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1.
Semin Cell Dev Biol ; 69: 131-139, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28478299

RESUMO

The cluster of almost 60 protocadherin genes, divided into the α, ß and γ subgroups, is a hallmark of vertebrate nervous system evolution. These clustered protocadherins (Pcdhs) are of interest for several reasons, one being the arrangement of the genes, which allows epigenetic regulation at the cluster and single-cell identity. Another reason is the still ambiguous effect of Pcdhs on cell-cell interaction. Unlike the case for classical cadherins, which typically mediate strong cell adhesion and formation of adherens junctions, it has been challenging to ascertain exactly how Pcdhs affect interacting cells. In some instances, Pcdhs appear to promote the association of membranes, while in other cases the Pcdhs are anti-adhesive and cause avoidance of interacting membranes. It is clear that Pcdh extracellular domains bind homophillically in an antiparallel conformation, typical of adhesive interactions. How can molecules that would seemingly bind cells together be able to promote the avoidance of membranes? It is possible that Pcdh trafficking will eventually provide insights into the role of these molecules at the cell surface. We have found that endogenous and expressed Pcdhs are generally less efficient at targeting to cell junctions and synapses than are classical cadherins. Instead, Pcdhs are prominently sequestered in the endolysosome system or other intracellular compartments. What role this trafficking plays in the unique mode of cell-cell interaction is a current topic of investigation. It is tempting to speculate that modulation of endocytosis and endolysosomal trafficking may be a part of the mechanism by which Pcdhs convert from adhesive to avoidance molecules.


Assuntos
Caderinas/metabolismo , Sequência de Aminoácidos , Animais , Caderinas/química , Caderinas/genética , Membrana Celular/metabolismo , Endocitose , Humanos , Modelos Biológicos , Transporte Proteico , Sinapses/metabolismo
2.
Molecules ; 24(4)2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30813387

RESUMO

Six new hybrids based on ß-[Mo8O26]4- polyoxometalates, [Ni(H2biim)3]2[ß-Mo8O26]•8DMF(1); (DMA)2[M(H2biim)2(H2O)2][ß-Mo8O26]•4DMF (M = Ni (2), Co (3)), DMA = dimethyl-ammonium, H2biim=2,2'-biimidazole); [M(H2biim)(DMF)3]2[ß-Mo8O26]•2DMF (M = Zn (4), Cu (5)); [(DMA)2[Cu(DMF)4][ß-Mo8O26]•2DMF]n (6), have been successfully synthesized and characterized. Compounds 2⁻5 show favorable capacity to adsorb methylene blue (MB) at room temperature, and they can selectively capture MB molecules from binary-mixture solutions of MB/MO (MO = Methyl Orange), or MB/RhB (RhB = Rhodamine B). Compound 3 can uptake up to 521.7 mg g-1 MB cationic dyes rapidly, which perform the maximum adsorption in an hour among the reported materials as far as we know. The compounds are stable and still work very efficiently after three cycles. For compound 3, the preliminary adsorption mechanism studies indicated that the adsorption is an ion exchange process and the adsorption behavior of polyoxometalate-complex can be benefited from additional exchangeable protons in the complex cations.


Assuntos
Imidazóis/química , Compostos de Tungstênio/química , Poluentes Químicos da Água/química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno/química , Estrutura Molecular , Nanotecnologia , Rodaminas/química , Temperatura
3.
Chem Commun (Camb) ; 56(26): 3809-3812, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32129778

RESUMO

The as-synthesized (TBA)8H5[Nd(SiW11O39)2] manifested high catalytic activity for cyanosilylation of ketones, and its catalytic activity could be improved further through rational design of the reaction micro-environment beyond the molecular level, and the corresponding mechanism has been systematically studied.

4.
Chem Asian J ; 13(9): 1199-1205, 2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29484830

RESUMO

A pure inorganic 2D network molybdophosphate, [Mn3 Mo12 O24 (OH)6 (HPO3 )8 (H2 O)6 ]4- (1 a), synthesized through microwave irradiation with the existence of Mn2+ and organic cations and isolated as [(CH3 )2 NH2 ]3 Na[Mn3 Mo12 O24 (OH)6 (HPO3 )8 (H2 O)6 ]⋅12 H2 O (1), is found to possess highly enhanced performance in lithium-ion batteries' anode materials. The molecule shows multielectron redox properties suitable for producing anode materials with a specific capacity of 602 mA h g-1 at 100 mA g-1 after 50 cycles in lithium-ion batteries, although its specific capacity is the highest among all the reported pure inorganic 2D polyoxometalates to date, the cyclic stability is not that satisfactory. A hybrid nanocomposite of this 2D network and polypyrrole cations effectively reduces the capacity fading in initial cycles, and increases the stability and improves the electrochemical performance of lithium-ion batteries as well.

5.
Dalton Trans ; 45(8): 3268-71, 2016 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-26843033

RESUMO

The microwave-driven synthesis of a heteropoly blue cluster yields a redox active cluster, [(HPO3)6Mo21O60(H2O)4](8-), templated by six phosphite anions whereby two phosphites template a tri-lucunary {Mo15} Dawson structure, and one templates a {Mo6} ring with two of the three remaining phosphites acting as bridging ligands connecting the ring to the {Mo15}.

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