915 research outputs found
Influence of production batch related parameters on static and fatigue resistance of LPBF produced AlSi7Mg0.6
In laser powder bed fusion (LPBF), the influence material properties are often determined as a function of the inclination with respect to the build direction. In industrial production with variable component shapes and dimensions, the part orientation will often be a matter of the available space in the build volume. Additionally, build-to-build variability is an important factor that may impact the mechanical properties that are often not quantified. Such sources of variability are of great importance for highly demanding sectors such as aviation and aerospace, where lightweight Al-alloys are often used with the geometrical freedom given by the LPBF process. Hence, this work systematically investigates the influence of production batch-related parameters together with part inclination in the LPBF of AlSi7Mg0.6 alloy. Three builds were executed to quantify the impact of the batch, part position, and inclination on the static and fatigue resistance of the alloy in a completely randomized experimental design using an industrial LPBF machine. The results were analysed by the appropriate statistical methods both for discrete and functional data. The results showed that while the part orientation only influenced the static properties, the part position significantly affected the fatigue life demonstrated by the different low cycle fatigue life coefficients
Empirical vulnerability curves for Italian mansory buildings: evolution of vulnerability model from the DPM to curves as a function of accelertion
In the framework of the emergency management in the case of seismic events, the evaluation of the expected damage represents a basic requirement for risk informed planning. Seismic risk is defined by the probability to reach a level of damage on given exposed elements caused by seismic events occurring in a fixed period and in a fixed area. To this purpose, the expected seismic input, the exposed elements and their vulnerability have to be correctly evaluated. The aim of the research is to define a correct model of vulnerability curves, in PGA, for masonry structures in Italy, by heuristic approach starting from damage probability matrices (DPMs). To this purpose, the PLINIVS database, containing data on major Italian seismic events, has been used and supported by “critical” assumption on missing data. To support the reliability of this assumption, two vulnerability models, considering or not the hypothesis on the missing data, have been estimated and used to calculate the seismic scenario of the L’Aquila 2009 earthquake through the IRMA (Italian Risk MAp) platform. Finally, a comparison between the outcomes elaborated by IRMA platform and the observed damage collected in the AEDES forms, has been done. © 2020, The Author(s)
Digital holography as 3D tracking tool for assessing acoustophoretic particle manipulation
The integration of digital holography (DH) imaging and the acoustic manipulation
of micro-particles in a microfluidic environment is investigated. The ability of DH to provide
efficient 3D tracking of particles inside a microfluidic channel is exploited to measure the
position of multiple objects moving under the effect of stationary ultrasound pressure fields.
The axial displacement provides a direct verification of the numerically computed positions
of the standing wave’s node, while the particle’s transversal movement highlights the
presence of nodes in the planar direction. Moreover, DH is used to follow the aggregation
dynamics of trapped spheres in such nodes by using aggregation rate metrics
ASSESSMENT OF PHYSICAL ACTIVITY IN AN OUTPATIENT OBESITY CLINIC IN SOUTHERN ITALY: RESULTS FROM A STANDARDIZED QUESTIONNAIRE.
Potential of native and bioprocessed brewers' spent grains as organic soil amendments
Introduction: The use of novel soil amendments and the exploitation of plant growth-promoting microorganisms are considered promising tools for developing a more sustainable agriculture in times when ensuring high-yield productions with limited resources is essential.
Methods: In this study, the potential of brewers' spent grain (BSG), the major by-product of the brewing industry, as organic soil amendment, was investigated. Bioprocessed BSG, obtained by an enzymatic treatment coupled with fermentation, together with native BSG, were used as amendments in a pot-trial. An integrated analytical approach aimed at assessing the modification of the physicochemical properties of a typical Mediterranean alkaline agricultural soil, and the plant growth-promoting effect on escarole (Cichorium endivia var. Cuartana), was carried out.
Results: The use of biomasses led to soil organic content and total nitrogen content up to 72 and 42% higher, compared to the unamended soils. Moreover, the lower pH and the higher organic acids content doubled phosphorus availability. Although the number of leaves per plant in escaroles from pots amended with native and bioprocessed BSG did not show any difference compared to plants cultivated on unamended pots, the average fresh weight per escarole head, was higher in pots amended with bioprocessed BSG.
Discussion: Hence, the results collected so far encourage BSG application for agricultural purpose, while solving the problem of disposing of such abundant side stream
Safety of lornoxicam in G-6-PDH deficiency
Objective: To assess the safety of lornoxicam in subjects with G-6-PDH deficiency. Methods: Open controlled 2-week in vivo study on lornoxicam 8 mg bid in subjects with G-6-PDH deficiency suffering from rheumatic diseases. Results: In 8 male patients with the Mediterranean form of G-6-PDH deficiency (mean age ± SD, 54.3 years ± 7.2) lornoxicam showed no influence on red blood cells (RBC) survival curve. The RBC half-life was the same before and after two weeks of treatment. Conclusions: Lornoxicam caused no RBC damage and evidenced favourable safety in subjects with G-6-PDH deficiency, suffering from rheumatic diseases
Cancer risk in oil refinery workers : a pooled mortality study in Italy
Background: Oil refinery workers are exposed to several well-established carcinogens and working in this type of industry has been classified by IARC as probable carcinogen to humans (Group 2A). Objectives: To examine the mortality experience of workers employed in four Italian oil refineries. Methods: The cohort included 5112 male workers ever employed between 1949 and 2011. The average follow-up period was 49 years. Standardized mortality ratios (SMR) and 95% Confidence Intervals (CI) were calculated using as reference age-gender-calendar specific regional rates. Analyses by duration of employment and latency were performed. Results: In the whole cohort, pleural cancer (6 deaths, SMR 1.59; 95% CI 0.71-3.53), brain cancer (14 deaths, SMR 1.47; 95% CI 0.87-2.49) and lymphatic leukemia (LL) (8 deaths, SMR 1.81; 95% CI 0.91-3.62) showed increased risks. All pleural cancers occurred after 10 years of latency and the highest risk was observed among workers with duration 6520 years; the brain cancer excess was confined in the shortest duration and latency. The LL (and chronic lymphatic leukemia in particular) excess regarded workers with latency and duration longer than 20 years. Four deaths from acute myeloid leukemia (AML) were observed and all occurred after 20 years of latency (SMR 1.55, 95% CI 0.58-4.12); a two-fold-increased risk was observed in the longest duration. No increased risk for skin cancer has been observed in our study population. Conclusion: Our findings are consistent with recent evidence of an increased mortality from pleural and hematopoietic malignancies (AML and LL) among oil refinery workers. However, the lack of individual quantitative exposure data and the small number of observed events prevent the identification of the possible causal role of individual chemicals, including benzene, especially at the current very low exposure levels
A possible role for nitric oxide in modulating the functional cyclosporine toxicity by arginine
A possible role for nitric oxide in modulating the functional cyclosporine toxicity by arginine. The renal damage consequent to cyclosporine A (CsA) administration ranges from hemodynamic alterations to irreversible chronic lesions. The initial vasoconstriction depends upon the imbalance between the various modulators of the renal vascular tone, among which the most powerful are endothelins and nitric oxide (NO). CsA could play a crucial role by inhibiting the Ca++/calmodulin-mediated activation of the constitutive NO synthase (NOS) isoform, which converts L-arginine (L-Arg) into NO and citrulline, with a 1:1 stoichiometry. To investigate the possibility of modulating CsA nephrotoxicity with L-Arg we studied six groups (G) of Lewis rats treated with daily gavage up to eight weeks: G1, CsA 40 mg/kg; G2, G1 plus L-Arg 300 mg/kg; G3, G2 plus the competitive inhibitor of NOS, NG-nitro-L-Arg (L-NNA); G4, L-Arg alone; G5, L-NNA alone; and G6, controls receiving vehicle alone. After eight weeks L-Arg treated rats were protected against the toxic effects of CsA [creatinine (Cr) values, G2, 0.62 ± 0.05 mg/dl vs. G1, 0.99 ± 0.16 mg/dl, P < 0.001; proteinuria (P), G2, 7.2 ± 1.02 mg/day vs. G1, 15.1 ± 1.9 mg/day, P < 0.01]. The administration of L-NNA abolished the protective effect of L-Arg (G3, Cr 1.23 ± 0.16 mg/dl; P 16.9 = 2.3; P < 0.02 and P < 0.005, respectively vs. G2). The levels of Cr in G2 rats were superimposable to control groups. The NOS activity, evaluated by measuring [3H]citrulline formation from [3H]L-Arg in kidney homogenates, was blocked by L-NNA in G5 (0.019 ± 0.009 pmol/min/mg proteins vs. G6 0.047 ± 0.002, P < 0.01). NOS activity was significantly increased versus controls in G1 (0.110 ± 0.032, P < 0.01) and G2 (0.088 ± 0.009, P < 0.02), while L-NNA reversed this phenomenon (G3, 0.052 ± 0.03). The expression of mRNA encoding for cNOS and iNOS was only slightly increased in CsA-treated rats. We suggest that CsA treatment increases NOS activity in the kidney by a mechanism which does not require a de novo synthesis of the enzyme. Such an increase, that may be devoted to counterbalance the vasoconstrictive effects of the drug, is unable to reduce the toxic effect of CsA in the absence of exogenous L-Arg. Administration of L-Arg is likely to reduce CsA nephrotoxicity by accomplishing the higher request of activated NOS for its substrate, thus potentiating NO synthesis in the kidney.
Factors predicting survival in patients with locally advanced pancreatic cancer undergoing pancreatectomy with arterial resection
Pancreatectomy with arterial resection is a treatment option in selected patients with locally advanced pancreatic cancer. This study aimed to identify factors predicting cancer-specific survival in this patient population. A single-Institution prospective database was used. Pre-operative prognostic factors were identified and used to develop a prognostic score. Matching with pathologic parameters was used for internal validation. In a patient population with a median Ca 19.9 level of 19.8 U/mL(IQR: 7.1–77), cancer-specific survival was predicted by: metabolic deterioration of diabetes (OR = 0.22, p = 0.0012), platelet count (OR = 1.00; p = 0.0013), serum level of Ca 15.3 (OR = 1.01, p = 0.0018) and Ca 125 (OR = 1.02, p = 0.00000137), neutrophils-to-lymphocytes ratio (OR = 1.16; p = 0.00015), lymphocytes-to-monocytes ratio (OR = 0.88; p = 0.00233), platelets-to-lymphocytes ratio (OR = 0.99; p = 0.00118), and FOLFIRINOX neoadjuvant chemotherapy (OR = 0.57; p = 0.00144). A prognostic score was developed and three risk groups were identified. Harrell’s C-Index was 0.74. Median cancer-specific survival was 16.0 months (IQR: 12.3–28.2) for the high-risk group, 24.7 months (IQR: 17.6–33.4) for the intermediate-risk group, and 39.0 months (IQR: 22.7–NA) for the low-risk group (p = 0.0003). Matching the three risk groups against pathology parameters, N2 rate was 61.9, 42.1, and 23.8% (p = 0.04), median value of lymph-node ratio was 0.07 (IQR: 0.05–0.14), 0.04 (IQR:0.02–0.07), and 0.03 (IQR: 0.01–0.04) (p = 0.008), and mean value of logarithm odds of positive nodes was − 1.07 ± 0.5, − 1.3 ± 0.4, and − 1.4 ± 0.4 (p = 0.03), in the high-risk, intermediate-risk, and low-risk groups, respectively. An online calculator is available at www.survivalcalculator-lapdac-arterialresection.org. The prognostic factors identified in this study predict cancer-specific survival in patients with locally advanced pancreatic cancer and low Ca 19.9 levels undergoing pancreatectomy with arterial resection
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