11 research outputs found
Diagnostic et traitement de la Maladie du charbon à localisation palpébrale: à propos d’un cas et revue de littérature
L´anthrax est une zoonose causée par le Bacillus anthracis. les humains contractent généralement cette maladie dans des régions endémiques, par contact direct avec des animaux infectés ou avec leurs produits contaminés. Les localisations palpébrales sont rares dans la pratique clinique et posent des problèmes de diagnostic différentiel. Les auteurs rapportent l'observation d'un patient admis dans un tableau de cellulite préseptale, avec escarre noirâtre étendue de la paupière supérieure et oedème extensif de l´hémiface, faisant suspecter une localisation palpébrale de la maladie du charbon. L'examen bactériologique a permis de confirmer le diagnostic. Le patient a bénéficié d´une antibiothérapie à base de pénicilline G avec une bonne évolution.Key words: Maladie du charbon, oeil, oedème, blépharoplasti
Microscopic annealing process and its impact on superconductivity in T'-structure electron-doped copper oxides
High-transition-temperature superconductivity arises in copper oxides when
holes or electrons are doped into the CuO2 planes of their insulating parent
compounds. While hole-doping quickly induces metallic behavior and
superconductivity in many cuprates, electron-doping alone is insufficient in
materials such as R2CuO4 (R is Nd, Pr, La, Ce, etc.), where it is necessary to
anneal an as-grown sample in a low-oxygen environment to remove a tiny amount
of oxygen in order to induce superconductivity. Here we show that the
microscopic process of oxygen reduction repairs Cu deficiencies in the as-grown
materials and creates oxygen vacancies in the stoichiometric CuO2 planes,
effectively reducing disorder and providing itinerant carriers for
superconductivity. The resolution of this long-standing materials issue
suggests that the fundamental mechanism for superconductivity is the same for
electron- and hole-doped copper oxides.Comment: 23 pages, 3 figures, accepted for publication in Nature Material
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
The electron-doped cuprates: superconducting properties and pressure effects
We report some of the results that we have obtained from the study of the electromagnetic properties of the electron-doped L2-xCexCuO4 high temperature superconductors. We will show evidence of the strong anisotropic character of the superconducting properties of these materials, displaying 2D behavior. The competing effects of lattice contraction and charge transfer on the dependence of the critical temperature under pressure are analyzed
Aetiology, epidemiology and clinical characteristics of acute moderate-to-severe diarrhoea in children under 5 years of age hospitalized in a referral paediatric hospital in Rabat, Morocco
[email protected] address: Centro de Investigación, Universidad Peruana de Ciencias Aplicadas, Lima, PerúThe objective of the study was to describe the aetiology, epidemiology and clinical characteristics of the principal causes of acute infectious diarrhoea requiring hospitalization among children under 5 years of age in Rabat, Morocco. A prospective study was conducted from March 2011 to March 2012, designed to describe the main pathogens causing diarrhoea in hospitalized children >2 months and less than 5 years of age. Among the 122 children included in the study, enteroaggregative Escherichia coli (EAEC) and rotavirus were the main aetiological causes of diarrhoea detected. Twelve (9.8 %) children were referred to an intensive care unit, while two, presenting infection by EAEC, and EAEC plus Shigella sonnei, developed a haemolytic uraemic syndrome. Additionally, six (4.9 %) deaths occurred, with EAEC being isolated in four of these cases. Diarrhoeagenic E. coli and rotavirus play a significant role as the two main causes of severe diarrhoea, while other pathogens, such as norovirus and parasites, seem to have a minimal contribution. Surveillance and prevention programmes to facilitate early recognition and improved management of potentially life-threatening diarrhoea episodes are needed.Revisión por pare
Streptococcus pneumoniae carriage among healthy and sick pediatric patients before the generalized implementation of the 13-valent pneumococcal vaccine in Morocco from 2010 to 2011
Nasopharyngeal carriage studies provide insights into the local
prevalence of circulating pneumococcal serotypes. These data are
critical to vaccination monitoring, as they allow for the
prediction and assessment of impact. Very little data are
available on the carriage of pneumococcal serotypes in Morocco.
Here, we describe the prevalence of Streptococcus pneumoniae
carriage and serotype distribution among 697 pediatric patients
with ages ranging from 2 to 59 months who were admitted to a
Moroccan hospital with severe pneumonia, as well as 195 healthy
infants and young children who were recruited at a vaccination
clinic. Carriage rates were 40.5% (79/195) for healthy children
and 22.8% (159/697) for sick children. The most commonly
observed circulating serotypes included 6A, 6B and 19F, all of
which are included in the current 13-valent anti-pneumococcal
conjugate vaccine that was recently introduced in Morocco.
Monitoring of circulating serotypes remains necessary after
vaccine introduction to assess whether serotype replacement is
occurring