103 research outputs found

    Alkali release from aggregates in long-service concrete structures. Laboratory test evaluation and ASR prediction

    Get PDF
    Il lavoro propone un semplice modello per la previsione dello sviluppo di espansione deleteria da reazione alcali-silice (ASR) in strutture di calcestruzzo progettate per lunga vita di servizio. Il modello è basato su parametri di composizione e di reattività legati alla ASR, compreso il contributo in alcali a lungo termine da parte degli aggregati. Questo contributo è stato stimato attraverso una prova di estrazione di laboratorio, appositamente sviluppata con lo scopo di massimizzare il rilascio in tempi di prova relativamente brevi e con basso rapporto soluzione lisciviante/aggregato. Il metodo di prova proposto è basato sullo standard italiano riportato nella norma UNI 11417-2 e consiste nel sottoporre l'aggregato a lisciviazione con una soluzione satura di idrossido di calcio a 105°C, in autoclave. Sono stati sottoposti a prova nove aggregati (sette sabbie e due aggregati grossi), il rapporto in peso lisciviante/aggregato era pari a 0,6, il rapporto Ca(OH)2 solida/aggregato era pari a 0,05 ed il tempo di prova 120 ore. I risultati delle prove sono stati utilizzati nel modello di previsione dell'espansione deleteria a lungo termine, ottenendo delle previsioni del tutto congruenti con le informazioni sul comportamento reale dei materiali, nonché con le raccomandazioni riportate nel CEN/TR 16349:2012.This paper proposes a simple model for predicting the development of deleterious expansion from alkali-silica reaction (ASR) in long-service concrete structures. This model is based on some composition and reactivity parameters related to ASR, including the long-term alkali contribution by aggregates to concrete structures. This alkali contribution was estimated by means of a laboratory extraction test, appositely developed in this study in order to maximize the alkali extraction within relatively short testing times and with low leaching solution/aggregate ratios. The proposed test is a modification of the Italian Standard test method UNI 11417-2 (Ente Nazionale Italiano di Normazione) and it consists of subjecting an aggregate sample to leaching with saturated calcium hydroxide solution in a laboratory autoclave at 105 degrees C. Nine natural ASR-susceptible aggregates (seven sands and two coarse aggregates) were tested and the following optimized test conditions were found: leaching solution/aggregate weight ratio = 0.6; solid calcium hydroxide/aggregate weight ratio = 0.05; test duration = 120 h. The results of the optimized alkali extraction tests were used in the proposed model for predicting the potential development of long-term ASR expansion in concrete dams. ASR predictions congruent with both the field experience and the ASR prevention criteria recommended by European Committee for Standardization Technical Report CEN/TR 16349: 2012 were found, thus indicating the suitability of the proposed model

    Residual capability of alkali binding by hydrated pozzolanic cements in long-service concrete structures

    Get PDF
    An experimental procedure was developed and applied to cement pastes made with two different pozzolanic cements (CEM IV/B (P) and CEM IV/B (V)) in order to ascertain the existence of a residual capability of alkali binding by long-term hydrated pozzolanic cements and, at the same time, to evaluate the alkali retention capability and the concentration of OH- ions in the pore solution of such cementitious matrices. The developed procedure consisted of accelerated curing of cement paste specimens (150 days at 60°C and 100% RH), subsequent leaching tests at 60°C for 30 days by using deionized water or basic solutions (NaOH or KOH at different concentrations) as leaching media, and correlation of the leaching test results with a simple mass balance equation for sodium and potassium ions. The developed procedure was found to be appropriate for evaluating both the pore liquid alkalinity and the alkali retention capability by long-term hydrated pozzolanic cement pastes. A residual capability of alkali binding was also identified for both tested pozzolanic cements, thus indicating their potential ability to prevent (CEM IV/B (V)) or minimize (CEM IV/B (P)) the risk of deleterious expansion associated to alkali-aggregate reaction in long-service concrete structures, like concrete dams

