155 research outputs found
Optimal seismic upgrading of a reinforced concrete school building with metal-based devices using an efficient multi-criteria decision-making method
In the paper, the seismic retrofitting of an existing reinforced concrete school building located in the district of Naples has been examined. The school, which was designed to sustain gravity load only, is composed of seven constructions separated with seismic joints. One of these constructions has been retrofitted with different intervention techniques, namely reinforced concrete walls, steel concentric, eccentric and buckling restrained braces and steel shear panels, whose non-linear behaviour under seismic actions in terms of performance point detection have been evaluated and compared using Capacity Spectrum Method. Finally, the choice of the best intervention technique from economic, structural and environmental point of view has been done utilising an efficient multi-criteria decision-making (MCDM) method, the so-called TOPSIS method. From the performed analyses it was found that buckling restrained
braces provide optimal solution for the seismic upgrading of the examined reinforced concrete school building
Innovative and Traditional Techniques for Seismic Retrofitting of an Existing RC School Building: Life Cycle Assessment and Performance Ranking through MCDM Methods
Effects of physical exercise on adiponectin, leptin, and inflammatory markers in childhood obesity: systematic review and meta-analysis
Background: New findings on adipose tissue physiology and obesity-Associated inflammation status suggest that modification of the adipokine level can be relevant for the long-Term prevention of obesity-Associated chronic disease. Objectives: The scope of the present study was to investigate the effectiveness of physical exercise in reducing the systemic inflammation related to obesity in children. Methods: We conducted a systematic review with meta-Analysis of controlled randomized trials, identified through electronic database search, which investigated the effect of physical exercise, without concomitant dietary intervention, on adiponectin, leptin, and/or other inflammatory markers in children up to age 18 years with a body mass index greater than the 95th percentile for age and sex. Results: Seven trials were included in the meta-Analysis, with a total of 250 participants. Compared with the control group without any lifestyle modification, the physical exercise resulted in a reduction in leptin [standardized mean difference (SMD)-1.13; 95% confidence interval (95%CI):-1.89 to-0.37; I2 = 79.9%] and interleukin-6 (SMD-0.84; 95%CI:-1.45 to-0.23, I2 = 0.9%) and an increase in adiponectin plasma concentration (SMD 0.69; 95%CI: 0.02-1.35; I2 = 74.3%). Conclusions: These results indicate that physical exercise improved the inflammatory state in children with obesity. It is unclear whether this effect can reduce the risk of cardiovascular and metabolic disease in adulthood. Clinical trials with a uniform intervention protocol and outcome measurements are required to put our knowledge on adipose tissue biology into a clinical perspective
Role of polymer network and gelation kinetics on the mechanical properties and adsorption capacity of chitosan hydrogels for dye removal
Chitosan (CS) hydrogels are receiving growing attention as adsorbents for water purification purposes. The conditions of preparation of this class of materials play a crucial in the determination of their performances; however, this aspect is often neglected in the literature. In this study, we deal with this issue, focusing on the structure-property relationships of CS hydrogels obtained by phase inversion method. We show that the concentration of the starting solution determines the density and strength of intermolecular interactions, and that the gelation kinetics dictates the hydrogel structure at the microscale. Consequently, even subtle changes in the preparation protocol can cause significant differences in the performances of CS hydrogels in terms of mechanical properties and dye adsorption capacity. The observed trends are often neither trivial nor monotonic. Nonetheless, we demonstrate that they can be interpreted looking at the CS network structure, which can be inferred by rheological measurements
Global permittivity mapping of the Martian surface from SHARAD
SHARAD is a subsurface sounding radar aboard NASA's Mars Reconnaissance Orbiter, capable of detecting dielectric discontinuities in the subsurface caused by compositional and/or structural changes. Echoes coming from the surface contain information on geometric properties at metre scale and on the permittivity of the upper layers of the Martian crust. A model has been developed to estimate the effect of surface roughness on echo power, depending on statistical parameters such as RMS height and topothesy. Such model is based on the assumption that topography can be characterized as a self-affine fractal, and its use allows the estimation of the dielectric properties of the first few metres of the Martian soil. A permittivity map of the surface of Mars is obtained, covering several large regions across the planet surface. The most significant correspondence with geology is observed at the dichotomy boundary, with high dielectric constant on the highlands side (7 to over 10) and lower on the lowlands side (3 to 7). Other geological correlations are discussed
A robust numerical model for characterizing the syngas composition in a downdraft gasification process
CRMS/CFSPID subjects carrying D1152H CFTR variant: can the second variant be a predictor of disease development?
