Electrolyte-Gated Organic Field-Effect Transistors for Quantitative Monitoring of the Molecular Dynamics of Crystallization at the Solid-Liquid Interface.

Quantitative measurements of molecular dynamics at the solid-liquid interface are of crucial importance in a wide range of fields, such as heterogeneous catalysis, energy storage, nanofluidics, biosensing, and crystallization. In particular, the molecular dynamics associated with nucleation and crystal growth is very challenging to study because of the poor sensitivity or limited spatial/temporal resolution of the most widely used analytical techniques. We demonstrate that electrolyte-gated organic field-effect transistors (EGOFETs) are able to monitor in real-time the crystallization process in an evaporating droplet. The high sensitivity of these devices at the solid-liquid interface, through the electrical double layer and signal amplification, enables the quantification of changes in solute concentration over time and the transport rate of molecules at the solid-liquid interface during crystallization. Our results show that EGOFETs offer a highly sensitive and powerful, yet simple approach to investigate the molecular dynamics of compounds crystallizing from water.

Validation of a real-time polymerase chain reaction for the detection and quantification of the nucleic acid of Histoplasma from equine clinical samples.

Histoplasma capsulatum var. farciminosum (HCF) is a dimorphic fungus that causes epizootic lymphangitis in equids. Current diagnostic approaches, including culture, microscopy, and clinical presentation, lack speed, sensitivity, and specificity when diagnosing clinical cases. In this study, equine blood and pus samples on Whatman FTA cards from Senegal (n = 3), The Gambia (n = 19), Ethiopia (n = 16), and Mali (n = 13) were tested using a real-time PCR (qPCR) protocol. The assay was optimized and tested for its suitability to detect and quantify HCF in blood and pus loaded onto Whatman FTA cards at sampling. Whatman FTA cards were tested for their suitability for use with qPCR and were found to recover DNA more efficiently than from direct extraction. Using TaqMan fluorescent probes and specific primers, the assay demonstrated 100% analytical specificity when detecting multiple strains of Histoplasma and no false positives with off-target organisms. The assay's diagnostic performance was measured against an existing nested internal transcribed spacer PCR protocol using a receiver operating characteristic curve. The test was found to have a diagnostic specificity and sensitivity of 100% and 71.4%, respectively, when analyzing pus samples using a cycle threshold (Ct) cutoff determined by Youden's index (27.75). Blood sample cutoff Ct value was proposed at 34.55. Further optimization is required to improve the performance of the protocol when applied to blood samples. This study has, for the first time, demonstrated the ability to detect and quantify the DNA of Histoplasma spp. in equine blood and pus samples with a high degree of accuracy, providing a platform to further investigate the pathogenesis and epidemiology of this disease. IMPORTANCE: Histoplasmosis is a neglected yet major cause of morbidity and mortality in both equids and people in resource-scarce settings. One of the major hindrances to the control of histoplasmosis is a lack of readily available diagnostic tests. Tests are needed to support clinical decision-making and to be applied in population-based research to further understand this disease in situ. This paper reports, for the first time, the validation and application of a qPCR to detect Histoplasma directly from equine clinical samples, bypassing the need to culture this notoriously difficult organism. We report and comment on the performance of the qPCR in comparison with our previously developed nested PCR.

Real-time monitoring of crystallization from solution by using an interdigitated array electrode sensor.

Monitoring crystallization events in real-time is challenging but crucial for understanding the molecular dynamics associated with nucleation and crystal growth, some of nature's most ubiquitous phenomena. Recent observations have suggested that the traditional nucleation model, which describes the nucleus having already the final crystal structure, may not be valid. It appears that the molecular assembly can range during nucleation from crystalline to partially ordered to totally amorphous phases, and can change its structure during the crystallization process. Therefore, it is of critical importance to develop methods that are able to provide real-time monitoring of the molecular interactions with high temporal resolution. Here, we demonstrate that a simple and scalable approach based on interdigitated electrode array sensors (IESs) is able to provide insights on the dynamics of the crystallization process with a temporal resolution of 15 ms.

[A case study of galen aneurysmal malformation in Bamako]. / Malformation anévrismale de la veine de galien à Bamako à propos d'un cas.

Galen aneurysmal malformation is a rare complex congenital vascular malformation of the brain, (less than 1% of intracranial arteriovenous malformations) characterized by pseudoaneurismal dilation of Galen's ampulla associated with one or several arteriovenous fistulas. In most cases, diagnosis is made in the neonatal or postnatal period, exceptionally in adulthood. We report the case of an 18-year male patient hospitalized for psychomotor retardation. Brain computed tomography (CT) scan using spontaneous contrast (A,B,C) showed voluminous isodense mass in the pineal region behind the third ventricle with peripheral calcifications, compatible with large vein of galen aneurysm. Its anteroposterior diameter was 8.5cm, its transverse diameter was 3cm in the axial plane (C) and its height was 3cm in the sagittal plane (G). Imaging objectified homogeneous contrast enhancement (D,E,F,G,H,I). The mass was associated with dilation of the superior sagittal sinus measured at 2.7cm (A,D), of transverse sinuses measured at 1.5cm to the right and at 1,1cm to the left (B,E). Multiple venous perianeurysmal derivations (I), hydrocephaly and small parenchymal cortical-subcortical calcifications were detected. Embolization can't be performed in Bamako, so the patient is waiting for transfer.

[Kartagener's syndrome found incidentally during assessment of infertile couple: a case study]. / Syndrome de Kartagener de découverte fortuite au cours d'un bilan d'infécondité du couple à propos d'un cas.

Kartagener's syndrome is a rare primitive ciliary dyskinesia (DCP) characterized by a clinical triad: sinusitis, bronchiectasis and complete or incomplete situs inversus. It is a rare congenital autosomal recessive disease. We report a case of Kartagener syndrome in an infertile couple with akinospermia detected using spermogram.

Gas Blow Coating: A Deposition Technique To Control the Crystal Morphology in Thin Films of Organic Semiconductors.

Rapid, large-scale, and low-cost coating methods that enable precise control of the crystal growth of organic semiconductors are essential to deliver high-performance devices that are robust and reproducible. In this work, a novel method is presented based on a gas blow coating technique, enabling the deposition of thin films of organic semiconductors, whose morphology can be optimized by adjusting the deposition parameters. We demonstrate the deposition of aligned single crystals of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) by gas blow coating and their use as active layers in organic field-effect transistor (OFET) devices. The OFETs of TIPS-pentacene and C8-BTBT have charge mobilities of 0.15 and 1.4 cm2 V-1 s-1, respectively, with low threshold voltages and on/off ratios exceeding 105. This coating method can also be extended to polymeric semiconductors: films based on poly(3-hexylthiophene) and poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno[3,2-b]thiophene)] are realized, establishing gas blow coating as a novel and efficient technique for the deposition of thin films of organic semiconductors.

Hémosidérose du système nerveux central: apport diagnostique de l'Imagerie par Résonnace Magnétique / Hemosiderosis of the central nervous system: diagnostic contribution of Magnetic Resonnace Imagery

Introduction. L'hémosidérose du système nerveux central est une pathologie rare liée au dépôt d'hémosidérine à la surface du cerveau, des nerfs crâniens et de la moelle épinière secondaire à un saignement chronique. Nous rapportons un cas d'hémosidérose du système nerveux central chez une patiente jeune dans un tableau de méningite. A travers notre observation nous voulons décrire l'apport diagnostique de l'Imagerie par Resonnace Magnétique dans cette pathologie. Observation. Patiente de 39ans, sans antécédents particuliers, avait consulté au service des urgences pour des céphalées d'apparition brutale associées à des nausées. Le scanner cérébral objectivait un discret effacement des sillons corticaux et une sinusite sphénoïdale. L'Imagerie par Resonnace Magnétique cérébrale et médullaire objectivait un dépôt d'hémosidérine en hyposignal T2 Echo de gradient au niveau du cortex cérébral et de la moelle épinière. Le bilan étiologie du saignement chronique était négatif à l'angio-Imagerie par Resonnace Magnétique du polygone de Willis. La glycorachie était à 1,5g/l pour une glycémie à 5,6g/l (hypoglycorachie), la protéinorachie était à 2,43g/l sans bactériémie mais présence de 590 éléments dont 72% de lymphocytes et 27% de polynucléaires neutrophiles. Conclusion. L'Imagerie par Resonnace Magnétique est une technique indispensable au diagnostic de l'hémosidérose cérébro-méningée.

Aspects scanographiques des traumatismes du rachis

Objectifs : Etablir le profil épidémiologique des patients et répertorier les lésions retrouvées à la tomodensitométrie.Méthodes : Etude prospective descriptive sur une période de douze mois (de février 2015 à janvier 2016), portant sur des patients ayant bénéficiés d'une exploration tomodensitométrique pour traumatisme rachidien. Résultats : les traumatismes du rachis représentait 3,7% (n=100/2676) de l'ensemble des examens scanographiques effectués durant la période d'étude. Il y avait 83 % (n=83) d'hommes (sex-ratio de 4,88). La tranche d'âge 16 - 30 ans était la plus touchée avec 55% (n=55). Les accidents de la voie publique (AVP) représentaient 75% (n=75) des étiologies suivis de la chute de hauteur avec 16%(n=16). Les troubles neurologiques étaient le motif de réalisation de l'examen TDM dans 60%(n=60). Les atteintes rachidiennes étaient reparties comme suite : rachis cervical 43%(n=43), charnière cervico-dorsale 2%(n=2), rachis dorsal 22%(n=22), charnière dorso-lombaire 7%(n=7), rachis lombosacré 26%(n=26). Les lésions instables représentaient 76%(n=76) et les lésions stables 24%(n=24). Les fractures vertébrales représentaient 52%(n=52) suivies par les fractures luxations 46%(n=46).Conclusion : Le scanner est l'examen fondamental à réaliser dans le bilan initial des traumatismes rachidiens afin de préciser le caractère stable ou instable des lésions