9,058 research outputs found
Comparative studies on the flocculation efficiencies of Moringa oleifera (MO), polyacrylamide-grafted gum arabic (GA-g-PAAM) and blended products of MO and PA-g-PAAM
Graft copolymerization of polyacrylamide onto gum arabic was carried out in aqueous medium at room temperature (30 oC) using previously optimized concentrations of initiator (ceric ion) and the monomer (acrylamide). The percentage graft yield was high (70%) due to optimization of reaction conditions. Reactive blends of Moringa oleifera (MO) and the graft copolymer (GA-g-PAAM) were also synthesized in different ratios of MO to GA-g-PAAM. The blended and unblended graft copolymers and Moringa oleifera were characterized by infrared (IR) spectroscopy. Flocculation capabilities of GA-g-PAAM, the reactive blends (RB), the physical blends (PB) and Moringa oleifera were studied on turbid river water using UV-Visible spectrophotometry at three different wavelengths (λ=400, λ=600 and λ=800 nm) in order to observe the effect of wavelength on flocculation efficiency. The results generally showed that the flocculation efficiency was a function of both flocculation time allowed and the wavelength of UV- radiation used. Hence, the flocculation efficiency was higher for longer flocculation times and longer wavelengths of UV-radiation and vice versa. The flocculation efficiencies obtained after 24 hours at λ=800 nm followed the order below: MO (99.61%) > GA-g-PAAM (94.30%) > MO & GA-g-PAAM 3:1 RB (91.16%) > 1:3 RB (89.58%) > 1:1 PB (87.07%) > 1:1 RB (82.35%). The sludge produced by the above water treatment chemicals was small in volume, biodegradable and consequently did not promote environmental degradation. Through chemical derivatization, gum arabic was transformed into a water treatment chemical with more advantages over conventional coagulants.Keywords: Sludge, Biodegradable, Environment, Turbid water, Derivatization, Coagulan
A novel PAX5 rearrangement in TCF3-PBX1 acute lymphoblastic leukemia: a case report.
BACKGROUND: Chromosome translocations are a hallmark of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Additional genomic aberrations are also crucial in both BCP-ALL leukemogenesis and treatment management. Herein, we report the phenotypic and molecular cytogenetic characterization of an extremely rare case of BCP-ALL harboring two concomitant leukemia-associated chromosome translocations: t(1;19)(q23;q13.3) and t(9;17)(p13;q11.2). Of note, we described a new rearrangement between exon 6 of PAX5 and a 17q11.2 region, where intron 3 of SPECC1 is located. This rearrangement seems to disrupt PAX5 similarly to a PAX5 deletion. Furthermore, a distinct karyotype between diagnosis and relapse samples was observed, disclosing a complex clonal evolution during leukemia progression. CASE PRESENTATION: A 16-year-old boy was admitted febrile with abdominal and joint pain. At clinical investigation, he presented with anemia, splenomegaly, low white blood cell count and 92% lymphoblast. He was diagnosed with pre-B ALL and treated according to high risk GBTLI-ALL2009. Twelve months after complete remission, he developed a relapse in consequence of a high central nervous system and bone marrow infiltration, and unfortunately died. CONCLUSIONS: To our knowledge, this is the first report of a rearrangement between PAX5 and SPECC1. The presence of TCF3-PBX1 and PAX5-rearrangement at diagnosis and relapse indicates that both might have participated in the malignant transformation disease maintenance and dismal outcome
Properties of humic substances isolated from different natural sources
The purpose of study was to determine properties of humic substances by combination of modern and traditional methods. Humic substances isolated from three different sources from Mongolia such as peloid from Lake Gurban nuur, coal from Baganuur deposit and oil shale from Shine khudag deposit. On the basis of determination H/C and O/C atomic ratios in humic substances by elemental analysis, confirmed existing of aromatic structures in the molecules and oxidized functional groups. Have been studied the structure of humic substances by spectral method. For example infrared spectrums showed that humic substances are characterizing with poly-structural components, with different quantity in the samples. Light adsorption of samples in the UV-Vis region, a decrease on the absorption intensity with an increase of the wave length was observed (Fig. 2). The high ratio Đ/ĐĄ, attributed to stretching of C=C bond of aromatic rings in IR spectrums, the high content of functional groups, lower extinction coefficients, confirmed that aromatic fragments to prevail than aliphatic chain fragments in structure of all studied HS. DOI: http://dx.doi.org/10.5564/mjc.v14i0.199 Mongolian Journal of Chemistry 14 (40), 2013, p51-5
Endocardite infectieuse en milieu cardiologique Dakarois: Ă©tude descriptive Ă propos de 39 cas
Lâendocardite infectieuse est une complication frĂ©quente des cardiopathies rhumatismales. Lâobjectif de ce travail Ă©tait de faire une Ă©tude descriptive de lâendocardite infectieuse, en milieu hospitalier Dakarois. Il sâagit dâune Ă©tude rĂ©trospective, descriptive, rĂ©alisĂ©e Ă la clinique cardiologique de lâhĂŽpital Aristide Le Dantec, durant la pĂ©riode allant de Janvier
2004 Ă DĂ©cembre 2008. Etaient inclus tous les patients hospitalisĂ©s et traitĂ©s pour endocardite infectieuse certaine ou probable, selon les critĂšres de Durack. Nous avons Ă©tudiĂ© les paramĂštres Ă©pidĂ©miologiques, cliniques, biologiques et Ă©chocardiographiques. Le nombre total dâadmissions dans le service durant la pĂ©riode dâĂ©tude Ă©tait de 3746 patients, dont 870 pour valvulopathies rhumatismales. Nous avions enregistrĂ© 39 cas dâendocardite infectieuse soit une prĂ©valence de 1,04% et 4,48% valvulopathies rhumatismales. LâĂąge moyen de nos
patients Ă©tait de 24 plus ou moins 11,5 ans avec des extrĂȘmes de 6 et 52 ans. Plus de la moitiĂ© des patients soit 58,9 % (23 patients) avaient moins de 25 ans. On notait une lĂ©gĂšre prĂ©dominance fĂ©minine avec un sex-ratio homes/femmes de 0,95. La porte dâentrĂ©e Ă©tait essentiellement bucco-dentaire 40%. LâanĂ©mie Ă©tait constante avec un taux dâhĂ©moglobine moyen Ă 8,4g/dl. Les hĂ©mocultures Ă©taient positives chez 6 patients et le Staphylococcus Aureus Ă©tait le germe le plus retrouvĂ©. LâĂ©lectrocardiogramme avait montrĂ© des troubles du rythme et de la conduction respectivement dans 69,2 et 10,2% des cas. LâĂ©chographie cardiaque mettait en Ă©vidence des vĂ©gĂ©tations chez tous les patients, une rupture de cordage dans 6 cas et un abcĂšs chez trois patients. Lâendocardite infectieuse constitue encore une rĂ©alitĂ© dans nos rĂ©gions. Elle survient habituellement sur cardiopathie rhumatismale. Son diagnostic repose sur les hĂ©mocultures et lâĂ©chocardiographie
NDR Kinases Are Essential for Somitogenesis and Cardiac Looping during Mouse Embryonic Development
Studies of mammalian tissue culture cells indicate that the conserved and distinct NDR isoforms, NDR1 and NDR2, play essential cell biological roles. However, mice lacking either Ndr1 or Ndr2 alone develop normally. Here, we studied the physiological consequences of inactivating both NDR1 and NDR2 in mice, showing that the lack of both Ndr1/Ndr2 (called Ndr1/2-double null mutants) causes embryonic lethality. In support of compensatory roles for NDR1 and NDR2, total protein and activating phosphorylation levels of the remaining NDR isoform were elevated in mice lacking either Ndr1 or Ndr2. Mice retaining one single wild-type Ndr allele were viable and fertile. Ndr1/2-double null embryos displayed multiple phenotypes causing a developmental delay from embryonic day E8.5 onwards. While NDR kinases are not required for notochord formation, the somites of Ndr1/2-double null embryos were smaller, irregularly shaped and unevenly spaced along the anterior-posterior axis. Genes implicated in somitogenesis were down-regulated and the normally symmetric expression of Lunatic fringe, a component of the Notch pathway, showed a left-right bias in the last forming somite in 50% of all Ndr1/2-double null embryos. In addition, Ndr1/2-double null embryos developed a heart defect that manifests itself as pericardial edemas, obstructed heart tubes and arrest of cardiac looping. The resulting cardiac insufficiency is the likely cause of the lethality of Ndr1/2-double null embryos around E10. Taken together, we show that NDR kinases compensate for each other in vivo in mouse embryos, explaining why mice deficient for either Ndr1 or Ndr2 are viable. Ndr1/2-double null embryos show defects in somitogenesis and cardiac looping, which reveals their essential functions and shows that the NDR kinases are critically required during the early phase of organogenesis
Hypertension artérielle pulmonaire au cours de la sclérodermie: à propos de 12 cas
Introduction: La survenue de l’hypertension artérielle pulmonaire (HTAP) est un tournant dans l’évolution de la sclérodermie. L’objectif de cette étude est de décrire les aspects épidémiologiques et évolutifs de l’HTAP au cours de la sclérodermie systémique.Méthodes: Nous avons réalisé une étude descriptive concernant des patients suivis pour sclérodermie systémique, au service de Dermatologie de l’hôpital Aristide Le Dantec entre Janvier 2000 et Août 2009. Ces patients étaient inclus dans l’étude après exploration cardio-vasculaire (ECG, échocardiographie-Doppler). Nous avons étudié les paramètres épidémiologiques, cliniques, paracliniques et évolutifs des patients. Résultats: Nous avons enregistré 12 cas d’hypertension artérielle pulmonaire parmi les 83 patients atteints de sclérodermie systémique soit une prévalence de 14,45%. L’âge moyen des patients était de 43,58 ans ± 12,5 ans et le sex-ratio (H/F) de 0,33. Sur le plan clinique, la dyspnée était quasi constante (75%) et la douleur thoracique présente dans 25% des cas. Le syndrome de Raynaud était observé chez 8 patients soit 66,67% de nos patients. L’électrocardiogramme montrait des signes de surcharge droite chez 4 malades (33,33%) et la radiographie thoracique en faveur d’une fibrose pulmonaire chez 4 patients. L’échocardiographie-Doppler notait une insuffisance tricuspide importante dans 58, 33% des cas (7 patients), une pression artérielle pulmonaire systolique (PAPs) en moyenne de 66,25 ± 29,3 mmHg, une dilatation des cavités cardiaques droites dans 5 cas et un mouvement paradoxal du septum interventriculaire chez 3 malades (33,33%). Il était également noté 3 cas (25%) d’épanchement péricardique. Nous avons déploré 4 décès (33,33%).Conclusion: L’hypertension artérielle pulmonaire est une complication fréquente et grave de la sclérodermie. Son dépistage, grâce à l’échocardiographie- Doppler systématique, constitue une étape fondamentale de la prise en charge
Faible taux de succĂšs du sevrage tabagique Ă court et moyen termes au dĂ©cours dâun infarctus aigu du myocarde dans un service de cardiologie de Dakar au SĂ©nĂ©gal
Introduction:Le tabagisme est un puissant facteur de risque cardio-vasculaire. Son sevrage semble moins bien pris en compte chez les coronariens. Les objectifs de ce travail étaient d’évaluer la prévalence du tabagisme et le sevrage tabagique au décours d’un infarctus du myocarde dans un service de cardiologie au Sénégal. Méthodes: Il s’agit d’une étude transversale et descriptive réalisée entre janvier 2008 et juin 2010. Nous avons recruté les patients hospitalisés pour infarctus du myocarde puis les fumeurs actifs ont été inclus dans notre enquête. Les malades étaient sensibilisés pour l’arrêt du tabac puis suivis à 3 mois, 6 mois et 12 mois pour évaluer le sevrage tabagique. Résultats: Nous avons recensé 82 patients hospitalisés pour un infarctus du myocarde, parmi eux 26 sujets (25 hommes) étaient fumeurs (31,7%). L’âge moyen des sujets fumeurs était de 56 ± 11,5 ans. La consommation moyenne de tabac était de 32 ± 14 paquets-année et le score moyen de Fagerström de 8. Tous les patients ont arrêté le tabac pendant l’hospitalisation. Après un suivi de 3 mois, 45% des patients ont repris le tabac, 65% à 6 mois et 85% à 12 mois. Conclusion: Le tabagisme est assez fréquent chez les patients sénégalais présentant un infarctus du myocarde. Le taux de sevrage tabagique à court et moyen termes est faible. Le sevrage tabagique devrait alors constituer un objectif privilégié dans la prévention des maladies cardio-vasculaires.Key words: Tabagisme, sevrage, coronaropathie, risque cardio-vasculaire, Senega
[Evaluation of malaria rapid diagnostic test Optimal-ITÂź pLDH along the Plasmodium falciparum distribution limit in Mauritania].
Performance of the malaria Rapid Diagnostic Test (RDT) OptiMal-ITÂź was evaluated in Mauritania where malaria is low and dependent on a short transmission season. Slide microscopy was considered as the reference method of diagnosis. Febrile patients with suspected malaria were recruited from six health facilities, 3 urban and 3 rural, during two periods (December 2011 to February 2012, and August 2012 to March 2013). Overall, 780 patients were sampled, with RDT and thick blood film microscopy results being obtained for 759 of them. Out of 774 slides examined, of which 200 were positive, P. falciparum and P. vivax mono-infections were detected in 63.5% (127) and 29.5% (59), while P. falciparum/P. vivax coinfections were detected in 7% (14). Both species were observed in all study sites, although in significantly different proportions. The proportions of thick blood film and OptiMal-ITÂź RDT positive individuals was 26.3% and 30.3% respectively. Sensitivity and specificity of OptiMal-ITÂź RDT were 89% [95% CI, 84.7-93.3] and 91.1% [88.6-93.4]. Positives and negative predictive values were 78.1% [72.2-83.7] and 95.9% [94.1-97.5]. These diagnostic values are similar to those generally reported elsewhere, and support the use of RDTs as the main diagnostic tool for malaria in Mauritanian health facilities. In the future, choice of RDTs to be used must take account of thermostability in a hot, dry environment and their ability to detect P. falciparum and P. vivax
Experimental investigation of alternative transmission functions: quantitative evidence for the importance of non-linear transmission dynamics in host-parasite systems
1. Understanding pathogen transmission is crucial for predicting and managing disease. Nonetheless, experimental comparisons of alternative functional forms of transmission remain rare, and those experiments that are conducted are often not designed to test the full range of possible forms. 2. To differentiate among 10 candidate transmission functions, we used a novel experimental design in which we independently varied four factorsâduration of exposure, numbers of parasites, numbers of hosts and parasite densityâin laboratory infection experiments. 3. We used interactions between amphibian hosts and trematode parasites as a model system and all candidate models incorporated parasite depletion. An additional manipulation involving anaesthesia addressed the effects of host behaviour on transmission form. 4. Across all experiments, nonlinear transmission forms involving either a power law or a negative binomial function were the bestâfitting models and consistently outperformed the linear densityâdependent and densityâindependent functions. By testing previously published data for two other hostâmacroparasite systems, we also found support for the same nonlinear transmission forms. 5. Although manipulations of parasite density are common in transmission studies, the comprehensive set of variables tested in our experiments revealed that variation in density alone was least likely to differentiate among competing transmission functions. Across hostâpathogen systems, nonlinear functions may often more accurately represent transmission dynamics and thus provide more realistic predictions for infection
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