Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Gels ; 9(8)2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37623054

RESUMO

As an important inorganic material, alumina ceramic nanofibers have attracted more and more attention because of their excellent thermal stability, high melting point, low thermal conductivity, and good chemical stability. In this paper, the preparation conditions for alumina spinning gel, such as the experimental raw materials, spin finish aid, aging time, and so on, are briefly introduced. Then, various methods for preparing the alumina ceramic nanofibers are described, such as electrospinning, solution blow spinning, centrifugal spinning, and some other preparation processes. In addition, the application of alumina ceramic nanofibers in thermal insulation, high-temperature filtration, catalysis, energy storage, water restoration, sound absorption, bioengineering, and other fields are described. The wide application prospect of alumina ceramic nanofibers highlights its potential as an advanced functional material with various applications. This paper aims to provide readers with valuable insights into the design of alumina ceramic nanofibers and to explore their potential applications, contributing to the advancement of various technologies in the fields of energy, environment, and materials science.

2.
RSC Adv ; 13(27): 18480-18487, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37346944

RESUMO

Water pollution caused by the continuous development of industrialization has always been a common concern of mankind. Herein, a novel strategy to fabricate a high-performance composite membrane based on dual-network structured nonwoven net/UHMWPE nanopores via a thermal phase separation and composite technique is reported. By thermal phase separation of ultra-high-molecular weight polyethylene (UHMWPE)/liquid paraffin (LP), this approach enables 3D nanopores to tightly bond with a nonwoven net to form a dual-network structure. The dual-network composite membrane possesses the integrated features of pore structure and high porosity (89.9%). After modification with hyperbranched polymers (HBPs), the composite membrane with the desirable surface chemistry achieves high-efficiency filtration (water flux = 1054 L m-2 h-1, rejection rate = 50 nm PS nanospheres almost close to 100%, and antibacterial properties). The fabrication of such composites may provide new insights into the design and development of high-performance filtration and separation materials for various applications.

3.
PeerJ ; 10: e13998, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36157055

RESUMO

Background: Plukenetia volubilis is cultivated as a valuable oilseed crop, and its mature seeds are rich in polyunsaturated fatty acids (FAs), which are widely used in food and pharmaceutical industries. Recently, next-generation sequencing (NGS) transcriptome studies in P. volubilis indicated that some candidate genes were involved in oil biosynthesis. The NGS were inaccuracies in assembly of some candidate genes, leading to unknown errors in date analyses. However, single molecular real-time (SMRT) sequencing can overcome these assembled errors. Unfortunately, this technique has not been reported in P. volubilis. Methods: The total oil content of P. volubilis seed (PVS) was determined using Soxhlet extraction system. The FA composition were analyzed by gas chromatography. Combining PacBio SMRT and Illumina technologies, the transcriptome analysis of developing PVS was performed. Functional annotation and differential expression were performed by BLAST software (version 2.2.26) and RSEM software (version 1.2.31), respectively. The lncRNA-targeted transcripts were predicted in developing PVS using LncTar tool. Results: By Soxhlet extraction system, the oil content of superior plant-type (SPT) was 13.47% higher than that of inferior plant-type (IPT) at mature PVS. The most abundant FAs were C18:2 and C18:3, among which C18:3 content of SPT was 1.11-fold higher than that of IPT. Combined with PacBio and Illumina platform, 68,971 non-redundant genes were obtained, among which 7,823 long non-coding RNAs (lncRNAs) and 7,798 lncRNA-targeted genes were predicted. In developing seed, the expressions of 57 TFs showed a significantly positive correlation with oil contents, including WRI1-like1, LEC1-like1, and MYB44-like. Comparative analysis of expression profiles between SPT and IPT implied that orthologs of FAD3, PDCT, PDAT, and DAGT2 were possibly important for the accumulation of polyunsaturated FAs. Together, these results provide a reference for oil biosynthesis of P. volubilis and genetic improvement of oil plants.


Assuntos
RNA Longo não Codificante , Transcriptoma , Transcriptoma/genética , RNA Longo não Codificante/metabolismo , Ácidos Graxos Insaturados , Perfilação da Expressão Gênica , Sementes/genética
4.
Int J Mol Sci ; 23(14)2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35887255

RESUMO

As a new tumor treatment strategy, photothermal therapy (PTT) has the advantages of accuracy, ease of administration, a high efficiency and low side effects. Photothermal transduction agents (PTAs) are the key factor which play an important role in PTT. The mechanism of PTT is discussed in detail. The photothermal conversion efficiency (PCE) can be improved by increasing the light absorption and reducing the light scattering of photothermal conversion agents. Additionally, non-radiative relaxation path attenuation can also promote energy conversion to obtain a higher value in terms of PCE. The structure and photothermal characteristics of various kinds of PTAs (metal materials, carbon-based nanomaterials, two-dimensional nanomaterials, and organic materials) were compared and analyzed. This paper reviews the antitumor applications of photothermal synergistic therapies, including PTT combined with immunotherapy, chemotherapy, and photodynamic therapy. This review proposes that these PTAs promote the development of photothermal synergistic therapies and have a great potential in the application of tumor treatment.


Assuntos
Nanopartículas , Nanoestruturas , Neoplasias , Fotoquimioterapia , Humanos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Fototerapia/métodos , Terapia Fototérmica
5.
J Colloid Interface Sci ; 603: 771-782, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34229119

RESUMO

In this work, a metal-organic framework material, zeolitic imidazolate framework-90 (ZIF-90), was firstly used to encapsulate laccase (LAC) and to prepare ZIF-90/LAC biocomposites. Afterward, the composites were combined with bacterial cellulose (BC) and carboxylated multi-walled carbon nanotubes (c-MWCNTs) by a facile method to achieve a novel cellulose membrane with biocatalytic function, displaying excellent detection and degradation properties towards phenolic pollutant. Notably, the membrane was directly employed as a biosensor electrode, and it exhibited a linear response to catechol from 20 to 400 µM with a detection limit of 1.86 µM (S/N = 3), as well as satisfactory selectivity, reproducibility, and stability. In addition, the biocatalytic membrane showed higher degradation efficiency towards catechol than pure LAC, and the catechol degradation efficiency of the membrane generally ranged from 93.4% to 82.1% for five cycles. Moreover, the membrane was successfully applied in enzyme membrane reactor (EMR), achieving satisfactory results. The novel membrane harbors a broad application prospect in the fields of real-time monitor and treatment of phenolic wastewater.


Assuntos
Poluentes Ambientais , Estruturas Metalorgânicas , Nanotubos de Carbono , Lacase , Reprodutibilidade dos Testes
6.
ACS Omega ; 6(2): 1352-1360, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33490794

RESUMO

This study reports a novel, multifunctional, and easily obtained modifier to support the rapid advancements in the field of filtration. Polydopamine (PDA) particles (PDAPs) have been reported as a filler for constructing polymer composites, but because of their poor thermal stability, the use of PDAPs in high-temperature blend melt systems to construct antifouling membranes was rare. In this paper, high-thermal-stability methoxy polyethylene glycol amine (mPEG-NH2)-functionalized PDA nanoparticles (mPDAPs) were first used as a modifier in high-temperature blend melt polymer composites to construct antifouling composite membranes. First, high-thermal-stability mPDAPs with an average diameter of about 390 nm were prepared by immobilized mPEG-NH2 on the PDAP surface, then melt blend mPDAPs with ultrahigh-molecular-weight polyethylene/liquid paraffin (LP) solution and thermally reduced phase separation (TIPS) to construct antifouling membranes. A combination of properties including mechanical properties, filtration efficiency, and antifouling properties of hybrid composite membranes was investigated and demonstrated that mPDAPs were an efficient modifier for high-temperature melt blending systems. The aim of this study was to provide an effective approach to improve the membrane filtration performance by bulk hybrid modification of multifunctional nanoparticles.

7.
Polymers (Basel) ; 12(10)2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33066175

RESUMO

Electret filters are widely used in particulate matter filtration due to their filtration efficiency that can be greatly improved by electrostatic forces without sacrificing the air resistance. However, the attenuation of the filtration efficiency remains a challenge. In this study, we report a novel strategy for producing an electret melt blown filter with superior filtration efficiency stability through a thermally stimulated charging method. The proposed approach optimizes the crystal structure and therefore results in the increased production probability of the charge traps. In addition, the re-trapping phenomenon caused by the thermal stimulation during the charging process can greatly increase the proportion of deep charge to shallow charge and improve the charge stability. A superior electret melt blown filtration material with a high filtration efficiency of 99.65%, low pressure drop of 120 Pa, and satisfactory filtration efficiency stability was produced after three cyclic charging times. The excellent filtration performance indicated that the developed material is a good air filtration candidate component for personal protection applications.

8.
Polymers (Basel) ; 12(6)2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32560399

RESUMO

Biofilms formed on skin wound lead to inflammation and a delay of healing. In the present work, a novel textile pile debridement material was prepared and treated by plasma. Samples before and after plasma treatment were characterized by a series of methods, including scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and water uptake capacity. Besides, mechanical, coagulation, and in vitro biofilm removal performances of the textile pile debridement material were evaluated, with a medical gauze as a control. The results demonstrate that the plasma treatment produced corrosions and oxygen-containing polar groups on the fiber surface, offering an enhanced water uptake capacity of the textile pile debridement material. In addition, compressive tests certify the mechanical performances of the textile pile debridement material in both dry and wet conditions. The results from a kinetic clotting time test suggest a favorable ability to promote blood coagulation. Furthermore, the results of an MTT cell viability assay, SEM, and confocal laser scanning microscopy (CLSM) illustrate that the textile pile debridement material demonstrates a more superior in vitro biofilm removal performance than medical gauze. All of these characterizations suggest that the textile pile debridement material can offer a feasible application for clinical wound debridement.

9.
Molecules ; 23(10)2018 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-30301225

RESUMO

A co-based porous metal-organic framework (MOF) of zeolitic imidazolate framework-67 (ZIF-67) and carbon nanofibers (CNFs) was utilized to prepare a ZIF-67/CNFs composite via a one-pot synthesis method. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) were employed to investigate the morphology, structure, and composition of the resulting composite. A novel high-performance non-enzymatic electrochemical sensor was constructed based on the ZIF-67/CNFs composite. The ZIF-67/CNFs based sensor exhibited enhanced electrocatalytic activity towards H2O2 compared to a pure ZIF-67-based sensor, due to the synergistic effects of ZIF-67 and CNFs. Meanwhile, chronoamperometry was utilized to explore the detection performance of the sensor. Results showed the sensor displayed high-efficiency electrocatalysis towards H2O2 with a detection limit of 0.62 µM (S/N = 3), a sensitivity of 323 µA mM-1 cm-2, a linear range from 0.0025 to 0.19 mM, as well as satisfactory selectivity and long-term stability. Furthermore, the sensor demonstrated its application potential in the detection of H2O2 in food.


Assuntos
Técnicas Biossensoriais , Peróxido de Hidrogênio/isolamento & purificação , Estruturas Metalorgânicas/química , Nanofibras/química , Carbono/química , Peróxido de Hidrogênio/química
10.
Nanoscale ; 10(5): 2454-2460, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29336462

RESUMO

Hematite is an earth-abundant and ubiquitous semiconductor with a suitable bandgap of 2.1 eV for solar water splitting. Unfortunately, it suffers from a low conduction band position compared to the H+/H2 potential and typically an external bias has to be applied. Here, we demonstrate carbon dot-hematite (CD-Fe2O3) nanocomposites as photocatalysts for visible-light-driven overall water splitting without any external bias or scavenger. Notably, the CD-Fe2O3 nanocomposites (carbon dots, 5 wt%) show a hydrogen evolution rate of 0.390 µmol h-1 and an oxygen evolution rate of 0.225 µmol h-1 under visible light illumination. In our system, carbon dots have been well coupled with hematite and are detected to generate a photo-induced potential. This photo-potential can be combined with hematite to meet the requirement for overall water splitting. In addition, carbon dots can significantly improve the charge separation efficiency. Our finding may greatly enhance the practical application of hematite for solar water splitting.