Background: There are no predictive factors of evolution of cystic fibrosis (CF) screen positive inconclusive diagnosis subjects (CFSPIDs). Aim: to define the role of the second CFTR variant as a predictive factor of disease evolution in CFSPIDs carrying the D1152H variant. Methods: We retrospectively evaluated clinical characteristics and outcome of CFSPIDs carrying the D1152H variant followed at five Italian CF centers. CFSPIDs were divided in two groups: Group A: compound heterozygous for D1152H and a CF-causing variant; Group B: compound heterozygous for D1152H and a: (i) non CF-causing variant, (ii) variant with varying clinical consequences, or (iii) variant with unknown significance. The variants were classified according to CFTR2 mutation database. Results:We enrolled 43 CFSPIDs with at least one D1152H variant: 28 (65.1%) were classified in the group A, and 15 (34.9%) in the Group B. CFSPIDs of group A had the first IRT significantly higher compared to those of group B (p < 0.05) and had a more severe clinical outcome during the follow-up. At the end of the study period, after a mean follow-up of 40.6 months (range 6–91.6), 4 (9.3%) out of 43 CFSPIDs progressed to CFTR-RD or CF. All these subjects were in the group A. Conclusions: The genetic profile could help predict the risk of disease evolution in CFSPIDs carrying D1152H, revealing the subjects that need a more frequent follow-up
Effects of atorvastatin treatment on sICAM-1 and plasma nitric oxide levels in hypercholesterolemic subjects.
This study investigated the behavior of soluble intercellular adhesion molecule-1 (sICAM-1) and serum nitric oxide (NO) products, nitrite/nitrate (NO 2-NO,-), in subjects with primary hypercholesterolemia (HCh) without other risk factors and atherosclerosis. The effect of a short-term cholesterol-lowering treatment with atorvastatin, an HMG-CoA reductase inhibitor, on the levels of sICAM-1 and NO2-/NO3 were also investigated. After 4 weeks of placebo administration, 40 HCh (15 males and 25 females) were randomized in 2 groups: 20 subjects (atorvastatin group) received 10 mg/day of atorvastatin and the remaining 20 (placebo group) continued to take placebo. At baseline and after 4 and 12 weeks of atorvastatin or placebo administration, serum sICAM-1 and NO2-/NO3-levels were evaluated. The basal levels of these parameters were compared with those of 20 healthy subjects (C), matched for sex and age. Hypercholesterolemic subjects showed sICAM-1 and NO2-/NO3-basal values that were higher (331.7 ± 60.3 ng/mL vs. 202.3 ± 32.3 ng/mL, p<0.001) and lower (10.4 ± 2.5 μmol/L vs. 20.7 ± 4.4 μmol/L, p<0.01) than controls. No correlation between sICAM-1 or NO products and plasma cholesterol values was found, whereas there was an inverse correlation between sICAM-1 and NO2-/NO3-levels. Atorvastatin administration significantly decreased sICAM-1 and increased NO2-/NO3-levels, however these changes were not correlated with the reduction of plasma cholesterol. These data support the hypothesize that patients with HCh with no signs of arterial lesions, may have latent atherosclerosis, expressed as an increase of sICAM-1 and decrease in NO product levels. An improvement in the levels of these parameters after a short-time treatment with atorvastatin was also demonstrated
Compact and tunable stretch bioreactor advancing tissue engineering implementation. Application to engineered cardiac constructs
Physical stimuli are crucial for the structural and functional maturation of tissues both in vivo and in vitro . In tissue engineering applications, bioreactors have become fundamental and effective tools for provid- ing biomimetic culture conditions that recapitulate the native physical stimuli. In addition, bioreactors play a key role in assuring strict control, automation, and standardization in the production process of cell-based products for future clinical application. In this study, a compact, easy-to-use, tunable stretch bioreactor is proposed. Based on customizable and low-cost technological solutions, the bioreactor was designed for providing tunable mechanical stretch for biomimetic dynamic culture of different engineered tissues. In-house validation tests demonstrated the accuracy and repeatability of the imposed mechanical stimulation. Proof of concepts biological tests performed on engineered cardiac constructs, based on de- cellularized human skin scaffolds seeded with human cardiac progenitor cells, confirmed the bioreactor Good Laboratory Practice compliance and ease of use, and the effectiveness of the delivered cyclic stretch stimulation on the cardiac construct maturation
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