The two-way shape memory behaviour of crosslinked poly(ϵ-caprolactone) systems with largely varied network density

The two-way shape memory behaviour of semicrystalline networks was investigated on systems based on poly(epsilon-caprolactone) featuring significantly different network architecture. Crosslinked poly(epsilon-caprolactone)s were prepared by thermal curing from methacrylic end-capped linear chains having various methacrylation degrees. By conveniently reducing the methacrylation degree, the crosslink density of cured materials was varied over a range of one order of magnitude, leading to comparable changes in the material compliance in the rubbery region, but only to moderate variations in melting and crystallization temperatures (T-m and T-c) and in the crystallinity content. When subjected to constant non-zero stress and to cooling-heating cycles from above T-m to below T-c, the materials undergo a reversible two-way elongation-contraction effect, whose extent depends on material structure and applied stress. The structural changes in the crystalline phase accompanying the cooling-induced elongation were studied through differential scanning calorimetry and X-ray diffraction analyses. The elongation process involves different contributions of entropy- and crystallization-driven processes, whose amounts were investigated as a function of the loading conditions and the molecular architecture. The role of the network density towards a controlled two-way response is evidenced, showing that a proper value of the crosslink density has to be identified to maximize the two-way elongation capabilities

Regional Outcome Evaluation Program (P.Re.Val.E.): Reduction of inequality in access to effective health care in the Lazio region of Italy (2012–2015)

<div><p>Background</p><p>Inequalities in health among groups of various socio-economic status (as measured by education, occupation, and income) constitute one of the main challenges for public health. Since 2006, the Lazio Regional Outcome Evaluation Program (P.Re.Val.E.), presents a set of indicators of hospital performance based on quality standards driven by strong clinical recommendations, and measures the variation in the access to effective health care for different population groups and providers in the Lazio Region. One of the aims of the program was to compare population subgroups in order to promote equity in service provision. Since June 2013, a new management strategy has been put in place that assigned specific goals based on performance assessment to the chief executive officers of the hospitals.</p><p>Aim</p><p>To evaluate whether, in recent years, there has been a reduction in the differential access to effective health care, among individuals with different educational levels.</p><p>Methods</p><p>We enrolled all patients discharged from both public and private hospitals of the Lazio region between 2012 and 2015, living in Lazio region. We analysed the proportion of patients with ST-elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention within 90 minutes (primary PCI), the proportion of patients with hip fracture (HF) who underwent surgery within 2 days, and the proportion of women with primary C-section. We applied multivariate logistic regression models to assess the effect of educational level on health outcomes, adjusting for demographic characteristics and comorbidities that could affect the outcomes. For each year of the study period, we compared adjusted proportions of outcomes for the highest and the lowest level of education by using percentage differences.</p><p>Results</p><p>In the Lazio region, 44.6% of STEMI patients (N = 3,299) were treated with primary PCI, 54.4% of patients with hip fractures (N = 6,602) underwent surgery within 2 days, and 27.7% of women without a previous C-section (N = 34,718) delivered via C-section, in 2015. The corresponding proportions in 2012 were 27.8%, 31.3% and 31.5%, respectively. By comparing the adjusted proportions in patients with the highest education level (a university degree or higher) to those with the lowest level education level (None/Primary school), a decrease in the percentage difference was observed during the study period. In STEMI and delivery cohorts, the improvement of outcomes involved the least and the most educated patients, respectively, and the difference between the two educational levels was close to zero in 2015, whereas for hip patients, the improvement was more evident among the less educated patients.</p><p>Conclusions</p><p>In the Lazio region, we observed a reduction in the differential access to effective heath care by educational level, in different clinical areas. Different factors might explain these results. On top of the public disclosure of outcome data, the management strategy applied in mid-2013 might have driven the overall improvement of the health system for the considered conditions, helping to achieve a fairer access to health.</p></div

Long-Term Outcome of Acute Coronary Syndromes in Young Patients

Introduction: Acute coronary syndromes (ACS) in young patients are uncommon and their influence on morbidity and mortality in this population is still debated. Aim: We investigated clinical and angiographic characteristics, risk factors and outcome in young patients diagnosed with ACS, compared with those of older patients, evaluating survival free from death and/or nonfatal myocardial infarction (MI) and/or coronary revascularization (primary endpoint), and then with respect to each component of the primary endpoint. Methods: We retrospectively analyzed 1696 patients diagnosed with ACS between 2007 and 2013. 116 were aged ≤45 years (young adults), 1116 were >45 and <75 years (older adults) and 464 were ≥75 years. Results: Young adults were mostly male, with a prevalent diagnosis of STEMI, had less frequently typical cardiovascular risk factors and lower prevalence of extensive coronary artery disease. Over a median 3 years follow up, survival free from composite endpoint was better in young than in older adult patients (11.2 vs. 24.2%; p = 0.001), mainly due to a lower rate of death while the occurrence of non fatal MI and of coronary revascularization was similar (7.8 vs. 8.7%, p = 0.86; 8.7 vs. 12.9%, p = 0.23 respectively). Diabetes was the strongest independent risk factor of worse prognosis in the young cohort (OR 3.47; 95% CI 1.01–11.9; p = 0.04). Conclusions: Young adults showed peculiar clinical features and lower mortality compared with older adults. Morbidity was not different between the two populations, with diabetes independently associated with a worse prognosis

Two-way reversible shape memory behaviour of crosslinked poly(ε-caprolactone)

Polymers capable of reversible “two-way” shape memory behaviour are of great interest for applications where reversible actuation is demanded, and semicrystalline crosslinked systems have been indicated as an interesting solution towards this end. In this work we have explored the two-way shape memory response of semicrystalline poly(ε-caprolactone)-based polymer networks, prepared with various macromolecular architectures starting from linear, three- and four-arm star poly(ε-caprolactone) func- tionalized with methacrylate end-groups. All the materials have revealed two-way shape memory capabilities. The effect arises from an elongation process that takes place when the material is cooled under an applied load below the crystallization temperature, and that is completely reversed when heated again above melting temperature, in a manner that strongly depends on the applied load and on the material crosslink density. Two-dimensional XRD analysis, carried out on elongated specimens, shows that the elongation on cooling is accompanied by a change in the crystallinity orientation along the direction of stretch

Hip fracture: Proportion of intervention within 2 days.

<p>Adjusted proportions for the lowest and highest educational levels and percentage differences, 2012–2015.</p

STEMI: Proportion of patients treated with PCI within 90'.

<p>Adjusted proportions for the lowest and highest educational levels and percentage differences, 2012–2015.</p

Association between outcomes and educational level at the beginning and end of the study period (2012 and 2015).

<p>Association between outcomes and educational level at the beginning and end of the study period (2012 and 2015).</p

Proportions of outcomes, Lazio region 2012–2015.

<p>Proportions of outcomes, Lazio region 2012–2015.</p

One-way and two-way shape memory behaviour of semi-crystalline networks based on sol-gel cross-linked poly(\u3b5-caprolactone)

In this work we have explored the shape memory capabilities of a novel type of covalently cross-linked semi-crystalline polymers, prepared by exploiting the mild solegel chemistry, starting from alkoxysilane-terminated poly(\u3b5-caprolactone) (PCL), and using silica-based domains as cross-link points. By adopting PCL precursors with different molecular weights, semi-crystalline networks with well defined cross-link densities and with different crystallization and melting temperatures were obtained. Beside a satisfying one-way shape memory behaviour, the materials have displayed a significant two- way shape memory response, undergoing a reversible elongation-contraction process between two distinguished strain levels when subjected to a constant load and cyclically heated/cooled on a temperature region spanning from below the crystallization temperature to above the melting temperature. The applied load and the cross-link density are revealed as key-parameters to obtain tailored actuations. Concurrent wide-angle X-ray diffraction (WAXD) and DSC analyses allowed to ascribe the effect to a structural evolution process occurring during melting and crystallization