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961.
Tool use has been observed in a variety of primate species, including both New and Old World monkeys. However, such reports
mainly address the most prodigious tool users and frequently limit discussions of tool-using behavior to a foraging framework.
Here, we present observations of novel and spontaneous tool use in wild black-handed spider monkeys (Ateles geoffroyi), where female spider monkeys used detached sticks in a self-directed manner. We introduce factors to explain Ateles tool-using abilities and limitations, and encourage the synthesis of relevant research in order to gain insight into the
cognitive abilities of spider monkeys and the evolution of tool-using behaviors in primates. 相似文献
962.
Tayyab A. Mansoor Rita M. Ramalho Silva Mulhovo Cecília M.P. Rodrigues Maria José U. Ferreira 《Bioorganic & medicinal chemistry letters》2009,19(15):4255-4258
Three known (1–3) and a novel (4) monoterpene indole alkaloids have been isolated from the methanol extract of leaves of Tabernaemontana elegans and their structures were elucidated by a series of spectroscopic experiments, involving NMR, MS, UV, and IR techniques. The isolated monoterpene indole alkaloids along with previously described β-carbolines (5–7) from the same specimen were studied for their apoptosis induction activity in human hepatoma HuH-7 cells. Methodology for apoptosis induction studies included cell viability assays, nuclear morphology assessments, and general caspase-3-like activity assays. The monoterpene indole alkaloids, tabernaemontanine (1) and vobasine (3) showed the most promising apoptosis induction profile in HuH-7 cells. 相似文献
963.
Rodolphe Tabuce Laurent Marivaux Renaud Lebrun Mohammed Adaci Mustapha Bensalah Pierre-Henri Fabre Emmanuel Fara Helder Gomes Rodrigues Lionel Hautier Jean-Jacques Jaeger Vincent Lazzari Fateh Mebrouk Stéphane Peigné Jean Sudre Paul Tafforeau Xavier Valentin Mahammed Mahboubi 《Proceedings. Biological sciences / The Royal Society》2009,276(1676):4087-4094
Recent fossil discoveries have demonstrated that Africa and Asia were epicentres for the origin and/or early diversification of the major living primate lineages, including both anthropoids (monkeys, apes and humans) and crown strepsirhine primates (lemurs, lorises and galagos). Competing hypotheses favouring either an African or Asian origin for anthropoids rank among the most hotly contested issues in paleoprimatology. The Afrocentric model for anthropoid origins rests heavily on the >45 Myr old fossil Algeripithecus minutus from Algeria, which is widely acknowledged to be one of the oldest known anthropoids. However, the phylogenetic position of Algeripithecus with respect to other primates has been tenuous because of the highly fragmentary fossils that have documented this primate until now. Recently recovered and more nearly complete fossils of Algeripithecus and contemporaneous relatives reveal that they are not anthropoids. New data support the idea that Algeripithecus and its sister genus Azibius are the earliest offshoots of an Afro–Arabian strepsirhine clade that embraces extant toothcombed primates and their fossil relatives. Azibius exhibits anatomical evidence for nocturnality. Algeripithecus has a long, thin and forwardly inclined lower canine alveolus, a feature that is entirely compatible with the long and procumbent lower canine included in the toothcomb of crown strepsirhines. These results strengthen an ancient African origin for crown strepsirhines and, in turn, strongly challenge the role of Africa as the ancestral homeland for anthropoids. 相似文献
964.
Maria A.F. Vera-DiVaio Antônio C.C. Freitas Helena C. Castro Sérgio de Albuquerque Lucio M. Cabral Carlos R. Rodrigues Magaly G. Albuquerque Rita C.A. Martins Maria G.M.O. Henriques Luiza R.S. Dias 《Bioorganic & medicinal chemistry》2009,17(1):295-302
Chagas disease (American trypanosomiasis) is one of the most important parasitic diseases with serious social and economic impacts mainly on Latin America. This work reports the synthesis, in vitro trypanocidal evaluation, cytotoxicity assays, and molecular modeling and SAR/QSAR studies of a new series of N-phenylpyrazole benzylidene-carbohydrazides. The results pointed 6k (X = H, Y = p-NO2, pIC50 = 4.55 M) and 6l (X = F, Y = p-CN, pIC50 = 4.27 M) as the most potent derivatives compared to crystal violet (pIC50 = 3.77 M). The halogen-benzylidene-carbohydrazide presented the lowest potency whereas 6l showed the most promising profile with low toxicity (0% of cell death). The best equation from the 4D-QSAR analysis (Model 1) was able to explain 85% of the activity variability. The QSAR graphical representation revealed that bulky X-substituents decreased the potency whereas hydrophobic and hydrogen bond acceptor Y-substituents increased it. 相似文献
965.
