46 research outputs found
Cadre méthodologique de gestion du cycle de vie appliqué à l'industrie papetière
Gestion du cycle de vie -- Système de gestion environnementale -- Analyse du cycle de vie -- Analyse de décisions multicritère -- Combinaison des outils de GCV -- ACV des deux usines à l'étude -- Lien entre les articles et organisation de la synthèse -- Développement des méthodes -- Cadre méthodologique proposé -- Forces et limites du cadre de GCV proposé -- Approche hybride multi-niveaux pour la définition des frontières -- Famille cohérente de critères -- Méthode de normalisation basée sur le concept de distance à la cible -- Cas spécifique de la GCV stratégique prospective
Inhibitory effects of cytoskeleton disrupting drugs and GDP-locked Rab mutants on bradykinin B2 receptor cycling
The bradykinin (BK) B2 receptor (B2R) is G protein coupled and phosphorylated upon agonist stimulation; its endocytosis and recycling are documented. We assessed the effect of drugs that affect the cytoskeleton on B2R cycling. These drugs were targeted to tubulin (paclitaxel, or the novel combretastatin A-4 mimetic 3,4,5-trimethoxyphenyl-4-(2-oxoimidazolidin-1-yl)benzenesulfonate [IMZ-602]) and actin (cytochalasin D). Tubulin ligands did not alter agonist-induced receptor endocytosis, as shown using antibodies reactive with myc-tagged B2Rs (microscopy, cytofluorometry), but rather reduced the progression of the ligand–receptor–β-arrestin complex from the cell periphery to the interior. The 3 fluorescent probes of this complex (B2R-green fluorescent protein [B2R-GFP], the fluorescent agonist fluorescein-5-thiocarbamoyl-D-Arg-[Hyp3, Igl5, Oic7, Igl8]-BK and β-arrestin2–GFP) were condensed in punctuate structures that remained close to the cell surface in the presence of IMZ-602. Cytochalasin D selectively inhibited the recycling of endocytosed B2R-GFP (B2R-GFP imaging, [3H]BK binding). Dominant negative (GDP-locked)-Rab5 and -Rab11 reproduced the effects of inhibitors of tubulin and actin, respectively, on the cycling of B2R-GFP. GDP-locked-Rab4 also inhibited B2R-GFP recycling to the cell surface. Consistent with the displacement of cargo along specific cytoskeletal elements, Rab5-associated progression of the endocytosed BK B2R follows microtubules toward their (−) end, while its recycling progresses along actin fibers to the cell surface. However, tubulin ligands do not suppress the tested desensitization or resensitization mechanisms of the B2
Implications of integrating electricity supply dynamics into life cycle assessment: a case study of renewable distributed generation
Electricity supply is frequently cited as a significant hot spot in life cycle assessment (LCA) results. Despite its importance, however, LCA research continues to overuse simplified methodologies regarding electricity supply modeling. This work aims to demonstrate the usefulness of electricity trade analysis (proposed model) for integrating the short-term dynamics of electricity supply and refining LCA results. Distributed generation using renewable energy is applied as a case study to demonstrate how electricity trade analysis provides more refined estimates when environmental impact abatements are assessed compared with the conventional (simplified) approaches in LCA. Grid-connected photovoltaic panel (3 kWp mono- and poly-crystalline) and micro-wind turbine (1, 10 and 30 kW) environmental impact abatements are investigated by determining the displaced marginal electricity production on an hourly basis. The results indicate that environmental impact abatements calculated using the developed short-term time horizon approach can be significantly different (up to 200% difference) from those obtained using a simplified approach. Recommendations are provided to LCA practitioners to address this issue of differing results
Implications of integrating electricity supply dynamics into life cycle assessment: a case study of renewable distributed generation
Electricity supply is frequently cited as a significant hot spot in life cycle assessment (LCA) results. Despite its importance, however, LCA research continues to overuse simplified methodologies regarding electricity supply modeling. This work aims to demonstrate the usefulness of electricity trade analysis (proposed model) for integrating the short-term dynamics of electricity supply and refining LCA results. Distributed generation using renewable energy is applied as a case study to demonstrate how electricity trade analysis provides more refined estimates when environmental impact abatements are assessed compared with the conventional (simplified) approaches in LCA. Grid-connected photovoltaic panel (3 kWp mono- and poly-crystalline) and micro-wind turbine (1, 10 and 30 kW) environmental impact abatements are investigated by determining the displaced marginal electricity production on an hourly basis. The results indicate that environmental impact abatements calculated using the developed short-term time horizon approach can be significantly different (up to 200% difference) from those obtained using a simplified approach. Recommendations are provided to LCA practitioners to address this issue of differing results
Sleep and wake disturbances following traumatic brain injury
Traumatic brain injury (TBI) is a major health concern in industrialised countries. Sleep and
wake disturbances are among the most persistent and disabling sequelae after TBI. Yet,
despite the widespread complaints of post-TBI sleep and wake disturbances, studies on their
etiology, pathophysiology, and treatments remain inconclusive. This narrative review aims to
summarise the current state of knowledge regarding the nature of sleep and wake disturbances
following TBI, both subjective and objective, spanning all levels of severity and phases postinjury. A second goal is to outline the various causes of post-TBI sleep-wake disturbances.
