Polarization and potentiometric studies of cobalt and copper oxidised ores in ammonium chloride medium

This research study was conducted to evaluate the dissolution and electrochemical behaviour of low grade Cu-Co oxide ore (0.4% Cu; 3% Co) in ammonium chloride media (NH4Cl) by means of polarization and potentiometric measurements. Polarization measurements were carried out to evaluate the electrochemical behaviour as well as the leaching and re-passivation behaviour of the ores at pH of 9.5, 9.6, 9.7 and 9.8 in NH4Cl solution. In all the pH tested, the potential changed from negative to electropositive values suggesting formation of passive film on the surface of the ore which lowered the dissolution rates. Stable behaviours as were as high dissolution rate were observed at pH of 9.5. Potentiometric measurements were carried out at constant current and varying potential to study the reactivity of Cu-Co oxide ores in 0.25M, 0.5M and 1M of NH4Cl solution. In this test the dissolution rates increased with increasing concentration and the pH decreased with increasing concentration and time suggesting production of acid as oxidation reaction takes place, the ranges of pH are depicted in the Pourbaix diagrams. Stable behaviours were observed in 1M of solution. All observations made in these measurements are confirmed by AAS, XRF, SEM and XRD analysis

Technological assessment of product screens (137sc16/17) performance

Performance of two product screens (137Sc-16/17) constantly flooding at UG2 plant were assessed. Root causes for the flooding were investigated as well as a benchmarking with the performance of non-flooding screens performance. Samples for the screens 137Sc-16/17 feed and oversize were collected for three days, and prepared according to plant standards for sample preparations in order to obtain the particle size distribution (PSD). The first PSD results of the feed were given to Barcandyle which is mechanical engineering experts for screen sizing and their findings were used in this project for optimization purposes. The PSDs of the screens undersize, oversize and feed were used to draw cumulative percent passing and these graphs were used with the effective formula in order to determine screen performances. It was observed that 137SC-17 was more efficient than 137SC-16 and also that the major cause of flooding was due to the woodchips blinding the screen panels. From these findings the aperture size of 137SC-16 was changed from 0.63mm to 0.8mm. The screens still flood during spikes time due insufficient picking points for wood at UG2 plant

Direct association between rainfall and non-typhoidal <i>Salmonella</i> bloodstream infections in hospital-admitted children in the Democratic Republic of Congo

Abstract Non-typhoidal Salmonella (NTS) ranks first among causes of bloodstream infection in children under five years old in the Democratic Republic of Congo and has a case fatality rate of 15%. Main host-associated risk factors are Plasmodium falciparum malaria, anemia and malnutrition. NTS transmission in sub-Saharan Africa is poorly understood. NTS bloodstream infections mostly occur during the rainy season, which may reflect seasonal variation in either environmental transmission or host susceptibility. We hypothesized that environment- and host-associated factors contribute independently to the seasonal variation in NTS bloodstream infections in children under five years old admitted to Kisantu referral hospital in 2013–2019. We used remotely sensed rainfall and temperature data as proxies for environmental factors and hospital data for host-associated factors. We used principal component analysis to disentangle the interrelated environment- and host-associated factors. With timeseries regression, we demonstrated a direct association between rainfall and NTS variation, independent of host-associated factors. While the latter explained 17.5% of NTS variation, rainfall explained an additional 9%. The direct association with rainfall points to environmental NTS transmission, which should be explored by environmental sampling studies. Environmental and climate change may increase NTS transmission directly or via host susceptibility, which highlights the importance of preventive public health interventions

A genomic appraisal of invasive Salmonella Typhimurium and associated antibiotic resistance in sub-Saharan Africa

Invasive non-typhoidal Salmonella (iNTS) disease manifesting as bloodstream infection with high mortality is responsible for a huge public health burden in sub-Saharan Africa. Salmonella enterica serovar Typhimurium (S. Typhimurium) is the main cause of iNTS disease in Africa. By analysing whole genome sequence data from 1303 S. Typhimurium isolates originating from 19 African countries and isolated between 1979 and 2017, here we show a thorough scaled appraisal of the population structure of iNTS disease caused by S. Typhimurium across many of Africa’s most impacted countries. At least six invasive S. Typhimurium clades have already emerged, with ST313 lineage 2 or ST313-L2 driving the current pandemic. ST313-L2 likely emerged in the Democratic Republic of Congo around 1980 and further spread in the mid 1990s. We observed plasmid-borne as well as chromosomally encoded fluoroquinolone resistance underlying emergences of extensive-drug and pan-drug resistance. Our work provides an overview of the evolution of invasive S. Typhimurium disease, and can be exploited to target control measures

Congrès AFMED 2017 : Pratique de l’anesthésie générale lors de la césarienne au Centre hospitalier Monkole: Practice of general anesthesia during the Caesarean section at the Monkole Hospital Center

Context and objective. General anesthesia in obstetrics is a difficult anesthesia because of physiological changes related to pregnancy. These changes build up the risk of maternal morbidity and mortality mainly because of the difficulties of airway management. In addition, general anesthesia compromises the adaptation of the newborn to extra uterine life. Thus, it has precise and codified indications, in particular extreme emergencies. This study aimed to assess the compliance of the indications of general anesthesia for cesarean section in the Monkole Hospital Center. Methods. This is a retrospective descriptive and documentary study carried out during the period from January 2011 to December 2016. It covered all Caesarean sections performed during this period. The south-after variables were: age of Caesarean women, BMI, parity; age of pregnancy, follow-up of prenatal consultations, indication of Caesarean section, degree of urgency, ASA class and its justification, reasons and modalities of general anesthesia, intubation difficulties, per operative incidents, postoperative complications and fetal-maternal outcomes.Results. Of 980 Caesarean sections performed during this period, 53, i.e. 5.4% were performed under general anesthesia. The average age of women is 30.41 years with extremes of 17 and 42 years. The average BMI is 21.66Kg /m2 with extremes ranging from 17.4 to 36.9. Paucigravids were the majority with 33.96%. Pregnancy was at term in 66.03%, premature in 30.18% and post-term in 3.77%. 60.4% of women did not follow prenatal consultations or followed them outside Monkole. The indications for Caesarean sections were maternal (41.5%), adnexal (43.39%), fetal 11.3% and mixed (3.77%). Caesarean section was urgent in 46 cases, i.e. 86.8%. The ASA class was III (37.73%); I (26.4%); II (22.64%) and IV (13.2%). The ASA justification was: hemorrhagic shock: 20.75%, moderate anemia 15.9%, severe anemia 13.2%, severe preeclampsia 18.88% of which 13.2% eclampsia; obesity 7.54 and pericarditis 1.88%. Mallampati scores were I in 72.2%, II in 16.98%, III in 3.77%, while the Cormak and Lehane scores were I in 83.01% and II in 16.98%. General anesthesia was indicated right away for 36 women, i.e. 67.9% and by conversion of local regional anesthesia in 32.1%, the reason for the conversion was anxiety in 7 cases, failure of local regional anesthesia in 4 cases, hemorrhage in 3 cases, insufficient block in 2 cases and vomiting with desaturation in 1 case. 47 women were intubated according to the rapid sequence induction technique; 6 with propofol alone without curare (conversion), the success rate of intubation was 100%. Induction was made with propofol 60.37%, ketamine 33.97% and propofol + ketamine 3.77%. Maintenance was provided by isoflurane in 79.24%, ketamine in 13.2% and propofol in 4%. Fentanyl (31%) and sufentanil(16%) were given after cord clamping and in 11.3% no morphine was used because of the certainty of the spinal block. Non-depolarizing curare (pancuronium) was used for maintenance in 18.86% of women. 51 women, i.e. 96.2% were extubated on the table, 1 at the fourth hour and 1 never. Preoperative anesthetic incidents were: hypotension in 6 cases, desaturation in 1 case. Surgical / obstetric incident were hemorrhage in 3 cases and atony in 1 case. Post-operative complications included: 3 cases of decompensated anemia, each one of them for the uterine arteries ligature, postpartum eclampsia, haematoma with vesico-vaginal fistula and stercoraceous fistula. There was one maternal death from uncontrollable hemorrhage in a woman with a placenta praevia percreta eroding the bladder. 15 fetuses, i.e. 28.3% were stillborn, 23, i.e. 43% had a good APGAR in the first minute, 15, i.e. 28.03% had a low APGAR but were recovered after resuscitation.