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The detailed biological investigations about combined effects of novel polyphenolic and photo-plasmonic nanoparticles loaded graphene nanosheets on coronary endothelial cells and isolated rat aortic rings
摘要： In this study, the effect of Polyp-Au-GO nanocomposite on VSMC proliferation, cell cycle proteins, down-regulation of mRNA in the rat was tested. Briefly, Polyp-Au-GO composite material was synthesized and characterized by UV-Vis spectra, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Polyp-Au-GO composite exhibited the absorbance peak at 530nm. XRD analysis confirmed the crystalline particle with size ranging between 16.5-32.6 nm. The crystallinity differences of the nanocomposite were examined by Raman spectroscopy analysis. The presence of a strong band (1500 cm-1) and the absence of other lower frequency bands confirmed that the absence of crystallinity of Polyp-Au-GO nanocomposite. The thermal properties of Polyp-Au-GO nanocomposite were determined by TGA analysis. The results revealed that 15% of its weight loss has occurred at 300 °C. Further, the growth of VSMCs was inhibited by the treatment of Polyp-Au-GO composite at 72 h. The IC50 value was registered at 0.57 μg/mL. Additionally, the Polyp-Au-GO composite arrest G1 cell cycle and down-regulated cell cycle proteins. These Polyp-Au-GO composite inhibited of CEC proliferation. These results suggest that Polyp-Au-GO composite inhibits VSMC proliferation and TNF-R-mediated inflammatory responses. This Polyp-Au-GO composite also reduced the extracellular ERK1/2 phosphorylation. Furthermore, Polyp-Au-GO composite inhibited TNF-R-evoked inflammatory responses. Moreover, Polyp-Au-GO composite inhibited TNF-R-evoked inflammatory responses. This study suggested the therapeutic role of Polyp-Au-GO composite in cardiovascular disease.
关键词： inflammation,cardiac disease,vascular smooth cells,Nanocomposite,biomedical
更新于2025-09-12 10:27:22
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Imaging of X-Ray-Excited Emissions from Quantum Dots and Biological Tissue in Whole Mouse
摘要： optical imaging in clinical and preclinical settings can provide a wealth of biological information, particularly when coupled with targetted nanoparticles, but optical scattering and absorption limit the depth and resolution in both animal and human subjects. two new hybrid approaches are presented, using the penetrating power of X-rays to increase the depth of optical imaging. foremost, we demonstrate the excitation by X-rays of quantum-dots (QD) emitting in the near-infrared (niR), using a clinical X-ray system to map the distribution of QDs at depth in whole mouse. We elicit a clear, spatially-resolved NIR signal from deep organs (brain, liver and kidney) with short (1 second) exposures and tolerable radiation doses that will permit future in vivo applications. furthermore, X-ray-excited endogenous emission is also detected from whole mouse. the use of keV X-rays to excite emission from QDs and tissue represent novel biomedical imaging technologies, and exploit emerging QDs as optical probes for spatial-temporal molecular imaging at greater depth than previously possible.
关键词： biomedical imaging,Biological tissue,Whole Mouse,Quantum Dots,NIR signal,X-ray-excited emissions
更新于2025-09-12 10:27:22
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Leveraging Domain Knowledge to Improve Microscopy Image Segmentation With Lifted Multicuts
摘要： The throughput of electron microscopes has increased significantly in recent years, enabling detailed analysis of cell morphology and ultrastructure in fairly large tissue volumes. Analysis of neural circuits at single-synapse resolution remains the flagship target of this technique, but applications to cell and developmental biology are also starting to emerge at scale. On the light microscopy side, continuous development of light-sheet microscopes has led to a rapid increase in imaged volume dimensions, making Terabyte-scale acquisitions routine in the field. The amount of data acquired in such studies makes manual instance segmentation, a fundamental step in many analysis pipelines, impossible. While automatic segmentation approaches have improved significantly thanks to the adoption of convolutional neural networks, their accuracy lags behind human annotations and requires additional manual proof-reading. A still major hindrance to further improvements is the limited field of view of the segmentation networks preventing them from learning to exploit the expected cell morphology or other prior biological knowledge which humans use to inform their segmentation decisions. In this contribution, we show how such domain-specific information can be leveraged by expressing it as long-range interactions in a graph partitioning problem known as the lifted multicut problem. Using this formulation, we demonstrate significant improvement in segmentation accuracy for four challenging boundary-based segmentation problems from neuroscience and developmental biology.
关键词： biomedical image analysis,biological priors,instance segmentation,LM segmentation,connectomics,EM segmentation
更新于2025-09-11 14:15:04
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Remelt processing and microstructure of selective laser melted Ti25Ta
摘要： In this study, elemental powder mixtures of Ti25Ta, an alloy with promise for orthopaedic applications, were processed using Selective Laser Melting (SLM), an emerging manufacturing method for bespoke implants. Material density and homogeneity was investigated as a function of laser scan speed and scanning strategy. Dense (> 99.99 %), pore free material was obtained at optimised processing parameters and a ‘remelt’ scan strategy improved melting of the Ta powders, avoiding keyhole formation. Tensile and ultrasonic modulus testing of the SLM Ti25Ta revealed that the processed material has a similar yield strength to SLM commercially pure Ti, namely 426 ± 15 MPa, with a significant reduction of elastic modulus to 65 ± 5 GPa. The remelt scan strategy increased the yield strength to 545 ± 9 MPa, without altering the elastic modulus, however reduced the elongation from 25 ± 1 to 11 ± 4 %. TEM analysis revealed the microstructure consisted of predominantly hexagonal α′ martensite with a limited amount of orthorhombic α′′ martensite formed in the Ta-rich regions near partially melted Ta particles, specifically facilitated by enhanced diffusion occurring during the remelt scan. The composition range for the α′′ phase was observed to be approximately 40-50 wt.% Ta. Electron back-scattered imaging (BSI) and back scattered diffraction (EBSD) revealed the formation of the prior β grains with close to equiaxed morphology and a slight texture in the α′ martensite. The application of the remelt scan disrupted the prior β grain structure and resulted in randomly oriented α′ laths.
关键词： Mechanical properties,Biomedical,Selective laser melting,Titanium,Tantalum
更新于2025-09-11 14:15:04
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Controlled aggregation of amphiphilic aggregation‐induced emission polycation and superparamagnetic iron oxide nanoparticles as fluorescence/magnetic resonance imaging probes
摘要： Fluorescence/magnetic resonance (MR) dual-mode imaging, which combines the excellent single-cell sensitivity of ?uorescence imaging and the high spatial resolution of MR imaging, has been applied to different biomedical applications. However, the aggregation-caused quenching characteristic of most ?uorescence molecules often put limits in their applications. Herein, a ?uorescence/MR dual-mode imaging probe [polyethylene glycol-polyethylenimine-tetraphenylethene (PEG-PEI-TPE)/superparamagnetic iron oxide (SPIO)] with aggregation-induced emission characteristic is prepared by coupling poly(acrylic acid)-coated SPIO with PEG-PEI-TPE. The ?uorescence intensity and lifetime of PEG-PEI-TPE/SPIO is higher than PEG-PEI-TPE especially at lower polymer concentrations (≤0.2 mg mL?1). Moreover, the ?uorescence intensity of PEG-PEI-TPE/SPIO gradually increased along with the decline of the pH from 9.0 to 4.0, which is bene?cial for studying intracellular organelles. The T2 relaxivity of PEG-PEI-TPE/SPIO is 212.3 Fe mM?1 s?1 under a 3.0 T MR scanner. Cell labeling experiment shows that PEG-PEI-TPE/SPIO can effectively label RAW 264.7 and Hela cells, and labeled cells are visible under both ?uorescence and clinical MR examinations.
关键词： composites,drug delivery systems,dyes/pigments,biomedical applications,self-assembly
更新于2025-09-11 14:15:04
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Magneto-Plasmonic Co@Pt@Au Nanocrystals for Biosensing and Therapeutics
摘要： Multifunctional nanoparticles (NPs) exhibiting high magnetic property and plasmonic resonance, are expected to be advanced nanomaterials which enable therapy, detection and diagnosis simultaneously for medical applications. To achieve the practical performance of the multifunctional NPs, the precise design and synthesis both are required. In this work, considering the chemical stability and controllability, Co-Pt@Au core-shell NPs, which exhibit high magnetic property and plasmonic resonance were theoretically designed based on calculation and then experimentally synthesized using alcohol reduction method. Co-Pt NPs were uniformly synthesized using a technique which enables reduction control of Pt through the formation of Pt-oleylamine complex. Moreover, depending on Co/Pt ratio, distribution of Co and Pt in a nanoparticle were precisely controlled, and as a result, Co-Pt alloy and Co@Pt core-shell NPs were individually prepared. In particular, Co@Pt NPs exhibit a high magnetic property and are suitable for Au coating due to a small lattice mismatch. In fact, Au coating onto Co@Pt NPs was successfully performed via inhomogeneous nucleation, which results in Co@Pt@Au NPs exhibiting plasmonic response of Au with high magnetic property and being dispersed in water by ligand-exchange for in-vivo use. The developed synthetic method enables designed synthesis of complicated multicomponent nanoparticles through tunable reduction reaction and provides highly potential NPs for transport and sensing applications.
关键词： Biomedical nanomaterials,Pt-Oleylamine complex,Magnetic and plasmonic properties,Magnetic transport,Alcohol reduction method,Sensing,Co@Pt@Au colloidal nanoparticles,Ligand exchange
更新于2025-09-11 14:15:04
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Radioluminescence in biomedicine: physics, applications, and models
摘要： The electromagnetic spectrum contains different frequency bands useful for medical imaging and therapy. Short wavelengths (ionizing radiation) are commonly used for radiological and radionuclide imaging and for cancer radiation therapy. Intermediate wavelengths (optical radiation) are useful for more localized imaging and for photodynamic therapy. Finally, longer wavelengths are the basis for magnetic resonance imaging and for hyperthermia treatments. Recently, there has been a surge of interest for new biomedical methods that synergize optical and ionizing radiation by exploiting the ability of ionizing radiation to stimulate optical emissions. These physical phenomena, together known as radioluminescence, are being used for applications as diverse as radionuclide imaging, radiation therapy monitoring, phototherapy, and nanoparticle- based molecular imaging. This review provides a comprehensive treatment of the physics of radioluminescence and includes simple analytical models to estimate the luminescence yield of scintillators and nanoscintillators, Cherenkov radiation, air fluorescence, and biologically endogenous radioluminescence. Examples of methods that use radioluminescence for diagnostic or therapeutic applications are reviewed and analyzed in light of these quantitative physical models of radioluminescence.
关键词： Cherenkov luminescence,nanotechnology,Radioluminescence,biomedical imaging,scintillators,radiation therapy
更新于2025-09-11 14:15:04
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A Fast Fluorescence Background Suppression Method for Raman Spectroscopy Based on Stepwise Spectral Reconstruction
摘要： Raman spectroscopy is a rapid and non-destructive technique for detecting unique spectral fingerprints from biological samples. Raw Raman spectra often come with strong fluorescence background, which makes spectral interpretation challenging. Although fluorescence background can be suppressed experimentally, this approach requires sophisticated and costly instruments. For convenience and cost-effectiveness, numerical methods have been used frequently to remove fluorescence background. Unfortunately, many of such methods suffer from long computation time. Therefore, a fast numerical method for fluorescence suppression is highly desirable especially in Raman spectroscopic imaging where Raman measurements from many pixels need to be processed rapidly. In response to this demand, we propose a fast numerical method for fluorescence background suppression based on the strategy of stepwise spectral reconstruction that we previously developed. Compared with traditional computational methods, including polynomial fitting, wavelet transform, Fourier transform, and peak detection, our results consistently show significant advantages in both accuracy and computational efficiency when tested on Raman spectra measured from phantoms and cells as well as surfaced enhanced Raman spectra from blood serum samples. In particular, our method yields clean Raman spectra closest to the reference results generated by polynomial fitting while several orders of magnitude faster than others. Therefore, the proposed fast fluorescence suppression method is promising in Raman spectroscopic imaging or related application in which high computation efficiency is critical and a calibration dataset is available.
关键词： Raman spectroscopy,fluorescence suppression,Raman imaging,Biomedical signal processing
更新于2025-09-11 14:15:04
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A Signal Processing Method for Respiratory Rate Estimation through Photoplethysmography
摘要： Monitoring of respiration is crucial for determining a patient′s health status, specially previously and after an operation. However, many conventional methods are difficult to use in a spontaneously ventilating patient. This paper presents a method for estimating respiratory rate from the signal of a photoplethysmograph. This is a non-invasive sensor that can be used to obtain an estimation of beats per minute of a given patient by measuring light reflection on the patient’s blood vessel and counting changes in blood flow. The PPG signal also offers information about respiration, so respiratory rate can be obtained through signal processing. The proposed method based on digital filtering was implemented in a wearable device and tested on 30 volunteers, and the results were compared with the ones measured by traditional ways. The results show that there is no statistically significant difference between the data measured by the device and the traditional method.
关键词： biomedical signal processing,telemedicine,photoplethysmography,respiratory rate
更新于2025-09-11 14:15:04
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New frontiers in biomedical science and engineering during 2014–2015
摘要： The International Conference on Biomedical Engineering and Biotechnology (ICBEB) is an international meeting held once a year. This, the fourth International Conference on Biomedical Engineering and Biotechnology (ICBEB2015), will be held in Shanghai, China, during August 18th-21st, 2015. This annual conference intends to provide an opportunity for researchers and practitioners at home and abroad to present the most recent frontiers and future challenges in the fields of biomedical science, biomedical engineering, biomaterials, bioinformatics and computational biology, biomedical imaging and signal processing, biomechanical engineering and biotechnology, etc. The papers published in this issue are selected from this Conference, which witness the advances in biomedical engineering and biotechnology during 2014–2015.
关键词： ICBEB,biomedical imaging,Frontiers in biomedical engineering
更新于2025-09-10 09:29:36