    Lyophilized amniotic membrane patch (LAMPatch) as a replacement of tamponades in the treatment of primary rhegmatogenous retinal detachment

    Get PDF
    Background: The basis of retinal detachment repair is sealing the retinal breaks. In order to seal the retinal breaks, chorioretinal adhesion around these lesions has to be achieved. Laser retinopexy is not immediate thus necessitates the use of a temporal endotamponade to maintain both tissues in apposition. We propose the use of a patch of lyophilized human amniotic membrane (LAMPatch) in order to occlude the retinal tear effectively until the chorioretinal adhesion is settled, overcoming the risks and limitations of the current tamponades. Methods: 23-gauge vitrectomy was performed on eyes with primary retinal detachment with single retinal breaks of less than one-hour extension. A LAMPatch was deployed over the retinal breaks after retina was repositioned with perfluorocarbon. Neither gas nor silicon oil were injected. Results: Six eyes of six patients with total or partial retinal detachment were included. Retinas remained reattached in all cases until the end on follow-up (3, 5 months). Best-corrected visual acuity at 1-week postop was between 20/30 and 20/100. Neither elevations of intraocular pressure, cataracts nor signs of inflammation were registered during follow-up. No second surgeries were needed. Conclusion: This technique has proven to be safe and effective in this small case series. No intraocular pressure rise, inflammation or cataracts were registered until last follow-up visit.Fil: Saravia, Mario. No especifíca;Fil: Zeman Bardeci, Luis Alberto. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Berra, Alejandro. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

    Dynein Function and Protein Clearance Changes in Tumor Cells Induced by a Kunitz-Type Molecule, Amblyomin-X

    Get PDF
    Amblyomin-X is a Kunitz-type recombinant protein identified from the transcriptome of the salivary glands of the tick Amblyomma cajennense and has anti-coagulant and antitumoral activity. the supposed primary target of this molecule is the proteasome system. Herein, we elucidated intracellular events that are triggered by Amblyomin-X treatment in an attempt to provide new insight into how this serine protease inhibitor, acting on the proteasome, could be comparable with known proteasome inhibitors. the collective results showed aggresome formation after proteasome inhibition that appeared to occur via the non-exclusive ubiquitin pathway. Additionally, Amblyomin-X increased the expression of various chains of the molecular motor dynein in tumor cells, modulated specific ubiquitin linkage signaling and inhibited autophagy activation by modulating mTOR, LC3 and AMBRA1 with probable dynein involvement. Interestingly, one possible role for dynein in the mechanism of action of Amblyomin-X was in the apoptotic response and its crosstalk with autophagy, which involved the factor Bim; however, we observed no changes in the apoptotic response related to dynein in the experiments performed. the characteristics shared among Amblyomin-X and known proteasome inhibitors included NF-kappa B blockage and nascent polypeptide-dependent aggresome formation. Therefore, our study describes a Kunitz-type protein that acts on the proteasome to trigger distinct intracellular events compared to classic known proteasome inhibitors that are small-cell-permeable molecules. in investigating the experiments and literature on Amblyomin-X and the known proteasome inhibitors, we also found differences in the structures of the molecules, intracellular events, dynein involvement and tumor cell type effects. These findings also reveal a possible new target for Amblyomin-X, i.e., dynein, and may serve as a tool for investigating tumor cell death associated with proteasome inhibition.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Butantan Inst, Biochem & Biophys Lab, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biochem, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biochem, São Paulo, BrazilFAPESP: 2011/05969-4FAPESP: CAT/CEPID 1998/14307-9FAPESP: CETICs 2013/07467-1Web of Scienc

    Amblyomin-X induces ER stress, mitochondrial dysfunction, and caspase activation in human melanoma and pancreatic tumor cell

    Get PDF
    During the last two decades, new insights into proteasome function and its role in several human diseases made it a potential therapeutic target. In this context, Amblyomin-X is a Kunitz-type FXa inhibitor similar to endogenous tissue factor pathway inhibitor (TFPI) and is a novel proteasome inhibitor. Herein, we have demonstrated Amblyomin-X cytotoxicity to different tumor cells lines such as pancreatic (Panc1, AsPC1BxPC3) and melanoma (SK-MEL-5 and SK-MEL-28). Of note, Amblyomin-X was not cytotoxic to normal human fibroblast cells. In addition, Amblyomin-X promoted accumulation of ER stress markers (GRP78 and GADD153) in sensitive (SK-MEL-28) and bortezomib-resistant (Mia-PaCa-2) tumor cells. The intracellular calcium concentration [Ca2+] (i) was slightly modulated in human tumor cells (SK-MEL-28 and Mia-PaCa-2) after 24 h of Amblyomin-X treatment. Furthermore, Amblyomin-X induced mitochondrial dysfunction, cytochrome-c release, PARP cleavage, and activation of caspase cascade in both human tumor (SK-MEL-28 and Mia-PaCa-2) cells. These investigations might help in further understanding of the antitumor properties of Amblyomin-X.Sao Paulo Research Foundation (FAPESP)National Council of Technological and Scientific Development (CNPq, INCTTox)Coordination of Improvement of Higher Education Personnel (CAPES)Uniao Quimica Farmaceutica NacionalButantan Inst, Biochem & Biophys Lab, Ave Vital Brazil 1500, BR-05503900 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Biochem, Sao Paulo, SP, BrazilUniv Sao Paulo, Inst Chem, Dept Biochem, Sao Paulo, BrazilUniv Sao Paulo, Sch Med, Expt Oncol Med Invest Lab, LIM 24, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Biochem, Sao Paulo, SP, BrazilFAPESP: 2010/52669-3FAPESP: 2010/07958-7FAPESP: 2011/05969-4FAPESP: CAT/CEPID 1998/14307-9FAPESP: CETICs 2013/07467-1Web of Scienc

    30 años de la LISMI: un recorrido de inclusión

    Get PDF
    Con este folleto, el CERMI desea rendir tributo a una norma legal provechosa para el propósito que perseguía, recopilando los artículos publicados para conmemorar este aniversario en los últimos meses en cemi.es semanal, el periódico de la discapacidad, en los que varias personas significadas de juicio certero se pronuncian sobre el valor de la LISMI, 30 años después

    Psychological treatments and psychotherapies in the neurorehabilitation of pain. Evidences and recommendations from the italian consensus conference on pain in neurorehabilitation

    Get PDF
    BACKGROUND: It is increasingly recognized that treating pain is crucial for effective care within neurological rehabilitation in the setting of the neurological rehabilitation. The Italian Consensus Conference on Pain in Neurorehabilitation was constituted with the purpose identifying best practices for us in this context. Along with drug therapies and physical interventions, psychological treatments have been proven to be some of the most valuable tools that can be used within a multidisciplinary approach for fostering a reduction in pain intensity. However, there is a need to elucidate what forms of psychotherapy could be effectively matched with the specific pathologies that are typically addressed by neurorehabilitation teams. OBJECTIVES: To extensively assess the available evidence which supports the use of psychological therapies for pain reduction in neurological diseases. METHODS: A systematic review of the studies evaluating the effect of psychotherapies on pain intensity in neurological disorders was performed through an electronic search using PUBMED, EMBASE, and the Cochrane Database of Systematic Reviews. Based on the level of evidence of the included studies, recommendations were outlined separately for the different conditions. RESULTS: The literature search yielded 2352 results and the final database included 400 articles. The overall strength of the recommendations was medium/low. The different forms of psychological interventions, including Cognitive-Behavioral Therapy, cognitive or behavioral techniques, Mindfulness, hypnosis, Acceptance and Commitment Therapy (ACT), Brief Interpersonal Therapy, virtual reality interventions, various forms of biofeedback and mirror therapy were found to be effective for pain reduction in pathologies such as musculoskeletal pain, fibromyalgia, Complex Regional Pain Syndrome, Central Post-Stroke pain, Phantom Limb Pain, pain secondary to Spinal Cord Injury, multiple sclerosis and other debilitating syndromes, diabetic neuropathy, Medically Unexplained Symptoms, migraine and headache. CONCLUSIONS: Psychological interventions and psychotherapies are safe and effective treatments that can be used within an integrated approach for patients undergoing neurological rehabilitation for pain. The different interventions can be specifically selected depending on the disease being treated. A table of evidence and recommendations from the Italian Consensus Conference on Pain in Neurorehabilitation is also provided in the final part of the pape