11.
J Mater Chem B ; 6(36): 5708-5717, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32254977

RESUMO

Multifunctional carbon dots (CDs) with lifetime thermal sensing, nucleolus imaging, and antialgal activity properties were synthesized directly from ascorbic acid aqueous solution by a one-step electrochemical method at room temperature. The as-prepared CDs are responsive to temperature and exhibit an accurate linear response of fluorescence intensity vs. temperature (20-100 °C). These CDs can enter a cell and nucleolus, adsorb on the nucleic acids (DNA and RNA) and the fluorescence intensity of CDs is increased by the adsorption of nucleic acids. In addition, the CDs can inhibit the activity of RuBisCO in Anabaena sp., leading to reducing the growth of Anabaena sp. All these properties make the CDs serve as effective fluorescence-based nanothermometers, nucleolus probes, and antialgal agents.

12.
Adv Mater ; 29(32)2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28640515

RESUMO

Self-healing is the way by which nature repairs damage and prolongs the life of bio entities. A variety of practical applications require self-healing materials in general and self-healing polymers in particular. Different (complex) methods provide the rebonding of broken bonds, suppressing crack, or local damage propagation. Here, a simple, versatile, and cost-effective methodology is reported for initiating healing in bulk polymers and self-healing and anticorrosion properties in polymer coatings: introduction of carbon dots (CDs), 5 nm sized carbon nanocrystallites, into the polymer matrix forming a composite. The CDs are blended into polymethacrylate, polyurethane, and other common polymers. The healing/self-healing process is initiated by interfacial bonding (covalent, hydrogen, and van der Waals bonding) between the CDs and the polymer matrix and can be optimized by modifying the functional groups which terminate the CDs. The healing properties of the bulk polymer-CD composites are evaluated by comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that are healed and by following the self-healing of scratches intentionally introduced to polymer-CD composite coatings. The composite coatings not only possess self-healing properties but also have superior anticorrosion properties compared to those of the pure polymer coatings.

13.
Nanoscale ; 9(1): 298-304, 2017 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-27910981

RESUMO

Electrochemical reduction of CO2 is a key component of many prospective artificial technologies for renewable carbon-containing fuels, but it still suffers from the high overpotentials required to drive the process, low selectivity for diversiform products and the high cost of the catalyst. Here, we report that Cu-CDots nanocorals is a highly efficient, low-cost and stable electrocatalyst for CO2 reduction in aqueous solution. The major product of CO2 reduction on the Cu-CDots nanocorals is HCOOH with an inconceivable low overpotential of 0.13 V and a high Faraday efficiency of 79% at a moderate potential of -0.7 V vs. RHE. In the present system, CDots can increase the adsorption capacity of CO2 molecules and H+, which play important roles in CO2 reduction. The high selectivity of HCOOH for CO2 reduction may be ascribed to that CDots can greatly diminish the HCOOH desorption energy and improve the catalytic selectivity for HCOOH. Furthermore, Cu-CDots nanocorals exhibit a long-term stability during 5 h-electrolysis.

14.
J Long Term Eff Med Implants ; 26(1): 13-42, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27649761

RESUMO

The reconstruction of the right ventricular outflow tract (RVOT) system represents a considerable challenge for both manufacturers and surgeons because the patients requiring this type of devices have a very diverse set of anatomical challenges that can lead to complications and subsequent early device failures. We conducted an indepth investigation of a porcine-valve conduit explanted from a patient following an adverse event. A control device was analyzed as a reference. The rapid aging of the porcine valve in the right side of the heart together with major thrombus formation raises several questions. The difficulties encountered with materials used and also the design features of the conduits are once again highlighted. This group of patients continues to increase in number due to success in the surgical outcomes in early childhood. Therefore, there is a greater demand for an appropriate device. However, much work is still needed to achieve this goal, and the best approach to achieving success remains unanswered.


Assuntos
Bioprótese , Próteses Valvulares Cardíacas , Ventrículos do Coração/cirurgia , Falha de Prótese , Animais , Cardiopatias Congênitas , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Procedimentos de Cirurgia Plástica , Suínos , Obstrução do Fluxo Ventricular Externo
15.
J Long Term Eff Med Implants ; 26(1): 49-78, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27649763

RESUMO

The Bentall procedure introduced in 1968 represents an undisputed cure to treat multiple pathologies involving the aortic valve and the ascending thoracic aorta. Over the years, multiple modifications have been introduced as well as a standardized approach to the operation with the goal to prevent long-term adverse events. The BioValsalva prosthesis provides a novel manner to more efficiently reconstruct the aortic valve together with the anatomy of the aortic root with the implantation of a valved conduit. This prosthesis comprises three sections: the collar supporting the valve; the skirt mimicking the Valsalva, which is suitable for the anastomoses with the coronary arteries; and the main body of the graft, which is designed to replace the ascending aorta. The BioValsalva prosthesis allows the Bentall operation to be used in patients whose aortic valve cannot be spared.


