Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Langmuir ; 40(23): 12078-12088, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38805683

RESUMO

Oily wastewater has caused serious threats to the environment; thus, high-performance absorbing materials for effective oil-water separation technology have attracted increasing attention. Herein, we develop a magnetic, hydrophobic, and lipophilic hyperporous elastic material (HEM) templated by high internal phase emulsions (HIPE), in which free-radical polymerization of butyl acrylate (BA) and divinylbenzene (DVB) is employed in the presence of poly(dimethylsiloxane) (PDMS), lecithin surfactant, and modified Fe3O4 nanoparticles. The adoption of the emulsion template with nanoparticles as both stabilizers and cross-linkers endows the HEM with biomimetic hierarchical open-cell micropores and elastic cross-linked networks, generating an oil absorbent with outstanding mechanical stability. Compressive fatigue resistance of the HEM is demonstrated to endure 2000 mechanical cycles without plastic deformation or strength degradation. By exploiting the synergistic effect of hierarchical structures and low-surface-energy components, the resulting HEM also possesses excellent and robust hydrophobicity (water contact angle of 164°) and good oil absorption capacity, in which Fe3O4 nanoparticles lead to convenient magnetically controlled oil recyclability as well. Notably, the unique biomimetic microporous structure demonstrates superior oil retention capacity (>95% at 1000 rpm and >60% at 10,000 rpm) over the state-of-the-art porous materials for a diverse variety of oils to reduce the risk of secondary oil leakage, along with good recoverability by squeezing owing to the excellent compression resilience. These excellent performances of our HEM provide broad prospects for practical applications in oil-water separation, energy conversion, and smart soft robotics.

2.
Angew Chem Int Ed Engl ; : e202403068, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38687308

RESUMO

Organic self-assembled molecules (OSAMs) based hole transporting materials play a pivotal role in achieving highly efficient and stable inverted perovskite solar cells (IPSCs). However, the reported carbazol-based OSAMs have serious drawbacks, such as poor solubility in alcohol solution, worse matched energy arrangement with perovskite, and limited molecular species, which greatly limit the device performance. To address above problems, a novel OSAM 4-(3,6-glycol monomethyl ether-9H-carbazol-9-yl) butyl]phosphonic acid (GM-4PACz) was synthesized as hole-transporting material by introducing glycol monomethyl ether (GM) side chains at carbazolyl unit. GM groups enhance the surface energy of Indium Tin Oxide (ITO)/SAM substrate to facilitate the nucleation and growth of up perovskite film, suppress cation defects, release the residual stress at SAM/perovskite interface, and evaluate energy level for matching with perovskite. Consequently, the GM-4PACz based IPSC achieves a champion PCE of 25.52%, a respectable open-circuit voltage (VOC) of 1.21 V, a high stability, possessing 93.29% and 91.75% of their initial efficiency after aging in air for 2000 h or tracking at maximum power point for 1000 h, respectively.

3.
ACS Nano ; 17(21): 21935-21946, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37922489

RESUMO

Noninvasive testing and continuous monitoring of ultralow-concentration hormones in biofluids have attracted increasing interest for health management and personalized medicine, in which saliva could fulfill the demand. Steroid sex hormones such as progesterone (P4) and ß-estradiol (E2) are crucial for female wellness and reproduction; however, their concentrations in saliva can vary down to sub-pM and constantly fluctuate over several orders of magnitude. This remains a major obstacle toward user-friendly and reliable monitoring at home with low-cost flexible biosensors. Herein we introduce a 3D micropyramidal electrode architecture to address such challenges and achieve an ultrasensitive flexible electrochemical immunosensor with sub-fM-level detection capability of salivary sex hormones within a few minutes. This is enabled by micropyramidal electrode arrays consisting of a poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) thin film as the coating layer and electrochemically decorated gold nanoparticles (AuNPs) to improve the antibody immobilization. The enhanced mass transport around the 3D tips provided by the micropyramidal architecture is discovered to improve the detection limit by 3 orders of magnitude, pushing it to as low as ∼100 aM for P4 and ∼20 aM for E2, along with a wide linear range up to µM. Accordingly, these hormones down to sub-fM in >1000-fold-diluted saliva samples can be accurately measured by the printed soft immunosensors, thus allowing at-home testing through simple saliva dilution to minimize the interfering substances instead of centrifugation. Finally, monitoring of the female ovarian hormone cycle of both P4 and E2 is successfully demonstrated based on the centrifuge-free saliva testing during a period of 4 weeks. This ultrasensitive and soft 3D microarchitected electrode design is believed to provide a universal platform for a diverse variety of applications spanning from accurate clinical diagnostics and counselling and in vivo detection of bioactive species to environmental and food quality tracing.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Feminino , Humanos , Nanopartículas Metálicas/química , Ouro/química , Imunoensaio , Polímeros/química , Eletrodos , Hormônios Esteroides Gonadais , Esteroides , Hormônios , Técnicas Eletroquímicas
4.
Appl Opt ; 62(27): 7233-7239, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37855579

