Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 18(12): e0295533, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38060552

RESUMO

The time and space of the support structure applying is related to the overall stability of the roadway after excavation directly. Designed twenty-four groups of roadway support schemes with time and space dimensions, and studied the stability characteristics of roadway in different schemes by using Fast Lagrangian Analysis of Continua in Three Dimensions. The main conclusions are as follows: the influence of energy dissipation (time) and support position (space) on the stability of the roadway is not a linear relationship, and supporting at the appropriate opportunity can be beneficial. Established the "displacement-dissipation energy" curve, founding that there is an obvious "jump" phenomenon in the dissipation energy of surrounding rock during the process of gradually increasing displacement. A novel method for determining the optimum supporting opportunity of roadway based on energy dissipation was proposed, based on the above finding. This study can provide an original idea for the determination of roadway supporting opportunity.

2.
Angew Chem Int Ed Engl ; 62(29): e202302723, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37178394

RESUMO

The emulation of functions and behaviors of biological synapses using electronic devices has inspired the development of artificial neural networks (ANNs) in biomedical interfaces. Despite the achievements, artificial synapses that can be selectively responsive to non-electroactive biomolecules and directly operate in biological environments are still lacking. Herein, we report an artificial synapse based on organic electrochemical transistors and investigate the selective modulation of its synaptic plasticity by glucose. The enzymatic reaction between glucose and glucose oxidase results in long-term modulation of the channel conductance, mimicking selective binding of biomolecules to their receptors and consequent long-term modulation of the synaptic weight. Moreover, the device shows enhanced synaptic behaviors in the blood serum at a higher glucose concentration, which suggests its potential application in vivo as artificial neurons. This work provides a step towards the fabrication of ANNs with synaptic plasticity selectively mediated by biomolecules for neuro-prosthetics and human-machine interfaces.


Assuntos
Sinapses , Transistores Eletrônicos , Humanos , Sinapses/química , Redes Neurais de Computação , Plasticidade Neuronal , Eletrólitos
3.
ACS Appl Mater Interfaces ; 8(1): 588-99, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26666712

RESUMO

Herein, nanocomposite membranes are fabricated based on functionalized graphene oxides (FGOs) and sulfonated poly(ether ether ketone) (SPEEK), followed by being impregnated with imidazole-type ionic liquid (IL). The functional groups (acidic group or basic group) on FGOs generate strong interfacial interactions with SPEEK chains and then adjust their motion and stacking. As a result, the nanocomposite membranes possess tunable interfacial domains as determined by its free volume characteristic, which provides regulated location for IL storage. The stored ILs act as hopping sites for water-free proton conduction along the FGO-constructed interfacial channels. The microstructure at SPEEK-FGO interface governs the IL uptake and distribution in nanocomposite membrane. Different from GO and vinyl imidazole functionalized GO (VGO), the presence of acidic (-SO3H) groups confers the p-styrenesulfonic acid functionalized GO (SGO) incorporated nanocomposite membrane loose interface and strong electrostatic attraction with imidazole-type IL, imparting an enhanced IL uptake and anhydrous proton conductivity. Nanocomposite membrane containing 7.5% SGO attains the maximum IL uptake of 73.7% and hence the anhydrous conductivity of 21.9 mS cm(-1) at 150 °C, more than 30 times that of SPEEK control membrane (0.69 mS cm(-1)). In addition, SGOs generate electrostatic attractions to the ILs confined within SGO-SPEEK interface, affording the nanocomposite membrane enhanced IL retention ability.

4.
J Hazard Mater ; 287: 373-83, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25677474

RESUMO

Silica spheres modified by poly (ionic liquid) brushes, a novel positively charged nanomaterial is prepared by atom transfer radical polymerization (ATRP). A high flux positively charged loose nanofiltration membrane is fabricated via "blending-phase inversion" method. The morphology structures, hydrophilicity, thermal and mechanical properties, permeation performance of these membranes are investigated in detail. The results reveal that the hybrid membranes have enhanced surface hydrophilicity, water permeability, thermal stability, and mechanical properties. Characterization of membrane separation properties shows that the hybrid membranes possess higher salt permeability and relatively higher rejection for reactive dyes, which may open opportunities for the recycling of reactive dyes wastewater. Moreover, such hybrid membranes have an outstanding operational stability and salts concentration showed little effect on the separation properties.


Assuntos
Líquidos Iônicos/química , Membranas Artificiais , Nanosferas/química , Polímeros/química , Dióxido de Silício/química , Corantes/química , Filtração , Interações Hidrofóbicas e Hidrofílicas , Troca Iônica , Permeabilidade , Sais/química , Propriedades de Superfície , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Água/química , Poluentes Químicos da Água/química
5.
Water Sci Technol ; 67(7): 1519-24, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23552240

RESUMO

In this study, a three-bore polyethersulfone (PES) hollow fiber ultrafiltration (UF) membrane with antibacterial properties was prepared by phase inversion, using PES as the membrane material, N,N-dimethylacetamide (DMAC) as solvent, polyvinylpyrrolidone (PVP) and AgNO3 as additives. The silver particles were detected by X-ray photoelectron spectroscopy. The effect of AgNO3 content on the antibacterial properties and separation performance was studied in detail. The membranes showed good antibacterial activity against Escherichia coli after adding AgNO3 and the antibacterial rate of PES/AgNO3 UF membrane with AgNO3 content of 1 wt% could reach 99.9% after running for 48 hours. Moreover, the bovine serum albumin solution filtration results indicated that the PES/AgNO3 membranes had a certain degree of antifouling performance. Therefore, three-bore PES/AgNO3 membranes have a potential application to reduce both bacterial and organic fouling in water treatment.


Assuntos
Incrustação Biológica/prevenção & controle , Membranas Artificiais , Polímeros/química , Nitrato de Prata/química , Sulfonas/química , Ultrafiltração , Antibacterianos/química , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica
6.
J Inorg Biochem ; 118: 59-64, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23123339

RESUMO

Halloysite nanotubes (HNTs), natural nanotube, have been developed as a support for loading of antibacterial agents. Firstly, HNTs were modified by silane coupling agent (KH-792). And then, modified HNTs were immersed in silver nitrate solution and a complex reaction between the two amino groups of KH-792 and silver ions formed, leading to large clusters on the surface of HNTs. Finally, these silver containing clusters were converted into silver nanoparticles (Ag NPs) with about 5nm diameter by reduction process. A new antibacterial agent, Ag NPs/HNTs, was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning transmission electron microscopy-energy dispersive X-ray analysis (STEM-EDX). The antibacterial test indicated that Ag NPs/HNTs showed good antibacterial performance against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus).


Assuntos
Silicatos de Alumínio/química , Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Compostos de Prata/farmacologia , Antibacterianos/síntese química , Argila , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Pós , Compostos de Prata/síntese química , Staphylococcus aureus/efeitos dos fármacos
7.
Water Sci Technol ; 66(4): 799-803, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22766869

RESUMO

In this study, a three-bore polyethersulfone (PES) hollow fiber ultrafiltration (UF) membrane with antibacterial properties was prepared by phase inversion, using PES as the membrane material, N,N-dimethylacetamide (DMAC) as solvent, polyvinylpyrrolidone (PVP) and CuCl(2) as additives. The effect of CuCl(2) content on the water flux and rejection was studied and the antibacterial properties of PES hollow fiber UF membrane were also investigated. The water flux results indicated that the hydrophilic properties of PES UF membranes were improved after adding CuCl(2). The rejection of PVA-50000 was expected to drop slightly but remain high above 96%. The membranes showed good antibacterial activity against Escherichia coli (E. coli) after adding CuCl(2) and the antibacterial rate of PES/CuCl(2) UF membranes was close to 100% after running for 48 h. PES hollow fiber UF membranes with antibacterial properties were prepared through the formation of the water-soluble PVP/Cu(2+) complex with spatial network structure, which have good antibacterial and hydrophilic properties. Therefore, this study could provide an effective method for membrane antifouling.


