Gyroscopic Instability of a Drop Trapped Inside an Inclined Circular Hydraulic Jump

International audienceA drop of moderate size deposited inside a circular hydraulic jump remains trapped at the shock front and does not coalesce with the liquid flowing across the jump. For a small inclination of the plate on which the liquid is impacting, the drop does not always stay at the lowest position and oscillates around it with a sometimes large amplitude, and a frequency that slightly decreases with flow rate. We suggest that this striking behavior is linked to a gyroscopic instability in which the drop tries to keep constant its angular momentum while sliding along the jump

STUDY OF CRUDE EXTRACTS FROM CASSIA SIEBERIANA ROOT BARK AND KHAYA GRANDIFOLIOLA TRUNK BARK: PHYTOCHEMICAL SCREENING, QUANTITATIVE ANALYSIS AND RADICAL SCAVENGING ACTIVITY

Objective: Cassia sieberiana and Khaya grandifoliola are two plants commonly used in traditional medicine in Côte d’Ivoire. Photochemical screening of crud extract obtained from C. sieberiana root bark and K. grandifoliola trunk bark revealed the presence of alkaloids, sterols, terpenes, polyphenols, flavonoids, coumarins, tannins, reducing sugars, glycosides, carbohydrates, cardiac glycosides and saponins. Methods: Quantitative analysis was screened in C. sieberiana root bark and K. grandifoliola trunk bark. Results: The results respectively showed high concentrations of total phenols (225.57±7.57 and 186.75±12.76 μgGAE/mg), total flavonoids (64.70±5.25 and 117.88±8, 68 μgQE/mg) and total tannins (170.60±5.85 and 39.96±1, 58 μgTAE/mg). The antioxidant activity of the glycosides extracts CS1, KG1 and their corresponding aglycones CS2, KG2 of these plants has been studied by scavenging free radicals by DPPH and that, compared with L-ascorbic acid (vitamin C, IC50 = 0.07 µg/ml). IC50 values of CS1 (2.69 µg/ml), KG1 (3.16 µg/ml) and CS2 (1.30 µg/ml), KG2 (0.726 µg/ml) showed that the aglycones are clearly more effective than the glycosides. Conclusion: Qualitative analysis of Cassia sieberiana root bark and Khaya grandifoliola trunk bark showed a presence of a variety of secondary metabolites in these plants, when the quantitative analysis concludes that they contain phenolic compounds, flavonoids and tannins to varied contents

Preparation of gem-difluorinated retrohydroxamic-fosmidomycin

International audienceFrom several decades, some organophosphorus compounds specifically designed to alterbiological systems were introduced on market as agrochemicals (ie glyphosate and glufosinate asherbicides). Nevertheless, it becomes necessary to find new compounds in order to counter plantresistances already observed with glyphosate. Fosmidomicyn and its N-acetyl analogues FR-900098 were perceived as starting points for elaboration of new herbicide candidates, targetingthe second enzyme of the non-mevalonate pathway in plants, the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DOXP reductoisomerase or DXR). It is expected that theenhancement of bioactivity compared to the parent compounds, might be reached by insertion oftwo fluorine atoms close to the phosphonate function. Indeed, the presence of both fluorineatoms could improve the lipophilicity, affect the pKa of the phosphonic acid function and theninduce better activities. Herein, the synthesis of gem-difluorinated analogues of retrohydroxamicfosmidomycin and FR-900098-ester is reported using a radical addition mediated by acobaloxime comple

Caractérisation Phytochimique et Activité Larvicide d’extraits Bruts de Plantes Issues de la Pharmacopée Traditionnelle du Niger sur les Larves d’Anopheles gambiae S.L.

