The role of microstructure in the thermal fatigue of solder joints.

Thermal fatigue is a common failure mode in electronic solder joints, yet the role of microstructure is incompletely understood. Here, we quantify the evolution of microstructure and damage in Sn-3Ag-0.5Cu joints throughout a ball grid array (BGA) package using EBSD mapping of localised subgrains, recrystallisation and heavily coarsened Ag3Sn. We then interpret the results with a multi-scale modelling approach that links from a continuum model at the package/board scale through to a crystal plasticity finite element model at the microstructure scale. We measure and explain the dependence of damage evolution on (i) the ß-Sn crystal orientation(s) in single and multigrain joints, and (ii) the coefficient of thermal expansion (CTE) mismatch between tin grains in cyclic twinned multigrain joints. We further explore the relative importance of the solder microstructure versus the joint location in the array. The results provide a basis for designing optimum solder joint microstructures for thermal fatigue resistance.

Quality of patient-reported outcome reporting in trials of diabetes in pregnancy: A systematic review.

AIMS: Patient-reported outcomes (PROs) are reports of the patient's health status that come directly from the patient without interpretation by the clinician or anyone else. They are increasingly used in randomised controlled trials (RCTs). In this systematic review we identified RCTs conducted in women with diabetes in pregnancy which included PROs in their primary or secondary outcomes. We then evaluated the quality of PRO reporting against an internationally accepted reporting framework (Consolidated Standards of Reporting Trials (CONSORT-PRO) guidelines). METHODS: We searched online databases for studies published 2013-2021 using a combination of keywords. Two authors reviewed all abstracts independently. Data on study characteristics and the quality of PRO reporting were extracted from relevant studies. We conducted a multiple regression analysis to identify factors associated with high quality reporting. RESULTS: We identified 7122 citations. Thirty-five articles were included for review. Only 17% of RCTs included a PRO as a primary or secondary outcome. Out of a maximum score of 100 the median score was 46, indicating sub-optimal reporting. A multiple regression analysis did not reveal any factors associated with high quality reporting. CONCLUSIONS: Researchers should be mindful of the importance of PRO inclusion and reporting and include reliable PROs in trials.

Diabetes care and pregnancy outcomes for women with pregestational diabetes in Ireland.

AIMS: Pre-gestational diabetes mellitus (PGDM) is associated with adverse outcomes. We aimed to examine pregnancies affected by PGDM; report on these pregnancy outcomes and compare outcomes for patients with type 1 versus type 2 diabetes mellitus; compare our findings to published Irish and United Kingdom (UK) data and identify potential areas for improvement. METHODS: Between 2016 and 2018 information on 679 pregnancies from 415 women with type 1 Diabetes Mellitus and 244 women with type 2 diabetes was analysed. Data was collected on maternal characteristics; pregnancy preparation; glycaemic control; pregnancy related complications; foetal and maternal outcomes; unscheduled hospitalisations; congenital anomalies and perinatal deaths. RESULTS: Only 15.9% of women were adequately prepared for pregnancy. Significant deficits were identified in availability and attendance at pre-pregnancy clinic, use of folic acid, attaining appropriate glycaemic targets and appropriate retinal screening. The majority of pregnancies (n = 567, 83.5%) resulted in a live birth but the large number of infants born large for gestational age (LGA) (n = 280, 49.4%), born prematurely <37 weeks and requiring neonatal intensive care unit (NICU) admission continue to be significant issues. CONCLUSIONS: This retrospective cohort study identifies multiple targets for improvements in the provision of care to women with pre-gestational DM which are likely to translate into better pregnancy outcomes.

Metabolic phenotypes of early gestational diabetes mellitus and their association with adverse pregnancy outcomes.

