160 research outputs found

    Control of Mechanical and Fracture Properties in Two-phase Materials Reinforced by Continuous, Irregular Networks

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    Composites with high strength and high fracture resistance are desirable for structural and protective applications. Most composites, however, suffer from poor damage tolerance and are prone to unpredictable fractures. Understanding the behavior of materials with an irregular reinforcement phase offers fundamental guidelines for tailoring their performance. Here, we study the fracture nucleation and propagation in two phase composites, as a function of the topology of their irregular microstructures. We use a stochastic algorithm to design the polymeric reinforcing network, achieving independent control of topology and geometry of the microstructure. By tuning the local connectivity of isodense tiles and their assembly into larger structures, we tailor the mechanical and fracture properties of the architected composites, at the local and global scale. Finally, combining different reinforcing networks into a spatially determined meso-scale assembly, we demonstrate how the spatial propagation of fractures in architected composite materials can be designed and controlled a priori.Comment: 31 Pages, 4 Figures, 12 SI Figure

    Serum Cystatin C for the diagnosis of acute Kidney Injury in Patients Admitted in the Emergency Department

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    BACKGROUND: Early diagnosis of acute kidney injury (AKI) at emergency department (ED) is a challenging issue. Current diagnostic criteria for AKI poorly recognize early renal dysfunction and may cause delayed diagnosis. We evaluated the use of serum cystatin C (CysC) for the early and accurate diagnosis of AKI in patients hospitalized from the ED. METHODS: In a total of 198 patients (105 males and 93 females), serum CysC, serum creatinine (sCr), and estimated glomerular filtration rate (eGFR) were calculated at 0, 6, 12, 24, 48, and 72 hours after presentation to the ED. We compared two groups according to the presence or absence of AKI. RESULTS: Serial assessment of CysC, sCr, and eGFR was not a strong, reliable tool to distinguish AKI from non-AKI. CysC > 1.44 mg/L at admission, both alone (Odds Ratio = 5.04; 95%CI 2.20-11.52; P < 0.0002) and in combination with sCr and eGFR (Odds Ratio = 5.71; 95%CI 1.86-17.55; P < 0.002), was a strong predictor for the risk of AKI. CONCLUSIONS: Serial assessment of CysC is not superior to sCr and eGFR in distinguishing AKI from non-AKI. Admission CysC, both alone and in combination with sCr and eGFR, could be considered a powerful tool for the prediction of AKI in ED patients

    Earthquake characteristics and structural properties of the Southern Tyrrhenian basin from full seismic wave simulations

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    Modelling the response of seismic wavefields to sharp lateral variations in crustal discontinuities is essential for seismic tomography application and path effects correction in earthquake source characterization. This is particularly relevant when wavefields cross back-arc oceanic basins, i.e. mixed continental-oceanic settings. High-frequency (>0.05 Hz) seismic waves resonate and get absorbed across these settings due to a shallow Moho, crustal heterogeneities, and energy leakage. Here, we provide the first high-frequency wave-equation model of full seismograms propagating through realistic 3D back-arc basins. Inversion by parameters trial based on correlation analyses identifies P-, S- and coda-wave as attributes able to estimate jointly 3D Moho variations, sediment thickness, and earthquake source characteristics using data from a single regional earthquake. We use as data waveforms produced by the Accumoli earthquake (Central Italy, 2016), propagating across the Southern Tyrrhenian basin and recorded across Southern Italy. The best model comprises a deep Moho (∼ 18 km) in the middle of the basin and a crustal pinch with the continental crust in Sicily. The deep Moho corresponds to the Issel Bridge, a portion of continental crust trapped between the Vavilov and Marsili volcanic centres. The Accumoli earthquake is optimally described at a depth of 7.3 km using a boxcar with rise time of 6 s. Our results show that the early S-wave coda comprises trapped and reverberating phases sensitive to crustal interfaces. Forward modelling these waves is computationally expensive; however, adding these attributes to tomographic procedures allows modelling both source and structural parameters across oceanic basins

    Endovascular aortic graft infection resulting in retroperitoneal abscess: report of a case

