Genesis and mechanism of microstructural scale deformation and cracking in ZnAlMg coatings

In-depth investigation of the microscale deformation behavior of ZnAlMg coatings is essential to reveal the origin and mechanism of cracking in these coatings. In this work anisotropic microstructural damage and cracking of multiphase Zn1.8Al1.8Mg alloy coatings produced by hot-dip galvanization process on a steel substrate have been studied extensively. Nanoindentation coupled with orientation image microscopy (OIM) is utilized to determine the local micro ductility/strength of the existing phases as well as the orientation dependent micromechanical properties of primary zinc grains. Plastic deformation and damage behavior of the coating are evaluated through in-situ tensile/bending tests, micro-digital image correlation and in-situ OIM analyses. Stress distribution fields and nucleation sites of cracks within the coating microstructure are investigated using extended finite element method. Three quantitative plastic deformation-based criteria are revealed to correlate the coating microstructure to micro-mechanical properties to comprehend the cracking phenomenon. In particular, the binary eutectic is identified as the most detrimental constituent for compatible plastic deformation. Local strain hardening exponent and Schmid factor of primary zinc grains are found to play a significant role in clarifying the cracking behavior. The results of this study are considered as an important step towards designing microstructure controlled ZnAlMg coatings with superior formability

Even transient rapid infancy weight gain is associated with higher BMI in young adults and earlier menarche.

BACKGROUND: Early postnatal rapid 'catch-up' weight gain has been consistently associated with subsequent higher obesity risk and earlier pubertal development. In many low- and middle-income countries, infancy catch-up weight gain is transient and often followed by growth faltering. We explored the hypothesis that even transient catch-up weight gain during infancy is associated with later obesity risk and earlier puberty. METHODS: A total of 2352 (1151 male, 1201 female) black South African children in the birth to twenty prospective birth cohort study (Johannesburg-Soweto) underwent serial measurements of body size and composition from birth to 18 years of age. At the age of 18 years, whole-body fat mass and fat-free mass were determined using dual-energy X-ray absorptiometry. Pubertal development was assessed by the research team between ages 9 and 10 years, and it was recorded annually from the age of 11 years using a validated self-assessment protocol. RESULTS: Catch-up weight gain from birth to the age of 1 year, despite being followed by growth faltering between ages 1 and 2 years, was associated with greater mid-upper arm circumference (P=0.04) and skinfold thickness (P=0.048) at 8 years of age, and with higher weight (P<0.001) and body mass index (P=0.001) at 18 years of age after adjustment for sex, age, smoking during pregnancy, birth order, gestational age, formula-milk feeding and household socio-economic status. Infancy catch-up weight gain was also associated with younger age at menarche in girls (P<0.001). This association persisted after adjustment for smoking during pregnancy, birth order, gestational age, formula-milk feeding and household socio-economic status (P=0.005). CONCLUSION: Transient catch-up weight gain from birth to the age of 1 year among children born in a low-income area of South Africa was associated with earlier menarche and greater adiposity in early adulthood. This observation suggests that modifiable determinants of rapid infancy weight gain may be targeted in order to prevent later obesity and consequences of earlier puberty in girls.We are grateful to all study participants, their families and research assistants. Birth to twenty has been supported by The Wellcome Trust, Human Sciences Research Council, Medical Research Council, University of the Witwatersrand, the South African-Netherlands Programme on Alternative Development and the Anglo American Chairman’s Fund.This is the author accepted manuscript. The final version is available via NPG at http://www.nature.com/ijo/journal/vaop/ncurrent/full/ijo201525a.html

Insulin sensitivity assessed by stable isotopes with oral glucose administration: validation with euglycaemic clamp.

Methods of determining insulin sensitivity that use an oral challenge of glucose are preferred to those using intravenous administration since the measurement is made in conditions more akin to normal physiology. One previously reported protocol (ODILE) studies glucose uptake in isolation from absorption and endogenous production by the intravenous administration of tracer approximately forty-five minutes after the oral dose is given. However, this methodology has not been validated against other accredited procedures. This study utilizes the euglycemic hyperinsulinemic clamp in order to validate the ODILE method

Insulin administration and rate of glucose appearance in people with type 1 diabetes.

OBJECTIVE: To assess whether prandial insulin, in addition to basal insulin, has an effect on the rate of glucose appearance from a meal in people with type 1 diabetes. RESEARCH DESIGN AND METHODS: The rate of glucose appearance from a mixed meal (Ra(meal)) was investigated in six adult (aged 24 +/- 2 years), lean (BMI 23.6 +/- 1.5 kg/m(2)) subjects with well-controlled type 1 diabetes (duration 7.9 +/- 6.9 years, A1C 7.6 +/- 0.9%) with/without prandial insulin. Actrapid was infused to maintain euglycemia before meals were consumed. Subjects consumed two identical meals on separate occasions, and Ra(meal) was measured using a dual isotope method. [6,6-(2)H(2)]glucose was incorporated into the meal (0.081 g/kg body wt), and a primed constant/variable rate infusion of [1,2,3,4,5,6,6-(2)H(2)]glucose was administered. In the tests with prandial insulin, an additional bolus dose of Actrapid was given 20 min before the meal at 0.1 units/kg body wt. RESULTS: Insulin concentration with prandial insulin was significantly higher than during basal insulin studies (119 +/- 16 vs. 66 +/- 15 pmol/l, P = 0.03 by paired t test). Despite differences in insulin concentration, there were no differences in total glucose appearance (3,398 +/- 197 vs. 3,307 +/- 343 micromol/kg) or time taken for 25% (33.1 +/- 3.3 vs. 31.7 +/- 3.5 min), 50% (54.6 +/- 3.5 vs. 54.1 +/- 4.7 min), and 75% (82.9 +/- 7.1 vs. 82.8 +/- 5.8 min) of total glucose appearance. The fraction of the glucose dose appearing in the circulation was the same for basal (73 +/- 8%) and prandial (75 +/- 4%) study days. CONCLUSIONS: These results suggest that meal glucose appearance is independent of prandial insulin concentration in people with type 1 diabetes

