Geopolymer/PEG Hybrid Materials Synthesis and Investigation of the Polymer Influence on Microstructure and Mechanical Behavior

Geopolymers are aluminosilicate inorganic polymers, obtained from the alkali activation of powders containing SiO2+Al2O3>80wt%, mainly proposed as environmentally friendly building materials. In this work, metakaolin-based geopolymers have been prepared and a water-soluble polymer, polyethylene glycol (PEG), has been added in different percentages to obtain organic-inorganic hybrid geopolymers. The influence of both the polymer amount and aging time on the structure and the mechanical behavior of the materials were investigated. FTIR spectroscopy allowed us to follow the evolution of the aluminosilicate framework during the geopolymerization process. This analysis revealed that PEG leads to a network which is rich in Al-O-Si bonds and forms H-bonds with the inorganic phase. SEM microscope showed that the two phases are interpenetrated on micrometric scales. Traction and bending tests have been carried out on appropriate samples to investigate the mechanical behavior of the obtained hybrids, showing that both PEG content and aging time affect the material behavior

Retrospective Survey on the Prevalence and Outcome of Prior Autoimmune Disease in Patients with Aplastic Anemia Reported to the Registry of the European Group for Blood and Marrow Transplantation

Abstract BACKGROUND: Aplastic anemia (AA) is rarely described after a diagnosis of autoimmune disease (aID). AIMS: To assess the prevalence of prior aID in patients with AA recorded in the registry of the European Group for Blood and Marrow Transplantation (EBMT) and to evaluate treatment and outcome. METHODS: 1,251 AA patients from 18 EBMT centers were assessed. RESULTS: Fifty patients (4%) were eligible: 22 males and 28 females with a median age of 46 years at the diagnosis of aID and of 51 years at the diagnosis of AA. Information on the treatment of AA was available in 49 patients: 38 received only immunosuppressive therapy (IST), 8 patients underwent hematopoietic stem cell transplantation (HSCT) - 6 as first-line therapy and 2 after failure of IST - whilst 3 patients had a spontaneous recovery. After a median follow-up of 3.19 years, 32 patients were alive, including 7 of the 8 patients who underwent HSCT. Only 6 of 32 patients who were alive at the last follow-up were receiving IST for AA. CONCLUSIONS: Most cases of AA following aID benefitted from IST or HSCT if a matched donor was available. Further prospective investigation is needed to assess the effects of IST on the outcome of underlying aID

Retrospective Survey on the Prevalence and Outcome of Prior Autoimmune Disease in Patients with Aplastic Anemia Reported to the Registry of the European Group for Blood and Marrow Transplantation

Abstract BACKGROUND: Aplastic anemia (AA) is rarely described after a diagnosis of autoimmune disease (aID). AIMS: To assess the prevalence of prior aID in patients with AA recorded in the registry of the European Group for Blood and Marrow Transplantation (EBMT) and to evaluate treatment and outcome. METHODS: 1,251 AA patients from 18 EBMT centers were assessed. RESULTS: Fifty patients (4%) were eligible: 22 males and 28 females with a median age of 46 years at the diagnosis of aID and of 51 years at the diagnosis of AA. Information on the treatment of AA was available in 49 patients: 38 received only immunosuppressive therapy (IST), 8 patients underwent hematopoietic stem cell transplantation (HSCT) - 6 as first-line therapy and 2 after failure of IST - whilst 3 patients had a spontaneous recovery. After a median follow-up of 3.19 years, 32 patients were alive, including 7 of the 8 patients who underwent HSCT. Only 6 of 32 patients who were alive at the last follow-up were receiving IST for AA. CONCLUSIONS: Most cases of AA following aID benefitted from IST or HSCT if a matched donor was available. Further prospective investigation is needed to assess the effects of IST on the outcome of underlying aID

Impact of the intensity of the pretransplantation conditioning regimen in patients with prior invasive aspergillosis undergoing allogeneic hematopoietic stem cell transplantation: a retrospective survey of the Infectious Diseases Working Party of the European Group for Blood and Marrow Transplantation

In this retrospective study, we analyzed the outcomes of 129 patients who underwent an allogeneic hematopoietic stem cell transplantation (allo-HSCT) and had a history of probable or proven invasive aspergillosis (IA), of whom 57 (44%) received a reduced-intensity conditioning (RIC). Overall, 27 patients with IA progressed after the allo-HSCT (cumulative incidence [CumInc] at 2 years, 22%). The variables that increased the 2-year CumInc of IA progression were (1) longer duration of neutropenia after transplantation; (2) advanced status of the underlying disease; and (3) less than 6 weeks from start of systemic anti-Aspergillus therapy and the allo-HSCT. In addition, (4) conventional myeloablative conditioning increased the risk of progression early after transplantation (before day 30) only, while 3 variables increased the risk beyond day 30 were (5) cytomegalovirus disease; (6) bone marrow or cord blood as source of stem cells; and (7) grades II to IV acute graft-versus-host disease (GVHD). A risk model for progression was generated, defined as low (0-1 risk factors, 6% incidence), intermediate (2-3 risk factors, 27% incidence), or high risk (> or = 3 risk factors, 72% incidence [P < .001]). These findings may help in the interpretation and design of future studies on secondary prophylaxis of IA after an allo-HSCT

Geopolymer/PEG Hybrid Materials Synthesis and Investigation of the Polymer Influence on Microstructure and Mechanical Behavior

Geopolymers are aluminosilicate inorganic polymers, obtained from the alkali activation of powders containing SiO2+Al2O3>80wt%, mainly proposed as environmentally friendly building materials. In this work, metakaolin-based geopolymers have been prepared and a water-soluble polymer, polyethylene glycol (PEG), has been added in different percentages to obtain organic-inorganic hybrid geopolymers. The influence of both the polymer amount and aging time on the structure and the mechanical behavior of the materials were investigated. FTIR spectroscopy allowed us to follow the evolution of the aluminosilicate framework during the geopolymerization process. This analysis revealed that PEG leads to a network which is rich in Al-O-Si bonds and forms H-bonds with the inorganic phase. SEM microscope showed that the two phases are interpenetrated on micrometric scales. Traction and bending tests have been carried out on appropriate samples to investigate the mechanical behavior of the obtained hybrids, showing that both PEG content and aging time affect the material behavior