devices under controlled climatic conditions, together with measurements with SiPMs from other distributors are reported and discussed with emphasis on progress in the understanding of operational principles and the reduction of noise. Results from the test beam application of the SiPMs are also reported and future plans are discusse

Design and simulation of losses in Ge/SiGe terahertz quantum cascade laser waveguides

The waveguide losses from a range of surface plasmon and double metal waveguides for Ge/Si1−xGex THz quantum cascade laser gain media are investigated at 4.79 THz (62.6 μm wavelength). Double metal waveguides demonstrate lower losses than surface plasmonic guiding with minimum losses for a 10 μm thick active gain region with silver metal of 21 cm−1 at 300 K reducing to 14.5 cm−1 at 10 K. Losses for silicon foundry compatible metals including Al and Cu are also provided for comparison and to provide a guide for gain requirements to enable lasers to be fabricated in commercial silicon foundries. To allow these losses to be calculated for a range of designs, the complex refractive index of a range of nominally undoped Si1−xGex with x = 0.7, 0.8 and 0.9 and doped Ge heterolayers were extracted from Fourier transform infrared spectroscopy measurements between 0.1 and 10 THz and from 300 K down to 10 K. The results demonstrate losses comparable to similar designs of GaAs/AlGaAs quantum cascade laser plasmon waveguides indicating that a gain threshold of 15.1 cm−1 and 23.8 cm−1 are required to produce a 4.79 THz Ge/SiGe THz laser at 10 K and 300 K, respectively, for 2 mm long double metal waveguide quantum cascade lasers with facet coatings

Terahertz absorption-saturation and emission from electron-doped germanium quantum wells

We study radiative relaxation at terahertz frequencies in n-type Ge/SiGe quantum wells, optically pumped with a terahertz free electron laser. Two wells coupled through a tunneling barrier are designed to operate as a three-level laser system with non-equilibrium population generated by optical pumping around the 1→3 intersubband transition at 10 THz. The non-equilibrium subband population dynamics are studied by absorption-saturation measurements and compared to a numerical model. In the emission spectroscopy experiment, we observed a photoluminescence peak at 4 THz, which can be attributed to the 3→2 intersubband transition with possible contribution from the 2→1 intersubband transition. These results represent a step towards silicon-based integrated terahertz emitters

Control of electron-state coupling in asymmetric Ge/Si−Ge quantum wells

Theoretical predictions indicate that the n-type Ge / Si − Ge multi-quantum-well system is the most promising material for the realization of a Si -compatible THz quantum cascade laser operating at room temperature. To advance in this direction, we study, both experimentally and theoretically, asymmetric coupled multi-quantum-well samples based on this material system, that can be considered as the basic building block of a cascade architecture. Extensive structural characterization shows the high material quality of strain-symmetrized structures grown by chemical vapor deposition, down to the ultrathin barrier limit. Moreover, THz absorption spectroscopy measurements supported by theoretical modeling unambiguously demonstrate inter-well coupling and wavefunction tunneling. The agreement between experimental data and simulations allows us to characterize the tunneling barrier parameters and, in turn, achieve highly controlled engineering of the electronic structure in forthcoming unipolar cascade systems based on n-type Ge / Si − Ge multi-quantum-wells

Control of Electron-State Coupling in Asymmetric Ge/Si-Ge Quantum Wells

Theoretical predictions indicate that the n-type Ge/Si-Ge multi-quantum-well system is the most promising material for the realization of a Si-compatible THz quantum cascade laser operating at room temperature. To advance in this direction, we study, both experimentally and theoretically, asymmetric coupled multi-quantum-well samples based on this material system, that can be considered as the basic building block of a cascade architecture. Extensive structural characterization shows the high material quality of strain-symmetrized structures grown by chemical vapor deposition, down to the ultrathin barrier limit. Moreover, THz absorption spectroscopy measurements supported by theoretical modeling unambiguously demonstrate inter-well coupling and wavefunction tunneling. The agreement between experimental data and simulations allows us to characterize the tunneling barrier parameters and, in turn, achieve highly controlled engineering of the electronic structure in forthcoming unipolar cascade systems based on n-type Ge/Si-Ge multi-quantum-wells