Background Every year, over 4 million children are treated for severe acute malnutrition with varying program performance. This study sought to explore the predictors of time to recovery from and ...non-response to outpatient treatment of SAM. Methods Children with weight-for-height z-score (WHZ) <-3 and/or mid-upper arm circumference (MUAC) <115 mm, without medical complications were enrolled in a trial (called MANGO) from outpatient clinics in Burkina Faso. Treatment included a weekly ration of ready-to-use therapeutic foods. Recovery was declared with WHZ ≥-2 and/or MUAC ≥125 mm, for two weeks without illness. Children not recovered by 16 weeks were considered as non-response to treatment. Predictors studied included admission characteristics, morbidity and compliance during treatment and household characteristics. Cox proportional hazard models were fitted and restricted mean time to recovery calculated. Logistic regression was used to analyse non-response to treatment. Results Fifty-five percent of children recovered and mean time to recovery was eight weeks while 13% ended as non-response to treatment. Independent predictors of longer time to recovery or non-response included low age, being admitted with WHZ <-3, no illness nor anaemia at admission, illness episodes during treatment, skipped or missed visits, low maternal age and not practising open defecation. Eighty-four percent of children had at least one and 59% at least two illness episodes during treatment. This increased treatment duration by 1 to 4 weeks. Thirty-five percent of children missed at least one treatment visit. One missed visit predicted 3 weeks longer and two or more missed visits 5 weeks longer treatment duration. Conclusions Both longer time to recovery and higher non-response to treatment seem most strongly associated with illness episodes and missed visits during treatment. This indicates that prevention of illnesses would be key to shortening the treatment duration and that there is a need to seek ways to facilitate adherence.
Treatment of children with uncomplicated severe acute malnutrition (SAM) is based on ready-to-use therapeutic foods (RUTF) and aims for quick regain of lost body tissues while providing sufficient ...micronutrients to restore diminished body stores. Little evidence exists on the success of the treatment to establish normal micronutrient status. We aimed to assess the changes in vitamin A and iron status of children treated for SAM with RUTF, and explore the effect of a reduced RUTF dose.
We collected blood samples from children 6–59 months old with SAM included in a randomised trial at admission to and discharge from treatment and analysed haemoglobin (Hb) and serum concentrations of retinol binding protein (RBP), ferritin (SF), soluble transferrin receptor (sTfR), C-reactive protein (CRP) and α1-acid glycoprotein (AGP). SF, sTfR and RBP were adjusted for inflammation (CRP and AGP) prior to analysis using internal regression coefficients. Vitamin A deficiency (VAD) was defined as RBP < 0.7 μmol/l, anaemia as Hb < 110 g/l, storage iron deficiency (sID) as SF < 12 μg/l, tissue iron deficiency (tID) as sTfR > 8.3 mg/l and iron deficiency anaemia (IDA) as both anaemia and sID. Linear and logistic mixed models were fitted including research team and study site as random effects and adjusting for sex, age and outcome at admission.
Children included in the study (n = 801) were on average 13 months of age at admission to treatment and the median treatment duration was 56 days IQR: 35; 91 in both arms. Vitamin A and iron status markers did not differ between trial arms at admission or at discharge. Only Hb was 1.7 g/l lower (95% CI −0.3, 3.7; p = 0.088) in the reduced dose arm compared to the standard dose, at recovery. Mean concentrations of all biomarkers improved from admission to discharge: Hb increased by 12% or 11.6 g/l (95% CI 10.2, 13.0), RBP increased by 13% or 0.12 μmol/l (95% CI 0.09, 0.15), SF increased by 36% or 4.4 μg/l (95% CI 3.1, 5.7) and sTfR decreased by 16% or 1.5 mg/l (95% CI 1.0, 1.9). However, at discharge, micronutrient deficiencies were still common, as 9% had VAD, 55% had anaemia, 35% had sID, 41% had tID and 21% had IDA.
Reduced dose of RUTF did not result in poorer vitamin A and iron status of children. Only haemoglobin seemed slightly lower at recovery among children treated with the reduced dose. While improvement was observed, the vitamin A and iron status remained sub-optimal among children treated successfully for SAM with RUTF. There is a need to reconsider RUTF fortification levels or test other potential strategies in order to fully restore the micronutrient status of children treated for SAM.
•Severe acute malnutrition (SAM) is treated with ready-to-use therapeutic foods (RUTF).•RUTF are supposed to restore normal micronutrient status during treatment.•We show that by anthropometric recovery 9% and 35% are still vitamin A and iron deficient.•RUTF nutrient content should be revised.•Post-discharge intervention strategies could be tested to reduce deficiencies.
Copper passivation by metal doping Lanzani, G.; Kangas, T.; Laasonen, K.
Journal of alloys and compounds,
08/2009, Letnik:
482, Številka:
1
Journal Article
Recenzirano
A computational Density Functional Theory (DFT) study of metal-doped copper surfaces and their reactivity with atomic oxygen is reported. The surface segregation and passivation potential of several ...different dopant metals (Mg, V, Cr, Al and Zn) on Cu(1
1
0) surface was investigated. The dopant atoms were placed on different layers of the surface, and the interaction with oxygen was studied at a coverage of 0.25
ML. Without oxygen the Mg, Al and Zn will segregate to the surface but the segregation energies are not large. The presence of oxygen changed this situation dramatically, now in all cases the metals will segregate to the surface and the segregation energies are large except for zinc. Also the sub-surface dopant layers will increase the oxygens binding to the Cu(1
1
0) surface. This suggests that the oxygen will enrich the dopants to and near to the surface and in this way helps to form a passivating layer on the copper alloy.
The role of the surface orientation and the oxygen coverage was investigated with Al-doped Cu(1
1
0), Cu(1
0
0) and Cu(1
1
1) surfaces. The results shows that Al should segregate on the surface layer, and the enrichment is more pronounced with the more dense surfaces (1
1
1) and (1
0
0). Also the oxygen coverage was tested with Al-doped Cu(1
1
0), Cu(1
0
0) and Cu(1
1
1) surfaces. The coverage varied from 0 to 1.0
ML. The calculated segregation energies are negative in all coverages, and they increase rapidly with the oxygen coverage. This indicates that aluminium has a strong tendency to segregate to the surface, making Al a good passivation element for copper surfaces.
Treatment of children with uncomplicated severe acute malnutrition (SAM) is based on ready-to-use therapeutic foods (RUTF) prescribed based on body weight and administered at home. Treatment ...performance is typically monitored through weight gain. We previously reported that a reduced dose of RUTF resulted in weight gain velocity similar to standard dose. Here we investigate the change in body composition of children treated for SAM and compare it to community controls, and describe the effect of a reduced RUTF dose on body composition at recovery.
Body composition was measured via bio-electrical impedance analysis at admission and recovery among a sub-group of children with SAM participating in a clinical trial and receiving a reduced or a standard dose of RUTF. Non-malnourished children were measured to represent community controls. Linear mixed regression models were fitted.
We obtained body composition data from 452 children at admission, 259 at recovery and 97 community controls. During SAM treatment the average weight increased by 1.20 kg of which 0.55 kg (45%) was fat-free mass (FFM) and 0.67 kg (55%) was fat mass (FM). At recovery, children treated for SAM had 1.27 kg lower weight, 0.38 kg lower FFM, and 0.90 kg lower FM compared to community controls. However, their fat-free mass index (FFMI) was not different from community controls (Δ0.2 kg/m2; 95% CI −0.1, 0.4). No differences were observed in FFM, FM or fat mass index (FMI) between the study arms at recovery. However, FFMI was 0.35 kg/m2 higher at recovery with the reduced compared to standard dose (p = 0.007) due to slightly lower height (Δ0.22 cm; p = 0.25) and higher FFM (Δ0.11 kg; p = 0.078) in the reduced dose group.
Almost half of the weight gain during SAM treatment was FFM. Compared to community controls, children recovered from SAM had a lower FM while their height-adjusted FFM was similar. There was no evidence of a differential effect of a reduced RUTF dose on the tissue accretion of treated children when compared to standard treatment.
•Severe acute malnutrition (SAM) is treated with ready-to-use therapeutic foods (RUTF).•Recovery from SAM is monitored in terms of weight gain.•The type of tissue gained during treatment is poorly known.•In this study, about 1/2 of the weight gained was fat free mass.•At recovery, treated children remained deficient particularly in fat mass.
Ready-to-use-therapeutic-foods (RUTF) was designed for the nutritional management of children with uncomplicated severe acute malnutrition (SAM) treated as outpatients. However, to our knowledge, no ...study has evaluated the availability, use and consumption of RUTF within the beneficiary household in programs and in the context of a reduction in the dose of RUTF.
This study, assessed the effect of a reduction in RUTF dose on the availability, use, consumption, and perceptions of caregivers on RUTF prescribed to 516 children treated for SAM, aged 6–59 months in Burkina Faso.
Children received a weekly dose of RUTF according to their treatment arm until recovery. Data were collected by structured individual in-depth interviews, with caregivers one month and two months post-admission. Differences between children receiving reduced RUTF (intervention arm) and those receiving standard RUTF (control arm) were assessed by Poisson, logistic, and ordered logistic regression model.
RUTF was available for the whole week in 95% in intervention arm compared to about 98% in control arm (p > 0.05). Starting from week 3 onwards, children in intervention arm consumed an average of 9 sachets of RUTF per week compared to 15 sachets in control arm (p < 0.001) and 5% of children in intervention arm reported leftover compared to 11% in control arm (p < 0.05). About 40% of children in intervention arm consumed RUTF at least 3-times per day compared to 82% in control arm (p < 0.001). The amount of RUTF prescribed was perceived as sufficient in 93% by caregivers in intervention arm against 97% in control arm (p > 0.05).
In conclusion, reducing the dose of RUTF did not affect the availability of RUTF during treatment but did reduce leftover and the frequency of consumption of RUTF.
Ready-to-use therapeutic foods (RUTF) are designed to cover the daily nutrient requirements of children with severe acute malnutrition (SAM). However, with the transfer of uncomplicated SAM care from ...the hospital environment to the community level, children will be able to consume complementary and family foods (CFF) in addition to RUTF, and this might decrease the quantity of RUTF needed for recovery.
Using an individually randomized clinical trial, we investigated the effects of a reduced RUTF dose on the daily energy and macronutrient intakes, the proportion of energy coming from CFF, and the mean probability of adequacy (MPA) of intake in 11 micronutrients of 516 children aged 6–59 mo who were treated for SAM in Burkina Faso.
The data were collected using a single 24-h multipass dietary recall, 1 mo after starting treatment, from December 2016 to August 2018, repeated on a subsample of 66 children. Differences between children receiving the reduced RUTF (intervention arm) and those receiving standard RUTF (control arm) were assessed by linear mixed models.
Daily energy intake was lower (P < 0.01) in the intervention arm (mean ± SD 1321 ± 339 kcal) than in the control arm (1467 ± 319 kcal). CFF contributed to 40% of the daily energy intake in the intervention and 35% in the control arm. The MPA for 11 micronutrients was 0.89 ± 0.1 in the intervention arm and 0.95 ± 0.07 in the control arm (P = 0.06).
Reducing the dose of RUTF during SAM treatment had a negative impact on daily energy intake of the children. Despite this, children covered their recommended energy intake. The energy intake coming from CFF was similar between arms, suggesting that children's feeding practices did not change due to the reduction in RUTF in this context. This trial was registered at the IRSCTN registry as ISRCTN50039021.
In order to understand the first steps of the Cu(1
0
0) oxidation we performed first principles calculations for on-surface and sub-surface oxygen on this surface. According to our calculations, the ...adsorption energies for all on-surface site oxygen atoms increase, whereas the energies of the sub-surface atoms decrease with the increasing oxygen coverage. At coverage 1
ML and higher on the reconstructed surface, structures including both on- and sub-surface atoms are energetically more favourable than structures consisting only of on-surface adsorbates. On the ideal (1
0
0) surface this change can be perceived at coverage 0.75
ML.
PDF
