Higher Growth Velocity Research Articles

Decoupling effect stimulated independent dendrite growth of eutectic phases under microgravity and containerless states

Eutectic growth process is usually characterized by the simultaneous coupled growth of two different solids within one uniform liquid phase, while fluid dynamics normally predicts the equiaxed shrinkage for floating viscous droplets on freezing. Here a decoupling effect was induced by the microgravity and containerless states aboard space station, which led to the independent dendrite growth of two eutectic phases within extremely undercooled liquid Nb-Si refractory alloy. The confronting fluid flow pattern driven by polar heterogeneous nucleation was found to stimulate the elongated surface deformation of alloy droplet at a high dendrite growth velocity.

Preoperative Feeding Fortification Among Infants with Congenital Heart Disease is Associated with Higher Growth Velocity in the First 30 Days Post-repair and Lower BMI Percentile for Age at 10 Years: A Retrospective Cohort Study.

It remains unclear how preoperative nutrition fortification impacts postoperative growth trajectories and nutritional status among infants with congenital heart disease. A single center retrospective cohort study was performed to evaluate measures of growth among patients who underwent cardiac repair at 0-18months of age for atrial septal defect, ventricular septal defect, atrioventricular septal defect, or tetralogy of Fallot. Cohorts were analyzed at 0-30 and 31-60days post-repair as well as at 2, 5, and 10years of age. Records of 24 patients who received fortified nutrition and 60 patients who received unfortified nutrition preoperatively were reviewed. Those with fortified nutrition had higher growth velocities in the first 30days post-repair compared to those with unfortified nutrition: 28.4 (23.8-83.3) grams per day versus 16.7 (7.1-21.4) grams per day, p = 0.004. Weight percentile for age was higher in the unfortified group at 2, 5, and 10years of age (p = 0.02, p = 0.045, and p = 0.01). Body mass index (BMI) percentile for age was higher in the unfortified group at 5 and 10years of age (p = 0.045 and p = 0.02) with a trend toward higher prevalence of either overweight or obesity compared to the fortified group (p = 0.13). reoperative nutrition fortification among infants with congenital heart disease is associated with higher growth velocity in the first 30days post-repair and lower BMI percentile for age at 10years. Further studies are needed to evaluate the association between preoperative nutrition fortification and postoperative outcomes, nutritional status, and prevalence of obesity in adolescence and adulthood.

Determination of growth and developmental stages in hand-wrist radiographs : Can fractal analysis in combination with artificial intelligence be used?

The goal of this work was to assess the classification of maturation stage using artificial intelligence (AI) classifiers. Hand-wrist radiographs (HWRs) from 1067 individuals aged between 7and 18years were included. Fifteen regions of interest were selected for fractal dimension (FD) analysis. Five predictive models with different inputs were created (model1: only FD; model2: FD and Chapman sesamoid stage; model3: FD, age, and sex; model4: FD, Chapman sesamoid stage, age, and sex; model5: Chapman sesamoid stage, age, and sex). The target diagnoses were accelerating growth velocity, very high growth velocity, and decreasing growth velocity. Four AI algorithms were applied: multilayer perceptron (MLP), support vector machine (SVM), gradient boosting machine (GBM) and C5.0 decision tree classifier. All AI algorithms except for C5.0 yielded similar overall predictive accuracies for the five models. In order from lowest to highest, the predictive accuracies of the models were as follows: model1 < model3 < model2 < model5 < model4. The highest overall F1 score, which was used instead of accuracy especially for models with unbalanced data, was obtained for models1,2, and3 based on SVM, for model4 based on MLP, and for model5 based on C5.0. Adding Chapman sesamoid stage, chronologic age, and sex as additional inputs to the FD values significantly increased the F1 score. Applying FD analysis to HWRs is not sufficient to predict maturation stage in growing patients but can be considered agrowth rate prediction method if combined with the Chapman sesamoid stage, age, and sex.

