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1.
Adv Mater ; : e2407712, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940342

RESUMO

Developing strong and simultaneously tough polymeric materials with excellent thermal stability and mechanical performance even under extreme temperatures is truly a challenge. In a disruptive progress, continuous polymeric yarns are developed with a combination of high tensile strength of (1145 ± 44) MPa and ultrahigh toughness of (350 ± 24) J g-1 and high thermomechanical properties from -196 to 200 °C. The comprehensive thermomechanical performance of this yarn surpasses that of previously developed polymeric materials and dragline spider silks. The results demonstrate that the molecular structure of polyimide (PI) with the incorporation of flexible-rigid macromolecular, hierarchically spiral-oriented fibers, and high glass transition temperature (248 °C) are keys for the yarn's notable comprehensive performance in thermomechanical properties. The materials are ideal for technical components exposed to high thermomechanical loadings, such as those encountered in spacecraft or automotive engineering for safety-critical applications.

2.
Sci Rep ; 14(1): 1448, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38228854

RESUMO

Breast cancer is a significant global health burden, causing a substantial number of deaths. Systemic metastatic tumour cell dissemination is a major cause of poor outcomes. Understanding the mechanisms underlying metastasis is crucial for effective interventions. Changes in the extracellular matrix play a pivotal role in breast cancer metastasis. In this work, we present an advanced multimodal X-ray computed tomography, by combining Small-angle X-ray Scattering Tensor Tomography (SAXS-TT) and X-ray Fluorescence Computed Tomography (XRF-CT). This approach likely brings out valuable information about the breast cancer metastasis cascade. Initial results from its application on a breast cancer specimen reveal the collective influence of key molecules in the metastatic mechanism, identifying a strong correlation between zinc accumulation (associated with matrix metalloproteinases MMPs) and highly oriented collagen. MMPs trigger collagen alignment, facilitating breast cancer cell intravasation, while iron accumulation, linked to angiogenesis and vascular endothelial growth factor VEGF, supports cell proliferation and metastasis. Therefore, these findings highlight the potential of the advanced multimodal X-ray computed tomography approach and pave the way for in-depth investigation of breast cancer metastasis, which may guide the development of novel therapeutic approaches and enable personalised treatment strategies, ultimately improving patient outcomes in breast cancer management.


Assuntos
Neoplasias da Mama , Melanoma , Neoplasias Cutâneas , Humanos , Feminino , Neoplasias da Mama/patologia , Fator A de Crescimento do Endotélio Vascular , Raios X , Espalhamento a Baixo Ângulo , Difração de Raios X , Metaloproteinases da Matriz/metabolismo , Colágeno , Metástase Neoplásica
3.
ACS Nano ; 15(3): 3754-3807, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33650433

RESUMO

X-ray-based analytics are routinely applied in many fields, including physics, chemistry, materials science, and engineering. The full potential of such techniques in the life sciences and medicine, however, has not yet been fully exploited. We highlight current and upcoming advances in this direction. We describe different X-ray-based methodologies (including those performed at synchrotron light sources and X-ray free-electron lasers) and their potentials for application to investigate the nano-bio interface. The discussion is predominantly guided by asking how such methods could better help to understand and to improve nanoparticle-based drug delivery, though the concepts also apply to nano-bio interactions in general. We discuss current limitations and how they might be overcome, particularly for future use in vivo.


Assuntos
Nanopartículas , Síncrotrons , Lasers , Radiografia , Raios X
4.
J Radiat Res ; 49(5): 527-32, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18667793

RESUMO

An investigation was carried out to study the potential use of the angular distribution of scattered photons by human breast samples for a rapid identification of neoplasias of breast tissues. This technique has possible applications as diagnostic aid for breast cancer. In this work, a commercial powder diffractometer was used to obtain the scattering profiles from breast tissues histopathologically classified as normal breast tissues, fibroadenomas (benign breast diseases) and carcinomas (malignant breast diseases), in the interval 0.02A(-1) < x < 0.62A(-1). The experimental methods and data corrections are discussed in detail, and they included background subtraction, polarization, self-attenuation and geometric effects. The validation of the experimental procedure was achieved through an analysis of water sample. The results showed that the scattering profile is a unique impression of each type of tissue, being correlated with their microscopic morphological features. Multivariate analysis was applied to these profiles in order to verify if the information carried by these scattering profiles allow the differentiation between normal, benign and malignant breast tissues. The statistical analysis results showed that a correct identification of 75% of the analyzed samples is accomplished. The values of sensibility and specificity of this method in correctly differentiating between normal and neoplastic samples were 95.6% and 82.3%, respectively, while the values for differentiation between benign and malignant neoplasias were 78.6% and 62.5%. These initial results indicate the feasible use of commercial powder diffractometer to provide a rapid diagnostic with a high sensitivity.


Assuntos
Neoplasias da Mama/classificação , Neoplasias da Mama/diagnóstico , Diagnóstico por Computador/métodos , Prótons , Refratometria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Pós , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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