148 research outputs found

    Segmented multifunctional poly(ether ester) polymers containing H-bonding units. Preparation and charactization

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    A series of poly(ether ester)s containing amide and carbamate groups as H-bonding units and 13-50 mol-% of poly(ethylene glycol) (PEG) segments were prepared by polycondensation in bulk using Ti(OBu)4 as a catalyst. The copolymers were obtained starting from PEG/1,4-butanediol mixtures and a synthetic monomer carrying H-bonding groups. These polymers were designed for biomedical applications, where material biodegradability is required. The influence of the nature of the H-bonding units, the length of the polymethylene spacer between the H-bonding groups and the PEG content on the thermal and solubility properties of the copolymers was investigated. Amide-containing copolymers were more thermally stable than those containing carbamate groups. The PEG content also slightly affected the polymer thermal stability. The DSC traces of all samples presented multiple transitions, whose shape and peak temperature were strongly dependent on the PEG content. Polymer hydrophilicity, surface free energy and equilibrium swelling in phosphate buffer solution (PBS) at 37 °C were mainly influenced by the PEG content, whereas the nature of the H-bonding groups had little effect

    Thermal, Mechanical and Micromechanical Analysis of PLA/PBAT/POE-g-GMA Extruded Ternary Blends

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    In order to toughen Poly(lactic) acid and binary blends with low PBAT content while maintaining a high biodegradability of the final material, poly(lactic) acid (PLA)/poly(butylene-adipate-co-terephthalate) (PBAT)/ polyolefin elastomer grafted with glycidyl methacrylate (POE-g-GMA) extruded ternary blends have been investigated in this work from a thermal, mechanical, and rheological point of view. The two elastomers have been added in different amounts as dispersed phases into the PLA matrix, paying attention to the final objective: the design of a 90% biodegradable formulation according to EN 13432. These ternary blends exhibited improved impact properties but still low elongation at break. Consequently, to the ternary composition with the best compromise of PLA quantity, biodegradability and thermo-mechanical properties (81 wt.% PLA, 9 wt.% PBAT, and 10 wt.% POE-g-GMA) a small quantity (10 wt.%) of a biobased plasticizer was added in order to further increase the impact properties in parallel with the tensile flexibility. Two types of plasticizers were investigated, one not reactive [Acetyl Tributyl Citrate (ATBC)], and one reactive [Glycidyl ether (EJ-400)]. A micromechanical study, in order to investigate the toughening mechanism of these systems, was carried out on the final formulations. They were also examined by dilatometric tests and elasto-plastic fracture mechanics correlating the data obtained to the morphology and to the rheological properties. In conclusion, the best compromise between impact, tensile properties and biodegradability content was achieved using the reactive plasticizer (EJ-400) whose interaction with the matrix is confirmed by the FT-IR analysis

    Divergences in insulin resistance between the different phenotypes of the polycystic ovary syndrome

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    Context/Objective: Current diagnostic criteria for polycystic ovary syndrome (PCOS) have generated distinct PCOS phenotypes, based on the different combinations of diagnostic features found in each patient. Our aim was to assess whether either each single diagnostic feature or their combinations into the PCOS phenotypes may predict insulin resistance in these women. Patients/Design: A total of 137 consecutive Caucasian women with PCOS, diagnosed by the Rotterdam criteria, underwent accurate assessment of diagnostic and metabolic features. Insulin sensitivity was measured by the glucose clamp technique. Results: Among women with PCOS, 84.7% had hyperandrogenism, 84.7% had chronic oligoanovulation, and 89% had polycystic ovaries. According to the individual combinations of these features, 69.4% of women had the classic phenotype, 15.3% had the ovulatory phenotype, and 15.3% had the normoandrogenic phenotype. Most subjects (71.4%) were insulin resistant. However, insulin resistance frequency differed among phenotypes, being 80.4%, 65.0%, and 38.1%, respectively, in the 3 subgroups (P < .001). Although none of the PCOS diagnostic features per se was associated with the impairment in insulin action, after adjustment for covariates, the classic phenotype and, to a lesser extent, the ovulatory phenotype were independently associated with insulin resistance, whereas the normoandrogenic phenotype was not. Metabolic syndrome frequency was also different among phenotypes (P = .030). Conclusions: There is a scale of metabolic risk among women with PCOS. Although no single diagnostic features of PCOS are independently associated with insulin resistance, their combinations, which define PCOS phenotypes, may allow physicians to establish which women should undergo metabolic screening. In metabolic terms, women belonging to the normoandrogenic phenotype behave as a separate group

