22 research outputs found
Cobalt(II) complexes bearing 2-imino-1,10-phenanthroline ligands: synthesis, characterization and ethylene oligomerization
Compound Heterozygous CHAT Gene Mutations of a Large Deletion and a Missense Variant in a Chinese Patient With Severe Congenital Myasthenic Syndrome With Episodic Apnea
Congenital myasthenic syndromes (CMSs) are a group of inherited disorders caused by genetic defects in neuromuscular junctions. Mutations in CHAT, encoding choline acetyltransferase, cause congenital myasthenic syndrome with episodic apnea (CMS-EA), a rare autosomal recessive disease characterized by respiratory insufficiency with cyanosis and apnea after infections, fever, vomiting, or excitement. To date, no studies have reported deletions comprised of multiple exons. Here, using next generation sequencing, we identified compound heterozygous mutations, namely a large maternally inherited deletion, including exons 4, 5, and 6, and a paternally inherited missense variant (c.914T>C [p.Ile305Thr]) in CHAT in a Chinese patient with a severe phenotype of CMS-EA. Furthermore, the large deletion was also validated by real-time fluorescence quantitative polymerase chain reaction. The patient was a 10-month-old boy, who presented with a weak cry and feeding difficulties soon after birth, ptosis at 4 months old, episodic apnea after fever at 9 months old, and respiratory insufficiency with cyanosis and apnea that required intubation after a respiratory tract infection at 10 months old. Unfortunately, he died in the Pediatric Intensive Care Unit soon after hospitalization. The patient’s elder sister had similar clinical manifestations, and she died prior to the age of 2 months old without a diagnosis. Genotype-phenotype correlation analysis revealed that loss-of-function mutations in exons 4–6 of CHAT might cause more severe CMS-EA. To our knowledge, this is the first study to show compound heterozygous CHAT mutations consisting of a large deletion and missense mutation in a patient with CMS-EA
Synthèse de nouveaux complexes des métaux de transition et application en catalyse d'oligomérisation et, ou de polymerization de l'éthylène
Les polyoléfines représentent environ la moitié du marché des polymères de synthèse. L'oligomérisation catalytique de l'éthylène représente l'accès principal aux a-oléfines linéaires qui sont utilisées pour la préparation de lubrifiants, de détergents, de surfactants, de plastifiants et comme comonomères dans la fabrication de polyéthylène linéaire basse density (LLDPE). Ce travail a porté sur la synthèse de ligands tridentates 2-imino-1,10-phénanthroline et 2-imino-9-phényl-1,10-phénanthroline et de leurs complexes du fer, du cobalt et du nickel dont certains sont très actifs en oligomérisation de l'éthylène. Les paramètres électroniques et stériques qui influencent les résultats catalytiques ont été examinés en détail. Par ailleurs, des complexes mono- and dinucléaires du cobalt avec des ligands bidentes phosphino- et phosphinito-oxazoline ont été synthétisés au cours de cette thèse. Ils ont montré une activité catalytique modérée en présence de MAO ou AlEtCl2 comme cocatalyseur.Polyolefins represent about half the market of the synthesized polymeric materials. The catalytic oligomerization of ethylene is currently the primary source of linear a-olefins which are extensively used for the preparation of synthetic lubricants, detergent intermediates, surfactants, plasticizers and as comonomers to synthesize linear low-density polyethylene (LLDPE). This work deals with the synthesis of 2-imino-1,10-phenanthroline and 2-imino-9-phenyl-1,10-phenanthroline tridentate ligand and of their iron, cobalt and nickel complexes of which some are very active in the catalytic ethylene oligomerization. Stereoelectronic parameters influencing the catalytic properties have been examined in detail. Furthermore, mono- and dinuclear cobalt complexes with phosphino- and phosphinito-oxazoline ligands have been prepared in the course of this thesis. They have shown moderate catalytic activity in the presence of MAO or AlEtCl2 as cocatalyst
Synthèse de nouveaux complexes des métaux de transition et application en catalyse d'oligomérisation et, ou de polymerization de l'éthylène
Les polyoléfines représentent environ la moitié du marché des polymères de synthèse. L'oligomérisation catalytique de l'éthylène représente l'accès principal aux a-oléfines linéaires qui sont utilisées pour la préparation de lubrifiants, de détergents, dePolyolefins represent about half the market of the synthesized polymeric materials. The catalytic oligomerization of ethylene is currently the primary source of linear a-olefins which are extensively used for the preparation of synthetic lubricants, dete
Synthèse de nouveaux complexes des métaux de transition et application en catalyse d oligomérisation et / ou de polymerization de l éthylène
Les polyoléfines représentent environ la moitié du marché des polymères de synthèse. L'oligomérisation catalytique de l'éthylène représente l'accès principal aux a-oléfines linéaires qui sont utilisées pour la préparation de lubrifiants, de détergents, de surfactants, de plastifiants et comme comonomères dans la fabrication de polyéthylène linéaire basse density (LLDPE). Ce travail a porté sur la synthèse de ligands tridentates 2-imino-1,10-phénanthroline et 2-imino-9-phényl-1,10-phénanthroline et de leurs complexes du fer, du cobalt et du nickel dont certains sont très actifs en oligomérisation de l'éthylène. Les paramètres électroniques et stériques qui influencent les résultats catalytiques ont été examinés en détail. Par ailleurs, des complexes mono- and dinucléaires du cobalt avec des ligands bidentes phosphino- et phosphinito-oxazoline ont été synthétisés au cours de cette thèse. Ils ont montré une activité catalytique modérée en présence de MAO ou AlEtCl2 comme cocatalyseur.Polyolefins represent about half the market of the synthesized polymeric materials. The catalytic oligomerization of ethylene is currently the primary source of linear a-olefins which are extensively used for the preparation of synthetic lubricants, detergent intermediates, surfactants, plasticizers and as comonomers to synthesize linear low-density polyethylene (LLDPE). This work deals with the synthesis of 2-imino-1,10-phenanthroline and 2-imino-9-phenyl-1,10-phenanthroline tridentate ligand and of their iron, cobalt and nickel complexes of which some are very active in the catalytic ethylene oligomerization. Stereoelectronic parameters influencing the catalytic properties have been examined in detail. Furthermore, mono- and dinuclear cobalt complexes with phosphino- and phosphinito-oxazoline ligands have been prepared in the course of this thesis. They have shown moderate catalytic activity in the presence of MAO or AlEtCl2 as cocatalyst.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF
Polybutadiene Vitrimers with Tunable Epoxy Ratios: Preparation and Properties
Traditional crosslinked diene rubber has excellent thermal–mechanical properties and solvent resistance, yet it is incapable of being recycled via universal molding or injecting. Vitrimers, a new class of covalently crosslinked polymer networks, can be topologically rearranged with the associative exchange mechanism, endowing them with thermoplasticity. Introducing the concept of vitrimers into crosslinked networks for the recycling of rubbers is currently an attractive research topic. However, designing tailored rubber vitrimers still remains a challenge. Herein, polybutadiene (PB) vitrimers with different structures were prepared via partial epoxidation of double bonds and ring-opening esterification reactions. Their mechanical and relaxation properties were investigated. It was found that the increasing crosslinking density can increase tensile strength and activation energy for altering the network topology. The influence of side-group effects on their relaxation properties shows that an increase in the number of epoxy groups on the polybutadiene chain can increase the chance of an effective exchange of disulfide units. This work provides a simple network design which can tune vitrimer properties via altering the crosslinking density and side-group effects
Dezocine Prevents Postoperative Hyperalgesia in Patients Undergoing Open Abdominal Surgery
Objective. Postoperative hyperalgesia is very frequent and hard to treat. Dezocine is widely used and has a modulatory effect for thermal hyperalgesia in animal models. So, this study was designed to investigate the potential role of dezocine in decreasing postoperative hyperalgesia for patients undergoing open abdominal surgery. Methods. This is a randomized, double-blinded, and placebo-controlled trial. 50 patients for elective open gastrectomy were randomly allocated to either a true treatment group (0.15 mg/kg intravenous dezocine at the end of surgery) or a sham treatment group (equivalent volume of saline) in a 1 : 1 ratio. Patients were followed up for 48 hours postoperatively and pain threshold to Von Frey filaments, pain scores, PCIA consumption, rescue analgesics use, sedation score, and occurrence of postoperative nausea and vomiting were recorded. Results. Patients in the true treatment group experienced statistically significantly higher pain threshold on forearm and smaller extent of peri-incisional hyperalgesia than the sham treatment group. Rescue analgesic use, cumulative PCIA consumption, and pain scores were statistically significantly decreased in the true treatment group compared to the sham treatment group. Conclusions. Dezocine offers a significant antihyperalgesic and analgesic effect in patients undergoing elective open gastrectomy for up to 48 hours postoperatively
Polyethyleneimine-Modified UiO-66-NH2(Zr) Metal–Organic Frameworks: Preparation and Enhanced CO2 Selective Adsorption
Pt Catalyzed Hydrosilylation of Fluorinated Phenoxy-Imine Ligands with Hydrosilanes
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