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    Infection is a rare complication of aortoiliac endovascular procedures, with an incidence inferior to 0.5%, and it may result in a retroperitoneal abscess potentially evolving to sepsis and gastrointestinal bleeding. In more than 50% of cases endovascular aortoiliac prosthetic grafts infection occur months or years after the procedure. The growing number of endovascular procedures, and as the actually midterm follow up in most cases, septic sequelae will no doubt continue to occur with increased frequency and may represent an emerging problem in the ED for the emergency physician. Endovascular graft infection begins with unspecific clinical manifestations. An high index of suspicion in any patient with an aortic stent graft presenting prolonged or recurrent fever and or abdominal or back pain and a low threshold for obtaining CT scan should increase the clinician's ability to make a timely diagnosis in the ED setting

    Metallurgical and Technological Investigation on Augustean Auxiliary Coins from Thraco-Moesia

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    The impressive amount of Augustean coins coming from the Thraco-Moesia area (classified in numismatic terms as “Limesfalsa”), raises some juridical and technical questions as to who were the issuing authorities and to the production techniques involved. In the present investigation a representative sampling of such coins, based on metallographic and chemical analysis, was compared on the basis of metallographic and chemical analysis to some regular coins coming from the mint of Rome. The main results can be summarized as follows:L’impressionnante quantité de monnaies augustéennes provenant de la région Thraco-Mésienne (appelées «Limesfalsa» en numismatique pose des questions juridiques et techniques comme : quelles étaient les autorités d’émission et quelles étaient les techniques de production employées

    Relazioni tra obiettivi e quantificazione degli outcome della ricerca europea in agricoltura

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    a stima dell’analisi del contributo della ricerca in agricoltura rappresenta un tema di forte attualità sia per l’accountability della spesa pubblica sia per avere una misurazione dei benefici sulla collettività. Sebbene la letteratura economico-agraria abbia enfatizzato il ruolo della ricerca per migliorare l’efficienza dei sistemi produttivi (migliorando il rapporto input/output), evidenze empiriche e la rilevanza di nuove tematiche collegate alla ricerca agricola (ad esempio bio-econcomia) hanno evidenziato la necessità di analizzare impatti della spesa in ricerca rispetto a dimensioni che vadano oltre la produttività (ad esempio sulla qualità della vita e sul benessere nelle aree rurali, sulla mitigazione degli effetti del cambiamenti climatico, sulla riduzione delle esternalità negative). La letteratura economico-agraria ha dettagliatamente affrontato la stima degli impatti della ricerca, applicando modelli causali tra la spesa e la produttività dei fattori impiegati. In questi lavori gli impatti sono misurati mediante variabili di efficienza delle risorse e di sicurezza alimentare. Alston et al. (2000), attraverso una meta-analisi di 289 studi, identificano tassi di rendimento della spesa in R&D in agricoltura pari all’82% (media) e al 44% (mediana). Recentemente Hurley et al. (2014), mediante una meta-analisi su 372 studi, hanno confermato trend positivi della spesa per ricerca in agricoltura. Smeets Kristkova et al. (2015) concludono identificando una maggiore distanza tra spesa per ricerca ed impatti nell’ambito pubblico, rispetto al privato; vi sono rendimenti maggiori nelle colture annuali e nella zootecnia. Gli stessi autori hanno inoltre evidenziato time lags tra la spesa in ricerca ed impatti maggiori della ricerca pubblica rispetto a quella privata. Mentre la crescita economica o il tasso di rendimento della ricerca (pubblica) sono temi sufficientemente studiati dalla letteratura, gli impatti sulla varie dimensioni della sostenibilità e sul welfare sono meno investigati. Le cause possono essere ricondotte a: a) difficoltà nell’identificare le priorità della ricerca agricola; b) mancanza di modelli logico-interpretativi per identificare la causalità tra spesa ed impatti su più obiettivi, c) la mancanza di indicatori o proxy soprattutto ai temi ambientali e sociali. Nel complesso, se la stima degli impatti della ricerca sulla produttività dei fattori o delle risorse è tuttora un tema complesso e di forte attualità, la stima del contributo della ricerca alla sostenibilità dei sistemi agricoli e sul welfare della collettività rappresenta una sfida metodologica ed empirica. Il modello agricolo europeo ha subito diverse sollecitazioni negli ultimi anni, legate sia alle pressioni esercitate dai cambiamenti della società (mobilità delle persone, salute, invecchiamento ecc.) sia in risposta alle principali sfide globali (sicurezza alimentare, cambiamento climatico, ecc.). I nuovi drivers (tra cui lo sviluppo della bio-economia, l’intensificazione sostenibile, ecc.) hanno motivato la creazione di nuovi filoni di ricerca, enfatizzando il ruolo strategico delle conoscenze e delle nuove tecnologie nella creazione del benessere da parte della collettività (Viaggi, 2015). Il presente lavoro intende analizzare le principali problematiche inerenti alla stima degli impatti della ricerca sulle dimensioni della sostenibilità (economica, ambientale e sociale) e mediante il confronto tra priorità della ricerca europea e analisi dei indicatori/variabili disponibili, nonchè intende identificare le principali carenze metodologiche e di date sulla stima degli impatti della ricerca. Il contributo presenta le prime riflessioni emerse nell’ambito del progetto europeo Impresa (EU-FP7 Measurement of Research Impact in European Agriculture)

    Short-term and long-term effects of tibolone in postmenopausal women

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    Background: Tibolone is a synthetic steroid used for the treatment of menopausal symptoms, on the basis of short-term data suggesting its efficacy. We considered the balance between the benefits and risks of tibolone. Objectives: To evaluate the effectiveness and safety of tibolone for treatment of postmenopausal and perimenopausal women. Search methods: In October 2015, we searched the Gynaecology and Fertility Group (CGF) Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and PsycINFO (from inception), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and clinicaltrials.gov. We checked the reference lists in articles retrieved. Selection criteria: We included randomised controlled trials (RCTs) comparing tibolone versus placebo, oestrogens and/or combined hormone therapy (HT) in postmenopausal and perimenopausal women. Data collection and analysis: We used standard methodological procedures of The Cochrane Collaboration. Primary outcomes were vasomotor symptoms, unscheduled vaginal bleeding and long-term adverse events. We evaluated safety outcomes and bleeding in studies including women either with or without menopausal symptoms. Main results: We included 46 RCTs (19,976 women). Most RCTs evaluated tibolone for treating menopausal vasomotor symptoms. Some had other objectives, such as assessment of bleeding patterns, endometrial safety, bone health, sexuality and safety in women with a history of breast cancer. Two included women with uterine leiomyoma or lupus erythematosus. Tibolone versus placebo Vasomotor symptoms Tibolone was more effective than placebo (standard mean difference (SMD) -0.99, 95% confidence interval (CI) -1.10 to -0.89; seven RCTs; 1657 women; moderate-quality evidence), but removing trials at high risk of attrition bias attenuated this effect (SMD -0.61, 95% CI -0.73 to -0.49; odds ratio (OR) 0.33, 85% CI 0.27 to 0.41). This suggests that if 67% of women taking placebo experience vasomotor symptoms, between 35% and 45% of women taking tibolone will do so. Unscheduled bleeding Tibolone was associated with greater likelihood of bleeding (OR 2.79, 95% CI 2.10 to 3.70; nine RCTs; 7814 women; I2 = 43%; moderate-quality evidence). This suggests that if 18% of women taking placebo experience unscheduled bleeding, between 31% and 44% of women taking tibolone will do so. Long-term adverse events Most of the studies reporting these outcomes provided follow-up of two to three years (range three months to three years). Breast cancer We found no evidence of differences between groups among women with no history of breast cancer (OR 0.52, 95% CI 0.21 to 1.25; four RCTs; 5500 women; I2= 17%; very low-quality evidence). Among women with a history of breast cancer, tibolone was associated with increased risk (OR 1.5, 95% CI 1.21 to 1.85; two RCTs; 3165 women; moderate-quality evidence). Cerebrovascular events We found no conclusive evidence of differences between groups in cerebrovascular events (OR 1.74, 95% CI 0.99 to 3.04; four RCTs; 7930 women; I2 = 0%; very low-quality evidence). We obtained most data from a single RCT (n = 4506) of osteoporotic women aged 60 to 85 years, which was stopped prematurely for increased risk of stroke. Other outcomes Evidence on other outcomes was of low or very low quality, with no clear evidence of any differences between the groups. Effect estimates were as follows: \u2022 Endometrial cancer: OR 2.04, 95% CI 0.79 to 5.24; nine RCTs; 8504 women; I2 = 0%. \u2022 Cardiovascular events: OR 1.38, 95% CI 0.84 to 2.27; four RCTs; 8401 women; I2 = 0%. \u2022 Venous thromboembolic events: OR 0.85, 95% CI 0.37 to 1.97; 9176 women; I2 = 0%. \u2022 Mortality from any cause: OR 1.06, 95% CI 0.79 to 1.41; four RCTs; 8242 women; I2 = 