On the auxetic behaviour of metamaterials with re-entrant cell structures

In the present paper a two dimensional plate, made by structural straight elements and showing an auxetic behaviour, is considered. Theoretical, experimental and numerical analyses for the characterisation of its mechanical properties are presented and compared. The main geometrical parameters of an elementary cell affecting the deformation behaviour are highlighted, with emphasis to the negative values of the Poisson’s ratio

Mid-term results of complex distal humeral fractures.

The aim of this study was to assess outcomes following open reduction and internal fixation in complex fractures of the distal humerus. Between 2000 and 2006, 34 patients were operated for complex fractures of the distal humerus. Bone fixation was obtained with a reverse Y-shaped reconstruction plate in 13 cases and with double plating in 21 cases. At final follow-up, all the patients were assessed with the Mayo Elbow Performance Score. Satisfactory results were observed in 71% of the cases despite a high rate of complications. Age over 65 years is correlated with increased risk for an inferior postoperative result. Complex distal humeral fractures are difficult to treat and are associated with a high incidence of complications. It is therefore mandatory to obtain good anatomical reduction and a stable fixation of lateral and medial columns of the distal humerus. The results observed in older patients suggest that an alternative treatment for these patients may be joint replacement

Analysis of changes in crop farming in the Dudh Koshi (Nepal) driven by climate changes

Nepal is one of the poorest nations of the world and the Koshi Basin includes some of the poorest regions of this country. It's farming system is subsistence agriculture, mainly rainfed, with crop productivity among the lowest in South Asia. Nepal is also severely impacted by climate changes, such as retreat of glaciers, rise in temperature, erratic rainfalls and increase in frequency of extreme weather. This paper describes the spatio-temporal evolution of cultivated land in Dudh Koshi during the last four decades (1970s-2010s), by mapping the farming of its four main cereals in the districts of Solukhumbu, Okhaldunga and Kothang from space. The analysis of satellite time series showed a 10% of increment in farmland from 1970s to 1990s, and about 60% in the following twenty years. With a shift of cropping to higher altitudes. Data belonging to of the second twenty years are strongly correlated with the population growth observed in the same period (0.97<0.99) and consistent with the average daily caloric intake. Finding confirms the result of recent studies that agriculture practices once distributed in lowland areas have now spread to higher altitudes and seems to suggest that demographic and socioeconomic pressures are driving the expansion, while climatic and topographic parameters are just channeling the expansion. Apart from any policies that could change the tack, Dudh Koshi should be able to meet the increasing demand of cereals in the near future and climate seems not being a limiting factor for further development as it will be the availability of an irrigation system

The new small tyrosine-kinase inhibitor ARQ531 targets acute myeloid leukemia cells by disrupting multiple tumor-addicted programs

Tyrosine kinases have been implicated in promoting tumorigenesis of several human cancers. Exploiting these vulnerabilities has been shown to be an effective anti-tumor strategy as demonstrated for example by the Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib, for treatment of various blood cancers. Here, we characterize a new multiple kinase inhibitor, ARQ531, and evaluate its mechanism of action in preclinical models of acute myeloid leukemia. Treatment with ARQ531, by producing global signaling pathway deregulation, resulted in impaired cell cycle progression and survival in a large panel of leukemia cell lines and patient-derived tumor cells, regardless of the specific genetic background and/or the presence of bone marrow stromal cells. RNA-seq analysis revealed that ARQ531 constrained tumor cell proliferation and survival through Bruton's tyrosine kinase and transcriptional program dysregulation, with proteasome-mediated MYB degradation and depletion of short-lived proteins that are crucial for tumor growth and survival, including ERK, MYC and MCL1. Finally, ARQ531 treatment was effective in a patient-derived leukemia mouse model with significant impairment of tumor progression and survival, at tolerated doses. These data justify the clinical development of ARQ531 as a promising targeted agent for the treatment of patients with acute myeloid leukemia

Chronic constipation diagnosis and treatment evaluation: The "CHRO.CO.DI.T.E." study

Background: According to Rome criteria, chronic constipation (CC) includes functional constipation (FC) and irritable bowel syndrome with constipation (IBS-C). Some patients do not meet these criteria (No Rome Constipation, NRC). The aim of the study was is to evaluate the various clinical presentation and management of FC, IBS-C and NRC in Italy. Methods: During a 2-month period, 52 Italian gastroenterologists recorded clinical data of FC, IBS-C and NRC patients, using Bristol scale, PAC-SYM and PAC-QoL questionnaires. In addition, gastroenterologists were also asked to record whether the patients were clinically assessed for CC for the first time or were in follow up. Diagnostic tests and prescribed therapies were also recorded. Results: Eight hundred seventy-eight consecutive CC patients (706 F) were enrolled (FC 62.5%, IBS-C 31.3%, NRC 6.2%). PAC-SYM and PAC-QoL scores were higher in IBS-C than in FC and NRC. 49.5% were at their first gastroenterological evaluation for CC. In 48.5% CC duration was longer than 10 years. A specialist consultation was requested in 31.6%, more frequently in IBS-C than in NRC. Digital rectal examination was performed in only 56.4%. Diagnostic tests were prescribed to 80.0%. Faecal calprotectin, thyroid tests, celiac serology, breath tests were more frequently suggested in IBS-C and anorectal manometry in FC. More than 90% had at least one treatment suggested on chronic constipation, most frequently dietary changes, macrogol and fibers. Antispasmodics and psychotherapy were more frequently prescribed in IBS-C, prucalopride and pelvic floor rehabilitation in FC. Conclusions: Patients with IBS-C reported more severe symptoms and worse quality of life than FC and NRC. Digital rectal examination was often not performed but at least one diagnostic test was prescribed to most patients. Colonoscopy and blood tests were the "first line" diagnostic tools. Macrogol was the most prescribed laxative, and prucalopride and pelvic floor rehabilitation represented a "second line" approach. Diagnostic tests and prescribed therapies increased by increasing CC severity

Radiation environment analysis and effects on optical communication payload for GEO satellite

The increasing need of faster data transmission is leading to the spread of optical technologies as the future of space high-speed communication; the potential of this branch of telecommunication is not fully developed, bringing with it both big challenges and great rewards. The purpose of this thesis, developed in the frame of the "Very High Throughput Satellite" project at the Deutsches Zentrum für Luft-und Raumfahrt, is to investigate the Geostationary Earth Orbit (GEO) radiation environment and its effect on optical and electronic COTS devices, as long as consequences on the overall system performance for a free-space optical communication payload. In the first part, an overview of environmental conditions is reported, together with the main models and software exploited in the analysis. Then, a deeper study on system components is carried, with a specific attention on radiation drawbacks on those more susceptible to the harsh context of the mission: here the main focus is given to Total Ionization Dose (TID) effects, having a major relevance and being those for which more data and models are available. In different components the spotlight is not only on possible issues due to the interaction with particles but also on consequences on the overall communication system, with a consequent deterioration of the optical link. As a conclusion, a Python model is developed in order to simulate the cumulative effect of radiation conditions on the payload for a hypothetical 15 years mission; results show various levels of consequences for different devices, with differences also among electrical and optical apparatuses. The system's response itself is investigated by considering the variation of the overall Signal-to-Noise Ratio (SNR). Moreover, tests are performed to gather data for different shielding thicknesses and exposure time for a more complete analysis

Progettazione di un impianto di climatizzazione a servizio di un edificio ospedaliero

Il seguente elaborato tratta di un progetto preliminare e successivamente esecutivo svolto durante il tirocinio all'interno dello studio Zecchini & Associati di Sassuolo (MO). L'obiettivo che mi sono posto con il seguente elaborato di Tesi è l'ideazione e il dimensionamento di un impianto energetico per la ristrutturazione in ambiente ospedaliero con annesso cambio di destinazione d'uso. L'intervento è relativo ad una zona dell'ospedale in questione. Sono messe in luce le criticità rilevate e viene studiato un intervento di ristrutturazione con un nuovo impianto di climatizzazione, comprensivo di trattamento dell'aria e impianto per gas biomedicali. La riconversione prevede un adattamento ad ambulatori di locali inizialmente adibiti ad uffici. Tra questi viene approfondita la realizzazione di un ambulatorio chirurgico, considerato a livello normativo come una sala operatoria, che rispecchia le caratteristiche di camera bianca ISO 7. Le difficoltà dell'intervento consistono nel soddisfare i requisiti molto restrittivi in un locale inizialmente non ideato per uno scopo così specifico come una camera bianca e nel giungere a un valido compromesso soddisfacendo i limiti prefissati, visto e considerato che i locali in questione sono nati con una destinazione d'uso del tutto differente