The basis for ductility evaluation in SFRC structures in MC2020: An investigation on slabs and shallow beams

The paper presents a synthesis of an extensive experimental campaign on linear and two-dimensional steel fiber reinforced concrete (SFRC) structural elements carried out to check the ductility requirements aimed at guaranteeing limit analysis approaches for the computation of ultimate load-bearing capacity of SFRC structures; special attention is devoted to the role of the degree of redundancy of the structure. In particular, full-scale shallow beams and slabs reinforced with steel fibers (with or without conventional longitudinal reinforcement) were tested in two different laboratories: the Politecnico di Milano (PoliMI) and the University of Brescia (UniBS). In this experimental campaign, two different fiber contents and fiber types were considered. The experimental investigation, carried out within the activities to support Annex L of Eurocode 2, was fundamental also for developing the design rules included in the fib Model Code 2020 and allowed to formulate conclusions regarding optimization of the mix design, ductility, and design prediction at the ultimate capacity

MUSCULAR SYNERGISM DURING CORE STABILITY EXERCISES

The aim of this study was to compare the myoelectric activity and synergism of Core region muscles among exercises commonly prescribed for Core training. The myoelectric activity of seven men was collected and the activation ratio among lumbar erector spinae (LES), lumbar multifidus (MT), external oblique (EO) and rectus abdominis (RA) were compared among eight exercises. The results suggest that EO has higher activation during frontal bridge, side bridge and “bird dog” exercises, RA has higher activation during frontal and side bridge, while LES and MT demonstrated higher activation during “bird dog” and double leg and single leg back bridge. We concluded that to train all muscles groups in a synergic way, in different postures, it should be prescribed at least one variation of the exercises that presents the flexor, lateral flexor and extensor pattern

DIFFERENCES IN THE FREQUENCY OF MYOELECTRIC ACTIVATION OF LOWER LIMBS BETWEEN SINGLE AND DOUBLE LEG LANDINGS IN MALES

The frequency of myoelectric activation seems to be related to the recruitment of different motor units (Wakeling, 2009). Fast muscle fibers are responsible to the production of higher forces related to the slow fibers (Wakeling, 2009). Therefore, the pattern of activation of some muscles could be associated to the risk of injuries (Bealieau et al., 2008). However, it is not well described whether the muscular activation, in the time-frequency domain, used by males in tasks with different mechanical stresses would truly be related to the strategies of protection of the ACL. The aim of this research was to compare the instantaneous median frequency (IMF) of the EMG signal of lower limbs muscles between different landing tasks in males

Determinants of frontline tyrosine kinase inhibitor choice for patients with chronic-phase chronic myeloid leukemia: A study from the Registro Italiano LMC and Campus CML

BackgroundImatinib, dasatinib, and nilotinib are tyrosine kinase inhibitors (TKIs) approved in Italy for frontline treatment of chronic-phase chronic myeloid leukemia (CP-CML). The choice of TKI is based on a combined evaluation of the patient's and the disease characteristics. The aim of this study was to analyze the use of frontline TKI therapy in an unselected cohort of Italian patients with CP-CML to correlate the choice with the patient's features. MethodsA total of 1967 patients with CP-CML diagnosed between 2012 and 2019 at 36 centers throughout Italy were retrospectively evaluated; 1089 patients (55.4%) received imatinib and 878 patients (44.6%) received a second-generation (2G) TKI. ResultsSecond-generation TKIs were chosen for most patients aged <45 years (69.2%), whereas imatinib was used in 76.7% of patients aged >65 years (p < .001). There was a predominant use of imatinib in intermediate/high European long-term survival risk patients (60.0%/66.0% vs. 49.7% in low-risk patients) and a limited use of 2G-TKIs in patients with comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease, previous neoplasms, ischemic heart disease, or stroke and in those with >3 concomitant drugs. We observed a greater use of imatinib (61.1%) in patients diagnosed in 2018-2019 compared to 2012-2017 (53.2%; p = .002). In multivariable analysis, factors correlated with imatinib use were age > 65 years, spleen size, the presence of comorbidities, and & GE;3 concomitant medications. ConclusionsThis observational study of almost 2000 cases of CML shows that imatinib is the frontline drug of choice in 55% of Italian patients with CP-CML, with 2G-TKIs prevalently used in younger patients and in those with no concomitant clinical conditions. Introduction of the generic formulation in 2018 seems to have fostered imatinib use

Physicians’ Perceptions of Clinical Utility of a Digital Health Tool for Electronic Patient-Reported Outcome Monitoring in Real-Life Hematology Practice. Evidence From the GIMEMA-ALLIANCE Platform

Digital health tools are increasingly being used in cancer care and may include electronic patient-reported outcome (ePRO) monitoring systems. We examined physicians’ perceptions of usability and clinical utility of a digital health tool (GIMEMA-ALLIANCE platform) for ePRO monitoring in the real-life practice of patients with hematologic malignancies. This tool allows for the collection and assessment of ePROs with real-time graphical presentation of results to medical staff. Based on a predefined algorithm, automated alerts are sent to medical staff. Participating hematologists completed an online survey on their experience with the platform. Of the 201 patients invited to participate between December 2020 and June 2021 (cut-off date for current analysis), 180 (90%) agreed to enter the platform and had a median age of 57 years. Twenty-three hematologists with a median age of 42 years and an average of 17 years of experience in clinical practice were surveyed. All hematologists agreed or strongly agreed that the platform was easy to use, and 87%, agreed or strongly agreed that ePROs data were useful to enhance communication with their patients. The majority of physicians (78%) accessed the platform at least once per month to consult the symptom and health status profile of their patients. The frequency of access was independent of physician sex (p=0.393) and years of experience in clinical practice (p=0.404). In conclusion, our preliminary results support the clinical utility, from the perspective of the treating hematologist, of integrating ePROs into the routine cancer care of patients with hematologic malignancies

Integrated multislice CT and Tc-99m Sestamibi SPECT-CT evaluation of solitary pulmonary nodules

Abstract Purpose. The purpose of this study was to evaluate efficacy of multislice computed tomography (MSCT) and single photon emission computed tomography (SPECT)-CT with Tc-99m Sestamibi in the assessment of solitary pulmonary nodules of uncertain significance. Scintigraphy was performed using a ‘hybrid’ g-camera that allows simultaneous acquisition of SPECT and CT images, with interesting results in diagnostic oncology. Materials and methods. Between September 2003 and August 2004, 23 patients with a solitary pulmonary nodule detected on CT underwent SPECT-CT using Tc-99m Sestamibi as a radiotracer. Nodules with positive scintigraphy were immediately subjected to biopsy or surgical resection. Nodules with negative scintigraphy were followed up after 3–4 months by MSCT with automatic segmentation software (Advanced Lung Analysis, ALA) and histological characterisation. Results. Of the 23 nodules (size range 0.8–2 cm) discovered with MSCT, 11 showed intense uptake of Tc-99m Sestamibi. Ten lesions were true positive: seven adenocarcinomas, one squamous cell carcinoma, one large cell carcinoma and one metastasis. The only false positive was histologically classified as a large cell granuloma. Twelve lesions had negative scintigraphy: five fibrous lesions, three hamartomas, three granulomas and one adenocarcinoma (false negative). Benign nodules without tracer uptake underwent another CT scan 3–4 months later, which confirmed stability of the nodule size. Correlation of Sestamibi SPECT with histology showed sensitivity (Se) of 90.9 %, specificity (Sp) of 91.6 %, diagnostic accuracy of 91.3 %, positive predictive value (PPV) of 90.9% and negative predictive value (NPV) of 91.6 %. Conclusions. The integrated use of MSCT and Tc-99m Sestamibi SPECT-CT could be very useful in the management of solitary pulmonary nodules (SPNs). In particular, in our preliminary study, scintigraphy provided significant diagnostic information to differentiate benign from suspicious pulmonary nodules. The use of scintigraphy could be helpful to anticipate histological assessment and surgical treatment of SPNs identified at CT