Synergistic control of microstructures and properties in eutectic high-entropy alloys via directional solidification and strong magnetic field

The AlCoCrFeNi2.1 eutectic high-entropy alloy (Ni2.1 EHEA), as an exemplary representative of the high-entropy alloy family, has garnered significant research attention owing to its exceptional comprehensive properties. In this study, we investigated the influence of various growth velocities on the microstructure, lamellar spacing, and mechanical properties of the Ni2.1 EHEA. We observed that at lower growth velocities, the structure consisted of an alternating face-centered-cubic (FCC) phase and B2 phase lamellae aligned in a single direction, with the lamellae orientation parallel to the direction of the heat flow. The yield strength increased with the growth rate, while the ultimate tensile strength decreased with increasing the growth velocity. Ductility remained relatively consistent, and a double yield phenomenon was observed in the elastic-plastic deformation region. Under conditions of high growth velocities, the microstructure transitioned from a single-directional full lamellar structure to a multi-stage lamellar arrangement. The most favorable comprehensive mechanical properties were achieved at a growth rate of 200 μm/s, resulting in a yield strength of 450 MPa, an ultimate tensile strength of 1092 MPa, and a remarkable ductility of ∼32% in the directionally solidified samples—double that of the arc-melted sample. The evolution law of directional solidification structures under the coupling effect of different magnetic fields and different growth rates was studied. The interaction of the thermoelectric-magnetic force and thermoelectric-magnetic convection and the potential mechanism of microstructure evolution under the effect of magnetic field were deeply analyzed. The results reveal that at a growth rate of 2 μm/s, the spacing between eutectic layers decreases as the magnetic induction intensity increases, leading to the transformation of some regular layers into spherical layers. Similarly, at a growth velocity of 10 μm/s, the eutectic structure exhibited a Columnar-to-equiaxed transition (CET). However, as the growth rate further increases, the limited exposure time to the magnetic field prevented significant structural changes.

Associations between collagen X biomarker and linear growth velocity in a pediatric chronic kidney disease cohort.

Collagen X biomarker (CXM) is a novel biomarker of linear growth velocity. We investigated whether CXM correlated with measuredgrowth velocity in children with impaired kidney function. We used data from children aged 2 through 16years old enrolled in the Chronic Kidney Disease in Children (CKiD) study. We assessed the association between CXM level and growth velocity based on height measurements obtained at study visits using linear regression models constructed separately by sex, with and without adjustment for CKD covariates. Linear mixed-effects models were used to capture the between-individual and within-individual CXM changes over time associated with concomitant changes in growth velocity from baseline through follow-up. A total of 967 serum samples from 209 participants were assayed for CXM. CXM correlated more strongly in females compared to male participants. After adjustment for growth velocity and CKD covariates, only proteinuria in male participants affected CXM levels. Finally, we quantified the between- and within-participant associations between CXM level and growth velocity. A between-participant increase of 24% and 15% in CXM level in females and males, respectively, correlated with a 1cm/year higher growth velocity. Within an individual participant, on average, 28% and 13% increases in CXM values in females and males, respectively, correlated with a 1cm/year change in measured growth. CXM measurement is potentially a valuable aid for monitoring growth in pediatric CKD. However, future research, including studies of CXM metabolism, is needed to clarify whether CXM can be a surrogate of growth in children with CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Complete solute trapping of rapidly growing nickel dendrites within liquid Ni72Mo28 hypoeutectic alloy

The rapid dendrite growth in highly undercooled liquid Ni72Mo28 hypoeutectic alloy was accomplished by containerless processing via electromagnetic levitation and drop tube techniques. The (Ni) dendrites achieved a high growth velocity of 26 m/s at the maximum undercooling of 226 K (0.14 TL) under levitated state. Remarkable dendritic structure refinement and Mo solubility extension were observed with the increase in undercooling. For freely falling alloy droplets, the largest undercooling was enhanced to 246 K (0.15 TL), which resulted in thorough solute trapping and almost segregationless solidification. A microstructure transition from columnar dendrite to equiaxed dendrite took place once alloy undercooling exceeded a threshold about 74–79 K. In addition, the Vickers hardness of primary (Ni) dendrite was significantly improved, which was caused by the extension of Mo solubility and microstructure refinement.