&nbsp;Conclusion. The practice of general anesthesia for cesarean section at the Monkole hospital responds generally to international recommendations probably because of the permanent presence of specialist physicians. An analytical and especially multicentric study is necessary to make the state of the practice in the Kinshasa city and why not on the national territory. Contexte et objectif. L‟anesthésie générale en obstétrique est une anesthésie difficile à cause des modifications physiologiques liées à la grossesse. Ces modifications augmentent le risque morbidité et de mortalité maternelle surtout à causes des difficultés de la gestion des voies aériennes. En plus l‟anesthésie générale compromet l‟adaptation du nouveau-né à la vie extra-utérine. Ainsi elle a des indications précises et codifiées en particulier les urgences extrêmes (1, 2, 3, 4,5). Cette étude a été menée dans l‟objectif de vérifier la conformité des indications de l‟anesthésie générale pour césarienneMéthodes. Il s‟est agi d‟une étude documentaire réalisée pendant la période allant de janvier 2011 à décembre 2016 au Centre Hospitalier de Monkole. Elle a porté sur toutes les césariennes pratiquées durant cette période. Les variables recherchées ont été : l‟âge des femmes césarisées, l‟IMC, la parité ; l‟âge de la grossesse, le suivi de CPN, l‟indication de la césarienne, le degré d‟urgence, la classe ASA et sa justification, les motifs et les modalités de réalisation de l‟anesthésie générale, les difficultés d‟intubation, les incidents per opératoires, les complications postopératoires et l‟issu foeto-maternel.Résultats. Sur 980 césariennes réalisées pendant cette période, 53 soit 5,4% ont été faites sous anesthésie générale. L‟âge moyen des femmes est de 30,41 ans avec des extrêmes de 17 et 42 ans. L‟IMC moyen est de 21,66Kg/m2 avec des extrêmes allant de 17,4 et 36,9. Les paucipares étaient majoritaires avec 33,96%. La grossesse était à terme dans 66,03%, prématurée dans 30,18% et post-terme dans 3,77%. 60,4% des femmes n‟avaient pas suivi les CPN ou les avaient suivies en dehors de Monkole. Les indications de la césariennes étaient maternelles (41,5%), annexielles (43,39%), foetales 11,3% et mixte (3,77%). La césarienne était urgente dans 46 cas soit 86,8%. La classe ASA était III (37,73%) ; I (26,4%) II (22,64% et IV (13,2%). La justification de l‟ASA était : choc hémorragique : 20,75%, anémie modérée : 15,9% ; anémie sévère : 13,2% ; prééclampsie sévère : 18,88% dont 13,2% d‟éclampsie ; obésité : 7,54 et péricardite :&nbsp;1,88%. Les scores de Mallampati étaient I dans 72,2%, II dans 16,98%, III dans 3,77% alors les scores de Cormak et Lehane étaient de I dans 83,01% et II dans 16,98%. L‟anesthésie générale a été indiquée d‟emblée chez 36 femmes soit 67,9% et par conversion de l‟ALR dans 32,1%. Le motif de la conversion était l‟anxiété dans 7 cas, l‟échec de l‟ALR dans 4 cas, l‟hémorragie dans 3 cas, le bloc insuffisant dans 2 cas et le vomissement avec désaturation dans un cas. 47 femmes ont été intubé selon la technique d‟induction à séquence rapide ; 6 avec le propofol seul sans curare (conversion), le taux de réussite de l‟intubation était de 100%. L‟induction a été faite avec le propofol 60,37%, kétamine 33,97% et propofol plus kétamine 3,77%. L‟entretien a été assuré avec l‟isoflurane dans 79,24%, la kétamine dans 13,2% et le propofol dans 4%. Le fentanyl (31%) et le sufentanil (16%) ont été donné après clampage du cordon et dans 11,3% aucun morphinique n‟a été utilisé à cause de la certitude du bloc rachidien. Le curare non dépolarisant (pancuronium) a été utilisé en entretien chez 18,86% des femmes. 51 femmes soit 96.2% ont été extubées sur table, une à la quatrième heure et une jamais. Les incidents peropératoires anesthésiques ont été l‟hypotension dans 6 cas, la désaturation dans un cas les incidents chirurgicaux/obstétricaux ont été l‟hémorragie dans 3 cas et l‟atonie dans un cas. Les complications postopératoires étaient : 3 cas d‟anémie décompensées un cas chacun pour la ligature des uretères, l‟éclampsie du postpartum, l‟hématome avec fistule vésico-vaginale et la fistule stercorale. Il ya eu un décès maternel par hémorragie incontrôlable chez une femme ayant un placenta praevia percreta érodant la vessie. 15 foetus soit 28,3% étaient mort-nés, 23 soit 43% aveint un bon APGAR à la première minute, 15 soit 28,03% avaient un APGAR faible mais ont été récupérés après réanimation.Conclusion. La pratique de l‟anesthésie générale pour césarienne au centre hospitalier Monkole répond globalement aux recommandations internationales probablement à cause de la présence permanente des médecins spécialistes. Une étude analytique et surtout multicentrique nous semble nécessaire pour faire l‟état de lieux de la pratique dans la ville de Kinshasa et pourquoi pas sur l‟étendue du territoire national

