The mechanical behaviour of old masonry needs to be properly evaluated to quantify the safety and serviceability of real structures, in view of their rehabilitation and/or seismic reliability ...assessment. Among the factors affecting such behaviour, the presence of moisture, mainly from rising damp, plays a key role in the deterioration of old masonry structures, due to salt crystallisation, frost damage, etc. Water presence in the material pores may also directly influence their mechanical properties (compressive and tensile strength, elastic modulus), due to the interactions with the pore surface, enhancement of crack propagation velocity and other mechanisms. Although the effect of water saturation has been investigated for clay-bearing rocks, ceramics and concrete, its consequences on the mechanical behaviour of brick masonry still requires in-depth study. The compressive strength and Young's modulus of fired-clay bricks, cement-based and lime-based mortars as well as masonry triplets were therefore investigated, in dry and wet conditions. The results are interpreted in the light of the microstructural features of the materials, i.e., total void amount and pore size distribution.
•The influence of gaps between lamellas on the behavior of timber panels is investigated.•A thick-plate homogenization modeling is applied and compared to experimental data.•Existing simplified ...methods deviate from the in-plane and transverse shear behavior.•The thick-plate homogenization can predict well the elastic mechanical behavior.•The modified mechanical response by the presence of gaps has been quantified.
In the present paper, the influence of periodic gaps between lamellas of Cross Laminated Timber (CLT) on the panel’s elastic behavior is analyzed by means of a periodic homogenization scheme for thick plates having periodic geometry. Both small gaps, due to the fabrication process of not-gluing lateral lamellas, and wider gaps are investigated. The results obtained with the periodic homogenization scheme are compared to existing closed-form solutions and available experimental data. It appears that the plate bending stiffness can be well predicted with both homogenization and simplified methods, while only the homogenization approach is in agreement with the experimental in-plane and out-of-plane shear behavior. The influence of several properties of CLT lay-up on the mechanical response is pointed out as well.
Abstract
Introduction
Regular exercise reduces morbidity and mortality from cardiovascular diseases through cardiac and systemic adaptations including the increased coronary blood flow, an improved ...endothelial function, a slower progression of atherosclerotic processes as well as the stabilization of pre-existing lesions. However, long-term exercise is frequently associated with adverse cardiovascular events in 35-year older subjects because of a cardiac remodeling that predisposes to malignant arrhythmias and to an earlier atherosclerosis. Moreover, in athletes, ischemia is often silent with a higher risk of sudden cardiac death.
Purpose
The aim of our observational study was to evaluate the efficacy of preparticipation screening in identifying the presence of coronary artery disease (CAD) in a population of asymptomatic master athletes.
Methods
Between 2018 and 2019, 420 35-year older athletes (mean age: 55 + 17) underwent a preparticipation screening at the University of Pisa. None of them reported cardiovascular risk factors or previous cardiovascular diseases. After a physical examination, all subjects were submitted to spirometry and ECG stress test.
Results
The ECG stress test demonstrated signs of myocardial ischemia (ST depression > 1 mm) in 41 subjects; 3 athletes showed a frequency-dependent left bundle-branch block; 24 subjects had exercise-induced premature ventricular complexes during the ECG stress test. These subjects underwent further evaluations (Tc-99 myocardial perfusion SPECT and coronary angio-CT) to detect the presence of perfusion defects or coronary abnormalities: 26 athletes had an important coronary atherosclerosis with significant stenosis in one or more vessels and later subjected to Percutaneous transluminal coronary angioplasty (PTCA) or to coronary artery bypass grafting (CABG). 5 athletes presented a coronary myocardial bridge and 1 subject was demonstrated to have an anomalous origin of the left coronary.
Conclusions
Preparticipation screening in 35-year-older athletes was able to detect the presence of obstructive coronary artery disease (CAD) in the 38% of suspected cases and anomalous origin or intramural coronary course in 8,8% of cases that showed electric abnormalities during the stress test. Despite recent conflicting opinions about the scientific value of the preparticipation screening in young athletes, the present study demonstrated that it was fundamental to early detect silent conditions that could predispose master athletes to adverse cardiovascular events.
Abstract
Background
Different non-pharmacological strategies have been studied in patients with stable coronary artery disease (CAD). However, the potential benefits of laughter therapy cardiac ...rehabilitation (LTRehab) for patients with stable CAD have not been fully investigated, especially through randomized clinical trials (RCT).
Purpose
This study aimed to evaluate the impact of LTRehab on functional capacity, endothelial function, and inflammatory biomarkers in CAD patients.
Methods
This is a randomized, parallel-design, examiner-blinded, controlled clinical trial conducted from August 2016 to December 2020. Peak oxygen uptake (VO2peak) and flow-mediated dilation (FMD) were measured using maximal cardiopulmonary exercise testing (CPET) and ultrasound, respectively. Inflammatory biomarkers, including interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-alpha, vascular cell adhesion molecule (VCAM), and intercellular adhesion molecule (ICAM), were measured. Thirteen patients were assigned to the LTRehab group, who watched two self-selected comedy sessions per week, and thirteen patients to the control group (CG), who watched two neutral documentaries (24 movies per group). Generalized Estimated Equations were used to identify the main factors of Group, Time, and the interaction between Group*Time. The Bonferroni correction was applied to identify differences. P < 0.05 was considered statistically significant. This study was approved by the Institutional Review Board (protocol No. 13-0124). Furthermore, it was conducted in accordance with Resolution no.466/12 of the National Health Council.
Results
A total of 26 CAD patients (69% male; mean age of 63.58 ± 9.97 years) were included in the study. There was a significant interaction between Group*Time (P<0.01) for VO2peak (LTRehab group: 19.09±0.85 to 21.06±1.00 vs. CG: 23.21±1.74 to 22.24±1.96 mL.kg-1.min-1). There was a mean difference of 1.98±0.45 between times for the LTRehab group with significant Bonferroni correction (P<0.01), but not for the control group (-0.96±0.75, P=0.20). Nitroglycerin-mediated vasodilation (endothelium-independent function) and VCAM showed significant differences in the Time factor (P = 0.02 and P = 0.05, respectively). All CPET tests reached maximal criteria (R>1.10).
Conclusion
This is the first RCT to evaluate the impact of LTRehab on CAD patients, showing an increase in VO2peak and improvements in endothelium-independent function and inflammatory biomarkers. LTRehab may constitute an effective form of cardiac rehabilitation in this patient population.
Swine are attracting increasing attention as a biomedical model, due to many immunological similarities with humans. However, porcine macrophage polarization has not been extensively analyzed. ...Therefore, we investigated porcine monocyte-derived macrophages (moMΦ) triggered by either IFN-γ + LPS (classical activation) or by diverse "M2-related" polarizing factors: IL-4, IL-10, TGF-β, and dexamethasone. IFN-γ and LPS polarized moMΦ toward a proinflammatory phenotype, although a significant IL-1Ra response was observed. Exposure to IL-4, IL-10, TGF-β, and dexamethasone gave rise to four distinct phenotypes, all antithetic to IFN-γ and LPS. Some peculiarities were observed: IL-4 and IL-10 both enhanced expression of IL-18, and none of the "M2-related" stimuli induced IL-10 expression. Exposures to TGF-β and dexamethasone were characterized by enhanced levels of TGF-β2, whereas stimulation with dexamethasone, but not TGF-β2, triggered CD163 upregulation and induction of CCL23. Macrophages stimulated with IL-10, TGF-β, or dexamethasone presented decreased abilities to release proinflammatory cytokines in response to TLR2 or TLR3 ligands: IL-10 showed a powerful inhibitory activity for CXCL8 and TNF release, whereas TGF-β provided a strong inhibitory signal for IL-6 production. While our results emphasized porcine macrophage plasticity broadly comparable to human and murine macrophages, they also highlighted some peculiarities in this species.
•Experimental study on conditioned masonry triplets.•Investigation on the shear behaviour of masonry triplets.•Mechanical and material microstructural parameters are investigated.•Damp/salts presence ...affects the structural behaviour of masonry.
In this paper an experimental study conducted on fired-clay brick masonry triplets built with cement- and hydraulic lime-based mortars and subjected to artificial weathering cycles is presented. A cycle is constituted by (1) a wetting phase by capillary rise of either a saline solution or deionized water and (2) a drying phase in oven. The aim of the accelerate weathering cycles is to simulate on-site conditions of masonry structures subjected to rising damp and salts attack due to daily and seasonal microclimatic changes. For comparison purposes, triplets subjected to drying cycles only were also considered. At the end of the weathering process, the triplets were shear tested in order to quantitative assess the separate and combined effect of water and salts within the pores on the mechanical behaviour. Shear parameters were interpreted on the basis of the microstructural characteristics of the constituent materials. Particular attention was given to the pore size distribution, salt amount, and distribution within the specimens after the conditioning procedure, finding significant correlations. Results show that the triplets shear behaviour is influenced by the damp/salts presence to a different extent depending on the materials involved.
Wall shear stress (WSS) is an important stimulus in vascular remodelling and vascular lesion development. The current methods to assess and predict the risk associated with specific unsteady WSS ...consider the WSS mean values or the presence of reverse phases described by the oscillatory shear index. Recent evidence has shown that the accuracy of these methods is limited, especially with respect to the venous environment. Unsteady WSS are characterised by several features that may individually affect endothelial cells. Consequently, we assessed the effects of averaged WSS (TAWSS), temporal WSS gradient (TWSSG), maximum WSS (WSS peak) and reverse phase (OSI) by applying different WSS profiles to venous EC
in-vitro
, using a real-time controlled cone-and-plate cell-shearing device for 24 h. We found that TWSSG and WSS peak affect cell elongation and alignment respectively. We also found that the WSS waveforms with a peak of 1.5 Pa or higher significantly correlate with the induction of a protective phenotype. Cell phenotype induced by these high peak waveforms does not correlate to what is predicted by the hemodynamic indices currently used. The definition of reliable hemodynamic indices can be used to inform the computational models aimed at estimating the hemodynamic effects on vascular remodelling.
Radical science provides new insights and elaborates new concepts that depart significantly from past paradigms. Radical innovation creates entirely new markets or product classes, or leads to major ...product replacements within existing markets. After providing a brief summary of the scholarly debate concerning the identification and measure of radical science and innovation, we review three new contributions to the topic and suggest areas of future research.
Nordic walking's (NW) degree of effectiveness regarding health-related parameters in people with Parkinson's Disease (PD) is a subject of debate. While NW seems to improve functionality, a clear ...non-motor benefit has not been demonstrated. The aim of this randomized controlled trial was to compare the effects of 9-week NW and free walking (FW) training programs on quality of life, cognitive function, and depressive symptoms in individuals with PD. Thirty-three people with PD, (Hoehn and Yahr 1-4) were randomized into two groups: NW (
= 16) and FW (
= 17). We analyzed quality of life, cognitive function, depressive symptoms, and motor symptoms. Significant improvements were found in the overall, physical, psychological, social participation, and intimacy domains of quality of life, as well as in cognitive function and depressive symptoms for both groups. Only the NW group showed improvement in the autonomy domain. Individuals with PD had a similar enhancement of non-motor symptoms after walking training, with or without poles. However, the NW group showed a more significant improvement in the autonomy domain, strengthening the applied and clinical potential of NW in people with PD. Future studies are needed to determine the efficacy of walking training without poles in subjects with PD.
Extracellular vesicles (EVs) are nanometric-membrane-bound sub-cellular structures, which can be recovered from milk. Milk EVs have drawn increasing interest due to their potential biomedical ...applications, therefore it is important to investigate their impact on key immune cells, such as macrophages.
In this work, the immunomodulatory effects of goat milk EVs on untreated (moMФ) and classically activated (moM1) porcine monocyte-derived macrophages were investigated using flow cytometry, ELISA, and gene expression assays.
These particles were efficiently internalized by macrophages and high doses (60 mg protein weight) triggered the upregulation of MHC I and MHC II DR on moMФ, but not on moM1. In moMФ, exposure to low doses (0.6 mg) of mEVs enhanced the gene expression of IL10, EBI3, and IFNB, whereas high doses up-regulated several pro-inflammatory cytokines. These nanosized structures slightly modulated cytokine gene expression on moM1. Accordingly, the cytokine (protein) contents in culture supernatants of moMФ were mildly affected by exposure to low doses of mEVs, whereas high doses promoted the increased release of TNF, IL-8, IL-1a, IL-1b, IL-1Ra, IL-6, IL-10, and IL-12. The cytokines content in moM1 supernatants was not critically affected.
Overall, our data support a clinical application of these molecules: they polarized macrophages toward an M1-like phenotype, but this activation seemed to be controlled, to prevent potentially pathological over-reaction to stressors.
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