Review - Interactions between diatoms and stainless steel: focus on biofouling and biocorrosion

There is a considerable body of information regarding bacterially enhanced corrosion, however, this review focuses on diatoms (unicellular algae) whose contribution to biocorrosion is less well studied. The reasons why diatoms have been neglected in studies of biocorrosion in natural waters are discussed and the question whether diatoms should be considered as inert with respect of electrochemical processes is considered. A particular focus is given to the case of stainless steels (SS), which are widely used in variety of applications in natural waters. Basic information on the cell biology of diatoms is included in the review, particularly with respect to their ability to 'sense' and adhere to surfaces. Investigations at the nanoscale are reviewed as these studies provide information about the behavior of cells at interfaces. Recent advances include the use of atomic force microscopy (AFM), although only a few studies have been applied to diatoms. Regarding the electrochemical behavior of SS, the mechanisms by which diatoms influence the potential ennoblement process is discussed. Such studies reveal the association of diatoms, in addition to bacteria, with biocorrosion processes

Angiodysplasies des maxillaires de l’enfant

Les angiodysplasies des maxillaires sont des affections rares et graves. Leur mauvais pronostic est surtout lié aux complications hémorragiques redoutables, dues le plus souvent à des extractions dentaires abusives sans examens radiologiques préalables. L’angio-IRM a permis d’une manière non invasive une meilleure connaissance de ces lésions en étudiant leur angio-architecture et leur hémodynamique. Jadis, le seul traitement efficace consistait en une exérèse chirurgicale mutilante entraînant des complications esthétiques et fonctionnelles sévères avec une morbidité importante. Actuellement, la radiologie interventionnelle a révolutionné la prise en charge grâce à l’artériographie hypersélective et àla découverte de nouveaux matériaux d’obturation plus faciles à manier. L’embolisation hypersélective est devenue l’arme de première intention en raison de son caractère conservateur et de son faible taux de  complications. Le but de ce travail est de rappeler les différents aspects étiopathogéniques, cliniques et para cliniques des angiodysplasieset de définir l’attitude thérapeutique.Mots clefs : angiodysplasie, embolisation, chirurgie

The Potential of Magnesium Alloys as Bioabsorbable/ Biodegradable Implants for Biomedical Applications

The potential of magnesium alloys as bioabsorbable / biodegradable implants for biomedical applications has been extensively studied as emerging direction. This paper gives a review of current topics in this field. Research activities related to biomedical magnesium alloys have been pursued in two main directions, orthopedic and cardiovascular implants, by investigating different aspects of alloying system design, novel structures, degradation rate control, and surface modification methods. Magnesium alloys are currently considered for applications as load-bearing implant devices such as plates, screws and pins for repairing bone fracture. Highly important direction of research is degradable coronary stents. Degradable vessel stents promote stable vessel regeneration, unlike permanent stents. Different combinations of alloying elements have been investigated in order to decrease corrosion rate.Tribological issues are also important for understanding of different phenomenon related to prolongation of Mg alloys corrosion degradation time/rate, such as tribocorrosion, corrosion fatigue, and fatigue crack growth behavior

Effectiveness of a package of postpartum family planning interventions on the uptake of contraceptive methods until twelve months postpartum in Burkina Faso and the Democratic Republic of Congo: The YAM DAABO study protocol

© 2018 The Author(s). Background: Postpartum family planning (PPFP) information and services can prevent maternal and child morbidity and mortality in low-resource countries, where high unmet need for PPFP remains despite opportunities offered by routine postnatal care visits. This study aims to identify a package of PPFP interventions and determine its effectiveness on the uptake of contraceptive methods during the first year postpartum. We hypothesize that implementing a PPFP intervention package that is designed to strengthen existing antenatal and postnatal care services will result in an increase in contraceptive use. Methods: This is an operational research project using a complex intervention design with three interacting phases. The pre-formative phase aims to map study sites to establish a sampling frame. The formative phase employs a participatory approach using qualitative methodology to identify barriers and catalysts to PPFP uptake to inform the design of a PPFP intervention package. The intervention phase applies a cluster randomized-controlled trial design based at the primary healthcare level, with the experimental group implementing the PPFP package, and the control group implementing usual care. The primary outcome is modern contraceptive method uptake at twelve months postpartum. Qualitative research is embedded in the intervention phase to understand the operational reasons for success or failure of PPFP services. Discussion: Designing, testing, and scaling-up effective, affordable, and sustainable health interventions in low-resource countries is critical to address the high unmet need for PPFP. Due to socio-cultural complexities surrounding contraceptive use, this research assumes that this is more effectively accomplished by engaging key stakeholders, including adolescents, women, men, key community members, service providers, and policy-makers. At the individual level, knowledge, attitudes, and behaviors of women and couples toward PPFP will likely be influenced by a set of low-cost interventions. At the health service delivery level, the implementation of this trial will probably require a shift in behavior and accountability of providers regarding the systematic integration of PPFP into their clinical practice, as well as the optimization of health service organization to ensure the availability of competent staff and contraceptive supplies. Trial registration: Retrospectively registered in the Pan African Clinical Trials Registry (PACTR201609001784334, 27 September 2016)

