Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Methods Mol Biol ; 2671: 307-318, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37308652

RESUMO

Recent experiments have shown that the molecular complex of vault has large conformational changes at its shoulder and cap regions in solution. From the comparison of two configuration structures, it has been found that the shoulder region can twist and move outward, while the cap region will rotate and push upward correspondingly. To further understand these experimental results, in this paper, we study the vault dynamics for the first time. Since vault has an extremely large-sized structure with around 63,336 Cα atoms, traditional normal mode method with the Cα coarse-grained representation will fall short. We employ a newly invented multiscale virtual particle-based anisotropic network model (MVP-ANM). To reduce the complexity, the 39-folder vault structure is coarse-grained to about 6000 virtual particles, which significantly reduces the computational cost while still maintaining the basic structure information. Among the 14 low frequency eigenmodes from Mode 7 to Mode 20, two eigenmodes, i.e., Mode 9 and Mode 20, are found to be directly associated with the experimental observations. In Mode 9, shoulder region undergoes a significant expansion while the cap part is lifted upward. In Mode 20, a clear rotation of both shoulder and cap regions is well observed. Our results are consistent with the experimental observations. More importantly, these low frequency eigenmodes indicate that the vault waist, shoulder and lower cap regions are the most likely regions for the opening of the vault particle. And the opening mechanism is highly likely to be rotation and expansion at these regions. As far as we know, this is the first work to provide the normal mode analysis for the vault complex.


Assuntos
Anisotropia , Rotação
2.
Front Psychol ; 13: 948634, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35992418

RESUMO

A significant characteristic of live streaming commerce is that popularity cues are tactically created and utilized to improve product sales, as atmospheric cues. However, research on live streaming commerce that investigates the effects of popularity cues is scarce. This study aims to reveal the role of popularity cues, including streamer popularity and product popularity, in promoting consumers' impulse purchase. Following the stimulus-organism-response paradigm, this study reveals the underlying mechanism. This study surveyed 402 customers and empirically demonstrates that streamer popularity and product popularity can trigger consumers' impulse purchase by enhancing perceived streamer reputation and perceived competition, respectively. Meanwhile, perceived power, as an inherent factor of consumers, plays a moderating role that only attenuates the effect of streamer popularity on perceived streamer reputation. This study contributes to a better understanding of the working mechanism of popularity cues and offers practical insights into how to effectively utilize these atmospheric cues in live streaming commerce.

3.
Sci Rep ; 12(1): 9699, 2022 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-35690623

RESUMO

Hodge theory reveals the deep intrinsic relations of differential forms and provides a bridge between differential geometry, algebraic topology, and functional analysis. Here we use Hodge Laplacian and Hodge decomposition models to analyze biomolecular structures. Different from traditional graph-based methods, biomolecular structures are represented as simplicial complexes, which can be viewed as a generalization of graph models to their higher-dimensional counterparts. Hodge Laplacian matrices at different dimensions can be generated from the simplicial complex. The spectral information of these matrices can be used to study intrinsic topological information of biomolecular structures. Essentially, the number (or multiplicity) of k-th dimensional zero eigenvalues is equivalent to the k-th Betti number, i.e., the number of k-th dimensional homology groups. The associated eigenvectors indicate the homological generators, i.e., circles or holes within the molecular-based simplicial complex. Furthermore, Hodge decomposition-based HodgeRank model is used to characterize the folding or compactness of the molecular structures, in particular, the topological associated domain (TAD) in high-throughput chromosome conformation capture (Hi-C) data. Mathematically, molecular structures are represented in simplicial complexes with certain edge flows. The HodgeRank-based average/total inconsistency (AI/TI) is used for the quantitative measurements of the folding or compactness of TADs. This is the first quantitative measurement for TAD regions, as far as we know.


