Dynamic shear behaviour of truss towers for wind turbines

The global interest in renewable energy sources has increased the attention to the manufacturing of wind turbine towers, since they are largely diffused in seismic areas too. Different types of towers have been produced in recent years. Among them, the truss structures assure a reduced mass and the modular characteristics necessary for easy transportation. Reduced costs of production, installation and maintenance are typical of these structures. Nonlinear dynamics is an efficient framework to analyze structures subjected to variable actions, i.e. to assess the seismic safety of wind turbine towers in case of earthquake actions. This study outlines a procedure to evaluate the post-elastic behavior of truss towers for wind turbines. Rigid-plastic behaviour is taken into account to develop approximate solutions for the problem of a tower modeled as a vertical cantilever beam and subjected to harmonic base motion. A comparison with the results of a finite element model is proposed

Can Twitter be a source of information on allergy? Correlation of pollen counts with tweets reporting symptoms of allergic rhinoconjunctivitis and names of antihistamine drugs

Pollen forecasts are in use everywhere to inform therapeutic decisions for patients with allergic rhinoconjunctivitis (ARC). We exploited data derived from Twitter in order to identify tweets reporting a combination of symptoms consistent with a case definition of ARC and those reporting the name of an antihistamine drug. In order to increase the sensitivity of the system, we applied an algorithm aimed at automatically identifying jargon expressions related to medical terms. We compared weekly Twitter trends with National Allergy Bureau weekly pollen counts derived from US stations, and found a high correlation of the sum of the total pollen counts from each stations with tweets reporting ARC symptoms (Pearson's correlation coefficient: 0.95) and with tweets reporting antihistamine drug names (Pearson's correlation coefficient: 0.93). Longitude and latitude of the pollen stations affected the strength of the correlation. Twitter and other social networks may play a role in allergic disease surveillance and in signaling drug consumptions trends

a continuous model for the railway track analysis in the lateral plane

Abstract This paper deals with a mechanical model for the analysis of the railway track behaviour built by exploiting the periodicity of the track-structure. The starting point of this study is the analysis of the inner forces transferring modes. They have been determined by the unit principal vectors analysis of the base cell transfer matrix. The proposed model is able to reproduce accurately the track behaviour in transferring its inner forces. However, solutions that are equilibrated but not kinematically admissible are obtained from it when transversal loads are applied. In additions, only boundary conditions compatibles with the track transferring modes can be satisfied. This inconsistency is eliminated by superposition of a corrective deformed shape. This is derived from the eigenvectors of the transfer matrix pertaining to self-equilibrated systems of bending moments decaying along the track. The application field of the proposed track model is also discussed and the results of a validation study carried out by F.E. analysis are finally presented

Form factors of descendant operators in the massive Lee-Yang model

The form factors of the descendant operators in the massive Lee-Yang model are determined up to level 7. This is first done by exploiting the conserved quantities of the integrable theory to generate the solutions for the descendants starting from the lowest non-trivial solutions in each operator family. We then show that the operator space generated in this way, which is isomorphic to the conformal one, coincides, level by level, with that implied by the $S$-matrix through the form factor bootstrap. The solutions we determine satisfy asymptotic conditions carrying the information about the level that we conjecture to hold for all the operators of the model.Comment: 23 page

The Role of Natural Killer Cells in the Immune Response in Kidney Transplantation

Natural killer cells (NK) represent a population of lymphocytes involved in innate immune response. In addition to their role in anti-viral and anti-tumor defense, they also regulate several aspects of the allo-immune response in kidney transplant recipients. Growing evidence suggests a key role of NK cells in the pathogenesis of immune-mediated graft damage in kidney transplantation. Specific NK cell subsets are associated with operational tolerance in kidney transplant patients. On the other side, allo-reactive NK cells are associated with chronic antibody-mediated rejection and graft loss. Moreover, NK cells can prime the adaptive immune system and promote the migration of other immune cells, such as dendritic cells, into the graft leading to an increased allo-immune response and, eventually, to chronic graft rejection. Finally, activated NK cells can infiltrate the transplanted kidney and cause a direct graft damage. Interestingly, immunosuppression can influence NK cell numbers and function, thus causing an increased risk of post-transplant neoplasia or infection. In this review, we will describe how these cells can influence the innate and the adaptive immune response in kidney transplantation and how immunosuppression can modulate NK behavior

GLP-1 receptor agonists and renal outcomes in patients with diabetes mellitus type 2 and diabetic kidney disease: State of the art

Background: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are highly effective in improving glycaemic control either as monotherapy or in combination with other hypoglycaemic drugs, and have low incidence of side effects, such as hypoglycaemia, nausea and weight gain, thus increasing patients' adherence to therapy. Methods: In this review we report the most recent studies demonstrating the beneficial effects of GLP-1RAs on renal outcomes, and also discuss the direct and indirect mechanisms through which they confer kidney protection. Finally, we discuss the metabolic and anti-inflammatory effects of GLP-1RAs in diabetic patients with COVID-19 disease. Results: GLP-1RAs have a nephroprotective action, which is expressed through both indirect (improvement of blood pressure and glycaemic control, weight loss) and direct (restoration of normal intrarenal haemodynamics, prevention of ischaemic and oxidative damage) effects. They have shown also metabolic and anti-inflammation beneficial effects in patients with COVID-19 disease. Conclusions: GLP-1RAs prevent albuminuria and slow the decline of renal function towards end stage renal disease in patients with diabetic kidney disease. They might be an opportunity to break the typical inflammation processes of COVID-19 disease

Correlation between choriocapillaris density and retinal sensitivity in age-related macular degeneration

Purpose: The purpose of this study was to investigate the relationship between perfusion of the choriocapillaris (CC) and retinal sensitivity in eyes with intermediate agerelated macular degeneration (iAMD). Methods: This prospective study included patients with iAMD and healthy controls. All enrolled subjects underwent optical coherence tomography angiography (OCT-A) in order to compute the percent perfused choriocapillaris area (PPCA). In patients with iAMD, microperimetry (MP) testing was performed in order to quantify: mean retinal sensitivity (MRS), over an area of 10 degrees; mean macular sensitivity (MMS), over the macular area scanned with OCT-A; and retinal sensitivity (RS) in each macular point. Results: Eighteen eyes of 13 patients were included in the analysis. In addition, 18 eyes of 12 healthy subjects were enrolled as controls. No statistically significant difference (P value > 0.2) was observed in age between patients (73.9 ± 2.0 years) and controls (70.1 ± 2.8 years). We observed significantly lower values of PPCA between patients with iAMD and healthy controls (42.0% ± 3.8% vs. 66.4% ± 3.0%; -Β = 23.8%; P value < 0.001). Among iAMD eyes, higher values of PPCA were significantly associated with higher values of MRS (P value=0.002) and MMS (P value=0.013). Finally, higher values of RS in eachmacular point analyzedwithMPwere significantly (P value<0.001) associated with higher values of PPCA computed in circular regions of interest (ROIs) centered in each analyzed MP point with radii of 0.5 degrees and 1.0 degree. Conclusions: Using OCT-A, we demonstrated a significant association between CC impairment and macular dysfunction, quantified by MP, in iAMD eyes. Translational Relevance: OCT-A could be a useful tool for detecting CC alterations and to monitor disease progression

Oct analysis in patients with relapsing-remitting multiple sclerosis during fingolimod therapy: 2-year longitudinal retrospective study

Many studies have demonstrated the usefulness of some optical coherence tomography (OCT) parameters, like total macular volume (TMV) and retinal nerve fiber layer thickness (RNFL-T), for monitoring patients with multiple sclerosis (MS). However, there are no real-world, long-term studies on patients with relapsing-remitting MS (RR-MS) treated with fingolimod. Therefore, the purpose of this study was to describe retinal changes associated with fingolimod therapy during a two-year follow-up while considering previous episodes of optic neuritis (ON). Patients diagnosed with RR-MS and treated with fingolimod (46 in total) underwent a two-year follow-up. Based on previous ON history, we identified 16 ON+ and 30 ON− patients. The ophthalmological evaluations, including visual field (VF) examination and OCT, were performed at a baseline at 3–6, 12 and 24 months to evaluate the progression rate for each parameter. When analyzing the whole sample, OCT showed no cases of macular edema. Instead, we observed a significant reduction rate in the central retinal thickness (CRT) (p<0.001), TMV (p < 0.001) and RNFL (p < 0.05). Moreover, we observed a significant difference in the progression rate between ON+ and ON− patients, relative to the VF and RNFL (p < 0.05) examinations. OCT highlighted a significant progression rate of retinal damage in MS patients despite fingolimod therapy, especially in MS ON+ patients

Therapy of age-related exudative macular degeneration with anti-vascular endothelial growth factor drugs: An Italian real life study

Aim: To evaluate the real utilization of ranibizumab and aflibercept in the daily management of patients with neovascular age-related macular degeneration (nAMD) treated at the Eye Clinic of Campania University L.Vanvitelli. Background: Therapy with anti-vascular endothelial growth factor represents the gold standard in wet age-related macular degeneration. There are nonreal life italian studies of this therapy in the literature. Objective: To analyze in our sample the post-therapy variations of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) observed at the end of a 12-month follow-up period. Methods: This real-life study analyzes 109 patients that underwent monthly checks for the first 4 months and then every 2 months until the end of the 12-month follow-up. The sample was first analyzed in its entirety, subsequently subdivided into 3 groups based on baseline BCVA, age, and the number of intravitreal injections performed, in order to identify possible predictive elements of the anti-VEGF response. Results: On average, patients underwent 4.16 ± 1.58 intravitreal anti-VEGF injections in 1 year. At the end of the 12-month follow-up, the patients’ average BCVA increased from 33.01 letters to 33.75 letters (+0.74 ± 9,4 letters), while the average CRT decreased from 346.86 µm to 265.39 µm (-81.47 ± 121 µm). Conclusion: The study shows the efficacy of anti-VEGF therapy in the stabilization of BCVA in nAMD, confirming the differences in visual outcomes compared to clinical trials, mainly for economic-organizational reasons