3 research outputs found
DĂ©terminer comment le Global Protocol for Community-Scale Greenhouse Gas Emission Inventories, orientĂ© pour la rĂ©alisation dâinventaires dâĂ©missions de gaz Ă effet de serre de grandes villes, peut ĂȘtre adaptĂ© et appliquĂ© aux petites et moyennes municipalitĂ©s quĂ©bĂ©coises
Lâobjectif de cet essai est de dĂ©terminer comment le Global Protocol for Community-Scale Greenhouse Gas Emission Inventories, orientĂ© pour la rĂ©alisation dâinventaires dâĂ©missions de gaz Ă effet de serre des grandes villes, peut ĂȘtre adaptĂ© et appliquĂ© aux petites et moyennes organisations municipales quĂ©bĂ©coises. Ă travers un portrait des inventaires dâĂ©missions de gaz Ă effet de serre municipaux rĂ©alisĂ©s au QuĂ©bec, des forces, des faiblesses, des opportunitĂ©s et des menaces sont ciblĂ©es pour chacun des secteurs dĂ©finis dans ce protocole.
Les inventaires dâĂ©missions de gaz Ă effet de serre sont des outils qui permettent aux municipalitĂ©s de cibler les sources des Ă©missions de gaz Ă effet de serre les plus importantes pour mettre en place des mesures de mitigation. De plus, les inventaires permettent de faire un suivi important pour dĂ©finir si les objectifs de rĂ©duction de la municipalitĂ© ont Ă©tĂ© atteints. Dâune part, lâutilisation de ce nouveau protocole doit permettre de capter les variations des Ă©missions de gaz Ă effet de serre de la municipalitĂ©, de lâautre, il doit comptabiliser des Ă©missions de gaz Ă effet de serre qui sont de compĂ©tence municipale. Dans le contexte quĂ©bĂ©cois, des enjeux de gouvernance, dâaccessibilitĂ© aux donnĂ©es locales et de gestion des Ă©missions de gaz Ă effet de serre, reliĂ©es ou non aux compĂ©tences municipales, peuvent influencer les rĂ©sultats de rĂ©duction des Ă©missions. Ainsi, si les donnĂ©es utilisĂ©es pour comptabiliser les Ă©missions de gaz Ă effet de serre ne proviennent pas, en totalitĂ© ou en partie, de sources locales, il est peu probable que les variations des Ă©missions de gaz Ă effet de serre soient significatives dans lâinventaire et, par le fait mĂȘme, quâun suivi sur lâatteinte des objectifs soit rĂ©alisable. De plus, certains secteurs et sous-secteurs du Global Protocol for Community-Scale Greenhouse Gas Emission Inventories ne sont pas de compĂ©tences municipales, il est donc peu probable que des mesures de mitigation rĂ©alisables soient intĂ©grĂ©es dans un plan dâaction de rĂ©duction dâĂ©missions de gaz Ă effet de serre. Les principales recommandations qui Ă©mergent de cet essai permettent donc de prioriser les secteurs et les sous-secteurs dâun inventaire dâĂ©missions de gaz Ă effet de serre municipal pour amĂ©liorer la collecte de donnĂ©es locales dans le but de capter les variations des Ă©missions Ă lâĂ©chelle de la municipalitĂ©. La prioritĂ© Ă©tablie dans les recommandations est dĂ©finie selon lâimportance de la part en Ă©missions de gaz Ă effet de serre du secteur ou du sous-secteur et selon sa pertinence dans un cadre municipal.
De ce fait, les municipalitĂ©s se doivent dâutiliser des mĂ©thodes proposĂ©es par le Global Protocol for Community-Scale Greenhouse Gas Emission Inventories pour amĂ©liorer leur collecte de donnĂ©es locales. Cette amĂ©lioration de la qualitĂ© de donnĂ©es permettra dâĂ©valuer les mesures de mitigation Ă prĂ©coniser dans un futur plan dâaction et de prendre des dĂ©cisions Ă lâaide de mesures provenant de donnĂ©es locales
Synthesis, crystal structure, magnetic, spectroscopic, and theoretical investigations of two new nitronyl-nitroxide complexes
International audienceTwo mononuclear complexes [(Et3NH)[M(hfac)2L] (Mâ=âNi, 1; Zn, 2) have been synthesized using a nitronyl-nitroxide radical substituted nitrophenol, that is 2-(2-hydroxy-3-methoxy-5-nitrophenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide-1-oxyl, HL, as a proligand. The crystal structures of 1 and 2 have been solved and indicate an octahedral coordination geometry of the metal ions. The magnetic behavior for 1 is characterized by a strong antiferromagnetic metalâradical interaction (J = â351â±â1âcmâ1; H = âJSNiSRad). This exchange interaction was rationalized by DFT calculations. The EPR spectra recorded in both solution and solid state at 120âK confirm the S = Âœ ground state for 1
Antitumor Properties of a New Macrocyclic Tetranuclear Oxidovanadium(V) Complex with 3-Methoxysalicylidenvaline Ligand
A wide variety of metal-based compounds have been obtained and studied for their antitumor activity since the intensely used cytostatic drugs (e.g., cisplatin) failed to accomplish their expected pharmacological properties. Thus, we aimed to develop a new vanadium-based drug and assess its antitumor properties using the human hepatocarcinoma (HepG2) cell line. The compound was synthesized from vanadyl sulfate, DL-valine, and o-vanillin and was spectrally and structurally characterized (UV-Vis, IR, CD, and single-crystal/powder-XRD). Compound stability in biological media, cell uptake, and the interaction with albumin were assessed. The mechanisms of its antitumor activity were determined compared to cisplatin by performing cytotoxicity, oxidative and mitochondrial status, DNA fragmentation, β-Tubulin synthesis investigation, and cell cycle studies. Herein, we developed a macrocyclic tetranuclear oxidovanadium(V) compound, [(VVO)(L)(CH3O)]4, having coordinated four Schiff base (H2L) ligands, 3-methoxysalicylidenvaline. We showed that [(VVO)(L)(CH3O)]4: (i) has pH-dependent stability in biological media, (ii) binds to albumin in a dose-dependent manner, (iii) is taken up by cells in a time-dependent way, (iv) has a higher capacity to induce cell death compared to cisplatin (IC50 = 6 μM vs. 10 μM), by altering the oxidative and mitochondrial status in HepG2 cells. Unlike cisplatin, which blocks the cell cycle in the S-phase, the new vanadium-based compound arrests it in S and G2/M-phase, whereas no differences in the induction of DNA fragmentation and reduction of β-Tubulin synthesis between the two were determined. Thus, the [(VVO)(L)(CH3O)]4 antitumor mechanism involved corroboration between the generation of oxidative species, mitochondrial dysfunction, degradation of DNA, cell cycle arrest in the S and G2/M-phase, and β-Tubulin synthesis reduction. Our studies demonstrate the potent antitumor activity of [(VVO)(L)(CH3O)]4 and propose it as an attractive candidate for anticancer therapy