Accurate determination of key surface properties that determine the efficient separation of bovine milk BSA and LF proteins

The aim of this work is to accurately measure fundamental surface properties, i.e., zeta potential, isoelectric point and protein size that determine the optimal separation conditions of Bovine serum albumin and lactoferrin, two high added value food proteins whose similarity in weight makes their separation a scientific and technical challenge. The systematic study of these proteins’ surface properties was performed under different conditions: (i) 3.0 < pH < 10.0, (ii) electrolyte type: KCl, NaCl and CaCl2 and concentration (0.01–0.1 M KCl) and (iii) protein concentration in the range of 0.04–4.0 g L-1 for BSA and 0.01–1.0 g L-1 for LF with the objective of establishing the optimal separation conditions. Finally, the comparison of the experimental and theoretically calculated values revealed significant deviations under specific conditions, highlighting the simplicity of the theoretical assumptions and leading to the conclusion that the use of experimental surface properties is still needed for the correct design of food protein separation processes.Financial support from the Projects CTQ2011-25262, CTM2011- 23912 and CTQ2012- 31639 (Ministerio de Economía y Competitividad-MINECO/SPAIN and Fondo Europeo de Desarrollo Regional-FEDER) is gratefully acknowledged

Rapid weight gain during infancy and subsequent adiposity: a systematic review and meta-analysis of evidence.

The contribution of rapid weight gain (RWG) during infancy to later adiposity has received considerable investigation. The present systematic review and meta-analysis aimed to update the literature on association between RWG and subsequent adiposity outcomes. Electronic searches were undertaken in EMBASE, MEDLINE, psycINFO, PubMed and ScienceDirect. Studies that examined the associations between RWG (a change in weight z-scores > 0.67) during infancy (from birth to age 2 years) and subsequent adiposity outcomes were included. Random effects meta-analysis was conducted to obtain the weighted-pooled estimates of the odds of overweight/obesity for those with RWG. Seventeen studies were eligible for inclusion with the majority of studies (15/17) being of high/acceptable quality and reporting positive associations between RWG during infancy and later adiposity outcomes. RWG in infancy was associated with overweight/obesity from childhood to adulthood (pooled odds ratio = 3.66, 95% confidence interval: 2.59-5.17, I2  > 75%). Subgroup analyses revealed that RWG during infancy was associated with higher odds of overweight/obesity in childhood than in adulthood, and RWG from birth to 1 year was associated with higher odds of overweight/obesity than RWG from birth to 2 years. The present study supports that RWG during infancy is a significant predictor of adiposity in later life

Delayed β-cell response and glucose intolerance in young women with Turner syndrome

<p>Abstract</p> <p>Background</p> <p>To investigate glucose homeostasis in detail in Turner syndrome (TS), where impaired glucose tolerance (IGT) and type 2 diabetes are frequent.</p> <p>Methods</p> <p>Cross sectional study of women with Turner syndrome (TS)(n = 13) and age and body mass index matched controls (C) (n = 13), evaluated by glucose tolerance (oral and intravenous glucose tolerance test (OGTT and IVGTT)), insulin sensitivity (hyperinsulinemic, euglycemic clamp), beta-cell function (hyperglycaemic clamp, arginine and GLP-1 stimulation) and insulin pulsatility.</p> <p>Results</p> <p>Fasting glucose and insulin levels were similar. Higher glucose responses was seen in TS during OGTT and IVGTT, persisting after correction for body weight or muscle mass, while insulin responses were similar in TS and C, despite the higher glucose level in TS, leading to an insufficient increase in insulin response during dynamic testing. Insulin sensitivity was comparable in the two groups (TS vs. control: 8.6 ± 1.8 vs. 8.9 ± 1.8 mg/kg*30 min; p = 0.6), and the insulin responses to dynamic β-cell function tests were similar. Insulin secretion patterns examined by deconvolution analysis, approximate entropy, spectral analysis and autocorrelation analysis were similar. In addition we found low IGF-I, higher levels of cortisol and norepinephrine and an increased waist-hip ratio in TS.</p> <p>Conclusions</p> <p>Young normal weight TS women show significant glucose intolerance in spite of normal insulin secretion during hyperglycaemic clamping and normal insulin sensitivity. We recommend regularly testing for diabetes in TS.</p> <p>Trial Registration</p> <p>Registered with <url>http://clinicaltrials.com</url>, ID nr: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00419107">NCT00419107</a></p