Search results for "insert"

Near-infrared imaging and structured light ranging for automatic catheter insertion

2006

Vein localization and catheter insertion constitute the first and perhaps most important phase of many medical procedures. Currently, catheterization is performed manually by trained personnel. This process can prove problematic, however, depending upon various physiological factors of the patient. We present in this paper initial work for localizing surface veins via near-infrared (NIR) imaging and structured light ranging. The eventual goal of the system is to serve as the guidance for a fully automatic (i.e., robotic) catheterization device. Our proposed system is based upon near-infrared (NIR) imaging, which has previously been shown effective in enhancing the visibility of surface vein…

Inégalités territoriales dans l'accès à l'alternance : le cas des jeunes des QPV

2023

Mechanistic Study of Stepwise Methylisocyanide Coupling and C-H Activation Mediated by a Low-Valent Main Group Molecule

2013

An experimental and DFT investigation of the mechanism of the coupling of methylisocyanide and C-H activation mediated by the germylene (germanediyl) Ge(Ar(Me6))2 (Ar(Me6) = C6H3-2,6(C6H2-2,4,6-Me3)2) showed that it proceeded by initial MeNC adduct formation followed by an isomerization involving the migratory insertion of the MeNC carbon into the Ge-C ligand bond. Addition of excess MeNC led to sequential insertions of two further MeNC molecules into the Ge-C bond. The insertion of the third MeNC leads to methylisocyanide methyl group C-H activation to afford an azagermacyclopentadienyl species. The X-ray crystal structures of the 1:1 (Ar(Me6))2GeCNMe adduct, the first and final insertion …

Reactivity and Selectivity of Ortho-Metalated Rhodium(II) Complexes in C−H Insertion Reactions of α-Diazo Compounds

1998

Regioselective intramolecular C−H insertion reactions of α-diazo β-keto esters and α-diazo ketones are mediated by Rh2[OOCR]4-x[PC]x (x = 1, 2; PC = ortho-metalated phosphine; R = CH3, C3F7). In particular, the intramolecular transformation of 1-diazo-5-methyl-3-propyl-2-hexanone catalyzed by Rh2[OOCCH3]2[PC]2 (PC = (C6H4)P(C6H5)2, head-to-tail (H−T) configuration) afforded only the tertiary C−H insertion product. By comparison, no C−H insertion reaction was promoted by doubly metalated complexes with a head-to-head (H−H) configuration. Rh2[OOCR]3[PC] compounds were found to be less suited for these type of reactions.

Le syndrome du diplôme et le chômage des jeunes diplômés, le cas de la Haute-Volta

1983

Référence interne : 83046

Diastereoselective Insertion of Isocyanide into the Alkyl−Metal Bond of Methylbenz[ e ]indenyl ansa ‐Zirconocene Complexes

2004

Alkylation of ansa-zirconocene [Zr{(η5-C5H5)SiMe2(MBI)}Cl2] (MBI = η5-2-Me−C13H7) with MgRCl gave the dimethyl complex [Zr{(η5-C5H5)SiMe2(MBI)}Me2], but unresolvable mixtures containing mono-alkylated compounds were obtained when bulkier alkyls were used. However pure dialkyl complexes [Zr{(η5-C5H5)SiMe2(MBI)}R2] (R = CH2Ph, CH2SiMe3) were easily obtained using K(CH2Ph) and Li(CH2SiMe3) as alkylating agents. Diastereoselective insertion into the MBI-unprotected Zr−R bond was observed when all of these dialkyl complexes were treated with 2,6-xylyl isocyanide to give the iminoacyl compounds [Zr{(η5-C5H5)SiMe2(MBI)}R{CR[η2-N-(2,6-xylyl)]}] (R = Me, CH2Ph, CH2SiMe3). All of the new complexes we…

Roles of a conserved proline in the internal fusion peptide of Ebola glycoprotein

2004

AbstractThe structural determinants underlying the functionality of viral internal fusion peptides (IFPs) are not well understood. We have compared EBOwt (GAAIGLAWIPYFGPAAE), representing the IFP of the Ebola fusion protein GP, and EBOmut (GAAIGLAWIPYFGRAAE) derived from a non-functional mutant with conserved Pro537 substituted by Arg. P537R substitution did not abrogate peptide-membrane association, but interfered with the ability to induce bilayer destabilization. Structural determinations suggest that Pro537 is required to preserve a membrane-perturbing local conformation in apolar environments.

Risk factors associated with adverse events in neonates with peripherally inserted central catheter

2019

Abstract Background Peripherally inserted central catheters have become a priority in infants who require long-term intravenous therapy, but their use involves certain risks. Objective The aim of the study was to describe the occurrence of adverse events in newborns with peripherally inserted central catheters and to determine the risk factors associated with them. Methods A descriptive cross-sectional study was designed and performed. All neonates with peripherally inserted central catheters from October 1st, 2014 to September 30th, 2015 were included. The adverse events and sociodemographic and clinical variables related to neonates and analysed catheters were recorded. Results A total of…

Hypoxia-induced reduction of sVEGFR-2 levels in human colonic microvascular endothelial cells in vitro: Comparative study with HUVEC.

2008

The functionality of large-vessel endothelial cells, such as human umbilical vein endothelial cells (HUVEC), may differ significantly from that in the microvasculature. We established a method for the isolation of human colonic microvascular endothelial cells (HCMEC). Since colonic diseases are often accompanied by hypoxia we examined its effects on HCMEC of five individuals in comparison with HUVEC, with respect to the secretion of the soluble form of the two important vascular endothelial growth factor (VEGF) receptors, VEGFR-1 and 2. After dissociation by dispase/collagenase of mucosal and submucosal tissue obtained from normal adult colon, HCMEC were isolated using CD31-coated magnetic …

Les jeunes en situation de NEET : le rôle des compétences de base

2021

International audience; Enjeu prioritaire des politiques publiques nationales et européennes, les jeunes qui ne sont ni en emploi, ni en études, ni en formation connaissent un risque d’exclusion plus ou moins marqué selon les pays. Si le niveau d'éducation joue un rôle central dans ces situations, l’approche par les compétences de base permet d’affiner la focale. Les données internationales montrent en effet qu’un même niveau de diplôme ne certifie pas partout le même niveau de compétences. Comment s’expliquent ces écarts ? Dans quelle mesure ces compétences protègent-elles des situations de NEET indépendamment du diplôme ?