17 documents found, page 1 of 2
Mesoporous Carbon as effective and sustainable catalyst for fine chemistry
Castanheiro, J; Matos, I; Bernardo, M; Neves, P; Vital, J; Fonseca, IIt is well known that activated carbon with welldeveloped porosity is a promising material that have been used for several applications, from adsorption to catalysis. Research in this field has intensified in recent years, looking for new and improved characteristics and applications. Our research group, recently renamed Materials for Adsorption and Catalysis group (MAC) in LAQV-REQUIMTE, has also devoted many ...
Methoxylation of a-pinene over mesoporous carbons and microporous
Castanheiro, J; Matos, I; Silva, M; Ruiz-Rosas, R; Vital, J; Rodríguez-Mirasol, J; Cordero, T; Fonseca, IA biomass derived carbon, a commercial microporous carbon and a xerogel mesoporous carbon catalysts were used in the study of a-pinene methoxilation reaction and the influence of textural and physical–chemical properties of the carbons was evaluated. Biomass carbon presented the higher activity, whereas the commercial one is the less active in the conditions studied. The main product of the reaction was a-terpi...
Alkoxylation of camphene over silica-occluded tungstophosphoric acid
Castanheiro, J; Caiado, M; Machado, A; Santos, R; Matos, I; Fonseca, I; Ramos, A; Valente, A; Vital, JSilica-occluded tungstophosphoric acid (PW-Ssg) was used as an efficient, nvironmentally friendly heterogeneous catalyst for the liquid-phase alkoxylation of camphene into their more valuable alkyl isobornyl ether, which is used as perfume and cosmetic products, in the pharmaceutical industry, as well as in the food industry. The lkoxylation of camphene with C1–C4 alcohols (methanol, ethanol, 1- propanol, 2-pro...
Feedback control of chromosome separation by a midzone Aurora B gradient
Afonso, O; Matos, I; Pereira, AJ; Aguiar, P; Lampson, MA; Maiato, HAccurate chromosome segregation during mitosis requires the physical separation of sister chromatids before nuclear envelope reassembly (NER). However, how these two processes are coordinated remains unknown. Here, we identified a conserved feedback control mechanism that delays chromosome decondensation and NER in response to incomplete chromosome separation during anaphase. A midzone-associated Aurora B gradi...
Mesoporous carbon as an efficient catalyst for alcoholysis and aminolysis of ep...
Matos, I; Neves, P; Castanheiro, J; Perez-Mayoral, E; Martin-Aranda, R; Duran-Valle, C; Vital, J; Botelho do Rego, A; Fonseca, IThe ring opening reaction of epoxides by alcohols and amines using mesoporous activated carbon as efficient and environmentally friendly heterogeneous catalyst is reported. Carbon xerogels were synthesized by polymerization of resorcinol and formaldehyde. The surface of the activated carbon was oxidized in liquid phase with HNO3 and then functionalized with H2SO4. Chemical and textural characterization by eleme...
SBA-15 with sulfonic acid groups as a Green Catalyst for the acetoxylation of α...
Machado, J; Castanheiro, J; Matos, I; Ramos, A; Vital, J; Fonseca, IThe acetoxylation of a-pinene was carried out over SBA-15 with sulfonic acid groups. The products of acetoxylation of a-pinene are acetates (a-terpinyl acetate, bornyl acetate and b-fenchyl acetate) and hydrocarbons (camphene, tricyclene, limonene, g-terpinene, terpinolene and a-terpinene). Catalysts with different amount of sulfonic acid groups were prepared. It was observed that the activity increases with in...
Opening of epoxides with amines promoted by activated mesoporous carbons
Matos, I; Neves, P; Castanheiro, J; Ramos, A; Vital, J; Fonseca, IThe modification of mesoporous carbons has proven to be active in ring opening reaction with both alcohols and amines.
Methoxylation of alpha-pinene over heteropolyacids immobilized in silica
Pito, DS; Matos, I; Fonseca, I; Ramos, A; Vital, J; Castanheiro, JoséThe methoxylation of a-pinene was studied using heteropolyacids immobilized on silica as catalysts, at 60 ºC, being the a-terpinyl methyl ether the main product. Tungstophosphoric acid (PW), molybdophosphoric acid (PMo), tungstosilicic acid (SiW) and molybdosilicic acid (SiMo) were immobilized on silica by sol–gel method. It was observed that the catalytic activity of the silica-supported heteropolyacids decrea...
Kalirin: a novel genetic risk factor for ischemic stroke
Krug, T; Manso, H; Gouveia, L; Sobral, J; Xavier, J; Albergaria, I; Gaspar, G; Correia, M; Viana-Baptista, M; Simões, R; Pinto, A; Taipa, R; Ferreira, CCerebrovascular and cardiovascular diseases are the leading causes of death and disability worldwide. They are complex disorders resulting from the interplay of genetic and environmental factors, and may share several susceptibility genes. Several recent studies have implicated variants of the Kalirin (KALRN) gene with susceptibility to cardiovascular and metabolic phenotypes, but no studies have yet been perfo...
Mitochondrial haplogroup H1 is protective for ischemic stroke in Portuguese pat...
Rosa, A; Fonseca, BV; Krug, T; Manso, H; Gouveia, L; Albergaria, I; Gaspar, G; Correia, M; Viana-Baptista, M; Simões, RM; Pinto, AN; Taipa, RBACKGROUND: The genetic contribution to stroke is well established but it has proven difficult to identify the genes and the disease-associated alleles mediating this effect, possibly because only nuclear genes have been intensely investigated so far. Mitochondrial DNA (mtDNA) has been implicated in several disorders having stroke as one of its clinical manifestations. The aim of this case-control study was to ...