Globally, although sleep-wake complaints are reported in all studies and across all levels of
severity, consensus regarding the objective nature of these disturbances is not unanimous and
varies widely across studies. In order to optimize recovery in TBI survivors, further studies are
required to shed light on the complexity and heterogeneity of post-TBI sleep and wake
disturbances, and to fully grasp the best timing and approach for intervention
Bradykinin receptors : agonists, antagonists, expression, signaling and adaptation to sustained stimulation
Bradykinin-related peptides, the kinins, are blood-derived peptides that stimulate 2 G protein–coupled receptors, the
B1 and B2 receptors (B1R, B2R). The pharmacologic and molecular identities of these 2 receptor subtypes will be
succinctly reviewed, with emphasis on drug development, receptor expression, signaling, and adaptation to
persistent stimulation. Peptide and nonpeptide antagonists and fluorescent ligands have been produced for each
receptor. The B2R is widely and constitutively expressed in mammalian tissues, whereas the B1R is mostly inducible
under the effect of cytokines during infection and immunopathology. Both receptor subtypes mediate the vascular
aspects of inflammation (vasodilation, edema formation). On this basis, icatibant, a peptide antagonist of the B2R, is
approved in the management of hereditary angioedema attacks. Other clinical applications are still elusive despite
the maturity of the medicinal chemistry efforts applied to kinin receptors. While both receptor subtypes are mainly
coupled to the Gq protein and related second messengers, the B2R is temporarily desensitized by a cycle of
phosphorylation/endocytosis followed by recycling, whereas the nonphosphorylable B1R is relatively resistant to
desensitization and translocated to caveolae on activation
Synthetic Plasmodium-Like Hemozoin Activates the Immune Response: A Morphology - Function Study
Increasing evidence points to an important role for hemozoin (HZ), the malaria pigment, in the immunopathology related to this infection. However, there is no consensus as to whether HZ exerts its immunostimulatory activity in absence of other parasite or host components. Contamination of native HZ preparations and the lack of a unified protocol to produce crystals that mimic those of Plasmodium HZ (PHZ) are major technical limitants when performing functional studies with HZ. In fact, the most commonly used methods generate a heterogeneous nanocrystalline material. Thus, it is likely that such aggregates do not resemble to PHZ and differ in their inflammatory properties. To address this issue, the present study was designed to establish whether synthetic HZ (sHZ) crystals produced by different methods vary in their morphology and in their ability to activate immune responses. We report a new method of HZ synthesis (the precise aqueous acid-catalyzed method) that yields homogeneous sHZ crystals (Plasmodium-like HZ) which are very similar to PHZ in their size and physicochemical properties. Importantly, these crystals are devoid of protein and DNA contamination. Of interest, structure-function studies revealed that the size and shape of the synthetic crystals influences their ability to activate inflammatory responses (e.g. nitric oxide, chemokine and cytokine mRNA) in vitro and in vivo. In summary, our data confirm that sHZ possesses immunostimulatory properties and underline the importance of verifying by electron microscopy both the morphology and homogeneity of the synthetic crystals to ensure that they closely resemble those of the parasite. Periodic quality control experiments and unification of the method of HZ synthesis are key steps to unravel the role of HZ in malaria immunopathology