Assuntos
Cromossomos , Análise de Dados , Estrutura Molecular
4.
Head Neck Pathol ; 13(4): 635-642, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30888638

RESUMO

Proliferative verrucous leukoplakia (PVL) is a premalignant condition of the oral mucosa with > 70% chance of progression to squamous cell carcinoma (SCC), while lacking the common risks and behavior seen in non-PVL oral squamous carcinogenesis. PVL follows a multi-stage slow, relentless and usually multifocal expansion of surface epithelial thickening that over time takes on a verrucous architecture, eventually leading to verrucous carcinoma and/or dysplasia followed by "conventional" SCC, a process that takes years and is notoriously difficult to manage. As mucosal surfaces and carcinomas arising at these sites, are colonized by microorganisms, host receptors for microbial products have received attention as potential contributors to carcinogenesis. Studies show that microbial pattern recognition toll-like receptor (TLR)2 in various epithelial cells is upregulated in premalignant lesions and in malignant cells and can activate oncogenic pathways. Because of the highly progressive nature of PVL, we examined TLR2 expression in well-characterized PVL samples by immunohistochemistry. We found that, similar to epithelial dysplasia and SCC, PVL keratinocytes throughout the epithelial thickness showed diffuse TLR2 expression even in early stage lesions prior to onset of dysplasia. In contrast, oral mucosal samples in the absence of hyperorothokeratosis or dysplasia, expressed TLR2 primarily in the basal and parabasal layers. Given the high rates of PVL transformation and the previously established pro-cancer role of high TLR2 expression in malignant oral squamous cells, it is important to determine how its' expression and functions are regulated in the oral squamous epithelium, and what is the specific TLR2 role in carcinogenesis.


Assuntos
Biomarcadores Tumorais/análise , Leucoplasia Oral/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Receptor 2 Toll-Like/biossíntese , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Leucoplasia Oral/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo
5.
Urol Int ; 88(4): 470-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22433441

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effect of cyanidin-3-O-ß-D-glucopyranoside (C3G) concentrated materials from mulberry fruit on improvement and protection of erectile function. MATERIALS AND METHODS: Sprague-Dawley rats (12 weeks old) were divided into three groups (n = 12 in each): normal control, diabetes mellitus (DM), and DM with C3G concentrated material treatment (DM + C3G). DM and DM + C3G group rats received a single injection of streptozotocin (50 mg/kg), and 4 weeks after induction of diabetes, the DM + C3G group rats were treated with daily concentrated material treatment (10 mg/kg) dissolved in water for 8 weeks. After 12 weeks of streptozotocin injections, the rats in each group underwent intracavernosal pressure measurement and then the corporal tissues were sampled. RESULTS: The DM group rats showed markedly lower erectile parameters than those in the control group, whereas rats in the DM + C3G group showed improved erectile function by minimizing corporal apoptosis and increasing the expression of endothelial nitric oxide synthase (NOS) and neuronal NOS protein. A significant increase in 8-hydroxy-2-deoxyguanosine (8-OHdG) was shown in the DM group compared with the normal group. However, in the DM + C3G group, 8-OHdG was statistically significantly reduced compared with the DM group. CONCLUSIONS: The current study is the first to suggest that C3G concentrated materials may have a potency to improve and protect erectile function under conditions of diabetes-induced oxidative stress.


Assuntos
Antocianinas/farmacologia , Antioxidantes/farmacologia , Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Experimental/tratamento farmacológico , Disfunção Erétil/prevenção & controle , Morus , Estresse Oxidativo/efeitos dos fármacos , Ereção Peniana/efeitos dos fármacos , Pênis/efeitos dos fármacos , 8-Hidroxi-2'-Desoxiguanosina , Animais , Antocianinas/isolamento & purificação , Antioxidantes/isolamento & purificação , Apoptose/efeitos dos fármacos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Complicações do Diabetes/etiologia , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Complicações do Diabetes/fisiopatologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Disfunção Erétil/etiologia , Disfunção Erétil/metabolismo , Disfunção Erétil/patologia , Disfunção Erétil/fisiopatologia , Frutas , Marcação In Situ das Extremidades Cortadas , Masculino , Morus/química , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Pênis/metabolismo , Pênis/patologia , Pênis/fisiopatologia , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...