44 research outputs found

    3D Printing Filaments Facilitate the Development of Evanescent Wave Plastic Optical Fiber (POF) Chemosensors

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    One of the major difficulties in the development of evanescent wave optical fiber sensors (EWOFS) lies in the complexity of the manufacturing of the chemosensitive element, particularly when using plastic optical fibers (POFs). While these fibers are appealing waveguides thanks to their low cost, ease of connectorization and robustness, the need for removing the cladding material complicates the EWOFS fabrication. In this paper we discuss how 3D printing filaments can serve as an alternative to commercially available POF for the development of EWOFS. In the process of replacing the traditional POF, we compared the performance of two EWOFS for monitoring airborne formaldehyde. These sensitive elements were manufactured either from 1.75 mm diameter 3D printing filaments, or from a commercially available POF. After the optimization of their respective fabrication protocols, the analytical performance of the two formaldehyde EWOFS was compared in terms of sensitivity and reproducibility. In this regard, the easy-to-manufacture 3D printing filament-based waveguides provided 5-fold lower detection limits with respect to the commercial POF-based sensors. Although no statistically significant differences were found in terms of reproducibility, the simplification of the sensor manufacturing process together with the increased analytical performance for chemical sensing spur the use of 3D printing filaments for the development of new POF-based EWOFS.Depto. de Química OrgánicaFac. de Ciencias QuímicasTRUEEU-LIFE Programpu

    Knowledge gaps on paediatric respiratory infections in Morocco, Northern Africa

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    BACKGROUND: The burden of acute respiratory infections (ARI) among Moroccan children remains significant. However, scarce information is available regarding trends in its epidemiology and etiology, or regarding its associated prognostic factors. The purpose of this work was to review available data on the burden of ARI among children under five years of age in Morocco. METHODS: A systematic review was conducted for the period 1997-2014 using the PRISMA proposed methodology. Various online databases were screened, in addition to physical libraries of Moroccan medical schools, and official reports of the Moroccan Ministry of Health. Search queries in English and French languages included: Respiratory Tract Infections, pneumonia, epidemiology, etiology, microbiology, mortality and Morocco. The documents were included for analysis when they reported original data on the incidence, distribution, or a clinical description of the diseases or their etiology or described clinical management or national preventive strategies. RESULTS: Thirty-two documents were included in the final analysis. 21 of which had been published. In 2012, ARI caused 13% of paediatric deaths, half of the consultations at health facilities and third of the paediatric admissions. The microorganisms more frequently identified among hospitalized children were Streptococcus pneumoniae (38%) and Haemophilus influenza type b (Hib) (15%). The MOH introduced Hib vaccines into the national immunization program (PNI) in 2007and the 13-valent vaccine against pneumococcus in 2010. The national first line antibiotics recommended for non-severe ambulatory treatment is Amoxicillin. Studies of antibiotic resistance showed from 1998 to 2008 a 22% increase in the rate of penicillin non-susceptibility among Streptococcus pneumoniae isolates. Viral respiratory infections and the role attributed to air pollution in the incidence of ARI have been poorly characterized. CONCLUSIONS: Further efforts should be made towards the development of adequate surveillance programs to better clarify the epidemiology, etiology, antimicrobial susceptibility patterns and the effectiveness of the preventives and curatives strategies in place against paediatric ARIs in Morocco. Additionally, a holistical approach should be used to identify the heath determinants of ARIs among children

    Diseño de un workload real para un benchmark de bases de datos orientadas a grafos

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    82 p.Junto al surgimiento de aplicaciones que requieren almacenar y analizar grandes cantidades de información no estructurada y compleja, surgen tambien los sistemas de gestión de bases de datos orientadas a grafos (SGBDG). Estos sistemas se caracterizan porque su enfoque no está en gestionar datos de forma individual y aislada,sino que ponen énfasis en las relaciones existentes entre dichos datos. El surgimiento de los SGBDG trae consigo la necesidad de realizar benchmarking sobre ellos a modo de poder establecer comparaciones. En este contexto, GDBench es un benchmark enfocado a evaluar el rendimiento de sistemas de bases de datos considerando como caso de uso una red social. Sin embargo, la carga de trabajo (workload) de GDBench no representa un escenario real. En efecto, el workload utilizado por GDBench era aleatorio, no considerando una lógica desde el punto de vista del orden en el que eran ejecutadas las operaciones. En esta memoria se presenta el desarrollo de un workload real, basado en el análisis de una red social existente (Facebook), para GDBench. El nuevo workload simula el comportamiento de un conjunto de usuarios interactuando en la red social definida por el esquema de datos de GDBench, combinando un conjunto de 6 consultas interactivas y 6 consultas analíticas. El benchmark resultante fue evaluado sobre cuatro sistemas de bases de datos, considerando aquellas orientadas a grafos (Sparksee y Neo4j), RDF (Apache Jena) y relacional (PostgreSQL). Sobre cada uno de los sistemas de bases de datos se ejecut o el workload aleatorio y el workload real. Al realizar la comparación de resultados, se obtuvo que si bien se produjeron diferencias en los tiempos de ejecución de las consultas que conformaban el workload, éstas no fueron lo su cientemente signi cativas como para alterar los resultados del proceso de benchmarking. Como trabajo futuro se plantea un uso más intensivo del benchmark para evaluar la influencia del workload en el proceso de benchmarking. Palabras claves: SGBDG, BDOG, Benchmarking, Work ow, Workload./ABSTRACT: Along with the emergence of applications that require storing and analyzing large amounts of unstructured and complex information, graph database management systems (GDBMS) also emerge. These systems are characterized because their approach is not to manage data in an individual and isolated way, but rather they emphasize the relations existing between the data. The emergence of GDBMS brings with it the need to perform benchmarking on these systems so that comparisons can be made. In this context, GDBench is a benchmark oriented to evaluate the performance of database systems considering social network as a use case. However, GDBench's workload does not represent a real scenario. In fact, the workload used by GDBench was random, not considering a logic from the point of view of the order in which the operations were executed. In this document we present the development of a real workload, based on the analysis of an existing social network (Facebook). The new workload simulates the behavior of a set of users interacting in the social network de ned by the GDBench data schema, combining a set of 6 interactive queries and 6 analytic queries. The resulting benchmark was evaluated on four database systems, considering those oriented to graphs (Sparksee and Neo4j), RDF (Apache Jena) and relational (PostgreSQL). Over each database system was executed either the random workload and the real workload. When we compared the results we found that there were differences in the execution times of the queries, but the di erences were not signi cant enough to alter the results of the benchmarking process. As future work, we propose a more intensive use of the benchmark to evaluate the influence of workload in the benchmarking process

    Luminescent molecularly imprinted polymer nanocomposites for emission intensity and lifetime rapid sensing of tenuazonic acid mycotoxin

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    Tenuazonic acid ((5S)-3-acetyl-5-[(2S)-butan-2-yl]-4-hydroxy-2,5-dihydro-1H-pyrrol-2-one, TeA) is a widespread Alternaria fungi mycotoxin in food produce. This toxin may be allergenic and provoke hay fever and asthma. Therefore, rapid methods to selectively detect TeA are needed. With this aim, we have engineered a novel trifunctional (red-luminescent, polymerizable, TeA-sensitive) ruthenium(II)-bipyridyl complex with 2,2′-biimidazole. Its peripheral N–H moieties recognize the enolate form of 1,3-dicarbonyl compounds (including TeA) in partially aqueous media. Such a binding decreases the luminescence intensity and lifetime (0.2 μs) of the Ru(II) probe. The probe also bears acrylate groups that allow radical copolymerization with methacrylamide and ethylene glycol dimethacrylate in the presence of TeA, to yield 9-nm thick luminescent molecularly imprinted polymer (MIP) shells onto 200-nm silica cores. The SiO2@Ru-MIP nanocomposite displays a very fast response (<5 s) suitable for real-time detection of TeA. No cross-sensitivity to other common food mycotoxins that also contain a β-hydroxycarbonyl moiety (alternariol, β-zeranol, cyclopiazonic acid) is observed. Detection limits of 63.8 μg L⁻1 and 75.2 μg L⁻1 under steady-state and time-resolved luminescence detection, respectively, have been measured without further optimization. The use of emission lifetime variations to monitor the levels of a target analyte has never been reported for a luminescent MIP-based sensor

    Detection of Streptococcus pneumoniae and Haemophilus influenzae type B by real-time PCR from dried blood spot samples among children with pneumonia: a useful approach for developing countries

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    Correction https://doi.org/10.1371/journal.pone.0147678Background: Dried blood spot (DBS) is a reliable blood collection method for storing samples at room temperature and easily transporting them. We have previously validated a Real-Time PCR for detection of Streptococcus pneumoniae in DBS. The objective of this study was to apply this methodology for the diagnosis of S. pneumoniae and Haemophilus influenzae b (Hib) in DBS samples of children with pneumonia admitted to two hospitals in Mozambique and Morocco. Methods: Ply and wzg genes of S. pneumoniae and bexA gene of Hib, were used as targets of Real-Time PCR. 329 DBS samples of children hospitalized with clinical diagnosis of pneumonia were tested. Results: Real-Time PCR in DBS allowed for a significant increase in microbiological diagnosis of S. pneumoniae and Hib. When performing blood bacterial culture, only ten isolates of S. pneumoniae and none of Hib were detected (3·0% positivity rate, IC95% 1·4-5·5%). Real-Time PCR from DBS samples increased the detection yield by 4x fold, as 30 S. pneumoniae and 11 Hib cases were detected (12·4% positivity rate, IC95% 9·0-16·5%; P<0·001). Conclusion: Real-Time PCR applied in DBS may be a valuable tool for improving diagnosis and surveillance of pneumonia caused by S. pneumoniae or Hib in developing countries

    Etiology, epidemiology and clinical characteristics of acute moderate-to-severe diarrhea in children under 5 years of age hospitalized in a referral pediatric hospital in Rabat, Morocco

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    The objective of the study was to describe the etiology, epidemiology, and clinical characteristics of the principal causes of acute infectious diarrhea 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 diarrhea in hospitalized children >2 months and less than 5 years of age. Among the 122 children included in the study, Enteroaggregative E. coli (EAEC) and rotavirus were the main etiologic causes of diarrhea detected. Twelve (9.8%) children were referred to the intensive care unit, while 2, presenting infection by EAEC and EAEC plus a Shigella sonnei respectively, developed a hemolytic uremic syndrome. Additionally, 6 (4.9%) deaths occurred with EAEC being isolated in four of these cases. Diarrheogenic E. coli and rotavirus play a significant role as the two main causes of severe diarrhea while other pathogens such as norovirus or parasites seem to have a minimal contribution. Surveillance and prevention programs to facilitate early recognition and improved management of potentially life-threatening diarrhea-episodes are needed

    Characterization of Vaginal Escherichia coli Isolated from Pregnant Women in Two Different African Sites

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    The relevance of vaginal colonization of pregnant women by Escherichia coli is poorly understood, despite these strains sharing a similar virulence profile with other extraintestinal pathogenic E. coli producing severe obstetric and neonatal infections. We characterized the epidemiology, antimicrobial susceptibility and virulence profiles of 84 vaginal E. coli isolates from pregnant women from Rabat (Morocco) and Manhica (Mozambique), two very distinct epidemiological settings. Low levels of antimicrobial resistance were observed to all drugs tested, except for trimethoprim-sulfamethoxazole in Manhica, where this drug is extensively used as prophylaxis for opportunistic HIV infections. The most prevalent virulence factors were related to iron acquisition systems. Phylogroup A was the most common in Rabat, while phylogroups E and non-typeable were the most frequent in Manhica. Regardless of the apparently "low virulence" of these isolates, the frequency of infections is higher and the outcomes more devastating in constrained-resources conditions, especially among pregnant women and newborns

    Prevalence, antimicrobial resistance and serotype distribution of group B streptococcus isolated among pregnant women and newborns in Rabat, Morocco

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    PURPOSE: Group B streptococcus (GBS) is an important cause of neonatal sepsis worldwide. Data on the prevalence of maternal GBS colonization, risk factors for carriage, antibiotic susceptibility and circulating serotypes are necessary to tailor adequate locally relevant public health policies. METHODOLOGY: A prospective study including pregnant women and their newborns was conducted between March and July 2013 in Morocco. We collected clinical data and vagino-rectal and urine samples from the recruited pregnant women, together with the clinical characteristics of, and body surface samples from, their newborns. Additionally, the first three newborns admitted every day with suspected invasive infection were recruited for a thorough screening for neonatal sepsis. Serotypes were characterized by molecular testing. RESULTS: A total of 350 pregnant women and 139 of their newborns were recruited. The prevalence of pregnant women colonized by GBS was 24 %. In 5/160 additional sick newborns recruited with suspected sepsis, the blood cultures were positive for GBS. Gestational hypertension and vaginal pruritus were significantly associated with a vagino-rectal GBS colonization in univariate analyses. All of the strains were susceptible to penicillin, while 7 % were resistant to clindamycin and 12 % were resistant to erythromycin. The most common GBS serotypes detected included V, II and III. CONCLUSION: In Morocco, maternal GBS colonization is high. Penicillin can continue to be the cornerstone of intrapartum antibiotic prophylaxis. A pentavalent GBS vaccine (Ia, Ib, II, III and V) would have been effective against the majority of the colonizing cases in this setting, but a trivalent one (Ia, Ib and III) would only prevent 28 % of the cases

    Quality of care and maternal mortality in a tertiary-level hospital in Mozambique: a retrospective study of clinicopathological discrepancies

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    Background: Although an increasing number of pregnant women in resource-limited areas deliver in health-care facilities, maternal mortality remains high in these settings. Inadequate diagnosis and management of common life-threatening conditions is an important determinant of maternal mortality. We analysed the clinicopathological discrepancies in a series of maternal deaths from Mozambique and assessed changes over 10 years in the diagnostic process. We aimed to provide data on clinical diagnostic accuracy to be used for improving quality of care and reducing maternal mortality. Methods: We did a retrospective analysis of clinicopathological discrepancies in 91 maternal deaths occurring from Nov 1, 2013, to March 31, 2015 (17 month-long period), at a tertiary-level hospital in Mozambique, using complete diagnostic autopsies as the gold standard to ascertain cause of death. We estimated the performance of the clinical diagnosis and classified clinicopathological discrepancies as major and minor errors. We compared the findings of this analysis with those of a similar study done in the same setting 10 years earlier. Findings: We identified a clinicopathological discrepancy in 35 (38%) of 91 women. All diagnostic errors observed were classified as major discrepancies. The sensitivity of the clinical diagnosis for puerperal infections was 17% and the positive predictive value was 50%. The sensitivity for non-obstetric infections was 48%. The sensitivity for eclampsia was 100% but the positive predictive value was 33%. Over the 10-year period, the performance of clinical diagnosis did not improve, and worsened for some diagnoses, such as puerperal infection. Interpretation: Decreasing maternal mortality requires improvement of the pre-mortem diagnostic process and avoidance of clinical errors by refining clinical skills and increasing the availability and quality of diagnostic tests. Comparison of post-mortem information with clinical diagnosis will help monitor the reduction of clinical errors and thus improve the quality of care
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