Impact of Periodic Current Pulses on Li-Ion Battery Performance

International audiencePulse charging and pulse discharging have been reported by many authors in the literature to improve the performance of various secondary electrochemical cells. Only a few authors mentioned the effects of such charge and discharge method on lithium-ion batteries. The overall objective of this work is to experimentally investigate the impact of certain current pulse profiles on the electrical performance of Li-ion batteries. The results highlight a detrimental impact of periodic pulses on the cell performance compared to profiles with constant current

Effect of a Successful Intensive Lifestyle Program on Insulin Sensitivity and Glucose Tolerance in Obese Youth

OBJECTIVE—To evaluate the impact on glucose metabolism of a lifestyle program (the Yale Bright Bodies Program) for obese children

Randomized controlled trial of a good practice approach to treatment of childhood obesity in Malaysia: Malaysian childhood obesity treatment trial (MASCOT)

Context. Few randomized controlled trials (RCTs) of interventions for the treatment of childhood obesity have taken place outside the Western world. Aim. To test whether a good practice intervention for the treatment of childhood obesity would have a greater impact on weight status and other outcomes than a control condition in Kuala Lumpur, Malaysia. Methods. Assessor-blinded RCT of a treatment intervention in 107 obese 7- to 11-year olds. The intervention was relatively low intensity (8 hours contact over 26 weeks, group based), aiming to change child sedentary behavior, physical activity, and diet using behavior change counselling. Outcomes were measured at baseline and six months after the start of the intervention. Primary outcome was BMI z-score, other outcomes were weight change, health-related quality of life (Peds QL), objectively measured physical activity and sedentary behavior (Actigraph accelerometry over 5 days). Results. The intervention had no significant effect on BMI z score relative to control. Weight gain was reduced significantly in the intervention group compared to the control group (+1.5 kg vs. +3.5 kg, respectively, t-test p < 0.01). Changes in health-related quality of life and objectively measured physical activity and sedentary behavior favored the intervention group. Conclusions. Treatment was associated with reduced rate of weight gain, and improvements in physical activity and quality of life. More substantial benefits may require longer term and more intensive interventions which aim for more substantive lifestyle changes

Utility of Hemoglobin A1c for Diagnosing Prediabetes and Diabetes in Obese Children and Adolescents

OBJECTIVE-Hemoglobin A(1c) (A1C) has emerged as a recommended diagnostic tool for identifying diabetes and subjects at risk for the disease. This recommendation is based on data in adults showing the relationship between A1C with future development of diabetes and microvascular complications. However, studies in the pediatric population are lacking. RESEARCH DESIGN AND METHODS-We studied a multiethnic cohort of 1,156 obese children and adolescents without a diagnosis of diabetes (male, 40%/female, 60%). All subjects underwent an oral glucose tolerance test (OGTT) and A1C measurement. These tests were repeated after a follow-up time of similar to 2 years in 218 subjects. RESULTS-At baseline, subjects were stratified according to A1C categories: 77% with normal glucose tolerance (A1C 6.5%). In the at risk for diabetes category, 47% were classified with prediabetes or diabetes, and in the diabetes category, 62% were classified with type 2 diabetes by the OGTT. The area under the curve receiver operating characteristic for A1C was 0.81 (95% Cl 0.70-0.92). The threshold for identifying type 2 diabetes was 5.8%, with 78% specificity and 68% sensitivity. In the subgroup with repeated measures, a multivariate analysis showed that the strongest predictors of 2-h glucose at follow-up were baseline A1C and 2-h glucose, independently of age, ethnicity, sex, fasting glucose, and follow-up time. CONCLUSIONS-The American Diabetes Association suggested that an A1C of 6.5% underestimates the prevalence of prediabetes and diabetes in obese children and adolescents. Given the low sensitivity and specificity, the use of A1C by itself represents a poor diagnostic tool for prediabetes and type 2 diabetes in obese children and adolescents

Rapport final du projet européen CatClay sur les processus de migration des cations dans les roches argileuses indurées

