Treatment of displaced intra-articular calcaneal fractures by ligamentotaxis: current concepts’ review

Introduction: A large variety of therapeutic modalities for calcaneal fractures have been described in the literature. No single treatment modality for displaced intra-articular calcaneal fractures has proven superior over the other. This review describes and compares the different percutaneous distractional approaches for intra-articular calcaneal fractures. The history, technique, anatomical and fracture considerations, limitations and the results of different distractional approaches reported in the literature are reviewed. Method: Literature review on different percutaneous distractional approaches for displaced intra-articular calcaneal fractures. Results: Eight studies in which application of a distraction technique was used for the treatment of calcaneal fractures were identified. Because of the use of different classification, techniques, and outcome scoring systems, a meta-analysis was not possible. A literature review reveals overall fair to poor result in 10-29% of patients. Ten up to 26% of patients are unable to return to work after percutaneous treatment of their fracture. A secondary arthrodesis has to be performed in 2-15% of the cases. Infectious complications occur in 2-15%. Some loss of reduction is reported in 4-67%. Conclusion: Percutaneous distractional reduction and fixation appears to be a safe technique with overall good results and an acceptable complication rate, compared with other treatment modalities for displaced intra-articular calcaneal fractures. A meta-analysis, based on Cochrane Library criteria is not possible, because of a lack of level 1 and 2 trials on this subject

Impact of Diabetes on Postinfarction Heart Failure and Left Ventricular Remodeling

Diabetes mellitus, the metabolic syndrome, and the underlying insulin resistance are increasingly associated with diastolic dysfunction and reduced stress tolerance. The poor prognosis associated with heart failure in patients with diabetes after myocardial infarction is likely attributable to many factors, important among which is the metabolic impact from insulin resistance and hyperglycemia on the regulation of microvascular perfusion and energy generation in the cardiac myocyte. This review summarizes epidemiologic, pathophysiologic, diagnostic, and therapeutic data related to diabetes and heart failure in acute myocardial infarction and discusses novel perceptions and strategies that hold promise for the future and deserve further investigation

Fly ash geopolymers: effect of admixtures on fresh and hardened properties

One of the most important challenges for the cement industry is to find sustainable solutions to mitigate environmental footprint of its activities. Geopolymers are particularly attractive for this purpose; the use of waste as precursors, along with a room temperature curing, makes these materials low-polluting binders potentially suitable for sustainable building products. The lack of information on effective admixtures is limiting the practical acceptance of geopolymer concrete. The purpose of this paper is to study the influence of different superplasticizers, commonly used in Portland cement concrete technology, on properties of fly-ash based geopolymers. First, second and third generation superplasticizers (i.e., lignin-, naphthalene-, melamine-, polycarboxylic ether, acrylic based superplasticizers) have been used for the preparation of pastes and mortars. Two different amounts of admixture were tested: 0.6wt% and 1.0wt% by mass of binder. Among the investigated admixtures, the polycarboxylic ether based superplasticizer is the most effective. With a dosage of 1.0wt % by mass of fly ash it can be achieved an increase in workability of both geopolymer pastes and mortars without compromising the final strength of hardened material

Thermal properties of fly ash based geopolymers containing refractory powder

Abstract from the Young Researchers\u2019 Forum, XIII AIMAT Congress and SIB Congress - Ischia, Italy, July 2016. Geopolymers are a new class of material synthetized through the alkali activation of a low-calcium aluminosilicate precursor. Several studies highlighted their remarkable thermal stability. However, the majority of the research focus on metakaolin-based geopolymers and, in most of the cases, a thermal curing is performed. This study, instead, aims to investigate the thermal properties of fly ash-based geopolymers containing refractory powder, cured both at room and high (70\ub0C) temperature

Study of the influence of different admixtures on the properties of alkali-activated materials

In the last years many studies have been addressed on the development of new types of cement with the aim to find a sustainable alternative to traditional ordinary Portland cement. Alkali-activated materials (AAM) seem particularly attractive for this purpose, even if effective admixtures such as plasticizers still need to be designed limiting so far the diffusion of AAM for geopolymer concrete preparation. AAM come from the alkali-activation of aluminosilicate powders with suitable amorphous content. Among all the suitable aluminosilicate precursors, great interest is nowadays focused on the possibility to activate industrial waste (e.g., slag or fly ash). The use of waste as precursors, along with a room temperature curing, makes these materials low-polluting binders potentially suitable for green building products. The purpose of this paper is to study the influence of different superplasticizers on the AAM properties. In particular, first, second and third generation superplasticizers (i.e., lignin-, naphthalene-, melamine-, polycarboxylic ether-, and acrylic based superplasticizers) have been used for the preparation of carbon fly ash pastes and mortars in order to improve their physical and mechanical properties at the fresh and hardened state. Different amounts were tested with the aim to determine the best concentration. The results are then compared with those of reference AAM prepared without any admixture addition. Among the investigated admixtures, the mix with the polycarboxylic ether based plasticizer has the best behavior in terms of both fresh and hardened state properties. The optimum amount of SP corresponds to a dosage of 1% by mass of fly ash. Test results show an increase in terms of workability of both geopolymeric pastes and mortars in comparison with AAM samples without any admixture addition. Moreover the use of polycarboxylic ether based superplasticizer does not compromise the final strength of hardened material

Assessing the suitability of fly ash geopolymer for strengthening existing reinforced concrete structure

Abstract from the Young Researchers’ Forum, XIII AIMAT Congress and SIB Congress - Ischia, Italy, July 2016. Fiber-reinforced cementitious matrix (FRCM) composites have gained increasing interest as newly developed system for strengthening reinforced concrete structures. FRCM system provides for the embedding of high-strength fibers into an inorganic matrix. The possibility of using geopolymers instead of cementitious matrix is very attractive since this new class of inorganic material, synthetized through the alkali activation of an aluminosilicate precursor, showed competitive features when compared to cement based materials in both terms of performances and sustainability. However, research dealing with the use of geopolymer for strengthening and rehabilitation of reinforced concrete structures with externally-bonded composite materials are limited