-
Journal of Cell Science Nov 2020One of the challenges in modern fluorescence microscopy is to reconcile the conventional utilization of microscopes as exploratory instruments with their emerging and... (Review)
Review
One of the challenges in modern fluorescence microscopy is to reconcile the conventional utilization of microscopes as exploratory instruments with their emerging and rapidly expanding role as a quantitative tools. The contribution of microscopy to observational biology will remain enormous owing to the improvements in acquisition speed, imaging depth, resolution and biocompatibility of modern imaging instruments. However, the use of fluorescence microscopy to facilitate the quantitative measurements necessary to challenge hypotheses is a relatively recent concept, made possible by advanced optics, functional imaging probes and rapidly increasing computational power. We argue here that to fully leverage the rapidly evolving application of microscopes in hypothesis-driven biology, we not only need to ensure that images are acquired quantitatively but must also re-evaluate how microscopy-based experiments are designed. In this Opinion, we present a reverse logic that guides the design of quantitative fluorescence microscopy experiments. This unique approach starts from identifying the results that would quantitatively inform the hypothesis and map the process backward to microscope selection. This ensures that the quantitative aspects of testing the hypothesis remain the central focus of the entire experimental design.
Topics: Microscopy, Fluorescence; Optics and Photonics; Research Design
PubMed: 33154172
DOI: 10.1242/jcs.250027 -
Bio Systems Oct 2021Waves on the surface of developing eggs/embryos need to be viewed from all sides of their 3D tissue. The ball microscope will enable tracking of cellular waves and...
Waves on the surface of developing eggs/embryos need to be viewed from all sides of their 3D tissue. The ball microscope will enable tracking of cellular waves and determine their interactions with the cells on the surface. Nine microscopes are arrayed in a spherical formation around an imaging stage to create whole surface images of objects anywhere from 0.5 mm to 60 mm in size. The 3D printed ball-based microscope is made using nine, Opti-Tekscope OT-HD Digital USB Microscope Camera Magnifiers. Eight of the microscope cameras fit into the ball at 90° angles to each other and one bottom microscope is used for a base to hold the stage. The base will support a customised cuvette to hold the embryo in water. The microscopes are the size of a pen (13 cm long and 1 cm in diameter) and each have a ring light around their diameter for self illumination. The nine microscopes can be attached to a microcontroller for time-lapse automated imaging. This microscope will be compared to other microscopes developed for the same purpose. The microscope can be used for time lapse imaging of the surface of small 3D objects and can be used to view Axolotl salamander embryo development as the Axolotl embryos are 2 mm in diameter. Other amphibian eggs can also be imaged using this technique.
Topics: Amphibians; Animals; Embryo, Nonmammalian; Image Processing, Computer-Assisted; Microscopy, Confocal; Printing, Three-Dimensional
PubMed: 34339809
DOI: 10.1016/j.biosystems.2021.104498 -
Arquivos de Neuro-psiquiatria Apr 2021The longstanding study of gross anatomy experienced a considerable improvement with the advent of the microscope in the early 17th century. The representative...
The longstanding study of gross anatomy experienced a considerable improvement with the advent of the microscope in the early 17th century. The representative personality of this new era certainly was Marcello Malpighi, seen as "founder of microscopic anatomy". He studied, with a rudimentary compound microscope, numerous tissues and organs of several classes of animals, as well as plants. He described, for the first time, the microscopic structure of the nervous system, identifying in the gray matter of its various levels minute elements he took as "glands". It should be reminded that the concept of "cell" (and "nerve cell") was unknown at his time. Many researchers followed, performing microscopic studies, but without better results, and Malpighi's view was maintained until the beginning of the 19th century, when new histological processing and staining techniques appeared, as well as improved microscopes.
Topics: Animals; Cerebral Cortex; Gray Matter; History, 17th Century; Italy; Nervous System; Neurons; Staining and Labeling
PubMed: 34133516
DOI: 10.1590/0004-282X-ANP-2020-0309 -
Journal of Microscopy Feb 2019The need to improve access to microscopes in low-resource and educational settings coupled with the global proliferation of camera-enabled cellphones has recently led to...
The need to improve access to microscopes in low-resource and educational settings coupled with the global proliferation of camera-enabled cellphones has recently led to an explosion in new developments in portable, low-cost microscopy. The availability of accurate ball lenses has resulted in many variants of van Leeuwenhoek-like microscopes. Combined with cellphones, they have the potential for use as portable microscopes in education and clinics. The need for reproducibility in such applications implies that control over focus is critical. Here, we describe a 3D-printed focussing mechanism based on a rack and pinion mechanism, coupled to a ball lens- based microscope. We quantify the time-stability of the focussing mechanism through an edge-based contrast measure used in autofocus cameras and apply it to 'thin smear' blood sample infected with Plasmodium as well as onion skin cells. We show that stability of the z-focus is in the micrometre range. This development could, we believe, serve to further enhance the utility of a low-cost and robust microscope and encourage further developments in field microscopes based on the Open Source principle. LAY DESCRIPTION: The wide spread of cellphones with cameras makes them an attractive platform for digital microscopy. Such microscopes could help improve microscope access in clinics and classrooms in the form of 'field microscopes', if they could be adapted for imaging cells. We integrate a 3D printed focussing mechanism made with recyclable plastic with ball-lens microscope of the Leeuwenhoek type. We demonstrate how the device can help stabilise to a focal plane for acquiring movies of a thin-smear of blood infected with Plasmodium and onion skin cells using a cellphone. The stability of focus is expectedly less precise as compared to research-grade microscopes, but is of the range of a few micrometers. We believe, the focussing device demonstrates it is possible to obtain reliable and reproducible images of typical samples used in clinics and classrooms. By making the design files of this device open-source we believe it could serve as a small step in improved, affordable and accurate 'field microscopes'.
Topics: Cell Phone; Microscopy; Optical Imaging; Printing, Three-Dimensional
PubMed: 30417401
DOI: 10.1111/jmi.12765 -
European Journal of Dentistry Oct 2022Frequent consumption of acidic beverages and dietary preservatives in younger generation, diet-conscious (celebrities), and obese individuals have a rapid impact on...
OBJECTIVES
Frequent consumption of acidic beverages and dietary preservatives in younger generation, diet-conscious (celebrities), and obese individuals have a rapid impact on demineralization of the teeth. An attempt was made to analyze the erosive potential of various acidic beverages.
MATERIALS AND METHODS
One hundred and ninety extracted human permanent teeth were sectioned longitudinally, pre-weighed, randomly grouped, and placed in nine acidic beverages (200 mL) with predetermined pH, i.e., three commercially available fruit juices, three carbonated drinks, and three dietary preservatives.
STATISTICAL ANALYSIS
The sectioned specimens ( = 10) were analyzed at time intervals of 12, 24, 48, and 96 days. Mean weight loss was calculated, and surface changes were assessed under a stereomicroscope. The demineralization pattern and microscopic changes were observed under a compound and polarizing microscope. One-way analysis of variance test followed by Tukey's post-hoc analysis was employed.
RESULTS
Overall the maximum demineralizing effect was caused by vinegar and apple cider. In the fruit juices category, lemon juice induced significant changes, while in the carbonated drinks category Coca-Cola induced the maximum changes and in the category of food preservatives vinegar induced the maximum changes. Severe discoloration was seen with respect to Coca-Cola followed by Mountain Dew (carbonated drink).
CONCLUSION
The present study is unique as three different types of microscopes have been employed and both dentin and enamel of permanent teeth have been analyzed. In addition, the effect of dietary preservatives on hard tissues was evaluated. Oral health educators can reinforce important practices such as decreasing the frequency of consumption and time duration of beverage contact with the teeth. Also, the use of mouth rinses and buffering agents after the consumption of dietary beverages can be advocated along with regular fluoride application for those who are regular consumers.
PubMed: 35436789
DOI: 10.1055/s-0041-1742131 -
Archives of Plastic Surgery Nov 2017Cleft lip and palate repair requires a deep and small surgical field and is usually performed by surgeons wearing surgical loupes. Surgeons with loupes can obtain a...
BACKGROUND
Cleft lip and palate repair requires a deep and small surgical field and is usually performed by surgeons wearing surgical loupes. Surgeons with loupes can obtain a wider surgical view, although headlights are required for the deepest procedures. Surgical microscopes offer comfort and a clear and magnification-adjustable surgical site that can be shared with the whole team, including observers, and easily recorded to further the education of junior surgeons. Magnification adjustments are convenient for precise procedures such as muscle dissection of the soft palate.
METHODS
We performed a comparative investigation of 18 cleft operations that utilized either surgical loupes or microscopy. Paper-based questionnaires were completed by staff nurses to evaluate what went well and what could be improved in each procedure. The operating time, complication rate, and scores of the questionnaire responses were statistically analyzed.
RESULTS
The operating time when microscopy was used was not significantly longer than when surgical loupes were utilized. The surgical field was clearly shared with surgical assistants, nurses, anesthesiologists, and students via microscope-linked monitors. Passing surgical equipment was easier when sharing the surgical view, and preoperative microscope preparation did not interfere with the duties of the staff nurses.
CONCLUSIONS
Surgical microscopy was demonstrated to be useful during cleft operations.
PubMed: 29069876
DOI: 10.5999/aps.2017.01060 -
Micromachines Apr 2022For many parasitic diseases, the microscopic examination of clinical samples such as urine and stool still serves as the diagnostic reference standard, primarily because...
For many parasitic diseases, the microscopic examination of clinical samples such as urine and stool still serves as the diagnostic reference standard, primarily because microscopes are accessible and cost-effective. However, conventional microscopy is laborious, requires highly skilled personnel, and is highly subjective. Requirements for skilled operators, coupled with the cost and maintenance needs of the microscopes, which is hardly done in endemic countries, presents grossly limited access to the diagnosis of parasitic diseases in resource-limited settings. The urgent requirement for the management of tropical diseases such as schistosomiasis, which is now focused on elimination, has underscored the critical need for the creation of access to easy-to-use diagnosis for case detection, community mapping, and surveillance. In this paper, we present a low-cost automated digital microscope-the Schistoscope-which is capable of automatic focusing and scanning regions of interest in prepared microscope slides, and automatic detection of eggs in captured images. The device was developed using widely accessible distributed manufacturing methods and off-the-shelf components to enable local manufacturability and ease of maintenance. For proof of principle, we created a egg dataset of over 5000 images captured from spiked and clinical urine samples from field settings and demonstrated the automatic detection of eggs using a trained deep neural network model. The experiments and results presented in this paper collectively illustrate the robustness, stability, and optical performance of the device, making it suitable for use in the monitoring and evaluation of schistosomiasis control programs in endemic settings.
PubMed: 35630110
DOI: 10.3390/mi13050643 -
RSC Advances Aug 2018Resistive switching memories have been regarded as one of the most up and coming memory systems and researchers have shown great interest in them because of their simple... (Review)
Review
Resistive switching memories have been regarded as one of the most up and coming memory systems and researchers have shown great interest in them because of their simple structure, high speed and low fabrication cost. These memory systems also have great potential for scaling, however, this has been difficult to achieve without detailed understanding of underlying switching mechanisms. Meanwhile, scaling down could also raise reliability concerns in its performance. This work provides an overview of various switching mechanisms and their investigations at nanoscale levels using high resolution microscopy techniques. In this mini review, the main focus was to understand the working mechanism derived from the so-called filament model. The high resolution conductive atomic force microscope, transmission electron microscope and scanning electron microscopes are the best tools available to investigate the dynamics of filamentary switching. Several issues with the existing techniques are also highlighted.
PubMed: 35542462
DOI: 10.1039/c8ra05340e -
Translational Vision Science &... Apr 2021Specular and confocal microscopes are important tools to monitor the health of the corneal endothelium (CE), but their high costs significantly limit accessibility in...
PURPOSE
Specular and confocal microscopes are important tools to monitor the health of the corneal endothelium (CE), but their high costs significantly limit accessibility in low-resource environments. We developed and validated a low-cost, fully automated method to quantitatively evaluate the CE using smartphone-based specular microscopy.
METHODS
A OnePlus 7 Pro smartphone attached to a Topcon SL-D701 slit-lamp was used to image the central corneal endothelium of 30 eyes using the specular reflection technique. A novel on-device image processing algorithm automatically computed endothelial cell density (ECD), percentage of hexagonal cells (HEX), and coefficient of variation (CV) values. These values were compared with the ECD, HEX, and CV generated by a Tomey EM-4000 specular microscope used to image the same set of eyes.
RESULTS
No significant differences were found in ECD (2799 ± 156 cells/mm2 vs. 2779 ± 166 cells/mm2; P = 0.28) and HEX (52 ± 6% vs. 53 ± 6%; P = 0.50) computed by smartphone-based specular imaging and specular microscope, respectively. A statistically significant difference in CV (34 ± 3% vs. 30 ± 3%; P < 0.01) was found between the two methods. The concordance achieved between the smartphone-based method and the Tomey specular microscope is very similar to the concordance between two specular microscopes reported in the literature.
CONCLUSIONS
Smartphone-based specular imaging and automated analysis is a low-cost method to quantitatively evaluate the CE with accuracy comparable to the clinical standard.
TRANSLATIONAL RELEVANCE
This tool can be used to screen the CE in low-resource regions and prompt investigation of suspected corneal endotheliopathies.
Topics: Cell Count; Endothelium, Corneal; Microscopy; Reproducibility of Results; Smartphone
PubMed: 34003981
DOI: 10.1167/tvst.10.4.4 -
Cureus Jan 2018The ideal visualization tools in microneurosurgery should provide magnification, illumination, wide fields of view, ergonomics, and unobstructed access to the surgical...
The ideal visualization tools in microneurosurgery should provide magnification, illumination, wide fields of view, ergonomics, and unobstructed access to the surgical field. The operative microscope was the predominant innovation in modern neurosurgery. Recently, a high-definition three-dimensional (3D) exoscope was developed. We describe the first applications in pediatric neurosurgery. The VITOM 3D exoscope (Karl Storz GmbH, Tuttlingen, Germany) was used in pediatric microneurosurgical operations, along with an OPMI PENTERO operative microscope (Carl Zeiss AG, Jena, Germany). Experiences were retrospectively evaluated with five-level Likert items regarding ease of preparation, image definition, magnification, illumination, field of view, ergonomics, accessibility of the surgical field, and general user-friendliness. Three operations were performed: supratentorial open biopsy in the supine position, infratentorial brain tumor resection in the park bench position, and myelomeningocele closure in the prone position. While preparation and image definition were rated equal for microscope and exoscope, the microscope's field of view, illumination, and user-friendliness were considered superior, while the advantages of the exoscope were seen in ergonomics and the accessibility of the surgical field. No complications attributed to visualization mode occurred. In our experience, the VITOM 3D exoscope is an innovative visualization tool with advantages over the microscope in ergonomics and the accessibility of the surgical field. However, improvements were deemed necessary with regard to field of view, illumination, and user-friendliness. While the debate of a "perfect" visualization modality is influenced by personal preference, this novel visualization device has the potential to become a valuable tool in the neurosurgeon's armamentarium.
PubMed: 29581920
DOI: 10.7759/cureus.2108