International audienceIn the framework of the feasibility studies on the radioactive waste disposal in deep argillaceous formations, it isnow well established that the transport properties of solutes in clay rocks, i.e. parameter values for Fick’s law, are mainlygoverned by the negatively charged clay mineral surface. While a good understanding of the diffusive behaviour of non-reactiveanionic and neutral species is now achieved, much effort has to be placed on improving understanding of coupledsorption/diffusion phenomena for sorbing cations. Indeed, several cations known to form highly stable surface complexes withsites on mineral surfaces migrate more deeply into clay rock than expected. Therefore, the overall objective of the EC CatClayproject is to address this issue, using a ‘bottom-up’ approach, in which simpler, analogous systems (here a compacted clay,‘pure’ illite) are experimentally studied and modelled, and then the transferability of these results to more complex materials, i.e.the clay rocks under consideration in France, Switzerland and Belgium for hosting radioactive waste disposal facilities, isverified. The cations of interest were chosen for covering a representative range of cations families: from a moderately sorbingcation, the strontium, to three strongly sorbing cations, Co(II), Zn(II) and Eu(III). For the 4 years of this project, much effort wasdevoted to developing and applying specific experimental methods needed for acquiring the high precision, reliable data neededto test the alternative hypotheses represented by different conceptual-numerical models. The enhanced diffusion of the sorbingcations of interest was confirmed both in the simpler analogous illite system for Sr2+, Co(II) and Zn(II), but also in the naturalclay rocks, except for Eu(III). First modelling approach including diffusion in the diffuse double layer (DDL) promisinglysucceeded in reproducing the experimental data under the various conditions both in illite and clay rocks, even though someassumptions made have to be verified. In parallel, actual 3D geometrical pore size distributions of compacted illite, and in lessextent, clay rock samples, were successfully determined by combining TEM and FIB-nt analyses on materials maintained in awater-like saturation state by means of an extensive impregnation step. Based on this spatial distribution of pores, first numericaldiffusion experiments were carried at the pore scale through virtual illite, enabling a better understanding of how transferpathways are organized in the porous media. Finally, the EC CatClay project allowed a better understanding of the migration ofstrongly sorbing tracers through low permeability ‘clay rock’ formations, increasing confidence in our capacity to demonstratethat the models used to predict radionuclide migration through these rocks are scientifically sound

In-situ diffusion of HTO, 22Na+, Cs+ and I- in Opalinus Clay at the Mont Terri underground rock laboratory

The diffusion properties of the Opalinus Clay were studied in the underground research laboratory at Mont Terri (Canton Jura, Switzerland) and the results were compared with diffusion data measured in the laboratory on small-scale samples. The diffusion of HTO, Na-22(+), Cs+ and I- were investigated for a period of 10 months. The diffusion equipment used in the field experiment was designed in such a way that a solution of tracers was circulated through a sintered metal screen placed at the end of a borehole drilled in the formation. The concentration decrease caused by the diffusion of tracers into the rock could be followed with time and allowed first estimations of the effective diffusion coefficient. After 10 months, the diffusion zone was over-cored and the tracer profiles measured. From these profiles, effective diffusion coefficients and rock capacity factors Could be extracted by applying a two-dimensional transport model including diffusion and sorption. The simulations were done with the reactive transport code CRUNCH. In addition, results obtained from through-diffusion experiments oil small-sized samples with HTO, Cl-36(-) and Na-22(+) are presented and compared with the in situ data. In all cases. excellent agreement between the two data sets exists. Results for Cs+ indicated five times higher diffusion rates relative to HTO. Corresponding laboratory diffusion measurements are still lacking. However. our Cs+ data are in qualitative agreement wish through-diffusion data for Callovo-Oxfordian argillite rock samples. which also indicate significantly higher effective diffusivities for Cs+ relative to HTO

Environmental Factors in the Relapse and Recurrence of Inflammatory Bowel Disease:A Review of the Literature

The causes of relapse in patients with Crohn's disease (CD) and ulcerative colitis (UC) are largely unknown. This paper reviews the epidemiological and clinical data on how medications (non-steroidal anti-inflammatory drugs, estrogens and antibiotics), lifestyle factors (smoking, psychological stress, diet and air pollution) may precipitate clinical relapses and recurrence. Potential biological mechanisms include: increasing thrombotic tendency, imbalances in prostaglandin synthesis, alterations in the composition of gut microbiota, and mucosal damage causing increased permeability

OMG Do Not Say LOL: Obese Adolescents' Perspectives on the Content of Text Messages to Enhance Weight Loss Efforts

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93769/1/oby.2011.266.pd

A smartphone intervention for adolescent obesity: study protocol for a randomised controlled non-inferiority trial

Background There are few evidence-based mobile health solutions for treating adolescent obesity. The primary aim of this parallel non-inferiority trial is to assess the effectiveness of an experimental smartphone application in reducing obesity at 12 months, compared to the Temple Street W82GO Healthy Lifestyles intervention. Methods/design The primary outcome measure is change in body mass index standardised deviation score at 12 months. The secondary aim is to compare the effect of treatment on secondary outcomes, including waist circumference, insulin sensitivity, quality of life, physical activity and psychosocial health. Adolescents with a body mass index at or above the 98th percentile (12 to 17 years) will be recruited from the Obesity clinic at Temple Street Children’s University Hospital in Dublin, Ireland. W82GO is a family-based lifestyle change intervention delivered in two phases over 12 months. In the current study, participants will be randomised for phase two of treatment to either usual care or care delivered via smartphone application. One hundred and thirty-four participants will be randomised between the two study arms. An intention-to-treat analysis will be used to compare treatment differences between the groups at 12 months. Discussion The results of this study will be disseminated via open access publication and will provide important information for clinicians, patients and policy makers regarding the use of mobile health interventions in the management of adolescent obesity. Trial registration Clinicaltrials.gov NCT01804855