Vinícius R. Campos Paula A. Abreu Helena C. Castro Carlos R. Rodrigues Alessandro K. Jordo Vitor F. Ferreira Maria C.B.V. de Souza Fernanda da C. Santos Laura A. Moura Thaisa S. Domingos Carla Carvalho Eldio F. Sanchez Andr L. Fuly Anna C. Cunha 《Bioorganic & medicinal chemistry》2009,17(21):7429-7434
The current treatment used against envenomation by Lachesis muta venom still presents several side effects. This paper describes the synthesis, pharmacological and theoretical evaluations of new 1-arylsulfonylamino-5-methyl-1H-[1,2,3]-triazole-4-carboxylic acid ethyl esters (8a–f) tested against the hemolytic profile of the L. muta snake venom. Their structures were elucidated by one- and two-dimensional NMR techniques (1H, APT, HETCOR 1JCH and nJCH, n = 2, 3) and high-resolution electrospray ionization mass spectrometry. The series of triazole derivatives significantly neutralized the hemolysis induced by L. muta crude venom presenting a dose-dependent inhibitory profile (IC50 = 30−83 μM) with 1-(4′-chlorophenylsulfonylamino)-5-methyl-1H-[1,2,3]-triazole-4-carboxylic acid ethyl ester (8e) being the most potent compound. The theoretical evaluation revealed the correlation of the antiophidian profile with the coefficient distribution and density map of the Highest Occupied Molecular Orbitals (HOMO) of these molecules. The elucidation of this new series may help on designing new and more efficient antiophidian molecules. 相似文献
966.
Ana Carolina C. Asbahr Luzia Franco Andersson Barison Caroline W.P. Silva Humberto G. Ferraz Letícia N.C. Rodrigues 《Bioorganic & medicinal chemistry》2009,17(7):2718-2723
The aim of this study was to determine whether inclusion complexes between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and finasteride (FIN) are formed, and to characterize these. Equimolar FIN/HPβCD solid systems in the presence or absence of 0.1% (w/v) of polyvinylpyrrolidone K30 (PVP K30) or 0.3% of chitosan were prepared by coevaporation and freeze-drying methods. The systems were characterized by phase solubility, NMR, DSC, and XRD analysis. The results suggest that true binary and ternary inclusion complexes were formed. 相似文献
967.
Sandra S. Rodrigues José A. Fernandes Maria M. Marques 《Inorganica chimica acta》2009,362(4):1275-1281
[M(P3C2tBu2)(CO)3I] (M = Mo, 1, W, 2) have been synthesised and reacted with PCl5 for oxidation study purposes. Compounds Ti(P3C2tBu2)(Ind)Cl2], 3, and [Zr(P3C2tBu2)(Cp)Cl2], 4, were detected spectroscopically, but showed to be too unstable to be isolated. A Ti(IV) complex, [Ti(P3C2tBu2)Cl3], 5, has been formed from the reaction of [TiCl4] with the base-free ligand K(P3C2tBu2), while the Ti(III) species, [Ti(P3C2tBu2) Cl2(THF)], 6, was prepared from [TiCl3(THF)3]. Compounds 5 and 6 were studied as ethylene catalyst precursors after activation with MAO. In the studied conditions, complex 5 is the most active one with an activity of 2.2 × 105 g(molTi [E] h)−1, one order of magnitude higher than compound 6. The produced polymer is linear polyethylene. 相似文献
968.
969.
Susana Frases Bruno Pontes Marcio L. Rodrigues Arturo Casadevall 《Biophysical journal》2009,97(4):937-945
Microbial capsules are important for virulence, but their architecture and physical properties are poorly understood. The human pathogenic fungus Cryptococcus neoformans has a large polysaccharide capsule that is necessary for virulence and is the target of protective antibody responses. To study the C. neoformans capsule we developed what we believe is a new approach whereby we probed the capsular elastic properties by applying forces using polystyrene beads manipulated with optical tweezers. This method allowed us to determine the Young's modulus for the capsule in various conditions that affect capsule growth. The results indicate that the Young's modulus of the capsule decreases with its size and increases with the Ca2+ concentration in solution. Also, capsular polysaccharide manifests an unexpected affinity for polystyrene beads, a property that may function in attachment to host cells and environmental structures. Bead probing with optical tweezers provides a new, nondestructive method that may have wide applicability for studying the effects of growth conditions, immune components, and drugs on capsular properties. 相似文献