Height and Growth Velocity in Children and Adolescents Undergoing Obesity Treatment: A Prospective Cohort Study.

Pediatric obesity affects endocrine conditions, which may alter growth. This work aimed to investigate the effect of obesity severity and obesity treatment outcome on growth. This prospective cohort study included children (aged 3-18 years) enrolled in the Swedish Childhood Obesity Treatment Register (BORIS) (1998-2020). Obesity was categorized as class I and class II obesity. Obesity treatment outcome was measured as body mass index (BMI) z score changes and categorized into good (BMI z score reduction of ≥0.25), intermediate, and poor (increasing BMI z score). Height for age z score, final height, and growth velocity were compared between class I and class II obesity. Further, the effect of obesity treatment outcome on growth velocity during 2-year follow-up was assessed. A total of 27 997 individuals (mean age 10.2 ± 3.6 years) were included. Individuals with class II obesity were on average taller than those with class I obesity during childhood. Among males, reduced growth spurt was observed in class I obesity, and even absent in class II obesity. Females exhibited a similar but less pronounced pattern. Good obesity treatment outcome yielded lower growth velocity at ages 3 to 9 years but higher growth velocity at ages 10 to 13 years compared to poor treatment outcome. Obesity severity is positively associated with height and growth velocity in childhood. A hampered growth spurt during puberty should be anticipated, particularly in adolescents with severe obesity. Therefore no difference in final height between class I and class II obesity is expected. Successful obesity treatment does not harm, but rather normalizes, the growth velocity pattern.

Influencing factors for the development and severity of bronchopulmonary dysplasia in preterm infants with a gestational age of

To study the influencing factors for the development and severity of bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g. A retrospective analysis was performed on the medical data of preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g who were admitted to Women and Children's Hospital Affiliated to Xiamen University from January 1, 2017 to December 31, 2021. According to oxygen dependence on day 28 after birth, they were divided into two groups: BPD (n=218) and non-BPD (n=142). According to disease severity based on oxygen concentration required at the corrected age of 36 weeks or at discharge, the infants with BPD were divided into two groups: mild BPD (n=154) and moderate/severe BPD (n=64). Indices such as perinatal data and nutritional status were compared between groups. The multivariate logistic regression analysis was used to determine the influencing factors for BPD and its severity. The incidence rate and severity of BPD increased with the reduction in gestational age and birth weight (P<0.05). The multivariate logistic regression analysis showed that a long duration of invasive mechanical ventilation (OR=1.320, P<0.05), hemodynamically significant patent ductus arteriosus (OR=2.032, P<0.05), and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.041, P<0.05) were risk factors for BPD, while an older gestational age was a protective factor against BPD (OR=0.535, P<0.05). Early-onset sepsis (OR=2.524, P<0.05) and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.029, P<0.05) were risk factors for moderate/severe BPD, while a high mean weight growth velocity was a protective factor against moderate/severe BPD (OR=0.906, P<0.05). The incidence rate and severity of BPD in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g can be reduced by shortening the duration of invasive mechanical ventilation, giving early treatment of early-onset sepsis and hemodynamically significant patent ductus arteriosus, adopting active enteral nutritional strategies, and increasing mean weight growth velocity.

Early childhood growth in Daasanach pastoralists of Northern Kenya: Distinct patterns of faltering in linear growth and weight gain.

