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1.
Materials (Basel) ; 16(23)2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38068071

RESUMO

In this review, we systematically reviewed the recent advances in the development of ultrafine shape memory alloys with unique shape memory effects and superelastic behavior using amorphous metallic materials. Its scientific contribution involves defining and expanding the range of fabrication methods for single-phase ultrafine/nanocrystalline alloys with multicomponent systems. In multicomponent amorphous alloys, the crystallization mechanism depends on the alloy composition and is a selectable factor in the alloy designing method, considering the thermodynamic and physical parameters of constituent elements. The crystallization kinetics can be controlled by modulating the annealing condition in a supercooled liquid state with consideration of the crystalline temperature of the amorphous alloys. The phase stability of austenite and martensite phases in ultrafine shape memory alloys developed from amorphous precursors is determined according to alloy composition and grain size, which strongly influence the shape memory effect and superelastic behavior. A methodological framework is subsequently suggested to develop the ultrafine shape memory alloys based on the systematic alloy designing method, which can be considered an important strategy for developing novel ultrafine/nanocrystalline shape memory alloys with excellent shape memory and superelastic effects.

2.
IEEE Trans Pattern Anal Mach Intell ; 45(6): 7174-7194, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36318560

RESUMO

Cost aggregation is a process in image matching tasks that aims to disambiguate the noisy matching scores. Existing methods generally tackle this by hand-crafted or CNN-based methods, which either lack robustness to severe deformations or inherit the limitation of CNNs that fail to discriminate incorrect matches due to limited receptive fields and inadaptability. In this paper, we introduce Cost Aggregation with Transformers (CATs) to tackle this by exploring global consensus among initial correlation map with the help of some architectural designs that allow us to benefit from global receptive fields of self-attention mechanism. To this end, we include appearance affinity modeling, which helps to disambiguate the noisy initial correlation maps. Furthermore, we introduce some techniques, including multi-level aggregation to exploit rich semantics prevalent at different feature levels and swapping self-attention to obtain reciprocal matching scores to act as a regularization. Although CATs can attain competitive performance, it may face some limitations, i.e., high computational costs, which may restrict its applicability only at limited resolution and hurt performance. To overcome this, we propose CATs++, an extension of CATs. Concretely, we introduce early convolutions prior to cost aggregation with a transformer to control the number of tokens and inject some convolutional inductive bias, then propose a novel transformer architecture for both efficient and effective cost aggregation, which results in apparent performance boost and cost reduction. With the reduced costs, we are able to compose our network with a hierarchical structure to process higher-resolution inputs. We show that the proposed method with these integrated outperforms the previous state-of-the-art methods by large margins. Codes and pretrained weights are available at: https://ku-cvlab.github.io/CATs-PlusPlus-Project-Page/.

3.
ACS Appl Mater Interfaces ; 8(5): 3250-7, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26780371

RESUMO

Polymeric three-dimensional inverse-opal (IO) structures provide unique structural properties useful for various applications ranging from optics to separation technologies. Despite vast needs for IO functionalization to impart additional chemical properties, this task has been seriously challenged by the intrinsic limitation of polymeric porous materials that do not allow for the easy penetration of waterborne moieties or precursors. To overcome this restriction, we present a robust and straightforward method of employing a dipping-based surface modification with polydopamine (PDA) inside the IO structures, and demonstrate their application to catalytic membranes via synthetic incorporation of Ag nanoparticles. The PDA coating offers simultaneous advantages of achieving the improved hydrophilicity required for the facilitated infiltration of aqueous precursors and successful creation of nucleation sites for a reduction of growth of the Ag nanoparticles. The resulting Ag nanoparticle-incorporated IO structures are utilized as catalytic membranes for the reduction of 4-nitrophenol to its amino derivatives in the presence of NaBH4. Synergistically combined characteristics of high reactivity of Ag nanoparticles along with a greatly enhanced internal surface area of IO structures enable the implementation of remarkably improved catalytic performance, exhibiting a good conversion efficiency greater than 99% while minimizing loss in the membrane permeability.

4.
AJR Am J Roentgenol ; 198(2): W163-72, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22268207

RESUMO

OBJECTIVE: The purposes of this study were to assess chronologic changes in normal growth plate after radiofrequency-induced thermal injury and to evaluate the feasibility of MRI for revealing alteration of the growth plate. MATERIALS AND METHODS: Radiofrequency ablation was performed on the right proximal tibia of 13 8-week-old New Zealand White rabbits. An 18-gauge cooled-tip electrode with a 5-mm active tip was placed distal to the physis under fluoroscopic guidance. MRI, including T1- and T2-weighted images, gradient-recalled echo images, and contrast-enhanced T1-weighted images, was performed 2, 4, and 12 weeks after ablation. Rabbits were sacrificed 2 (n = 4), 4 (n = 4), and 12 weeks (n = 5) after ablation. The sequential changes in the ablated zone, the injured physis, and the nonablated portion of the physis were correlated between MRI features and histologic results. RESULTS: Diameter of the nonenhancing lesion on MR images strongly correlated with the size of the region of coagulation necrosis at gross examination. The intraclass correlation coefficients were 0.98 and 0.94 for the long and short axes (p < 0.001). On gradient-recalled echo images, physial conspicuity was less in the injured physis than in the nonablated portion and less in the ablated than the control tibia. Physial conspicuity was graded for comparison with physial thickness at microscopic examination. The thickness of the physis was less in the ablated than in the control tibia 4 and 12 weeks after treatment (p < 0.05, paired Student t test). The cartilage column of the injured physis was delaminated 2 weeks after treatment, and a bone bridge through the injured physis was detected at 4 weeks. CONCLUSION: Radiofrequency-induced thermal injury causes early closure of the physis. MRI can depict the extent of radiofrequency-induced thermal injury and alterations in the physis that lead to early closure.


Assuntos
Ablação por Cateter/métodos , Lâmina de Crescimento/cirurgia , Imageamento por Ressonância Magnética/métodos , Fraturas Salter-Harris , Tíbia/cirurgia , Análise de Variância , Animais , Meios de Contraste , Gadolínio DTPA , Lâmina de Crescimento/patologia , Coelhos
5.
J Microbiol Biotechnol ; 21(1): 100-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21301199

RESUMO

A method for the rapid detection and quantification of Newcastle disease virus (NDV) produced in an animal cell culture-based production system was developed to enhance the speed of the NDV vaccine manufacturing process. A SYBR Green I-based real-time RT-PCR was designed with a conventional, inexpensive RT-PCR kit targeting the F gene of the NDV LaSota strain. The method developed in this study was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The validation results satisfied the predetermined acceptance criteria. The validated method was used to quantify virus samples produced in an animal cell culture-based production system. The method was able to quantify the NDV samples from mid- or late-production phases, but not effective on samples from the early-production phase. For comparison with other quantifiable methods, immunoblotting, plaque assay, and tissue culture infectious dose 50 (TCID50) assay were also performed with the NDV samples. The results demonstrated that the real-time RT-PCR method is suitable for the rapid quantification of virus particles produced in an animal cell-culture-based production system irrespective of viral infectivity.


Assuntos
Doença de Newcastle/virologia , Vírus da Doença de Newcastle/isolamento & purificação , Doenças das Aves Domésticas/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Linhagem Celular , Galinhas , Immunoblotting , Doença de Newcastle/diagnóstico , Vírus da Doença de Newcastle/genética , Doenças das Aves Domésticas/diagnóstico , Ensaio de Placa Viral/métodos
6.
Biotechnol Lett ; 32(11): 1599-607, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20607360

RESUMO

Most animal cell culture media can be buffered using bicarbonate and high pressure CO(2) in a closed system. However, in an open system, the pH of the culture media increases continuously due to the marked difference in CO(2) pressure between the culture media and the atmosphere. Therefore, it is important to measure the exact pH of the culture media in an intact closed system. In this study, a pH measurement method was developed using visible light. The pH was calculated from light absorbance by the cells and by the culture media. This method was successfully applied to both suspension and anchorage-dependent cell cultures.


