Influence of the hip joint modeling approaches on the kinematics of human gait

The influence of the hip joint formulation on the kinematic response of the model of human gait is investigated throughout this work. To accomplish this goal, the fundamental issues of the modeling process of a planar hip joint under the framework of multibody systems are revisited. In particular, the formulations for the ideal, dry, and lubricated revolute joints are described and utilized for the interaction of femur head inside acetabulum or the hip bone. In this process, the main kinematic and dynamic aspects of hip joints are analyzed. In a simple manner, the forces that are generated during human gait, for both dry and lubricated hip joint models, are computed in terms of the system’s state variables and subsequently introduced into the dynamics equations of motion of the multibody system as external generalized forces. Moreover, a human multibody model is considered, which incorporates the different approaches for the hip articulation, namely ideal joint, dry, and lubricated models. Finally, several computational simulations based on different approaches are performed, and the main results presented and compared to identify differences among the methodologies and procedures adopted in this work. The input conditions to the models correspond to the experimental data capture from an adult male during normal gait. In general, the obtained results in terms of positions do not differ significantly when the different hip joint models are considered. In sharp contrast, the velocity and acceleration plotted vary significantly. The effect of the hip joint modeling approach is clearly measurable and visible in terms of peaks and oscillations of the velocities and accelerations. In general, with the dry hip model, intra-joint force peaks can be observed, which can be associated with the multiple impacts between the femur head and the cup. In turn, when the lubricant is present, the system’s response tends to be smoother due to the damping effects of the synovial fluid.The first and third authors express their gratitude to the Portuguese Foundation for Science and Technology for the PhD grants SFRH/BD/76573/2011 and SFRH/BD/64477/2009, respectively. The authors would like to thank to the Portuguese Foundation for Science and Technology through the project UID/EEA/04436/2013. The authors are also gratefully acknowledge the financial support from QREN (Quadro de Referência Estratégico Nacional - National Strategic Reference Framework), for this study “INOVSHOES - Padronizar para Customizar Calçado Ortopédico”, project n.º 2010/12032

Fluorescence studies on new potential antitumoral 1,3-diarylurea derivatives in the thieno[3,2-b]pyridine series encapsulated in magnetoliposomes

Magnetic nanoparticles of magnetite and of nickel core with silica shell were prepared and either covered with a lipid bilayer or entrapped in liposomes, forming magnetoliposomes. New potential antitumoral 1,3-diarylurea derivatives of thieno[3,2-b]pyridines were then encapsulated in liposomes and magnetoliposomes and their photophysical behavior was investigated.Fundação para a Ciência e a Tecnologia (FCT), FEDER, COMPETE/QREN/EU for financial support to CFUM (PEst-C/FIS/UI0607/2011) and CQ/UM (PEst-C/QUI/UI0686/2011) and to research projects PTDC/QUI/81238/2006 (FCOMP-01-0124-FEDER-007467), PTDC/QUIQUI/111060/2009 (FCOMP-01-0124-FEDER-015603)

New 1,3-diarylureas linked by C-C Suzuki coupling to the methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate moiety: synthesis and fluorescence studies in solution and in lipid membranes

New six fluorescent 1,3-diarylureas linked by C-C Suzuki coupling to the 6-position of the methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate moiety were prepared by reaction of the amino groups on the ortho or meta positions relative to the C-C bond of the Suzuki coupling products, with different para-substituted arylisocyanates (H, OMe, CN), in high to excellent yields. The fluorescence properties of the 1,3-diarylureas in solution and in lipid membranes of egg-yolk phosphatidylcholine (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylglycerol (DPPG) or dioctadecyldimethylammonium bromide (DODAB), with or without cholesterol (Ch), were studied. The six 1,3-diarylureas have reasonable fluorescence quantum yields in several solvents (between 0.02 and 0.69) and present a moderately solvent sensitive emission, but are not fluorescent in alcohols and water. The compounds bearing the arylurea moiety in the meta position relative to the C-C bond, especially with the OMe and CN substituents, present the better solvatochromic properties. Incorporation of the six compounds in lipid membranes indicates that all the compounds are deeply located in the hydrophobic region of the lipid bilayers, feeling the transition between the rigid gel phase and fluid phases.To the Foundation for the Science and Technology (FCT, Portugal) for inancial support to the NMR portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho). To the FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Research Centres, CQ/UM [PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)] and CFUM [PEst-C/FIS/UI0607/2011 (F-COMP-01-0124-FEDER-022711)], and to the research projects PTDC/QUI/81238/2006 (FCOMP-01-0124-FEDER-007467) (photophysical studies) and PTDC/QUI-QUI/111060/2009 (F-COMP-01-0124-FEDER-015603) (organic synthesis)