Assuntos
Membranas Artificiais , Polímeros , Sulfonas , Antibacterianos/farmacologia , Carga Bacteriana , Cobre/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Povidona , Ultrafiltração/instrumentação
8.
Water Sci Technol ; 65(1): 171-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22173422

RESUMO

Three-bore hollow fiber charged nanofiltration (NF) membrane was prepared by interfacial polymerization (IP). The results showed that the flux and rejection of NF membrane prepared in this study increased with the increasing in the operating pressure. The water flux decreased and rejection for obvious dyes increased as the solute concentration increased. The separation factor for mixture of Xylenol orange/NaCl decreased when NaCl concentration in solution increased and could reach to as high as 18. In addition, three-bore hollow fiber charged nanofiltration membrane prepared in this study has excellent stability for strong acid (pH = 3), strong alkali (pH = 11) and high temperature solution (80 °C).


Assuntos
Corantes/química , Filtração/instrumentação , Membranas Artificiais , Sais/química , Purificação da Água/instrumentação , Carbonatos/química , Concentração de Íons de Hidrogênio , Cloreto de Magnésio/química , Nanotecnologia/instrumentação , Fenilenodiaminas/química , Polímeros/química , Pressão , Cloreto de Sódio/química , Sulfatos/química , Sulfonas , Temperatura , Poluentes Químicos da Água/química
9.
J Colloid Interface Sci ; 354(1): 152-9, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21084093

RESUMO

Poly(4-vinylpyridine) (P4VP) brushes were grafted onto microporous polysulfone (PSF) membranes via surface-initiated atom transfer radical polymerization (SI-ATRP) and then immobilized copper (II) ions on the modified membrane. Copper-loaded membranes exhibited excellent antibacterial properties with the added advantage of repeated use. The chemical composition and surface morphology of the functionalized membrane was characterized by ATR-FTIR, XPS, SEM, and AFM. The results showed that P4VP brushes clustered to rod-shaped covering and the sub-layer of membrane maintained sponge-like structures at the same time. Additionally, the kinetic study of SI-ATRP reaction revealed that the chain length of P4VP brushes increased linearly as the polymerization time increased. The antibacterial effects of copper-loaded CMPSF-g-P4VP membrane against Escherichiacoli were examined and the antibacterial efficiency reached 100% when 2.49wt.% of copper (II) ions was immobilized on membrane. The presented results could serve as a good starting point for the fabrication of antibacterial CMPSF membranes for waste-water treatment applications.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Cobre/farmacologia , Escherichia coli/efeitos dos fármacos , Membranas Artificiais , Polivinil/química , Antibacterianos/química , Cobre/química , Microscopia Eletrônica de Varredura , Modelos Biológicos , Estrutura Molecular , Propriedades de Superfície
10.
Nat Genet ; 42(11): 1005-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20953187

RESUMO

We extended our previous genome-wide association study for psoriasis with a multistage replication study including 8,312 individuals with psoriasis (cases) and 12,919 controls from China as well as 3,293 cases and 4,188 controls from Germany and the United States and 254 nuclear families from the United States. We identified six new susceptibility loci associated with psoriasis in the Chinese study containing the candidate genes ERAP1, PTTG1, CSMD1, GJB2, SERPINB8 and ZNF816A (combined P < 5 × 10⁻8) and replicated one locus, 5q33.1 (TNIP1-ANXA6), previously reported (combined P = 3.8 × 10⁻²¹) in the European studies. Two of these loci showed evidence for association in the German study at ZNF816A and GJB2 with P = 3.6 × 10⁻³ and P = 7.9 × 10⁻³, respectively. ERAP1 and ZNF816A were associated with type 1 (early onset) psoriasis in the Chinese Han population (test for heterogeneity P = 6.5 × 10⁻³ and P = 1.5 × 10⁻³, respectively). Comparisons with the results of previous GWAS of psoriasis highlight the heterogeneity of disease susceptibility between the Chinese and European populations. Our study identifies new genetic susceptibility factors and suggests new biological pathways in psoriasis.


Assuntos
Povo Asiático/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Psoríase/genética , Aminopeptidases/genética , Conexina 26 , Conexinas/genética , Replicação do DNA , Alemanha/epidemiologia , Humanos , Proteínas de Membrana/genética , Antígenos de Histocompatibilidade Menor , Proteínas de Neoplasias/genética , Securina , Serpinas/genética , Proteínas Supressoras de Tumor , Estados Unidos/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA