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1.
Nat Commun ; 12(1): 4993, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404798

RESUMO

Dissipative self-assembly, which requires a continuous supply of fuel to maintain the assembled states far from equilibrium, is the foundation of biological systems. Among a variety of fuels, light, the original fuel of natural dissipative self-assembly, is fundamentally important but remains a challenge to introduce into artificial dissipative self-assemblies. Here, we report an artificial dissipative self-assembly system that is constructed from light-induced amphiphiles. Such dissipative supramolecular assembly is easily performed using protonated sulfonato-merocyanine and chitosan based molecular and macromolecular components in water. Light irradiation induces the assembly of supramolecular nanoparticles, which spontaneously disassemble in the dark due to thermal back relaxation of the molecular switch. Owing to the presence of light-induced amphiphiles and the thermal dissociation mechanism, the lifetimes of these transient supramolecular nanoparticles are highly sensitive to temperature and light power and range from several minutes to hours. By incorporating various fluorophores into transient supramolecular nanoparticles, the processes of aggregation-induced emission and aggregation-caused quenching, along with periodic variations in fluorescent color over time, have been demonstrated. Transient supramolecular assemblies, which act as fluorescence modulators, can also function in human hepatocellular cancer cells.


Assuntos
Corantes Fluorescentes/química , Nanopartículas/química , Água/química , Fluorescência , Células Hep G2 , Humanos , Cinética , Substâncias Macromoleculares , Temperatura
2.
Soft Matter ; 16(2): 375-382, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31803877

RESUMO

The self-assembly of triphenylene (TP)-based side-chain discotic liquid crystalline polymers (SDLCPs) with different grafting densities was investigated by using the dissipative particle dynamics (DPD) method. We explored the coupling effect between the main chain and the side-chain TP discogens with various length alkyl tails, and how the rigidity of the main chain, grafting density and spacer lengths affect the self-assembled morphologies of SDLCPs. By changing the above factors, we have obtained nine phases. It is deduced that a moderate grafting density, a polymer backbone with sufficient length and alkyl tails with medium length ensure SDLCPs form ordered columnar mesophases. It is worth noting that double columnar phases (Colne-Col and Colh-Col) were obtained with high grafting densities and sufficiently long backbones. All these results provide an effective basis and helpful guidance for the in-depth research of such kinds of fascinating organic semiconducting materials, SDLCPs, from the perspective of grafting density.

3.
Chemistry ; 24(48): 12607-12612, 2018 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-29809287

RESUMO

In this paper we designed a kind of aggregation-induced emission (AIE) chiral fluorescence emitters (R/S-BINOL-CN enantiomers) in the aggregate state. Chiral emissive nematic liquid crystals (N*-LCs) prepared by doping this kind of AIE-active R/S-BINOL-CN enantiomers into a common achiral nematic liquid crystal (N-LC, E7) can self-assemble as the regularly planar Grandjean texture leading to high luminescence dissymmetry factor (glum ) of aggregation-induced circularly polarized luminescence (AI-CPL) signal up to 0.41, which can be attributed to dipolar interactions from polar cyano groups and π-π interactions between binaphthyl moiety of the dopant R/S-BINOL-CN and biphenyl group of the host molecules (E7).

4.
Adv Mater ; 28(48): 10684-10691, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27731536

RESUMO

A bioinspired photodetector with signal transmissible to neuron cells is fabricated. Photoisomerization of the dye molecules embedded in the ferroelectric polymer membrane achieves electric polarization change under visible light. The photodetector realizes high sensitivity, color recognition, transient response, and 3D visual detection with resolution of 25 000 PPI, and, impressively, directly transduces the signal to neuron cells.


Assuntos
Materiais Biomiméticos/química , Materiais Biomiméticos/efeitos da radiação , Neurônios/citologia , Neurônios/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Transdução de Sinais/efeitos da radiação , Animais , Cor , Corantes/química , Corantes/efeitos da radiação , Eletricidade , Isomerismo , Luz , Células PC12 , Ratos
5.
Chemistry ; 21(9): 3671-81, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25619819

RESUMO

A series of meta-substituted fatty acid octaester derivatives and their transition-metal complexes of meso- tetraphenyl porphyrins (TPP-8OOCR, with R = C(n-1)H(2n-1), n = 8, 12, or 16) have been prepared through very simple synthesis protocols. The thermotropic phase behavior and the liquid crystalline (LC) organization structures of the synthesized porphyrin derivatives were systematically investigated by a combination of differential scanning calorimetry (DSC), polarized optical microscopy (POM), and variable-temperature small-angle X-ray scattering/wide-angle X-ray scattering (SAXS/WAXS) techniques. The shorter octanoic acid ester substituted porphyrin (C8-TPP) did not show liquid crystallinity and its metal porphyrins exhibited an uncommon columnar mesophase. The lauric acid octaester (C12-TPP) and the palmitic acid octaester (C16-TPP) series porphyrins generated hexagonal columnar mesophase Colh. Moreover, the metal porphyrins C12-TPPM and C16-TPPM with M = Zn, Cu, or Ni, exhibited well-organized Colh mesophases of broad LC temperature ranges increasing in the order of TPPNi

Assuntos
Complexos de Coordenação/síntese química , Ácidos Graxos/química , Ácidos Láuricos/química , Metais/química , Ácido Palmítico/química , Porfirinas/química , Elementos de Transição/química , Complexos de Coordenação/química , Ésteres , Estrutura Molecular , Difração de Raios X
6.
Int J Clin Exp Pathol ; 8(10): 12300-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26722416

RESUMO

Between April 2010 and April 2014, 39 consective adult patients (> 18 years) with PDA associated severe pulmonary hypertension underwent transesophageal echocardiography guided patent ductus arteriosus occlusion through a parasternal minimally invasive approach. Among 39 patients, the procedure was successful in 32 cases (82.1%) and failed in 7 cases (17.9%). In the failed cases, 3 cases had a large residual shunt and 4 cases had persistent pulmonary hypertension. The mean minimum miameter of the successfully closed PDAs was 15.2 ± 2.1 mm (range 9 to 24), and the mean diameter of the mushroom-shaped occluder was 17.5 ± 2.5 mm (range 11 to 26). The pulmonary artery pressure decreased significantly after occlusion (P < 0.05), but there were no significant differences in the aortic pressure and blood oxygen saturation before and after occlusion (P > 0.05). Echocardiography performed on the first postoperative day showed decreased volume within the left atrium, left ventricle, and pulmonary artery in 23 cases, decreased volume within the left atrium and left ventricle in 4 cases, and no change in the volume of the atrium and ventricle in 3 cases. A minor residual shunt was observed in 6 cases. The posteroanterior chest X-ray showed improved pulmonary congestion in all cases and significantly reduced cardiothoracic ratio in 25 cases. Patients were followed-up at least for 1 year. No symptoms including palpitation, dyspnoea, or chest tightness were observed. The heart function ranged from NYHA class I to II. A minor residual shunt was observed only in one case. There were varying degrees of decrease in volume within the atrium and ventricle. In conclusion, transesophageal echocardiography guided patent ductus arteriosus occlusion through a parasternal minimally invasive approach is a feasible and effective method for the treatment of PDA in adults with severe pulmonary hypertension.


Assuntos
Permeabilidade do Canal Arterial/diagnóstico por imagem , Ecocardiografia Transesofagiana/métodos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/diagnóstico por imagem , Adolescente , Adulto , Idoso , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Próteses e Implantes , Artéria Pulmonar/patologia , Resultado do Tratamento , Adulto Jovem
7.
J Colloid Interface Sci ; 359(1): 56-67, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21507412

RESUMO

The preparation and application of overbased nanodetergents with excess alkaline calcium carbonate is a good example of nanotechnology in practice. The phase transformation of calcium carbonate is of extensive concern since CaCO(3) serves both as an important industrial filling material and as the most abundant biomineral in nature. Industrially valuable overbased nanodetergents have been prepared based on calcium salts of heavy alkylbenzene sulfonate by a one-step process under ambient pressure, the carbonation reaction has been monitored by the instantaneous temperature changes and total base number (TBN). A number of analytical techniques such as TGA, DLS, SLS, TEM, FTIR, and XRD have been utilized to explore the carbonation reaction process and phase transformation mechanism of calcium carbonate. An enhanced understanding on the phase transformation of calcium carbonate involved in calcium sulfonate nanodetergents has been achieved and it has been unambiguously demonstrated that amorphous calcium carbonate (ACC) transforms into the vaterite polymorph rather than calcite, which would be of crucial importance for the preparation and quality control of lubricant additives and greases. Our results also show that a certain amount of residual Ca(OH)(2) prevents the phase transformation from ACC to crystalline polymorphs. Moreover, a vaterite nanodetergent has been prepared for the first time with low viscosity, high base number, and uniform particle size, nevertheless a notable improvement on its thermal stability is required for potential applications.


