2,991 research outputs found
Insights on the antigorite structure from Mossbauer and FTIR spectroscopies
No full textPure, selected samples of antigorite (#7 and #18, from Elba Island veins, Italy, with superperiodicities of 38 and 49 Angstrom, respectively) have been analyzed by Mossbauer and infrared spectroscopies. Mossbauer data indicate that most of the iron is present as ferrous iron (88.6% Fe2+ in #7 and 83.2% Fe2+ in #18). Both ferrous and ferric iron occur in octahedral coordination; ferric iron in tetrahedral coordination has not been detected. The infrared spectra of antigorites #7 and #18 are similar, with minor shifts in peak positions. More in general, the comparison with other vein antigorites from the Elba suite (#2, #4, #11, #16) rules out any relation between modulation wavelength and IR behaviour. Evident differences arise from the comparison between antigorite and lizardite spectra. The absorption bands corresponding to stretching of the basal Si-O bonds are systematically shifted towards higher wavenumbers in antigorite with respect to lizardite (from 951 to 979-991 cm(-1)), suggesting higher energy of the bridging bonds. In contrast, antigorite and lizardite show the same IR patterns in the apical Si-O stretching vibrations (1073-1084 cm(-1)). The OH stretching region (3700-3400 cm(-1)) indicates similar structural arrangement for the inner O-H in antigorite and lizardite, whereas the absence of the broad band at similar to3440 cm(-1) in antigorite indicates the lack of important hydrogen bonding in the interlayer. Other IR differences (e.g., absence of Si-O bending and of external OH bending in lizardite) are explained as due to different symmetries (monoclinic antigorite vs. trigonal lizardite).
We conclude that antigorite and lizardite share common features (similar iron coordination and disordered distribution within the magnesium octahedra), but differ in the oxidation state (more reduced antigorite), in the tetrahedral sheet size (basal Si-O bond shrinked by 0.009 Angstrom in antigorite) and in the interlayer connections mechanism (absence of hydrogen bond in antigorite)
Adeloneivaia pallida Lemaire 1982
No full text<p> <i>Adeloneivaia pallida</i> Lemaire, 1982.</p> <p> <i>Adeloneivaia subangulata pallida</i> Lemaire, 1982a: 63, figs 12, 13.</p> <p> <i>Adeloneivaia pallida</i> – Brechlin & Meister 2011c: 7.</p> <p> DÉTERMINATION. — Morphologique.Moléculaire (BOLD:AAB0229 pour <i>Adeloneivaia subangulata subangulata</i>).</p> <p>LOCALITÉ TYPE. — Pérou: Amazonas (Lemaire 1982a).</p> <p> HISTORIQUE. — Précédemment cité de Guyane comme <i>Adeloneivaia subangulata subangulata</i> (Herrich-Schäffer, [1855]) (Lemaire 1988b).</p> <p>RÉPARTITION GÉOGRAPHIQUE. — Guyano-amazonienne.</p> <p>DISTRIBUTION EN GUYANE. — Connu des trois zones biogéographiques.</p> <p>HABITAT EN GUYANE. — Forêts primaire et secondaire, savane.</p> <p> MATÉRIEL DU MITARAKA EXAMINÉ. — <b>Guyane •</b> 1♀; Maripasoula, Mitaraka, Crique Alama (DZ); alt. 310 m; 2°14’1.9”N, 54°27’38.1”W; La Planète revisitée, MNHN / PNI Guyane; APA-973-1; 23.II-26. III.2015; E. Poirier leg.; MNHN • 1 ♀; mêmes données que précédent; Coll. FB • 1 ♀; Maripasoula, Mitaraka, Crique Alama (DZ); alt. 310 m; 2°14’1.9”N, 54°27’38.1”W; La Planète revisitée, MNHN / PNI Guyane; autorisation APA-973-2; 11-21.VIII.2015; FB leg.; MNHN.</p>Published as part of <i>Bénéluz, Frédéric, 2021, Liste commentée des Saturniidae (Lepidoptera, Bombycoidea) de Guyane, avec la liste des taxons récoltés au Mitaraka (extrême sud-ouest guyanais), pp. 759-809 in Zoosystema 43 (31)</i> on page 770, DOI: 10.5252/zoosystema2021v43a31, <a href="http://zenodo.org/record/5796817">http://zenodo.org/record/5796817</a>
Hylesia (Hylesia) vassali Lemaire 1988
No full text<p> <i>Hylesia</i> (<i>Hylesia</i>) <i>vassali</i> Lemaire, 1988.</p> <p> <i>Hylesia vassali</i> Lemaire, 1988a: 60, figs 13, 20.</p> <p> <i>Hylesia</i> (<i>Hylesia</i>) <i>vassali</i> – Brechlin <i>et al.</i> 2016: 93.</p> <p>DÉTERMINATION. — Morphologique.Moléculaire (BOLD:AAE5118).</p> <p>LOCALITÉ TYPE. — Guyane (Lemaire 1988a).</p> <p>RÉPARTITION GÉOGRAPHIQUE. — Guyane (Lemaire 2002).</p> <p>DISTRIBUTION EN GUYANE. — Connu des trois zones biogéographiques.</p> <p>HABITAT EN GUYANE. — Forêt primaire.</p> <p> MATÉRIEL DU MITARAKA EXAMINÉ. — <b>Guyane •</b> 2 ♂; Maripasoula, Mitaraka, Crique Alama (DZ); alt. 310 m; 2°14’1.9”N, 54°27’38.1”W; La Planète revisitée, MNHN / PNI Guyane; APA-973-1; 23.II-26. III.2015; E. Poirier leg.; MNHN • 1 ♂; mêmes données que précédent; Coll. FB.</p>Published as part of <i>Bénéluz, Frédéric, 2021, Liste commentée des Saturniidae (Lepidoptera, Bombycoidea) de Guyane, avec la liste des taxons récoltés au Mitaraka (extrême sud-ouest guyanais), pp. 759-809 in Zoosystema 43 (31)</i> on pages 780-781, DOI: 10.5252/zoosystema2021v43a31, <a href="http://zenodo.org/record/5796817">http://zenodo.org/record/5796817</a>
Comment sont étudiées les populations de poissons du lac d’Annecy ?
No full textGOULON C., LEMAIRE M., ZANELLA D., GUILLARD J., 2018. Comment sont étudiées les populations de poissons du lac d’Annecy ? ALP 201
Comment sont étudiées les populations de poissons du lac d’Annecy ?
No full textGOULON C., LEMAIRE M., ZANELLA D., GUILLARD J., 2018. Comment sont étudiées les populations de poissons du lac d’Annecy ? ALP 201
The Modified Lemaire Procedure
No full textBackground: Anterolateral rotatory instability (ALRI) may be one reasons why anterior cruciate ligament (ACL) reconstructions fail. An additional reconstruction of the anterolateral structures reduces the graft rupture rate by 50%. The modified Lemaire procedure is one of the lateral extra-articular tenodeses (LET) to restrain ALRI. The purpose of the present video is to describe this technique in detail. Indications: According to the international anterolateral complex consensus group indications may include revision ACL reconstruction, high grade pivot shift, generalized ligamentous laxity, like genu recurvatum, and young patients returning to pivoting activities. However, clinical evidence to recommend specific indications is still missing. Technique description: A 7 to 10 mm wide strip of the iliotibial tract, attached to Gerdy tubercle is shuttled deep to the lateral collateral ligament and is then attached proximal to the lateral femoral epicondyle. The biomechanical principle behind this is to place the graft posterior to the transverse axis of rotation through the entire range of motion. This posterior pull will restrain internal rotation and the anterior subluxation of the lateral tibial plateau. Results: Newer comparative studies show a reduced graft rupture rate and higher rate of returning to preinjury level, when adding an anterolateral extra-articular reconstruction to the ACL reconstruction at 2 years follow-up. At long-term follow-up there was also a trend toward decreased graft rupture rate. However, one must be aware of the possible increased risk of lateral compartment osteoarthritis. Conclusion: The modified Lemaire procedure is an easy-to-use addon to the ACL reconstruction, which can effectively reduce graft failure rate
Aldolases from biodiversity: exploration of their substrates promiscuity
No full textInternational audienceFor many years, aldolases catalysing stereoselective C-C bond formation have been considered essential for synthetic applications.[1] Biocatalysed aldolisation reactions are performed under mild conditions, without any protections and are therefore highly valuable for the development of green synthetic processes. In addition, there is room for new C-C bond forming enzymes to construct more complex molecules since this category of enzymes is underused when compared with other biocatalysts.[2] The classification of aldolases is based on the structure of natural nucleophiles leading to five main classes: dihydroxyacetone phosphate- (DHAP), pyruvate-, ethanal-, dihydroxyacetone- (DHA), and glycine- aldolases.[1a] Concerning their substrate specificity, one generally admitted that if they accept a broad range of aldehydes as electrophiles, most of them are strictly dependent on a sole nucleophile substrate.Our work highlight that aldolases are not always dependent on aldehydes as electrophile or on a sole nucleophile substrates. They complete the recent discoveries reported by us and others on their higher nucleophile tolerance.[3] Recent results in exploring nucleophile and electrophile substrates promiscuity among aldolases from biodiversity (see scheme) will be described.In particular, we have revisited DHAP-dependent aldolases with ketones as electrophiles.[4] We have demonstrated that rhamnulose-1-phosphate aldolases display an unprecedented versatility for activated ketones. We selected and characterized a rhamnulose aldolase from Bacteroides thetaio-taomicron as a proof of concept. DHAP was added to several hydroxylated ketones used as electro-philes. This aldol addition was stereoselective and produced branched-chain monosaccharide adducts with a tertiary alcohol moiety, which is rather difficult to prepare optically pure. Other nucleophiles [5] or electrophiles, with different aldolase classes are currently under investigation in our lab, which would confirmed the unprecedented substrate tolerance among aldolases.References:1. (a) P. Clapés, X. Garrabou, Adv. Synth. Catal. 2011, 353, 2263-2283; (b) P. Clapés, W. D. Fessner, G. A. Sprenger, A. K. Samland, Curr. Opin. Chem. Biol. 2010, 14, 154-167; (c) M. Müller, Adv. Synth. Catal. 2012, 354, 3161-3174; (d) M. Brovetto, D. Gamenara, P. Mendez, G. Seoane, Chem. Rev. 2011, 111, 4346-4403; (e) A. Bolt, A. Berry, A. Nelson, Arch. Biochem. Biophys. 2008, 474, 318-330; (f) A. K. Samland, G. A. Sprenger, Appl. Microbiol. Biotechnol. 2006, 71, 253-264.2. N. J. Turner, E. O'Reilly Nature Chem. Biol. 2013, 9, 285–288.3 (a) R. Roldaú n, K. Hernandez, J. Joglar, J. Bujons, T. Parella, I. Saú nchez-Moreno, V. Hélaine, M. Lemaire, C. Gueú rard-Heú laine, W.-D. Fessner, and P. Clapeú s ACS Catal. 2018, 8, 8804−880. (b) I. Sanchez-Moreno, T. Scheidt, V. Hélaine, M. Lemaire, T. Parella, P. Clapés, W.-D. Fessner, C. Guérard-Hélaine Chem. Eur. J., 2017, 23, 2005-2009. (c) V. de Berardinis, C. Guérard-Hélaine, E. Darii, K. Bastard, V. Hélaine, A. Mariage, J.-L. Petit, N. Poupard, I. Sanchez-Moreno, M. Stam, T. Gefflaut, M. Salanoubat, M. Lemaire Green Chem., 2017, 19, 519-526.4 (a) V. Laurent, E. Darii, A. Aujon, M. Debacker, J.-L. Petit, V. Hélaine, T. Liptaj, M. Breza, L. Nauton, M. Traïkia, M. Salanoubat, M. Lemaire, C. Guérard-Hélaine, V. de Berardinis Angew. Chem., Int. Ed. Engl., 2018, 57, 5467-5471. (b) M. Salanoubat, M. Lemaire, C. Guérard-Hélaine, V. de Berardinis WO 2018/215476 A1.5 V. Laurent, A. Uzel, V. Hélaine, L. Nauton, M. Traïkia, T. Gefflaut, M. Salanoubat, V. de Berardinis, M. Lemaire and C. Guérard-Hélaine Adv. Synth. Catal. 2019, accepted (special Biotrans 2019 issue
Aldolases from biodiversity: exploration of their substrates promiscuity
No full textInternational audienceFor many years, aldolases catalysing stereoselective C-C bond formation have been considered essential for synthetic applications.[1] Biocatalysed aldolisation reactions are performed under mild conditions, without any protections and are therefore highly valuable for the development of green synthetic processes. In addition, there is room for new C-C bond forming enzymes to construct more complex molecules since this category of enzymes is underused when compared with other biocatalysts.[2] The classification of aldolases is based on the structure of natural nucleophiles leading to five main classes: dihydroxyacetone phosphate- (DHAP), pyruvate-, ethanal-, dihydroxyacetone- (DHA), and glycine- aldolases.[1a] Concerning their substrate specificity, one generally admitted that if they accept a broad range of aldehydes as electrophiles, most of them are strictly dependent on a sole nucleophile substrate.Our work highlight that aldolases are not always dependent on aldehydes as electrophile or on a sole nucleophile substrates. They complete the recent discoveries reported by us and others on their higher nucleophile tolerance.[3] Recent results in exploring nucleophile and electrophile substrates promiscuity among aldolases from biodiversity (see scheme) will be described.In particular, we have revisited DHAP-dependent aldolases with ketones as electrophiles.[4] We have demonstrated that rhamnulose-1-phosphate aldolases display an unprecedented versatility for activated ketones. We selected and characterized a rhamnulose aldolase from Bacteroides thetaio-taomicron as a proof of concept. DHAP was added to several hydroxylated ketones used as electro-philes. This aldol addition was stereoselective and produced branched-chain monosaccharide adducts with a tertiary alcohol moiety, which is rather difficult to prepare optically pure. Other nucleophiles [5] or electrophiles, with different aldolase classes are currently under investigation in our lab, which would confirmed the unprecedented substrate tolerance among aldolases.References:1. (a) P. Clapés, X. Garrabou, Adv. Synth. Catal. 2011, 353, 2263-2283; (b) P. Clapés, W. D. Fessner, G. A. Sprenger, A. K. Samland, Curr. Opin. Chem. Biol. 2010, 14, 154-167; (c) M. Müller, Adv. Synth. Catal. 2012, 354, 3161-3174; (d) M. Brovetto, D. Gamenara, P. Mendez, G. Seoane, Chem. Rev. 2011, 111, 4346-4403; (e) A. Bolt, A. Berry, A. Nelson, Arch. Biochem. Biophys. 2008, 474, 318-330; (f) A. K. Samland, G. A. Sprenger, Appl. Microbiol. Biotechnol. 2006, 71, 253-264.2. N. J. Turner, E. O'Reilly Nature Chem. Biol. 2013, 9, 285–288.3 (a) R. Roldaú n, K. Hernandez, J. Joglar, J. Bujons, T. Parella, I. Saú nchez-Moreno, V. Hélaine, M. Lemaire, C. Gueú rard-Heú laine, W.-D. Fessner, and P. Clapeú s ACS Catal. 2018, 8, 8804−880. (b) I. Sanchez-Moreno, T. Scheidt, V. Hélaine, M. Lemaire, T. Parella, P. Clapés, W.-D. Fessner, C. Guérard-Hélaine Chem. Eur. J., 2017, 23, 2005-2009. (c) V. de Berardinis, C. Guérard-Hélaine, E. Darii, K. Bastard, V. Hélaine, A. Mariage, J.-L. Petit, N. Poupard, I. Sanchez-Moreno, M. Stam, T. Gefflaut, M. Salanoubat, M. Lemaire Green Chem., 2017, 19, 519-526.4 (a) V. Laurent, E. Darii, A. Aujon, M. Debacker, J.-L. Petit, V. Hélaine, T. Liptaj, M. Breza, L. Nauton, M. Traïkia, M. Salanoubat, M. Lemaire, C. Guérard-Hélaine, V. de Berardinis Angew. Chem., Int. Ed. Engl., 2018, 57, 5467-5471. (b) M. Salanoubat, M. Lemaire, C. Guérard-Hélaine, V. de Berardinis WO 2018/215476 A1.5 V. Laurent, A. Uzel, V. Hélaine, L. Nauton, M. Traïkia, T. Gefflaut, M. Salanoubat, V. de Berardinis, M. Lemaire and C. Guérard-Hélaine Adv. Synth. Catal. 2019, accepted (special Biotrans 2019 issue
Supplemental_Material - Cadmium-Induced Renal Cell Toxicity Is Associated With MicroRNA Deregulation
No full textSupplemental_Material for Cadmium-Induced Renal Cell Toxicity Is Associated With MicroRNA Deregulation by J. Lemaire, C. Van der Hauwaert, G. Savary, E. Dewaeles, M. Perrais, J. M. Lo Guidice, N. Pottier, F. Glowacki and C. Cauffiez in International Journal of Toxicology</p
Aldolases from biodiversity: exploration of their substrates promiscuity
No full textInternational audienceFor many years, aldolases catalysing stereoselective C-C bond formation have been considered essential for synthetic applications.[1] Biocatalysed aldolisation reactions are performed under mild conditions, without any protections and are therefore highly valuable for the development of green synthetic processes. In addition, there is room for new C-C bond forming enzymes to construct more complex molecules since this category of enzymes is underused when compared with other biocatalysts.[2] The classification of aldolases is based on the structure of natural nucleophiles leading to five main classes: dihydroxyacetone phosphate- (DHAP), pyruvate-, ethanal-, dihydroxyacetone- (DHA), and glycine- aldolases.[1a] Concerning their substrate specificity, one generally admitted that if they accept a broad range of aldehydes as electrophiles, most of them are strictly dependent on a sole nucleophile substrate.Our work highlight that aldolases are not always dependent on aldehydes as electrophile or on a sole nucleophile substrates. They complete the recent discoveries reported by us and others on their higher nucleophile tolerance.[3] Recent results in exploring nucleophile and electrophile substrates promiscuity among aldolases from biodiversity (see scheme) will be described.In particular, we have revisited DHAP-dependent aldolases with ketones as electrophiles.[4] We have demonstrated that rhamnulose-1-phosphate aldolases display an unprecedented versatility for activated ketones. We selected and characterized a rhamnulose aldolase from Bacteroides thetaio-taomicron as a proof of concept. DHAP was added to several hydroxylated ketones used as electro-philes. This aldol addition was stereoselective and produced branched-chain monosaccharide adducts with a tertiary alcohol moiety, which is rather difficult to prepare optically pure. Other nucleophiles [5] or electrophiles, with different aldolase classes are currently under investigation in our lab, which would confirmed the unprecedented substrate tolerance among aldolases.References:1. (a) P. Clapés, X. Garrabou, Adv. Synth. Catal. 2011, 353, 2263-2283; (b) P. Clapés, W. D. Fessner, G. A. Sprenger, A. K. Samland, Curr. Opin. Chem. Biol. 2010, 14, 154-167; (c) M. Müller, Adv. Synth. Catal. 2012, 354, 3161-3174; (d) M. Brovetto, D. Gamenara, P. Mendez, G. Seoane, Chem. Rev. 2011, 111, 4346-4403; (e) A. Bolt, A. Berry, A. Nelson, Arch. Biochem. Biophys. 2008, 474, 318-330; (f) A. K. Samland, G. A. Sprenger, Appl. Microbiol. Biotechnol. 2006, 71, 253-264.2. N. J. Turner, E. O'Reilly Nature Chem. Biol. 2013, 9, 285–288.3 (a) R. Roldaú n, K. Hernandez, J. Joglar, J. Bujons, T. Parella, I. Saú nchez-Moreno, V. Hélaine, M. Lemaire, C. Gueú rard-Heú laine, W.-D. Fessner, and P. Clapeú s ACS Catal. 2018, 8, 8804−880. (b) I. Sanchez-Moreno, T. Scheidt, V. Hélaine, M. Lemaire, T. Parella, P. Clapés, W.-D. Fessner, C. Guérard-Hélaine Chem. Eur. J., 2017, 23, 2005-2009. (c) V. de Berardinis, C. Guérard-Hélaine, E. Darii, K. Bastard, V. Hélaine, A. Mariage, J.-L. Petit, N. Poupard, I. Sanchez-Moreno, M. Stam, T. Gefflaut, M. Salanoubat, M. Lemaire Green Chem., 2017, 19, 519-526.4 (a) V. Laurent, E. Darii, A. Aujon, M. Debacker, J.-L. Petit, V. Hélaine, T. Liptaj, M. Breza, L. Nauton, M. Traïkia, M. Salanoubat, M. Lemaire, C. Guérard-Hélaine, V. de Berardinis Angew. Chem., Int. Ed. Engl., 2018, 57, 5467-5471. (b) M. Salanoubat, M. Lemaire, C. Guérard-Hélaine, V. de Berardinis WO 2018/215476 A1.5 V. Laurent, A. Uzel, V. Hélaine, L. Nauton, M. Traïkia, T. Gefflaut, M. Salanoubat, V. de Berardinis, M. Lemaire and C. Guérard-Hélaine Adv. Synth. Catal. 2019, accepted (special Biotrans 2019 issue
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