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1.
Nanomaterials (Basel) ; 11(11)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34835630

RESUMO

A superhydrophobic macroporous material composed of hollow hemispherical MXene (HSMX) was synthesized by the thermal annealing of MXene-wrapped cationic polystyrene spheres (CPS@MXene). Notably, the spherical MXene shells exhibited highly efficient catalysis of the carbonization of CPS into carbon nanoparticles. Their insertion into the interlayer of MXene increased the d-spacing and created hollow hemispheres. The as-prepared HSMX with nanoscale walls had a lower packing density than MXene, but higher porosity, total pore volume, and total pore area. Moreover, the stacking of hollow hemispheres promoted the formation of a highly undulating macroporous surface and significantly improved the surface roughness of the HSMX-based 3D membrane, resulting in superhydrophobicity with a water contact angle of 156.4° and a rolling angle of 6°. As a result, the membrane exhibited good separation efficiency and Flux for emulsifier-stabilized water-in-paraffin liquid emulsions, which was dependent on its superhydrophobic performance and strong demulsification ability derived from the razor effect originating from the ultrathin walls of HSMX. This work provides a facile approach for the transformation of highly hydrophilic 2D MXene into superhydrophobic 3D HSMX, and opens a new pathway for the development of advanced MXene-based materials for environmental remediation applications.

2.
J Am Chem Soc ; 140(36): 11387-11394, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30096226

RESUMO

Helical structures are ubiquitous in biological materials and often serve a structural purpose. Bioinspired helical materials can be challenging to synthesize and rarely reach the degree of hierarchy of their natural counterparts. Here we report the first example of particles synthesized by direct emulsification of polypeptides found to display spiral morphologies in the dry state. The polypeptides were α-helical homo- and copolypeptides of γ-benzyl glutamate and allylglycine. The chirality of the spirals was controlled by the chirality of the α-helices. Notably, right-handed α-helical polypeptides (rich in l residues) produced clockwise spirals, whereas left-handed α-helical polypeptides (rich in d residues) produced the enantiomorphs, i.e., counterclockwise spirals. The disruption of the α-helical conformation by the introduction of chiral defects led to less regular spirals and in some cases their suppression. A hypothesis for the transmission of helicity and chirality from a molecular to a higher hierarchical level, involving fibril bundling of coiled α-helices, is proposed.


Assuntos
Peptídeos/síntese química , Tamanho da Partícula , Peptídeos/química , Conformação Proteica em alfa-Hélice , Estereoisomerismo , Propriedades de Superfície
3.
Dis Markers ; 2017: 9506527, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28630527

RESUMO

PURPOSE: The study was designed to evaluate the disease outcome based on multiple biomarkers related to cerebral ischemia. METHODS: Rats were randomly divided into sham, permanent middle cerebral artery occlusion, and edaravone-treated groups. Cerebral ischemia was induced by permanent middle cerebral artery occlusion surgery in rats. To form a simplified crosstalk network, the related multiple biomarkers were chosen as S100ß, HIF-1α, IL-1ß, PGI2, TXA2, and GSH-Px. The levels or activities of these biomarkers in plasma were detected before and after ischemia. Concurrently, neurological deficit scores and cerebral infarct volumes were assessed. Based on a mathematic model, network balance maps and three integral disruption parameters (k, φ, and u) of the simplified crosstalk network were achieved. RESULTS: The levels or activities of the related biomarkers and neurological deficit scores were significantly impacted by cerebral ischemia. The balance maps intuitively displayed the network disruption, and the integral disruption parameters quantitatively depicted the disruption state of the simplified network after cerebral ischemia. The integral disruption parameter u values correlated significantly with neurological deficit scores and infarct volumes. CONCLUSION: Our results indicate that the approach based on crosstalk network may provide a new promising way to integrally evaluate the outcome of cerebral ischemia.


Assuntos
Isquemia Encefálica/sangue , Modelos Teóricos , Animais , Biomarcadores/sangue , Isquemia Encefálica/patologia , Epoprostenol/sangue , Glutationa Peroxidase/sangue , Subunidade alfa do Fator 1 Induzível por Hipóxia/sangue , Interleucina-1beta/sangue , Masculino , Ratos , Ratos Sprague-Dawley , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Tromboxano A2/sangue
4.
Acta Pharmacol Sin ; 38(3): 362-370, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28042873

RESUMO

Cardiovascular complications represent a leading cause of mortality in patients with type 2 diabetes mellitus (T2DM). During such complicated progression, subtle variations in the cardiovascular risk (CVR)-related biomarkers have been used to identify cardiovascular disease at the incipient stage. In this study we attempt to integrally characterize the progression of cardiovascular complications and to assess the beneficial effects of metformin combined with salvianolic acid A (Sal A), in Goto-Kakizaki (GK) rats with spontaneous T2DM. The rats were treated with metformin (200 mg·kg-1·d-1, ig) alone or in combination with Sal A (1 mg·kg-1·d-1, ip) at ages from 8 to 22 weeks. During the treatment, the levels of asymmetric dimethylarginine, L-arginine, superoxide dismutase, malondialdehyde, glucose, high density lipoprotein and low density lipoprotein were assessed. Based on alterations in these biomarkers, a mini-network balance model was established using matrixes and vectors. Radar charts were created to visually depict the disruption of CVR-related modules (endothelial function, oxidative stress, glycation and lipid profiles). The description for the progression of cardiovascular disorder was quantitatively represented by u, the dynamic parameter of the model. The modeling results suggested that untreated GK rats tended to have more severe cardiovascular complications than the treatment groups. Metformin monotherapy retarded disease deterioration, whereas the combination treatment ameliorated the disease progression via restoring the balance. The current study, which focused on the balance of the mini-network and interactions among CVR-related modules, proposes a novel method for evaluating the progression of cardiovascular complications in T2DM as well as a more beneficial intervention strategy.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Complicações do Diabetes/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Modelos Biológicos , Alcenos/uso terapêutico , Animais , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Progressão da Doença , Quimioterapia Combinada , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Polifenóis/uso terapêutico , Ratos Wistar
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