Hot sheet metal forming strategies for high-strength aluminum alloys: a review-fundamentals and applications

In the past decade, aluminum alloys have become important structural materials in the automotive industry, thanks to their low density, high strength, high fracture toughness, and good fatigue performance. However, an important limitation of aluminum alloys is their poor formability at room temperature; as a result, numerous studies have been conducted with the aim of developing forming techniques to overcome this and facilitate the forming of more complex-shaped components. Following an overview on the metallurgical background of aluminum alloys, this article reviews recent developments in forming processes for aluminum alloys. The focus is on process variants at room temperature and at higher temperatures and on a new hot forming technique promising considerable improvements in formability. This review summarizes the influence of different process parameters on microstructures and mechanical properties. Particular emphasis is given to process design and to the underlying microstructural phenomena governing the strengthening mechanisms

Extrusion foaming of PHBV

This paper reports work on extrusion foaming of poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) with a chemical blowing agent based on sodium bicarbonate and citric acid and calcium carbonate nucleation agent. It includes investigations in the effects of rheological behaviour of the polymer, blowing agent, nucleation agent and processing conditions on the foam density and morphology. The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) is a natural biodegradable polyester with high crystallinity, low melt viscosity and slow crystallisation rate and high sensitivity to the thermal degradation at temperatures above its melting point, making it particularly difficult to control the foaming process. Use of negative gradient temperature profile was found beneficial to minimise the thermal degradation and achieve necessary melt strength to stabilise the cell structure. Solidification of the super-cooled polymer melt occurring at the die was discussed in relation to the selection of the temperature profile and rheological behaviour and solidification of the poly(3-hydroxybutyrate-co-3- hydroxyvalerate) characterised by rotational rheometry. In addition to extrusion foaming conditions, effect of the blowing and nucleation agents on rheology of the polymer, the cell refinement on foam density and morphology were discussed. The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was extruded with a twin screw extruder fitted with a strand die yielding up to 60% density reduction with uniform fine cell structure. © 2013 The Author(s)

Developing a Strategic Plan for Community Based Research in Springfield

There is a unique opportunity to improve the health of the residents of Springfield. In combination, the Baystate affiliated Community Health Centers (CHC’s) and Caring Health Center—a Federally Qualified Health Center (FQHC)—care for a large percentage of the total population of Springfield. Baystate’s and Caring’s CHC’s have partnered through the BeHealthy ACO to provide much of this care. Because a large and concentrated population with substantive challenges is served, focus could be downstream (i.e. healthcare oriented) or upstream (i.e. policy, social, political) or some combination thereof. Many faculty, staff, and trainees in these systems in general and in the CHC’s specifically are interested and have the content knowledge regarding social determinates of health and health care delivery but would benefit from a coordinated system and mentoring structure to make a more meaningful impact. Creating a community based infrastructure for alignment and coordination among key stakeholders (e.g healthcare delivery systems, academic institutions, community based organizations, government entities, and others) will help assure common goals, efforts, and sustainability are maximized. The purpose of this session is to brainstorm how to further leverage existing and potential partnerships towards research that emanates from needs of the community and addresses these needs in a systematic, rigorous, and sustainable manner. The ideas generated in this session will serve to guide the development of a strategic plan for community based research in Springfield. An open panel discussion of current state (stakeholders, resources, ongoing efforts) and early steps to begin developing a strategic plan will be followed by an open forum to brainstorm for next steps. The brainstorming topics include, but are not limited to: potential avenues of inquiry, model for engagement by CHC faculty and trainees, establishing and/or enhancing collaborations between local institutional stakeholders, assuring input and engagement of the community, and grant procurement strategies

Maternal psychiatric disease and epigenetic evidence suggest a common biology for poor fetal growth

BACKGROUND: We sought to identify and characterize predictors of poor fetal growth among variables extracted from perinatal medical records to gain insight into potential etiologic mechanisms. In this process we reevaluated a previously observed association between poor fetal growth and maternal psychiatric disease. METHODS: We evaluated 449 deliveries of >36 weeks gestation that occurred between 9/2008 and 9/2010 at the Women and Infants Hospital in Providence Rhode Island. This study group was oversampled for Small-for-Gestational-Age (SGA) infants and excluded Large-for-Gestational-Age (LGA) infants. We assessed the associations between recorded clinical variables and impaired fetal growth: SGA or Intrauterine Growth Restriction (IUGR) diagnosis. After validating the previously observed association between maternal psychiatric disease and impaired fetal growth we addressed weaknesses in the prior studies by explicitly considering antidepressant use and the timing of symptoms with respect to pregnancy. We then evaluated DNA methylation levels at 27 candidate loci in placenta from a subset of these deliveries (n = 197) to examine if epigenetic variation could provide insight into the mechanisms that cause this co-morbidity. RESULTS: Infants of mothers with prenatal psychiatric disease (Depression, Anxiety, OCD/Panic) had increased odds of poor fetal growth (OR(adjusted) = 3.36, 95%CI: 1.38-8.14). This relationship was similar among those who were treated with antidepressants (OR(adjusted) = 3.69, 95%CI: 1.31-10.45) and among those who were not (OR(adjusted) = 3.19, 95%CI: 1.30-7.83). Among those with a history of psychiatric disease but no active disease in pregnancy the OR(adjusted) was 0.45 (95%CI: 0.09-2.35). A locus near the transcription start site of the leptin receptor (cg21655790) had methylation levels that were decreased in the presence of: 1) SGA/IUGR, and 2) active but not resolved psychiatric disease (among mothers not on antidepressants). CONCLUSIONS: These results validate and further characterize the association between maternal psychiatric disease and poor fetal growth. Because the association appears to depend on active psychiatric disease, this suggests a transient and potentially modifiable pathophysiology. The molecular findings in this study suggest that altered leptin signaling may be involved in the biological mechanisms that link prenatal maternal psychiatric symptoms and poor fetal growth. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12884-015-0627-8) contains supplementary material, which is available to authorized users

The Impact of Antenatal Depression on Perinatal Outcomes in Australian Women

In Australia, there is limited evidence on the impact of antenatal depression on perinatal outcomes. This study investigates the association between maternal depressive symptoms during pregnancy and key perinatal outcomes, including birth weight, gestational age at birth, breastfeeding indicators and postnatal depressive symptoms.A retrospective cohort of mothers (N = 17,564) of all infants born in public health facilities within South Western Sydney Local Health District and Sydney Local Health District in 2014, in the state of New South Wales (NSW), Australia, was enumerated from routinely collected antenatal data to investigate the risk of adverse perinatal outcomes associated with maternal depressive symptoms during pregnancy. Antenatal depressive symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS). Logistic regression models that adjusted for confounders were conducted to determine associations between antenatal depressive symptoms and low birth weight, early gestational age at birth (<37 weeks), breast feeding indicators and postnatal depressive symptoms.The prevalence of maternal depressive symptoms during pregnancy was 7.0% in the cohort, and was significantly associated with postnatal depressive symptoms [Adjusted Odd Ratios (AOR) = 6.4, 95% CI: 4.8-8.7, P<0.001]. Antenatal depressive symptoms was associated with a higher odds of low birth weight [AOR = 1.7, 95% CI: 1.2-2.3, P = 0.003] and a gestational age at birth of <37 weeks [AOR = 1.3, 95% CI: 1.1-1.7, P = 0.018] compared to women who reported lower EPDS scores in antenatal period. Antenatal depressive symptoms were not strongly associated with non-exclusive breast feeding in the early postnatal period.Maternal depressive symptoms in the antenatal period are strongly associated with postnatal depressive symptoms and adverse perinatal outcomes in Australian infants. Early identification of antenatal and postnatal depressive symptoms, and referral for appropriate management could benefit not only the mother's mental health, but also the infant's health and development