Assuntos
Valva Aórtica/cirurgia , Bioprótese , Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas , Desenho de Prótese , Animais , Humanos , Teste de Materiais , Suínos
16.
J Long Term Eff Med Implants ; 26(2): 97-121, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28094735

RESUMO

The Bentall procedure introduced in 1968 represents an undisputed cure to treat multiple pathologies involving the aortic valve and the ascending thoracic aorta. Over the years, multiple modifications have been introduced as well as a standardized approach to the operation with the goal to prevent long-term adverse events. The Gelweave Valsalva graft provides a novel manner to more efficiently reconstruct the anatomy of the aortic root either with a valve-sparing procedure or with the implantation of a valved conduit (bioprosthesis or mechanical valve). The prosthesis holds three sections: the collar anchoring the valve; the skirt mimicking the Valsalva, which is suitable for the anastomoses with the coronary arteries; and the main body of the graft, which is designed to replace the ascending aorta. The Gelweave Valsalva graft allows the Bentall operation to be standardized, and it provides a potential for longer durability with reduced adverse events.


Assuntos
Aorta , Bioprótese , Implante de Prótese Vascular , Implante de Prótese de Valva Cardíaca , Valva Aórtica , Humanos , Desenho de Prótese
17.
Materials (Basel) ; 9(4)2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-28773428

RESUMO

Fiber shedding is a critical problem in biomedical textile debridement materials, which leads to infection and impairs wound healing. In this work, single fiber pull-out test was proposed as an in vitro evaluation for the fiber shedding property of a textile pile debridement material. Samples with different structural design (pile densities, numbers of ground yarns and coating times) were prepared and estimated under this testing method. Results show that single fiber pull-out test offers an appropriate in vitro evaluation for the fiber shedding property of textile pile debridement materials. Pull-out force for samples without back-coating exhibited a slight escalating trend with the supplement in pile density and number of ground yarn plies, while back-coating process significantly raised the single fiber pull-out force. For fiber shedding mechanism analysis, typical pull-out behavior and failure modes of the single fiber pull-out test were analyzed in detail. Three failure modes were found in this study, i.e., fiber slippage, coating point rupture and fiber breakage. In summary, to obtain samples with desirable fiber shedding property, fabric structural design, preparation process and raw materials selection should be taken into full consideration.

18.
J Long Term Eff Med Implants ; 25(3): 179-200, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26756557

RESUMO

An aortoesophageal fistula following surgery for a ruptured 6.6-cm thoracic aneurysm in a 69-year-old female was repaired using a 34-mm woven prosthetic graft. A follow-up computed tomography (CT) scan at 10 days postoperatively revealed a dissection-like picture in the region of the graft, which was treated conservatively. The patient eventually died from sepsis and multiorgan failure. At autopsy, the graft was retrieved in situ and studied by detailed gross, microscopy, and scanning electron microscopy (SEM) examination. Gross observation confirmed that the dissection resulted from the rolling of the internal capsule downstream. A massive thrombus anchored at the proximal anastomosis and held by a narrow head was also noted. The thrombus demonstrated reorganization in the area of the anastomosis, with a false lumen in its distal half. The reminder of the thrombus consisted of layered fibrin. After gross examination, the fabric graft was found to be flawless. Additional detailed studies were also done using microscopy, SEM, and gross examination.


Assuntos
Aorta Torácica/diagnóstico por imagem , Dissecção Aórtica/diagnóstico por imagem , Prótese Vascular/efeitos adversos , Trombose/diagnóstico por imagem , Trombose/etiologia , Idoso , Anastomose Cirúrgica/efeitos adversos , Aorta Torácica/cirurgia , Evolução Fatal , Feminino , Humanos , Microscopia Eletrônica de Varredura , Trombose/patologia , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...