COVID-19 lockdown related to decrease in premature birth rate and increase in birth weight in metropolitan France

IntroductionThe worldwide rate of preterm birth (PTB) has been increasing over the last two decades. COVID-19 lockdowns provide a unique opportunity to assess the effects of socioenvironmental and lifestyle factors on premature birth and birth weight. We explored the effects of COVID-19 lockdowns on the PTB rate and birth weight at a nationwide scale in France until one year after their occurrence.Material and MethodsThis national retrospective observational study evaluated the rate of PTB and birth weight in France from January 2016 to December 2020. Data were obtained from the national Programme Médicalisé des Systèmes d'Information database. The rates of global and sub-categories of PTB were tested. The birth weight was studied before and after lockdown for all live births, for term and premature neonates, and for each category of low birth weight (LBW) by a stratified analysis.ResultsData from 2,949,372 births from January 2016 to December 2019, including 228,857 PTB, were compared to those of 699,344 births and 51,886 PTB from January to December 2020. The national rate of PTB decreased significantly from 7.7% to 7.3%, when compared with the 2016–2019 period. This decrease was persistent up to 9 months later. It was observed only for moderate PTB, whereas very PTB and extremely PTB remained stable. The national mean birth weight for full-term babies increased after the lockdown and was still observable up to 8 months later (+0.16%, p < 0.0001). The proportion of children with LBW also decreased 2 months after lockdown (−0.15%; p = 0.02). For VLBW, the difference only appeared over the 6-month post-lockdown period (−0.06%; p = 0.006).ConclusionThis nationwide study shows a significant reduction in prematurity and a significant increase in birth weight in France after the lockdown for a period of time not limited to the lockdown itself. A more in-depth study of the factors determining these variations may help to drive PTB prevention policies

Sodium bicarbonate for severe metabolic acidaemia – Authors' reply

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Proteomic profile determination of autosomal aneuploidies by mass spectrometry on amniotic fluids

<p>Abstract</p> <p>Background</p> <p>Prenatal diagnosis of chromosomal abnormalities by cytogenetic analysis is time-consuming, expensive, and requires highly qualified technicians. Rapid diagnosis of aneuploidies followed by reassurance of women with normal results can be performed by molecular analysis of uncultured foetal cells. In the present study, we developed a proteomic fingerprinting approach coupled with a statistical classification method to improve diagnosis of aneuploidies, including trisomies 13, 18, and 21, in amniotic fluid samples.</p> <p>Results</p> <p>The proteomic spectra obtained from 52 pregnant women were compiled, normalized, and mass peaks with mass-to-charge ratios between 2.5 and 50 kDa identified. Peak information was combined together and analysed using univariate statistics. Among the 208 expressed protein peaks, 40 differed significantly between aneuploid and non aneuploid samples, with AUC diagnostic values ranging from 0.71 to 0.91. Hierarchical clustering, principal component analysis and support vector machine (SVM) analysis were performed. Two class predictor models were defined from the training set, which resulted in a prediction accuracy of 92.3% and 96.43%, respectively. Using an external and independent validation set, diagnostic accuracies were maintained at 87.5% and 91.67%, respectively.</p> <p>Conclusion</p> <p>This pilot study demonstrates the potential interest of protein expression signature in the identification of new potential biological markers that might be helpful for the rapid clinical management of high-risk pregnancies.</p

Rôle de l'inertie microscopique lors de la rupture dynamique de matériaux ductiles

Ces travaux portent sur la modélisation de l'endommagement ductile de matériaux métalliques. Un modèle d'endommagement continu à base micromécanique a été mis point. L'originalité de celui-ci est qu'il incorpore des effets d'inertie liés aux mouvements de matière à l'échelle de microstructure du matériau. Ce modèle a été intégré dans un code de calculs par EF. Les simulations réalisées montrent que l'inertie microscopique pourrait jouer un rôle important lors de la rupture dynamique. En outre, elle induit un effet régularisant qui réduit la sensibilité au maillage lors des simulations

Toward Defining the Threshold Between Low and High Glucose Variability in Diabetes

International audienceOBJECTIVE:To define the threshold for excess glucose variability (GV), one of the main features of dysglycemia in diabetes.RESEARCH DESIGN AND METHODS:A total of 376 persons with diabetes investigated at the University Hospital of Montpellier (Montpellier, France) underwent continuous glucose monitoring. Participants with type 2 diabetes were divided into several groups-groups 1, 2a, 2b, and 3 (n = 82, 28, 65, and 79, respectively)-according to treatment: 1) diet and/or insulin sensitizers alone; 2) oral therapy including an insulinotropic agent, dipeptidyl peptidase 4 inhibitors (group 2a) or sulfonylureas (group 2b); or 3) insulin. Group 4 included 122 persons with type 1 diabetes. Percentage coefficient of variation for glucose (%CV = [(SD of glucose)/(mean glucose)] × 100) and frequencies of hypoglycemia (interstitial glucose 36% were compared with those with %CV ≤36%.CONCLUSIONS:A %CV of 36% appears to be a suitable threshold to distinguish between stable and unstable glycemia in diabetes because beyond this limit, the frequency of hypoglycemia is significantly increased, especially in insulin-treated subjects

An adaptation of the LMS method to determine expression variations in profiling data

The authors are indebted to Dr Irene Lopez-Vidriero (CNB-CSIC, Madrid) for help with the Latin square dataset analysis with MAS5. Drs Alain Henaut and Ulrich Mansmann for critical reading of the manuscript and useful propositions and comments. We would like to acknowledge Dr Andrew Kramar for his help in improving the English.One of the major issues in expression profiling analysis still is to outline proper thresholds to determine differential expression, while avoiding false positives. The problem being that the variance is inversely proportional to the log of signal intensities. Aiming to solve this issue, we describe a model, expression variation (EV), based on the LMS method, which allows data normalization and to construct confidence bands of gene expression, fitting cubic spline curves to the Box–Cox transformation. The confidence bands, fitted to the actual variance of the data, include the genes devoid of significant variation, and allow, based on the confidence bandwidth, to calculate EVs. Each outlier is positioned according to the dispersion space (DS) and a P-value is statistically calculated to determine EV. This model results in variance stabilization. Using two Affymetrix-generated datasets, the sets of differentially expressed genes selected using EV and other classical methods were compared. The analysis suggests that EV is more robust on variance stabilization and on selecting differential expression from both rare and strongly expressed genes.This work was supported by funds from the Association pour la Recherche sur le Cancer (contract ARC 5122) and the CIT program of the Ligue Nationale Contre le Cancer; work in JAGS’ lab was financed by grant number DAMD17-02-1-0339 from the USAMRAA breast cancer program and SAF2003-00519 from the Spanish Ministry of Education and Science. The package has been developed in Excel (Microsoft) and is available upon request. Funding to pay the Open Access publication charges for this article was provided by the Spanish Ministry of Education and Science.Peer reviewe

Influence of surface chemistry of fiber and lignocellulosic materials on adhesion properties with polybutylene succinate at nanoscale

The production of bio-based composites with enhanced characteristics constitutes a strategic action to minimize the use of fossil fuel resources. The mechanical performances of these materials are related to the specific properties of their components, as well as to the quality of the interface between the matrix and the fibers. In a previous research study, it was shown that the polarity of the matrix played a key role in the mechanisms of fiber breakage during processing, as well as on the final properties of the composite. However, some key questions remained unanswered, and new investigations were necessary to improve the knowledge of the interactions between a lignocellulosic material and a polar matrix. In this work, for the first time, atomic force microscopy based on force spectroscopy measurements was carried out using functionalized tips to characterize the intermolecular interactions at the single molecule level, taking place between poly(butylene succinate) and four different plant fibers. The efficiency of the tip functionalization was checked out by scanning electron microscopy and energy-dispersive X-ray spectroscopy, whereas the fibers chemistry was characterized by Fourier-transform infrared spectroscopy. Larger interactions at the nanoscale level were found between the matrix and hypolignified fibers compared to lignified ones, as in control experiments on single lignocellulosic polymer films. These results could significantly aid in the design of the most appropriate composite composition depending on its final use

An optimized finite-element library: Akantu

Akantu means a little element in Kinyarwanda, a Bantu language. From now on it is also an opensource object-oriented library which has the ambition to be generic and efficient

Comportement dynamique des matériaux ductiles. Modèle d'endommagement élasto-viscoplastique et simulation numérique du test d'impact de plaques

La rupture ductile des matériaux métalliques est un processus se déroulant en trois étapes : la nucléation, la croissance et la coalescence de vides. Aux grandes vitesses de sollicitation, les effets de micro-inertie, engendrés par la croissance rapide des cavités, influencent le comportement macroscopique du matériau. Nous proposons dans un premier temps un modèle d'endommagement dynamique par nucléation et croissance de vides, basé sur une approche d'homogénéisation. Ce modèle tient compte du comportement élasto-viscoplastique du matériau et est une extension de précédents travaux. Dans un second temps, le modèle est implanté dans le code de calculs par éléments finis Abaqus/Explicit via un sous-programme utilisateur Vumat. Les résultats de simulations numériques du test d'impact de plaques révèlent une bonne concordance avec les données expérimentales sur le tantale obtenues par Roy (2003) et permettent d'interpréter finement les expériences

Psychometric comparison of three behavioural scales for the assessment of pain in critically ill patients unable to self-report

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