1,721,456 research outputs found
Contributions to knowledge of Diptera Chamaemyiidae: VI. Ethological and morphological notes on Leucopis (Leucopomyia) silesiaca Egger and Leucopis (Leucopomyia) alticeps Czerny
No full textCosa c'è di nuovo a proposito di enterocolite necrotizzante ?
Full text linkSecondo la teoria patogenetica classica formulata nel 1969 da J.R.Lloyd, l’enterocolite necrotizzante nel neonato prematuro (NEC) dovrebbe essere
l’evento finale di un “cascata” che, partendo da un’ischemia intestinale “da stress”, induce alterazioni nella barriera mucosa intestinale con traslocazione
e colonizzazione batterica della parete, perforazione e morte. Nuove ipotesi patogenetiche vedono invece la NEC come il risultato finale di una serie di
squilibri indotti dall’immaturità del sistema gastrointestinale, delle funzioni digestive, della regolazione circolatoria, delle difese immunitarie del neonato. La vascolarizzazione intestinale è alterata in seguito a sovvertimenti nel sistema di regolazione vascolare intrinseco ed estrinseco; la barriera mucosa è
alterata in conseguenza a squilibri fra segnali pro-infiammatori ed anti-infiammatori, che aggravano le lesioni della parete sino a determinarne la completa
distruzione; la flora intestinale è squilibrata in favore dei batteri patogeni tanto da alterare le difese immunitarie intestinali. L’evento scatenante della NEC
dovrebbe essere quindi un’apoptosi degli enterociti, seguita dallo scatenarsi della risposta infiammatoria come evento finale. Le misure preventive della NEC includono l’allattamento al seno, il ricorso a probiotici e ad antibiotici, l’incremento delle difese immunitarie mediante
supplementazione di IgA, l’infusione di EGF, GCSF e EPO ricombinante per ostacolare l’apoptosi e la somministrazione di L-arginina e/ o glutammina per
migliorare la regolazione del flusso vascolare intestinale.
Le possibili opzioni chirurgiche includono la laparotomia con resezione del segmento necrotico seguita da enterotomia o anastomosi primaria, oppure il
drenaggio peritoneale primario (PPD) in anestesia locale, oppure la tecnica clip & drop. Il PPD ha guadagnato popolarità come trattamento risolutivo della
NEC perforata, benché recenti lavori abbiano posto in dubbio questo approccio in favore della classica laparotomia
Estimation of corrosion propagation in carbonated reinforced concrete structures by monitoring of the electrical resistivity of concrete [Stima della propagazione della corrosione in strutture in calcestruzzo armato carbonatate attraverso il monitoraggio della resistività del calcestruzzo]
No full textIn chlorides-free environment, carbonation-induced corrosion is the main form of degradation of reinforced concrete. When carbonation reaches the reinforcement, this become active and corrosion can occur. The end of the service life of the reinforced concrete structure depends on the corrosion propagation. In this paper the results of a research that aims to estimate the corrosion rate of reinforcement with different concrete cover by monitoring the electrical resistivity of concrete was reported. The experimental tests were carried out on carbonated reinforced concrete specimens exposed in a climatic chamber and outdoor, unsheltered from the rain. Within the specimens specific probes for measuring the electrical resistivity of concrete at different concrete cover depths were embedded. The corrosion rate of the reinforcement was measured by the linear polarization resistance technique
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
[Perspectives on treatment of the renal failure]
No full textThe next decade will face an increase in the number of patients affected by end-stage renal disease. In line with the growing incidence of type 2 diabetes, hypertension and old age in the general population, we can expect a dramatic increase of uremic patients needing a substitutive treatment of renal function. On the basis of the current trends, we expect an exponential growth of cardiovascular complications in both dialysis and transplant populations. Progress in the treatment of end-stage renal disease will aim at the prevention of cardiovascular complications, that remain the leading cause of morbidity and mortality in uremic patients. Preventive interventions for cardiovascular complications should focus on traditional risk factors, such as hypertension, dyslipidemia and obesity, diabetes mellitus, smoking, as well as on the non traditional risk factors inherent in the uremic state, such as anemia, hyperphosphoremia, hyperhomocysteinemia, inflammation and malnutrition. Recent and future innovations in peritoneal dialysis solutions include a larger use of icodextrin, a glucose polymer able to enhance ultrafiltration while inducing less glycation and caloric absorption, and perhaps improving blood pressure control. The gene therapy directed to the mesothelial cells should bring about improvements in nutrition, cardiovascular comorbidity, and dialysis adequacy. Patients submitted to increased hemodialysis time or to the implementation of a night or daily hemodialysis program have shown better blood pressure control, cardiovascular stability, tolerability and perhaps reduced mortality. Modifications of dialysis schedules clearly indicate another road to future improvements in renal replacement therapy. In the field of kidney transplantation, much improvement has already been achieved regarding the prevention of acute rejection, and the new therapeutic strategies are aimed at reducing the incidence of the adverse reactions of immunosuppressive drugs, as well as of the chronic allograft nephropathy. Induction of transplantation tolerance remains the most attractive target, which now seems closer than before because many of the mechanisms involved in the tolerance induction have been better elucidated
Possibili implementazioni dell’approccio bim nelle fasi di gestione e manutenzione delle infrastrutture di trasporto
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