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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 the American Chemical Society Jul 2023The natural extracellular matrix, with its heterogeneous structure, provides a stable and dynamic biophysical framework and biochemical signals to guide cellular...
The natural extracellular matrix, with its heterogeneous structure, provides a stable and dynamic biophysical framework and biochemical signals to guide cellular behaviors. It is challenging but highly desirable to develop a synthetic matrix that emulates the heterogeneous fibrous structure with macroscopic stability and microscopical dynamics and contains inductive biochemical signals. Herein, we introduce a peptide fiber-reinforced hydrogel in which the stiff ß-sheet fiber functions as a multivalent cross-linker to enhance the hydrogel's macroscopic stability. The dynamic imine cross-link between the peptide fiber and polymer network endows the hydrogel with a microscopically dynamic network. The obtained fibrillar nanocomposite hydrogel, with its cell-adaptable dynamic network, enhances cell-matrix and cell-cell interactions and therefore significantly promotes the mechanotransduction, metabolic energetics, and osteogenesis of encapsulated stem cells. Furthermore, the hydrogel can codeliver a fiber-attached inductive drug to further enhance osteogenesis and bone regeneration. We believe that our work provides valuable guidance for the design of cell-adaptive and bioactive biomaterials for therapeutic applications.
Topics: Hydrogels; Mechanotransduction, Cellular; Biomimetics; Bone Regeneration; Peptides; Osteogenesis
PubMed: 37428960
DOI: 10.1021/jacs.3c02210 -
Frontiers in Endocrinology 2023Somatotropinomas are the main cause of acromegaly. Surgery is the primary and most efficient method of treatment. The study aimed to compare the radicality of... (Randomized Controlled Trial)
Randomized Controlled Trial
INTRODUCTION
Somatotropinomas are the main cause of acromegaly. Surgery is the primary and most efficient method of treatment. The study aimed to compare the radicality of small-sized and medium (<30 mm) somatotropinoma removal and the incidence of postoperative complications in patients with acromegaly when using microscopic and endoscopic techniques.
METHODS
In this randomized controlled trial, a total of 83 patients with acromegaly underwent transspheroidal endoscopy or microscopic surgery. Somatotropinoma was the cause of acromegaly in all cases. Patients were randomly divided into two comparison groups depending on the applied surgical technique. Group 1 (n = 40) consisted of patients who underwent adenomectomy with transnasal transsphenoidal access by a microscope. Group 2 (n = 43) included patients who underwent the same surgical procedure with an endoscope. The following indicators were assessed: radicality of tumor removal, treatment effectiveness, postoperative complications, and remission rate.
RESULTS
The study has shown that removal of somatotropinoma in patients with acromegaly using endoscopic technique increases the radicality of tumor removal in comparison with microscopic technique. Total removal of somatotropinoma was successful in 88.4% of cases when using the endoscopic technique. Secondly, the segmentation of patients according to their tumor characteristics poses challenges, primarily owing to the rarity of acromegaly as a disease. The difference between groups was not statistically significant (p=1.02). There were no statistically significant differences in basal GH level and IGF-1 level between groups (p=0.546 and p=0.784, respectively).
DISCUSSION
Endonasal transsphenoidal endoscopic adenomectomy is proven efficacy, a less traumatic degree, and higher somatotropinoma removal radicality. Both surgical methods lead to disease remission.
Topics: Humans; Acromegaly; Endoscopy; Adenoma; Growth Hormone-Secreting Pituitary Adenoma; Postoperative Complications; Pituitary Neoplasms
PubMed: 37766690
DOI: 10.3389/fendo.2023.1128345 -
BioRxiv : the Preprint Server For... Jun 2024Connectomics provides essential nanometer-resolution, synapse-level maps of neural circuits to understand brain activity and behavior. However, few researchers have...
Connectomics provides essential nanometer-resolution, synapse-level maps of neural circuits to understand brain activity and behavior. However, few researchers have access to the high-throughput electron microscopes necessary to generate enough data for whole circuit or brain reconstruction. To date, machine-learning methods have been used after the collection of images by electron microscopy (EM) to accelerate and improve neuronal segmentation, synapse reconstruction and other data analysis. With the computational improvements in processing EM images, acquiring EM images has now become the rate-limiting step. Here, in order to speed up EM imaging, we integrate machine-learning into real-time image acquisition in a singlebeam scanning electron microscope. This SmartEM approach allows an electron microscope to perform intelligent, data-aware imaging of specimens. SmartEM allocates the proper imaging time for each region of interest - scanning all pixels equally rapidly, then re-scanning small subareas more slowly where a higher quality signal is required to achieve accurate segmentability, in significantly less time. We demonstrate that this pipeline achieves a 7-fold acceleration of image acquisition time for connectomics using a commercial single-beam SEM. We apply SmartEM to reconstruct a portion of mouse cortex with the same accuracy as traditional microscopy but in less time.
PubMed: 38915594
DOI: 10.1101/2023.10.05.561103 -
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 -
Neurophotonics Apr 2024The development of genetically encoded fluorescent indicators of neural activity with millisecond dynamics has generated demand for ever faster two-photon (2P) imaging...
SIGNIFICANCE
The development of genetically encoded fluorescent indicators of neural activity with millisecond dynamics has generated demand for ever faster two-photon (2P) imaging systems, but acoustic and mechanical beam scanning technologies are approaching fundamental limits. We demonstrate that potassium tantalate niobate (KTN) electro-optical deflectors (EODs), which are not subject to the same fundamental limits, are capable of ultrafast two-dimensional (2D) 2P imaging .
AIM
To determine if KTN-EODs are suitable for 2P imaging, compatible with 2D scanning, and capable of ultrafast imaging of genetically encoded indicators with millisecond dynamics.
APPROACH
The performance of a commercially available KTN-EOD was characterized across a range of drive frequencies and laser parameters relevant to 2P microscopy. A second KTN-EOD was incorporated into a dual-axis scan module, and the system was validated by imaging signals from ASAP3, a genetically encoded voltage indicator.
RESULTS
Optimal KTN-EOD deflection of laser light with a central wavelength of 960 nm was obtained up to the highest average powers and pulse intensities tested (power: 350 mW; pulse duration: 118 fs). Up to 32 resolvable spots per line at a 560 kHz line scan rate could be obtained with single-axis deflection. The complete dual-axis EO 2P microscope was capable of imaging a by field-of-view at over 10 kHz frame rate with lateral resolution. We demonstrate imaging of neurons expressing ASAP3 with high temporal resolution.
CONCLUSIONS
We demonstrate the suitability of KTN-EODs for ultrafast 2P cellular imaging , providing a foundation for future high-performance microscopes to incorporate emerging advances in KTN-based scanning technology.
PubMed: 38841422
DOI: 10.1117/1.NPh.11.2.025005 -
European Archives of... May 2024To analyze and compare the available data about the outcomes of endoscopic and microscopic type I tympanoplasty. (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To analyze and compare the available data about the outcomes of endoscopic and microscopic type I tympanoplasty.
DATA SOURCES
PubMed, Cochrane library Ovid, Scopus, Google scholar, and ClinicalTrials.
METHODS
We conducted a meta-analysis in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. We included comparative studies describing type I tympanoplasty, and comparing surgical outcomes of the endoscope with the microscope in terms of efficacy and safety.
RESULTS
Our systematic search yielded 22 studies meeting the inclusion criteria and eligible for analysis. The pooled graft uptake rates and audiological results of endoscopic and microscopic tympanoplasty demonstrated non-significant differences. In contrast, endoscopic type I tympanoplasty outperforms microscopic tympanoplasty regarding a highly significant decrease not only in pooled mean operative time but also in the pooled complications rate.
CONCLUSIONS
Based on our meta-analysis, the surgical outcomes of endoscope-assisted and microscope-assisted type I tympanoplasty in terms of postoperative hearing outcomes and the graft uptake rate were comparable. On the contrary, operative time and complications rate proved to be significantly reduced with endoscopy compared to microscopy. Hence, the endoscope is as efficient as the microscope in type I tympanoplasty but less invasive, fewer in complications and shorter in operative time.
Topics: Humans; Tympanoplasty; Microscopy; Treatment Outcome; Myringoplasty; Endoscopy; Endoscopes; Tympanic Membrane Perforation; Retrospective Studies
PubMed: 37966540
DOI: 10.1007/s00405-023-08305-1 -
SLAS Discovery : Advancing Life... Oct 2023The field of high content imaging has steadily evolved and expanded substantially across many industry and academic research institutions since it was first described in...
The field of high content imaging has steadily evolved and expanded substantially across many industry and academic research institutions since it was first described in the early 1990's. High content imaging refers to the automated acquisition and analysis of microscopic images from a variety of biological sample types. Integration of high content imaging microscopes with multiwell plate handling robotics enables high content imaging to be performed at scale and support medium- to high-throughput screening of pharmacological, genetic and diverse environmental perturbations upon complex biological systems ranging from 2D cell cultures to 3D tissue organoids to small model organisms. In this perspective article the authors provide a collective view on the following key discussion points relevant to the evolution of high content imaging: • Evolution and impact of high content imaging: An academic perspective • Evolution and impact of high content imaging: An industry perspective • Evolution of high content image analysis • Evolution of high content data analysis pipelines towards multiparametric and phenotypic profiling applications • The role of data integration and multiomics • The role and evolution of image data repositories and sharing standards • Future perspective of high content imaging hardware and software.
Topics: Image Processing, Computer-Assisted; Humans; High-Throughput Screening Assays; Software; Animals; Microscopy; Cell Culture Techniques
PubMed: 37666456
DOI: 10.1016/j.slasd.2023.08.009 -
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 -
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