AIMS: To describe the metabolic phenotypes of early gestational diabetes mellitus and their association with adverse pregnancy outcomes. METHODS: We performed a post hoc analysis using data from the Vitamin D And Lifestyle Intervention for gestational diabetes prevention (DALI) trial conducted across nine European countries (2012-2014). In women with a BMI ≥29 kg/m2 , insulin resistance and secretion were estimated from the oral glucose tolerance test values performed before 20 weeks, using homeostatic model assessment of insulin resistance and Stumvoll first-phase indices, respectively. Women with early gestational diabetes, defined by the International Association of Diabetes and Pregnancy Study Groups criteria, were classified into three groups: GDM-R (above-median insulin resistance alone), GDM-S (below-median insulin secretion alone), and GDM-B (combination of both) and the few remaining women were excluded. RESULTS: Compared with women in the normal glucose tolerance group (n = 651), women in the GDM-R group (n = 143) had higher fasting and post-load glucose values and insulin levels, with a greater risk of having large-for-gestational age babies [adjusted odds ratio 3.30 (95% CI 1.50-7.50)] and caesarean section [adjusted odds ratio 2.30 (95% CI 1.20-4.40)]. Women in the GDM-S (n = 37) and GDM-B (n = 56) groups had comparable pregnancy outcomes with those in the normal glucose tolerance group. CONCLUSIONS: In overweight and obese women with early gestational diabetes, higher degree of insulin resistance alone was more likely to be associated with adverse pregnancy outcomes than lower insulin secretion alone or a combination of both.

Diabetes in pregnancy: worse medical outcomes in type 1 diabetes but worse psychological outcomes in gestational diabetes.

BACKGROUND: Women with diabetes experience an increased risk of adverse pregnancy outcomes. AIM: We aim to describe and quantify the psychological impact of the diagnosis of diabetes in pregnant women with type 1 diabetes and gestational diabetes mellitus (GDM) compared to each other and to their counterparts without diabetes. DESIGN: This is a survey-based study with prospective collection of pregnancy outcome data. METHODS: A total of 218 pregnant women (50% with diabetes) were administered questionnaires relating to psychological health. Maternal and neonatal characteristics and pregnancy outcomes were collected. Associations between key psychometric and health outcome variables were examined. RESULTS: At least 25% of women in all three pregnancy groups had scores indicating affective distress in at least one domain. Compared to those with type 1 diabetes, women with GDM evidenced a greater number of uplifts in pregnancy (U = 94, P = 0.041), but also higher levels of overall anxiety (U = 92, P = 0.03) and stress (U = 82, P < 0.01). Women with GDM also had significantly elevated overall depression scores, compared with the control group (U = 34, P = 0.02). Both groups of women with diabetes had clinically elevated levels of diabetes-related distress. There were no associations between maternal psychological variables and pregnancy outcomes. CONCLUSIONS: This work highlights a potential role for targeted psychological interventions to address and relieve symptoms of anxiety and depression among pregnant women with diabetes.

Care of women with diabetes before, during and after pregnancy: time for a new approach?

AIMS: This study assesses the impact of pregnancy and pre-pregnancy care on longer-term treatment goals in women with diabetes. METHODS: This retrospective study included women with Type 1 (n = 247) and Type 2 diabetes (n = 137) who were evaluated before, during and after pregnancy. RESULTS: Among women with Type 1 diabetes, average HbA1c at 12 months post-partum was similar to the preconception level [63 vs. 64 mmol/mol (7.9% vs. 8.0%), P = 0.60]. This was also the case for women with Type 2 diabetes [52 vs. 52 mmol/mol (6.9% vs. 6.9%), P = 0.79]. At 12 months post-partum, there was no improvement in other measures of diabetes control and one in five women are lost to follow-up from clinical care. In total, 44.9% of women with Type 1 diabetes and 27.7% of those with Type 2 diabetes attended pre-pregnancy care. Attendees maintained superior glycaemic control throughout the study and were more likely to be receiving specialist care post-partum. CONCLUSIONS: These findings identify a need to change our approach to the reproductive care of women with diabetes. In particular, efforts should be made to ensure all women have access to and attend pre-pregnancy care, and barriers to engagement with post-partum care should be addressed.

Abnormal glucose tolerance post-gestational diabetes mellitus as defined by the International Association of Diabetes and Pregnancy Study Groups criteria.

OBJECTIVE: An increase in gestational diabetes mellitus (GDM) prevalence has been demonstrated across many countries with adoption of the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) diagnostic criteria. Here, we determine the cumulative incidence of abnormal glucose tolerance among women with previous GDM, and identify clinical risk factors predicting this. DESIGN: Two hundred and seventy women with previous IADPSG-defined GDM were prospectively followed up for 5years (mean 2.6) post-index pregnancy, and compared with 388 women with normal glucose tolerance (NGT) in pregnancy. METHODS: Cumulative incidence of abnormal glucose tolerance (using American Diabetes Association criteria for impaired fasting glucose, impaired glucose tolerance and diabetes) was determined using the Kaplan-Meier method of survival analysis. Cox regression models were constructed to test for factors predicting abnormal glucose tolerance. RESULTS: Twenty-six percent of women with previous GDM had abnormal glucose tolerance vs 4% with NGT, with the log-rank test demonstrating significantly different survival curves (P<0.001). Women meeting IADPSG, but not the World Health Organization (WHO) 1999 criteria, had a lower cumulative incidence than women meeting both sets of criteria, both in the early post-partum period (4.2% vs 21.7%, P<0.001) and at longer-term follow-up (13.7% vs 32.6%, P<0.001). Predictive factors were glucose levels on the pregnancy oral glucose tolerance test, family history of diabetes, gestational week at testing, and BMI at follow-up. CONCLUSIONS: The proportion of women developing abnormal glucose tolerance remains high among those with IADPSG-defined GDM. This demonstrates the need for continued close follow-up, although the optimal frequency and method needs further study.

On rate-dependent polycrystal deformation: the temperature sensitivity of cold dwell fatigue.

A temperature and rate-dependent crystal plasticity framework has been used to examine the temperature sensitivity of stress relaxation, creep and load shedding in model Ti-6Al polycrystal behaviour under dwell fatigue conditions. A temperature close to 120°C is found to lead to the strongest stress redistribution and load shedding, resulting from the coupling between crystallographic slip rate and slip system dislocation hardening. For temperatures in excess of about 230°C, grain-level load shedding from soft to hard grains diminishes because of the more rapid stress relaxation, leading ultimately to the diminution of the load shedding and hence, it is argued, the elimination of the dwell debit. Under conditions of cyclic stress dwell, at temperatures between 20°C and 230°C for which load shedding occurs, the rate-dependent accumulation of local slip by ratcheting is shown to lead to the progressive cycle-by-cycle redistribution of stress from soft to hard grains. This phenomenon is termed cyclic load shedding since it also depends on the material's creep response, but develops over and above the well-known dwell load shedding, thus providing an additional rationale for the incubation of facet nucleation.

Postpartum glucose testing for women with gestational diabetes mellitus: Improving regional recall rates.

Our aim was to evaluate attendance for postpartum glucose testing among women attending five antenatal centres with a diagnosis of GDM in the preceding pregnancy. A central, regional coordinator who made verbal and written contact with each individual facilitated a favourable recall rate of 75%.

Micro-scale testing and micromechanical modelling for high cycle fatigue of CoCr stent material.

This paper presents a framework of experimental testing and crystal plasticity micromechanics for high cycle fatigue (HCF) of micro-scale L605 CoCr stent material. Micro-scale specimens, representative of stent struts, are manufactured via laser micro-machining and electro-polishing from biomedical grade CoCr alloy foil. Crystal plasticity models of the micro-specimens are developed using a length scale-dependent, strain-gradient constitutive model and a phenomenological (power-law) constitutive model, calibrated from monotonic and cyclic plasticity test data. Experimental microstructural characterisation of the grain morphology and precipitate distributions is used as input for the polycrystalline finite element (FE) morphologies. Two microstructure-sensitive fatigue indicator parameters are applied, using local and non-local (grain-averaged) implementations, for the phenomenological and length scale-dependent models, respectively, to predict fatigue crack initiation (FCI) in the HCF experiments.

The management of type 1 and type 2 diabetes in pregnancy.

Pregestational diabetes is a common medical complication of pregnancy and preconception planning is an essential component of care for affected women of childbearing age. Once pregnant, structured care in a multidisciplinary team setting is necessary to ensure optimal outcomes. Although significant progress has been made, these women and their offspring remain to have a significantly elevated risk of multiple adverse complications. Structured programmes using information technology and enabling access to novel technologies may facilitate our goal of ensuring an outcome closer to that of a pregnancy unaffected by diabetes.

Gender differences in undergraduate medicine in Galway: a tale of two curricula.

AIMS: Medical teaching in the National University of Ireland Galway (NUIG) has undergone a shift from subject- to system-based learning. Our aims were to examine differences between genders in academic performance in medicine across two different curricula. METHODS: Results of each student graduating between 2007 and 2012 for each subject undertaken over the medical degree were obtained from the Medical School. Data were collected with respect to gender, nationality and mode of entry, and analysis completed using SPSS. RESULTS: The cohort included 360 females and 249 males. 396 students read from a subject-based curriculum and 213 a system-based course. Females outperformed males in 19/24 (79 %) subjects in the subject-based curriculum, and in 9/38 (24 %) in the system-based course. Males were more likely to fail and less likely to achieve an honours degree. Multivariate analysis showed nationality and gender to be significant predictive factors. CONCLUSION: Females outperformed males overall. Differences were most pronounced in a subject-based curriculum. Nationality and gender were found to be significant factors in determining overall results.

ATLANTIC DIP: simplifying the follow-up of women with previous gestational diabetes.

OBJECTIVE: Previous gestational diabetes (GDM) is associated with a significant lifetime risk of type 2 diabetes. In this study, we assessed the performance of HbA1c and fasting plasma glucose (FPG) measurements against that of 75 g oral glucose tolerance testing (OGTT) for the follow-up screening of women with previous GDM. METHODS: Two hundred and sixty-six women with previous GDM underwent the follow-up testing (mean of 2.6 years (s.d. 1.0) post-index pregnancy) using HbA1c (100%), and 75 g OGTT (89%) or FPG (11%). American Diabetes Association (ADA) criteria for abnormal glucose tolerance were used. DESIGN, COHORT STUDY, AND RESULTS: The ADA HbA1c high-risk cut-off of 39 mmol/mol yielded sensitivity of 45% (95% CI 32, 59), specificity of 84% (95% CI 78, 88), negative predictive value (NPV) of 87% (95% CI 82, 91) and positive predictive value (PPV) of 39% (95% CI 27, 52) for detecting abnormal glucose tolerance. ADA high-risk criterion for FPG of 5.6 mmol/l showed sensitivity of 80% (95% CI 66, 89), specificity of 100% (95% CI 98, 100), NPV of 96% (95% CI 92, 98) and PPV of 100% (95% CI 91, 100). Combining HbA1c ≥39 mmol/mol with FPG ≥5.6 mmol/l yielded sensitivity of 90% (95% CI 78, 96), specificity of 84% (95% CI 78, 88), NPV of 97% (95% CI 94, 99) and PPV of 56% (95% CI 45, 66). CONCLUSIONS: Combining test cut-offs of 5.6 mmol/l and HbA1c 39 mmol/mol identifies 90% of women with abnormal glucose tolerance post-GDM (mean 2.6 years (s.d.1.0) post-index pregnancy). Applying this follow-up strategy will reduce the number of OGTT tests required by 70%, will be more convenient for women and their practitioners, and is likely to lead to increased uptake of long-term retesting by these women whose risk for type 2 diabetes is substantially increased.

Atlantic DIP: subject recruitment, data collection, missing data management and analysis procedures.

This paper describes the experiences related to the universal screening study for gestational diabetes mellitus (GDM) with reference to the subject recruitment process, data collection processes, (data entry, editing, quality assurance) and statistical analysis including the importance of missing data.

Changing clinical practice can improve clinical outcomes for women with pre-gestational diabetes mellitus.

Prospective evaluation of pregnancy outcomes in women with pre-gestational diabetes over 6 years. The ATLANTIC Diabetes in Pregnancy group represents 5 antenatal centres along the Irish Atlantic seaboard, providing care for women with diabetes throughout pregnancy. In 2007 the group published a report that recognised that women were poorly prepared for pregnancy and that outcomes were sub-optimal. A change in practice occurred, offering women specialist-led, evidence-based care, both pre-pregnancy and combined antenatal/diabetes clinics during pregnancy. We now compare outcomes from 2005-2007 with 2008-2010. There was an increase in the numbers attending pre-conception care. Glycemic control before and throughout pregnancy improved. There was an overall increase in live births and decrease in perinata mortality rate. There was a decrease in large-for-gestational-age babies in mothers with Type 1 Diabetes. Elective Caesarean section rates increased while emergency section rates decreased. More women had Type 2 diabetes over time and these women were more likely to be obese. Changing the process of clinical care delivery can improve outcomes in for women with pre-gestational diabetes.

A regional pre-pregnancy care (PPC) programme for women with type 1 and type 2 diabetes.

Unfortunately the risks associated with pregnancy in a woman with Diabetes (Type 1 and Type 2) continue to be high. However these risks can be reduced significantly with pregnancy planning and pre-pregnancy care. We report here the establishment of a regional pre pregnancy service and the interim results of its benefits. Pre pregnancy care is as vital as combined diabetes antenatal care for women with diabetes and must become the norm for this population.

ATLANTIC DIP: pregnancy outcomes for women with type 1 and type 2 diabetes.

ATLANTIC DIP prospectively evaluated the perinatal and maternal outcomes of pregnancies complicated by Type 1 and Type 2 diabetes during 2006/2007 in 5 antenatal centres. All women with established diabetes for at least 6 months prior to the index pregnancy and booking for antenatal care between 1/1/2006 and 31/12/2007 were included in the study. Results were collected electronically via the DIAMOND Diabetes Information System. Pregnancy outcome was compared with that of the background population receiving antenatal care in the region during the same time. There were 104 singleton pregnancies during the period of study. The stillbirth rate (SBR) of 25/1000 was 5 times greater than that reported in the background population at 5/1000 and the perinatal mortality rate (PMR) of 25/1000 was 3.5 times greater than background 7/1000. The congenital malformation rate (CMR) of 24/1000 was twice that observed in the background population. Women were not well prepared for pregnancy with 28% receiving pre pregnancy care (PPC), 43% receiving pre pregnancy folic acid and 51% achieving a HbA1C < = 7% at first antenatal visit. Pregnancy induced hypertension (PIH) and/or pre eclampsia toxaemia (PET) were three times more common than in women in the background population. In conclusion women are not well prepared for pregnancy. Maternal and infant morbidity and infant mortality are greater in women with diabetes. A regional pre pregnancy care (PPC) programme and centralised glucose management are urgently needed.

Atlantic DIP: the prevalence and consequences of gestational diabetes in Ireland.

ATLANTIC DIP carried out a universal screening programme for gestational diabetes mellitus (GDM) along the Irish Atlantic seaboard. Using a 75g OGTT and new International Association of Diabetes in Pregnancy Study Groups (IADPSG) cut off points for diagnosis we found the prevalence of GDM to be 12.4%. Pregnancies complicated by GDM displayed increased morbidities for mother and infant when compared to women who had normal glucose tolerance. With rising obesity levels and older age of mothers, both risk factors for GDM, these results would support a national universal screening programme.