    What is the role of the placebo effect for pain relief in neurorehabilitation? Clinical implications from the Italian consensus conference on pain in neurorehabilitation

    Get PDF
    Background: It is increasingly acknowledged that the outcomes of medical treatments are influenced by the context of the clinical encounter through the mechanisms of the placebo effect. The phenomenon of placebo analgesia might be exploited to maximize the efficacy of neurorehabilitation treatments. Since its intensity varies across neurological disorders, the Italian Consensus Conference on Pain in Neurorehabilitation (ICCP) summarized the studies on this field to provide guidance on its use. Methods: A review of the existing reviews and meta-analyses was performed to assess the magnitude of the placebo effect in disorders that may undergo neurorehabilitation treatment. The search was performed on Pubmed using placebo, pain, and the names of neurological disorders as keywords. Methodological quality was assessed using a pre-existing checklist. Data about the magnitude of the placebo effect were extracted from the included reviews and were commented in a narrative form. Results: 11 articles were included in this review. Placebo treatments showed weak effects in central neuropathic pain (pain reduction from 0.44 to 0.66 on a 0-10 scale) and moderate effects in postherpetic neuralgia (1.16), in diabetic peripheral neuropathy (1.45), and in pain associated to HIV (1.82). Moderate effects were also found on pain due to fibromyalgia and migraine; only weak short-term effects were found in complex regional pain syndrome. Confounding variables might have influenced these results. Clinical implications: These estimates should be interpreted with caution, but underscore that the placebo effect can be exploited in neurorehabilitation programs. It is not necessary to conceal its use from the patient. Knowledge of placebo mechanisms can be used to shape the doctor-patient relationship, to reduce the use of analgesic drugs and to train the patient to become an active agent of the therapy

    Beta-Blocker Use in Older Hospitalized Patients Affected by Heart Failure and Chronic Obstructive Pulmonary Disease: An Italian Survey From the REPOSI Register

    Get PDF
    Beta (β)-blockers (BB) are useful in reducing morbidity and mortality in patients with heart failure (HF) and concomitant chronic obstructive pulmonary disease (COPD). Nevertheless, the use of BBs could induce bronchoconstriction due to β2-blockade. For this reason, both the ESC and GOLD guidelines strongly suggest the use of selective β1-BB in patients with HF and COPD. However, low adherence to guidelines was observed in multiple clinical settings. The aim of the study was to investigate the BBs use in older patients affected by HF and COPD, recorded in the REPOSI register. Of 942 patients affected by HF, 47.1% were treated with BBs. The use of BBs was significantly lower in patients with HF and COPD than in patients affected by HF alone, both at admission and at discharge (admission, 36.9% vs. 51.3%; discharge, 38.0% vs. 51.7%). In addition, no further BB users were found at discharge. The probability to being treated with a BB was significantly lower in patients with HF also affected by COPD (adj. OR, 95% CI: 0.50, 0.37-0.67), while the diagnosis of COPD was not associated with the choice of selective β1-BB (adj. OR, 95% CI: 1.33, 0.76-2.34). Despite clear recommendations by clinical guidelines, a significant underuse of BBs was also observed after hospital discharge. In COPD affected patients, physicians unreasonably reject BBs use, rather than choosing a β1-BB. The expected improvement of the BB prescriptions after hospitalization was not observed. A multidisciplinary approach among hospital physicians, general practitioners, and pharmacologists should be carried out for better drug management and adherence to guideline recommendations
    • …
    corecore