Assuntos
Ácidos Alcanossulfônicos/química , Carbonato de Cálcio/química , Cálcio/química , Detergentes/síntese química , Nanoestruturas/química , Detergentes/química , Tamanho da Partícula , Transição de Fase , Propriedades de Superfície
8.
Chemistry ; 15(14): 3474-87, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19219863

RESUMO

A novel series of asymmetrically end-capped mesogenic oligothiophenes, with various oligothiophene core lengths, alkoxy tail lengths, and molecular polarities through introducing alkylsulfanyl or alkylsulfonyl functionalities as the terminal group, have been synthesized by palladium-catalyzed Suzuki cross-coupling and Kumada cross-coupling reactions as key steps. For the single end-capped oligothiophenes, C(m)O-Ar-OT(4)-H in which m=10, 12, 14, 16, and 18, all of these oligomers exhibited a broad temperature range of highly ordered smectic E and enantiotropic nematic phases, apart from the one with the longest octadecyloxy tail. For the double end-capped series C(10)O-Ar-OT(n)-R, R=Ph-SC(6) or Ph-SO(2)C(6) in which n=1, 2, 3, and 4, oligomers with more than one thiophene ring exhibited smectic A and smectic C phases, various crystal polymorphs and/or unusual low-temperature condensed phases. In the nonpolar, alkylsulfanylphenyl-substituted oligothiophene series, both the crystal/solid melting point and mesogenic clear point increased significantly with an increasing oligothiophene conjugation length. In the polar, alkylsulfonylphenyl-substituted oligothiophene series, all the oligomers showed increased melting points, but decreased mesogenic temperature intervals than those of their corresponding alkylsulfanyl counterparts. Remarkably, two different helical structures showing distinct striated textures or striped patterns were observed with a pitch of several to tens of micrometers under a polarized optical microscope upon cooling from their preceding fluidic smectic phases. The unusual twisted smectic layer structures in the thin solid films exhibiting distinct supramolecular chirality of both handednesses, revealed by circular dichroism measurements, were further confirmed by XRD analyses characterized by a sharp layer reflection together with its higher orders and diffuse wide-angle scatterings. In addition, initial studies showed that the highly ordered smectic phase of the single end-capped oligothiophenes can be utilized to improve field-effect charge mobility. C(10)O-Ar-OT(4)-H showed a hole mobility of 0.07 cm(2) V(-1) s(-1) when deposited on octyltrichlorosilane-treated substrates at 140 degrees C and the on/off current ratios reached 5 x 10(5); on the other hand, its mobility was only 8 x 10(-3) cm(2) V(-1) s(-1) on the same substrate when deposited at room temperature.

9.
Langmuir ; 21(2): 578-85, 2005 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-15641826

RESUMO

Aspirin and 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) are deposited from their alcoholic mixed solution onto highly oriented pyrolytic graphite (HOPG) by spin coating. The film structure and morphology are characterized by atomic force microscopy (AFM). The barely soluble DMPE forms a highly oriented stripe phase as a result of its one-dimensional epitaxy with the HOPG lattice. The bilayer stripe pattern exposes the cross section of the lipid bilayer lamellae and enables the direct visualization of the molecular interactions of drug or biological molecules with either the hydrophobic or the hydrophilic part of the phospholipid bilayer. The bilayer pattern affects the aspirin molecular deposition and aggregation. AFM shows that the aspirin molecules prefer to deposit and aggregate along the aliphatic interior part of the bilayer pattern, giving rise to parallel dimer rods in registry with the underlying pattern. The nonpolar interactions between aspirin and the phospholipid bilayer are consistent with the lipophilic nature of aspirin. The bilayer pattern not only stabilizes the rodlike aggregate structure of aspirin at low aspirin concentration but also inhibits crystallization of aspirin at high aspirin concentration. Molecular models show that the width of the DMPE aliphatic chain interior can accommodate no more than two aspirin dimers. The bilayer confinement may prevent aspirin from reaching its critical nucleus size. This study illustrates a general method to induce a metastable or amorphous form of an active pharmaceutical ingredient (API) by chemical confinement under high undercooling conditions. Metastable and amorphous solids often display better solubility and bioavailability than the stable crystalline form of the API.


Assuntos
Aspirina/química , Bicamadas Lipídicas/química , Fosfolipídeos/química , Metanol/química , Microscopia de Força Atômica , Fosfatidiletanolaminas/química , Propriedades de Superfície
10.
J Am Chem Soc ; 126(50): 16290-1, 2004 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-15600308

RESUMO

This communication describes a spin-coating method to nucleate organic molecular rods of uniform size from an inorganic nanoparticle at a solid surface. The particle-rod hybrid structure spontaneously forms when a film is spin coated from a mixed 2-propanol solution of arachidic acid (AA) and nanoparticles of cadmium selenide capped by mercaptoundecanoic acid (MUA-CdSe) on graphite. AFM images show that MUA-CdSe nanoparticles nucleate single crystalline rods of AA with a cross section of a single unit cell of the C-form. The solution-based process potentially allows the precise tuning of the wetting profile of the solution on the surface-attached nanoparticle, which provides the reservoir for the growth of the single crystalline rods. The results suggest that nanoparticles can be regarded as nanoseeds for the nucleation of guest crystals. It should be possible to further functionalize the AA rods by electrostatic complexation with metal or organic ions.


Assuntos
Compostos de Cádmio/química , Ácidos Eicosanoicos/química , Nanoestruturas/química , Compostos de Selênio/química , Grafite/química , Nanotecnologia/métodos , Eletricidade Estática
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