Investigations of early childhood growth among small-scale populations are essential for understanding human life history variation and enhancing the ability to serve such communities through global public health initiatives. This study characterizes early childhood growth trajectories and identifies differences in growth patterns relative to international references among Daasanach semi-nomadic pastoralist children living in a hot, arid region of northern Kenya. A large sample of height and weight measures were collected from children (N=1756; total observations=4508; age=0-5 years) between 2018 and 2020. Daasanach growth was compared to international reference standards and Daasanach-specific centile growth curves and pseudo-velocity models were generated using generalized additive models for location scale and size. Compared to World Health Organization (WHO) reference, relatively few Daasanach children were stunted (14.3%), while a large proportion were underweight (38.5%) and wasted (53.6%). Additionally, Daasanach children had a distinctive pattern of growth, marked by an increase in linear growth velocity after 24 months of age and relatively high linear growth velocity throughout the rest of early childhood. These results identify a unique pattern of early childhood growth faltering among children in a small-scale population and may reflect a thermoregulatory adaptation to their hot, arid environment. As linear growth and weight gain remain important indicators of health, the results of this study provide insight into growth velocity variations. This study has important implications for global public health efforts to identify and address sources of early growth faltering and undernutrition in small-scale populations.

Impact of Intrauterine Growth Restriction and Placental Insufficiency on Nutritional Outcomes of Extremely Low Birth Weight Infants.

Introduction The aim of our study was to assess the impact of intrauterine growth restriction (IUGR) and placental insufficiency (PI) on the nutritional outcomes of extremely low birth weight (ELBW) infants. Methods We conducted a six-year retrospective case-control study that included 117 ELBW infants. Of these, 58 infants had IUGR and 59 were born appropriate-for-gestational age (AGA). Infants with IUGR were further divided based on the presence or absence of PI, as determined by umbilical arterial doppler velocimetry on serial ultrasounds. Results IUGR infants with PI had the lowest enteral calorie intake at 28 days of life (DOL) (median intake- IUGR+PI: 32 vs IUGR-PI: 93 vs AGA: 110 kcal/kg/day; p-value 0.011) and at 36 weeks corrected gestational age (CGA) (median intake- IUGR+PI: 102 vs IUGR-PI: 125 vs AGA: 119 kcal/kg/day; p-value 0.012). These infants also trended towards requiring a longer duration of total parenteral nutrition (TPN) (median duration - IUGR+PI: 35 vs IUGR-PI: 25 vs AGA: 21 days; p-value 0.054) and higher incidence of conjugated hyperbilirubinemia (IUGR+PI: 43% IUGR-PI: 29% vs AGA: 16%; p-value 0.058), but these results did not reach statistical significance. Despite challenges with enteral nutrition, IUGR infants with PI showed good catch-up growth and had higher growth velocities over the first month of life, compared to AGA controls. Conclusion IUGR in the presence of PI is associated with significantly poorer enteral nutritional outcomes in ELBW infants. However, with the support of optimal parenteral nutrition these infants showed good catch-up growth.

Formation of three-phase eutectic grains on primary phases: Observations from correlative imaging

We investigate the interaction between three-phase eutectic and a primary phase during solidification of an off-eutectic Al-Ag-Cu alloy through correlative imaging. In situ synchrotron X-radiography reveals the locations and orientations of primary Al2Cu rods, with respect to the surrounding eutectic. We also identified an unusually high and anisotropic eutectic growth velocity, often exceeding 100 μm/s when the growth front was parallel to the surface of a primary Al2Cu rod. By combining these results with three-dimensional (3D) focused ion beam tomography, scanning electron microscopy, and electron backscatter diffraction, we demonstrate that this anomaly results from two-dimensional (2D) dendrites, or ‘fingers’, of Al and Ag2Al that spread along the primary Al2Cu rod surfaces; meanwhile, protrusions of Al2Cu grow in between pockets of the fingers and into the surrounding eutectic, preserving their crystallographic orientations and morphology in the process. We propose a competitive growth relationship between the three phases of the eutectic to explain these features as well as the diversity of two- and three-phase microstructures obtained at the onset of eutectic solidification.

Exploring “No Man's Land”—Arrhenius Crystallization of Thin‐Film Phase Change Material at 1 000 000 K s−1 via Nanocalorimetry

AbstractNon‐volatile phase‐change memory (PCM) devices are based on phase‐change materials such as Ge2Sb2Te5 (GST). PCM requires critically high crystallization growth velocity (CGV) for nanosecond switching speeds, which makes its material‐level kinetics investigation inaccessible for most characterization methods and remains ambiguous. In this work, nanocalorimetry enters this “no‐man's land” with scanning rate up to 1 000 000 K s−1 (fastest heating rate among all reported calorimetric studies on GST) and smaller sample‐size (10–40 nm thick) typical of PCM devices. Viscosity of supercooled liquid GST (inferred from the crystallization kinetic) exhibits Arrhenius behavior up to 290 °C, indicating its low fragility nature and thus a fragile‐to‐strong crossover at ≈410 °C. Thin‐film GST crystallization is found to be a single‐step Arrhenius process dominated by growth of interfacial nuclei with activation energy of 2.36 ± 0.14 eV. Calculated CGV is consistent with that of actual PCM cells. This addresses a 10‐year‐debate originated from the unexpected non‐Arrhenius kinetics measured by commercialized chip‐based calorimetry, which reports CGV 103−105 higher than those measured using PCM cells. Negligible thermal lag (&lt;1.5 K) and no delamination is observed in this work. Melting, solidification, and specific heat of GST are also measured and agree with conventional calorimetry of bulk samples.

Constitutional supercooling and corresponding microstructure transition triggered by high magnetic field gradient during directional solidification of Al-Fe eutectic alloy

Directional solidification experiments of eutectic AlFe alloys were carried out under different high magnetic field gradients. High magnetic field gradient changed the microstructure selection during solidification process, induced the solidification microstructure to undergo eutectic instability, cellular transition, single-phase instability, and dendrite transition, which is similar to the planar-cellular-dendritic crystal growth pattern transition usually induced by an increasing growth velocity without magnetic field. The single phase was proved to be formed through an independent nucleation mechanism during single-phase instability. The effect of high magnetic field gradient on solidification was analyzed. Through the coupling effect of magnetic force and Lorentz force on solute migration and diffusion during solidification, high magnetic field gradient triggered a constitutional supercooling at the front of solid-liquid interface, which led to the growth pattern transition. A solidification model of eutectic alloy under high magnetic field gradient was proposed, and the microstructure selection map of AlFe alloy under gradient magnetic field was qualitatively drawn for the first time. This work proved that an alloy material with a microstructure usually obtained at high growth velocity can be obtained at a low growth velocity by applying a high magnetic field gradient, and suggested a new potential method for the future controlling of alloy structures and properties.

Growth Dynamics following Growth hormone treatment in group of Iraqi patients with Turner’s Syndrome

Background: Short stature is a well-known consequence of Turner’s syndrome (TS) and treatment with growth hormone can be improved the height of those patients, determination of the growth hormone velocity dynamics can help us to predict the optimum period for growth hormone treatment response. Objective: To study growth dynamics, which explained by height standard deviation, growth velocity and growth velocity standard deviation subsequent to growth hormone treatment in patients with Turner’s syndrome. Patient and Methods: During the period from January 2010 to January 2020, medical records of (30) patients with Turner’s syndrome (TS) were registered for this study, treated with growth hormone (GH). Where growth hormone (GH) dose was 0.06 IU/kg/day. Patients' height, mid-parental height (MPH), Bone age, the target height, the height standard deviation value, growth velocity and growth velocity standard deviation value were measured during Periodic follow-up of the patients every (3) months. Growth dynamics that explained by growth velocity, growth velocity Standard deviation and height standard deviation were compared before and after finishing treatment. Results: The average of height at beginning of treatment was 1.04±0.49 and the average of height at end of treatment is 1.3±0.154. While the difference in average is significant p=0.002. The difference between average of height standard deviation value at beginning of treatment and the average of height standard deviation value at end of treatment is also significant p =0.001. The first 2 years had the highest growth velocity and after that the growth velocity almost steady the same. The first year had lowest growth velocity standard deviation and the last year had the highest growth velocity standard deviation. There was no side effects observed was observed during treatment protocol. Conclusion: The growth velocity dynamics peak was more encountered during the first two years of treatment making it the optimum period of interest for compliance with growth hormone treatment.

Risk Factors for Rebound After Correction of Genu Valgum in Skeletal Dysplasia Patients Treated by Tension Band Plates.

Growth modulation using tension band plates (TBPs) is increasingly important for lower limb deformity correction in patients with skeletal dysplasia (SKD). Development of rebound deformity is a concern after TBP removal. Data regarding this complication are rare; therefore, we evaluated the prevalence and risk factors for rebound deformity in children with SKD undergoing correction of genu valgum using TBP. All patients with SKD with genu valgum treated by TBP at the distal femur or/and proximal tibia at a single center were reviewed. Inclusion criteria were: (1) minimum 2-year follow-up after TBP removal or having revision surgery for rebound deformity and (2) implant removal age for girls 14 years and below and boys 16 years and below. Exclusion criteria were any femoral/tibial osteotomies during TBP treatment or follow-up. A change of ≥3 degrees of mechanical lateral distal femoral and/or medial proximal tibial angle was accepted as rebound deformity and analyzed statistically. Thirty-three patients (59 limbs; 52 femur and 29 tibia physes) met our criteria. Mean follow-up after implant removal was 43.7 months. Rebound deformities were seen in 43 limbs (39 femurs and 13 tibias). Boys had more rebound than girls; however, this was not influenced by body mass index. Femurs had more rebound than tibias. Patients in the rebound group were younger than the nonrebound group. Time from application to removal of TBP was shorter in the rebound versus nonrebound group. Overcorrected limbs had more rebound deformity than not overcorrected. The difference in growth velocity of lower limbs in the rebound versus nonrebound group was statistically significant. Patients with epiphyseal dysplasia had more rebound than metaphyseal dysplasia, but this was not statistically significant. Risk factors for developing a rebound deformity after correction of genu valgum using TBP in SKD included male sex, TBP surgery at a young age, short duration of TBP implantation, overcorrected extremity (mechanical axis deviation ≤1), and high percent growth velocity after TBP removal. Level IV-retrospective study.

Rapid eutectic growth: from rod growth to diffusionless solidification.

Numerous experimental data on the rapid solidification of eutectic systems exhibit the formation of metastable solid phases with the initial (nominal) chemical composition. This fact is explained by the suppression of eutectic decomposition due to diffusionless (chemically partitionless) solidification beginning at a high but finite growth velocity of crystals. In the present work, a model is suggested for the diffusionless growth to analyse the atomic diffusion in the rod eutectic couples growing into supercooled liquid. A simplified calculating method for the equation related to the Bessel function in the solution of the growth of rod eutectics is obtained. This method can also be used in the calculation of other rod eutectic growth models. This article is part of the theme issue 'Transport phenomena in complex systems (part 2)'.

Rod eutectic growth in bulk undercooled melts

This article proposes an analytical model to understand the rod growth of eutectic in the bulk undercooled melt. Based on the previous derivations of the lamellar eutectic growth models, relaxing the assumptions of small Péclet numbers, the model is derived by considering melt kinetic and thermal undercoolings. The intent of this model is to predict the transitions in eutectic pattern for conditions of the low and high growth velocities. In addition to investigation of the transition between lamellar and rod eutectic patterns, mathematical simplifications of solving Bessel function are presented as well, which is the most important priority to model calculation.

Serum and Urinary Osteocalcin in Healthy 7- to 19-Year-Old Finnish Children and Adolescents.