RESUMO

Phase sensitive amplifiers (PSAs) based on optical parametric amplification feature near noiseless amplification, which is of considerable benefit for improving the performance of optical communication systems. Currently, the majority of research on PSAs is carried out on the basis of highly nonlinear fibers or periodically poled lithium niobite waveguides, with the impediments of being susceptible to environmental interference and requiring complex temperature control systems to maintain quasi-phase matching conditions, respectively. Here, a near-noiseless and small-footprint PSA based on dispersion-engineered AlGaAs-on-insulator (AlGaAsOI) waveguides is proposed and demonstrated theoretically. The phase-dependent gain and the phase-to-phase transfer function of the PSA are calculated to analyze its characteristics. Furthermore, we investigate in detail the effects of linear loss, nonlinear coefficient, and pump power on the PSA gain and noise figure (NF) in AlGaAsOI waveguides. The results show that a PSA based on an AlGaAsOI waveguide is feasible with a maximum phase sensitive gain of 33 dB, achieving an NF of less than 1 dB over a gain bandwidth of 245 nm with a gain of >15d B, which completely covers the S + C + L band. This investigation is worthwhile for noiseless PSAs on photonic integrated chips, which are promising for low-noise optical amplification, multifunctional photonic integrated chips, quantum communication, and spectroscopy, and as a reference for low-noise PSAs depending on the third-order nonlinearity, χ (3), of the waveguide material.

5.
ACS Appl Mater Interfaces ; 14(10): 12583-12595, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35230799

RESUMO

Hydrogel electrolytes as soft ionic conductors have been extensively exploited to establish skinlike and biocompatible devices. However, in many common hydrogels, there exists irreversible elongation upon prolonged stretching cycles and poor interfacial contact, which have significantly hindered their practical applications where long-term operation at large deformations is needed. Herein, multifunctional soft electronic devices with reversible stretchability and improved electrode/electrolyte interfaces are demonstrated by employing polyacrylamide-based double-network organohydrogel electrolytes soaked with a high content of tannic acid (TA) that affords multiple noncovalent interactions and redox activity. Performances of the TA-rich gels are evaluated for the first time in realizing shape-recoverable stretchable devices against repeated deformations to 500% strain, with superior gel-electrode interfaces exhibiting both intimate adhesion and boosted electrochemical capacitance of >200 mF·cm-2. A maximal 4-fold higher capacitance can be achieved by introducing TA and ethylene glycol (EG) into hydrogels. Moreover, a soft electronic system consisting of stretchable supercapacitors and gel-based microsensors was demonstrated, in which the electronic performance of these devices can be well preserved after >1000 repeated cycles at strains of up to 200%, without obvious residual strain or electrode delamination. This could pave a route to the design of multifunctional gel networks tackling both the mechanical and interfacial issues in soft and biocompatible devices.

6.
J Colloid Interface Sci ; 616: 858-871, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35257935

RESUMO

The development of the effective diagnostic method for the determination of cancer biomarkers is one of the most promising strategies for early clinical diagnosis of cancer. Here, based on the preparation of heterogeneous cuprous oxide coated silver (Ag@Cu2O) nanocomposites/graphitic carbon nitride (g-C3N4)/cadmium sulfide (CdS) nanoarrays structure, a highly sensitive photoelectrochemical (PEC) biosensor for the examination of carcinoembryonic antigen (CEA) has been constructed successfully. The combination of photoactive semiconductor materials g-C3N4 and CdS increases the electron transfer rate between them and enhances their photocurrent response, thus greatly increasing the concentration detection range. At the same time, the specific recognition between antigen and antibody is used to form a sandwich structure secondary antibody (Ab2)/CEA/antibody (Ab1). And because Ag@Cu2O has the function of absorbing light and consuming electron donor. Therefore, the successful measurement of CEA was achieved by labeling Ag@Cu2O on Ab2 and finally immobilizing it on the sensor to correlate the current reduction with the CEA concentration. The sandwich PEC biosensor proposed by this signal amplification strategy under optimal conditions has good analytical performance for CEA, with a wide linear detection range (from 10-5 to 1 ng/mL) and a low detection limit of 0.0011 pg/mL. The PEC biosensor constructed by this method showed high sensitivity, excellent anti-interference ability, favourable repeatability, and good stability.


Assuntos
Técnicas Biossensoriais , Nanocompostos , Cádmio , Compostos de Cádmio , Antígeno Carcinoembrionário , Cobre , Técnicas Eletroquímicas/métodos , Grafite , Imunoensaio/métodos , Limite de Detecção , Nanocompostos/química , Compostos de Nitrogênio , Prata , Sulfetos
7.
Angew Chem Int Ed Engl ; 56(26): 7625-7629, 2017 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-28508525

RESUMO

Multicomponent nanoparticles can be synthesized with either homogeneous or phase-segregated architectures depending on the synthesis conditions and elements incorporated. To understand the parameters that determine their structural fate, multicomponent metal-oxide nanoparticles consisting of combinations of Co, Ni, and Cu were synthesized by using scanning probe block copolymer lithography and characterized using correlated electron microscopy. These studies revealed that the miscibility, ratio of the metallic components, and the synthesis temperature determine the crystal structure and architecture of the nanoparticles. A Co-Ni-O system forms a rock salt structure largely owing to the miscibility of CoO and NiO, while Cu-Ni-O, which has large miscibility gaps, forms either homogeneous oxides, heterojunctions, or alloys depending on the annealing temperature and composition. Moreover, a higher-ordered structure, Co-Ni-Cu-O, was found to follow the behavior of lower ordered systems.


Assuntos
Nanopartículas Metálicas/química , Óxidos/química , Polietilenoglicóis/química , Cobalto/química , Cobre/química , Glutationa/química , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Estrutura Molecular , Níquel/química , Oxirredução , Temperatura
8.
Sci Rep ; 6: 21197, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26887530

RESUMO

The hyaluronan synthase 2 (HAS2)-hyaluronic acid (HA)-CD44-Caspase-3 pathway is involved in ovarian granulosa cell (GC) functions in mammals. HAS2 is a key enzyme required for HA synthesis and is the key factor in this pathway. However, the regulation of HAS2 and the HAS2-mediated pathway by microRNAs in GCs is poorly understood. Here, we report that miR-26b regulates porcine GC (pGC) apoptosis through the HAS2-HA-CD44-Caspase-3 pathway by binding directly to the 3'- untranslated region of HAS2 mRNA. Knockdown of miR-26b reduced pGC apoptosis. Luciferase reporter assays demonstrated that HAS2 is a direct target of miR-26b in pGCs. Knockdown and overexpression of miR-26b increased and decreased, respectively, HA content, and HAS2 and CD44 expression in pGCs. At the same time, inhibition and overexpression of miR-26b decreased and increased the expression of Caspase-3, a downstream factor in the HAS2-HA-CD44 pathway. Moreover, knockdown of HAS2 enhanced pGC apoptosis, reduced the inhibitory effects of a miR-26b inhibitor on pGC apoptosis, repressed HA content and CD44 expression, and promoted Caspase-3 expression. In addition, overexpression of HAS2 has a opposite effect. Collectively, miR-26b positively regulates pGC apoptosis via a novel HAS2-HA-CD44-Caspase-3 pathway by targeting the HAS2 gene.


Assuntos
Apoptose/fisiologia , Caspase 3/metabolismo , Glucuronosiltransferase/metabolismo , Células da Granulosa/metabolismo , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , MicroRNAs/metabolismo , Animais , Caspase 3/genética , Feminino , Glucuronosiltransferase/genética , Células da Granulosa/citologia , Células HeLa , Humanos , Receptores de Hialuronatos/genética , Ácido Hialurônico/genética , MicroRNAs/genética , Suínos
9.
Chem Asian J ; 5(10): 2266-70, 2010 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-20677323

RESUMO

Gold-directed polypyrrole (PPy) nanoarrays are fabricated by hydrogel-assisted nanotransfer edge printing (HnTEP) and electrochemical polymerization. Gold nanoarrays are fabricated through the HnTEP method, which involves metal deposition, hydrogel etching, and nanotransfer edge printing. By utilizing the well-positioned gold nanostructures, PPy nanoarrays with smooth morphology and controllable dimensions are fabricated through in situ electrochemical polymerization, the results of which are characterized by scanning electron microscopy and atomic force microscopy. A gas sensor based on PPy nanoarrays results in excellent sensing capabilities towards NH3 detection, especially the sensitivity and fast response. This method appears to be general and may aid in the future design and implementation of other active materials which can also be manipulated by the same procedure and serve as functional components for chemical sensing, optoelectronics, biodetection, and other applications.

10.
Mol Genet Genomics ; 281(1): 67-75, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18987886

RESUMO

The Deleted in Azoospermia (DAZ) genes encode potential RNA-binding proteins that are expressed exclusively in the germ-line. The bovine Deleted in Azoospermia-like gene is a strong candidate for male cattle-yak infertility. In this work, with the goe goal to further reveal the genetic cause of male cattle-yak sterility, another bovine DAZ family gene, b-boule, was isolated and characterized. The b-boule gene is predicted to encode a polypeptide of 295 amino acids with an RNP-type RNA recognition domain. Tertiary structure analysis shows that b-boule binds specifically to polypyrimidine RNAs and might act as a nuclear ribonucleoprotein particle auxiliary factor during germ cell formation and morphological changes of germ cells. RT-PCR assays revealed that b-boule was expressed specifically in the adult testis. However, an extremely low level of expression was detected in the testis of sterile male cattle-yaks. Microstructure of the testes from sterile males showed that type A spermatogonia were the only germ cells present and that few germ cells developed further than the stage of pachytene spermatocytes. These results suggest that b-boule may function in bovine spermatogenesis, and that low levels of b-boule expression might lead to male sterility in cattle-yaks.


Assuntos
Bovinos/genética , Proteínas de Ligação a RNA/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Doenças dos Bovinos/genética , Doenças dos Bovinos/patologia , Clonagem Molecular , Cruzamentos Genéticos , Primers do DNA/genética , Infertilidade Masculina/genética , Infertilidade Masculina/patologia , Infertilidade Masculina/veterinária , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Homologia de Sequência de Aminoácidos , Espermatogênese/genética , Testículo/patologia
11.
Macromol Rapid Commun ; 30(18): 1589-93, 2009 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-21638426

RESUMO

An ultralow-limit gas microsensor based on an ultrathin conducting oligoaniline film integrated with microscale gold electrodes is developed. A nanoscale oligoaniline film is fabricated on a poly(dimethylsiloxane) (PDMS) substrate using graft polymerization using FeCl(3) , a mild oxidant, rather than conventional (NH(4) )(2) S(2) O(8) . The as-fabricated film is around 14 nm in thickness and above 85% transmittance on a PDMS substrate with a smooth surface morphology and high conductivity. Taking NH(3) as a protocol, the nanoscale oligoaniline film microsensor shows an ultralow detection limit to the ppb level with more rapid response and high sensitivity to NH(3) compared to the thicker PANI film using conventional methods.

12.
Zoolog Sci ; 22(12): 1339-46, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16462106

RESUMO

FoxO1 is a transcription factor implicated in a multitude of physiological processes including cell cycle progression, apoptosis and insulin signaling. Recent findings indicate that FoxO1 is a key regulator during the proliferation and maturation of granulosa cells. Over the past several years, it has become evident that nitric oxide (NO) and cGMP modulate ovarian function. There has been no information, however, about whether NO-cGMP affects FoxO1 expression or about the relationship between NO-cGMP and FoxO1. In the present study, we used immunoblot analysis to determine whether NO and cGMP affect FoxO1 expression in cultured granulosa cells. Our results clearly showed that FSH suppressed FoxO1 expression in a time-dependent manner, and that NO-cGMP stimulated FoxO1 expression in cultured granulosa cells. In addition, this stimulatory effects of NO and cGMP can be blocked by FSH in cultured granulosa cells. These findings demonstrate that NO and cGMP influence FoxO1 expression possibly through antagonizing the action of FSH in cultured granulosa cells. Results of both immunoblot analysis and immunohistochemistry also show that estradiol implantation do not affect the expression of FoxO1 in rat granulosa cells as gonadotrophins do, indicating that mechanism of estradiol on granulosa cells is different from gonadotrophins. Together, our experiments suggest that expression of FoxO1 in rat granulosa cells can be regulated by gonadotrophins and the NO/cGMP signaling pathway.


Assuntos
GMP Cíclico/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica , Células da Granulosa/citologia , Células da Granulosa/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Óxido Nítrico/metabolismo , Animais , Células Cultivadas , Cromonas/farmacologia , Estradiol/farmacologia , Feminino , Gonadotropinas Equinas/farmacologia , Células da Granulosa/efeitos dos fármacos , Morfolinas/farmacologia , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA