Effects of new openings on the in/plane behaviour of unreinforced brick masonry walls

Existing brick masonry buildings are frequently modified to satisfy nowadays living demands. Such modifications may include new windows or doors that connect two rooms and require openings to be cut from load bearing walls. In current design practice, these interventions are generally designed and verified for vertical load, but the structural behavior of these altered walls when submitted to in-plane loads (due to seismic actions) is not yet fully understood. Thus, design practice may be inaccurately estimated. The objective of this work is to evaluate, numerically and experimentally, the effects of introducing openings in masonry solidbrick walls subjected to in-plane loading. Three main parameters are considered for the numerical studies: i) walls dimensions, ii) opening type, iii) opening size. As expected, results show that walls with medium-large openings are the most vulnerable case-scenario. These numerical results have addressed the design of a representative wall tested at the University of Brescia. The preliminary results of this experimental program are included in this pape

Experimental and numerical assessment of masonry walls with new openings strengthened with steel frame

The creation of new openings in masonry walls is a frequent intervention executed in existing buildings of unreinforced masonry composed of clay bricks. These openings are widely seen at the street-level, where spaces are modified to create new windows or doors for new stores, garages or offices. Depending on their size and position, these interventions may cause significant decrease of the wall’s original in-plane strength and stiffness, thus, compromising the building seismic resistance. For example, when several garages are created, one after another, the risk of inducing the soft-story mechanism, when earthquake forces arrive, increases. Another example is when a door of significant size is introduced in an originally solid masonry wall, which was a key object to guarantee the box-like behavior of the structure. The opening would reduce the cross section of the remaining piers and spandrel, and thus, weaken the wall’s seismic strength. These changes in the original wall have consequences in the box-like behavior, as during earthquake events, the load demands on the remaining shear walls might be larger than their shear capacity. Therefore, strengthening techniques must restore as much as possible the loss of stiffness and strength. Besides, for masonry structures, the technique must be reversible and respect the compatibility between materials, particularly in the case of protected assets. In an attempt to complying with these requirements, engineering practitioner often introduce steel profiles forming a frame inside the opening. Steel is usually preferred because of its high level of reversibility and the stiffness and strength it can provide to masonry without substantially increasing the building self-weight. The design of this steel frame and the stiffness of the masonry wall with opening is based in the available analytical tools, i.e., the Timoshenko Beam Theory. From these calculations, the loss of stiffness when passing from a solid wall to a perforated wall is about 75% for cantilever boundary conditions and 55% for double-fixed. Thus, very stiff profiles for the steel frame are required. In theory, these profiles are capable of fully restoring the stiffness and resistance. The present work is dedicated to evaluate the effectiveness of this steel frame technique by means of experimental and numerical methods. The experimental program was designed to provide full assessment of the effects of introducing a new door opening in brick masonry walls, from the perforation process to the application of in-plane cyclic loads . A flexible steel frame was designed using numerical tools and consisted in four profiles welded together and tied to the surrounding masonry wall by means of dry-driven dowels. The numerical model was validated against the experimental results, and show that neither a very stiff steel frame nor a more flexible one is capable of restoring the original solid wall’s stiffness. However, both are capable of restoring the in-plane strength and ductility. This paper, also shows that using a very stiff profile might lead to a rather brittle response of the reinforced wall, as the masonry starts cracking before activating the frame. This would not happen with a more flexible profileItalian Ministry of Education, University, and Research (MIUR) for her Doctoral Scholarship is gratefully acknowledged. The Authors also thank the technicians A. del Barba, A. Botturi from laboratory Pietro Pis

Diagnostic performance of endoscopic ultrasound-guided tissue acquisition of splenic lesions: systematic review with pooled analysis

Background: Focal splenic lesions are usually incidentally discovered on radiological assessments. Although percutaneous tissue acquisition (TA) under trans-abdominal ultrasound guidance is a well-established technique for obtaining cyto-histological diagnosis of focal splenic lesions, endoscopic ultrasound (EUS)-guided TA has been described in several studies, reporting different safety and outcomes. The aim was to assess the pooled safety, adequacy, and accuracy of EUS-TA of splenic lesions. Methods: A comprehensive review of available evidence was conducted at the end of November 2021. All studies including more than five patients and reporting about the safety, adequacy, and accuracy of EUS-TA of the spleen were included. Results: Six studies (62 patients) were identified; all studies have been conducted using fine-needle aspiration (FNA) needles. Pooled specimen adequacy and accuracy of EUS-TA for spleen characterization were 92.8% [95% confidence interval (CI), 86.3%-99.3%] and 88.2% (95% CI, 79.3%-97.1%), respectively. The pooled incidence of adverse events (six studies, 62 patients) was 4.7% (95% CI, 0.4%-9.7%). Conclusion: EUS-FNA of the spleen is a safe technique with high diagnostic adequacy and accuracy. The EUS-guided approach could be considered a valid alternative to the percutaneous approach for spleen TA

Digital droplet PCR is a specific and sensitive tool for detecting IDH2 mutations in acute myeloid leukemia patients

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) interfere with cellular metabolism contributing to oncogenesis. Mutations of IDH2 at R140 and R172 residues are observed in 20% of acute myeloid leukemias (AML), and the availability of the IDH2 inhibitor Enasidenib made IDH2 mutational screening a clinical need. The aim of this study was to set a new quantitative polymerase chain reaction (PCR) technique, the drop-off digital droplet PCR (drop-off ddPCR), as a sensitive and accurate tool for detecting IDH2 mutations. With this technique we tested 60 AML patients. Sanger sequencing identified 8/60 (13.5%) mutated cases, while ddPCR and the amplification refractory mutation system (ARMS) PCR, used as a reference technique, identified mutations in 13/60 (21.6%) cases. When the outcome of IDH2-mutated was compared to that of wild-type patients, no significant difference in terms of quality of response, overall survival, or progression-free survival was observed. Finally, we monitored IDH2 mutations during follow-up in nine cases, finding that IDH2 can be considered a valid marker of minimal residual disease (MRD) in 2/3 of our patients. In conclusion, a rapid screening of IDH2 mutations is now a clinical need well satisfied by ddPCR, but the role of IDH2 as a marker for MRD still remains a matter of debate

Intensive post-operative follow-up of breast cancer patients with tumour markers: CEA, TPA or CA15.3 vs MCA and MCA-CA15.3 vs CEA-TPA-CA15.3 panel in the early detection of distant metastases

BACKGROUND: In breast cancer current guidelines do not recommend the routine use of serum tumour markers. Differently, we observed that CEA-TPA-CA15.3 (carcinoembryonic (CEA) tissue polypeptide (TPA) and cancer associated 115D8/DF3 (CA15.3) antigens) panel permits early detection and treatment for most relapsing patients. As high sensitivity and specificity and different cut-off values have been reported for mucin-like carcinoma associated antigen (MCA), we compared MCA with the above mentioned tumour markers and MCA-CA15.3 with the CEA-TPA-CA15.3 panel. METHODS: In 289 breast cancer patients submitted to an intensive post-operative follow-up with tumour markers, we compared MCA (cut-off values, ≥ 11 and ≥ 15 U/mL) with CEA or CA15.3 or TPA for detection of relapse. In addition, we compared the MCA-CA15.3 and CEA-TPA-CA15.3 tumour marker panels. RESULTS: Distant metastases occurred 19 times in 18 (6.7%) of the 268 patients who were disease-free at the beginning of the study. MCA sensitivity with both cut-off values was higher than that of CEA or TPA or CA15.3 (68% vs 10%, 26%, 32% and 53% vs 16%, 42%, 32% respectively). With cut-off ≥ 11 U/mL, MCA showed the lowest specificity (42%); with cut-off ≥ 15 U/mL, MCA specificity was similar to TPA (73% vs 72%) and lower than that of CEA and CA15.3 (96% and 97% respectively). With ≥ 15 U/mL MCA cut-off, MCA sensitivity increased from 53% to 58% after its association with CA15.3. Sensitivity of CEA-TPA-CA15.3 panel was 74% (14 of 19 recurrences). Eight of the 14 recurrences early detected with CEA-TPA-CA15.3 presented as a single lesion (oligometastatic disease) (5) or were confined to bony skeleton (3) (26% and 16% respectively of the 19 relapses). With ≥ 11 U/mL MCA cut-off, MCA-CA15.3 association showed higher sensitivity but lower specificity, accuracy and positive predictive value than the CEA-TPA-CA15.3 panel. CONCLUSION: At both the evaluated cut-off values serum MCA sensitivity is higher than that of CEA, TPA or CA15.3 but its specificity is similar to or lower than that of TPA. Overall, CEA-TPA-CA15.3 panel is more accurate than MCA-CA15.3 association and can "early" detect a few relapsed patients with limited metastatic disease and more favourable prognosis. These findings further support the need for prospective randomised clinical trial to assess whether an intensive post-operative follow-up with an appropriate use of serum tumour markers can significantly improve clinical outcome of early detected relapsing patients

Bistable Percepts in the Brain: fMRI Contrasts Monocular Pattern Rivalry and Binocular Rivalry

The neural correlates of binocular rivalry have been actively debated in recent years, and are of considerable interest as they may shed light on mechanisms of conscious awareness. In a related phenomenon, monocular rivalry, a composite image is shown to both eyes. The subject experiences perceptual alternations in which the two stimulus components alternate in clarity or salience. The experience is similar to perceptual alternations in binocular rivalry, although the reduction in visibility of the suppressed component is greater for binocular rivalry, especially at higher stimulus contrasts. We used fMRI at 3T to image activity in visual cortex while subjects perceived either monocular or binocular rivalry, or a matched non-rivalrous control condition. The stimulus patterns were left/right oblique gratings with the luminance contrast set at 9%, 18% or 36%. Compared to a blank screen, both binocular and monocular rivalry showed a U-shaped function of activation as a function of stimulus contrast, i.e. higher activity for most areas at 9% and 36%. The sites of cortical activation for monocular rivalry included occipital pole (V1, V2, V3), ventral temporal, and superior parietal cortex. The additional areas for binocular rivalry included lateral occipital regions, as well as inferior parietal cortex close to the temporoparietal junction (TPJ). In particular, higher-tier areas MT+ and V3A were more active for binocular than monocular rivalry for all contrasts. In comparison, activation in V2 and V3 was reduced for binocular compared to monocular rivalry at the higher contrasts that evoked stronger binocular perceptual suppression, indicating that the effects of suppression are not limited to interocular suppression in V1

The perception of color from motion

We introduce and explore a color phenomenon which requires the prior perception of motion to produce a spread of color over a region defined by motion. We call this motion-induced spread of color dynamic color spreading. The perception of dynamic color spreading is yoked to the perception of apparent motion: As the ratings of perceived motion increase, the ratings of color spreading increase. The effect is most pronounced if the region defined by motion is near 1 degree of visual angle. As the luminance contrast between the region defined by motion and the surround changes, perceived saturation of color spreading changes while perceived hue remains roughly constant. Dynamic color spreading is sometimes, but not always, bounded by a subjective contour. We discuss these findings in terms of interactions between color and motion pathways

To be objective in Experimental Phenomenology: a Psychophysics application

Background Several scientific psychologists consider the approach for the study of perceptive problems of the Experimental Phenomenology is problematic, namely that the phenomenological demonstrations are subjectively based and they do not produce quantifiable results. Aim The aim of this study is to show that Experimental Phenomenology can lead to conclusions objective and quantifiable and propose a procedure allowing to obtain objective measuring using the Rasch mathematical model able to describe the experimental data gathered in Experimental Phenomenology procedures. Method In order to demonstrate this, a Psychophysics simulated study is proposed. Results/conclusions It is possible to carry out a fundamental measurement starting from Experimental Phenomenology by way of the Theory of Conjoint Measurement