107 research outputs found
Seismic Response of Acceleration-Sensitive Non-Structural Components in Buildings
This paper aims at highlighting the main mechanical parameters controlling the behavior of the so-called âacceleration-sensitiveâ non-structural components (NSCs). The first reports a short review of the current state of knowledge and the critical issues dealing with the prediction of the seismic response of NSCs. Then, the paper presents the results of a numerical parametric analysis intended to capture the key features of the coupled dynamic response of a two-degree-of-freedom (2DOF) system supposed to be representative of both main structure and ânon-structuralâ component (NSC). The main parameters controlling the dynamic response of NSCs emerge from this study, which could pave the way towards formulating more mechanically consistent relationships for evaluating the peak accelerations induced by seismic shakings on NSCs in buildings
cost competitive steel devices for seismic retrofittingof rc frames model identification and nonlinear analysis
Seismic retrofitting of existing reinforced concrete (RC) buildings, designed in the last decades in seismic areas, is one of the most complex tasks for structural engineers: in fact, it includes several issues, such as quantifying the capacity of existing members, designing the supplemental ones and analysing the whole structure. This paper is intended as a contribution to clarifying some of those issues. First of all, a model based on using 1D finite elements with fiber section discretization is proposed for simulating the behaviour of a cost-competitive steel device that can be employed as a link in Y-shaped eccentric bracings (EB): particularly, the cyclic response and the low-cycle fatigue degradation is modelled, based on the results of obtained in a previous experimental research carried out at the University of Salerno. Secondly, the global response of an existing RC frame equipped with the aforementioned devices is investigated via Non Linear Time History (NLTH) analyses. Taking into account the lowcycle fatigue often leads to significantly more severe seismic displacement demand value on the retrofitted structure: a close correlation is unveiled between some specific features of the seismic signals adopted in the NLTH and the actual influence of low-cycle fatigue
Engineering properties of geopolymer concrete: a review
Geopolymer concrete (GPC) could be a solution that uses a cementless binder and recycled materials for producing concrete, while reducing the carbon dioxide emission and the demand for raw materials. In addition to the environmental aspect, previous studies on GPC showed that it can achieve mechanical characteristics higher than those of ordinary Portland concrete (OPC) such as greater strength a few days after casting, and it can be suitable for structural applications. In this paper, the state-of-the-art review of GPC is presented through an extensive literature analysis to determine the most recent information regarding the engineering properties of geopolymer concrete and the critical issues that prevent its widespread use and to put forward suggestions for future research. In particular, the physical properties in both fresh and hardened states and the mechanical characteristics are investigated; the structural performance of geopolymer concrete elements is also outlined
Fish Skin Graft: Narrative Review and First Application for Abdominal Wall Dehiscence in Children
Summary: Acellular fish skin grafts (FSGs) are tissue-based products created by
minimally processing the skin of the Atlantic cod (Gadus morhua). The FSG is rich
in omega-3 and facilitates tissue regeneration by supporting revascularization and
ingrowth in the proliferation and remodeling phases of wound healing. FSG is structurally
more similar to human skin than antiviral-processed skin substitutes such
as amniotic membrane, and there are no known prion, bacterial, or viral diseases
that can be transmitted from North-Atlantic cod to humans. The FSG is processed
using a proprietary method that preserves the structure and lipid composition of
the skin. FSG is CE marked, and US Food and Drug Administration cleared for
multiple clinical applications in partial and full-thickness wounds. FSG is currently
the only acellular dermal matrix product that does not originate from mammalian
tissues. For this narrative review, Medline and UpToDate were used to include a
total of 21 articles published from 2015 to 2022 about fish skin graft use. We also
reported a case of a 7-year-old boy who underwent treatment with FSG for abdominal
wall dehiscence at our department of pediatric surgery, IRCCS SantâOrsola-
Malpighi, Alma Mater Studiorum, University of Bologna, University Hospital of
Bologna. FSG provides a valuable and sustainable treatment that improves wound
healing in both adult and pediatric populations. We described the first application
of an FSG for wound dehiscence of the abdominal wall in a pediatric patient,
reporting how FSG was completely reabsorbed and improved the skinâs repai
Ask Doctor Smartphone! An App to Help Physicians Manage Foreign Body Ingestions in Children
Abstract: Background: Foreign body ingestion (FBI) represents the most common cause of emergent
gastrointestinal endoscopy in children. FBIâs management can be quite challenging for physicians
because of the variability of the clinical presentation, and the decision tree becomes even more
intricate because of patient-specific variables that must be considered in the pediatric age range
(e.g., age of patients and neuropsychiatric disorders) in addition to the mere characteristics of the
foreign body. We present an application for smartphones designed for pediatricians and pediatric
surgeons based on the latest guidelines from the official pediatric societies. The app aims to help
physicians manage FBI quickly and properly in children. Materials and methods: The latest pediatric
FBI management guidelines were reviewed and summarized. The flow chart we obtained guided
the development of a smartphone application. A questionnaire was administered to all pediatric
surgeon trainees at our institute to test the feasibility and helpfulness of the application. Results:
An app for smartphones was obtained and shared for free on the Google Play Store and Apple
Store. The app guides the physician step by step in the diagnostic process, analyzing all patient- and
foreign body-specific characteristics. The app consultation ends with a suggestion of the most proper
decision to make in terms of further radiological investigations and the indication and timing of
endoscopy. A questionnaire administered to trainees proved the app to be useful and easy to use.
Conclusion: We developed an app able to help pediatricians and pediatric surgeons manage FBI in
children, providing standardized and updated recommendations in a smart and easily available way
Identification of a proteasome-targeting arylsulfonamide with potential for the treatment of Chagas' disease
Phenotypic screening identified an arylsulfonamide compound with activity against Trypanosoma cruzi, the causative agent of Chagasâ disease. Comprehensive mode of action studies revealed that this compound primarily targets the T. cruzi proteasome, binding at the interface between ÎČ4 and ÎČ5 subunits that catalyze chymotrypsin-like activity. A mutation in the ÎČ5 subunit of the proteasome was associated with resistance to compound 1, while overexpression of this mutated subunit also reduced susceptibility to compound 1. Further genetically engineered and in vitro-selected clones resistant to proteasome inhibitors known to bind at the ÎČ4/ÎČ5 interface were cross-resistant to compound 1. Ubiquitinated proteins were additionally found to accumulate in compound 1-treated epimastigotes. Finally, thermal proteome profiling identified malic enzyme as a secondary target of compound 1, although malic enzyme inhibition was not found to drive potency. These studies identify a novel pharmacophore capable of inhibiting the T. cruzi proteasome that may be exploitable for anti-chagasic drug discovery
Valorising faba bean residual biomass : Effect of farming system and planting time on the potential for biofuel production
Research was carried out in southern Italy with the aim to assess the quality of faba bean residual biomass and its potential for biorefinery application. Faba bean is a sustainable crop, due to its ability to fix atmospheric nitrogen, and a large amount of biomass remains after harvest which can be valorised for energy production. Greenhouse and early planting are known to affect pod yield and, in this respect, even the residual biomass quality needs to be assessed. For this purpose, the effects of five planting times (i.e. the dates of transplants ranging from 27 September to 22 November at two-week interval, earlier and later than the common planting date of 25 October in Naples province) on pods yield, residual biomass, and saccharification potential were evaluated in faba bean grown in open field and in greenhouse. The third planting time resulted in the highest fruit and residual biomass yield under greenhouse, whereas the fourth was the best in open field. Harvest index was best affected by the third and fourth planting times in open field. Greenhouse grown biomass showed higher values of lignin, hemicellulose and pectin, compared to open field, whereas the opposite trend was recorded with cellulose. Lignin content showed a gradual decrease from the first to the last planting time (17.7%â13.7% biomass fraction respectively), as well as pectin (from 14.1 to 11.5% biomass fraction); conversely, cellulose increased from the first to the last planting time (from 41.1 to 48.7% biomass fraction). Glucose was the most represented monosaccharide (46.7 mol%), followed by xylose (27.4 mol%) and galactose (9.9 mol%). Overall, the potential of faba bean residual biomass for energy production was best affected by open field growing, the latest planting time and alkali pre-treatment, the latter giving the highest value of saccharification (60.7 g kgâ1 hâ1 compared to 27.6 relevant to hot water pre-treatment)
Association Between Preexisting Versus Newly Identified Atrial Fibrillation and Outcomes of Patients With Acute Pulmonary Embolism
Background Atrial fibrillation (AF) may exist before or occur early in the course of pulmonary embolism (PE). We determined the PE outcomes based on the presence and timing of AF. Methods and Results Using the data from a multicenter PE registry, we identified 3 groups: (1) those with preexisting AF, (2) patients with new AF within 2 days from acute PE (incident AF), and (3) patients without AF. We assessed the 90-day and 1-year risk of mortality and stroke in patients with AF, compared with those without AF (reference group). Among 16 497 patients with PE, 792 had preexisting AF. These patients had increased odds of 90-day all-cause (odds ratio [OR], 2.81; 95% CI, 2.33-3.38) and PE-related mortality (OR, 2.38; 95% CI, 1.37-4.14) and increased 1-year hazard for ischemic stroke (hazard ratio, 5.48; 95% CI, 3.10-9.69) compared with those without AF. After multivariable adjustment, preexisting AF was associated with significantly increased odds of all-cause mortality (OR, 1.91; 95% CI, 1.57-2.32) but not PE-related mortality (OR, 1.50; 95% CI, 0.85-2.66). Among 16 497 patients with PE, 445 developed new incident AF within 2 days of acute PE. Incident AF was associated with increased odds of 90-day all-cause (OR, 2.28; 95% CI, 1.75-2.97) and PE-related (OR, 3.64; 95% CI, 2.01-6.59) mortality but not stroke. Findings were similar in multivariable analyses. Conclusions In patients with acute symptomatic PE, both preexisting AF and incident AF predict adverse clinical outcomes. The type of adverse outcomes may differ depending on the timing of AF onset.info:eu-repo/semantics/publishedVersio
Comparison of seven prognostic tools to identify low-risk pulmonary embolism in patients aged <50 years
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