Congrès AFMED 2017 : Anesthésie lors de la césarienne indiquée pour pré éclampsie sévère au Centre Hospitalier Monkole: Anesthesia during caesarean section indicated for severe preeclampsia at the Monkole hospital center

Contexte and objective. Pregnant hypertensive pathologies represent a major cause of maternal morbidity and mortality worldwide. Preeclampsia, which is a frequent cause of caesarean section, affects both the mother and the fetus and therefore anesthesia has a dual purpose: the survival of the mother and the child often premature. The choice of anesthesia type is guided by the balance of benefits and risks of each technique. The loco regional anesthesia especially the spinal anesthesia when possible is the best bet for Anesthésie, Pré-éclampsie sévère, Césarienne, Clinique de MONKOLE performing the caesarean section in preeclampsia (1, 2,3). This study was carried out in order to give rise to the practice of anesthesia during a caesarean section indicated for severe preeclampsia at the MONKOLEhospital center.Methods. It was a retrospective documentary descriptive study carried through at the MONKOLE hospital center during the period from January 2011 to December 2015. It concerned the files of all women who went through caesarean section for severe preeclampsia in this hospital during the study period. The interest variables were: socio-demographic characteristics (age of the women, BMI and season ofoccurrence), clinical-obstetrical characteristics (parity, place of prenatal consultations, age of gestation, birthweight, severity criteria), anesthetic characteristics(degree of urgency, type of anesthesia, preoperative incidents, time of extubation) and fetal-maternal and neonatal outcomes (APGAR at the first minute, postoperative complications of preeclampsia, early neonatal mortality, and maternal mortality).Results. During that period, 980 women went under caesarean section, of whom 142 for preeclampsia (18.8%) and 98 for severe preeclampsia (10%). The average age was 30.48 years and the cohort of 18 to 35 years represented 69.4% and 28.6% was over 35. Of them, 49% had normal BMI, 30.6% over weighted, 17.3% were obese and 3.1% were lean. The preeclampsia predominated during periods of transition between rainy and the dry seasons. The primigravids have accounted for 41.9%, the paucigravids 31.6%, the multigravids 20.4% and the great multigravids 6.1%. 39.8% of women have followed the prenatal consultations out of Monkole. 51% of pregnancies were preterm, 45.9% at term and 3.1% in post-term. The birth weight was less than 2500g in 47.5%, normal in 50.5% and more than 4000g in 2%. The severity criteria were: acute fetal distress (28.6%), severe and rebel hypertension (23.4%), eclampsia (13.3%),FNIHD (13.3%), death in utero (9.2%), intrauterine growth retardation (8.2%), severe oligo-amniosis (2%), Hellp syndrome (1%) and placenta senescence (1%). The caesarean section was performed urgently in 74.4%. Spinal anesthesia was perform in 86.7%, of 13 patients operated under general anesthesia with intubation, 12 were extubated on the table, one at the fourth hour, the most frequent preoperative incident was hypotension in 5.1% followed by anxiety 4.1%. The post-operative complications were eclampsia 2% and anemia of various causes in 3%. There were 9 stillbirths (9.1%), 69.7% of newborns had good APGAR, 21 (21.2%) were recovered after resuscitation, 2 premature neonatal deaths and no maternal deaths.Conclusion. This study suggests that loco regional anesthesia precisely the spinal anesthesia is the most common technique used during the caesarean section performed for severe preeclampsia at the MONKOLE hospital center. This is in line with literature data. Ahigh-power analytical study looking for the determinants of the choice of more multicentrictechnique seems necessary. Contexte et objectif. Les pathologies hypertensives gravidiques de la grossesse représentent une cause majeure de morbidité et mortalité maternelles dans le monde. La pré-éclampsie qui est une cause fréquente de la césarienne retentit tant sur la mère que sur le foetus et donc l‟anesthésie a un double objectif : la survie de la mère et de l‟enfant souvent prématuré. Le choix du type d‟anesthésie est guidé par la balance des avantages et des risques de chaque technique. L‟anesthésie locorégionale en particulier la rachianesthésie lorsqu‟elle est possible représente la technique de choix pour la réalisation d‟une césarienne chez une pré-éclamptique. Cette étude a été menée dans l‟objectif de déterminer la pratique d‟anesthésie lors d‟une césarienne indiquée pour pré-éclampsie sévère au Centre hospitalier MONKOLE.Méthodes. Il s‟agissait d‟une étude documentaire descriptive réalisée au Centre hospitalier MONKOLE pendant le période allant de janvier 2011 à décembre 2015. Elle a concerné les dossiers de toutes les femmes césarisées pour pré-éclampsie sévère dans cet hôpital durant la période d‟étude. Les variables d‟intérêt ont été : les caractéristiques sociodémographiques (âge de la femme, l‟IMC et la saison de survenue), les caractéristiques clinico-obstétricales (parité, lieu de CPN, âge gestationnel, poids de naissance, critères de sévérité) les caractéristiques anesthésiques (degré d‟urgence, type d‟anesthésie, incidents peropératoires, moment de l‟extubation) et l‟issu foeto-maternel et néonatal (APGAR à la première minute, complications post-opératoires de la pré-éclampsie, mortalité néonatale précoce et mortalité maternelle).Résultats. Durant cette période, 980 femmes ont été césarisées dont 142 pour pré-éclampsie soit 18,8% et 98 pour pré-éclampsie sévère soit 10%. L‟âge moyen est de 30,48 ans et la tranche d‟âge de 18 à 35 ans représentait 69,4% et 28,6% avaient plus de 35ans. Sur ces parturientes, 49% avaient un IMC normal, 30,6% en surpoids, 17,3% étaient obèses et 3,1% maigres. La pré-éclampsie prédominait durant les périodes de transition entre les saisons de pluie et saison sèche. Les primipares ont représenté 41,9%, les paucipares 31,6%, les multipares 20,4% et les grandes multipares 6,1%.&nbsp;Environ 39.8% des femmes avaient suivi la CPN en dehors de MONKOLE. 51% des grossesses étaient avant terme, 45,9% à terme et 3,1% en post-terme. Le poids de naissance était inférieur à 2500g dans 47,5%, normal dans 50,5% et plus de 4000g dans 2%. Les critères de la sévérité ont été : souffrance foetale aiguë (28,6%), HTA sévère rebelle (23,4%), éclampsie (13,3%), DPPNI (13,3%), mort in utéro (9,2%), retard de croissance intra-utérine (8,2%), oligo-amnios sévère (2%), Hellp syndrome (1%) et sénescence placentaire (1%). La césarienne a été pratiquée en urgence dans 71,4%. La rachianesthésie a été pratiquée dans 86,7%, de 13 gestantes opérées sous anesthésie générale avec intubation, 12 ont été extubées sur table, une à la quatrième heure, l‟incident peropératoire le plus fréquent était l‟hypotension dans 5,1% suivie de l‟anxiété 4,1%. Les complications postopératoires étaient l‟éclampsie 2% et l‟anémie de cause diverse 3%. Il y a eu 9 mort-nés (9,1%), 69,7% des nouveau-nés avaient un bon APGAR, 21 (21,2%) ont été récupérés après réanimation, 2 cas mort néonatale précoce et aucun décès maternel.Conclusion. Cette étude suggère que l‟anesthésie locorégionale, précisément la rachianesthésie, est la technique la plus utilisée lors de la césarienne pratiquée pour pré-éclampsie sévère au centre hospitalier MONKOLE. Ce qui est conforme aux données de la littérature. Une étude analytique de grande puissance recherchant les déterminants du choix de la technique mieux multicentrique semble nécessaire

Blood lead levels in the Kinshasa population : a pilot study

Objective Leadedgasoline and lead paints are still in use in the Democratic Republic of Congo but data on blood lead levels in the general population are not available. We evaluated the Pb impregnation in children and adults (0 - 70 years old) in Kinshasa. Methods Blood lead was measured by atomic absorption in a sample of 485 healthy people (268 men and 217 women) living in Kinshasa between May 2003 and June 2004. Results Geometric mean blood lead was 120 µg/L (95% CI: 115 -125), with a higher concentration in men than in women (127 vs 114 µg/L, p=0.01). Sixty-three percent of children aged less than 6 years old presented blood lead levels above the 100 µg threshold. In the adult population, occupations with a potential risk of exposure to gasoline (car mechanics or garage owners, taxi drivers, conveyors and gas pump attendants) were associated with an extra blood lead of about 65µg/L. Conclusion This study indicates a relatively important Pb impregnation of the Kinshasa population. It demonstrates the existence of a major public health issue requiring corrective actions and the implementation of an appropriate regulatio

Anthropometric and aesthetic outcomes for the nasolabial region in 101 consecutive African children with unilateral cleft lip one year after repair using the anatomical subunit approximation technique

One hundred and one patients with complete or incomplete cleft lip underwent the anatomical subunit approximation technique for repair. The patients were followed up prospectively for 1year. The objective of this study was to determine the outcomes for the nasolabial area through anthropometric measurements and assessment of the Asher-McDade Aesthetic Index and Steffensen's criteria at 1year after surgery. Six assessors (three cleft surgeons and three non-surgeon medical professionals) examined cropped images; reliability was assessed using Cronbach's alpha. The difference in lip length between the healthy and operated sides was 0.61mm and the difference in nostril diameter was 0.37mm (differences not significant). The average scar width was 2.78±1.35mm. Hypertrophic scars were observed in 9.9% of cases. The average Asher-McDade Aesthetic Index rating varied between 1.35 and 1.98 for all parameters. Cronbach's alpha coefficient was 0.83, 0.89, 0.98, and 0.89 for nasal form, nasal symmetry, vermilion border, and nasolabial profile, respectively. Steffensen's criteria rated appearance as 'good' in 69.3% to 91.1% of cases. The anatomical subunit approximation technique can be performed in Sub-Saharan Africans for all types of unilateral cleft lip. It significantly improves the length of the medial and lateral lips, leaving an acceptable scar. A study with a larger sample size and longer follow-up is warranted.status: publishe

Feeding Rabbits in Traditional System With Improved Forage Legumes in South-Kivu. D. R. Congo

<p>To investigate for an efficient feeding of rabbits in the traditional system essentially with some improved high yield forage legumes. Two animal nutrition trials were conducted from September 2011 to February 2012 in Mugwahi farm in Nyangezi, South-Kivu, D. R. Congo. Five female rabbits replicated three times were fed essentially in traditional system with supplements of improved forage legumes; first with <em>Leucaena diversifolia</em> from the selection of CIAT in Colombia and second with<em> Desmodium intortum. </em>Five others as local controls were fed only on local forages.</p><p>The palatability evaluation showed that <em>Calliandra calothyrsus </em>was most appreciated by rabbits; <em>Desmodium intortum </em>and <em>Leucaena diversifolia</em> had a moderate palatability.<em> </em>The weight gain showed that rabbits which received a supplement of <em>Leucaena diversifolia </em>grew better than those fed on local forages.</p><p>In term of palatability, the various forages supplied to female rabbits only <em>C. calothyrsus </em>performed significantly with a high RIP during the first trial and the improved forages <em>D. intortum </em>and <em>L. diversifolia</em> had a moderate one during the second trial. Regarding the weight gain of rabbits, the introduced forages; <em>L. diversifolia</em> performed better than the local ones. The cropping of improved legumes constitutes an alternative to avoid long walks to collect fodder which is scarce in villages. These good forages on farm could remain available even in the dry season. Studies to determine the constraints of adoption of forage crops by the farmers will improve forage production.</p