In the preventive fight against malaria, natural products are considered better because they are biodegradable and therefore more respectful of the environment and the ecosystem. In the framework of the research of new insecticidal molecules, the present study concerns, the phytochemical screening and the evaluation of the larvicidal activity of the extracts (aqueous and methanolic) of 26 plants on the larvae of Anopheles gambiae sl. been carried out according to a WHO protocol (1985). The phytochemical profile of the plants was determined according to the standard methods of characterization (color reactions). High larvicidal activity against Anopheles gambiae larvae after 24 h and then 48 h exposure was observed. Crotalaria podocarpa, Momordica balsamina, Xeromphis nilotica and Senna occidentalis showed a 100% mortality rate after 24 hours of exposure. The larvicidal activity is much more important after 48 hours. A 100% mortality was observed with Senna occidentalis, Momordica balsamina, Ocimum basilicum, Citrus sinensis, Striga hermontheca, Xeromphis. nilotica, Crotalaria podocarpa, Diospyros mespiliformis, Cymbopogon citratus, Cleome viscosa and Combretum micrantum. Poor larvicidal activity was observed on the one hand with the methanolic extracts of Crotalaria podocarpa and Aloe vera and on the other with the aqueous extracts of Citrus sinensis, Ocimum basilicum and Aloe vera. Phytochemicalscreening revealed the presence of five major groups of compounds, including saponosides, terpenes sterols, flavonoids, tannins and alkaloids, which are also present in the aqueous and methanolic extracts of the various plant samples. These chemical groups could justify the traditional use of these plants.Dans la lutte préventive contre le paludisme, les produits naturels sont considérés comme meilleurs car biodégradables et donc plus respectueux de l’environnement et de le écosystème. Dans le cadre de la recherche des nouvelles molécules insecticides, la présente étude concerne, le screening phytochimique et l’évaluation de l’activité larvicide des extraits (aqueux et méthanoliques) de 26 plantes sur les larves d’Anophèles gambiae s.l. Les tests larvicides ont été réalisés selon un protocole de l’OMS(1985). Le profil phytochimique des plantes a été déterminé suivant les méthodes standards de caractérisation (réactions colorées). Une forte activité larvicide vis-à-vis des larves d’Anophèles gambiae après 24h puis 48h d’exposition a été observée. Crotalaria podocarpa, Momordica balsamina, Xeromphis nilotica et Senna occidentalis ont montré un taux de mortalité de 100% après 24h d’exposition. L’activité larvicide est beaucoup plus importante après 48h. Une mortalité de 100% a été observée avec Senna occidentalis, Momordica balsamina, Ocimum basilicum, Citrus sinensis, Striga hermontheca, Xeromphis. nilotica, Crotalaria podocarpa, Diospyros mespiliformis, Cymbopogon citratus, Cleome viscosa et Combretum micrantum. De faibles activités larvicides ont été constatées d’une part avec les extraits méthanoliques de Crotalaria podocarpa et Aloe vera et d’autre part avec les extraits aqueux de Citrus sinensis, Ocimum basilicum et Aloe vera. Le screening phytochimique a mis en évidence la présence de cinq (5) grands groupes de composés parmi lesquels les saponosides, les terpènes stérols, les flavonoïdes, les tanins et les alcaloïdes aussi bien présents dans les extraits aqueux et méthanoliques des différents échantillons des plantes. Ces groupes chimiques pourraient justifier l’utilisation traditionnelle de ces plantes

NMDA receptor channels: Labeling of MK-801 with iodine-125 and fluorine-18

Methods for labeling the glutamate channel blocking agent MK-801 with iodine-125 (125I) and fluorine-18 (18F) are described. Radioiodine was incorporated in the 1- or 3-positions of the aromatic ring of (+/-)MK-801 by solid-state halogen exchange techniques. Attachment of the [18F]fluoromethyl group to the bridgehead methyl position was achieved by reaction of [18F]fluoride with the triflamide alcohol 8 or the novel cyclic sulfamate 9 recently reported by Merck chemists. Radiochemical yields of (+/-)13-[18F]- fluoromethyl-MK-801 were >72%, EOB; radiochemical purity >99%. In competitive binding studies using rat brain homogenates, (+/-)3-bromo-MK-801 showed greater affinity than (+/-)MK-801 for the glutamate-linked channel. The experimental log P (2.1 +/- 0.1) of MK-801 is optimal for transit of the blood-brain barrier. These preliminary findings support further testing of 3-[123I]iodo-MK-801 and (+/-)13-[18F]fluoromethyl-MK-801 as possible agents for in vivo mapping of the glutamate receptor complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27605/1/0000649.pd

