95 research outputs found
Punching of reinforced concrete slab without shear reinforcement: standard models and new proposal
Reinforced concrete (RC) slabs are characterized by reduced construction time, versatility, and easier space partitioning. Their structural behavior is not straightforward and, specifically, punching shear strength is a current research topic. In this study an experimental database of 113 RC slabs without shear reinforcement under punching loads was compiled using data available in the literature. A sensitivity analysis of the parameters involved in the punching shear strength assessment was conducted, which highlighted the importance of the flexural reinforcement that are not typically considered for punching shear strength. After a discussion of the current international standards, a new proposed model for punching shear strength and rotation of RC slabs without shear reinforcement was discussed. It was based on a simplified load-rotation curve and new failure criteria that takes into account the flexural reinforcement effects. This experimental database was used to validate the approaches of the current international standards as well as the new proposed model. The latter proved to be a potentially useful design tool
Influence of Ceramic Recycled Aggregates on the Properties of Prestressed Precast Concrete Elements
This work presents the results of an experimental study performed on the mechanical behavior of concrete manufactured with ceramic recycled aggregates (CRA), from precast ventilation ducts, that once made have been rejected by defective. The ultimate objective is to use these wastes to manufacture prestressed concrete joists used in building floors. The coarse fraction and the fine fraction have been considered. The work has been carried out in three phases: characterization of the material, characterization of concrete with CRA and manufacturing and testing of prestressed joists. With the results obtained it is determined the influence of the ceramic recycled aggregate on the properties analyzed. There are not enough studies about prestressed elements that include the replacement of the aggregate in the fine fraction. In view of the results obtained could both of fine and coarse fraction can be used in these applications
Outcomes of pregnancies after kidney transplantation: lessons learned from CKD. A comparison of transplanted, nontransplanted chronic kidney disease patients and low-risk pregnancies: a multicenter nationwide analysis.
BACKGROUND: Kidney transplantation (KT) may restore fertility in CKD. The reasons why materno-foetal outcomes are still inferior to the overall population are only partially known. Comparison with the CKD population may offer some useful insights for management and counselling.Aim of this study was to analyse the outcomes of pregnancy after KT, compared with a large population of non-transplanted CKD patients and with low-risk control pregnancies, observed in Italy the new millennium.
METHODS: We selected 121 live-born singletons after KT (Italian study group of kidney in pregnancy, national coverage about 75%), 610 live-born singletons in CKD and 1418 low-risk controls recruited in 2 large Italian Units, in the same period (2000-2014). The following outcomes were considered: maternal and foetal death; malformations; preterm delivery; small for gestational age baby (SGA); need for the neonatal intensive care unit (NICU); doubling of serum creatinine or increase in CKD stage. Data were analysed according to kidney diseases, renal function (staging according to CKD-EPI), hypertension, maternal age, partity, ethnicity.
RESULTS: Materno-foetal outcomes are less favourable in CKD and KT as compared with the low-risk population. CKD stage and hypertension are important determinants of results. KT patients with e-GFR >90 have worse outcomes compared with CKD stage 1 patients; the differences level off when only CKD patients affected by glomerulonephritis or systemic diseases ('progressive CKD') are compared with KT. In the multivariate analysis, risk for preterm and early-preterm delivery was linked to CKD stage (2-5 versus 1: RR 3.42 and 3.78) and hypertension (RR 3.68 and 3.16) while no difference was associated with being a KT or a CKD patient.
CONCLUSIONS: The materno-foetal outcomes in patients with kidney transplantation are comparable with those of nontransplanted CKD patients with similar levels of kidney function impairment and progressive and/or immunologic kidney diseas
Towards frailty biomarkers:Candidates from genes and pathways regulated in aging and age-related diseases
Objective: Use of the frailty index to measure an accumulation of deficits has been proven a valuable method for identifying elderly people at risk for increased vulnerability, disease, injury, and mortality. However, complementary molecular frailty biomarkers or ideally biomarker panels have not yet been identified. We conducted a systematic search to identify biomarker candidates for a frailty biomarker panel. Methods: Gene expression databases were searched (http://genomics.senescence.info/genes including GenAge, AnAge, LongevityMap, CellAge, DrugAge, Digital Aging Atlas) to identify genes regulated in aging, longevity, and age-related diseases with a focus on secreted factors or molecules detectable in body fluids as potential frailty biomarkers. Factors broadly expressed, related to several \u201challmark of aging\u201d pathways as well as used or predicted as biomarkers in other disease settings, particularly age-related pathologies, were identified. This set of biomarkers was further expanded according to the expertise and experience of the authors. In the next step, biomarkers were assigned to six \u201challmark of aging\u201d pathways, namely (1) inflammation, (2) mitochondria and apoptosis, (3) calcium homeostasis, (4) fibrosis, (5) NMJ (neuromuscular junction) and neurons, (6) cytoskeleton and hormones, or (7) other principles and an extensive literature search was performed for each candidate to explore their potential and priority as frailty biomarkers. Results: A total of 44 markers were evaluated in the seven categories listed above, and 19 were awarded a high priority score, 22 identified as medium priority and three were low priority. In each category high and medium priority markers were identified. Conclusion: Biomarker panels for frailty would be of high value and better than single markers. Based on our search we would propose a core panel of frailty biomarkers consisting of (1) CXCL10 (C-X-C motif chemokine ligand 10), IL-6 (interleukin 6), CX3CL1 (C-X3-C motif chemokine ligand 1), (2) GDF15 (growth differentiation factor 15), FNDC5 (fibronectin type III domain containing 5), vimentin (VIM), (3) regucalcin (RGN/SMP30), calreticulin, (4) PLAU (plasminogen activator, urokinase), AGT (angiotensinogen), (5) BDNF (brain derived neurotrophic factor), progranulin (PGRN), (6) \u3b1-klotho (KL), FGF23 (fibroblast growth factor 23), FGF21, leptin (LEP), (7) miRNA (micro Ribonucleic acid) panel (to be further defined), AHCY (adenosylhomocysteinase) and KRT18 (keratin 18). An expanded panel would also include (1) pentraxin (PTX3), sVCAM/ICAM (soluble vascular cell adhesion molecule 1/Intercellular adhesion molecule 1), defensin \u3b1, (2) APP (amyloid beta precursor protein), LDH (lactate dehydrogenase), (3) S100B (S100 calcium binding protein B), (4) TGF\u3b2 (transforming growth factor beta), PAI-1 (plasminogen activator inhibitor 1), TGM2 (transglutaminase 2), (5) sRAGE (soluble receptor for advanced glycosylation end products), HMGB1 (high mobility group box 1), C3/C1Q (complement factor 3/1Q), ST2 (Interleukin 1 receptor like 1), agrin (AGRN), (6) IGF-1 (insulin-like growth factor 1), resistin (RETN), adiponectin (ADIPOQ), ghrelin (GHRL), growth hormone (GH), (7) microparticle panel (to be further defined), GpnmB (glycoprotein nonmetastatic melanoma protein B) and lactoferrin (LTF). We believe that these predicted panels need to be experimentally explored in animal models and frail cohorts in order to ascertain their diagnostic, prognostic and therapeutic potential
Associations between depressive symptoms and disease progression in older patients with chronic kidney disease: results of the EQUAL study
Background Depressive symptoms are associated with adverse clinical outcomes in patients with end-stage kidney disease; however, few small studies have examined this association in patients with earlier phases of chronic kidney disease (CKD). We studied associations between baseline depressive symptoms and clinical outcomes in older patients with advanced CKD and examined whether these associations differed depending on sex. Methods CKD patients (>= 65 years; estimated glomerular filtration rate <= 20 mL/min/1.73 m(2)) were included from a European multicentre prospective cohort between 2012 and 2019. Depressive symptoms were measured by the five-item Mental Health Inventory (cut-off <= 70; 0-100 scale). Cox proportional hazard analysis was used to study associations between depressive symptoms and time to dialysis initiation, all-cause mortality and these outcomes combined. A joint model was used to study the association between depressive symptoms and kidney function over time. Analyses were adjusted for potential baseline confounders. Results Overall kidney function decline in 1326 patients was -0.12 mL/min/1.73 m(2)/month. A total of 515 patients showed depressive symptoms. No significant association was found between depressive symptoms and kidney function over time (P = 0.08). Unlike women, men with depressive symptoms had an increased mortality rate compared with those without symptoms [adjusted hazard ratio 1.41 (95% confidence interval 1.03-1.93)]. Depressive symptoms were not significantly associated with a higher hazard of dialysis initiation, or with the combined outcome (i.e. dialysis initiation and all-cause mortality). Conclusions There was no significant association between depressive symptoms at baseline and decline in kidney function over time in older patients with advanced CKD. Depressive symptoms at baseline were associated with a higher mortality rate in men
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The potential impact of the COVID-19 pandemic on global antimicrobial and biocide resistance : an AMR Insights global perspective
The COVID-19 pandemic presents a serious public health challenge in all countries. However, repercussions of
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on future global health
are still being investigated, including the pandemicâs potential effect on the emergence and spread of global
antimicrobial resistance (AMR). Critically ill COVID-19 patients may develop severe complications, which may
predispose patients to infection with nosocomial bacterial and/or fungal pathogens, requiring the extensive
use of antibiotics. However, antibiotics may also be inappropriately used in milder cases of COVID-19
infection. Further, concerns such as increased biocide use, antimicrobial stewardship/infection control, AMR
awareness, the need for diagnostics (including rapid and point-of-care diagnostics) and the usefulness of
vaccination could all be components shaping the influence of the COVID-19 pandemic. In this publication, the
authors present a brief overview of the COVID-19 pandemic and associated issues that could influence
the pandemicâs effect on global AMR.This study was supported by internal funding.https://academic.oup.com/jacamram2022School of Health Systems and Public Health (SHSPH
Industrial heritage revaluation: structural repair of old industrial masonry chimneys
Brick masonry chimneys are the symbol and heritage of Industrial Revolution. They characterize the ski line of many cities and landscapes and bear testimony to the industrial characteristics of an area.
Today these structures require conservation: they show loss of verticality and considerable longitudinal cracks due to use. These cracks have deteriorated due to neglect and lack of maintenance.
There is no easy solution for repairing brick masonry chimneys because besides the static problems, the architectural integrity and their historical value must be respected.
In this paper a method of repairing single flue chimneys is presented. It ensures the structural monolithicity of the chimneys and stabilizes the cracks without damaging its structural integrity. The proposed method consists of inserting a series of steel rings inside the flue for the full height of the chimneys at predetermined distances. These series of steel rings are transversally placed and joined to the wall by anchors and prestressed.
To evaluated the overall effects of this method on the stability of the chimney static linear elastic model, using the FEM method, was carried out
«Fuggiro al par del vento, al par del lampo »Parodia della guerra e eroismo nei Paralipomeni di Leopardi
Lâarticle se propose dâanalyser les cinq premiers chants des ParalipomĂšnes de Giacomo Leopardi pour mieux comprendre le dĂ©roulement et les raisons de la guerre que cette Ćuvre raconte. On constatera, alors, quâil sâagit dâune parodie gĂ©nĂ©rale des combats qui ne concerne pas seulement la satire politique de la pĂ©riode de la Restauration. En effet, la guerre devient, en ce cas, lâoccasion pour une rĂ©flexion plus vaste sur certains idĂ©aux. En particulier, Ă travers lâimage hĂ©roĂŻque du soldat « Rubatocchi », on voit lâincarnation dâune vertu que le narrateur / poĂšte croit dĂ©sormais disparue du monde
Le traduzioni in lingua sarda ogliastrinadella Batracomiomachiae dei Paralipomeni di Giacomo Leopardi
Lâarticle se propose dâillustrer lâĂ©dition bilingue en sarde et italien de la Batrachomyomachie et des ParalipomĂšnes de Giacomo Leopardi, par quelques rĂ©flexions sur la langue, la traduction et lâintertextualitĂ©. Lâanalyse du paratexte, en particulier, rĂ©vĂšle une sorte dâhistoire dans lâhistoire qui rend cette Ă©dition encore plus unique. Aussi espĂšre-t-on susciter dâautres Ă©tudes critiques et spĂ©cialisĂ©es sur ce texte
AffidabilitĂ dei modelli di calcolo per lâanalisi a collasso di travi inflesse precompresse a cavi non aderenti
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