Improving early detection of keratoconus by Non Contact Tonometry. A computational study and new biomarkers proposal.

Keratoconus is a progressive ocular disorder affecting the corneal tissue, leading to irregular astigmatism and decreased visual acuity. The architectural organization of corneal tissue is altered in keratoconus, however, data from ex vivo testing of biomechanical properties of keratoconic corneas are limited and it is unclear how their results relate to true mechanical properties in vivo. This study explores the mechanical properties of keratoconic corneas through numerical simulations of non-contact tonometry (NCT) reproducing the clinical test of the Corvis ST device. Three sensitivity analyses were conducted to assess the impact of corneal material properties, size, and location of the pathological area on NCT results. Additionally, novel asymmetry-based indices were proposed to better characterize corneal deformations and improve the diagnosis of keratoconus. Our results show that the weakening of corneal material properties leads to increased deformation amplitude and altered biomechanical response. Furthermore, asymmetry indices offer valuable information for locating the pathological tissue. These findings suggest that adjusting the Corvis ST operation, such as a camera rotation, could enhance keratoconus detection and provide insights into the relative position of the affected area. Future research could explore the application of these indices in detecting early-stage keratoconus and assessing the fellow eye's risk for developing the pathology.

New Materials and Technologies for Durability and Conservation of Building Heritage.

The increase in concrete structures' durability is a milestone to improve the sustainability of buildings and infrastructures. In order to ensure a prolonged service life, it is necessary to detect the deterioration of materials by means of monitoring systems aimed at evaluating not only the penetration of aggressive substances into concrete but also the corrosion of carbon-steel reinforcement. Therefore, proper data collection makes it possible to plan suitable restoration works which can be carried out with traditional or innovative techniques and materials. This work focuses on building heritage and it highlights the most recent findings for the conservation and restoration of reinforced concrete structures and masonry buildings.

A detailed methodology to model the Non Contact Tonometry: a Fluid Structure Interaction study.

Understanding the corneal mechanical properties has great importance in the study of corneal pathologies and the prediction of refractive surgery outcomes. Non-Contact Tonometry (NCT) is a non-invasive diagnostic tool intended to characterize the corneal tissue response in vivo by applying a defined air-pulse. The biomarkers inferred from this test can only be considered as indicators of the global biomechanical behaviour rather than the intrinsic biomechanical properties of the corneal tissue. A possibility to isolate the mechanical response of the corneal tissue is the use of an inverse finite element method, which is based on accurate and reliable modelling. Since a detailed methodology is still missing in the literature, this paper aims to construct a high-fidelity finite-element model of an idealized 3D eye for in silico NCT. A fluid-structure interaction (FSI) simulation is developed to virtually apply a defined air-pulse to a 3D idealized eye model comprising cornea, limbus, sclera, lens and humors. Then, a sensitivity analysis is performed to examine the influence of the intraocular pressure (IOP) and the structural material parameters on three biomarkers associated with corneal deformation. The analysis reveals the requirements for the in silico study linked to the correct reproduction of three main aspects: the air pressure over the cornea, the biomechanical properties of the tissues, and the IOP. The adoption of an FSI simulation is crucial to capture the correct air pressure profile over the cornea as a consequence of the air-jet. Regarding the parts of the eye, an anisotropic material should be used for the cornea. An important component is the sclera: the stiffer the sclera, the lower the corneal deformation due to the air-puff. Finally, the fluid-like behavior of the humors should be considered in order to account for the correct variation of the IOP during the test which will, otherwise, remain constant. The development of a strong FSI tool amenable to model coupled structures and fluids provides the basis to find the biomechanical properties of the corneal tissue in vivo.

The Improvement of Durability of Reinforced Concretes for Sustainable Structures: A Review on Different Approaches.

The topic of sustainability of reinforced concrete structures is strictly related with their durability in aggressive environments. In particular, at equal environmental impact, the higher the durability of construction materials, the higher the sustainability. The present review deals with the possible strategies aimed at producing sustainable and durable reinforced concrete structures in different environments. It focuses on the design methodologies as well as the use of unconventional corrosion-resistant reinforcements, alternative binders to Portland cement, and innovative or traditional solutions for reinforced concrete protection and prevention against rebars corrosion such as corrosion inhibitors, coatings, self-healing techniques, and waterproofing aggregates. Analysis of the scientific literature highlights that there is no preferential way for the production of "green" concrete but that the sustainability of the building materials can only be achieved by implementing simultaneous multiple strategies aimed at reducing environmental impact and improving both durability and performances.

Nutritional parameters associated with prognosis in non-critically ill hospitalized COVID-19 patients: The NUTRI-COVID19 study.

BACKGROUND & AIMS: To investigate the association between the parameters used in nutritional screening assessment (body mass index [BMI], unintentional weight loss [WL] and reduced food intake) and clinical outcomes in non-critically ill, hospitalized coronavirus disease 2019 (COVID-19) patients. METHODS: This was a prospective multicenter real-life study carried out during the first pandemic wave in 11 Italian Hospitals. In total, 1391 patients were included. The primary end-point was a composite of in-hospital mortality or admission to ICU, whichever came first. The key secondary end-point was in-hospital mortality. RESULTS: Multivariable models were based on 1183 patients with complete data. Reduced self-reported food intake before hospitalization and/or expected by physicians in the next days since admission was found to have a negative prognostic impact for both the primary and secondary end-point (P < .001 for both). No association with BMI and WL was observed. Other predictors of outcomes were age and presence of multiple comorbidities. A significant interaction between obesity and multi-morbidity (≥2) was detected. Obesity was found to be a risk factor for composite end-point (HR = 1.36 [95%CI, 1.03-1.80]; P = .031) and a protective factor against in-hospital mortality (HR = 0.32 [95%CI, 0.20-0.51]; P < .001) in patients with and without multiple comorbidities, respectively. Secondary analysis (patients, N = 829), further adjusted for high C-reactive protein (>21 mg/dL) and LDH (>430 mU/mL) levels yielded consistent findings. CONCLUSIONS: Reduced self-reported food intake before hospitalization and/or expected by physicians in the next days since admission was associated with negative clinical outcomes in non-critically ill, hospitalized COVID-19 patients. This simple and easily obtainable parameter may be useful to identify patients at highest risk of poor prognosis, who may benefit from prompt nutritional support. The presence of comorbidities could be the key factor, which may determine the protective or harmful role of a high body mass index in COVID-19.

Saccharomyces boulardii for the prevention of antibiotic-associated diarrhea in adult hospitalized patients: a single-center, randomized, double-blind, placebo-controlled trial.

OBJECTIVES: Antibiotic-associated diarrhea (AAD) and Clostridium difficile-associated diarrhea (CDAD) are common complications of antibiotic use. Probiotics were effective in preventing AAD and CDAD in several randomized controlled trials. This study was aimed at testing the effect of Saccharomyces boulardii on the occurrence of AAD and CDAD in hospitalized patients. METHODS: A single-center, randomized, double-blind, placebo-controlled, parallel-group trial was performed. Patients being prescribed antibiotics or on antibiotic therapy for <48 h were eligible. Exclusion criteria were ongoing diarrhea, recent assumption of probiotics, lack of informed consent, inability to ingest capsules, and severe pancreatitis. Patients received a capsule containing S. boulardii or an indistinguishable placebo twice daily within 48 h of beginning antibiotic therapy, continued treatment for 7 days after antibiotic withdrawal, and were followed for 12 weeks after ending antibiotic treatment. RESULTS: Of 562 consecutive eligible patients, 275 patients aged 79.2 ± 9.8 years (134 on placebo) were randomized and 204 aged 78.4 ± 10.0 years (98 on placebo) completed the follow-up. AAD developed in 13.3% (13/98) of the patients receiving placebo and in 15.1% (16/106) of those receiving S. boulardii (odds ratio for S. boulardii vs. placebo, 1.16; 95% confidence interval (CI), 0.53-2.56). Five cases of CDAD occurred, 2 in the placebo group (2.0%) and 3 in the probiotic group (2.8%; odds ratio for S. boulardii vs. placebo, 1.40; 95% CI, 0.23-8.55). There was no difference in mortality rates (12.7% vs. 15.6%, P=0.60). CONCLUSIONS: In elderly hospitalized patients, S. boulardii was not effective in preventing the development of AAD.

