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1.
R Soc Open Sci ; 10(6): 221601, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37293361

RESUMO

Research on pedestrian dynamics has generally dealt with temporary gatherings of people who do not know each other personally. These gatherings are often framed as highly individualized encounters in which social interactions play no or only a marginal role. However, recent research based on self-categorization theory showed the relevance of salient social identity for crowd dynamics. Drawing on the interactionist approach of social identity theory and the work of Erving Goffman and Alfred Schütz, this paper aims to show that anonymous encounters are carefully concerted social phenomena. The authors present the results of an exploratory social psychological experiment (N = 83), in which groups of participants were asked to wait for 5 min in a designated area with different communicative conditions and then to walk to a narrow exit. Based on the assumption that communication and conformity to expectations influences the behaviour of those present, we introduced four modifications during the waiting time and analysed questionnaire data and video recordings in a mixed-methods design. The results show that direct communication correlates with higher speed, cell phone use with greater distance to the nearest neighbour, and unexpected behaviour with slower movement.

2.
J Inorg Biochem ; 217: 111382, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33588278

RESUMO

Hypoxia activated Co(III) complexes as prodrugs may provide with a selective delivery of cytotoxic or antibacterial compounds. Whithin this field sixteen novel Co(III) ternary complexes with the general formula [Co(4N)(flav)](ClO4)2, where 4N = tris(2-aminoethyl)amine (tren) or tris(2-pyridylmethyl)amine (tpa) and flav = deprotonated form of differently substituted flavonols have been synthesized, characterized, and their cytotoxicity assayed under both normoxic and hypoxic conditions. Molecular structures of two free flavonols and seven complexes are also reported. In all the complexes the bioligands exhibited the expected (O,O) coordination mode and the complexes showed a slightly distorted octahedral geometry. Cyclic voltammetric studies revealed that both the substituents of the flavonoles and the type of 4N donor ligands had an impact on the reduction potential of the complex. The ones containing tren demonstrated significantly higher stability than the tpa analogues, making these former compounds promising candidates for the development of hypoxia-activated prodrug complexes. Tpa complexes showed higher activity against both selected human cancer cell lines (A549, A431) than their free ligand flavonols, indicating that the anticancer activity of the bioligand can be enhanced upon complexation. However, slight hypoxia-selectivity was found only for a tren complex (11) with moderate cytotoxicity.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Flavonoides/farmacologia , Antineoplásicos/síntese química , Hipóxia Celular/fisiologia , Linhagem Celular Tumoral , Cobalto/química , Complexos de Coordenação/síntese química , Flavonoides/síntese química , Humanos , Ligantes , Estrutura Molecular , Oxirredução , Estereoisomerismo
3.
Biomed Res Int ; 2020: 3798537, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32047810

RESUMO

BACKGROUND: Comparison of single-level open and minimally invasive transforaminal lumbar interbody fusions (O-TLIF and MI-TLIF) of a single surgeon and presentation of his MI-TLIF learning curve in a retrospective observational cohort study. METHODS: 27 MI-TLIF and 31 O-TLIF patients, performed between 03/01/2013 and 03/31/2018, were compared regarding the operative time, blood loss, blood transfusion frequency, postoperative length of stay (LOS), and adverse events. An overall comparison of pre- and postoperative Oswestry Disability Index (ODI) results and Visual Analog Score (VAS) results of low back and leg pain was performed in the case of the two techniques. For a learning curve presentation, the MI-TLIF cases were compared and the optimal operative time was determined. RESULTS: The gender ratio and age did not differ in the groups. Operative time showed no difference (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (p=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (. CONCLUSIONS: Similar operative time and postoperative quality of life improvement can be achieved by MI-TLIF procedure as with O-TLIF, and additionally LOS and blood loss can be reduced. When comparing parameters, MI-TLIF can be an alternative option for O-TLIF with a similar complication profile. The learning curve of MI-TLIF can be steep, although it depends on the circumstances.


Assuntos
Degeneração do Disco Intervertebral/cirurgia , Curva de Aprendizado , Vértebras Lombares/cirurgia , Região Lombossacral/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Duração da Cirurgia , Adulto , Perda Sanguínea Cirúrgica , Feminino , Humanos , Degeneração do Disco Intervertebral/patologia , Tempo de Internação , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Qualidade de Vida , Estudos Retrospectivos
4.
Redox Biol ; 16: 314-321, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29573705

RESUMO

Collagen IV is a major component of the basement membrane in epithelial tissues. The NC1 domains of collagen IV protomers are covalently linked together through sulfilimine bonds, the formation of which is catalyzed by peroxidasin. Although hydrogen peroxide is essential for this reaction, the exact source of the oxidant remains elusive. Members of the NOX/DUOX NADPH oxidase family are specifically devoted to the production of superoxide and hydrogen peroxide. Our aim in this study was to find out if NADPH oxidases contribute in vivo to the formation of collagen IV sulfilimine crosslinks. We used multiple genetically modified in vivo model systems to provide a detailed assessment of this question. Our data indicate that in various peroxidasin-expressing tissues sulfilimine crosslinks between the NC1 domains of collagen IV can be readily detected in the absence of functioning NADPH oxidases. We also analyzed how subatmospheric oxygen levels influence the collagen IV network in collagen-producing cultured cells with rapid matrix turnover. We showed that collagen IV crosslinks remain intact even under strongly hypoxic conditions. Our hypothesis is that during collagen IV network formation PXDN cooperates with a NOX/DUOX-independent H2O2 source that is functional also at very low ambient oxygen levels.


Assuntos
Colágeno Tipo IV/metabolismo , Células Epiteliais/metabolismo , Proteínas da Matriz Extracelular/metabolismo , NADPH Oxidases/metabolismo , Peroxidase/metabolismo , Membrana Basal/metabolismo , Catálise , Linhagem Celular , Oxidases Duais/metabolismo , Matriz Extracelular , Humanos , Peróxido de Hidrogênio/metabolismo , Oxigênio/metabolismo , Superóxidos/metabolismo , Peroxidasina
5.
J Org Chem ; 82(9): 4578-4587, 2017 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-28441016

RESUMO

The article describes the development of Buchwald-Hartwig amination of different bromoflavones with amino acid and peptide derivatives as nitrogen source giving unique structures. The previously observed racemization, which occurred during the synthesis of flavone-amino acid hybrids, was successfully prevented in most cases. The biological assays of these novel structures showed cytotoxic effects on different cancer cell lines.


Assuntos
Aminoácidos/química , Dipeptídeos/química , Flavonas/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Cinética , Testes de Sensibilidade Microbiana , Análise Espectral/métodos
6.
Pharmaceutics ; 5(2): 318-28, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24058724

RESUMO

Efforts to take advantage of the beneficial activities of thyrotropin-releasing hormone (TRH) in the brain are hampered by its poor metabolic stability and lack of adequate central nervous system bioavailability. We report here novel and metabolically stable analogs that we derived from TRH by replacing its amino-terminal pyroglutamyl (pGlu) residue with pyridinium-containing moieties. Exploratory studies have shown that the resultant compounds were successfully delivered into the mouse brain after systemic administration via their bioprecursor prodrugs, where they manifested neuropharmacological responses characteristic of the endogenous parent peptide. On the other hand, the loss of potency compared to TRH in a model testing antidepressant-like effect with a simultaneous preservation of analeptic activity has been observed, when pGlu was replaced with trigonelloyl residue. This finding may indicate an opportunity for designing TRH analogs with potential selectivity towards cholinergic effects.

7.
Mol Divers ; 16(1): 91-102, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22307767

RESUMO

Copper(I)-catalyzed alkyne-azide 1,3-cycloaddition reaction (CuAAC, Sharpless-Meldal reaction) of various α-azido ketones such as substituted 2-azidoacetophenones, 2-azidobenzosuberone and 3-azido(thio)chromanones with terminal alkynes was studied. The reaction resulted in the formation of the expected 1,2,3-triazoles in moderate to good yields although the reactivity was somewhat lower than in the case of simple azides. Reaction of ethynylchromones as alkynes gave interesting dichromonoid systems bridged by a triazole unit.


Assuntos
Alcinos/síntese química , Azidas/síntese química , Benzeno/química , Cromonas/química , Química Click/métodos , Cetonas/síntese química , Triazóis/síntese química , Alcinos/química , Azidas/química , Ciclização , Cetonas/química , Triazóis/química
8.
Chem Soc Rev ; 40(5): 2797-847, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21331407

RESUMO

Organic azides are known and utilized in the synthetic organic chemistry as amine precursors, potential sources of nitrenes, dipoles useful in 1,3-dipolar cycloadditions and starting materials of phosphoranes for a long time, and their literature has been overviewed by several authors. On the other hand, there are some special subclasses within the azides which possess peculiar and interesting properties differing from those of the majority and offering extra synthetic possibilities. In this critical review we wish to give an exhaustive overview on the synthesis and synthetic potential of α-azido ketones and related systems, an underestimated group of compounds. The enhanced acidity of the α-hydrogen offers various new synthetic applications including the creation of a new C-C bond, while the joint presence of the carbonyl and vinyl functions of α-azido-α,ß-unsaturated ketones results in a special reactivity, too. Chemo- and stereoselectivity issues also represent important points which are discussed in detail. Finally, the usefulness of the titled derivatives in the synthesis of various heterocycles is reviewed (273 references).

9.
J Chromatogr Sci ; 42(9): 478-83, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15693188

RESUMO

Effective enantiomeric separations of erythro- and threo-8.O.4'-neolignans with different aromatic substitution pattern (1a-i, 2a-i) are achieved on the commercially available chiral stationary phase cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD). It is shown that the chiral recognition of the stationary phase is significantly dependent on the substitution pattern of the racemic compounds. Online liquid chromatography (LC)-circular dichroism (CD) analysis allows for the establishment of a correlation between the absolute configuration of the separated erythro-8.O.4'-neolignans and their characteristic CD transitions, which could be used to determine or revise the configuration of previously isolated erythro-8.O.4'-neolignans. Although the absolute configurations of threo-isomers is not determined unambiguously from the LC-CD analysis, it is proven that both their elution order and chiroptical properties are significantly influenced by the substitution pattern of the aromatic rings.


Assuntos
Dicroísmo Circular/métodos , Lignanas/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Lignanas/química , Estereoisomerismo
10.
J Antibiot (Tokyo) ; 56(3): 296-305, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12760686

RESUMO

The structure of the antifungal metabolite coniothyriomycin was systematically modified by changing the acids of the open chain imide, modification of the hydrophobicity, variation in the degree of saturation, replacement of carbons by nitrogen or oxygen, and incorporation of the open chain molecule into cyclic arrangements. Structure-activity studies showed that antifungal activity was retained by replacement of phenylacetic acids by benzoic acids in the imide structure but diminished by hydrogenation of the fumaric ester part.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Imidas/química , Imidas/farmacologia , Antifúngicos/síntese química , Imidas/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Relação Estrutura-Atividade
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