-
Biomedical Optics Express Aug 2023Traditional miniaturized fluorescence microscopes are critical tools for modern biology. Invariably, they struggle to simultaneously image with a high spatial resolution...
Traditional miniaturized fluorescence microscopes are critical tools for modern biology. Invariably, they struggle to simultaneously image with a high spatial resolution and a large field of view (FOV). Lensless microscopes offer a solution to this limitation. However, real-time visualization of samples is not possible with lensless imaging, as image reconstruction can take minutes to complete. This poses a challenge for usability, as real-time visualization is a crucial feature that assists users in identifying and locating the imaging target. The issue is particularly pronounced in lensless microscopes that operate at close imaging distances. Imaging at close distances requires shift-varying deconvolution to account for the variation of the point spread function (PSF) across the FOV. Here, we present a lensless microscope that achieves real-time image reconstruction by eliminating the use of an iterative reconstruction algorithm. The neural network-based reconstruction method we show here, achieves more than 10000 times increase in reconstruction speed compared to iterative reconstruction. The increased reconstruction speed allows us to visualize the results of our lensless microscope at more than 25 frames per second (fps), while achieving better than 7 µm resolution over a FOV of 10 mm. This ability to reconstruct and visualize samples in real-time empowers a more user-friendly interaction with lensless microscopes. The users are able to use these microscopes much like they currently do with conventional microscopes.
PubMed: 37799697
DOI: 10.1364/BOE.490199 -
Journal of Oral and Maxillofacial... 2022Pathologists come across various structures in the microscopic sections that are unrelated to the tissues. Artifacts can occur in the tissue from the time the area is...
BACKGROUND
Pathologists come across various structures in the microscopic sections that are unrelated to the tissues. Artifacts can occur in the tissue from the time the area is prepared for biopsy, during fixation, grossing, processing, sectioning and staining of the specimen. Food substances may get entrapped into the oral tissues and can lead to misdiagnosis. The aim of this study was to observe the microscopic appearances of commonly implanted food particles.
METHODS
Fourteen food samples were procured from a local market in Chennai, India. This included guava, chilli, chickpeas, channa dal (split chickpeas), cucumber, brinjal, carrot, capsicum, cabbage and urad dal and brown chickpea. The food samples were fixed in 10% formalin for 24 h and were subsequently processed. Hematoxylin and eosin staining was performed, and the sections were observed under the microscope.
RESULTS
Each specimen revealed unique, distinct histology of each food type. Channa dal microscopically in hematoxylin- and eosin-stained sections revealed round-to-oval structures with central pale eosinophilic lobulation. Capsicum showed round-to-polygonal structures of different shapes and sizes with clear central areas. Urad dal microscopically showed cluster of 5-6 eosinophilic structures separated by regular partitions.
CONCLUSION
It is important to study the microscopic appearances of commonly implanted food particles to prevent any diagnostic dilemmas. Further studies are required involving various other food particles and their microscopic appearances.
PubMed: 36588857
DOI: 10.4103/jomfp.jomfp_117_21 -
Frontiers in Chemistry 2022As a typical microscopic imaging technology, the emergence of the microscope has accelerated the pace of human exploration of the micro world. With the development of... (Review)
Review
As a typical microscopic imaging technology, the emergence of the microscope has accelerated the pace of human exploration of the micro world. With the development of science and technology, microscopes have developed from the optical microscopes at the time of their invention to electron microscopes and even atomic force microscopes. The resolution has steadily improved, allowing humans to expand the field of research from the initial animal and plant tissues to microorganisms such as bacteria, and even down to the nanolevel. The microscope is now widely used in life science, material science, geological research, and other fields. It can be said that the development of microscopes also promotes the development of micro- and nanotechnology. It is foreseeable that microscopes will play a significant part in the exploration of the microworld for a long time to come. The development of microscope technology is the focus of this study, which summarized the properties of numerous microscopes and discussed their applications in micro and nanotechnology. At the same time, the application of microscopic imaging technology in micro- and nanofields was investigated based on the properties of various microscopes.
PubMed: 35864864
DOI: 10.3389/fchem.2022.931169 -
ArXiv Oct 2023Scanning-probe and wide-field magnetic microscopes based on Nitrogen-Vacancy (NV) centers in diamond have enabled remarkable advances in the study of biology and...
Scanning-probe and wide-field magnetic microscopes based on Nitrogen-Vacancy (NV) centers in diamond have enabled remarkable advances in the study of biology and materials, but each method has drawbacks. Here, we implement an alternative method for nanoscale magnetic microscopy based on optical control of the charge state of NV centers in a dense layer near the diamond surface. By combining a donut-beam super-resolution technique with optically detected magnetic resonance spectroscopy, we imaged the magnetic fields produced by single 30-nm iron-oxide nanoparticles. The magnetic microscope has a lateral spatial resolution of ~100 nm, and it resolves the individual magnetic dipole features from clusters of nanoparticles with interparticle spacings down to ~190 nm. The magnetic feature amplitudes are more than an order of magnitude larger than those obtained by confocal magnetic microscopy due to the smaller characteristic NV-nanoparticle distance within nearby sensing voxels. We analyze the magnetic point-spread function and sensitivity as a function of the microscope's spatial resolution and identify sources of background fluorescence that limit the present performance, including diamond second-order Raman emission and imperfect NV charge-state control. Our method, which uses less than 10 mW laser power and can be parallelized by patterned illumination, introduces a new format for nanoscale magnetic imaging.
PubMed: 37873018
DOI: No ID Found -
Computational and Structural... 2022Microscopic images are widely used in basic biomedical research, disease diagnosis and medical discovery. Obtaining high-quality in-focus microscopy images has been a...
MOTIVATION
Microscopic images are widely used in basic biomedical research, disease diagnosis and medical discovery. Obtaining high-quality in-focus microscopy images has been a cornerstone of the microscopy. However, images obtained by microscopes are often out-of-focus, resulting in poor performance in research and diagnosis.
RESULTS
To solve the out-of-focus issue in microscopy, we developed a Cycle Generative Adversarial Network (CycleGAN) based model and a multi-component weighted loss function. We train and test our network in two self-collected datasets, namely Leishmania parasite dataset captured by a bright-field microscope, and bovine pulmonary artery endothelial cells (BPAEC) captured by a confocal fluorescence microscope. In comparison to other GAN-based deblurring methods, the proposed model reached state-of-the-art performance in correction. Another publicly available dataset, human cells dataset from the Broad Bioimage Benchmark Collection is used for evaluating the generalization abilities of the model. Our model showed excellent generalization capability, which could transfer to different types of microscopic image datasets.
AVAILABILITY AND IMPLEMENTATION
Code and dataset are publicly available at: https://github.com/jiangdat/COMI.
PubMed: 35521557
DOI: 10.1016/j.csbj.2022.04.003 -
Nature Methods Jul 2022Cameras are a crucial part of microscopes and are also built into many kinds of instruments. To make their output comparable takes standards.
Cameras are a crucial part of microscopes and are also built into many kinds of instruments. To make their output comparable takes standards.
Topics: Microscopy; Photography; Reference Standards
PubMed: 35750961
DOI: 10.1038/s41592-022-01545-9 -
Pathologica Dec 2023Counting stuff under the microscope is part of the duties of a surgical pathologist. Many textbooks and articles still report the surface area as the number of... (Review)
Review
Counting stuff under the microscope is part of the duties of a surgical pathologist. Many textbooks and articles still report the surface area as the number of high-power fields (HPFs) counted. This is bad, since the area displayed by an HPF varies between two microscopes. It is therefore necessary to express the surface as mm. This is a how to guide written for the resident who has to measure the HPF of the microscope for the first time. The Resident can either calibrate the microscope with a stage micrometer slide (a small ruler on a glass slide) or compute the surface area of the HPF using the numbers on the eyepiece and the magnification objective. for "10X/22" eyepiece and a "40X" objective, the diameter of the HPF is 22/40 = 0.55 (if no other magnification is present), and the surface is 0.238 mm. The young resident might then ask: "How far off-target was I when I counted the number of HPFs that the chief resident declared to be correct?" Probably not that much: although legitimate in principle and correct in math, the size of the problem is often overstated since microscopes are not that different after all and because pathology is not just about counting.
Topics: Microscopy; Pathology
PubMed: 38180138
DOI: 10.32074/1591-951X-900 -
Scientific Reports Jul 2019An optical microscope enables image-based findings and diagnosis on microscopic targets, which is indispensable in many scientific, industrial and medical settings. A...
An optical microscope enables image-based findings and diagnosis on microscopic targets, which is indispensable in many scientific, industrial and medical settings. A standard benchtop microscope platform, equipped with e.g., bright-field and phase-contrast modes, is of importance and convenience for various users because the wide-field and label-free properties allow for morphological imaging without the need for specific sample preparation. However, these microscopes never have capability of acquiring molecular contrast in a label-free manner. Here, we develop a simple add-on optical unit, comprising of an amplitude-modulated mid-infrared semiconductor laser, that is attached to a standard microscope platform to deliver the additional molecular contrast of the specimen on top of its conventional microscopic image, based on the principle of photothermal effect. We attach this unit, termed molecular-contrast unit, to a standard phase-contrast microscope, and demonstrate high-speed label-free molecular-contrast phase-contrast imaging of silica-polystyrene microbeads mixture and molecular-vibrational spectroscopic imaging of HeLa cells. Our simple molecular-contrast unit can empower existing standard microscopes and deliver a convenient accessibility to the molecular world.
Topics: HeLa Cells; Humans; Lasers, Semiconductor; Light; Microscopy, Phase-Contrast; Microspheres; Molecular Imaging; Polystyrenes; Silicon Dioxide; Spectrophotometry, Infrared
PubMed: 31316091
DOI: 10.1038/s41598-019-46383-6 -
ArXiv Jul 2023Microscopes are essential for the biomechanical and hydrodynamical investigation of small aquatic organisms. We report a do-it-yourself microscope (GLUBscope) that...
Microscopes are essential for the biomechanical and hydrodynamical investigation of small aquatic organisms. We report a do-it-yourself microscope (GLUBscope) that enables the visualization of organisms from two orthogonal imaging planes - top and side views. Compared to conventional imaging systems, this approach provides a comprehensive visualization strategy of organisms, which could have complex shapes and morphologies. The microscope was constructed by combining custom 3D-printed parts and off-the-shelf components. The system is designed for modularity and reconfigurability. Open-source design files and build instructions are provided in this report. Additionally, proof-of-use experiments (particularly with Hydra) and other organisms that combine the GLUBscope with an analysis pipeline were demonstrated to highlight the system's utility. Beyond the applications demonstrated, the system can be used or modified for various imaging applications.
PubMed: 37547659
DOI: No ID Found -
Micromachines May 2022A fluorescence microscope is one of the most important tools for biomedical research and laboratory diagnosis. However, its high cost and bulky size hinder the...
A fluorescence microscope is one of the most important tools for biomedical research and laboratory diagnosis. However, its high cost and bulky size hinder the application of laboratory microscopes in space-limited and low-resource applications. Here, in this work, we proposed a portable and cost-effective fluorescence microscope. Assembled from a set of 3D print components and a webcam, it consists of a three-degree-of-freedom sliding platform and a microscopic imaging system. The microscope is capable of bright-field and fluorescence imaging with micron-level resolution. The resolution and field of view of the microscope were evaluated. Compared with a laboratory-grade inverted fluorescence microscope, the portable microscope shows satisfactory performance, both in the bright-field and fluorescence mode. From the configurations of local resources, the microscope costs around USD 100 to assemble. To demonstrate the capability of the portable fluorescence microscope, we proposed a quantitative polymerase chain reaction experiment for meat product authenticating applications. The portable and low-cost microscope platform demonstrates the benefits in space-constrained environments and shows high potential in telemedicine, point-of-care testing, and more.
PubMed: 35744483
DOI: 10.3390/mi13060869