Fibrosis is associated with adiponectin resistance in chronic hepatitis C virus infection.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is frequently associated with insulin resistance which has been suggested to promote fibrotic progression. Adiponectin, an adipocyte-derived insulin-sensitizing hormone, might play a protective role against hepatic fibrosis. MATERIALS AND METHODS: This observational case-control study investigated the adiponectin status in insulin resistant, nondiabetic, chronic HCV-infected patients (n=54; 13 women, 41 men) compared with age-, sex- and BMI-matched healthy controls. Liver biopsies from patients with chronic HCV hepatitis were analysed for the adiponectin and adiponectin receptors (ADIPOR) 1 and 2 mRNA and protein expressions. RESULTS: Serum adiponectin levels were higher in patients with chronic HCV hepatitis than in healthy controls (12·1±4·7 vs. 9·5±4·4 mg L(-1) in men, P = 0·01; 18·2±4·4 vs. 13·6±5·3mgL(-1) in women, P=0·02). BMI, HDL cholesterol and triglycerides levels correlated with adiponectin levels both in patients and in controls, while no correlation with glucose, insulin and HOMA-IR values could be detected. Nonetheless, insulin resistance was predictive of steatosis and fibrosis in chronic HCV-infected patients. Interestingly, patients with none or mild fibrosis showed serum adiponectin levels similar to those in healthy controls, while hyperadiponectinemia was associated with moderate to severe stages of fibrosis. Hyperadiponectinemia was unlikely sustained by liver production as hepatocytes did not express the protein. ADIPOR1 mRNA, but not ADIPOR2 levels, was reduced in chronic HCV hepatitis. The reduced ADIPOR1 expression was confirmed by immunohistochemistry. CONCLUSIONS: In patients with chronic HCV hepatitis, fibrosis was associated with hyperadiponectinemia. Chronic HCV-infected hepatocytes showed reduced ADIPOR1 expression, suggesting a pattern of adiponectin resistance.

Cardiac, neuroadrenergic, and portal hemodynamic effects of prolonged aldosterone blockade in postviral child A cirrhosis.

OBJECTIVES: The present study was designed to determine the effects of long-term antialdosterone treatment on cardiac structural and functional alterations, portal and systemic hemodynamic as well as adrenergic dysfunction characterizing Child A cirrhotic patients with F1 esophageal varices. METHODS: Twenty-two Child A postviral preascitic cirrhotic patients were randomly allocated to 200 mg/day K-Canrenoate (13 patients, age 59.6 +/- 2.2 yr, mean + SEM) or no-drug treatment (9 patients, age 61.8 +/- 2.3) for a 6-month-period. Measurements, which included hepatic venous pressure gradient (HVPG), left ventricular wall thickness, left ventricular end-diastolic volume and diastolic function (LVWT, LVEDV, and E/A ratio, echocardiography), and muscle sympathetic nerve activity (MSNA, microneurography, peroneal nerve), were obtained at baseline and following 6 months of drug or no-drug treatment. Ten healthy age-matched subjects served as controls. RESULTS: Cirrhotic patients were characterized by increased HVPG, LVWT, and MSNA values and by a depressed E/A ratio. K-Canrenoate treatment significantly reduced HVPG (from 15.3 +/- 1.0 to 13.8 +/- 0.8 mmHg, p < 0.05), LVWT (from 21.8 +/- 0.5 to 20.7 +/- 0.6 mm, p < 0.02), and LVEDV (from 99.2 +/- 7 to 86.4 +/- 6 ml, p < 0.01), leaving E/A ratio and MSNA almost unaltered. No significant change was observed in the untreated group of cirrhotic patients followed for 6 months without intervention. CONCLUSIONS: These data provide evidence that aldosterone blockade by long-term K-Canrenoate administration improves hepatic hemodynamics by lowering HVPG and ameliorates cardiac structure and function by favoring a reduction in LVWT and LVEDV as well. They also show, however, that this therapeutic intervention neither improves left ventricular diastolic dysfunction nor exerts sympathoinhibitory effects.