Assuntos
Colorimetria/métodos , Meios de Cultura/química , Animais , Técnicas de Cultura de Células , Linhagem Celular , Concentração de Íons de Hidrogênio
7.
Appl Microbiol Biotechnol ; 85(5): 1509-20, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19730851

RESUMO

Newcastle disease virus (NDV) is not only one of the most economically important pathogen of poultry but also has a potential as anticancer virotherapy. The role of NDV V protein in virus-production kinetics was investigated using DF-1 cell-based production system. The presence of an anti-interferon (IFN)-alpha antibody resulted in enhanced NDV production kinetics in a dose-dependent manner by blocking binding of NDV-induced IFN to its receptor. To prepare DF-1 cell whose cellular IFN signaling is blocked efficiently, stable cell lines expressing either lentogenic or velogenic NDV V protein known as an IFN antagonist were established. The overexpression of NDV V protein enhanced NDV production kinetics and expedited the rate of NDV production, while it had no effect on Japanese encephalitis virus production. NDV V protein functions as an IFN antagonist by inhibiting the increase in type I IFNs by NDV infection. The IFN signals in cells expressing NDV V protein were weakened by decreased activation or expression of the dsRNA-activated enzymes. These IFN antagonist activities enhance rapid virus replication and spread in the early phase of viral infection and will be useful in improving the production of viral vaccine strains.


Assuntos
Fibroblastos/virologia , Interferon-alfa/antagonistas & inibidores , Vírus da Doença de Newcastle/fisiologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Cultura de Vírus/métodos , Replicação Viral , Animais , Linhagem Celular , Embrião de Galinha , Chlorocebus aethiops , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Fibroblastos/imunologia , Regulação Viral da Expressão Gênica , Imunidade Inata , Interferon-alfa/genética , Interferon-alfa/imunologia , Interferon-alfa/metabolismo , Cinética , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/imunologia , Receptor de Interferon alfa e beta/metabolismo , Transdução de Sinais , Transfecção , Células Vero
8.
AJR Am J Roentgenol ; 193(5): 1347-53, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19843752

RESUMO

OBJECTIVE: The purpose of our study was to determine the MRI findings of rheumatoid arthritis (RA) and tuberculous arthritis, with emphasis on differential diagnostic features. MATERIALS AND METHODS: MR images of 63 joints in 62 patients with clinically or pathologically proven RA (36 joints in 35 patients) or tuberculous arthritis (27 joints in 27 patients) were evaluated retrospectively with regard to pattern and degree of synovial thickening, size of bone erosions, rim enhancement at bone erosions, degree of bone marrow and periarticular soft-tissue edema, and presence and number of extraarticular cystic masses. MRI findings were compared between RA and tuberculous arthritis by statistical analysis using kappa statistics, the Mann-Whitney U test, linear-by-linear association, and the chi-square test. RESULTS: Nonuniform and greater degree of synovial thickening was more frequent in RA (p < 0.01); the thicker the synovial membrane, the greater the likelihood of RA (p < 0.01). Bone erosions of tuberculous arthritis were larger (p < 0.01), and the likelihood of tuberculous arthritis increased proportionally to the increment of size of the bone erosions (p < 0.01). Rim enhancement at bone erosion was more frequent in tuberculous arthritis (p < 0.01). Extraarticular cystic masses were more frequently seen and more numerous in tuberculous arthritis (p < 0.01). CONCLUSION: Uniform synovial thickening, large size of bone erosion, rim enhancement at site of bone erosion, and extraarticular cystic masses were more frequent and more numerous in tuberculous arthritis. MRI may be helpful in the differentiation between RA and tuberculous arthritis.


Assuntos
Artrite Reumatoide/diagnóstico , Imageamento por Ressonância Magnética/métodos , Tuberculose Osteoarticular/diagnóstico , Adolescente , Adulto , Idoso , Artrite Reumatoide/patologia , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatísticas não Paramétricas , Tuberculose Osteoarticular/patologia
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