From side streams to building blocks: gas phase conversion of biomass-derived feedstocks to valuable monomers

This thesis describes the chemical conversion of methyl levulinate (ML), a biorefinery side stream, to the valuable monomers methyl vinyl ketone (MVK) and methyl acrylate (MA). In the first part of the project, platinum 5 wt% on sulfided carbon was found to afford up to 18% yield of MVK from ML at 300°C. In the second part of the project, conversion of ML to methyl-3-acetoxypropanoate (M3AP) through a Baeyer-Villiger (BV) oxidation was studied. The thus-formed M3AP could be successfully converted to methyl acrylate (MA) in 97% yield via elimination of acetic acid in the gas phase at 600 °C.Diese Dissertation beschreibt die chemische Umwandlung von Methyllevulinat (ML) in die wertvollen Monomere Methylvinylketon (MVK) und Methylacrylat (MA). In dem ersten Teil des Projekts wurde festgestellt, dass 5 Gew .-% Platin auf sulfidiertem Kohlenstoff bis zu 18% MVK-Ausbeute aus ML bei 300 ° C liefern. In dem zweiten Teil des Projekts wurde die Umwandlung von ML in Methyl-3-acetoxypropanoat (M3AP) durch eine Baeyer-Villiger Oxidation untersucht. Das so gebildete M3AP konnte erfolgreich in 97% Ausbeute durch Eliminierung von Essigsäure in der Gasphase bei 600 °C in MA umgewandelt werden

CONTRIBUTION DES MANUELS SCOLAIRES DE LA MATIÈRE D’ ACTIVITÉ SCIENTIFIQUE” DANS LE DÉVELOPPEMENT DE L’ESPRIT SCIENTIFIQUE DES APPRENANTS DU CYCLE PRIMAIRE MAROCAIN

RésuméLe cycle primaire représente un terrain fertile et le moment adéquat d’initiation à l’acquisition de l’esprit scientifique. Les manuels scolaires ; comme moyen didactique le plus utiliséet le plus distribué et comme document éducatif porteur des savoirs ; permettent d’accroîtrela qualité des apprentissages des apprenants qui les utilisent. Ainsi, le manuel de la matière «Activité scientifique » est un élément central dans la pratique pédagogique, et un des facteursles plus efficaces pour améliorer la qualité de l’enseignement des sciences et le développementde l’esprit scientifique chez les apprenants.La présente étude met en relief la contribution des manuels scolairesde la matière « Activité scientifique » au cycle primaire marocain dans l’acquisition et le développement de l’espritscientifique chez les apprenants. Ainsi, une investigation analytique des manuels de la matièrede tous les niveaux du cycle est adoptée. L’analyse portera sur deux volets : contenu scientifiqueet démarche pédagogique.L’analyse des manuels étudiés a été faite selon des critères plus précis. Elle plaide en faveurd’une vision positive concernant les processus d›appropriation de connaissances scientifiqueset de l’enseignement. Ainsi, la méthodologie utilisée est plus ancrée dans la didactique moderne des sciences. Ce qui prouve une contribution marquante des activités de la matière dansle développement de la pensée des apprenants

Deep Brain Stimulation in Moroccan Patients With Parkinson's Disease: The Experience of Neurology Department of Rabat

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known as a therapy of choice of advanced Parkinson's disease. The present study aimed to assess the beneficial and side effects of STN DBS in Moroccan Parkinsonian patients.Material and Methods: Thirty five patients underwent bilateral STN DBS from 2008 to 2016 in the Rabat University Hospital. Patients were assessed preoperatively and followed up for 6 to 12 months using the Unified Parkinson's Disease Rating Scale in four conditions (stimulation OFF and ON and medication OFF and ON), the levodopa-equivalent daily dose (LEDD), dyskinesia and fluctuation scores and PDQ39 scale for quality of life (QOL). Postoperative side effects were also recorded.Results: The mean age at disease onset was 42.31 ± 7.29 years [28–58] and the mean age at surgery was 54.66 ± 8.51 years [34–70]. The median disease duration was 11.95 ± 4.28 years [5–22]. Sixty-three percentage of patients were male. 11.4% of patients were tremor dominant while 45.71 showed akinetic-rigid form and 42.90 were classified as mixed phenotype. The LEDD before surgery was 1200 mg/day [800-1500]. All patients had motor fluctuations whereas non-motor fluctuations were present in 61.80% of cases. STN DBS decreased the LEDD by 51.72%, as the mean LEDD post-surgery was 450 [188-800]. The UPDRS-III was improved by 52.27%, dyskinesia score by 66.70% and motor fluctuations by 50%, whereas QOL improved by 27.12%. Post-operative side effects were hypophonia (2 cases), infection (3 cases), and pneumocephalus (2 cases).Conclusion: Our results showed that STN DBS is an effective treatment in Moroccan Parkinsonian patients leading to a major improvement of the most disabling symptoms (dyskinesia, motor fluctuation) and a better QOL

Association caryotype 47XYY et déficit en 5 alpha réductase révélée par un micropénis: à propos d’un cas et revue de la littérature

Les sujets 47XYY ont souvent un fonctionnement gonadotrope normal, l´association à un déficit en 5alpha réductase chez ces sujets est rare ; la présentation clinique classique des déficits en 5 alpha réductase est un pseudohermaphrodisme masculin, rarement un micropénis comme mode de révélation. Le traitement par énanthate de testostérone du micropénis ne donne pas de bons résultats dans les déficits en 5alpha réductase, la dihydrotestostérone(DHT) à une efficacité prouvée dans ce cas. Nous rapportons l´observation d´un patient de 17 ans, référé dans notre formation pour la prise en charge d´un micropénis ne répondant pas aux 2 cures à base d´énanthate de testostérone. Le bilan notait une testostérone normale, des gonadotrophines à la limite supérieure de la normale, une DHT basse, avec augmentation du rapport testostérone/DHT > 20.caryotype 47XYY. Le déficit en 5 alpha réductase chez ces sujets pose la problématique d´une simple coïncidence, ou d´un lien effectif

Phosphine-free cobalt catalyst precursors for the selective hydrogenation of olefins.

International audienc

Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality