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Morphological evolution of upconversion nanoparticles and their biomedical signal generation
摘要： Advancements in the fabrication of upconversion nanoparticles (UCNPs) for synthetic control can enable a broad range of applications in biomedical systems. Herein, we experimentally verified the role of the hydrothermal reaction (HR) time in the synthesis of NaYF4:20%Yb3+/3%Er3+ UCNPs on their morphological evolution and phase transformation at different temperatures. Characterizations of the as-prepared UCNPs were conducted using X-ray diffraction (XRD), electron microscopy and spectroscopy, and thermogravimetric and upconversion (UC) luminescence analysis. We demonstrated that determining the optimal HR time, also referred to here as the threshold time, can produce particles with good homogeneity, hexagonal phase, and UC luminescence efficiency. Subsequently, the polymer coated UCNPs maintained their original particle size distribution and luminescence properties, and showed improved dispersibility in a variety of solvents, cellular nontoxicity, in vitro bioimaging, and biocompatibility as compared to the bare UCNP. Besides this, polyacrylic acid conjugated UCNPs (UCNP@PAA) also revealed the strong anticancer effect by conjugating with doxorubicin (DOX) as compared to the free DOX. Based on these findings, we suggest that these particles will be useful in drug-delivery systems and as in vivo bioimaging agents synchronously.
关键词： phase transformation,morphological evolution,biomedical applications,hydrothermal reaction,upconversion nanoparticles
更新于2025-09-09 09:28:46
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A review of optical methods for continuous glucose monitoring
摘要： Frequent glucose monitoring is a fundamental part of diabetes management, and good glucose control is important for long-term health outcomes. New types of electrochemical sensors that allow for continuous glucose monitoring (CGM) have become an important tool for diabetes management, although they still have drawbacks such as short lifetime and a need for frequent calibration. Other technologies are still being researched for CGM, in an attempt to replace the electrochemical sensors. Optical methods have several advantages for CGM, including potentially long sensor lifetimes and short measurement times, and many developments have been made over the last decades. This paper will review optical measurement methods for CGM, their challenges, and the current research status. The different methods will be compared, and the future prospects for optical methods will be discussed.
关键词： Optical spectroscopy,glucose sensors,continuous glucose monitoring,quantitative optical methods,biomedical applications
更新于2025-09-09 09:28:46
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Scan-Less, Kilo-Pixel, Line-Field Confocal Phase Imaging with Spectrally Encoded Dual-Comb Microscopy
摘要： Confocal laser microscopy (CLM) is a powerful tool in life science research and industrial inspection, and its image acquisition rate is boosted by scan-less imaging techniques. However, optical-intensity-based image contrast in CLM makes it difficult to visualize transparent non-fluorescent objects or reflective objects with nanometer unevenness. In this paper, we introduce an optical frequency comb (OFC) to scan-less CLM to give optical-phase-based image contrast. One-dimensional (1-D) image pixels of a sample are separately encoded onto OFC modes via 1-D spectral encoding by using OFC as an optical carrier of amplitude and phase with a vast number of discrete frequency channels. Then, line-field confocal information of amplitude and phase are decoded from mode-resolved OFC amplitude and phase spectra obtained by dual-comb spectroscopy. The proposed confocal phase imaging will further expand the applications of CLM.
关键词： optical interferometry,optical microscopy,Biomedical imaging
更新于2025-09-09 09:28:46
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Future prospects of fluoride based upconversion nanoparticles for emerging applications in biomedical and energy harvesting
摘要： Rare earth doped/codoped phosphors have been extensively studied for different types of applications based on their intense luminescence features. For this, researchers have tried to choose the inorganic host matrices having both a low phonon cut-off frequency and a high refractive index. Many articles have been published on oxide based phosphor materials, but due to their high cut-off phonon frequency, use of these materials is restricted for optical based applications. This is why additional research has been carried out on fluoride based host materials because of their low phonon frequencies, low composition degradation, and high quantum efficiency. In this paper, the authors review the rare earth fluoride based host nano- and micromaterials for different applications and discuss possible mechanisms.
关键词： biomedical applications,fluoride based upconversion nanoparticles,energy harvesting,luminescence,rare earth doped phosphors
更新于2025-09-09 09:28:46
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Reduction of False Microaneurysms in Retinal Fundus Images using Fuzzy C-Means Clustering in terms NLM Anisotropic Filter
摘要： The identification of MAs is an important phase in the research and grading of suffering from diabetes retinopathy. We present clustering strategy to identify the microaneurysms from the optic disk and cup in the retinal fundus pictures. Fuzzy C-Means (FCM) Clustering is used for clustering the information in which the information factors are grouped with different account level. The first and major phase is preprocessing function, in which the optic cup and disk of the feedback picture is being turned. Originally the optic hard disk is turned in some position and the range between the information factors is calculated and a group is established in accordance with the centroid. For retrieving micro aneurysms in all retinal images in our previous work we used SVM Classification filter in Fuzzy C-Means Clustering. In this paper we propose an effective filtering technique for micro aneurysms detection in retinal image preprocessing. Instead of SVM Filtering in terms of technique we used NLM Anisotropic Filter to process retinal images. Tested on the various simulated retina data repositories combining rotation and scaling, the developed method presents good results and shows robustness to rotations and scale changes.
关键词： Biomedical image processing,pattern recognition,Fuzzy C Means Clustering,Fundus Image,image classification,Anisotropic Diffusion Filter,medical decision-making,Non-Local Methodologies,Spatial Information
更新于2025-09-09 09:28:46
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A Biomedical Surface Enhanced Raman Scattering Substrate: Functionalized Three-Dimensional Porous Membrane Decorated with Silver Nanoparticles
摘要： We fabricated a simple, cheap, and functional surface enhanced Raman scattering substrate for biomedical application. Hotspots between two close silver nanoparticles distributed in the skeleton of a three-dimensional porous membrane, especially in the pores, were formed. The dual poles of micropores in the membrane were discussed. The pores could protect the silver nanoparticles in the pores from being oxidized, which makes the membrane effective for a longer period of time. In addition, Staphylococcus aureus cells could be trapped by the micropores and then the Raman signal became stronger, indicating that the functional surface enhanced Raman scattering substrate is reliable.
关键词： three-dimensional porous membrane,biomedical application,silver nanoparticles,surface enhanced Raman scattering
更新于2025-09-09 09:28:46
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Biosensor-based feature extraction and physiological parameters measurement for biomedical applications
摘要： Physiological signal processing has significantly increased recently among the biomedical researchers for developing wearable standalone devices. Wearable devices are essential in hospital which is used for various biomedical applications such as heart rate and blood pressure measurement. In noisy environment, producing an algorithm for the physiological signal processing and feature extraction is an essential task which depends on the physiological conditions. In this paper, the software-based algorithms are developed for physiological signal processing and physiological parameter measurement. This paper presents biosensor-based real-time acquisition, processing and peak detection of ECG and PPG signals for heart rate, pulse rate and blood pressure measurement. ECG and PPG amplifiers were designed and the real-time signals are acquired through analogue devices and processed using LabVIEW and MatLab environment. The advantages of proposed work are very simple, low cost, easy integration with programming environment and gives continuous monitoring of physiological signals.
关键词： PPG signal,heart rate,ECG signal,biomedical signal processing
更新于2025-09-09 09:28:46
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Advanced fluorescence microscopy techniques for the life sciences
摘要： The development of super-resolved fluorescence microscopy, for which the Nobel Prize was awarded in 2014, has been a topic of interest to physicists and biologists alike. It is inevitable that numerous questions in biomedical research cannot be answered by means other than direct observation. In this review, advances to fluorescence microscopy are covered in a widely accessible fashion to facilitate its use in decisions related to its acquisition and utilization in biomedical research.
关键词： Nobel Prize,direct observation,fluorescence microscopy,super-resolution,biomedical research
更新于2025-09-09 09:28:46
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Near <scp>IR</scp> Photochemistry for Biology: Exploiting the Optical Window of Tissue
摘要： Photoactive molecules enable much of modern biology and biochemistry – a vast library of fluorescent chromophores is used to track and label cellular structures and macromolecules. However, photochemistry is better-known to the synthetic or physical organic chemist as a “light switch” that turns on unusual excited-state reactivity, isomerization, or dynamic adjustment of structure. This review details a rapidly growing approach to bio-photochemistry that uses low-energy near-IR wavelengths not only for imaging, but for close spatial control over chemical switching events in biosystems. Emphasis is placed on topics of biomedical interest: release of gaseous biological messengers, uncaging of drugs, nano-therapeutics, and modification of biomaterials.
关键词： drug uncaging,bio-photochemistry,nano-therapeutics,biomaterials modification,optical window of tissue,biomedical applications,gasotransmitters,Near IR photochemistry
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Singapore, Singapore (2018.4.22-2018.4.26)] 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Vibration Energy Harvester Driven Wearable Biomedical Diagnostic System
摘要： Smart fabric technology (SFT) makes easier to monitor physiological parameters. Smart Fabric technology or An electronic textile (e-textile) is prepared by incorporating wearable systems along with sensors deployed for body parameters which are used by doctors as markers to summarize health status. Such existing systems are battery driven and required cumbersome maintenance .It is the main cause for limited life span and lack of biocompatibility. These limitations are well addressed by proposing energy harvesting device (EHD) as an alternative to battery. It is basically an energy transduction mechanism in which vibration energy converted to useful electrical energy. This work focuses on low cost fabrication of EHD to make SFT self powered. The fabricated device is built out of polymer substrate , silver electrodes and zinc oxide as piezoelectric material .The devices have been characterized and found electric potential of 2.51Vpeak, 0.76Vrms whereas power was 12.61μWpeak, and 1.18μWrms for 500K(cid:159) load at 53Hz peak resonant frequency. The power demand of commercially available cardiac sensor, adaptive pace maker, pulse oxymeter, sensor node demand power in the range of 1(cid:541)W to 100(cid:541)W .This reveals feasibility of energy harvester as an power source for SFT. Array of series and parallelly connected EHD can be deployed for fulfilling demand of integrated SFT.
关键词： Energy harvesting device,Biomedical sensing,e-Textiles
更新于2025-09-09 09:28:46