Case Report: COVID-19 and Lassa Fever Coinfection in an Ebola Suspected Patient in Guinea

ABSTRACT. In this case report, we describe a clinical presentation and therapeutic history of a unique case diagnosed with Lassa fever and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a 23-year-old man from Yomou prefecture in southeast Guinea identified with suspected Ebola Virus Disease (EVD) in the midst of an ongoing outbreak of that disease in the same region. On May 3, 2021, he was admitted to the Nzérékoré Epidemic disease treatment center where his clinical condition deteriorated significantly. Laboratory testing performed on the same day reveals a negative EVD polymerase chain reaction (PCR). Three days later, the patient was tested positive for SARS-CoV-2 and Lassa fever by reverse transcriptase PCR (RT-PCR) assays. Laboratory examination also indicated severe hematological and biochemical deteriorations in the patient. This case substantiates the need for systematic differential diagnosis during epidemic-prone disease outbreaks to better manage severely unwell patients.</jats:p

TECHNOLOGICAL PROPERTIES OF RAW CLAY BASED CERAMIC TILES: INFLUENCE OF TALC

Local clay from Burkina Faso has been used as a basic raw material in the formulation of ceramic tile with a natural talc (0 - 4% wt) as a flux. The used sintering temperatures are between 950 and 1100 °C with one hour as hold at heating rate of 5 °C∙min-1. The different technological properties (shrinkage, water absorption and mechanical strength) are improved when the sintering temperature exceeds 1000 °C. The mixture with 4% wt of talc provides better properties than the other grades. The tiles obtained at 1050 °C with 4% wt of talc have similar characteristics to those obtained at 1100 °C without talc. An energy gain with a difference of temperature of 50 °C could be made with the use of talc as the adjuvant

A study of adsorption of cadmium, copper and lead by two clays from Burkina Faso

International audienceWater pollution caused by natural and anthropogenic causes become a major problem for many countries around the world in trying to find adequate and accessible means of treating polluted water. For more than a decade, research is focused on local adsorbent materials such as clays. It is in this dynamic that two clays extracted in Burkina Faso and referenced KORO and SIT were used to evaluate their capacities to reduce the content of heavy metals in aqueous solutions simulating waste water. The monitoring of the removal processes uses electrochemical characterizations, as voltammetry, evidencing a removal degree of heavy metals exceeding 90%. Characterizations of the process were also obtained by X-ray diffraction, Infrared Spectroscopy and Scanning Electron Microscopy. It is shown that the removal process occurs through the formation of clay-heavy metals complexes with both KORO and SIT. The three major mechanisms that were evidenced are complexation, ion-exchange and precipitation

A study of adsorption of cadmium, copper and lead by two clays from Burkina Faso

International audienc

PREPARATION OF POZZOLAN WITH A RAW CLAY MATERIAL FROM BURKINA FASO / PREPARATION D’UNE POUZZOLANE A BASE D’UNE MATIERE PREMIERE ARGILEUSE DU BURKINA FASO

A raw clay material from Burkina Faso has been characterized for pozzolan elaboration. The analysis showed that SiO2 (45.91 wt. %), Al2O3 (28.29 wt. %) and Fe2O3 (9.75 wt. %) are the main oxides and kaolinite (71 wt. %) is the principle mineral. The sample has been activated at 680 °C during 2 or 5 hours. The pozzolanic activity has been accessed by coupling several methods. The chemical methods showed the good lime fixing ability by the activated sample. At the first 24 hours, more than 50 wt. % of the lime is fixed and at 28 days around 90 wt. % of lime are fixed. Mineralogical analyses showed the disappearing of portlandite (CH) and the formation of new C-S-H hydrates. The pozzolanic index (81 %) calculated from mechanical strength of mortars made with 25 wt. % substitution of cement by the pozzolan confirm it suitability for portland cement replacement in the field of building materials

Study of thermal shock and chemical durability of a porcelain formulated from local raw materials from Burkina Faso

This work evaluates the resistance to chemical attack and thermal shock of porcelain formulated from local raw materials from Burkina Faso for their validation in real use. A kaolinitic clay, a pegmatite and sand were used for the formulation of porcelain tiles. Some samples were shaped by casting into porous molds and sintered at a temperature of 1240 °C. The average heating rate is 10 °C/min up to the final given temperature. These porcelains were immersed to a depth of 25 mm in test solutions and kept closed at 20 °C for 12 days. Six concentrations of test solutions were prepared to perform these tests: ammonium chloride (100 g/L); hydrochloric acid (3% and 18% by volume); lactic acid (5% by volume); citric acid (100 g/L) and alkali KOH (30 g/L and 100 g/L). The test showed that these porcelains are resistant to chemical attacks with insignificant mass variations ranging from −0.030 to 0.053 wt%. The results of the thermal shock test show that formulated porcelains are resistant to the brutal variation of temperature. The results obtained qualify the porcelains for industrial and real use

Étude des propriétés mécaniques des géomateriaux argileux associant la décoction de Parkia Biglobosa (néré)

International audienceResearches for non-energy intensive construction products, that are durable and cheaper is today of global concern because of the limited resources (energy, financial, etc.). To address this issue, the present work presents the combination of the decoction of pods of Parkia Biglobosa (néré) that is rich in tannins compounds including gallic acid, epicatechin gallate and epigallocatechin, with a clay-sand mixture. The clay used is referenced KORO and contains montmorillonite, illite, quartz, albite, orthoclase, kaolinite and goethite. The study of the mechanical properties of geomaterials formulated from the mixture shows that they have values of mechanical resistance higher and that their behavior becomes viscoplastic. This is due to the formation of chemical complexes from carboxylic groups of tannins macromolecules with the iron oxy-hydroxide in the interlayer spacing of clay minerals. This process is enhanced by the sorption of tannins on the surface of clay minerals.La recherche de produits de construction non énergivores, résistants et moins coûteux est de nos jour une préoccupation mondiale du fait des ressources (énergétiques, financières,…) limitées. Dans ce travail, nous avons associé la décoction de gousses de Parkiabiglobosa (Néré) riche en tanins, notamment en acide gallique, épicatéchine et épigallocatéchine gallate, à un mélange argile–sable afin de répondre à cette problématique. L’argile utilisée est référencée KORO et contient de la montmorillonite, de l’illite, du quartz, de l’albite, de l’orthose, de la kaolinite et de la goethite. L’étude des propriétés mécaniques des géomatériaux formulés à partir du mélange montre qu’ils présentent des valeurs de résistances mécaniques plus élevées et que leur comportement devient viscoplastique. Cela est dû à la formation de complexes chimiques entre les atomes de fer des oxy-hydroxydes dans l’espace interfoliaire des minéraux argileux et les radicaux carboxyliques des macromolécules de tanins. Ce processus est accentué par la sorption des tanins à la surface des minéraux de l’argile

Étude des propriétés mécaniques des géomateriaux argileux associant la décoction de Parkia Biglobosa (néré)

International audienc

Physical, thermal and mechanical properties of adobes stabilized with fonio (Digitaria exilis) straw

International audienceThis study deals with the influence of fonio straw on the physical, thermal and mechanical properties of adobes. The raw materials (soil and fonio straw from Burkina Faso) were characterized from the chemical (ICP-AES), mineralogical (XRD, DSC-TGA, IR), geotechnical (particle size distribution, Atterberg limits, methylene blue value) and microstructural (SEM-EDS) points of view. The physical (thermal conductivity, capillarity water absorption, porosity, erodibility) and mechanical (compressive and flexural strength) properties of the adobes were studied with specific attention paid to their damage and fracture behavior. Because of the biochemical composition of fonio straw (presence of quasi-crystalline cellulose and hemicelluloses, which are hydrophilic compounds), its association with the clay matrix increased water absorption and was accompanied by a significant porosity due to the air trapped during mixing. The insulating character of the cellulose and the low density resulting from the high porosity contributed to an appreciable reduction of the thermal conductivity of these adobes. The use of small amounts of fonio straw improved the mechanical properties of the adobes and made them less brittle. This improvement was linked to the good adhesion between fonio straw and the clay matrix, greatly reduced propagation of fissures in the composites and the high tensile strength of fonio straw because of its cellulose content. Thus, fonio-straw-reinforced adobes have interesting properties for use as cheap construction materials in the Sahelian zones and could contribute significantly to the thermal comfort of the inhabitants in this hot climat

Physical, thermal and mechanical properties of adobes stabilized with fonio (Digitaria exilis) straw

International audienceThis study deals with the influence of fonio straw on the physical, thermal and mechanical properties of adobes. The raw materials (soil and fonio straw from Burkina Faso) were characterized from the chemical (ICP-AES), mineralogical (XRD, DSC-TGA, IR), geotechnical (particle size distribution, Atterberg limits, methylene blue value) and microstructural (SEM-EDS) points of view. The physical (thermal conductivity, capillarity water absorption, porosity, erodibility) and mechanical (compressive and flexural strength) properties of the adobes were studied with specific attention paid to their damage and fracture behavior. Because of the biochemical composition of fonio straw (presence of quasi-crystalline cellulose and hemicelluloses, which are hydrophilic compounds), its association with the clay matrix increased water absorption and was accompanied by a significant porosity due to the air trapped during mixing. The insulating character of the cellulose and the low density resulting from the high porosity contributed to an appreciable reduction of the thermal conductivity of these adobes. The use of small amounts of fonio straw improved the mechanical properties of the adobes and made them less brittle. This improvement was linked to the good adhesion between fonio straw and the clay matrix, greatly reduced propagation of fissures in the composites and the high tensile strength of fonio straw because of its cellulose content. Thus, fonio-straw-reinforced adobes have interesting properties for use as cheap construction materials in the Sahelian zones and could contribute significantly to the thermal comfort of the inhabitants in this hot climat