Children and adolescents have high bone turnover marker (BTM) levels due to high growth velocity and rapid bone turnover. Pediatric normative values for BTMs reflecting bone formation and resorption are vital for timely assessment of healthy bone turnover, investigating skeletal diseases, or monitoring treatment outcomes. Optimally, clinically feasible measurement protocols for BTMs would be validated and measurable in both urine and serum. We aimed to (a) establish sex- and age-specific reference intervals for urinary and serum total and carboxylated osteocalcin (OC) in 7- to 19-year-old healthy Finnish children and adolescents (n = 172), (b) validate these against standardized serum and urinary BTMs, and (c) assess the impact of anthropometry, pubertal status, and body composition on the OC values. All OC values in addition to other BTMs increased with puberty and correlated with pubertal growth, which occurred and declined earlier in girls than in boys. The mean serum total and carboxylated OC and urinary OC values and percentiles for sex-specific age categories and pubertal stages were established. Correlation between serum and urinary OC was weak, especially in younger boys, but improved with increasing age. The independent determinants for OC varied, the urinary OC being the most robust while age, height, weight, and plasma parathyroid hormone (PTH) influenced serum total and carboxylated OC values. Body composition parameters had no influence on any of the OC values. In children and adolescents, circulating and urinary OC reflect more accurately growth status than bone mineral density (BMD) or body composition. Thus, validity of OC, similar to other BTMs, as a single marker of bone turnover, remains limited. Yet, serum and urinary OC similarly to other BTMs provide a valuable supplementary tool when assessing longitudinal changes in bone health with repeat measurements, in combination with other clinically relevant parameters.

Effects of Recombinant Human Growth Hormone Treatment, Depending on the Therapy Start in Different Nutritional Phases in Paediatric Patients with Prader-Willi Syndrome: A Polish Multicentre Study.

Recombinant human growth hormone (rhGH) treatment is an established management in patients with Prader–Willi syndrome (PWS), with growth promotion and improvement in body composition and possibly the metabolic state. We compared anthropometric characteristics, insulin-like growth factor 1 (IGF1) levels, metabolic parameters and the bone age/chronological age index (BA/CA) in 147 children with PWS, divided according to age of rhGH start into four groups, corresponding to nutritional phases in PWS. We analysed four time points: baseline, rhGH1 (1.21 ± 0.81 years), rhGH2 (3.77 ± 2.17 years) and rhGH3 (6.50 ± 2.92 years). There were no major differences regarding height SDS between the groups, with a higher growth velocity (GV) (p = 0.00) and lower body mass index (BMI) SDS (p < 0.05) between the first and older groups during almost the whole follow-up. IGF1 SDS values were lower in group 1 vs. other groups at rhGH1 and vs. groups 2 and 3 at rhGH2 (p < 0.05). Glucose metabolism parameters were favourable in groups 1 and 2, and the lipid profile was comparable in all groups. BA/CA was similar between the older groups. rhGH therapy was most effective in the youngest patients, before the nutritional phase of increased appetite. We did not observe worsening of metabolic parameters or BA/CA advancement in older patients during a comparable time of rhGH therapy.

Relationship between Microstructure Evolution and Tensile Properties of AlSi10Mg Alloys with Varying Mg Content and Solidification Cooling Rates

This work explored and contrasted the effect of microstructure on the tensile properties of AlSi10Mg alloys generated by transient directional solidification depending on variations in cooling rate and magnesium (Mg) content (i.e., 0.45 and 1 wt.% Mg), with a focus on understanding the dendritic growth and phases constitution. Optical and scanning electron (SEM) microscopies, CALPHAD, and thermal analysis were used to describe the microstructure, forming phases, and resulting tensile properties. The findings showed that the experimental evolution of the primary dendritic spacing is very similar when both directionally solidified (DS) Al-10 wt.% Si-0.45 wt.% Mg and Al-10 wt.% Si-1 wt.% Mg alloys samples are compared. The secondary dendritic spacing was lower for the alloy with more Mg, especially considering the range of high growth velocities. Moreover, a greater fraction of (Al + Si + Mg2Si) ternary eutectic islands surrounding the α-Al dendritic matrix was noted for the alloy with 1 wt.% Mg. As a result of primary dendritic spacings greater than 180 μm related to lower cooling rates, slightly higher tensile properties were attained for the Al-10 wt.% Si-0.45 wt.% Mg alloy. In contrast, combining dendritic refining (&lt;150 μm) and a larger Mg2Si fraction, fast-solidified DS Al-10 wt.% Si-1 wt.% Mg samples exhibited higher tensile strength and elongation. The control of cooling rate and fineness of the dendritic array provided a new insight related to the addition of Mg in slightly higher levels than conventional ones, capable of achieving a better balance of tensile properties in AlSi10Mg alloys.