    Evaluation of background parenchymal enhancement on breast MRI: A systematic review

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    Objective: To perform a systematic review of the methods used for background parenchymal enhancement (BPE) evaluation on breast MRI. Methods: Studies dealing with BPE assessment on breast MRI were retrieved from major medical libraries independently by four reviewers up to 6October 2015. The keywords used for database searching are "background parenchymal enhancement", "parenchymal enhancement", "MRI" and "breast". The studies were included if qualitative and/or quantitative methods for BPE assessment were described. Results: Of the 420 studies identified, a total of 52 articles were included in the systematic review. 28 studies performed only a qualitative assessment of BPE, 13 studies performed only a quantitative assessment and 11 studies performed both qualitative and quantitative assessments. A wide heterogeneity was found in the MRI sequences and in the quantitative methods used for BPE assessment. Conclusion: A wide variability exists in the quantitative evaluation of BPE on breast MRI. More studies focused on a reliable and comparable method for quantitative BPE assessment are needed. Advances in knowledge: More studies focused on a quantitative BPE assessment are needed

    Trans-synaptic degeneration in the optic pathway. A study in clinically isolated syndrome and early relapsing-remitting multiple sclerosis with or without optic neuritis

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    Increasing evidence suggest that neuronal damage is an early and diffuse feature of Multiple Sclerosis (MS) pathology. Analysis of the optic pathway may help to clarify the mechanisms involved in grey matter damage in MS. Purpose of our study was to investigate the relationship between inflammation and neurodegeneration and to achieve evidence of trans-synaptic degeneration in the optic pathway in MS at clinical onset

    Monomers, Materials and Energy from Coffee By-Products: A Review

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    open11siIn recent years, the circular economy and sustainability have gained attention in the food industry aimed at recycling food industrial waste and residues. For example, several plant-based materials are nowadays used in packaging and biofuel production. Among them, by-products and waste from coffee processing constitute a largely available, low cost, good quality resource. Coffee production includes many steps, in which by-products are generated including coffee pulp, coffee husks, silver skin and spent coffee. This review aims to analyze the reasons why coffee waste can be considered as a valuable source in recycling strategies for the sustainable production of bio-based chemicals, materials and fuels. It addresses the most recent advances in monomer, polymer and plastic filler productions and applications based on the development of viable biorefinery technologies. The exploration of strategies to unlock the potential of this biomass for fuel productions is also revised. Coffee by-products valorization is a clear example of waste biorefinery. Future applications in areas such as biomedicine, food packaging and material technology should be taken into consideration. However, further efforts in techno-economic analysis and the assessment of the feasibility of valorization processes on an industrial scale are needed.openSisti, Laura; Celli, Annamaria; Totaro, Grazia; Cinelli, Patrizia; Signori, Francesca; Lazzeri, Andrea; Bikaki, Maria; Corvini, Philippe; Ferri, Maura; Tassoni, Annalisa; Navarini, LucianoSisti, Laura; Celli, Annamaria; Totaro, Grazia; Cinelli, Patrizia; Signori, Francesca; Lazzeri, Andrea; Bikaki, Maria; Corvini, Philippe; Ferri, Maura; Tassoni, Annalisa; Navarini, Lucian

    Metabolic inflexibility is a feature of women with polycystic ovary syndrome and is associated with both insulin resistance and hyperandrogenism