Single-cell sequencing of the human midbrain reveals glial activation and a neuronal state specific to Parkinson's disease

Parkinson's disease (PD) etiology is associated with genetic and environmental factors that lead to a loss of dopaminergic neurons. However, the functional interpretation of PD-associated risk variants and how other midbrain cells contribute to this neurodegenerative process are poorly understood. Here, we profiled >41,000 single-nuclei transcriptomes of postmortem midbrain tissue from 6 idiopathic PD (IPD) patients and 5 matched controls. We show that PD-risk variants are associated with glia- and neuron-specific gene expression patterns. Furthermore, Microglia and astrocytes presented IPD-specific cell proliferation and dysregulation of genes related to unfolded protein response and cytokine signalling. IPD-microglia revealed a specific pro-inflammatory trajectory. Finally, we discovered a neuronal cell cluster exclusively present in IPD midbrains characterized by CADPS2 overexpression and a high proportion of cycling cells. We conclude that elevated CADPS2 expression is specific to dysfunctional dopaminergic neurons, which have lost their dopaminergic identity and unsuccessful attempt to re-enter the cell cycle

Time to Long-Acting Reversible Contraceptive Uptake Over Twelve Months Postpartum: Findings of the Yam Daabo Cluster Randomized-Controlled Trial in Burkina Faso and the Democratic Republic of the Congo.

Purpose: An earlier adoption of contraceptive methods during the postpartum period could help women to extend the inter-pregnancy interval. This article aimed to determine and compare the timing of long-acting reversible contraceptives (LARC) use (ie, intrauterine device and implant) in Burkina Faso (BF) and DR Congo (DRC) between the intervention and control groups. Patients and Methods: A total of 1120 postpartum women were enrolled and followed up to 12 months postpartum. We used Yam-Daabo trial data which was a multi-intervention, single-blinded, cluster-randomised controlled trial done in primary health-care centres (clusters) in both countries. Centres were randomly allocated to receive the six-component intervention or standard antenatal and postnatal care in matched pairs (1:1). We did a secondary analysis using Royston-Parmar’s semi-parametric model to estimate the effect of the interventions on the median time of LARC uptake. Results: Our analysis included 567 postpartum women in BF (284 in the intervention group and 283 in the control group) and 553 in the DRC (274 in the intervention group and 279 in the control group). After showing an increase in family planning use in these two African countries, Yam Daabo’s interventions showed a reduction of the median time of LARCs adoption in the intervention group compared to the control group in both countries (difference of 39 days in Burkina Faso; difference of 86 days in the DR Congo). Conclusion: The Yam Daabo intervention package resulted in increased and earlier adoption of LARC in rural settings in Burkina Faso and urban settings in DR Congo. Such an intervention could be relevant in similar contexts in Sub-Saharan Africa with very high fertility rates and high unmet needs for contraception

Effectiveness of post-partum family planning interventions on contraceptive use and method mix at 1 year after childbirth in Kinshasa, DR Congo (Yam Daabo): a single-blind, cluster-randomised controlled trial.

BACKGROUND:In rural Burkina Faso, a package of six low-technology, post-partum contraceptive interventions (ie, refresher training for providers, a counselling tool, supportive supervision, daily availability of contraceptive services, client appointment cards, and invitation letters to attend appointments for partners), aimed at strengthening existing primary health-care services and enhancing demand for them, doubled the use of modern contraceptives at 12 months post partum (ie, 55% uptake in intervention recipients vs 29% in routine-care users). This study assessed the effect of a similar package but in urban settings of Kinshasa province, Democratic Republic of the Congo, in an effort to reduce the unmet need for post-partum family planning. METHODS:Yam Daabo was a multi-intervention, single-blinded, cluster-randomised controlled trial done in six primary health-care centres (clusters) in Kinshasa. Centres were randomly allocated to receive the six-component intervention or standard antenatal and postnatal care in matched pairs (1:1) on the basis of number of monthly births, the ratio of health workers per population in the health zone, and the urban and suburban settings. Only data analysts could be masked to cluster allocation. Health-care facilities were eligible if they provided a continuum of antenatal, delivery, and postnatal care, were well stocked with contraceptives, and were situated close to the main study centre. All pregnant women presenting to the six centres were eligible if they were in their third pregnancy trimester and had no counterindications to deliver in the facility. The main outcome was prevalence of use of modern contraceptives at 12 months after delivery. Analysis was by modified intention-to-treat using generalised linear mixed models or Fisher's exact test for small groups. Prevalence ratios were adjusted for cluster effects and baseline characteristics. This study was registered with the Pan-African Clinical Trials Registry (PACTR201609001784334). FINDINGS:From July 1, 2016, to Feb 2, 2017, eight of 52 clinics assessed for eligibility met the criteria and were randomised. Of 690 women approached, 576 (83%) women were enrolled: 286 in the four intervention clusters and 290 in the four control clusters. Of them, 519 (90%) completed the 12-month study exit interview (252 in the intervention group and 267 in the control group) and were included in the intention-to-treat analysis. At 12 months, 115 (46%) of 252 women in the intervention group and 94 (35%) of 267 in the control group were using modern contraceptives (adjusted prevalence ratio [PR] 1·58, 95% CI 0·74-3·38), with significant differences in the use of contraceptive implants (22% vs 6%; adjusted PR 4·36, 95% CI 1·96-9·70), but without difference in the use of short-acting contraceptives (23% vs 28%; 0·92, 0·29-2·98) and non-modern or inappropriate methods (7% vs 18%; 0·45, 0·13-1·54). There were no serious adverse events or maternal deaths related to the study. INTERPRETATION:The Yam Daabo intervention package did not have a significant effect on the overall use of effective modern contraceptives but significantly increased implant use in women post partum who live in urban settings in Kinshasa up to a year after childbirth. However, interferences from external family planning initiatives in the control group might have diminished differences between the services received. Such an intervention could be potentially relevant in similar contexts in DR Congo and other countries. FUNDING:Government of France; UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction

Discontinuation and switching of postpartum contraceptive methods over twelve months in Burkina Faso and the Democratic Republic of the Congo: a secondary analysis of the Yam Daabo trial.

IntroductionWomen who use contraceptive methods sometimes stop early, use methods intermittently, or switched contraceptive methods. All these events (discontinuations and switching) contribute to the occurrence of unwanted and close pregnancies. This study aimed to explore contraceptive discontinuation and switching during the Yam-Daabo project to measure the effect of interventions on the continuation of contraceptive methods use.MethodsWe conducted a secondary analysis of the Yam-Daabo trial data. We choose the discontinuation and switching of a modern contraceptive method as outcome measures. We performed a survival analysis using the Stata software package to estimate the effect of the interventions on contraceptive discontinuation. We also studied the main reasons for discontinuation and switching.ResultsIn total, 637 out of the 1120 women used at least one contraceptive method (of any type), with 267 women in the control and 370 in the intervention group. One hundred seventy-nine women of the control group used modern methods compared to 279 women of the intervention group with 24 and 32 who discontinued, respectively. We observed no statistically significant association between interventions and modern methods discontinuation and switching. However, modern methods' discontinuation was higher in pills and injectables users than implants and IUDs users. The pooled data comparison showed that, in reference to the women who had not switched while using a modern method, the likelihood of switching to a less or equal effectiveness method among the women of the control group was 3.8(95% CI: 1.8-8.0) times the likelihood of switching to a less or equal effectiveness method among the women of the intervention group. And this excess was statistically significant (p ConclusionThe results of this study show no statistically significant association between interventions and modern methods discontinuation. Discontinuation is more related to the methods themselves than to any other factor. It is also essential to set up specific actions targeting women's partners and influential people in the community to counter inhibiting beliefs.Trial registrationPan African Clinical Trials Registry (PACTR201609001784334, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1784 )