0%. Tibolone versus combined HT Vasomotor symptoms Combined HT was more effective than tibolone (SMD 0.17, 95% CI 0.06 to 0.28; OR 1.36, 95% CI 1.11 to 1.66; nine studies; 1336 women; moderate-quality evidence). This result was robust to a sensitivity analysis that excluded trials with high risk of attrition bias, suggesting a slightly greater disadvantage of tibolone (SMD 0.25, 95% CI 0.09 to 0.41; OR 1.57, 95% CI 1.18 to 2.10). This suggests that if 7% of women taking combined HT experience vasomotor symptoms, between 8% and 14% of women taking tibolone will do so. Unscheduled bleeding Tibolone was associated with a lower rate of bleeding (OR 0.32, 95% CI 0.24 to 0.41; 16 RCTs; 6438 women; I2 = 72%; moderate-quality evidence). This suggests that if 47% of women taking combined HT experience unscheduled bleeding, between 18% and 27% of women taking tibolone will do so. Long-term adverse events Most studies reporting these outcomes provided follow-up of two to three years (range three months to three years). Evidence was of very low quality, with no clear evidence of any differences between the groups. Effect estimates were as follows: \u2022 Endometrial cancer: OR 1.47, 95% CI 0.23 to 9.33; five RCTs; 3689 women; I2 = 0%. \u2022 Breast cancer: OR 1.69, 95% CI 0.78 to 3.67; five RCTs; 4835 women; I2 = 0%. \u2022 Venous thromboembolic events: OR 0.44, 95% CI 0.09 to 2.14; four RCTs; 4529 women; I2 = 0%. \u2022 Cardiovascular events: OR 0.63, 95% CI 0.24 to 1.66; two RCTs; 3794 women; I2 = 0%. \u2022 Cerebrovascular events: OR 0.76, 95% CI 0.16 to 3.66; four RCTs; 4562 women; I2 = 0%. \u2022 Mortality from any cause: only one event reported (two RCTs; 970 women). Authors' conclusions: Moderate-quality evidence suggests that tibolone is more effective than placebo but less effective than HT in reducing menopausal vasomotor symptoms, and that tibolone is associated with a higher rate of unscheduled bleeding than placebo but with a lower rate than HT. Compared with placebo, tibolone increases recurrent breast cancer rates in women with a history of breast cancer, and may increase stroke rates in women over 60 years of age. No evidence indicates that tibolone increases the risk of other long-term adverse events, or that it differs from HT with respect to long-term safety. Much of the evidence was of low or very low quality. Limitations included high risk of bias and imprecision. Most studies were financed by drug manufacturers or failed to disclose their funding source

    The role of life cycle thinking-based methodologies in the development of waste management plans

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    The aim of this article is to examine how Life Cycle Thinking (LCT) contributes to the development of Waste Management Plans (WMPs). The case of Italy has been deeply investigated. The article first analyses whether and how the LCT methodologies were applied to the 21 regional WMPs; then, it draws indications for using LCT in the preparation of a WMP. Moreover, it outlines why the Life Cycle Assessment (LCA) methodology could be used as a powerful tool for regional planning in the waste field, analysing the indications for preparing a WMP that already exist at the European level and in the Italian National WM Programme. Results reveal that only four of the 21 regional WMPs include comprehensive and site-specific LCA studies. Building on these case study results, insights into the opportunities and benefits associated with incorporating LCT methodologies into WMP development and implementation are provided. This study underscores the critical importance of LCT and LCA in promoting sustainable waste management practices, ensuring compliance with European directives, and offering a foundation for more informed regional planning strategies
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