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    Context: Metabolic inflexibility, ie, the impaired ability of the body to switch from fat to carbohydrate oxidation under insulin-stimulated conditions, is associated with insulin resistance. This alteration in metabolic plasticity can lead to organ dysfunction and is considered a key issue among the abnormalities of the metabolic syndrome. It is still unknown whether this phenomenon occurs in women with polycystic ovary syndrome (PCOS). Objective: Our objective was to examine whether metabolic inflexibility is a feature of PCOS women and whether hyperandrogenism may contribute to this phenomenon. Design and Patients: Eighty-nine Caucasian women with PCOS were submitted to hyperinsulinemic-euglycemic clamp. Respiratory exchange ratios were evaluated at baseline and during hyperinsulinemia by indirect calorimetry to quantify substrate oxidative metabolism. Total testosterone was measured by liquid chromatography mass spectrometry and free testosterone by equilibrium dialysis. Setting: Outpatients were seen in a tertiary care academic center. Main Outcome Measure: Metabolic flexibility was assessed by the change in respiratory quotient upon insulin stimulation. Results: Sixty-five of the 89 PCOS women(73%) had increased serum free testosterone, 68 (76%) were insulin resistant, and 62 (70%) had an impaired metabolic flexibility. Comparison of hyperandrogenemic and normoandrogenemic women showed that the 2 subgroups were of similar age but differed in terms of several anthropometric and metabolic features. In particular, hyperandrogenemic women had greater body mass index (32.9 +/- 1.0 vs 24.7 +/- 0.9 kg/m(2), P < .001) and lower glucose utilization during the clamp (9.2 +/- 0.4 vs 10.9 +/- 0.7 mg/kg fat-free mass . min, P < .023) and metabolic flexibility (0.09 +/- 0.06 vs 0.12 +/- 0.01, P < .014). In univariate analysis, metabolic flexibility was associated with several anthropometric, endocrine, and metabolic features. In multivariate analysis, this feature was directly associated with baseline respiratory quotient and insulin sensitivity and inversely with free testosterone and free fatty acids concentrations under insulin suppression (R-2 = 0.634, P < .001). Conclusions: Metabolic inflexibility is a feature of PCOS women. Both insulin resistance and androgen excess might contribute to this abnormality

    Steroid treatment of acute graft-versus-host disease grade I: A randomized trial

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    Patients with acute graft-versus-host disease (GvHD) grade I were randomized to an observation arm (n=85) or to a treatment arm (n=86) consisting of 6-methylprednisolone 1 mg/kg/day, after stratification for age and donor type. The primary end point was development of grade II-IV GvHD. The cumulative incidence of grade II-IV GvHD was 50% in the observation arm and 33% in the treatment arm (P=0.005). However, grade III-IV GvHD was comparable (13% vs. 10%, respectively; P=0.6), and this was true for sibling and alternative donor transplants. Moderate/severe chronic GvHD was also comparable (17% vs. 9%). In multivariate analysis, an early interval between transplant and randomization

    Unmanipulated haploidentical transplants compared with other alternative donors and matched sibling grafts

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    We studied 459 consecutive patients with hematologic malignancies, median age 44&nbsp;years (range, 15 to 71&nbsp;years), who underwent transplantation with grafts from identical sibling donors (SIB; n&nbsp;=&nbsp;176), matched unrelated donors (MUD; n&nbsp;=&nbsp;43), mismatched unrelated donors (mmUD; n&nbsp;=&nbsp;43), unrelated cord blood (UCB; n&nbsp;=&nbsp;105) or HLA-haploidentical family donors (HAPLO; n&nbsp;=&nbsp;92). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate in the SIB recipients; antithymocyte globulin for the MUD, mmUD, and UCB recipients; and post-transplantation cyclophosphamide, cyclosporine, and mycophenolate in the HAPLO recipients. Conditioning regimens were mostly myeloablative (69%). Advanced disease phase was more frequent, but not significantly so, in the HAPLO and mmUD groups (P&nbsp;=&nbsp;.08). Acute GVHD grade II-IV was significantly less frequent in the HAPLO, UCB, and MUD groups (14% to 21%) compared with the SIB (31%) and mmUD (42%) groups (P&nbsp;&lt;&nbsp;.001), and there was a trend toward less moderate-severe chronic GVHD in the HAPLO and UCB groups (P&nbsp;=&nbsp;.053). The proportion of patients off cyclosporine at 1&nbsp;year ranged from 55% for the SIB group to 81% for the HAPLO group (P&nbsp;&lt;&nbsp;.001). Transplantation-related mortality at 2&nbsp;years was lower in the HAPLO and SIB groups (18% to 24%) compared with the MUD, mmUD, and UCB groups (33% to 35%; P&nbsp;=&nbsp;.10). Relapse rate was comparable in the 5 groups (P&nbsp;=&nbsp;.80). The 4-year actuarial survival was 45% in the SIB group, 43% in the MUD group, 40% in the mmUD group, 34% in the UCB group, and 52% in the HAPLO group (P&nbsp;=&nbsp;.10). In multivariate analysis, advanced disease was a negative predictor of survival (hazard ratio [HR], 2.4; P&nbsp;&lt;&nbsp;.0001), together with a diagnosis of acute leukemia (HR, 1.8; P&nbsp;=&nbsp;.0001); HAPLO grafts were comparable to SIB (P&nbsp;=&nbsp;.80), whereas UCB had inferior survival (P&nbsp;=&nbsp;.03). In conclusion, unmanipulated haploidentical family donor transplants are an additional option for patients lacking a matched sibling donor
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