New potential antitumoral di(hetero)arylether derivatives in the thieno[3,2-b]pyridine series : synthesis and fluorescence studies in solution and in nanoliposomes

New fluorescent methoxylated di(hetero)arylethers in the thieno[3,2-b]pyridine series were prepared by a copper-catalyzed Ullmann-type C-O coupling of the methyl 3-amino-6-bromothieno[3,2-b]pyridine-2-carboxylate with ortho, meta and para-methoxyphenols, using N,N-dimethylglycine as the ligand and Cs2CO3 as the base. The compounds obtained were tested for their inhibitory growth activity in three human tumor cell lines MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), NCI-H460 (non-small cell lung cancer). The di(hetero)arylethers bearing a methoxy group in the ortho and meta positions showed very low GI50 values (1.1 - 2.5 µM) in all the three tumor cell lines. Their fluorescence properties in solution and when encapsulated in different nanoliposome formulations, composed either by egg-yolk phosphatidylcholine (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dimyristoyl phosphatidylglycerol (DMPG), dioctadecyldimethylammonium bromide (DODAB), distearoyl phosphatidylcholine (DSPC), with or without cholesterol (Ch), or distearoyl phosphatidylethanolamine-(polyethylene glycol)2000 (DSPE-PEG), were studied. All compounds can be carried in the hydrophobic region of the liposome membrane. The liposomes with incorporated compounds are nanometric in size (diameter lower than 150 nm) and have generally low polydispersity.Fundação para a Ciência e a Tecnologia (FCT) - Bruker Avance III 400-Univ. Minho).Fundo Europeu de Desenvolvimento Regional (FEDER)Research Centres, CQ/UM - PEstC/QUI/UI0686/2011, FCOMP-01-0124-FEDER-022716)] and CFUM [PEst-C/FIS/UI0607/2011, F-COMP-01-0124-FEDER-022711)], PTDC/QUI/81238/2006, (FCOMP-01-0124-FEDER-007467) (photophysical studies), PTDC/QUI-QUI/111060/2009 (F-COMP-01-0124-FEDER-015603) (organic synthesis and biological studies)COMPETE/QREN/EU

Identification of Eschweilenol C in derivative of Terminalia fagifolia Mart. and green synthesis of bioactive and biocompatible silver nanoparticles

A green synthetic route was developed to prepare silver nanoparticles (AgNPs) in aqueous solution for biological applications. Eschweilenol C, a compound derivative ellagic acid was identified as the main constituent of the aqueous fraction of the ethanolic extract of Terminalia fagifolia Mart. by NMR analysis. In the green synthesis, the ethanolic extract of T. fagifolia and its aqueous fraction were used to promote silver reduction and nanoparticle stabilization. The synthesized AgNPs presented a spherical or polygonal morphology shape by TEM analysis and AgNPs showed high levels of antioxidant and considerable antibacterial and antifungal activities. Synthesized nanoparticles presented significant antioxidant activity by sequestration of DPPH and ABTS radicals, in addition to iron reduction (FRAP assay) and measurement of antioxidant capacity in ORAC units, in addition, AgNP synthesized with the aqueous fraction also demonstrated antioxidant potential in microglial cells. Gram-positive and Gram-negative bacteria were susceptible to growth inhibition by the nanoparticles, among which the AgNPs formed by the ethanolic extract was the most effective. The data obtained by AFM images suggested that AgNPs could lead to the lysis of bacteria and subsequent death. The antifungal assays showed high efficiency against yeasts and dermatophytes. This work represents the first description of antifungal activity by AgNPs against Fonsecaea pedrosoi, the etiologic agent of chromoblastomycosis. In relation to biocompatibility, the AgNPs induced lower haemolysis than AgNO3.We thank Herbert Kogler and Reinhard Wimmer for the identification of Eschweilenol C. The NMR laboratory at Aalborg University is supported by the Obel Family, SparNord and Carlsberg foundations.The authors are grateful to Carla Eiras (LIMAV/CT/UFPI) and to FCT and EU for financial support through project UID/QUI/50006/2013– POCI-01-0145-FEDER-007265 from COMPETE and projectNORTE-01-0145-FEDER-000011 from COMPETE. Thanks to Andreia Pinto for help with the TEM measurements at Instituto de Medicina Molecular (IMM). This work was supported by the Histology and Comparative Pathology Laboratory of the IMMinfo:eu-repo/semantics/publishedVersio