Multidetector CT and Dentascan software: Dosimetric evaluation and technique improvement [TC multistrato con software Dentascan: Valutazioni dosimetriche ed ottimizzazione della tecnica]

Purpose. The development of new operative techniques in oral and maxillofacial surgery within the last few years has led to an increasing demand for Dentascan examination, also in paediatric patients. It is necessary to modify acquisition parameters to reduce the absorbed dose. The aim of this study was to define a Dentascan protocol in which a reduced X-ray dose could be used. Materials and methods. Dosimeters were applied to the eyes, mouth, parotid glands, thyroid and back of the neck of an anthropomorphic Plexiglas phantom that underwent multidetector computed tomography (MDCT) Dentascan examinations. Both 120kV and 80 kV were used to study the mandibular and maxillary arches. Results. Examinations obtained with the 80 kV protocol showed a ten-fold reduction in the absorbed dose, without affecting image quality. Conclusions. We suggest a Dentascan protocol that reduces the X-ray dose administered to the patient while ensuring the same high diagnostic accuracy

Influence of fiber orientation and structural-integrity reinforcement on the flexural behavior of elevated slabs

In the last decades, research works regarding the behavior of Fiber-Reinforced Concrete (FRC) showed that the use of fibers enhances the mechanical behavior of Reinforced Concrete (RC) structures both at Serviceability Limit State (SLS) and Ultimate Limit State (ULS). It is also well recognized that the design of these elements should take into consideration fiber orientation since the residual properties of the material can be different depending on the fiber inclination with respect to the cracking plane. This article presents the results of an experimental program aimed at evaluating the influence of fiber orientation on the flexural response of elevated slabs. Both Vibrated Fiber-Reinforced Concrete (VFRC) and Self-Compacting Fiber-Reinforced Concrete (SCFRC) were analyzed. Seven elevated slabs (250 × 250 × 15 cm) were cast following the most common casting process adopted in practice by using VFRC (2 specimens), SCFRC (4 specimens) and plain concrete (1 specimen). The post-cracking mechanical properties evaluated by three-point bending tests on 192 notched beams sawn from three FRC slabs showed that, for a given fiber type and amount, the fiber orientation in slabs was comparable varying both concrete workability and casting procedure. The structural behavior of the remaining four slabs was studied both by experimental tests and numerical analyses. The slabs were simply supported at the corners and subjected to center-point loading. Results showed that the response in flexure was related to the average residual properties obtained from small beams sawn from slabs. Finally, the importance of having a structural-integrity reinforcement in FRC elevated slabs under flexure was also underlined by the numerical study

A practical approach for monitoring reinforcement corrosion in steel fiber reinforced concrete elements exposed to chloride rich environments

The use of fibers in Reinforced Concrete (RC) elements changes their cracking pattern, leading to narrower and more closely spaced cracks. In addition, the presence of fibers can improve the steel-to-concrete bond behavior reducing the steel-to-concrete interface damage after cracking. Cracks and steel-to-concrete interface damage work like paths, for aggressive agents, to reach the rebar in cracking elements, reducing the initiation period of the corrosion process, and favoring the corrosion at the intersection between cracks and reinforcement. In this context, this article discusses an experimental program on tension ties mechanically cracked and exposed to a chloride-rich environment with the purpose to check and eventually adequate the typical electrochemical measurements, used in the case of RC elements, for Steel Fiber Reinforced Concrete (SFRC). Adjustments related to degradation morphology and interference of steel fibers are proposed and used on Fiber Reinforced Concrete (FRC) elements for monitoring the influence of cracks and fibers on corrosion propagation. Finally, these proposed modifications were checked and validated against the results obtained by monitoring SFRC beams in the cracked stage