RESUMO
Rapid and sensitive detection of food-borne bacteria has remained challenging over the past few decades. We propose a surface-enhanced Raman scattering sensing strategy based on a novel bioinspired surface-enhanced Raman scattering substrate, which can directly detect dye molecular residues and food-borne pathogen microorganisms in the environment. The surface-enhanced Raman scattering platform consists of a natural diatomite microporous array decorated with a metal-phenolic network that enables the in situ reduction of gold nanoparticles. The as-prepared nanocomposites display excellent surface-enhanced Raman scattering activity with the lowest limit of detection and the maximum Raman enhancement factor of dye molecules up to 10-11 M and 1.18 × 107, respectively. For food-borne bacterial detection, a diatomite microporous array decorated with a metal polyphenol network and gold nanoparticle-based surface-enhanced Raman scattering analysis is capable of distinguishing the biochemical fingerprint information of Staphylococcus aureus and Escherichia coli, indicating the great potential for strain identification.
Assuntos
Terra de Diatomáceas , Escherichia coli , Ouro , Análise Espectral Raman , Staphylococcus aureus , Análise Espectral Raman/métodos , Staphylococcus aureus/isolamento & purificação , Terra de Diatomáceas/química , Escherichia coli/isolamento & purificação , Ouro/química , Nanopartículas Metálicas/química , Microbiologia de Alimentos , Propriedades de Superfície , Tamanho da PartículaRESUMO
The research of sleep staging is not only the basis of diagnosing sleep related diseases, but also the precondition of evaluating sleep quality, and has important clinical significance. In recent years, the research of automatic sleep staging based on computer has become a hotspot and made some achievements. Feature extraction and feature classification are two key technologies in automatic sleep staging system. In order to achieve effective automatic sleep staging, we proposed a new automatic sleep staging method which combines the energy features and least squares support vector machines (LS-SVM). Firstly, we used FIR band-pass filter to extract the energy features of Pz-Oz channel sleep electroencephalogram (EEG) signals, and compared them with those from wavelet packet transform method. Then we designed an LS-SVM classifier to realize the automatic sleep stage classification. The research showed that FIR band-pass filter (with the Kaiser window) performed better than wavelet packet transform (WPT) for energy feature extraction just in terms of the data from the Sleep-EDF Database and the LS-SVM classifier (with the RBF Kernel function) designed was good, and the automatic sleep staging method proposed in this paper was better than many similar methods from other studies with an average accuracy of 88.89% and had a very prosperous application future.
Assuntos
Fases do Sono , Máquina de Vetores de Suporte , Eletroencefalografia , Humanos , Análise dos Mínimos QuadradosRESUMO
Near-infrared surface-enhanced Raman scattering (NIR SERS) imaging is now a promising molecular imaging technology due to its narrow spectral bandwidth, low background interference and deep imaging depth. In this work, we report a novel strategy for fabrication of NIR SERS nanoprobes without using any expensive and highly toxic organic dyes. Multifunctional conducting polymer (CP) materials, serving as both biocompatible surface coatings and NIR-active reporters, are directly fabricated on the surface of gold nanorods (GNRs) via facile oxidative polymerization. The dye-free NIR SERS nanoprobes (GNR-CPs) exhibit good structural stability, good biocompatibility and intriguing NIR SERS activity. GNR-CPs also show an extraordinary NIR photothermal transduction efficiency, indicating the potential for cancer therapy. The applications of GNR-CPs as new types of theranostic agents for NIR SERS imaging and high-performance photothermal therapy are accomplished in vitro and in vivo.
Assuntos
Nanopartículas/química , Neoplasias/terapia , Fotoquímica , Análise Espectral Raman , Animais , Materiais Biocompatíveis/química , Linhagem Celular Tumoral , Corantes/química , Feminino , Humanos , Camundongos , Microscopia Eletrônica de Transmissão , Nanomedicina , Transplante de Neoplasias , Neoplasias/diagnóstico , Neoplasias/patologia , Polímeros/química , Espectroscopia de Luz Próxima ao Infravermelho , Propriedades de Superfície , Raios UltravioletaRESUMO
A photonic traditional Chinese medicine (TCM) information therapy was developed that has applications in whole health nursing including the prevention and treatment of ischemic cardiovascular and cerebrovascular diseases as well as the conditioning of the subhealth state. This therapy utilizes the beam of a 630 nm LED light to irradiate the oropharynx, while simultaneously employing two beams of 650 nm LED light to irradiate corresponding acupuncture points resulting in a synergistic outcome. This method was named "1 + 2 phototherapy." The principle mechanism of the therapy is a series of photon induced biological effects that are triggered by stimulating the photosensitive tissues of the oropharynx. This tissue includes the oral mucosa, capillaries, lymph nodes, saliva glands, nerves, and Jingluo and is stimulated by light beams of certain photon energy and imitative acupuncture information. Thermal tomography imaging shows that the average temperature of the upper-body was improved significantly after oropharyngeal irradiation under irradiation of "Futu point": the heat radiation of the spine, as well as chest, shoulders, arms, and clavicle, increased under irradiation of "Hoku," whereas the overall average temperature was below the temperature before irradiation. The experiment indicates that this therapy can promote blood circulation, regulate varied physiological parameters, and have holistic effects in whole health nursing.