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Vers la recherche de structures antagonistes de l'action de la phencyclidine

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Product Class 12: Alkylphosphonium Salts

International audienc

Nouveaux phosphinosucres ou phostines (hétérocycles phosphorés polyhydroxylés à activité anticancéreuse)

Les phosphinosucres appelés aussi phostines sont des analogues phosphorés des sucres pyranoses et des C-arylglycosides. L'évaluation biologique de ses composés a révélé une activité anticancéreuse des phosphinosucres sur les cellules de glioblastome multiforme, un cancer particulièrement malin et invasif qui ne possède pas de solution thérapeutique. Dans le but de comprendre les mécanismes d'action des phosphinosucres et la stéréo-dépendance de leur activité biologique, la caractérisation des diastéréomères de phostines a été menée. Suite à cette détermination structurale, le développement de synthèses diastéréosélectives a permis d'obtenir un mélange fortement enrichi en diastéréomère le plus actif par une séquence réactionnelle qui a mis en jeu une réaction d'oxydation de phosphinosucres -hydroxylés en a-cétophosphinosucres, suivie d'une réduction diastéréosélective. Afin d'améliorer l'activité antiproliférative des phosphinosucres, une diversification chimique a été réalisée. Les variations du groupement aryle lié à l'atome de phosphore nous ont amené à développer une synthèse des aryl-hydrogénophosphinates qui a permis d'obtenir une large variété de ces composés. Par la suite, les aryl-hydrogénophosphinates obtenus ont été engagés dans la synthèse des phostines . De plus, des variations chimiques sur le carbone en position a de l'atome de phosphore ont été entreprises et ont permis l'élaboration de plusieurs composés (triflate, azido, amino, déoxy et triazolyles), puis finalement à l'analogue phosphinosucre du N-acétylglucosamine qui a présenté une importante activité anticancéreuse in vitro.Phosphinosugars also called phostines are new cyclic phosphinates, analogs of carbohydrates and C-aryglycosides, with phosphorus atom mimicking the anomeric carbon. Biological screening tests of these compounds revealed an anticancer activity against glioblastoma multiform, a highly invasive and malignant tumor without curative therapy.With the aim of understanding the phosphinosugars mode of action and their stereo-dependent biological activity, characterization of four phosphinosugars diastereomers formed during the chemical process has been performed. After their structural determination, diastereoselective synthesis enabled us to obtain an enriched mixture of the most active diastereomer based on an oxidation of -hydroxyled phosphinosugars in corresponding -keto phosphinosugars followed by a diastereoselective reduction. Thereafter, antiproliferative activity of phoshinosugars was performed by chemical diversification. Modification of the aryl group linked to phosphorus atom led us to develop aryl-hydrogenophosphinate synthesis to create a broad variety of these structures. Then, the expected aryl-hydrogenophosphinates were used for phostines preparation. Furthermore, chemical modifications on the carbon in a position of phosphorus atom were led and furnished several new compounds (triflate, azido, amino, deoxy and triazolyl), as well as the phosphinosugar analog of N-acetylglucosamine which presented in vitro a high anticancer activity.MONTPELLIER-Ecole Nat.Chimie (341722204) / SudocSudocFranceF

Acyclic to cyclic aminophosphonic and phosphinic acids

International audienceThe results presented in this account deal with the synthesis of acyclic α- or β-aminophosphonates or phosphinates and with the synthesis of heterocyclic compounds, where the phosphorus and/or the nitrogen atoms can be embedded in the heterocyclic core, showing new perspectives in bioactive molecules